ambient water toxicity: Topics by WorldWideScience.org

Sample records for ambient water toxicity

Monitoring the levels of toxic air pollutants in the ambient air of ...

African Journals Online (AJOL)

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The ambient air quality in Freetown, Sierra Leone was investigated for the first time for toxic air pollutants. ..... 215 Switzerland), in a water bath at temperature of 55°C and pressure of ..... scraps. Furthermore, the prolonged use of generators.
78 FR 52192 - Final Aquatic Life Ambient Water Quality Criteria For Ammonia-Freshwater 2013

Science.gov (United States)

2013-08-22

... ambient water quality criteria for the protection of aquatic life from effects of ammonia in freshwater... ammonia to freshwater aquatic life. On December 30, 2009, EPA published draft national recommended water... freshwater are intended to protect aquatic life and do not address human health toxicity data. The water...
Tracking pyrethroid toxicity in surface water samples: Exposure dynamics and toxicity identification tools for laboratory tests with Hyalella azteca (Amphipoda).

Science.gov (United States)

Deanovic, Linda A; Stillway, Marie; Hammock, Bruce G; Fong, Stephanie; Werner, Inge

2018-02-01

Pyrethroid insecticides are commonly used in pest control and are present at toxic concentrations in surface waters of agricultural and urban areas worldwide. Monitoring is challenging as a result of their high hydrophobicity and low toxicity thresholds, which often fall below the analytical methods detection limits (MDLs). Standard daphnid bioassays used in surface water monitoring are not sensitive enough to protect more susceptible invertebrate species such as the amphipod Hyalella azteca and chemical loss during toxicity testing is of concern. In the present study, we quantified toxicity loss during storage and testing, using both natural and synthetic water, and presented a tool to enhance toxic signal strength for improved sensitivity of H. azteca toxicity tests. The average half-life during storage in low-density polyethylene (LDPE) cubitainers (Fisher Scientific) at 4 °C of 5 pyrethroids (permethrin, bifenthrin, lambda-cyhalothrin, cyfluthrin, and esfenvalerate) and one organophosphate (chlorpyrifos; used as reference) was 1.4 d, and piperonyl butoxide (PBO) proved an effective tool to potentiate toxicity. We conclude that toxicity tests on ambient water samples containing these hydrophobic insecticides are likely to underestimate toxicity present in the field, and mimic short pulse rather than continuous exposures. Where these chemicals are of concern, the addition of PBO during testing can yield valuable information on their presence or absence. Environ Toxicol Chem 2018;37:462-472. © 2017 SETAC. © 2017 SETAC.
Early Detection of Biofouling on Water Purification Membranes by Ambient Ionization Mass Spectrometry Imaging.

Science.gov (United States)

Jakka Ravindran, Swathy; Kumar, Ramesh; Srimany, Amitava; Philip, Ligy; Pradeep, Thalappil

2018-01-02

By direct analysis of water purification membranes using ambient ionization mass spectrometry, an attempt has been made to understand the molecular signatures of bacterial fouling. Membrane based purification methods are used extensively in water treatment, and a major challenge for them is biofouling. The buildup of microbes and their extracellular polymeric matrix clog the purification membranes and reduce their efficiency. To understand the early stages of bacterial fouling on water purification membranes, we have used desorption electrospray ionization mass spectrometry (DESI MS), where ion formation occurs in ambient conditions and the ionization event is surface sensitive. Biosurfactants at the air-water interface generated by microorganisms as a result of quorum sensing, influence the water-membrane interface and are important for the bacterial attachment. We show that these biosurfactants produced by bacteria can be indicator molecular species signifying initiation of biofilms on membrane surfaces, demonstrated by specific DESI MS signatures. In Pseudomonas aeruginosa, one of the best studied models for biofilm formation, this process is mediated by rhamnolipids forewarning bacterial fouling. Species dependent variation of such molecules can be used for the precise identification of the microorganisms, as revealed by studies on P. aeroginosa (ATCC 25619). The production of biosurfactants is tightly regulated at the transcriptional level by the quorum-sensing (QS) response. Thus, secretion of these extracellular molecules across the membrane surface allows rapid screening of the biofilm community. We show that, the ambient ionization mass spectrometry can detect certain toxic heavy metals present in water, using surfactant-metal complexes as analytes. We believe that such studies conducted on membranes in various input water streams will help design suitable membrane processes specific to the input streams.
An assessment of whole effluent toxicity testing as a means of regulating waters produced by the oil and gas industry

International Nuclear Information System (INIS)

Hill, S.L.; Bergman, H.L.

1993-01-01

Approximately 500 million barrels of produced water are discharged to Wyoming's surface waters by the oil and gas industry. This discharges are of two types: direct and indirect. The direct discharges have been issued NPDES permits requiring whole effluent toxicity testing. Toxicity testing requirements have not been incorporated into permits written for indirect discharges because of the applicability of toxicity testing for regulating these waters has not been determined. Preliminary testing has shown that most produced waters are toxic at the point of discharge because of high concentrations of hydrogen sulfide, but that the toxicity of an indirect discharge is often lost before it reaches a receiving stream. Thus, whole effluent toxicity testing of an indirect discharge may be overly stringent, resulting in treatment or reinjection of the water or closure of the well. Any of these options would have severe economic consequences for oil producers and the state's agricultural industry. The purpose of this study was to determine whether whole effluent toxicity testing actually predicts the in-stream effects of indirect discharges on water quality and benthic invertebrate populations. The authors will report the results of short-term ambient toxicity tests and in-stream bioassessments performed upstream and downstream of six indirect discharges located in four drainages in Wyoming
Copper bioavailability and toxicity to Mytilus galloprovincialis in Shelter Island Yacht Basin, San Diego, CA.

Science.gov (United States)

Bosse, Casey; Rosen, Gunther; Colvin, Marienne; Earley, Patrick; Santore, Robert; Rivera-Duarte, Ignacio

2014-08-15

The bioavailability and toxicity of copper (Cu) in Shelter Island Yacht Basin (SIYB), San Diego, CA, USA, was assessed with simultaneous toxicological, chemical, and modeling approaches. Toxicological measurements included laboratory toxicity testing with Mytilus galloprovincialis (Mediterranean mussel) embryos added to both site water (ambient) and site water spiked with multiple Cu concentrations. Chemical assessment of ambient samples included total and dissolved Cu concentrations, and Cu complexation capacity measurements. Modeling was based on chemical speciation and predictions of bioavailability and toxicity using a marine Biotic Ligand Model (BLM). Cumulatively, these methods assessed the natural buffering capacity of Cu in SIYB during singular wet and dry season sampling events. Overall, the three approaches suggested negligible bioavailability, and isolated observed or predicted toxicity, despite an observed gradient of increasing Cu concentration, both horizontally and vertically within the water body, exceeding current water quality criteria for saltwater. Published by Elsevier Ltd.
Toxicity of waters from the Rochester Embayment Area of Concern to the plankton species Pseudokirchneriella subcapitata and Ceriodaphnia dubia

Science.gov (United States)

Baldigo, Barry P.; Duffy, Brian T.; Smith, Alexander J.; George, Scott D.

2016-01-01

The lower Genesee River and Rochester Embayment of Lake Ontario are a designated Area of Concern (AOC) under the binational Great Lakes Water Quality Agreement. The “degradation of phytoplankton and zooplankton populations” or plankton Beneficial Use Impairment (BUI) was classified as unknown and in need of further assessment in this AOC because water quality data suggested plankton communities could be effected and community data were either unavailable or indicated impacts. The plankton BUI may now be obsolete because local contaminant sources have been largely eliminated. The present study was conducted between July 2013 and August 2014 to assess the BUI-removal criteria: “AOC plankton bioassays confirm that toxicity in ambient waters (i.e., no growth inhibition) is not significantly higher than comparable non-AOC controls”. Acute and chronic toxicity of waters from 13 sites were quantified seasonally using standardized bioassays with the green alga Pseudokirchneriella subcapitata and water flea Ceriodaphnia dubia to test the hypothesis that toxicity of waters from AOC sites was not higher than that of waters from comparable non-AOC reference sites. Survival and reproduction of C. dubia did not differ significantly between site types, systems, or months. The growth of P. subcapitata did not differ between site types, but differed among systems and months. All results indicate that waters from AOC sites were no more toxic to both plankton species than waters from reference sites. Assuming test species represent natural plankton assemblages, water quality should not negatively affect survival and growth of resident plankton populations in the Rochester Embayment AOC.
Modeling the effects of reformulated gasoline usages on ambient concentrations of ozone and five air toxics

International Nuclear Information System (INIS)

Ligocki, M.P.; Schulhof, R.R.; Jackson, R.E.; Jimenez, M.M.; Atkinson, D.

1993-01-01

The use of reformulated gasolines to reduce motor-vehicle-related hydrocarbon emissions has been mandated by the 1990 Clean Air Act Amendments for nine severely polluted urban areas. Using a version of the Urban Airshed Model that includes explicit representation of five motor-vehicle-related air toxics, the effects of reformulated gasoline usage on ambient ozone and toxics concentrations were simulated. Simulations were conducted for two urban areas. Baltimore-Washington and Houston, for the year 1995. Additional simulation were conducted for Baltimore-Washington including winter and 1999 scenarios. In the Baltimore-Washington areas, the 1995 Federal reformulated gasoline scenario produce reductions of 1.1 percent in simulated peak ozone and 2.7 percent in the areal extent of simulated ozone exceedances. Simulated ozone reductions were much smaller in Houston. In the reformulated gasoline simulations, secondary formulation of formaldehyde and acetaldehyde was reduced, and decreases in ambient benzene and polycyclic organic matter (POM) concentrations were simulated. Larger reductions in ozone and toxics concentrations were simulated for reformulated gasolines meeting California Phase II standards than for those meeting Federal standards. The effects of reductions in motor-vehicle-related nitrogen oxides (NO x ) emissions, alone and in combination with hydrocarbon reductions, were also examined
Chemical mixtures in untreated water from public-supply wells in the U.S.--occurrence, composition, and potential toxicity.

Science.gov (United States)

Toccalino, Patricia L; Norman, Julia E; Scott, Jonathon C

2012-08-01

Chemical mixtures are prevalent in groundwater used for public water supply, but little is known about their potential health effects. As part of a large-scale ambient groundwater study, we evaluated chemical mixtures across multiple chemical classes, and included more chemical contaminants than in previous studies of mixtures in public-supply wells. We (1) assessed the occurrence of chemical mixtures in untreated source-water samples from public-supply wells, (2) determined the composition of the most frequently occurring mixtures, and (3) characterized the potential toxicity of mixtures using a new screening approach. The U.S. Geological Survey collected one untreated water sample from each of 383 public wells distributed across 35 states, and analyzed the samples for as many as 91 chemical contaminants. Concentrations of mixture components were compared to individual human-health benchmarks; the potential toxicity of mixtures was characterized by addition of benchmark-normalized component concentrations. Most samples (84%) contained mixtures of two or more contaminants, each at concentrations greater than one-tenth of individual benchmarks. The chemical mixtures that most frequently occurred and had the greatest potential toxicity primarily were composed of trace elements (including arsenic, strontium, or uranium), radon, or nitrate. Herbicides, disinfection by-products, and solvents were the most common organic contaminants in mixtures. The sum of benchmark-normalized concentrations was greater than 1 for 58% of samples, suggesting that there could be potential for mixtures toxicity in more than half of the public-well samples. Our findings can be used to help set priorities for groundwater monitoring and suggest future research directions for drinking-water treatment studies and for toxicity assessments of chemical mixtures in water resources. Published by Elsevier B.V.
Early Evolution of the Toxicity Identification Evaluation Process: Contributions from the USEPA Effluent Testing Program

Science.gov (United States)

As part of its whole effluent testing program, the USEPA developed an effects-directed analysis (EDA) approach to identifying the cause of toxicity in toxic effluents or ambient waters, an EDA process termed a “Toxicity Identification Evaluation” (TIE), which is the focus of this...
Chemical mixtures in untreated water from public-supply wells in the U.S. — Occurrence, composition, and potential toxicity

International Nuclear Information System (INIS)

Toccalino, Patricia L.; Norman, Julia E.; Scott, Jonathon C.

2012-01-01

Chemical mixtures are prevalent in groundwater used for public water supply, but little is known about their potential health effects. As part of a large-scale ambient groundwater study, we evaluated chemical mixtures across multiple chemical classes, and included more chemical contaminants than in previous studies of mixtures in public-supply wells. We (1) assessed the occurrence of chemical mixtures in untreated source-water samples from public-supply wells, (2) determined the composition of the most frequently occurring mixtures, and (3) characterized the potential toxicity of mixtures using a new screening approach. The U.S. Geological Survey collected one untreated water sample from each of 383 public wells distributed across 35 states, and analyzed the samples for as many as 91 chemical contaminants. Concentrations of mixture components were compared to individual human-health benchmarks; the potential toxicity of mixtures was characterized by addition of benchmark-normalized component concentrations. Most samples (84%) contained mixtures of two or more contaminants, each at concentrations greater than one-tenth of individual benchmarks. The chemical mixtures that most frequently occurred and had the greatest potential toxicity primarily were composed of trace elements (including arsenic, strontium, or uranium), radon, or nitrate. Herbicides, disinfection by-products, and solvents were the most common organic contaminants in mixtures. The sum of benchmark-normalized concentrations was greater than 1 for 58% of samples, suggesting that there could be potential for mixtures toxicity in more than half of the public-well samples. Our findings can be used to help set priorities for groundwater monitoring and suggest future research directions for drinking-water treatment studies and for toxicity assessments of chemical mixtures in water resources. - Highlights: ► We assessed mixtures in untreated groundwater samples from public-supply wells. ► A screening
A scheme for regulating toxic substances to water quality of Chamsil upstream water system

Energy Technology Data Exchange (ETDEWEB)

Kim, Kang Suk; Kim, Jee Hoon [Korea Environment Institute, Seoul (Korea)

1998-12-01

This study asserts to reflect a concept of toxicity thoroughly in the present water quality concept. It presents an appropriate solution to control toxic substances flowing into the Chamsil upstream water system. Although a regulation of toxic substances into major rivers in Korea other than Han river is also required urgently, it will be studied in future. It is expected that this study on Chamsil upstream would be a cornerstone for establishing a national regulation policy of toxic substances into water system. 28 refs., 1 fig., 36 tabs.
Effects of water quality parameters on boron toxicity to Ceriodaphnia dubia.

Science.gov (United States)

Dethloff, Gail M; Stubblefield, William A; Schlekat, Christian E

2009-07-01

The potential modifying effects of certain water quality parameters (e.g., hardness, alkalinity, pH) on the acute toxicity of boron were tested using a freshwater cladoceran, Ceriodaphnia dubia. By comparison, boron acute toxicity was less affected by water quality characteristics than some metals (e.g., copper and silver). Increases in alkalinity over the range tested did not alter toxicity. Increases in water hardness appeared to have an effect with very hard waters (>500 mg/L as CaCO(3)). Decreased pH had a limited influence on boron acute toxicity in laboratory waters. Increasing chloride concentration did not provide a protective effect. Boron acute toxicity was unaffected by sodium concentrations. Median acute lethal concentrations (LC(50)) in natural water samples collected from three field sites were all greater than in reconstituted laboratory waters that matched natural waters in all respects except for dissolved organic carbon. Water effect ratios in these waters ranged from 1.4 to 1.8. In subsequent studies using a commercially available source of natural organic matter, acute toxicity decreased with increased dissolved organic carbon, suggesting, along with the natural water studies, that dissolved organic carbon should be considered further as a modifier of boron toxicity in natural waters where it exceeds 2 mg/L.
Chemical mixtures in untreated water from public-supply wells in the U.S. - Occurrence, composition, and potential toxicity

Energy Technology Data Exchange (ETDEWEB)

Toccalino, Patricia L., E-mail: ptocca@usgs.gov [U.S. Geological Survey (USGS), 6000 J Street, Placer Hall, Sacramento, California 95819 (United States); Norman, Julia E., E-mail: jnorman@usgs.gov [USGS, 2130 SW 5th Avenue, Portland, Oregon 97201 (United States); Scott, Jonathon C., E-mail: jon@usgs.gov [USGS, 202 NW 66th Street, Oklahoma City, Oklahoma 73116 (United States)

2012-08-01

Chemical mixtures are prevalent in groundwater used for public water supply, but little is known about their potential health effects. As part of a large-scale ambient groundwater study, we evaluated chemical mixtures across multiple chemical classes, and included more chemical contaminants than in previous studies of mixtures in public-supply wells. We (1) assessed the occurrence of chemical mixtures in untreated source-water samples from public-supply wells, (2) determined the composition of the most frequently occurring mixtures, and (3) characterized the potential toxicity of mixtures using a new screening approach. The U.S. Geological Survey collected one untreated water sample from each of 383 public wells distributed across 35 states, and analyzed the samples for as many as 91 chemical contaminants. Concentrations of mixture components were compared to individual human-health benchmarks; the potential toxicity of mixtures was characterized by addition of benchmark-normalized component concentrations. Most samples (84%) contained mixtures of two or more contaminants, each at concentrations greater than one-tenth of individual benchmarks. The chemical mixtures that most frequently occurred and had the greatest potential toxicity primarily were composed of trace elements (including arsenic, strontium, or uranium), radon, or nitrate. Herbicides, disinfection by-products, and solvents were the most common organic contaminants in mixtures. The sum of benchmark-normalized concentrations was greater than 1 for 58% of samples, suggesting that there could be potential for mixtures toxicity in more than half of the public-well samples. Our findings can be used to help set priorities for groundwater monitoring and suggest future research directions for drinking-water treatment studies and for toxicity assessments of chemical mixtures in water resources. - Highlights: Black-Right-Pointing-Pointer We assessed mixtures in untreated groundwater samples from public
Single and double long pulse laser ablation of aluminum induced in air and water ambient

International Nuclear Information System (INIS)

Akbari Jafarabadi, Marzieh; Mahdieh, Mohammad Hossein

2017-01-01

Highlights: • Laser ablation of aluminum target by single and double pulse (∼ 5 ns delay) in ambient air and distilled water • Comparing with air, in ambient water, plasma confinement results in higher crater depth. • In comparison with single pulse laser ablation, the absorption of the laser pulse energy is higher for double pulse regime. • As a result of ablated material expansion, the crater depth is decreased if the target is placed at lower depth. - Abstract: In this paper, single pulse and double pulse laser ablation of an aluminum target in two interaction ambient was investigated experimentally. The interaction was performed by nanosecond Nd:YAG laser beam in air and four depths (i.e. 9, 13, 17, and 21 mm) of distilled water ambient. The irradiation was carried out in single and collinear double pulse configurations in both air and liquid ambient. Crater geometry (depth and diameter) was measured by an optical microscope. The results indicated that the crater geometry strongly depends on both single pulse and double pulse configurations and interaction ambient. In single pulse regime, the crater diameter is higher for all water depths compared to that of air. However, the crater depth, depend on water depth, is higher or lower than the crater depth in air. In double pulse laser ablation, there are greater values for both crater diameters and crater depths in the water.
Application of TIE's in assessing toxicity associated with oil sands process waters

International Nuclear Information System (INIS)

MacKinnon, M.

1998-01-01

The hot water digestion process which separates bitumen from oil sands produces large volumes of process-affected waters which are extremely toxic to aquatic organisms. At Syncrude Canada's northeastern Alberta plant, the toxic waters are contained on the site and none are discharged. Organic acids, hydrocarbons and salts are leached into the tailings waters. A toxicity identification evaluation (TIE) test was used to confirm the main contributors to the acute toxicity in these waters. A battery bioassay approach as well as field and laboratory testing was used to understand the source, pathway and duration of the toxicity. Bioassays helped in developing ways in which to mitigate toxicity issues in both reclamation and operational waters. It was demonstrated that natural bioremediation of process-affected waters can reduce acute and chronic toxicity. The long term reclamation impacts of these waters has yet to be determined
Relationships among exceedences of metals criteria, the results of ambient bioassays, and community metrics in mining-impacted streams.

Science.gov (United States)

Griffith, Michael B; Lazorchak, James M; Herlihy, Alan T

2004-07-01

If bioassessments are to help diagnose the specific environmental stressors affecting streams, a better understanding is needed of the relationships between community metrics and ambient criteria or ambient bioassays. However, this relationship is not simple, because metrics assess responses at the community level of biological organization, while ambient criteria and ambient bioassays assess or are based on responses at the individual level. For metals, the relationship is further complicated by the influence of other chemical variables, such as hardness, on their bioavailability and toxicity. In 1993 and 1994, U.S. Environmental Protection Agency (U.S. EPA) conducted a Regional Environmental Monitoring and Assessment Program (REMAP) survey on wadeable streams in Colorado's (USA) Southern Rockies Ecoregion. In this ecoregion, mining over the past century has resulted in metals contamination of streams. The surveys collected data on fish and macroinvertebrate assemblages, physical habitat, and sediment and water chemistry and toxicity. These data provide a framework for assessing diagnostic community metrics for specific environmental stressors. We characterized streams as metals-affected based on exceedence of hardness-adjusted criteria for cadmium, copper, lead, and zinc in water; on water toxicity tests (48-h Pimephales promelas and Ceriodaphnia dubia survival); on exceedence of sediment threshold effect levels (TELs); or on sediment toxicity tests (7-d Hyalella azteca survival and growth). Macroinvertebrate and fish metrics were compared among affected and unaffected sites to identify metrics sensitive to metals. Several macroinvertebrate metrics, particularly richness metrics, were less in affected streams, while other metrics were not. This is a function of the sensitivity of the individual metrics to metals effects. Fish metrics were less sensitive to metals because of the low diversity of fish in these streams.
Personal and ambient exposures to air toxics in Camden, New Jersey.

Science.gov (United States)

Lioy, Paul J; Fan, Zhihua; Zhang, Junfeng; Georgopoulos, Panos; Wang, Sheng-Wei; Ohman-Strickland, Pamela; Wu, Xiangmei; Zhu, Xianlei; Harrington, Jason; Tang, Xiaogang; Meng, Qingyu; Jung, Kyung Hwa; Kwon, Jaymin; Hernandez, Marta; Bonnano, Linda; Held, Joann; Neal, John

2011-08-01

Personal exposures and ambient concentrations of air toxics were characterized in a pollution "hot spot" and an urban reference site, both in Camden, New Jersey. The hot spot was the city's Waterfront South neighborhood; the reference site was a neighborhood, about 1 km to the east, around the intersection of Copewood and Davis streets. Using personal exposure measurements, residential ambient air measurements, statistical analyses, and exposure modeling, we examined the impact of local industrial and mobile pollution sources, particularly diesel trucks, on personal exposures and ambient concentrations in the two neighborhoods. Presented in the report are details of our study design, sample and data collection methods, data- and model-analysis approaches, and results and key findings of the study. In summary, 107 participants were recruited from nonsmoking households, including 54 from Waterfront South and 53 from the Copewood-Davis area. Personal air samples were collected for 24 hr and measured for 32 target compounds--11 volatile organic compounds (VOCs*), four aldehydes, 16 polycyclic aromatic hydrocarbons (PAHs), and particulate matter (PM) with an aerodynamic diameter 0.6) was found between benzene and MTBE in both locations. These results suggest that automobile exhausts were the main contributors to benzene and MTBE air pollution in both neighborhoods. Formaldehyde and acetaldehyde concentrations were found to be high in both neighborhoods. Mean (+/- SD) concentrations of formaldehyde were 20.2 +/- 19.5 microg/m3 in Waterfront South and 24.8 +/- 20.8 microg/m3 in Copewood-Davis. A similar trend was observed for the two compounds during the saturation-sampling campaigns. The results indicate that mobile sources (i.e., diesel trucks) had a large impact on formaldehyde and acetaldehyde concentrations in both neighborhoods and that both are aldehyde hot spots. The study also showed that PM2.5, aldehydes, BTEX, and MTBE concentrations in both Waterfront South
Plume residence and toxic material accumulation

International Nuclear Information System (INIS)

Spigarelli, S.A.; Holpuch, R.

1975-01-01

Increased growth rates and 137 Cs concentrations in plume resident trout are thought to be the result of increased metabolism, food consumption, and activity caused by exposure to increased water temperature and flow in thermal discharges. These exposure conditions could contribute to increased accumulation of biologically active, toxic substances by primary forage and predator fish species in the Great Lakes. Uptake and retention of various toxic substances by predators depend on concentrations in forage species (trophic transfer), ambient water, and point source effluents (direct uptake). Contaminants of immediate concern in Great Lakes systems (e.g., chlorinated hydrocarbons) accumulate in adipose tissue, and body concentrations have been correlated with total lipid content in fish. In addition to direct toxic effects on fish, many lipophilic contaminants are known to cause severe human health problems when ingested at concentrations commonly found in Lake Michigan salmonids. Although power plants may or may not be the direct source of a toxic substance, the thermal discharge environment may contribute to the accumulation of toxic substances in fish and the transfer of these materials to man
Ambient-temperature incubation for the field detection of Escherichia coli in drinking water.

Science.gov (United States)

Brown, J; Stauber, C; Murphy, J L; Khan, A; Mu, T; Elliott, M; Sobsey, M D

2011-04-01

Escherichia coli is the pre-eminent microbiological indicator used to assess safety of drinking water globally. The cost and equipment requirements for processing samples by standard methods may limit the scale of water quality testing in technologically less developed countries and other resource-limited settings, however. We evaluate here the use of ambient-temperature incubation in detection of E. coli in drinking water samples as a potential cost-saving and convenience measure with applications in regions with high (>25°C) mean ambient temperatures. This study includes data from three separate water quality assessments: two in Cambodia and one in the Dominican Republic. Field samples of household drinking water were processed in duplicate by membrane filtration (Cambodia), Petrifilm™ (Cambodia) or Colilert® (Dominican Republic) on selective media at both standard incubation temperature (35–37°C) and ambient temperature, using up to three dilutions and three replicates at each dilution. Matched sample sets were well correlated with 80% of samples (n = 1037) within risk-based microbial count strata (E. coli CFU 100 ml−1 counts of 1000), and a pooled coefficient of variation of 17% (95% CI 15–20%) for paired sample sets across all methods. These results suggest that ambient-temperature incubation of E. coli in at least some settings may yield sufficiently robust data for water safety monitoring where laboratory or incubator access is limited.

Elevated CO_2 levels increase the toxicity of ZnO nanoparticles to goldfish (Carassius auratus) in a water-sediment ecosystem

International Nuclear Information System (INIS)

Yin, Ying; Hu, Zhengxue; Du, Wenchao; Ai, Fuxun; Ji, Rong; Gardea-Torresdey, Jorge L.; Guo, Hongyan

2017-01-01

Highlights: • Elevated CO_2 increased the Zn content in suspension by reducing pH value. • Elevated CO_2 led to higher Zn accumulation in fish tissues. • Elevated CO_2 also intensified the oxidative damage to fish induced by nZnO. - Abstract: Concerns about the environmental safety of metal-based nanoparticles (MNPs) in aquatic ecosystems are increasing. Simultaneously, elevated atmospheric CO_2 levels are a serious problem worldwide, making it possible for the combined exposure of MNPs and elevated CO_2 to the ecosystem. Here we studied the toxicity of nZnO to goldfish in a water-sediment ecosystem using open-top chambers flushed with ambient (400 ± 10 μL/L) or elevated (600 ± 10 μL/L) CO_2 for 30 days. We measured the content of Zn in suspension and fish, and analyzed physiological and biochemical changes in fish tissues. Results showed that elevated CO_2 increased the Zn content in suspension by reducing the pH value of water and consequently enhanced the bioavailability and toxicity of nZnO. Elevated CO_2 led to higher accumulation of Zn in fish tissues (increased by 43.3%, 86.4% and 22.5% in liver, brain and muscle, respectively) when compared to ambient. Elevated CO_2 also intensified the oxidative damage to fish induced by nZnO, resulting in higher ROS intensity, greater contents of MDA and MT and lower GSH content in liver and brain. Our results suggest that more studies in natural ecosystems are needed to better understand the fate and toxicity of nanoparticles in future CO_2 levels.
Physicochemical transformation and algal toxicity of engineered nanoparticles in surface water samples

International Nuclear Information System (INIS)

Zhang, Luqing; Li, Jingyi; Yang, Kun; Liu, Jingfu; Lin, Daohui

2016-01-01

Most studies on the behavior and toxicity of engineered nanoparticles (NPs) have been conducted in artificial water with well-controlled conditions, which are dramatically different from natural waters with complex compositions. To better understand the fate and toxicity of NPs in the natural water environment, physicochemical transformations of four NPs (TiO_2, ZnO, Ag, and carbon nanotubes (CNTs)) and their toxicities towards a unicellular green alga (Chlorella pyrenoidosa) in four fresh water and one seawater sample were investigated. Results indicated that water chemistry had profound effects on aggregation, dissolution, and algal toxicity of the NPs. The strongest homoaggregation of the NPs was associated with the highest ionic strength, but no obvious correlation was observed between the homoaggregation of NPs and pH or dissolved organic matter content of the water samples. The greatest dissolution of ZnO NPs also occurred in seawater with the highest ionic strength, while the dissolution of Ag NPs varied differently from ZnO NPs. The released Zn"2"+ and especially Ag"+ mainly accounted for the algal toxicity of ZnO and Ag NPs, respectively. The NP-cell heteroagglomeration occurred generally for CNTs and Ag NPs, which contributed to the observed nanotoxicity. However, there was no significant correlation between the observed nanotoxicity and the type of NP or the water chemistry. It was thus concluded that the physicochemical transformations and algal toxicities of NPs in the natural water samples were caused by the combined effects of complex water quality parameters rather than any single influencing factor alone. These results will increase our knowledge on the fate and effects of NPs in the aquatic environment. - Highlights: • Transformation and algal toxicity of four NPs in five surface water samples were studied. • The transformation and toxicity were dependent on the types of NPs and water samples. • No single water parameter alone was
Toxicity profile of labile preservative bronopol in water: The role of more persistent and toxic transformation products

International Nuclear Information System (INIS)

Cui Na; Zhang Xiaoxiang; Xie Qing; Wang Se; Chen Jingwen; Huang Liping; Qiao Xianliang; Li Xuehua; Cai Xiyun

2011-01-01

Transformation products usually differ in environmental behaviors and toxicological properties from the parent contaminants, and probably cause potential risks to the environment. Toxicity evolution of a labile preservative, bronopol, upon primary aquatic degradation processes was investigated. Bronopol rapidly hydrolyzed in natural waters, and primarily produced more stable 2-bromo-2-nitroethanol (BNE) and bromonitromethane (BNM). Light enhanced degradation of the targeted compounds with water site specific photoactivity. The bond order analysis theoretically revealed that the reversible retroaldol reactions were primary degradation routes for bronopol and BNE. Judging from toxicity assays and the relative pesticide toxicity index, these degradation products (i.e., BNE and BNM), more persistent and higher toxic than the parent, probably accumulated in natural waters and resulted in higher or prolonging adverse impacts. Therefore, these transformation products should be included into the assessment of ecological risks of non-persistent and low toxic chemicals such as the preservative bronopol. - The preservative bronopol is non-persistent and low toxic, but some transformation products can cause higher or prolonging adverse impacts.
Toxicity profile of labile preservative bronopol in water: The role of more persistent and toxic transformation products

Energy Technology Data Exchange (ETDEWEB)

Cui Na; Zhang Xiaoxiang; Xie Qing; Wang Se; Chen Jingwen; Huang Liping; Qiao Xianliang; Li Xuehua [Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China); Cai Xiyun, E-mail: xiyuncai@dlut.edu.c [Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China)

2011-02-15

Transformation products usually differ in environmental behaviors and toxicological properties from the parent contaminants, and probably cause potential risks to the environment. Toxicity evolution of a labile preservative, bronopol, upon primary aquatic degradation processes was investigated. Bronopol rapidly hydrolyzed in natural waters, and primarily produced more stable 2-bromo-2-nitroethanol (BNE) and bromonitromethane (BNM). Light enhanced degradation of the targeted compounds with water site specific photoactivity. The bond order analysis theoretically revealed that the reversible retroaldol reactions were primary degradation routes for bronopol and BNE. Judging from toxicity assays and the relative pesticide toxicity index, these degradation products (i.e., BNE and BNM), more persistent and higher toxic than the parent, probably accumulated in natural waters and resulted in higher or prolonging adverse impacts. Therefore, these transformation products should be included into the assessment of ecological risks of non-persistent and low toxic chemicals such as the preservative bronopol. - The preservative bronopol is non-persistent and low toxic, but some transformation products can cause higher or prolonging adverse impacts.
Bioluminescent bioreporter pad biosensor for monitoring water toxicity.

Science.gov (United States)

Axelrod, Tim; Eltzov, Evgeni; Marks, Robert S

2016-01-01

Toxicants in water sources are of concern. We developed a tool that is affordable and easy-to-use for monitoring toxicity in water. It is a biosensor composed of disposable bioreporter pads (calcium alginate matrix with immobilized bacteria) and a non-disposable CMOS photodetector. Various parameters to enhance the sensor's signal have been tested, including the effect of alginate and bacterium concentrations. The effect of various toxicants, as well as, environmental samples were tested by evaluating their effect on bacterial luminescence. This is the first step in the creation of a sensitive and simple operative tool that may be used in different environments. Copyright © 2015 Elsevier B.V. All rights reserved.
Elevated CO{sub 2} levels increase the toxicity of ZnO nanoparticles to goldfish (Carassius auratus) in a water-sediment ecosystem

Energy Technology Data Exchange (ETDEWEB)

Yin, Ying; Hu, Zhengxue [State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210046 (China); Du, Wenchao, E-mail: du@nju.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210046 (China); Ai, Fuxun; Ji, Rong [State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210046 (China); Gardea-Torresdey, Jorge L. [Department of Chemistry, The University of Texas at El Paso, El Paso, TX 79968 (United States); Environmental Science and Engineering PhD program, The University of Texas at El Paso, El Paso, TX 79968 (United States); University of California Center for Environmental Implications of Nanotechnology (UC CEIN), The University of Texas at El Paso, El Paso, TX 79968 (United States); Guo, Hongyan, E-mail: hyguo@nju.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210046 (China)

2017-04-05

Highlights: • Elevated CO{sub 2} increased the Zn content in suspension by reducing pH value. • Elevated CO{sub 2} led to higher Zn accumulation in fish tissues. • Elevated CO{sub 2} also intensified the oxidative damage to fish induced by nZnO. - Abstract: Concerns about the environmental safety of metal-based nanoparticles (MNPs) in aquatic ecosystems are increasing. Simultaneously, elevated atmospheric CO{sub 2} levels are a serious problem worldwide, making it possible for the combined exposure of MNPs and elevated CO{sub 2} to the ecosystem. Here we studied the toxicity of nZnO to goldfish in a water-sediment ecosystem using open-top chambers flushed with ambient (400 ± 10 μL/L) or elevated (600 ± 10 μL/L) CO{sub 2} for 30 days. We measured the content of Zn in suspension and fish, and analyzed physiological and biochemical changes in fish tissues. Results showed that elevated CO{sub 2} increased the Zn content in suspension by reducing the pH value of water and consequently enhanced the bioavailability and toxicity of nZnO. Elevated CO{sub 2} led to higher accumulation of Zn in fish tissues (increased by 43.3%, 86.4% and 22.5% in liver, brain and muscle, respectively) when compared to ambient. Elevated CO{sub 2} also intensified the oxidative damage to fish induced by nZnO, resulting in higher ROS intensity, greater contents of MDA and MT and lower GSH content in liver and brain. Our results suggest that more studies in natural ecosystems are needed to better understand the fate and toxicity of nanoparticles in future CO{sub 2} levels.
Ambient water quality criteria for polycyclic aromatic hydrocarbons (PAHs)

Energy Technology Data Exchange (ETDEWEB)

Nagpal, N.K.

1993-08-13

Ambient water quality criteria are established for polyaromatic hydrocarbons (PAH) in British Columbia. Major sources of PAH in the atmosphere and aquatic environments include, for the atmosphere, forest and prairie fires, agricultural burning, refuse burning, enclosed incineration, and heating and power, and for the aquatic environment, petroleum spillage, atmospheric deposition, wastewaters, surface land runoff, and biosynthesis. Details are presented of PAH and their characteristics, forms and transformations, occurrence in the environment, drinking water concerns, aquatic life concerns, wildlife concerns, livestock water supply concerns, and irrigation concerns. Application of criteria for aquatic life is discussed including phototoxic vs long term criteria, assessment of existing water quality, setting water quality objectives, and PAH levels in smoked fish. 221 refs., 5 figs., 30 tabs.
Toxicity assessment of water at different stages of treatment using Microtox assay

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Pogorzelec Marta

2017-01-01

Full Text Available Number of potentially toxic hydrophobic organic contaminants e.g. polycyclic aromatic hydrocarbons, pesticides, polychlorinated biphenyls and dioxins having entered aquatic environment, including potential sources of drinking water. Unfortunately, not all micropollutants can be removed during water treatment processes. What is more, disinfectants can react with some organic compounds already present in the water, and form disinfection by-products which also can be toxic. The aim of this study was to assess toxicity of water at different stages of water treatment and to verify usefulness semipermeable membrane devices in monitoring of drinking water. For this purpose, semipermeable membrane devices (SPMDs were deployed in a surface water treatment plant. To determine the effect of water treatment on the presence of toxic micropollutants, study was conducted for a period of 5 months. Three sampling places were chosen: raw water input, stream of water just before disinfection and treated water output. After sampling dialysis in organic solvent was carried out and extracts were then analyzed with the Microtox acute toxicity test. The study has indicated the utility as well as some limitations of combining SPMDs with bioluminescence assay in the monitoring of biological effects of bioavailable hydrophobic pollutants in drinking water.
Toxicity identification evaluations of produced-water effluents

International Nuclear Information System (INIS)

Sauer, T.C.; Costa, H.J.; Brown, J.S.; Ward, T.J.

1997-01-01

Toxicity identification evaluations (TIEs) were performed on 14 produced-water (PW) samples of various salinities from inland and offshore oil- and gas-production facilities operated by different companies in Wyoming, Texas, California, and Louisiana (USA) to evaluate the efficacy of TIE procedures in determining potential toxicants in PW effluents. The research involved acute (24- and 48-h) freshwater and marine toxicity tests on whole PW and PW fractions generated by standard US Environmental Protection Agency and PW-specific fractionation schemes. Factors influencing PW TIEs were investigated, such as the effect of salinity in selecting fractionation manipulations, the effect of toxicity test replication (i.e., reproducibility) in distinguishing changes in toxicities between whole PW and its fractions, and the suitability of different test species in PW TIEs. The results obtained and lessons learned from conducting these PW TIEs are presented in this article. Components, or fractions, contributing to toxicity differed for each PW with no specific fraction being consistently toxic. For most PW samples, toxicity attributed to any one fraction represented only part of the toxicity of the whole sample. However, no more than two fraction types were identified as potential toxicants in any sample. Potential toxicants identified during this study, besides salinity, included acidic and basic organic compound class fractions, particulates removed by filtration at pH 11, ammonia, hydrocarbons, hydrogen sulfide, material removed by pH change, and volatile compounds
Occurrence and Concentrations of Toxic VOCs in the Ambient Air of Gumi, an Electronics-Industrial City in Korea

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Sung-Ok Baek

2015-08-01

Full Text Available This study was carried out to characterize the occurrence and concentrations of a variety of volatile organic compounds (VOCs including aliphatic, aromatic, halogenated, nitrogenous, and carbonyl compounds, in the ambient air of Gumi City, where a large number of electronics industries are found. Two field monitoring campaigns were conducted for a one year period in 2003/2004 and 2010/2011 at several sampling sites in the city, representing industrial, residential and commercial areas. More than 80 individual compounds were determined in this study, and important compounds were then identified according to their abundance, ubiquity and toxicity. The monitoring data revealed toluene, trichloroethylene and acetaldehyde to be the most significant air toxics in the city, and their major sources were mainly industrial activities. On the other hand, there was no clear evidence of an industrial impact on the concentrations of benzene and formaldehyde in the ambient air of the city. Overall, seasonal variations were not as distinct as locational variations in the VOCs concentrations, whereas the within-day variations showed a typical pattern of urban air pollution, i.e., increase in the morning, decrease in the afternoon, and an increase again in the evening. Considerable decreases in the concentrations of VOCs from 2003 to 2011 were observed. The reductions in the ambient concentrations were confirmed further by the Korean PRTR data in industrial emissions within the city. Significant decreases in the concentrations of benzene and acetaldehyde were also noted, whereas formaldehyde appeared to be almost constant between the both campaigns. The decreased trends in the ambient levels were attributed not only to the stricter regulations for VOCs in Korea, but also to the voluntary agreement of major companies to reduce the use of organic solvents. In addition, a site planning project for an eco-friendly industrial complex is believed to play a contributory
Bacterial decontamination using ambient pressure nonthermal discharges

Energy Technology Data Exchange (ETDEWEB)

Birmingham, J.G.; Hammerstrom, D.J.

2000-02-01

Atmospheric pressure nonthermal plasmas can efficiently deactivate bacteria in gases, liquids, and on surfaces, as well as can decompose hazardous chemicals. This paper focuses on the changes to bacterial spores and toxic biochemical compounds, such as mycotoxins, after their treatment in ambient pressure discharges. The ability of nonthermal plasmas to decompose toxic chemicals and deactivate hazardous biological materials has been applied to sterilizing medical instruments, ozonating water, and purifying air. In addition, the fast lysis of bacterial spores and other cells has led us to include plasma devices within pathogen detection instruments, where nucleic acids must be accessed. Decontaminating chemical and biological warfare materials from large, high value targets such as building surfaces, after a terrorist attack, are especially challenging. A large area plasma decontamination technology is described.
76 FR 67437 - Draft Aquatic Life Ambient Water Quality Criteria for Carbaryl-2011

Science.gov (United States)

2011-11-01

... ENVIRONMENTAL PROTECTION AGENCY [EPA-HQ-OW-2011-0787; FRL-9483-8] Draft Aquatic Life Ambient Water... National Water Quality Criteria for the Protection of Aquatic Organisms and Their Uses (1985), (EPA/R-85... authorized Tribes in adopting water quality standards for protecting aquatic life and human health. These...
Monitoring of heavy/toxic metals and halides in surface/ground water (abstract)

International Nuclear Information System (INIS)

Viqar-un-Nisa; Ahmed, R.; Husain, M.

1999-01-01

Water is essential for maintaining physical and social life. Human and animal consumption is perhaps the most evident essential use of water. Water quality and quantity have become critical issues, affecting all life. The importance of water in our lives, combined with the threats, make water resources use a global problem. Among the different pollutants toxic metals, metalloids and halides have special significance. Industrial effluents and municipal wastewater are normally drained into water streams, rivers and other reservoirs thus polluting these significantly. Quality of our water resources especially is an issue, which continues to arouse the attention of concerned scientists, legislators and the general public. Among various pollutant chemicals, the heavy metals and metalloids are present at trace levels in various compartments of the environment. Some metals become toxic even at trace levels because of the important features that distinguishes metals from other pollutants is that they are not biodegradable. The halides like Cl, Br, and I from different sources can enter easily into water systems and then they make their way directly into the human body. The intake of toxic as wells as essential elements through water and other food items like vegetables, milk wheat flour etc. is significant. The abundance or deficiency of these meals as well as halides results in abnormal metabolic functions. Due to excessive demand for trace analysis in water and other materials a variety of techniques and instrumentation has been developed. Determination of heavy metals ions is of the highest interest in environmental analysis. Among the food materials water is most important because of their large consumption by man. Also toxic metals in water may be in dissolved ionic form, which directly go into human metabolism and start their toxic action. Presence of even small amounts of toxic metals in drinking water can produce serious health hazards. (author)
Water quality criteria for hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX)

Energy Technology Data Exchange (ETDEWEB)

Etnier, E.L.

1989-04-01

The occurrence of the munitions compound hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in groundwater surrounding Army ammunition plants may result in contamination of local drinking water supplies. RDX exerts its primary toxic effect in humans on the central nervous system, but also involves gastrointestinal and renal effects. Symptomatic effects following acute exposure include hyperirritability, nausea, vomiting, generalized epileptiform seizures, and prolonged postictal confusion and amnesia. Health effects data were analyzed for RDX, and although no controlled human studies exist concerning the acute or chronic toxic effects of exposure to RDX, sufficient animal toxicity data are available to derive an ambient water quality criterion for the protection of human health. This paper summarizes the available literature on metabolism of RDX and human and animal toxicity. Based on noncarcinogenic mammalian toxicity data, and following the methodologies of the U.S. Environmental Protection Agency, an ambient water quality criterion for the protection of human health of 103 micrograms/liter is proposed for ingestion of drinking water and aquatic foodstuffs. A criterion of 105 micrograms/liter is proposed for ingestion of drinking water alone.54 references.
Influence of ambient temperatures on performance of a CO2 heat pump water heating system

International Nuclear Information System (INIS)

Yokoyama, Ryohei; Shimizu, Takeshi; Ito, Koichi; Takemura, Kazuhisa

2007-01-01

In residential applications, an air-to-water CO 2 heat pump is used in combination with a domestic hot water storage tank, and the performance of this system is affected significantly not only by instantaneous ambient air and city water temperatures but also by hourly changes of domestic hot water consumption and temperature distribution in the storage tank. In this paper, the performance of a CO 2 heat pump water heating system is analyzed by numerical simulation. A simulation model is created based on thermodynamic equations, and the values of model parameters are estimated based on measured data for existing devices. The calculated performance is compared with the measured one, and the simulation model is validated. The system performance is clarified in consideration of seasonal changes of ambient air and city water temperatures
Avoiding toxicity from water-borne contaminants in hemodialysis: new challenges in an era of increased demand for water.

Science.gov (United States)

Ward, Richard A

2011-05-01

Water is necessary for all hemodialysis treatments. However, drinking water contains a range of substances that are toxic to patients on hemodialysis. Thus, all dialysis facilities are equipped with a water treatment system that removes those substances from the water before it is used to prepare dialysate. Increased demand for water and ever-evolving drinking water regulations are leading to changes in drinking water quality that may compromise the ability of typical dialysis water treatment systems to adequately remove substances that are known to be toxic or to deal with unexpected increases in other substances of unknown toxicity. In addition to these external challenges to dialysis water quality, the growing recognition that microbial contaminants in dialysate contribute to long-term morbidity has led to more stringent microbiological quality standards for dialysate and a consequent need to control biofilm formation in the fluid pathways involved in dialysate preparation. Avoiding toxicity from water contaminants in this dynamic environment requires a comprehensive approach to water treatment, including flexibility regarding the choice of water treatment processes, close communication with the suppliers of drinking water, and an emphasis on training technicians responsible for monitoring and maintaining all aspects of the fluid handling systems. Copyright © 2011 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.
Use of hydra for chronic toxicity assessment of waters intended for human consumption

International Nuclear Information System (INIS)

Arkhipchuk, Victor V.; Blaise, Christian; Malinovskaya, Maria V.

2006-01-01

Methods developed with the cnidarian, Hydra attenuata (Pallas), have proven effective for screening acute toxicity in aqueous samples, whereas their use in revealing (sub)chronic toxic effects have had mitigated success. We therefore sought to explore manifestations of hydra mortality and abnormal morphological changes, as well as the reproductive capacity of hydras to further enhance the bioassay sensitivity and to assess (sub)chronic toxicity. These parameters were recorded following the onset of experiments after 8, 12 and 19-21 days of hydra exposure. Results obtained with potable waters (30 brands of bottled waters and artesian waters from 9 wells) showed chronic sublethal and lethal effects or reproduction rate inhibition for most samples. The effectiveness of the hydra toxicity test was demonstrated in comparison with other widely used bioassays. Our previous and present investigations suggest that hydra is a reliable and relevant test organism for the assessment of acute and chronic water toxicity. - Hydra is a reliable and relevant test organism for the assessment of acute and chronic toxicity of waters intended for human consumption
Thermal Stress and Toxicity | Science Inventory | US EPA

Science.gov (United States)

Elevating ambient temperature above thermoneutrality exacerbates toxicity of most air pollutants, insecticides, and other toxic chemicals. On the other hand, safety and toxicity testing of toxicants and drugs is usually performed in mice and rats maintained at subthermoneutral temperatures of —22 °C. When exposed to chemical toxicants under these relatively cool conditions, rodents typically undergo a regulated hypothermic response, characterized by preference for cooler ambient temperatures and controlled reduction in core temperature. Reducing core temperature delays the clearance of most toxicants from the body; however, a mild hypothermia also improves recovery and survival from the toxicant. Raising ambient temperature to thermoneutrality and above increases the rate of clearance of the toxicant but also exacerbates toxicity. Furthermore, heat stress combined with work or exercise is likely to worsen toxicity. Body temperature of large mammals, including humans, does not decrease as much in response to exposure to a toxicant. However, heat stress tan nonetheless worsen toxic outcome in humans through a variety of mechanisms. For example, heat-induced sweating and elevation in skin blood flow accelerates uptake of some insecticides. Epidemiological studies suggest that thermal stress may exacerbate the toxicity of airborne pollutants such as ozone and particulate matter. Overall, translating results of studies in rodents to that of humans is a formidable
FOR SELECTED ORGANIC MICROPOLLUTANTS ELIMINATION AND CHANGE OF WATER TOXICITY

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Mariusz Dudziak

2016-12-01

Full Text Available All of the available and applicable chemical oxidants were found to affect the quality of the treated water or wastewater. It has been commonly observed that the oxidation processes generate by-products, which often possess unknown biological activity. Accordingly, the present study assessed the degree of degradation of mixture of selected micropollutants and the change of the solution toxicity in the UV/TiO2/H2O2 hybrid process. Water containing bisphenol A and diclofenac at a concentration of 1 mg/dm3 was treated. For toxicological evaluation of solution sample were used three different tests, ie. enzymatic Microtox® using luminescent strain of marine bacteria Aliivibrio fischeri, survival of the crustaceans Daphnia magna and the growth of duckweed Lemna minor. Decomposition of tested micropollutants depend on the processing time and the type of the oxidizing compound. However, during the process we observed adverse effects of water toxicity. The toxicity was documented in both bacteria and water plant.
Precipitation of metals in produced water : influence on contaminant transport and toxicity

International Nuclear Information System (INIS)

Azetsu-Scott, K.; Wohlgeschaffen, G.; Yeats, P.; Dalziel, J.; Niven, S.; Lee, K.

2006-01-01

Produced water contains a number of compounds of environmental concern and is the largest volume waste stream from oil and gas production activities. Recent studies have shown that chemicals dissolved in waste water from oil platforms stunted the growth of North Sea cod and affected their breeding patterns. Scientific research is needed to identify the impact of produced water discharges on the environment as well as to identify acceptable disposal limits for produced water. This presentation provided details of a study to characterize produced water discharged within the Atlantic regions of Canada. The study included dose response biological effect studies; research on processes controlling the transport and transformation of contaminants associated with produced water discharges and the development of risk assessment models. The sample location for the study was a site near Sable Island off the coast of Nova Scotia. Chemical analysis of the produced water was conducted as well as toxicity tests. Other tests included a time-series particulate matter sedimentation test; time-series metal and toxicity analysis; time-series change in metal precipitates tests and a produced water/seawater layering experiment. Dissolved and particulate fractions were presented, and the relationship between toxicity and particulate concentrations was examined. Results of the study suggested that produced water contaminants are variable over spatial and temporal scales due to source variations and changes in discharge rates. Chemical changes occur within 24 hours of produced water being mixed with seawater and facilitate contaminant partitioning between the surface micro layer, water column and sediments. Changes in the toxicity of the produced water are correlated with the partitioning of chemical components. The impact zone may be influenced by chemical kinetics that control the distribution of potential toxic metals. Further research is needed to investigate the effects of low level

Field Validation of Toxicity Tests to Evaluate the Potential for Beneficial Use of Produced Water

Energy Technology Data Exchange (ETDEWEB)

Joseph Bidwell; Jonathan Fisher; Naomi Cooper

2008-03-31

This study investigated potential biological effects of produced water contamination derived from occasional surface overflow and possible subsurface intrusion at an oil production site along the shore of Skiatook Lake, Oklahoma. We monitored basic chemistry and acute toxicity to a suite of standard aquatic test species (fathead minnow-Pimephales promelas, Daphnia pulex, Daphnia magna, and Ceriodaphnia dubia) in produced water and in samples taken from shallow groundwater wells on the site. Toxicity identification evaluations and ion toxicity modeling were used to identify toxic constituents in the samples. Lake sediment at the oil production site and at a reference site were also analyzed for brine intrusion chemically and by testing sediment toxicity using the benthic invertebrates, Chironomus dilutus, and Hyallela azteca. Sediment quality was also assessed with in situ survival and growth studies with H. azteca and the Asian clam, Corbicula fluminea, and by benthic macroinvertebrate community sampling. The produced water was acutely toxic to the aquatic test organisms at concentrations ranging from 1% to 10% of the whole produced water sample. Toxicity identification evaluation and ion toxicity modeling indicated major ion salts and hydrocarbons were the primary mixture toxicants. The standardized test species used in the laboratory bioassays exhibited differences in sensitivity to these two general classes of contaminants, which underscores the importance of using multiple species when evaluating produced water toxicity. Toxicity of groundwater was greater in samples from wells near a produced water injection well and an evaporation pond. Principle component analyses (PCA) of chemical data derived from the groundwater wells indicated dilution by lake water and possible biogeochemical reactions as factors that ameliorated groundwater toxicity. Elevated concentrations of major ions were found in pore water from lake sediments, but toxicity from these ions was
[The toxicity variation of organic extracts in drinking water treatment processes].

Science.gov (United States)

Mei, M; Wei, S; Zijian, W; Wenhua, W; Baohua, Z; Suxia, Z

2001-01-01

Source water samples and outlet water samples from different treatment processes of the Beijing Ninth Water Works were concentrated in situ with XAD-2 filled columns. GC-MS analysis and toxic assessment including acute toxicity evaluation by luminescent bacterium bioassay(Q67 strains) and mutagenicity assessment by Ames test(TA98 and TA100 strains with and without S9 addition) were conducted on these samples. The results showed that prechlorination caused the direct and indirect frame shift mutagenicity as well as indirect base pair substitute mutagenicity. Addition of coagulant may increase the base pair substitute mutagenic effects greatly. Sand and coal filtration and granular activated carbon filtration could effectively remove most of the formed mutagens. The rechlorination do not obviously increase the mutagenic effects. No mutagenic effect was observed in tap water. Acute toxicity showed the same variation with that of mutagenicity during the treatment processes. Sample from flocculation treatment process was found to be the most toxic sample. Results of GC-MS analysis showed that water in this plant was not contaminated by PCB. Concentrations of toluene, naphthalene and phenol increased in flocculation treatment process and in tap water. However, the concentrations of these substances were at the level of microgram/L, therefore, were not high enough to cause mutagenicity.
LEVEL OF TOXICITY WATER AREA «TULENIY» AS A RESULT OF BIOASSAY

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A. F. Sokolsky

2014-01-01

Full Text Available Aim. To determine the toxicity of marine waters area " tuleniy ".Location. Area " tuleniy ".Methods. Determining the level of toxicity of marine waters area "seal" method for biological testing was conducted according tothe guidelines approved by the Ministry of natural resources (guidance on the definition of ..., 2002; Dolzhenko, 1978. Guide prepared by the Center for Russian register of hydraulic structures and the state water cadastre of the MNR of Russia jointly with specialists of the Institute Committee of Russia and the UNION of ecological problems of the Ministry of Ukraine. The basis of the proposed system of marine toxicity biotests based on the results of generalization of experimental research based on the problem of pollution of water bodies and numerous literature data, making it possible to identify features of the response of aquatic organisms of different taxonomic groups to toxic impurities of different nature and origin. Experimental studies were conducted on the culture of marine unicellular algae Phaeodactylum tricornutum on planktonic crustacea Acartia tonsa, the larvae of the chironomid Chironomus gr.salinarius and juvenile guppies Poecillia reticulata Peters.Results. Comparative analysis of the results of research from 2001 to 2006 showed no acute toxic effect on the test object zooplankton and phytoplanton.Main conclusions. Throughout the study period (2001-2003, 2005-2006, you must allocate the spring of 2002, when it was recorded,the average of the lowest five years of research, the level of toxicity of water for the analyzed area.Considering the results of biological testing of the surveyed area by periods, it should be noted that the average level of toxicity of the waters did not undergo significant changes and were on the same level, not exceeding 17,6% (table. 1. According to the classification shown in table 2, the water in the surveyed area is assessed as "non-toxic".
Investigation of the potential influence of production treatment chemicals on produced water toxicity

International Nuclear Information System (INIS)

Stine, E.R.; Gala, W.R.; Henry, L.R.

1993-01-01

Production treatment chemicals represent a diverse collection of chemical classes, added at various points from the wellhead to the final flotation cell, to prevent operational upsets and enhance the separation of oil from water. Information in the literature indicates that while many treatment chemicals are thought to partition into oil and not into the produced water, there are cases where a sufficiently water soluble treatment chemical is added at high enough concentrations to suggest that the treatment chemical may add to the aquatic toxicity of the produced water. A study was conducted to evaluate the potential effect of production treatment chemicals on the toxicity of produced waters using the US EPA Seven-day Mysidopsis bahia Survival, Growth and Fecundity Test. Samples of produced water were collected and tested for toxicity from three platforms under normal operating conditions, followed by repeated sampling and testing after a 72-hour period in which treatment chemical usage was discontinued, to the degree possible. Significant reductions in produced water toxicity were observed for two of the three platforms tested following either cessation of treatment chemical usage, or by comparing the toxicity of samples collected upstream and downstream of the point of treatment chemical addition
Acute and chronic toxicity studies of the water extract from dried ...

African Journals Online (AJOL)

Acute and chronic toxicities of the water extract from the dried fruits of Terminalia bellerica (Gaertn.) Roxb. were assessed in both female and male rats. For the study of acute toxicity, a single oral administration of the water extract at a dose of 5,000 mg/kg body weight (10 female, 10 male) was performed and the results ...
Renal Cell Toxicity of Water-Soluble Coal Extracts from the Gulf Coast

Science.gov (United States)

Ojeda, A. S.; Ford, S.; Ihnat, M.; Gallucci, R. M.; Philp, P. R.

2017-12-01

In the Gulf Coast, many rural residents rely on private well water for drinking, cooking, and other domestic needs. A large portion of this region contains lignite coal deposits within shallow aquifers that potentially leach organic matter into the water supply. It is proposed that the organic matter leached from low-rank coal deposits contributes to the development of kidney disease, however, little work has been done to investigate the toxicity of coal extracts. In this study, human kidney cells (HK-2) were exposed to water-soluble extracts of Gulf Coast Coals to assess toxicity. Cell viability was measured by direct counts of total and necrotic cells. A dose-response curve was used to generate IC50 values, and the extracts showed significant toxicity that ranged from 0.5% w/v to 3% w/v IC50. The most toxic extract was from Louisiana where coal-derived organic material has been previously linked to high incidents of renal pelvic cancer (RPC). Although the toxic threshold measured in this study is significantly higher than the concentration of organic matter in the groundwater, typically affected areas may consume contaminated water over a lifetime. It is possible that the cumulative toxic effects of coal-derived material contribute to the development of disease.
Dredged Material Evaluations: Review of Zooplankton Toxicity Test Methods for Marine Water Quality Evaluations

Science.gov (United States)

2016-09-01

term impacts of the DM while settling through the water column (elutriate toxicity tests), and long-term toxicity (whole sediment toxicity tests) and...elutriates are prepared according to guidance (USEPA/USACE 1991; 1998) by mixing sediment and site water and allowing settling for prescribed periods...of water and waste water . 17th ed. Washington, DC: APHA. Arnold, W. R., R. L. Diamond, and D. S. Smith. 2010a. The effects of salinity, pH, and
Spatial and temporal distributions of toxicity in receiving waters around an oil effluent discharge site

International Nuclear Information System (INIS)

Krause, P.R.

1994-01-01

Distributions of pollutants from a point source discharge within the water column may vary in both time and space. In this study, they examined the spatial and temporal patterns of toxicity from an oil production effluent (produced water) discharge plume using sea urchin fertilization and development bioassays. Specifically, they tested the sensitivity and response patterns of sea urchin gametes and early life stages exposed to receiving waters sampled along a 1 km transact near an active produced water outfall. Fertilization success and development of larvae to the pluteus stage varied significantly with proximity to the outfall, with reduced fertilization and larval development found closer to the outfall. Although estimated toxicity in receiving water samples, based on fertilization success, was variable in time -- perhaps responding to variation in the quantity or make-up of produced water discharges -- the general spatial pattern of toxicity along the sampling transact remained relatively constant. Strong evidence that field toxicity was directly attributable to produced water effluents was provided by sampling the receiving waters while the produced water discharge was not operating. At such a time, no toxicity was found at any of the field sites. Receiving water toxicity data, along with toxicity data from the effluent itself, were used to prepare a ''map'' of effective effluent concentrations along the sampling transect
Evaluation of a novel automated water analyzer for continuous monitoring of toxicity and chemical parameters in municipal water supply.

Science.gov (United States)

Bodini, Sergio F; Malizia, Marzio; Tortelli, Annalisa; Sanfilippo, Luca; Zhou, Xingpeng; Arosio, Roberta; Bernasconi, Marzia; Di Lucia, Stefano; Manenti, Angela; Moscetta, Pompeo

2018-08-15

A novel tool, the DAMTA analyzer (Device for Analytical Monitoring and Toxicity Assessment), designed for fully automated toxicity measurements based on luminescent bacteria as well as for concomitant determination of chemical parameters, was developed and field-tested. The instrument is a robotic water analyzer equipped with a luminometer and a spectrophotometer, integrated on a thermostated reaction plate which contains a movable carousel with 80 cuvettes. Acute toxicity is measured on-line using a wild type Photobacterium phosphoreum strain with measurable bioluminescence and unaltered sensitivity to toxicants lasting up to ten days. The EC50 values of reference compounds tested were consistent with A. fischeri and P. phosphoreum international standards and comparable to previously published data. Concurrently, a laboratory trial demonstrated the feasibility of use of the analyzer for the determination of nutrients and metals in parallel to the toxicity measurements. In a prolonged test, the system was installed only in toxicity mode at the premises of the World Fair "Expo Milano-2015″, a high security site to ensure the quality of the supplied drinking water. The monitoring program lasted for six months during which ca. 2400 toxicity tests were carried out; the results indicated a mean non-toxic outcome of -5.5 ± 6.2%. In order to warrant the system's robustness in detecting toxic substances, Zn was measured daily with highly reproducible inhibition results, 70.8 ± 13.6%. These results assure that this novel toxicity monitor can be used as an early warning system for protection of drinking water sources from emergencies involving low probability/high impact contamination events in source water or treated water. Copyright © 2018 Elsevier Inc. All rights reserved.
Toxicity of sediments and pore water from Brunswick Estuary, Georgia

Science.gov (United States)

Winger, Parley V.; Lasier, Peter J.; Geitner, Harvey

1993-01-01

A chlor-alkali plant in Brunswick, Georgia, USA, discharged >2 kg mercury/d into a tributary of the Turtle River-Brunswick Estuary from 1966 to 1971. Mercury concentrations in sediments collected in 1989 along the tributary near the chlor-alkali plant ranged from 1 to 27 μg/g (dry weight), with the highest concentrations found in surface (0–8 cm) sediments of subtidal zones in the vicinity of the discharge site. Toxicity screening in 1990 using Microtox® bioassays on pore water extracted on site from sediments collected at six stations distributed along the tributary indicated that pore water was highly toxic near the plant discharge. Ten-day toxicity tests on pore water from subsequent sediment samples collected near the plant discharge confirmed high toxicity to Hyalella azteca, and feeding activity was significantly reduced in whole-sediment tests. In addition to mercury in the sediments, other metals (chromium, lead, and zinc) exceeded 50 μg/g, and polychlorobiphenyl (PCB) concentrations ranged from 67 to 95 μg/g. On a molar basis, acid-volatile sulfide concentrations (20–45 μmol/g) in the sediments exceeded the metal concentrations. Because acid-volatile sulfides bind with cationic metals and form metal sulfides, which are generally not bioavailable, toxicities shown by these sediments were attributed to the high concentrations of PCBs and possibly methylmercury.
Presence, origin and importance of toxic substances in drinking water

Energy Technology Data Exchange (ETDEWEB)

Seemayer, N H

1980-01-01

The ubiquitous, environmental toxic substances representing a risk to health, and of importance with respect to the production of drinking water, largely belong to the following groups: cancerogenic, polycyclic, aromatic hydrocarbons, aromatic amines, N-nitroso compounds, pesticides. In addition the following substances: polychlorinated biphenyls, hormones, antibiotics, halogen hydrocarbons and heavy metals such as mercury, cadmium, lead, vanadium, chromium etc. Today, there is full appreciation of the qualitative aspects associated with the burdening of the environmental factor 'water' with toxic substances. However, as to the quantitative aspects, especially those relating to a combined effect of toxic substances adding to the total burden of man with noxious environmental agents, data are still lacking. The assessment of the chronic action exercised by minute and very minute concentrations of potentially toxic, cancerogenic or mutagenic substances possess a particularly complex problem for the environmental and water hygiene. Nowadays, there are basically 3 possibilities of solving this problem: epidemiological-statistical analyses, long-term animal experiments and in-vitro short-term tests. The epidemiological-statistical analysis can make a valuable contribution to the evaluation of the risk to human health of polluted drinking water and may also furnish the first clues to an incipient danger. However, it has to be considered that epidemiological studies deal with multifactorial events and that a monocausality is difficult to establish.
Future research needs associated with the assessment of potential human health risks from exposure to toxic ambient air pollutants

DEFF Research Database (Denmark)

Möller, Lennart; Schuetzle, Dennis; Autrup, Herman

1994-01-01

of identification and quantification of toxics in source emissions and ambient air, atmospheric transport and chemistry, exposure level assessment, the development of improved in vitro bioassays, biomarker development, the development of more accurate epidemiological methodologies, and risk quantification...... techniques. Studies are described that will be necessary to assess and reduce the level of uncertainties associated with each step of the risk assessment process. International collaborative research efforts between industry and government organizations are recommended as the most effective way to carry out...
Pesticide Toxicity Index: a tool for assessing potential toxicity of pesticide mixtures to freshwater aquatic organisms

Science.gov (United States)

Nowell, Lisa H.; Norman, Julia E.; Moran, Patrick W.; Martin, Jeffrey D.; Stone, Wesley W.

2014-01-01

Pesticide mixtures are common in streams with agricultural or urban influence in the watershed. The Pesticide Toxicity Index (PTI) is a screening tool to assess potential aquatic toxicity of complex pesticide mixtures by combining measures of pesticide exposure and acute toxicity in an additive toxic-unit model. The PTI is determined separately for fish, cladocerans, and benthic invertebrates. This study expands the number of pesticides and degradates included in previous editions of the PTI from 124 to 492 pesticides and degradates, and includes two types of PTI for use in different applications, depending on study objectives. The Median-PTI was calculated from median toxicity values for individual pesticides, so is robust to outliers and is appropriate for comparing relative potential toxicity among samples, sites, or pesticides. The Sensitive-PTI uses the 5th percentile of available toxicity values, so is a more sensitive screening-level indicator of potential toxicity. PTI predictions of toxicity in environmental samples were tested using data aggregated from published field studies that measured pesticide concentrations and toxicity to Ceriodaphnia dubia in ambient stream water. C. dubia survival was reduced to ≤ 50% of controls in 44% of samples with Median-PTI values of 0.1–1, and to 0% in 96% of samples with Median-PTI values > 1. The PTI is a relative, but quantitative, indicator of potential toxicity that can be used to evaluate relationships between pesticide exposure and biological condition.
Gold-Catalyzed Aerobic Oxidation of 5-Hydroxymethylfurfural in Water at Ambient Temperature

DEFF Research Database (Denmark)

Gorbanev, Yury; Kegnæs, Søren; Woodley, John

2009-01-01

The aerobic oxidation of 5-hydroxymethylfurfural, a versatile biomass-derived chemical, is examined in water with a titania-supported gold-nanoparticle catalyst at ambient temperature (30 degrees C). The selectivity of the reaction towords 2,5-furandicarboxylic acid and the intermediate oxidation...
Effect of water hardness on peracetic acid toxicity to zebrafish, Danio rerio, embryos

DEFF Research Database (Denmark)

Marchand, Pierre_André; Strauss, David L.; Wienke, Andreas

2013-01-01

The use of peracetic acid (PAA) in aquaculture has been suggested as an alternative therapeutic agent. Few data are available concerning fish toxicity by PAA or factors that modify this toxicity. The aim of this study was to investigate the influence of water hardness on the acute toxicity of PAA...... acidic in low hardness. In conclusion, aquaculturists using PAA should pay attention to water hardness to avoid acidosis...
Toxic pressure of herbicides on microalgae in Dutch estuarine and coastal waters

Science.gov (United States)

Booij, Petra; Sjollema, Sascha B.; van der Geest, Harm G.; Leonards, Pim E. G.; Lamoree, Marja H.; de Voogt, W. Pim; Admiraal, Wim; Laane, Remi W. P. M.; Vethaak, A. Dick

2015-08-01

For several decades now, there has been an increase in the sources and types of chemicals in estuarine and coastal waters as a consequence of anthropogenic activities. This has led to considerable concern about the effects of these chemicals on the marine food chain. The fact is that estuarine and coastal waters are the most productive ecosystems with high primary production by microalgae. The toxic pressure of specific phytotoxic chemicals now poses a major threat to these ecosystems. In a previous study, six herbicides (atrazine, diuron, irgarol, isoproturon, terbutryn and terbutylazine) were identified as the main contaminants affecting photosynthesis in marine microalgae. The purpose of this study is to investigate the toxic pressure of these herbicides in the Dutch estuarine and coastal waters in relation to the effective photosystem II efficiency (ΦPSII) in microalgae. Temporal and spatial variations in the concentrations of these herbicides were analyzed based on monitoring data. Additionally, a field study was carried out in which chemical analysis of water was performed and also a toxicity assessment using the Pulse Amplitude Modulation (PAM) fluorometry assay that measures ΦPSII. The toxic pressure on ΦPSII in microalgae has decreased with 55-82% from 2003 to 2012, with the Western Scheldt estuary showing the highest toxic pressure. By combining toxicity data from the PAM assay with chemical analysis of herbicide concentrations, we have identified diuron and terbutylazine as the main contributors to the toxic pressure on microalgae. Although direct effects are not expected, the toxic pressure is close to the 10% effect level in the PAM assay. A compliance check with the current environmental legislation of the European Union revealed that the quality standards are not sufficient to protect marine microalgae.
Ambient iron-mediated aeration (IMA) for water reuse.

Science.gov (United States)

Deng, Yang; Englehardt, James D; Abdul-Aziz, Samer; Bataille, Tristan; Cueto, Josenrique; De Leon, Omar; Wright, Mary E; Gardinali, Piero; Narayanan, Aarthi; Polar, Jose; Tomoyuki, Shibata

2013-02-01

Global water shortages caused by rapidly expanding population, escalating water consumption, and dwindling water reserves have rendered water reuse a strategically significant approach to meet current and future water demand. This study is the first to our knowledge to evaluate the technical feasibility of iron-mediated aeration (IMA), an innovative, potentially economical, holistic, oxidizing co-precipitation process operating at room temperature, atmospheric pressure, and neutral pH, for water reuse. In the IMA process, dissolved oxygen (O₂) was continuously activated by zero-valent iron (Fe⁰) to produce reactive oxygen species (ROS) at ambient pH, temperature, and pressure. Concurrently, iron sludge was generated as a result of iron corrosion. Bench-scale tests were conducted to study the performance of IMA for treatment of secondary effluent, natural surface water, and simulated contaminated water. The following removal efficiencies were achieved: 82.2% glyoxylic acid, ~100% formaldehyde as an oxidation product of glyoxylic acid, 94% of Ca²⁺ and associated alkalinity, 44% of chemical oxygen demand (COD), 26% of electrical conductivity (EC), 98% of di-n-butyl phthalate (DBP), 80% of 17β-estradiol (E2), 45% of total nitrogen (TN), 96% of total phosphorus (TP), 99.8% of total Cr, >90% of total Ni, 99% of color, 3.2 log removal of total coliform, and 2.4 log removal of E. Coli. Removal was attributed principally to chemical oxidation, precipitation, co-precipitation, coagulation, adsorption, and air stripping concurrently occurring during the IMA treatment. Results suggest that IMA is a promising treatment technology for water reuse. Copyright © 2012 Elsevier Ltd. All rights reserved.
Bioelectrochemical biosensor for water toxicity detection: generation of dual signals for electrochemical assay confirmation.

Science.gov (United States)

Yang, Yuan; Wang, Yan-Zhai; Fang, Zhen; Yu, Yang-Yang; Yong, Yang-Chun

2018-02-01

Toxicity assessment of water is of great important to the safety of human health and to social security because of more and more toxic compounds that are spilled into the aquatic environment. Therefore, the development of fast and reliable toxicity assessment methods is of great interest and attracts much attention. In this study, by using the electrochemical activity of Shewanella oneidensis MR-1 cells as the toxicity indicator, 3,5-dichlorophenol (DCP) as the model toxic compound, a new biosensor for water toxicity assessment was developed. Strikingly, the presence of DCP in the water significantly inhibited the maximum current output of the S. oneidensis MR-1 in a three-electrode system and also retarded the current evolution by the cells. Under the optimized conditions, the maximum current output of the biosensor was proportional to the concentration of DCP up to 30 mg/L. The half maximal inhibitory concentration of DCP determined by this biosensor is about 14.5 mg/L. Furthermore, simultaneous monitoring of the retarded time (Δt) for current generation allowed the identification of another biosensor signal in response to DCP which could be employed to verify the electrochemical result by dual confirmation. Thus, the present study has provided a reliable and promising approach for water quality assessment and risk warning of water toxicity.
Study on mutagenic and toxic compounds in lake water used as drinking water supply

International Nuclear Information System (INIS)

Monarca, S.; Zanardini, A.

1996-01-01

Trace amounts of mutagenic and toxic substances are frequently found in drinking water, causing a great concern for their potential health effects. Aim of this work is to develop a reliable and efficient screening method for detecting aquatic mutagens and toxins in surface water used for human consumption. For this purpose different methods of concentration of lake water have been experimented by using three different solid phase extraction systems at different pHs and studying the adsorbates by means of a mutagenicity test (Ames test), a toxicity test (LUMIStox) and chemical analysis (GC,MS). This integrated chemical/biological approach showed to be a suitable system for the preliminary choice of an efficient screening method for aquatic mutagens and toxins and to give useful data for the evaluation of potential health hazards
Small Microbial Three-Electrode Cell Based Biosensor for Online Detection of Acute Water Toxicity.

Science.gov (United States)

Yu, Dengbin; Zhai, Junfeng; Liu, Changyu; Zhang, Xueping; Bai, Lu; Wang, Yizhe; Dong, Shaojun

2017-11-22

The monitoring of toxicity of water is very important to estimate the safety of drinking water and the level of water pollution. Herein, a small microbial three-electrode cell (M3C) biosensor filled with polystyrene particles was proposed for online monitoring of the acute water toxicity. The peak current of the biosensor related with the performance of the bioanode was regarded as the toxicity indicator, and thus the acute water toxicity could be determined in terms of inhibition ratio by comparing the peak current obtained with water sample to that obtained with nontoxic standard water. The incorporation of polystyrene particles in the electrochemical cell not only reduced the volume of the samples used, but also improved the sensitivity of the biosensor. Experimental conditions including washing time with PBS and the concentration of sodium acetate solution were optimized. The stability of the M3C biosensor under optimal conditions was also investigated. The M3C biosensor was further examined by formaldehyde at the concentration of 0.01%, 0.03%, and 0.05% (v/v), and the corresponding inhibition ratios were 14.6%, 21.6%, and 36.4%, respectively. This work provides a new insight into the development of an online toxicity detector based on M3C biosensor.

Fact Sheet: Notice of Ambient Water Quality Criteria Document for Tributyltin (TBT) - Final

Science.gov (United States)

Information pertaining to 2004 Final Acute and Chronic Ambient Aquatic Life Water Quality Criteria for Tributyltin (TBT) for freshwater and saltwater. This fact sheet includes the safe levels of TBT that should protect the majority of species.
Hazardous air pollutant handbook: measurements, properties, and fate in ambient air

Energy Technology Data Exchange (ETDEWEB)

Spicer, C.W. (ed.); Gordon, S.M.; Kelly, T.J.; Holdren, M.W.; Mukund, R. [Battelle, Columbus, OH (United States)

2002-07-01

Focussing on the 188 hazardous air pollutants (HAPs) identified in the Title III of the US Clean Air Act Amendments, this work reviews the methods used to identify, measure, and locate the presence of toxics in ambient air. After a classification and characterization of the HAPs, the current status of ambient measurement methods are surveyed and categorized according to applicable, likely, and potential methods. The results of studies of ambient air concentrations of the HAPs are presented. Methods used to study atmospheric transformations of toxic air pollutants are reviewed and the concept of atmospheric lifetimes of HAPs is discussed.
Pilot study investigating ambient air toxics emissions near a Canadian kraft pulp and paper facility in Pictou County, Nova Scotia.

Science.gov (United States)

Hoffman, Emma; Guernsey, Judith R; Walker, Tony R; Kim, Jong Sung; Sherren, Kate; Andreou, Pantelis

2017-09-01

Air toxics are airborne pollutants known or suspected to cause cancer or other serious health effects, including certain volatile organic compounds (VOCs), prioritized by the US Environmental Protection Agency (EPA). While several EPA-designated air toxics are monitored at a subset of Canadian National Air Pollution Surveillance (NAPS) sites, Canada has no specific "air toxics" control priorities. Although pulp and paper (P&P) mills are major industrial emitters of air pollutants, few studies quantified the spectrum of air quality exposures. Moreover, most NAPS monitoring sites are in urban centers; in contrast, rural NAPS sites are sparse with few exposure risk records. The objective of this pilot study was to investigate prioritized air toxic ambient VOC concentrations using NAPS hourly emissions data from a rural Pictou, Nova Scotia Kraft P&P town to document concentration levels, and to determine whether these concentrations correlated with wind direction at the NAPS site (located southwest of the mill). Publicly accessible Environment and Climate Change Canada data (VOC concentrations [Granton NAPS ID: 31201] and local meteorological conditions [Caribou Point]) were examined using temporal (2006-2013) and spatial analytic methods. Results revealed several VOCs (1,3-butadiene, benzene, and carbon tetrachloride) routinely exceeded EPA air toxics-associated cancer risk thresholds. 1,3-Butadiene and tetrachloroethylene were significantly higher (p towns and contribute to poor health in nearby communities.
Grey water treatment in UASB reactor at ambient temperature.

Science.gov (United States)

Elmitwalli, T A; Shalabi, M; Wendland, C; Otterpohl, R

2007-01-01

In this paper, the feasibility of grey water treatment in a UASB reactor was investigated. The batch recirculation experiments showed that a maximum total-COD removal of 79% can be obtained in grey-water treatment in the UASB reactor. The continuous operational results of a UASB reactor treating grey water at different hydraulic retention time (HRT) of 20, 12 and 8 hours at ambient temperature (14-24 degrees C) showed that 31-41% of total COD was removed. These results were significantly higher than that achieved by a septic tank (11-14%), the most common system for grey water pre-treatment, at HRT of 2-3 days. The relatively lower removal of total COD in the UASB reactor was mainly due to a higher amount of colloidal COD in the grey water, as compared to that reported in domestic wastewater. The grey water had a limited amount of nitrogen, which was mainly in particulate form (80-90%). The UASB reactor removed 24-36% and 10-24% of total nitrogen and total phosphorus, respectively, in the grey water, due to particulate nutrients removal by physical entrapment and sedimentation. The sludge characteristics of the UASB reactor showed that the system had stable performance and the recommended HRT for the reactor is 12 hours.
Investigation of toxic influence of Ignalina NPP waste water on Spirodela polyrrhiza culture

International Nuclear Information System (INIS)

Lakachauskiene, R.; Marchiulioniene, D.

1995-01-01

The influence of Ignalina NPP waste waters and of water taken in different biotop of lake Drukshiai on Spirodela polyrrhiza culture (growth intensity, biomass and morphological changes) was investigated. It was revealed that most polluted waters formed by Ignalina NPP outcomes were from industrial - rain sewerage and economic - domestic waste waters. Toxicity of all investigated waters was higher in autumn (October) than it was in spring (March -April). Comparative analysis of the data obtained in 1992-1994 indicated the growing tendency of toxicity in Ignalina NPP waste waters as well as lake Drukshiai water. (author). 5 refs., 4 figs
Phytoremediation of wastewater toxicity using water hyacinth (Eichhornia crassipes) and water lettuce (Pistia stratiotes).

Science.gov (United States)

Victor, Kouamé Kouamé; Séka, Yapoga; Norbert, Kouadio Kouakou; Sanogo, Tidou Abiba; Celestin, Atsé Boua

2016-10-02

This paper elucidates the phytoremediation potential of water hyacinth and water lettuce on the reduction of wastewater toxicity. Acute toxicity tests were performed in an aquarium with a population of Sarotherodon melanotheron, contaminated by different concentrations of wastewaters before and after phytoremediation with Eichhornia crassipes and Pistia stratiotes. Lethal concentrations (LC50) of the fish's population obtained during 24 hours of exposures were determined. COD, BOD, ammonium, TKN and PO4(3-) concentrations in wastewaters were of 1850.29, 973.33, 38.34, 61.49 and 39.23 mg L(-1), respectively, for each plant. Phytoremediation reduced 58.87% of ammonium content, 50.04% of PO4(3-), 82.45% of COD and 84.91% of BOD. After 15 days of the experiment, metal contents in treated wastewaters decreased from 6.65 to 97.56% for water hyacinth and 3.51 to 93.51% for water lettuce tanks. Toxicity tests showed that the mortality of fish exposed increased with increase in concentration of pollutants in wastewaters and the time of exposure. Therefore, the highest value of LC50 was recorded for fish subjected to 3 hours of exposure (16.37%). The lowest rate was obtained after an exposure of 20 to 24 hours (5.85%). After phytoremediation, the effluents purified by Eichhornia crassipes can maintain the fish life beyond 24 hours of exposure.
Water quality and toxicity of river water downstream of the uranium mining facility at Pocos de Caldas, MG, Brazil

International Nuclear Information System (INIS)

Lauria, Dejanira C.; Vascocnellos, Luisa M.H.; Simoes, Francisco F. Lamego; Clain, Almir F.; Scassiotti, Walter F.; Antunes, Ivan; Ferreira, Ana M.; Nascimento, Marcos R.L.

2009-01-01

The uranium mining site of Pocos de Caldas consists of open mine pit, tailings, waste rock dumps and an acid rock drainage problem, which has the potential to impact upon freshwater of the Ribeirao das Antas catchment. The high level of manganese (value of 1.8 mg/L) contained in the discharge water (DW) is an important factor affecting the water quality of the river (water quality criterion for aquatic life for Mn is 0.1 mg/L). Water quality criteria (WQC) are used for regulatory purpose and intended to define concentrations of chemicals in water that are protective of aquatic life and human health. WQC is a standard, although it is recognized that in some instances these criteria may be overprotective as metal bioavailability and hence toxicity is dependent on water chemistry. The toxicity assessment of WD was performed by bioassays with Daphnia similis and Ceriodaphnia dubia as bioindicators. As DW showed no toxicity to the organisms and the chemical analysis and dose assessments pointed U and Mn as the most important metals for water toxicity, the U and Mn toxicities were evaluated in the DW spiked with U and Mn. Acute uranium toxicity (48 h immobilisation test) for Daphnia similis was determined as a LC50 value (concentration that is toxic to 50% of test organisms) around 0.05-0.06 mg/L, value close to the one found for effects on reproduction, a 7 day LOEC (lowest observed effect concentration) of 0.062 mg/L for Ceriodaphnia dubia. The value of NOEC (no-observed effect concentration) for U was 0.03 mg U/L, which is higher than the concentration corresponded to the authorized dose limit for 238 U (0.004 mg/L) and higher than the uranium WQC (0.02 mg U/L). The manganese concentration in the DW is lower than the found value of LC50 (11.5 mg/L), LOEC (10 mg/L) and NOEC (5 mg Mn/L). (author)
Influence of bioassay volume, water column height, and octanol-water partition coefficient on the toxicity of pesticides to rainbow trout.

Science.gov (United States)

Altinok, Ilhan; Capkin, Erol; Boran, Halis

2011-06-01

Effects of water volume and water column height on toxicity of cypermethrin, carbaryl, dichlorvos, tetradifon, maneb, captan, carbosulfan endosulfan and HgCl₂ to juvenile rainbow trout (Oncorhynchus mykiss, 3.2 ± 0.7 g) were evaluated in different glass aquaria under static conditions. When fish were exposed to the chemical compounds in 23 cm water column height (25 L), their mortality ranged between 0% and 58%. At the same water volume, but lower water column height (9 cm), mortality of fish increased significantly and was in a range from 60% to 95%. At the same water column height, toxic effects of chemicals were significantly higher in 25 L water volume than that of 8.5 L, water except maneb which has lowest (-0.45) octanol-water partition coefficient value. Mortality rates ratio of 9 and 23 cm water column height ranged between 1.12 and 90 while mortality rates ratio of 9 and 25 L water volume ranged between 1.20 and 4.0. Because actual exposure concentrations were not affected by either water volume or water column height, we propose that increased pesticides' toxicity was related to an increase in bioassay volume, since more pesticide molecules were able to interact with or accumulate the fish. However, there seem to be no relationship between the effects of water volume, water column height and Kow value of chemicals with regard to toxicity in juvenile rainbow trout.
Selection of a Battery of Rapid Toxicity Sensors for Drinking Water Evaluation

National Research Council Canada - National Science Library

van der Schalie, William H; James, Ryan R; Gargan, II., Thomas P

2006-01-01

.... Ten toxicity sensors utilizing enzymes, bacteria, or vertebrate cells were tested to determine the minimum number of sensors that could rapidly identify toxicity in water samples containing one of 12...
Effects of water chemistry on the dissolution of ZnO nanoparticles and their toxicity to Escherichia coli

International Nuclear Information System (INIS)

Li Mei; Lin Daohui; Zhu Lizhong

2013-01-01

The dissolution of ZnO nanoparticles (nano-ZnO) plays an important role in the toxicity of nano-ZnO to the aquatic organisms. The effects of water chemistry such as pH, ionic components, and dissolved organic matter (DOM) on the dissolution of nano-ZnO and its toxicity to Escherichia coli (E. coli) were investigated in synthetic and natural water samples. The results showed that the toxicity of nano-ZnO to E. coli depended on not only free Zn 2+ but also the coexisting cations which could reduce the toxicity of Zn 2+ . Increasing solution pH, HPO 4 2− , and DOM reduced the concentration of free Zn 2+ released from nano-ZnO, and thus lowered the toxicity of nano-ZnO. In addition, both Ca 2+ and Mg 2+ dramatically reduced the toxicity of Zn 2+ to E. coli. These results highlight the importance of water chemistry on the toxicity evaluation of nano-ZnO in natural waters. - Highlights: ► The effects of water chemistry on the toxicity of nano-ZnO were investigated. ► Increasing solution pH, HPO 4 2− , and DOM reduced nano-ZnO toxicity to E. coli. ► Ca 2+ and Mg 2+ could dramatically reduce the toxicity of nano-ZnO to E. coli. ► Free Zn 2+ ions and water hardness together controlled nano-ZnO toxicity in waters. - The toxicity of nano-ZnO to E. coli depended on not only free Zn 2+ but also Ca 2+ and Mg 2+ which could reduce the toxicity of Zn 2+ .
Unidades de Pediatría Ambiental

OpenAIRE

PARÍS M, ENRIQUE; MOLINA M, HELIA; RÍOS B, JUAN CARLOS

2007-01-01

Se considera que una Unidad de Pediatría Ambiental es una estructura con roles claramente definidos, situada preferentemente en un centro de salud, especializada en afecciones pediátricas, relacionadas al ambiente. Estos centros pueden proporcionar asesoramiento, información y tratamiento, promover la investigación, entrenar a profesionales, educar al público e informar a las autoridades responsables. Su personal, especialmente entrenado en problemas ambientales, incluye: pediatras, toxicólog...
Bioretention storm water control measures decrease the toxicity of copper roof runoff.

Science.gov (United States)

LaBarre, William J; Ownby, David R; Rader, Kevin J; Lev, Steven M; Casey, Ryan E

2017-06-01

The present study evaluated the ability of 2 different bioretention storm water control measures (SCMs), planter boxes and swales, to decrease the toxicity of sheet copper (Cu) roofing runoff to Daphnia magna. The present study quantified changes in storm water chemistry as it passed through the bioretention systems and utilized the biotic ligand model (BLM) to assess whether the observed D. magna toxicity could be predicted by variations found in water chemistry. Laboratory toxicity tests were performed using select storm samples with D. magna cultured under low ionic strength conditions that were appropriate for the low ionic strength of the storm water samples being tested. The SCMs decreased toxicity of Cu roof runoff in both the BLM results and the storm water bioassays. Water exiting the SCMs was substantially higher than influent runoff in pH, ions, alkalinity, and dissolved organic carbon and substantially lower in total and dissolved Cu. Daphnids experienced complete mortality in untreated runoff from the Cu roof (the SCM influent); however, for planter and swale effluents, survival averaged 86% and 95%, respectively. The present study demonstrated that conventional bioretention practices, including planter boxes and swales, are capable of decreasing the risk of adverse effects from sheet Cu roof runoff to receiving systems, even before considering dilution of effluents in those receiving systems and associated further reductions in copper bioavailability. Environ Toxicol Chem 2017;36:1680-1688. © 2016 SETAC. © 2016 SETAC.
Metals and metalloids in the water-bloom-forming cyanobacteria and ambient water from Nanquan coast of Taihu Lake, China.

Science.gov (United States)

Su, Yanping; Liu, Hongbo; Yang, Jian

2012-08-01

Concentrations of 12 metal(oid)s were investigated in the bloom-forming cyanobacteria and ambient water samples collected monthly between March 2009 and February 2010 at the Nanquan coast of Taihu Lake, China. The metal(oid) concentrations in ambient water decreased in the order Fe > Zn > Ni ≈ As ≈ Cu > Mn > Ag > Cr > Se > Cd > Co > Tl, while those in cyanobacteria followed a sequence Fe > Mn > Zn > Cu ≈ Ni > Co > Ag > Cr ≈ As > Cd > Tl > Se. The metal(loid) burdens removed by cyanobacteria were estimated as 164 t Fe, 12.4 t Mn, 3.6 t Zn, 2.0 t Ni, 2.0 t Cu, 0.5 t As, 0.5 t Cr, 0.4 t Cd, 0.9 t Ag, 1.1 t Co, 0.2 t Tl, and 0.09 t Se during the 2008-2010 bloom seasons.
2011 NATA - Risks and Annual Ambient Concentrations

Data.gov (United States)

U.S. Environmental Protection Agency — This dataset includes the modeled annual ambient concentrations and risks at the census tract level for the 2011 National Air Toxics Assessment. All concentrations...
Toxic impact of bromide and iodide on drinking water disinfected with chlorine or chloramines.

Science.gov (United States)

Yang, Yang; Komaki, Yukako; Kimura, Susana Y; Hu, Hong-Ying; Wagner, Elizabeth D; Mariñas, Benito J; Plewa, Michael J

2014-10-21

Disinfectants inactivate pathogens in source water; however, they also react with organic matter and bromide/iodide to form disinfection byproducts (DBPs). Although only a few DBP classes have been systematically analyzed for toxicity, iodinated and brominated DBPs tend to be the most toxic. The objectives of this research were (1) to determine if monochloramine (NH2Cl) disinfection generated drinking water with less toxicity than water disinfected with free chlorine (HOCl) and (2) to determine the impact of added bromide and iodide in conjunction with HOCl or NH2Cl disinfection on mammalian cell cytotoxicity and genomic DNA damage induction. Water disinfected with chlorine was less cytotoxic but more genotoxic than water disinfected with chloramine. For both disinfectants, the addition of Br(-) and I(-) increased cytotoxicity and genotoxicity with a greater response observed with NH2Cl disinfection. Both cytotoxicity and genotoxicity were highly correlated with TOBr and TOI. However, toxicity was weakly and inversely correlated with TOCl. Thus, the forcing agents for cytotoxicity and genotoxicity were the generation of brominated and iodinated DBPs rather than the formation of chlorinated DBPs. Disinfection practices need careful consideration especially when using source waters containing elevated bromide and iodide.
Evaluation of Ignalina NPP waste waters toxicity by use of biotest complex

International Nuclear Information System (INIS)

Marchiulioniene, D.

1995-01-01

The impact of lake Drukshiai various biotop waters and bottom sediments on test-organisms Tradescantia higher plants, as well as trout Salmo gairdneri spawn and larvae was investigated in 1988 - 1994. It was determined that toxic matters, heavy metals and radionuclides among them, discharge into lake Drukshiai with Ignalina NPP waste waters. They accumulate in components of ecosystem, especially in bottom sediments. The gradual increase of toxic impact caused by water and bottom sediments is observed in the investigated lake biotops. The highest toxity levels were in 1993. Maximal toxity is caused by chemical matters. (author). 11 refs., 4 tabs., 3 figs
Particulate Photocatalyst Sheets Based on Carbon Conductor Layer for Efficient Z-Scheme Pure-Water Splitting at Ambient Pressure.

Science.gov (United States)

Wang, Qian; Hisatomi, Takashi; Suzuki, Yohichi; Pan, Zhenhua; Seo, Jeongsuk; Katayama, Masao; Minegishi, Tsutomu; Nishiyama, Hiroshi; Takata, Tsuyoshi; Seki, Kazuhiko; Kudo, Akihiko; Yamada, Taro; Domen, Kazunari

2017-02-01

Development of sunlight-driven water splitting systems with high efficiency, scalability, and cost-competitiveness is a central issue for mass production of solar hydrogen as a renewable and storable energy carrier. Photocatalyst sheets comprising a particulate hydrogen evolution photocatalyst (HEP) and an oxygen evolution photocatalyst (OEP) embedded in a conductive thin film can realize efficient and scalable solar hydrogen production using Z-scheme water splitting. However, the use of expensive precious metal thin films that also promote reverse reactions is a major obstacle to developing a cost-effective process at ambient pressure. In this study, we present a standalone particulate photocatalyst sheet based on an earth-abundant, relatively inert, and conductive carbon film for efficient Z-scheme water splitting at ambient pressure. A SrTiO 3 :La,Rh/C/BiVO 4 :Mo sheet is shown to achieve unassisted pure-water (pH 6.8) splitting with a solar-to-hydrogen energy conversion efficiency (STH) of 1.2% at 331 K and 10 kPa, while retaining 80% of this efficiency at 91 kPa. The STH value of 1.0% is the highest among Z-scheme pure water splitting operating at ambient pressure. The working mechanism of the photocatalyst sheet is discussed on the basis of band diagram simulation. In addition, the photocatalyst sheet split pure water more efficiently than conventional powder suspension systems and photoelectrochemical parallel cells because H + and OH - concentration overpotentials and an IR drop between the HEP and OEP were effectively suppressed. The proposed carbon-based photocatalyst sheet, which can be used at ambient pressure, is an important alternative to (photo)electrochemical systems for practical solar hydrogen production.
The contribution of waste water treatment plants to PBDEs in ambient air

International Nuclear Information System (INIS)

Martellini, Tania; Jones, Kevin C.; Sweetman, Andy; Giannoni, Martina; Pieri, Francesca; Cincinelli, Alessandra

2012-01-01

Air samples were collected at different sites in and around two wastewater treatment plants (WWTPs) located in central Italy to determine the concentrations, compositional profiles and contribution to ambient levels of eight polybrominated diphenyl ethers (PBDEs). The investigated WWTPs were selected as they treat industrial wastewater produced by local textile industries along with municipal wastewater. PBDE concentrations within the WWTPs were higher than those measured at reference sites located 4 and 5 km away with BDE-209 dominating the BDE congener composition in all air samples in 2008. Ambient PBDE concentrations measured in and around the WWTPs and estimates of emissions from aeration tanks suggest that WWTPs are sources of PBDEs to ambient air. Principal component analysis and Pearson correlations confirmed this result. The effect of distance from the plant and wind direction on atmospheric concentrations was also investigated. Although the primary fate of PBDEs in WWTPs will be partitioning to sewage sludge, this study suggests that plants can provide a measurable source of these compounds to local ambient air. - Highlights: ► Levels and distribution profiles of PBDEs in the atmosphere surrounding two WWTPs. ► Airborne polybrominated diphenyl ethers in the surrounding area of two WWTPs in Italy. ► To investigate WWTPs as sources of PBDEs to the atmosphere. ► Samples collected downwind respect to the plant showed BDE-209 as dominant congener. ► The effect of distance and wind direction on atmospheric concentrations was also investigated. - Waste water treatment plants as sources of PBDEs to the ambient air.
Assessing the effect of marginal water use efficiency on water use of loblolly pine and sweetgum in ambient and elevated CO2 conditions

Science.gov (United States)

Kim, D.; Medvigy, D.; Xu, X.; Oren, R.; Ward, E. J.

2017-12-01

Stomata are the common pathways through which diffusion of CO2 and water vapor take place in a plant. Therefore, the responses of stomatal conductance to environmental conditions are important to quantify carbon assimilation and water use of plants. In stomatal optimality theory, plants may adjust the stomatal conductance to maximize carbon assimilation for a given water availability. The carbon cost for unit water loss, marginal water use efficiency (λ), depends on changes in atmospheric CO2 concentration and pre-dawn leaf water potential. The relationship can be described by λ with no water stress (λ0) and the sensitivity of λ to pre-dawn leaf water potential (β0), which may vary by plant functional type. Assessment of sensitivity of tree and canopy water use to those parameters and the estimation of the parameters for individual plant functional type or species are needed. We modeled tree water use of loblolly pine (Pinus taeda) and sweetgum (Liquidambar styraciflua) in ambient and elevated CO2 (+200 µmol mol-1) at the Duke Forest free-air CO2 enrichment (FACE) site with Ecosystem Demography model 2 (ED2), a demographic terrestrial biosphere model that scales up individual-level competition for light, water and nutrients to the ecosystem-level. Simulated sap flux density for different tree size classes and species was compared to observations. The sensitivity analysis with respect to the model's hydraulic parameters was performed. The initial results showed that the impacts of λ on tree water use were greater than other hydraulic traits in the model, such as vertical hydraulic conductivity and leaf and stem capacitance. With 10% increase in λ, modeled water flow from root to leaf decreased by 2.5 and 1.6% for P. taeda and by 7.9 and 5.1% for L. styraciflua in ambient and elevated CO2 conditions, respectively. Values of hydraulic traits (λ0 and β0) for P. taeda and L. styraciflua in ambient an elevated CO2 conditions were also suggested.
Ground and surface water developmental toxicity at a municipal landfill--Description and weather-related variation

Science.gov (United States)

Bruner, M.A.; Rao, M.; Dumont, J.N.; Hull, M.; Jones, T.; Bantle, J.A.

1998-01-01

Contaminated groundwater poses a significant health hazard and may also impact wildlife such as amphibians when it surfaces. Using FETAX (Frog Embryo Teratogenesis Assay-Xenopus), the developmental toxicity of ground and surface water samples near a closed municipal landfill at Norman, OK, were evaluated. The groundwater samples were taken from a network of wells in a shallow, unconfined aquifer downgradient from the landfill. Surface water samples were obtained from a pond and small stream adjacent to the landfill. Surface water samples from a reference site in similar habitat were also analyzed. Groundwater samples were highly toxic in the area near the landfill, indicating a plume of toxicants. Surface water samples from the landfill site demonstrated elevated developmental toxicity. This toxicity was temporally variable and was significantly correlated with weather conditions during the 3 days prior to sampling. Mortality was negatively correlated with cumulative rain and relative humidity. Mortality was positively correlated with solar radiation and net radiation. No significant correlations were observed between mortality and weather parameters for days 4–7 preceding sampling.

Pharmaceuticals, hormones, personal-care products, and other organic wastewater contaminants in water resources: Recent research activities of the U.S. Geological Survey's toxic substances hydrology program

Science.gov (United States)

Focazio, Michael J.; Kolpin, Dana W.; Buxton, Herbert T.

2003-01-01

Recent decades have brought increasing concerns for potential contamination of water resources that could inadvertently result during production, use, and disposal of the numerous chemicals offering improvements in industry, agriculture, medical treatment, and even common household products. Increasing knowledge of the environmental occurrence or toxicological behavior of these contaminants from various studies in Europe, United States, and elsewhere has resulted in increased concern for potential adverse environmental and human health effects (Daughton and Ternes, 1999). Ecologists and public health experts often have incomplete understandings of the toxicological significance of many of these contaminants, particularly long-term, low-level exposure and when they occur in mixtures with other contaminants (Daughton and Ternes, 1999; Kümmerer, 2001). In addition, these ‘emerging contaminants’ are not typically monitored or assessed in ambient water resources. The need to understand the processes controlling the transport and fate of these contaminants in the environment, and the lack of knowledge of the significance of long-term exposures have increased the need to study environmental occurrence down to trace (nanogram per liter) levels. Furthermore, the possibility that mixtures of environmental contaminants may interact synergistically or antagonistically has increased the need to characterize the types of mixtures that are found in our waters. The U.S. Geological Survey’s Toxic Substances Hydrology Program (Toxics Program) is developing information and tools on emerging water-quality issues that will be used to design and improve water-quality monitoring and assessment programs of the USGS and others, and for proactive decision-making by industry, regulators, the research community, and the public (http://toxics.usgs.gov/regional/emc.html). This research on emerging water-quality issues includes a combination of laboratory work to develop new analytical
Pore-Water Carbonate and Phosphate As Predictors of Arsenate Toxicity in Soil.

Science.gov (United States)

Lamb, Dane T; Kader, Mohammed; Wang, Liang; Choppala, Girish; Rahman, Mohammad Mahmudur; Megharaj, Mallavarapu; Naidu, Ravi

2016-12-06

Phytotoxicity of inorganic contaminants is influenced by the presence of competing ions at the site of uptake. In this study, interaction of soil pore-water constituents with arsenate toxicity was investigated in cucumber (Cucumis sativa L) using 10 contrasting soils. Arsenate phytotoxicity was shown to be related to soluble carbonate and phosphate. The data indicated that dissolved phosphate and carbonate had an antagonistic impact on arsenate toxicity to cucumber. To predict arsenate phytotoxicity in soils with a diverse range of soil solution properties, both carbonate and phosphate were required. The relationship between arsenic and pore-water toxicity parameters was established initially using multiple regression. In addition, based on the relationship with carbonate and phosphate we successively applied a terrestrial biotic ligand-like model (BLM) including carbonate and phosphate. Estimated effective concentrations from the BLM-like parametrization were strongly correlated to measured arsenate values in pore-water (R 2 = 0.76, P soils.
How to accurately assay the algal toxicity of pesticides with low water solubility

International Nuclear Information System (INIS)

Ma Jianyi; Chen Jianmeng

2005-01-01

A novel method for assaying and calculating the toxicity of water-insoluble pesticides to green algae has been put forward in this work. First, a solvent is selected for use in bioassays; there should be a detailed screening to identify a solvent with inherently low toxicity to the test organism. Second, the EC 50 is determined for selected pesticides by measuring the toxicity of various concentrations of each of the selected pesticides in a fixed concentration of selected solvent. Third, concentrations of the selected solvent are varied and the EC 50 of each pesticide tested is assayed at a fixed concentration. Fourth, several suitable groups of solvent concentrations are selected and the corresponding EC 50 values of tested pesticides are considered to establish the linear regression equation. Letting the solvent concentration be zero, one calculates the corresponding EC 50 value, which corresponds to the inherent toxicity of the tested pesticide. - A new method is described for assaying the toxicity of water insoluble pesticides
Toxicity of acid mine pit lake water remediated with limestone and phosphorus

Energy Technology Data Exchange (ETDEWEB)

Neil, L.L.; McCullough, C.D.; Lund, M.A.; Evans, L.H.; Tsvetnenko, Y. [Edith Cowan University, Joondalup, WA (Australia)

2009-11-15

Pit lakes are increasingly common worldwide and have potential to provide many benefits. However, lake water toxicity may require remediation before beneficial end uses can be realised. Three treatments to remediate AMD (pH similar to 4.8) pit lake water containing elevated concentrations of Al and Zn from Collie, Western Australia were tested in mesocosms. Treatments were: (a) limestone neutralisation (L), (b) phosphorus amendment (P), and c) combined limestone neutralisation and phosphorus amendment (L+P). Laboratory bioassays with Ceriodaphnia cf. dubia, Chlorella protothecoides and Tetrahymena thermophila assessed remediation. Limestone neutralisation increased pH and reduced heavy metal concentrations by 98% (Al) to 14% (Mg), removing toxicity to the three test species within 2 months. Phosphorus amendment removed toxicity after 6 months of treatment. However, phosphorus amendment to prior limestone neutralisation failed to reduce toxicity more than limestone neutralisation alone. Low concentrations of both phosphorus and nitrogen appear to limit phytoplankton population growth in all treatments.
Toxicity of acid mine pit lake water remediated with limestone and phosphorus.

Science.gov (United States)

Neil, Luke L; McCullough, Clint D; Lund, Mark A; Evans, Louis H; Tsvetnenko, Yuri

2009-11-01

Pit lakes are increasingly common worldwide and have potential to provide many benefits. However, lake water toxicity may require remediation before beneficial end uses can be realised. Three treatments to remediate AMD (pH approximately 4.8) pit lake water containing elevated concentrations of Al and Zn from Collie, Western Australia were tested in mesocosms. Treatments were: (a) limestone neutralisation (L), (b) phosphorus amendment (P), and (c) combined limestone neutralisation and phosphorus amendment (L+P). Laboratory bioassays with Ceriodaphnia cf. dubia, Chlorella protothecoides and Tetrahymena thermophila assessed remediation. Limestone neutralisation increased pH and reduced heavy metal concentrations by 98% (Al) to 14% (Mg), removing toxicity to the three test species within 2 months. Phosphorus amendment removed toxicity after 6 months of treatment. However, phosphorus amendment to prior limestone neutralisation failed to reduce toxicity more than limestone neutralisation alone. Low concentrations of both phosphorus and nitrogen appear to limit phytoplankton population growth in all treatments.
Refinery water (intake and effluent) quality: Update of 1970s with 1990s toxicity testing

International Nuclear Information System (INIS)

Chapman, P.M.; Paine, M.D.; Moran, T.; Kierstead, T.

1994-01-01

The quality of two separate refinery intake waters and effluents was investigated: Petro-Canada (Oakville) and Novacor (Corunna Operations). This study comprised eight different test organized and 22 different toxicity end points, was built on and complemented pioneering 1970s work at the Petro-Canada refinery, and was designed to (a) determine any changes in effluent quality, (b) determine any previously unsuspected effluent toxicity, and (c) determine any potential for chronic toxicity in the effluent. Although Petro-Canada has steadily reduced contaminants in its effluent since the earlier study, toxicity has not changed and no new toxic effects were identified. Effect thresholds for the most sensitive animal species (Daphnia pulex) were 1 to 10% effluent in both studies. The Novacor effluent had lesser effects on biota than the Petro-Canada effluent. Intake waters demonstrated toxicity in some tests. Chronic effects on invertebrates and fish in receiving waters are predicted not to occur in the Novacor effluent is diluted 10- to 20-fold and the Petro-Canada effluent is diluted 50- to 100-fold
Contaminant levels and toxicity of sediments and water of Baltimore Harbor and Back River, Maryland

International Nuclear Information System (INIS)

Logan, D.T.; Jacobs, F.; Mehrotra, N.

1995-01-01

The Patapsco and Back River Watershed drains the Baltimore metropolitan area, Maryland's most heavily industrialized and urbanized region. Due to the intensive development and industrialization of the Baltimore metropolitan area over the past 250 years, high levels of contaminants have been discharged into Baltimore Harbor on the Patapsco River and into the Back River. Pollutants historically discharged include heavy metals, petroleum hydrocarbons, pesticides, cyanide, sewage, other organic chemicals, and nutrients. Sources have included industrial and municipal discharges, sewerage overflows, urban runoff, and leaks and spills from vessels and on-land facilities. The Maryland Department of the Environment undertook this study of ambient conditions as part of a developing strategy to assess and improve conditions in the Chesapeake Bay and its tributaries. Past studies were compiled, evaluated, and synthesized to identify the areas of degraded conditions and contaminants of possible concern. Sediment contaminant levels were assessed using historical sediment chemistry data, Effects Range Low and Median concentrations (ER-L and ER-M) as toxicological benchmarks, and a sum of toxicity units approach for multiple contaminants. Data on toxicity testing and biological monitoring was compared to sediment and water quality data. Fish tissue data were used to examine bioaccumulated chemicals. A computerized Geographical Information System (GIS) was used to manipulate and display complex geographical data. The final identification of areas and chemicals of potential concern relied on a syntheses of these results as well as information on present and past contaminant loadings
Method Development and Monitoring of Cyanotoxins in Water (ACS Central Presentation)

Science.gov (United States)

Increasing occurrence of cyanobacterial harmful algal blooms (HABs) in ambient waters has become a worldwide concern. Numerous cyanotoxins can be produced during HAB events which are toxic to animals and humans. Validated standardized methods that are rugged, selective and sensit...
Development of a toxicity-based fractionation approach for the identification of phototoxic PAHs in pore water

International Nuclear Information System (INIS)

Kosian, P.A.; Makynen, E.A.; Ankley, G.T.; Monson, P.D.

1995-01-01

Environmental matrices often contain complex mixtures of chemical compounds, however, typically only a few chemicals are responsible for observed toxicity. To determine those chemicals responsible for toxicity, a toxicity-based fractionation technique coupled with gas chromatography/mass spectrometry (GC/MS) has been used for the isolation and identification of nonpolar toxicants in aqueous samples. In this study, this technique was modified to separate and identify polycyclic aromatic hydrocarbons (PAHs) responsible for phototoxicity in pore water. Whole pore water, obtained from sediments collected near an oil refinery discharge site, was found to be toxic to Lumbriculus variegatus in the presence of ultraviolet (UV) light. Solid phase extraction disks and high pressure liquid chromatography were used, in conjunction with toxicity tests with L. variegatus, to extract and fractionate phototoxic chemicals from the pore water. GC/MS analysis was performed on the toxic fractions and a tentative list of compound identifications were made based on interpretation of mass spectra and elution information from the chromatographic separation. The compounds identified include PAHs and substituted PAHs that are known or predicted to be phototoxic in the presence of UV light. The results show that a modified toxicity-based fractionation approach can be successfully applied to identify phototoxic PAHs in sediment pore water and therefore used in the assessment of contaminated sediments
Acute and chronic toxicity of effluent water from an abandoned uranium mine.

Science.gov (United States)

Antunes, S C; Pereira, R; Gonçalves, F

2007-08-01

Inactive or abandoned mines represent a significant source of environmental, chemical, physical, and aesthetic impact. Among concerning situations, the occurrence of abandoned or semi-abandoned mine-associated ponds (for sedimentation of solids, for effluent neutralization, or for washing the ore) is a common feature in this type of system. These ponds are a source of contamination for the groundwater resources and adjacent soils, because they lack appropriate impermeabilization. The use of this water for agriculture may also pose chronic risks to humans. In Portugal, these problems have been diagnosed and some remediation projects have been developed. The purpose of our study was to evaluate the acute and chronic toxicity of water samples collected from the aquatic system surrounding an abandoned uranium mine (Cunha Baixa, Mangualde, Central Portugal). The present study focuses on the water compartment, whose toxicity was evaluated by means of standard toxicity assays using two Daphnia species (D. longispina and D. magna). Three different ponds were used in the characterization of the aquatic system from Cunha Baixa mine: a reference pond (Ref), a mine effluent treatment pond (T), and a mine pit pond (M). Metal analyses performed in the water samples from these ponds showed values that, in some cases, were much higher than maximum recommendable values established (especially Al, Mn) by Portuguese legislation for waters for crop irrigation. Acute toxicity was only observed in the mine pit pond, with EC(50) values of 28.4% and 50.4% for D. longispina and D. magna, respectively. The significant impairment of chronic endpoints, translated in reductions in the population growth rate for both species, gives rise to concerns regarding the potential risks for aquatic zooplanktonic communities, from local receiving waters, potentially exposed to point source discharges of the treated and nontreated effluent from Cunha Baixa uranium mine.
Thermoregulatory responses to environmental toxicants: The interaction of thermal stress and toxicant exposure

International Nuclear Information System (INIS)

Leon, Lisa R.

2008-01-01

Thermal stress can have a profound impact on the physiological responses that are elicited following environmental toxicant exposure. The efficacy by which toxicants enter the body is directly influenced by thermoregulatory effector responses that are evoked in response to high ambient temperatures. In mammals, the thermoregulatory response to heat stress consists of an increase in skin blood flow and moistening of the skin surface to dissipate core heat to the environment. These physiological responses may exacerbate chemical toxicity due to increased permeability of the skin, which facilitates the cutaneous absorption of many environmental toxicants. The core temperature responses that are elicited in response to high ambient temperatures, toxicant exposure or both can also have a profound impact on the ability of an organism to survive the insult. In small rodents, the thermoregulatory response to thermal stress and many environmental toxicants (such as organophosphate compounds) is often biphasic in nature, consisting initially of a regulated reduction in core temperature (i.e., hypothermia) followed by fever. Hypothermia is an important thermoregulatory survival strategy that is used by small rodents to diminish the effect of severe environmental insults on tissue homeostasis. The protective effect of hypothermia is realized by its effects on chemical toxicity as molecular and cellular processes, such as lipid peroxidation and the formation of reactive oxygen species, are minimized at reduced core temperatures. The beneficial effects of fever are unknown under these conditions. Perspective is provided on the applicability of data obtained in rodent models to the human condition
Impact of methanol and CNG fuels on motor-vehicle toxic emissions

International Nuclear Information System (INIS)

Black, F.; Gabele, P.

1991-01-01

The 1990 Clean Air Act Amendments require that the Environmental Protection Agency investigate the need for reduction of motor vehicle toxic emissions such as formaldehyde, acetaldehyde, benzene, 1,3-butadiene, and polycyclic organic matter. Toxic organic emissions can be reduced by utilizing the control technologies employed for regulated THC (NMHC) and CO emissions, and by changing fuel composition. The paper examines emissions associated with the use of methanol and compressed natural gas fuels. Both tailpipe and evaporative emissions are examined at varied ambient temperatures ranging from 20 C to 105 F. Tailpipe emissions are also examined over a variety of driving cycles with average speeds ranging from 7 to 48 mph. Results suggest that an equivalent ambient temperatures and average speeds, motor vehicle toxic emissions are generally reduced with methanol and compressed natural gas fuels relative to those with gasoline, except for formaldehyde emissions, which may be elevated. As with gasoline, tailpipe toxic emissions with methanol and compressed natural gas fuels generally increase when ambient temperature or average speed decreases (the sensitivity to these variables is greater with methanol than with compressed natural gas). Evaporative emissions generally increase when fuel volatility or ambient temperature increases (however, the relative contribution of evaporative sources to the aggregate toxic compound emissions is small)
Development of Low-Toxicity Wastewater Stabilization for Spacecraft Water Recovery Systems

Science.gov (United States)

Adam, Niklas; Mitchell, Julie; Pickering, Karen; Carrier, Chris; Vega, Letty; Muirhead, Dean

2014-01-01

Wastewater stabilization was an essential component of the spacecraft water cycle. The purpose of stabilizing wastewater was two-fold. First, stabilization prevents the breakdown of urea into ammonia, a toxic gas at high concentrations. Second, it prevents the growth of microorganisms, thereby mitigating hardware and water quality issues due to due biofilm and planktonic growth. Current stabilization techniques involve oxidizers and strong acids (pH=2) such as chromic and sulfuric acid, which are highly toxic and pose a risk to crew health. The purpose of this effort was to explore less toxic stabilization techniques, such as food-grade and commercial care preservatives. Additionally, certain preservatives were tested in the presence of a low-toxicity organic acid. Triplicate 300-mL volumes of urine were dosed with a predetermined quantity of stabilizer and stored for two weeks. During that time, pH, total organic carbon (TOC), ammonia, and turbidity were monitored. Those preservatives that showed the lowest visible microbial growth and stable pH were further tested in a six-month stability study. The results of the six-month study are also included in this paper.
Insecticide toxicity to Hyalella curvispina in runoff and stream water within a soybean farm (Buenos Aires, Argentina).

Science.gov (United States)

Mugni, H; Ronco, A; Bonetto, C

2011-03-01

Toxicity to the locally dominant amphipod Hyalella curvispina was assessed in a first-order stream running through a cultivated farm. Cypermethrin, chlorpyrifos, endosulfan and glyphosate were sprayed throughout the studied period. Toxicity was assayed under controlled laboratory conditions with runoff and stream water samples taken from the field under steady state and flood conditions. Ephemeral toxicity pulses were observed as a consequence of farm pesticide applications. After pesticide application, runoff water showed 100% mortality to H. curvispina for 1 month, but no mortality thereafter. Toxicity persistence was shortest in stream water, intermediate in stream sediments and longest in soil samples. Runoff had a more important toxicity effect than the exposure to direct aerial fumigation. The regional environmental features determining fast toxicity dissipation are discussed. Copyright © 2010. Published by Elsevier Inc.
Solid-state, ambient-operation thermally activated delayed fluorescence from flexible, non-toxic gold-nanocluster thin films: towards the development of biocompatible light-emitting devices

Science.gov (United States)

Talite, M. J. A.; Lin, H. T.; Jiang, Z. C.; Lin, T. N.; Huang, H. Y.; Heredia, E.; Flores, A.; Chao, Y. C.; Shen, J. L.; Lin, C. A. J.; Yuan, C. T.

2016-08-01

Luminescent gold nanoclusters (AuNCs) with good biocompatibility have gained much attention in bio-photonics. In addition, they also exhibit a unique photo-physical property, namely thermally activated delayed fluorescence (TADF), by which both singlet and triplet excitons can be harvested. The combination of their non-toxic material property and unique TADF behavior makes AuNCs biocompatible nano-emitters for bio-related light-emitting devices. Unfortunately, the TADF emission is quenched when colloidal AuNCs are transferred to solid states under ambient environment. Here, a facile, low-cost and effective method was used to generate efficient and stable TADF emissions from solid AuNCs under ambient environment using polyvinyl alcohol as a solid matrix. To unravel the underlying mechanism, temperature-dependent static and transient photoluminescence measurements were performed and we found that two factors are crucial for solid TADF emission: small energy splitting between singlet and triplet states and the stabilization of the triplet states. Solid TADF films were also deposited on the flexible plastic substrate with patterned structures, thus mitigating the waveguide-mode losses. In addition, we also demonstrated that warm white light can be generated based on a co-doped single emissive layer, consisting of non-toxic, solution-processed TADF AuNCs and fluorescent carbon dots under UV excitation.
Using Rainbow Trout to Measure Arsenic Toxicity in Water

Directory of Open Access Journals (Sweden)

Kazem Naddafi

2006-06-01

Full Text Available The purpose of this study is to determine arsenic toxicity on rainbow trout. Acute toxicity of arsenic was determined by measuring the lethal effects on rainbow trout in static conditions. Five aquariums of 25×30×30 cm with five concentrations of 5,10,15,20 and 25 mg/L of arsenic were prepared and then ten fishes were added to each concentration. Also one aquarium with similar conditions was considered as a control with no arsenic solution. Hardness, temperature and dissolved oxygen of dilution water were determined by standard methods, and concentration of dissolved oxygen, pH and temperature of solution test in time periods of 2,4,6,8,24,48,72 and 96 hrs were measured. Water temperature of aquarium was regulated by circulation of water in refrigerator through indirect conduction with solution test. LC50 was measured at intervals of 24,48,72 and 96 hrs by SPSS software and respectively showed 28.13,21.77,15.78 and 12.72 mg/L.Probit curve was drawn by Harvard Chart XL software, and LC50 curve was drawn by Excel software.
Contribution of waste water treatment plants to pesticide toxicity in agriculture catchments.

Science.gov (United States)

Le, Trong Dieu Hien; Scharmüller, Andreas; Kattwinkel, Mira; Kühne, Ralph; Schüürmann, Gerrit; Schäfer, Ralf B

2017-11-01

Pesticide residues are frequently found in water bodies and may threaten freshwater ecosystems and biodiversity. In addition to runoff or leaching from treated agricultural fields, pesticides may enter streams via effluents from wastewater treatment plants (WWTPs). We compared the pesticide toxicity in terms of log maximum Toxic Unit (log mTU) of sampling sites in small agricultural streams of Germany with and without WWTPs in the upstream catchments. We found an approximately half log unit higher pesticide toxicity for sampling sites with WWTPs (p pesticide toxicity in streams with WWTPs. A few compounds (diuron, terbuthylazin, isoproturon, terbutryn and Metazachlor) dominated the herbicide toxicity. Pesticide toxicity was not correlated with upstream distance to WWTP (Spearman's rank correlation, rho = - 0.11, p > 0.05) suggesting that other context variables are more important to explain WWTP-driven pesticide toxicity. Our results suggest that WWTPs contribute to pesticide toxicity in German streams. Copyright © 2017 Elsevier Inc. All rights reserved.
Influence of ammonia on forming the toxicity of waters from the surface sources of water supply determined on Carassius auratus gibelio (Bloch, 1782

Directory of Open Access Journals (Sweden)

Е. Arystarkhova

2018-03-01

Full Text Available Purpose. Determination of the influence of ammonia in waters from surface sources of water supply of Zhytomyr city on forming the toxicity of these waters determined by test-reactions of atypical motor activity of Carassius auratus gibelio (Bloch, 1782 with the use of the «time sampling» method during 2012–2014. Methodology. Biotesting was performed at the Municipal Enterprise "Zhytomyrvodokanal". Water samples were taken once a month time from the Teteriv river reservoirs and tap water network and then placed into aquaria (8 dm3 on a group. Control and experimental groups of fish were formed according to the following scheme: control group — samples of settled (24 hours tap water; experimental group D-1 — water samples from the Denyshivske reservoir; experimental group D-2 — water samples from the Vidsichne water intake. Test specimens were females of C. auratus gibelio. Biotesting was conducted using the «time sampling» method by keeping fish (n=30 in water for 12 hours. The toxicity indexes of waters were calculated on the basis of the following test-reactions: spiral-like and vector movements, jumping out from water, immobilization and death of fish. Statistical processing of study results were performed using cross-correlation and regression analysis in MS Excel 2007 and Statistica-6. Findings. The study showed an effect of ammonia on the toxicity of waters from reservoirs of the Teteriv river that was determined by atypical motor activity with the use of the «time sampling» method, which consisted in the instantaneous fixation of the number of individuals that favored one or another act of behavior. It was shown that females not adapted to the action of ammonia reacted to its concentration in water of more than 0.55 mg/dm3 by disorders in movements. Unlike fish of experience groups, only single pathological acts were observed in the control group. A positive moderate relationship, which had a tendency to an increase, was
2011 NATA - Air Toxics Monitors

Data.gov (United States)

U.S. Environmental Protection Agency — This dataset includes annual (2005 - 2013) statistics of measured ambient air toxics concentrations (in micrograms per cubic meter) and associated risk estimates for...
Strains of toxic and harmful microalgae, from waste water, marine, brackish and fresh water.

Science.gov (United States)

Rodríguez-Palacio, M C; Crisóstomo-Vázquez, L; Alvarez-Hernández, S; Lozano-Ramírez, C

2012-01-01

Some microalgae are economically important in Mexico and the world because they can be potentially toxic. Algal explosive population growths are named harmful algal blooms and are frequently recorded in Mexico. The authors set up potentially toxic microalgae cultures from the Gulf of Mexico (Garrapatas tideland, Barberena river, Carpintero lagoon in Tamaulipas State; Chalchoapan and Catemaco lakes in Veracruz State), from the Mexican Pacific Ocean, Guerrero, Colima and Michoacán States, and from interior water bodies such as Vicente Aguirre dam, Chapultepec lake and several waste water treatment plants. This research is about the diversity and abundance of phytoplankton in relation a specific site because of harmful algal bloom events. Microalgae cultures are useful in order to solve taxonomic problems, to know life cycles, molecular studies, for the study of toxic species, and the isolation of useful metabolites. The cultures for this research are clonal, non-axenic, semi-continuous, 12:12 light/dark photoperiod, 20 ± 1 °C temperature and 90.5 µmol m(-2)s(-1) illumination. Four different culture media were used. This collection is open to the worldwide scientific community as a source of organisms in controlled conditions that can be used as a useful tool for microalgae research work.

Evaluation of water column and sediment toxicity from an abandoned uranium mine using a battery of bioassays

International Nuclear Information System (INIS)

Antunes, S.C.; Figueiredo, D.R. de; Marques, S.M.; Castro, B.B.; Pereira, R.; Goncalves, F.

2007-01-01

Uranium mining activities in Cunha Baixa, Mangualde (Portugal), were extensive between 1967 and 1993, with high production of poor ore. Ore exploitation left millions of tons of tailings in the surrounding area, close to human houses. Contamination of the area (water and soil compartment) presently represents a serious hazard to humans and wildlife. The aim of this work was to evaluate the acute toxicity of water and sediments from a pond that floods a uranium mine pit, in two periods (spring and autumn). High contents of metals were found in water samples (chiefly Mn, Fe, Al, U, Sr). A battery of assays was applied to screen the acute toxicity of the different compartments using algae, crustaceans and dipterans. Results showed that the sediments were non-toxic, unlike the superficial water. Water toxicity was higher in the autumn, when the effluent was more acidic, compared to spring. In the water toxicity assays, the relative sensitivity of the test species used was Daphnia longispina > Pseudokirchneriella subcapitata > Daphnia magna. The present study is part of the chemical and ecotoxicological characterisation of the aquatic compartment performed in the Tier 1 of the Ecological Risk Assessment of the Cunha Baixa mining area
Investigating salt and naphthenic acids interactions in the toxicity of oil sands process water to freshwater invertebrates

International Nuclear Information System (INIS)

Turcotte, D.; Kautzman, M.; Wojnarowicz, P.; Cutter, J.; Bird, E.; Liber, K.

2010-01-01

The hot water extraction process used to produce bitumens from oil sands produces a large volume of oil sands process water (OSPW) that contain elevated concentrations of naphthenic acids (NA) and salts. Many oil sands reclamation projects are proposing the use of OSPW as part of reconstructed wetlands projects. This study investigated the toxicity of OSPW to freshwater invertebrates. The toxic interactions between NA and salinity on freshwater invertebrates were assessed. Bioassays with laboratory-cultured Ceriodaphnia dubia were conducted to determine the toxicity of OSPW from selected water bodies. The study showed that while the concentrations of NAs and salinity were elevated in OSPW waters that caused toxic responses, the concentrations of salinity ions varied greatly among the OSPW samples. Results of the study suggested that ion composition may be a factor in toxicity. Interactions between NAs and salinity were then assessed by performing bioassays with mixtures representing major ion combinations in OSPW.
Water Adsorption on a-Fe2O3(0001) at Near Ambient Conditions

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, Susumu

2011-08-19

We have investigated hydroxylation and water adsorption on {alpha}-Fe{sub 2}O{sub 3}(0001) at water vapor pressures up to 2 Torr and temperatures ranging from 277 to 647 K (relative humidity (RH) {le} 34%) using ambient-pressure X-ray photoelectron spectroscopy (XPS). Hydroxylation occurs at the very low RH of 1 x 10{sup -7} % and precedes the adsorption of molecular water. With increasing RH, the OH coverage increases up to one monolayer (ML) without any distinct threshold pressure. Depth profiling measurements showed that hydroxylation occurs only at the topmost surface under our experimental conditions. The onset of molecular water adsorption varies from {approx}2 x 10{sup -5} to {approx} 4 x 10{sup -2} % RH depending on sample temperature and water vapor pressure. The coverage of water reaches 1 ML at {approx}15% RH and increases to 1.5 ML at 34% RH.
Influência do ambiente no consumo de água de bebida de vacas leiteiras Influence of the ambient conditions on water intake by dairy cows

Directory of Open Access Journals (Sweden)

Maurício Perissinotto

2005-06-01

Full Text Available O presente trabalho foi desenvolvido em uma fazenda comercial produtora de gado de leite, criadora de gado holandês, localizada no município de São Pedro, SP. O período de coleta de dados compreendeu seis dias não consecutivos, nos meses de outubro e novembro de 2001, englobando 6 vacas em lactação, alojadas em um sistema de freestall. O consumo médio de água das vacas foi medido por meio de hidrômetro acoplado aos bebedouros. A temperatura de globo negro, a umidade relativa do ar, temperatura do ambiente e a velocidade do vento, foram registradas a cada hora, no período das 8 às 18 h. O principal objetivo do trabalho foi quantificar o consumo de água das vacas leiteiras, além de determinar o horário de maior consumo, a freqüência de uso dos bebedouros e o tempo de permanência do animal no bebedouro, relacionando-os com os índices de conforto térmico e a produção de leite. Verificou-se que o comportamento dos animais foi alterado em dias termicamente mais estressantes, resultando em aumento no número de visitas e no tempo de permanência dos animais nos bebedouros assim como em aumento no tempo real de consumo de água pelos animais.The study was carried out with six Holstein cows, in mid-lactation, reared in a freestall barn of a commercial dairy farm located in São Pedro city, in the State of São Paulo. During the trial the ambient parameters were recorded hourly from 8:00 AM to 6:00 PM inside and outside the barn: black globe temperature, dry bulb temperature, relative humidity and air velocity. The freestall barn had water facility with enough water flow to supply all the animals ad libitum. An additional drinking water facility was at the exit of the milking parlor. Average water intake of each group was measured using hydrometer. The data was used to quantify the lactating cows' water intake, to determine the frequency of use, the time cows spent drinking water and relating it to the ambient temperature humidity
A high-flow humidograph for testing the water uptake by ambient aerosol

Energy Technology Data Exchange (ETDEWEB)

Ten Brink, H.M.; Khlystov, A.; Kos, G.P.A. [ECN Fuels Conversion and Environment, Petten (Netherlands); Tuch, T. [Institut of Medical Data Management, Biometrics and Epidemiology, Ludwig-Maximilian University, Muenich (Germany); Roth, C.; Kreyling, W. [Institute for Inhalation Biology, GSF National Research Center for Environment and Health, Neuherberg/Muenich (Germany)

1999-10-01

A scanning humidograph, with an air flow rate of 0.5 m{sup 3} s{sup -1} was built to investigate the uptake of water and its effect on sizing, collection and light-scattering of ambient aerosol. The performance of the system was assessed with laboratory particles of ammonium nitrate, ammonium sulfate and sodium chloride which are the major hygroscopic components of ambient aerosol. The increase in size at the deliquescence points, which ideally is a stepwise function of relative humidity, occurs over a range of 3% RH units. This is shown to be an optimum value in a system of such large dimensions. Because of the strong temperature increase of the vapor pressure of ammonium nitrate, its evaporative loss was investigated as a function of heating/drying temperature. The loss of pure test aerosol, with a mass distribution similar to that in the ambient atmosphere, was found to be acceptable for drying temperatures of up to 40C. The sizing of deliquesced aerosol by LAS-X monitors was tested and found to be a complex function of RH. In Berner low pressure impactors growth of hygroscopic aerosol was not observed, not even at an RH approaching saturation. 21 refs.
Role of pH on the acute toxicity of sulfite in water. [Carassius auratus; Leistes reticulatus

Energy Technology Data Exchange (ETDEWEB)

Sano, H.

1976-01-01

The toxicity of sulfite to fish decreases with increasing pH value, because the HSO/sub 3//sup -/ ion is more toxic than the SO/sub 3//sup 2 -/ ion. An effective sulfite concentration S/sub eff/ which is proportional to the toxicity on fish is expressed by the following equation: S/sub eff/ = (HSO/sub 3//sup -/) + f(SO/sub 3//sup 2 -/), where f is a coefficient which expresses the change of toxicity of sulfite depending on the pH of the water, and varies for each species of fish. For goldfish, owing to the very small toxic contribution of SO/sub 3//sup 2 -/ ion (f = 0.07), the pH dependence of the toxicity of sulfite on pH was so strong that sulfite seemed almost non-toxic in basic solution. However, f for guppy is somewhat larger (f = 0.20) so that the toxicity of sulfite weakly depends on the pH value of water.
Changing patterns in water toxicity associated with current use pesticides in three California agriculture regions.

Science.gov (United States)

Anderson, Brian S; Phillips, Bryn M; Voorhees, Jennifer P; Deng, Xin; Geraci, Jeff; Worcester, Karen; Tjeerdema, Ron S

2018-03-01

Regulation of agriculture irrigation water discharges in California, USA, is assessed and controlled by its 9 Regional Water Quality Control Boards under the jurisdiction of the California State Water Resources Control Board. Each Regional Water Board has developed programs to control pesticides in runoff as part of the waste discharge requirements implemented through each region's Irrigated Lands Regulatory Program. The present study assessed how pesticide use patterns differ in the Imperial (Imperial County) and the Salinas and Santa Maria (Monterey County) valleys, which host 3 of California's prime agriculture areas. Surface-water toxicity associated with current use pesticides was monitored at several sites in these areas in 2014 and 2015, and results were linked to changes in pesticide use patterns in these areas. Pesticide use patterns appeared to coincide with differences in the way agriculture programs were implemented by the 2 respective Regional Water Quality Control Boards, and these programs differed in the 2 Water Board Regions. Different pesticide use patterns affected the occurrence of pesticides in agriculture runoff, and this influenced toxicity test results. Greater detection frequency and higher concentrations of the organophosphate pesticide chlorpyrifos were detected in agriculture runoff in Imperial County compared to Monterey County, likely due to more rigorous monitoring requirements for growers using this pesticide in Monterey County. Monterey County agriculture runoff contained toxic concentrations of pyrethroid and neonicotinoid pesticides, which impacted amphipods (Hyalella azteca) and midge larvae (Chironomus dilutus) in toxicity tests. Study results illustrate how monitoring strategies need to evolve as regulatory actions affect change in pesticide use and demonstrate the importance of using toxicity test indicator species appropriate for the suite of contaminants in runoff in order to accurately assess environmental risk. Integr
A novel approach for rapidly and cost-effectively assessing toxicity of toxic metals in acidic water using an acidophilic iron-oxidizing biosensor.

Science.gov (United States)

Yang, Shih-Hung; Cheng, Kuo-Chih; Liao, Vivian Hsiu-Chuan

2017-11-01

Contamination by heavy metals and metalloids is a serious environmental and health concern. Acidic wastewaters are often associated with toxic metals which may enter and spread into agricultural soils. Several biological assays have been developed to detect toxic metals; however, most of them can only detect toxic metals in a neutral pH, not in an acidic environment. In this study, an acidophilic iron-oxidizing bacterium (IOB) Strain Y10 was isolated, characterized, and used to detect toxic metals toxicity in acidic water at pH 2.5. The colorimetric acidophilic IOB biosensor was based on the inhibition of the iron oxidizing ability of Strain Y10, an acidophilic iron-oxidizing bacterium, by metals toxicity. Our results showed that Strain Y10 is acidophilic iron-oxidizing bacterium. Thiobacillus caldus medium (TCM) (pH 2.5) supplied with both S 4 O 6 2- and glucose was the optimum growth medium for Strain Y10. The optimum temperature and pH for the growth of Strain Y10 was 45 °C and pH 2.5, respectively. Our study demonstrates that the color-based acidophilic IOB biosensor can be semi-quantitatively observed by eye or quantitatively measured by spectrometer to detect toxicity from multiple toxic metals at pH 2.5 within 45 min. Our study shows that monitoring toxic metals in acidic water is possible by using the acidophilic IOB biosensor. Our study thus provides a novel approach for rapid and cost-effective detection of toxic metals in acidic conditions that can otherwise compromise current methods of chemical analysis. This method also allows for increased efficiency when screening large numbers of environmental samples. Copyright © 2017 Elsevier Ltd. All rights reserved.
Method and apparatus for the treatment of radioactive or toxic waste waters

Energy Technology Data Exchange (ETDEWEB)

Hofstaetter, K; Glock, J; Jakusch, H

1976-05-26

A method is described which proposes to store radioactive or toxic waste water in a binder, e.g. bitumen, for disposal. First of all, the liquid contained in the waste water is evaporated so that the radioactive or toxic part remains in solid form. This solid, whose specific gravity must be higher than that of the binder, is put on the surface of the binder, e.g. bitumen. Due to gravity it is embedded by sedimentation and completely covered by the binder. An apparatus with two variants to carry out the process is described, with particular emphasis on the advantages as compared to conventional methods.
Associations between water physicochemistry and Prymnesium parvum presence, abundance, and toxicity in west Texas reservoirs

Science.gov (United States)

VanLandeghem, Matthew M.; Farooqi, Mukhtar; Southard, Greg M.; Patino, Reynaldo

2015-01-01

Toxic blooms of golden alga (Prymnesium parvum) have caused substantial ecological and economic harm in freshwater and marine systems throughout the world. In North America, toxic blooms have impacted freshwater systems including large reservoirs. Management of water chemistry is one proposed option for golden alga control in these systems. The main objective of this study was to assess physicochemical characteristics of water that influence golden alga presence, abundance, and toxicity in the Upper Colorado River basin (UCR) in Texas. The UCR contains reservoirs that have experienced repeated blooms and other reservoirs where golden alga is present but has not been toxic. We quantified golden alga abundance (hemocytometer counts), ichthyotoxicity (bioassay), and water chemistry (surface grab samples) at three impacted reservoirs on the Colorado River; two reference reservoirs on the Concho River; and three sites at the confluence of these rivers. Sampling occurred monthly from January 2010 to July 2011. Impacted sites were characterized by higher specific conductance, calcium and magnesium hardness, and fluoride than reference and confluence sites. At impacted sites, golden alga abundance and toxicity were positively associated with salinity-related variables and blooms peaked at ~10°C and generally did not occur above 20°C. Overall, these findings suggest management of land and water use to reduce hardness or salinity could produce unfavorable conditions for golden alga.
Management of toxic cyanobacteria for drinking water production of Ain Zada Dam.

Science.gov (United States)

Saoudi, Amel; Brient, Luc; Boucetta, Sabrine; Ouzrout, Rachid; Bormans, Myriam; Bensouilah, Mourad

2017-07-01

Blooms of toxic cyanobacteria in Algerian reservoirs represent a potential health problem, mainly from drinking water that supplies the local population of Ain Zada (Bordj Bou Arreridj). The objective of this study is to monitor, detect, and identify the existence of cyanobacteria and microcystins during blooming times. Samples were taken in 2013 from eight stations. The results show that three potentially toxic cyanobacterial genera with the species Planktothrix agardhii were dominant. Cyanobacterial biomass, phycocyanin (PC) concentrations, and microcystin (MC) concentrations were high in the surface layer and at 14 m depth; these values were also high in the treated water. On 11 May 2013, MC concentrations were 6.3 μg/L in MC-LR equivalent in the drinking water. This study shows for the first time the presence of cyanotoxins in raw and treated waters, highlighting that regular monitoring of cyanobacteria and cyanotoxins must be undertaken to avoid potential health problems.
Future research needs associated with the assessment of potential human health risks from exposure to toxic ambient air pollutants

DEFF Research Database (Denmark)

Möller, Lennart; Schuetzle, Dennis; Autrup, Herman

1994-01-01

of identification and quantification of toxics in source emissions and ambient air, atmospheric transport and chemistry, exposure level assessment, the development of improved in vitro bioassays, biomarker development, the development of more accurate epidemiological methodologies, and risk quantification......This paper presents key conclusions and future research needs from a Workshop on the Risk Assessment of Urban Air, Emissions, Exposure, Risk Identification, and Quantification, which was held in Stockholm during June 1992 by 41 participants from 13 countries. Research is recommended in the areas...... techniques. Studies are described that will be necessary to assess and reduce the level of uncertainties associated with each step of the risk assessment process. International collaborative research efforts between industry and government organizations are recommended as the most effective way to carry out...
Sediment and toxic contaminant transport modeling in coastal waters

International Nuclear Information System (INIS)

Onishi, Y.; Mayer, D.W.; Argo, R.S.

1982-02-01

A hydrodynamic model, CAFE-I, a wave refraction model, LO3D, and a sediment and contaminant transport model, FETRA, were selected as tools for evaluating exposure levels of radionuclides, heavy metals, and other toxic chemicals in coastal waters. Prior to the application of these models to the Irish Sea and other coastal waters, the finite element model, FETRA, was tested to demonstrate its ability to simulate sediment and contaminant interactions (e.g., adsorption and desorption), and the mechanisms governing the transport, deposition, and resuspension of contaminated sediments
Toxicity and chemical analyses of airport runoff waters in Poland.

Science.gov (United States)

Sulej, Anna Maria; Polkowska, Zaneta; Wolska, Lidia; Cieszynska, Monika; Namieśnik, Jacek

2014-05-01

The aim of this study was to assess the ecotoxicological effects of various compounds in complex airport effluents using a chemical and ecotoxicological integrated strategy. The present work deals with the determination of sum of PCBs, PAHs, pesticides, cations, anions, phenols, anionic, cationic, non-ionic detergents, formaldehyde and metals--as well as TOC and conductivity--in runoff water samples collected from 2009 to 2011 at several locations on two Polish international airports. Two microbiotests (Vibrio fischeri bacteria and the crustacean Thamnocephalus platyurus) have been used to determine the ecotoxicity of airport runoff waters. The levels of many compounds exceeded several or even several tens of times the maximum permissible levels. Analysis of the obtained data shows that samples that displayed maximum toxicity towards the bioindicators Vibrio fischeri were not toxic towards Thamnocephalus platyurus. Levels of toxicity towards T. platyurus are strongly correlated with pollutants that originate from the technological operations related to the maintenance of airport infrastructure. The integrated (chemical-ecotoxicological) approach to environmental contamination assessment in and around airports yields extensive information on the quality of the environment. These methodologies can be then used as tools for tracking the environmental fate of these compounds and for assessing the environmental effect of airports. Subsequently, these data will provide a basis for airport infrastructure management.
Influence of solar radiation and biotic interactions on bacterial and eukaryotic communities associated with sewage decomposition in ambient water

Science.gov (United States)

Sewage and ambient water both consist of a highly complex array of bacteria and eukaryotic microbes. When these communities are mixed, the persistence of sewage-derived pathogens in environmental waters can represent a significant public health concern. Solar radiation and biot...
Calcium homeostasis in low and high calcium water acclimatized Oreochromis mossambicus exposed to ambient and dietary cadmium

NARCIS (Netherlands)

Pratap, H.B.; Wendelaar Bonga, S.E.

2007-01-01

The effects of cadmium administered via ambient water (10 mg/l) or food (10 mgCd/fish/day) on plasma calcium, corpuscles of Stannius and bony tissues of Oreochromis mossambicus acclimated to low calcium (0.2 mM) and high calcium (0.8 mM) water were studied for 2, 4, 14 and 35 days. In low calcium
Carbon dioxide laser absorption spectra of toxic industrial compounds

International Nuclear Information System (INIS)

Loper, G.L.; Sasaki, G.R.; Stamps, M.A.

1982-01-01

CO 2 laser absorption cross-section data are reported for acrolein, styrene, ethyl acrylate, trichloroethylene, vinyl bromide, and vinylidene chloride. These data indicate that sub parts per billion level, interference-free detection limits should be possible for these compounds by the CO 2 laser photoacoustic technique. Photoacoustic detectabilities below 40 ppb should be possible for these compounds in the presence of ambient air concentrations of water vapor and other anticipated interferences. These compounds are also found not to be important inerference in the detection of toxic hydrazine-based rocket fuels by CO 2 laser spectroscopic techniques
Development and Validation of an On-Line Water Toxicity Sensor with Immobilized Luminescent Bacteria for On-Line Surface Water Monitoring.

NARCIS (Netherlands)

Woutersen, Marjolijn; van der Gaag, Bram; Abrafi Boakye, Afua; Mink, Jan; Marks, Robert S; Wagenvoort, Arco J; Ketelaars, Henk A M; Brouwer, Bram; Heringa, Minne B

2017-01-01

Surface water used for drinking water production is frequently monitored in The Netherlands using whole organism biomonitors, with for exampleDaphnia magnaorDreissenamussels, which respond to changes in the water quality. However, not all human-relevant toxic compounds can be detected by these
Testing the toxicity of metals, phenol, effluents, and receiving waters by root elongation in Lactuca sativa L.

Science.gov (United States)

Lyu, Jie; Park, Jihae; Kumar Pandey, Lalit; Choi, Soyeon; Lee, Hojun; De Saeger, Jonas; Depuydt, Stephen; Han, Taejun

2018-03-01

Phytotoxicity tests using higher plants are among the most simple, sensitive, and cost-effective of the methods available for ecotoxicity testing. In the present study, a hydroponic-based phytotoxicity test using seeds of Lactuca sativa was used to evaluate the water quality of receiving waters and effluents near two industrial sites (Soyo and Daejon) in Korea with respect to the toxicity of 10 metals (As, Cd, Cr, Cu, Fe, Pb, Mn, Hg, Ni, Zn) and phenol, and of the receiving waters and effluents themselves. First, the L. sativa hydroponic bioassay was used to determine whether the receiving water or effluents were toxic; then, the responsible toxicant was identified. The results obtained with the L. sativa bioassay ranked the EC 50 toxicities of the investigated metal ions and phenol as: Cd > Ni > Cu > Zn > Hg > phenol > As > Mn > Cr > Pb > Fe. We found that Zn was the toxicant principally responsible for toxicity in Daejeon effluents. The Daejeon field effluent had a higher Zn concentration than permitted by the effluent discharge criteria of the Ministry of Environment of Korea. Our conclusion on the importance of Zn toxicity was supported by the results of the L. sativa hydroponic assay, which showed that the concentration of Zn required to inhibit root elongation in L. sativa by 50% (EC 50 ) was higher in the Daejeon field effluent than that of pure Zn. More importantly, we proved that the L. sativa hydroponic test method can be applied not only as an alternative tool for determining whether a given waste is acceptable for discharge into public water bodies, but also as an alternative method for measuring the safety of aquatic environments using EC 20 values, with respect to the water pollutants investigated (i.e., Cd, Cr, Cu, Pb, Mn, Hg, Ni, Zn, and phenol). Copyright © 2017. Published by Elsevier Inc.
A portable cell-based impedance sensor for toxicity testing of drinking water.

Science.gov (United States)

Curtis, Theresa M; Widder, Mark W; Brennan, Linda M; Schwager, Steven J; van der Schalie, William H; Fey, Julien; Salazar, Noe

2009-08-07

A major limitation to using mammalian cell-based biosensors for field testing of drinking water samples is the difficulty of maintaining cell viability and sterility without an on-site cell culture facility. This paper describes a portable automated bench-top mammalian cell-based toxicity sensor that incorporates enclosed fluidic biochips containing endothelial cells monitored by Electric Cell-substrate Impedance Sensing (ECIS) technology. Long-term maintenance of cells on the biochips is made possible by using a compact, self-contained disposable media delivery system. The toxicity sensor monitors changes in impedance of cell monolayers on the biochips after the introduction of water samples. The fluidic biochip includes an ECIS electronic layer and a polycarbonate channel layer, which together reduce initial impedance disturbances seen in commercially available open well ECIS chips caused by the mechanics of pipetting while maintaining the ability of the cells to respond to toxicants. A curve discrimination program was developed that compares impedance values over time between the control and treatment channels on the fluidic biochip and determines if they are significantly different. Toxicant responses of bovine pulmonary artery endothelial cells grown on fluidic biochips are similar to cells on commercially-available open well chips, and these cells can be maintained in the toxicity sensor device for at least nine days using an automated media delivery system. Longer-term cell storage is possible; bovine lung microvessel endothelial cells survive for up to four months on the fluidic biochips and remain responsive to a model toxicant. This is the first demonstration of a portable bench top system capable of both supporting cell health over extended periods of time and obtaining impedance measurements from endothelial cell monolayers after toxicant exposure.

Migration of toxicants from plastics into drinking water during storage ...

African Journals Online (AJOL)

In this study, migration of toxicants, such as, manufacturing additives and previously adsorbed materials into drinking water stored inside plastic containers was investigated. The study considered virgin containers as well as those previously used to store sulphuric acid, calcium hypochlorite, methyl ethyl ketone (MEK) and ...
Toxic effects of juvenile sablefish, Anoplopoma fimbria by ammonia exposure at different water temperature.

Science.gov (United States)

Kim, Jun-Hwan; Park, Hee-Ju; Hwang, In-Ki; Han, Jae-Min; Kim, Do-Hyung; Oh, Chul Woong; Lee, Jung-Sick; Kang, Ju-Chan

2017-09-01

Juvenile sablefish, Anoplopoma fimbria (mean length 17.1±2.4cm, and mean weight 75.6±5.7g) were used to evaluate toxic effects on antioxidant systems, immune responses, and stress indicators by ammonia exposure (0, 0.25, 0.75, and 1.25mg/L) at different water temperature (12 and 17°C) in 1 and 2 months. In antioxidant responses, superoxide dismutase (SOD) and catalase (CAT) were significantly increased by ammonia exposure, whereas glutathione (GSH) was decreased. In immune responses, lysozyme and phagocytosis activity were significantly increased by ammonia exposure. In stress indicators, plasma glucose, heat shock protein 70 (HSP 70), and cortisol were significantly increased. At high water temperature (17°C), alterations by ammonia exposure were more distinctly. The results of this study indicated that ammonia exposure can induce toxic effects in the sablefish, and high water temperature can affect the ammonia exposure toxicity. Copyright © 2017 Elsevier B.V. All rights reserved.
On the use of mixture toxicity assessment in REACH and the water framework directive

DEFF Research Database (Denmark)

Syberg, Kristian; Jensen, T.S.; Cedergreen, Nina

2009-01-01

This review seeks to connect the scientific theory of mixture toxicity to its implementation within different regulatory frameworks. The aim is to demonstrate how mixture toxicity assessment can be more thoroughly integrated into the European chemical regulations, REACH and the Water Framework...... of how the methods could be applied within REACH and WFD. It is concluded that oncentration addition should be applied as a default model for mixture toxicity assessment. Furthermore, it is concluded that REACH and WFD only include mixture toxicity assessments in specific situations. However, it is shown...
Simulation of heavy metal contamination of fresh water bodies: toxic ...

African Journals Online (AJOL)

Michael Horsfall

www.bioline.org.br/ja. Simulation of heavy metal contamination of fresh water bodies: toxic effects in the ... 96 hours (though sampling was done at the 48th hour). Biochemical markers of ... silver, while enhancing the bioavailability of mercury in Ceriodaphnia ..... Biochemical and molecular disorders of bilirubin metabolism.
Isobaric-isothermal Monte Carlo simulations from first principles: Application to liquid water at ambient conditions

Energy Technology Data Exchange (ETDEWEB)

McGrath, M; Siepmann, J I; Kuo, I W; Mundy, C J; VandeVondele, J; Hutter, J; Mohamed, F; Krack, M

2004-12-02

A series of first principles Monte Carlo simulations in the isobaric-isothermal ensemble were carried out for liquid water at ambient conditions (T = 298 K and p = 1 atm). The Becke-Lee-Yang-Parr (BLYP) exchange and correlation energy functionals and norm-conserving Goedecker-Teter-Hutter (GTH) pseudopotentials were employed with the CP2K simulation package to examine systems consisting of 64 water molecules. The fluctuations in the system volume encountered in simulations in the isobaric-isothermal ensemble requires a reconsideration of the suitability of the typical charge density cutoff and the regular grid generation method previously used for the computation of the electrostatic energy in first principles simulations in the microcanonical or canonical ensembles. In particular, it is noted that a much higher cutoff is needed and that the most computationally efficient method of creating grids can result in poor simulations. Analysis of the simulation trajectories using a very large charge density cutoff at 1200 Ry and four different grid generation methods point to a substantially underestimated liquid density of about 0.85 g/cm{sup 3} resulting in a somewhat understructured liquid (with a value of about 2.7 for the height of the first peak in the oxygen/oxygen radial distribution function) for BLYP-GTH water at ambient conditions.
Influence of Solar Radiation and Biotic Interactions on Bacterial and Eukaryotic Communities Associated with Sewage Decomposition in Ambient Water - Poster

Science.gov (United States)

Sewage and ambient water both consist of a highly complex array of bacteria and eukaryotic microbes. When these communities are mixed, the persistence of sewage-derived pathogens in environmental waters can represent a significant public health concern. Solar radiation and biotic...
The influence of particles on bioavailability and toxicity of pesticides in surface water.

Science.gov (United States)

Knauer, Katja; Homazava, Nadzeya; Junghans, Marion; Werner, Inge

2017-07-01

Environmental risk assessment is an essential part of the approval process for pesticides. Exposure concentrations are compared with ecotoxicological data obtained from standardized laboratory studies and, if available, from field studies to determine the risk of a substance or formulation for aquatic communities. Predicted concentrations in surface waters are derived using, for example, the European FOrum for the Co-ordination of pesticide fate models and their USe (FOCUS) or the German Exposit models, which distinguish between exposure to dissolved and particle-associated pesticide concentrations, because the dissolved concentration is thought to be the best predictor of bioavailability and toxicity. Water and particle-associated concentrations are estimated based on the organic carbon-water partitioning coefficient (K OC ). This review summarizes published information on the influence of natural suspended solids on bioavailability and toxicity of pesticides to aquatic organisms (algae, invertebrates and fish), and the value of log K OC and log K OW (octanol-water coefficient) as sole predictors of the bioavailable fraction is discussed. The information showed that: 1) the quality and origin of suspended solids played an important role in influencing pesticide bioavailability and toxicity; 2) a decrease in toxicity due to the presence of suspended solids was shown only for pyrethroid insecticides with log K OW greater than 5, but the extent of this reduction depended on particle concentration and size, and potentially also on the ecotoxicological endpoint; 3) for pesticides with a log K OW less than 3 (e.g., triazines, carbamates, and organophosphates), the impact of particles on bioavailability and toxicity is small and species dependent; and 4) pesticide bioavailability is greatly influenced by the test species and their physiology (e.g., feeding behavior or digestion). We conclude that exposure of aquatic organisms to pesticides and environmental risk of many
EVALUATING THE ROLE OF ION COMPOSITION ON THE TOXICITY OF COPPER TO CERIODAPHNIA DUBIA IN VERY HARD WATERS

Science.gov (United States)

The mitigating effect of increasing hardness on metal toxicity is reflected in water quality criteria in the United States. - - - Copper toxicity did not consistently vary as a function of hardness, but likely as a function of other water quality characteristics (e.g. alkalinity ...
Properties and cellular effects of particulate matter from direct emissions and ambient sources.

Science.gov (United States)

Jin, Wenjie; Su, Shu; Wang, Bin; Zhu, Xi; Chen, Yilin; Shen, Guofeng; Liu, Junfeng; Cheng, Hefa; Wang, Xilong; Wu, Shuiping; Zeng, Eddy; Xing, Baoshan; Tao, Shu

2016-10-14

The pollution of particulate matter (PM) is of great concern in China and many other developing countries. It is generally recognized that the toxicity of PM is source and property dependent. However, the relationship between PM properties and toxicity is still not well understood. In this study, PM samples from direct emissions of wood, straw, coal, diesel combustion, cigarette smoking and ambient air were collected and characterized for their physicochemical properties. Their expression of intracellular reactive oxygen species (ROS) and levels of inflammatory cytokines (i.e., tumor necrosis factor-α (TNF-α)) was measured using a RAW264.7 cell model. Our results demonstrated that the properties of the samples from different origins exhibited remarkable differences. Significant increases in ROS were observed when the cells were exposed to PMs from biomass origins, including wood, straw and cigarettes, while increases in TNF-α were found for all the samples, particularly those from ambient air. The most important factor associated with ROS generation was the presence of water-soluble organic carbon, which was extremely abundant in the samples that directly resulted from biomass combustion. Metals, endotoxins and PM size were the most important properties associated with increases in TNF-α expression levels. The association of the origins of PM particles and physicochemical properties with cytotoxic properties is illustrated using a cluster analysis.
Multisensor Capacitance Probes for Simultaneously Monitoring Rice Field Soil-Water- Crop-Ambient Conditions.

Science.gov (United States)

Brinkhoff, James; Hornbuckle, John; Dowling, Thomas

2017-12-26

Multisensor capacitance probes (MCPs) have traditionally been used for soil moisture monitoring and irrigation scheduling. This paper presents a new application of these probes, namely the simultaneous monitoring of ponded water level, soil moisture, and temperature profile, conditions which are particularly important for rice crops in temperate growing regions and for rice grown with prolonged periods of drying. WiFi-based loggers are used to concurrently collect the data from the MCPs and ultrasonic distance sensors (giving an independent reading of water depth). Models are fit to MCP water depth vs volumetric water content (VWC) characteristics from laboratory measurements, variability from probe-to-probe is assessed, and the methodology is verified using measurements from a rice field throughout a growing season. The root-mean-squared error of the water depth calculated from MCP VWC over the rice growing season was 6.6 mm. MCPs are used to simultaneously monitor ponded water depth, soil moisture content when ponded water is drained, and temperatures in root, water, crop and ambient zones. The insulation effect of ponded water against cold-temperature effects is demonstrated with low and high water levels. The developed approach offers advantages in gaining the full soil-plant-atmosphere continuum in a single robust sensor.
Toxicity of pentachlorophenol to aquatic organisms under naturally varying and controlled environmental conditions

Energy Technology Data Exchange (ETDEWEB)

Hedtke, S.F.; West, C.W.; Allen, K.N.; Norberg-King, T.J.; Mount, D.I.

1986-06-01

The toxicity of pentachlorophenol (PCP) was determined in the laboratory for 11 aquatic species. Tests were conducted seasonally in ambient Mississippi River water and under controlled conditions in Lake Superior water. Fifty-one acute toxicity tests were conducted, with LC50 values ranging from 85 micrograms/L for the white sucker Catastomus commersoni during the summer to greater than 7770 micrograms/L for the isopod Asellus racovitzai during the winter. The effect of PCP on growth and/or reproduction was determined for seven species. The most sensitive chronically exposed organisms were the cladoceran Ceriodaphnia reticulata and the snail Physa gyrina. The greatest variation in toxicity was due to species sensitivity. Within a given, season there was as much as a 40-fold difference in LC50 values between species. For any one species, the maximum variation in LC50 between seasons was approximately 14-fold. There were also substantial differences in acute-chronic relationships, with acute/chronic ratios ranging from greater than 37 for C. reticulata to 1 for Simocephalus vetulus. It is suggested that the composition of the aquatic community should be the most important consideration in estimating the potential environmental effects of PCP.
Comparative toxicity test of water-accommodated fractions of oils and oil dispersants to marine organisms

International Nuclear Information System (INIS)

1989-01-01

This reference method describes a simple procedure for comparing the toxicity of oil, oil dispersants, and mixtures thereof, to marine animals. It allows the toxicity of different dispersants to be rapidly compared to that of oil, or of a mixture of oil an oil dispersant. It is designed for routine monitoring and screening purposes and is not appropriate as a research method. The physical and chemical properties of oil dispersants create many difficulties in the measurements of their toxicity to marine organisms. Strictly speaking, their toxicity can only be accurately estimated using complex procedures and apparatus. (A relatively simple apparatus for preparing oil/water or oil/water/oil dispersant emulsions is described in Appendix B). Simpler methods can provide useful information, provided their limitations are clearly understood and taken into consideration in the assessment and application of their results. Some of the special considerations relating to the measurement of the toxicity of oil and oil dispersants are described in Appendix A. The Appendix also explains the rationale and limitations of the method described here. 3 refs, 4 figs, 2 tabs
Effect of water treatment residuals on soil phosphorus, copper and aluminium availability and toxicity

Energy Technology Data Exchange (ETDEWEB)

Lombi, E., E-mail: enzo.lombi@unisa.edu.a [CSIRO Land and Water, Centre for Environmental Contaminant Research, PMB 2, Glen Osmond, SA 5064 (Australia); Centre for Environmental Risk Assessment and Remediation, University of South Australia, Building X, Mawson Lakes Campus, Mawson Lakes, SA 5095 (Australia); CRC CARE, PO Box 486, Salisbury, SA 5106 (Australia); Stevens, D.P. [CSIRO Land and Water, Centre for Environmental Contaminant Research, PMB 2, Glen Osmond, SA 5064 (Australia); Arris Pty Ltd, PO Box 5143, Burnley, Victoria 3121 (Australia); McLaughlin, M.J. [CSIRO Land and Water, Centre for Environmental Contaminant Research, PMB 2, Glen Osmond, SA 5064 (Australia); Soil and Land Systems, University of Adelaide, PMB 1, Glen Osmond, SA 5064 (Australia)

2010-06-15

Water treatment residuals (WTRs) are produced by the treatment of potable water with coagulating agents. Beneficial recycling in agriculture is hampered by the fact that WTRs contain potentially toxic contaminants (e.g. copper and aluminium) and they bind phosphorus strongly. These issues were investigated using a plant bioassay (Lactuca sativa), chemical extractions and an isotopic dilution technique. Two WTRs were applied to an acidic and a neutral pH soil at six rates. Reductions in plant growth in amended soils were due to WTR-induced P deficiency, rather than Al or Cu toxicity. The release of potentially toxic Al from WTRs was found to be mitigated by their alkaline nature and pH buffering capacity. However, acidification of WTRs was shown to release more soluble Al than soil naturally high in Al. Copper availability was relatively low in all treatments. However, the lability of WTR-Cu increased when the WTR was applied to the soil. - The effect of water treatment residue application to soil was investigated in relation to phosphorus availability, and copper and aluminium phytotoxicity.
Effect of water treatment residuals on soil phosphorus, copper and aluminium availability and toxicity

International Nuclear Information System (INIS)

Lombi, E.; Stevens, D.P.; McLaughlin, M.J.

2010-01-01

Water treatment residuals (WTRs) are produced by the treatment of potable water with coagulating agents. Beneficial recycling in agriculture is hampered by the fact that WTRs contain potentially toxic contaminants (e.g. copper and aluminium) and they bind phosphorus strongly. These issues were investigated using a plant bioassay (Lactuca sativa), chemical extractions and an isotopic dilution technique. Two WTRs were applied to an acidic and a neutral pH soil at six rates. Reductions in plant growth in amended soils were due to WTR-induced P deficiency, rather than Al or Cu toxicity. The release of potentially toxic Al from WTRs was found to be mitigated by their alkaline nature and pH buffering capacity. However, acidification of WTRs was shown to release more soluble Al than soil naturally high in Al. Copper availability was relatively low in all treatments. However, the lability of WTR-Cu increased when the WTR was applied to the soil. - The effect of water treatment residue application to soil was investigated in relation to phosphorus availability, and copper and aluminium phytotoxicity.
Application of enzyme multibiosensor for toxicity analysis of real water samples of different origin

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Soldatkin A. P.

2009-06-01

Full Text Available Aim. The analysis of toxicity of different water samples with the multibiosensor developed earlier. Methods. The potentiometric multibiosensor with several immobilized enzymes as bioselective elements and the matrix of pH-sensitive field effect transistors as transducers of the biochemical signal into the electric one was applied for the analysis. Results. The bioselective elements of the multibiosensor were developed using acetylcholinesterase, butyryl- cholinesterase, urease, glucose oxidase, and three-enzyme system (invertase, mutarotase, glucose oxidase. The measurement of toxic compounds in water samples of different origin was performed using the constructed sensor. The results obtained were compared with those obtained by the conventional methods of toxic agent’s analysis (atomic absorption spectrometry, thin-film chroma- tography, and atomic absorbic analyser of mercury. Conclusion. A strong conformity between the results obtained with the multibiosensor and traditional methods has been shown.
CORMIX2: An expert system for hydrodynamic mixing zone analysis of conventional and toxic multiport diffuser discharges

International Nuclear Information System (INIS)

Akar, P.J.; Jirka, G.H.

1991-12-01

One of the most important tasks in the management of water quality is the ability to achieve pollutant concentrations within regulated standards. The Cornell Mixing Zone Expert System (CORMIX) is a series of software systems for the analysis, prediction, and design of aqueous toxic or conventional pollutant discharges into watercourses, with emphasis on the geometry and dilution characteristics of the initial mixing zone. The present development, subsystem CORMIX2 is concerned with submerged multiport discharges into flowing water environments, such as rivers, lakes, estuaries, and coastal waters. It includes effects of ambient stratification, dynamic attachment of the plume to the bottom of the receiving water, and the limiting case of stagnant conditions
Trophic state and toxic cyanobacteria density in optimization modeling of multi-reservoir water resource systems.

Science.gov (United States)

Sulis, Andrea; Buscarinu, Paola; Soru, Oriana; Sechi, Giovanni M

2014-04-22

The definition of a synthetic index for classifying the quality of water bodies is a key aspect in integrated planning and management of water resource systems. In previous works [1,2], a water system optimization modeling approach that requires a single quality index for stored water in reservoirs has been applied to a complex multi-reservoir system. Considering the same modeling field, this paper presents an improved quality index estimated both on the basis of the overall trophic state of the water body and on the basis of the density values of the most potentially toxic Cyanobacteria. The implementation of the index into the optimization model makes it possible to reproduce the conditions limiting water use due to excessive nutrient enrichment in the water body and to the health hazard linked to toxic blooms. The analysis of an extended limnological database (1996-2012) in four reservoirs of the Flumendosa-Campidano system (Sardinia, Italy) provides useful insights into the strengths and limitations of the proposed synthetic index.
Toxicity of sediment pore water associated with offshore oil and gas platforms in the Gulf of Mexico

International Nuclear Information System (INIS)

Carr, R.S.; Chapman, D.C.

1993-01-01

As a part of a multidisciplinary program to assess the long-term impacts of offshore petroleum production in the Gulf of Mexico, a series of sediment porewater toxicity tests were conducted. Sediments were samples from five petroleum production platforms along five radial transects. Pore water was extracted from the sediment using a pressure extraction device, centrifuged, and frozen for later toxicity testing and chemical analysis. The sea urchin (Arbacia punctulata) embryological development assay and fertilization assay were used to assess porewater toxicity. Significant decreases in normal development of embryos was observed at 14 stations and fertilization was reduced at three stations. All stations with reduced fertilization also showed impaired development in the embryological development assay. All but three toxic sites were within 150 m of the platform. The six most toxic stations were at one platform near the Flower Garden reef, occurring near the platform along three radii; toxicity was always greater at the first site on a radium than at the second. Toxicity is discussed in relation to metal and hydrocarbon concentrations in whole sediment and in pore water
Studies of ambient noise in shallow water environments off Mexico and Alaska: characteristics, metrics and time-synchronization applications

Science.gov (United States)

Guerra, Melania

Sound in the ocean originates from multiple mechanisms, both natural and anthropogenic. Collectively, underwater ambient noise accumulates valuable information about both its sources and the oceanic environment that propagates this noise. Characterizing the features of ambient noise source mechanisms is challenging, but essential, for properly describing an acoustic environment. Disturbances to a local acoustic environment may affect many aquatic species that have adapted to be heavily dependent on this particular sense for survival functions. In the case of marine mammals, which are federally protected, demand exists for understanding such potential impacts, which drives important scientific efforts that utilize passive acoustic monitoring (PAM) tools to inform regulatory decisions. This dissertation presents two independent studies that use PAM data to investigate the characteristics of source mechanisms that dominate ambient noise in two diverse shallow water environments. The study in Chapter 2 directly addresses the concern of how anthropogenic activities can degrade the effectiveness of PAM. In the Alaskan Beaufort Sea, an environment where ambient noise is normally dominated by natural causes, seismic surveys create impulsive sounds to map the composition of the bottom. By inspecting single-sensor PAM data, the spectral characteristics of seismic survey airgun reverberation are measured, and their contribution to the overall ambient noise is quantified. This work is relevant to multiple ongoing mitigation protocols that rely on PAM to acoustically detect marine mammal presence during industrial operations. Meanwhile, Chapter 3 demonstrates that by analyzing data from multiple PAM sensors, features embedded in both directional and omnidirectional ambient noise can be used to develop new time-synchronization processing techniques for aligning autonomous elements of an acoustic array, a tool commonly used in PAM for detecting and tracking marine mammals. Using
Nickel toxicity to cardinal tetra (Paracheirodon axelrodi) differs seasonally and among the black, white and clear river waters of the Amazon basin.

Science.gov (United States)

Holland, Aleicia; Wood, Chris M; Smith, D Scott; Correia, Tiago Gabriel; Val, Adalberto L

2017-10-15

This study investigated the acute toxicity of nickel (Ni) to cardinal tetra (Paracheirodon axelrodi), within the three main water types of the Amazon basin: black (Rio Negro), white (Rio Solimões) and clear (Rio Tapajós) during the wet and dry season at pH 7 (representative of white and clear rivers) and pH 4 (representative of black waters). The influence of dissolved organic carbon (DOC) quality on Ni toxicity within the three waters was also explored via the use of DOC isolates. Differences in water chemistry, DOC quality and ion concentrations were shown between waters and between seasons. Toxicity of Ni was shown to vary between river waters, seasons, and pHs. Ni was significantly less toxic during the dry season at pH 4 in all three river waters; for example, black water during the wet season had an LC 50 of 9.72 mg Ni/L compared to 41.5 mg Ni/L during the dry season. At pH 7, contrasting effects in toxicity between seasons were shown between black and clear waters (black: wet = 28.9 mg/L, dry = 17.3 mg/L; clear: wet = 13.8 mg/L, dry = 24.1 mg/L). There were no significant differences in Ni toxicity for white waters at pH 7 (white: wet = 22.2 mg/L, dry = 21.8). Overall, Ni was shown to be more toxic at pH 7 than at pH 4 except in black water during the wet season. Toxicity of Ni at pH 4 was positively related to DOC concentration and amount of humic-like and fulvic-like DOC and negatively related to fluorescence index. Therefore, at pH 4, Ni is more toxic in waters containing more allochthonous DOC, consisting of higher amounts of humic-like and fulvic-like components. LC 50 values for the different DOC concentrates at the same DOC concentration of 4.5 mg/L (black: 26.8 mg/L; white: 73.3 mg/L; clear: 49.2) support the river water findings at pH 4 (Ni more toxic in presence of black DOC) indicating that DOC quality alone can influence Ni toxicity at this pH. Copyright © 2017 Elsevier Ltd. All rights reserved.

Acute and chronic toxicity of sediment samples from Guanabara Bay (RJ during the rainy period

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Luciane Alves Maranho

2010-06-01

Full Text Available Guanabara Bay is a marine-estuarine environment of high ecological and socio-economic importance, subject to a variety of environmental impacts. Sediment is the eventual repository for most substances introduced into water bodies and may, therefore, provide an integrated measure of the environmental quality, which can be assessed by many different approaches. In this project, the quality of sediments from Guanabara Bay was evaluated by the ecotoxicological approach: whole-sediment toxicity tests, using Tiburonella viscana, and porewater, elutriate and sediment-water interface chronic toxicity tests, using embryos of Lytechinus variegatus, were applied. Sediments were collected at 14 sampling stations, distributed across the bay. Chronic tests showed significant toxicity in most of the sediment samples. Sediments from stations 1, 2, 3, 6, 8, 10, 11, 12 and 15 showed acute toxicity as well. The results of the different tests were well correlated, and their integration showed that the sediments analyzed were considered unsuitable for aquatic life, resulting in the environmental degradation of Guanabara Bay. In this context, the control of pollution sources and multi-purpose management are required to improve the environmental quality.A Baía de Guanabara é um ambiente marinho-estuarino de grande relevância ecológica e sócio-econômica, e sujeita a uma ampla gama de impactos ambientais. O sedimento é o principal destino para a maioria das substâncias introduzidas nos corpos d'água, podendo fornecer uma medida integrada da qualidade ambiental, a qual pode ser avaliada por várias abordagens. Neste projeto, a qualidade de sedimentos da Baía de Guanabara foi por uma abordagem ecotoxicológica, por meio de testes de toxicidade aguda de sedimento integral, utilizando Tiburonella viscana, e testes de toxicidade crônica de água intersticial, elutriato e interface sedimento-água, utilizando embriões de Lytechinus variegatus. Os sedimentos foram
Behavioral, clinical, and pathological characterization of acid metalliferous water toxicity in mallards

Science.gov (United States)

Isanhart, John P.; Wu, Hongmei; Pandher, Karamjeet; MacRae, Russell K.; Cox, Stephen B.; Hooper, Michael J.

2011-01-01

From September to November 2000, United States Fish and Wildlife Service biologists investigated incidents involving 221 bird deaths at 3 mine sites located in New Mexico and Arizona. These bird deaths primarily involved passerine and waterfowl species and were assumed to be linked to consumption of acid metalliferous water (AMW). Because all of the carcasses were found in or near pregnant leach solution ponds, tailings ponds, and associated lakes or storm water retention basins, an acute-toxicity study was undertaken using a synthetic AMW (SAMW) formulation based on the contaminant profile of a representative pond believed to be responsible for avian mortalities. An acute oral-toxicity trial was performed with a mixed-sex group of mallards (Anas platyrhynchos). After a 24-h pretreatment food and water fast, gorge drinking was evident in both SAMW treatment and control groups, with water consumption rates greatest during the initial drinking periods. Seven of nine treated mallards were killed in extremis within 12 h after the initiation of dose. Total lethal doses of SAMW ranged from 69.8 to 270.1 mL/kg (mean ± SE 127.9 ± 27.1). Lethal doses of SAMW were consumed in as few as 20 to 40 min after first exposure. Clinical signs of SAMW toxicity included increased serum uric acid, aspartate aminotransferase, creatine kinase, potassium, and P levels. PCV values of SAMW-treated birds were also increased compared with control mallards. Histopathological lesions were observed in the esophagus, proventriculus, ventriculus, and duodenum of SAMW-treated mallards, with the most distinctive being erosion and ulceration of the kaolin of the ventriculus, ventricular hemorrhage and/or congestion, and duodenal hemorrhage. Clinical, pathological, and tissue-residue results from this study are consistent with literature documenting acute metal toxicosis, especially copper (Cu), in avian species and provide useful diagnostic profiles for AMW toxicity or mortality events. Blood and
Investigation of metal toxicity to tropical biota. Recommendations for revision of Australian water quality guidelines

International Nuclear Information System (INIS)

Marchich, S.

1997-01-01

The specific objectives of this study were to: review available data on the toxicity of metals to aquatic biota in tropical Australia; identify metals considered to be priority toxicants to aquatic biota in tropical Australia; and employ previously developed toxicity testing protocols for two tropical freshwater species to obtain preliminary toxicity data for two priority metals. From the literature review, it was concluded that insufficient metal toxicity data exist for Australian tropical species. Data were absent for a range of metals (eg Ag, As, Al, Cr, Hg, Ni, Sb and Se) listed in the current Australian water quality guidelines. Aluminium, Cd, Co, Cu, Ni, Mn, Pb, U, V and Zn were identified as priority metals of potential ecotoxicological concern in aquatic ecosystems of tropical Australia, largely as a consequence of mining activities, but also from urban impacts. Instead of testing the toxicity of the priority metals for which data do not currently exist (ie Al, Co, Ni and V), it was deemed more important to conduct further experimental work on Cu and U, in the context of elucidating the relatively high variability in the toxic response of these two metals. As a result, Cu and U were selected and toxicity tests conducted using two tropical freshwater species (green hydra (Hydra viridissima) and gudgeon fish (Mogurnda mogurnda)) from the Australian wet/dry tropics using test protocols designed to maximise the greatest sensitivity of metal response in the shortest period of time. Hydra viridissima was about eight times more sensitive to Cu than U, whereas M. mogurnda was about twenty times more sensitive. Once differences between the sublethal and lethal endpoints of the two organisms were corrected by statistical extrapolation, H. viridissima was approximately seven times more sensitive than M. mogurnda to U, but only about three times more sensitive to Cu. Both species were more sensitive to Cu than U. These results are generally consistent with those from
The biomonitoring and bioremediation of toxic water resulting from municipal waste storage of Somârd, Sibiu county

OpenAIRE

Ioan C. Oprea; Dana Malschi; Liviu O. Muntean

2013-01-01

This paper presents information from the specialty literature and laboratory experimental results on biomonitoring, phytoextraction, biodegradation, and biotransformation of toxic water pollutants at the biotechnology laboratory of the Faculty of Environmental Science and Engineering. The study was conducted in laboratory micro tanks with contaminated water from the municipal landfill water storage pit with toxic bund of Somârd/Medias, Sibiu County, in order to research and develo...
Potential for photoenhanced toxicity of spilled oil in Prince William Sound and Gulf of Alaska Waters

International Nuclear Information System (INIS)

Barron, M.G.; Ka'aihue, L.

2001-01-01

Photoenhanced toxicity is the increase in the toxicity of a chemical in the presence of ultraviolet light (UV) compared to a standard laboratory test conducted with fluorescent lighting (minimal UV). Oil products, weathered oil, and specific polycyclic aromatic compounds present in oil are 2 to greater than 1000 times more toxic in the presence of UV. The photoenhanced toxicity of oil to fish and aquatic invertebrates appears to occur through a process of photosensitization, rather than photomodification of the aqueous phase oil. In photosensitization, the bioaccumulated chemical transfers light energy to other molecules causing toxicity through tissue damage rather than a narcosis mechanism. The available evidence indicates that phototoxic components of oil are specific 3-5 ring polycyclic aromatic hydrocarbons (PAHs) and heterocycles. Determinants of photoenhanced toxicity include the extent of oil bioaccumulation in aquatic organisms and the spectra and intensity of UV exposure. No studies have specifically investigated the photoenhanced toxicity of spilled oil in Alaska waters. Although there are substantial uncertainties, the results of this evaluation indicate there is potential for photoenhanced toxicity of spilled oil in Prince William Sound and the Gulf of Alaska. The potential hazard of photoenhanced toxicity may be greatest for embryo and larval stages of aquatic organisms that are relatively translucent to UV and inhabit the photic zone of the water column and intertidal areas. Photoenhanced toxicity should be considered in oil spill response because the spatial and temporal extent of injury to aquatic organisms may be underestimated if based on standard laboratory bioassays and existing toxicity databases. Additionally, the choice of counter measures and oil removal operations may influence the degree of photoenhanced toxicity. (author)
Microencapsulated Aliivibrio fischeri in Alginate Microspheres for Monitoring Heavy Metal Toxicity in Environmental Waters

Directory of Open Access Journals (Sweden)

Dedi Futra

2014-12-01

Full Text Available In this article a luminescence fiber optic biosensor for the microdetection of heavy metal toxicity in waters based on the marine bacterium Aliivibrio fischeri (A. fischeri encapsulated in alginate microspheres is described. Cu(II, Cd(II, Pb(II, Zn(II, Cr(VI, Co(II, Ni(II, Ag(I and Fe(II were selected as sample toxic heavy metal ions for evaluation of the performance of this toxicity microbiosensor. The loss of bioluminescence response from immobilized A. fischeri bacterial cells corresponds to changes in the toxicity levels. The inhibition of the luminescent biosensor response collected at excitation and emission wavelengths of 287 ± 2 nm and 487 ± 2 nm, respectively, was found to be reproducible and repeatable within the relative standard deviation (RSD range of 2.4–5.7% (n = 8. The toxicity biosensor based on alginate micropsheres exhibited a lower limit of detection (LOD for Cu(II (6.40 μg/L, Cd(II (1.56 μg/L, Pb(II (47 μg/L, Ag(I (18 μg/L than Zn(II (320 μg/L, Cr(VI (1,000 μg/L, Co(II (1700 μg/L, Ni(II (2800 μg/L, and Fe(III (3100 μg/L. Such LOD values are lower when compared with other previous reported whole cell toxicity biosensors using agar gel, agarose gel and cellulose membrane biomatrices used for the immobilization of bacterial cells. The A. fischeri bacteria microencapsulated in alginate biopolymer could maintain their metabolic activity for a prolonged period of up to six weeks without any noticeable changes in the bioluminescence response. The bioluminescent biosensor could also be used for the determination of antagonistic toxicity levels for toxicant mixtures. A comparison of the results obtained by atomic absorption spectroscopy (AAS and using the proposed luminescent A. fischeri-based biosensor suggests that the optical toxicity biosensor can be used for quantitative microdetermination of heavy metal toxicity in environmental water samples.
Toxicity of aluminium in natural waters controlled by type rather than quantity of natural organic matter

International Nuclear Information System (INIS)

Papathanasiou, Grigorios; White, Keith N.; Walton, Rachel; Boult, Stephen

2011-01-01

Extension of the conditions under which Al toxicity is tested is required. Environmentally representative preparation of waters is used in investigating roles of alginate (AA) and humic acids (HA) in partitioning of Al (0.5 mg L -1 ), subsequent uptake and accumulation by and toxicity to Lymnaea stagnalis. HA and AA did not alter precipitation of Al(OH) 3 , but altered subsequent behaviour of Al. High (40 mg L -1 ) HA concentrations, and to a lesser extent AA, prevented settling and availability for benthic grazing but made deposited Al more likely to be ingested. HA detoxified but AA increased toxicity relative to Al alone. Low concentration (4 mg L -1 ) AA and HA do not change partitioning but increase uptake; they both detoxify, but AA less than HA. The study shows OC:Al ratio is critical in predicting Al behaviour in natural waters, also uptake is mediated by snail behaviour, not solely a function of concentration and form of Al. Therefore, predicting Al behaviour will be subject to errors in determining relevant water composition and response of biota to the new speciation. However, with respect to toxicity, rather than other aspects of Al behaviour, different ratios of HA and Al are insignificant compared to whether AA is present rather than HA. - Highlights: → Toxicity assessment in which environmental relevance is of primary concern. → Mass balance of Al monitored throughout the exposure period. → Al behaviour influenced by concentration of organic matter. → Strong dependence of toxicity on type rather than concentration of organic matter. → Toxicity is a function of Al behaviour but also animal behaviour.
Urgent need to reevaluate the latest World Health Organization guidelines for toxic inorganic substances in drinking water.

Science.gov (United States)

Frisbie, Seth H; Mitchell, Erika J; Sarkar, Bibudhendra

2015-08-13

The World Health Organization (WHO) has established guidelines for drinking-water quality that cover biological and chemical hazards from both natural and anthropogenic sources. In the most recent edition of Guidelines for Drinking-water Quality (2011), the WHO withdrew, suspended, did not establish, or raised guidelines for the inorganic toxic substances manganese, molybdenum, nitrite, aluminum, boron, nickel, uranium, mercury, and selenium. In this paper, we review these changes to the WHO drinking-water guidelines, examining in detail the material presented in the WHO background documents for each of these toxic substances. In some cases, these WHO background documents use literature reviews that do not take into account scientific research published within the last 10 or more years. In addition, there are instances in which standard WHO practices for deriving guidelines are not used; for example, rounding and other mathematical errors are made. According to published meeting reports from the WHO Chemical Aspects Working Group, the WHO has a timetable for revising some of its guidelines for drinking-water quality, but for many of these toxic substances the planned changes are minimal or will be delayed for as long as 5 years. Given the limited nature of the planned WHO revisions to the inorganic toxic substances and the extended timetable for these revisions, we suggest that governments, researchers, and other stakeholders might establish independent recommendations for inorganic toxic substances and possibly other chemicals to proactively protect public health, or at the very least, revert to previous editions of the Guidelines for Drinking-water Quality, which were more protective of public health.
Preparation of Zeolite/Zinc Oxide Nanocomposites for toxic metals removal from water

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Abdullah A. Alswata

Full Text Available This research work has proposed preparation of Zeolite/Zinc Oxide Nanocomposite (Zeolite/ZnO NCs by using a co-precipitation method. Then, the prepared Nanocomposite has been tested for adsorption of Lead Pb (II and Arsenic As (V from aqueous solution under the room pressure and temperature. After that, the prepared adsorbent has been studied by several techniques. For adsorption process; the effect of the adsorbent masses, contact time, PH and initial metals concentration as well as, the kinetics and isotherm for adsorption process have been investigated. The results revealed that; ZnO nanoparticles (NPs with average diameter 4.5 nm have successfully been loaded into Zeolite. The optimum parameters for the removal of the toxic metals 93% and 89% of Pb (II and As (V, respectively, in 100 mg/L aqua solutions were pH4, 0.15 g and 30 min. According to the obtained results; pseudo second-order kinetic and Langmuir isotherm model have higher correlation coefficients and provided a better agreement with the experimental data. The prepared sorbent showed an economical and effective way to remove the heavy toxic metals due to its ambient operation conditions, low- consumption energy and facile regeneration method. Keywords: Zeolite, ZnO, Nanocomposites, Adsorbent, Kinetic, Isotherm
Biochars made from agro-industrial by-products remove chlorine and lower water toxicity

Science.gov (United States)

Tzachristas, Andreas; Xirou, Maria; Manariotis, Ioannis D.; Dailianis, Stefanos; Karapanagioti, Hrissi K.

2016-04-01

Chlorination is the most common disinfection process for water and treated wastewater. For the industrial use of water in food production, chlorine can add undesired taste and odor to the final product. For this reason, dechlorination is desired for food industries that use municipal tap water. For treated wastewater discharge or reuse, chlorine can be toxic to the receiving aqueous systems and to the irrigated plants. In both the above cases, dechlorination is also required. Traditionally activated carbon has been used as the ideal material for the removal of chlorine. The main mechanisms that describe the interaction between activated carbon and HOCl or OCl- are described by the following equations (AWWA, 1990): HOCl + C* → C*O + H+ + Cl- (1), OCl- + C* → C*O + Cl- (2) Where C* and C*O represent the activated carbon surface and a surface oxide, respectively. The present study proposes the use of agro-industrial by-products for the production of biochars that will be used for dechlorination of tap-water used for food-industry production. Different raw materials such as malt spent rootlets, coffee residue, olive and grape seeds, etc. are used for the production of biochar. Various temperatures and air-to-solid ratios are tested for optimizing biochar production. Batch tests as well as a column test are employed to study the dechlorination efficiency and kinetics of the different raw and biochar materials as well as those of commercial activated carbons. As chlorine concentration increases the removal also increases linearily. After 1 and 24 hours of contact the chlorine relative removal efficiencies for the biochar made from olive seeds are 50 and 77 ± 4%, respectively. It seems that the removal kinetics are faster during the first hour; then, removal continues but with a slower rate. Most of the biochars tested (with 3 mg of solid in 20 mL of chlorine solution at initial concentration Co=1.5 mg/L) demonstrated removal efficiencies with an average of 9.4 ± 0
Does water chemistry affect the dietary uptake and toxicity of silver nanoparticles by the freshwater snail Lymnaea stagnalis?

International Nuclear Information System (INIS)

Oliver, Ana López-Serrano; Croteau, Marie-Noële; Stoiber, Tasha L.; Tejamaya, Mila; Römer, Isabella; Lead, Jamie R.; Luoma, Samuel N.

2014-01-01

Silver nanoparticles (AgNPs) are widely used in many applications and likely released into the aquatic environment. There is increasing evidence that Ag is efficiently delivered to aquatic organisms from AgNPs after aqueous and dietary exposures. Accumulation of AgNPs through the diet can damage digestion and adversely affect growth. It is well recognized that aspects of water quality, such as hardness, affect the bioavailability and toxicity of waterborne Ag. However, the influence of water chemistry on the bioavailability and toxicity of dietborne AgNPs to aquatic invertebrates is largely unknown. Here we characterize for the first time the effects of water hardness and humic acids on the bioaccumulation and toxicity of AgNPs coated with polyvinyl pyrrolidone (PVP) to the freshwater snail Lymnaea stagnalis after dietary exposures. Our results indicate that bioaccumulation and toxicity of Ag from PVP-AgNPs ingested with food are not affected by water hardness and by humic acids, although both could affect interactions with the biological membrane and trigger nanoparticle transformations. Snails efficiently assimilated Ag from the PVP-AgNPs mixed with diatoms (Ag assimilation efficiencies ranged from 82 to 93%). Rate constants of Ag uptake from food were similar across the entire range of water hardness and humic acid concentrations. These results suggest that correcting regulations for water quality could be irrelevant and ineffective where dietary exposure is important. - Highlights: • AgNP coated with polyvinyl pyrrolidone (PVP), PVP-AgNP were efficiently assimilated by Lymnaea stagnalis. • Water chemistry has no influence on the dietary uptake of PVP-AgNP by snails. - L. Stagnalis assimilated PVP-AgNPs efficiently from food and water chemistry had no influence on their uptake and toxicity
Effects of water chemistry and surface contact on the toxicity of silver nanoparticles to Bacillus subtilis.

Science.gov (United States)

Yi, Jun; Cheng, Jinping

2017-07-01

The growing use of silver nanoparticles (AgNPs) has created concerns about its potential impacts on natural microbial communities. In this study, the physicochemical properties of AgNPs and its toxicity on natural bacteria Bacillus subtilis (B. subtilis) were investigated in aqueous conditions. The characterization data showed that AgNPs highly aggregated in aqueous conditions, and the hydrodynamic diameter of AgNPs in aqueous conditions was larger than its primary size. The studied AgNPs was less toxic to B. subtilis in estuarine water as compared to that in Milli-Q water and artificial seawater, which might be due to the observed enhanced aggregation of AgNPs in estuarine water. The toxicity of AgNPs to B. subtilis was greatly reduced when their surface contact was blocked by a dialysis membrane. Scanning electron microscope images showed that exposure contact to AgNPs resulted in damage of the microbial cell wall and enhanced formation of fibrillar structures. These results suggest that particle-cell contact is largely responsible for the observed toxicity of AgNPs in B. subtilis. This study can help to understand the potential impacts of AgNPs to natural microbes, especially in the complex aquatic environments.
The Effect of Ambient Water Quality on Lakefront Property Values: Evidence from Coeur d'Alene, Idaho

Science.gov (United States)

Liao, H.

2015-12-01

Climate warming is causing water temperatures to increase and subsequent changes in water quality. To develop innovative approaches for mitigating the possible negative social consequences of such changes, more research efforts are needed to investigate how people perceive and respond to ambient water quality. This research examines the amenity value of water quality in the areas centered on Lake Coeur d'Alene of Northern Idaho. Through a hedonic analysis, we find that two important water-quality variables have had significant effects on lakefront property values, including Secchi disc reading, a technical measure of water clarity, and the presence of Eurasian watermilfoil, an aquatic invasive species. We further explore the spatial heterogeneity of water-quality benefits along the urban-rural gradient and find that access to urban amenities has strengthened the water-quality benefits in the lakefront housing market. Our findings could be used to incentivize private property owners and stakeholders to commit time and funding to cope with the potential degradation of water quality under climate change.
Toxic metals' concentration in water of Kriveljska Reka and its tributaries and influence of water there

International Nuclear Information System (INIS)

Lukic, D.; Zlatkovic, S.; Vuckovic, M.; Jovanovic, R.

2002-01-01

Kriveljska reka is near Bor, a big mining basin in East Serbia. This river is formed from two not so big rivers: Cerova reka and Valja Mare. Kriveljska reka flow past village Veliki Krivelj. Veliki Krivelj is one of the most important mining strip in Bor area. Therefore, Kriveljska reka is the reception for waste waters of some sections of Mining Basin Bor, situated on its banks. We will present to you concentrations of 7 toxic metals, pH-value and chemical oxygen demand in 8 points at Kriveljska reka and waste waters' influence on quality of this river's water. Based on our results, we can conclude that waste waters from Mining Basin Bor contaminate Kriveljska reka and at last we have a dead river. (author)
Trophic State and Toxic Cyanobacteria Density in Optimization Modeling of Multi-Reservoir Water Resource Systems

Directory of Open Access Journals (Sweden)

Andrea Sulis

2014-04-01

Full Text Available The definition of a synthetic index for classifying the quality of water bodies is a key aspect in integrated planning and management of water resource systems. In previous works [1,2], a water system optimization modeling approach that requires a single quality index for stored water in reservoirs has been applied to a complex multi-reservoir system. Considering the same modeling field, this paper presents an improved quality index estimated both on the basis of the overall trophic state of the water body and on the basis of the density values of the most potentially toxic Cyanobacteria. The implementation of the index into the optimization model makes it possible to reproduce the conditions limiting water use due to excessive nutrient enrichment in the water body and to the health hazard linked to toxic blooms. The analysis of an extended limnological database (1996–2012 in four reservoirs of the Flumendosa-Campidano system (Sardinia, Italy provides useful insights into the strengths and limitations of the proposed synthetic index.
Toxicity reduction for pharmaceuticals mixture in water by electron beam irradiation

International Nuclear Information System (INIS)

Boiani, Nathalia Fonseca; Tominaga, Flavio Kiyoshi; Borrely, Sueli Ivone

2015-01-01

The incorrect disposal of products is committing the environment quality once the aquatic environment is the main vehicle for dispersion of pollutants. Among the highlighted contaminants there are the pharmaceuticals, which are also released to the aquatic environment through the domestic sewage, hospitals and effluents. The monitoring of these pharmaceuticals in the environment has grown, showing many of them as persistent pollutants. Pharmaceuticals from different therapeutic classes have been detected in domestic sewage, surface water and groundwater around the world. Several studies evidenced Fluoxetine Hydrochloride residues in waters. Another important product is the Propranolol, used for heart disease treatments as far as fluoxetine is applied for treating mental diseases. The objective of this study was to apply the radiation processing for the abatement of pollutant in waters. Electron beam accelerator was used during irradiation of the mixture (Propranolol + Fluoxetine Hydrochloride) in aqueous solution. Acute toxicity assays were carried out for Vibrio fischeri marine bacterium, 15 minutes exposure. The results showed that irradiation (2.5kGy and 5.0kGy) enhanced the average effective concentration of the mixture, which means reduction of toxicity (56.34%, 55.70% respectively). Inverse effect was obtained with 7.5 kGy and 10 kGy. (author)
Toxicity reduction for pharmaceuticals mixture in water by electron beam irradiation

Energy Technology Data Exchange (ETDEWEB)

Boiani, Nathalia Fonseca; Tominaga, Flavio Kiyoshi; Borrely, Sueli Ivone, E-mail: flavio_tominaga@hotmail.com, E-mail: sborrely@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

The incorrect disposal of products is committing the environment quality once the aquatic environment is the main vehicle for dispersion of pollutants. Among the highlighted contaminants there are the pharmaceuticals, which are also released to the aquatic environment through the domestic sewage, hospitals and effluents. The monitoring of these pharmaceuticals in the environment has grown, showing many of them as persistent pollutants. Pharmaceuticals from different therapeutic classes have been detected in domestic sewage, surface water and groundwater around the world. Several studies evidenced Fluoxetine Hydrochloride residues in waters. Another important product is the Propranolol, used for heart disease treatments as far as fluoxetine is applied for treating mental diseases. The objective of this study was to apply the radiation processing for the abatement of pollutant in waters. Electron beam accelerator was used during irradiation of the mixture (Propranolol + Fluoxetine Hydrochloride) in aqueous solution. Acute toxicity assays were carried out for Vibrio fischeri marine bacterium, 15 minutes exposure. The results showed that irradiation (2.5kGy and 5.0kGy) enhanced the average effective concentration of the mixture, which means reduction of toxicity (56.34%, 55.70% respectively). Inverse effect was obtained with 7.5 kGy and 10 kGy. (author)
Assessment of acute toxicity of water soluble fraction of diesel on ...

African Journals Online (AJOL)

Acute toxicity of water soluble fraction (WSF) of diesel fuel was assessed by evaluating its effects on growth of two marine microalgae, Isochrysis and Chaetoceros. Pure cultures of each of the two microalgae were exposed to concentrations of 0% (controls), 5%, 10%, 15% and 20% of diesel WSF (in triplicates) and allowed ...
Water hardness reduces the accumulation and toxicity of uranium in a freshwater macrophyte (Ceratophyllum demersum)

Energy Technology Data Exchange (ETDEWEB)

Markich, Scott J., E-mail: smarkich@optusnet.com.au

2013-01-15

There is a lack of good quality data and mechanistic understanding on the effects of true water hardness (calcium (Ca) and magnesium (Mg)) on the bioavailability and toxicity of uranium (U) to freshwater biota. This study determined the effect of true water hardness (20, 75, 150, 275 and 400 mg CaCO{sub 3} L{sup −1}) on the cell surface binding affinity (log K), accumulation and toxicity (growth inhibition) of U in a submerged, rootless, macrophyte (Ceratophyllum demersum) in a synthetic freshwater with constant alkalinity (13 mg CaCO{sub 3} L{sup −1}) and pH (6.2) over 7 days. A 20-fold increase in water hardness resulted in a 4-fold decrease in U toxicity (median effect concentration (EC50) = 134 μg L{sup −1} U at 20 mg CaCO{sub 3} L{sup −1} hardness, increasing to 547 μg L{sup −1} U at 400 mg CaCO{sub 3} L{sup −1} hardness), cell surface binding affinity (log K = 6.25 at 20 mg CaCO{sub 3} L{sup −1} hardness, decreasing to log K = 5.64 at 400 mg CaCO{sub 3} L{sup −1} hardness) and accumulation (the concentration factor decreased from 63 at 20 mg CaCO{sub 3} L{sup −1} hardness to 15 at 400 mg CaCO{sub 3} L{sup −1} hardness) of U. Calcium provided a 4-fold greater protective effect against U accumulation and toxicity compared to Mg. Speciation calculations indicated negligible differences in the percentages of key U species (UO{sub 2}{sup 2+}, UO{sub 2}OH{sup +}, UO{sub 2}(OH){sub 2}) over the range of water hardness tested. The inhibition of U binding at the cell surface, and subsequent uptake, by C. demersum, with increasing Ca and/or Mg concentration, may be explained in terms of (i) competition between Ca{sup 2+}/Mg{sup 2+} and UO{sub 2}{sup 2+} (and/or UO{sub 2}OH{sup +}) for physiologically active sites at the cell surface, and/or (ii) reduced negative charge (electrical potential) at the cell surface, resulting in a decrease in the activity of UO{sub 2}{sup 2+} (and/or UO{sub 2}OH{sup +}) at the plant/water interface (boundary layer
Vegetated Treatment Systems for Removing Contaminants Associated with Surface Water Toxicity in Agriculture and Urban Runoff.

Science.gov (United States)

Anderson, Brian S; Phillips, Bryn M; Voorhees, Jennifer P; Cahn, Michael

2017-05-15

Urban stormwater and agriculture irrigation runoff contain a complex mixture of contaminants that are often toxic to adjacent receiving waters. Runoff may be treated with simple systems designed to promote sorption of contaminants to vegetation and soils and promote infiltration. Two example systems are described: a bioswale treatment system for urban stormwater treatment, and a vegetated drainage ditch for treating agriculture irrigation runoff. Both have similar attributes that reduce contaminant loading in runoff: vegetation that results in sorption of the contaminants to the soil and plant surfaces, and water infiltration. These systems may also include the integration of granulated activated carbon as a polishing step to remove residual contaminants. Implementation of these systems in agriculture and urban watersheds requires system monitoring to verify treatment efficacy. This includes chemical monitoring for specific contaminants responsible for toxicity. The current paper emphasizes monitoring of current use pesticides since these are responsible for surface water toxicity to aquatic invertebrates.

Does water chemistry affect the dietary uptake and toxicity of silver nanoparticles by the freshwater snail Lymnaea stagnalis?

Science.gov (United States)

López-Serrano Oliver, Ana; Croteau, Marie-Noële; Stoiber, Tasha L.; Tejamaya, Mila; Römer, Isabella; Lead, Jamie R.; Luoma, Samuel N.

2014-01-01

Silver nanoparticles (AgNPs) are widely used in many applications and likely released into the aquatic environment. There is increasing evidence that Ag is efficiently delivered to aquatic organisms from AgNPs after aqueous and dietary exposures. Accumulation of AgNPs through the diet can damage digestion and adversely affect growth. It is well recognized that aspects of water quality, such as hardness, affect the bioavailability and toxicity of waterborne Ag. However, the influence of water chemistry on the bioavailability and toxicity of dietborne AgNPs to aquatic invertebrates is largely unknown. Here we characterize for the first time the effects of water hardness and humic acids on the bioaccumulation and toxicity of AgNPs coated with polyvinyl pyrrolidone (PVP) to the freshwater snail Lymnaea stagnalis after dietary exposures. Our results indicate that bioaccumulation and toxicity of Ag from PVP-AgNPs ingested with food are not affected by water hardness and by humic acids, although both could affect interactions with the biological membrane and trigger nanoparticle transformations. Snails efficiently assimilated Ag from the PVP-AgNPs mixed with diatoms (Ag assimilation efficiencies ranged from 82 to 93%). Rate constants of Ag uptake from food were similar across the entire range of water hardness and humic acid concentrations. These results suggest that correcting regulations for water quality could be irrelevant and ineffective where dietary exposure is important.
Toxicity of copper to the marine amphipod Allorchestes compressa in the presence of water- and lipid-soluble ligands

Energy Technology Data Exchange (ETDEWEB)

Ahsanullah, M; Florence, T M

1984-12-01

Acute toxicity tests were carried out on the marine amphipod Allorchestes compressa Dana using copper sulfate and some organocopper complexes. For copper sulfate, 96 h LC50 values of 0.11 and 0.5 mg Cu/liter were determined for the juveniles and the adults, respectively. Juveniles were about 4.5 times more sensitive to copper than adults Organocopper complexes were tested on adults only. The three water soluble ligands nitrotriacetic acid, 8-hydroxyquinoline-5-sulfoic acid and tannic acid ameliorated copper toxicity by decreasing the concentration of free ionic copper while lipid-soluble ligands such as oxine and potassium ethylxanthogenate increased copper toxicity, presumably as a result of the complexes diffusing through the cell membrane and participating in injurious reaction. The copper complex with 2,9-dimethyl-1,10-phenanthroline was the most toxic complex tested. It is suggested that the presence of these ligands in the receiving water should be taken into consideration when establishing water quality criteria. 19 references, 2 figures, 3 tables.
In situ and laboratory bioassays with Chironomus riparius larvae to assess toxicity of metal contamination in rivers: the relative toxic effect of sediment versus water contamination.

Science.gov (United States)

Faria, Mafalda S; Lopes, Ricardo J; Nogueira, António J A; Soares, Amadeu M V M

2007-09-01

We used bioassays employing head capsule width and body length increase of Chironomus riparius larvae as end points to evaluate metal contamination in streams. Bioassays were performed in situ near an abandoned Portuguese goldmine in the spring of 2003 and 2004. Bioassays also were performed under laboratory conditions with water and sediment collected from each stream to verify if laboratory bioassays could detect in situ toxicity and to evaluate the relative contribution of sediment and water to overall toxicity. We used field sediments with control water and control sediments with field water to discriminate between metal contamination in water and sediment. Field water with dry and sieved, organic matter-free, and nontreated sediments was used to determine the toxicity of heavy metals that enter the organism through ingested material. In both in situ and laboratory bioassays, body length increase was significantly inhibited by metal contamination, whereas head capsule width was not affected. Body length increase was more affected by contaminated sediment compared to contaminated water. The lowest-effect level of heavy metals was observed in the dry and sieved sediment that prevented ingestion of sediment particles by larvae. These results suggest that body length increase of C. riparius larvae can be used to indicate the impact of metal contamination in rivers. Chironomus riparius larvae are more affected by heavy metals that enter the organism through ingested sediment than by heavy metals dissolved in the water column. Nevertheless, several factors, such as the particle size and organic matter of sediment, must be taken into account.
Interaction and dynamics of ambient water adlayers on graphite probed using AFM voltage nanolithography and electrostatic force microscopy

International Nuclear Information System (INIS)

Gowthami, T; Raina, Gargi; Kurra, Narendra

2014-01-01

In this work, we report the impact of the interaction and dynamics of increasing ambient water adlayers on etch patterns on a hydrophobic highly oriented pyrolytic graphite (HOPG) surface obtained using atomic force microscopy (AFM) voltage nanolithography in contact mode by applying a positive bias to the sample. The changes in the dimensions of the etch patterns were investigated as a function of the increasing number of water adlayers present on the HOPG, which is varied by changing the time interval since HOPG cleavage. Changes in the width of the etch patterns and the surrounding water droplets were monitored with time, using intermittent-contact-mode AFM. Electrostatic force microscopy (EFM) has been employed to study the charged nature of the etch patterns and the neighboring water film with time. The width of the etch patterns made on freshly cleaved HOPG shows an increase of ∼33% over 48 h, whereas nine-day-old cleaved HOPG shows a 79% increase over the same period. No changes in the dimensions are observed while imaging in a nitrogen atmosphere soon after lithography. In ambient conditions, the EFM phase shift of the patterns shows a large change of ∼84–88% over 30 h. This study demonstrates the effect of the stored electrostatic energy of a polarized ice-like water adlayer, resulting in changes in the dimensions of the etch patterns long after lithography, whereas liquid-like water droplets do not affect the etch patterns. (paper)
Toxicity studies of the water extract from the calyces of Hibiscus ...

African Journals Online (AJOL)

Acute and chronic toxicities of the water extract from calyces of Hibiscus sabdariffa were studied in male and female rats. After 14 days of a single oral administration of test substance 5,000 mg/kg body weight, measurement of the body and organ weights, necropsy and health monitoring were performed. No signs and ...
Sediment and toxic contaminant transport modeling in coastal waters

International Nuclear Information System (INIS)

Onishi, Yasuo; Mayer, D.W.; Argo, R.S.

1982-01-01

Models are presented to estimate the migration of toxic contaminants in coastal waters. Ocean current is simulated by the vertically-averaged, finite element, two-demensional model known as CAFE-I with the Galerkin weighted residual technique. The refraction of locally generated waves or swells is simulated by the wave refraction model, LO3D. Using computed current, depth, and wave characteristics, the finite element model, FETRA, simulated sediment and contaminant transport in coastal waters, estuaries and rivers. Prior to the application of these models to the Irish Sea and other coastal waters, the finite element model, FETRA, was tested to demonstrate its ability to simulate sediment and contaminant interaction, and the mechanism governing the transport, deposition, and resuspension of contaminated sediment. Several simple equations such as the unsteady, advection-diffusion equation, the equation for noncohesive-sediment load due to wind-induced waves in offshore and surf zones, and the equation for sediment-radionuclide transport simulation were solved during the preliminary testing of the model. (Kato, T.)
Toxicity of fluoride to aquatic species and evaluation of toxicity modifying factors.

Science.gov (United States)

Pearcy, Krysta; Elphick, James; Burnett-Seidel, Charlene

2015-07-01

The present study was performed to investigate the toxicity of fluoride to a variety of freshwater aquatic organisms and to establish whether water quality variables contribute substantively to modifying its toxicity. Water hardness, chloride, and alkalinity were tested as possible toxicity modifying factors for fluoride using acute toxicity tests with Hyalella azteca and Oncorhynchus mykiss. Chloride appeared to be the major toxicity modifying factor for fluoride in these acute toxicity tests. The chronic toxicity of fluoride was evaluated with a variety of species, including 3 fish (Pimephales promelas, O. mykiss, and Salvelinus namaycush), 3 invertebrates (Ceriodaphnia dubia, H. azteca, and Chironomus dilutus), 1 plant (Lemna minor), and 1 alga (Pseudokirchneriella subcapitata). Hyalella azteca was the most sensitive species overall, and O. mykiss was the most sensitive species of fish. The role of chloride as a toxicity modifying factor was inconsistent between species in the chronic toxicity tests. © 2015 SETAC.
Amelioration of chronic fluoride toxicity by calcium and fluoride-free water in rats.

Science.gov (United States)

Shankar, Priyanka; Ghosh, Sudip; Bhaskarachary, K; Venkaiah, K; Khandare, Arjun L

2013-07-14

The study was undertaken to explore the amelioration of chronic fluoride (F) toxicity (with low and normal Ca) in rats. The study was conducted in two phases. In phase I (6 months), seventy-six Wistar, weanling male rats were assigned to four treatment groups: normal-Ca (0·5 %) diet (NCD), Ca+F - ; low-Ca (0·25 %) diet (LCD), Ca - F - ; NCD +100 parts per million (ppm) F water, Ca+F+; LCD +100 ppm F water, Ca - F+. In phase II (reversal experiment, 3 months), LCD was replaced with the NCD. Treatment groups Ca+F+ and Ca - F+ were divided into two subgroups to compare the effect of continuation v. discontinuation along with Ca supplementation on reversal of chronic F toxicity. In phase I, significantly reduced food efficiency ratio (FER), body weight gain (BWG), faecal F excretion, serum Ca and increased bone F deposition were observed in the treatment group Ca - F+. Reduced serum 25-hydroxy-vitamin D3, increased 1,25-dihydroxy-vitamin D3 and up-regulation of Ca-sensing receptor, vitamin D receptor and S100 Ca-binding protein G (S100G) were observed in treatment groups Ca - F - and Ca - F+. In phase II (reversal phase), FER, BWG and serum Ca in treatment groups Ca - F+/Ca+F - and Ca - F+/Ca+F+ were still lower, as compared with other groups. However, other variables were comparable. Down-regulation of S100G was observed in F-fed groups (Ca+F+/Ca+F+ and Ca - F+/Ca+F+) in phase II. It is concluded that low Ca aggravates F toxicity, which can be ameliorated after providing adequate Ca and F-free water. However, chronic F toxicity can interfere with Ca absorption by down-regulating S100G expression irrespective of Ca nutrition.
Integrating the fish embryo toxicity test as triad element for sediment toxicity assessment based on the water framework directive approach

Energy Technology Data Exchange (ETDEWEB)

Bartzke, Mariana [Dept. Aquatic Ecotoxicology, Goethe Univ. Frankfurt am Main (Germany); Gobio GmbH, Aarbergen/Kettenbach (Germany); Dept. Bioanalytical Ecotoxicology, Helmholtz Centre for Environmental Research, UFZ, Leipzig (Germany); Delov, Vera [Dept. Aquatic Ecotoxicology, Goethe Univ. Frankfurt am Main (Germany); Gobio GmbH, Aarbergen/Kettenbach (Germany); Ecotoxicology, Fraunhofer Inst. for Molecular Biology and Applied Ecology IME, Aachen (Germany); Stahlschmidt-Allner, Petra; Allner, Bernhard [Gobio GmbH, Aarbergen/Kettenbach (Germany); Oehlmann, Joerg [Dept. Aquatic Ecotoxicology, Goethe Univ. Frankfurt am Main (Germany)

2010-04-15

Purpose: The objective of this study was to complement analyses according to the European Union Water Framework Directive (WFD) with a sediment toxicity analysis as part of an integrated river assessment. To this end, Hessian water courses were analyzed using the sediment quality triad concept according to Chapman with chemical analyses, in situ effect evaluations, and ecotoxicological assessments. For the ecotoxicological assessment (fish embryo toxicity test with Danio rerio), a new evaluation scheme was developed, the fish teratogenicity index (FTI), that allows for a classification of sediments into ecological quality classes compliant to the WFD. Materials and methods sediment and macrozoobenthos samples were taken from tributaries of the rivers Fulda and Lahn. Sediments were characterized regarding particle size, carbon, heavy metals, and polyaromatic hydrocarbon content. Macroinvertebrate samples were taken via multi-habitat sampling. The fish embryo toxicity test with D. rerio was conducted as a contact assay on the basis of DIN 38415-6. Results and discussion The integrated assessment indicated a significant influence of heavy metals and carbon content on macroinvertebrate communities. The bioaccessibility of sediment pollutants were clearly demonstrated by the FTI, which showed a wide range of adverse effects. A significant linear relationship between metals and the FTI was detected. However, there was no statistically significant evidence that macroinvertebrate communities were affected by the hydromorphological quality clements at the sampling sites. Conclusions The new scheme for the assessment of fish embryo toxicity test was successfully applied. The results suggest that sediment compounds impact macroinvertebrate communities and early development of fish. It demonstrates that the quality of sediments should be evaluated on a routine basis as part of an integrated river assessment. (orig.)
Disturbances to metal partitioning during toxicity testing of iron(II)-rich estuarine pore waters and whole sediments.

Science.gov (United States)

Simpson, Stuart L; Batley, Graeme E

2003-02-01

Metal partitioning is altered when suboxic estuarine sediments containing Fe(II)-rich pore waters are disturbed during collection, preparation, and toxicity testing. Experiments with model Fe(II)-rich pore waters demonstrated the rates at which adsorptive losses of Cd, Cu, Ni, Mn, Pb, and Zn occur upon exposure to air. Experiments with Zn-contaminated estuarine sediments demonstrated large and often unpredictable changes to metal partitioning during sediment storage, removal of organisms, and homogenization before testing. Small modifications to conditions, such as aeration of overlying waters, caused large changes to the metal partitioning. Disturbances caused by sediment collection required many weeks for reestablishment of equilibrium. Bioturbation by benthic organisms led to oxidation of pore-water Fe(II) and lower Zn fluxes because of the formation of Fe hydroxide precipitates that adsorb pore-water Zn. For five weeks after the addition of organisms to sediments, Zn fluxes increased slowly as the organisms established themselves in the sediments, indicating that the establishment of equilibrium was not rapid. The results are discussed in terms of the dynamic nature of suboxic, Fe(II)-rich estuarine sediments, how organisms perturb their environment, and the importance of understanding chemistry in toxicity testing with whole sediments or pore water. Recommendations are provided for the handling of sediments for toxicity testing.
Biosorption and toxicity responses to arsenite (As[III]) in Scenedesmus quadricauda.

Science.gov (United States)

Zhang, Jianying; Ding, Tengda; Zhang, Chunlong

2013-08-01

Toxicity and biosorption responses to arsenite (As[III]) were examined in a 96-h exposure study using Scenedesmus quadricauda, one of the most popular green algae distributed in freshwaters in China. Results indicated that the pH-dependent distribution of two arsenite species (H2AsO3(-) and H3AsO3) played an important role in biosorption and toxicity. The undissociated H3AsO3 was more toxic than its monoanionic H2AsO3(-) through comparison of algal cell numbers, chlorophyll-a contents, and algal ultrastructural changes observed with transmission electron microscopy. An effective biosorption of 89.0mgg(-1) at 100mgL(-1) As[III] was found in the treatments with an initial pH of 9.3 and 25.2μgg(-1) at 0.03mgL(-1) As[III] at an initial pH of 8.2 as a result of the predominant species of H2AsO3(-) under the ambient pH and Eh conditions. Our results imply that S. quadricauda may provide a new means for the removal of toxic arsenite species present in contaminated surface water. Copyright © 2013 Elsevier Ltd. All rights reserved.
Toxicity of silicon carbide nanowires to sediment-dwelling invertebrates in water or sediment exposures

Science.gov (United States)

Mwangi, Joseph N.; Wang, Ning; Ritts, Andrew; Kunz, James L.; Ingersoll, Christopher G.; Li, Hao; Deng, Baolin

2011-01-01

Silicon carbide nanowires (SiCNW) are insoluble in water. When released into an aquatic environment, SiCNW would likely accumulate in sediment. The objective of this study was to assess the toxicity of SiCNW to four freshwater sediment-dwelling organisms: amphipods (Hyalella azteca), midges (Chironomus dilutus), oligochaetes (Lumbriculus variegatus), and mussels (Lampsilis siliquoidea). Amphipods were exposed to either sonicated or nonsonicated SiCNW in water (1.0 g/L) for 48 h. Midges, mussels, and oligochaetes were exposed only to sonicated SiCNW in water for 96 h. In addition, amphipods were exposed to sonicated SiCNW in whole sediment for 10 d (44% SiCNW on dry wt basis). Mean 48-h survival of amphipods exposed to nonsonicated SiCNW in water was not significantly different from the control, whereas mean survival of amphipods exposed to sonicated SiCNW in two 48-h exposures (0 or 15% survival) was significantly different from the control (90 or 98% survival). In contrast, no effect of sonicated SiCNW was observed on survival of midges, mussels, or oligochaetes. Survival of amphipods was not significantly reduced in 10-d exposures to sonicated SiCNW either mixed in the sediment or layered on the sediment surface. However, significant reduction in amphipod biomass was observed with the SiCNW either mixed in sediment or layered on the sediment surface, and the reduction was more pronounced for SiCNW layered on the sediment. These results indicated that, under the experimental conditions, nonsonicated SiCNW in water were not acutely toxic to amphipods, sonicated SiCNW in water were acutely toxic to the amphipods, but not to other organisms tested, and sonicated SiCNW in sediment affected the growth but not the survival of amphipods.
Analysis of 'wet-landscape' surface water fractions using medaka embryo-toxicity bioassay

Energy Technology Data Exchange (ETDEWEB)

Peters, L. E.; McConkey, B. J.; Vanden Heuvel, M. R. (Waterloo, Univ., Dept, of Biology, Waterloo, ON (Canada)); MacKinnon, M. D. (Syncrude Canada Ltd., Fort McMurray, AB (Canada)) Munkittricx, K. (Environment Canada, Burlington, ON (Canada))

1998-01-01

The self-sustaining biological potential of Syncrude's 'wetland-scape' waste disposal method was evaluated by testing water extracts from experimental pits of different ages and fine tailings/natural water compositions. This waste disposal method involves capping fine tailings with a layer of surface water. Preliminary estimates suggests a higher incidence of mortality and deformity in Japanese Medaka embryos incubated in pit waters containing elevated concentrations of naphthenates. Another study on adult perch stocked in the demonstration pit indicated the presence of PAHs in the fish bile at biologically relevant concentrations. This study was designed to determine the causative agents of the fish embryo toxicity and the level of concentrations at which chronic effects occur. The water extracts were fractionated into acid (containing naphthenates) and base-neutral (containing PAHs) components and tested using the Japanese Medaka bioassay. Endpoints measured were the presence of deformity, hatch success, swim-bladder inflation, length at hatch and time to mortality. HPLC analysis showed that PAHs were present at concentrations in the part/billion and the parts/million range. This is being taken as an indication that PAHs are not directly responsible for the observed toxicity to the embryos.
TIC-Tox: A preliminary discussion on identifying the forcing agents of DBP-mediated toxicity of disinfected water.

Science.gov (United States)

Plewa, Michael J; Wagner, Elizabeth D; Richardson, Susan D

2017-08-01

The disinfection of drinking water is a major public health achievement; however, an unintended consequence of disinfection is the generation of disinfection by-products (DBPs). Many of the identified DBPs exhibit in vitro and in vivo toxicity, generate a diversity of adverse biological effects, and may be hazards to the public health and the environment. Only a few DBPs are regulated by several national and international agencies and it is not clear if these regulated DBPs are the forcing agents that drive the observed toxicity and their associated health effects. In this study, we combine analytical chemical and biological data to resolve the forcing agents associated with mammalian cell cytotoxicity of drinking water samples from three cities. These data suggest that the trihalomethanes (THMs) and haloacetic acids may be a small component of the overall cytotoxicity of the organic material isolated from disinfected drinking water. Chemical classes of nitrogen-containing DBPs, such as the haloacetonitriles and haloacetamides, appear to be the major forcing agents of toxicity in these samples. These findings may have important implications for the design of epidemiological studies that primarily rely on the levels of THMs to define DBP exposure among populations. The TIC-Tox approach constitutes a beginning step in the process of identifying the forcing agents of toxicity in disinfected water. Copyright © 2017. Published by Elsevier B.V.
Toxicity of diesel water accommodated fraction toward microalgae, Pseudokirchneriella subcapitata and Chlorella sp. MM3.

Science.gov (United States)

Ramadass, Kavitha; Megharaj, Mallavarapu; Venkateswarlu, Kadiyala; Naidu, Ravi

2017-08-01

Diesel is a commonly used fuel and a key pollutant on water surface through leaks and accidental spills, thus creating risk directly to planktons as well as other aquatic organisms. We assessed the toxicty of diesel and its water accommodated fraction (WAF) towards two microalgal species, Pseudokirchneriella subcapitata and Chlorella sp. MM3. The toxicity criteria included were: chlorophyll a content as a growth parameter and induction of enzyme activities linked to oxidative stress. Increase in concentrations of diesel or its WAF significantly increased toxicity towards growth, measured in terms of chlorophyll a content in both the algae. Activities of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POX) and catalase (CAT) in response to addition of diesel or diesel WAF to the microalgal cultures were dose-dependent. Diesel WAF was more toxic than diesel itself, suggesting that use of WAF may be more relevant for environmental risk assessment of diesel. The overall response of the antioxidant enzymes to toxicants' stress followed the order: POX≥SOD>CAT. The present study clearly demonstrated the use of SOD, POX and CAT as suitable biomarkers for assessing diesel pollution in aquatic ecosystem. Copyright © 2017 Elsevier Inc. All rights reserved.
Ambient Space and Ambient Sensation

DEFF Research Database (Denmark)

Schmidt, Ulrik

The ambient is the aesthetic production of the sensation of being surrounded. As a concept, 'ambient' is mostly used in relation to the music genre 'ambient music' and Brian Eno's idea of environmental background music. However, the production of ambient sensations must be regarded as a central...... aspect of the aesthetization of modern culture in general, from architecture, transport and urbanized lifeforms to film, sound art, installation art and digital environments. This presentation will discuss the key aspects of ambient aesthetization, including issues such as objectlessness...
A comparative assessment of the acute inhalation toxicity of vanadium compounds.

Science.gov (United States)

Rajendran, N; Seagrave, J C; Plunkett, L M; MacGregor, J A

2016-11-01

Vanadium compounds have become important in industrial processes, resulting in workplace exposure potential and are present in ambient air as a result of fossil fuel combustion. A series of acute nose-only inhalation toxicity studies was conducted in both rats and mice in order to obtain comparative data on the acute toxicity potential of compounds used commercially. V 2 O 3 , V 2 O 4 , and V 2 O 5 , which have different oxidation states (+3, +4, +5, respectively), were delivered as micronized powders; the highly water-soluble and hygroscopic VOSO 4 (+4) could not be micronized and was instead delivered as a liquid aerosol from an aqueous solution. V 2 O 5 was the most acutely toxic micronized powder in both species. Despite its lower overall percentage vanadium content, a liquid aerosol of VOSO 4 was more toxic than the V 2 O 5 particles in mice, but not in rats. These data suggest that an interaction of characteristics, i.e., bioavailability, solubility and oxidation state, as well as species sensitivity, likely affect the toxicity potential of vanadium compounds. Based on clinical observations and gross necropsy findings, the lung appeared to be the target organ for all compounds. The level of hazard posed will depend on the specific chemical form of the vanadium. Future work to define the inhalation toxicity potential of vanadium compounds of various oxidation states after repeated exposures will be important in understanding how the physico-chemical and biological characteristics of specific vanadium compounds interact to affect toxicity potential and the potential risks posed to human health.
The impact of iodinated X-ray contrast agents on formation and toxicity of disinfection by-products in drinking water.

Science.gov (United States)

Jeong, Clara H; Machek, Edward J; Shakeri, Morteza; Duirk, Stephen E; Ternes, Thomas A; Richardson, Susan D; Wagner, Elizabeth D; Plewa, Michael J

2017-08-01

The presence of iodinated X-ray contrast media (ICM) in source waters is of high concern to public health because of their potential to generate highly toxic disinfection by-products (DBPs). The objective of this study was to determine the impact of ICM in source waters and the type of disinfectant on the overall toxicity of DBP mixtures and to determine which ICM and reaction conditions give rise to toxic by-products. Source waters collected from Akron, OH were treated with five different ICMs, including iopamidol, iopromide, iohexol, diatrizoate and iomeprol, with or without chlorine or chloramine disinfection. The reaction product mixtures were concentrated with XAD resins and the mammalian cell cytotoxicity and genotoxicity of the reaction mixture concentrates was measured. Water containing iopamidol generated an enhanced level of mammalian cell cytotoxicity and genotoxicity after disinfection. While chlorine disinfection with iopamidol resulted in the highest cytotoxicity overall, the relative iopamidol-mediated increase in toxicity was greater when chloramine was used as the disinfectant compared with chlorine. Four other ICMs (iopromide, iohexol, diatrizoate, and iomeprol) expressed some cytotoxicity over the control without any disinfection, and induced higher cytotoxicity when chlorinated. Only iohexol enhanced genotoxicity compared to the chlorinated source water. Copyright © 2017. Published by Elsevier B.V.
Toxicity of methylmercury injected into eggs when dissolved in water versus corn oil

Science.gov (United States)

Heinz, G.H.; Hoffman, D.J.; Klimstra, J.D.; Stebbins, K.R.; Kondrad, S.L.

2011-01-01

In a previous study, the embryotoxicity of methylmercury dissolved in corn oil was compared among 26 species of birds. Corn oil is not soluble in the water-based matrix that constitutes the albumen of an egg. To determine whether the use of corn oil limited the usefulness of this earlier study, a comparison was made of the embryotoxicity of methylmercury dissolved in corn oil versus water. Mallard (Anas platyrhynchos) and chicken (Gallus gallus) eggs were injected with methylmercury chloride dissolved in corn oil or water to achieve concentrations of 0, 0.2, 0.4, 0.8, and 1.6??g/g mercury in the egg on a wet weight basis. Hatching success at each dose of mercury was compared between the two solvents. For mallards, 16.4% of the eggs injected with 1.6??g/g mercury dissolved in water hatched, which was statistically lower than the 37.6% hatch rate of eggs injected with 1.6??g/g mercury dissolved in corn oil, but no differences in hatching success were observed between corn oil and water at any of the other doses. With chicken eggs, no significant differences occurred in percentage hatch of eggs between corn oil and water at any of the mercury doses. Methylmercury dissolved in corn oil seems to have a toxicity to avian embryos similar to that of does methylmercury dissolved in water. Consequently, the results from the earlier study that described the toxicity of methylmercury dissolved in corn oil to avian embryos were probably not compromised by the use of corn oil as a solvent. ?? 2011 SETAC.
Setting priorities for ambient air quality objectives

International Nuclear Information System (INIS)

2004-10-01

Alberta has ambient air quality objectives in place for several pollutants, toxic substances and other air quality parameters. A process is in place to determine if additional air quality objectives are required or if existing objectives should be changed. In order to identify the highest priority substances that may require an ambient air quality objective to protect ecosystems and public health, a rigorous, transparent and cost effective priority setting methodology is required. This study reviewed, analyzed and assessed successful priority setting techniques used by other jurisdictions. It proposed an approach for setting ambient air quality objective priorities that integrates the concerns of stakeholders with Alberta Environment requirements. A literature and expert review were used to examine existing priority-setting techniques used by other jurisdictions. An analysis process was developed to identify the strengths and weaknesses of various techniques and their ability to take into account the complete pathway between chemical emissions and damage to human health or the environment. The key strengths and weaknesses of each technique were identified. Based on the analysis, the most promising technique was the tool for the reduction and assessment of chemical and other environmental impacts (TRACI). Several considerations for using TRACI to help set priorities for ambient air quality objectives were also presented. 26 refs, 8 tabs., 4 appendices

STUDY ON REMOVAL OF TOXIC METALS FROM WATER USING BIOMATERIALS USING AS AN ADSORBENTS

OpenAIRE

R. S. Dubey*, Triptaran Kaur

2017-01-01

In today’s date when we talk about purity of things nothing can be placed in the category of being pure. From air to water to soil to food everything is polluted. Pollution can be defined as presence of inappropriate material which may cause harm to living beings. Here we talked about the contaminated water and find out the harmful ingredients present in it. I have studied the presence of toxic metals like copper, cadmium and chromium in our water. Water being the most essential part of once ...
Effects of Cd and Ni toxicity to Ceratophyllum demersum under environmentally relevant conditions in soft and hard water including a German lake

Energy Technology Data Exchange (ETDEWEB)

Andresen, Elisa, E-mail: Elisa.Andresen@uni-konstanz.de [University of Konstanz, Department of Biology, D-78457 Konstanz (Germany); Opitz, Judith, E-mail: Daniela.Opitz@uni-konstanz.de [University of Konstanz, Department of Biology, D-78457 Konstanz (Germany); Thomas, George, E-mail: George.Thomas@uni-konstanz.de [University of Konstanz, Department of Biology, D-78457 Konstanz (Germany); Stärk, Hans-Joachim, E-mail: Ha-Jo.Staerk@ufz.de [UFZ – Helmholtz Centre for Environmental Research, Department of Analytical Chemistry, Permoserstr. 15, D-04318 Leipzig (Germany); Dienemann, Holger, E-mail: Holger.Dienemann@smul.sachsen.de [Saxon State Company for Environment and Agriculture, Business Domain 5 (Laboratory), Department 53, Bitterfelder Str. 25, D-04849 Bad Düben (Germany); Jenemann, Kerstin, E-mail: Kerstin.Jenemann@smul.sachsen.de [Sächsisches Landesamt für Umwelt, Landwirtschaft und Geologie, Abteilung Wasser, Boden, Wertstoffe, Zur Wetterwarte 11, D-01109 Dresden (Germany); Dickinson, Bryan C., E-mail: Bryan.Dickinson@gmail.com [Harvard University, Department of Chemistry and Chemical Biology, 12 Oxford Street, Cambridge, MA 02138 (United States); Küpper, Hendrik, E-mail: Hendrik.Kuepper@uni-konstanz.de [University of Konstanz, Department of Biology, D-78457 Konstanz (Germany); University of South Bohemia, Faculty of Biological Sciences and Institute of Physical Biology, Branišovská 31, CZ-370 05 České Budejovice (Czech Republic)

2013-10-15

Highlights: •Hardly any macrophytic growth occurred in an oligotrophic hard water lake in Germany. •All parameters were optimal, besides elevated, nanomolar concentrations of Ni and Cd. •We cultivated submerged macrophytes in real and simulated hard and soft lake water. •Nanomolar Cd and Ni inhibited the plants’ photosynthetic light reactions in soft water. •The inhibition was synergistic, i.e. stronger than the addition of Cd and Ni effects. -- Abstract: Even essential trace elements are phytotoxic over a certain threshold. In this study, we investigated whether heavy metal concentrations were responsible for the nearly complete lack of submerged macrophytes in an oligotrophic lake in Germany. We cultivated the rootless aquatic model plant Ceratophyllum demersum under environmentally relevant conditions like sinusoidal light and temperature cycles and a low plant biomass to water volume ratio. Experiments lasted for six weeks and were analysed by detailed measurements of photosynthetic biophysics, pigment content and hydrogen peroxide production. We established that individually non-toxic cadmium (3 nM) and slightly toxic nickel (300 nM) concentrations became highly toxic when applied together in soft water, severely inhibiting photosynthetic light reactions. Toxicity was further enhanced by phosphate limitation (75 nM) in soft water as present in many freshwater habitats. In the investigated lake, however, high water hardness limited the toxicity of these metal concentrations, thus the inhibition of macrophytic growth in the lake must have additional reasons. The results showed that synergistic heavy metal toxicity may change ecosystems in many more cases than estimated so far.
Effects of Cd and Ni toxicity to Ceratophyllum demersum under environmentally relevant conditions in soft and hard water including a German lake

International Nuclear Information System (INIS)

Andresen, Elisa; Opitz, Judith; Thomas, George; Stärk, Hans-Joachim; Dienemann, Holger; Jenemann, Kerstin; Dickinson, Bryan C.; Küpper, Hendrik

2013-01-01

Highlights: •Hardly any macrophytic growth occurred in an oligotrophic hard water lake in Germany. •All parameters were optimal, besides elevated, nanomolar concentrations of Ni and Cd. •We cultivated submerged macrophytes in real and simulated hard and soft lake water. •Nanomolar Cd and Ni inhibited the plants’ photosynthetic light reactions in soft water. •The inhibition was synergistic, i.e. stronger than the addition of Cd and Ni effects. -- Abstract: Even essential trace elements are phytotoxic over a certain threshold. In this study, we investigated whether heavy metal concentrations were responsible for the nearly complete lack of submerged macrophytes in an oligotrophic lake in Germany. We cultivated the rootless aquatic model plant Ceratophyllum demersum under environmentally relevant conditions like sinusoidal light and temperature cycles and a low plant biomass to water volume ratio. Experiments lasted for six weeks and were analysed by detailed measurements of photosynthetic biophysics, pigment content and hydrogen peroxide production. We established that individually non-toxic cadmium (3 nM) and slightly toxic nickel (300 nM) concentrations became highly toxic when applied together in soft water, severely inhibiting photosynthetic light reactions. Toxicity was further enhanced by phosphate limitation (75 nM) in soft water as present in many freshwater habitats. In the investigated lake, however, high water hardness limited the toxicity of these metal concentrations, thus the inhibition of macrophytic growth in the lake must have additional reasons. The results showed that synergistic heavy metal toxicity may change ecosystems in many more cases than estimated so far
Toxicity assessment and modelling of Moringa oleifera seeds in water purification by whole cell bioreporter.

Science.gov (United States)

Al-Anizi, Ali Adnan; Hellyer, Maria Theresa; Zhang, Dayi

2014-06-01

Moringa oleifera has been used as a coagulation reagent for drinking water purification, especially in developing countries such as Malawi. This research revealed the cytoxicity and genotoxicity of M. oleifera by Acinetobacter bioreporter. The results indicated that significant cytoxicity effects were observed when the powdered M. oleifera seeds concentration is from 1 to 50 mg/L. Through direct contact, ethanolic-water extraction and hexane extraction, the toxic effects of hydrophobic and hydrophilic components in M. oleifera seeds were distinguished. It suggested that the hydrophobic lipids contributed to the dominant cytoxicity, consequently resulting in the dominant genotoxicity in the water-soluble fraction due to limited dissolution when the M. oleifera seeds granule concentration was from 10 to 1000 mg/L. Based on cytoxicity and genotoxicity model, the LC50 and LC90 of M. oleifera seeds were 8.5 mg/L and 300 mg/L respectively and their genotoxicity was equivalent to 8.3 mg mitomycin C per 1.0 g dry M. oleifera seed. The toxicity of M. oleifera has also remarkable synergistic effects, suggesting whole cell bioreporter as an appropriate and complementary tool to chemical analysis for environmental toxicity assessment. Copyright © 2014 Elsevier Ltd. All rights reserved.
Toxicity of granular activated carbon treated coal gasification water as determined by the Microtox test and Escherichia coli.

Science.gov (United States)

Makino, Y; Adams, J C; McTernan, W F

1986-01-01

The Microtox assay and various parameters (growth, ATP concentration and electrochemical detection) of Escherichia coli were used to assess the toxicity of various levels of granular activated carbon treated coal gasification process water. The generation time of E. coli was statistically significantly slower at the level of 50 percent treatment than any other level of treatment. No differences were seen for ATP concentration per cell or in the electrochemical detection methods for any level treatment. There was a very high correlation between total organic carbon removal by GAC treatment and reduction in toxicity as measured by the Microtox system. However, even the treated water which had 91 percent of the TOC removed was still highly toxic.
Barley root hair growth and morphology in soil, sand, and water solution media and relationship with nickel toxicity.

Science.gov (United States)

Lin, Yanqing; Allen, Herbert E; Di Toro, Dominic M

2016-08-01

Barley, Hordeum vulgare (Doyce), was grown in the 3 media of soil, hydroponic sand solution (sand), and hydroponic water solution (water) culture at the same environmental conditions for 4 d. Barley roots were scanned, and root morphology was analyzed. Plants grown in the 3 media had different root morphology and nickel (Ni) toxicity response. Root elongations and total root lengths followed the sequence soil > sand > water. Plants grown in water culture were more sensitive to Ni toxicity and had greater root hair length than those from soil and sand cultures, which increased root surface area. The unit root surface area as root surface area per centimeter of length of root followed the sequence water > sand > soil and was found to be related with root elongation. Including the unit root surface area, the difference in root elongation and 50% effective concentration were diminished, and percentage of root elongations can be improved with a root mean square error approximately 10% for plants grown in different media. Because the unit root surface area of plants in sand culture is closer to that in soil culture, the sand culture method, not water culture, is recommended for toxicity parameter estimation. Environ Toxicol Chem 2016;35:2125-2133. © 2016 SETAC. © 2016 SETAC.
Heavy metal concentrations and toxicity in water and sediment from stormwater ponds and sedimentation tanks.

Science.gov (United States)

Karlsson, Kristin; Viklander, Maria; Scholes, Lian; Revitt, Mike

2010-06-15

Sedimentation is a widely used technique in structural best management practices to remove pollutants from stormwater. However, concerns have been expressed about the environmental impacts that may be exerted by the trapped pollutants. This study has concentrated on stormwater ponds and sedimentation tanks and reports on the accumulated metal concentrations (Cd, Cr, Ni, Pb, and Zn) and the associated toxicity to the bacteria Vibrio fischeri. The metal concentrations are compared with guidelines and the toxicity results are assessed in relation to samples for which metal concentrations either exceed or conform to these values. The water phase metal concentrations were highest in the ponds whereas the sedimentation tanks exhibited a distinct decrease towards the outlet. However, none of the water samples demonstrated toxicity even though the concentrations of Cu, Pb, and Zn exceeded the threshold values for the compared guidelines. The facilities with higher traffic intensities had elevated sediment concentrations of Cr, Cu, Ni, and Zn which increased towards the outlet for the sedimentation tanks in agreement with the highest percentage of fine particles. The sediments in both treatment facilities exhibited the expected toxic responses in line with their affinity for heavy metals but the role of organic carbon content is highlighted. Copyright 2010 Elsevier B.V. All rights reserved.
Assessment of internal contamination problems associated with bioregenerative air/water purification systems

Science.gov (United States)

Johnson, Anne H.; Bounds, B. Keith; Gardner, Warren

1990-01-01

The emphasis is to characterize the mechanisms of bioregenerative revitalization of air and water as well as to assess the possible risks associated with such a system in a closed environment. Marsh and aquatic plants are utilized for purposes of wastewater treatment as well as possible desalinization and demineralization. Foliage plants are also being screened for their ability to remove toxic organics from ambient air. Preliminary test results indicate that treated wastewater is typically of potable quality with numbers of pathogens such as Salmonella and Shigella significantly reduced by the artificial marsh system. Microbiological analyses of ambient air indicate the presence of bacilli as well as thermophilic actinomycetes.
Kinetics of the degradation of sulfur mustard on ambient and moist concrete

International Nuclear Information System (INIS)

Brevett, Carol A.S.; Sumpter, Kenneth B.; Nickol, Robert G.

2009-01-01

The rate of degradation of the chemical warfare agent sulfur mustard, bis(2-chloroethyl) sulfide, was measured on ambient and moist concrete using 13 C Solid State Magic Angle Spinning Nuclear Magnetic Resonance (SSMAS NMR). Three samples of concrete made by the same formulation, but differing in age and alkalinity were used. The sulfur mustard eventually degraded to thiodiglycol and 1,4-oxathiane via the intermediate sulfonium ions CH-TG, H-TG, H-2TG and O(CH 2 CH 2 ) 2 S + CH 2 CH 2 OH on all of the concrete samples, and in addition formed 8-31% vinyl moieties on the newer, more alkaline concrete samples. This is the first observation of the formation of O(CH 2 CH 2 ) 2 S + CH 2 CH 2 OH on a solid substrate. The addition of 2-chloroethanol to concrete on which mustard had fully degraded to thiodiglycol and 1,4-oxathiane resulted in the formation of O(CH 2 CH 2 ) 2 S + CH 2 CH 2 OH, thus demonstrating the reversibility of sulfur mustard degradation pathways. The sulfur mustard degradation half-lives on ambient concrete at 22 deg. C ranged from 3.5 to 54 weeks. When the substrates were moistened, the degradation half-lives at 22 deg. C ranged from 75 to 350 h. The degradation of sulfur mustard occurred more quickly at elevated temperatures and with added water. The non-volatile toxic sulfonium ions persisted for months to years on concrete at 22 deg. C and weeks to months on concrete at 35 deg. C, before decomposing to the relatively non-toxic compounds thiodiglycol and 1,4-oxathiane
Investigating copper toxicity in the tropical fish cardinal tetra (Paracheirodon axelrodi) in natural Amazonian waters: Measurements, modeling, and reality

International Nuclear Information System (INIS)

Crémazy, Anne; Wood, Chris M.; Smith, D. Scott; Ferreira, Márcio S.; Johannsson, Ora E.; Giacomin, Marina; Val, Adalberto L.

2016-01-01

Highlights: • Copper toxicity to a tropical fish varied greatly in different Amazonian waters. • The biotic ligand model could not capture this variability. • Possible physiological protection was offered by natural organic matter. • Care must be used in applying BLM to fish in tropical waters. - Abstract: Copper at high concentrations is an ionoregulatory toxicant in fish and its toxicity is known to be strongly modulated by the water chemistry. The toxicity of Cu to the tropical fish cardinal tetra (Paracheirodon axelrodi) was investigated in waters from two major rivers of the Amazon watershed: the Rio Negro (filtered <0.45 μm, pH 5.6, DOC = 8.4 mg L"−"1, Na = 33 μM, Ca = 8 μM) and the Rio Solimões (filtered <0.45 μm, pH 6.7, DOC = 2.8 mg L"−"1, Na = 185 μM, Ca = 340 μM), as well as in a natural “reference water” (groundwater) which was almost DOC-free (pH 6.0, DOC = 0.34 mg L"−"1, Na = 53 μM, Ca = 5 μM). Acute 96-h mortality, Cu bioaccumulation and net flux rates of Na"+, Cl"−, K"+ and total ammonia were determined in P. axelrodi exposed in each water. Copper speciation in each water was determined by two thermodynamic models and by potentiometry, and its toxicity was predicted based on the biotic ligand model (BLM) framework. Our results indicate that high Na"+ loss is the main mode of toxic action of Cu in P. axelrodi, in accordance with general theory. Cardinal tetra showed a particularly high ability to tolerate Cu and to maintain Na"+ balance, similar to the ability of this and other endemic Rio Negro species to tolerate low pH and ion-poor conditions. Cu toxicity was lower in Rio Negro than in the other two waters tested, and the free [Cu"2"+] at the LC50, as determined by any of the three speciation methods tested, was approximately 10-fold higher. This variation could not be captured by a realistic set of BLM parameters. At least in part, this observation may be due to gill physiological alterations induced by the abundant
Investigating copper toxicity in the tropical fish cardinal tetra (Paracheirodon axelrodi) in natural Amazonian waters: Measurements, modeling, and reality

Energy Technology Data Exchange (ETDEWEB)

Crémazy, Anne, E-mail: acremazy@zoology.ubc.ca [Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Wood, Chris M. [Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Smith, D. Scott [Department of Chemistry and Biochemistry, Wilfrid Laurier University, Waterloo, ON N2L 3C5 (Canada); Ferreira, Márcio S. [Laboratory of Ecophysiology and Molecular Evolution, National Institute for Amazonian Research, Manaus, AM (Brazil); Johannsson, Ora E.; Giacomin, Marina [Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Val, Adalberto L. [Laboratory of Ecophysiology and Molecular Evolution, National Institute for Amazonian Research, Manaus, AM (Brazil)

2016-11-15

Highlights: • Copper toxicity to a tropical fish varied greatly in different Amazonian waters. • The biotic ligand model could not capture this variability. • Possible physiological protection was offered by natural organic matter. • Care must be used in applying BLM to fish in tropical waters. - Abstract: Copper at high concentrations is an ionoregulatory toxicant in fish and its toxicity is known to be strongly modulated by the water chemistry. The toxicity of Cu to the tropical fish cardinal tetra (Paracheirodon axelrodi) was investigated in waters from two major rivers of the Amazon watershed: the Rio Negro (filtered <0.45 μm, pH 5.6, DOC = 8.4 mg L{sup −1}, Na = 33 μM, Ca = 8 μM) and the Rio Solimões (filtered <0.45 μm, pH 6.7, DOC = 2.8 mg L{sup −1}, Na = 185 μM, Ca = 340 μM), as well as in a natural “reference water” (groundwater) which was almost DOC-free (pH 6.0, DOC = 0.34 mg L{sup −1}, Na = 53 μM, Ca = 5 μM). Acute 96-h mortality, Cu bioaccumulation and net flux rates of Na{sup +}, Cl{sup −}, K{sup +} and total ammonia were determined in P. axelrodi exposed in each water. Copper speciation in each water was determined by two thermodynamic models and by potentiometry, and its toxicity was predicted based on the biotic ligand model (BLM) framework. Our results indicate that high Na{sup +} loss is the main mode of toxic action of Cu in P. axelrodi, in accordance with general theory. Cardinal tetra showed a particularly high ability to tolerate Cu and to maintain Na{sup +} balance, similar to the ability of this and other endemic Rio Negro species to tolerate low pH and ion-poor conditions. Cu toxicity was lower in Rio Negro than in the other two waters tested, and the free [Cu{sup 2+}] at the LC50, as determined by any of the three speciation methods tested, was approximately 10-fold higher. This variation could not be captured by a realistic set of BLM parameters. At least in part, this observation may be due to gill
Selection of a bioassay battery to assess toxicity in the affluents and effluents of three water-treatment plants

Directory of Open Access Journals (Sweden)

Paola Bohórquez-Echeverry

2012-08-01

Full Text Available The assessment of water quality includes the analysis of both physical-chemical and microbiological parameters. However,none of these evaluates the biological effect that can be generated in ecosystems or humans. In order to define the most suitable organismsto evaluate the toxicity in the affluent and effluent of three drinking-water treatment plants, five acute toxicity bioassays were used,incorporating three taxonomic groups of the food chain. Materials and methods. The bioassays used were Daphnia magna and Hydraattenuata as animal models, Lactuca sativa and Pseudokirchneriella subcapitata as plant models, and Photobacterium leioghnathi asbacterial model. To meet this objective, selection criteria of the organisms evaluated and cluster analysis were used to identify the mostsensitive in the affluent and effluent of each plant. Results. All organisms are potentially useful in the assessment of water quality bymeeting four essential requirements and 17 desirable requirements equivalent to 100% acceptability, except P. leioghnathi which doesnot meet two essential requirements that are the IC50 for the toxic reference and the confidence interval. The animal, plant and bacterialmodels showed different levels of sensitivity at the entrance and exit of the water treatment systems. Conclusions. H. attenuata, P.subcapitata and P. leioghnathi were the most effective organisms in detecting toxicity levels in the affluents and D. magna, P. subcapitataand P. leioghnathi in the effluents.
Assessment of the chemical toxicity of long-lived radionuclides on the basis of Who guidelines for drinking-water quality

International Nuclear Information System (INIS)

Renaud-Salis, V.; Menetrier, F.; Leudet, A.; Flury-Herard, A.

2003-01-01

The current assessment of health risks related to long lived radionuclides waste management is not complete if accounting only for radiological toxicity aspects. Although such an approach is justified for a large number of radionuclides of concern, it nevertheless cannot be exclusive and generalised: the chemical toxicity should be considered for radionuclides with a radioactive half-life exceeding 10 5 years. When assessing the chemical or radiological toxicity of a radionuclide, a reference dose applied to drinking water consumption (0.1 mSv/year) can be compared to existing toxicological data. Such an approach has been used by the World Health Organization for natural uranium, for which a guideline value in drinking water derived from its chemical toxicity (2 μg/l) is recommended. WHO's approach is used here for illustrating that the potential chemical toxicity of an element is to be considered for assessing health risks related to long-lived radionuclides. (authors)
Combined exposure to ambient UVB radiation and nitrite negatively affects survival of amphibian early life stages

International Nuclear Information System (INIS)

Macias, Guadalupe; Marco, Adolfo; Blaustein, Andrew R.

2007-01-01

Many aquatic species are sensitive to ambient levels of ultraviolet-B radiation (UVB) and chemical fertilizers. However, recent studies indicate that the interaction among multiple stressors acting simultaneously could be contributing to the population declines of some animal species. Therefore, we tested the potential synergistic effects between ambient levels of UVB and a contaminant, sodium nitrite in the larvae of two amphibian species, the common European toad Bufo bufo and the Iberian green frog Rana perezi. We studied R. perezi from both mountain and coastal populations to examine if populations of the same species varied in their response to stressors in different habitats. Both species were sensitive to the two stressors acting alone, but the interaction between the two stressors caused a multiplicative impact on tadpole survival. For B. bufo, the combination of UVB and nitrite was up to seven times more lethal than mortality for each stressor alone. In a coastal wetland, the combination of UVB and nitrite was four times more toxic for R. perezi than the sum of the effect on mortality for each stressor alone. One mg/L of nitrite killed half the population of R. perezi at Gredos Mountains at day 10 in the absence of UVB. In the presence of UVB, 50% of the tadpoles from the same experiment died at day 7. Similar toxic response were found for R. perezi in two highly contrasted environments suggesting this synergistic interaction can be a widespread phenomenon. The interaction of excess chemical fertilizers and manure with ambient UVB radiation could be contributing to the global decline of some amphibian species. We suggest that potential exposure to UVB radiation be accounted for when assessing water quality criteria regarding nitrite pollution
Combined exposure to ambient UVB radiation and nitrite negatively affects survival of amphibian early life stages

Energy Technology Data Exchange (ETDEWEB)

Macias, Guadalupe [Donana Biological Station, CSIC, Spanish Council for Scientific Research. P.O. Box 1056, Sevilla 41013 (Spain); Marco, Adolfo [Donana Biological Station, CSIC, Spanish Council for Scientific Research. P.O. Box 1056, Sevilla 41013 (Spain)], E-mail: amarco@ebd.csic.es; Blaustein, Andrew R. [Department of Zoology, Oregon State University, Corvallis, Oregon, 97331 (United States)

2007-10-15

Many aquatic species are sensitive to ambient levels of ultraviolet-B radiation (UVB) and chemical fertilizers. However, recent studies indicate that the interaction among multiple stressors acting simultaneously could be contributing to the population declines of some animal species. Therefore, we tested the potential synergistic effects between ambient levels of UVB and a contaminant, sodium nitrite in the larvae of two amphibian species, the common European toad Bufo bufo and the Iberian green frog Rana perezi. We studied R. perezi from both mountain and coastal populations to examine if populations of the same species varied in their response to stressors in different habitats. Both species were sensitive to the two stressors acting alone, but the interaction between the two stressors caused a multiplicative impact on tadpole survival. For B. bufo, the combination of UVB and nitrite was up to seven times more lethal than mortality for each stressor alone. In a coastal wetland, the combination of UVB and nitrite was four times more toxic for R. perezi than the sum of the effect on mortality for each stressor alone. One mg/L of nitrite killed half the population of R. perezi at Gredos Mountains at day 10 in the absence of UVB. In the presence of UVB, 50% of the tadpoles from the same experiment died at day 7. Similar toxic response were found for R. perezi in two highly contrasted environments suggesting this synergistic interaction can be a widespread phenomenon. The interaction of excess chemical fertilizers and manure with ambient UVB radiation could be contributing to the global decline of some amphibian species. We suggest that potential exposure to UVB radiation be accounted for when assessing water quality criteria regarding nitrite pollution.
Overview of Chronic Oral Toxicity Values for Chemicals Present in Hydraulic Fracturing Fluids, Flowback and Produced Waters

Science.gov (United States)

as part of EPA's Hydraulic Fracturing Drinking Water Assessment, EPA is summarizing existing toxicity data for chemicals reported to be used in hydraulic fracturing fluids and/or found in flowback or produced waters from hydraulically fractured wells
Detection of toxic compounds in real water samples using a conductometric tyrosinase biosensor

International Nuclear Information System (INIS)

Anh, Tuan Mai; Dzyadevych, Sergei V.; Prieur, Nicolas; Duc, Chien Nguyen; Pham, T.D.; Renault, Nicole Jaffrezic; Chovelon, Jean-Marc

2006-01-01

A conductometric tyrosinase biosensor for the detection of some toxic compounds including diuron, atrazine, and copper ions was developed. The work of this biosensor is based on the principle of change of conductivity of the enzyme membrane when tyrosinase either interacts with 4-chlorophenol substrate or is inhibited by pollutants. The different samples tested were solutions containing diuron, atrazine, copper, lead and zinc ions, mixtures of copper/atrazine or copper/diuron and real water samples coming from a Vietnamese river. In the last case, classical techniques such as GC-MS or atomic absorption spectrometry were used in order to estimate exact concentration of these species in real water samples. Results have shown that such a biosensor could be used as an early warning system for the detection of these pollutants, as no matrix effect coming from the real sample was observed and no synergetic or antagonist effects were found for the mixture of toxic compounds. In addition, results were coherent with the content of the tyrosinase inhibitors
Detection of toxic compounds in real water samples using a conductometric tyrosinase biosensor

Energy Technology Data Exchange (ETDEWEB)

Anh, Tuan Mai [Laboratoire d' Application de la Chimie a l' Environnement, UMR CNRS 5634, Universite Claude Bernard Lyon I, 43 Boulevard du 11 Nov. 1918, 69622 Villeurbanne Cedex (France); International Training Institute for Materials Science (ITIMS), Hanoi University of Technology, 1 Dai Co Viet, Hanoi, Vietnam (Viet Nam); Dzyadevych, Sergei V. [Laboratory of Biomolecular Electronics, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, 150 Zabolotnogo Str., Kiev 03143 (Ukraine); Prieur, Nicolas [Institute of Natural Products Chemistry, Vietnam National Centre for Science and Technology, Hoang Quoc Viet Str., Hanoi, Vietnam (Viet Nam); Duc, Chien Nguyen [International Training Institute for Materials Science (ITIMS), Hanoi University of Technology, 1 Dai Co Viet, Hanoi, Vietnam (Viet Nam); Pham, T.D. [International Training Institute for Materials Science (ITIMS), Hanoi University of Technology, 1 Dai Co Viet, Hanoi, Vietnam (Viet Nam); Renault, Nicole Jaffrezic [Ecole Centrale de Lyon, CEGELY, UMR CNRS 5005, 36 Avenue Guy de Collongue, 69134 Ecully Cedex (France); Chovelon, Jean-Marc [Laboratoire d' Application de la Chimie a l' Environnement, UMR CNRS 5634, Universite Claude Bernard Lyon I, 43 Boulevard du 11 Nov. 1918, 69622 Villeurbanne Cedex (France)]. E-mail: chovelon@univ-lyon1.fr

2006-03-15

A conductometric tyrosinase biosensor for the detection of some toxic compounds including diuron, atrazine, and copper ions was developed. The work of this biosensor is based on the principle of change of conductivity of the enzyme membrane when tyrosinase either interacts with 4-chlorophenol substrate or is inhibited by pollutants. The different samples tested were solutions containing diuron, atrazine, copper, lead and zinc ions, mixtures of copper/atrazine or copper/diuron and real water samples coming from a Vietnamese river. In the last case, classical techniques such as GC-MS or atomic absorption spectrometry were used in order to estimate exact concentration of these species in real water samples. Results have shown that such a biosensor could be used as an early warning system for the detection of these pollutants, as no matrix effect coming from the real sample was observed and no synergetic or antagonist effects were found for the mixture of toxic compounds. In addition, results were coherent with the content of the tyrosinase inhibitors.
The significance of water ionic strength on aluminium toxicity in brown trout (Salmo trutta L.)

Energy Technology Data Exchange (ETDEWEB)

Alstad, Nina E.W. [Department of Biology, University of Oslo, P.O. Box 1066 Blindern, N-0316 Oslo (Norway); Kjelsberg, Birgitte M. [Department of Biology, University of Oslo, P.O. Box 1066 Blindern, N-0316 Oslo (Norway); Voellestad, L. Asbjoern [Department of Biology, University of Oslo, P.O. Box 1066 Blindern, N-0316 Oslo (Norway); Lydersen, Espen [Norwegian Institute for Water Research, P.O. Box 173 Kjelsaas, N-0411 Oslo (Norway); Poleo, Antonio B.S. [Department of Biology, University of Oslo, P.O. Box 1066 Blindern, N-0316 Oslo (Norway)]. E-mail: toni.poleo@bio.uio.no

2005-01-01

The toxicity of aluminium to fish is related to interactions between aluminium and the gill surface. We investigated the possible effect of water ionic strength on this interaction. The mortality of brown trout (Salmo trutta L.) exposed to three different degrees of Al polymerisation was compared in water with increased ionic strength (mean 7.31 x 10{sup -4} M) after additions of the base cations Ca{sup 2+}, Mg{sup 2+}, Na{sup +} or K{sup +}, and in water with no such addition (mean ionic strength 5.58 x 10{sup -4} M). Only a very slight ameliorating effect of increased ionic strength was observed, while the degree of Al polymerisation was of major importance in fish mortality. In addition, it was observed that smaller fish survived the Al exposures for a longer time than larger fish. We hypothesise that this is because larger fish are more susceptible to hypoxia than smaller fish. - Ionic strength has a slight ameliorating effect on Al toxicity in brown trout.
The significance of water ionic strength on aluminium toxicity in brown trout (Salmo trutta L.)

International Nuclear Information System (INIS)

Alstad, Nina E.W.; Kjelsberg, Birgitte M.; Voellestad, L. Asbjoern; Lydersen, Espen; Poleo, Antonio B.S.

2005-01-01

The toxicity of aluminium to fish is related to interactions between aluminium and the gill surface. We investigated the possible effect of water ionic strength on this interaction. The mortality of brown trout (Salmo trutta L.) exposed to three different degrees of Al polymerisation was compared in water with increased ionic strength (mean 7.31 x 10 -4 M) after additions of the base cations Ca 2+ , Mg 2+ , Na + or K + , and in water with no such addition (mean ionic strength 5.58 x 10 -4 M). Only a very slight ameliorating effect of increased ionic strength was observed, while the degree of Al polymerisation was of major importance in fish mortality. In addition, it was observed that smaller fish survived the Al exposures for a longer time than larger fish. We hypothesise that this is because larger fish are more susceptible to hypoxia than smaller fish. - Ionic strength has a slight ameliorating effect on Al toxicity in brown trout

Influence of Ambient Humidity on the Voltage Response of Ionic Polymer-Metal Composite Sensor.

Science.gov (United States)

Zhu, Zicai; Horiuchi, Tetsuya; Kruusamäe, Karl; Chang, Longfei; Asaka, Kinji

2016-03-31

Electrical potential based on ion migration exists not only in natural systems but also in ionic polymer materials. In order to investigate the influence of ambient humidity on voltage response, classical Au-Nafion IPMC was chosen as the reference sample. Voltage response under a bending deformation was measured in two ways: first, continuous measurement of voltage response in the process of absorption and desorption of water to study the tendency of voltage variation at all water states; second, measurements at multiple fixed ambient humidity levels to characterize the process of voltage response quantitatively. Ambient humidity influences the voltage response mainly by varying water content in ionic polymer. Under a step bending, the amplitude of initial voltage peak first increases and then decreases as the ambient humidity and the inherent water content decrease. This tendency is explained semiquantitatively by mass storage capacity related to the stretchable state of the Nafion polymer network. Following the initial peak, the voltage shows a slow decay to a steady state, which is first characterized in this paper. The relative voltage decay during the steady state always decreases as the ambient humidity is lowered. It is ascribed to progressive increase of the ratio between the water molecules in the cation hydration shell to the free water. Under sinusoidal mechanical bending excitation in the range of 0.1-10 Hz, the voltage magnitude increases with frequency at high ambient humidity but decreases with frequency at low ambient humidity. The relationship is mainly controlled by the voltage decay effect and the response speed.
Reproductive toxicity of a mixture of regulated drinking-water disinfection by-products in a multigenerational rat bioassay

Science.gov (United States)

BACKGROUND:Trihalomethanes (THMs) and haloaretic acids (HAAs) are regulated disinfection by-products (DBPs); their joint reproductive toxicity in drinking water is unknown.OBJECTIVE: We aimed to evaluate a drinking water mixture of the four regulated THMs and five regulated HAAs ...
Pelletized ponderosa pine bark for adsorption of toxic heavy metals from water

Science.gov (United States)

Miyoung Oh; Mandla A. Tshabalala

2007-01-01

Bark flour from ponderosa pine (Pinus ponderosa) was consolidated into pellets using citric acid as cross-linking agent. The pellets were evaluated for removal of toxic heavy metals from synthetic aqueous solutions. When soaked in water, pellets did not leach tannins, and they showed high adsorption capacity for Cu(ll), Zn(ll), Cd(ll). and Ni(ll) under both equilibrium...
Reproductive toxicity assessment of surface water of the Tai section of the Yangtze River, China by in vitro bioassays coupled with chemical analysis

International Nuclear Information System (INIS)

Wang Xiaoyi; Wu Jiang; Hao Yingqun; Zhu Bingqing; Shi Wei; Hu Guanjiu; Han Xiaodong; Giesy, John P.; Yu Hongxia

2011-01-01

Reproductive toxicity of organic extracts of the surface water from the Tai section of the Yangtze River was assessed by in vitro cytotoxity assays and selected persistent organic pollutants including PCBs, OCPs and PAHs were quantified by instrumental analysis. Eleven of the US EPA priority PAHs were detected. Individual PAHs were found to range from 0.7 to 20 ng/L. Concentrations of BaP did not exceed the national drinking water source quality standard of China. However, a 286-fold concentrated organic extract induced significant reproductive toxicity in adult male rats. The morphology of cells, MTT assay and LDH release assay were all affected by exposure to the organic extracts of water. The results of the reproductive toxicity indicated that PAHs posed the greatest risk of the chemicals studied. The compounds present in the water could be bioconcentrated and result in adverse effects. - Highlights: → Only 11 PAHs of US EPA priority PAHs were detected in surface water the Yangtze River. → Level of BaP didn't exceed national drinking water source quality standard of China. → 286-fold concentrated organic extracts induced great reproductive toxicity in rats. → PAHs posed the greatest risk of the chemicals studied. → The compounds in the water could be bioconcentrated and result in adverse effects. - In vitro bioassay responses observed in Yangtze River source water extracts showed great reproductive toxicity, and PAHs were responsible.
Elucidating mechanisms of toxic action of dissolved organic chemicals in oil sands process-affected water (OSPW).

Science.gov (United States)

Morandi, Garrett D; Wiseman, Steve B; Guan, Miao; Zhang, Xiaowei W; Martin, Jonathan W; Giesy, John P

2017-11-01

Oil sands process-affected water (OSPW) is generated during extraction of bitumen in the surface-mining oil sands industry in Alberta, Canada, and is acutely and chronically toxic to aquatic organisms. It is known that dissolved organic compounds in OSPW are responsible for most toxic effects, but knowledge of the specific mechanism(s) of toxicity, is limited. Using bioassay-based effects-directed analysis, the dissolved organic fraction of OSPW has previously been fractionated, ultimately producing refined samples of dissolved organic chemicals in OSPW, each with distinct chemical profiles. Using the Escherichia coli K-12 strain MG1655 gene reporter live cell array, the present study investigated relationships between toxic potencies of each fraction, expression of genes and characterization of chemicals in each of five acutely toxic and one non-toxic extract of OSPW derived by use of effects-directed analysis. Effects on expressions of genes related to response to oxidative stress, protein stress and DNA damage were indicative of exposure to acutely toxic extracts of OSPW. Additionally, six genes were uniquely responsive to acutely toxic extracts of OSPW. Evidence presented supports a role for sulphur- and nitrogen-containing chemical classes in the toxicity of extracts of OSPW. Copyright © 2017 Elsevier Ltd. All rights reserved.
TOXIC EFFECTS OF CHLOROPICRIN AND IMPACT OF SORBED WATER STEAM ON PROTECTION

Directory of Open Access Journals (Sweden)

Milena Nikolić

2013-01-01

Full Text Available Chloropicrin is a chemical substance that has a very toxic effect. Exerts its effect on the respiratory system. Causes pulmonary edema and difficult breathing and suffocating effect. Respiratory protection may be carried into execution respiratory filters. On the protective power filter based on active coal affects adsorbed water vapor. This paper presents the results of the adsorption of water vapor on activated carbon from 5% to 25%. Was used for the experiment apparatus for dynamic adsorption, the results showed that the humidity of 5% coal provides most power protection, while humidity of 25% minimum protective power.
Toxicity alarm: Case history

International Nuclear Information System (INIS)

Hogan, D.; Retallack, J.

1993-01-01

In late fall 1991, the Novacor petrochemical plant near Joffre, Alberta experienced a toxicity alarm, the first since its startup 14 years ago. Fish exposed to a normal toxicity test were stressed within 2 h and showed 100% mortality after 24 h. A history of the events leading up to, during, and after the toxicity alarm is presented. The major effluent sources were three cooling water systems. Although these sources are well characterized, the event causes were not immediately clear. Initial toxic screening indicated that one was very toxic, another moderately toxic, and the third not toxic at all. All three systems utilized the same chemical treatment program to avoid fouling: stabilized phosphates with minor variants. The most toxic of the cooling systems operated at 10-12 cycles, had three chemicals for biocide control, and had three makeup streams. Toxic and nontoxic system characteristics were compared. An in-depth modified toxicity identification and evaluation program was then performed to identify and evaluate the cause of the toxicity alarm for future prevention. The most probable causes of toxicity were identified by elimination. The combination of high numbers of cycles, hydrocarbons in the makeup water, and bromine added as an antifoulant resulted in formation of aromatic bromamines which are capable of causing the toxic condition experienced. 2 tabs
Removal of toxic chemicals from water with activated carbon

Science.gov (United States)

Dawson, V.K.; Marking, L.L.; Bills, T.D.

1976-01-01

Activated carbon was effective in removing fish toxicants and anesthetics from water solutions. Its capacity to adsorb 3-trifluoromethyl-4-nitrophenol (TFM), antimycin, NoxfishA? (5% rotenone), Dibrorms, juglone, MSa??222, and benzocaine ranged from 0.1 to 64 mg per gram of carbon. The adsorptive capacity (end point considered as a significant discharge) of activated carbon for removal of TFM was determined at column depths of 15, 30, and 60 cm; temperatures of 7, 12, 17, and 22 C; pH's of 6.5, 7.5, 8.5, and 9.5; and flow rates of 50, 78, 100, 200, and 940 ml/min. Adsorptive capacity increased when the contact time was increased by reducing the flow rate or increasing the column depth. The adsorptive capacity was not significantly influenced by temperature but was substantially higher at pH 6.5 than at the other pH's tested. A practical and efficient filter for purifying chemically treated water was developed.
Determination of mercury in ambient water samples by anodic stripping voltammetry on screen-printed gold electrodes.

Science.gov (United States)

Bernalte, E; Marín Sánchez, C; Pinilla Gil, E

2011-03-09

The applicability of commercial screen-printed gold electrodes (SPGEs) for the determination of Hg(II) in ambient water samples by square wave anodic stripping voltammetry has been demonstrated. Electrode conditioning procedures, chemical and instrumental variables have been optimized to develop a reliable method capable of measuring dissolved mercury in the low ng mL(-1) range (detection limit 1.1 ng mL(-1)), useful for pollution monitoring or screening purposes. The proposed method was tested with the NIST 1641d Mercury in Water Standard Reference Material (recoveries 90.0-110%) and the NCS ZC 76303 Mercury in Water Certified Reference Material (recoveries 82.5-90.6%). Waste water samples from industrial origin and fortified rain water samples were assayed for mercury by the proposed method and by a reference ICP-MS method, with good agreement. Screen printing technology thus opens a useful way for the construction of reliable electrochemical sensors for decentralized or even field Hg(II) testing. Copyright © 2011 Elsevier B.V. All rights reserved.
Use of zeolite for removing ammonia and ammonia-caused toxicity in marine toxicity identification evaluations.

Science.gov (United States)

Burgess, R M; Perron, M M; Cantwell, M G; Ho, K T; Serbst, J R; Pelletier, M C

2004-11-01

Ammonia occurs in marine waters including effluents, receiving waters, and sediment interstitial waters. At sufficiently high concentrations, ammonia can be toxic to aquatic species. Toxicity identification evaluation (TIE) methods provide researchers with tools for identifying aquatic toxicants. For identifying ammonia toxicity, there are several possible methods including pH alteration and volatilization, Ulva lactuca addition, microbial degradation, and zeolite addition. Zeolite addition has been used successfully in freshwater systems to decrease ammonia concentrations and toxicity for several decades. However, zeolite in marine systems has been used less because ions in the seawater interfere with zeolite's ability to adsorb ammonia. The objective of this study was to develop a zeolite method for removing ammonia from marine waters. To accomplish this objective, we performed a series of zeolite slurry and column chromatography studies to determine uptake rate and capacity and to evaluate the effects of salinity and pH on ammonia removal. We also assessed the interaction of zeolite with several toxic metals. Success of the methods was also evaluated by measuring toxicity to two marine species: the mysid Americamysis bahia and the amphipod Ampelisca abdita. Column chromatography proved to be effective at removing a wide range of ammonia concentrations under several experimental conditions. Conversely, the slurry method was inconsistent and variable in its overall performance in removing ammonia and cannot be recommended. The metals copper, lead, and zinc were removed by zeolite in both the slurry and column treatments. The zeolite column was successful in removing ammonia toxicity for both the mysid and the amphipod, whereas the slurry was less effective. This study demonstrated that zeolite column chromatography is a useful tool for conducting marine water TIEs to decrease ammonia concentrations and characterize toxicity.
Maryland air toxics regulation applicable to a natural gas compressor station

International Nuclear Information System (INIS)

Weidemann, H.A.; Hoffman, P.M.

1992-01-01

Columbia Gas Transmission Corporation submitted an air permit application to the Maryland Department of the Environment to construct a natural gas compressor station near Rutledge, Maryland. The station consists of three natural gas-fueled internal combustion reciprocating engines, each rated at 3200 horsepower. Maximum potential pollutant emissions associated with the station operation did not trigger Prevention of Significant Deterioration review or nonattainment area New Source review. However, a minor source air permit cannot be issued without addressing Maryland's toxic air regulations. Columbia initiated a detailed investigation of toxic air pollutants, including a stack test of an identical engine. Based on this information, the proposed station was subject to the toxic air regulation for acetaldehyde, acrolein, benzene, crotonaldehyde, and formaldehyde. Compliance with the toxic air regulation for crotonaldehyde was demonstrated by having an emission rate less than the threshold emission rate, specified in the regulation. The ambient air quality impact of the other four pollutants was determined using the Industrial Source Complex dispersion model and resulted in predicted concentrations below the pollutant-specific acceptable ambient level. A carcinogenic impact analysis was performed for acetaldehyde, benzene, and formaldehyde to demonstrate compliance with the accepted risk of one in one hundred thousand
Ambient Volatility of Triethyl Phosphate

Science.gov (United States)

2017-08-01

of materials is predictable using Raoult’s law. This report details the measurement of the effect of water vapor partial pressure on the volatility...empirical correlation taking into account nonideal behavior was developed to enable estimation of TEPO volatility at any combination of ambient...of the second component is expected to be one-half as much as in the absence of water vapor. Similarly, the measured volatility of the second
Comparative toxicity of water soluble fractions of four oils on the growth of a Microalga

Digital Repository Service at National Institute of Oceanography (India)

Phatarpekar, P.V.; Ansari, Z.A.

Toxic effects of water soluble fractions (WSF) of four different fuel oils on a microalga. Tetraselmis gracilis, were examined and compared. On applying different concentrations of WSF, a decrease in cell population was observed. Depending...
Organic micropollutants (OMPs) in natural waters: Oxidation by UV/H2O2 treatment and toxicity assessment.

Science.gov (United States)

Rozas, Oscar; Vidal, Cristiane; Baeza, Carolina; Jardim, Wilson F; Rossner, Alfred; Mansilla, Héctor D

2016-07-01

Organic micropollutants (OMPs) are ubiquitous in natural waters even in places where the human activity is limited. The presence of OMPs in natural water sources for human consumption encourages the evaluation of different water purification technologies to ensure water quality. In this study, the Biobío river (Chile) was selected since the watershed includes urban settlements and economic activities (i.e. agriculture, forestry) that incorporate a variety of OMPs into the aquatic environment, such as pesticides, pharmaceuticals and personal care products. Atrazine (herbicide), caffeine (psychotropic), diclofenac (anti-inflammatory) and triclosan (antimicrobial) in Biobío river water and in different stages of a drinking and two wastewater treatment plants downstream Biobío river were determined using solid phase extraction (SPE) and liquid chromatography/tandem mass spectrometry (LC-MS/MS) and electrospray ionization (ESI). Quantification of these four compounds showed concentrations in the range of 8 ± 2 to 55 ± 10 ng L(-1) in Biobío river water, 11 ± 2 to 74 ± 21 ng L(-1) in the drinking water treatment plant, and 60 ± 10 to 15,000 ± 1300 ng L(-1) in the wastewater treatment plants. Caffeine was used as an indicator of wastewater discharges. Because conventional water treatment technologies are not designed to eliminate some emerging organic pollutants, alternative treatment processes, UV and UV/H2O2, were employed. The transformation of atrazine, carbamazepine (antiepileptic), diclofenac and triclosan was investigated at laboratory scale. Both processes were tested at different UV doses and the Biobío river water matrix effects were evaluated. Initial H2O2 concentration used was 10 mg L(-1). Results showed that, the transformation profile obtained using UV/H2O2 at UV doses up to 900 mJ cm(-2), followed the trend of diclofenac > triclosan > atrazine > carbamazepine. Furthermore acute toxicity tests with Daphnia magna were carried
Trends in Surface-Water Quality at Selected Ambient-Monitoring Network Stations in Kentucky, 1979-2004

Science.gov (United States)

Crain, Angela S.; Martin, Gary R.

2009-01-01

Increasingly complex water-management decisions require water-quality monitoring programs that provide data for multiple purposes, including trend analyses, to detect improvement or deterioration in water quality with time. Understanding surface-water-quality trends assists resource managers in identifying emerging water-quality concerns, planning remediation efforts, and evaluating the effectiveness of the remediation. This report presents the results of a study conducted by the U.S. Geological Survey, in cooperation with the Kentucky Energy and Environment Cabinet-Kentucky Division of Water, to analyze and summarize long-term water-quality trends of selected properties and water-quality constituents in selected streams in Kentucky's ambient stream water-quality monitoring network. Trends in surface-water quality for 15 properties and water-quality constituents were analyzed at 37 stations with drainage basins ranging in size from 62 to 6,431 square miles. Analyses of selected physical properties (temperature, specific conductance, pH, dissolved oxygen, hardness, and suspended solids), for major ions (chloride and sulfate), for selected metals (iron and manganese), for nutrients (total phosphorus, total nitrogen, total Kjeldahl nitrogen, nitrite plus nitrate), and for fecal coliform were compiled from the Commonwealth's ambient water-quality monitoring network. Trend analyses were completed using the S-Plus statistical software program S-Estimate Trend (S-ESTREND), which detects trends in water-quality data. The trend-detection techniques supplied by this software include the Seasonal Kendall nonparametric methods for use with uncensored data or data censored with only one reporting limit and the Tobit-regression parametric method for use with data censored with multiple reporting limits. One of these tests was selected for each property and water-quality constituent and applied to all station records so that results of the trend procedure could be compared among
Toxicity of Water Samples Collected in the Vicinity of F and H Seepage Basin 1990-1995

Energy Technology Data Exchange (ETDEWEB)

Specht, W.L. [Westinghouse Savannah River Company, AIKEN, SC (United States); Bowers, B.

1996-09-01

Water and contaminants from the F- and H-Area Seepage Basins outcrop as shallow groundwater seeps down gradient from the basins. In 1990, 1991, 1993, 1994, and 1995, toxicity tests were performed on water collected from a number of these seeps, as well as from several locations in Fourmile Branch and several uncontaminated reference locations.
Identification of developmentally toxic drinking water disinfection byproducts and evaluation of data relevant to mode of action

International Nuclear Information System (INIS)

Colman, Joan; Rice, Glenn E.; Wright, J. Michael; Hunter, E. Sidney; Teuschler, Linda K.; Lipscomb, John C.; Hertzberg, Richard C.; Simmons, Jane Ellen; Fransen, Margaret; Osier, Mark; Narotsky, Michael G.

2011-01-01

Reactions between chemicals used to disinfect drinking water and compounds present in source waters produce chemical mixtures containing hundreds of disinfection byproducts (DBPs). Although the results have been somewhat inconsistent, some epidemiological studies suggest associations may exist between DBP exposures and adverse developmental outcomes. The potencies of individual DBPs in rodent and rabbit developmental bioassays suggest that no individual DBP can account for the relative risk estimates reported in the positive epidemiologic studies, leading to the hypothesis that these outcomes could result from the toxicity of DBP mixtures. As a first step in a mixtures risk assessment for DBP developmental effects, this paper identifies developmentally toxic DBPs and examines data relevant to the mode of action (MOA) for DBP developmental toxicity. We identified 24 developmentally toxic DBPs and four adverse developmental outcomes associated with human DBP exposures: spontaneous abortion, cardiovascular defects, neural tube defects, and low birth weight infancy. A plausible MOA, involving hormonal disruption of pregnancy, is delineated for spontaneous abortion, which some epidemiologic studies associate with total trihalomethane and bromodichloromethane exposures. The DBP data for the other three outcomes were inadequate to define key MOA steps.
Kinetics of the degradation of sulfur mustard on ambient and moist concrete

Energy Technology Data Exchange (ETDEWEB)

Brevett, Carol A.S. [SAIC, Gunpowder Branch, P.O. Box 68, APG, MD 21010-0068 (United States)], E-mail: carol.brevett@us.army.mil; Sumpter, Kenneth B. [U.S. Army Edgewood Chemical Biological Center, 5183 Blackhawk Road, Aberdeen Proving Ground, MD 21010-5424 (United States); Nickol, Robert G. [SAIC, Gunpowder Branch, P.O. Box 68, APG, MD 21010-0068 (United States)

2009-02-15

The rate of degradation of the chemical warfare agent sulfur mustard, bis(2-chloroethyl) sulfide, was measured on ambient and moist concrete using {sup 13}C Solid State Magic Angle Spinning Nuclear Magnetic Resonance (SSMAS NMR). Three samples of concrete made by the same formulation, but differing in age and alkalinity were used. The sulfur mustard eventually degraded to thiodiglycol and 1,4-oxathiane via the intermediate sulfonium ions CH-TG, H-TG, H-2TG and O(CH{sub 2}CH{sub 2}){sub 2}S{sup +}CH{sub 2}CH{sub 2}OH on all of the concrete samples, and in addition formed 8-31% vinyl moieties on the newer, more alkaline concrete samples. This is the first observation of the formation of O(CH{sub 2}CH{sub 2}){sub 2}S{sup +}CH{sub 2}CH{sub 2}OH on a solid substrate. The addition of 2-chloroethanol to concrete on which mustard had fully degraded to thiodiglycol and 1,4-oxathiane resulted in the formation of O(CH{sub 2}CH{sub 2}){sub 2}S{sup +}CH{sub 2}CH{sub 2}OH, thus demonstrating the reversibility of sulfur mustard degradation pathways. The sulfur mustard degradation half-lives on ambient concrete at 22 deg. C ranged from 3.5 to 54 weeks. When the substrates were moistened, the degradation half-lives at 22 deg. C ranged from 75 to 350 h. The degradation of sulfur mustard occurred more quickly at elevated temperatures and with added water. The non-volatile toxic sulfonium ions persisted for months to years on concrete at 22 deg. C and weeks to months on concrete at 35 deg. C, before decomposing to the relatively non-toxic compounds thiodiglycol and 1,4-oxathiane.
A Broad Spectrum Catalytic System for Removal of Toxic Organics from Water by Deep Oxidation - Final Report

Energy Technology Data Exchange (ETDEWEB)

Sen, Ayusman

2000-12-01

A most pressing need for the DOE environmental management program is the removal of toxic organic compounds present in groundwater and soil at specific DOE sites. While several remediation procedures have been proposed, they suffer from one or more drawbacks. The objective of the present research was to develop new catalytic procedures for the removal of toxic organic compounds from the environment through their deep oxidation to harmless products. In water, metallic palladium was found to catalyze the deep oxidation of a wide variety of toxic organic compounds by dioxygen at 80-90 C in the presence of carbon monoxide or dihydrogen. Several classes of organic compounds were examined: benzene, phenol and substituted phenols, nitro and halo organics, organophosphorus, and organosulfur compounds. In every case, deep oxidation to carbon monoxide, carbon dioxide, and water occurred in high yields, resulting in up to several hundred turnovers over a 24 hour period. For substrates susceptible to hydrogenation, the conversions were generally high with dihydrogen than with carbon monoxide. It is clear from the results obtained that we have discovered an exceptionally versatile catalytic system for the deep oxidation of toxic organic compounds in water. This system possesses several attractive features not found simultaneously in other reported systems. These are (a) the ability to directly utilize dioxygen as the oxidant, (b) the ability to carry out the deep oxidation of a particularly wide range of functional organics, and (c) the ease of recovery of the catalyst by simple filtration.
Fabrication and optimizing of metal nano silicate as toxic metal absorbent from sea water

OpenAIRE

Solgi, Leila

2013-01-01

Pure Water, is a crucial demand of creature life. Following industrial development, extra amount of toxic metals such as chromium enters the environmental cycle through the sewage, which is considered as a serious threat for organisms. One of the modern methods of filtration and removal of contaminants in water, is applying Nano-technology. According to specific property of silicate materials, in this article we try to survey increased power in composites and various absorption in several mor...

FLUORIDE TOXICITY – A HARSH REALITY

OpenAIRE

Bandlapalli Pavani; Mandava Ragini; David Banji; Otilia J F Banji; N Gouri Pratusha

2011-01-01

There are many incidents of fluoride toxicity whether it is acute or chronic. Fluoride toxicity is an environmental hazard which arises from the upper layers of geological crust and is dissolved in water. Prolonged drinking of such water causes chronic fluoride toxicity. Use of fluoride containing compounds for various purposes such as dental products, metal, glass, refrigerator and chemical industries act as a source of fluoride poisoning and increase the risk of toxicity. This review reflec...
Effects of ambient conditions on fuel cell vehicle performance

Science.gov (United States)

Haraldsson, K.; Alvfors, P.

Ambient conditions have considerable impact on the performance of fuel cell hybrid vehicles. Here, the vehicle fuel consumption, the air compressor power demand, the water management system and the heat loads of a fuel cell hybrid sport utility vehicle (SUV) were studied. The simulation results show that the vehicle fuel consumption increases with 10% when the altitude increases from 0 m up to 3000 m to 4.1 L gasoline equivalents/100 km over the New European Drive Cycle (NEDC). The increase is 19% on the more power demanding highway US06 cycle. The air compressor is the major contributor to this fuel consumption increase. Its load-following strategy makes its power demand increase with increasing altitude. Almost 40% of the net power output of the fuel cell system is consumed by the air compressor at the altitude of 3000 m with this load-following strategy and is thus more apparent in the high-power US06 cycle. Changes in ambient air temperature and relative humidity effect on the fuel cell system performance in terms of the water management rather in vehicle fuel consumption. Ambient air temperature and relative humidity have some impact on the vehicle performance mostly seen in the heat and water management of the fuel cell system. While the heat loads of the fuel cell system components vary significantly with increasing ambient temperature, the relative humidity did not have a great impact on the water balance. Overall, dimensioning the compressor and other system components to meet the fuel cell system requirements at the minimum and maximum expected ambient temperatures, in this case 5 and 40 °C, and high altitude, while simultaneously choosing a correct control strategy are important parameters for efficient vehicle power train management.
SEWAGE DECOMPOSITION IN AMBIENT WATER: INFLUENCE OF SOLARRADIATION AND BIOTIC INTERACTIONS ON MICROORGANISM COMMUNITIES AND BACTEROIDALES REAL-TIME QUANTITATIVE PCR MEASUREMENTS - poster

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AIMS: Sewage and ambient water both consist of a highly complex array of bacteria and eukaryotic microbes. When these communities are mixed, solar radiation and biotic interactions (predation and competition) can influence pathogen decay based on experiments targeting indicator ...
Surface-Water Quality Conditions and Long-Term Trends at Selected Sites within the Ambient Water-Quality Monitoring Network in Missouri, Water Years 1993-2008

Science.gov (United States)

Barr, Miya N.; Davis, Jerri V.

2010-01-01

The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, collects data pertaining to the surface-water resources of Missouri. These data are collected as part of the Missouri Ambient Water-Quality Monitoring Network and constitute a valuable source of reliable, impartial, and timely information for developing an improved understanding of water resources in the State. Six sites from the Ambient Water-Quality Monitoring Network, with data available from the 1993 through 2008 water years, were chosen to compare water-quality conditions and long-term trends of dissolved oxygen, selected physical properties, total suspended solids, dissolved nitrate plus nitrite as nitrogen, total phosphorous, fecal indicator bacteria, and selected trace elements. The six sites used in the study were classified in groups corresponding to the physiography, main land use, and drainage basin size, and represent most stream types in Missouri. Long-term trends in this study were analyzed using flow-adjusted and non-flow adjusted models. Highly censored datasets (greater than 5 percent but less than 50 percent censored values) were not flow-adjusted. Trends that were detected can possibly be related to changes in agriculture or urban development within the drainage basins. Trends in nutrients were the most prevalent. Upward flow-adjusted trends in dissolved nitrate plus nitrite (as nitrogen) concentrations were identified at the Elk River site, and in total phosphorus concentrations at the South Fabius and Grand River sites. A downward flow-adjusted trend was identified in total phosphorus concentrations from Wilson Creek, the only urban site in the study. The downward trend in phosphorus possibly was related to a phosphorus reduction system that began operation in 2001 at a wastewater treatment plant upstream from the sampling site. Total suspended solids concentrations indicated an upward non-flow adjusted trend at the two northern sites (South Fabius
Study of radon concentration and toxic elements in drinking and irrigated water and its implications in Sungai Petani, Kedah, Malaysia

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Nisar Ahmad

2015-07-01

Full Text Available The radon activity concentration and toxic elements have been assessed in drinking and irrigated water samples collected from different locations of Sungai Petani, Kedah, Malaysia. The water samples were collected from wells, streams and taps. A calibrated alpha spectrometer RAD-7 (Model 2890 and Atomic Absorption Spectrometers (Perkin–Elmer, Model AAnalyst 200, Shimadzu, Model AA-700 were used to estimate radon activity concentration and toxic elements, respectively. Maximum average value of radon concentration among the various types of water sources was found 14.7 ± 1.44 Bq/l in well water used for drinking and irrigation and minimum was found 5.37 ± 0.58 Bq/l in tap water used for drinking. Contribution of radon in drinking water to indoor air and age dependent associated annual effective doses were calculated from the measured radon concentration and were found less than lower limit of recommended action level. The activity concentrations of Ni > Pb > Cd > As > Cr were found higher for streams water as compared to wells and tap water. Values of radon concentration in well water were found higher than EPA recommended level and lower than WHO action level while the annual effective doses and level of toxic elements in water reported in this study were found lower than recommended level.
Coastal upwelling linked to toxic Pseudo-nitzschia australis blooms in Los Angeles coastal waters, 2005-2007

KAUST Repository

Schnetzer, Astrid; Jones, Burton; Schaffner, Rebecca A.; Cetinić, Ivona; Fitzpatrick, Elizabeth; Miller, Peter E.; Seubert, Erica L.; Caron, David A.

2013-01-01

Harmful algal blooms dominated by the diatom Pseudo-nitzschia spp. have become a perennial but variable event within surface waters near the greater Los Angeles area. Toxic blooms during spring seasons from 2005 to 2007 varied strongly in their overall toxicity and duration. Differences in bloom dynamics were linked to differences in storm-induced river discharge following episodic rain events and coastal upwelling, both major coastal processes that led to the injection of nutrients into coastal surface waters. Heavy river runoff during early 2005, a record-rainfall year, favored a phytoplankton community mainly comprised of algal taxa other than Pseudo-nitzschia. The spring bloom during 2005 was associated with low domoic acid surface concentrations and minor contributions of (mainly) P. delicatissima to the diatom assemblage. In contrast, highly toxic P. australis-dominated blooms during spring seasons of 2006 and 2007 were linked to strong upwelling events. River discharge quotas in 2006 and 2007, in contrast to 2005, fell well below annual averages for the region. Surface toxin levels were linked to colder, more saline (i.e. upwelled) water over the 3-year study, but no such consistent relationship between domoic acid levels and other physiochemical parameters, such as macronutrient concentrations or nutrient ratios, was observed. © The Author 2013. Published by Oxford University Press. All rights reserved.
Coastal upwelling linked to toxic Pseudo-nitzschia australis blooms in Los Angeles coastal waters, 2005-2007

KAUST Repository

Schnetzer, Astrid

2013-06-10

Harmful algal blooms dominated by the diatom Pseudo-nitzschia spp. have become a perennial but variable event within surface waters near the greater Los Angeles area. Toxic blooms during spring seasons from 2005 to 2007 varied strongly in their overall toxicity and duration. Differences in bloom dynamics were linked to differences in storm-induced river discharge following episodic rain events and coastal upwelling, both major coastal processes that led to the injection of nutrients into coastal surface waters. Heavy river runoff during early 2005, a record-rainfall year, favored a phytoplankton community mainly comprised of algal taxa other than Pseudo-nitzschia. The spring bloom during 2005 was associated with low domoic acid surface concentrations and minor contributions of (mainly) P. delicatissima to the diatom assemblage. In contrast, highly toxic P. australis-dominated blooms during spring seasons of 2006 and 2007 were linked to strong upwelling events. River discharge quotas in 2006 and 2007, in contrast to 2005, fell well below annual averages for the region. Surface toxin levels were linked to colder, more saline (i.e. upwelled) water over the 3-year study, but no such consistent relationship between domoic acid levels and other physiochemical parameters, such as macronutrient concentrations or nutrient ratios, was observed. © The Author 2013. Published by Oxford University Press. All rights reserved.
High mortality of Red Sea zooplankton under ambient solar radiation.

Science.gov (United States)

Al-Aidaroos, Ali M; El-Sherbiny, Mohsen M O; Satheesh, Sathianeson; Mantha, Gopikrishna; Agustī, Susana; Carreja, Beatriz; Duarte, Carlos M

2014-01-01

High solar radiation along with extreme transparency leads to high penetration of solar radiation in the Red Sea, potentially harmful to biota inhabiting the upper water column, including zooplankton. Here we show, based on experimental assessments of solar radiation dose-mortality curves on eight common taxa, the mortality of zooplankton in the oligotrophic waters of the Red Sea to increase steeply with ambient levels of solar radiation in the Red Sea. Responses curves linking solar radiation doses with zooplankton mortality were evaluated by exposing organisms, enclosed in quartz bottles, allowing all the wavelengths of solar radiation to penetrate, to five different levels of ambient solar radiation (100%, 21.6%, 7.2%, 3.2% and 0% of solar radiation). The maximum mortality rates under ambient solar radiation levels averaged (±standard error of the mean, SEM) 18.4±5.8% h(-1), five-fold greater than the average mortality in the dark for the eight taxa tested. The UV-B radiation required for mortality rates to reach ½ of maximum values averaged (±SEM) 12±5.6 h(-1)% of incident UVB radiation, equivalent to the UV-B dose at 19.2±2.7 m depth in open coastal Red Sea waters. These results confirm that Red Sea zooplankton are highly vulnerable to ambient solar radiation, as a consequence of the combination of high incident radiation and high water transparency allowing deep penetration of damaging UV-B radiation. These results provide evidence of the significance of ambient solar radiation levels as a stressor of marine zooplankton communities in tropical, oligotrophic waters. Because the oligotrophic ocean extends across 70% of the ocean surface, solar radiation can be a globally-significant stressor for the ocean ecosystem, by constraining zooplankton use of the upper levels of the water column and, therefore, the efficiency of food transfer up the food web in the oligotrophic ocean.
High mortality of Red Sea zooplankton under ambient solar radiation.

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Ali M Al-Aidaroos

Full Text Available High solar radiation along with extreme transparency leads to high penetration of solar radiation in the Red Sea, potentially harmful to biota inhabiting the upper water column, including zooplankton. Here we show, based on experimental assessments of solar radiation dose-mortality curves on eight common taxa, the mortality of zooplankton in the oligotrophic waters of the Red Sea to increase steeply with ambient levels of solar radiation in the Red Sea. Responses curves linking solar radiation doses with zooplankton mortality were evaluated by exposing organisms, enclosed in quartz bottles, allowing all the wavelengths of solar radiation to penetrate, to five different levels of ambient solar radiation (100%, 21.6%, 7.2%, 3.2% and 0% of solar radiation. The maximum mortality rates under ambient solar radiation levels averaged (±standard error of the mean, SEM 18.4±5.8% h(-1, five-fold greater than the average mortality in the dark for the eight taxa tested. The UV-B radiation required for mortality rates to reach ½ of maximum values averaged (±SEM 12±5.6 h(-1% of incident UVB radiation, equivalent to the UV-B dose at 19.2±2.7 m depth in open coastal Red Sea waters. These results confirm that Red Sea zooplankton are highly vulnerable to ambient solar radiation, as a consequence of the combination of high incident radiation and high water transparency allowing deep penetration of damaging UV-B radiation. These results provide evidence of the significance of ambient solar radiation levels as a stressor of marine zooplankton communities in tropical, oligotrophic waters. Because the oligotrophic ocean extends across 70% of the ocean surface, solar radiation can be a globally-significant stressor for the ocean ecosystem, by constraining zooplankton use of the upper levels of the water column and, therefore, the efficiency of food transfer up the food web in the oligotrophic ocean.
CYTOTOXICITY AND MUTAGENESIS METHODS FOR EVALUATING TOXICITY REMOVAL FROM WASTEWATERS

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This project was a feasibility study of the effectiveness of a mammalian cell cytotoxicity assay and a mammalian cell mutagenesis assay for monitoring the toxicity and mutagenicity of influent and effluent wastewater at treatment plants. In the cytotoxicity assay, ambient samples...
The Effects of Temperature and Hydrostatic Pressure on Metal Toxicity: Insights into Toxicity in the Deep Sea.

Science.gov (United States)

Brown, Alastair; Thatje, Sven; Hauton, Chris

2017-09-05

Mineral prospecting in the deep sea is increasing, promoting concern regarding potential ecotoxicological impacts on deep-sea fauna. Technological difficulties in assessing toxicity in deep-sea species has promoted interest in developing shallow-water ecotoxicological proxy species. However, it is unclear how the low temperature and high hydrostatic pressure prevalent in the deep sea affect toxicity, and whether adaptation to deep-sea environmental conditions moderates any effects of these factors. To address these uncertainties we assessed the effects of temperature and hydrostatic pressure on lethal and sublethal (respiration rate, antioxidant enzyme activity) toxicity in acute (96 h) copper and cadmium exposures, using the shallow-water ecophysiological model organism Palaemon varians. Low temperature reduced toxicity in both metals, but reduced cadmium toxicity significantly more. In contrast, elevated hydrostatic pressure increased copper toxicity, but did not affect cadmium toxicity. The synergistic interaction between copper and cadmium was not affected by low temperature, but high hydrostatic pressure significantly enhanced the synergism. Differential environmental effects on toxicity suggest different mechanisms of action for copper and cadmium, and highlight that mechanistic understanding of toxicity is fundamental to predicting environmental effects on toxicity. Although results infer that sensitivity to toxicants differs across biogeographic ranges, shallow-water species may be suitable ecotoxicological proxies for deep-sea species, dependent on adaptation to habitats with similar environmental variability.
Mitigating with macrophytes: submersed plants reduce the toxicity of pesticide-contaminated water to zooplankton.

Science.gov (United States)

Brogan, William R; Relyea, Rick A

2013-03-01

In ecotoxicology, appreciation is growing for the influence that ecological interactions have on the toxicity of contaminants, such as insecticides, to sensitive species. Most previous studies, however, have focused on factors that exacerbate insecticide effects on species, while factors that may mitigate these effects have been relatively ignored. In aquatic habitats, a small number of studies have shown that submersed macrophytes can remove some insecticides from the water column via sorption. Although examining sorption dynamics is important for understanding the environmental fate of insecticides, whether and to what extent macrophytes actually mitigate insecticide effects on aquatic species remains unknown. In the present study, the authors examined how much and how quickly several realistic densities of the macrophyte Elodea canadensis decreased the toxicity of the insecticide malathion to Daphnia magna, a keystone aquatic herbivore. To do this, the authors quantified Daphnia survival in outdoor test systems (0.95 L) exposed to a factorial combination of five Elodea densities crossed with five malathion concentrations. The authors discovered that malathion's lethality to Daphnia decreased with increasing Elodea density. Furthermore, the rate at which Elodea reduced malathion's toxicity in the water column increased with macrophyte density. These results provide strong evidence that submersed macrophytes can mitigate the ecological impacts of a popular insecticide and further support that ecological interactions can strongly influence contaminant environmental effects. Copyright © 2013 SETAC.
Characterization of selenium in ambient aerosols and primary emission sources.

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De Santiago, Arlette; Longo, Amelia F; Ingall, Ellery D; Diaz, Julia M; King, Laura E; Lai, Barry; Weber, Rodney J; Russell, Armistead G; Oakes, Michelle

2014-08-19

Atmospheric selenium (Se) in aerosols was investigated using X-ray absorption near-edge structure (XANES) spectroscopy and X-ray fluorescence (XRF) microscopy. These techniques were used to determine the oxidation state and elemental associations of Se in common primary emission sources and ambient aerosols collected from the greater Atlanta area. In the majority of ambient aerosol and primary emission source samples, the spectroscopic patterns as well as the absence of elemental correlations suggest Se is in an elemental, organic, or oxide form. XRF microscopy revealed numerous Se-rich particles, or hotspots, accounting on average for ∼16% of the total Se in ambient aerosols. Hotspots contained primarily Se(0)/Se(-II). However, larger, bulk spectroscopic characterizations revealed Se(IV) as the dominant oxidation state in ambient aerosol, followed by Se(0)/Se(-II) and Se(VI). Se(IV) was the only observed oxidation state in gasoline, diesel, and coal fly ash, while biomass burning contained a combination of Se(0)/Se(-II) and Se(IV). Although the majority of Se in aerosols was in the most toxic form, the Se concentration is well below the California Environmental Protection Agency chronic exposure limit (∼20000 ng/m(3)).
Acute toxicity of pyraclostrobin and trifloxystrobin to Hyalella azteca.

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Morrison, Shane A; McMurry, Scott T; Smith, Loren M; Belden, Jason B

2013-07-01

Fungicide application rates on row crop agriculture have increased across the United States, and subsequently, contamination of adjacent wetlands can occur through spray drift or field runoff. To investigate fungicide toxicity, Hyalella azteca amphipods were exposed to 2 fungicide formulations, Headline and Stratego, and their active strobilurin ingredients, pyraclostrobin and trifloxystrobin. Water-only exposures resulted in similar median lethal concentration (LC50; 20-25 µg/L) values for formulations and strobilurin ingredients, suggesting that toxicity is due to strobilurin ingredients. These values were below concentrations that could occur following spray drift over embedded cropland wetlands. When fungicides were added to overlying water of sediment-water microcosms, toxicity was reduced by 500% for Headline and 160% for Stratego, compared with water-only exposures, based on the total amount of fungicide added to the systems. In addition, when fungicides were added to sediment prior to the addition of water, the reduction in toxicity was even greater, with no toxicity occurring at environmentally relevant levels. Differences in toxicity among exposure groups were explained by dissipation from water as toxicity values based on measured water concentrations were within 20% between all systems. The present study reinforces previous studies that Headline and Stratego are toxic to nontarget aquatic organisms. However, the presence of sediment is likely to ameliorate some toxicity of fungicide formulations, especially if spraying occurs prior to wetland inundation. Copyright © 2013 SETAC.
Acute toxicity and inactivation tests of CO2 on invertebrates in drinking water treatment systems.

Science.gov (United States)

Yin, Wen-Chao; Zhang, Jin-Song; Liu, Li-Jun; Zhao, Jian-Shu; Li, Tuo

2011-01-01

In addition to the esthetic problem caused by invertebrates, researchers are recently starting to be more aware of their potential importance in terms of public health. However, the inactivation methods of invertebrates which could proliferate in drinking water treatment systems are not well developed. The objective of this study is to assess the acute toxicity and inactivation effects of CO2 on familiar invertebrates in water treatment processes. The results of this study revealed that CO2 has a definite toxicity to familiar invertebrates. The values of 24-h LC50 (median lethal concentration) were calculated for each test with six groups of invertebrates. The toxicity of CO2 was higher with increasing concentrations in solution but was lower with the increase in size of the invertebrates. Above the concentration of 1,000 mg/L for the CO2 solution, the 100% inactivation time of all the invertebrates was less than 5 s, and in 15 min, the inactivation ratio showed a gradient descent with a decline in concentration. As seen for Mesocyclops thermocyclopoides, by dosing with a sodium bicarbonate solution first and adding a dilute hydrochloric acid solution 5 min later, it is possible to obtain a satisfactory inactivation effect in the GAC (granular activated carbon) filters.
Ammonia production, excretion, toxicity, and defense in fish: A Review

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Alex Y K Ip

2010-10-01

Full Text Available Many fishes are ammonotelic but some species can detoxify ammonia to glutamine or urea. Certain fish species can accumulate high levels of ammonia in the brain or defense against ammonia toxicity by enhancing the effectiveness of ammonia excretion through active NH4+ transport, manipulation of ambient pH, or reduction in ammonia permeability through the branchial and cutaneous epithelia. Recent reports on ammonia toxicity in mammalian brain reveal the importance of permeation of ammonia through the blood-brain barrier and passages of ammonia and water through transporters in the plasmalemma of brain cells. Additionally, brain ammonia toxicity could be related to the passage of glutamine through the mitochondrial membranes into the mitochondrial matrix. On the other hand, recent reports on ammonia excretion in fish confirm the involvement of Rhesus glycoproteins in the branchial and cutaneous epithelia. Therefore, this review focuses on both the earlier literature and the up-to-date information on the problems and mechanisms concerning the permeation of ammonia, as NH3, NH4+ or proton-neutral nitrogenous compounds, across mitochondrial membranes, the blood-brain barrier, the plasmalemma of neurons, and the branchial and cutaneous epithelia of fish. It also addresses how certain fishes with high ammonia tolerance defend against ammonia toxicity through the regulation of the permeation of ammonia and related nitrogenous compounds through various types of membranes. It is hoped that this review would revive the interests in investigations on the passage of ammonia through the mitochondrial membranes and the blood-brain barrier of ammonotelic fishes and fishes with high brain ammonia-tolerance, respectively.
Toxicity of common ions to marine organisms

International Nuclear Information System (INIS)

Pillard, D.A.; DuFresne, D.L.; Evans, J.

1995-01-01

Produced waters from oil and gas drilling operations are typically very saline, and these may cause acute toxicity to marine organisms due to osmotic imbalances as well as to an excess or deficiency of specific common ions. In order to better understand the relationship between toxicity and ion concentration, laboratory toxicity tests were conducted using mysid shrimp (Mysidopsis bahia), sheepshead minnow (Cyprinodon variegatus), and inland silverside (Menidia beryllina). For each species the ionic concentration of standard laboratory water was proportionally increased or decreased to produce test solutions with a range of salinities. Organisms were exposed for 48 hours. Individual ions (sodium, potassium, calcium, magnetsium, strontium, chloride, bromide, sulfate, bicarbonate, and borate) were also manipulated to examine individual ion toxicity. The three test species differ in their tolerance of salinity. Mysid shrimp show a marked decrease in survival at salinities less than approximately 5 ppt. Both fish species tolerated low salinity water, however, silversides were less tolerant of saline waters (salinity greater than 40 ppt). There were also significant differences in the responses of the organisms to different ions. The results show that the salinity of the test solution may play an important role in the responses of the organisms to the produced water effluent. Predictable toxicity/ion relationships developed in this study can be used to estimate whether toxicity in a produced water is a result of common ions, salinity, or some other unknown toxicant
Acute and subchronic toxicity study of the water extract from dried fruits of Piper nigrum L. in rats

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Kanjana Jaijoy

2007-03-01

Full Text Available The study was carried out to evaluate acute and subchronic toxicities of the water extract from the dried fruits of Piper nigrum L. A single oral administration of the extract at a dose of 5,000 mg/kg body weight (5 male, 5 female did not produce signs of toxicity, behavioral changes, mortality, changes on gross appearance or histopathological changes of internal organs. The subchronic toxicity was determined by oral feeding both male and female rats (10 male, 10 female daily with the test substance at the doses of 300, 600 and 1,200 mg/kg body weight continuously for 90 days. The examinations of signs, animal behavior and health monitoring showed no abnormalities in the test groups as compared to the controls. The test and control groups (on the 90th day and the satellite group (on the 118th day were analyzed by measuring their final body and organ weights, taking necropsy, and examining hematology, blood clinical chemistry and histopathology. The results suggest that the water extract from the dried fruits of P. nigrum does not cause acute or subchronic toxicities in either male or female rats.
Acute and subchronic toxicity study of the water extract from root of Imperata cylindrica (Linn. Raeusch. in rats

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Siharat Chunlaratthanaphorn

2007-03-01

Full Text Available The water extract from root of Imperata cylindrica (Linn. Raeusch. was studied for acute and subchronic toxicities. The extract at a single dose of 5,000 mg/kg was administered orally to female and male rats (5 male, 5 female. After 14 days, signs and behavioral changes, mortality, gross and histopathological changes of internal organs were examined. The extract did not produce signs of toxicity. For the subchronic toxicity test, the extract at doses of 300, 600 and 1,200 mg/kg body weight was orally administered to rats daily for 90 days (10 male, 10 female. The observation of signs, behavior and health status showed no abnormality in the test groups as compared with the controls. At the end of the study, necropsy and histopathology examination were performed in all animals in the control group, the test groups and the satellite group in which the extract was discontinued for another 28 days. Body and organ weights, hematological and blood clinical chemistry were also examined. The results suggest that the water extract of Imperata cylindrica (Linn. Raeusch does not cause acute and subchronic toxicities in rats.
Preparation and Testing of Impedance-based Fluidic Biochips with RTgill-W1 Cells for Rapid Evaluation of Drinking Water Samples for Toxicity

Science.gov (United States)

2016-03-07

109 | e53555 | Page 1 of 8 Video Article Preparation and Testing of Impedance-based Fluidic Biochips with RTgill-W1 Cells for Rapid Evaluation of...www.jove.com/ video /53555 DOI: doi:10.3791/53555 Keywords: Environmental Sciences, Issue 109, Fish cells, impedance, sensors, biochip, water toxicity...sensitivity to cholinesterase-inhibiting pesticides . Applications for this toxicity detector are for rapid field-portable testing of drinking water

Ceriodaphnia dubia as a potential bio-indicator for assessing acute aluminum oxide nanoparticle toxicity in fresh water environment.

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Sunandan Pakrashi

Full Text Available Growing nanomaterials based consumer applications have raised concerns about their potential release into the aquatic ecosystems and the consequent toxicological impacts. So environmental monitoring of the nanomaterials in aqueous systems becomes imperative. The current study reveals the potential of Ceriodaphnia dubia (C. dubia as a bio-indicator for aluminum oxide nanoparticles in a fresh water aquatic ecosystem where it occupies an important ecological niche as a primary consumer. This study aims to investigate the aluminium oxide nanoparticle induced acute toxicity on Ceriodaphnia dubia in a freshwater system. The bioavailability of the aluminum oxide nanoparticles has been studied with respect to their aggregation behavior in the system and correlated with the toxicity endpoints. The oxidative stress generated by the particles contributed greatly toward their toxicity. The crucial role of leached aluminium ion mediated toxicity in the later phases (48 h and 72 h in conjunction with the effects from the nano-sized particles in the initial phases (24 h puts forth the dynamics of nanotoxicity in the test system. The internalization of nanoparticles (both gross and systemic uptake as substantiated through the transmission electron microscopy (TEM and inductively coupled plasma optical emission spectral (ICP-OES analysis was another major contributor toward acute toxicity. Concluding the present study, Ceriodaphnia dubia can be a promising candidate for bio-monitoring the aluminium oxide nanoparticles in a fresh water system.
Toxicity of water-soluble fractions of biodiesel fuels derived from castor oil, palm oil, and waste cooking oil.

Science.gov (United States)

Leite, Maria Bernadete Neiva Lemos; de Araújo, Milena Maria Sampaio; Nascimento, Iracema Andrade; da Cruz, Andrea Cristina Santos; Pereira, Solange Andrade; do Nascimento, Núbia Costa

2011-04-01

Concerns over the sustained availability of fossil fuels and their impact on global warming and pollution have led to the search for fuels from renewable sources to address worldwide rising energy demands. Biodiesel is emerging as one of the possible solutions for the transport sector. It shows comparable engine performance to that of conventional diesel fuel, while reducing greenhouse gas emissions. However, the toxicity of products and effluents from the biodiesel industry has not yet been sufficiently investigated. Brazil has a very high potential as a biodiesel producer, in view of its climatic conditions and vast areas for cropland, with consequent environmental risks because of possible accidental biodiesel spillages into water bodies and runoff to coastal areas. This research determined the toxicity to two marine organisms of the water-soluble fractions (WSF) of three different biodiesel fuels obtained by methanol transesterification of castor oil (CO), palm oil (PO), and waste cooking oil (WCO). Microalgae and sea urchins were used as the test organisms, respectively, for culture-growth-inhibition and early-life-stage-toxicity tests. The toxicity levels of the analyzed biodiesel WSF showed the highest toxicity for the CO, followed by WCO and the PO. Methanol was the most prominent contaminant; concentrations increased over time in WSF samples stored up to 120 d. Copyright © 2010 SETAC.
Water and organic nitrate detection in an AMS. Laboratory characterization and application to ambient measurements

Energy Technology Data Exchange (ETDEWEB)

Mensah, Amewu A.

2011-08-12

Atmospheric aerosols were studied by three different means. Laboratory experiments determined the relative ionization efficiency of water (RIE{sub H2O}) in an Aerodyne Aerosol Mass Spectrometers (AMS), simulation chamber experiments gave insight to the reaction products of biogenic volatile organic compounds (BVOC) oxidation products, and the findings were applied to two field campaign measurements at Cabauw, NL, in May 2008 and February 2009. Knowing the liquid water content of aerosol particles is vital for the assessment of their climate forcing potential. A value of 2 for RIE{sub H2O} was determined by studying oxalate salts with different amounts of crystal water. BVOCs contribute much more to the global budget of VOCs than anthropogenic ones but oxidation products in terms of secondary organic aerosol often correlate to anthropogenic tracers such as NO{sub x} from fossil fuel burning. In atmospheric simulation chamber experiments, organic nitrates from BVOC-NO{sub 3} oxidation showed higher vapor pressures than pure organic compounds produced in the same reactions. Organic nitrates comprised up to approx. 41 % of the particulate phase. A specific fragmentation ratio of nitrate (NO{sub 2}{sup +}/NO{sup +}) of 0.1 was found by high resolution AMS analysis differing strongly from the value of 0.4 known for the most abundant ambient NO{sub 3} specie (NH{sub 4}NO{sub 3}). Ambient average particulate mass loadings were 9.72 {mu}g/m{sup 3} dominated by organics (40 %) in 2008 and 5.62 {mu}g/m{sup 3} dominated by nitrate (42 %) in 2009. Data comparison to collocated instruments showed good agreement. Positive Matrix Factorization analysis of the particulate organic fraction distinguished semi and low volatile oxygenated organic aerosol (OOA) as well as hydrocarbon like organic aerosol (HOA) in both campaigns. An additional highly oxygenated OA with a mass spectrum very similar to fulvic acid was found in 2008. The average contribution of organic nitrate to the
Occurrence of the Microcystins MC-LW and MC-LF in Dutch Surface Waters and Their Contribution to Total Microcystin Toxicity

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Elisabeth J. Faassen

2013-07-01

Full Text Available Microcystins (MCs are the most frequently found cyanobacterial toxins in freshwater systems. Many MC variants have been identified and variants differ in their toxicity. Recent studies showed that the variants MC-LW and MC-LF might be more toxic than MC-LR, the variant that is most abundant and mostly used for risk assessments. As little is known about the presence of these two variants in The Netherlands, we determined their occurrence by analyzing 88 water samples and 10 scum samples for eight MC variants ((dm-7-MC-RR, MC-YR, (dm-7-MC-LR, MC-LY, MC-LW and MC-LF by liquid chromatography with tandem mass spectrometry detection. All analyzed MC variants were detected, and MC-LW and/or MC-LF were present in 32% of the MC containing water samples. When MC-LW and MC-LF were present, they contributed to nearly 10% of the total MC concentrations, but due to their suspected high toxicity, their average contribution to the total MC toxicity was estimated to be at least 45%. Given the frequent occurrence and possible high toxicity of MC-LW and MC-LF, it seems better to base health risk assessments on the toxicity contributions of different MC variants than on MC-LR concentrations alone.
The analysis of toxic connections content in water by spectral methods

Science.gov (United States)

Plotnikova, I. V.; Chaikovskaya, O. N.; Sokolova, I. V.; Artyushin, V. R.

2017-08-01

The current state of ecology means the strict observance of measures for the utilization of household and industrial wastes that is connected with very essential expenses of means and time. Thanks to spectroscopic devices usage the spectral methods allow to carry out the express quantitative and qualitative analysis in a workplace and field conditions. In a work the application of spectral methods by studying the degradation of toxic organic compounds after preliminary radiation of various sources is shown. Experimental data of optical density of water at various influences are given.
Preparation and Testing of Impedance-based Fluidic Biochips with RTgill-W1 Cells for Rapid Evaluation of Drinking Water Samples for Toxicity.

Science.gov (United States)

Brennan, Linda M; Widder, Mark W; McAleer, Michael K; Mayo, Michael W; Greis, Alex P; van der Schalie, William H

2016-03-07

This manuscript describes how to prepare fluidic biochips with Rainbow trout gill epithelial (RTgill-W1) cells for use in a field portable water toxicity sensor. A monolayer of RTgill-W1 cells forms on the sensing electrodes enclosed within the biochips. The biochips are then used for testing in a field portable electric cell-substrate impedance sensing (ECIS) device designed for rapid toxicity testing of drinking water. The manuscript further describes how to run a toxicity test using the prepared biochips. A control water sample and the test water sample are mixed with pre-measured powdered media and injected into separate channels of the biochip. Impedance readings from the sensing electrodes in each of the biochip channels are measured and compared by an automated statistical software program. The screen on the ECIS instrument will indicate either "Contamination Detected" or "No Contamination Detected" within an hour of sample injection. Advantages are ease of use and rapid response to a broad spectrum of inorganic and organic chemicals at concentrations that are relevant to human health concerns, as well as the long-term stability of stored biochips in a ready state for testing. Limitations are the requirement for cold storage of the biochips and limited sensitivity to cholinesterase-inhibiting pesticides. Applications for this toxicity detector are for rapid field-portable testing of drinking water supplies by Army Preventative Medicine personnel or for use at municipal water treatment facilities.
Heavy metals, PAHs and toxicity in stormwater wet detention ponds

DEFF Research Database (Denmark)

Wium-Andersen, Tove; Nielsen, Asbjørn Haaning; Hvitved-Jacobsen, Thorkild

2011-01-01

Concentrations of 6 different heavy metals and total Polycyclic Aromatic Hydrocarbons (PAH) were determined in stormwater runoff and in the pond water of two Danish wet detention ponds. The pond water samples were analyzed for toxic effects, using the algae Selenastrum capricornutum as a test...... organism. Stormwater and pond water from a catchment with light industry showed high levels of heavy metals, especially zinc and copper. The pond water showed high toxic effects and copper were found to be the main toxicant. Additionally, a large part of the copper was suspected to be complex bound......, reducing the potential toxicity of the metal. Another catchment (residential) produced stormwater and pond water with moderate concentration of heavy metals. The pond water occasionally showed toxic effects but no correlation between heavy metals and toxicity was identified. PAHs concentrations were...
Investigation of the precipitation of Na2SO4 in supercritical water

DEFF Research Database (Denmark)

Voisin, T.; Erriguible, A.; Philippot, G.

2017-01-01

solubility in sub-and supercritical water is determined on a wide temperature range using a continuous set-up. Crystallite sizes formed after precipitation are measured with in situ synchrotron wide angle X-ray scattering (WAXS). Combining these experimental results, a numerical modeling of the precipitation......SuperCritical Water Oxidation process (SCWO) is a promising technology for treating toxic and/or complex chemical wastes with very good efficiency. Above its critical point (374 degrees C, 22.1 MPa), water exhibits particular properties and organic compounds can be easily dissolved and degraded...... with the addition of oxidizing agents. But these interesting properties imply a main drawback regarding inorganic compounds. Highly soluble at ambient temperature in water, these inorganics (such as salts) are no longer soluble in supercritical water and precipitate into solids, creating plugs in SCWO processes...
Oxidative Stress, DNA Damage, and Inflammation Induced by Ambient Air and Wood Smoke Particulate Matter in Human A549 and THP-1 Cell Lines

DEFF Research Database (Denmark)

Danielsen, Pernille Høgh; Møller, Peter; Jensen, Keld Alstrup

2011-01-01

PM (WSPM) is poorly assessed. We assessed a wide spectrum of toxicity end points in human A549 lung epithelial and THP-1 monocytic cell lines comparingWSPM from high or low oxygen combustion and ambient PM collected in a village with many operating wood stoves and from a rural background area...... from the wood stove area. Expression of oxoguanine glycosylase 1, lymphocyte function-associated antigen-1, and interleukin-6 did not change. We conclude that WSPM has small particle size, high level of PAH, low level of water-soluble metals, and produces high levels of free radicals, DNA damage...
Anaerobic biodegradability and toxicity of complex or toxicant wastewater

International Nuclear Information System (INIS)

Wills Betancur, B.A.

1995-01-01

As a first approximation to wastewater classification in susceptibility terms to treatment by anaerobic biological system, anaerobic biodegradability trials are accomplished to leached of sanitary landfill, to wastewater of coffee grain wet treatment plant and to wastewater of fumaric acid recuperation plant. In the last Plant, anaerobic toxicity trials and lethal toxicity on the Daphnia pulex micro-crustacean are made too. Anaerobic biological trials are made continuing the Wageningen University (Holland) Methodology (1.987). Lethal toxicity biological trials are made following the Standard Methods for the Examination of Water and Wastewater(18th edition, 1992). In development of this investigation project is found that fumaric acid recuperation plant leached it has a low anaerobic biodegradability, a high anaerobic toxicity and a high lethal toxicity over Daphnia pulex, for such reasons this leached is cataloged as complex and toxic wastewater. The other hand, wastewater of coffee grain wet treatment plant and wastewater of sanitary landfill they are both highly biodegradability and not-toxic, for such reasons these wastewaters are cataloged as susceptible to treatment by anaerobic biological system
Determination of water quality, toxicity and estrogenic activity in a nearshore marine environment in Rio de Janeiro, Southeastern Brazil.

Science.gov (United States)

do Nascimento, Marilia Teresa Lima; Santos, Ana Dalva de Oliveira; Felix, Louise Cruz; Gomes, Giselle; de Oliveira E Sá, Mariana; da Cunha, Danieli Lima; Vieira, Natividade; Hauser-Davis, Rachel Ann; Baptista Neto, José Antonio; Bila, Daniele Maia

2018-03-01

Endocrine disrupting compounds (EDCs) can be found in domestic sewage, wastewater treatment plant effluents, natural water, rivers, lakes and in the marine environment. Jurujuba Sound, located in the state of Rio de Janeiro, Southeastern Brazil, receives untreated sewage into its waters, one the main sources of aquatic contamination in this area. In this context, the aim of the present study was to evaluate the estrogenic potential of water sampled from different depths and from areas with differential contamination levels throughout Jurujuba Sound. Water quality was evaluated and acute toxicity assays using Allviibrio fischeri were conducted, while estrogenic activity of the water samples was determined by a Yeast Estrogen Screening assay (YES). Water quality was mostly within the limits established for marine waters by the Brazilian legislation, with only DOC and ammoniacal nitrogen levels above the maximum permissible limits. No acute toxicity effects were observed in the Allivibrio fisheri assay. The YES assay detected moderate estrogenic activity in bottom water samples from 3 sampling stations, ranging from 0.5 to 3.2ngL -1 , as well as in one surface water sample. Estrogenic activity was most frequently observed in samples from the bottom of the water column, indicating adsorption of estrogenic compounds to the sediment. Copyright © 2017 Elsevier Inc. All rights reserved.
Single Laboratory Validated Method for Determination of Cylindrospermopsin and Anatoxin-a in Ambient Water by Liquid Chromatography/ Tandem Mass Spectrometry (LC/MS/MS)

Science.gov (United States)

This product is an LC/MS/MS single laboratory validated method for the determination of cylindrospermopsin and anatoxin-a in ambient waters. The product contains step-by-step instructions for sample preparation, analyses, preservation, sample holding time and QC protocols to ensu...
Application of reverse osmosis membrane for separation of toxic metal in water

International Nuclear Information System (INIS)

Syahril Ahmad

2010-01-01

Experimental separation of toxic metal in water has been done using reverse osmosis membrane made from composite material. Experiment was done by simulation in which metals that will be observed solved with water in different concentration and then used as feed solution in reverse osmosis process. Metals observed were Cr"6"+, Mn"2"+ and Pb"2"+ and reverse osmosis process was done at pressure of 40 Bar for all metals. Experiment result showed that value of feed solution concentration would affect flux and coefficient rejection of membrane. Composite membrane with polyacrylamide as active layer of membrane can reject metals observed with value of rejection coefficient more than 90%, except for Mn"2"+metal that have concentration 250 ppm and 500 ppm. (author)
Concentrations, sources and human health risk of inhalation exposure to air toxics in Edmonton, Canada.

Science.gov (United States)

Bari, Md Aynul; Kindzierski, Warren B

2017-04-01

With concern about levels of air pollutants in recent years in the Capital Region of Alberta, an investigation of ambient concentrations, sources and potential human health risk of hazardous air pollutants (HAPs) or air toxics was undertaken in the City of Edmonton over a 5-year period (2009-2013). Mean concentrations of individual HAPs in ambient air including volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs) and trace metals ranged from 0.04 to 1.73 μg/m 3 , 0.01-0.54 ng/m 3 , and 0.05-3.58 ng/m 3 , respectively. Concentrations of benzene, naphthalene, benzo(a)pyrene (BaP), arsenic, manganese and nickel were far below respective annual Alberta Ambient Air Quality Objectives. Carcinogenic and non-carcinogenic risk of air toxics were also compared with risk levels recommended by regulatory agencies. Positive matrix factorization identified six air toxics sources with traffic as the dominant contributor to total HAPs (4.33 μg/m 3 , 42%), followed by background/secondary organic aerosol (SOA) (1.92 μg/m 3 , 25%), fossil fuel combustion (0.92 μg/m 3 , 11%). On high particulate air pollution event days, local traffic was identified as the major contributor to total HAPs compared to background/SOA and fossil fuel combustion. Carcinogenic risk values of traffic, background/SOA and metals industry emissions were above the USEPA acceptable level (1 × 10 -6 ), but below a tolerable risk (1 × 10 -4 ) and Alberta benchmark (1 × 10 -5 ). These findings offer useful preliminary information about current ambient air toxics levels, dominant sources and their potential risk to public health; and this information can support policy makers in the development of appropriate control strategies if required. Copyright © 2017 Elsevier Ltd. All rights reserved.
Identification of water soluble and particle bound compounds causing sublethal toxic effects. A field study on sediments affected by a chlor-alkali industry

International Nuclear Information System (INIS)

Bosch, Carme; Olivares, Alba; Faria, Melissa; Navas, Jose M.; Olmo, Ivan del; Grimalt, Joan O.; Pina, Benjamin; Barata, Carlos

2009-01-01

A combination of cost effective sublethal Daphnia magna feeding tests, yeast- and cell culture-based bioassays and Toxicity Identification Evaluation (TIE) procedures was used to characterize toxic compounds within sediments collected in a river area under the influence of the effluents from a chlor-alkali industry (Ebro River, NE Spain). Tests were designed to measure and identify toxic compounds in the particulate and filtered water fractions of sediment elutriates. The combined use of bioassays responding to elutriates and dioxin-like compounds evidenced the existence of three major groups of hazardous contaminants in the most contaminated site: (A) metals such as cadmium and mercury bound to sediment fine particles that could be easily resuspended and moved downstream, (B) soluble compounds (presumably, lye) able to alkalinize water to toxic levels, and (C) organochlorine compounds with high dioxin-like activity. These results provided evidence that elutriate D. magna feeding responses can be used as surrogate assays for more tedious chronic whole sediment tests, and that the incorporation of such tests in sediment TIE procedures may improve the ability to identify the toxicity of particle-bound and water-soluble contaminants in sediments.
Circadian Rhythm of Ambient Noise Off the Southeast Coast of India

Science.gov (United States)

Kannan, R.; Latha, G.; Prashanthi Devi, M.

An ambient noise system consisting of a vertical linear hydrophone array was deployed in the shallow waters off Chennai, southeast coast of India from 1 August to 16 September 2013 to record ambient ocean noise of frequencies up to 10kHz. Biological sounds, which are broadband, short duration signals resulting from Terapon theraps, a native species, are a prominent feature of the ocean soundscape. Terapon activity peaks at 8pm and 11pm, and its presence is not observed after 12 midnight in both the months. In the other period, the ambient noise fluctuation is due to wind and vessel traffic. Hence, the present study focuses on the description of the ambient noise fluctuation over two 12h periods, i.e., 12 midnight-12 noon considered as period I, and 12 noon-12 midnight as period II in order to show the circadian rhythm of ambient noise. In this study area, Terapon vocalization reached 25dB above the ambient noise level and it dominates the short-term spectra records in the 0.4-4kHz range. All Terapon signals had daily patterns of sound production with highest levels of activity after dusk during the study period. The result shows that the circadian rhythm of ambient noise is mainly of biological sound generated by Terapon and it is reported first time in the shallow waters off the southeast coast of India.
Toxicity evaluation of boron nitride nanospheres and water-soluble boron nitride in Caenorhabditis elegans.

Science.gov (United States)

Wang, Ning; Wang, Hui; Tang, Chengchun; Lei, Shijun; Shen, Wanqing; Wang, Cong; Wang, Guobin; Wang, Zheng; Wang, Lin

2017-01-01

Boron nitride (BN) nanomaterials have been increasingly explored for potential biological applications. However, their toxicity remains poorly understood. Using Caenorhabditis elegans as a whole-animal model for toxicity analysis of two representative types of BN nanomaterials - BN nanospheres (BNNSs) and highly water-soluble BN nanomaterial (named BN-800-2) - we found that BNNSs overall toxicity was less than soluble BN-800-2 with irregular shapes. The concentration thresholds for BNNSs and BN-800-2 were 100 µg·mL -1 and 10 µg·mL -1 , respectively. Above this concentration, both delayed growth, decreased life span, reduced progeny, retarded locomotion behavior, and changed the expression of phenotype-related genes to various extents. BNNSs and BN-800-2 increased oxidative stress levels in C. elegans by promoting reactive oxygen species production. Our results further showed that oxidative stress response and MAPK signaling-related genes, such as GAS1 , SOD2 , SOD3 , MEK1 , and PMK1 , might be key factors for reactive oxygen species production and toxic responses to BNNSs and BN-800-2 exposure. Together, our results suggest that when concentrations are lower than 10 µg·mL -1 , BNNSs are more biocompatible than BN-800-2 and are potentially biocompatible material.
Capture of toxic radioactive and heavy metal ions from water by using titanate nanofibers

Energy Technology Data Exchange (ETDEWEB)

Xu, Jiasheng, E-mail: jiashengxu@bhu.edu.cn [Liaoning Province Key Laboratory for Synthesis and Application of Functional Compounds, College of Chemistry, Chemical Engineering and Food Safety, Center of Science and Technology Experiment, Bohai University, 19 Sci-tech Road, Jinzhou 121013 (China); Zhang, He; Zhang, Jie [Liaoning Province Key Laboratory for Synthesis and Application of Functional Compounds, College of Chemistry, Chemical Engineering and Food Safety, Center of Science and Technology Experiment, Bohai University, 19 Sci-tech Road, Jinzhou 121013 (China); Kim, Eui Jung [School of Chemical Engineering and Bioengineering, University of Ulsan, Ulsan 680-749 (Korea, Republic of)

2014-11-25

Highlights: • Three types of titanate nanofibers were prepared via a hydrothermal porcess. • These nanofibers show availability for removal of the toxic ions from water. • The equilibrium data were fitted well with the Langmuir model. - Abstract: Three types of titanate nanofibers (sodium titanate nanofibers (TNF-A), potassium/sodium titanate nanofibers (TNF-B), potassium titanate nanofibers (TNF-C)) were prepared via a hydrothermal treatment of anatase powders in different alkali solutions at 170 °C for 96 h, respectively. The as-prepared nanofibers have large specific surface area and show availability for the removal of radioactive and heavy metal ions from water system, such as Ba{sup 2+} (as substitute of {sup 226}Ra{sup 2+}) and Pb{sup 2+} ions. The TNF-A shows a better capacity in the removal of Ba{sup 2+} and Pb{sup 2+} than TNF-B and TNF-C. Structural characterization of the materials was performed with powder X-ray diffraction (XRD), scanning electron microscopy (SEM) equipped with energy dispersive spectrometer (EDS) and with inductively coupled plasma optical emission spectrometry (ICP-OES). It is found that the equilibrium data fit well with the Langmuir model. This study highlights that nanoparticles of inorganic ion exchangers with layered structure are potential materials for efficient removal of the toxic ions from contaminated water.
In utero exposure to toxic air pollutants and risk of childhood autism.

Science.gov (United States)

von Ehrenstein, Ondine S; Aralis, Hilary; Cockburn, Myles; Ritz, Beate

2014-11-01

Genetic and environmental factors are believed to contribute to the development of autism, but relatively few studies have considered potential environmental risks. Here, we examine risks for autism in children related to in utero exposure to monitored ambient air toxics from urban emissions. Among the cohort of children born in Los Angeles County, California, 1995-2006, those whose mothers resided during pregnancy in a 5-km buffer around air toxics monitoring stations were included (n = 148,722). To identify autism cases in this cohort, birth records were linked to records of children diagnosed with primary autistic disorder at the California Department of Developmental Services between 1998 and 2009 (n = 768). We calculated monthly average exposures during pregnancy for 24 air toxics selected based on suspected or known neurotoxicity or neurodevelopmental toxicity. Factor analysis helped us identify the correlational structure among air toxics, and we estimated odds ratios (ORs) for autism from logistic regression analyses. Autism risks were increased per interquartile range increase in average concentrations during pregnancy of several correlated toxics mostly loading on 1 factor, including 1,3-butadiene (OR = 1.59 [95% confidence interval = 1.18-2.15]), meta/para-xylene (1.51 [1.26-1.82]), other aromatic solvents, lead (1.49 [1.23-1.81]), perchloroethylene (1.40 [1.09-1.80]), and formaldehyde (1.34 [1.17-1.52]), adjusting for maternal age, race/ethnicity, nativity, education, insurance type, parity, child sex, and birth year. Risks for autism in children may increase following in utero exposure to ambient air toxics from urban traffic and industry emissions, as measured by community-based air-monitoring stations.
Humidity Effects on Fragmentation in Plasma-Based Ambient Ionization Sources.

Science.gov (United States)

Newsome, G Asher; Ackerman, Luke K; Johnson, Kevin J

2016-01-01

Post-plasma ambient desorption/ionization (ADI) sources are fundamentally dependent on surrounding water vapor to produce protonated analyte ions. There are two reports of humidity effects on ADI spectra. However, it is unclear whether humidity will affect all ADI sources and analytes, and by what mechanism humidity affects spectra. Flowing atmospheric pressure afterglow (FAPA) ionization and direct analysis in real time (DART) mass spectra of various surface-deposited and gas-phase analytes were acquired at ambient temperature and pressure across a range of observed humidity values. A controlled humidity enclosure around the ion source and mass spectrometer inlet was used to create programmed humidity and temperatures. The relative abundance and fragmentation of molecular adduct ions for several compounds consistently varied with changing ambient humidity and also were controlled with the humidity enclosure. For several compounds, increasing humidity decreased protonated molecule and other molecular adduct ion fragmentation in both FAPA and DART spectra. For others, humidity increased fragment ion ratios. The effects of humidity on molecular adduct ion fragmentation were caused by changes in the relative abundances of different reagent protonated water clusters and, thus, a change in the average difference in proton affinity between an analyte and the population of water clusters. Control of humidity in ambient post-plasma ion sources is needed to create spectral stability and reproducibility.

Contribution of post-harvest agricultural paddy residue fires in the N.W. Indo-Gangetic Plain to ambient carcinogenic benzenoids, toxic isocyanic acid and carbon monoxide

Science.gov (United States)

Praphulla Chandra, Boggarapu; Sinha, Vinayak

2016-04-01

In the North West Indo-Gangetic Plain (N.W.IGP), large scale post-harvest paddy residue fires occur every year during the months of October-November. This anthropogenic perturbation causes contamination of the atmospheric environment with adverse impacts on regional air quality posing health risks for the population exposed to high concentrations of carcinogens such as benzene and toxic VOCs such as isocyanic acid. These gases and carbon monoxide are known to be emitted from biomass fires along with acetonitrile. Yet no long-term in-situ measurements quantifying the impact of this activity have been carried out in the N.W. IGP. Using high quality continuous online in-situ measurements of these gases at a strategic downwind site over a three year period from 2012 to 2014, we demonstrate the strong impact of this anthropogenic emission activity on ambient concentrations of these gases. In contrast to the pre-paddy harvest period, excellent correlation of benzenoids, isocyanic acid and CO with acetonitrile (a biomass burning chemical tracer); (r ≥ 0.82) and distinct VOC/acetonitrile emission ratios were observed for the post-paddy harvest period which was also characterized by high ambient concentrations of these species. The average concentrations of acetonitrile (1.62 ± 0.18 ppb), benzene (2.51 ± 0.28 ppb), toluene (3.72 ± 0.41 ppb), C8-aromatics (2.88 ± 0.30 ppb), C9-aromatics (1.55 ± 0.19 ppb) and CO (552 ± 113 ppb) in the post-paddy harvest periods were about 1.5 times higher than the annual average concentrations. For isocyanic acid, a compound with both primary and secondary sources, the concentration in the post-paddy harvest period was 0.97 ± 0.17 ppb. The annual average concentrations of benzene, a class A carcinogen, exceeded the annual exposure limit of 1.6 ppb at NTP mandated by the National Ambient Air Quality Standard of India (NAAQS). We show that mitigating the post-harvest paddy residue fires can lower the annual average concentration of
Det Ambiente

DEFF Research Database (Denmark)

Schmidt, Ulrik

Det ambiente er iscenesættelsen af en karakteristisk sanseoplevelse, der er kendetegnet ved fornemmelsen af at være omgivet. I dag bliver begrebet om det ambiente mest anvendt i forbindelse med musikgenren ’ambient musik’. Det ambiente er dog ikke essentielt knyttet til det musikalske, men må...... forstås som et betydeligt bredere fænomen i den moderne æstetiske kultur, der spiller en væsentlig rolle i oplevelsen af moderne transportformer, arkitektur, film, lydkunst, installationskunst og digitale multimedieiscenesættelser. En forståelse af det ambiente er derfor centralt for forståelsen af en...... moderne æstetiseret oplevelseskultur i almindelighed. Da det ambiente ikke hidtil har været gjort til genstand for en mere indgående teoretisk behandling, er der dog stor usikkerhed omkring, hvad fænomenet overhovedet indebærer. Hovedformålet med Det ambiente – Sansning, medialisering, omgivelse er derfor...
Toxicity of effluents from gasoline stations oil-water separators to early life stages of zebrafish Danio rerio.

Science.gov (United States)

Alves, Romulo Nepomuceno; Mariz, Célio Freire; Paulo, Driele Ventura de; Carvalho, Paulo S M

2017-07-01

Used petroleum hydrocarbons and gasoline stations runoff are significant sources of polycyclic aromatic hydrocarbons (PAHs) to aquatic ecosystems. Samples of the final effluent of oil-water-separators were collected at gasoline stations in the metropolitan region of Recife, Brazil, before release to sewage or rainwater systems. Effluent soluble fractions (ESF) were prepared and bioassays were performed according to the Fish Embryo Toxicity Test. The test involved exposing zebrafish Danio rerio embryos to dilutions of the ESFs for 96 h, with daily examination of lethality and sublethal morphological effects integrated through the General Morphology Score (GMS), based on the achievement of developmental hallmarks. Frequencies of abnormalities were recorded after exposures. ESF LC50-96h (lethal concentration to 50% of exposed embryos) in the most toxic effluent achieved 8.9% (v/v), equivalent to 11 μg phenanthrene equivalents L -1 . GMS scores indicated significantly delayed embryo-larval development at ESF dilutions of 10% and 20% from effluents of all gas stations. Major abnormalities detected after the 96 h exposure included the presence of a yolk sac not fully absorbed coupled with the lack of an inflated swim bladder, lack of both pectoral fins, and the failure to develop a protruding mouth. Effective equivalent PAH concentrations that induce a 50% frequency of larvae without an inflated swim bladder (EC50) were 4.9 μg phenanthrene L -1 , 21.8 μg naphthalene L -1 , and 34.1 μg chrysene L -1 . This study shows that PAHs in ESFs from gas stations oil water separators are toxic to zebrafish, contributing to the toxicity of urban storm waters. Copyright © 2017 Elsevier Ltd. All rights reserved.
High-throughput sequencing reveals microbial communities in drinking water treatment sludge from six geographically distributed plants, including potentially toxic cyanobacteria and pathogens.

Science.gov (United States)

Xu, Hangzhou; Pei, Haiyan; Jin, Yan; Ma, Chunxia; Wang, Yuting; Sun, Jiongming; Li, Hongmin

2018-04-10

The microbial community structures of drinking water treatment sludge (DWTS) generated for raw water (RW) from different locations and with different source types - including river water, lake water and reservoir water -were investigated using high-throughput sequencing. Because the unit operations in the six DWTPs were similar, community composition in fresh sludge may be determined by microbial community in the corresponding RW. Although Proteobacteria, Cyanobacteria, Bacteroidetes, Firmicutes, Verrucomicrobia, and Planctomycetes were the dominant phyla among the six DWTS samples, no single phylum exhibited similar abundance across all the samples, owing to differences in total phosphorus, chemical oxygen demand, Al, Fe, and chloride in RW. Three genera of potentially toxic cyanobacteria (Planktothrix, Microcystis and Cylindrospermopsis), and four potential pathogens (Escherichia coli, Bacteroides ovatus, Prevotella copri and Rickettsia) were found in sludge samples. Because proliferation of potentially toxic cyanobacteria and Rickettsia in RW was mainly affected by nutrients, while growth of Escherichia coli, Bacteroides ovatus and Prevotella copri in RW may be influenced by Fe, control of nutrients and Fe in RW is essential to decrease toxic cyanobacteria and pathogens in DWTS. Copyright © 2018 Elsevier B.V. All rights reserved.
Investigation of Water Safety in Non-treated Drinking Water with Trace Toxic Metals.

Science.gov (United States)

Ly, Suw Young; Kim, Dae Hong; Lee, Ga Eun

2013-09-01

The trace toxic metal copper was assayed using mercury immobilized on a carbon nanotube electrode (MCW), with a graphite counter and a reference electrode. In this study, a macro-scale convection motor was interfaced with a MCW three-electrode system, in which a handmade MCW was optimized using cyclic- and square-wave stripping voltammetry. An analytical electrolyte for tap water was used instead of an expensive acid or base ionic solution. Under these conditions, optimum parameters were 0.09 V amplitude, 40 Hz frequency, 0.01 V incremental potential, and a 60-s accumulation time. A diagnostic working curve was obtained from 50.0 to 350 μg/L. At a constant Cu(II) concentration of 10.0 μg/L, the statistical relative standard deviation was 1.78% (RSD, n = 15), the analytical accumulation time was only 60 s, and the analytical detection limit approached 4.6 μg/L (signal/noise = 3). The results were applied to nontreated drinking water. The content of the analyzed copper using 9.0 and 4.0 μg/L standards were 8.68 μg/L and 3.96 μg/L; statistical values R(2) = 0.9987 and R(2) = 0.9534, respectively. This method is applicable to biological diagnostics or food surveys.
Control of aliphatic halogenated DBP precursors with multiple drinking water treatment processes: Formation potential and integrated toxicity.

Science.gov (United States)

Zhang, Yimeng; Chu, Wenhai; Yao, Dechang; Yin, Daqiang

2017-08-01

The comprehensive control efficiency for the formation potentials (FPs) of a range of regulated and unregulated halogenated disinfection by-products (DBPs) (including carbonaceous DBPs (C-DBPs), nitrogenous DBPs (N-DBPs), and iodinated DBPs (I-DBPs)) with the multiple drinking water treatment processes, including pre-ozonation, conventional treatment (coagulation-sedimentation, pre-sand filtration), ozone-biological activated carbon (O 3 -BAC) advanced treatment, and post-sand filtration, was investigated. The potential toxic risks of DBPs by combing their FPs and toxicity values were also evaluated. The results showed that the multiple drinking water treatment processes had superior performance in removing organic/inorganic precursors and reducing the formation of a range of halogenated DBPs. Therein, ozonation significantly removed bromide and iodide, and thus reduced the formation of brominated and iodinated DBPs. The removal of organic carbon and nitrogen precursors by the conventional treatment processes was substantially improved by O 3 -BAC advanced treatment, and thus prevented the formation of chlorinated C-DBPs and N-DBPs. However, BAC filtration leads to the increased formation of brominated C-DBPs and N-DBPs due to the increase of bromide/DOC and bromide/DON. After the whole multiple treatment processes, the rank order for integrated toxic risk values caused by these halogenated DBPs was haloacetonitriles (HANs)≫haloacetamides (HAMs)>haloacetic acids (HAAs)>trihalomethanes (THMs)>halonitromethanes (HNMs)≫I-DBPs (I-HAMs and I-THMs). I-DBPs failed to cause high integrated toxic risk because of their very low FPs. The significant higher integrated toxic risk value caused by HANs than other halogenated DBPs cannot be ignored. Copyright © 2017. Published by Elsevier B.V.
Decreased toxicity of aluminium when the ionic strength increases in water; Blir aluminium mindre toksisk naar ionestyrken i vannet oeker?

Energy Technology Data Exchange (ETDEWEB)

Alstad, E W [Oslo Univ. (Norway)

1996-01-01

The conference paper evaluates the acute mortality of fish caused by the toxicity of aluminium in water. The evaluation is based on the polymerization hypothesis. According to the author, the level of toxicity decreases when the concentration and charge of ions increase. The paper presents the preliminary results from the executed experiment. 2 refs., 2 figs., 1 tab.
Toxicity and transfer of polyvinylpyrrolidone-coated silver nanowires in an aquatic food chain consisting of algae, water fleas, and zebrafish

Energy Technology Data Exchange (ETDEWEB)

Chae, Yooeun; An, Youn-Joo, E-mail: anyjoo@konkuk.ac.kr

2016-04-15

Highlights: • Trophic transfer of silver nanowires (AgNWs) was studied in an aquatic food chain. • The transfer of AgNWs from algae to fish via water fleas was observed. • Toxicity of long AgNWs on aquatic organisms is higher than that of short ones. • AgNWs damage the gut of water fleas and may cause undernourishment. • Quantity of lipid droplets increased with increasing exposure concentration. - Abstract: Nanomaterials of various shapes and dimensions are widely used in the medical, chemical, and electronic industries. Multiple studies have reported the ecotoxicological effects of nanaoparticles when released in aquatic and terrestrial ecosystems; however, information on the toxicity of silver nanowires (AgNWs) to freshwater organisms and their transfer through the food webs is limited. In the present study, we aimed to evaluate the toxicity of 10- and 20-μm-long AgNWs to the alga Chlamydomonas reinhardtii, the water flea Daphnia magna, and the zebrafish and study their movement through this three-species food chain using a variety of qualitative and quantitative methods as well as optical techniques. We found that AgNWs directly inhibited the growth of algae and destroyed the digestive organs of water fleas. The results showed that longer AgNWs (20 μm) were more toxic than shorter ones (10 μm) to both algae and water fleas, but shorter AgNWs were accumulated more than longer ones in the body of the fish. Overall, this study suggests that AgNWs are transferred through food chains, and that they affect organisms at higher trophic levels, potentially including humans. Therefore, further studies that take into account environmental factors, food web complexity, and differences between nanomaterials are required to gain better understanding of the impact of nanomaterials on natural communities and human health.
Toxicity and transfer of polyvinylpyrrolidone-coated silver nanowires in an aquatic food chain consisting of algae, water fleas, and zebrafish

International Nuclear Information System (INIS)

Chae, Yooeun; An, Youn-Joo

2016-01-01

Highlights: • Trophic transfer of silver nanowires (AgNWs) was studied in an aquatic food chain. • The transfer of AgNWs from algae to fish via water fleas was observed. • Toxicity of long AgNWs on aquatic organisms is higher than that of short ones. • AgNWs damage the gut of water fleas and may cause undernourishment. • Quantity of lipid droplets increased with increasing exposure concentration. - Abstract: Nanomaterials of various shapes and dimensions are widely used in the medical, chemical, and electronic industries. Multiple studies have reported the ecotoxicological effects of nanaoparticles when released in aquatic and terrestrial ecosystems; however, information on the toxicity of silver nanowires (AgNWs) to freshwater organisms and their transfer through the food webs is limited. In the present study, we aimed to evaluate the toxicity of 10- and 20-μm-long AgNWs to the alga Chlamydomonas reinhardtii, the water flea Daphnia magna, and the zebrafish and study their movement through this three-species food chain using a variety of qualitative and quantitative methods as well as optical techniques. We found that AgNWs directly inhibited the growth of algae and destroyed the digestive organs of water fleas. The results showed that longer AgNWs (20 μm) were more toxic than shorter ones (10 μm) to both algae and water fleas, but shorter AgNWs were accumulated more than longer ones in the body of the fish. Overall, this study suggests that AgNWs are transferred through food chains, and that they affect organisms at higher trophic levels, potentially including humans. Therefore, further studies that take into account environmental factors, food web complexity, and differences between nanomaterials are required to gain better understanding of the impact of nanomaterials on natural communities and human health.
The Occurrence and Toxicity of Disinfection Byproducts in European Drinking Waters in Relation with the HIWATE Epidemiology Study

Science.gov (United States)

Jeong, Clara H.; Wagner, Elizabeth D.; Siebert, Vincent R.; Anduri, Sridevi; Richardson, Susan D.; Daiber, Eric J.; McKague, A. Bruce; Kogevinas, Manolis; Villanueva, Cristina M.; Goslan, Emma H.; Luo, Wentai; Isabelle, Lorne M.; Pankow, James F.; Grazuleviciene, Regina; Cordier, Sylvaine; Edwards, Susan C.; Righi, Elena; Nieuwenhuijsen, Mark J.; Plewa, Michael J.

2012-01-01

The HIWATE (Health Impacts of long-term exposure to disinfection byproducts in drinking WATEr) project was a systematic analysis that combined the epidemiology on adverse pregnancy outcomes and other health effects with long term exposure to low levels of drinking water disinfection byproducts (DBPs) in the European Union. The present study focused on the relationship of the occurrence and concentration of DBPs with in vitro mammalian cell toxicity. Eleven drinking water samples were collected from 5 European countries. Each sampling location corresponded with an epidemiological study for the HIWATE program. Over 90 DBPs were identified; the range in the number of DBPs and their levels reflected the diverse collection sites, different disinfection processes, and the different characteristics of the source waters. For each sampling site, chronic mammalian cell cytotoxicity correlated highly with the numbers of DBPs identified and the levels of DBP chemical classes. Although there was a clear difference in the genotoxic responses among the drinking waters, these data did not correlate as well with the chemical analyses. Thus, the agents responsible for the genomic DNA damage observed in the HIWATE samples may be due to unresolved associations of combinations of identified DBPs, unknown emerging DBPs that were not identified, or other toxic water contaminants. This study represents the first to integrate quantitative in vitro toxicological data with analytical chemistry and human epidemiologic outcomes for drinking water DBPs. PMID:22958121
RADIONUCLIDE TRANSPORT MODELS UNDER AMBIENT CONDITIONS

Energy Technology Data Exchange (ETDEWEB)

S. Magnuson

2004-11-01

The purpose of this model report is to document the unsaturated zone (UZ) radionuclide transport model, which evaluates, by means of three-dimensional numerical models, the transport of radioactive solutes and colloids in the UZ, under ambient conditions, from the repository horizon to the water table at Yucca Mountain, Nevada.
Calcification of the cold-water coral Lophelia pertusa, under ambient and reduced pH

Directory of Open Access Journals (Sweden)

J.-P. Gattuso

2009-08-01

Full Text Available The cold-water coral Lophelia pertusa is one of the few species able to build reef-like structures and a 3-dimensional coral framework in the deep oceans. Furthermore, deep cold-water coral bioherms may be among the first marine ecosystems to be affected by ocean acidification. Colonies of L. pertusa were collected during a cruise in 2006 to cold-water coral bioherms of the Mingulay reef complex (Hebrides, North Atlantic. Shortly after sample collection onboard these corals were labelled with calcium-45. The same experimental approach was used to assess calcification rates and how those changed due to reduced pH during a cruise to the Skagerrak (North Sea in 2007. The highest calcification rates were found in youngest polyps with up to 1% d−1 new skeletal growth and average rates of 0.11±0.02% d−1±S.E.. Lowering pH by 0.15 and 0.3 units relative to the ambient level resulted in calcification being reduced by 30 and 56%. Lower pH reduced calcification more in fast growing, young polyps (59% reduction than in older polyps (40% reduction. Thus skeletal growth of young and fast calcifying corallites suffered more from ocean acidification. Nevertheless, L. pertusa exhibited positive net calcification (as measured by 45Ca incorporation even at an aragonite saturation state (Ωa below 1.
Synthesis of ammonia directly from air and water at ambient temperature and pressure

Science.gov (United States)

Lan, Rong; Irvine, John T. S.; Tao, Shanwen

2013-01-01

The N≡N bond (225 kcal mol−1) in dinitrogen is one of the strongest bonds in chemistry therefore artificial synthesis of ammonia under mild conditions is a significant challenge. Based on current knowledge, only bacteria and some plants can synthesise ammonia from air and water at ambient temperature and pressure. Here, for the first time, we report artificial ammonia synthesis bypassing N2 separation and H2 production stages. A maximum ammonia production rate of 1.14 × 10−5 mol m−2 s−1 has been achieved when a voltage of 1.6 V was applied. Potentially this can provide an alternative route for the mass production of the basic chemical ammonia under mild conditions. Considering climate change and the depletion of fossil fuels used for synthesis of ammonia by conventional methods, this is a renewable and sustainable chemical synthesis process for future. PMID:23362454
Synthesis of ammonia directly from air and water at ambient temperature and pressure.

Science.gov (United States)

Lan, Rong; Irvine, John T S; Tao, Shanwen

2013-01-01

The N≡N bond (225 kcal mol⁻¹) in dinitrogen is one of the strongest bonds in chemistry therefore artificial synthesis of ammonia under mild conditions is a significant challenge. Based on current knowledge, only bacteria and some plants can synthesise ammonia from air and water at ambient temperature and pressure. Here, for the first time, we report artificial ammonia synthesis bypassing N₂ separation and H₂ production stages. A maximum ammonia production rate of 1.14 × 10⁻⁵ mol m⁻² s⁻¹ has been achieved when a voltage of 1.6 V was applied. Potentially this can provide an alternative route for the mass production of the basic chemical ammonia under mild conditions. Considering climate change and the depletion of fossil fuels used for synthesis of ammonia by conventional methods, this is a renewable and sustainable chemical synthesis process for future.
Longevity and reproduction of Ceriodaphnia dubia in receiving waters

International Nuclear Information System (INIS)

Stewart, A.J.; Konetsky, B.K.

1998-01-01

Seven-day tests with Ceriodaphnia dubia are commonly used to estimate toxicity of effluents or receiving waters but can sometimes yield no toxicity outcomes even if pollutants are present. The authors conducted two sets of full life-cycle tests with C. dubia to (1) determine whether tests with longer exposure periods to low concentrations of contaminants in ambient water might reveal evidence of toxicity that could not be discerned from 7-d tests and (2) determine the relative importance of water quality versus food as factors influencing C. dubia longevity and reproduction. In the first set of tests, C. dubia was reared in diluted mineral water (a negative control), water from a stream impacted by coal fly-ash, or water from a retention basin containing sediments contaminated with mercury, other metals, and polychlorinated biphenyls. The second set of tests used water from the retention basin only. Before testing, though, water in the second set of tests was either filtered or not filtered, and food was either added or not added. Ceriodaphnia dubia longevity and reproduction did not differ much among the three water types in the first set of tests, but both longevity and reproduction were strongly affected by the filtering and food-addition treatments in the second set of tests. Thus, C. dubia appeared to be relatively insensitive to general water quality factors but sensitive to food-related factors. In five of the six full life-cycle tests, lifetime reproduction by C. dubia could not be reliably predicted from reproduction data from the first 7 d of testing. The increase in predictability of lifetime reproduction of C. dubia as a function of test duration also differed among water types in the first set of tests and among treatments in the second set of tests. This, it may not be possible to reliably extrapolate the results of 7-d tests with C. dubia to longer time scales
Human Health Effects Associated with Exposure to Toxic Cyanobacteria

Science.gov (United States)

Reports of toxic cyanobacteria blooms are increasing worldwide. Warming and eutrophic surface water systems support the development of blooms. We examine the evidence for adverse human health effects associated with exposure to toxic blooms in drinking water, recreational water a...
Modeling Aquatic Toxicity through Chromatographic Systems.

Science.gov (United States)

Fernández-Pumarega, Alejandro; Amézqueta, Susana; Farré, Sandra; Muñoz-Pascual, Laura; Abraham, Michael H; Fuguet, Elisabet; Rosés, Martí

2017-08-01

Environmental risk assessment requires information about the toxicity of the growing number of chemical products coming from different origins that can contaminate water and become toxicants to aquatic species or other living beings via the trophic chain. Direct toxicity measurements using sensitive aquatic species can be carried out but they may become expensive and ethically questionable. Literature refers to the use of chromatographic measurements that correlate to the toxic effect of a compound over a specific aquatic species as an alternative to get toxicity information. In this work, we have studied the similarity in the response of the toxicity to different species and we have selected eight representative aquatic species (including tadpoles, fish, water fleas, protozoan, and bacteria) with known nonspecific toxicity to chemical substances. Next, we have selected four chromatographic systems offering good perspectives for surrogation of the eight selected aquatic systems, and thus prediction of toxicity from the chromatographic measurement. Then toxicity has been correlated to the chromatographic retention factor. Satisfactory correlation results have been obtained to emulate toxicity in five of the selected aquatic species through some of the chromatographic systems. Other aquatic species with similar characteristics to these five representative ones could also be emulated by using the same chromatographic systems. The final aim of this study is to model chemical products toxicity to aquatic species by means of chromatographic systems to reduce in vivo testing.
NATIONAL COW MILK SURVEY FOR PERSISTENT, BIOACCUMULATIVE AND TOXIC (PBT) POLLUTANTS

Science.gov (United States)

This is a survey for persistent, bioaccumulative, and toxic (PBT) pollutants in the U.S. milk supply. The EPA Environmental Radiation Ambient Monitoring System (ERAMS) was used to collect two sets of milk samples, one set in July 2000 and the second in January 2001. ERAMS has abo...
Toxicity of water and sediment from stormwater retarding basins to Hydra hexactinella

DEFF Research Database (Denmark)

Rosenkrantz, Rikke Tjørnhøj; Pollino, Carmel A.; Nugegoda, Dayanthi

2008-01-01

of 50 ml/L and 100 ml/L, while the 7 h pulse exposure caused a significant increase in the mean population growth rate compared to the control. Water samples from the two other retarding basins were found non-toxic to H. hexactinella. This is the first study to employ sediment tests with Hydra spp....... on stormwater sediments and a lower population growth rate was observed for organisms exposed to sediment from the Avoca St retarding basins. The behavioral study showed that H. hexactinella tended to avoid the sediment-water interface when exposed to sediment from all retarding basins, compared...... to the reference sediment. Further work is needed to determine the long-term effects of stormwater polluted sediments and acute effects due to organism exposure to short-term high concentrations during rain events. (C) 2008 Elsevier Ltd. All rights reserved....
Validating potential toxicity assays to assess petroleum hydrocarbon toxicity in polar soil.

Science.gov (United States)

Harvey, Alexis Nadine; Snape, Ian; Siciliano, Steven Douglas

2012-02-01

Potential microbial activities are commonly used to assess soil toxicity of petroleum hydrocarbons (PHC) and are assumed to be a surrogate for microbial activity within the soil ecosystem. However, this assumption needs to be evaluated for frozen soil, in which microbial activity is limited by liquid water (θ(liquid)). Influence of θ(liquid) on in situ toxicity was evaluated and compared to the toxicity endpoints of potential microbial activities using soil from an aged diesel fuel spill at Casey Station, East Antarctica. To determine in situ toxicity, gross mineralization and nitrification rates were determined by the stable isotope dilution technique. Petroleum hydrocarbon-contaminated soil (0-8,000 mg kg(-1)), packed at bulk densities of 1.4, 1.7, and 2.0 g cm(-3) to manipulate liquid water content, was incubated at -5°C for one, two, and three months. Although θ(liquid) did not have a significant effect on gross mineralization or nitrification, gross nitrification was sensitive to PHC contamination, with toxicity decreasing over time. In contrast, gross mineralization was not sensitive to PHC contamination. Toxic response of gross nitrification was comparable to potential nitrification activity (PNA) with similar EC25 (effective concentration causing a 25% effect in the test population) values determined by both measurement endpoints (400 mg kg(-1) for gross nitrification compared to 200 mg kg(-1) for PNA), indicating that potential microbial activity assays are good surrogates for in situ toxicity of PHC contamination in polar regions. Copyright © 2011 SETAC.

Radionuclide Transport Models Under Ambient Conditions

International Nuclear Information System (INIS)

Moridis, G.; Hu, Q.

2001-01-01

The purpose of Revision 00 of this Analysis/Model Report (AMR) is to evaluate (by means of 2-D semianalytical and 3-D numerical models) the transport of radioactive solutes and colloids in the unsaturated zone (UZ) under ambient conditions from the potential repository horizon to the water table at Yucca Mountain (YM), Nevada
Analysis of Toxic and Non-Toxic Alexandrium (Dinophyceae) Species Using Ribosomal RNA Gene Sequences

Science.gov (United States)

1993-02-01

Therriault, J.-C. (1988). Cladistic analysis of electrophoretic variants within the toxic dinoflagellate genus Protogonyaulax. Botanica Marina 31: 39- 51. 8... Botanica Marina 34: 575-587. Halegraeff, G. M., and Bolch, C.J. (1992). Transport of toxic dinoflagellate cysts via ship’s ballast water: implications...analysis of electrophoretic variants within the toxic dinoflagellate genus Protogonv-u.!a,. Botanica Marina 31: 39-51. Curran, J., Baillie, D.L
Assessment of hydrogen bonding effect on ionization of water from ambient to supercritical region–MD simulation approach

International Nuclear Information System (INIS)

Swiatla-Wojcik, D.; Mozumder, A.

2014-01-01

We present a novel, molecular dynamics (MD) simulation based, strategy to analyze how the degree of hydrogen bonding may influence the ionization and dissociation of water upon heating from ambient to supercritical temperatures. Calculations show a negligible change in the ionization energy up to 200 °C. At higher temperatures the ionization energy increases due to the decreasing degree of hydrogen bonding. The influence of density (pressure) is pronounced in the supercritical region. The ionization is more energy consuming in the less dense fluid. We also show that high temperature and low density may promote dissociation of the electronically excited water molecules. Implications on the initial radiation chemical yields of the hydrated electron, hydrogen atom and hydroxyl radical are discussed. - Highlights: • Up to 200 °C changes in the vertical and adiabatic ionization potentials are negligible. • At higher temperatures ionization is more energy consuming. • Ionization potential increases with decreasing density of supercritical water. • High temperature and low density promote dissociation of the excited molecules
Ambient particulate matter air pollution and cardiopulmonary diseases.

Science.gov (United States)

Thurston, George; Lippmann, Morton

2015-06-01

Population exposures to ambient outdoor particulate matter (PM) air pollution have been assessed to represent a major burden on global health. Ambient PM is a diverse class of air pollution, with characteristics and health implications that can vary depending on a host of factors, including a particle's original source of emission or formation. The penetration of inhaled particles into the thorax is dependent on their deposition in the upper respiratory tract during inspiration, which varies with particle size, flow rate and tidal volume, and in vivo airway dimensions. All of these factors can be quite variable from person to person, depending on age, transient illness, cigarette smoke and other short-term toxicant exposures that cause transient bronchoconstriction, and occupational history associated with loss of lung function or cumulative injury. The adverse effects of inhaled PM can result from both short-term (acute) and long-term (chronic) exposures to PM, and can range from relatively minor, such as increased symptoms, to very severe effects, including increased risk of premature mortality and decreased life expectancy from long-term exposure. Control of the most toxic PM components can therefore provide major health benefits, and can help guide the selection of the most human health optimal air quality control and climate change mitigation policy measures. As such, a continued improvement in our understanding of the nature and types of PM that are most dangerous to health, and the mechanism(s) of their respective health effects, is an important public health goal. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.
Removal of soluble toxic metals from water

International Nuclear Information System (INIS)

Buckley, L.P.; Vijayan, S.; McConeghy, G.J.; Maves, S.R.; Martin, J.F.

1990-05-01

The removal of selected, soluble toxic metals from aqueous solutions has been accomplished using a combination of chemical treatment and ultrafiltration. The process has been evaluated at the bench-scale and is undergoing pilot-scale testing. Removal efficiencies in excess of 95-99% have been realized. The test program at the bench-scale investigated the limitations and established the optimum range of operating parameters for the process, while the tests conducted with the pilot-scale process equipment are providing information on longer-term process efficiencies, effective processing rates, and fouling potential of the membranes. With the typically found average concentrations of the toxic metals in groundwaters at Superfund sites used as the feed solution, the process has decreased levels up to 100-fold or more. Experiments were also conducted with concentrated solutions to determine their release from silica-based matrices. The solidified wastes were subjected to EP Toxicity test procedures and met the criteria successfully. The final phase of the program involving a field demonstration at a uranium tailings site will be outlined
A seeded ambient temperature ferrite process for treatment of AMD ...

African Journals Online (AJOL)

A seeded ambient temperature ferrite process for treatment of AMD waters: magnetite formation in the presence and absence of calcium ions under steady state operation. ... promising for AMD treatment. Keywords: Ferrite process, Magnetite seed, Calcium interference, Acid mine drainage (WaterSA: 2003 29(2): 117-124) ...
Urban net-zero water treatment and mineralization: experiments, modeling and design.

Science.gov (United States)

Englehardt, James D; Wu, Tingting; Tchobanoglous, George

2013-09-01

Water and wastewater treatment and conveyance account for approximately 4% of US electric consumption, with 80% used for conveyance. Net zero water (NZW) buildings would alleviate demands for a portion of this energy, for water, and for the treatment of drinking water for pesticides and toxic chemical releases in source water. However, domestic wastewater contains nitrogen loads much greater than urban/suburban ecosystems can typically absorb. The purpose of this work was to identify a first design of a denitrifying urban NZW treatment process, operating at ambient temperature and pressure and circum-neutral pH, and providing mineralization of pharmaceuticals (not easily regulated in terms of environmental half-life), based on laboratory tests and mass balance and kinetic modeling. The proposed treatment process is comprised of membrane bioreactor, iron-mediated aeration (IMA, reported previously), vacuum ultrafiltration, and peroxone advanced oxidation, with minor rainwater make-up and H2O2 disinfection residual. Similar to biological systems, minerals accumulate subject to precipitative removal by IMA, salt-free treatment, and minor dilution. Based on laboratory and modeling results, the system can produce potable water with moderate mineral content from commingled domestic wastewater and 10-20% rainwater make-up, under ambient conditions at individual buildings, while denitrifying and reducing chemical oxygen demand to below detection (<3 mg/L). While economics appear competitive, further development and study of steady-state concentrations and sludge management options are needed. Copyright © 2013 Elsevier Ltd. All rights reserved.
Effects of nanoplastics and microplastics on toxicity, bioaccumulation, and environmental fate of phenanthrene in fresh water.

Science.gov (United States)

Ma, Yini; Huang, Anna; Cao, Siqi; Sun, Feifei; Wang, Lianhong; Guo, Hongyan; Ji, Rong

2016-12-01

Contamination of fine plastic particles (FPs), including micrometer to millimeter plastics (MPs) and nanometer plastics (NPs), in the environment has caught great concerns. FPs are strong adsorbents for hydrophobic toxic pollutants and may affect their fate and toxicity in the environment; however, such information is still rare. We studied joint toxicity of FPs with phenanthrene to Daphnia magna and effects of FPs on the environmental fate and bioaccumulation of 14 C-phenanthrene in fresh water. Within the five sizes particles we tested (from 50 nm to 10 μm), 50-nm NPs showed significant toxicity and physical damage to D. magna. The joint toxicity of 50-nm NPs and phenanthrene to D. magna showed an additive effect. During a 14-days incubation, the presence of NPs significantly enhanced bioaccumulation of phenanthrene-derived residues in daphnid body and inhibited the dissipation and transformation of phenanthrene in the medium, while 10-μm MPs did not show significant effects on the bioaccumulation, dissipation, and transformation of phenanthrene. The differences may be attributed to higher adsorption of phenanthrene on 50-nm NPs than 10-μm MPs. Our findings underlined the high potential ecological risks of FPs, and suggested that NPs should be given more concerns, in terms of their interaction with hydrophobic pollutants in the environment. Copyright © 2016 Elsevier Ltd. All rights reserved.
Effects of ambient temperature and water vapor on chamber pressure and oxygen level during low atmospheric pressure stunning of poultry.

Science.gov (United States)

Holloway, Paul H; Pritchard, David G

2017-08-01

The characteristics of the vacuum used in a low atmospheric pressure stunning system to stun (render unconscious) poultry prior to slaughter are described. A vacuum chamber is pumped by a wet screw compressor. The vacuum pressure is reduced from ambient atmospheric pressure to an absolute vacuum pressure of ∼250 Torr (∼33 kPa) in ∼67 sec with the vacuum gate valve fully open. At ∼250 Torr, the sliding gate valve is partially closed to reduce effective pumping speed, resulting in a slower rate of decreasing pressure. Ambient temperature affects air density and water vapor pressure and thereby oxygen levels and the time at the minimum total pressure of ∼160 Torr (∼21 kPa) is varied from ∼120 to ∼220 sec to ensure an effective stun within the 280 seconds of each cycle. The reduction in total pressure results in a gradual reduction of oxygen partial pressure that was measured by a solid-state electrochemical oxygen sensor. The reduced oxygen pressure leads to hypoxia, which is recognized as a humane method of stunning poultry. The system maintains an oxygen concentration of air always reduces the oxygen concentrations to a value lower than in dry air. The partial pressure of water and oxygen were found to depend on the pump down parameters due to the formation of fog in the chamber and desorption of water from the birds and the walls of the vacuum chamber. © The Author 2017. Published by Oxford University Press on behalf of Poultry Science Association.
The water-soluble fraction of potentially toxic elements in contaminated soils: relationships between ecotoxicity, solubility and geochemical reactivity.

Science.gov (United States)

Rocha, L; Rodrigues, S M; Lopes, I; Soares, A M V M; Duarte, A C; Pereira, E

2011-09-01

To better understand the impacts posed by soil contamination to aquatic ecosystems it is crucial to characterise the links between ecotoxicity, chemical availability and geochemical reactivity of potentially toxic elements (PTE's) in soils. We evaluated the adverse effects of water extracts obtained from soils contaminated by chemical industry and mining, using a test battery including organisms from different trophic levels (bacteria, algae and daphnids). These tests provided a quick assessment of the ecotoxicity of soils with respect to possible adverse effects on aquatic organisms although the ecotoxicological responses could be related to the solubility of PTE's only to a limited extent. The analysis of results of bioassays together with the chemical characterisation of water extracts provided additional relevant insight into the role of conductivity, pH, Al, Fe, and Mn of soil extracts on toxicity to organisms. Furthermore, an important conclusion of this study was that the toxicity of extracts to the aquatic organisms could also be related to the soil properties (pH, Org C and Fe(ox)) and to the reactivity of PTE's in soils which in fact control the soluble fraction of the contaminants. The combined assessment of ecotoxicity in water fractions, solubility and geochemical reactivity of PTE's in soils provided a more comprehensive understanding of the bioavailability of inorganic contaminants than ecotoxicological or chemical studies alone and can therefore be most useful for environmental risks assessment of contaminated soils. Copyright © 2011 Elsevier Ltd. All rights reserved.
Microcystis aeruginosa : source of toxic microcystins in drinking water

African Journals Online (AJOL)

, which is the most common toxic cyanobacterium in eutrophic freshwater. The association of environmental parameters with cyanobacterial blooms and the toxicity of microcystin are discussed. Also, the synthesis of the microcystins, as well as ...
Numerical study of ambient pressure for laser-induced bubble near a rigid boundary

Science.gov (United States)

Li, BeiBei; Zhang, HongChao; Han, Bing; Lu, Jian

2012-07-01

The dynamics of the laser-induced bubble at different ambient pressures was numerically studied by Finite Volume Method (FVM). The velocity of the bubble wall, the liquid jet velocity at collapse, and the pressure of the water hammer while the liquid jet impacting onto the boundary are found to increase nonlinearly with increasing ambient pressure. The collapse time and the formation time of the liquid jet are found to decrease nonlinearly with increasing ambient pressure. The ratios of the jet formation time to the collapse time, and the displacement of the bubble center to the maximal radius while the jet formation stay invariant when ambient pressure changes. These ratios are independent of ambient pressure.
Some Durability Aspects of Ambient Cured Bottom Ash Geopolymer Concrete

Directory of Open Access Journals (Sweden)

Saravanakumar R.

2017-09-01

Full Text Available The present study examines some durability aspects of ambient cured bottom ash geopolymer concrete (BA GPC due to accelerated corrosion, sorptivity, and water absorption. The bottom ash geopolymer concrete was prepared with sodium based alkaline activators under ambient curing temperatures. The sodium hydroxide used concentration was 8M. The performance of BA GPC was compared with conventional concrete. The test results indicate that BA GPC developes a strong passive layer against chloride ion diffusion and provides better protection against corrosion. Both the initial and final rates of water absorption of BA GPC were about two times less than those of conventional concrete. The BA GPC significantly enhanced performance over equivalent grade conventional concrete (CC.
Cardiopulmonary Toxicity Induced by Ambient Particulate Matter (BI City Concentrated Ambient Particle Study)

Energy Technology Data Exchange (ETDEWEB)

Annette Rohr; James Wagner Masako Morishita; Gerald Keeler; Jack Harkema

2010-06-30

Alterations in heart rate variability (HRV) have been reported in rodents exposed to concentrated ambient particles (CAPs) from different regions of the United States. The goal of this study was to compare alterations in cardiac function induced by CAPs in two distinct regional atmospheres. AirCARE 1, a mobile laboratory with an EPA/Harvard fine particle (particulate matter <2.5 {micro}m; PM{sub 2.5}) concentrator was located in urban Detroit, MI, where the PM mixture is heavily influenced by motor vehicles, and in Steubenville, OH, where PM is derived primarily from long-range transport and transformation of power plant emissions, as well as from local industrial operations. Each city was studied during both winter and summer months, for a total of four sampling periods. Spontaneously hypertensive rats instrumented for electrocardiogram (ECG) telemetry were exposed to CAPs 8 h/day for 13 consecutive days during each sampling period. Heart rate (HR), and indices of HRV (standard deviation of the average normal-to-normal intervals [SDNN]; square root of the mean squared difference of successive normal-to-normal intervals [rMSSD]), were calculated for 30-minute intervals during exposures. A large suite of PM components, including nitrate, sulfate, elemental and organic carbon, and trace elements, were monitored in CAPs and ambient air. In addition, a unique sampler, the Semi-Continuous Elements in Air Sampler (SEAS) was employed to obtain every-30-minute measurements of trace elements. Positive matrix factorization (PMF) methods were applied to estimate source contributions to PM{sub 2.5}. Mixed modeling techniques were employed to determine associations between pollutants/CAPs components and HR and HRV metrics. Mean CAPs concentrations in Detroit were 518 and 357 {micro}g/m{sup 3} (summer and winter, respectively) and 487 and 252 {micro}g/m{sup 3} in Steubenville. In Detroit, significant reductions in SDNN were observed in the summer in association with cement
Is the OECD acute worm toxicity test environmentally relevant? The effect of mineral form on calculated lead toxicity

International Nuclear Information System (INIS)

Davies, N.A.Nicola A.; Hodson, M.E.Mark E.; Black, S.Stuart

2003-01-01

The current OECD acute worm toxicity test does not relate well to ambient conditions. - In a series of experiments the toxicity of lead to worms in soil was determined following the draft OECD earthworm reproduction toxicity protocol except that lead was added as solid lead nitrate, carbonate and sulphide rather than as lead nitrate solution as would normally be the case. The compounds were added to the test soil to give lead concentrations of 625-12500 μg Pb g -1 of soil. Calculated toxicities of the lead decreased in the order nitrate>carbonate>sulphide, the same order as the decrease in the solubility of the metal compounds used. The 7-day LC 50 (lethal concentration when 50% of the population is killed) for the nitrate was 5321±275 μg Pb g -1 of soil and this did not change with time. The LC 50 values for carbonate and sulphide could not be determined at the concentration ranges used. The only parameter sensitive enough to distinguish the toxicities of the three compounds was cocoon (egg) production. The EC 50 s for cocoon production (the concentration to produce a 50% reduction in cocoon production) were 993, 8604 and 10246 μg Pb g -1 of soil for lead nitrate, carbonate and sulphide, respectively. Standard toxicity tests need to take into account the form in which the contaminant is present in the soil to be of environmental relevance
Assessing the toxicity of sodium chloride to the glochidia of freshwater mussels: Implications for salinization of surface waters

Energy Technology Data Exchange (ETDEWEB)

Gillis, Patricia L., E-mail: patty.gillis@ec.gc.ca [National Water Research Institute, Environment Canada, 867 Lakeshore Road, Burlington, ON L7R-4A6 (Canada)

2011-06-15

Chloride concentrations in surface waters have increased significantly, a rise attributed to road salt use. In Canada, this may be a concern for endangered freshwater mussels, many with ranges limited to southern Ontario, Canada's most road-dense region. The acute toxicity of NaCl was determined for glochidia, the mussel's larval stage. The 24 h EC50s of four (including two Canadian endangered) species ranged from 113-1430 mg Cl L{sup -1} (reconstituted water, 100 mg CaCO{sub 3} L{sup -1}). To determine how mussels would respond to a chloride pulse, natural river water (hardness 278-322 mg CaCO{sub 3} L{sup -1}) was augmented with salt. Lampsilis fasciola glochidia were significantly less sensitive to salt in natural water (EC50s 1265-1559 mg Cl L{sup -1}) than in reconstituted water (EC50 285 mg L{sup -1}). Chloride data from mussel habitats revealed chloride reaches levels acutely toxic to glochidia (1300 mg L{sup -1}). The increased salinization of freshwater could negatively impact freshwater mussels, including numerous species at risk. - Highlights: > Compared to other aquatic organisms glochidia are very sensitive to chloride. > Glochidia were less sensitive to salt in natural water than in reconstituted water. > Glochidia were less sensitive to salt in hard water than in soft water. > Road salt runoff may pose a threat to the reproduction of freshwater mussels. > Salinization of freshwater could negatively impact numerous species at risk. - Freshwater mussel larvae were acutely sensitive to sodium chloride, such that chloride levels in some Canadian rivers may pose a threat to the survival of this early life stage.
Assessing the toxicity of sodium chloride to the glochidia of freshwater mussels: Implications for salinization of surface waters

International Nuclear Information System (INIS)

Gillis, Patricia L.

2011-01-01

Chloride concentrations in surface waters have increased significantly, a rise attributed to road salt use. In Canada, this may be a concern for endangered freshwater mussels, many with ranges limited to southern Ontario, Canada's most road-dense region. The acute toxicity of NaCl was determined for glochidia, the mussel's larval stage. The 24 h EC50s of four (including two Canadian endangered) species ranged from 113-1430 mg Cl L -1 (reconstituted water, 100 mg CaCO 3 L -1 ). To determine how mussels would respond to a chloride pulse, natural river water (hardness 278-322 mg CaCO 3 L -1 ) was augmented with salt. Lampsilis fasciola glochidia were significantly less sensitive to salt in natural water (EC50s 1265-1559 mg Cl L -1 ) than in reconstituted water (EC50 285 mg L -1 ). Chloride data from mussel habitats revealed chloride reaches levels acutely toxic to glochidia (1300 mg L -1 ). The increased salinization of freshwater could negatively impact freshwater mussels, including numerous species at risk. - Highlights: → Compared to other aquatic organisms glochidia are very sensitive to chloride. → Glochidia were less sensitive to salt in natural water than in reconstituted water. → Glochidia were less sensitive to salt in hard water than in soft water. → Road salt runoff may pose a threat to the reproduction of freshwater mussels. → Salinization of freshwater could negatively impact numerous species at risk. - Freshwater mussel larvae were acutely sensitive to sodium chloride, such that chloride levels in some Canadian rivers may pose a threat to the survival of this early life stage.
Solar photo-Fenton treatment of microcystin-LR in aqueous environment: Transformation products and toxicity in different water matrices

Science.gov (United States)

Transformation products and toxicity patterns of microcystin-LR (MC-LR), a common cyanotoxin in freshwaters, during degradation by solar photo-Fenton process were studied in the absence and presence of two major water components, namely fulvic acid and alkalinity. The transformat...
Zebrafish and clean water technology: assessing soil bioretention as a protective treatment for toxic urban runoff.

Science.gov (United States)

McIntyre, J K; Davis, J W; Incardona, J P; Stark, J D; Anulacion, B F; Scholz, N L

2014-12-01

Urban stormwater contains a complex mixture of contaminants that can be acutely toxic to aquatic biota. Green stormwater infrastructure (GSI) is a set of evolving technologies intended to reduce impacts on natural systems by slowing and filtering runoff. The extent to which GSI methods work as intended is usually assessed in terms of water quantity (hydrology) and quality (chemistry). Biological indicators of GSI effectiveness have received less attention, despite an overarching goal of protecting the health of aquatic species. Here we use the zebrafish (Danio rerio) experimental model to evaluate bioinfiltration as a relatively inexpensive technology for treating runoff from an urban highway with dense motor vehicle traffic. Zebrafish embryos exposed to untreated runoff (48-96h; six storm events) displayed an array of developmental abnormalities, including delayed hatching, reduced growth, pericardial edema, microphthalmia (small eyes), and reduced swim bladder inflation. Three of the six storms were acutely lethal, and sublethal toxicity was evident across all storms, even when stormwater was diluted by as much as 95% in clean water. As anticipated from exposure to cardiotoxic polycyclic aromatic hydrocarbons (PAHs), untreated runoff also caused heart failure, as indicated by circulatory stasis, pericardial edema, and looping defects. Bioretention treatment dramatically improved stormwater quality and reversed nearly all forms of developmental toxicity. The zebrafish model therefore provides a versatile experimental platform for rapidly assessing GSI effectiveness. Copyright © 2014 Elsevier B.V. All rights reserved.
Effect of ambient temperature and sodium bicarbonate supplementation on water and electrolyte balances in dry and lactating Holstein cows.

Science.gov (United States)

Khelil-Arfa, H; Faverdin, P; Boudon, A

2014-01-01

The aim of this study was to quantify the effect of the interaction between 2 constant ambient temperatures [thermoneutrality (TN; 15°C) and high temperature (HT; 28°C)] and 2 levels of Na bicarbonate supplementation [calculated to provide diet Na contents of 0.20%DM (Na-) and 0.50%DM (Na+)] on water partitioning in dairy cows. Treatments were compared on 4 dry and 4mid-lactation Holstein cows according to 2 Latin squares (1 for each physiological stage) over the course of 4 periods of 15d. Diets consisted of a total mixed ration based on maize silage. Dry cows were restricted to their protein and energy requirements, whereas lactating cows were fed ad libitum. The daily average temperature-humidity index was 59.4 for TN and 73.2 for HT. Lactating and dry cows had higher vaginal temperatures at HT than at TN, but the increase was more pronounced in lactating cows (+1.05 vs. +0.12°C for vaginal temperature, respectively). Dry matter intake (DMI) of lactating cows decreased by 2.3kg/d at HT. Free water intake (FWI) and estimated volume of water lost to evaporation increased at HT in both lactating and dry cows; no interactions were observed between temperature and physiological stage. When expressed as a proportion of DMI, the increase in evaporation that occurred with increasing temperature was completely compensated for by an increase in FWI for both physiological stages. The urinary water excretion increased slightly at HT in lactating cows but not in dry cows, which may be related to the low chloride content of the offered diet. High Na supplementation increased DMI slightly in lactating cows, but milk yield was not affected. Sodium supplementation did not limit the decrease in DMI observed in lactating cows at HT; this observation is likely due to the high diet electrolyte balance of the offered diets. Sodium supplementation increased FWI in lactating cows and urinary flow in both physiological states. The interaction between ambient temperature and Na

Acute toxicity of water soluble fraction of petroleum, diesel and gasoline for newly hatched larvae of marine pejerrey Odontesthes Argentinensis

Energy Technology Data Exchange (ETDEWEB)

Rodrigues, Ricardo V.; Miranda-Filho, Kleber C.; Gusmao, Emeline P.; Moreira, Caue B.; Santos, Renato A.; Oliveira, Marcelo G.; Sampaio, Luis Andre [Fundacao Universidade do Rio Grande (FURG), RS (Brazil)

2008-07-01

The hydrocarbons of petroleum are the main aquatic pollutants and can cause toxicity to aquatic organisms, however, only a few toxicological studies were already conducted with early life stages of fish. The aim of this work was to determine the toxicity (LC50-96h) of water soluble fraction (WSF) of petroleum, diesel and gasoline for newly hatched larvae of marine pejerrey Odontesthes argentinensis. During the experiments the concentrations tested were: to petroleum (5%, 10%, 25%, 50%, 75%, and 100% of), to diesel (1%, 2%, 4%, 8%, 16%, 32%, e 64% of WSF) and to gasoline (1%, 2.5%, 5%, 10%, and 20% of WSF) plus a control to each pollutant. All treatments were done with 3 repetitions and 30 larvae. During the experiments the water quality were maintained at temperature 22,5 deg C, salinity 30, pH 7.95 and dissolved oxygen approximately around 4mg/L. The petroleum presented an CL50-96h equal to 70.68% (65.73 - 76.01), while the diesel and gasoline presented the toxicity values of 13.46% (10.19-17.79) and 5.48% (4.85-6.20), respectively. The results demonstrated a higher toxicity of light fuels (diesel and gasoline) compared to heavy petroleum. (author)
The water extract of Veratrilla baillonii could attenuate the subacute toxicity induced by Aconitum brachypodum.

Science.gov (United States)

Yu, You; Yi, Xue-Jia; Mei, Zhi-Yi; Li, Jun; Huang, Xian-Ju; Yang, Guang-Zhong; Ma, Li-Qun; Gao, Yue

2016-12-01

Aconitum brachypodum Diels (Family Ranunculaceae) is a Chinese ethnodrug and is well known for both its therapeutic application and high toxicity. However, no detoxication strategy is available for the complete elimination of the toxicity of Aconitum plants. Veratrilla baillonii Franch is believed to possess antitoxic effects on the toxicity induced by Aconitum plants and has been clinically used for hundreds of time by Naxi and Lisu nationalities in Yunnan Province of China. To further address the mechanism of the detoxication of Veratrilla baillonii, the effect of water decoction of Veratrilla baillonii (WVBF) on subacute toxicology of SD rats induced by Aconitum brachypodum (CFA), a genus Aconitum, was determined and studied in the present work. The clinical behavior and number of survivors for different dosage of WVBF (25, 50, 100mg/kg) on CFA (4mg/kg) induced rats were observed until day 28. Histological changes and haematological parameters were evaluated. Moreover, Na + -K + -ATPase pathway in heart as well as key enzymes in liver were determined to further discuss the mechanism. The results showed that the exposure of CFA led to some subacute toxicity to rats, especially male ones, accompanied with abnormality of serum biochemical index in rats' serum. The toxicological target organs of CFA may be the heart, liver, kidney and brain. It is demonstrated that WVBF could attenuate the toxicity induced by Aconitum brachypodum via promoting the metabolic enzymes CYP3A1 and CYP3A2 in liver, downregulating the expression of Sodium/Calcium exchanger 1 (NCX1) and SCN5A sodium channal mRNA, and inducing Na + /K + -ATPase activity in heart. This study provides insights into detoxifying measures of Aconitum plants. Aconitum brachypodum may lead to subacute toxicity of rats after long term of administration, and the toxicity could be attenuated by Veratrilla baillonii via promoting the metabolic enzymes in liver, downregulating the expression of NCX1 and SCN5A mRNA, and
Role of Bioadsorbents in Reducing Toxic Metals

OpenAIRE

Mathew, Blessy Baby; Jaishankar, Monisha; Biju, Vinai George; Krishnamurthy Nideghatta Beeregowda

2016-01-01

Industrialization and urbanization have led to the release of increasing amounts of heavy metals into the environment. Metal ion contamination of drinking water and waste water is a serious ongoing problem especially with high toxic metals such as lead and cadmium and less toxic metals such as copper and zinc. Several biological materials have attracted many researchers and scientists as they offer both cheap and effective removal of heavy metals from waste water. Therefore it is urgent to st...
NODC Standard Format Marine Toxic Substances and Pollutants (F144) Data (1971-1989) (NODC Accession 0014199)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data type contains data on ambient concentrations of toxic substances and other pollutants in the marine environment. The data derive from laboratory analyses...
Toxicity studies of the water extract from the calyces of Hibiscus sabdariffa L. in rats.

Science.gov (United States)

Sireeratawong, Seewaboon; Itharat, Arunporn; Khonsung, Parirat; Lertprasertsuke, Nirush; Jaijoy, Kanjana

2013-01-01

Acute and chronic toxicities of the water extract from calyces of Hibiscus sabdariffa were studied in male and female rats. After 14 days of a single oral administration of test substance 5,000 mg/kg body weight, measurement of the body and organ weights, necropsy and health monitoring were performed. No signs and differences of the weights or behaviour compared to the control rats were observed. The results indicated that the single oral administration of H. sabdariffa extract in the amount of 5,000 mg/kg body weight does not produce acute toxicity. The chronic toxicity was determined by oral feeding both male and female rats daily with the extract at the doses of 50, 100, and 200 mg/kg body weight for 270 days. The examinations of signs, animal behaviour and health monitoring showed no defects in the test groups compared to the control groups. Both test and control groups (day 270th) and satellite group (day 298th) were analysed by measuring their final body and organ weights, taking necropsy, and examining haematology, blood clinical chemistry, and microanatomy. Results showed no differences from the control groups. Overall, our study demonstrated that an oral administration of H. sabdariffa extract at the doses of 50, 100 and 200 mg/kg body weight for 270 days does not cause chronic toxicity in rat.
Periodismo ambiental

Directory of Open Access Journals (Sweden)

Lucía Lemos

2015-01-01

Full Text Available Los periodistas toman el tema del medio ambiente cada vez más en serio. El uso de temas relacionados con el medio ambiente, debe estar ligado al análisis socio-económico y a las posibilidades de comunicación y educación de diferentes regiones del mundo. A continuación se presenta un resumen de la situación ambiental, las acciones de prensa y comunicación que se llevan a cabo en América Central (Panamá, El Salvador, Costa Rica y en Sudamérica Brasil,Colombia, Chile, México, y Perú. Se concluye en la necesidad de formar hábitos ecológicos. Los comunicadores deben presentar soluciones a los problemas, fomentar campañas comunes, compartir información y velar por el ambiente ambiente para que las generaciones futuras no tengan que perecer.
Impact of emissions from natural gas production facilities on ambient air quality in the Barnett Shale area: a pilot study.

Science.gov (United States)

Zielinska, Barbara; Campbell, Dave; Samburova, Vera

2014-12-01

Rapid and extensive development of shale gas resources in the Barnett Shale region of Texas in recent years has created concerns about potential environmental impacts on water and air quality. The purpose of this study was to provide a better understanding of the potential contributions of emissions from gas production operations to population exposure to air toxics in the Barnett Shale region. This goal was approached using a combination of chemical characterization of the volatile organic compound (VOC) emissions from active wells, saturation monitoring for gaseous and particulate pollutants in a residential community located near active gas/oil extraction and processing facilities, source apportionment of VOCs measured in the community using the Chemical Mass Balance (CMB) receptor model, and direct measurements of the pollutant gradient downwind of a gas well with high VOC emissions. Overall, the study results indicate that air quality impacts due to individual gas wells and compressor stations are not likely to be discernible beyond a distance of approximately 100 m in the downwind direction. However, source apportionment results indicate a significant contribution to regional VOCs from gas production sources, particularly for lower-molecular-weight alkanes (gas production. Implications: Rapid and extensive development of shale gas resources in recent years has created concerns about potential environmental impacts on water and air quality. This study focused on directly measuring the ambient air pollutant levels occurring at residential properties located near natural gas extraction and processing facilities, and estimating the relative contributions from gas production and motor vehicle emissions to ambient VOC concentrations. Although only a small-scale case study, the results may be useful for guidance in planning future ambient air quality studies and human exposure estimates in areas of intensive shale gas production.
Evaluation and refinement of a field-portable drinking water toxicity sensor utilizing electric cell-substrate impedance sensing and a fluidic biochip.

Science.gov (United States)

Widder, Mark W; Brennan, Linda M; Hanft, Elizabeth A; Schrock, Mary E; James, Ryan R; van der Schalie, William H

2015-07-01

The US Army's need for a reliable and field-portable drinking water toxicity sensor was the catalyst for the development and evaluation of an electric cell-substrate impedance sensing (ECIS) device. Water testing technologies currently available to soldiers in the field are analyte-specific and have limited capabilities to detect broad-based water toxicity. The ECIS sensor described here uses rainbow trout gill epithelial cells seeded on fluidic biochips to measure changes in impedance for the detection of possible chemical contamination of drinking water supplies. Chemicals selected for testing were chosen as representatives of a broad spectrum of toxic industrial compounds. Results of a US Environmental Protection Agency (USEPA)-sponsored evaluation of the field portable device were similar to previously published US Army testing results of a laboratory-based version of the same technology. Twelve of the 18 chemicals tested following USEPA Technology Testing and Evaluation Program procedures were detected by the ECIS sensor within 1 h at USEPA-derived human lethal concentrations. To simplify field-testing methods further, elimination of a procedural step that acclimated cells to serum-free media streamlined the test process with only a slight loss of chemical sensitivity. For field use, the ECIS sensor will be used in conjunction with an enzyme-based sensor that is responsive to carbamate and organophosphorus pesticides. Copyright © 2014 John Wiley & Sons, Ltd.
Ketamine and the metabolite norketamine: persistence and phototransformation toxicity in hospital wastewater and surface water.

Science.gov (United States)

Lin, Angela Yu-Chen; Lee, Wan-Ning; Wang, Xiao-Huan

2014-04-15

Ketamine has been increasingly used both recreationally and medicinally around the world. Although the metabolic pathways to form its metabolite norketamine have been carefully investigated in humans and animals, knowledge of their environmental occurrence and fate is limited. In this study, we investigated the occurrence of ketamine and norketamine in 20 natural bodies of water, effluents from 13 hospitals, two wastewater treatment plants and one water supply plant. Ketamine was found at concentrations as high as 10 μg/L. Ketamine and norketamine were consistently found in similar concentrations (ketamine/norketamine ratio: 0.3-4.6) in the collected water samples, and this ratio similar to that found in urine samples. Dark incubation experiments have shown that ketamine is not susceptible to microbial degradation or hydrolysis. Phototransformation was demonstrated to significantly reduce the concentration of ketamine and norketamine in river waters (t(1/2) = 12.6 ± 0.4 and 10.1 ± 0.4 h, respectively) and resulted in byproducts that are similar to human metabolites. Both direct and indirect photolysis led to the N-demethylation of ketamine to form norketamine and other byproducts, including hydroxy-norketamine (HNK), dehydronorketamine (DNK), hydroxy-ketamine (HK) and isomer forms of ketamine and norketamine. Irradiated solutions exhibited higher toxicity (via the Microtox test). Although a final risk assessment could not be made due to a lack of studies on the chronic effects on aquatic organisms, the high and persistent environmental occurrences of ketamine and norketamine as well as the increasingly acute toxicity of the photo byproducts demonstrate the importance of including metabolites in evaluation of the overall risk of ketamine. Copyright © 2014 Elsevier Ltd. All rights reserved.
A fresh look at road salt: aquatic toxicity and water-quality impacts on local, regional, and national scales.

Science.gov (United States)

Corsi, Steven R; Graczyk, David J; Geis, Steven W; Booth, Nathaniel L; Richards, Kevin D

2010-10-01

A new perspective on the severity of aquatic toxicity impact of road salt was gained by a focused research effort directed at winter runoff periods. Dramatic impacts were observed on local, regional, and national scales. Locally, samples from 7 of 13 Milwaukee, Wisconsin area streams exhibited toxicity in Ceriodaphnia dubia and Pimephales promelas bioassays during road-salt runoff. Another Milwaukee stream was sampled from 1996 to 2008 with 72% of 37 samples exhibiting toxicity in chronic bioassays and 43% in acute bioassays. The maximum chloride concentration was 7730 mg/L. Regionally, in southeast Wisconsin, continuous specific conductance was monitored as a chloride surrogate in 11 watersheds with urban land use from 6.0 to 100%. Elevated specific conductance was observed between November and April at all sites, with continuing effects between May and October at sites with the highest specific conductance. Specific conductance was measured as high as 30,800 μS/cm (Cl = 11,200 mg/L). Chloride concentrations exceeded U.S. Environmental Protection Agency (USEPA) acute (860 mg/L) and chronic (230 mg/L) water-quality criteria at 55 and 100% of monitored sites, respectively. Nationally, U.S. Geological Survey historical data were examined for 13 northern and 4 southern metropolitan areas. Chloride concentrations exceeded USEPA water-quality criteria at 55% (chronic) and 25% (acute) of the 168 monitoring locations in northern metropolitan areas from November to April. Only 16% (chronic) and 1% (acute) of sites exceeded criteria from May to October. At southern sites, very few samples exceeded chronic water-quality criteria, and no samples exceeded acute criteria.
Oil sands tailings leachability and toxicity evaluation

International Nuclear Information System (INIS)

Gulley, J.R.

1995-01-01

Fine tailings disposal and reclamation is a major issue facing the oil sands mining and extraction industry. Government regulations dictate that reclamation must return the site to a level of self-sustaining biological capability which approximates the natural condition. A two-phase laboratory program has been completed to investigate the suitability of alternative reclamation materials. For the first phase of the study, chemical and toxicological analyses were carried out on 13 different reclamation and reference materials (solid phase and extractions). Seedling emergence, nematode maturation, algal growth and bacterial luminescence for leachate samples showed a range of sensitivities in response to the tested materials, although phytotoxicity tests were generally the most sensitive. With the exception of one test material, high toxicity ratings were consistent with that expected from the chemical data. The second phase of the study focused on the evaluation of chemical and toxicological conditions in leachate water generated using bench-scale column percolation tests. Leachate water equivalent to 10 pore volume replacements was generated and temporal variations in toxicity and chemistry monitored. Similar to phase 1 findings, phytotoxicity tests were the most sensitive tests to leachate waters. For most materials tested, most toxicity was removed after 2--3 porewater replacements. More persistent toxicity was noted for samples containing bitumen (e.g., fine tails and oil sands). No clear correspondence was noted between chemical concentrations and toxicity in leachate waters
Characterizing toxicity of metal-contaminated sediments from mining areas

International Nuclear Information System (INIS)

Besser, John M.; Brumbaugh, William G.; Ingersoll, Christopher G.

2015-01-01

Highlights: • We review methods for testing toxicity of sediments affected by metals. • Toxicity testing provides site-specific assessment of impacts on resident biota. • Goals are to document extent of toxicity and associations with metal exposure. • Need to characterize bioavailability of metals in sediment and pore water. • Toxicity data is basis for guidelines used to predict hazards of metal toxicity. - Abstract: This paper reviews methods for testing the toxicity of metals associated with freshwater sediments, linking toxic effects with metal exposure and bioavailability, and developing sediment quality guidelines. The most broadly applicable approach for characterizing metal toxicity is whole-sediment toxicity testing, which attempts to simulate natural exposure conditions in the laboratory. Standard methods for whole-sediment testing can be adapted to test a wide variety of taxa. Chronic sediment tests that characterize effects on multiple endpoints (e.g., survival, growth, and reproduction) can be highly sensitive indicators of adverse effects on resident invertebrate taxa. Methods for testing of aqueous phases (pore water, overlying water, or elutriates) are used less frequently. Analysis of sediment toxicity data focuses on statistical comparisons between responses in sediments from the study area and responses in one or more uncontaminated reference sediments. For large or complex study areas, a greater number of reference sediments is recommended to reliably define the normal range of responses in uncontaminated sediments – the ‘reference envelope’. Data on metal concentrations and effects on test organisms across a gradient of contamination may allow development of concentration-response models, which estimate metal concentrations associated with specified levels of toxic effects (e.g. 20% effect concentration or EC20). Comparisons of toxic effects in laboratory tests with measures of impacts on resident benthic invertebrate
Toxicity Identification Evaluation (TIE) of Belford Roxo industrial plant effluent and its contribution in water quality of downstream of Sarapui River, Iguacu River sub-basin, Baia da Guanabara Basin, RJ, Brazil

International Nuclear Information System (INIS)

Pires, Luiz Eduardo Botelho

2006-01-01

The quality of Belford Roxo Industrial Plant effluent and water from Sarapui River were evaluated with Daphnia similis, Ceriodaphnia dubia and Danio rerio acute and chronic toxicity tests. In association with the ecotoxicological monitoring, the Toxicity Identification Evaluation procedure were performed and the identification of the toxic compounds was possible. The Chloride ion was identified as the major toxic compound in the effluent with additional effects of Metals, Ammonium and Sulfide. For the Sarapui River, the compounds of Phosphorus and Nitrogen were identified as the major toxic compounds with addictive effects of Metals, Ammonium and Sulfide. Although the environmental impact estimation based on the effluent toxicity suggests a minor impact on the water quality of Sarapui River, this was already sufficiently contaminated to make impracticable the establishment of an aquatic community. The constant discharge of untreated sludge promotes the eutrophication of this water body and makes impossible the equilibrium of this ecosystem. (author)
Relationship and variation of qPCR and culturable enterococci estimates in ambient surface waters are predictable

Science.gov (United States)

Whitman, Richard L.; Ge, Zhongfu; Nevers, Meredith B.; Boehm, Alexandria B.; Chern, Eunice C.; Haugland, Richard A.; Lukasik, Ashley M.; Molina, Marirosa; Przybyla-Kelly, Kasia; Shively, Dawn A.; White, Emily M.; Zepp, Richard G.; Byappanahalli, Muruleedhara N.

2010-01-01

The quantitative polymerase chain reaction (qPCR) method provides rapid estimates of fecal indicator bacteria densities that have been indicated to be useful in the assessment of water quality. Primarily because this method provides faster results than standard culture-based methods, the U.S. Environmental Protection Agency is currently considering its use as a basis for revised ambient water quality criteria. In anticipation of this possibility, we sought to examine the relationship between qPCR-based and culture-based estimates of enterococci in surface waters. Using data from several research groups, we compared enterococci estimates by the two methods in water samples collected from 37 sites across the United States. A consistent linear pattern in the relationship between cell equivalents (CCE), based on the qPCR method, and colony-forming units (CFU), based on the traditional culturable method, was significant (P 10CFU > 2.0/100 mL) while uncertainty increases at lower CFU values. It was further noted that the relative error in replicated qPCR estimates was generally higher than that in replicated culture counts even at relatively high target levels, suggesting a greater need for replicated analyses in the qPCR method to reduce relative error. Further studies evaluating the relationship between culture and qPCR should take into account analytical uncertainty as well as potential differences in results of these methods that may arise from sample variability, different sources of pollution, and environmental factors.
The use of bacteria for detecting toxic effects of pollutants in soil and water

Science.gov (United States)

Obiakor, Maximilian; Wilson, Susan; Tighe, Matthew; Pereg, Lily

2017-04-01

Microbial abundance and diversity are essential for sustaining soil structure and function and have been strongly linked to human health and wellbeing. Antimony (Sb) in the environment can present an ecological hazard and depending on concentration can be lethal. The toxic effects of Sb(III) and Sb(V) on the model soil bacterium Azospirillum brasilense Sp7 were assessed in exposure-dose-response assays and water samples from an Sb contaminated creek were analyzed for bacterial mortality. In both cases, Sb(III) and Sb(V) greatly affected the survival of A. brasilense Sp7 cells. The Sb(III) had a greater toxic effect than Sb(V) at all concentrations tested. Critical concentrations of Sb also caused variant colonies to appear, indicating both acute and sub-lethal effects, which were dose and time dependent. This work demonstrates the usefulness of A. brasilense as an indicator species to detect harmful effects of an environmental pollutant of emerging concern.
Guidelines for the disposal of dangerous and toxic wastes so as to minimize or prevent environmental and water pollution

CSIR Research Space (South Africa)

Rudd, RT

1978-01-01

Full Text Available Modern society is producing ever increasing quantities of dangerous and/or toxic wastes, which require safe and effective disposal if they are not to pose a threat to our water supplies or the environment in general....
Isobaric-Isothermal Molecular Dynamics Utilizing Density Functional Theory: An Assessment of the Structure and Density of Water at Near-Ambient Conditions

International Nuclear Information System (INIS)

Schmidt, J.; VandeVondele, J.; Kuo, I.W.; Sebastiani, D.; Siepmann, J.I.; Hutter, J.; Mundy, C.J.

2009-01-01

We present herein a comprehensive density functional theory study toward assessing the accuracy of two popular gradient-corrected exchange correlation functionals on the structure and density of liquid water at near ambient conditions in the isobaric-isothermal ensemble. Our results indicate that both PBE and BLYP functionals under predict the density and over structure the liquid. Adding the dispersion correction due to Grimme(1, 2) improves the predicted densities for both BLYP and PBE in a significant manner. Moreover, the addition of the dispersion correction for BLYP yields an oxygen-oxygen radial distribution function in excellent agreement with experiment. Thus, we conclude that one can obtain a very satisfactory model for water using BLYP and a correction for dispersion.
Influence of selected water quality characteristics on the toxicity of lambda-cyhalothrin and gamma-cyhalothrin to Hyalella azteca.

Science.gov (United States)

Smith, S; Lizotte, R E

2007-11-01

This study was conducted to assess the influence of suspended solids, dissolved organic carbon, and phytoplankton (as chlorophyll a) water quality characteristics on lambda-cyhalothrin and gamma-cyhalothrin aqueous toxicity to Hyalella azteca using natural water from 12 ponds and lakes in Mississippi, USA with varying water quality characteristics. H. azteca 48-h immobilization EC50 values ranged from 1.4 to 15.7 ng/L and 0.6 to 13.4 ng/L for lambda-cyhalothrin and gamma-cyhalothrin, respectively. For both pyrethroids, EC50 values linearly increased as turbidity, suspended solids, dissolved organic carbon and chlorophyll a concentrations increased.
Fundamental study of a one-step ambient temperature ferrite ...

African Journals Online (AJOL)

... involves the controlled oxidation of ferrous-containing AMD water at ambient ... solutions under controlled pH and oxidation conditions (pH 10.5, air flow rate ... The kinetics of the reaction under the investigated conditions were found to be ...
Source water assessment and nonpoint sources of acutely toxic contaminants: A review of research related to survival and transport of Cryptosporidium parvum

Science.gov (United States)

Walker, Mark J.; Montemagno, Carlo D.; Jenkins, Michael B.

1998-12-01

Amendments to the Safe Drinking Water Act (PL-930123) in 1996 required that public water supply managers identify potential sources of contamination within contributing areas. Nonpoint sources of acutely toxic microbial contaminants, such as Cryptosporidium parvum, challenge current approaches to source identification and management as a first step toward developing management plans for public water supply protection. Little may be known about survival and transport in the field environment, prescribed practices may not be designed to manage such substances, and infective stages may be present in vast numbers and may resist water treatment and disinfection processes. This review summarizes research related to survival and transport of C. parvum oocysts, as an example of an acutely toxic contaminant with nonpoint sources in animal agriculture. It discusses ∥1) significance of infected domesticated animals as potential sources of C. parvum, (2) laboratory and field studies of survival and transport, and (3) approaches to source control in the context of public health protection.

Relationship between ambient air pollution and DNA damage in Polish mothers and newborns

International Nuclear Information System (INIS)

Whyatt, R.M.; Santella, R.M.; Jedrychowski, W.; Garte, S.J.; Bell, D.A.; Ottman, R.; Gladek-Yarborough, A.; Cosma, G.; Young, T.L.; Cooper, T.B.; Randall, M.C.; Manchester, D.K.; Perera, F.P.

1998-01-01

Industrialized regions in Poland are characterized by high ambient pollution, including polycyclic aromatic hydrocarbons (PAHs) from coal burning for industry and home heating. In experimental bioassays, certain PAHs are transplacental carcinogens and developmental toxicants. The amount of PAHs bound to DNA (PAH-DNA adducts) in maternal and umbilical white blood cells were measured in 70 mothers and newborns from Krakow, Poland. Modulation of adduct levels by genotypes previously linked to risk of lung cancer, specifically glutathione S-transferase M1(GSTM1) and cytochrome P4501A1 (CYP1A1). There was a dose-related increase in maternal and newborn adduct levels with ambient pollution at the women's place of residence among subjects who were not employed away from home (p less than or equal to 0.05). Maternal smoking (active and passive) significantly increased maternal (p less than or equal to 0.01) but not newborn adduct levels. Results indicate that PAH-induced DNA damage in mothers and newborns is increased by ambient air pollution
Evaporative water loss, relative water economy and evaporative partitioning of a heterothermic marsupial, the monito del monte (Dromiciops gliroides).

Science.gov (United States)

Withers, Philip C; Cooper, Christine E; Nespolo, Roberto F

2012-08-15

We examine here evaporative water loss, economy and partitioning at ambient temperatures from 14 to 33°C for the monito del monte (Dromiciops gliroides), a microbiotheriid marsupial found only in temperate rainforests of Chile. The monito's standard evaporative water loss (2.58 mg g(-1) h(-1) at 30°C) was typical for a marsupial of its body mass and phylogenetic position. Evaporative water loss was independent of air temperature below thermoneutrality, but enhanced evaporative water loss and hyperthermia were the primary thermal responses above the thermoneutral zone. Non-invasive partitioning of total evaporative water loss indicated that respiratory loss accounted for 59-77% of the total, with no change in respiratory loss with ambient temperature, but a small change in cutaneous loss below thermoneutrality and an increase in cutaneous loss in and above thermoneutrality. Relative water economy (metabolic water production/evaporative water loss) increased at low ambient temperatures, with a point of relative water economy of 15.4°C. Thermolability had little effect on relative water economy, but conferred substantial energy savings at low ambient temperatures. Torpor reduced total evaporative water loss to as little as 21% of normothermic values, but relative water economy during torpor was poor even at low ambient temperatures because of the relatively greater reduction in metabolic water production than in evaporative water loss. The poor water economy of the monito during torpor suggests that negative water balance may explain why hibernators periodically arouse to normothermia, to obtain water by drinking or via an improved water economy.
Haloacetonitriles: metabolism and toxicity.

Science.gov (United States)

Lipscomb, John C; El-Demerdash, Ebtehal; Ahmed, Ahmed E

2009-01-01

The haloacetonitriles (HANs) exist in drinking water exclusively as byproducts of disinfection. HANs are found in drinking water more often, and in higher concentrations, when surface water is treated by chloramination. Human exposure occurs through consumption of finished drinking water; oral and dermal contact also occurs, and results from showering, swimming and other activities. HANs are reactive and are toxic to gastrointestinal tissues following oral administration. Such toxicity is characterized by GSH depletion, increased lipid peroxidation, and covalent binding of HAN-associated radioactivity to gut tissues. The presence of GSH in cells is an important protective mechanism against HAN toxicity; depletion of cellular GSH results in increased toxicity. Some studies have demonstrated an apparently synergistic effect between ROS and HAN administration, that may help explain effects observed in GI tissues. ROS are produced in gut tissues, and in vitro evidence indicates that ROS may contribute to the degradation and formation of reactive intermediates from HANs. The rationale for ROS involvement may involve HAN-induced depletion of GSH and the role of GSH in scavenging ROS. In addition to effects on GI tissues, studies show that HAN-derived radiolabel is found covalently bound to proteins and DNA in several organs and tissues. The addition of antioxidants to biologic systems protects against HAN-induced DNA damage. The protection offered by antioxidants supports the role of oxidative stress and the potential for a threshold in han-induced toxicity. However, additional data are needed to substantiate evidence for such a threshold. HANs are readily absorbed from the GI tract and are extensively metabolized. Elimination occurs primarily in urine, as unconjugated one-carbon metabolites. Evidence supports the involvement of mixed function oxidases, the cytochrome P450 enzyme family and GST, in HAN metabolism. Metabolism represents either a detoxification or
Modulation of protein fermentation does not affect fecal water toxicity: a randomized cross-over study in healthy subjects.

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Karen Windey

Full Text Available Protein fermentation results in production of metabolites such as ammonia, amines and indolic, phenolic and sulfur-containing compounds. In vitro studies suggest that these metabolites might be toxic. However, human and animal studies do not consistently support these findings. We modified protein fermentation in healthy subjects to assess the effects on colonic metabolism and parameters of gut health, and to identify metabolites associated with toxicity.After a 2-week run-in period with normal protein intake (NP, 20 healthy subjects followed an isocaloric high protein (HP and low protein (LP diet for 2 weeks in a cross-over design. Protein fermentation was estimated from urinary p-cresol excretion. Fecal metabolite profiles were analyzed using GC-MS and compared using cluster analysis. DGGE was used to analyze microbiota composition. Fecal water genotoxicity and cytotoxicity were determined using the Comet assay and the WST-1-assay, respectively, and were related to the metabolite profiles.Dietary protein intake was significantly higher during the HP diet compared to the NP and LP diet. Urinary p-cresol excretion correlated positively with protein intake. Fecal water cytotoxicity correlated negatively with protein fermentation, while fecal water genotoxicity was not correlated with protein fermentation. Heptanal, 3-methyl-2-butanone, dimethyl disulfide and 2-propenyl ester of acetic acid are associated with genotoxicity and indole, 1-octanol, heptanal, 2,4-dithiapentane, allyl-isothiocyanate, 1-methyl-4-(1-methylethenyl-benzene, propionic acid, octanoic acid, nonanoic acid and decanoic acid with cytotoxicity.This study does not support a role of protein fermentation in gut toxicity. The identified metabolites can provide new insight into colonic health.ClinicalTrial.gov NCT01280513.
Structure elucidation and toxicity analyses of the radiolytic products of aflatoxin B{sub 1} in methanol-water solution

Energy Technology Data Exchange (ETDEWEB)

Wang, Feng [Institute of Agro-food Science and Technology of Chinese Academy of Agricultural Sciences, 2nd Yuanmingyuan West Road, Hai Dian District, Beijing 100193 (China); Key Opening Laboratory of Agricultural Products Processing and Quality Control, Ministry of Agriculture, 2nd Yuanmingyuan West Road, Hai Dian District, Beijing 100193 (China); Graduate School of Chinese Academy of Agricultural Sciences, 12th Zhongguancun South Road, Hai Dian District, Beijing 100081 (China); Xie, Fang [Institute of Agro-food Science and Technology of Chinese Academy of Agricultural Sciences, 2nd Yuanmingyuan West Road, Hai Dian District, Beijing 100193 (China); Key Opening Laboratory of Agricultural Products Processing and Quality Control, Ministry of Agriculture, 2nd Yuanmingyuan West Road, Hai Dian District, Beijing 100193 (China); Xue, Xiaofeng [Bee Research Institute of Chinese Academy of Agricultural Sciences, 1st Xiangshan North Ditch, Hai Dian District, Beijing 100093 (China); Wang, Zhidong; Fan, Bei [Institute of Agro-food Science and Technology of Chinese Academy of Agricultural Sciences, 2nd Yuanmingyuan West Road, Hai Dian District, Beijing 100193 (China); Key Opening Laboratory of Agricultural Products Processing and Quality Control, Ministry of Agriculture, 2nd Yuanmingyuan West Road, Hai Dian District, Beijing 100193 (China); Ha, Yiming, E-mail: wxfay2011@hotmail.com [Institute of Agro-food Science and Technology of Chinese Academy of Agricultural Sciences, 2nd Yuanmingyuan West Road, Hai Dian District, Beijing 100193 (China); Key Opening Laboratory of Agricultural Products Processing and Quality Control, Ministry of Agriculture, 2nd Yuanmingyuan West Road, Hai Dian District, Beijing 100193 (China)

2011-09-15

Highlights: {yields} Radiolytic products of aflatoxin B{sub 1} were produced under gamma irradiation. {yields} Seven key radiolytic products were structure-elucidated. {yields} Free-radical species in radiolytic solution resulted in the formation of products. {yields} Based on the structure-activity relationship analysis, the toxicity of radiolytic products was significantly reduced compared with that of AFB{sub 1}. {yields} The addition reaction on furan ring double bond was the reason for the reduced toxicity. - Abstract: The identification of the radiolytic products of mycotoxins is a key issue in the feasibility study of gamma ray radiation detoxification. Methanol-water solution (60:40, v/v) spiked with aflatoxin B{sub 1} (AFB{sub 1}; 20 mg L{sup -1}) was irradiated with Co{sup 60} gamma ray to generate radiolytic products. Liquid chromatography-quadruple time-of-flight mass spectrometry was applied to identify the radiolytic products of AFB{sub 1}. Accurate mass and proposed molecular formulas with a high-matching property of more than 20 radiolytic products were obtained. Seven key radiolytic products were proposed based on the molecular formulas and tandem mass spectrometry spectra. The analyses of toxicity and formation pathways were proposed based on the structure of the radiolytic products. The addition reaction caused by the free-radical species in the methanol-water solution resulted in the formation of most radiolytic products. Based on the structure-activity relationship analysis, the toxicity of radiolytic products was significantly reduced compared with that of AFB{sub 1} because of the addition reaction that occurred on the double bond in the terminal furan ring. For this reason, gamma irradiation is deemed an effective tool for the detoxification of AFB{sub 1}.
Hazard index for underground toxic material

International Nuclear Information System (INIS)

Smith, C.F.; Cohen, J.J.; McKone, T.E.

1980-06-01

To adequately define the problem of waste management, quantitative measures of hazard must be used. This study reviews past work in the area of hazard indices and proposes a geotoxicity hazard index for use in characterizing the hazard of toxic material buried underground. Factors included in this index are: an intrinsic toxicity factor, formulated as the volume of water required for dilution to public drinking-water levels; a persistence factor to characterize the longevity of the material, ranging from unity for stable materials to smaller values for shorter-lived materials; an availability factor that relates the transport potential for the particular material to a reference value for its naturally occurring analog; and a correction factor to accommodate the buildup of decay progeny, resulting in increased toxicity
Hazard index for underground toxic material

Energy Technology Data Exchange (ETDEWEB)

Smith, C.F.; Cohen, J.J.; McKone, T.E.

1980-06-01

To adequately define the problem of waste management, quantitative measures of hazard must be used. This study reviews past work in the area of hazard indices and proposes a geotoxicity hazard index for use in characterizing the hazard of toxic material buried underground. Factors included in this index are: an intrinsic toxicity factor, formulated as the volume of water required for dilution to public drinking-water levels; a persistence factor to characterize the longevity of the material, ranging from unity for stable materials to smaller values for shorter-lived materials; an availability factor that relates the transport potential for the particular material to a reference value for its naturally occurring analog; and a correction factor to accommodate the buildup of decay progeny, resulting in increased toxicity.
Development and Validation of an On-Line Water Toxicity Sensor with Immobilized Luminescent Bacteria for On-Line Surface Water Monitoring.

Science.gov (United States)

Woutersen, Marjolijn; van der Gaag, Bram; Abrafi Boakye, Afua; Mink, Jan; Marks, Robert S; Wagenvoort, Arco J; Ketelaars, Henk A M; Brouwer, Bram; Heringa, Minne B

2017-11-22

Surface water used for drinking water production is frequently monitored in The Netherlands using whole organism biomonitors, with for example Daphnia magna or Dreissena mussels, which respond to changes in the water quality. However, not all human-relevant toxic compounds can be detected by these biomonitors. Therefore, a new on-line biosensor has been developed, containing immobilized genetically modified bacteria, which respond to genotoxicity in the water by emitting luminescence. The performance of this sensor was tested under laboratory conditions, as well as under field conditions at a monitoring station along the river Meuse in The Netherlands. The sensor was robust and easy to clean, with inert materials, temperature control and nutrient feed for the reporter organisms. The bacteria were immobilized in sol-gel on either an optical fiber or a glass slide and then continuously exposed to water. Since the glass slide was more sensitive and robust, only this setup was used in the field. The sensor responded to spikes of genotoxic compounds in the water with a minimal detectable concentration of 0.01 mg/L mitomycin C in the laboratory and 0.1 mg/L mitomycin C in the field. With further optimization, which should include a reduction in daily maintenance, the sensor has the potential to become a useful addition to the currently available biomonitors.
Development and Validation of an On-Line Water Toxicity Sensor with Immobilized Luminescent Bacteria for On-Line Surface Water Monitoring

Directory of Open Access Journals (Sweden)

Marjolijn Woutersen

2017-11-01

Full Text Available Surface water used for drinking water production is frequently monitored in The Netherlands using whole organism biomonitors, with for example Daphnia magna or Dreissena mussels, which respond to changes in the water quality. However, not all human-relevant toxic compounds can be detected by these biomonitors. Therefore, a new on-line biosensor has been developed, containing immobilized genetically modified bacteria, which respond to genotoxicity in the water by emitting luminescence. The performance of this sensor was tested under laboratory conditions, as well as under field conditions at a monitoring station along the river Meuse in The Netherlands. The sensor was robust and easy to clean, with inert materials, temperature control and nutrient feed for the reporter organisms. The bacteria were immobilized in sol-gel on either an optical fiber or a glass slide and then continuously exposed to water. Since the glass slide was more sensitive and robust, only this setup was used in the field. The sensor responded to spikes of genotoxic compounds in the water with a minimal detectable concentration of 0.01 mg/L mitomycin C in the laboratory and 0.1 mg/L mitomycin C in the field. With further optimization, which should include a reduction in daily maintenance, the sensor has the potential to become a useful addition to the currently available biomonitors.
78 FR 2340 - Energy Conservation Program: Test Procedures for Residential Water Heaters and Commercial Water...

Science.gov (United States)

2013-01-11

... corresponded to the levels in the American Society of Heating, Refrigerating and Air Conditioning Engineers... provides a brief history of DOE's more recent test procedure rulemakings related to residential water... performance (e.g., such as ambient air temperature, ambient relative humidity, and inlet water temperature...
Toxicity evaluation of boron nitride nanospheres and water-soluble boron nitride in Caenorhabditis elegans

Directory of Open Access Journals (Sweden)

Wang N

2017-08-01

Full Text Available Ning Wang,1 Hui Wang,2 Chengchun Tang,3 Shijun Lei,1 Wanqing Shen,1 Cong Wang,1 Guobin Wang,4 Zheng Wang,1,4 Lin Wang1,5 1Research Center for Tissue Engineering and Regenerative Medicine, Union Hospital, 2Department of Medical Genetics, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 3Boron Nitride Research Center, School of Materials Science and Engineering, Hebei University of Technology, Tianjin, 4Department of Gastrointestinal Surgery, 5Department of Clinical Laboratory, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China Abstract: Boron nitride (BN nanomaterials have been increasingly explored for potential biological applications. However, their toxicity remains poorly understood. Using Caenorhabditis elegans as a whole-animal model for toxicity analysis of two representative types of BN nanomaterials – BN nanospheres (BNNSs and highly water-soluble BN nanomaterial (named BN-800-2 – we found that BNNSs overall toxicity was less than soluble BN-800-2 with irregular shapes. The concentration thresholds for BNNSs and BN-800-2 were 100 µg·mL-1 and 10 µg·mL-1, respectively. Above this concentration, both delayed growth, decreased life span, reduced progeny, retarded locomotion behavior, and changed the expression of phenotype-related genes to various extents. BNNSs and BN-800-2 increased oxidative stress levels in C. elegans by promoting reactive oxygen species production. Our results further showed that oxidative stress response and MAPK signaling-related genes, such as GAS1, SOD2, SOD3, MEK1, and PMK1, might be key factors for reactive oxygen species production and toxic responses to BNNSs and BN-800-2 exposure. Together, our results suggest that when concentrations are lower than 10 µg·mL-1, BNNSs are more biocompatible than BN-800-2 and are potentially biocompatible material. Keywords: boron nitride nanomaterials, Caenorhabditis elegans, nanotoxicology
Excretory nitrogen metabolism and defence against ammonia toxicity in air-breathing fishes.

Science.gov (United States)

Chew, S F; Ip, Y K

2014-03-01

With the development of air-breathing capabilities, some fishes can emerge from water, make excursions onto land or even burrow into mud during droughts. Air-breathing fishes have modified gill morphology and morphometry and accessory breathing organs, which would tend to reduce branchial ammonia excretion. As ammonia is toxic, air-breathing fishes, especially amphibious ones, are equipped with various strategies to ameliorate ammonia toxicity during emersion or ammonia exposure. These strategies can be categorized into (1) enhancement of ammonia excretion and reduction of ammonia entry, (2) conversion of ammonia to a less toxic product for accumulation and subsequent excretion, (3) reduction of ammonia production and avoidance of ammonia accumulation and (4) tolerance of ammonia at cellular and tissue levels. Active ammonia excretion, operating in conjunction with lowering of ambient pH and reduction in branchial and cutaneous NH₃ permeability, is theoretically the most effective strategy to maintain low internal ammonia concentrations. NH₃ volatilization involves the alkalization of certain epithelial surfaces and requires mechanisms to prevent NH₃ back flux. Urea synthesis is an energy-intensive process and hence uncommon among air-breathing teleosts. Aestivating African lungfishes detoxify ammonia to urea and the accumulated urea is excreted following arousal. Reduction in ammonia production is achieved in some air-breathing fishes through suppression of amino acid catabolism and proteolysis, or through partial amino acid catabolism leading to alanine formation. Others can slow down ammonia accumulation through increased glutamine synthesis in the liver and muscle. Yet, some others develop high tolerance of ammonia at cellular and tissue levels, including tissues in the brain. In summary, the responses of air-breathing fishes to ameliorate ammonia toxicity are many and varied, determined by the behaviour of the species and the nature of the environment in
Water turnover in reindeer. Some environmental implications

International Nuclear Information System (INIS)

Cameron, R.D.; Luick, J.R.; White, R.G.

1982-01-01

The nutritional and climatic effects on water turnover (determined using tritiated water) in reindeer are described. At low ambient temperatures (ca. -20 0 C) water turnover is related to protein and mineral intake, which is reflected in the relations of faecal and urinary water to nitrogen and ash excretion via these avenues. As ambient temperature increases, respiratory water, faecal water and urine flow increase, resulting in an increase in water turnover
Ambient Noise Tomography and Microseism Directionalities across the Juan de Fuca Plate

Science.gov (United States)

Tian, Ye

Ambient noise tomography has been well developed over the past decade and proven to be effective in studying the crust and upper mantle structure beneath the Earth’s continents. With new seismic array deployments beginning in the oceans, the application of the tomographic methods based on ambient noise observed at ocean bottom seismometers (OBSs) has become an important topic for research. In this thesis, I investigate the application of ambient noise tomography to oceanic bottom seismic data recorded by the Cascadia Initiative experiment across the Juan de Fuca plate. With higher local noise levels recorded by OBSs, I find that traditional data processing procedures used in ambient noise tomography produce measurable Rayleigh wave Green’s functions between deep ocean stations, whereas the shallow water stations are severely contaminated by both tilt noise and compliance noise and require new methods of processing. Because the local noise level varies across the study region, four semi-independent studies are conducted to both utilize the quieter deep-water stations and to address the problem posed by noisy shallow water stations. First, I construct an age-dependent shear wave speed model of the crust and uppermost mantle with 18 deep-water stations near the Juan de Fuca Ridge. The model possess a shallow low shear velocity zone near the ridge and has its sedimentary thickness, lithospheric thickness, and mantle shear wave speeds increase systematically with age Second, I investigate the locations and mechanisms of microseism generation using ambient noise cross-correlations constructed between 61 OBSs and 42 continental stations near the western US coast and find that the primary and secondary microseisms are generated at different locations and possibly have different physical mechanisms. Third, I show that tilt and compliance noise on the vertical components of the OBSs can be reduced substantially using the horizontal components and the differential
Atmosphere and Ambient Space

DEFF Research Database (Denmark)

Schmidt, Ulrik

Atmosphere and Ambient Space This paper explores the relation between atmosphere and ambient space. Atmosphere and ambient space share many salient properties. They are both ontologically indeterminate, constantly varying and formally diffuse and they are both experienced as a subtle, non......-signifying property of a given space. But from a certain point of view, the two concepts also designate quite dissimilar experiences of space. To be ’ambient’ means to surround. Accordingly, ambient space is that space, which surrounds something or somebody. (Gibson 1987: 65) Since space is essentially...... of a surrounding character, all space can thus be described as having a fundamentally ambient character. So what precisely is an ambient space, then? As I will argue in my presentation, ambient space is a sensory effect of spatiality when a space is experienced as being particularly surrounding: a ‘space effect...
Retrospective analysis of associations between water quality and toxic blooms of golden alga (Prymnesium parvum) in Texas reservoirs: Implications for understanding dispersal mechanisms and impacts of climate change

Science.gov (United States)

Patino, Reynaldo; Dawson, D.; VanLandeghem, Matthew M.

2014-01-01

Toxic blooms of golden alga (GA, Prymnesium parvum) in Texas typically occur in winter or early spring. In North America, they were first reported in Texas in the 1980s, and a marked range expansion occurred in 2001. Although there is concern about the influence of climate change on the future distribution of GA, factors responsible for past dispersals remain uncertain. To better understand the factors that influence toxic bloom dispersal in reservoirs, this study characterized reservoir water quality associated with toxic GA blooms since 2001, and examined trends in water quality during a 20-year period bracketing the 2001 expansion. Archived data were analyzed for six impacted and six nonimpacted reservoirs from two major Texas basins: Brazos River and Colorado River. Data were simplified for analysis by pooling spatially (across sampling stations) and temporally (winter, December-February) within reservoirs and generating depth-corrected (1 m) monthly values. Classification tree analysis [period of record (POR), 2001-2010] using salinity-associated variables (specific conductance, chloride, sulfate), dissolved oxygen (DO), pH, temperature, total hardness, potassium, nitrate+nitrite, and total phosphorus indicated that salinity best predicts the toxic bloom occurrence. Minimum estimated salinities for toxic bloom formation were 0.59 and 1.02 psu in Brazos and Colorado River reservoirs, respectively. Principal component analysis (POR, 2001-2010) indicated that GA habitat is best defined by higher salinity relative to nonimpacted reservoirs, with winter DO and pH also being slightly higher and winter temperature slightly lower in impacted reservoirs. Trend analysis, however, did not reveal monotonic changes in winter water quality of GA-impacted reservoirs during the 20-year period (1991-2010) bracketing the 2001 dispersal. Therefore, whereas minimum levels of salinity are required for GA establishment and toxic blooms in Texas reservoirs, the lack of trends in
Licenciamento ambiental e sustentabilidade

Directory of Open Access Journals (Sweden)

Marcelo Macedo Valinhas

2011-12-01

Full Text Available A sustentabilidade está apoiada principalmente nas dimensões econômica, ambiental e social. No entanto, sem a dimensão política ela não se constrói. Um dos principais instrumentos de comando e controle da política nacional de meio ambiente, o licenciamento ambiental é um processo contínuo de gestão ambiental pública e privada. Analisou-se o processo de licenciamento ambiental como acoplamento estrutural entre os sistemas social, econômico e ambiental. Apesar da constatação de críticas aos mecanismos de comando e controle dos últimos anos, foi verificado que o Estado do Rio de Janeiro tem buscado integrar a política ambiental do Estado à gestão ambiental privada e que esta integração busca atender às demandas dos sistemas sociais e econômicos para as questões ambientais. Em linhas gerais, este caminho segue as estratégias e ações propostas na Agenda 21 brasileira.
Using combined bio-omics methods to evaluate the complicated toxic effects of mixed chemical wastewater and its treated effluent

International Nuclear Information System (INIS)

Zhang, Yan; Deng, Yongfeng; Zhao, Yanping; Ren, Hongqiang

2014-01-01

Highlights: • Mice exposed to mixed chemical wastewater and its treated effluent for 90 days. • Hepatic transcriptomic alterations were analyzed by digital gene expression. • Serum metabolomic alterations were analyzed by proton nuclear magnetic resonance. • The water samples induced disruption of lipid metabolism and hepatotoxicity. • Omics approaches are valuable to evaluate the complicated toxicity of wastewater. - Abstract: Mixed chemical wastewaters (MCWW) from industrial park contain complex mixtures of trace contaminants, which cannot be effectively removed by wastewater treatment plants (WWTP) and have become an unignored threat to ambient environment. However, limited information is available to evaluate the complicated toxic effects of MCWW and its effluent from wastewater treatment plant (WTPE) from the perspective of bio-omics. In this study, mice were exposed to the MCWW and WTPE for 90 days and distinct differences in the hepatic transcriptome and serum metabolome were analyzed by digital gene expression (DGE) and proton nuclear magnetic resonance ( 1 H-NMR) spectra, respectively. Our results indicated that disruption of lipid metabolism in liver and hepatotoxicity were induced by both MCWW and WTPE exposure. WTPE is still a health risk to the environment, which is in need of more attention. Furthermore, we demonstrated the potential ability of bio-omics approaches for evaluating toxic effects of MCWW and WTPE
Using combined bio-omics methods to evaluate the complicated toxic effects of mixed chemical wastewater and its treated effluent

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yan; Deng, Yongfeng; Zhao, Yanping; Ren, Hongqiang, E-mail: hqren@nju.edu.cn

2014-05-01

Highlights: • Mice exposed to mixed chemical wastewater and its treated effluent for 90 days. • Hepatic transcriptomic alterations were analyzed by digital gene expression. • Serum metabolomic alterations were analyzed by proton nuclear magnetic resonance. • The water samples induced disruption of lipid metabolism and hepatotoxicity. • Omics approaches are valuable to evaluate the complicated toxicity of wastewater. - Abstract: Mixed chemical wastewaters (MCWW) from industrial park contain complex mixtures of trace contaminants, which cannot be effectively removed by wastewater treatment plants (WWTP) and have become an unignored threat to ambient environment. However, limited information is available to evaluate the complicated toxic effects of MCWW and its effluent from wastewater treatment plant (WTPE) from the perspective of bio-omics. In this study, mice were exposed to the MCWW and WTPE for 90 days and distinct differences in the hepatic transcriptome and serum metabolome were analyzed by digital gene expression (DGE) and proton nuclear magnetic resonance ({sup 1}H-NMR) spectra, respectively. Our results indicated that disruption of lipid metabolism in liver and hepatotoxicity were induced by both MCWW and WTPE exposure. WTPE is still a health risk to the environment, which is in need of more attention. Furthermore, we demonstrated the potential ability of bio-omics approaches for evaluating toxic effects of MCWW and WTPE.
A three-dimensional carbon nanotube network for water treatment

International Nuclear Information System (INIS)

Camilli, L; Pisani, C; Scarselli, M; Castrucci, P; De Crescenzi, M; Gautron, E; D’Orazio, F; Passacantando, M; Moscone, D

2014-01-01

The bulk synthesis of freestanding carbon nanotube (CNT) frameworks is developed through a sulfur-addition strategy during an ambient-pressure chemical vapour deposition process, with ferrocene used as the catalyst precursor. This approach enhances the CNTs’ length and contorted morphology, which are the key features leading to the formation of the synthesized porous networks. We demonstrate that such a three-dimensional structure selectively uptakes from water a mass of toxic organic solvent (i.e. o-dichlorobenzene) about 3.5 times higher than that absorbed by individual CNTs. In addition, owing to the presence of highly defective nanostructures constituting them, our samples exhibit an oil-absorption capacity higher than that reported in the literature for similar CNT sponges. (paper)

Determination of heat purgeable and ambient purgeable volatile organic compounds in water by gas chromatography/mass spectrometry

Science.gov (United States)

Rose, Donna L.; Sandstrom, Mark W.; Murtagh, Lucinda K.

2016-09-08

Two new analytical methods have been developed by the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL) that allow the determination of 37 heat purgeable volatile organic compounds (VOCs) (USGS Method O-4437-16 [NWQL Laboratory Schedule (LS) 4437]) and 49 ambient purgeable VOCs (USGS Method O-4436-16 [NWQL LS 4436]) in unfiltered water. This report documents the procedures and initial performance of both methods. The compounds chosen for inclusion in the methods were determined as having high priority by the USGS National Water-Quality Assessment (NAWQA) Program. Both methods use a purge-and-trap technique with gas chromatography/mass spectrometry. The compounds are extracted from the sample by bubbling helium through a 25-milliliter sample. For the polar and less volatile compounds, the sample is heated at 60 degrees Celsius, whereas the less polar and more volatile compounds are purged using a separate analytical procedure at ambient temperature. The compounds are trapped on a sorbent trap, desorbed into a gas chromatograph/mass spectrometer for separation, and then identified and quantified. Sample preservation is recommended for both methods by adding a 1:1 solution of hydrochloric acid (HCl [1:1]) to water samples to adjust the pH to 2. Analysis within 14 days from sampling is recommended.The heat purgeable method (USGS Method O-4437-16) operates with the mass spectrometer in the simultaneous full scan/selected ion monitoring mode. This method supersedes USGS Method O-4024-03 (NWQL LS 4024). Method detection limits (MDLs) for fumigant compounds 1,2-dibromoethane, 1,2-dichloropropane, 1,2,3-trichloropropane, chloropicrin, and 1,2-dibromo-3-chloropropane range from 0.002 to 0.010 microgram per liter (µg/L). The MDLs for all remaining heat purgeable VOCs range from 0.006 µg/L for tert-butyl methyl ether to 3 µg/L for alpha-terpineol. Calculated holding times indicate that 36 of the 37 heat purgeable VOCs are stable for a minimum of 14 days
Characterizing toxicity of metal-contaminated sediments from mining areas

Science.gov (United States)

Besser, John M.; Brumbaugh, William G.; Ingersoll, Christopher G.

2015-01-01

This paper reviews methods for testing the toxicity of metals associated with freshwater sediments, linking toxic effects with metal exposure and bioavailability, and developing sediment quality guidelines. The most broadly applicable approach for characterizing metal toxicity is whole-sediment toxicity testing, which attempts to simulate natural exposure conditions in the laboratory. Standard methods for whole-sediment testing can be adapted to test a wide variety of taxa. Chronic sediment tests that characterize effects on multiple endpoints (e.g., survival, growth, and reproduction) can be highly sensitive indicators of adverse effects on resident invertebrate taxa. Methods for testing of aqueous phases (pore water, overlying water, or elutriates) are used less frequently. Analysis of sediment toxicity data focuses on statistical comparisons between responses in sediments from the study area and responses in one or more uncontaminated reference sediments. For large or complex study areas, a greater number of reference sediments is recommended to reliably define the normal range of responses in uncontaminated sediments – the ‘reference envelope’. Data on metal concentrations and effects on test organisms across a gradient of contamination may allow development of concentration-response models, which estimate metal concentrations associated with specified levels of toxic effects (e.g. 20% effect concentration or EC20). Comparisons of toxic effects in laboratory tests with measures of impacts on resident benthic invertebrate communities can help document causal relationships between metal contamination and biological effects. Total or total-recoverable metal concentrations in sediments are the most common measure of metal contamination in sediments, but metal concentrations in labile sediment fractions (e.g., determined as part of selective sediment extraction protocols) may better represent metal bioavailability. Metals released by the weak-acid extraction
Toxic waste liquor disposal

International Nuclear Information System (INIS)

Burton, W.R.

1985-01-01

Toxic waste liquors, especially radio active liquors, are disposed in a sub-zone by feeding down a bore hole a first liquid, then a buffer liquid (e.g. water), then the toxic liquors. Pressure variations are applied to the sub-zone to mix the first liquid and liquors to form gels or solids which inhibit further mixing and form a barrier between the sub-zone and the natural waters in the environment of the sub-zone. In another example the location of the sub-zone is selected so that the environement reacts with the liquors to produce a barrier around the zone. Blind bore holes are used to monitor the sub-zone profile. Materials may be added to the liquor to enhance barrier formation. (author)
[Optimization of solid-phase extraction for enrichment of toxic organic compounds in water samples].

Science.gov (United States)

Zhang, Ming-quan; Li, Feng-min; Wu, Qian-yuan; Hu, Hong-ying

2013-05-01

A concentration method for enrichment of toxic organic compounds in water samples has been developed based on combined solid-phase extraction (SPE) to reduce impurities and improve recoveries of target compounds. This SPE method was evaluated in every stage to identify the source of impurities. Based on the analysis of Waters Oasis HLB without water samples, the eluent of SPE sorbent after dichloromethane and acetone contributed 85% of impurities during SPE process. In order to reduce the impurities from SPE sorbent, soxhlet extraction of dichloromethane followed by acetone and lastly methanol was applied to the sorbents for 24 hours and the results had proven that impurities were reduced significantly. In addition to soxhlet extraction, six types of prevalent SPE sorbents were used to absorb 40 target compounds, the lgK(ow) values of which were within the range of 1.46 and 8.1, and recovery rates were compared. It was noticed and confirmed that Waters Oasis HLB had shown the best recovery results for most of the common testing samples among all three styrenedivinylbenzene (SDB) polymer sorbents, which were 77% on average. Furthermore, Waters SepPak AC-2 provided good recovery results for pesticides among three types of activated carbon sorbents and the average recovery rates reached 74%. Therefore, Waters Oasis HLB and Waters SepPak AC-2 were combined to obtain a better recovery and the average recovery rate for the tested 40 compounds of this new SPE method was 87%.
A molecular study on bacterial resistance to arsenic-toxicity in surface and underground waters of Latium (Italy).

Science.gov (United States)

Davolos, Domenico; Pietrangeli, Biancamaria

2013-10-01

Latium, a region in central Italy, is known for its extensive volcanic areas that make a significant contribution to the arsenic (As) contamination of freshwater environments, even though some degree of As water pollution may be caused by human activities. The information available on indigenous As-resistant prokaryotes in aquatic environments of Latium is, however, still limited. In this study, we describe new bacteria that are resistant to arsenic toxicity and were isolated from the surface waters of Lake Vico and the Sacco River, two groundwater systems in Latium, as well as from bottled natural mineral water from the same region. The 16S rRNA gene sequence analysis for the As-resistant strains in lake and river waters points to a prevalence of β- and γ-Proteobacteria, while α-Proteobacteria, Firmicutes and Bacteroidetes are represented to a lesser extent. By contrast, solely γ-Proteobacteria were isolated from groundwater samples. The presence of Actinobacteria was documented exclusively in bottled mineral water. In addition, we conducted a DNA sequence-based study on the gene codifying arsB, an As(III) efflux membrane protein pump related to arsenic resistance, for all the As-resistant bacterial isolates. A phylogenetic analysis was carried out on the newly sequenced 16S rRNA genes and arsB in the present study as well as on an additional 16S rRNA/arsB dataset we obtained previously from Lake Albano, from the Tiber and from a well in Bassano Romano located in Latium (Davolos and Pietrangeli, 2011). Overall, the phylogenetic diversity of As-resistant bacteria in underground water was very limited if compared with lentic and lotic waters. Lastly, our molecular data support the hypothesis that the horizontal gene transfer of ars in As-containing freshwater environments is not limited to closely-related genomes, but also occurs between bacteria that are distant from an evolutionary viewpoint, thereby indicating that such genetic events may be considered a
Assessing sediment contamination using six toxicity assays

Directory of Open Access Journals (Sweden)

Allen G. BURTON Jr.

2001-08-01

Full Text Available An evaluation of sediment toxicity at Lake Orta, Italy was conducted to compare a toxicity test battery of 6 assays and to evaluate the extent of sediment contamination at various sediment depths. Lake Orta received excessive loadings of copper and ammonia during the 1900’s until a large remediation effort was conducted in 1989-90 using lime addition. Since that time, the lake has shown signs of a steady recovery of biological communities. The study results showed acute toxicity still exists in sediments at a depth of 5 cm and greater. Assays that detected the highest levels of toxicity were two whole sediment exposures (7 d using Hyalella azteca and Ceriodaphnia dubia. The MicrotoxR assay using pore water was the third most sensitive assay. The Thamnotox, Rototox, Microtox solid phase, and Seed Germination-Root Elongation (pore and solid phase assays showed occasional to no toxicity. Based on similarity of responses and assay sensitivity, the two most useful assays were the C. dubia (or H. azteca and Microtox pore water. These assays were effective at describing sediment toxicity in a weight-of-evidence approach.
Saúde Ambiental: uma Análise dos Resultados das Conferências Nacionais de Meio Ambiente, Saúde e Saúde Ambiental

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Maria Beatriz Maury de Carvalho

2010-08-01

Full Text Available A representação nas políticas públicas do conceito de saúde ambiental, como expressão do equilíbrio da rede de conexões entre a sociedade humana e a natureza é discutida neste trabalho, no intuito de demonstrar o status quo da saúde ambiental nas políticas públicas no país. Primeiro foi traçado o histórico da “ambientalização na saúde”, do conceito de saúde ambiental e da institucionalização das políticas ambientais e de saúde ambiental no âmbito dos Ministérios do Meio Ambiente e da Saúde. As interações entre as políticas de Saúde e de Meio Ambiente para a efetivação de uma Política Nacional de Saúde Ambiental e as intersecções dos resultados das Conferências Nacionais de Saúde, Meio Ambiente e Saúde Ambiental foram analisadas; concluindo- se com os avanços conseguidos pelos dois setores, os desafios para a articulação intersetorial e a participação social para a construção de políticas públicas de saúde ambiental.
Acute toxicity of fire-retardant and foam-suppressant chemicals to yalella azteca (Saussure)

Science.gov (United States)

McDonald, Susan F.; Hamilton, Steven J.; Buhl, Kevin J.; Heisinger, James F.

1997-01-01

Acute toxicity tests were conducted with Hyalella azteca Saussure (an amphipod) exposed in soft and hard waters to three fire retardants (Fire-Trol GTS-R, Fire-Trol LCG-R, and Phos-Chek D75-F) and two foam suppressants (Phos-Chek WD-881 and Silv-Ex). The chemicals were slightly to moderately toxic to amphipods. The most toxic chemical to amphipods in soft and hard water was Phos-Chek WD-881 (96-h mean lethal concentration [LC50] equal to 10 mg/L and 22 mg/L, respectively), and the least toxic chemical to amphipods in soft water was Fire-Trol GTS-R (96-h LC50 equal to 127 mg/L) and in hard water was Fire-Trol LCG-R (96-h LC50 equal to 535 mg/L). Concentrations of ammonia in tests with the three fire retardants and both water types were greater than reported LC50 values and probably were the major toxic component. Estimated un-ionized ammonia concentrations near the LC50 were frequently less than the reported LC50 ammonia concentrations for amphipods. The three fire retardants were more toxic in soft water than in hard water even though ammonia and un-ionized ammonia concentrations were higher in hard water tests than in soft water tests. The accidental entry of fire-fighting chemicals into aquatic environments could adversely affect aquatic invertebrates, thereby disrupting ecosystem function.
Multiple linear regression models for predicting chronic aluminum toxicity to freshwater aquatic organisms and developing water quality guidelines.

Science.gov (United States)

DeForest, David K; Brix, Kevin V; Tear, Lucinda M; Adams, William J

2018-01-01

The bioavailability of aluminum (Al) to freshwater aquatic organisms varies as a function of several water chemistry parameters, including pH, dissolved organic carbon (DOC), and water hardness. We evaluated the ability of multiple linear regression (MLR) models to predict chronic Al toxicity to a green alga (Pseudokirchneriella subcapitata), a cladoceran (Ceriodaphnia dubia), and a fish (Pimephales promelas) as a function of varying DOC, pH, and hardness conditions. The MLR models predicted toxicity values that were within a factor of 2 of observed values in 100% of the cases for P. subcapitata (10 and 20% effective concentrations [EC10s and EC20s]), 91% of the cases for C. dubia (EC10s and EC20s), and 95% (EC10s) and 91% (EC20s) of the cases for P. promelas. The MLR models were then applied to all species with Al toxicity data to derive species and genus sensitivity distributions that could be adjusted as a function of varying DOC, pH, and hardness conditions (the P. subcapitata model was applied to algae and macrophytes, the C. dubia model was applied to invertebrates, and the P. promelas model was applied to fish). Hazardous concentrations to 5% of the species or genera were then derived in 2 ways: 1) fitting a log-normal distribution to species-mean EC10s for all species (following the European Union methodology), and 2) fitting a triangular distribution to genus-mean EC20s for animals only (following the US Environmental Protection Agency methodology). Overall, MLR-based models provide a viable approach for deriving Al water quality guidelines that vary as a function of DOC, pH, and hardness conditions and are a significant improvement over bioavailability corrections based on single parameters. Environ Toxicol Chem 2018;37:80-90. © 2017 SETAC. © 2017 SETAC.
Influence of water temperature and waterborne cadmium toxicity on growth performance and metallothionein-cadmium distribution in different organs of Nile tilapia, Oreochromis niloticus (L.).

Science.gov (United States)

Abdel-Tawwab, Mohsen; Wafeek, Mohammed

2014-10-01

Cadmium (Cd) is believed to be one of the most abundant and ubiquitously distributed toxins in the aquatic system. This metal is released to the aquatic environment from both anthropogenic sources, such as industrial, agricultural and urban effluents as well as natural sources, such as rocks and soils. Otherwise, the temperature increase of water bodies, which has been observed due to global climatic changes, has been shown to increase Cd toxicity for several aquatic animal species including fish. In the present study, Nile tilapia, Oreochromis niloticus (L.), (26.0 ± 0.38 g) were reared at 20, 24, 28, or 32 °C and exposed to 0.0 or 0.5mg Cd/L for 8 weeks to investigate effects of water temperature, Cd toxicity and their interaction on fish performance as well as metallothionein (MT) and Cd distribution in different fish organs. It was found that fish reared in Cd-free group at 28 °C showed the optimum growth and feed intake, while Cd-exposed fish showed low growth and feed intake irrespective to water temperature. A synergetic relationship between water temperature and Cd toxicity was observed where Cd toxicity increased as water temperature increased and the worse growth was obtained in Cd-exposed fish reared at 32 °C. Additionally, the highest Cd residues in different fish organs were detected in Cd-exposed fish reared at 32 °C. Similarly, MT concentrations in different fish organs increased as water temperature increased especially in Cd-exposed fish groups. A high positive correlation between MT and Cd concentrations in fish organs was detected. The distribution of MT and Cd levels was in the order of liver>kidney>gills>muscles. The present study revealed that the optimum water temperature suitable for Nile tilapia growth is 28 °C. Additionally, Cd exposure had a deteriorate effect on the growth and health of Nile tilapia. This hazardous effect increased as water temperature increased. Further, liver and kidney were the prime sites of Cd accumulation
Antioxidant Capacity, Phenolic Constituents and Toxicity of Hot Water Extract from Red Maple Buds.

Science.gov (United States)

Meda, Naamwin R; Poubelle, Patrice E; Stevanovic, Tatjana

2017-06-01

The present study reports, for the first time, the results of the antioxidant capacity and the phenolic composition of a hot water extract from red maple buds (RMB), as well as its safety. In this regard and comparatively to antioxidant standards, this extract exhibits a significant antiradical capacity when tested by 2,2-diphenyl-1-picrylhydrazyl (DPPH · ) and anion superoxide trapping assays. High-resolution mass spectrometric and nuclear magnetic resonance analyses permitted to determine for the first time, in red maple species, cyanidin-3-O-glucoside, quercetin-3-O-galactoside, quercetin-3-O-arabinoside, and quercetin. Also, the quantification of individual phenolics by high-performance liquid chromatography method revealed that ginnalin A at 117.0 mg/g is the major compound of RMB hot water extract. Finally, using flow cytometry evaluation, the extract of RMB was determined to have no toxicity neither to cause significant modification of apoptosis process, up to concentration of 100 μg/ml, on human peripheral blood neutrophils. These results allow anticipating various fields of application of RMB water extract. © 2017 Wiley-VHCA AG, Zurich, Switzerland.
Determination of arsenic in ambient water at sub-part-per-trillion levels by hydride generation Pd coated platform collection and GFAAS detection.

Science.gov (United States)

Liang, L; Lazoff, S; Chan, C; Horvat, M; Woods, J S

1998-11-01

A method for trace determination of total arsenic in ambient waters is described. Arsenic is separated on-line from a large volume water sample by hydride generation and purging, pre-collected on a Pd coated pyrolytic platform cuvette using a simple and inexpensive system, and finally detected by GFAAS. Instrument parameters, hydride generation, transportation, and collection were optimized. The analytical behavior for major species including As(3+), As(5+), monomethyl As (MMA), and dimethyl As (DMA) were investigated individually. Problems arising from use of the system were discussed and eliminated. The necessity of sample digestion and an efficient digestion method were studied. Sample digestion for water with low organic content such as tap water and clean ground water and some clean surface water can be omitted. The method detection limit (MDL) is 0.3 ng l(-1) for a 25 ml water sample. Recoveries close to 100% with R.S.D.rain, sewage effluent, and saline water from different origins in the US, China, and Canada were collected and analyzed using ultra clean sampling and analysis techniques. The background levels of As in most water analyzed were established for the first time, and found to be far above the EPA's health effect criteria, 18 ng l(-1).
Two-dimensional wetting: the role of atomic steps on the nucleation of thin water films on BaF2(111) at ambient conditions.

Science.gov (United States)

Cardellach, M; Verdaguer, A; Santiso, J; Fraxedas, J

2010-06-21

The interaction of water with freshly cleaved BaF(2)(111) surfaces at ambient conditions (room temperature and under controlled humidity) has been studied using scanning force microscopy in different operation modes. The images strongly suggest a high surface diffusion of water molecules on the surface indicated by the accumulation of water at step edges forming two-dimensional bilayered structures. Steps running along the 110 crystallographic directions show a high degree of hydrophilicity, as evidenced by small step-film contact angles, while steps running along other directions exhibiting a higher degree of kinks surprisingly behave in a quite opposite way. Our results prove that morphological defects such as steps can be crucial in improving two-dimensional monolayer wetting and stabilization of multilayer grown on surfaces that show good lattice mismatch with hexagonal ice.
Det ambiente

DEFF Research Database (Denmark)

Schmidt, Ulrik

Om begrebet "det ambiente", der beskriver, hvad der sker, når vi fornemmer baggrundsmusikkens diskrete beats, betragter udsigten gennem panoramavinduet eller tager 3D-brillerne på og læner os tilbage i biografsædet. Bogen analyserer, hvorfan ambiente oplevelser skabes, og hvilke konsekvenser det...
Ambient Sensors

NARCIS (Netherlands)

Börner, Dirk; Specht, Marcus

2014-01-01

This software sketches comprise two custom-built ambient sensors, i.e. a noise and a movement sensor. Both sensors measure an ambient value and process the values to a color gradient (green > yellow > red). The sensors were built using the Processing 1.5.1 development environment. Available under
Correlation-study about the ambient dose rate and the weather conditions

Science.gov (United States)

Furuya, Masato; Hatano, Yuko; Aoyama, Tomoo; Igarashi, Yasuhito; Kita, Kazuyuki; Ishizuka, Masahide

2016-04-01

The long-term radiation risks are believed to be heavily affected by the resuspension process. We therefore focus on the surface-atmosphere exchange process of released radioactive materials in this study. Radioactive materials were deposited on the soil and float in the air, and such complicated process are influenced by the weather conditions deeply. We need to reveal the correlation between the weather conditions and the ambient dose rate. In this study, we study the correlation between the weather conditions and the ambient dose rate with the correction of the decrease due to the radioactive decay. We found that there is a negative correlation between the ambient dose rate and the soil water content by the correlation coefficient. Using this result, we reconstruct the ambient dose rate from the weather conditions by the multiple regression analysis and found that the reconstructed data agree with the observation very well. Using Kalman filter, which can be sequentially updates the state estimate, we obtained such a good agreement.
Dioxins and environment Dioxinas y medio ambiente

Directory of Open Access Journals (Sweden)

Jimena García Lobo

2011-12-01

Full Text Available With the generic term of dioxin is named the groups of the polychlorinated dibenzo-p-dioxins (PCDD and the polychlorinated dibenzofuran (PCDF, typical representans of the persistent organic compounds (POPs. They are obtained as not desired secondary products from several industrial process in which chlorine is used in some of its phases. The dioxins have centrated in the last decade an important part if the medical investigations in environmental health do to its notable toxicity, since they are one of the more powerful toxic chemical substances created by mankind, characterized for affecting the nervous and inmunitary system, being implicated into appearance of difference types of cancer and causing the appearance of several endocrine disorders, because of what they have been nowadays classified as endocrine disruptors. On degradation, bioaccumulation and on a large scale atmospheric transport capacity between the several environmental phases, make them to be considerate nowadays as dangerous compounds for human beings.Con el término genérico dioxinas se designa al grupo de las dibenzo-p-dioxinas policloradas (PCDD y de los dibenzofuranos policlorados (PCDF, representantes típicos de los compuestos orgánicos persistentes (COPs. Se obtienen como productos secundarios no deseados de diversos procesos industriales en los que se emplea cloro en alguna de sus etapas. Las dioxinas han centrado en la última década una parte importante de la investigación médica en salud ambiental debido a su notable toxicidad, ya que son las sustancias químicas peligrosas más potentes creadas por el hombre, afectando al sistema nervioso e inmunitario, estando implicadas en la aparición de distintos tipos de cáncer y provocando la aparición de alteraciones hormonales, clasificándose actualmente como disruptores endocrinos. Por otra parte, su persistencia en el medio ambiente, resistencia a la degradación, bioacumulación y capacidad de transporte atmosf
Pedagogía ambiental y didáctica ambiental como fundamentos del currículo para la formación ambiental

OpenAIRE

Julio César Tovar-Gálvez

2013-01-01

Se trata el problema de la fundamentación del currículo para la formación ambiental en la educación superior, frente a lo cual es necesario construir los conceptos de pedagogía ambiental y de didáctica ambiental. El marco teórico permite definir las categorías "lo pedagógico" y "lo didáctico", a partir de lo cual se analiza la literatura y con ello definir pedagogía ambiental y didáctica ambiental. El estado del arte permite establecer que existen dos sustentos teóricos: a) uno que se cimenta...
Removal of the precursors of N-nitrosodiethylamine (NDEA), an emerging disinfection byproduct, in drinking water treatment process and its toxicity to adult zebrafish (Danio rerio).

Science.gov (United States)

Zheng, Jian; Lin, Tao; Chen, Wei

2018-01-01

N-nitrosodiethylamine (NDEA) is one of the emerging nitrogenous disinfection byproducts with probable cytotoxicity, genotoxicity, and carcinogenesis. Its potential toxicological effects have received extensive attention but remain to be poorly understood. In this study, changes in NDEA precursors in drinking water treatment process were studied using the trial of its formation potential (FP), and the toxicity induced by NDEA to adult zebrafish was investigated. NDEA FP in the raw water of Taihu Lake ranged from 46.9 to 68.3 ng/L. The NDEA precursors were removed effectively by O 3 /BAC process. Hydrophilic fraction and low-molecular-weight fraction (stress and antioxidant defense to zebrafish metabolism system at concentrations over 5 μg/L. After a 42-day exposure, a significant DNA damage was observed in zebrafish liver cells at NDEA concentrations beyond 500 μg/L. This study investigated NDEA properties in both engineering prospective and toxicity evaluation, thus providing comprehensive information on its control in drinking water treatment process and its toxicity effect on zebrafish as a model animal. Copyright © 2017 Elsevier Ltd. All rights reserved.
Selective Removal of Toxic Metals like Copper and Arsenic from Drinking Water Using Phenol-Formaldehyde Type Chelating Resins

Directory of Open Access Journals (Sweden)

Debasis Mohanty

2009-01-01

Full Text Available The concentration of different toxic metals has increased beyond environmentally and ecologically permissible levels due to the increase in industrial activity. More than 100 million people of Bangladesh and West Bengal in India are affected by drinking ground water contaminated with arsenic and some parts of India is also affected by poisoning effect of copper, cadmium and fluoride. Different methods have been evolved to reduce the arsenic concentration in drinking water to a maximum permissible level of 10 μg/L where as various methods are also available to separate copper from drinking water. Of the proven methods available today, removal of arsenic by polymeric ion exchangers has been most effective. While chelating ion exchange resins having specific chelating groups attached to a polymer have found extensive use in sorption and pre concentration of Cu2+ ions. Both the methods are coupled here to separate and preconcentrate toxic metal cation Cu2+ and metal anion arsenate(AsO4– at the same time. We have prepared a series of low-cost polymeric resins, which are very efficient in removing copper ion from drinking water and after coordinating with copper ion they act as polymeric ligand exchanger, which are efficiently removing arsenate from drinking water. For this purpose Schiff bases were prepared by condensing o-phenylenediamine with o-, m-, and p-hydroxybenzaldehydes. Condensing these phenolic Schiff bases with formaldehyde afforded the chelating resins in high yields. These resins are loaded with Cu2+, Ni2+ 2+, and Fe3+ ions. The resins and the polychelates are highly insoluble in water. In powdered form the metal ion-loaded resins are found to very efficiently remove arsenate ion from water at neutral pH. Resins loaded with optimum amount of Cu2+ ion is more effective in removing arsenate ions compared to those with Fe3+ ion, apparently because Cu2+ is a stronger Lewis acid than Fe3+. Various parameters influencing the removal of the

A toxicity reduction evaluation for an oily waste treatment plant exhibiting episodic effluent toxicity.

Science.gov (United States)

Erten-Unal, M; Gelderloos, A B; Hughes, J S

1998-07-30

A Toxicity Reduction Evaluation (TRE) was conducted on the oily wastewater treatment plant (Plant) at a Naval Fuel Depot. The Plant treats ship and ballast wastes, berm water from fuel storage areas and wastes generated in the fuel reclamation plant utilizing physical/chemical treatment processes. In the first period of the project (Period I), the TRE included chemical characterization of the plant wastewaters, monitoring the final effluent for acute toxicity and a thorough evaluation of each treatment process and Plant operating procedures. Toxicity Identification Evaluation (TIE) procedures were performed as part of the overall TRE to characterize and identify possible sources of toxicity. Several difficulties were encountered because the effluent was saline, test organisms were marine species and toxicity was sporadic and unpredictable. The treatability approach utilizing enhancements, improved housekeeping, and operational changes produced substantial reductions in the acute toxicity of the final effluent. In the second period (Period II), additional acute toxicity testing and chemical characterization were performed through the Plant to assess the long-term effects of major unit process improvements for the removal of toxicity. The TIE procedures were also modified for saline wastewaters to focus on suspected class of toxicants such as surfactants. The TRE was successful in reducing acute toxicity of the final effluent through process improvements and operational modifications. The results indicated that the cause of toxicity was most likely due to combination of pollutants (matrix effect) rather than a single pollutant.
Improving the ecological relevance of toxicity tests on scleractinian corals: Influence of season, life stage, and seawater temperature

Science.gov (United States)

Hedouin, Laetitia; Wolf, Ruth E.; Phillips, Jeff; Gates, Ruth D.

2016-01-01

Metal pollutants in marine systems are broadly acknowledged as deleterious: however, very little data exist for tropical scleractinian corals. We address this gap by investigating how life-history stage, season and thermal stress influence the toxicity of copper (Cu) and lead (Pb) in the coral Pocillopora damicornis. Our results show that under ambient temperature, adults and larvae appear to tolerate exposure to unusually high levels of copper (96 h-LC50 ranging from 167 to 251 μg Cu L−1) and lead (from 477 to 742 μg Pb L−1). Our work also highlights that warmer conditions (seasonal and experimentally manipulated) reduce the tolerance of adults and larvae to Cu toxicity. Despite a similar trend observed for the response of larvae to Pb toxicity to experimentally induced increase in temperature, surprisingly adults were more resistant in warmer condition to Pb toxicity. In the summer adults were less resistant to Cu toxicity (96 h-LC50 = 175 μg L−1) than in the winter (251 μg L−1). An opposite trend was observed for the Pb toxicity on adults between summer and winter (96 h-LC50 of 742 vs 471 μg L−1, respectively). Larvae displayed a slightly higher sensitivity to Cu and Pb than adults. An experimentally induced 3 °C increase in temperature above ambient decreased larval resistance to Cu and Pb toxicity by 23–30% (96 h-LC50 of 167 vs 129 μg Cu L−1 and 681 vs 462 μg Pb L−1).
Removal of toxic chromium from aqueous solution, wastewater and saline water by marine red alga Pterocladia capillacea and its activated carbon

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Ahmed El Nemr

2015-01-01

Full Text Available Pterocladia capillacea, a red marine macroalgae, was tested for its ability to remove toxic hexavalent chromium from aqueous solution. A new activated carbon obtained from P. capillacea via acid dehydration was also investigated as an adsorbent for toxic chromium. The experiments were conducted to study the effect of important parameters such as pH, chromium concentration and adsorbent weight. Batch equilibrium tests at different pH conditions showed that at pH 1.0, a maximum chromium uptake was observed for both inactivated dried red alga P. capillacea and its activated carbon. The maximum sorption capacities for dried red alga and its activated carbon were about 12 and 66 mgg−1, respectively, as calculated by Langmuir model. The ability of inactivated red alga P. capillacea and developed activated carbon to remove chromium from synthetic sea water, natural sea water and wastewater was investigated as well. Different isotherm models were used to analyze the experimental data and the models parameters were evaluated. This study showed that the activated carbon developed from red alga P. capillacea is a promising activated carbon for removal of toxic chromium.
Uma medida de sustentabilidade ambiental: pegada hídrica A measure of environmental sustainability: water footprint

Directory of Open Access Journals (Sweden)

Vicente de P. R. da Silva

2013-01-01

Full Text Available Recentemente, o conceito da pegada hídrica foi introduzido como um indicador importante de consumo de água para a humanidade. A pegada hídrica é definida como o volume total de água utilizado durante a produção de bens e serviços, bem como o consumo direto de água pelos seres humanos. A água não é consumida só diretamente mas também indiretamente, nos processos de produção. Portanto, o cálculo da pegada hídrica permite quantificar o total de água consumida ao longo da cadeia de fornecimento global. Esta revisão de literatura analisa o estado da arte da pegada hídrica desde a sua criação, no encontro internacional de especialista em comércio de água virtual realizado em dezembro de 2002 na Holanda, até os dias atuais. Os principais resultados encontrados na literatura consultada indicam consenso de que a pegada hídrica é capaz de monitorar o impacto humano sobre o meio ambiente. Além do mais, esta metodologia tem uma vasta gama de aplicações que pode ser empregada em escalas que vão desde um único produto, um processo, setor, individuo, cidades, até mesmo nações e todo o planeta.The concept of the water footprint has been recently introduced as an important indicator for human induced water consumption. The water footprint is defined as the total volume of water used during production and consumption of goods and services as well as direct water consumption by human beings. Water is not only consumed directly but also indirectly in production processes. Therefore, calculating the water footprint enables to quantify total water consumed along the whole global supply chain. This review surveys the state of the art on water footprint since the International Expert Meeting on Virtual Water Trade, held in Delft, The Netherlands, in December 2002, until current days. The major findings linked to the consulted literature indicated that the water footprint is suitable for monitoring the human impact on the environment
Release of copper from sintered tungsten-bronze shot under different pH conditions and its potential toxicity to aquatic organisms

International Nuclear Information System (INIS)

Thomas, Vernon G.; Santore, Robert C.; McGill, Ian

2007-01-01

Sintered tungsten-bronze is a new substitute for lead shot, and is about to be deposited in and around the wetlands of North America. This material contains copper in the alloyed form of bronze. This in vitro study was performed according to U.S. Fish and Wildlife Service criteria to determine the dissolution rate of copper from the shot, and to assess the toxic risk that it may present to aquatic organisms. The dissolution of copper from tungsten-bronze shot, pure copper shot, and glass beads was measured in a buffered, moderately hard, synthetic water of pH 5.5, 6.6, and 7.8 over a 28-day period. The dissolution of copper from both the control copper shot and the tungsten-bronze shot was affected significantly by the pH of the water and the duration of dissolution (all p values < 0.000). The rate of copper release from tungsten bronze shot was 30 to 50 times lower than that from the copper shot, depending on pH (p < 0.0000). The observed expected environmental concentration of copper released from tungsten-bronze shot after 28 days was 0.02 μg/L at pH 7.8, and 0.4 μg/L at pH 5.6, using a loading and exposure scenario specific in a U.S. Fish and Wildlife Service protocol. Ratio Quotient values derived from the highest EEC observed in this study (0.4 μg/L), and the copper toxic effect levels for all aquatic species listed in the U.S. Environmental Protection Agency ambient water quality criteria database, were all far less than the 0.1 criterion value. Given the conditions stipulated by the U.S. Fish and Wildlife Service and the U.S. Environmental Protection Agency, heavy loading from discharged tungsten-bronze shot would not pose a toxic risk to potable water, or to soil. Consequently, it would appear that no toxic risks to aquatic organisms will attend the use of tungsten-bronze shot of the approved composition. Given the likelihood that sintered tungsten-bronze of the same formula will be used for fishing weights, bullets, and wheel balance weights, it is
Pharmaceuticals and personal care products in waters: occurrence, toxicity, and risk.

Science.gov (United States)

Cizmas, Leslie; Sharma, Virender K; Gray, Cole M; McDonald, Thomas J

2015-12-01

Pharmaceuticals and personal care products (PPCP) are compounds with special physical and chemical properties that address the care of animal and human health. PPCP have been detected in surface water and wastewater in the ng/L to µg/L concentration range worldwide. PPCP ecotoxicity has been studied in a variety of organisms, and multiple methods have been used to assess the risk of PPCP in the environment to ecological health. Here we review the occurrence, effects, and risk assessment of PPCP in aquatic systems, as well as the sustainability of current methods for managing PPCP contamination in aquatic systems. The major points are the following: (1) a number of PPCP present potential concerns at environmentally relevant concentrations. PPCP mixtures may produce synergistic toxicity. (2) Various methods have been used for the ecological risk assessment of PPCP in aquatic systems. There are similarities in these methods, but no consensus has emerged regarding best practices for the ecological risk assessment of these compounds. (3) Human health risk assessments of PPCP contamination in aquatic systems have generally indicated little cause for concern. However, there is a lack of information regarding whether antibiotic contamination in wastewater and aquatic systems could lead to an increase in clinically relevant antibiotic-resistant bacteria and antibiotic-resistant genes. (4) Over the next century, the combination of increasing global population size and potential droughts may result in reduced water availability, increased need for water reuse, and increasing concentrations of PPCP in wastewaters. The current wastewater treatment methods do not remove all PPCP effectively. This, coupled with the possibility that antibiotics may promote the development of antibiotic-resistant bacteria and antibiotic-resistant genes, leads to concerns about the sustainability of global water supplies.
Granular activated carbon for simultaneous adsorption and biodegradation of toxic oil sands process-affected water organic compounds.

Science.gov (United States)

Islam, Md Shahinoor; Zhang, Yanyan; McPhedran, Kerry N; Liu, Yang; Gamal El-Din, Mohamed

2015-04-01

Naphthenic acids (NAs) released into oil sands process-affected water (OSPW) during bitumen processing in Northern Alberta are problematic for oil sands industries due to their toxicity in the environment and resistance to degradation during conventional wastewater treatment processes. Granular activated carbon (GAC) has shown to be an effective media in removing biopersistent organics from wastewater using a combination of adsorption and biodegradation removal mechanisms. A simultaneous GAC (0.4 g GAC/L) adsorption and biodegradation (combined treatment) study was used for the treatment of raw and ozonated OSPW. After 28 days of batch treatment, classical and oxidized NAs removals for raw OSPW were 93.3% and 73.7%, and for ozonated OSPW were 96.2% and 77.1%, respectively. Synergetic effects of the combined treatment process were observed in removals of COD, the acid extractable fraction, and oxidized NAs, which indicated enhanced biodegradation and bioregeneration in GAC biofilms. A bacteria copy number >10(8) copies/g GAC on GAC surfaces was found using quantitative real time polymerase chain reaction after treatment for both raw and ozonated OSPW. A Microtox(®) acute toxicity test (Vibrio fischeri) showed effective toxicity removal (>95.3%) for the combined treatments. Therefore, the simultaneous GAC adsorption and biodegradation treatment process is a promising technology for the elimination of toxic OSPW NAs. Copyright © 2015 Elsevier Ltd. All rights reserved.
Ambient noise forecasting with a large acoustic array in a complex shallow water environment.

Science.gov (United States)

Rogers, Jeffrey S; Wales, Stephen C; Means, Steven L

2017-11-01

Forecasting ambient noise levels in the ocean can be a useful way of characterizing the detection performance of sonar systems and projecting bounds on performance into the near future. The assertion is that noise forecasting can be improved with a priori knowledge of source positions coupled with the ability to resolve closely separated sources in bearing. One example of such a system is the large aperture research array located at the South Florida Test Facility. Given radar and Automatic Identification System defined source positions and environmental information, transmission loss (TL) is computed from known source positions to the array. Source levels (SLs) of individual ships are then estimated from computed TL and the pre-determined beam response of the array using a non-negative least squares algorithm. Ambient noise forecasts are formed by projecting the estimated SLs along known ship tracks. Ambient noise forecast estimates are compared to measured beam level data and mean-squared error is computed. A mean squared error as low as 3.5 dB is demonstrated in 30 min forecast estimates when compared to ground truth.
Types for BioAmbients

Directory of Open Access Journals (Sweden)

Sara Capecchi

2010-02-01

Full Text Available The BioAmbients calculus is a process algebra suitable for representing compartmentalization, molecular localization and movements between compartments. In this paper we enrich this calculus with a static type system classifying each ambient with group types specifying the kind of compartments in which the ambient can stay. The type system ensures that, in a well-typed process, ambients cannot be nested in a way that violates the type hierarchy. Exploiting the information given by the group types, we also extend the operational semantics of BioAmbients with rules signalling errors that may derive from undesired ambients' moves (i.e. merging incompatible tissues. Thus, the signal of errors can help the modeller to detect and locate unwanted situations that may arise in a biological system, and give practical hints on how to avoid the undesired behaviour.
Measurement of Ambient Air Motion of D. I. Gasoline Spray by LIF-PIV

Science.gov (United States)

Yamakawa, Masahisa; Isshiki, Seiji; Yoshizaki, Takuo; Nishida, Keiya

Ambient air velocity distributions in and around a D. I. gasoline spray were measured using a combination of LIF and PIV techniques. A rhodamine and water solution was injected into ambient air to disperse the fine fluorescent liquid particles used as tracers. A fuel spray was injected into the fluorescent tracer cloud and was illuminated by an Nd: YAG laser light sheet (532nm). The scattered light from the spray droplets and tracers was cut off by a high-pass filter (>560nm). As the fluorescence (>600nm) was transmitted through the high-pass filter, the tracer images were captured using a CCD camera and the ambient air velocity distribution could be obtained by PIV based on the images. This technique was applied to a D. I. gasoline spray. The ambient air flowed up around the spray and entered into the tail of the spray. Furthermore, the relative velocity between the spray and ambient air was investigated.
One Health and Toxic Cyanobacteria | Science Inventory | US ...

Science.gov (United States)

One Health and toxic cyanobacteria Blooms of toxic freshwater blue-green algae or cyanobacteria (HABs) have been in the news after HABs associated with human and animal health problems have been reported in Florida, California and Utah during 2016. HABs occur in warm, slow moving or stagnant surface waters that are enriched with nutrients such as nitrogen and phosphorous. People are exposed to potentially toxic HABs during recreation in contaminated water, after exposure to contaminated drinking water or to blue-green algae supplements. Animals may be exposed to toxic HABs after drinking contaminated surface waters or coming into contact with HABs then ingesting cyanobacteria from their bodies during self-grooming activities. As HABs are being reported more frequently in the US, it is important for veterinarians to secure good exposure histories and to recognize the potential signs and health consequences of HAB exposures. We will review the current knowledge about human and animal health effects associated with freshwater HABs and scenarios that pose the highest risks for illnesses and deaths. This abstract does not necessarily reflect EPA policy. This is a summary of One Health and Cyanobacteria for public health and public practice veterinarians at the American Veterinary Medical Association annual convention. This product is associated with SSWR 4.01B
In situ and laboratory toxicity of coalbed natural gas produced waters with elevated sodium bicarbonate

Science.gov (United States)

Farag, Aïda M.; Harper, David D.; Skaar, Don

2014-01-01

Some tributaries in the Powder River Structural Basin, USA, were historically ephemeral, but now contain water year round as a result of discharge of coalbed natural gas (CBNG)-produced waters. This presented the opportunity to study field sites with 100% effluent water with elevated concentrations of sodium bicarbonate. In situ experiments, static renewal experiments performed simultaneously with in situ experiments, and static renewal experiments performed with site water in the laboratory demonstrated that CBNG-produced water reduces survival of fathead minnow (Pimephales promelas) and pallid sturgeon (Scaphirhynchus albus). Age affected survival of fathead minnow, where fish 2 d posthatch (dph) were more sensitive than 6 dph fish, but pallid sturgeon survival was adversely affected at both 4 and 6 dph. This may have implications for acute assays that allow for the use of fish up to 14 dph. The survival of early lifestage fish is reduced significantly in the field when concentrations of NaHCO3 rise to more than 1500 mg/L (also expressed as >1245 mg HCO3 (-) /L). Treatment with the Higgin's Loop technology and dilution of untreated water increased survival in the laboratory. The mixing zones of the 3 outfalls studied ranged from approximately 800 m to 1200 m below the confluence. These experiments addressed the acute toxicity of effluent waters but did not address issues related to the volumes of water that may be added to the watershed.
Alleviation of cadmium toxicity in Medicago sativa by hydrogen-rich water

Energy Technology Data Exchange (ETDEWEB)

Cui, Weiti; Gao, Cunyi; Fang, Peng [College of Life Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Lin, Guoqing [Laboratory Center of Life Sciences, Co. Laboratory of Nanjing Agricultural University and Carl Zeiss Far East, Nanjing Agricultural University, Nanjing 210095 (China); Shen, Wenbiao, E-mail: wbshenh@njau.edu.cn [College of Life Sciences, Nanjing Agricultural University, Nanjing 210095 (China)

2013-09-15

Highlights: • HRW can alleviate Cd-induced alfalfa seedling growth inhibition and DNA laddering. • HRW alleviates Cd-induced oxidative stress by activating antioxidant enzymes. • Cd uptake in alfalfa seedling roots was decreased by HRW. • HRW can re-establish glutathione homeostasis under Cd stress. -- Abstract: Hydrogen gas (H{sub 2}) induces plant tolerance to several abiotic stresses, including salinity and paraquat exposure. However, the role of H{sub 2} in cadmium (Cd)-induced stress amelioration is largely unknown. Here, pretreatment with hydrogen-rich water (HRW) was used to characterize physiological roles and molecular mechanisms of H{sub 2} in the alleviation of Cd toxicity in alfalfa plants. Our results showed that the addition of HRW at 10% saturation significantly decreased contents of thiobarbituric acid reactive substances (TBARS) caused by Cd, and inhibited the appearance of Cd toxicity symptoms, including the improvement of root elongation and seedling growth. These responses were related to a significant increase in the total or isozymatic activities of representative antioxidant enzymes, or their corresponding transcripts. In vivo imaging of reactive oxygen species (ROS), and the detection of lipid peroxidation and the loss of plasma membrane integrity provided further evidence for the ability of HRW to improve Cd tolerance significantly, which was consistent with a significant enhancement of the ratio of reduced/oxidized (homo)glutathione ((h)GSH). Additionally, plants pretreated with HRW accumulated less amounts of Cd. Together, this study suggested that the usage of HRW could be an effective approach for Cd detoxification and could be explored in agricultural production systems.
Alleviation of cadmium toxicity in Medicago sativa by hydrogen-rich water

International Nuclear Information System (INIS)

Cui, Weiti; Gao, Cunyi; Fang, Peng; Lin, Guoqing; Shen, Wenbiao

2013-01-01

Highlights: • HRW can alleviate Cd-induced alfalfa seedling growth inhibition and DNA laddering. • HRW alleviates Cd-induced oxidative stress by activating antioxidant enzymes. • Cd uptake in alfalfa seedling roots was decreased by HRW. • HRW can re-establish glutathione homeostasis under Cd stress. -- Abstract: Hydrogen gas (H 2 ) induces plant tolerance to several abiotic stresses, including salinity and paraquat exposure. However, the role of H 2 in cadmium (Cd)-induced stress amelioration is largely unknown. Here, pretreatment with hydrogen-rich water (HRW) was used to characterize physiological roles and molecular mechanisms of H 2 in the alleviation of Cd toxicity in alfalfa plants. Our results showed that the addition of HRW at 10% saturation significantly decreased contents of thiobarbituric acid reactive substances (TBARS) caused by Cd, and inhibited the appearance of Cd toxicity symptoms, including the improvement of root elongation and seedling growth. These responses were related to a significant increase in the total or isozymatic activities of representative antioxidant enzymes, or their corresponding transcripts. In vivo imaging of reactive oxygen species (ROS), and the detection of lipid peroxidation and the loss of plasma membrane integrity provided further evidence for the ability of HRW to improve Cd tolerance significantly, which was consistent with a significant enhancement of the ratio of reduced/oxidized (homo)glutathione ((h)GSH). Additionally, plants pretreated with HRW accumulated less amounts of Cd. Together, this study suggested that the usage of HRW could be an effective approach for Cd detoxification and could be explored in agricultural production systems
Two-Step Single Particle Mass Spectrometry for On-Line Monitoring of Polycyclic Aromatic Hydrocarbons Bound to Ambient Fine Particulate Matter

Science.gov (United States)

Zimmermann, R.; Bente, M.; Sklorz, M.

2007-12-01

Polycyclic aromatic hydrocarbons (PAH) are formed as trace products in combustion processes and are emitted to the atmosphere. Larger PAH have low vapour pressure and are predominantly bound to the ambient fine particulate matter (PM). Upon inhalation, PAH show both, chronic human toxicity (i.e. many PAH are potent carcinogens) as well as acute human toxicity (i.e. inflammatory effects due to oxi-dative stress) and are discussed to be relevant for the observed health effect of ambient PM. Therefore a better understanding of the occurrence, dynamics and particle size dependence of particle bound-PAH is of great interest. On-line aerosol mass spectrometry in principle is the method of choice to investigate the size resolved changes in the chemical speciation of particles as well the status of internal vs. external mixing of chemical constituents. However the present available aerosol mass spectrometers (ATOFMS and AMS) do not allow detection of PAH from ambient air PM. In order to allow a single particle based monitoring of PAH from ambient PM a new single particle laser ionisation mass spectrometer was built and applied. The system is based on ATOFMS principle but uses a two- step photo-ionization. A tracked and sized particle firstly is laser desorbed (LD) by a IR-laser pulse (CO2-laser, λ=10.2 μm) and subsequently the released PAH are selectively ionized by an intense UV-laser pulse (ArF excimer, λ=248 nm) in a resonance enhanced multiphoton ionisation process (REMPI). The PAH-ions are detected in a time of flight mass spectrometer (TOFMS). A virtual impactor enrichment unit is used to increase the detection frequency of the ambient particles. With the current inlet system particles from about 400 nm to 10 μm are accessible. Single particle based temporal profiles of PAH containing particles ion (size distribution and PAH speciation) have been recorded in Oberschleissheim, Germany from ambient air. Furthermore profiles of relevant emission sources (e
Architecture of optical sensor for recognition of multiple toxic metal ions from water.

Science.gov (United States)

Shenashen, M A; El-Safty, S A; Elshehy, E A

2013-09-15

Here, we designed novel optical sensor based on the wormhole hexagonal mesoporous core/multi-shell silica nanoparticles that enabled the selective recognition and removal of these extremely toxic metals from drinking water. The surface-coating process of a mesoporous core/double-shell silica platforms by several consequence decorations using a cationic surfactant with double alkyl tails (CS-DAT) and then a synthesized dicarboxylate 1,5-diphenyl-3-thiocarbazone (III) signaling probe enabled us to create a unique hierarchical multi-shell sensor. In this design, the high loading capacity and wrapping of the CS-DAT and III organic moieties could be achieved, leading to the formation of silica core with multi-shells that formed from double-silica, CS-DAT, and III dressing layers. In this sensing system, notable changes in color and reflectance intensity of the multi-shelled sensor for Cu(2+), Co(2+), Cd(2+), and Hg(2+) ions, were observed at pH 2, 8, 9.5 and 11.5, respectively. The multi-shelled sensor is added to enable accessibility for continuous monitoring of several different toxic metal ions and efficient multi-ion sensing and removal capabilities with respect to reversibility, selectivity, and signal stability. Copyright © 2013 Elsevier B.V. All rights reserved.
Combustion characteristics of water-insoluble elemental and organic carbon in size selected ambient aerosol particles

Directory of Open Access Journals (Sweden)

K. Wittmaack

2005-01-01

Full Text Available Combustion of elemental carbon (EC and organic carbon (OC contained in ambient aerosol matter was explored using scanning electron microscopy (SEM in combination with energy dispersive X-ray analysis (EDX. To ease identification of the particles of interest and to avoid or at least reduce interaction with simultaneously sampled inorganic oxides and salts, the approach used in this work differed in two ways from commonly applied procedures. First, rather than using a mixture of particles of vastly different sizes, as in PM10 or PM2.5, aerosol matter was collected in a 5-stage impactor. Second, the water soluble fraction of the collected matter was removed prior to analysis. Diesel soot particles, which appeared in the well-known form of chain-type aggregates, constituted the major fraction of EC. In contrast, OC containing particles were observed in a variety of shapes, including a sizable amount of bioaerosol matter appearing mostly in the size range above about 1 µm. During heating in ambient air for 1h, diesel soot particles were found to be stable up to 470°C, but complete combustion occurred in a narrow temperature interval between about 480 and 510°C. After diesel soot combustion, minute quantities of 'ash' were observed in the form of aggregated tiny particles with sizes less than 10 nm. These particles could be due to elemental or oxidic contaminants of diesel soot. Combustion of OC was observed over a wide range of temperatures, from well below 200°C to at least 500°C. Incompletely burnt bioaerosol matter was still found after heating to 600°C. The results imply that the EC fraction in aerosol matter can be overestimated significantly if the contribution of OC to a thermogram is not well separated.
Computational consideration on advanced oxidation degradation of phenolic preservative, methylparaben, in water: mechanisms, kinetics, and toxicity assessments

Energy Technology Data Exchange (ETDEWEB)

Gao, Yanpeng [State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Resources Utilization and Protection, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); An, Taicheng, E-mail: antc99@gig.ac.cn [State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Resources Utilization and Protection, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Fang, Hansun [State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Resources Utilization and Protection, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Ji, Yuemeng; Li, Guiying [State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Resources Utilization and Protection, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

2014-08-15

Graphical abstract: - Highlights: • Computational approach is effective to reveal the transformation mechanism of MPB. • MPB degradation was more dependent on the [{sup •} OH] than temperature during AOPs. • O{sub 2} could enhance MPB degradation, but more harmful products were formed. • The risks of MPB products in natural waters should be considered seriously. • The risks of MPB products can be overlooked in AOPs due to short half-time. - Abstract: Hydroxyl radicals ({sup •} OH) are strong oxidants that can degrade organic pollutants in advanced oxidation processes (AOPs). The mechanisms, kinetics, and toxicity assessment of the {sup •} OH-initiated oxidative degradation of the phenolic preservative, methylparaben (MPB), were systematically investigated using a computational approach, as the supplementary information for experimental data. Results showed that MPB can be initially attacked by {sup •} OH via OH-addition and H-abstraction routes. Among these routes, the {sup •} OH addition to the C atom at the ortho-position of phenolic hydroxyl group was the most significant route. However, the methyl-H-abstraction route also cannot be neglected. Further, the formed transient intermediates, OH-adduct ({sup •} MPB-OH{sub 1}) and dehydrogenated radical ({sup •} MPB(-H)α), could be easily transformed to several stable degradation products in the presence of O{sub 2} and {sup •} OH. To better understand the potential toxicity of MPB and its products to aquatic organisms, both acute and chronic toxicities were assessed computationally at three trophic levels. Both MPB and its products, particularly the OH-addition products, are harmful to aquatic organisms. Therefore, the application of AOPs to remove MPB should be carefully performed for safe water treatment.
Ambient water quality criteria for mercury: Technical appendix

Energy Technology Data Exchange (ETDEWEB)

Nagpal, N.K.

1989-01-01

This document discusses the effects of mercury on various water uses, including drinking water, aquatic life, wildlife, livestock water supply, irrigation, recreation and aesthetics, and industrial water supplies. Standards, objectives, and criteria from national and international jurisdictions are reviewed, providing a basis, along with other information available from the literature, for criteria recommended to protect water uses in British Columbia from anthropogenic mercury.
Biological efficacy and toxic effect of emergency water disinfection process based on advanced oxidation technology.

Science.gov (United States)

Tian, Yiping; Yuan, Xiaoli; Xu, Shujing; Li, Rihong; Zhou, Xinying; Zhang, Zhitao

2015-12-01

An innovative and removable water treatment system consisted of strong electric field discharge and hydrodynamic cavitation based on advanced oxidation technologies was developed for reactive free radicals producing and waterborne pathogens eliminating in the present study. The biological efficacy and toxic effects of this advanced oxidation system were evaluated during water disinfection treatments. Bench tests were carried out with synthetic microbial-contaminated water, as well as source water in rainy season from a reservoir of Dalian city (Liaoning Province, China). Results showed that high inactivation efficiency of Escherichia coli (>5 log) could be obtained for synthetic contaminated water at a low concentration (0.5-0.7 mg L(-1)) of total oxidants in 3-10 s. The numbers of wild total bacteria (108 × 10(3) CFU mL(-1)) and total coliforms (260 × 10(2) MPN 100 mL(-1)) in source water greatly reduced to 50 and 0 CFU mL(-1) respectively after treated by the advanced oxidation system, which meet the microbiological standards of drinking water, and especially that the inactivation efficiency of total coliforms could reach 100%. Meanwhile, source water qualities were greatly improved during the disinfection processes. The values of UV254 in particular were significantly reduced (60-80%) by reactive free radicals. Moreover, the concentrations of possible disinfection by-products (formaldehyde and bromide) in treated water were lower than detection limits, indicating that there was no harmful effect on water after the treatments. These investigations are helpful for the ecotoxicological studies of advanced oxidation system in the treatments of chemical polluted water or waste water. The findings of this work suggest that the developed water treatment system is ideal in the acute phases of emergencies, which also could offer additional advantages over a wide range of applications in water pollution control.

Data based ambient lighting control

NARCIS (Netherlands)

2012-01-01

In controlling an ambient lighting element, a category of data being rendered by a host is identified, ambient lighting data associated with the identified category is retrieved, and the retrieved ambient lighting data is rendered in correspondence with the rendered data. The retrieved ambient
Biotecnologia Ambiental. Aplicacions biotecnològiques a la millora del medi ambient

OpenAIRE

Blanch i Gisbert, Anicet

2010-01-01

La biotecnología ambiental comprende el conjunto de actividades tecnológicas que facilitan la comprensión y la gestión de los sistemas biológicos en el medio ambiente, con el fin de proveer productos y servicios. Actualmente, la gestión del medio ambiente y de sus recursos naturales no se comprende si no se realiza de manera sostenible. Los avances científicos y tecnológicos le están permitiendo a la biotecnología ambiental, el desarrollo de nuevas herramientas y aplicaciones con los que resp...
Evaluation of toxic risk assessment of arsenic in male subjects through drinking water in southern Sindh Pakistan.

Science.gov (United States)

Baig, Jameel Ahmed; Kazi, Tasneem Gul; Shah, Abdul Qadir; Afridi, Hassan Imran; Khan, Sumaira; Kolachi, Nida Fatima; Kandhro, Ghulam Abbas; Wadhwa, Sham Kumar; Shah, Faheem

2011-11-01

The arsenic (As) hazardous quotient was estimated based on concentration of As in drinking water and scalp hair of male subjects of two age groups (n=360) consuming As contaminated water at different levels and non-contaminated drinking water. The total As concentrations in drinking water of less-exposed (LE) and high-exposed (HE) areas was found to be 3- to 30-fold higher than the permissible limit of the World Health Organization (2004) for drinking water, while the levels of As in drinking water of non-exposed (NE) areas was within the permissible limit. The levels of As in scalp hair samples of male subjects of two age groups belonging to NE, LE, and HE areas ranged from 0.01 to 0.27, 0.11-1.31, and 0.36-6.80 μg/g, respectively. A significant correlation between As contents of drinking water and As concentration in scalp hair was observed in sub-district Gambit (r=0.825-0.852, p<0.001) as compared to those subjects belonging to LE sub-district Thari Mirwah. A toxicity risk assessment provides a hazard quotient corresponding to <10 that indicates non-carcinogenic exposure risk of understudy areas.
The future is 'ambient'

Science.gov (United States)

Lugmayr, Artur

2006-02-01

The research field of ambient media starts to spread rapidly and first applications for consumer homes are on the way. Ambient media is the logical continuation of research around media. Media has been evolving from old media (e.g. print media), to integrated presentation in one form (multimedia - or new media), to generating a synthetic world (virtual reality), to the natural environment is the user-interface (ambient media), and will be evolving towards real/synthetic undistinguishable media (bio-media or bio-multimedia). After the IT bubble was bursting, multimedia was lacking a vision of potential future scenarios and applications. Within this research paper the potentials, applications, and market available solutions of mobile ambient multimedia are studied. The different features of ambient mobile multimedia are manifold and include wearable computers, adaptive software, context awareness, ubiquitous computers, middleware, and wireless networks. The paper especially focuses on algorithms and methods that can be utilized to realize modern mobile ambient systems.
Subchronic and acute preclinical toxicity and some pharmacological effects of the water extract from leaves of Petiveria alliacea (Phytolaccaceae)

International Nuclear Information System (INIS)

Garcia Gonzalez, Mildred; Coto Morales, Teresita; Ocampo, Rafael; Pazos, Liliana

2006-01-01

The effects of the aqueous extract of Petiveria alliacea, leaves were tested on acute and sub-chronic toxicity, hematocrit and blood glucose level and intestinal motility of male albino NGP mice, of 20 to 25 g mean weight. Treatments were in all cases doses of 1000 and 2000 mg/kg animal weight and a control treatment with 0.5 ml distilled water, using 10 animals per treatment and administered orally every day (5 days per week). Experimental periods were 18 and 70 days for acute and sub chronic toxicity, respectively. No mortality nor any toxicity signs could be observed in both tests. A slight but significant increase in the glucose levels during the first three weeks was observed with the 1000 mg/kg dose but not for the higher 2000 mg/kg doses. After administering the dose once after a starving period of six hours, no significant differences in intestinal motility could be found. (author) [es
Subchronic and acute preclinic toxicity and some pharmacological effects of the water extract from leaves of Petiveria alliacea (Phytolaccaceae).

Science.gov (United States)

García-González, Mildred; Morales, Teresita Coto; Ocampo, Rafael; Pazos, Liliana

2006-12-01

We tested the effects of the aqueous extract of Petiveria alliacea leaves on acute and sub-chronic toxicity, hematocrit and blood glucose level and intestinal motility of male albino NGP mice of 20 to 25 g mean weight. Treatments were in all cases doses of 1,000 and 2,000 mg/kg animal weight and a control treatment with 0.5 ml distilled water, using 10 animals per treatment and administered orally every day (5 days per week). Experimental periods were 18 and 70 days for acute and sub chronic toxicity, respectively. No mortality nor any toxicity signs could be observed. A slight but significant increase in the glucose levels during the first three weeks was observed with the 1,000 mg/kg dose but not for the higher 2,000 mg/kg dose. After administering the doses once after a starving period of six hours, no significant differences in intestinal motility could be found.
Toxicity of medicinal plants used in traditional medicine in Northern Peru.

Science.gov (United States)

Bussmann, R W; Malca, G; Glenn, A; Sharon, D; Nilsen, B; Parris, B; Dubose, D; Ruiz, D; Saleda, J; Martinez, M; Carillo, L; Walker, K; Kuhlman, A; Townesmith, A

2011-09-01

The plant species reported here are traditionally used in Northern Peru for a wide range of illnesses. Most remedies are prepared as ethanol or aqueous extracts and then ingested. The aim of this study was to evaluate the potential toxicity of these extracts. The toxicity of ethanolic and water extracts of 341 plant species was determined using a brine-shrimp assay. Overall 24% of the species in water extract and 76% of the species in alcoholic extract showed elevated toxicity levels to brine-shrimp. Although in most cases multiple extracts of the same species showed very similar toxicity values, in some cases the toxicity of different extracts of the same species varied from non-toxic to highly toxic. Traditional preparation methods take different toxicity levels in aqueous and ethanol extracts into account when choosing the appropriate solvent for the preparation of a remedy. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.
Towards New Ambient Light Systems: a Close Look at Existing Encodings of Ambient Light Systems

Directory of Open Access Journals (Sweden)

Andrii Matviienko

2015-10-01

Full Text Available Ambient systems provide information in the periphery of a user’s attention. Their aim is to present information as unobtrusively as possible to avoid interrupting primary tasks (e.g. writing or reading. In recent years, light has been used to create ambient systems to display information. Examples of ambient light systems range from simple notification systems such as displaying messages or calendar event reminders, to more complex systems such as focusing on conveying information regarding health activity tracking. However, for ambient light systems, there is a broad design space that lacks guidelines on when to make use of light displays and how to design them. In this paper we provide a systematic overview of existing ambient light systems over four identified information classes derived from 72 existing ambient light systems. The most prominent encoding parameters among the surveyed ambient light systems are color, brightness, and their combination. By analyzing existing ambient light systems, we provide a first step towards developing guidelines for designing future ambient light systems.
Pulmonary toxicity of manufactured nanoparticles

Science.gov (United States)

Peebles, Brian Christopher

Manufactured nanomaterials have become ubiquitous in science, industry, and medicine. Although electron microscopy and surface probe techniques have improved understanding of the physicochemical properties of nanomaterials, much less is known about what makes nanomaterials toxic. Particulate matter less than 2.5 mum in effective aerodynamic diameter is easily inhaled and taken deep into the lungs. The toxicity of inhaled particulate matter is related to its size and surface chemistry; for instance, the smaller the size of particles, the greater their specific surface area. The chemistry and toxicity of insoluble particles depends on their surface area, since chemical reactions may happen with the environment on the surface. Oxidation and reduction may occur on the surfaces of particles after they are produced. For instance, it is known that carbonaceous particles from vehicle exhaust and industrial emission may interact with reactive species like ozone in their ambient environment, altering the surface chemistry of the particles. Reaction with species in the environment may cause changes in the chemical functionality of the surface and change the toxic properties of the particles when they are inhaled. Furthermore, metals on the surface of inhalable particles can contribute to their toxicity. Much attention has been given to the presence of iron on the surfaces of inhalable particles in the environment. After particle inhalation, particles are endocytosed by alveolar macrophages in the immune response to foreign matter. They are exposed to hydrogen peroxide in the oxidative burst, which can cause the iron-mediated production of hydroxyl free radicals via the Fenton reaction, causing oxidative stress that leads to inflammation and cell death. The toxicity of particles that contain metals depends on the redox activity and bioavailability of the metals, the causes of thich have not yet been adequately explored. In this thesis, electron paramagnetic spectroscopy showed
Comparative metal oxide nanoparticle toxicity using embryonic zebrafish

Directory of Open Access Journals (Sweden)

Leah C. Wehmas

2015-01-01

Full Text Available Engineered metal oxide nanoparticles (MO NPs are finding increasing utility in the medical field as anticancer agents. Before validation of in vivo anticancer efficacy can occur, a better understanding of whole-animal toxicity is required. We compared the toxicity of seven widely used semiconductor MO NPs made from zinc oxide (ZnO, titanium dioxide, cerium dioxide and tin dioxide prepared in pure water and in synthetic seawater using a five-day embryonic zebrafish assay. We hypothesized that the toxicity of these engineered MO NPs would depend on physicochemical properties. Significant agglomeration of MO NPs in aqueous solutions is common making it challenging to associate NP characteristics such as size and charge with toxicity. However, data from our agglomerated MO NPs suggests that the elemental composition and dissolution potential are major drivers of toxicity. Only ZnO caused significant adverse effects of all MO particles tested, and only when prepared in pure water (point estimate median lethal concentration = 3.5–9.1 mg/L. This toxicity was life stage dependent. The 24 h toxicity increased greatly (∼22.7 fold when zebrafish exposures started at the larval life stage compared to the 24 h toxicity following embryonic exposure. Investigation into whether dissolution could account for ZnO toxicity revealed high levels of zinc ion (40–89% of total sample were generated. Exposure to zinc ion equivalents revealed dissolved Zn2+ may be a major contributor to ZnO toxicity.
Toxicity of potassium chloride to veliger and byssal stage dreissenid mussels related to water quality

Science.gov (United States)

Moffitt, Christine M.; Stockton-Fiti, Kelly A.; Claudi, Renata

2016-01-01

Natural resource managers are seeking appropriate chemical eradication and control protocols for infestations of zebra mussels, Dreissena polymorpha (Pallas, 1769), and quagga mussels. D. rostiformis bugensis (Andrusov, 1897) that have limited effect on non-target species. Applications of low concentrations of potassium salt (as potash) have shown promise for use where the infestation and treatment can be contained or isolated. To further our understanding of such applications and obtain data that could support a pesticide registration, we conducted studies of the acute and chronic toxicity of potassium chloride to dreissenid mussels in four different water sources from infested and non-infested locations (ground water from northern Idaho, surface water from the Snake River, Idaho, USA, surface water from Lake Ontario, Ontario, Canada, and surface water from the Colorado River, Arizona, USA). We found short term exposure of veligers (29 d) at concentrations of 100 and 200 mg/L KCl. Rapid mortality occurred within 10 d of exposure to concentrations of 200 mg/L KCl, regardless of water source. Kaplan-Meier estimates of mean survival of byssal mussels in 100 mg/L KCl prepared in surface water from Idaho and Lake Ontario were 4.9 or 6.9 d, respectively; however, mean survival of mussels tested in the Colorado River water was > 23 d. The sodium content of the Colorado River water was nearly three times that measured in waters from the other locations, and we hypothesized sodium concentrations may affect mussel survival. To test our hypothesis, we supplemented Snake River and Lake Ontario water with NaCl to equivalent conductivity as the Colorado River, and found mussel survival increased to levels observed in tests of veliger and byssal mussels in Colorado River water. We recommend KCl disinfection and eradication protocols must be developed to carefully consider the water quality characteristics of treatment locations.
Effect of dry and wet ambient environment on the pulsed laser ablation of titanium

International Nuclear Information System (INIS)

Ali, Nisar; Bashir, Shazia; Umm-i-Kalsoom,; Akram, Mahreen; Mahmood, Khaliq

2013-01-01

Surface and structural properties of the laser irradiated titanium targets have been investigated under dry and wet ambient environments. For this purpose KrF Excimer laser of wavelength 248 nm, pulse duration of 20 ns and repetition rate of 20 Hz has been employed. The targets were exposed for various number of laser pulses ranging from 500 to 2000 in the ambient environment of air, de-ionized water and propanol at a fluence of 3.6 J/cm 2 . The surface morphology, chemical composition and crystallographical analysis were performed by using Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectroscopy (EDS) and X-ray Diffraction (XRD), respectively. For both central and peripheral ablated areas, significant difference in surface morphology has been observed in case of dry and wet ambient conditions. Large sized and diffused grains are observed in case of dry ablation. Whereas, in case of wet ablation, small sized, and well defined grains with distinct grain boundaries and significantly enhanced density are revealed. This difference is ascribed to the confinement effects of the liquid. The peripheral ablated area shows redeposition in case of dry ablation whereas small sized grain like structures are formed in case of wet ablation. EDS analysis exhibits variation in chemical composition under both ambient conditions. When the targets are treated in air environment, enhancement of the oxygen as well as nitrogen content is observed while in case of de-ionized water and propanol only increase in content of oxygen is observed. X-ray diffraction analysis exhibits formation of oxides and nitrides in case of air, whereas, in case of de-ionized water and propanol only oxides along with hydrides are formed. For various number of laser pulses the variation in the peak intensity, crystallinity and d-spacing is observed under both ambient conditions.
Toxic cyanobacteria and cyanotoxins in European waters – recent progress achieved through the CYANOCOST Action and challenges for further research

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Jussi Meriluoto

2017-05-01

Full Text Available This review aims to summarise the outcomes of some recent European research concerning toxic cyanobacteria and cyanotoxins, with an emphasis on developments within the framework of the CYANOCOST Action (COST Action ES1105, Cyanobacterial Blooms and Toxins in Water Resources: Occurrence, Impacts and Management. State of the art research and management capabilities in Europe on cyanobacteria have benefitted from input from the pure and applied life sciences, the human and animal health sectors, water engineers, economists and planners. Many of these professional groups have been brought together and they interacted favourably within the framework of CYANOCOST. Highlights of the Action include phycological and ecological studies, development of advanced techniques for cyanotoxin analysis, elucidation of cyanotoxin modes of action, management techniques to reduce cyanobacterial mass development, and research on methods and practices for cyanotoxin removal during drinking water treatment. The CYANOCOST Action has had an active outreach policy throughout its lifetime, resulting in e.g. three handbooks, two special issues in scientific journals and activities in the social media. The many contact channels to end-users, including environmental and drinking water supply authorities, health professionals and the general public are described in this review. Furthermore, the authors have identified a number of gaps in knowledge. Proposed directions for future research in the field of toxic cyanobacteria and cyanotoxins are also discussed.
Ambient air monitoring for mercury around an industrial complex

International Nuclear Information System (INIS)

Turner, R.R.; Bogle, M.A.

1991-01-01

Public and scientific interest in mercury in the environment has experienced an upsurge in the past few years, due in part to disclosures that fish in certain waters, which have apparently received no direct industrial discharges, were contaminated with mercury. Atmospheric releases of mercury from fossil fuel energy generators, waste incinerators and other industrial sources are suspected to be contributing to this problem. Such releases can be evaluated in a variety of ways, including stack sampling, material balance studies, soil/vegetation sampling and ambient air monitoring. Ambient air monitoring of mercury presents significant challenges because of the typically low concentrations (ng/m 3 ) encountered and numerous opportunities for sample contamination or analyte loss. There are presently no EPA-approved protocols for such sampling and analysis. Elemental mercury was used in large quantities at a nuclear weapons plant in Oak Ridge, Tennessee between 1950 and 1963 in a process similar to chloralkali production. Soil and water contamination with mercury were known to be present at the facility but outdoor ambient air contamination had not been investigated prior to the present study. In addition, one large building still contained original process equipment with mercury residuals. The objectives of this study were to establish a monitoring network for mercury which could be used (1) to demonstrate whether or not human health and the environment was being protected, and (2), to establish a decommissioning activities at the facility
Water Soluble Organic Nitrogen (WSON) in Ambient Fine Particles Over a Megacity in South China: Spatiotemporal Variations and Source Apportionment

Science.gov (United States)

Yu, Xu; Yu, Qingqing; Zhu, Ming; Tang, Mingjin; Li, Sheng; Yang, Weiqiang; Zhang, Yanli; Deng, Wei; Li, Guanghui; Yu, Yuegang; Huang, Zhonghui; Song, Wei; Ding, Xiang; Hu, Qihou; Li, Jun; Bi, Xinhui; Wang, Xinming

2017-12-01

Organic nitrogen aerosols are complex mixtures and important compositions in ambient fine particulate matters (PM2.5), yet their sources and spatiotemporal patterns are not well understood particularly in regions influenced by intensive human activities. In this study, filter-based ambient PM2.5 samples at four stations (one urban, two rural, plus one urban roadside) and PM samples from combustion sources (vehicle exhaust, ship emission, and biomass burning) were collected in the coastal megacity Guangzhou, south China, for determining water soluble organic nitrogen (WSON) along with other organic and inorganic species. The annual average WSON concentrations, as well as the ratios of WSON to water soluble total nitrogen, were all significantly higher at rural sites than urban sites. Average WSON concentrations at the four sites during the wet season were quite near each other, ranging from 0.41 to 0.49 μg/m3; however, they became 2 times higher at the rural sites than at the urban sites during the dry season. Five major sources for WSON were identified through positive matrix factorization analysis. Vehicle emission (29.3%), biomass burning (22.8%), and secondary formation (20.2%) were three dominant sources of WSON at the urban station, while vehicle emission (45.4%) and dust (28.6%) were two dominant sources at the urban roadside station. At the two rural sites biomass burning (51.1% and 34.1%, respectively) and secondary formation (17.8% and 30.5%, respectively) were dominant sources of WSON. Ship emission contributed 8-12% of WSON at the four sites. Natural vegetation seemed to have very minor contribution to WSON.
The sensitivity and reproducibility of the zebrafish (Danio rerio) embryo test for the screening of waste water quality and for testing the toxicity of chemicals.

Science.gov (United States)

Lahnsteiner, Franz

2008-07-01

The sensitivity of the zebrafish embryo test, a test proposed for routine waste water control, was compared with the acute fish toxicity test, in the determination of six types of waste water and ten different chemicals. The waste water was sampled from the following industrial processes: paper and cardboard production, hide tanning, metal galvanisation, carcass treatment and utilisation, and sewage treatment. The chemicals tested were: dimethylacetamide, dimethylsulphoxide, cadmium chloride, cyclohexane, hydroquinone, mercuric chloride, nickel chloride, nonylphenol, resmethrin and sodium nitrite. For many of the test substances, the zebrafish embryo test and the acute fish toxicity test results showed high correlations. However, there were certain environmentally-relevant substances for which the results of the zebrafish embryo test and the acute fish toxicity test differed significantly, up to 10,000-fold (Hg(2+) > 150-fold difference; NO(2)(-) > 300-fold; Cd(2+) > 200-fold; resmethrin > 10,000-fold). For the investigated waste water samples and chemicals, the survival rate of the zebrafish embryos showed high variations between different egg samples, within the range of the EC50 concentration. Subsequently, 5-6 parallel assays were deemed to be the appropriate number necessary for the precise evaluation of the toxicity of the test substances. Also, it was found that the sensitivities of different ontogenetic stages to chemical exposure differed greatly. During the first 12 hours after fertilisation (4-cell stage to the 5-somite stage), the embryos reacted most sensitively to test substance exposure, whereas the later ontogenetic stages showed only slight or no response, indicating that the test is most sensitive during the first 24 hours post-fertilisation.
Photoelectron spectroscopy under ambient pressure and temperature conditions

International Nuclear Information System (INIS)

Frank Ogletree, D.; Bluhm, Hendrik; Hebenstreit, Eleonore D.; Salmeron, Miquel

2009-01-01

We describe the development and applications of novel instrumentation for photoemission spectroscopy of solid or liquid surfaces in the presence of gases under ambient conditions of pressure and temperature. The new instrument overcomes the strong scattering of electrons in gases by the use of an aperture close to the surface followed by a differentially-pumped electrostatic lens system. In addition to the scattering problem, experiments in the presence of condensed water or other liquids require the development of special sample holders to provide localized cooling. We discuss the first two generations of Ambient Pressure PhotoEmission Spectroscopy (APPES) instruments developed at synchrotron light sources (ALS in Berkeley and BESSY in Berlin), with special focus on the Berkeley instruments. Applications to environmental science and catalytic chemical research are illustrated in two examples.
Ambient growth of highly oriented Cu{sub 2}S dendrites of superior thermoelectric behaviour

Energy Technology Data Exchange (ETDEWEB)

Mulla, Rafiq; Rabinal, M.K., E-mail: mkrabinal@yahoo.com

2017-03-01

Highlights: • A simple and ambient route to synthesize highly oriented dendrites of copper sulfide is proposed. • Remarkable enhancement is observed in Seebeck coefficient by room temperature, solution phase doping. • High thermoelectric power factor is observed at room temperature, indicating promising behaviour. - Abstract: Low-cost, non-toxic and efficient material is an urgent need for the thermoelectric energy conversion. Here, a rapid and ambient chemical route has been developed to grow dense and highly oriented dendrites of copper sulfide (Cu{sub 2}S) on copper substrate in a very simple approach, these films are uniform and covered with dense nanosheets. Room temperature solution doping of copper ions is carried out to improve thermoelectric performance. The Seebeck coefficient increased from ∼100 to 415 μV K{sup −1} with a slight decrease in electrical conductivity, this gives a high power factor (S{sup 2}σ) of about ∼400 μW m{sup −1} K{sup −2}. The improved thermoelectric properties in these films are accounted for resonant energy level doping and high phonon scattering. Such films with improved thermoelectric behaviour can be promising materials for energy conversion. The earth abundant, low cost, non toxic with a good thermoelectric property makes copper sulfide as a promising thermoelectric material for future applications.
Acute toxicity of fire control chemicals to Daphnia magna(Straus) and Selenastrum capricornutum(Printz)

Science.gov (United States)

McDonald, Susan F.; Hamilton, Steven J.; Buhl, Kevin J.; Heisinger, James F.

1996-01-01

Acute toxicity tests were conducted exposingDaphnia magnaStraus (daphnid) in soft and hard reconstituted waters (hardness 42 and 162 mg/liter as CaCO3, respectively), andSelenastrum capricornutumPrintz (algae) in ASTM algal assay medium (hardness 15 mg/liter as CaCO3) to fire retardants Fire-Trol GTS-R, Fire-Trol LCG-R, and Phos-Chek D75-F, and foam suppressants Phos-Chek WD-881 and Silv-Ex. The chemicals were slightly toxic to practically harmless to daphnids and moderately toxic to algae. Water quality did not consistently alter the toxicity of the test chemicals to daphnids. The most toxic chemical to daphnids was Silv-Ex (48-hr EC507 mg/liter in soft and hard waters), whereas the least toxic chemical to daphnids was Fire-Trol LCG-R (48-hr EC50848 mg/liter in soft water, 813 mg/liter in hard water). The most toxic chemical to algae was Fire-Trol LCG-R (96-hr IC5010 mg/liter), and the least toxic chemical was Phos-Chek D75-F (96-hr IC5079 mg/liter). Un-ionized ammonia concentrations near the EC50or IC50value in tests with the Fire-Trol compounds were frequently equal to or above reported LC50un-ionized ammonia concentrations. Un-ionized ammonia concentrations in tests with Phos-Chek D75-F were low, thus other toxic components present in the compounds probably contributed to the toxicity. When compared to the daphnids tested in ASTM soft water, the Fire-Trol compounds were most toxic to algae, whereas Phos-Chek D75-F and the foam suppressants were most toxic to daphnids. The results of these tests are comparable to those obtained from research conducted in other laboratories with the same species and similar chemicals. Accidental entry of fire-fighting chemicals into aquatic environments could adversely affect algae and aquatic invertebrates, thus disrupting ecosystem function.
An in situ postexposure feeding assay with Carcinus maenas for estuarine sediment-overlying water toxicity evaluations

International Nuclear Information System (INIS)

Moreira, Susana M.; Moreira-Santos, Matilde; Guilhermino, Lucia; Ribeiro, Rui

2006-01-01

This study developed and evaluated a short-term sublethal in situ toxicity assay for estuarine sediment-overlying waters, with the crab Carcinus maenas (L.) based on postexposure feeding. It consisted of a 48-h in situ exposure period followed by a short postexposure feeding period (30 min). A precise method for quantifying feeding, using the Polychaeta Hediste (Nereis) diversicolor Mueller as food source, was first developed. The sensitivity of the postexposure feeding response was verified by comparing it to that of lethality, upon cadmium exposure. The influence of environmental conditions prevailing during exposure (salinity, temperature, substrate, light regime, and food availability) on postexposure feeding was also addressed. The potential of this in situ assay was then investigated by deploying organisms at ten sites, located in reference and contaminated Portuguese estuaries. Organism recovery ranged between 90% and 100% and a significant postexposure feeding depression (16.3-72.7%) was observed at all contaminated sites relatively to references. - A new sub-lethal toxicity assay is presented for marine invertebrates

Assessment of suspended particulate matters and their heavy metal content in the ambient air of Mobarakeh city, Isfahan, Iran

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Avazali Saririan Mobarakeh

2014-01-01

Conclusion: This study showed that ambient air of Mobarakeh city is polluted by TSP. The high concentration of Fe and Ni in this area may be attributed to the nearby industrial emissions. Therefore, in industrial areas, efforts should be taken to control the atmospheric pollution in order to protect humans from hazardous health effects of these potentially toxic pollutants.
Water Biosensor Challenge to Address Toxicity of Water

Science.gov (United States)

An ongoing concern for water treatment systems and resource managers is the need to monitor for the presence of increasing number of pollutants from agricultural, municipal, and industrial outfalls that are present in U.S. source waters. The associated environmental compounds can...
Evaluation of an Absorption Heat Pump to Mitigate Plant Capacity Reduction Due to Ambient Temperature Rise for an Air-Cooled Ammonia and Water Cycle: Preprint

International Nuclear Information System (INIS)

Bharathan, D.; Nix, G.

2001-01-01

Air-cooled geothermal plants suffer substantial decreases in generating capacity at increased ambient temperatures. As the ambient temperature rises by 50 F above a design value of 50 F, at low brine-resource temperatures, the decrease in generating capacity can be more than 50%. This decrease is caused primarily by increased condenser pressure. Using mixed-working fluids has recently drawn considerable attention for use in power cycles. Such cycles are more readily amenable to use of absorption ''heat pumps.'' For a system that uses ammonia and water as the mixed-working fluid, this paper evaluates using an absorption heat pump to reduce condenser backpressure. At high ambient temperatures, part of the turbine exhaust vapor is absorbed into a circulating mixed stream in an absorber in series with the main condenser. This steam is pumped up to a higher pressure and heated to strip the excess vapor, which is recondensed using an additional air-cooled condenser. The operating conditions are chosen to reconstitute this condensate back to the same concentration as drawn from the original system. We analyzed two power plants of nominal 1-megawatt capacity. The design resource temperatures were 250 F and 300 F. Ambient temperature was allowed to rise from a design value of 50 F to 100 F. The analyses indicate that using an absorption heat pump is feasible. For the 300 F resource, an increased brine flow of 30% resulted in a net power increase of 21%. For the 250 F resource, the increase was smaller. However, these results are highly plant- and equipment-specific because evaluations must be carried out at off-design conditions for the condenser. Such studies should be carried out for specific power plants that suffer most from increased ambient temperatures
Ambient Dried Aerogels

Science.gov (United States)

Jones, Steven M.; Paik, Jong-Ah

2013-01-01

A method has been developed for creating aerogel using normal pressure and ambient temperatures. All spacecraft, satellites, and landers require the use of thermal insulation due to the extreme environments encountered in space and on extraterrestrial bodies. Ambient dried aerogels introduce the possibility of using aerogel as thermal insulation in a wide variety of instances where supercritically dried aerogels cannot be used. More specifically, thermoelectric devices can use ambient dried aerogel, where the advantages are in situ production using the cast-in ability of an aerogel. Previously, aerogels required supercritical conditions (high temperature and high pressure) to be dried. Ambient dried aerogels can be dried at room temperature and pressure. This allows many materials, such as plastics and certain metal alloys that cannot survive supercritical conditions, to be directly immersed in liquid aerogel precursor and then encapsulated in the final, dried aerogel. Additionally, the metalized Mylar films that could not survive the previous methods of making aerogels can survive the ambient drying technique, thus making multilayer insulation (MLI) materials possible. This results in lighter insulation material as well. Because this innovation does not require high-temperature or high-pressure drying, ambient dried aerogels are much less expensive to produce. The equipment needed to conduct supercritical drying costs many tens of thousands of dollars, and has associated running expenses for power, pressurized gasses, and maintenance. The ambient drying process also expands the size of the pieces of aerogel that can be made because a high-temperature, high-pressure system typically has internal dimensions of up to 30 cm in diameter and 60 cm in height. In the case of this innovation, the only limitation on the size of the aerogels produced would be in the ability of the solvent in the wet gel to escape from the gel network.
Microbial contamination and chemical toxicity of the Rio Grande

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Valles Adrian

2004-04-01

Full Text Available Abstract Background The Rio Grande River is the natural boundary between U.S. and Mexico from El Paso, TX to Brownsville, TX. and is one of the major water resources of the area. Agriculture, farming, maquiladora industry, domestic activities, as well as differences in disposal regulations and enforcement increase the contamination potential of water supplies along the border region. Therefore, continuous and accurate assessment of the quality of water supplies is of paramount importance. The objectives of this study were to monitor water quality of the Rio Grande and to determine if any correlations exist between fecal coliforms, E. coli, chemical toxicity as determined by Botsford's assay, H. pylori presence, and environmental parameters. Seven sites along a 112-Km segment of the Rio Grande from Sunland Park, NM to Fort Hancock, TX were sampled on a monthly basis between January 2000 and December 2002. Results The results showed great variability in the number of fecal coliforms, and E. coli on a month-to-month basis. Fecal coliforms ranged between 0–106 CFU/100 ml while E. coli ranged between 6 to > 2419 MPN. H. pylori showed positive detection for all the sites at different times. Toxicity ranged between 0 to 94% of inhibition capacity (IC. Since values above 50% are considered to be toxic, most of the sites displayed significant chemical toxicity at different times of the year. No significant correlations were observed between microbial indicators and chemical toxicity. Conclusion The results of the present study indicate that the 112-Km segment of the Rio Grande river from Sunland Park, NM to Fort Hancock, TX exceeds the standards for contact recreation water on a continuous basis. In addition, the presence of chemical toxicity in most sites along the 112-Km segment indicates that water quality is an area of concern for the bi-national region. The presence of H. pylori adds to the potential health hazards of the Rio Grande. Since no
Development of freshwater aquatic life criteria for Tetrabromobisphenol A in China

International Nuclear Information System (INIS)

Yang Suwen; Yan Zhenguang; Xu Fanfan; Wang Shengrui; Wu Fengchang

2012-01-01

Tetrabromobisphenol A (TBBPA) is the most widely used brominated flame retardant. It has been detected in the environment and has shown to high toxicity to aquatic organisms. To date no aquatic life criteria for TBBPA have been proposed. This work compiled all literature toxicity data of TBBPA on Chinese aquatic species. Eight resident Chinese aquatic organisms were used in toxicity tests to supplement the existing toxicity data for TBBPA. Ten genera mean acute values and three genera mean chronic values to freshwater aquatic animals, as well as two genera toxicity values to aquatic plants were collected. A criterion maximum concentration of 0.1475 mg/L and a criterion continuous concentration of 0.0126 mg/L were derived based on these data, according to the U.S. Environmental Protection Agency guidelines. These criteria may be useful in risk assessment of TBBPA in the ambient water environment. - Highlights: ► We collected all the published toxicity data of TBBPA to aquatic organisms. ► We performed acute and chronic toxicity testes with eight Chinese resident aquatic species. ► The acute and chronic water quality criteria of TBBPA were developed and validated. ► This work is valuable to predict the risks posed by TBBPA in ambient water environment. - An acute water quality criterion of 0.1475 mg/L and a chronic water quality criterion of 0.0126 mg/L for TBBPA in China were developed according to USEPA guidelines.
Acute gastrointestinal and genitourinary toxicity of image-guided intensity modulated radiation therapy for prostate cancer using a daily water-filled endorectal balloon

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Deville Curtiland

2012-05-01

Full Text Available Abstract Background Our purpose was to report acute gastrointestinal (GI and genitourinary (GU toxicity rates for prostate cancer patients undergoing image-guided intensity modulated radiation therapy (IG-IMRT with a daily endorectal water-filled balloon (ERBH2O, and assess associations with planning parameters and pretreatment clinical characteristics. Methods The first 100 patients undergoing prostate and proximal seminal vesicle IG-IMRT with indexed-lumen 100 cc ERBH2O to 79.2 Gy in 1.8 Gy fractions at our institution from 12/2008- 12/2010 were assessed. Pretreatment characteristics, organ-at-risk dose volume histograms, and maximum GU and GI toxicities (CTCAE 3.0 were evaluated. Logistic regression models evaluated univariate association between toxicities and dosimetric parameters, and uni- and multivariate association between toxicities and pretreatment characteristics. Results Mean age was 68 (range 51–88. Thirty-two, 49, and 19 patients were low, intermediate, and high-risk, respectively; 40 received concurrent androgen deprivation. No grade 3 or greater toxicities were recorded. Maximum GI toxicity was grade 0, 1, and 2 in 69%, 23%, and 8%, respectively. Infield (defined as 1 cm above/below the CTV rectal mean/median doses, D75, V30, and V40 and hemorrhoid history were associated with grade 2 GI toxicity (Ps Conclusion Prostate IG-IMRT using a daily ERBH2O shows low rates of acute GI toxicity compared to previous reports of air-filled ERB IMRT when using stringent infield rectum constraints and comparable GU toxicities.
CUIDADO AMBIENTAL E RESPONSABILIDADE: POSSÍVEL DIÁLOGO ENTRE PSICOLOGIA AMBIENTAL E LOGOTERAPIA

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Diogo Arnaldo Corrêa

2016-05-01

Full Text Available O cuidado ambiental vem sendo marcado pela tônica da conservação e da promoção da sustentabilidade. A premente necessidade de um dado compromisso e educação ambiental e de condutas pró-ambientais vem sendo defendida em vários contextos: na mídia, nas políticas públicas, por meio de campanhas sazonais. Todavia, pouco se descreve acerca do sentido presente nos modos de cuidado configurados a partir da inter-relação pessoa-ambiente. Nesta perspectiva, este estudo objetivou promover um possível diálogo a partir das contribuições da Psicologia Ambiental e da Logoterapia visando aproximar a noção de cuidado ambiental, delineada pela Psicologia Ambiental, à ideia de responsabilidade, como defendida pela Logoterapia, por meio de uma revisão bibliográfica. As articulações propositadas corroboraram, portanto, para acenar que a relação pessoa-ambiente pode ser arraigada em qualidade se a responsabilidade é reconhecida em sua propriedade de potencial humano, o que pode favorecer na emergência do sentido das atitudes e condutas pró-ambientais e explicitar o caráter de tarefa única e irrepetível inerente à vida.
Handbook of acute toxicity of chemicals to fish and aquatic invertebrates : summaries of toxicity tests conducted at Columbia National Fisheries Research Laboratory, 1965-78

Science.gov (United States)

Johnson, W. Waynon; Finley, Mack T.

1980-01-01

Acute toxicity is a major subject of research at Columbia National Fisheries Research Laboratory for evaluating the impact of toxic chemicals on fishery resources. The Laboratory has played a leading role in developing research technology for toxicity testing and data interpretation. In 1965-78, more than 400 chemicals were tested against a variety of invertebrates and fish species representative of both cold- and warm-water climates.The use of acute toxicity tests for assessing the potential hazard of chemical contaminants to aquatic organisms is well documented (Boyd 1957; Henderson et al. 1960; Sanders and Cope 1966; Macek and McAllister 1970). Static acute toxicity tests provide rapid and (within limits) reproducible concentration-response curves for estimating toxic effects of chemicals on aquatic organisms. These tests provide a database for determining relative toxicity of a large number of chemicals to a variety of species and for estimating acute effects of chemical spills on natural aquatic systems; they also assist in determining priority and design of additional toxicity studies.Acute toxicity tests usually provide estimates of the exposure concentration causing 50% mortality (LC50) to test organisms during a specified period of time. For certain invertebrates, the effective concentration is based on immobilization, or some other identifiable endpoint, rather than on lethality. The application of the LC50 has gained acceptance among toxicologists and is generally the most highly rated test for assessing potential adverse effects of chemical contaminants to aquatic life (Brungs and Mount 1978; American Institute for Biological Sciences 1978a).The literature contains numerous papers dealing with the acute toxicity of chemicals to freshwater organisms. However, there is a tremendous need for a concise compendium of toxicity data covering a large variety of chemicals and test species. This Handbook is a compilation of a large volume of acute toxicity data
Acute gastrointestinal and genitourinary toxicity of image-guided intensity modulated radiation therapy for prostate cancer using a daily water-filled endorectal balloon

International Nuclear Information System (INIS)

Deville, Curtiland; Both, Stefan; Bui, Viet; Hwang, Wei-Ting; Tan, Kay-See; Schaer, Mattia; Tochner, Zelig; Vapiwala, Neha

2012-01-01

Our purpose was to report acute gastrointestinal (GI) and genitourinary (GU) toxicity rates for prostate cancer patients undergoing image-guided intensity modulated radiation therapy (IG-IMRT) with a daily endorectal water-filled balloon (ERB H2O ), and assess associations with planning parameters and pretreatment clinical characteristics. The first 100 patients undergoing prostate and proximal seminal vesicle IG-IMRT with indexed-lumen 100 cc ERB H2O to 79.2 Gy in 1.8 Gy fractions at our institution from 12/2008- 12/2010 were assessed. Pretreatment characteristics, organ-at-risk dose volume histograms, and maximum GU and GI toxicities (CTCAE 3.0) were evaluated. Logistic regression models evaluated univariate association between toxicities and dosimetric parameters, and uni- and multivariate association between toxicities and pretreatment characteristics. Mean age was 68 (range 51–88). Thirty-two, 49, and 19 patients were low, intermediate, and high-risk, respectively; 40 received concurrent androgen deprivation. No grade 3 or greater toxicities were recorded. Maximum GI toxicity was grade 0, 1, and 2 in 69%, 23%, and 8%, respectively. Infield (defined as 1 cm above/below the CTV) rectal mean/median doses, D75, V30, and V40 and hemorrhoid history were associated with grade 2 GI toxicity (Ps < 0.05). Maximum acute GU toxicity was grade 0, 1, and 2 for 17%, 41%, and 42% of patients, respectively. Infield bladder V20 (P = 0.03) and pretreatment International Prostate Symptom Scale (IPSS) (P = 0.003) were associated with grade 2 GU toxicity. Prostate IG-IMRT using a daily ERB H2O shows low rates of acute GI toxicity compared to previous reports of air-filled ERB IMRT when using stringent infield rectum constraints and comparable GU toxicities
Modulation of parathion toxicity by glucose feeding: Is nitric oxide involved?

International Nuclear Information System (INIS)

Liu Jing; Gupta, Ramesh C.; Goad, John T.; Karanth, Subramanya; Pope, Carey

2007-01-01

Glucose feeding can markedly exacerbate the toxicity of the anticholinesterase insecticide, parathion. We determined the effects of parathion on brain nitric oxide and its possible role in potentiation of toxicity by glucose feeding. Adult rats were given water or 15% glucose in water for 3 days and challenged with vehicle or parathion (18 mg/kg, s.c.) on day 4. Functional signs, plasma glucose and brain cholinesterase, citrulline (an indicator of nitric oxide production) and high-energy phosphates (HEPs) were measured 1-3 days after parathion. Glucose feeding exacerbated cholinergic toxicity. Parathion increased plasma glucose (15-33%) and decreased cortical cholinesterase activity (81-90%), with no significant differences between water and glucose treatment groups. In contrast, parathion increased brain regional citrulline (40-47%) and decreased HEPs (18-40%) in rats drinking water, with significantly greater changes in glucose-fed rats (248-363% increase and 31-61% decrease, respectively). We then studied the effects of inhibiting neuronal nitric oxide synthase (nNOS) by 7-nitroindazole (7NI, 30 mg/kg, i.p. x4) on parathion toxicity and its modulation by glucose feeding. Co-exposure to parathion and 7NI led to a marked increase in cholinergic signs of toxicity and lethality, regardless of glucose intake. Thus, glucose feeding enhanced the accumulation of brain nitric oxide following parathion exposure, but inhibition of nitric oxide synthesis was ineffective at counteracting increased parathion toxicity associated with glucose feeding. Evidence is therefore presented to suggest that nitric oxide may play both toxic and protective roles in cholinergic toxicity, and its precise contribution to modulation by glucose feeding requires further investigation
Estudo comparativo dos parâmetros angulares da marcha humana em ambiente aquático e terrestre em indivíduos hígidos adultos jovens Comparative study of the angular parameters of human gait in water and land media in young higid adults

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Danieli Isabel Romanovitch Ribas

2007-12-01

Full Text Available Há um grande interesse em estudar o movimento humano dentro da água, uma vez que o meio já é utilizado para treinamento e reabilitação devido às diferentes propriedades mecânicas que oferece. No entanto, há uma carência de estudos sobre as características biomecânicas do andar em ambiente aquático. O presente estudo teve como objetivo determinar as variáveis angulares do joelho e tornozelo da marcha em ambiente aquático, e compará-las com o ambiente terrestre. Fizeram parte deste estudo dezenove adultos do sexo masculino, saudáveis, com média de idade de 24 anos. Os indivíduos caminharam em ambiente terrestre e em seguida no ambiente aquático com a água ao nível do processo xifóide do esterno, com velocidade auto-selecionada e confortável. Para a coleta de dados foi utilizada a cinemetria. As variáveis angulares analisadas apresentaram diferenças significativas em ambiente aquático quando comparadas com as do ambiente terrestre. Os resultados encontrados neste estudo contribuem para um melhor entendimento do andar no AA no contexto de treinamento e reabilitação.There is a great interest to study the human movement under water, once it is a means has been utilized as an alternative way for both training and rehabilitation value owing to different mechanical proprieties it offers. However, there is some information about the biomechanical characteristics of shallow water walking. For collection of the data the cinemetry was used. The present study aims purpose the determination angular characteristics knee and ankle during walking in water and comparing it to the standard of the gait done on land. They were part of this nineteen healthy adults of the sex male with mean 24 years. The individuals walked on land and water with xiphoid process level, with self-selected comfortable walking speeds. The variables joint angles investigated was differences considerably between in shallow water on land. The results in the
Evaluation and modeling of the parameters affecting fluoride toxicity level in aquatic environments by bioassay method

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Hamid Reza Shamsollahi

2014-04-01

Full Text Available Background: Fluoride exists in various forms in nature and water resources. , The rising level of fluoride in water resources due to discharge of industrial effluents can cause toxicity in aquatic organisms. To prevent toxicity, it is necessary to determine maximum fluoride toxicity as well as effluent discharge limits. The aim of this study was to determine the maximum fluoride toxicity and the factors affecting fluoride toxicity to provide a model in order to determine the effluent discharge limits. Methods: Daphnia magna bioassay in the absence of confounding factors was used to determine the maximum level of fluoride toxicity. Then, bioassay was repeated in the presence of the confounding factors (hardness, temperature and exposure time to determine their effects. Results: In the absence of intervening factors, fluoride LC50 levels determined after 24, 48 and 72 hours exposure were 4.9, 46.5 and 38.7 mg/l, respectively.. Also, the influence of confounding factors on LC50 values was reported significant by Minitab software. Conclusion: Increasing the water hardness reduced fluoride toxicity, and increasing the water temperature and exposure time increased fluoride toxicity in aquatic environments. Therefore, while determining the wastewater discharge limit in terms of fluoride concentration, it is essential to take the effect of confounding factors on fluoride toxicity into account in order to prevent toxicity in the open water resources.
Toxicities of selected substances to freshwater biota

Energy Technology Data Exchange (ETDEWEB)

Hohreiter, D.W.

1980-05-01

The amount of data available concerning the toxicity of various substances to freshwater biota is so large that it is difficult to use in a practical situation, such as environmental impact assessment. In this document, summary tables are presented showing acute and/or chronic toxicity of selected substances for various groups of aquatic biota. Each entry is referenced to its original source so that details concerning experimental conditions may be consulted. In addition, general information concerning factors modifying toxicity, synergisms, evidence of bioaccumulation, and water quality standards and criteria for the selected substances is given. The final table is a general toxicity table designed to provide an easily accessible and general indication of toxicity of selected substances in aquatic systems.
Ecological risk assessment in a large river-reservoir. 2: Fish community

International Nuclear Information System (INIS)

Suter, G.W. II; Barnthouse, L.W.; Efroymson, R.A.; Jager, H.

1999-01-01

This paper summarizes the assessment of risks to fishes in the Clinch River Operable Unit due to contaminants released by the US Department of Energy's activities on its Oak Ridge Reservation in Tennessee. This paper focuses on the most contaminated area, the Poplar Creek (PC) embayment. The assessment is of interest because of its use of five distinct lines of evidence: fish community surveys, fish body burdens, toxicity tests of ambient waters, suborganismal bioindicators, and single chemical toxicity tests. None of these lines of evidence provided unambiguous evidence of a significant risk, but the surveys indicated that the fish community in PC was depauperate, polychlorinated biphenyl body burdens may have been at toxic levels in catfish, one of the three tests of ambient water showed clear toxicity, some of the indicators were indicative of toxic effects, and concentrations that have been toxic in the laboratory were detected periodically. Interpretation was further complicated by upstream contamination of both the Clinch River and PC. The risk characterization was performed by evaluating each line of evidence separately and then weighing the evidence using an ecoepidemiological approach
Radionuclides and toxic elements transfer from the princess dump to water in Roodepoort, South Africa.

Science.gov (United States)

Dlamini, S G; Mathuthu, M M; Tshivhase, V M

2016-03-01

High concentrations of radionuclides and toxic elements in gold mine tailings facilities present a health hazard to the environment and people living near that area. Soil and water samples from selected areas around the Princess Mine dump were collected. Soil sampling was done on the surface (15 cm) and also 100 cm below the surface. Water samples were taken from near the dump, mid-stream and the flowing part of the stream (drainage pipe) passing through Roodepoort from the mine dump. Soil samples were analyzed by gamma-ray spectroscopy using a HPGe detector to determine the activity concentrations of (238)U, (232)Th and (4) (40)K from the activities of the daughter nuclides in the respective decay chains. The average activity concentrations for uranium and thorium in soil were calculated to be 129 ± 36.1 Bq/kg and 18.1 ± 4.01 Bq/kg, respectively. Water samples were analyzed using Inductively Coupled Plasma Mass Spectrometer. Transfer factors for uranium and thorium from soil to water (at point A closest to dump) were calculated to be 0.494 and 0.039, respectively. At point Z2, which is furthest from the dump, they were calculated to be 0.121 and 0.004, respectively. These transfer factors indicate that there is less translocation of the radionuclides as the water flows. Copyright © 2016 Elsevier Ltd. All rights reserved.
Acute and chronic toxicity of aluminum to a unionid mussel (Lampsilis siliquoidea) and an amphipod (Hyalella azteca) in water‐only exposures

Science.gov (United States)

Wang, Ning; Ivey, Chris D.; Brunson, Eric L.; Cleveland, Danielle; Ingersoll, Christopher G.; Stubblefield, William A.; Cardwell, Allison S.

2018-01-01

The US Environmental Protection Agency (USEPA) is reviewing the protectiveness of the national ambient water quality criteria (WQC) for aluminum (Al) and compiling a toxicity data set to update the WQC. Freshwater mussels are one of the most imperiled groups of animals in the world, but little is known about their sensitivity to Al. The objective of the present study was to evaluate acute 96‐h and chronic 28‐d toxicity of Al to a unionid mussel (Lampsilis siliquoidea) and a commonly tested amphipod (Hyalella azteca) at a pH of 6 and water hardness of 100 mg/L as CaCO3. The acute 50% effect concentration (EC50) for survival of both species was >6200 μg total Al/L. The EC50 was greater than all acute values in the USEPA acute Al data set for freshwater species at a pH range of 5.0 to based on dry weight was 163 μg total Al/L for the mussel and 409 μg total Al/L for the amphipod. Addition of the EC20s to the USEPA chronic Al data set for pH 5.0 to of the chronic data from the present study and recalculation of the chronic criterion would likely lower the proposed chronic criterion.
Occurrences of the toxic dinoflagellate Ostreopsis ovata in relation with environmental factors in Kerkennah Island (Southern coast of Tunisia

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Mounir Ben brahim

2015-08-01

Full Text Available Objective: To study the seasonal and monthly variability of the toxic dinoflagellate Ostreopsis ovata (O. ovata in relation to environmental parameters in Kerkennah Island. Methods: Three water samples replicate of one-litter were taken daily for ten consecutive days on 12 months. All sampling water was kept in the dark at ambient temperature until their microscopic observation. Environmental variables such as salinity and temperature were measured in the field concomitantly as phytoplankton sampling. Nutrients (ammonium, nitrite, nitrate, phosphate and silicate were analysed in laboratory with Auto-analyser Luebbe type. Cell identification and enumeration in water samples were performed with an inverted microscope after the sedimentation. Results: The highest abundance of O. ovata was recorded in summer. Analysis of variance showed significant difference of abundance between seasons, whereas no significant difference for month was detected. Factorial analysis ordination showed a positive correlation of Ostreopsis mainly with temperature and low correlation with nitrite and nitrate whereas the second axis (with 26.30% of variance showed that Ostreopsis was correlated with temperature and salinity. Conclusions: The maximum abundance of Ostreopsis was reached in summer when temperature was high and a low relationship between O. ovata and nutrient was detected.
Toxicity of carbon nanotubes to freshwater aquatic invertebrates

Science.gov (United States)

Mwangi, Joseph N.; Wang, Ning; Ingersoll, Christopher G.; Hardesty, Doug K.; Brunson, Eric L.; Li, Hao; Deng, Baolin

2012-01-01

Carbon nanotubes (CNTs) are hydrophobic in nature and thus tend to accumulate in sediments if released into aquatic environments. As part of our overall effort to examine the toxicity of carbon-based nanomaterials to sediment-dwelling invertebrates, we have evaluated the toxicity of different types of CNTs in 14-d water-only exposures to an amphipod (Hyalella azteca), a midge (Chironomus dilutus), an oligochaete (Lumbriculus variegatus), and a mussel (Villosa iris) in advance of conducting whole-sediment toxicity tests with CNTs. The results of these toxicity tests conducted with CNTs added to water showed that 1.00g/L (dry wt) of commercial sources of CNTs significantly reduced the survival or growth of the invertebrates. Toxicity was influenced by the type and source of the CNTs, by whether the materials were precleaned by acid, by whether sonication was used to disperse the materials, and by species of the test organisms. Light and electron microscope imaging of the surviving test organisms showed the presence of CNTs in the gut as well as on the outer surface of the test organisms, although no evidence was observed to show penetration of CNTs through cell membranes. The present study demonstrated that both the metals solubilized from CNTs such as nickel and the "metal-free" CNTs contributed to the toxicity.
Evaluation of an ambient air sampling system for tritium (as tritiated water vapor) using silica gel adsorbent columns

International Nuclear Information System (INIS)

Patton, G.W.; Cooper, A.T.; Tinker, M.R.

1995-08-01

Ambient air samples for tritium analysis (as the tritiated water vapor [HTO] content of atmospheric moisture) are collected for the Hanford Site Surface Environmental Surveillance Project (SESP) using the solid adsorbent silica gel. The silica gel has a moisture sensitive indicator which allows for visual observation of moisture movement through a column. Despite using an established method, some silica gel columns showed a complete change in the color indicator for summertime samples suggesting that breakthrough had occurred; thus a series of tests was conducted on the sampling system in an environmental chamber. The purpose of this study was to determine the maximum practical sampling volume and overall collection efficiency for water vapor collected on silica gel columns. Another purpose was to demonstrate the use of an impinger-based system to load water vapor onto silica gel columns to provide realistic analytical spikes and blanks for the Hanford Site SESP. Breakthrough volumes (V b ) were measured and the chromatographic efficiency (expressed as the number of theoretical plates [N]) was calculated for a range of environmental conditions. Tests involved visual observations of the change in the silica gel's color indicator as a moist air stream was drawn through the column, measurement of the amount of a tritium tracer retained and then recovered from the silica gel, and gravimetric analysis for silica gel columns exposed in the environmental chamber

A 13-week toxicity study of acrylamide administered in drinking water to hamsters.

Science.gov (United States)

Imai, Toshio; Kitahashi, Tsukasa

2014-01-01

Acrylamide (AA) is known to induce tumors in various organs/tissues in rats and mice. Epidemiological studies of oral exposure have generated controversial results but mortality studies of people who work with AA have indicated increased rates of pancreatic cancer. In the present study, for dose selection for chronic toxicity/carcinogenicity studies, 13-week toxicity of AA was evaluated in Syrian hamsters, which are sensitive to induction of pancreatic ductal carcinogenesis, at concentrations required to provide doses of 0 (control), 20, 30 and 50 mg kg(-1) body weight in drinking water. Treatment with AA caused abnormal gait advancing to hind limb paralysis in all males and females at 50 mg kg(-1). Body weights in 30 and 50 mg kg(-1) males and 50 mg kg(-1) females were lower than in the controls. At termination of the study, red blood cells (RBC) and hemoglobin (Hb) were decreased or showed a tendency for a decrease at 20 and 30 mg kg(-1) in females. Microscopically, axonal/myelin degeneration of sciatic nerves was observed in all AA-treated groups with dose dependence. No obvious changes were found in pancreatic ducts/ductules in any groups of animal. These results indicated the maximum tolerated dose for long-term studies of AA to be 20 mg kg(-1) or less in both male and female Syrian hamsters. Copyright © 2012 John Wiley & Sons, Ltd.
Environmental Exposure of Children to Toxic Trace Elements (Hg, Cr, As) in an Urban Area of Yucatan, Mexico: Water, Blood, and Urine Levels.

Science.gov (United States)

Arcega-Cabrera, F; Fargher, L; Quesadas-Rojas, M; Moo-Puc, R; Oceguera-Vargas, I; Noreña-Barroso, E; Yáñez-Estrada, L; Alvarado, J; González, L; Pérez-Herrera, N; Pérez-Medina, S

2018-05-01

Merida is the largest urban center in the Mexican State of Yucatan. Here domestic sewage is deposited in poorly built septic tanks and is not adequately treated. Because of contamination from such waste, water from the top 20 m of the aquifer is unsuitable for human consumption. Given this situation and because children are highly vulnerable to environmental pollution, including exposure to toxic trace elements, this study focused on evaluating the exposure of children to arsenic (As), chromium (Cr), and mercury (Hg) in water. It also evaluated the relationship between the levels of these elements in water and their concentrations in urine and blood. Among the 33 children monitored in the study, arsenic surpassed WHO limits for blood in 37% of the cases, which could result from the ingestion of poultry contaminated with organoarsenic compounds. In the case of WHO limits for Mercury, 65% of the water samples analyzed, 28% of urine samples, and 12% of blood samples exceeded them. Mercury exposure was correlated with biological sex, some lifestyle factors, and the zone in Merida in which children live. These data suggest that the levels of some toxic metals in children may be affected by water source, socioeconomic factors, and individual behavior.
Mechanisms behind pH changes by plant roots and shoots caused by elevated concentration of toxic elements

OpenAIRE

Javed, Muhammad Tariq

2011-01-01

Toxic elements are present in polluted water from mines, industrial outlets, storm water etc. Wetland plants take up toxic elements and increase the pH of the medium. In this thesis was investigated how the shoots of submerged plants and roots of emergent plants affected the pH of the surrounding water in the presence of free toxic ions. The aim was to clarify the mechanisms by which these plants change the surrounding water pH in the presence of toxic ions. The influence of Elodea canadensis...
Extraction tools for identification of chemical contaminants in estuarine and coastal waters to determine toxic pressure on primary producers.

Science.gov (United States)

Booij, Petra; Sjollema, Sascha B; Leonards, Pim E G; de Voogt, Pim; Stroomberg, Gerard J; Vethaak, A Dick; Lamoree, Marja H

2013-09-01

The extent to which chemical stressors affect primary producers in estuarine and coastal waters is largely unknown. However, given the large number of legacy pollutants and chemicals of emerging concern present in the environment, this is an important and relevant issue that requires further study. The purpose of our study was to extract and identify compounds which are inhibitors of photosystem II activity in microalgae from estuarine and coastal waters. Field sampling was conducted in the Western Scheldt estuary (Hansweert, The Netherlands). We compared four different commonly used extraction methods: passive sampling with silicone rubber sheets, polar organic integrative samplers (POCIS) and spot water sampling using two different solid phase extraction (SPE) cartridges. Toxic effects of extracts prepared from spot water samples and passive samplers were determined in the Pulse Amplitude Modulation (PAM) fluorometry bioassay. With target chemical analysis using LC-MS and GC-MS, a set of PAHs, PCBs and pesticides was determined in field samples. These compound classes are listed as priority substances for the marine environment by the OSPAR convention. In addition, recovery experiments with both SPE cartridges were performed to evaluate the extraction suitability of these methods. Passive sampling using silicone rubber sheets and POCIS can be applied to determine compounds with different structures and polarities for further identification and determination of toxic pressure on primary producers. The added value of SPE lies in its suitability for quantitative analysis; calibration of passive samplers still needs further investigation for quantification of field concentrations of contaminants. Copyright © 2013 Elsevier Ltd. All rights reserved.
[Toxicity and influencing factors of liquid chlorine on chironomid larvae].

Science.gov (United States)

Sun, Xing-Bin; Cui, Fu-Yi; Zhang, Jin-Song; Guo, Zhao-Hai; Xu, Feng; Liu, Li-Jun

2005-09-01

The excessive propagation of Chironomid larvae (red worm) in the sedimentation tanks is a difficult problem for the normal function of waterworks. The toxic effect of liquid chlorine on the different instar larvae of Chironomid was studied using distilled water as test sample. Furthermore, the effect of pH value, organic matter content, ammonia nitrogen, and algae content on toxicity of liquid chlorine was observed. The results show that the tolerance of Chironomid larvae to liquid chlorine is strengthened with the increase in instar. The 24h semi-lethal concentration (LC50) of liquid chlorine to the 4th instar larvae of Chironomid is 3.39 mg/L. Low pH value and high algae content are helpful to improve the toxic effect of liquid chlorine to Chironomid larvae. In neutral water body, the increase in organic matter content results in the decrease in the death rate of Chironomid larvae. The toxicity of liquid chlorine differs greatly in different concentrations of ammonia nitrogen. The death rate of the 4th instar larvae of Chironomid in raw water is higher by contrast with that in sedimentation tanks water for 24h disposal with various amount of liquid chlorine.
Biological treatment and toxicity of low concentrations of oily wastewater (bilgewater)

Energy Technology Data Exchange (ETDEWEB)

Stamper, D.M. [NAVSEA Carderrock Div., West Bethesda, MD (United States). Biological Sciences Group; Montgomery, M.T. [Naval Research Laboratory, Washington, DC (United States). Marine Biochemistry Section

2008-08-15

Oily waste water from ships occurs when materials leak, spill, or are washed off the decks and drain into the bilge compartments of ships. The wastes include diesel fuel, coolants, and engine, transmission, and hydraulic oils. Treatments for oily waste water in the United States Navy are based on a combination of density separation and ceramic membrane ultrafiltration techniques, which may not meet planned regulations that will require lower levels of oil pollutants. This study tested the biodegradability and toxicity of low concentrations of oily waste water in order to establish the feasibility of using a combined shipboard oily and sanitary waste water treatment system. The toxic effects of diesel fuel and other components of the waste water were also tested. The study showed that diluting the oily effluent with the sanitary waste stream resulted in waste water with low enough oil content to meet the anticipated changes in waste water regulations. The study also showed that the low concentrations of waste water were catabolized in the presence of the sanitary waste stream. A modified PolyTox assay was used to test the waste water samples. Results of the study showed that heterotrophic bacterial production rates did not show any toxic effects. The addition of detergent in the samples had no impact on toxicity levels. It was concluded that combining oil and sanitary waste water in a single biological treatment system is a feasible option for ensuring the future regulations are met. 37 refs., 2 tabs., 4 figs.
Interactive effects of ambient acidity and salinity on thyroid function during acidic and post-acidic acclimation of air-breathing fish (Anabas testudineus Bloch).

Science.gov (United States)

Peter, M C Subhash; Rejitha, V

2011-11-01

environmental acidity than ambient salinity and salinity interference nullifies the toxic effect of water acidification. Copyright © 2011 Elsevier Inc. All rights reserved.
Further evaluations of the toxicity of irradiated advanced heavy water reactor fuels.

Science.gov (United States)

Edwards, Geoffrey W R; Priest, Nicholas D

2014-11-01

The neutron economy and online refueling capability of heavy water moderated reactors enable them to use many different fuel types, such as low enriched uranium, plutonium mixed with uranium, or plutonium and/or U mixed with thorium, in addition to their traditional natural uranium fuel. However, the toxicity and radiological protection methods for fuels other than natural uranium are not well established. A previous paper by the current authors compared the composition and toxicity of irradiated natural uranium to that of three potential advanced heavy water fuels not containing plutonium, and this work uses the same method to compare irradiated natural uranium to three other fuels that do contain plutonium in their initial composition. All three of the new fuels are assumed to incorporate plutonium isotopes characteristic of those that would be recovered from light water reactor fuel via reprocessing. The first fuel investigated is a homogeneous thorium-plutonium fuel designed for a once-through fuel cycle without reprocessing. The second fuel is a heterogeneous thorium-plutonium-U bundle, with graded enrichments of U in different parts of a single fuel assembly. This fuel is assumed to be part of a recycling scenario in which U from previously irradiated fuel is recovered. The third fuel is one in which plutonium and Am are mixed with natural uranium. Each of these fuels, because of the presence of plutonium in the initial composition, is determined to be considerably more radiotoxic than is standard natural uranium. Canadian nuclear safety regulations require that techniques be available for the measurement of 1 mSv of committed effective dose after exposure to irradiated fuel. For natural uranium fuel, the isotope Pu is a significant contributor to the committed effective dose after exposure, and thermal ionization mass spectrometry is sensitive enough that the amount of Pu excreted in urine is sufficient to estimate internal doses, from all isotopes, as low
Measured Copper Toxicity to Cnesterodon decemmaculatus (Pisces: Poeciliidae and Predicted by Biotic Ligand Model in Pilcomayo River Water: A Step for a Cross-Fish-Species Extrapolation

Directory of Open Access Journals (Sweden)

María Victoria Casares

2012-01-01

Full Text Available In order to determine copper toxicity (LC50 to a local species (Cnesterodon decemmaculatus in the South American Pilcomayo River water and evaluate a cross-fish-species extrapolation of Biotic Ligand Model, a 96 h acute copper toxicity test was performed. The dissolved copper concentrations tested were 0.05, 0.19, 0.39, 0.61, 0.73, 1.01, and 1.42 mg Cu L-1. The 96 h Cu LC50 calculated was 0.655 mg L-1 (0.823-0.488. 96-h Cu LC50 predicted by BLM for Pimephales promelas was 0.722 mg L-1. Analysis of the inter-seasonal variation of the main water quality parameters indicates that a higher protective effect of calcium, magnesium, sodium, sulphate, and chloride is expected during the dry season. The very high load of total suspended solids in this river might be a key factor in determining copper distribution between solid and solution phases. A cross-fish-species extrapolation of copper BLM is valid within the water quality parameters and experimental conditions of this toxicity test.
Hospital and urban effluent waters as a source of accumulation of toxic metals in the sediment receiving system of the Cauvery River, Tiruchirappalli, Tamil Nadu, India.

Science.gov (United States)

Devarajan, Naresh; Laffite, Amandine; Ngelikoto, Patience; Elongo, Vicky; Prabakar, Kandasamy; Mubedi, Josué I; Piana, Pius T M; Wildi, Walter; Poté, John

2015-09-01

Hospital and urban effluents contain a variety of toxic and/or persistent substances in a wide range of concentrations, and most of these compounds belong to the group of emerging contaminants. The release of these substances into the aquatic ecosystem can lead to the pollution of water resources and may place aquatic organisms and human health at risk. Sediments receiving untreated and urban effluent waters from the city of Tiruchirappalli in the state of Tamil Nadu, India, are analyzed for potential environmental and human health risks. The sediment samples were collected from five hospital outlet pipes (HOP) and from the Cauvery River Basin (CRB) both of which receive untreated municipal effluent waters (Tiruchirappalli, Tamil Nadu, India). The samples were characterized for grain size, organic matter, toxic metals, and ecotoxicity. The results highlight the high concentration of toxic metals in HOP, reaching values (mg kg(-1)) of 1851 (Cr), 210 (Cu), 986 (Zn), 82 (Pb), and 17 (Hg). In contrast, the metal concentrations in sediments from CRB were lower than the values found in the HOP (except for Cu, Pb), with maximum values (mg kg(-1)) of 75 (Cr), 906 (Cu), 649 (Zn), 111 (Pb), and 0.99 (Hg). The metal concentrations in all sampling sites largely exceed the Sediment Quality Guidelines (SQGs) and the Probable Effect Concentration (PEC) for the Protection of Aquatic Life recommendation. The ecotoxicity test with ostracods exposed to the sediment samples presents a mortality rate ranging from 22 to 100 % (in sediments from HOP) and 18-87 % (in sediments from CRB). The results of this study show the variation of toxic metal levels as well as toxicity in sediment composition related to both the type of hospital and the sampling period. The method of elimination of hospital and urban effluents leads to the pollution of water resources and may place aquatic organisms and human health at risk.
Ambient pressure hydrometallurgical conversion of arsenic trioxide to crystalline scorodite

Energy Technology Data Exchange (ETDEWEB)

Debekaussen, R. [Corus Consulting and Technical Services, Delft (Netherlands); Droppert, D. [Solumet Inc., Montreal, PQ (Canada); Demopoulos, G. P. [McGill Univ., Dept. of Metallurgical Enginering, Montreal, PQ (Canada)

2001-06-01

Development of a novel process for the ambient pressure conversion of arsenic trioxide, a common, but extremely toxic by-product of the non-ferrous smelting industry, is described. The process consists of three main stages; (1) dissolution of arsenic trioxide, (2) oxidation of trivalent arsenic with the addition of hydrogen peroxide at 95 degree C, to pentavalent arsenic, and (3) step-wise precipitation of crystalline scorodite from highly concentrated arsenic containing solutions, by operating below a characteristics induction pH in the presence of seed material. The technical feasibility of the process has been confirmed by bench-scale testing of industrial flue dust material or acid plant effluents. 30 refs., 2 tabs., 5 figs.
Determination of heavy toxic metals in the environment indicator specimens (water, river sediment and kangkung plant) of Muria terrestrial

International Nuclear Information System (INIS)

J Djati Pramana; Sukirno; Bambang Irianto

2004-01-01

Analysis and evaluation contain of heavy toxic metals in the water kangkung plant (Ipomea reptans poir) and river sediment of five rivers sampling location at peninsula Muria region by NAA Instrumental method has been done. The method of sampling. preparation although analysis method according to standard procedure of environmental specimens analysis. Accordingly the quality standard of water group C although group D. the sample from fifth river location sampling was under allowed maximum Cd concentration. Correlation between variable location and kind of indicators to heavy metal concentration was shown by coefficient of Pearson correlation. Interpretation by statistic correlation was obtained. Correlation between kind indicators was indicated that river water has significant correlation with the kangkung plant about Cd concentration. (author)
Calibration and application of an automated seepage meter for monitoring water flow across the sediment-water interface.

Science.gov (United States)

Zhu, Tengyi; Fu, Dafang; Jenkinson, Byron; Jafvert, Chad T

2015-04-01

The advective flow of sediment pore water is an important parameter for understanding natural geochemical processes within lake, river, wetland, and marine sediments and also for properly designing permeable remedial sediment caps placed over contaminated sediments. Automated heat pulse seepage meters can be used to measure the vertical component of sediment pore water flow (i.e., vertical Darcy velocity); however, little information on meter calibration as a function of ambient water temperature exists in the literature. As a result, a method with associated equations for calibrating a heat pulse seepage meter as a function of ambient water temperature is fully described in this paper. Results of meter calibration over the temperature range 7.5 to 21.2 °C indicate that errors in accuracy are significant if proper temperature-dependence calibration is not performed. The proposed calibration method allows for temperature corrections to be made automatically in the field at any ambient water temperature. The significance of these corrections is discussed.
Ambient concentrations and personal exposure to polycyclic aromatic hydrocarbons (PAH) in an urban community with mixed sources of air pollution

Science.gov (United States)

ZHU, XIANLEI; FAN, ZHIHUA (TINA); WU, XIANGMEI; JUNG, KYUNG HWA; OHMAN-STRICKLAND, PAMELA; BONANNO, LINDA J.; LIOY, PAUL J.

2014-01-01

Assessment of the health risks resulting from exposure to ambient polycyclic aromatic hydrocarbons (PAH) is limited by a lack of environmental exposure data among the general population. This study characterized personal exposure and ambient concentrations of PAH in the Village of Waterfront South (WFS), an urban community with many mixed sources of air toxics in Camden, New Jersey, and CopeWood/Davis Streets (CDS), an urban reference area located ~1 mile east of WFS. A total of 54 and 53 participants were recruited from non-smoking households in WFS and CDS, respectively. In all, 24-h personal and ambient air samples were collected simultaneously in both areas on weekdays and weekends during summer and winter. The ambient PAH concentrations in WFS were either significantly higher than or comparable to those in CDS, indicating the significant impact of local sources on PAH pollution in WFS. Analysis of diagnostic ratios and correlation suggested that diesel truck traffic, municipal waste combustion and industrial combustion were the major sources in WFS. In such an area, ambient air pollution contributed significantly to personal PAH exposure, explaining 44–96% of variability in personal concentrations. This study provides valuable data for examining the impact of local ambient PAH pollution on personal exposure and therefore potential health risks associated with environmental PAH pollution. PMID:21364704
Pulsed-Plasma Disinfection of Water Containing Escherichia coli

Science.gov (United States)

Satoh, Kohki; MacGregor, Scott J.; Anderson, John G.; Woolsey, Gerry A.; Fouracre, R. Anthony

2007-03-01

The disinfection of water containing the microorganism, Escherichia coli (E. coli) by exposure to a pulsed-discharge plasma generated above the water using a multineedle electrode (plasma-exposure treatment), and by sparging the off-gas of the pulsed plasma into the water (off-gas-sparging treatment), is performed in the ambient gases of air, oxygen, and nitrogen. For the off-gas-sparging treatment, bactericidal action is observed only when oxygen is used as the ambient gas, and ozone is found to generate the bactericidal action. For the plasma-exposure treatment, the density of E. coli bacteria decreases exponentially with plasma-exposure time for all the ambient gases. It may be concluded that the main contributors to E. coli inactivation are particle species produced by the pulsed plasma. For the ambient gases of air and nitrogen, the influence of acidification of the water in the system, as a result of pulsed-plasma exposure, may also contribute to the decay of E. coli density.
POTENTIAL PATHOPHYSIOLOGICAL MECHANISMS OF ULTRAFINE PARTICLE TOXIC EFFECTS IN HUMANS

Directory of Open Access Journals (Sweden)

JASMINA JOVIĆ-STOŠIĆ

2008-03-01

Full Text Available Epidemiological and clinical studies suggested the association of the particulate matter ambient air pollution and the increased morbidity and mortality, mainly from respiratory and cardiovascular diseases. The size of particles has great influence on their toxicity, because it determines the site in the respiratory tract where they deposit. The most well established theory explaining the mechanisms behind the increased toxicity of ultrafine particles (UFP, < 0.1 µm is that it has to do with the increased surface area and/or the combination with the increased number of particles. Biological effects of UFP are also determined by their shape and chemical composition, so it is not possible to estimate their toxicity in a general way. General hypothesis suggested that exposure to inhaled particles induces pulmonary alveolar inflammation as a basic pathophysiological event, triggering release of various proinflammatory cytokines. Chronic inflammation is a very important underlying mechanism in the genesis of atherosclerosis and cardiovascular diseases. UFP can freely move through the circulation, but their effects on the secondary organs are not known yet, so more studies on recognizing toxicological endpoints of UFP are needed. Determination of UFP toxicity and the estimation of their internal and biologically active dose are necessary for the evidence based conclusions connecting air pollution by UFP and human diseases.
Levels of potentially toxic metals in water, sediment and peat from Wonderfonteinspruit, North West Province, South Africa.

Science.gov (United States)

Nsaka, Ntumba C; McCrindle, Robert I; Ambushe, Abayneh A

2018-04-30

Environmental monitoring of the levels of potentially toxic metals is of importance because of possible adverse effects on living species. This study was conducted to assess the levels of Cd, Cr, Cu, Hg, Mn, Pb, U and V in water, sediment and peat samples collected from the region of Wonderfonteinspruit. Water samples were simply filtered and acidified with HNO 3 prior to analysis. Sediment and peat were oven-dried, ground, sieved and mineralised using a microwave digestion system. Concentrations of the selected elements in all samples were determined by inductively coupled plasma-mass spectrometry. A Zeeman mercury analyser was also used for quantification of Hg in the same sediment and peat samples. The method validation was carried out using SRM 1643e water and BCR 320R sediment certified reference materials. The results showed no significant difference at 95% level of confidence between the certified and measured values after using the Student's t-test. The levels of Cd, Cr, Cu, Pb, V and U found in rivers and dams were lower than the tentative South African water quality range guideline for domestic and irrigation purposes. However, water from dams and certain rivers was unsuitable for irrigation and domestic use.
Pedagogía ambiental y didáctica ambiental: tendencias en la educación superior

Directory of Open Access Journals (Sweden)

Julio César Tovar-Gálvez

2017-01-01

Full Text Available El artículo aborda el problema del currículo de educación ambiental en la educación superior, para lo que se centra en los conceptos pedagogía ambiental y didáctica ambiental. La metodología consiste en realizar un estado del arte para identificar las tendencias existentes sobre pedagogía ambiental y didáctica ambiental, para desde allí diseñar una encuesta que es dirigida a profesores y estudiantes de programas con formación en lo ambiental, de algunas universidades en Bogotá, con el objetivo de identificar sus opiniones como expertos en lo ambiental. Los resultados muestran un especial énfasis en las tendencias sobre la complejidad, pero así mismo plantean la posibilidad de múltiples modelos según los contextos y necesidades.
Effect of ambient temperature and relative humidity on interfacial temperature during early stages of drop evaporation.

Science.gov (United States)

Fukatani, Yuki; Orejon, Daniel; Kita, Yutaku; Takata, Yasuyuki; Kim, Jungho; Sefiane, Khellil

2016-04-01

Understanding drop evaporation mechanisms is important for many industrial, biological, and other applications. Drops of organic solvents undergoing evaporation have been found to display distinct thermal patterns, which in turn depend on the physical properties of the liquid, the substrate, and ambient conditions. These patterns have been reported previously to be bulk patterns from the solid-liquid to the liquid-gas drop interface. In the present work the effect of ambient temperature and humidity during the first stage of evaporation, i.e., pinned contact line, is studied paying special attention to the thermal information retrieved at the liquid-gas interface through IR thermography. This is coupled with drop profile monitoring to experimentally investigate the effect of ambient temperature and relative humidity on the drop interfacial thermal patterns and the evaporation rate. Results indicate that self-generated thermal patterns are enhanced by an increase in ambient temperature and/or a decrease in humidity. The more active thermal patterns observed at high ambient temperatures are explained in light of a greater temperature difference generated between the apex and the edge of the drop due to greater evaporative cooling. On the other hand, the presence of water humidity in the atmosphere is found to decrease the temperature difference along the drop interface due to the heat of adsorption, absorption and/or that of condensation of water onto the ethanol drops. The control, i.e., enhancement or suppression, of these thermal patterns at the drop interface by means of ambient temperature and relative humidity is quantified and reported.
Evaluation of lithium as a toxicant and the modifying effect of sodium

International Nuclear Information System (INIS)

Kszos, L.A.; Stewart, A.J.; O'Reilly, S.E.

1995-01-01

Routine compliance tests conducted for a groundwater treatment facility at the Y-12 Plant on the Department of Energy's (DOE) Oak Ridge Reservation (ORR), TN, showed that the effluent was acutely toxic to Ceriodaphnia dubia and fathead minnow (Pimephales promelas) larvae. An evaluation of suspected contaminants revealed that increased toxicity coincided with increased concentrations of lithium. Lithium is a light, strong metal that is used in DOE operations, including fusion weapons and fission reactors. Little has been published about lithium toxicity. Toxicity tests were conducted with fathead minnows and C. dubia using lithium chloride and lithium tetraborate. Dilute mineral water (DMW) or the receiving stream water (East Fork Poplar Creek) was used as the dilution water in the toxicity evaluation. A concentration of 1 mg Li/L in DMW reduced the survival of both test species; 0.5 mg Li/L in DMW reduced C. dubia reproduction and minnow growth. Sodium appears to influence the toxicity of Li; the metal was six times more toxic in the low-sodium DMW than in stream water containing 30 mg Na/L. Tests with LiCl in combination with NaCl and NA 2 SO 4 demonstrated that the presence of sodium reduced the toxicity of Li to C. dubia. In laboratory tests with a snail (Elimia clavaeformis) common on the ORR, the feeding rate declined in 0.15 mg Li/L. Because Li has also been demonstrated to be toxic to several plant species, tests with LiCi were also conducted using buttercrunch lettuce (Lactuca saliva). The EC 50 for seed growth after 8 d incubation was 37.5 mg Li/L. These findings are significant because of widespread industrial use and potential accumulation of Li in soils

Comparison of methods for conducting marine and estuarine sediment porewater toxicity tests—extraction, storage, and handling techniques

Science.gov (United States)

Carr, R.S.; Chapman, D.C.

1995-01-01

A series of studies was conducted to compare different porewater extraction techniques and to evaluate the effects of sediment and porewater storage conditions on the toxicity of pore water, using assays with the sea urchin Arbacia punctulata. If care is taken in the selection of materials, several different porewater extraction techniques (pressurized squeezing, centrifugation, vacuum) yield samples with similar toxicity. Where the primary contaminants of concern are highly hydrophobic organic compounds, centrifugation is the method of choice for minimizing the loss of contaminants during the extraction procedure. No difference was found in the toxicity of pore water obtained with the Teflon® and polyvinyl chloride pressurized extraction devices. Different types of filters in the squeeze extraction devices apparently adsorbed soluble contaminants to varying degrees. The amount of fine suspended particulate material remaining in the pore water after the initial extraction varied among the methods. For most of the sediments tested, freezing and thawing did not affect the toxicity of porewater samples obtained by the pressurized squeeze extraction method. Pore water obtained by other methods (centrifugation, vacuum) and frozen without additional removal of suspended particulates by centrifugation may exhibit increased toxicity compared with the unfrozen sample.The toxicity of pore water extracted from refrigerated (4°C) sediments exhibited substantial short-term (days, weeks) changes. Similarly, sediment pore water extracted over time from a simulated amphipod solid-phase toxicity test changed substantially in toxicity. For the sediments tested, the direction and magnitude of change in toxicity of pore water extracted from both refrigerated and solid-phase test sediments was unpredictable.
Acute toxicity of potassium permanganate to fingerlings of the ...

African Journals Online (AJOL)

STORAGESEVER

2008-07-18

Jul 18, 2008 ... soft waters where other chemicals, such as copper sulphate, were too toxic ... mined by the KMnO4 demand of the water being treated. (Marecaux, 2006). ..... hatchery disease by treating the water supply. New York Conserva-.
USE OF ZEOLITE FOR REMOVING AMMONIA AND AMMONIA-CAUSED TOXCITY IN MARINE TOXICITY IDENTIFCATION EVALUATIONS (TIES)

Science.gov (United States)

Ammonia occurs in marine waters including effluents, receiving waters, and sediment interstitial waters. At sufficiently high concentrations, ammonia can be toxic to aquatic species. Toxicity identification evaluation (TIE) methods provide researchers with tools for identifyi...
POLÍTICA PÚBLICA AMBIENTAL Y AMBIENTE EN EL VALLE DEL CAUCA, 1991-2010

Directory of Open Access Journals (Sweden)

Álvaro Quiceno Martínez

2010-01-01

Full Text Available La política pública ambiental en el Valle del Cauca, a partir de 1991, va en contravía de la conservación ambiental al enfatizar en el crecimiento económico, la generación de plusvalía y la ampliación de la tasa de ganancia. Para la realización de esta investigación se adoptó como herramienta metodológica la revisión bibliográfica. Se halló que la política pública ambiental en el Valle se ha orientado a subsidiar monetaria, ecológica, ambiental y socialmente al sector cañicultor. Se concluye que dicha política ha contribuido al desequilibrio ecológico y al deterioro ambiental.
Ambiente e justiça: sobre a utilidade do conceito de racismo ambiental no contexto brasileiro

OpenAIRE

Silva, Lays Helena Paes e

2013-01-01

A ideia de crise ambiental suscita discussões a respeito de distintas concepções de natureza e de ambiente e das disputas simbólicas e materiais neste meio. Uma concepção que toma sociedade e ambiente como pares inseparáveis levou à emergência, nos Estados Unidos, de movimentos que introduziram conceitos como justiça ambiental e racismo ambiental. No Brasil, surgiram movimentos e estudos focados nas mesmas bandeiras de luta e nos mesmos conceitos. Considerando as especificidades do racismo no...
Treatment of toxic and hazardous organic wastes by wet oxidation process with oxygenated water at low temperature

International Nuclear Information System (INIS)

Piccinno, T.; Salluzzo, A.; Nardi, L.; Gili, M.; Luce, A.; Troiani, F.; Cornacchia, G.

1989-11-01

The wet oxidation process using air or molecular oxygen is a well-known process from long time. It is suitable to oxidize several types of waste refractory to the usual biological, thermal and chemical treatments. The drastic operating conditions (high pressures and temperatures) prevented its industrial development. In the last years a new interest was assigned to the process for the treatment of nuclear wastes (organic resins and exhaust organic wastes); the treatment is carried out at widely reduced operating conditions (atmospheric pressure and boiling temperature) by means of metallic catalysts and hydrogen peroxide. With some limits, the wet oxidation with hydrogen peroxide at low temperature can be applied to conventional waste waters containing toxic organic compounds. In the present report are summarized the activities developed at ENEA Fuel Cycle Department by the task force 'Deox' constituted by laboratory and plant specialists in order to verify the application of the wet oxidation process to the treatment of the toxic wastes. (author)
Development of polyurethane-based passive samplers for ambient monitoring of urban-use insecticides in water.

Science.gov (United States)

Liao, Chunyang; Richards, Jaben; Taylor, Allison R; Gan, Jay

2017-12-01

Widespread use of insecticides for the control of urban pests such as ants, termites, and spiders has resulted in contamination and toxicity in urban aquatic ecosystems in different regions of the world. Passive samplers are a convenient and integrative tool for in situ monitoring of trace contaminants in surface water. However, the performance of a passive sampler depends closely on its affinity for the target analytes, making passive samplers highly specific to the types of contaminants being monitored. The goal of this study was to develop a passive sampler compatible with a wide range of insecticides, including the strongly hydrophobic pyrethroids and the weakly hydrophobic fipronil and organophosphates. Of six candidate polymeric thin films, polyurethane film (PU) was identified to be the best at enriching the test compounds. The inclusion of stable isotope labeled analogs as performance reference compounds (PRCs) further allowed the use of PU film for pyrethroids under non-equilibrium conditions. The PU sampler was tested in a large aquarium with circulatory water flow, and also deployed at multiple sites in surface streams in southern California. The concentrations of pesticides derived from the PU sampler ranged from 0.5 to 18.5 ng/L, which were generally lower than the total chemical concentration measured by grab samples, suggesting that suspended particles and dissolved organic matter in water rendered them less available. The influence of suspended particles and dissolved organic matter on bioavailability was more pronounced for pyrethroids than for fipronils. The results show that the developed PU film sampler, when coupled with PRCs, may be used for rapid and sensitive in-situ monitoring of a wide range of insecticides in surface water. Copyright © 2017 Elsevier Ltd. All rights reserved.
Tennessee's East Fork Poplar Creek: A biological monitoring and abatement program

International Nuclear Information System (INIS)

Halbrook, R.S.; Loar, J.M.; Adams, S.M.; Black, M.C.; Boston, H.L.; Greeley, M.S. Jr.; Hill, W.R.; Hinzman, R.L.; McCarthy, J.F.; Peterson, M.J.; Ryon, M.G.; Schilling, E.M.; Smith, J.G.; Southworth, G.R.; Stewart, A.J.; Gatz, A.J.

1991-01-01

On May 1985, a Biological Monitoring Program was developed for East Fork Poplar Creek (EFPC) in eastern Tennessee, United States. This stream originates within the Oak Ridge Y-12 Plant that produces nuclear weapons components for the Department of Energy. Water and sediment in the stream contain metals, organic chemicals, and radionuclides from releases that have occurred over the past 45 years. The creek also receives urban and some agricultural runoff and effluent from the City of Oak Ridge's Wastewater Treatment Facility (WTF). The biological monitoring program includes four major tasks: (1) ambient toxicity testing: (2) bioaccumulation studies; (3) biological indicator studies; and (4) ecological monitoring of stream communities, including periphyton, benthic macroinvertebrates, and fish. Biological conditions are monitored at six sites on EFPC ranging from kilometer 24.4 near the headwaters to kilometer 6.3 near the month. A site on Brushy Fork, A stream just north of Oak Ridge, is used as reference. Ambient (instream) toxicity was monitored through the use of 7-day static-renewal tests that measured the survival and growth of fathead minnow (Pimephales promelas) larvae and the survival and reproduction of a microstrustacean (Ceriodaphnia dubia). Full-strength water from EFPC within the Y-12 Plant boundary was frequently toxic to Ceriodaphnia, but less frequently toxic to the minnow larvae. Chlorine has been identified as an important toxicant in upper EFPC. Water samples from six sites in EFPC downstream from the Y-12 Plant boundary were tested eight times with both species during a 2-year period (October, 1986 through October, 1988). These sites were ranked by the number of times they were ''best'' or ''worst'' for each species. Water samples collected for use in the ambient toxicity tests were routinely analyzed for conductivity, pH, alkalinity, hardness, total residual and free chlorine, and temperature
Enhanced monitor system for water protection

Science.gov (United States)

Hill, David E [Knoxville, TN; Rodriquez, Jr., Miguel [Oak Ridge, TN; Greenbaum, Elias [Knoxville, TN

2009-09-22

An automatic, self-contained device for detecting toxic agents in a water supply includes an analyzer for detecting at least one toxic agent in a water sample, introducing a means for introducing a water sample into the analyzer and discharging the water sample from the analyzer, holding means for holding a water sample for a pre-selected period of time before the water sample is introduced into the analyzer, and an electronics package that analyzes raw data from the analyzer and emits a signal indicating the presence of at least one toxic agent in the water sample.
Evaluation and modeling of the parameters affecting fluoride toxicity level in aquatic environments by bioassay method

OpenAIRE

Hamid Reza Shamsollahi; Hadi asady; Amir Hossein Mahvi; Zahra zolghadr

2014-01-01

Background: Fluoride exists in various forms in nature and water resources. , The rising level of fluoride in water resources due to discharge of industrial effluents can cause toxicity in aquatic organisms. To prevent toxicity, it is necessary to determine maximum fluoride toxicity as well as effluent discharge limits. The aim of this study was to determine the maximum fluoride toxicity and the factors affecting fluoride toxicity to provide a model in order to determine the effluent discha...
Seasonal variation of sediment toxicity in the Rivers Dommel and Elbe

International Nuclear Information System (INIS)

Hsu, P.; Matthaei, A.; Heise, S.; Ahlf, W.

2007-01-01

Contaminated sediment in the river basin has become a source of pollution with increasing importance to the aquatic ecosystem downstream. To monitor the temporal changes of the sediment bound contaminants in the River Elbe and the River Dommel monthly toxicity tests were applied to layered sediment and river water samples over the course of 10 months. There is an indication that contaminated sediments upstream adversely affected sediments downstream, but this process did not cause a continuous increase of sediment toxicity. A clear decrease of toxic effects in water and upper layer sediment was observed at the River Elbe station in spring related to high water discharge and algal blooms. The less obvious variation of sediment toxicity in the River Dommel could be explained by stable hydrological conditions. Future monitoring programmes should promote a more frequent and intensive sampling regime during these particular events for ecotoxicological evaluation. - Significant impacts of hydrological and biological factors on the ecotoxicological quality in two European rivers (Elbe and Dommel)
Toxicity of contaminants in lagoons and pannes of the Indiana Dunes National Lakeshore

International Nuclear Information System (INIS)

Gillespie, R.; Speelman, J.; Stewart, P.M.

1995-01-01

Contaminants in water and sediments of lagoons and pannes were 2--90 times greater at sites adjacent to slag and coal piles than those at reference sites. One site (Lagoon-US5) had sediments with very high concentrations of toxic organics (e.g. naphthalene, phenanthrene, dibenzofuran). Although analyses indicated a gradient of contaminant concentration with distance from their sources, toxicity assays were somewhat equivocal. With the exception of less reproduction in Ceriodaphnia at one lagoon site (US3 = 0.55 of reference), survival of fathead minnows and reproduction in Ceriodaphnia in lagoon and panne waters varied independently of the contaminant concentration. In fact, there was better Ceriodaphnia reproduction in water from two contaminated sites (Lagoon-US5, Panne-WP1) than in water from reference sites. Fathead minnow survival, Ceriodaphnia survival, Ceriodaphnia reproduction, amphipod survival, and amphipod growth varied among sites in toxicity assays with sediments, 100% mortality of fatheads at Lagoon-US5, 100% mortality of Ceriodaphnia at Lagoon-US3, and less survival of fathead minnows at Lagoon-US3 indicate possible toxicity from contaminants in sediments at these sites. Of all organisms and end-points tested, Ceriodaphnia survival seemed to be most closely associated with concentrations of contaminants in lagoon water and sediments. Amphipod survival also varied with contaminants in sediments, however, survival in sediments of contaminated sites ranged only from 0.90--0.93 of reference sites. Although the results are not consistent among organisms, toxicity assays indicate that sediments from the lagoon site with the highest contaminants (Lagoon-US5) and possibly those from another contaminated lagoon site (Lagoon-US3) could be toxic to aquatic organisms. Water and sediments from contaminated panne sites do not appear to be toxic to aquatic test organisms
Portable, accurate toxicity testing

International Nuclear Information System (INIS)

Sabate, R.W.; Stiffey, A.V.; Dewailly, E.L.; Hinds, A.A.; Vieaux, G.J.

1994-01-01

Ever tightening environmental regulations, severe penalties for non-compliance, and expensive remediation costs have stimulated development of methods to detect and measure toxins. Most of these methods are bioassays that must be performed in the laboratory; none previously devised has been truly portable. The US Army, through the Small Business Innovative Research program, has developed a hand-held, field deployable unit for testing toxicity of battlefield water supplies. This patented system employs the measurable quenching, in the presence of toxins, of the natural bioluminescence produced by the marine dinoflagellate alga Pyrocystis lunula. The procedure's inventor used it for years to measure toxicity concentrations of chemical warfare agents actually, their simulants, primarily in the form of pesticides and herbicides plus assorted toxic reagents, waterbottom samples, drilling fluids, even blood. While the procedure is more precise, cheaper, and faster than most bioassays, until recently it was immobile. Now it is deployable in the field. The laboratory apparatus has been proven to be sensitive to toxins in concentrations as low as a few parts per billion, repeatable within a variation of 10% or less, and unlike some other bioassays effective in turbid or colored media. The laboratory apparatus and the hand-held tester have been calibrated with the EPA protocol that uses the shrimplike Mysidopsis bahia. The test organism tolerates transportation well, but must be rested a few hours at the test site for regeneration of its light-producing powers. Toxicity now can be measured confidently in soils, water columns, discharge points, and many other media in situ. Most significant to the oil industry is that drilling fluids can be monitored continuously on the rig
A versatile bio-based material for efficiently removing toxic dyes, heavy metal ions and emulsified oil droplets from water simultaneously.

Science.gov (United States)

Li, Daikun; Li, Qing; Mao, Daoyong; Bai, Ningning; Dong, Hongzhou

2017-12-01

Developing versatile materials for effective water purification is significant for environment and water source protection. Herein, a versatile bio-based material (CH-PAA-T) was reported by simple thermal cross-linking chitosan and polyacrylic acid which exhibits excellent performances for removing insoluble oil, soluble toxic dyes and heavy metal ions from water, simultaneously. The adsorption capacities are 990.1mgg -1 for methylene blue (MB) and 135.9mgg -1 for Cu 2+ , which are higher than most of present advanced absorbents. The adsorption towards organic dyes possesses high selectivity which makes CH-PAA-T be able to efficiently separate dye mixtures. The stable superoleophobicity under water endows CH-PAA-T good performance to separate toluene-in-water emulsion stabilized by Tween 80. Moreover, CH-PAA-T can be recycled for 10 times with negligible reduction of efficiency. Such versatile bio-based material is a potential candidate for water purification. Copyright © 2017. Published by Elsevier Ltd.
Role of Bioadsorbents in Reducing Toxic Metals

Directory of Open Access Journals (Sweden)

Blessy Baby Mathew

2016-01-01

Full Text Available Industrialization and urbanization have led to the release of increasing amounts of heavy metals into the environment. Metal ion contamination of drinking water and waste water is a serious ongoing problem especially with high toxic metals such as lead and cadmium and less toxic metals such as copper and zinc. Several biological materials have attracted many researchers and scientists as they offer both cheap and effective removal of heavy metals from waste water. Therefore it is urgent to study and explore all possible sources of agrobased inexpensive adsorbents for their feasibility in the removal of heavy metals. The objective was to study inexpensive adsorbents like various agricultural wastes such as sugarcane bagasse, rice husk, oil palm shell, coconut shell, and coconut husk in eliminating heavy metals from waste water and their utilization possibilities based on our research and literature survey. It also shows the significance of developing and evaluating new potential biosorbents in the near future with higher adsorption capacity and greater reusable options.
Role of Bioadsorbents in Reducing Toxic Metals.

Science.gov (United States)

Mathew, Blessy Baby; Jaishankar, Monisha; Biju, Vinai George; Krishnamurthy Nideghatta Beeregowda

2016-01-01

Industrialization and urbanization have led to the release of increasing amounts of heavy metals into the environment. Metal ion contamination of drinking water and waste water is a serious ongoing problem especially with high toxic metals such as lead and cadmium and less toxic metals such as copper and zinc. Several biological materials have attracted many researchers and scientists as they offer both cheap and effective removal of heavy metals from waste water. Therefore it is urgent to study and explore all possible sources of agrobased inexpensive adsorbents for their feasibility in the removal of heavy metals. The objective was to study inexpensive adsorbents like various agricultural wastes such as sugarcane bagasse, rice husk, oil palm shell, coconut shell, and coconut husk in eliminating heavy metals from waste water and their utilization possibilities based on our research and literature survey. It also shows the significance of developing and evaluating new potential biosorbents in the near future with higher adsorption capacity and greater reusable options.
Role of Bioadsorbents in Reducing Toxic Metals

Science.gov (United States)

Jaishankar, Monisha; Biju, Vinai George; Krishnamurthy Nideghatta Beeregowda

2016-01-01

Industrialization and urbanization have led to the release of increasing amounts of heavy metals into the environment. Metal ion contamination of drinking water and waste water is a serious ongoing problem especially with high toxic metals such as lead and cadmium and less toxic metals such as copper and zinc. Several biological materials have attracted many researchers and scientists as they offer both cheap and effective removal of heavy metals from waste water. Therefore it is urgent to study and explore all possible sources of agrobased inexpensive adsorbents for their feasibility in the removal of heavy metals. The objective was to study inexpensive adsorbents like various agricultural wastes such as sugarcane bagasse, rice husk, oil palm shell, coconut shell, and coconut husk in eliminating heavy metals from waste water and their utilization possibilities based on our research and literature survey. It also shows the significance of developing and evaluating new potential biosorbents in the near future with higher adsorption capacity and greater reusable options. PMID:28090207
Acute and Subacute Toxicity Evaluation of Corn Silk Extract.

Science.gov (United States)

Ha, Ae Wha; Kang, Hyeon Jung; Kim, Sun Lim; Kim, Myung Hwan; Kim, Woo Kyoung

2018-03-01

Many studies have reported therapeutic efficacy of corn silk extract. However, research on its toxicity and safe dose range is limited. Thus, the objective of this study was to determine the acute and subacute toxicity of corn silk extract in ICR mice. To determine acute toxicity, corn silk extract containing high levels of maysin was orally administered to mice at a dose of 0 or 2,000 mg/kg. Clinical symptoms, mortality, and body weight changes were recorded for 14 days. To determine subacute toxicity, corn silk extract was orally administered to mice over a 4-week period, and then body weight, water and food consumption, and organ weight were determined. In addition, urine and serum analyses were performed. In the acute toxicity study, no death or abnormal symptoms was observed in all treatment groups during the study period. Body weights did not show any significant change compared to those of the control group. Lethal dose of corn silk extract was estimated to be more than 2,000 mg/kg. In the 4-week subacute toxicity study, there was no corn silk extract related toxic effect on body weight, water intake, food consumption, urine parameters, clinical chemistry, or organ weight. Histopathological examination showed no abnormality related to the administration of corn silk extract at 500 mg/kg. The maximum non-toxic dose of corn silk extract containing high levels of maysin was found to be more than 500 mg/kg.
Management of a toxic cyanobacterium bloom (Planktothrix rubescens) affecting an Italian drinking water basin: a case study.

Science.gov (United States)

Bogialli, Sara; Nigro di Gregorio, Federica; Lucentini, Luca; Ferretti, Emanuele; Ottaviani, Massimo; Ungaro, Nicola; Abis, Pier Paolo; Cannarozzi de Grazia, Matteo

2013-01-02

An extraordinary bloom of Planktothrix rubescens, which can produce microcystins (MCs), was observed in early 2009 in the Occhito basin, used even as a source of drinking water in Southern Italy. Several activities, coordinated by a task force, were implemented to assess and manage the risk associated to drinking water contaminated by cyanobacteria. Main actions were: evaluation of analytical protocols for screening and confirmatory purpose, monitoring the drinking water supply chain, training of operators, a dedicated web site for risk communication. ELISA assay was considered suitable for health authorities as screening method for MCs and to optimize frequency of sampling according to alert levels, and as internal control for the water supplier. A liquid chromatography-tandem mass spectrometric method able to quantify 9 MCs was optimized with the aim of supporting health authorities in a comprehensive risk evaluation based on the relative toxicity of different congeners. Short, medium, and long-term corrective actions were implemented to mitigate the health risk. Preoxidation with chlorine dioxide followed by flocculation and settling have been shown to be effective in removing MCs in the water treatment plant. Over two years, despite the high levels of cyanobacteria (up to 160 × 10(6) cells/L) and MCs (28.4 μg/L) initially reached in surface waters, the drinking water distribution was never limited.
Toxicity of zinc oxide nanoparticles to zebrafish embryo: a physicochemical study of toxicity mechanism

International Nuclear Information System (INIS)

Bai Wei; Zhang Zhiyong; Tian Wenjing; He Xiao; Ma Yuhui; Zhao Yuliang; Chai Zhifang

2010-01-01

The biological impact of engineered nanomaterials released into the aquatic environment is a major concern. In this work, the properties of ZnO nanoparticles (nano-ZnO, 30 nm) were characterized in a water suspension (E3 medium), and a zebrafish 96-h post fertilization (hpf) embryo-larval test was performed to assess the toxicity of nano-ZnO suspension. Nano-ZnO was found to readily form aggregates with different sizes; small aggregates (142.4-517.7 nm) were still suspended in E3 medium, but large aggregates (>1 μm) quickly deposited on the bottom of 24-well plates; nano-ZnO was partially dissolved to Zn species (Zn (dis) ) in E3 medium. In the nano-ZnO suspension, small aggregates, Zn (dis) , and large aggregates might jointly exert influence on the development of zebrafish embryos. The embryo toxicity test revealed that nano-ZnO killed zebrafish embryos (50 and 100 mg/L), retarded the embryo hatching (1-25 mg/L), reduced the body length of larvae, and caused tail malformation after the 96 hpf exposure. Zn (dis) only partially contributed to the toxicity of nano-ZnO. This research highlights the need to further investigate the ecotoxicity of nano-ZnO in the water environment.

Ecological risk assessment of toxic organic pollutant and heavy metals in water and sediment from a landscape lake in Tianjin City, China.

Science.gov (United States)

Zhang, Ying; Liu, Yuanyuan; Niu, Zhiguang; Jin, Shaopei

2017-05-01

To estimate the ecological risk of toxic organic pollutant (formaldehyde) and heavy metals (mercury (Hg), arsenic (As), cadmium (Cd), and chromium (Cr)) in water and sediment from a landscape Lake in Tianjin City, an ecological risk assessment was performed. The risk quotient (RQ) method and the AQUATOX model were used to assess the ecological risk of formaldehyde in landscape water. Meanwhile, the RQ method and the potential ecological risk index method were used to assess the ecological risk of four heavy metals in water and sediment from the studied landscape lake, respectively. The results revealed that the maximum concentration of formaldehyde in landscape water was lower than the environmental quality standards of surface water in China. The maximum simulated concentrations of formaldehyde in phytoplankton and invertebrates were 3.15 and 22.91 μg/L, respectively, which were far less than its toxicity data values (1000 and 510 μg/L, respectively), suggesting that formaldehyde in landscape water was at a safe level for aquatic organisms. The RQ model indicated that the risks of phytoplankton and invertebrates were higher than that of fish posed by Hg and Cd in landscape water, and the risks from As and Cr were acceptable for all test organisms. Cd is the most important pollution factor among all heavy metals in sediment from studied landscape lake, and the pollution factor sequence of heavy metals was Hg > As > Cr > Cd. The values of risk index (RI) for four heavy metals in samples a and b were 43.48 and 72.66, which were much lower than the threshold value (150), suggesting that the ecological risk posed by heavy metals in sediment was negligible.
To the issue of temperature-dependent behavior of standard molar volumes of components in the binary system (water + tetrahydrofuran) at ambient pressure

International Nuclear Information System (INIS)

Ivanov, Evgeniy V.

2014-01-01

Graphical abstract: The standard molar volume of tetrahydrofuran (THF) in water, V THF ∘ (■), is a close-to-linear function of temperature and becomes increasingly appreciable with rising of the latter. Herewith the molar volume of pure THF, V THF (□), is retained to be larger, as compared to V THF ∘ , over all the temperature range studied. - Highlights: • Densities of aqueous THF at nine temperatures from (278.15 to 318.15) K were measured. • Temperature-dependent standard molar volumes of THF in water were calculated. • The analysis of excess standard molar volumes in the (water + THF) system was made. • The use of Redlich–Kister equation to obtain standard molar volumes is discussed. - Abstract: This report presents a comparative analysis of temperature-dependent data on density of both dilute aqueous solutions of tetrahydrofuran (THF) and dilute solutions of water in THF, as well as standard molar volumes of water or THF as a solute. For this purpose, new results on studying the volume-related properties of THF in a water-rich region at temperatures from (278.15 to 318.15) K, with a step of 5 K, and at the ambient pressure have been derived densimetrically. In discussion, some comments on previously published investigations, being related to temperature-dependent changes in the solution density and standard molar volumes of components of the system (water + THF), have been made
Development of a numerical model for calculating exposure to toxic and nontoxic stressors in the water column and sediment from drilling discharges

NARCIS (Netherlands)

Rye, H.; Reed, M.; Frost, T.K.; Smit, M.G.D.; Durgut, S.

2008-01-01

Drilling discharges are complex mixtures of chemical components and particles which might lead to toxic and nontoxic stress in the environment. In order to be able to evaluate the potential environmental consequences of such discharges in the water column and in sediments, a numerical model was
Application of PIXE, NAA and other techniques to the determination of toxic elements in Bangladesh foodstuffs and drinking waters

International Nuclear Information System (INIS)

Tarafdar, S.A.; Khan, A.H.

1988-01-01

The main objective of the food monitoring programme is to study the applicability of PIXE, XRF, NAA and other related methods to toxic and essential trace elements analyses in foodstuffs and drinking water under the coordinated research programme of the IAEA and to collect baseline data on the status of such elements in foodstuffs and drinking water. The commonly consumed representative foodstuffs selected for Bangladesh are: rice, wheat, green vegetables, fish, milk and egg. In the previous year, only food items were studied but in this report drinking water is also included. The elements required by the project protocol are Cu, Cr, Fe, As, Se, Sb, Cd, Pb and Hg. In this report, the results obtained during the last contract period are presented with a plan for future work. 4 refs, 2 tabs
Normobaric pulmonary oxygen toxicity : experimental studies on the mechanism of the protective role of endotoxin and the role of surfactant.

NARCIS (Netherlands)

J. Klein (Jan)

1991-01-01

textabstractAdministration of above-ambient oxygen tensions, necessary for treatment of severe hypoxemia caused by respiratory failure or acute lung injury, is potentially toxic for the lungs. This thesis is based on six articles dealing with this topic: one review article and five articles
Water-Based Automobile Paints Potentially Reduce the Exposure of Refinish Painters to Toxic Metals

Directory of Open Access Journals (Sweden)

Der-Jen Hsu

2018-05-01

Full Text Available Exposure to lead-containing dusts is a global public health concern. This work addresses an important issue of whether eco-friendly water-based paints reduce the exposure potential of auto-repainting workers to metals. With this aim, metal levels in automobile paints and worker metal exposure were measured using both solvent- and water-based paints. The levels of metals, and particularly Pb, Cr (total, Fe, and Cu, in solvent-based paints varied greatly among colors and brands. Lead concentrations ranged from below the detection limit (~0.25 μg/g to 107,928 μg/g (dry film across all samples. In water-based paints, the concentrations of Pb and Cr (total were generally two to three orders of magnitude lower, but the concentrations of Al and Cu exceeded those in some solvent-based paints. The personal short-term exposure of workers who applied water-based paints of popular colors, such as black and white, were generally low, with Pb levels of less than <4 µg/m3 and Cr (total levels of less than 1 µg/m3. Conversely, mean short-term exposure to Pb during the painting of a yellow cab using solvent-based paints were 2028 µg/m3, which was ~14 times the Taiwan short-term permissible exposure limit, while the mean level of exposure to Cr (total was 290 µg/m3, which was well below the exposure limit. This study demonstrates that water-based paints reduce the exposure potential to lead, and highlights the importance of source control in limiting the toxic metals in paints.
Predicting toxic heavy metal movements in upper Sanyati catchment ...

African Journals Online (AJOL)

Water samples from boreholes located in areas where mining, mineral processing and agricultural activities were dominant, yielded the highest values of toxic heavy metals. Dilution Attenuation Factor (DAF) for each toxic heavy metal was calculated to observe metal behaviour along the contaminant path for each season.
Enhancement of parathion toxicity to quail by heat and cold exposure

Science.gov (United States)

Rattner, B.A.; Becker, J.M.; Nakatsugawa, T.

1987-01-01

Effects of ambient temperature on the acute oral toxicity of parathion were investigated in Japanese quail (Coturnix japonica) maintained at thermoneutral temperature (26.degree. C) or exposed to elevated (37.degree. C) or reduced (4.degree. C) temperatures commonly encountered by free-ranging wild birds. Based upon estimates of the median lethal dosage, there was up to a two-fold enhancement of parathion toxicity in birds chronically exposed to heat or cold. Twenty-four hours after administration of a low dosage (4 mg/kg body wt, po), there was markedly greater cholinesterase inhibition in surviving heat-exposed quail compared with those reared at 26.degree. C (e.g., brain acetylcholinesterase depression of 42% versus 12%). There were no differences in hepatic activities of parathion oxidase, paraoxonase, or paraoxon deethylase which could account for greater toxicity to chronically heat-exposed birds. In contrast, 4 mg parathion/kg wt elicited less plasma cholinesterase inhibition in cold-exposed quail compared to thermoneutral controls (e.g., birds is substantially influenced by environmental temperature.
Human health effects associated with exposure to toxic Cyanobacteria – what is the evidence?

Science.gov (United States)

Reports of toxic cyanobacteria blooms are increasing worldwide, as warming water and eutrophic surface water systems support the development of blooms. As awareness of toxic cyanobacteria blooms increases, reports of associated human and animal illnesses have also increased, but ...
Assessment of microplastic toxicity to embryonic development of the sea urchin Lytechinus variegatus (Echinodermata: Echinoidea).

Science.gov (United States)

Nobre, C R; Santana, M F M; Maluf, A; Cortez, F S; Cesar, A; Pereira, C D S; Turra, A

2015-03-15

Apart from the physiological impacts on marine organisms caused by ingesting microplastics, the toxicity caused by substances leaching from these particles into the environment requires investigation. To understand this potential risk, we evaluated the toxicity of virgin (raw) and beach-stranded plastic pellets to the development of embryos of Lytechinus variegatus, simulating transfers of chemical compounds to interstitial water and water column by assays of pellet-water interface and elutriate, respectively. Both assays showed that virgin pellets had toxic effects, increasing anomalous embryonic development by 58.1% and 66.5%, respectively. The toxicity of stranded pellets was lower than virgin pellets, and was observed only for pellet-water interface assay. These results show that (i) plastic pellets act as a vector of pollutants, especially for plastic additives found on virgin particles; and that (ii) the toxicity of leached chemicals from pellets depends on the exposure pathway and on the environmental compartment in which pellets accumulate. Copyright © 2015 Elsevier Ltd. All rights reserved.
Toxicity measurement in a waste water treatment plants using active sludge aerobic biological treatment. Medida de la toxicidad en una estacion depuradora de aguas residuales con tratamiento biologico aerobio por fangos activos

Energy Technology Data Exchange (ETDEWEB)

Serrano, J.E. (Surcis, Guadalajara (Spain))

1994-01-01

The need for reliability in the operation of waste water treatment plants is discussed. In aerobic biological treatments of whatever kind using active sludge, the bio toxicity can be determined by measuring the oxygen consumed in endogenous breathing. The difficulty lies in carrying out the bio toxicity test without effecting the concentration of the organic substrate of the wastes water. This is overcome by operating at maximum organic material load, thereby inducing maximun breathing. (Author)
Organophosphorus insecticides: Toxic effects and bioanalytical tests for evaluating toxicity during degradation processes

Directory of Open Access Journals (Sweden)

Čolović Mirjana B.

2013-01-01

Full Text Available Organophosphorus insecticides have been the most applied group of insecticides for the last two decades. Their main toxic effects are related to irreversible inactivation of acetylcholinesterase (AChE. Actually, they covalently bind to serine OH group in the enzyme active site forming phosphorylated enzyme that cannot hydrolyze acetylcholine. Organophosphorus insecticides in the environment undergo the natural degradation pathway including mainly homogeneous and heterogeneous hydrolysis (especially at high pH generating non-inhibiting products. Additionally, thio organophosphates are easily oxidized by naturally present oxidants and UV light, forming more toxic and stable oxons. Thus, oxidative degradation procedures, generally referred as advanced oxidation processes (AOP, have been applied for their efficient removal from contaminated waters. The most applied bioassays to monitor the organophosphate toxicity i.e. the detoxification degree during AOP are Vibrio fischeri and AChE bioassays. Vibrio fischeri toxicity test exploits bioluminescence as the measure of luciferase activity of this marine bacterium, whereas AChE bioassay is based on AChE activity inhibition. Both bioanalytical techniques are rapid (several minutes, simple, sensitive and reproducible. Vibrio fischeri test seems to be a versatile indicator of toxic compounds generated in AOP for organophosphorus insecticides degradation. However, detection of neurotoxic AChE inhibitors, which can be formed in AOP of some organophosphates, requires AChE bioassays. Therefore, AChE toxicity test is more appropriate for monitoring the degradation processes of thio organophosphates, because more toxic oxo organophosphates might be formed and overlooked by Vibrio fischeri bioluminescence inhibition. In addition, during organophosphates removal by AOP, compounds with strong genotoxic potential may be formed, which cannot be detected by standard toxicity tests. For this reason, determination of
Fingerprinting the reactive toxicity pathways of 50 drinking water disinfection by-products.

Science.gov (United States)

Stalter, Daniel; O'Malley, Elissa; von Gunten, Urs; Escher, Beate I

2016-03-15

A set of nine in vitro cellular bioassays indicative of different stages of the cellular toxicity pathway was applied to 50 disinfection by-products (DBPs) to obtain a better understanding of the commonalities and differences in the molecular mechanisms of reactive toxicity of DBPs. An Eschericia coli test battery revealed reactivity towards proteins/peptides for 64% of the compounds. 98% activated the NRf2-mediated oxidative stress response and 68% induced an adaptive stress response to genotoxic effects as indicated by the activation of the tumor suppressor protein p53. All DBPs reactive towards DNA in the E. coli assay and activating p53 also induced oxidative stress, confirming earlier studies that the latter could trigger DBP's carcinogenicity. The energy of the lowest unoccupied molecular orbital ELUMO as reactivity descriptor was linearly correlated with oxidative stress induction for trihalomethanes (r(2)=0.98) and haloacetamides (r(2)=0.58), indicating that potency of these DBPs is connected to electrophilicity. However, the descriptive power was poor for haloacetic acids (HAAs) and haloacetonitriles (r(2) (0.80, indicating that HAAs' potency is connected to both, electrophilicity and speciation. Based on the activation of oxidative stress response and the soft electrophilic character of most tested DBPs we hypothesize that indirect genotoxicity-e.g., through oxidative stress induction and/or enzyme inhibition-is more plausible than direct DNA damage for most investigated DBPs. The results provide not only a mechanistic understanding of the cellular effects of DBPs but the effect concentrations may also serve to evaluate mixture effects of DBPs in water samples. Copyright © 2016 Elsevier Ltd. All rights reserved.
Salud ambiental: conceptos y actividades

Directory of Open Access Journals (Sweden)

Gonzalo A. Ordóñez

2000-03-01

Full Text Available La finalidad del trabajo es aportar información y propuestas conceptuales que faciliten la tarea de quienes tienen a su cargo la sistematización institucional de la salud ambiental. Se hace un análisis de la noción de "ambiente" para la cual se sugiere una definición, y se examina el lugar de la salud ambiental en el contexto de los problemas ambientales y sus vertientes "verde" y "azul". Se examinan denominaciones equivalentes de salud ambiental y se introducen los servicios de salud ambiental. Se proporcionan varias definiciones y se da la oficial de salud ambiental adoptada por la OMS en Sofía, Bulgaria (1993. A continuación se transcriben las áreas básicas que a la salud ambiental le han asignado diversas organizaciones o reuniones, como la OPS, la OMS, el Programa 21 y otros. A partir de aquí se construye un repertorio bastante completo de áreas y subáreas y se encuentra que todos los listados son, en realidad, una reunión asistemática de tres tipos de constituyentes: determinantes (factores o hechos de la realidad física, procesos (conjuntos de intervenciones y funciones (conjuntos de acciones de gestión, los cuales pueden enfocarse matricialmente y llevan a individualizar actividades de los servicios de salud ambiental. Se proponen unas reglas de operación que permiten, en una especie de álgebra, construir expresiones para especificar con precisión las actividades y sus agregados. De este modo se logra disponer de un lenguaje simbólico común que puede ayudar a la intercomunicación, enseñanza e investigación en el ámbito de la salud ambiental.
Modeling time-dependent toxicity to aquatic organisms from pulsed exposure of PAHs in urban road runoff

International Nuclear Information System (INIS)

Zhang Wei; Ye Youbin; Tong Yindong; Ou Langbo; Hu Dan; Wang Xuejun

2011-01-01

Understanding of the magnitude of urban runoff toxicity to aquatic organisms is important for effective management of runoff quality. In this paper, the aquatic toxicity of polycyclic aromatic hydrocarbons (PAHs) in urban road runoff was evaluated through a damage assessment model. Mortality probability of the organisms representative in aquatic environment was calculated using the monitored PAHs concentration in road runoff. The result showed that the toxicity of runoff in spring was higher than those in summer. Analysis of the time-dependent toxicity of series of runoff water samples illustrated that the toxicity of runoff water in the final phase of a runoff event may be as high as those in the initial phase. Therefore, the storm runoff treatment systems or strategies designed for capture and treatment of the initial portion of runoff may be inappropriate for control of runoff toxicity. - Research highlights: → Toxicity resulting from realistic exposure patterns of urban runoff is evaluated. → Toxicity of runoff water in the final phase is as high as the initial phase. → Treatment of the initial runoff portion is inappropriate to abate runoff toxicity. - Toxicity to aquatic organisms after sequential pulsed exposure to PAHs in urban road runoff is evaluated.
Human Health and Toxic Cyanobacteria – What do we know?

Science.gov (United States)

Human Health and Toxic Cyanobacteria – What do we know?Elizabeth D. HilbornWarm, eutrophic surface water systems support the development of toxic cyanobacteria blooms in North Carolina and worldwide. These conditions are increasing with expanding human populations and clima...
Enhancing Water Evaporation with Floating Synthetic Leaves

Science.gov (United States)

Boreyko, Jonathan; Vieitez, Joshua; Berrier, Austin; Roseveare, Matthew; Shi, Weiwei

2017-11-01

When a wetted nanoporous medium is exposed to a subsaturated ambient environment, the water menisci assume a concave curvature to achieve a negative pressure. This negative water pressure is required to balance the mismatch in water activity across the water-air interface to achieve local equilibrium. Here, we show that the diffusive evaporation rate of water can be greatly modulated by floating a nanoporous synthetic leaf at the water's free interface. For high ambient humidities, adding the leaf serves to enhance the evaporation rate, presumably by virtue of the menisci enhancing the effective liquid-vapor surface area. For low humidities, the menisci cannot achieve a local equilibrium and retreat partway into the leaf, which increases the local humidity directly above the menisci. In light of these two effects, we find the surprising result that leaves exposed to an ambient humidity of 90 percent can evaporate water at the same rate as leaves exposed to only 50 percent humidity. These findings have implications for using synthetic trees to enhance steam generation or water harvesting. This work was supported by the National Science Foundation (CBET-1653631).
MODIFICANDO O AMBIENTE ESCOLAR ATRAVÉS DO PROJETO MEIO AMBIENTE: CULTIVANDO E CONHECENDO AS PLANTAS

Directory of Open Access Journals (Sweden)

Letícia Caroline Lopes

2011-07-01

Full Text Available O presente trabalho intitulado “MODIFICANDO O AMBIENTE ESCOLAR ATRAVÉS DO PROJETO MEIO AMBIENTE: CULTIVANDO E CONHECENDO AS PLANTAS” tem como desígnio apresentar o desenvolvimento do projeto “meio ambiente: cultivando e conhecendo as plantas”, no qual teve como proposta sensibilizar os alunos sobre a importância e preservação do meio ambiente através da prática e modificação do ambiente escolar, onde procurou-se utilizar materiais reciclados, tais como, garrafas pet, pneus velhos, carreteis de fios de eletricidade, e também mudas de arvore, plantas e hortaliças. Desta forma buscou se utilizar da criatividade dos envolvidos no processo para a transformação do ambiente escolar seco e vazio, para uma ambiente alegre, e acolhedor. O projeto foi elaborado pelas professoras da Extensão Betel, e aplicado em parceria com acadêmicos do sexto semestre do curso de Licenciatura em Pedagogia da Universidade do Estado do Mato Grosso (UNEMAT, campus de Sinop. Tendo como proposta a interdisciplinaridade, o projeto foi divido em três eixos orientados pelas professoras Edneuza Alves Trugillo, Sinóvia Rauber e Mariza Kreinner, abrangendo assim alunos e professoras de duas turmas de 2º Ano do Ensino Fundamental, e acadêmicos e professores da Universidade, os eixos foram arborização, jardinagem e horta, onde teve a duração de aproximadamente dois meses. A finalização das práticas obteve resultados satisfatórios e objetivos alcançados, tanto pela sensibilização dos alunos sobre a preservação e importância do meio-ambiente, quanto pela prática de intervenção pelos acadêmicos envolvidos no processo, que em coletividade conseguiram modificar o ambiente escolar através do objetivo do projeto, meio-ambiente, proporcionando assim um enriquecimento na formação acadêmica enquanto práticas pedagógicas.
Summarized water quality criteria

International Nuclear Information System (INIS)

Kempster, P.L.; Hattingh, W.H.J.; Van Vliet, H.R.

1980-08-01

The available world literature from 27 sources on existing water quality criteria are summarized for the 15 main uses of water. The minimum, median and maximum specified values for 96 different determinands are included. Under each water use the criteria are grouped according to the functional significance of the determinands e.g. aesthetic/physical effects, high toxic potential, low toxic potential etc. A synopsis is included summarizing salient facts for each determinand such as the conditions under which it is toxic and its relationship to other determinands. The significance of the criteria is briefly discussed and the importance of considering functional interactions between determinands emphasized in evaluating the potential for toxic or beneficial effects. From the source literature it appears that the toxic potential, in addition to being determined by concentration, is also affected by the origin of the substance concerned, i.e. whether from natural sources or from anthropogenic pollution
Educação ambiental na escola: a perspectiva estudantil sobre o meio ambiente e a propaganda ambiental na internet

Directory of Open Access Journals (Sweden)

Fernanda Reis de Pinho Tavares

2005-01-01

Full Text Available Este trabalho visa mostrar as idéias dos estudantes sobre um tema - a propaganda - refletindo como ela se insere na questão ambiental. Também abordamos como os alunos percebem questões como as relações, empresa, meio ambiente e sociedade. Foi realizado em uma oficina de Educação Ambiental, em uma escola particular de Lagoa Santa - MG, durante os meses de junho e julho de 2004. Analisaram-se sites de diversas empresas e ONG's (Organizações Não Governamentais. Em sua maioria os estudantes conseguiram posicionar-se criticamente em relação às entidades investigadas.

Acute and chronic toxicity study of the water accommodated fraction (WAF), chemically enhanced WAF (CEWAF) of crude oil and dispersant in the rock pool copepod Tigriopus japonicus.

Science.gov (United States)

Lee, Kyun-Woo; Shim, Won Joon; Yim, Un Hyuk; Kang, Jung-Hoon

2013-08-01

We determined the toxicity of the water accommodated hydrocarbon fraction (WAF), two chemically enhanced WAFs (CEWAFs; CEWAF-C, Crude oil+Corexit 9500 and CEWAF-H, Crude oil+Hiclean) of crude oil and two dispersants (Corexit 9500 and Hiclean) to the rock pool copepod Tigriopus japonicus. In the acute toxicity test, Corexit 9500 was the most toxic of all the chemicals studied. The nauplius stage of T. japonicus was more susceptible to the toxic chemicals studied than the adult female. The toxicity data using the nauplius stage was then considered as baseline to determine the spiking concentration of chemicals for chronic toxicity tests on the copepod. As the endpoints in the chronic toxicity test, survival, sex ratio, developmental time and fecundity of the copepod were used. All chemicals used in this study resulted in increased toxicity in the F1 generation. The lowest-observed-adverse-effect (LOAE) concentrations of WAF, CEWAF-H, CEWAF-C, Hiclean and Corexit 9500 were observed to be 50%, 10%, 0.1%, 1% and 1%, respectively. The results in present study imply that copepods in marine may be negatively influenced by spilled oil and dispersant. Copyright © 2013 Elsevier Ltd. All rights reserved.
Methods for chemical analysis of water and wastes

Energy Technology Data Exchange (ETDEWEB)

1979-03-01

This manual provides test procedures approved for the monitoring of water supplies, waste discharges, and ambient waters, under the Safe Drinking Water Act, the National Pollutant Discharge Elimination System, and Ambient Monitoring Requirements of Section 106 and 208 of Public Law 92-500. The test methods have been selected to meet the needs of federal legislation and to provide guidance to laboratories engaged in the protection of human health and the aquatic environment.
The toxicity of plutonium

International Nuclear Information System (INIS)

Crouse, P.L.

1994-01-01

Shipments of plutonium occasionally pass around the Cape coastal waters on its way to Japan from Europe. This invariably leads to a great deal of speculation of the dangers involved and of the extreme toxicity of plutonium, with the media and environmental groups claiming that (a) plutonium is the most toxic substance known to man, and that (b) a few kilograms of plutonium ground finely and dispersed in the atmosphere could kill every human being on earth. Comparisons with other poisons are drawn, e.g. common inorganic chemicals and biological agents. The original scare around the extraordinary toxicity of Pu seems to have started in 1974 with the claims of Tamplin and Cochran's hot particle theory about plutonium lodging in the sensitive portions of the lungs in small concentrated aggregates where they are much more effective in producing cancers. This theory, however, is regarded as thoroughly discredited by the experts in the field of radiotoxicity. 8 refs
Water at Interfaces

DEFF Research Database (Denmark)

Björneholm, Olle; Hansen, Martin Hangaard; Hodgson, Andrew

2016-01-01

The interfaces of neat water and aqueous solutions play a prominent role in many technological processes and in the environment. Examples of aqueous interfaces are ultrathin water films that cover most hydrophilic surfaces under ambient relative humidities, the liquid/solid interface which drives...
Comparison of Toxicities to Vibrio fischeri and Fish Based on Discrimination of Excess Toxicity from Baseline Level

Science.gov (United States)

Wang, Xiao H.; Yu, Yang; Huang, Tao; Qin, Wei C.; Su, Li M.; Zhao, Yuan H.

2016-01-01

Investigations on the relationship of toxicities between species play an important role in the understanding of toxic mechanisms to environmental organisms. In this paper, the toxicity data of 949 chemicals to fish and 1470 chemicals to V. fischeri were used to investigate the modes of action (MOAs) between species. The results show that although there is a positive interspecies correlation, the relationship is poor. Analysis on the excess toxicity calculated from toxic ratios (TR) shows that many chemicals have close toxicities and share the same MOAs between the two species. Linear relationships between the toxicities and octanol/water partition coefficient (log KOW) for baseline and less inert compounds indicate that the internal critical concentrations (CBRs) approach a constant both to fish and V. fischeri for neutral hydrophobic compounds. These compounds share the same toxic mechanisms and bio-uptake processes between species. On the other hand, some hydrophilic compounds exhibit different toxic effects with greatly different log TR values between V. fischeri and fish species. These hydrophilic compounds were identified as reactive MOAs to V. fischeri, but not to fish. The interspecies correlation is improved by adding a hydrophobic descriptor into the correlation equation. This indicates that the differences in the toxic ratios between fish and V. fischeri for these hydrophilic compounds can be partly attributed to the differences of bioconcentration between the two species, rather than the differences of reactivity with the target macromolecules. These hydrophilic compounds may more easily pass through the cell membrane of V. fischeri than the gill and skin of fish, react with the target macromolecules and exhibit excess toxicity. The compounds with log KOW > 7 exhibiting very low toxicity (log TR toxicity and MOAs. PMID:26901437
Phenotypic plasticity and fitness consequences in nematodes exposed to toxicants

NARCIS (Netherlands)

Kammenga, J.E.

1995-01-01

A prevailing view in ecotoxicology is that toxicants affect organisms by impairing lifecycle traits that arc most sensitive to these toxicants, a concept also adopted by national and international legislative authorities for deriving safe standards for contaminants in soil and water. For
Assessing toxicity of varying major ion concentrations to marine organisms

International Nuclear Information System (INIS)

Mount, D.R.; Quast, W.

1993-01-01

Recent regulatory developments have required that produced waters discharged in the Gulf of Mexico be monitored for toxicity to marine organisms. While produced water may contain a variety of indigenous and introduced chemicals, virtually all have moderate to high concentrations of major ions. Although seawater is also rich in these ions, excessive salinity can cause toxicity to marine organisms. Perhaps more importantly, toxicity to marine organisms can be caused by deviations from normal ion ratios even if the total salinity is within organism tolerances. To provide a better understanding of marine organism responses to variations in major ion concentrations, the authors conducted a series of laboratory experiments to quantify the responses of mysid shrimp (Mysidopsis bahia) and sheepshead minnows (Cyprinodon variegatus) to modifications of normal seawater chemistry. Acute testing included both increasing and decreasing the concentrations of individual ions relative to seawater, as well as altering total salinity. Results show these organisms can be adversely affected by this altered chemistry and their sensitivity is dependent upon the individual ions that are manipulated. Results from these studies are being incorporated into an overall strategy for evaluating the influence of major ion chemistry on produced water toxicity tests
Microbiological Studies of Semi-Preserved Natural Condiments Paste Stored in Refrigerator and Ambient Temperature

Science.gov (United States)

Dien, H. A.; Montolalu, R. I.; Mentang, F.; Mandang, A. S. K.; Rahmi, A. D.; Berhimpon, S.

2018-01-01

The aims of this studies were to prepare juice and raw condiment to be come semipreserve pastes, and to do microbial assessments on the both pastes during storing in refrigerator and ambient temperatures. For both pastes in refrigerator, samples were taken at 0, 2, 4, 5, 6, 8, 10, 15, 20, 25, and 30 days, and in ambient temperature samples were taken at 0, 1, 2, 3, 4, and 6 days. Assessment were done for TPC, total coliform and E. coli, Salmonella sp, Staphylococcus sp., Vibrio sp., pH and water content. The results shown that juice paste stored in refrigerator still good until 30 days (TPC 1,5x104 CFU/g), and in ambient temperature still good until 6 days (2x104 CFU/g). Condiment paste stored in refrigerator still good until 30 days (6.5x103 CFU/g), and in ambient temperature still good until 6 days (1.17x104 CFU/g). However, recommended that condiment paste stored in ambient temperature only until 4 days (7.3x103CFU/g), while that juice paste until 5 days (7.8x103CFU/g). There were no pathogenic bacteria found in all samples.
COMPLEJIDAD AMBIENTAL: PROPUESTAS ÉTICAS EMERGENTES DEL PENSAMIENTO AMBIENTAL LATINOAMERICANO

Directory of Open Access Journals (Sweden)

Noguera de Echeverri Ana Patricia

2008-07-01

Full Text Available En este artículo, se recogen las propuestas ético ambientales más importantes de la Escuela de Pensamiento Ambiental Latinoamericano, que ha ido construyéndose desde hace 30 años. Se destacan autores de primera línea en el campo de la construcción de Pensamiento Ambiental filosófico, como el Filósofo y Pensador Colombiano, de trascendencia latinoamericana, Augusto Ángel Maya, quien plantea la posibilidad de construir una Filosofía Ambiental Ético estética, dado que la Filosofía Moderna ha sido Metafísica, aún en sus corrientes empiristas, positivistas y neopositivistas. Se destaca la obra de Enrique Leff, mexicano, que propone los conceptos de Complejidad y Saber Ambiental, como puntos de partida de una ética en la educación, la ciencia y la tecnología, dentro de unas relaciones sistémicas y holísticas. Igualmente la propuesta ético estética compleja de Julio Carrizoza, colombiano, se hace presente en este ensayo, como una propuesta política fundamental ante problemas colombianos como son la violencia y la exclusión. Las propuestas de Filósofos colombianos de gran importancia en el campo de la Filosofía Política y Moral, que han desembocado en la propuesta de una Ética Ambiental, Pública y Comunicativa, como es el caso de Guillermo Hoyos Vásquez y de otros pensadores tanto de Colombia como de otros países latinoamericanos, se presentan en este espacio, con el fin de recoger de manera crítica nuestras ideas acerca de la posibilidad de una ética ambiental, es decir una ética descentrada, sin sujeto y sin objeto, una ética sistémica, donde los valores se construyen en las relaciones y donde la intricada trama de la vida, que ha venido construyéndose desde hace más de 2.500 millones de años, y de la cual somos meros hilos, pasa de ser objeto a ser valor primero en su más genuino sentido.
Contribution of post-harvest agricultural paddy residue fires in the N.W. Indo-Gangetic Plain to ambient carcinogenic benzenoids, toxic isocyanic acid and carbon monoxide.

Science.gov (United States)

Chandra, B P; Sinha, Vinayak

2016-03-01

In the north west Indo-Gangetic Plain (N.W.IGP), large scale post-harvest paddy residue fires occur every year during the months of October-November. This anthropogenic perturbation causes contamination of the atmospheric environment with adverse impacts on regional air quality posing health risks for the population exposed to high concentrations of carcinogens such as benzene and toxic VOCs such as isocyanic acid. These gases and carbon monoxide are known to be emitted from biomass fires along with acetonitrile. Yet no long-term in-situ measurements quantifying the impact of this activity have been carried out in the N.W. IGP. Using high quality continuous online in-situ measurements of these gases at a strategic downwind site over a three year period from 2012 to 2014, we demonstrate the strong impact of this anthropogenic emission activity on ambient concentrations of these gases. In contrast to the pre-paddy harvest period, excellent correlation of benzenoids, isocyanic acid and CO with acetonitrile (a biomass burning chemical tracer); (r≥0.82) and distinct VOC/acetonitrile emission ratios were observed for the post-paddy harvest period which was also characterized by high ambient concentrations of these species. The average concentrations of acetonitrile (1.62±0.18ppb), benzene (2.51±0.28ppb), toluene (3.72±0.41ppb), C8-aromatics (2.88±0.30ppb), C9-aromatics (1.55±0.19ppb) and CO (552±113ppb) in the post-paddy harvest periods were about 1.5 times higher than the annual average concentrations. For isocyanic acid, a compound with both primary and secondary sources, the concentration in the post-paddy harvest period was 0.97±0.17ppb. The annual average concentrations of benzene, a class A carcinogen, exceeded the annual exposure limit of 1.6ppb at NTP mandated by the National Ambient Air Quality Standard of India (NAAQS). We show that mitigating the post-harvest paddy residue fires can lower the annual average concentration of benzene and ensure
Det ambientes fænomenologi

DEFF Research Database (Denmark)

Walther-Hansen, Mads

2014-01-01

Det ambiente: sansning, medialisering, omgivelse er et aktuelt og ambitiøst værk. Bogen skildrer hvordan ambiente fænomener har fået en stigende betydning i den moderne verden, og redegør for måden hvorpå det ambiente virker ind på hele vores oplevelseskultur. Det er en levende, uprætentiøs og frem...
Comparison of Acute Toxicity of Algal Metabolites Using Bioluminescence Inhibition Assay

Directory of Open Access Journals (Sweden)

Hansa Jeswani

2015-01-01

Full Text Available Microalgae are reported to degrade hazardous compounds. However, algae, especially cyanobacteria are known to produce secondary metabolites which may be toxic to flora, fauna and human beings. The aim of this study was selection of an appropriate algal culture for biological treatment of biomass gasification wastewater based on acute toxicity considerations. The three algae that were selected were Spirulina sp., Scenedesmus abundans and a fresh water algal consortium. Acute toxicity of the metabolites produced by these algal cultures was tested at the end of log phase using the standard bioluminescence inhibition assay based on Vibrio fischeri NRRLB 11174. Scenedesmus abundans and a fresh water algal consortium dominated by cyanobacteria such as Phormidium, Chroococcus and Oscillatoria did not release much toxic metabolites at the end of log phase and caused only about 20% inhibition in bioluminescence. In comparison, Spirulina sp. released toxic metabolites and caused 50% bioluminescence inhibition at 3/5 times dilution of the culture supernatant (EC50.
Multiple inorganic toxic substances contaminating the groundwater of Myingyan Township, Myanmar: arsenic, manganese, fluoride, iron, and uranium.

Science.gov (United States)

Bacquart, Thomas; Frisbie, Seth; Mitchell, Erika; Grigg, Laurie; Cole, Christopher; Small, Colleen; Sarkar, Bibudhendra

2015-06-01

In South Asia, the technological and societal shift from drinking surface water to groundwater has resulted in a great reduction of acute diseases due to water borne pathogens. However, arsenic and other naturally occurring inorganic toxic substances present in groundwater in the region have been linked to a variety of chronic diseases, including cancers, heart disease, and neurological problems. Due to the highly specific symptoms of chronic arsenic poisoning, arsenic was the first inorganic toxic substance to be noticed at unsafe levels in the groundwater of West Bengal, India and Bangladesh. Subsequently, other inorganic toxic substances, including manganese, uranium, and fluoride have been found at unsafe levels in groundwater in South Asia. While numerous drinking water wells throughout Myanmar have been tested for arsenic, relatively little is known about the concentrations of other inorganic toxic substances in Myanmar groundwater. In this study, we analyzed samples from 18 drinking water wells (12 in Myingyan City and 6 in nearby Tha Pyay Thar Village) and 2 locations in the Ayeyarwaddy River for arsenic, boron, barium, beryllium, cadmium, cobalt, chromium, copper, fluoride, iron, mercury, manganese, molybdenum, nickel, lead, antimony, selenium, thallium, uranium, vanadium, and zinc. Concentrations of arsenic, manganese, fluoride, iron, or uranium exceeded health-based reference values in most wells. In addition, any given well usually contained more than one toxic substance at unsafe concentrations. While water testing and well sharing could reduce health risks, none of the wells sampled provide water that is entirely safe with respect to inorganic toxic substances. It is imperative that users of these wells, and users of other wells that have not been tested for multiple inorganic toxic substances throughout the region, be informed of the need for drinking water testing and the health consequences of drinking water contaminated with inorganic toxic
Toxicity of Kalanchoe spp to chicks.

Science.gov (United States)

Williams, M C; Smith, M C

1984-03-01

Leaves of Kalanchoe daigremontiana, K tubiflora, K fedtschenkoi, K tomentosa, K tomentosa X K beharensis, and 4 cultivars of K blossfeldiana were tested for toxicity to 2-week-old Leghorn chicks. These species were analyzed for percentage of alkaloids, aliphatic nitro compounds, soluble oxalates, and nitrates and were examined qualitatively for cyanogenic glycosides. The solubility of the toxic principle in K daigremontiana was determined. Leaves of K daigremontiana, K tubiflora, and K fedtschenkoi were toxic to chicks at dosage levels of 8 to 12 mg/g of body weight. Toxic signs included depression, muscular incoordination, twitching and spiraling of the neck, tremors, convulsions, paralysis, and death. Kalanchoe tomentosa, K tomentosa X K beharensis, and 4 cultivars of K blossfeldiana were nontoxic at the highest dosage levels tested. Aliphatic nitro compounds and cyanogenic glycosides were not detected in any species. Alkaloids, nitrates, and soluble oxalates were present only in nontoxic concentrations. The toxic principle in K daigremontiana was soluble in 50%, 80%, and 100% ethanol, slightly soluble in water and acetone, and insoluble in benzene, chloroform, and ether.
Evaluation of Daphnia ambigua for Routine Aquatic Toxicity Testing at the Savannah River Site

International Nuclear Information System (INIS)

Specht, W.L.; Harmon, S.M.

1997-09-01

Short-term whole effluent toxicity testing, which is currently a requirement of the U.S. EPA's National Pollution Discharge Elimination System (NPDES), commonly uses the cladoceran species Ceriodaphnia dubia. Despite the advantages to using a common test species to model the toxic effects of effluents, it could be argued that toxicity test results would be more meaningful if a wider variety of test organisms were commonly used. One particular argument against C. dubia is that tests conducted with this species do not always reflect local, site-specific conditions. The careful selection and use of an indigenous test species would produce a more realistic model of local instream effects and would account for regional differences in water quality. Permitted effluent discharges from Savannah River Site (SRS), a government weapons facility operated by the U.S. Department of Energy, require toxicity testing with C. dubia. However, water quality in these receiving streams is markedly different (lower pH and hardness) from standard laboratory water used for the culturing and testing of C. dubia, and it has been shown that this receiving water presents varying degrees of toxicity to C. dubia. Based on these results, it is possible that toxic effects observed during an effluent study could be the result of test organism stress from the dilution water and not the effects of SRS effluents. Therefore, this study addressed the substitution of C. dubia with an indigenous cladoceran species, Daphnia ambigua for routine regulatory testing at SRS. Given the indigenous nature of this species, combined with the fact that it has been successfully cultured by other investigators, D. ambigua was ideal for consideration as a replacement for C. dubia, but further study of the overall success and sensitivity of laboratory-reared D. ambigua was required. This investigation determined that D. ambigua could be laboratory cultured with only minimal changes to established regulatory protocol and
Persuasion in Ambient Intelligence

NARCIS (Netherlands)

Kaptein, M.C.; Markopoulos, P.; Ruyter, de B.E.R.; Aarts, E.H.L.

2010-01-01

Although the field of persuasive technologies has lately attracted a lot of attention, only recently the notion of ambient persuasive technologies was introduced. Ambient persuasive technologies can be integrated into every aspect of life, and as such have greater persuasive power than the
Complex mixture-associated hormesis and toxicity: the case of leather tanning industry.

Science.gov (United States)

Pagano, Giovanni; Castello, Giuseppe; Gallo, Marialuisa; Borriello, Ilaria; Guida, Marco

2008-01-01

A series of studies investigated the toxicities of tannery-derived complex mixtures, i.e. vegetable tannin (VT) from Acacia sp. or phenol-based synthetic tannin (ST), and waste-water from tannin-based vs. chromium-based tanneries. Toxicity was evaluated by multiple bioassays including developmental defects and loss of fertilization rate in sea urchin embryos and sperm (Paracentrotus lividus and Sphaerechinus granularis), and algal growth inhibition (Dunaliella tertiolecta and Selenastrum capricornutum). Both VT and ST water extracts resulted in hormetic effects at concentrations ranging 0.1 to 0.3%, and toxicity at levels > or =1%, both in sea urchin embryo and sperm, and in algal growth bioassays. When comparing tannin-based tannery wastewater (TTW) vs. chromium-based tannery effluent (CTE), a hormesis to toxicity trend was observed for TTW both in terms of developmental and fertilization toxicity in sea urchins, and in algal growth inhibition, with hormetic effects at 0.1 to 0.2% TTW, and toxicity at TTW levels > or =1%. Unlike TTW, CTE showed a monotonic toxicity increase from the lowest tested level (0.1%) and CTE toxicity at higher levels was significantly more severe than TTW-induced toxicity. The results support the view that leather production utilizing tannins might be regarded as a more environmentally friendly procedure than chromium-based tanning process.
Toxicity identification evaluation of cosmetics industry wastewater.

Science.gov (United States)

de Melo, Elisa Dias; Mounteer, Ann H; Leão, Lucas Henrique de Souza; Bahia, Renata Cibele Barros; Campos, Izabella Maria Ferreira

2013-01-15

The cosmetics industry has shown steady growth in many developing countries over the past several years, yet little research exists on toxicity of wastewaters it generates. This study describes a toxicity identification evaluation conducted on wastewater from a small Brazilian hair care products manufacturing plant. Physicochemical and ecotoxicological analyses of three wastewater treatment plant inlet and outlet samples collected over a six month period revealed inefficient operation of the treatment system and thus treated wastewater organic matter, suspended solids and surfactants contents consistently exceeded discharge limits. Treated wastewater also presented high acute toxicity to Daphnia similis and chronic toxicity to Ceriodaphnia dubia and Pseudokirchneriella subcapitata. This toxicity was associated with suspended solids, volatile or sublatable and non-polar to moderately polar organic compounds that could be recovered in filtration and aeration residues. Seven surfactants used in the largest quantities in the production process were highly toxic to P. subcapitata and D. similis. These results indicated that surfactants, important production raw materials, are a probable source of toxicity, although other possible sources, such as fragrances, should not be discarded. Improved treatment plant operational control may reduce toxicity and lower impact of wastewater discharge to receiving waters. Copyright © 2012 Elsevier B.V. All rights reserved.
Race, deprivation, and immigrant isolation: The spatial demography of air-toxic clusters in the continental United States.

Science.gov (United States)

Liévanos, Raoul S

2015-11-01

This article contributes to environmental inequality outcomes research on the spatial and demographic factors associated with cumulative air-toxic health risks at multiple geographic scales across the United States. It employs a rigorous spatial cluster analysis of census tract-level 2005 estimated lifetime cancer risk (LCR) of ambient air-toxic emissions from stationary (e.g., facility) and mobile (e.g., vehicular) sources to locate spatial clusters of air-toxic LCR risk in the continental United States. It then tests intersectional environmental inequality hypotheses on the predictors of tract presence in air-toxic LCR clusters with tract-level principal component factor measures of economic deprivation by race and immigrant status. Logistic regression analyses show that net of controls, isolated Latino immigrant-economic deprivation is the strongest positive demographic predictor of tract presence in air-toxic LCR clusters, followed by black-economic deprivation and isolated Asian/Pacific Islander immigrant-economic deprivation. Findings suggest scholarly and practical implications for future research, advocacy, and policy. Copyright © 2015 Elsevier Inc. All rights reserved.
Toxicity of fluorescent tracers and their degradation byproducts

Directory of Open Access Journals (Sweden)

Philippe Gombert

2017-01-01

Full Text Available Tracer tests are frequently used to delineate catchment area of water supply springs in karstic zones. In the karstic chalk of Normandy, the main tracers used are fluorescent: uranine, sulforhodamine B, naphtionate, and Tinopal®. In this area, a statistical analysis shows that less than half of the injected tracers joins the monitored restitution points and enters the drinking water system where they undergo chlorination. Most of the injected tracers is absorbed in the rock matrix or is thrown out of the aquifer via karstic springs: then it can join superficial waters where it is degraded due to the sun and air action. The paper presents firstly the laboratory degradation of a first batch of fluorescent tracers in contact with chlorine, in order to simulate their passage through a water treatment system for human consumption. A second batch of the same tracers is subjected to agents of natural degradation: ultraviolet illumination, sunlight and air sparging. Most tracers is degraded, and toxicity and ecotoxicity tests (on rats, daphniae and algae are performed on degradation byproducts. These tests do not show any acute toxicity but a low to moderate ecotoxicity. In conclusion, the most used fluorescent tracers of the Normandy karstic chalk and their artificial and natural degradation byproducts do not exhibit significant toxicity to humans and the aquatic environment, at the concentrations generally noted at the restitution points.

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