WorldWideScience

Sample records for ambient water toxicity

  1. Applicability of ambient toxicity testing to national or regional water-quality assessment

    Science.gov (United States)

    Elder, John F.

    1990-01-01

    Comprehensive assessment of the quality of natural waters requires a multifaceted approach. Descriptions of existing conditions may be achieved by various kinds of chemical and hydrologic analyses, whereas information about the effects of such conditions on living organisms depends on biological monitoring. Toxicity testing is one type of biological monitoring that can be used to identify possible effects of toxic contaminants. Based on experimentation designed to monitor responses of organisms to environmental stresses, toxicity testing may have diverse purposes in water-quality assessments. These purposes may include identification of areas that warrant further study because of poor water quality or unusual ecological features, verification of other types of monitoring, or assessment of contaminant effects on aquatic communities. Toxicity-test results are most effective when used as a complement to chemical analyses, hydrologic measurements, and other biological monitoring. However, all toxicity-testing procedures have certain limitations that must be considered in developing the methodology and applications of toxicity testing in any large-scale water-quality-assessment program. A wide variety of toxicity-test methods have been developed to fulfill the needs of diverse applications. The methods differ primarily in the selections made relative to four characteristics: (1) test species, (2) endpoint (acute or chronic), (3) test-enclosure type, and (4) test substance (toxicant) that functions as the environmental stress. Toxicity-test approaches vary in their capacity to meet the needs of large-scale assessments of existing water quality. Ambient testing, whereby the test organism is exposed to naturally occurring substances that contain toxicant mixtures in an organic or inorganic matrix, is more likely to meet these needs than are procedures that call for exposure of the test organisms to known concentrations of a single toxicant. However, meaningful

  2. Clinch River - Environmental Restoration Program (CR-ERP) study, Ambient water toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Simbeck, D.J.

    1997-06-01

    Clinch River - Environmental Restoration Program (CR-ERP) personnel and Tennessee Valley Authority (TVA) personnel conducted a study during the week of January 25-February 1, 1994, as described in the Statement of Work (SOW) document. The organisms specified for testing were larval fathead minnows, Pimephales promelas, and the daphnid, Ceriodaphnia dubia. Surface water samples were collected by TVA Field Engineering personnel from Clinch River Mile 9.0, Poplar Creek Mile 1.0, and Poplar Creek Mile 2.9 on January 24, 26, and 28. Samples were partitioned (split) and provided to the CR-ERP and TVA toxicology laboratories for testing. Exposure of test organisms to these samples resulted in no toxicity (survival or growth) to fathead minnows; however, toxicity to daphnids (significantly reduced reproduction) was demonstrated in undiluted samples from Poplar Creek Mile 1.0 in testing conducted by TVA based on hypothesis testing of data. Point estimation (IC{sub 25}) analysis of the data, however, showed no toxicity in PCM 1.0 samples.

  3. Clinch River - Environmental Restoration Program (CR-ERP) study, ambient water toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Simbeck, D.J.

    1997-06-01

    Clinch River - Environmental Restoration Program (CR-ERP) personnel and Tennessee Valley Authority (TVA) personnel conducted a study during the week of April 14-21, 1994, as described in the Statement of Work (SOW) document. The organisms specified for testing were larval fathead minnows, Pimephales promelas, and the daphnid, Ceriodaphnia dubia. Surface water samples were collected by TVA Field Engineering personnel from Poplar Creek Mile 4.3, Poplar Creek Mile 5.1, and Poplar Creek Mile 6.0 on April 13, 15, and 18. Samples were partitioned (split) and provided to the CR-ERP and TVA toxicology laboratories for testing. Exposure of test organisms to these samples resulted in no toxicity (survival or growth) to daphnids in undiluted samples; however, toxicity to fathead minnows (significantly reduced survival) was demonstrated in undiluted samples from Poplar Creek Miles 4.3 and 6.0 in testing conducted by TVA based on hypothesis testing of data. Daphnid reproduction was significantly less than controls in 50 percent dilutions of samples from Poplar Creek Miles 4.3 and 6.0, while no toxicity to fathead minnows was shown in diluted (50 percent) samples.

  4. Clinch River - Environmental Restoration Program (CR-ERP) pilot study, ambient water toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Simbeck, D.J.

    1997-06-01

    Clinch River - Environmental Restoration Program (CR-ERP) personnel and Tennessee Valley Authority (TVA) personnel conducted a pilot study during the week of April 22-29, 1993, prior to initiation of CR-ERP Phase II Sampling and Analysis activities as described in the Statement of Work (SOW) document. The organisms specified for testing were larval fathead minnows, Pimephales promelas, and the daphnid, Ceriodaphnia dubia. Surface water samples were collected by TVA Field Engineering personnel from Clinch River Mile 9.0 and Poplar Creek Kilometer 1.6 on April 21, 23, and 26. Samples were split and provided to the CR-ERP and TVA toxicology laboratories for testing. Exposure of test organisms to these samples resulted in no toxicity (survival, growth, or reproduction) to either species in testing conducted by TVA.

  5. Clinch River - Environmental Restoration Program (CR-ERP) study, ambient water toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Russell, C.L.

    1997-06-01

    Clinch River - Environmental Restoration Program (CR-ERP) personnel and Tennessee Valley Authority (TVA) personnel conducted a study during the week of July 22-29, 1993, as described in the Statement of Work (SOW) document. The organisms specified for testing were larval fathead minnows, Pimephales promelas, and the daphnid, Ceriodaphnia dubia. Surface water samples were collected by TVA Field Engineering personnel from Clinch River Mile 19.0 and Mile 22.0 on July 21, 23, and 26. Samples were split and provided to the CR-ERP and TVA toxicology laboratories for testing. Exposure of test organisms to these samples resulted in no toxicity (survival, growth, or reproduction) to either species in testing conducted by TVA.

  6. Clinch River - Environmental Restoration Program (CR-ERP) Study, ambient water toxicity. Final report, October 21, 1993--October 28, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Simbeck, D.J.

    1997-06-01

    Clinch River - Environmental Restoration Program (CR-ERP) personnel and Tennessee Valley Authority (TVA) personnel conducted a study during the week of October 21-28, 1993, as described in the Statement of Work (SOW) document. The organisms specified for testing were larval fathead minnows, Pimephales promelas, and the daphnid, Ceriodaphnia dubia. Due to serious reproduction/embryo abortion problems with the TVA daphnid cultures, TVA conducted tests during this study period using only fathead minnows. A split sample test using daphnids only will be scheduled during 1994 as a substitute for this study period. Surface water samples were collected by TVA Field Engineering personnel from Poplar Creek Mile 2.9, Mile 4.3, and Mile 5.1 on October 20, 22, and 25. Samples were split and provided to the CR-ERP and TVA toxicology laboratories for testing. Exposure of test organisms to these samples resulted in no toxicity (survival or growth) in testing conducted by TVA.

  7. Static renewal tests using Pimephales promelas (fathead minnows) and Ceriodaphnia dubia (daphnids). Clinch River-Environmental Restoration Program (CR-ERP) study, ambient water toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Russell, C.L.

    1993-12-31

    Clinch River-Environmental Restoration Program (CR-ERP) personnel and Tennessee Valley Authority (TVA) personnel conducted a study during the week of July 22--29, 1993. The organisms specified for testing were larval fathead minnows, Pimephales promelas, and the daphnid, Ceriodaphnia dubia. Surface water samples were collected by TVA Field engineering personnel from Clinch River Mile 19.0 and Mile 22.0 on July 21, 23, and 26. Samples were split and provided to the CR-ERP and TVA toxicology laboratories for testing. Exposure of test organisms to these samples resulted in no toxicity (survival, growth, or reproduction) to either species in testing conducted by TVA. Attachments to this report include: Chain of custody forms -- originals; Toxicity test bench sheets and statistical analyses; and Reference toxicant test information.

  8. Static renewal tests using Pimephales promelas (fathead minnows) and Ceriodaphnia dubia (daphnids). Clinch River-Environmental Restoration Program (CR-ERP) pilot study, ambient water toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Simbeck, D.J.

    1993-12-31

    Clinch River-Environmental Restoration Program (CR-ERP) personnel and Tennessee Valley Authority (TVA) personnel conducted a pilot study during the week of April 22--29, 1993, prior to initiation of CR-ERP Phase 2 Sampling and Analysis activities. The organisms specified for testing were larval fathead minnows, Pimephales promelas, and the daphnid, Ceriodaphnia dubia. Surface water samples were collected by TVA Field Engineering personnel from Clinch River Mile 9.0 and Poplar Creek Kilometer 1.6 on April 21, 23, and 26. Samples were split and provided to the CR-ERP and TVA toxicology laboratories for testing. Exposure of test organisms to these samples resulted in no toxicity (survival, growth, or reproduction) to either species in testing conducted by TVA. Attachments to this report include: Chain of custody forms -- originals; Toxicity test bench sheets and statistical analyses; Reference toxicant test information; and Personnel training documentation.

  9. Static renewal tests using Pimephales promelas (fathead minnows). Clinch River-Environmental Restoration Program (CR-ERP) study, ambient water toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Simbeck, D.J.

    1993-12-31

    Clinch River-Environmental Restoration Program (CR-ERP) personnel and Tennessee Valley Authority (TVA) personnel conducted a study during the week of October 21--28, 1993. The organisms specified for testing were larval fathead minnows, Pimephales promelas, and the daphnid, Ceriodaphnia dubia. Due to serious reproduction/embryo abortion problems with the TVA daphnid cultures, TVA conducted tests during this study period using only fathead minnows. Surface water samples were collected by TVA Field Engineering personnel from Poplar Creek Mile 2.9, Mile 4.3, and Mile 5.1 on October 20, 22, and 25. Samples were split and provided to the CR-ERP and TVA toxicology laboratories for testing. Exposure of test organisms to these samples resulted in no toxicity (survival or growth) in testing conducted by TVA. Attachments to this report include: Chain of custody forms -- originals; Toxicity test bench sheets and statistical analyses; and Reference toxicant test information.

  10. Static renewal tests using Pimephales promelas (fathead minnows) and Ceriodaphnia dubia (daphnids). Clinch River-Environmental Restoration Program (CR-ERP) study, ambient water toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Simbeck, D.J.

    1994-12-31

    Clinch River-Environmental Restoration Program (CR-ERP) personnel and Tennessee Valley Authority (TVA) personnel conducted a study during the week of January 25--February 1, 1994. The organisms specified for testing were larval fathead minnows, Pimephales promelas, and the daphnid, Ceriodaphnia dubia. Surface water samples were collected from Clinch River Mile 9.0, Poplar Creek Mile 1.0, and Poplar Creek Mile 2.9 on January 24, 26, and 28. Samples were partitioned and provided to the CR-ERP and TVA toxicology laboratories for testing. Exposure of test organisms to these samples resulted in no toxicity (survival or growth) to fathead minnows; however, toxicity to daphnids was demonstrated in undiluted samples from Poplar Creek Mile 1.0 in testing conducted by TVA based on hypothesis testing of data. Point estimation (IC{sub 25}) analysis of the data, however, showed no toxicity in PCM 1.0 samples. Attachments to this report include: Chain of custody forms -- originals; Toxicity test bench sheets and statistical analyses; Meter calibrations; and Reference toxicant test information.

  11. Liquid Water Structure from Anomalous Density under Ambient Condition

    Institute of Scientific and Technical Information of China (English)

    SUN Qiang; ZHENG Hai-Fei

    2006-01-01

    @@ From discussion of the structure of liquid water, we deduce that water under ambient condition is mainly composed of ice Ih-like molecular clusters and clathrate-like molecular clusters. The water molecular clusters remain in a state of chemical equilibrium (reversible clustering reactions). This structural model can be demonstrated by quantitative study on anomalous density with increasing temperature at ambient pressure.

  12. 78 FR 52192 - Final Aquatic Life Ambient Water Quality Criteria For Ammonia-Freshwater 2013

    Science.gov (United States)

    2013-08-22

    ... AGENCY Final Aquatic Life Ambient Water Quality Criteria For Ammonia-- Freshwater 2013 AGENCY... from effects of ammonia in freshwater (EPA 822-R-13-001). The final criteria incorporate the latest scientific knowledge on the toxicity of ammonia to freshwater aquatic life. On December 30, 2009,...

  13. Ocean Ambient Noise Studies for Shallow and Deep Water Environments

    Science.gov (United States)

    2014-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Ocean Ambient Noise Studies for Shallow and Deep Water...Siderius.php LONG-TERM GOALS The objective of this research is to study the ocean ambient noise field by means of new physics-based processing... ambient -noise field using a vertical line array has been developed by Harrison and Simons [Harrison, 2002]. The advantages of passive bottom-survey

  14. Deep Water Ambient Noise and Mode Processing

    Science.gov (United States)

    2014-09-30

    to this award. The Code 321 project is titled Random Matrix Theory ( RMT ) for Adaptive Beamforming (N00014-12-1-0048). The RMT project is using some...of the Philippine Sea data for testing adaptive beamformers. The RMT analysis focuses on sonar signal processing issues, rather than propagation...ambient noise, or tomography. The project described in this report may benefit from the results of the RMT project, but there is no direct overlap in

  15. Water Loss Under Hot Ambient Temperatures

    Directory of Open Access Journals (Sweden)

    S. K. Basu

    1978-07-01

    Full Text Available Male 4 rates were ambient temperature (40 degree,42 degree, and 44 degree calcius for different durations of time upto a maximum of 3 hours. It was observed that there was a rapid loss in body weight accompanied by considerable increase in body temperature of the animals during the first hour of exposure. Thereafter the rate of body weight loss and increase in body temperature were slow till the end of observation period. Intolerance to heat appears to be more correlated with critical body temperature rather than the extent of dehydration.

  16. 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

  17. 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

  18. EVALUATION OF THE PULMONARY TOXICITY OF AMBIENT PARTICULATE MATTER FROM CAMP VICTORY, IRAQ

    OpenAIRE

    Porter, K. L.; Green, F. H. Y.; Harley, R. A.; Vallyathan, V; Castranova, V.; Waldron, N. R.; Leonard, S.S.; Nelson, D E; Lewis, J. A.; Jackson, D A

    2015-01-01

    Anecdotal reports in the press and epidemiological studies suggest that deployment to Iraq and Afghanistan may be associated with respiratory diseases and symptoms in U.S. military personnel and veterans. Exposures during military operations were complex, but virtually all service members were exposed to high levels of respirable, geogenic dust. Inhalation of other dusts has been shown to be associated with adverse health effects, but the pulmonary toxicity of ambient dust from Iraq has not b...

  19. Risk of leukemia in relation to exposure to ambient air toxics in pregnancy and early childhood.

    Science.gov (United States)

    Heck, Julia E; Park, Andrew S; Qiu, Jiaheng; Cockburn, Myles; Ritz, Beate

    2014-07-01

    There are few established causes of leukemia, the most common type of cancer in children. Studies in adults suggest a role for specific environmental agents, but little is known about any effect from exposures in pregnancy to toxics in ambient air. In our case-control study, we ascertained 69 cases of acute lymphoblastic leukemia (ALL) and 46 cases of acute myeloid leukemia (AML) from California Cancer Registry records of children leukemia associated with one interquartile range increase in air toxic exposure. Risk of ALL was elevated with 3(rd) trimester exposure to polycyclic aromatic hydrocarbons (OR=1.16, 95% CI 1.04, 1.29), arsenic (OR=1.33, 95% CI 1.02, 1.73), benzene (OR=1.50, 95% CI 1.08, 2.09), and three other toxics related to fuel combustion. Risk of AML was increased with 3rd trimester exposure to chloroform (OR=1.30, 95% CI 1.00, 1.69), benzene (1.75, 95% CI 1.04, 2.93), and two other traffic-related toxics. During the child's first year, exposure to butadiene, ortho-xylene, and toluene increased risk for AML and exposure to selenium increased risk for ALL. Benzene is an established cause of leukemia in adults; this study supports that ambient exposures to this and other chemicals in pregnancy and early life may also increase leukemia risk in children.

  20. A system for the determination of trace-level polar and non-polar toxic organic compounds in ambient air

    Energy Technology Data Exchange (ETDEWEB)

    Tipler, A.; Dang, R.; Hoberecht, H. [Perkin Elmer Corp., Norwalk, CT (United States). Fresh Aire Lab.

    1994-12-31

    A gas chromatographic system is described for the determination of toxic organic compounds in ambient air. These compounds include all those specified within the US EPA Compendium Method TO14 and some polar additional analytes under consideration for the proposed TO15 Method. The system supports both on-line and off-line (passivated canisters and adsorption tubes) methods for sampling air--providing a fully automated analysis. A key feature of the system is that liquid cryogen is not required for either the analyte preconcentration or the subsequent chromatographic separation. Water management is achieved by dry-purging an adsorbent trap upon which the sample analytes have been retained. The performance of the system is demonstrated with conventional detection systems (electron capture and flame ionization) and with a mass spectrometer.

  1. ambiental

    Directory of Open Access Journals (Sweden)

    Roque Leal Salcedo

    2008-01-01

    Full Text Available El derecho internacional ambiental es un conocimiento de carácter transversal, que entre otras consideraciones refleja las preocupaciones de la sociedad por la implementación de un modelo de desarrollo sustentable para el respeto a las reglas del medio natural que garantizan la integridad y renovación de los sistemas naturales. El presente artículo enfoca esta visión a través del análisis de material documental revisado, entre ellos tratados internacionales que permiten distinguir el desarrollo del derecho internacional ambiental y el papel de Organización de las Naciones Unidas (ONU, en el propósito común del derecho individual y colectivo de disfrutar de una vida, un ambiente seguro, sano y ecológicamente equilibrado. En función a estas disertaciones las consideraciones finales exponen parte de la visión que ha estructurado la ONU y que representan un aporte considerable en el fomento de la conciencia mundial sobre la necesidad de establecer vínculos entre las naciones para el continuo desarrollo de esta rama del derecho.

  2. Water Power Calculator Temperature and Analog Input/Output Module Ambient Temperature Testing

    Energy Technology Data Exchange (ETDEWEB)

    Mark D. McKay

    2011-02-01

    Water Power Calculator Temperature and Analog input/output Module Ambient Temperature Testing A series of three ambient temperature tests were conducted for the Water Power Calculator development using the INL Calibration Laboratory’s Tenney Environmental Chamber. The ambient temperature test results demonstrate that the Moore Industries Temperature Input Modules, Analog Input Module and Analog Output Module, ambient temperature response meet or exceed the manufactures specifications

  3. Sinclair and Dyes Inlets Toxicity Study: An Assessment of Copper Bioavailability and Toxicity in Surface Waters Adjacent to the Puget Sound Naval Shipyard and Intermediate Maintenance Facility

    Science.gov (United States)

    2009-12-01

    E. Arias, and B.L. Swope of the Space and Naval Warfare Systems Center Pacific Environmental Sciences Branch, San Diego, California; J. Christian ...galloprovincialis) embryos in 48-hour embryo -larval development tests using protocols recommended by the U.S. Environmental Protection Agency (EPA) for...calculating water-effect ratios (WER). The ambient water samples from Sinclair and Dyes Inlets were not toxic to mussel embryos during the tests, and had

  4. 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

    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...... 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...

  5. Drinking water toxicity study of the environmental contaminant--Bromate.

    Science.gov (United States)

    Dongmei, Liu; Zhiwei, Wang; Qi, Zhu; Fuyi, Cui; Yujuan, Shan; Xiaodong, Liu

    2015-12-01

    Bromate is a byproduct of water disinfection that is produced when waters contain bromide treated with ozone. To investigate the level of the toxicity of bromate and find the most sensitive indicators in a short time, a series of toxicological assessments were conducted including the acute toxicity, cumulative toxicity, genetic toxicity and subacute toxicity of bromate (using Potassium Bromate to represent bromate). The LD50 of orally administered Potassium Bromate was 215 mg/kg in Wistar rats and 464 mg/kg in ICR mice. The cumulative toxicity of Potassium Bromate was not obvious. The Ames test, mouse bone marrow cell micronucleus test and mouse sperm abnormality test did not indicate mutagenicity. The results of the subacute study did not exhibit significant differences in most of the parameters, except the white blood cell count, which was significantly decreased in male rats. In addition, Potassium Bromate influenced the albumin, creatinine, total cholesterol, triglycerides and glucose levels in male rats to various extents. A thorough analysis of the above tests clearly demonstrates that bromate has toxicity, not obvious cumulative toxicity and the white blood cell count can be used as an indicator to reflect the toxicity of bromate and investigate bromate's toxic mechanism.

  6. Single and double long pulse laser ablation of aluminum induced in air and water ambient

    Science.gov (United States)

    Akbari Jafarabadi, Marzieh; Mahdieh, Mohammad Hossein

    2017-02-01

    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.

  7. Occurrence and Concentrations of Toxic VOCs in the Ambient Air of Gumi, an Electronics-Industrial City in Korea

    Directory of Open Access Journals (Sweden)

    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

  8. Toxicity of Ambient Particulate Matter IV: Acute toxicity study in pulmonary hypertensive rats after exposure to model compounds for the secondary aerosol fraction of PM10 - ammonium bisulfate, ferrosulfate and nitrate

    NARCIS (Netherlands)

    Cassee FR; Boere AJF; Fokkens PHB; Dormans JAMA; Bree L van; Rombout PJA; LEO; LPI

    1999-01-01

    This (4th) report on the toxicity of ambient particulate matter (PM) presents effects of the model compounds for PM in ambient air - ammonium bisulfate, ammonium ferrosulfate and ammonium nitrate - on healthy rats and rats with monocrotaline-induced pulmonary hypertension (PH). The objective was bas

  9. Manganese toxicity to tropical freshwater species in low hardness water.

    Science.gov (United States)

    Harford, Andrew J; Mooney, Thomas J; Trenfield, Melanie A; van Dam, Rick A

    2015-12-01

    Elevated manganese (Mn) is a common contaminant issue for mine water discharges, and previous studies have reported that its toxicity is ameliorated by H(+), Ca(2+), and Mg(2+) ions. In the present study, the toxicity of Mn was assessed in a high risk scenario, that is, the slightly acidic, soft waters of Magela Creek, Kakadu National Park, Northern Territory, Australia. Toxicity estimates were derived for 6 tropical freshwater species (Chlorella sp., Lemna aequinoctialis, Amerianna cumingi, Moinodaphnia macleayi, Hydra viridissima, and Mogurnda mogurnda). Low effect chronic inhibition concentration (IC10) and acute lethal concentration (LC05) values ranged between 140 μg L(-1) and 80,000 μg L(-1), with 3 of the species tested (M. macleayi, A. cumingi, and H. viridissima) being more sensitive to Mn than all but 1 species in the international literature (Hyalella azteca). A loss of Mn was observed on the final day for 2 of the H. viridissima toxicity tests, which may be a result of the complex speciation of Mn and biological oxidation. International data from toxicity tests conducted in natural water with a similar physicochemistry to Magela Creek water were combined with the present study's data to increase the sample size to produce a more reliable species sensitivity distribution. A 99% protection guideline value of 73 μg L(-1) (33-466 μg L(-1)) was derived; the low value of this guideline value reflects the higher toxicity of Mn in slightly acidic soft waters.

  10. 76 FR 67437 - Draft Aquatic Life Ambient Water Quality Criteria for Carbaryl-2011

    Science.gov (United States)

    2011-11-01

    ... AGENCY Draft Aquatic Life Ambient Water Quality Criteria for Carbaryl-- 2011 AGENCY: Environmental...) of the Clean Water Act (CWA), the Environmental Protection Agency (EPA) is announcing the availability of draft national recommended water quality criteria for the protection of aquatic life...

  11. Benthic invertebrate bioassays with toxic sediment and pore water

    Science.gov (United States)

    Giesy, John P.; Rosiu, Cornell J.; Graney, Robert L.; Henry, Mary G.

    1990-01-01

    The relative sensitivities of bioassays to determine the toxicity of sediments were investigated and three methods of making the sample dilutions required to generate dose-response relationships were compared. The assays studied were: (a) Microtox®, a 15-min assay ofPhotobacterium phosphoreum bioluminescence inhibition by pore water; (b) 48-h Daphnia magnalethality test in pore water; (c) 10-d subchronic assay of lethality to and reduction of weight gain by Chironomus tentans performed in either whole sediment or pore water; (d) 168-h acute lethality assay of Hexagenia limbata in either whole sediment or pore water. The three methods of diluting sediments were: (a) extracting pore water from the toxic location and dilution with pore water from the control station; (b) diluting whole sediment from the toxic location with control whole sediment from a reference location, then extracting pore water; and (c) diluting toxic, whole sediment with whole sediment from a reference location, then using the whole sediment in bioassays. Based on lethality, H. limbata was the most sensitive organism to the toxicity of Detroit River sediment. Lethality of D. magna in pore water was similar to that of H. limbata in whole sediment and can be used to predict effects of whole sediment toxicity to H. limbata. The concentration required to cause a 50% reduction in C. tentans growth (10-d EC50) was approximately that which caused 50% lethality of D. magna (48-h LC50) and was similar to the toxicity that restricts benthic invertebrate colonization of contaminated sediments. While the three dilution techniques gave similar results with some assays, they gave very different results in other assays. The dose-response relationships determined by the three dilution techniques would be expected to vary with sediment, toxicant and bioassay type, and the dose-response relationship derived from each technique needs to be interpreted accordingly.

  12. Surface desorption atmospheric pressure chemical ionization mass spectrometry for direct ambient sample analysis without toxic chemical contamination.

    Science.gov (United States)

    Chen, Huanwen; Zheng, Jian; Zhang, Xie; Luo, Mingbiao; Wang, Zhichang; Qiao, Xiaolin

    2007-08-01

    Ambient mass spectrometry, pioneered with desorption electrospray ionization (DESI) technique, is of increasing interest in recent years. In this study, a corona discharge ionization source is adapted for direct surface desorption chemical ionization of compounds on various surfaces at atmospheric pressure. Ambient air, with about 60% relative humidity, is used as a reagent to generate primary ions such as H(3)O(+), which is then directed to impact the sample surface for desorption and ionization. Under experimental conditions, protonated or deprotonated molecules of analytes present on various samples are observed using positive or negative corona discharge. Fast detection of trace amounts of analytes present in pharmaceutical preparations, viz foods, skins and clothes has been demonstrated without any sample pretreatment. Taking the advantage of the gasless setup, powder samples such as amino acids and mixtures of pharmaceutical preparations are rapidly analyzed. Impurities such as sudan dyes in tomato sauce are detected semiquantitatively. Molecular markers (e.g. putrescine) for meat spoilage are successfully identified from an artificially spoiled fish sample. Chemical warfare agent stimulants, explosives and herbicides are directly detected from the skin samples and clothing exposed to these compounds. This provides a detection limit of sub-pg (S/N > or = 3) range in MS2. Metabolites and consumed chemicals such as glucose are detected successfully from human skins. Conclusively, surface desorption atmospheric pressure chemical ionization (DAPCI) mass spectrometry, without toxic chemical contamination, detects various compounds in complex matrices, showing promising applications for analyses of human related samples.

  13. Interaction effects of ambient UV radiation and nutrient limitation on the toxic cyanobacterium Nodularia spumigena.

    Science.gov (United States)

    Mohlin, Malin; Wulff, Angela

    2009-05-01

    Nodularia spumigena is one of the dominating species during the extensive cyanobacterial blooms in the Baltic Sea. The blooms coincide with strong light, stable stratification, low ratios of dissolved inorganic nitrogen, and dissolved inorganic phosphorus. The ability of nitrogen fixation, a high tolerance to phosphorus starvation, and different photo-protective strategies (production of mycosporine-like amino acids, MAAs) may give N. spumigena a competitive advantage over other phytoplankton during the blooms. To elucidate the interactive effects of ambient UV radiation and nutrient limitation on the performance of N. spumigena, an outdoor experiment was designed. Two radiation treatments photosynthetic active radiation (PAR) and PAR +UV-A + UV-B (PAB) and three nutrient treatments were established: nutrient replete (NP), nitrogen limited (-N), and phosphorus limited (-P). Variables measured were specific growth rate, heterocyst frequency, cell volume, cell concentrations of MAAs, photosynthetic pigments, particulate carbon (POC), particulate nitrogen (PON), and particulate phosphorus (POP). Ratios of particulate organic matter were calculated: POC/PON, POC/POP, and PON/POP. There was no interactive effect between radiation and nutrient limitation on the specific growth rate of N. spumigena, but there was an overall effect of phosphorus limitation on the variables measured. Interaction effects were observed for some variables; cell size (larger cells in -P PAB compared to other treatments) and the carotenoid canthaxanthin (highest concentration in -N PAR). In addition, significantly less POC and PON (mol cell(-1)) were found in -P PAR compared to -P PAB, and the opposite radiation effect was observed in -N. Our study shows that despite interactive effects on some of the variables studied, N. spumigena tolerate high ambient UVR also under nutrient limiting conditions and maintain positive growth rate even under severe phosphorus limitation.

  14. Benzene toxicity of the occurrence of benzene in the ambient air of the Houston area

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Y.C.

    1980-01-01

    This study was conducted by either literature review or actual field survey. Results are summarized as follows: (1) long-term occupational exposure of workers to benzene vapor at levels of 3 to 7 ppM, 2 to 3 ppM and 1.6 ppM may result in a decreased level of leucocyte alkaline phosphates, an increased incidence of chromosome aberrations and an increased level of ALA in erythrocytes, respectively; (2) benzene is capable of causing fetotoxic effects in animals at levels as low as 10 ppM by volume; (3) exposure of animals to or less than 1 ppM benzene vapor may result in leucopenia, an inverse ratio of muscle antagonist chronaxy and a decreased level of ascorbic acid in fetus's and mother's liver as well as whole embryo; (4) benzene is causally associated with the increased incidence of pancytopenia, including unicytopenia, bicytopenia and aplastic anemia, and chromosome aberrations in occupational exposure population, and at best benzene must also be considered as a leukemogen; (5) since it can be emitted into the atmosphere from both man-made and natural sources, benzene in some concentrations is presented everywhere in the various compartments of the environment; (6) the findings of the emission of benzene from certain natural sources indicate that reducing benzene to a zero-level of exposure is theoretically impossible; (7) the annual average of benzene concentration detected in the Houston ambient air is 2.50 ppB, which is about 2.4 times higher than the nation-wide annual average exposure level and may have some health implications to the general public; and (8) in the Houston area, stationary sources are more important than mobile sources in contributing to benzene in the ambient air.

  15. Contribution of water-soluble and insoluble components and their hydrophobic/hydrophilic subfractions to the reactive oxygen species-generating potential of fine ambient aerosols.

    Science.gov (United States)

    Verma, Vishal; Rico-Martinez, Roberto; Kotra, Neel; King, Laura; Liu, Jiumeng; Snell, Terry W; Weber, Rodney J

    2012-10-16

    Relative contributions of water- and methanol-soluble compounds and their hydrophobic/hydrophilic subfractions to the ROS (reactive oxygen species)-generating potential of ambient fine aerosols (D(p) Hydrophobic and hydrophilic fractions were then subsequently segregated via a C-18 solid phase extraction column. The DTT assay response was significantly higher for the methanol extract, and for both extracts a substantial fraction of PM oxidative potential was associated with the hydrophobic compounds as evident from a substantial attenuation in DTT response after passing PM extracts through the C-18 column (64% for water and 83% for methanol extract; both median values). The DTT activities of water and methanol extracts were correlated with the water-soluble (R = 0.86) and water-insoluble organic carbon (R = 0.94) contents of the PM, respectively. Brown carbon (BrC), which predominantly represents the hydrophobic organic fraction (referred to as humic-like substances, HULIS), was also correlated with DTT activity in both the water (R = 0.78) and methanol extracts (R = 0.83). Oxidative potential was not correlated with any metals measured in the extracts. These findings suggest that the hydrophobic components of both water-soluble and insoluble organic aerosols substantially contribute to the oxidative properties of ambient PM. Further investigation of these hydrophobic organic compounds could help identify sources of a significant fraction of ambient aerosol toxicity.

  16. 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...

  17. Concentrations of toxic heavy metals in ambient particulate matter in an industrial area of northeastern China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This paper investigates concentrations of various heavy metals in ambient particulate matter(PM)and provide evidence for prevention from air pollution.The concentrations of heavy metal components in the PM were determined by inductively coupled plasma/Mass spectrometry(ICP/MS)from September 2000 to August 2002 in a northeast industrial city in China.Concentrations of Cd,Mn,Pb,Ni,Cr and As in the PM were 9.3,461.9,588.7,69.5,205.7 and 57.4 ng/m3 in the industrial area,and 5.7,245.5,305.0,31.4,58.8 and 32.5 ng/m3 in the main road,respectively.Concentrations of these heavy metals except Cd were significantly higher in the industrial area and main road than those in the suburban area(P<0.05 or P<0.01).The change curves of the six heavy metal concentrations show their concentrations increased in the winter and spring,but decreased in the summer and autumn.The results indicate that concentrations of the metals in the PM are relatively high in the indu.strial area and main road.

  18. FOR SELECTED ORGANIC MICROPOLLUTANTS ELIMINATION AND CHANGE OF WATER TOXICITY

    Directory of Open Access Journals (Sweden)

    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.

  19. Oxidation of parenteral lipid emulsion by ambient and phototherapy lights: potential toxicity of routine parenteral feeding.

    Science.gov (United States)

    Neuzil, J; Darlow, B A; Inder, T E; Sluis, K B; Winterbourn, C C; Stocker, R

    1995-05-01

    Vitamin E can be a prooxidant in isolated lipoprotein suspensions. Because lipid emulsions used in parenteral nutrition are lipoprotein-like suspensions rich in polyunsaturated fatty acids and vitamin E, we hypothesized that vitamin E may act as a prooxidant in lipid emulsions, as it is in lipoprotein suspensions. We therefore exposed an intravenously administered lipid emulsion (Intralipid) to a single spotlight commonly used in the treatment of neonatal jaundice, and measured the formation of triglyceride hydroperoxides by using high-performance liquid chromatography with postcolumn chemiluminescence detection. Concentrations of these hydroperoxides in different batches of fresh intralipid were usually approximately 10 mumol/L but increased up to 60 times after exposure to phototherapy light for a period of 24 hours, even though significant amounts of vitamin E were present at the end of the exposure. Triglyceride hydroperoxides were formed during phototherapy light exposure whether the intralipid was in plastic tubing used routinely for infusion or in glass containers. Ambient light also caused significant peroxidation of the formula lipids, although to a much lesser extent than observed with phototherapy light. For infants in the neonatal intensive care unit who were receiving intralipid but not phototherapy, solutions being infused at the end of 24 hours contained a mean of 40 mumol/L hydroperoxides. For infants receiving phototherapy, the mean was 97 mumol/L. Phototherapy light-induced formation of triglyceride hydroperoxides was prevented by covering the intralipid with aluminum foil or supplementation with sodium ascorbate before light exposure. We conclude that intralipid is highly susceptible to oxidation and that elevated levels of oxidized lipids can be formed during its clinical use, especially when intralipid infusion is combined with phototherapy. Because lipid hydroperoxides are cytotoxic and can cause adverse effects, inadvertent infusion of rancid

  20. Comparing the effectiveness of chronic water column tests with the crustaceans Hyalella azteca (order: Amphipoda) and Ceriodaphnia dubia (order: Cladocera) in detecting toxicity of current-use insecticides.

    Science.gov (United States)

    Deanovic, Linda A; Markiewicz, Dan; Stillway, Marie; Fong, Stephanie; Werner, Inge

    2013-03-01

    Standard U.S. Environmental Protection Agency laboratory tests are used to monitor water column toxicity in U.S. surface waters. The water flea Ceriodaphnia dubia is among the most sensitive test species for detecting insecticide toxicity in freshwater environments.Its usefulness is limited, however, when water conductivity exceeds 2,000 µS/cm (approximately 1 ppt salinity) and test effectiveness is insufficient. Water column toxicity tests using the euryhaline amphipod Hyalella azteca could complement C. dubia tests; however, standard chronic protocols do not exist. The present study compares the effectiveness of two water column toxicity tests in detecting the toxicity of two organophosphate (OP) and two pyrethroid insecticides: the short-term chronic C. dubia test, which measures mortality and fecundity, and a 10-d H. azteca test, which measures mortality and growth. Sensitivity was evaluated by comparing effect data, and end point variability was evaluated by comparing minimum significant differences. Tests were performed in synthetic water and filtered ambient water to quantify the influence of water matrix on effect concentrations. The H. azteca test detected pyrethroid toxicity far more effectively, while the C. dubia test was more sensitive to OPs. Among endpoints, H. azteca mortality was most robust. The results demonstrate that the H. azteca test is preferable when conductivity of water samples is 2,000 to 10,000 µS/cm or if contaminants of concern include pyrethroid insecticides.

  1. Integral toxicity test of sea waters by an algal biosensor.

    Science.gov (United States)

    Tonnina, Daniele; Campanella, Luigi; Sammartino, Maria Pia; Visco, Giovanni

    2002-04-01

    An integral toxicity test, based on an algal biosensor and suitable to be used in sea water, is presented. The biosensor was designed and built by coupling a Clark oxygen electrode as transducer and the marine alga Spirulina subsalsa as biological mediator; it constitutes the "core" in a lab-scale prototype of a flow apparatus suitable to continuously monitor, in sea water, the photosynthetic activity of the alga and, from its variation, the marine pollution from the toxicological point of view. Inorganic pollutants (heavy metals) were tested in previous researches while organic ones (chlorophenols, pesticides and surfactants) are the object of the present paper.

  2. Monitoring acute and chronic water column toxicity in the Northern Sacramento-San Joaquin Estuary, California, USA, using the euryhaline amphipod, Hyalella azteca: 2006 to 2007.

    Science.gov (United States)

    Werner, Inge; Deanovic, Linda A; Markiewicz, Dan; Khamphanh, Manisay; Reece, Charles K; Stillway, Marie; Reece, Charissa

    2010-10-01

    After the significant population decline of several pelagic fish species in the Northern Sacramento-San Joaquin (SSJ) Estuary (CA, USA) in 2002, a study was performed to monitor water column toxicity using the amphipod Hyalella azteca. From January 1, 2006 to December 31, 2007, water samples were collected biweekly from 15 to 16 sites located in large delta channels and main-stem rivers, selected based on prevalent distribution patterns of fish species of concern. Ten-day laboratory tests with H. azteca survival and relative growth as toxicity endpoints were conducted. The enzyme inhibitor piperonyl butoxide ([PBO], 25 µg/L) was added to synergize or antagonize pyrethroid or organophosphate (OP) insecticide toxicity, respectively. Significant amphipod mortality was observed in 5.6% of ambient samples. Addition of PBO significantly changed survival or growth in 1.1% and 10.1% of ambient samples, respectively. Sites in the Lower Sacramento River had the largest number of acutely toxic samples, high occurrence of PBO effects on amphipod growth (along with sites in the South Delta), and the highest total ammonia/ammonium concentrations (0.28 ± 0.15 mg/L). Ammonia/ammonium, or contaminants occurring in mixture with these, likely contributed to the observed toxicity. Pyrethroid insecticides were detected at potentially toxic concentrations. Overall, results of this study identified specific areas and contaminants of concern and showed that water in the Northern SSJ Estuary was at times acutely toxic to sensitive invertebrates.

  3. The combined effects of physicochemical properties of size-fractionated ambient particulate matter on in vitro toxicity in human A549 lung epithelial cells

    Directory of Open Access Journals (Sweden)

    Umme S. Akhtar

    2014-01-01

    Full Text Available Epidemiological and toxicological studies have suggested that the health effects associated with exposure to particulate matter (PM are related to the different physicochemical properties of PM. These effects occur through the initiation of differential cellular responses including: the induction of antioxidant defenses, proinflammatory responses, and ultimately cell death. The main objective of this study was to investigate the effects of size-fractionated ambient PM on epithelial cells in relation to their physicochemical properties. Concentrated ambient PM was collected on filters for three size fractions: coarse (aerodynamic diameter [AD] 2.5–10 μm, fine (0.15–2.5 μm, and quasi-ultrafine (<0.2 μm, near a busy street in Toronto, Ontario, Canada. Filters were extracted and analyzed for chemical composition and redox activity. Chemical analyses showed that the coarse, fine, and quasi-ultrafine particles were comprised primarily of metals, water-soluble species, and organic compounds, respectively. The highest redox activity was observed for fine PM. After exposure of A549 cells to PM (10–100 μg/ml for 4 h, activation of antioxidant, proinflammatory and cytotoxic responses were assessed by determining the expression of heme oxygenase (HMOX-1, mRNA, interleukin-8 (IL-8, mRNA, and metabolic activity of the cells, respectively. All three size fractions induced mass-dependent antioxidant, proinflammatory, and cytotoxic responses to different degrees. Quasi-ultrafine PM caused significant induction of HMOX-1 at the lowest exposure dose. Correlation analyses with chemical components suggested that the biological responses correlated mainly with transition metals and organic compounds for coarse and fine PM and with organic compounds for quasi-ultrafine PM. Overall, the observed biological responses appeared to be related to the combined effects of size and chemical composition and thus both of these physicochemical properties should be

  4. 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.

  5. Water adsorption on alpha-Fe2O3(0001) at near ambient conditions

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Susumu; Kendelewicz, Tom; Newberg, John T.; Ketteler, Guido; Starr, David E.; Mysak, Erin R.; Andersson, Klas J.; Ogasawara, Hirohito; Bluhm, Henrik; Salmeron, Miquel; Brown Jr., Gordon E.; Nilsson, Anders

    2009-11-23

    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) {<=} 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 I ML at {approx} 15% RH and increases to 1.5 ML at 34% RH.

  6. APL-UW Deep Water Propagation: Philippine Sea Signal Physics and North Pacific Ambient Noise and NPANL Support

    Science.gov (United States)

    2014-09-30

    APL-UW Deep Water Propagation: Philippine Sea Signal Physics and North Pacific Ambient Noise and NPANL Support Rex K. Andrew Principal...signals evolve during propagation through a dynamically-varying deep ocean, and how the oceanic ambient noise field varies throughout deep ocean...specifically the Philippine Sea. The second objective is to continue an 18-year long experiment utilizing the North Pacific Ambient Noise Laboratory to

  7. 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.

  8. Function of Serum Complement in Drinking Water Arsenic Toxicity

    Directory of Open Access Journals (Sweden)

    Laila N. Islam

    2012-01-01

    Full Text Available Serum complement function was evaluated in 125 affected subjects suffering from drinking water arsenic toxicity. Their mean duration of exposure was 7.4±5.3 yrs, and the levels of arsenic in drinking water and urine samples were 216±211 and 223±302 μg/L, respectively. The mean bactericidal activity of complement from the arsenic patients was 92% and that in the unexposed controls was 99% (P<0.01, but heat-inactivated serum showed slightly elevated activity than in controls. In patients, the mean complement C3 was 1.56 g/L, and C4 was 0.29 g/L compared to 1.68 g/L and 0.25 g/L, respectively, in the controls. The mean IgG in the arsenic patients was 24.3 g/L that was highly significantly elevated (P<0.001. Arsenic patients showed a significant direct correlation between C3 and bactericidal activity (P=0.014. Elevated levels of C4 indicated underutilization and possibly impaired activity of the classical complement pathway. We conclude reduced function of serum complement in drinking water arsenic toxicity.

  9. Effect of elevated ambient CO2 concentration on water use efficiency of Pinus sylvestriformis

    Institute of Scientific and Technical Information of China (English)

    Han Shijie; Zhang Junhui; Wang Chenrui; Zou Chunjing; Zhou Yumei; Wang Xiaochun

    1999-01-01

    Pinus sylvestriformis is an important species as an indicator of global climate changes in Changbai Mountain, China. The water use efficiency (WUE) of this species ( 11-year old ) was studied on response to elevated CO2 concentration at 500± 100 μL· L-1 by directly injecting CO2 into the canopy under natural condition in 1998-1999. The results showed that the elevated CO2 concentration reduced averagely stomatal opening, stomatal conductance and stomatal density to 78%, 80% and 87% respectively, as compared to normal ambient. The elevated CO2 reduced the transpiration and enhances the water use efficiency (WUE) of plant.

  10. Dynamic Adsorptive Removal of Toxic Chemicals for Purification of Water

    Directory of Open Access Journals (Sweden)

    Amit Saxena

    2005-04-01

    Full Text Available To determine the efficiency of carbon column for the removal of toxic chemicals from water, the adsorption of phenol in concentration range from 0.600 glt to 1.475 gll was studied on activecarbon of 80 CTC grade, 12 X 30 BSS particle size, 1280 m2/g surface area, and of coconut shell origin, under dynamic conditions at space velocity from 0.318 min-' to 4.24 min-' at 25 'C. The carbon column of 100 cm length and 2 cm diameter was found to be removing phenol from the aqueous solution of concentration 1.475 gll up to 84 min at 0.678 min-' space velocity at 5.0 ppm phenol breakthrough concentration. However, no phenol was observed in carbon-treated water after 80 min. The service life of carbon column (100 cm lengthX25 cm diameter was assessed through the water purification system developed at the Defence Laboratory, Jodhpur and was determined to be 4.095 days with twoas factor of safety for 10 ppm initial concentration of phenol at 0.678 min-' space velocity (corresponding to water flow rate. Effects of carbon bed length, water flow rate, and the phenol concentration were also studied.

  11. Alleviation of Zn toxicity by low water availability.

    Science.gov (United States)

    Disante, Karen B; Cortina, Jordi; Vilagrosa, Alberto; Fuentes, David; Hernández, Encarni I; Ljung, Karin

    2014-03-01

    Heavy metal contamination and drought are expected to increase in large areas worldwide. However, their combined effect on plant performance has been scantly analyzed. This study examines the effect of Zn supply at different water availabilities on morpho-physiological traits of Quercus suber L. in order to analyze the combined effects of both stresses. Seedlings were treated with four levels of zinc from 3 to 150 µM and exposed to low watering (LW) or high watering (HW) frequency in hydroponic culture, using a growth chamber. Under both watering regimes, Zn concentration in leaves and roots increased with Zn increment in nutrient solution. Nevertheless, at the highest Zn doses, Zn tissue concentrations were almost twice in HW than in LW seedlings. Functional traits as leaf photosynthetic rate and root hydraulic conductivity, and morphological traits as root length and root biomass decreased significantly in response to Zn supply. Auxin levels increased with Zn concentrations, suggesting the involvement of this phytohormone in the seedling response to this element. LW seedlings exposed to 150 µM Zn showed higher root length and root biomass than HW seedlings exposed to the same Zn dose. Our results suggest that low water availability could mitigate Zn toxicity by limiting internal accumulation. Morphological traits involved in the response to both stresses probably contributed to this response.

  12. 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.

  13. Are there toxic interactions between salinity and naphthenic acids in the toxicity of oil sands process water to freshwater invertebrates?

    Energy Technology Data Exchange (ETDEWEB)

    Turcotte, D.; Pasloski, A.; Lanser, B.; Alm, K.; Liber, K. [Saskatchewan Univ., Saskatoon, SK (Canada)

    2009-07-01

    Large volumes of water are used to extract oil from the oil sands in the Athabasca deposit. The resulting oil sands process water (OSPW) has been proposed for use in future reclamation landscapes. Therefore, it is necessary to evaluate the toxicity of OSPW to freshwater invertebrates in order to develop environmentally acceptable OSPW reclamation plans. The OSPW generally contains high concentrations of salts and naphthenic acids (NAs), but low levels of other contaminants such as PAHs and metals. This study investigated the combined toxic effect of NAs and salinity on freshwater invertebrates. Laboratory cultured Ceriodaphnia dubia were used initially to determine the toxicity of OSPW from selected water bodies. The pond waters that generated a toxic response had elevated levels of NAs and salinity, but the concentrations of salinity ions varied considerably among ponds. Results suggested that ion composition may be a factor in toxicity. Subsequent bioassays were performed with single salts and with mixtures representing major ion combinations present in the OSPW, such as carbonate, sulphate, chloride and sodium. The interaction between NAs and salinity was evaluated by exposing Ceriodaphnia dubia and Daphnia pulex to mixtures of NAs extracted from OSPW and relevant major ions chosen according to the salt toxicity test results.

  14. Developmental toxicity, acute toxicity and mutagenicity testing in freshwater snails Biomphalaria glabrata (Mollusca: Gastropoda) exposed to chromium and water samples.

    Science.gov (United States)

    Tallarico, Lenita de Freitas; Borrely, Sueli Ivone; Hamada, Natália; Grazeffe, Vanessa Siqueira; Ohlweiler, Fernanda Pires; Okazaki, Kayo; Granatelli, Amanda Tosatte; Pereira, Ivana Wuo; Pereira, Carlos Alberto de Bragança; Nakano, Eliana

    2014-12-01

    A protocol combining acute toxicity, developmental toxicity and mutagenicity analysis in freshwater snail Biomphalaria glabrata for application in ecotoxicological studies is described. For acute toxicity testing, LC50 and EC50 values were determined; dominant lethal mutations induction was the endpoint for mutagenicity analysis. Reference toxicant potassium dichromate (K2Cr2O7) was used to characterize B. glabrata sensitivity for toxicity and cyclophosphamide to mutagenicity testing purposes. Compared to other relevant freshwater species, B. glabrata showed high sensitivity: the lowest EC50 value was obtained with embryos at veliger stage (5.76mg/L). To assess the model applicability for environmental studies, influent and effluent water samples from a wastewater treatment plant were evaluated. Gastropod sensitivity was assessed in comparison to the standardized bioassay with Daphnia similis exposed to the same water samples. Sampling sites identified as toxic to daphnids were also detected by snails, showing a qualitatively similar sensitivity suggesting that B. glabrata is a suitable test species for freshwater monitoring. Holding procedures and protocols implemented for toxicity and developmental bioassays showed to be in compliance with international standards for intra-laboratory precision. Thereby, we are proposing this system for application in ecotoxicological studies.

  15. Van der Waals effects in ab initio water at ambient and supercritical conditions.

    Science.gov (United States)

    Jonchiere, Romain; Seitsonen, Ari P; Ferlat, Guillaume; Saitta, A Marco; Vuilleumier, Rodolphe

    2011-10-21

    Density functional theory (DFT) within the generalized gradient approximation (GGA) is known to poorly reproduce the experimental properties of liquid water. The poor description of the dispersion forces in the exchange correlation functionals is one of the possible causes. Recent studies have demonstrated an improvement in the simulated properties when they are taken into account. We present here a study of the effects on liquid water of the recently proposed semi-empirical correction of Grimme et al. [J. Chem. Phys. 132, 154104 (2010)]. The difference between standard and corrected DFT-GGA simulations is rationalized with a detailed analysis upon modifying an accurate parameterised potential. This allows an estimate of the typical range of dispersion forces in water. We also show that the structure and diffusivity of ambient-like liquid water are sensitive to the fifth neighbor position, thus highlighting the key role played by this neighbor. Our study is extended to water at supercritical conditions, where experimental and theoretical results are much more scarce. We show that the semi-empirical correction by Grimme et al. improves significantly, although somewhat counter-intuitively, both the structural and the dynamical description of supercritical water.

  16. 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.

  17. 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...

  18. Evaluation of toxicity: Whole-sediment versus overlying-water exposures with amphipod Hyalella azteca

    Science.gov (United States)

    Ingersoll, C.G.; Ivey, C.D.; Brunson, E.L.; Hardesty, D.K.; Kemble, N.E.

    2000-01-01

    A laboratory study was conducted to evaluate the toxicity of whole-sediment versus overlying-water exposures to the amphipod Hyalella azteca using field-collected sediments. Severe toxic effects (5-63% survival) were observed with amphipods exposed for 10 d in direct contact with sediment. In contrast, amphipods exposed only to overlying water in these sediment exposures did not exhibit any toxic effects.

  19. 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...

  20. Noise Model Analysis and Estimation of Effect due to Wind Driven Ambient Noise in Shallow Water

    Directory of Open Access Journals (Sweden)

    S. Sakthivel Murugan

    2011-01-01

    Full Text Available Signal transmission in ocean using water as a channel is a challenging process due to attenuation, spreading, reverberation, absorption, and so forth, apart from the contribution of acoustic signals due to ambient noises. Ambient noises in sea are of two types: manmade (shipping, aircraft over the sea, motor on boat, etc. and natural (rain, wind, seismic, etc., apart from marine mammals and phytoplanktons. Since wind exists in all places and at all time: its effect plays a major role. Hence, in this paper, we concentrate on estimating the effects of wind. Seven sets of data with various wind speeds ranging from 2.11 m/s to 6.57 m/s were used. The analysis is performed for frequencies ranging from 100 Hz to 8 kHz. It is found that a linear relationship between noise spectrum and wind speed exists for the entire frequency range. Further, we developed a noise model for analyzing the noise level. The results of the empirical data are found to fit with results obtained with the aid of noise model.

  1. On-line Measurement of Water-Soluble Ions in Ambient Particles

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Combining the system of rapid collection of ambient particles and ion chromatography, the system of rapid collection of fine particles and ion chromatography (RCFP-IC) was established to automatically analyze on-line the concentrations of water-soluble ions in ambient particles. Here, the general scheme of RCFP-IC is described and its basic performance is tested. The detection limit of RCFP-IC for SO42-,NO-3, NO-2, Cl- and F- is below 0.3 μg m-3. The collection efficiency of RCFP-IC increases rapidly with increasing sized particles. For particles larger than 300 nm, the collection efficiency approaches 100%. The precision of RCFP-IC is more than 90% over 28 repetitions. The response of RCFP-IC is very sensitive and no obvious cross-pollution is found during measurement. A comparison of RCFP-IC with an integrated filter measurement indicates that the measurement of RCFP-IC is comparable in both laboratory experiments and field observations. The results of the field experiment prove that RCFP-IC is an effective on-line monitoring system and is helpful in source apportionment and pollution episode monitoring.

  2. Copper toxicity and the influence of water quality of Dongnai River and Mekong River waters on copper bioavailability and toxicity to three tropical species.

    Science.gov (United States)

    Bui, Thanh-Khiet L; Do-Hong, L Chi; Dao, Thanh-Son; Hoang, Tham C

    2016-02-01

    The present study investigated copper (Cu) toxicity and the influence of water quality characteristics of Dongnai River and Mekong River (Vietnam) surface waters to three tropical species; Daphnia lumholtzi, Ceriodaphnia cornuta, and Danio rerio. The river waters had a range of water quality parameters that modify Cu bioavailability and toxicity. The range of total hardness, alkalinity, pH and dissolved organic carbon were 15-64 mg/L as CaCO3, 18-58 mg/L as CaCO3, 6.62-7.88, and 6.9-14.7 mg/l, respectively. The US EPA acute toxicity test method with a modification to the light photoperiod and temperature for tropical organisms was used to investigate Cu toxicity. Result of the present study found that Cu produced toxic effect to the studied organisms at low concentrations. The 48-h LC50 ranged from 3.92 to 8.61 µg/l, 2.92-9.56 µg/l, and 15.71-68.69 µg/l dissolved Cu for D. lumholtzi, C. cornuta, and D. rerio, respectively. In general, water quality had an influence on Cu bioavailability and toxicity to the studied organisms. The toxicity of Cu was higher in water with lower hardness, DOC, and/or pH. The present study indicates a contribution of Cu hydroxide and carbonate to Cu bioavailability to Mekong organisms. Results of the present study will be used for calibrating the US Cu Biotic Ligand Model (BLM) to Mekong River water and organisms in support of application of the BLM for setting site-specific Cu water quality guidelines in the ecosystem of the Lower Mekong River Basin.

  3. Thermal Stress and Toxicity

    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 te...

  4. Ecological impacts of lead mining on Ozark streams: toxicity of sediment and pore water.

    Science.gov (United States)

    Besser, John M; Brumbaugh, William G; Allert, Ann L; Poulton, Barry C; Schmitt, Christopher J; Ingersoll, Christopher G

    2009-02-01

    We studied the toxicity of sediments downstream of lead-zinc mining areas in southeast Missouri, using chronic sediment toxicity tests with the amphipod, Hyalella azteca, and pore-water toxicity tests with the daphnid, Ceriodaphnia dubia. Tests conducted in 2002 documented reduced survival of amphipods in stream sediments collected near mining areas and reduced survival and reproduction of daphnids in most pore waters tested. Additional amphipod tests conducted in 2004 documented significant toxic effects of sediments from three streams downstream of mining areas: Strother Creek, West Fork Black River, and Bee Fork. Greatest toxicity occurred in sediments from a 6-km reach of upper Strother Creek, but significant toxic effects occurred in sediments collected at least 14 km downstream of mining in all three watersheds. Toxic effects were significantly correlated with metal concentrations (nickel, zinc, cadmium, and lead) in sediments and pore waters and were generally consistent with predictions of metal toxicity risks based on sediment quality guidelines, although ammonia and manganese may also have contributed to toxicity at a few sites. Responses of amphipods in sediment toxicity tests were significantly correlated with characteristics of benthic invertebrate communities in study streams. These results indicate that toxicity of metals associated with sediments contributes to adverse ecological effects in streams draining the Viburnum Trend mining district.

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. Biodegradation of roxarsone by a bacterial community of underground water and its toxic impact.

    Science.gov (United States)

    Mafla, S; Moraga, R; León, C G; Guzmán-Fierro, V G; Yañez, J; Smith, C T; Mondaca, M A; Campos, V L

    2015-08-01

    Roxarsone is included in chicken food as anticoccidial and mainly excreted unchanged in faeces. Microorganisms biotransform roxarsone into toxic compounds that leach and contaminate underground waters used for human consumption. This study evaluated roxarsone biotransformation by underground water microorganisms and the toxicity of the resulting compounds. Underground water from an agricultural field was used to prepare microcosms, containing 0.05 mM roxarsone, and cultured under aerobic or anaerobic conditions. Bacterial communities of microcosms were characterized by PCR-DGGE. Roxarsone degradation was measured by HPLC/HG/AAS. Toxicity was evaluated using HUVEC cells and the Toxi-ChromoTest kit. Roxarsone degradation analysis, after 15 days, showed that microcosms of underground water with nutrients degraded 90 and 83.3% of roxarsone under anaerobic and aerobic conditions, respectively. Microcosms without nutrients degraded 50 and 33.1% under anaerobic and aerobic conditions, respectively. Microcosms including nutrients showed more roxarsone conversion into toxic inorganic arsenic species. DGGE analyses showed the presence of Proteobacteria, Firmicutes, Actinobacteria, Planctomycetes and Spirochaetes. Toxicity assays showed that roxarsone biotransformation by underground water microorganisms in all microcosms generated degradation products toxic for eukaryotic and prokaryotic cells. Furthermore, toxicity increased when roxarsone leached though a soil column and was further transformed by the bacterial community present in underground water. Therefore, using underground water from areas where roxarsone containing manure is used as fertilizer might be a health risk.

  10. Ambient water quality in aquifers used for drinking-water supplies, Gem County, southwestern Idaho, 2015

    Science.gov (United States)

    Bartolino, James R.; Hopkins, Candice B.

    2016-12-20

    In recent years, the rapid population growth in Gem County, Idaho, has been similar to other counties in southwestern Idaho, increasing about 54 percent from 1990 to 2015. Because the entire population of the study area depends on groundwater for drinking water supply (either from self-supplied domestic, community, or municipal-supply wells), this population growth, along with changes in land use (including potential petroleum exploration and development), indicated to the public and local officials the need to assess the quality of groundwater used for human consumption. To this end, the U.S. Geological Survey, in cooperation with Gem County and the Idaho Department of Environmental Quality, assessed the quality of groundwater from freshwater aquifers used for domestic supply in Gem County. A total of 47 domestic or municipal wells, 1 spring, and 2 surface-water sites on the Payette River were sampled during September 8–November 19, 2015. The sampled water was analyzed for a variety of constituents, including major ions, trace elements, nutrients, bacteria, radionuclides, dissolved gasses, stable isotopes of water and methane, and either volatile organic compounds (VOCs) or pesticides.To better understand analytical results, a conceptual hydrogeologic framework was developed in which three hydrogeologic units were described: Quaternary-Tertiary deposits (QTd), Tertiary Idaho Group rocks (Tig), and Tertiary-Cretaceous igneous rocks (TKi). Water levels were measured in 30 wells during sampling, and a groundwater-level altitude map was constructed for the QTd and Tig units showing groundwater flow toward the Emmett Valley and Payette River.Analytical results indicate that groundwater in Gem County is generally of good quality. Samples collected from two wells contained water with fluoride concentrations greater than the U.S. Environmental Protection Agency (EPA) Maximum Contaminant Level (MCL) of 4 milligrams per liter (mg/L), six wells contained arsenic at

  11. Combustion characteristics of water-insoluble elemental and organic carbon in size selected ambient aerosol particles

    Directory of Open Access Journals (Sweden)

    K. Wittmaack

    2005-04-01

    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 1 h, diesel soot particles were found to be stable up to 480°C, but complete combustion occurred in a narrow temperature interval between about 490 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.

  12. 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.

  13. Ambient Seismic Signals Observed in Iceberg?Filled Waters of the Ross Sea, Antarctica.

    Science.gov (United States)

    Macayeal, D. R.; Okal, E. A.; Aster, R. C.

    2006-12-01

    A two-year seismometer deployment on various icebergs in the Ross Sea and on the Ross Ice Shelf (PASSCAL project SOUTHBERG) have produced an unusual seismological "tone poem" constituting a sample of ambient conditions in an iceberg-covered, coastal sea of Antarctica. The original motivation of the project was to investigate the source of signals seen as T-phases in the equatorial Pacific [e.g., Talandier et al., 2002]. During the periods of continuous seismometer operation (i.e., during the October - April periods of 2003-4 and 2004-5 when photovoltaic charging systems kept seismometers in operation) on icebergs B15A, C16 and Nascent Iceberg (a site not yet calved from the Ross Ice Shelf), about 1300 events were observed (roughly one event per day). These events are attributed to the icebergs, and are loosely referred to as "iceberg tremor" due to their long duration (many hours) and spectral structure (e.g., characterized by clearly preferential frequencies in the 1-3 Hz range, accompanied by multiple harmonics of a variable-pitch fundamental). The purpose of this presentation is to give a general qualitative overview of the various categories of iceberg tremor, and to describe their relationship to other variables observed (e.g., iceberg drift velocity, iceberg-on-iceberg collision, iceberg-on-seabed scraping). Speculation on the cause or causes of iceberg tremor will be postponed pending further study. Suggestions as to the relationship between the ambient tone poem of iceberg-covered waters and hydro-acoustic and seismic signals seen in the ocean beyond Antarctica will be offered.

  14. 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

  15. Toxicity of Trinitrotoluene to Sheepshead Minnows in Water Exposures

    Science.gov (United States)

    2010-02-06

    more toxic than TNT to an amphipod Hyalella azteca (2 times) and the cladoceran Ceriodaphia dubia (30 times) (Griest et al., 1998). Substantial...the aquatic amphipod Hyalella Azteca . Ecotoxicol. Environ. Saf. 70, 38–46. Smock, L.A., Stoneburner, D.L., Clark, J.R., 1976. The toxic effects of...tetranitro-1,3,5,7-tetrazocine in sediments to Chironomus tentans and Hyalella azteca : low-dose hormesis and high-dose mortality. Environ. Toxicol. Chem. 21

  16. 75 FR 8698 - Extension of Request for Scientific Views for Draft 2009 Update Aquatic Life Ambient Water...

    Science.gov (United States)

    2010-02-25

    ... of the request for scientific views. SUMMARY: On December 30, 2009 (74 FR 69086), EPA announced the... 1, 2010 (a 60-day request for scientific views). Since publication, the Agency has received several... AGENCY Extension of Request for Scientific Views for Draft 2009 Update Aquatic Life Ambient Water...

  17. Improved HF183 quantitative real-time PCR assay for characterization of human fecal pollution in ambient surface water samples

    Science.gov (United States)

    Real-time quantitative PCR assays that target the human-associated HF183 bacterial cluster have been found to be some of the top performing methods for the characterization of human fecal pollution in ambient surface waters. The United States Environmental Protection Agency is planning to conduct a ...

  18. 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 ...

  19. EFFECTS OF WATER CHEMISTRY ON COPPER TOXICITY - WHAT'S MISSING FROM CURRENT MODELS?

    Science.gov (United States)

    Current models for the acute toxicity of cationic metals to aquatic organisms focus on the binding of free metal ions to gill surfaces. This binding, and the resultant toxicity, can be reduced by metal-complexing ligands in the exposure water, which lower the activity of the free...

  20. Stimulation of fecal bacteria in ambient waters by experimental inputs of organic and inorganic phosphorus.

    Science.gov (United States)

    Chudoba, Elizabeth A; Mallin, Michael A; Cahoon, Lawrence B; Skrabal, Stephen A

    2013-06-15

    Fecal microbial pollution of recreational and shellfishing waters is a major human health and economic issue. Microbial pollution sourced from stormwater runoff is especially widespread, and strongly associated with urbanization. However, non-point source nutrient pollution is also problematic, and may come from sources different from fecal-derived pollution (i.e. fertilization of farm fields, lawns and gardens, and ornamental urban areas). Fecal bacteria require nutrients; thus the impact of such nutrient loading on survival and abundance of fecal coliform bacteria in ambient waters was experimentally investigated in a constructed wetland in coastal North Carolina, USA. A series of nutrient-addition bioassays testing impacts of inorganic and organic nitrogen and phosphorus demonstrated that additions of neither organic nor inorganic nitrogen stimulated fecal coliform bacteria. However, phosphorus additions provided significant stimulation of fecal coliform growth at times; on other occasions such additions did not. Dilution bioassays combined with nutrient additions were subsequently devised to assess potential impacts of microzooplankton grazing on the target fecal bacteria populations. Results demonstrated grazing to be a significant bacterial reduction factor in 63% of tests, potentially obscuring nutrient effects. Thus, combining dilution experiments with nutrient addition bioassays yielded simultaneous information on microzooplankton grazing rates on fecal bacteria, fecal bacterial growth rates, and nutrient limitation. Overall, when tested against a non-amended control, additions of either organic or inorganic phosphorus significantly stimulated fecal coliform bacterial growth on 50% of occasions tested, with organic phosphorus generally providing greater stimulation. The finding of significant phosphorus stimulation of fecal bacteria indicates that extraneous nutrient loading can, at times, augment the impacts of fecal microbial pollution of shellfishing

  1. Toxicity bioassays for water from black-odor rivers in Wenzhou, China.

    Science.gov (United States)

    DeFu, He; RuiRui, Chen; EnHui, Zhu; Na, Chen; Bo, Yang; HuaHong, Shi; MinSheng, Huang

    2015-02-01

    Following urbanization, a large number of urban rivers were contaminated and turned to black-odor rivers. The traditional approach for detecting water quality is based on chemical or physical analysis. However, biological toxicity of black-odor water has been less addressed. As two typical black-odor rivers, Jiushanwai River (JS) and Shanxia River (SX) are tributaries of Wen-Rui Tang River in Wenzhou (south of China). The eco-safety of the urban rivers was evaluated by bioassay for water toxicity in this study. Ten and 5 sampling sites were respectively set along JS and SX. Water samples were collected monthly from October 2010 to October 2011. The general physical and chemical parameters of river water were monitored. In order to investigate the ecotoxicological effects of black-odor water, the following bioassays were used: (1) Fish acute toxicity test (Danio rerio, comprehensive toxicity), (2) luminescent bacteria bioassay (Qinghaiensis vibrio, toxicity to bacteria), and (3) tropical claw embryo assay (Xenopus tropicalis, embryo toxicity). Biotoxicity of black-odor rivers water was demonstrated by D. rerio, Q. vibrio, and X. tropicalis embryos. Toxicological effects of black-odor water were respectively shown by mortality of zebrafish, and by the relative inhibitory light rate of luminescent bacteria. However, luminescent bacteria were more sensitive to inspect biotoxicity than zebrafish. In X. tropicalis embryos test, toxicological effects of black-odor water were mostly shown by embryos' survival rate and teratogenic rate. Bioassay results showed that toxicity of SX water was higher than that of JS water, especially in summer. Statistical analysis of luminescent bacteria toxicity test showed that biotoxicity of SX and JS was high in summer, but low in winter and spring. The seasonal changes of water toxicity of the black-odor river were positively correlative with changes of water temperature (p ecotoxicological risk of black-odor rivers was demonstrated in

  2. Assessment of the effect of water quality on copper toxicity in Hyalella azteca

    Energy Technology Data Exchange (ETDEWEB)

    Richards, L. [Univ. of Guelph, Guelph, Ontario (Canada); Walsh, S.; Shultz, C.; Stuart, M. [Canadian Nuclear Laboratories, Chalk River, Ontario (Canada)

    2015-06-15

    The objective of this study was to test the hypothesis that when standard artificial media 5-salt culture water (SAM-5S) is used to test sediment toxicity of much lower ionic-strength aquatic ecosystems, the resulting toxicity estimates are lower than if the tests had been conducted in water of comparable ionic strength. Results showed that this concern was unfounded for testing of copper toxicity to Hyalella azteca (H. azteca) in Ottawa River water. Sediment testing is often conducted using a standard water that is prepared in the laboratory. However, this water may have an ionic strength that is different than local water bodies. It follows that laboratory results using the standard water may be unrepresentative. A study was undertaken to assess the copper tolerance of 2 strains of H. azteca in SAM-5S, diluted SAM-5S (similar in electrical conductivity to Ottawa River water), and Ottawa River water. Acute (96 h) copper toxicity tests were conducted with 9-16 day-old H. azteca. For a given water type, the 2 strains of H. azteca yielded comparable responses to copper. The highest copper tolerance was found in Ottawa River water (closely followed by SAM-5S), whereas the lowest copper tolerance was found in diluted SAM-5S. Our results suggest that sediment toxicity is not lowered by the higher ionic strength of SAM-5S and that sediment toxicity tests of Ottawa River sediments, conducted with SAM-5S, can be used to estimate the in situ toxicity of the sediments. (author)

  3. Portable Sensor for Rapid In Situ Measurement of Trace Toxic Metals in Water Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of a sensor to detect select trace toxic heavy metals (Ag, Cd, Mn, Ni, and Zn) in water is proposed. Using an automatic side-stream sampling technique,...

  4. Toxicity reduction in the treatment of refinery waste water

    Energy Technology Data Exchange (ETDEWEB)

    Eckenfelder, W.W. Jr.

    1995-12-31

    Aquatic Toxicity in refinery and petrochemical wastewaters may result from chemicals present in the feedstock, chemicals added or generated in the process, or chemicals generated during the wastewater treatment process, usually referred to as soluble microbial products (SMP). In most cases, the chemicals originally present or generated are biodegradable and can be removed in the biological treatment process. In some cases, a physical-chemical source treatment may be required. SMP generated through the wastewater treatment process are non-biodegradable and are best handled by the application of powdered activated carbon (PAC) integrated into the activated sludge process. This paper describes toxicity reduction in refinery effluents.

  5. Dispersion and toxicity of selected manufactured nanomaterials in natural river water samples: effects of water chemical composition.

    Science.gov (United States)

    Gao, Jie; Youn, Sejin; Hovsepyan, Anna; Llaneza, Veronica L; Wang, Yu; Bitton, Gabriel; Bonzongo, Jean-Claude J

    2009-05-01

    Experimental conditions that mimic likely scenarios of manufactured nanomaterials (MNs) introduction to aquatic systems were used to assessthe effect of nanoparticle dispersion/solubility and water chemical composition on MN-toxicity. Aqueous suspensions of fullerenes (C60), nanosilver (nAg), and nanocopper (nCu) were prepared in both deionized water and filtered (0.45 microm) natural river water samples collected from the Suwannee River basin, to emphasize differences in dissolved organic carbon (DOC) concentrations and solution ionic strengths (I). Two toxicity tests, the Ceriodaphnia dubia and MetPLATE bioassays were used. Results obtained from exposure studies show that water chemistry affects the suspension/solubility of MNs as well as the particle size distribution, resulting in a wide range of biological responses depending on the type of toxicity test used. Under experimental conditions used in this study, C60 exhibited no toxicity even when suspended concentrations exceeded 3 mg L(-1). MetPLATE results showed that the toxicity of aqueous suspensions of nCu tends to increase with increasing DOC concentrations, while increasing I reduces nCu toxicity. The use of the aquatic invertebrate C. dubia on the other hand showed a tendency for decreased mortality with increasing DOC and I. MetPLATE results for nAg showed decreasing trends in toxicity with increasing DOC concentrations and I. However, C. dubia exhibited contrasting biological responses, in that increasing DOC concentrations reduced toxicity, while the latter increased with increasing I. Overall, our results show that laboratory experiments that use DI-water and drastic MN-suspension methods may not be realistic as MN-dispersion and suspension in natural waters vary significantly with water chemistry and the reactivity of MNs.

  6. Study on the removal of toxic substance from river water using O3-GAC process

    Institute of Scientific and Technical Information of China (English)

    杨玉楠; 孙志荣; 王宝贞; 杨敏; 李文兰

    2004-01-01

    This paper studied on the removal of toxic substance from river water using O3-GAC process. The result of GC/MS analysis indicated that the number of organic compound species was decreased by 55. 1%. The species of toxic substance of raw water also dec reased from 16 to 5. The total removal rate of CODMn andUV254were 45% ~ 72% and 60% ~ 80% following O3-GAC treatment. It reflected that this process had a good effective on removing unsaturation organic which absorb UV and toxic organic containing nitrogen. The results of Ames test indicated that raw water had a relatively strong mutagicity on TA 98. The O3-GAC process had a good ability in removing mutagen in water. The effluent water' s mutagicity is minus. The results of the study indicated that the effluent of the O3-GAC process was meet the demand of drinking water.

  7. Effects of SO2 oxidation on ambient aerosol growth in water and ethanol vapours

    Directory of Open Access Journals (Sweden)

    A. Laaksonen

    2004-11-01

    Full Text Available Hygroscopicity (i.e. water vapour affinity of atmospheric aerosol particles is one of the key factors in defining their impacts on climate. Condensation of sulphuric acid onto less hygroscopic particles is expected to increase their hygrocopicity and hence their cloud condensation nuclei formation potential. In this study, differences in the hygroscopic and ethanol uptake properties of ultrafine aerosol particles in the Arctic air masses with a different exposure to anthropogenic sulfur pollution were examined. The main discovery was that Aitken mode particles having been exposed to polluted air were more hygroscopic and less soluble to ethanol than after transport in clean air. This aging process was attributed to sulfur dioxide oxidation and subsequent condensation during the transport of these particle to our measurement site. The hygroscopicity of nucleation mode aerosol particles, on the other hand, was approximately the same in all the cases, being indicative of a relatively similar chemical composition despite the differences in air mass transport routes. These particles had also been produced closer to the observation site typically 3–8 h prior to sampling. Apparently, these particles did not have an opportunity to accumulate sulphuric acid on their way to the site, but instead their chemical composition (hygroscopicity and ethanol solubility resembled that of particles produced in the local or semi-regional ambient conditions.

  8. Effects of SO2 oxidation on ambient aerosol growth in water and ethanol vapours

    Directory of Open Access Journals (Sweden)

    T. Petäjä

    2005-01-01

    Full Text Available Hygroscopicity (i.e. water vapour affinity of atmospheric aerosol particles is one of the key factors in defining their impacts on climate. Condensation of sulphuric acid onto less hygroscopic particles is expected to increase their hygrocopicity and hence their cloud condensation nuclei formation potential. In this study, differences in the hygroscopic and ethanol uptake properties of ultrafine aerosol particles in the Arctic air masses with a different exposure to anthropogenic sulfur pollution were examined. The main discovery was that Aitken mode particles having been exposed to polluted air were more hygroscopic and less soluble to ethanol than after transport in clean air. This aging process was attributed to sulphur dioxide oxidation and subsequent condensation during the transport of these particle to our measurement site. The hygroscopicity of nucleation mode aerosol particles, on the other hand, was approximately the same in all the cases, being indicative of a relatively similar chemical composition despite the differences in air mass transport routes. These particles had also been produced closer to the observation site typically 3–8 h prior to sampling. Apparently, these particles did not have an opportunity to accumulate sulphuric acid on their way to the site, but instead their chemical composition (hygroscopicity and ethanol solubility resembled that of particles produced in the local or semi-regional ambient conditions.

  9. Role of ureogenesis in tackling problems of ammonia toxicity during exposure to higher ambient ammonia in the air-breathing walking catfish Clarias batrachus

    Indian Academy of Sciences (India)

    Nirmalendu Saha; Shritapa Datta; Kuheli Biswas; Zaiba Y Kharbuli

    2003-12-01

    In the present study, the possible role of ureogenesis to avoid the accumulation of toxic ammonia to a lethal level under hyper-ammonia stress was tested in the air-breathing walking catfish Clarias batrachus by exposing the fish at 25 mM NH4Cl for 7 days. Excretion of ammonia by the NH4Cl-exposed fish was totally suppressed, which was accompanied by significant accumulation of ammonia in different body tissues. The walking catfish, which is otherwise predominantly ammoniotelic, turned totally towards ureotelism from ammoniotelism with a 5- to 6-fold increase of urea-N excretion during exposure to higher ambient ammonia. Stimulation of ureogenesis was accompanied with significant increase of some of the key urea cycle enzymes such as carbamyl phosphate synthetase (urea cycle-related), argininosuccinate synthetase and argininosuccinate lyase both in hepatic and non-hepatic tissues. Due to this unique physiological strategy of turning towards ureotelism from ammoniotelism via the induced urea cycle, this air-breathing catfish is able to survive in very high ambient ammonia, which they face in certain seasons of the year in the natural habitat.

  10. A new biological test of water toxicity-yeast Saccharomyces cerevisiae conductometric test.

    Science.gov (United States)

    Dolezalova, Jaroslava; Rumlova, Lubomira

    2014-11-01

    This new biological test of water toxicity is based on monitoring of specific conductivity changes of yeast Saccharomyces cerevisiae suspension as a result of yeast fermentation activity inhibition in toxic conditions. The test was verified on ten substances with various mechanisms of toxic effect and the results were compared with two standard toxicity tests based on Daphnia magna mobility inhibition (EN ISO 6341) and Vibrio fischeri bioluminescence inhibition (EN ISO 11348-2) and with the results of the S. cerevisiae lethal test (Rumlova and Dolezalova, 2012). The new biological test - S. cerevisiae conductometric test - is an express method developed primarily for field conditions. It is applicable in case of need of immediate information about water toxicity. Fast completion is an advantage of this test (time necessary for test completion is about 60min), the test is simple and the test organism - dried instant yeast - belongs among its biggest advantages because of its long-term storage life and broad availability.

  11. Seasonal evolution of the Yellow Sea Cold Water Mass and its interactions with ambient hydrodynamic system

    Science.gov (United States)

    Li, Jianchao; Li, Guangxue; Xu, Jishang; Dong, Ping; Qiao, Lulu; Liu, Shidong; Sun, Pingkuo; Fan, Zhisong

    2016-09-01

    The Yellow Sea Cold Water Mass (YSCWM) is an important component of the hydrodynamic system in the South Yellow Sea (SYS). However, its intricate interactions with the ambient flows over long time scales are not fully understood. This paper presents the analysis of the data set obtained from a seabed-mounted Acoustic Doppler Current Profiler (ADCP) deployed for nearly 1 year in the western SYS. It allowed us to study the evolution of YSCWM, including the seasonal changes of tidal currents, near-inertial oscillations (NIOs), and the wind-driven currents due to typhoons and winter storms. Strong NIOs were found near the bottom of mixed layer and in the pycnocline with nearly opposite current directions, with maximum velocity of nearly 20 cm·s-1 in summer. The YSCWM can also inhibit the direct downward energy transport in the water column due to typhoons. Conversely, the hydrodynamic system also feeds back to influence the change of YSCWM. A large current shear (S) of 20 cm·s-1·m-1 is generated near the top of pycnocline. Generally, the intensity and depth of the pycnocline determine S's magnitude and vertical location, respectively. Based on the monthly averaged density profile data, the Richardson number and wavelet analysis, the NIOs are considered to be capable of inducing predominant shear instability around the pycnocline. However, the NIOs are not strong enough to influence the lower YSCWM. In addition, in autumn, each fortnightly spring tide corresponds with a bottom temperature increase of nearly 2°C, indicating that tidal currents are the leading hydrodynamic driving force to decline the YSCWM.

  12. A Review on Toxic and Harmful Algae in Greek Coastal Waters (E. Mediterranean Sea)

    Science.gov (United States)

    Ignatiades, Lydia; Gotsis-Skretas, Olympia

    2010-01-01

    The Greek coastal waters are subjected to harmful algal bloom (HAB) phenomena due to the occurrence of species characterized as toxic (TX), potentially toxic (PT), and non-toxic, high biomass (HB) producers causing harm at multiple levels. The total number of (TX), (PT) and (HB) algae reported in this work are 61, but only 16 species have been associated with the occurrence of important HABs causing damage in the marine biota and the water quality. These phenomena are sporadic in time, space and recurrence of the causative species, and are related to the anthropogenically-induced eutrophication conditions prevailing in the investigated areas. PMID:22069623

  13. A Microfluidic Device for Continuous Sensing of Systemic Acute Toxicants in Drinking Water

    Directory of Open Access Journals (Sweden)

    Xinyan Zhao

    2013-12-01

    Full Text Available A bioluminescent-cell-based microfluidic device for sensing toxicants in drinking water was designed and fabricated. The system employed Vibrio fischeri cells as broad-spectrum sensors to monitor potential systemic cell toxicants in water, such as heavy metal ions and phenol. Specifically, the chip was designed for continuous detection. The chip design included two counter-flow micromixers, a T-junction droplet generator and six spiral microchannels. The cell suspension and water sample were introduced into the micromixers and dispersed into droplets in the air flow. This guaranteed sufficient oxygen supply for the cell sensors. Copper (Cu2+, zinc (Zn2+, potassium dichromate and 3,5-dichlorophenol were selected as typical toxicants to validate the sensing system. Preliminary tests verified that the system was an effective screening tool for acute toxicants although it could not recognize or quantify specific toxicants. A distinct non-linear relationship was observed between the zinc ion concentration and the Relative Luminescence Units (RLU obtained during testing. Thus, the concentration of simple toxic chemicals in water can be roughly estimated by this system. The proposed device shows great promise for an early warning system for water safety.

  14. 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.)

  15. Amines and amine-related compounds in surface waters: a review of sources, concentrations and aquatic toxicity.

    Science.gov (United States)

    Poste, Amanda E; Grung, Merete; Wright, Richard F

    2014-05-15

    This review compiles available information on the concentrations, sources, fate and toxicity of amines and amine-related compounds in surface waters, including rivers, lakes, reservoirs, wetlands and seawater. There is a strong need for this information, especially given the emergence of amine-based post-combustion CO2 capture technologies, which may represent a new and significant source of amines to the environment. We identify a broad range of anthropogenic and natural sources of amines, nitrosamines and nitramines to the aquatic environment, and identify some key fate and degradation pathways of these compounds. There were very few data available on amines in surface waters, with reported concentrations often below detection and only rarely exceeding 10 μg/L. Reported concentrations for seawater and reservoirs were below detection or very low, while for lakes and rivers, concentrations spanned several orders of magnitude. The most prevalent and commonly detected amines were methylamine (MA), dimethylamine (DMA), ethylamine (EA), diethylamine (DEA) and monoethanolamine (MEAT). The paucity of data may reflect the analytical challenges posed by determination of amines in complex environmental matrices at ambient levels. We provide an overview of available aquatic toxicological data for amines and conclude that at current environmental concentrations, amines are not likely to be of toxicological concern to the aquatic environment, however, the potential for amines to act as precursors in the formation of nitrosamines and nitramines may represent a risk of contamination of drinking water supplies by these often carcinogenic compounds. More research on the prevalence and toxicity of amines, nitrosamines and nitramines in natural waters is necessary before the environmental impact of new point sources from carbon capture facilities can be adequately quantified.

  16. Ice berg cracking events as identified from underwater ambient noise measurements in the shallow waters of Ny-Alesund, Arctic

    Science.gov (United States)

    Ashokan, M.; Latha, G.; Thirunavukkarasu, A.; Raguraman, G.; Venkatesan, R.

    2016-06-01

    This paper presents the work carried out on the analysis of preliminary underwater ambient noise measurements in the shallow waters of Kongsfjorden fjord, Arctic in the summer season, in which the ice berg cracking noise is identified. In the summer period, the melting of ice cover is fast and hence the ice bergs are free to move and float in the ocean. Underwater ambient noise has been acquired in the Kongsfjorden fjord, Arctic sea on 19th July 2015 at 5 m water depth, where the ocean depth is 50 m. Due to the tensile cracks at the surface of the sea ice by thermal expansion, ice berg calving and bobbing occurred near the experiment site. Analysis of power spectra shows that ice berg calving noise falls in the frequency band 100 Hz-500 Hz and the ice berg bobbing noise falls in the frequency band 200 Hz-400 Hz.

  17. Treatment of tunnel wash waters - experiments with organic sorbent materials. Part Ⅱ: Removal of toxic metals

    Institute of Scientific and Technical Information of China (English)

    PARUCH Adam M; ROSETH Roger

    2008-01-01

    In the first part of the article, the column and the bag experiments concerning removal of polycyclic aromatic hydrocarbons (PAHs) and nonpolar oil (NPO) from tunnel wash waters using organic sorbent materials have been described. This part presents the results of removal of toxic metals. The metals of concern (Al, As, Cd, Cr, Cu, Fe, Pb, Mo, Ni, and Zn) were selected based on the priority toxicant pollutants defined in surface water quality criteria. Concentrations of these metals in the collected effluents varied more than the concentrations of PAHs and NPO, and thus only metal contents were considered for statistical analyses. These analyses determined significant differences (P<0.05, P<0.01, and P<0.001) between the mean metal concentrations in the column effluents and those in applied wash water of road tunnel. The results obtained during both experiments revealed that the organic sorbents, and in particular their combination, removed toxic metals more effectively from wash water of road tunnel than from wash water of tunnel electrostatic filters. Among the investigated toxicants, Al and Fe showed the highest levels of reduction in the column experiment, 99.7% and 99.6%, respectively. The lowest reduction levels of 66.0% and 76.2% were found for Pb and Mo, respectively. The results of the bag experiment showed that even one day treatment of wash waters from tunnel electrostatic filters could reduce concentration of some toxicants by more than 70% (Al and Fe) and 80% (Cu).

  18. Development and application of a marine sediment pore-water toxicity test using Ulva fasciata zoospores

    Science.gov (United States)

    Hooten, R.L.; Carr, R.S.

    1998-01-01

    An acute (96 h) pore-water toxicity test protocol using germination and growth of Ulva fasciata zoospores as endpoints was developed to test the toxicity of marine and estuarine sediment pore-water samples. Tests with an organic toxicant (sodium dodecyl sulfate; SDS), three metals (Cd, Cu, and Zn), and ammonia (NH3) were conducted to determine zoospore sensitivity. Zoospore germination and gametophyte growth were as sensitive to SDS as sea urchin (Arbacia punctulata) fertilization and embryological development. Zoospore sensitivity to metals was greater than or comparable to that of adult macroalgae. Zoospores were less sensitive to NH3 than were other commonly used toxicity test organisms. Test results using this algal assay with sediment pore-water samples with high NH3 concentrations were compared with results from sea urchin fertilization and embryological development tests for the same samples. Ulva fasciata zoospore germination was not affected by samples with high NH3 concentrations that were toxic in both sea urchin tests. Zoospore tolerance of NH3 and sensitivity to other contaminants indicate that their response may be useful in toxicity identification evaluation studies with pore-water samples that contain high concentrations of unionized NH3.

  19. A microbial fuel cell-based biosensor for the detection of toxic components in water

    NARCIS (Netherlands)

    Stein, N.E.

    2011-01-01

    In a microbial fuel cell bacteria produce electricity. When water with a constant quality is lead passed the bacteria, a constant current will be measured. When toxic components enter the cell with the water, the bacteria are affected a

  20. Molecular Dynamics Simulation of Na(+)-Cl(-) Ion-Pair in Water-Methanol Mixtures under Supercritical and Ambient Conditions.

    Science.gov (United States)

    Keshri, Sonanki; Sarkar, Atanu; Tembe, B L

    2015-12-17

    Constrained molecular dynamics simulations have been performed to investigate the structure and thermodynamics of Na(+)-Cl(-) ion-pair association in water-methanol mixtures under supercritical and ambient conditions in dilute solutions. From the computed potentials of mean force (PMFs) we find that contact ion pairs (CIPs) are more stable than all other associated states of the ion pairs in both ambient and supercritical conditions. Stabilities of CIPs increase with increase in the mole fraction of methanol. In supercritical conditions, major changes in PMFs occur as we go from x(methanol) = 0.00 to x(methanol) = 0.50. The stable solvent shared ion pair (SShIP) which occurs in x(methanol) = 0.00 and 0.25, vanishes when x(methanol) is 0.50 or greater. The stabilities of these ion pairs increase with increasing temperature. Local structures around the ions are studied using the radial distribution functions, density profiles, angular distribution functions, running coordination numbers and excess coordination numbers. Preferential solvation analysis shows that both Na(+) and Cl(-) ions are preferentially solvated by water. From the calculation of enthalpies and entropies, we find that Na(+)-Cl(-) ion-pair association in water-methanol binary mixtures is endothermic and driven by entropy both in ambient as well as under supercritical conditions.

  1. 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

  2. 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

  3. Acute and chronic toxicity of lead in water and diet to the amphipod Hyalella azteca

    Science.gov (United States)

    Besser, J.M.; Brumbaugh, W.G.; Brunson, E.L.; Ingersoll, C.G.

    2005-01-01

    We evaluated the influence of waterborne and dietary lead (Pb) exposure on the acute and chronic toxicity of Pb to the amphipod Hyalella azteca. Test solutions were generated by a modified diluter with an extended (24-h) equilibration period. Acute (96-h) toxicity of Pb varied with water hardness in the range of 71 to 275 mg/L as CaCO3, despite similar dissolved Pb concentrations. Acute toxicity was greatest in soft test water, with less than 50% survival at the lowest dissolved Pb concentration (151 ??g/L). Survival also was significantly reduced in medium-hardness water but not in hard test water. In chronic (42-d) studies, amphipods were exposed to waterborne Pb and fed either a control diet or a diet equilibrated with waterborne Pb levels. For animals fed the control diet, the median lethal concentration (LC50) for Pb was 24 ??g/L (as dissolved Pb), and significant reductions in survival occurred at 16 ??g/L. Exposure to Pb-treated diets significantly increased toxicity across a wide range of dissolved Pb concentrations, with a LC50 of 16 ??g/L and significant reductions in growth and reproduction at 3.5 ??g/L. Significant effects on growth and reproduction occurred at dissolved Pb concentrations close to the current U.S. chronic water-quality criterion. Our results suggest that both aqueous- and dietary-exposure pathways contribute significantly to chronic Pb exposure and toxic effects in aquatic biota. ?? 2005 SETAC.

  4. Selection of a Battery of Rapid Toxicity Sensors for Drinking Water Evaluation

    Science.gov (United States)

    2006-01-01

    sensors for drinking water evaluation William H. van der Schalie a,∗, Ryan R. James b, Thomas P. Gargan II a a US Army Center for Environmental Health...complementary approach is to directly measure toxicity instead of individual chemical constituents. Ten toxicity ensors utilizing enzymes, bacteria, or...Objective (ATO) IV.MD.2004.03 William H. van der Schalie, Ryan R. James , and Thomas P. Gargan, II U.S. Army Center for Environmental Health Research, 568

  5. Development of a Fully Automated Flow Injection Analyzer Implementing Bioluminescent Biosensors for Water Toxicity Assessment

    Directory of Open Access Journals (Sweden)

    Constantinos Georgiou

    2010-07-01

    Full Text Available This paper describes the development of an automated Flow Injection analyzer for water toxicity assessment. The analyzer is validated by assessing the toxicity of heavy metal (Pb2+, Hg2+ and Cu2+ solutions. One hundred μL of a Vibrio fischeri suspension are injected in a carrier solution containing different heavy metal concentrations. Biosensor cells are mixed with the toxic carrier solution in the mixing coil on the way to the detector. Response registered is % inhibition of biosensor bioluminescence due to heavy metal toxicity in comparison to that resulting by injecting the Vibrio fischeri suspension in deionised water. Carrier solutions of mercury showed higher toxicity than the other heavy metals, whereas all metals show concentration related levels of toxicity. The biosensor’s response to carrier solutions of different pHs was tested. Vibrio fischeri’s bioluminescence is promoted in the pH 5–10 range. Experiments indicate that the whole cell biosensor, as applied in the automated fluidic system, responds to various toxic solutions.

  6. Evaluation of acute copper toxicity to larval fathead minnows (Pimephales promelas) in soft surface waters.

    Science.gov (United States)

    Van Genderen, Eric J; Ryan, Adam C; Tomasso, Joseph R; Klaine, Stephen J

    2005-02-01

    The hardness-based regulatory approach for Cu prescribes an extrapolation of the toxicity-versus-hardness relationship to low hardness (hardness surface waters. Seasonal water sampling was conducted at 24 sites throughout South Carolina, USA, to determine the site-specific influences of soft surface-water conditions on acute Cu toxicity. Concurrent toxicity tests in laboratory water, matched for hardness and alkalinity (modified method), also were conducted to allow calculation of water-effect ratios (WERs). In addition, tests were conducted at recommended hardness levels (recommended method) for comparison of WER methodology in soft water. Surface-water conditions (average+/-standard deviation, n = 53) were hardness of 16+/-8 mg/L as CaCO3, alkalinity of 18+/-11 mg/L as CaCO3, and dissolved organic carbon of 6+/-4 mg/L. Dissolved Cu 48-h median lethal concentration (LC50) values varied nearly 45-fold across the dataset and greater than four-fold at individual sites. Spatial (p hardness-based equation for Cu at 50 mg/L or less as CaCO3 would adequately protect fathead minnow populations in soft surface waters. The WER results presented here demonstrate the inconsistency between hardness-based criteria and the methodology for deriving site-specific water-quality criteria in low-hardness waters.

  7. Toxicity of Water Accommodated Fractions of Estonian Shale Fuel Oils to Aquatic Organisms.

    Science.gov (United States)

    Blinova, Irina; Kanarbik, Liina; Sihtmäe, Mariliis; Kahru, Anne

    2016-02-01

    Estonia is the worldwide leading producer of the fuel oils from the oil shale. We evaluated the ecotoxicity of water accommodated fraction (WAF) of two Estonian shale fuel oils ("VKG D" and "VKG sweet") to aquatic species belonging to different trophic levels (marine bacteria, freshwater crustaceans and aquatic plants). Artificial fresh water and natural lake water were used to prepare WAFs. "VKG sweet" (lower density) proved more toxic to aquatic species than "VKG D" (higher density). Our data indicate that though shale oils were very toxic to crustaceans, the short-term exposure of Daphnia magna to sub-lethal concentrations of shale fuel oils WAFs may increase the reproductive potential of survived organisms. The weak correlation between measured chemical parameters (C10-C40 hydrocarbons and sum of 16 PAHs) and WAF's toxicity to studied species indicates that such integrated chemical parameters are not very informative for prediction of shale fuel oils ecotoxicity.

  8. Water chemistry influences the toxicity of silver to the green-lipped mussel Perna viridis.

    Science.gov (United States)

    Vijayavel, Kannappan

    2010-08-01

    The study determined the influence and relative importance of water chemistry parameters (pH, alkalinity, hardness) on the acute toxicity of silver to the green mussel Perna viridis. A preliminary bioassay revealed that 4 mg L(-1) of silver caused 50% mortality (LC50) in 96 h for mussels placed in seawater with pH 8.5, hardness 1,872 mg L(-1), and alkalinity 172 mg L(-1). Mortality of mussels increased with decreasing pH and increasing hardness and alkalinity variables. In contrast the mortality decreased with increasing pH and decreasing hardness and alkalinity values. The water chemistry also affected the concentration of silver in experimental seawater and bioaccumulation of silver in mussels. The results revealed that the chemical properties of seawater must be considered while conducting toxicity tests with metals like silver. The possible explanations for the influence of water chemistry on silver toxicity to P. viridis are discussed.

  9. 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.

  10. 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

    2016-11-17

    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 2016;9999:1-9. © 2016 SETAC.

  11. 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.

  12. Acute and chronic toxicity of sodium sulfate to four freshwater organisms in water-only exposures.

    Science.gov (United States)

    Wang, Ning; Dorman, Rebecca A; Ingersoll, Christopher G; Hardesty, Doug K; Brumbaugh, William G; Hammer, Edward J; Bauer, Candice R; Mount, David R

    2016-01-01

    The acute and chronic toxicity of sulfate (tested as sodium sulfate) was determined in diluted well water (hardness of 100 mg/L and pH 8.2) with a cladoceran (Ceriodaphnia dubia; 2-d and 7-d exposures), a midge (Chironomus dilutus; 4-d and 41-d exposures), a unionid mussel (pink mucket, Lampsilis abrupta; 4-d and 28-d exposures), and a fish (fathead minnow, Pimephales promelas; 4-d and 34-d exposures). Among the 4 species, the cladoceran and mussel were acutely more sensitive to sulfate than the midge and fathead minnow, whereas the fathead minnow was chronically more sensitive than the other 3 species. Acute-to-chronic ratios ranged from 2.34 to 5.68 for the 3 invertebrates but were as high as 12.69 for the fish. The fathead minnow was highly sensitive to sulfate during the transitional period from embryo development to hatching in the diluted well water, and thus, additional short-term (7- to 14-d) sulfate toxicity tests were conducted starting with embryonic fathead minnow in test waters with different ionic compositions at a water hardness of 100 mg/L. Increasing chloride in test water from 10 mg Cl/L to 25 mg Cl/L did not influence sulfate toxicity to the fish, whereas increasing potassium in test water from 1 mg K/L to 3 mg K/L substantially reduced the toxicity of sulfate. The results indicate that both acute and chronic sulfate toxicity data, and the influence of potassium on sulfate toxicity to fish embryos, need to be considered when environmental guidance values for sulfate are developed or refined.

  13. Toxicity of uranium, molybdenum, nickel, and arsenic to Hyalella azteca and Chironomus dilutus in water-only and spiked-sediment toxicity tests.

    Science.gov (United States)

    Liber, Karsten; Doig, Lorne E; White-Sobey, Suzanne L

    2011-07-01

    A series of laboratory spiked-sediment toxicity tests with the amphipod Hyalella azteca and the midge Chironomus dilutus were undertaken to determine acute and chronic toxicity thresholds for uranium (U), molybdenum (Mo), nickel (Ni), and arsenic (As) based on both whole-sediment (total) and pore water exposure concentrations. Water-only toxicity data were also generated from separate experiments to determine the toxicities of these metals/metalloids under our test conditions and to help evaluate the hypothesis that pore water metal concentrations are better correlated with sediment toxicity to benthic organisms than whole-sediment metal concentrations. The relative toxicity of the four elements tested differed depending on which test species was used and whether whole-sediment or pore water metal concentrations were correlated with effects. Based on measured whole-sediment concentrations, Ni and As were the two most acutely toxic elements to H. azteca with 10-d LC50s of 521 and 532 mg/kg d.w., respectively. Measured pore water concentrations indicated that U and Ni were the two most acutely toxic elements, with 10-d LC50s to H. azteca of 2.15 and 2.05 mg/L, respectively. Based on pore water metal concentrations, the no-observed-effect concentrations (NOECs) for growth were (H. azteca and C. dilutus, respectively) 0.67 and 0.21 mg/L for U, azteca and C. dilutus, respectively) 2.99 and 0.48 mg/L for U, 0.37 and 2.33 mg/L for Ni, and 58.99 and 0.42 mg/L for As. For U and Ni, results from 96-h water-only acute toxicity tests correlated well with pore water metal concentrations in acutely toxic metal-spiked sediment. This was not true for As where metalloid concentrations in overlying water (diffusion from sediment) may have contributed to toxicity. The lowest whole-sediment LOEC reported here for As was 6.6- and 4-fold higher than the Canadian Council of Ministers of the Environment interim sediment quality guideline and the Canadian Nuclear Safety Commission (CNSC

  14. Artemia salina as test organism for assessment of acute toxicity of leachate water from landfills.

    Science.gov (United States)

    Svensson, B M; Mathiasson, L; Mårtensson, L; Bergström, S

    2005-03-01

    Artemia salina has, for the first time, been used as test organism for acute toxicity of leachate water from three landfills (the municipal landfills at Kristianstad, Sweden and Siauliai, Lithuania, and an industrial landfill at Stena fragmenting AB, Halmstad, as well as for leachate from Kristianstad treated in different ways in a pilot plan). Artemia can tolerate the high concentrations of chloride ions found in such waters. Large differences in toxicities were found, the leachate from Siauliai being the most toxic one. To increase the selectivity in the measurements, a fractionation was done by using ion exchange to separate ammonium/ammonia and metal ions from the leachate, and activated carbon adsorbents for organic pollutants. The influence of some metals and phenol compounds on the toxicity was investigated separately. It was found that most of the toxicity emanated from the ammonium/ammonia components in the leachate. However, there was also a significant contribution n from organic pollutants, other than phenol compounds, since separate experiments had in this latter case indicated negligible impact. The concentrations of metals were at a level, shown by separate experiments, where only small contribution to the toxicity could be expected.

  15. Effect of water quality on mercury toxicity to Photobacterium phosphoreum: Model development and its application in natural waters.

    Science.gov (United States)

    Wang, Xinghao; Qu, Ruijuan; Wei, Zhongbo; Yang, Xi; Wang, Zunyao

    2014-06-01

    Mercury (Hg) compounds are widely distributed toxic environmental and industrial pollutants and they may bring danger to growth and development of aquatic organisms. The distribution of Hg species in the 3 percent NaCl solution was calculated using the chemical equilibrium model Visual MINTEQ, which demonstrated that Hg was mainly complexed by chlorides in the pH range 5.0-9.0 and the proportions of HgCl4(2-), HgCl3(-) and HgCl2(aq) reached to 95 percent of total Hg. Then the effects of cations (Ca(2+), Mg(2+), K(+) and H(+)), anions (HCO3(-), NO3(-), SO4(2-) and HPO4(2-)) and complexing agents (ethylene diamine tetraacetic acid (EDTA) and dissolved organic matter (DOM)) on Hg toxicity to Photobacterium phosphoreum were evaluated in standardized 15min acute toxicity tests. The significant increase of 6.3-fold in EC50 data with increasing pH was observed over the tested pH range of 5.0-8.0, which suggested the possible competition between hydroxyl and the negatively charged chloro-complex. By contrast, it was found that major cations (Ca(2+), Mg(2+) and K(+)) have little effect on Hg toxicity to P. phosphoreum. An interesting finding was that the addition of HPO4(2-) significantly increased Hg toxicity, which may imply that the addition of phosphate increased the soluble Hg-chloro complex species. Additions of complexing agents (EDTA and DOM) into the exposure water increased Hg bioavailability via complexation of Hg. Finally, a model which incorporated the effect of pH, HPO4(2-), HCO3(-), SO4(2-) and DOM on Hg toxicity was developed to predict acute Hg toxicity for P. phosphoreum, which may be a useful tool in setting realistic water quality criteria for different types of water.

  16. 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.

  17. Toxicity of aluminium in natural waters controlled by type rather than quantity of natural organic matter

    Energy Technology Data Exchange (ETDEWEB)

    Papathanasiou, Grigorios [SEAES, University of Manchester, Manchester, M13 9PL (United Kingdom); Faculty of Life Sciences, University of Manchester, Manchester M13 9PT (United Kingdom); White, Keith N.; Walton, Rachel [Faculty of Life Sciences, University of Manchester, Manchester M13 9PT (United Kingdom); Boult, Stephen, E-mail: s.boult@manchester.ac.uk [SEAES, University of Manchester, Manchester, M13 9PL (United Kingdom)

    2011-11-15

    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{sup -1}), subsequent uptake and accumulation by and toxicity to Lymnaea stagnalis. HA and AA did not alter precipitation of Al(OH){sub 3}, but altered subsequent behaviour of Al. High (40 mg L{sup -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{sup -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: {yields} Toxicity assessment in which environmental relevance is of primary concern. {yields} Mass balance of Al monitored throughout the exposure period. {yields} Al behaviour influenced by concentration of organic matter. {yields} Strong dependence of toxicity on type rather than concentration of organic matter. {yields} Toxicity is a function of Al behaviour but also animal behaviour.

  18. Prioritization of constituents for national- and regional-scale ambient monitoring of water and sediment in the United States

    Science.gov (United States)

    Olsen, Lisa D.; Valder, Joshua F.; Carter, Janet M.; Zogorski, John S.

    2013-01-01

    A total of 2,541 constituents were evaluated and prioritized for national- and regional-scale ambient monitoring of water and sediment in the United States. This prioritization was done by the U.S. Geological Survey (USGS) in preparation for the upcoming third decade (Cycle 3; 2013–23) of the National Water-Quality Assessment (NAWQA) Program. This report provides the methods used to prioritize the constituents and the results of that prioritization. Constituents were prioritized by the NAWQA National Target Analyte Strategy (NTAS) work group on the basis of available information on physical and chemical properties, observed or predicted environmental occurrence and fate, and observed or anticipated adverse effects on human health or aquatic life. Constituents were evaluated within constituent groups that were determined on the basis of physical or chemical properties or on uses or sources. Some constituents were evaluated within more than one constituent group. Although comparable objectives were used in the prioritization of constituents within the different constituent groups, differences in the availability of information accessed for each constituent group led to the development of separate prioritization approaches adapted to each constituent group to make best use of available resources. Constituents were assigned to one of three prioritization tiers: Tier 1, those having the highest priority for inclusion in ambient monitoring of water or sediment on a national or regional scale (including NAWQA Cycle 3 monitoring) on the basis of their likelihood of environmental occurrence in ambient water or sediment, or likelihood of effects on human health or aquatic life; Tier 2, those having intermediate priority for monitoring on the basis of their lower likelihood of environmental occurrence or lower likelihood of effects on human health or aquatic life; and Tier 3, those having low or no priority for monitoring on the basis of evidence of nonoccurrence or lack of

  19. Water quality and toxicity of river water downstream of the uranium mining facility at Pocos de Caldas, MG, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Lauria, Dejanira C.; Vascocnellos, Luisa M.H.; Simoes, Francisco F. Lamego; Clain, Almir F., E-mail: dejanira@ird.gov.b, E-mail: luisa@ird.gov.b, E-mail: flamego@ird.gov.b, E-mail: almir@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Scassiotti, Walter F.; Antunes, Ivan, E-mail: scassiotti@inb.gov.b [Industrias Nucleares do Brasil (INB), Caldas, MG (Brazil); Ferreira, Ana M., E-mail: anaferreira@dmaepc.mg.gov.b [Departamento Municipal de Aguas e Esgotos de Pocos de Caldas (DMAE), Pocos de Caldas, MG (Brazil); Nascimento, Marcos R.L., E-mail: pmarcos@cnen.gov.b [Comissao Nacional de Energia Nuclear (LAPOC/CNEN-MG), Pocos de Caldas, MG (Brazil). Pocos de Caldas Lab.

    2009-07-01

    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 {sup 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)

  20. Application of enzyme multibiosensor for toxicity analysis of real water samples of different origin

    Directory of Open Access Journals (Sweden)

    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.

  1. Water-free Alkaline Polymer-inorganic Acid Complexes with High Conductivity at Ambient Temperature

    Institute of Scientific and Technical Information of China (English)

    O.V.Chervakov; M.V.Andriianova; V.V.Riabenko; A.V.Markevich; E.M.Shembel; D.Meshri

    2007-01-01

    1 Results Recently increased interest is shown to proton conducting materials based on the alkaline polymer-inorganic acid complexes that is caused by a possibility of their application as the high-temperature electrolyte systems for various electrochemical devices (fuel cells,sensors,lithium power sources etc.).Complexes of inorganic acids with the alkaline polymers (polybenzimidazoles[1],polyvinylpyridines[2]) are characterized by high ionic conductivity at ambient temperatures (up to 10-2 Ω-1·cm-1) a...

  2. The Combined Influence of Nuclear Quantum Effects and van der Waals Interactions on the Structure of Ambient Water

    CERN Document Server

    McMahon, Jeffrey M; Kolb, Brian; Thonhauser, Timo

    2014-01-01

    Path-integral molecular dynamics simulations based on density functional theory employing exchange-correlation density functionals capable of treating nonlocal van der Waals (vdW) interactions self-consistently provide a remarkably accurate description of ambient water. Moreover, they suggest that water's structure may be impacted by a combined influence between nuclear quantum effects and vdW interactions. The latter strongly favor the formation of a high-density liquid, whereas the inclusion of the former mitigates this by decreasing the mean hydrogen-bond (H-bond) distance. Examining the structure of water reveals that while the major fraction of molecules do in fact exhibit the traditional picture of near-tetrahedral coordination, the liquid considerably softer than previously simulations have suggested, including a much lower proportion of molecules double-donating H-bonds as well as a much larger distribution of their angles.

  3. Toxicity effects of water extracts of Holothuria atra Jaeger in mice

    Institute of Scientific and Technical Information of China (English)

    Ridzwan Bin Hashim; Nurul Alia Azizan; Zaitunnatakin Zamli; Farah Hanis Zulkipli; Nurzafirah Mazlan; Osama Yousef Althunibat

    2014-01-01

    Objective:To determine lethal median dose (LD50) and histopathological toxicity of water extract of Holothuria atra (H. atra) in mice. Methods: The behavioral changes, mortality and histopathology examination on liver were assessed in mice 14 d after the administration (i.p.) of H. atra water extract. Seven doses (10, 20, 30, 50, 100, 150 and 200 mg/kg) of H. atra were used. The control group was treated with normal saline. Results:In the acute study in mice, the water extracts of H. atra caused dose-dependent general behavior adverse affects and mortality. The main behavioral sign of toxicity was hypoactivity, noticed immediately after administration of the extract which was more obvious at the higher doses and persisted until death. Mortality increased with increasing doses, the calculated LD50 was 41 mg/kg in mice. The liver toxicity was confirmed by histopathological examination, which indicated the presence of abnormal hepatocytes with a distorted shape and undefined cell lining as well as enlarged nuclei in low doses groups. High doses groups indicated a more prominent distortion of the polyhedral hepatocytes with undefined cell lining, massive cytoplasm, pyknotic, karyorhexis and karyolytic nuclei (necrosis of hepatocytes). Control group showed polyhedral hepatocytes with defined cell lining arranged in cords and normal round nuclei, with granular cytoplasm. Conclusions: Because of the relatively low LD50 value in the acute study in mice, it may be concluded that the H. atra water extract is toxic.

  4. Development of a Low Toxicity Urine Pretreatment for Water Recovery in Space

    Science.gov (United States)

    Adam, Niklas; Alvarez, Giraldo; Mitchell, Julie; Pickering, Karen; Shull, Sarah; Carrier, Chris; Vega, Letty

    2015-01-01

    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. Additionally, the pretreatment formulations were tested to determine if the pretreated urine could be distilled to remove 85% of the water, as would occur on the ISS. The goal of the pretreatment was to produce no solids in the resulting brine at 85% water recovery.

  5. Effects of water chemistry on the chronic toxicity of lead to the cladoceran, Ceriodaphnia dubia.

    Science.gov (United States)

    Mager, Edward M; Brix, Kevin V; Gerdes, Robert M; Ryan, Adam C; Grosell, Martin

    2011-03-01

    As the first step toward parameterization of a chronic lead (Pb) biotic ligand model (BLM) for Ceriodaphnia dubia, 7-d toxicity tests were performed in waters modified to evaluate the influences of hardness, DOM (as Suwannee River NOM and Aldrich humic acid (HA)), pH (buffered with 4 mM MOPS) and alkalinity on the chronic toxicity of Pb. Calculated EC(20)s for the control base water test and each of the most extreme modified test waters were as follows in μg L(-1) Pb (95% confidence interval): base water control=45 (14-53), 5 mM CaSO(4)=22 (12-30), 32 mg L(-1) DOM=523 (388-573), 2.5 mM NaHCO(3)=73 (21-120) and pH 6.4 buffered with MOPS=3.9 μg L(-1) Pb (1-5). Results indicate that hardness does not protect against chronic toxicity of Pb to C. dubia, whereas HA does protect at the highest concentration tested (597 μM). Additionally, our findings suggest that low pH increases the chronic toxicity of Pb whereas increased alkalinity is protective. The findings reported herein support the need for a chronic Pb BLM as an alternative approach to hardness-based regulations.

  6. 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

  7. Toxicity of sediments and interstitial waters form the Southern California Bight

    Energy Technology Data Exchange (ETDEWEB)

    Bay, S.; Greenstein, D.; Brown, J.; Jirik, A. [Southern California Coastal Water Research Project, Westminster, CA (United States)

    1995-12-31

    The toxicity of 72 sediment samples collected during the EMAP Southern California Bight Pilot Project (SCBPP) was measured. Sediments from the mainland shelf between Point Conception and the Mexican border were collected from various depths and tested for toxicity using two methods. The toxicity of bulk sediment was measured using a 10-day amphipod (Ampelisca abdita) survival test. Interstitial water was also extracted from the samples and tested for toxicity using a 72-hour sea urchin (Strongylocentrotus purpuratus) embryo development test. Amphipod survival was high (> 80%) at all stations tested, although several sites near large sewage outfalls had statistically significant reductions in survival. No interference related to grain size variation was observed with the amphipod test. Most of the interstitial water samples produced abnormal sea urchin embryo development. Effects were not related to the presumed level of sediment contamination, but rather to ammonia concentration in virtually all cases. The impacts of sample handling procedures and ammonia on sediment toxicity data interpretation will be discussed.

  8. The water flea (Daphnia magna) as a sensitive indicator for the assessment of toxicity of synthetic detergents.

    Science.gov (United States)

    Lal, H; Misra, V; Viswanathan, P N; Murti, C R

    1984-10-01

    The water flea (Daphnia magna) was used as a sensitive indicator for assessing the toxicity due to synthetic detergents. Acute and chronic toxicity of detergents to the water flea was studied under laboratory conditions by following the median tolerance limit (TLM) at 48 hr and the rate of survival. A significant decrease in the rate of reproduction (number of hatching and neonates produced) were found at 21 days. During acute toxicity studies behavioural changes were also noticed.

  9. 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 ...

  10. Teratological effects of a panel of sixty water-soluble toxicants on zebrafish development.

    Science.gov (United States)

    Ali, Shaukat; Aalders, Jeffrey; Richardson, Michael K

    2014-04-01

    The zebrafish larva is a promising whole-animal model for safety pharmacology, environmental risk assessment, and developmental toxicity. This model has been used for the high-throughput toxicity screening of various compounds. Our aim here is to identify possible phenotypic markers of teratogenicity in zebrafish embryos that could be used for the assaying compounds for reproductive toxicity. We have screened a panel of 60 water-soluble toxicants to examine their effects on zebrafish development. A total of 22,080 wild-type zebrafish larvae were raised in 250 μL defined buffer in 96-well plates at a plating density of one embryo per well. They were exposed for a 96-h period starting at 24 h post-fertilization. A logarithmic concentration series was used for range-finding, followed by a narrower geometric series for developmental toxicity assessment. A total of 9017 survivors were analyzed at 5 days post-fertilization for nine phenotypes, namely, (1) normal, (2) pericardial oedema, (3) yolk sac oedema, (4) melanophores dispersed, (5) bent tail tip, (6) bent body axis, (7) abnormal Meckel's cartilage, (8) abnormal branchial arches, and (9) uninflated swim bladder. For each toxicant, the EC50 (concentration required to produce one or more of these abnormalities in 50% of embryos) was also calculated. For the majority of toxicants (55/60) there was, at the population level, a statistically significant, concentration-dependent increase in the incidence of abnormal phenotypes among survivors. The commonest abnormalities were pericardial oedema, yolk sac oedema, dispersed melanophores, and uninflated swim bladder. It is possible therefore that these could prove to be general indicators of reproductive toxicity in the zebrafish embryo assay.

  11. A Lymnaea stagnalis Embryo Test for Toxicity Bioindication of Acidification and Ammonia Pollution in Water

    Directory of Open Access Journals (Sweden)

    Robert Mazur

    2016-07-01

    Full Text Available The paper presents a study leading to a new acute toxicity test on embryonic and juvenile organisms of the great pond snail (Lymnaea stagnalis Linnaeus. Sulfuric acid, nitric acid, and ammonium hydroxide were used as waterborne toxicants in laboratory experiments. The exposure time was 24 h. Tests were conducted in 5–10 replications for each toxicant. The toxicity of the substances was classified according to different scales and the test’s sensitivity was compared to that of the commonly used bioindicator Daphnia magna Straus. The assessment of toxicity impact was supported by microscopic observations. The probit method was used as a parametric statistical procedure to estimate LC50 and the associated 95% confidence interval. Our study showed that the early developmental stages of Lymnaea stagnalis are very sensitive bioindicators, making it possible to detect even very low levels of the above-mentioned water toxicants. The highest toxicity is shown by ammonium hydroxide with LC50/24h values, respectively, 24.27 for embryos and 24.72 for juvenile forms, and the lowest is shown by nitric acid ions with LC50/24h values, respectively, 105.19 for embryos and 170.47 for juvenile forms. It is highly cost-effective due to simple and efficient breeding and the small size of the organisms in the bioassay population. Compared with Daphnia magna, relatively low concentrations of toxicants caused a lethal effect on embryonic and juvenile organisms of the great pond snail. Owing to their common occurrence and sensitivity, early developmental forms of Lymnaea stagnalis can be a valuable new tool in biomonitoring of the freshwater environment.

  12. 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.

  13. 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

  14. APL-UW Deep Water Propagation: Philippine Sea Signal Physics and North Pacific Ambient Noise

    Science.gov (United States)

    2015-10-15

    oceans (Dyer 1988, Roth et al. 2012). www.annualreviews.org • Sounds in the Ocean at 1–100 Hz 125 A nn u. R ev . M ar in e. S ci . 2 01 4. 6: 11 7...Acoust. Bull. 18:5–8 Roth E, Hildebrand J, Wiggins S, Ross D. 2012. Underwater ambient noise on the Chukchi Sea continental slope from 2006–2009. J...Thurstan, R.H., and C.M. Roberts. 2010. Ecological Meltdown in the Firth of Clyde, Scotland : Two Centuries of Change in a Coastal Marine Ecosystem. PLoS ONE

  15. Influence of water quality and age on nickel toxicity to fathead minnows (Pimephales promelas).

    Science.gov (United States)

    Hoang, Tham Chung; Tomasso, Joseph R; Klaine, Stephen J

    2004-01-01

    This research characterized the effects of water quality and organism age on the toxicity of nickel (Ni) to fathead minnows (Pimephales promelas) to facilitate the accurate development of site-specific water-quality criteria. Nickel sulfate hexahydrate (NiSO4 x 6H2O) was used as the Ni source for performing acute toxicity tests (median lethal concentration after 96-h exposure [96-h LC50]) with hardness, pH, alkalinity, and natural organic matter (NOM). The toxicity of Ni was inversely related to water hardness between hardness values of 20 and 150 mg/L (as CaCO3). Below 30 mg/L alkalinity, Ni toxicity was related to alkalinity. The effect of pH was confounded by hardness and the presence of NOM. In the absence of NOM, the toxicity of Ni increased as pH increased at high hardness and alkalinity. In general, 28-d-old fish were less sensitive than hardness and alkalinity (20 and 4 mg/L, respectively) to 5-fold at high hardness and alkalinity (100 and 400 mg/L, respectively). The presence of NOM (10 mg/L as dissolved organic carbon [DOC]) reduced Ni toxicity by up to 50%, but this effect appeared to be saturated above DOC at 5 mg/L. Incubating Ni with the NOM solution from 1 to 17 days had no effect on Ni toxicity. When using multivariate analysis, the 96-h LC50 for Ni was a function of fish age, alkalinity, hardness, and NOM (96-h LC50 = -0.642 + 0.270(fish age) + 0.005(alkalinity) + 0.018(hardness) + 0.138(DOC)). When using this model, we found a strong relationship between measured and predicted 96-h LC50 values (r2 = 0.94) throughout the treatment water qualities. The biotic ligand model (BLM) did not accurately predict Ni toxicity at high or low levels of alkalinity. Results of our research suggest that the BLM could be improved by considering NiCO3 to be bioavailable.

  16. Supercritical water oxidation for the destruction of toxic organic wastewaters: A review

    Institute of Scientific and Technical Information of China (English)

    VERIANSYAH Bambang; KIM Jae-Duck

    2007-01-01

    The destruction of toxic organic wastewaters from munitions demilitarization and complex industrial chemical clearly becomes an overwhelming problem if left to conventional treatment processes. Two options, incineration and supercritical water oxidation (SCWO), exist for the complete destruction of toxic organic wastewaters. Incinerator has associated problems such as very high cost and public resentment; on the other hand, SCWO has proved to be a very promising method for the treatment of many different wastewaters with extremely efficient organic waste destruction 99.99% with none of the emissions associated with incineration. In this review, the concepts of SCWO, result and present perspectives of application, and industrial status of SCWO are critically examined and discussed.

  17. 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

  18. Development of toxicity tolerant water hyacinth `(Eichhornea crassipes)` for effective treatment of raw sewage

    Energy Technology Data Exchange (ETDEWEB)

    Ayade, B.B. [Ibadan Univ. (Nigeria). Dept. of Botany and Microbiology

    1998-06-01

    Pioneering research efforts in the handling of municipal sewage in developing countries have involved the use of water hyacinth (Eichhornea crassipes) to purify sewage for possible re-use of the effluent water for domestic purposes. The ability of water hyacinth to remove pollution from raw sewage has been found to be impaired by sewage toxicity. Trials were therefore carried out to adapt water hyacinth to toxicity and thereby increase its ability to remove pollutants from raw sewage. The plants were adapted using an active bio-degrader consisting of Pseudomonas aeruginosa, Escherichia coli, Klebsiella ozaenae, Klebsiella edwardsiella and Baccillus subtilis. The adaption progressed through 20, 40, 60 and 80% sewage dilution until plants capable of growth in 100% raw sewage were obtained. Plants were observed for morphological growth and at four weeks, samples wer collected for tissue analysis. The plants progressively absorbed nutrients from sewage up to the fourth week, when signs of toxicity were observed through wilting, loss of turgidity and reduction in leaf number. However, plants that survived through a series of adaptations under various sewage dilutions exhibited luxuriant growth on raw sewage. In synergy with the active bio-degrader, the efficiency of the adapted water hyacinth to remove pollutants (nutrients) from raw sewage was enhanced by 93%. (orig.)

  19. Investigation of Toxic Heavy Metals in Drinking Water of Agra City, India

    Directory of Open Access Journals (Sweden)

    P. Susan Verghese

    2015-09-01

    Full Text Available Water quality of Agra city is impaired by the presence of large number of industries in the city. From the observed data it is found that drinking water of Agra city is contaminated with toxic heavy metals like chromium, copper, cadmium, lead, and nickel. Among all these heavy metals, chromium is found to be in comparatively large amounts because most of the leather industries located in Agra city adopt chrome tanning procedure as their basic step for dehairing and dehiding. Presence of high concentration of chromium and other heavy metals in drinking water pose deleterious effects on the health of human beings therefore it becomes necessary to employ certain technological methods to keep the concentration of such toxic heavy metals within their desirable limits.

  20. An automated overlying water-renewal system for sediment toxicity studies

    Energy Technology Data Exchange (ETDEWEB)

    Rand, G.M.; Wheat, J.V.; Carriger, J.F.; Lee, T.A

    2003-04-01

    A new system is described for sediment toxicity testing. - An automated water-renewal toxicity test system is described for exposing benthic invertebrates to whole sediments. The system will intermittently deliver laboratory or on-site water for overlying water replacement in sediment exposures. A range of cycle rates can be used to produce different volume additions of overlying water per day to exposure chambers. The system can be used with six different treatments and eight replicates per treatment producing 48 exposure chambers. Three formulated sediments with variable organic carbon (1.5%, 7.5%) and sand (14%, 63%) content were prepared to test the system exposing amphipods, Hyalella azteca and midges, Chironomus tentans in 10 day whole sediment tests. Intermittent water flow was used with a 90 min cycle time to create two volume additions of laboratory water per 24 h in exposure chambers (180 ml sediment, 320 ml water). Overlying water quality conditions, and survival and growth of both species were consistent and within acceptable limits for the testing requirements of the U.S. EPA guidelines for sediments with freshwater invertebrates.

  1. Monitoring of potentially toxic cyanobacteria using an online multi-probe in drinking water sources.

    Science.gov (United States)

    Zamyadi, A; McQuaid, N; Prévost, M; Dorner, S

    2012-02-01

    Toxic cyanobacteria threaten the water quality of drinking water sources across the globe. Two such water bodies in Canada (a reservoir on the Yamaska River and a bay of Lake Champlain in Québec) were monitored using a YSI 6600 V2-4 (YSI, Yellow Springs, Ohio, USA) submersible multi-probe measuring in vivo phycocyanin (PC) and chlorophyll-a (Chl-a) fluorescence, pH, dissolved oxygen, conductivity, temperature, and turbidity in parallel. The linearity of the in vivo fluorescence PC and Chl-a probe measurements were validated in the laboratory with Microcystis aeruginosa (r(2) = 0.96 and r(2) = 0.82 respectively). Under environmental conditions, in vivo PC fluorescence was strongly correlated with extracted PC (r = 0.79) while in vivo Chl-a fluorescence had a weaker relationship with extracted Chl-a (r = 0.23). Multiple regression analysis revealed significant correlations between extracted Chl-a, extracted PC and cyanobacterial biovolume and in vivo fluorescence parameters measured by the sensors (i.e. turbidity and pH). This information will help water authorities select the in vivo parameters that are the most useful indicators for monitoring cyanobacteria. Despite highly toxic cyanobacterial bloom development 10 m from the drinking water treatment plant's (DWTP) intake on several sampling dates, low in vivo PC fluorescence, cyanobacterial biovolume, and microcystin concentrations were detected in the plant's untreated water. The reservoir's hydrodynamics appear to have prevented the transport of toxins and cells into the DWTP which would have deteriorated the water quality. The multi-probe readings and toxin analyses provided critical evidence that the DWTP's untreated water was unaffected by the toxic cyanobacterial blooms present in its source water.

  2. The effect of the cation alkyl chain branching on mutual solubilities with water and toxicities

    Science.gov (United States)

    Kurnia, Kiki A.; Sintra, Tânia E.; Neves, Catarina M. S. S.; Shimizu, Karina; Lopes, José N. Canongia; Gonçalves, Fernando; Ventura, Sónia P. M.; Freire, Mara G.; Santos, Luís M. N. B. F.; Coutinho, João A. P.

    2014-01-01

    The design of ionic liquids has been focused on the cation-anion combinations but other more subtle approaches can be used. In this work the effect of the branching of the cation alkyl chain on the design of ionic liquids (ILs) is evaluated. The mutual solubilities with water and toxicities of a series of bis(trifluoromethylsulfonyl)-based ILs, combined with imidazolium, pyridinium, pyrrolidinium, and piperidinium cations with linear or branched alkyl chains, are reported. The mutual solubility measurements were carried out in the temperature range from (288.15 to 323.15) K. From the obtained experimental data, the thermodynamic properties of the solution (in the water-rich phase) were determined and discussed. The COnductor like Screening MOdel for Real Solvents (COSMO-RS) was used to predict the liquid-liquid equilibrium. Furthermore, molecular dynamic simulations were also carried out aiming to get a deeper understanding of these fluids at the molecular level. The results show that the increase in the number of atoms at the cation ring (from five to six) leads to a decrease in the mutual solubilities with water while increasing their toxicity, and as expected from the well-established relationship between toxicities and hydrophobicities of ILs. The branching of the alkyl chain was observed to decrease the water solubility in ILs, while increasing the ILs solubility in water. The inability of COSMO-RS to correctly predict the effect of branching alkyl chains toward water solubility on them was confirmed using molecular dynamic simulations to be due to the formation of nano-segregated structures of the ILs that are not taken into account by the COSMO-RS model. In addition, the impact of branched alkyl chains on the toxicity is shown to be not trivial and to depend on the aromatic nature of the ILs. PMID:25119425

  3. Surface chemistry of rare-earth oxide surfaces at ambient conditions: reactions with water and hydrocarbons

    Science.gov (United States)

    Külah, Elçin; Marot, Laurent; Steiner, Roland; Romanyuk, Andriy; Jung, Thomas A.; Wäckerlin, Aneliia; Meyer, Ernst

    2017-01-01

    Rare-earth (RE) oxide surfaces are of significant importance for catalysis and were recently reported to possess intrinsic hydrophobicity. The surface chemistry of these oxides in the low temperature regime, however, remains to a large extent unexplored. The reactions occurring at RE surfaces at room temperature (RT) in real air environment, in particular, in presence of polycyclic aromatic hydrocarbons (PAHs), were not addressed until now. Discovering these reactions would shed light onto intermediate steps occurring in automotive exhaust catalysts before reaching the final high operational temperature and full conversion of organics. Here we first address physical properties of the RE oxide, nitride and fluoride surfaces modified by exposure to ambient air and then we report a room temperature reaction between PAH and RE oxide surfaces, exemplified by tetracene (C18H12) on a Gd2O3. Our study evidences a novel effect – oxidation of higher hydrocarbons at significantly lower temperatures (~300 K) than previously reported (>500 K). The evolution of the surface chemical composition of RE compounds in ambient air is investigated and correlated with the surface wetting. Our surprising results reveal the complex behavior of RE surfaces and motivate follow-up studies of reactions between PAH and catalytic surfaces at the single molecule level. PMID:28327642

  4. 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.

  5. 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.

  6. In-situ X-ray photoelectron spectroscopy studies of water on metals and oxides at ambient conditions

    Energy Technology Data Exchange (ETDEWEB)

    Salmeron, Miquel; Yamamoto, S.; Bluhm, H.; Andersson, K.; Ketteler, G.; Ogasawara, H.; Salmeron, M.; Nilsson, A.

    2007-10-29

    X-ray photoelectron spectroscopy (XPS) is a powerful tool for surface and interface analysis, providing the elemental composition of surfaces and the local chemical environment of adsorbed species. Conventional XPS experiments have been limited to ultrahigh vacuum (UHV) conditions due to a short mean free path of electrons in a gas phase. The recent advances in instrumentation coupled with third-generation synchrotron radiation sources enables in-situ XPS measurements at pressures above 5 Torr. In this review, we describe the basic design of the ambient pressure XPS setup that combines differential pumping with an electrostatic focusing. We present examples of the application of in-situ XPS to studies of water adsorption on the surface of metals and oxides including Cu(110), Cu(111), TiO2(110) under environmental conditions of water vapor pressure. On all these surfaces we observe a general trend where hydroxyl groups form first, followed by molecular water adsorption. The importance of surface OH groups and their hydrogen bonding to water molecules in water adsorption on surfaces is discussed in detail.

  7. Evaluation of the effect of water type on the toxicity of nitrate to aquatic organisms.

    Science.gov (United States)

    Baker, Josh A; Gilron, Guy; Chalmers, Ben A; Elphick, James R

    2017-02-01

    A suite of acute and chronic toxicity tests were conducted to evaluate the sensitivity of freshwater organisms to nitrate (as sodium nitrate). Acute exposures with rainbow trout (Onchorhynchus mykiss) and amphipods (Hyalella azteca), as well as chronic exposures with H. azteca (14-d survival and growth), midges (Chironomus dilutus; 10-d survival and growth), daphnids (Ceriodaphnia dubia; 7-d survival and reproduction), and fathead minnows (Pimephales promelas; 7-d survival and growth) were used to determine sublethal and lethal effect concentrations. Modification of nitrate toxicity was investigated across a range of ionic strengths, created through the use of very soft water, and standard preparations of synthetic soft, moderately-hard and hard dilution waters. The most sensitive species tested were C. dubia and H. azteca, in soft water, with reproduction and growth IC25 values of 13.8 and 12.2 mg/L NO3-N, respectively. All of the organisms exposed to nitrate demonstrated significantly reduced effects with increasing ionic strength associated with changes in water type. Possible mechanisms responsible for the modifying effect of increasing major ion concentrations on nitrate toxicity are discussed.

  8. Evaluating the impact of ambient benzene vapor concentrations on product water from Condensation Water From Air technology.

    Science.gov (United States)

    Kinder, Katherine M; Gellasch, Christopher A; Dusenbury, James S; Timmes, Thomas C; Hughes, Thomas M

    2017-07-15

    Globally, drinking water resources are diminishing in both quantity and quality. This situation has renewed interest in Condensation Water From Air (CWFA) technology, which utilizes water vapor in the air to produce water for both potable and non-potable purposes. However, there are currently insufficient data available to determine the relationship between air contaminants and the rate at which they are transferred from the air into CWFA untreated product water. This study implemented a novel experimental method utilizing an environmental test chamber to evaluate how air quality and temperature affects CWFA untreated product water quality in order to collect data that will inform the type of water treatment required to protect human health. This study found that temperature and benzene air concentration affected the untreated product water from a CWFA system. Benzene vapor concentrations representing a polluted outdoor environment resulted in benzene product water concentrations between 15% and 23% of the USEPA drinking water limit of 5μg/l. In contrast, product water benzene concentrations representing an indoor industrial environment were between 1.4 and 2.4 times higher than the drinking water limit. Lower condenser coil temperatures were correlated with an increased concentration of benzene in the product water. Environmental health professionals and engineers can integrate the results of this assessment to predict benzene concentrations in the product water and take appropriate health protective measures.

  9. Influences of water chemistry on the acute toxicity of lead to Pimephales promelas and Ceriodaphnia dubia.

    Science.gov (United States)

    Mager, Edward M; Esbaugh, Andrew J; Brix, Kevin V; Ryan, Adam C; Grosell, Martin

    2011-01-01

    The acute toxicity of lead (Pb) was examined for fathead minnows (Pimephales promelas; 96-h) and daphnids (Ceriodaphnia dubia; 48-h) in waters modified for hardness (as CaSO₄), dissolved organic carbon (DOC; as Aldrich humic acid) and alkalinity (as NaHCO₃) for parameterization of an acute freshwater biotic ligand model (BLM). Additionally, acute (96-h) and chronic (30-d) bioassays were performed for P. promelas to more clearly define the influence of pH (5.5-8.3) on Pb toxicity as modified by addition of HCl or NaOH using an automated titration system. Results indicate that Ca(2+) is protective against acute Pb toxicity to P. promelas but not C. dubia. Strong protection was afforded by DOC and NaHCO(3) against acute Pb toxicity to P. promelas, whereas milder protection was observed for C. dubia with both parameters. Dissolved Pb LC50s from the P. promelas pH bioassays revealed a complex effect of pH on Pb toxicity, likely explained in part by Pb speciation and the competitive interaction of H(+) with ionic Pb(2+). Chronic pH bioassays also demonstrated that 30-d growth is not impaired in fathead minnows at relevant Pb concentrations. The findings reported herein suggest that development of separate BLMs for P. promelas and C. dubia should be considered.

  10. 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.

  11. Influence of water chemistry on the acute toxicity of copper and zinc to the cladoceran Ceriodaphnia cf dubia.

    Science.gov (United States)

    Hyne, Ross V; Pablo, Fleur; Julli, Moreno; Markich, Scott J

    2005-07-01

    This study determined the influence of key water chemistry parameters (pH, alkalinity, dissolved organic carbon [DOC], and hardness) on the aqueous speciation of copper and zinc and its relationship to the acute toxicity of these metals to the cladoceran Ceriodaphnia cf dubia. Immobilization tests were performed for 48-h in synthetic or natural waters buffered at various pH values from 5.5 to 8.4 (other chemical parameters held constant). The toxicity of copper to C. cf dubia decreased fivefold with increasing pH, whereas the toxicity of zinc increased fivefold with increasing pH. The effect of DOC on copper and zinc toxicity to C. cf dubia was determined using natural fulvic acid in the synthetic water. Increasing DOC was found to decrease linearly the toxicity of copper, with the mean effect concentration of copper that immobilized 50% of the cladocerans (EC50) value 45 times higher at 10 mg/L, relative to 0.1 mg/L DOC at pH 6.5. In contrast, the addition of 10 mg/L DOC only resulted in a very small (1.3-fold) reduction in the toxicity of zinc to C. cf dubia. Copper toxicity to C. cf dubia generally did not vary as a function of hardness, whereas zinc toxicity was reduced by a factor of only two, with an increase in water hardness from 44 to 374 mg CaCO3/L. Increasing bicarbonate alkalinity of synthetic waters (30-125 mg/L as CaCO3) decreased the toxicity of copper up to fivefold, which mainly could be attributed to the formation of copper-carbonate complexes, in addition to a pH effect. The toxicity of copper added to a range of natural waters with varying DOC content, pH, and hardness was consistent with the toxicity predicted using the data obtained from the synthetic waters.

  12. Phase state of ambient aerosol linked with water uptake and chemical aging in the southeastern US

    Science.gov (United States)

    Pajunoja, Aki; Hu, Weiwei; Leong, Yu J.; Taylor, Nathan F.; Miettinen, Pasi; Palm, Brett B.; Mikkonen, Santtu; Collins, Don R.; Jimenez, Jose L.; Virtanen, Annele

    2016-09-01

    During the summer 2013 Southern Aerosol and Oxidant Study (SOAS) field campaign in a rural site in the southeastern United States, the effect of hygroscopicity and composition on the phase state of atmospheric aerosol particles dominated by the organic fraction was studied. The analysis is based on hygroscopicity measurements by a Hygroscopic Tandem Differential Mobility Analyzer (HTDMA), physical phase state investigations by an Aerosol Bounce Instrument (ABI) and composition measurements using a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). To study the effect of atmospheric aging on these properties, an OH-radical oxidation flow reactor (OFR) was used to simulate longer atmospheric aging times of up to 3 weeks. Hygroscopicity and bounce behavior of the particles had a clear relationship showing higher bounce at elevated relative humidity (RH) values for less hygroscopic particles, which agrees well with earlier laboratory studies. Additional OH oxidation of the aerosol particles in the OFR increased the O : C and the hygroscopicity resulting in liquefying of the particles at lower RH values. At the highest OH exposures, the inorganic fraction starts to dominate the bounce process due to production of inorganics and concurrent loss of organics in the OFR. Our results indicate that at typical ambient RH and temperature, organic-dominated particles stay mostly liquid in the atmospheric conditions in the southeastern US, but they often turn semisolid when dried below ˜ 50 % RH in the sampling inlets. While the liquid phase state suggests solution behavior and equilibrium partitioning for the SOA particles in ambient air, the possible phase change in the drying process highlights the importance of thoroughly considered sampling techniques of SOA particles.

  13. Investigating salt and naphthenic acids interactions in the toxicity of oil sands process water to freshwater invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Turcotte, D.; Kautzman, M.; Wojnarowicz, P.; Cutter, J.; Bird, E.; Liber, K. [Saskatchewan Univ., Regina, SK (Canada)

    2010-07-01

    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.

  14. Development of Low-Toxicity Urine Stabilization for Spacecraft Water Recovery Systems

    Science.gov (United States)

    Adam, Niklas; Mitchell, Julie L.; Pickering, Karen D.

    2012-01-01

    Wastewater stabilization is an essential component of the spacecraft water cycle. The purpose of stabilizing wastewater is 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 is 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.

  15. Development of Low-Toxicity Wastewater Stabilization for Spacecraft Water Recovery Systems

    Science.gov (United States)

    Mitchell, Julie L.; Adam, Niklas; Pickering, Karen D.; Alvarez, Giraldo N.

    2015-01-01

    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-milliliter 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.

  16. Assessment of the toxicity of waste water from a textile industry to Cyprinus carpio.

    Science.gov (United States)

    Roopadevi, H; Somashekar, R K

    2012-03-01

    Static, short-term, acute toxicity tests were performed over a period of 96 hrs using different concentrations of influent and effluent of textile industry waste water with the objective of evaluating their acute toxicity on fresh water fish, Cyprinus carpio (common carp). The LC50 24, 48, 72 and 96 hr of influent and effluent were 25.9, 21.10, 15.66, 11.11% (v/v) and 63.18, 54.89, 48.62, 36.04% (v/v), respectively. The acute toxic unit TUa values for 24, 48, 72, 96 hr for influent and effluent are 3.85, 4.73, 6.38, 8.99 and 1.58, 1.82, 2.05, 2.77, respectively. Correspondingly, the TF was found to be 1, 1.22, 1.65 and 2.33 for influent, and for effluent 1, 1.15, 1.29 and 1.75. Total efficiency of the treatment was 69.16% and the safe concentration of effluent is set to be 3.60%. These data are highly useful in establishing limits of acceptability by the aquatic animals. The need to introduce toxicity evaluation assay for confirming the quality of effluent from the point view of effective environmental safe limits and to ensure integrity of aquatic environment, is stressed.

  17. 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.

  18. Steady state method to determine unsaturated hydraulic conductivity at the ambient water potential

    Science.gov (United States)

    HUbbell, Joel M.

    2014-08-19

    The present invention relates to a new laboratory apparatus for measuring the unsaturated hydraulic conductivity at a single water potential. One or more embodiments of the invented apparatus can be used over a wide range of water potential values within the tensiometric range, requires minimal laboratory preparation, and operates unattended for extended periods with minimal supervision. The present invention relates to a new laboratory apparatus for measuring the unsaturated hydraulic conductivity at a single water potential. One or more embodiments of the invented apparatus can be used over a wide range of water potential values within the tensiometric range, requires minimal laboratory preparation, and operates unattended for extended periods with minimal supervision.

  19. 流溪河水库局域水体环境影响度评价及有机污染物毒性效应%Ambient Severity Evaluation and Toxicity Effect of Organic Pollutants in Liuxihe Reservoir, China

    Institute of Scientific and Technical Information of China (English)

    刘凤; 刘立; 张荣飞; 钱新; 李梅

    2013-01-01

    The risk of water resources being contaminated by organic pollutants is of major concern.The Liuxihe reservoir is one of the most important fresh water resources for Guangzhou City,supplying nearly 60% of the city's fresh water demands.Identification and monitoring of these pollutants in the Liuxihe reservoir is of critical importance in an attempt to protect ecological and human health.In this study,semivolatile organic compounds(SOVCs) in Liuxihe reservoir were determined by a gas chromatography method with mass spectrometric (GC-MS) detection.Ambient severity due to exposure to these organic pollutants was evaluated with multimedia environmental goals(MEG).MEG is the environmental capacity of chemicals and limit values of emission which was calculated by environmental industry laboratory of United States Environmental Protection Agency(EPA).The environmental goals in the MEG,include air,water and soil,and each one is divided into health goals and ecological objectives.Ambient severity(AS) is the ratio of the measured concentration of a compound with the corresponding value of MEG,which is divided into health severity(ASⅠ) and ecology severity(ASⅡ).Higher values of AS mean pollutants cause more influence on water.The results indicated that total contents of 23 different SVOCs from water samples were 6.078 μg· L-1 and 24.952 μg· L-1,respectively,and benzo(a) anthracene,dibutyl phthalate and 2,4-nitrotoluene were the main SVOCs.The total ambient severity of both health and ecology was less than 1,which indicated that water in Liuxihe reservoir was still safe to health and ecology.Routine physical and chemical analysis was not sufficient to make comprehensive evaluation of water quality,so the establishment of an effective test method to evaluate the ecotoxicity of organic compounds in water was of importance to environmental monitoring.The potential toxicity of water samples on the microalgae Scenedesmus obliquus was measured.Organic extracts from the

  20. Acute and chronic oral toxicity of standardized water extract from the fruit of Phyllanthus emblica Linn.

    Directory of Open Access Journals (Sweden)

    K Jaijoy

    2010-03-01

    Full Text Available Summary: Phyllanthus emblica Linn. (Euphorbiaceae is an herbal plant commonly used in Asian traditional medicine systems for treatment of many disorders. In the present study, we investigated for the first time acute and chronic toxicity of the standardized water extract of P. emblica fruit. The water extract of P. emblica was prepared according to the Thai Herbal Pharmacopoeia and standardized to 20% gallic acid. For studying acute toxicity study, single oral dose of 5000 mg water extract /kg body weight was administered to Sprague Dawley rats (five females, five males. The results showed no toxicity in terms of general behavior change, mortality, or change in gross appearance of internal organs (LD50 > 5,000 mg/kg. Chronic toxicity was studied by daily oral dose (ten females, ten males of 300, 600 and 1,200 mg/kg for 270 days. The results showed slightly significant differences in the body and organ weights between the control and treatment groups. In addition, the rats were analyzed for final body and organ weights, necropsy, and hematological, blood chemical and histopathological parameters. Hematological analysis and clinical blood chemistry revealed slightly changes, but were within the normal limits. No gross or histopathology findings were observed in the treatment groups. Altogether, the standardized water extract from the fruit of P. emblica did not produce acute and chronic toxicity in its traditional uses. Industrial relevance: Traditional medicine is still stronghold of more than 50% of the world population, especially in developing countries. Nowadays, a number of medicinal plants (such as Phyllanthus emblica Linn. are commercially available on local markets as a tonic, food and/or dietary supplement product commonly used for clinical management of several conditions. Despite the widespread use of this plant, there is still little literature on the scientific evaluation of their toxicity. Results of the current study provide

  1. Toxicity test using medaka (Oryzias latipes) early fry and concentrated sample water as an index of aquatic habitat condition.

    Science.gov (United States)

    Yamashita, H; Haribowo, R; Sekine, M; Oda, N; Kanno, A; Shimono, Y; Shitao, W; Higuchi, T; Imai, T; Yamamoto, K

    2011-08-01

    The aim of the present study was to show a relationship between toxicity of 100-fold concentrated water and aquatic habitat conditions. Environmental waters are 100-fold concentrated with solid-phase extraction. Medaka early fry was exposed in these waters for 48 h. The number of death and disorder was counted at 1, 2, 3, 6, 12, 24, and 48 h; toxicity was expressed using inverse median effect time and median lethal time (ET (50)(-1), LT (50)(-1)). Average score per taxon (ASPT) for benthic animals and Index of Biotic Integrity (IBI) for fish were applied as indices of aquatic habitat conditions. The results of toxicity test were compared using ASPT and IBI. The different levels of toxicity were detected in the seawater of Japan. At the Husino River area, toxicity cannot be detected. In rivers, high toxicity appeared at urban districts without sewerage. By Spearman coefficient, the relationship between toxicity and high biochemical oxygen demand (BOD) were obtained. BOD household wastewater contains hydrophobic toxic matters; otherwise, seawater in industrial area does not show clear relationship between toxicity and chemical oxygen demand. Gas chromatography to mass spectrometry simultaneous analysis database may give an answer for the source of toxicity, but further test is required. Ratio of clear stream benthic animal sharply decreased over 0.25 of LT (50)(-1) or 0.5 of ET (50)(-1). Tolerant fish becomes dominant over 0.3 of LT (50)(-1) or 0.5-1.0 of ET (50)(-1). By Pearson product-moment correlation coefficient, correlation coefficient between toxicity and ASPT was obtained at -0.773 (ET (50)(-1)) and -0.742 (LT (50)(-1)) at 1 % level of significance with a high negative correlation. Toxicity (LT (50)(-1) ) has strong correlation with the ratio of tolerant species. By Pearson product-moment correlation coefficient, correlation coefficient between toxicity and IBI obtained were -0.155 (ET (50)(-1)) and -0.190 (LT (50)(-1)) at 1 % level of significance and has a

  2. The biomonitoring and bioremediation of toxic water resulting from municipal waste storage of Somârd, Sibiu county

    OpenAIRE

    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...

  3. Small guide establishing eco-toxicity of soil and water (In Romanian

    Directory of Open Access Journals (Sweden)

    Crina L. Mosneang

    2014-06-01

    Full Text Available Soil and water ecotoxicity is one of the major concerns with important implications for human and animal life's quality. Consequently, there were appeared many methods to determine the level of environmental pollution, which in the last decade have seen a tremendous development, with the implementation of European and national legislations. The present review is intended to familiarize readers with some indicators of water pollution and soil testing; testing that zebra fish and earthworm bodies recognized as viable and sensitive indicators of pollution.It describes the testing methodology known: acute and chronic toxicity on fish; determining pollution by using earthworms (OECD Protocol 207. In addition, analytical methodology chapter establishing eco-toxicity is summarized soil and gas chromatography coupled with mass spectrometry (GC-MS and applications in determining the degree of environmental pollution, and the last chapter is presented legislation manure management in the EU and Romanian legislation related.

  4. Small guide establishing eco-toxicity of soil and water (In Romanian

    Directory of Open Access Journals (Sweden)

    Crina Laura Mosneang

    2014-06-01

    Full Text Available Soil and water ecotoxicity is one of the major concerns with important implications for human and animal life’s quality. Consequently, there were appeared many methods to determine the level of environmental pollution, which in the last decade have seen a tremendous development, with the implementation of European and national legislations. The present review is intended to familiarize readers with some indicators of water pollution and soil testing; testing that zebra fish and earthworm bodies recognized as viable and sensitive indicators of pollution.It describes the testing methodology known: acute and chronic toxicity on fish; determining pollution by using earthworms (OECD Protocol 207. In addition, analytical methodology chapter establishing eco-toxicity is summarized soil and gas chromatography coupled with mass spectrometry (GC-MS and applications in determining the degree of environmental pollution, and the last chapter is presented legislation manure management in the EU and Romanian legislation related.

  5. Small guide establishing eco-toxicity of soil and water (In Romanian

    Directory of Open Access Journals (Sweden)

    Crina Laura Mosneang

    2014-05-01

    Full Text Available Soil and water ecotoxicity is one of the major concerns with important implications for human and animal life’s quality. Consequently, there were appeared many methods to determine the level of environmental pollution, which in the last decade have seen a tremendous development, with the implementation of European and national legislations. The present review is intended to familiarize readers with some indicators of water pollution and soil testing; testing that zebra fish and earthworm bodies recognized as viable and sensitive indicators of pollution.It describes the testing methodology known: acute and chronic toxicity on fish; determining pollution by using earthworms (OECD Protocol 207. In addition, analytical methodology chapter establishing eco-toxicity is summarized soil and gas chromatography coupled with mass spectrometry (GC-MS and applications in determining the degree of environmental pollution, and the last chapter is presented legislation manure management in the EU and Romanian legislation related.

  6. Elimination of drugs of abuse and their toxicity from natural waters by photo-Fenton treatment.

    Science.gov (United States)

    Catalá, M; Domínguez-Morueco, N; Migens, A; Molina, R; Martínez, F; Valcárcel, Y; Mastroianni, N; López de Alda, M; Barceló, D; Segura, Y

    2015-07-01

    This paper investigates the elimination of drugs of abuse from six different chemical classes and their metabolites in natural fluvial waters (nearby the output of a sewage system). Mineralization of these substances and toxicological characterization before and after treatment by a heterogeneous photo-Fenton system has been evaluated. This advanced oxidation technology was able to significantly reduce the concentration of the drugs of abuse in all the tested conditions (different hydrogen peroxide and catalyst loadings). However, toxicological analyses measured as inhibition of fern spore mitochondrial activity, showed only a complete elimination of acute and chronic toxicity when a higher solid catalyst loading was used (0.6 g/L). A lower catalyst loading of 0.2 g/L was not enough for toxicity elimination. These results evidence the need for combining toxicological tests and chemical analyses in order to establish the effectiveness of the water treatment technologies based on advanced oxidation processes.

  7. Sustainability, Water and Environment in Spain; Sostenibilidad, Agua y Medio Ambiente en Espana

    Energy Technology Data Exchange (ETDEWEB)

    Arias, M. M.

    2003-07-01

    The past June 5, Worldwide Day of the Environment, dedicated to the sweet water, the Spanish Club of the Environment realized, as every year, its particular celebration, with a lunch-colloquium over the situation of the sweet water in Spain. This article purports to order the debate, reflecting the degree of diversity of the discussed subjects. (Author)

  8. 77 FR 30280 - Final National Recommended Ambient Water Quality Criteria for Carbaryl-2012

    Science.gov (United States)

    2012-05-22

    ... about EPA's public docket visit the EPA Docket Center homepage at http://www.epa.gov/epahome/dockets.htm... Geological Survey National Water Quality Assessment Program reported carbaryl as the second most frequently...: Pesticides in the Nation's Streams and Ground Water, 1992-2001. Circular 1291. U.S. Geological Survey....

  9. Perinatal Toxicity and Carcinogenicity Studies of Styrene –Acrylonitrile Trimer, A Ground Water Contaminant

    OpenAIRE

    Behl, Mamta; Elmore, Susan A.; Malarkey, David E.; Hejtmancik, Milton R.; Gerken, Diane K.; Chhabra, Rajendra S.

    2013-01-01

    Styrene Acrylonitrile (SAN) Trimer is a by-product in the production of acrylonitrile styrene plastics. Following a report of a childhood cancer cluster in the Toms River section of Dover Township, New Jersey, SAN Trimer was identified as one of the groundwater contaminants at Reich Farm Superfund site in the township. The contaminants from the Reich Farm site’s ground water plume impacted two wells at the Parkway well field. The National Toxicology Program (NTP) studied the toxicity and carc...

  10. Toxicity effects of water extracts of Holothuria atra Jaeger in mice

    Institute of Scientific and Technical Information of China (English)

    Ridzwan; Bin; Hashim; Nurul; Alia; Azizan; Zaitunnatakin; Zamli; Farah; Hanis; Zulkipli; Nurzafirah; Mazlan; Osama; Yousef; Althunibat

    2014-01-01

    Objective:To determine lethal median dose(LD50) and histopalhological toxicity of water extract of Hololhuria atra(H,atra) in mice.Methods:The behavioral changes,mortality and histopathology examination on liver were assessed in mice 14 d after the administration(i.p.) of H.atra water extract.Seven doses 110,20,30,50.100.150 and 200 mg/kg) of H.atra were used.The control group was treated with normal saline,Results:In the acute study in mice,the water extracts of H,atra caused dose-dependent general behavior adverse affects and mortality.The main behavioral sign of toxicity was hypoactivity,noticed immediately after administration of the extract which was more obvious at the higher doses and persisted until death.Mortality increased with increasing doses,the calculated LD50was 41 mg/kg in mice.The liver toxicity was confirmed by histopalhological examination,which indicated the presence of abnormal hepatocytes with a distorted shape and undefined cell lining as well as enlarged nuclei in low doses groups.High doses groups indicated a more prominent distortion of the polyhedral hepatocytes with undefined cell lining,massive cytoplasm,pvknotic.karyorhexis and karyolytie nuclei(necrosis of hepatocytes).Control group showed polyhedral hepatocytes with defined cell lining arranged in cords and normal round nuclei,with granular cytoplasm.Conclusions:Because of the relatively low LD50 value in the acute study in mice,it may be concluded that the H.atra water extract is toxic.

  11. 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.

  12. Antimicrobial PVK:SWNT nanocomposite coated membrane for water purification: performance and toxicity testing.

    Science.gov (United States)

    Ahmed, Farid; Santos, Catherine M; Mangadlao, Joey; Advincula, Rigoberto; Rodrigues, Debora F

    2013-08-01

    This study demonstrated that coated nitrocellulose membranes with a nanocomposite containing 97% (wt%) of polyvinyl-N-carbazole (PVK) and 3% (wt%) of single-walled carbon nanotubes (SWNTs) (97:3 wt% ratio PVK:SWNT) achieve similar or improved removal of bacteria when compared with 100% SWNTs coated membranes. Membranes coated with the nanocomposite exhibited significant antimicrobial activity toward Gram-positive and Gram-negative bacteria (≈ 80-90%); and presented a virus removal efficiency of ≈ 2.5 logs. Bacterial cell membrane damage was considered a possible mechanism of cellular inactivation since higher efflux of intracellular material (Deoxyribonucleic acid, DNA) was quantified in the filtrate of PVK-SWNT and SWNT membranes than in the filtrate of control membranes. To evaluate possible application of these membrane filters for drinking water treatment, toxicity of PVK-SWNT was tested against fibroblast cells. The results demonstrated that PVK-SWNT was non toxic to fibroblast cells as opposed to pure SWNT (100%). These results suggest that it is possible to synthesize antimicrobial nitrocellulose membranes coated with SWNT based nanocomposites for drinking water treatment. Furthermore, membrane filters coated with the nanocomposite PVK-SWNT (97:3 wt% ratio PVK:SWNT) will produce more suitable coated membranes for drinking water than pure SWNTs coated membranes (100%), since the reduced load of SWNT in the nanocomposite will reduce the use of costly and toxic SWNT nanomaterial on the membranes.

  13. 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.

  14. 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.

  15. Toxic effects of chemical dispersant Corexit 9500 on water flea Daphnia magna.

    Science.gov (United States)

    Toyota, Kenji; McNabb, Nicole A; Spyropoulos, Demetri D; Iguchi, Taisen; Kohno, Satomi

    2017-02-01

    In 2010, approximately 2.1 million gallons of chemical dispersants, mainly Corexit 9500, were applied in the Gulf of Mexico to prevent the oil slick from reaching shorelines and to accelerate biodegradation of oil during the Deepwater Horizon oil spill. Recent studies have revealed toxic effects of Corexit 9500 on marine microzooplankton that play important roles in food chains in marine ecosystems. However, there is still little known about the toxic effects of Corexit 9500 on freshwater zooplankton, even though oil spills do occur in freshwater and chemical dispersants may be used in response to these spills. The cladoceran crustacean, water flea Daphnia magna, is a well-established model species for various toxicological tests, including detection of juvenile hormone-like activity in test compounds. In this study, we conducted laboratory experiments to investigate the acute and chronic toxicity of Corexit 9500 using D. magna. The acute toxicity test was conducted according to OECD TG202 and the 48 h EC50 was 1.31 ppm (CIs 0.99-1.64 ppm). The reproductive chronic toxicity test was performed following OECD TG211 ANNEX 7 and 21 days LOEC and NOEC values were 4.0 and 2.0 ppm, respectively. These results indicate that Corexit 9500 has toxic effects on daphnids, particularly during the neonatal developmental stage, which is consistent with marine zooplankton results, whereas juvenile hormone-like activity was not identified. Therefore, our findings of the adverse effects of Corexit 9500 on daphnids suggest that application of this type of chemical dispersant may have catastrophic impacts on freshwater ecosystems by disrupting the key food chain network. Copyright © 2016 John Wiley & Sons, Ltd.

  16. Toxicity of water-soluble gasoline fractions to fourth-instar larvae of the mosquito Aedes aegypti L

    Energy Technology Data Exchange (ETDEWEB)

    Berry, W.O.; Brammer, J.D.

    1977-07-01

    The toxicity of water-soluble components of gasoline to laboratory-reared fourth-instar larvae of the mosquito, Aedes aegypti (L.) was investigated. A median lethal dose (LD/sub 50/) and a non-lethal dose (NLD) were established for these larvae following a 24 h exposure to water-soluble fractions of benzene, toluene, and xylenes. Based on the actual amount of each component in solution, static toxicity/bioassays showed that acute toxicity of these monoaromatics increased in the sequence benzene, toluene, xylenes. However, toxicity increased in the sequence xylenes, benzene, toluene when results were examined with respect to the amount of aromatic added to water to produce the LD/sub 50/. The importance of determining the concentrations of compounds dissolved in water when conducting any investigation of biological effects of water pollutants is stressed.

  17. 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

  18. 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.

  19. 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

  20. Effect of increasing bromide concentration on toxicity in treated drinking water.

    Science.gov (United States)

    Sawade, Emma; Fabris, Rolando; Humpage, Andrew; Drikas, Mary

    2016-04-01

    Research is increasingly indicating the potential chronic health effects of brominated disinfection by-products (DBPs). This is likely to increase with elevated bromide concentrations resulting from the impacts of climate change, projected to include extended periods of drought and the sudden onset of water quality changes. This will demand more rigorous monitoring throughout distribution systems and improved water quality management at water treatment plants (WTPs). In this work the impact of increased bromide concentration on formation of DBPs following conventional treatment and chlorination was assessed for two water sources. Bioanalytical tests were utilised to determine cytotoxicity of the water post disinfection. Coagulation was shown to significantly reduce the cytotoxicity of the water, indicating that removal of natural organic matter DBP precursors continues to be an important factor in drinking water treatment. Most toxic species appear to form within the first half hour following disinfectant addition. Increasing bromide concentration across the two waters was shown to increase the formation of trihalomethanes and shifted the haloacetic acid species distribution from chlorinated to those with greater bromine substitution. This correlated with increasing cytotoxicity. This work demonstrates the challenges faced by WTPs and the possible effects increasing levels of bromide in source waters could have on public health.

  1. Selected streambed sediment compounds and water toxicity results for Westside Creeks, San Antonio, Texas, 2014

    Science.gov (United States)

    Crow, Cassi L.; Wilson, Jennifer T.; Kunz, James L.

    2016-12-01

    IntroductionThe Alazán, Apache, Martínez, and San Pedro Creeks in San Antonio, Texas, are part of a network of urban tributaries to the San Antonio River, known locally as the Westside Creeks. The Westside Creeks flow through some of the oldest neighborhoods in San Antonio. The disruption of streambed sediment is anticipated during a planned restoration to improve and restore the environmental condition of 14 miles of channelized sections of the Westside Creeks in San Antonio. These construction activities can create the potential to reintroduce chemicals found in the sediments into the ecosystem where, depending on hydrologic and environmental conditions, they could become bioavailable and toxic to aquatic life. Elevated concentrations of sediment-associated contaminants often are measured in urban areas such as San Antonio, Tex. Contaminants found in sediment can affect the health of aquatic organisms that ingest sediment. The gradual accumulation of trace elements and organic compounds in aquatic organisms can cause various physiological issues and can ultimately result in death of the aquatic organisms; in addition, subsequent ingestion of aquatic organisms can transfer the accumulated contaminants upward through the food chain (a process called biomagnification).The U.S. Geological Survey, in cooperation with the San Antonio River Authority, collected sediment samples and water samples for toxicity testing from sites on the Westside Creeks as part of an initial characterization of selected contaminants in the study area. Samples were collected in January 2014 during base-flow conditions and again in May 2104 after a period of stormwater runoff (poststorm conditions). Sediment samples were analyzed for selected constituents, including trace elements and organic contaminants such as pesticides, brominated flame retardants, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). In addition, as an indicator of ecological health (and

  2. 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.

  3. QSARS for Acute Toxicity of Halogenated Benzenes to Bacteria in Natural Waters

    Institute of Scientific and Technical Information of China (English)

    GUAN-GHUA LU; CHAO WANG; YU-MEI LI

    2006-01-01

    Objective To measure the acute toxicity of halogenated benzenes to bacteria in natural waters and to study quantitative relationships between the structure and activity of chemicals. Methods The concentration values causing 50% inhibition of bacteria growth (24h-IC50) were determined according to the bacterial growth inhibition test method. The energy of the lowest unoccupied molecular orbital and the net charge of carbon atom of 20 halogenated benzenes were calculated by the quantum chemical MOPAC program. Results The log1/IC50 values ranged from 4.79 for 2,4-dinitrochlorobenzene to 3.65 for chlorobenzene. A quantitative structure-activity relationship model was derived from the toxicity and structural parameters: log1/IC50 =-0.531(ELUMO)+1.693(Qc)+0.163(logP)+3.375. This equation was found to fit well (r2=0.860, s=0.106), and the average percentage error was only 1.98%. Conclusion Halogenated benzenes and alkyl halogenated benzenes are non-polar narcotics, and have hydrophobicity-dependent toxicity. The halogenated phenols and anilines exhibit a higher toxic potency than their hydrophobicity, whereas 2,4-dinitrochlorobenzene is electrophile with the halogen acting as the leaving group.

  4. Nectophotometer: an infrared motility monitor used to rapidly identify toxicity in effluents and receiving waters

    Science.gov (United States)

    Lo Pinto, Richard W.; Santelli, John

    2007-04-01

    A change in the motility pattern of fish and aquatic invertebrates when initially exposed to a toxin has long been used in tests designed to signal the presence of toxins in effluents and receiving waters. We have discovered that the level of motility change occurring within 2.5 hours of exposure to all concentrations of a test toxicant correlates well with mortality observed after three days exposure to the toxin, but that the first 30 minutes of exposure is a poor predictor of mortality. Defining this 'best to use exposure time' can increase the sensitivity of toxicity monitoring systems to a weak toxin, one that causes a motility change so minor that it may otherwise go unnoticed. Motility is monitored and automatically recorded using a Nectophotometer, an automated bio-monitor with computer interface that senses interruptions of infrared beams when organisms separately exposed to multiple concentrations of a toxin move through the beams. In our tests changes in the motility of Artemia salina within the first 2.5 hours of exposure predict 3 day mortality with an average accuracy of 89%. The Nectophotometer has promise for allowing rapid assessment of the toxicity to invertebrates and fish, and may also be used to assess airborne toxicity if motile insects respond in a similar manner.

  5. Nitrite toxicity of Litopenaeus vannamei in water containing low concentrations of sea salt or mixed salts

    Science.gov (United States)

    Sowers, A.; Young, S.P.; Isely, J.J.; Browdy, C.L.; Tomasso, J.R.

    2004-01-01

    The uptake, depuration and toxicity of environmental nitrite was characterized in Litopenaeus vannamei exposed in water containing low concentrations of artificial sea salt or mixed salts. In 2 g/L artificial sea salts, nitrite was concentrated in the hemolymph in a dose-dependent and rapid manner (steady-state in about 2 d). When exposed to nitrite in 2 g/L artificial sea salts for 4 d and then moved to a similar environment without added nitrite, complete depuration occurred within a day. Increasing salinity up to 10 g/L decreased uptake of environmental nitrite. Nitrite uptake in environments containing 2 g/L mixed salts (combination of sodium, potassium, calcium and magnesium chlorides) was similar to or lower than rates in 2 g/L artificial sea salt. Toxicity was inversely related to total dissolved salt and chloride concentrations and was highest in 2 g/L artificial sea salt (96-h medial lethal concentration = 8.4 mg/L nitrite-N). Animals that molted during the experiments did not appear to be more susceptible to nitrite than animals that did not molt. The shallow slope of the curve describing the relationship between toxicity and salinity suggests that management of nitrite toxicity in low-salinity shrimp ponds by addition of more salts may not be practical. ?? Copyright by the World Aquaculture Society 2004.

  6. Water as probe molecule for midgap states in nanocrystalline strontium titanate by conventional and synchronous luminescence spectroscopy under ambient conditions

    Science.gov (United States)

    Taylor, Sean; Samokhvalov, Alexander

    2017-03-01

    Alkaline earth metal titanates are broad bandgap semiconductors with applications in electronic devices, as catalysts, photocatalysts, sorbents, and sensors. Strontium titanate SrTiO3 is of interest in electronic devices, sensors, in the photocatalytic hydrogen generation, as catalyst and sorbent. Both photocatalysis and operation of electronic devices rely upon the pathways of relaxation of excited charge in the semiconductor, including relaxation through the midgap states. We report characterization of nanocrystalline SrTiO3 at room temperature by "conventional" vs. synchronous luminescence spectroscopy and complementary methods. We determined energies of radiative transitions in the visible range through the two midgap states in the nanocrystalline SrTiO3. Further, adsorption and desorption of vapor of water as "probe molecule" for midgap states in the nanocrystalline SrTiO3 was studied, for the first time, by luminescence spectroscopy under ambient conditions. Emission of visible light from the nanocrystalline SrTiO3 is significantly increased upon desorption of water and decreased (quenched) upon adsorption of water vapor, due to interactions with the surface midgap states.

  7. 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.

  8. In situ and laboratory toxicity of coalbed natural gas produced waters with elevated sodium bicarbonate

    Science.gov (United States)

    Farag, Aida 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.

  9. Mutagenicity and Immune Toxicity of Emulsion-type Sausage Cured with Plasma-treated Water.

    Science.gov (United States)

    Kim, Hyun-Joo; Sung, Nak-Yun; Yong, Hae In; Kim, Hanwool; Lim, Younggap; Ko, Kwang Hyun; Yun, Cheol-Heui; Jo, Cheorun

    2016-01-01

    Cold plasma has been developed to reduce microbial contamination and to improve safety of food and medical products. In addition, the technology can be used in the manufacture of sausages without addition of nitrite. To be applied in food industry commercially, the new technology should be safe and efficient. However, toxicological test of plasma-treated food is limited. Therefore, the purpose of this study was to determine the mutagenicity and immune toxicity of the meat products cured with plasma-treated water (PTW) as a nitrite source. Emulsion sausages were prepared with no nitrite (control), sodium nitrite (SCS), and PTW (SCP). For a mutagenicity test, the Ames test was performed with the sausage samples. For immune toxicity test, 8-wk-old female Balb/c mice were given free access to the sausages in order to evaluate the tumor necrosis factor (TNF)-α level. As a result, no mutagenicity was detected in the sausages by the Ames test. The serum TNF-α values were less than 10 pg/mL in mice after feeding control and treated samples for 32 d, indicating that no inflammatory response was occurred by feeding the sausages made by PTW. Therefore, the present study opens the possibility of using plasma-treated water as a nitrite source without any toxicity.

  10. Linking in Vitro Effects and Detected Organic Micropollutants in Surface Water Using Mixture-Toxicity Modeling.

    Science.gov (United States)

    Neale, Peta A; Ait-Aissa, Selim; Brack, Werner; Creusot, Nicolas; Denison, Michael S; Deutschmann, Björn; Hilscherová, Klára; Hollert, Henner; Krauss, Martin; Novák, Jiří; Schulze, Tobias; Seiler, Thomas-Benjamin; Serra, Helene; Shao, Ying; Escher, Beate I

    2015-12-15

    Surface water can contain countless organic micropollutants, and targeted chemical analysis alone may only detect a small fraction of the chemicals present. Consequently, bioanalytical tools can be applied complementary to chemical analysis to detect the effects of complex chemical mixtures. In this study, bioassays indicative of activation of the aryl hydrocarbon receptor (AhR), activation of the pregnane X receptor (PXR), activation of the estrogen receptor (ER), adaptive stress responses to oxidative stress (Nrf2), genotoxicity (p53) and inflammation (NF-κB) and the fish embryo toxicity test were applied along with chemical analysis to water extracts from the Danube River. Mixture-toxicity modeling was applied to determine the contribution of detected chemicals to the biological effect. Effect concentrations for between 0 to 13 detected chemicals could be found in the literature for the different bioassays. Detected chemicals explained less than 0.2% of the biological effect in the PXR activation, adaptive stress response, and fish embryo toxicity assays, while five chemicals explained up to 80% of ER activation, and three chemicals explained up to 71% of AhR activation. This study highlights the importance of fingerprinting the effects of detected chemicals.

  11. 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.

  12. Ordinary Toxicity of Chlorine Dioxide and By-products Chlorite and Chlorate in Water

    Institute of Scientific and Technical Information of China (English)

    王丽; 常爱敏; 黄君礼

    2003-01-01

    Acute toxicity and accumulated toxicity of chlorine dioxide (C1O2) and by-products chlorite ( C1O-2 ) and chlorate (C1O-3) in water acted on mice are studied by the method of Horn and accumulation coefficient.Subchronic toxicity of the mixture of C1O2 and C1O-2 and ClO-3 in water acted on rat is studied though feeding test for 90 days, including statistical analysis of variance on weight gaining, food utilization efficiency, index of blood and serum, liver (or kidney)to body weight ratio, and histopathological examination on liver and kidney. The results show that aqueous solution of C1O2, NaC1O2 and NaC1O3 (with the concentration of 276. 5 mg/L, 200 mg/L and 200 mg/L respectively) and the mixed aqueous solution of C1O2 with the concentration of 553 mg/L are actually non poisonous, and non-cumulative aqueous solution as well.

  13. Behavioral, clinical, and pathological characterization of acid metalliferous water toxicity in mallards

    Science.gov (United States)

    Isanhart, J.P.; Wu, H.; Pandher, K.; MacRae, R.K.; Cox, S.B.; Hooper, M.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

  14. Toxicity of Water and Sediment Samples Collected in the Vicinity of the Mixed Waste Management Facility, 1995 and 1996

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-07-01

    Three rounds of toxicity tests were conducted on water collected from eleven locations in the vicinity of the Mixed Waste Management Facility and four reference locations between January 1995 and April 1996.

  15. 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.

  16. Effect of Fenton treatment on the aquatic toxicity of bisphenol A in different water matrices

    DEFF Research Database (Denmark)

    Arslan-Alaton, Idil; Aytac, Ece; Kusk, Kresten Ole

    2014-01-01

    products. For this purpose, BPA was subjected to Fenton treatment in the growth medium of the test organisms employed as well as in real lake water. Treatment results indicated that BPA removals were fast and complete within less than a minute, whereas total organic carbon (TOC) removals were rather......Battery tests serve as integral tools to decide whether a treatment process is ecotoxicologically safe or not. In the present study, a battery of toxicity tests was employed to elucidate the toxicity of the potential endocrine-disrupting pollutant bisphenol A (BPA) and its advanced oxidation...... incomplete, speaking for the accumulation of refractory degradation products. The presence of chloride and/or natural organic matter influenced H2O2 consumption rates and the treatment performance of the Fenton's reagent as well. The sensitivity of the selected test organisms for BPA and its Fenton treatment...

  17. Transepidermal water loss in newborn infants. I. Relation to ambient humidity and site of measurement and estimation of total transepidermal water loss.

    Science.gov (United States)

    Hammarl-nd, K; Nilsson, G E; Oberg, P A; Sedin, G

    1977-09-01

    Insensible water loss (IWL) is an important factor in the thermoregulation and water balance of the newborn infant. A method for direct measurement of the rate of evaporation from the skin surface has been developed. The method, which is based on determination of the vapour pressure gradient close to the skin surface, allows free evaporation. From measurements performed on 19 newborns placed in incubators, a linear relation was found between the evaporation rate (ER) and the humidity of the environment at a constant ambient temperature. A 40% lower ER was recorded at a high relative humidity (60%) than at a low one (20%) in the incubator. At measurements on different sites of the body, a high ER was observed on the face and peripheral parts of the extremities, while ER at other sites was relatively low. By determining ER from different parts of the body and calculating the areas of the corresponding surfaces, the total cutaneous insensible water loss for the infant in question could be obtained. The transepidermal water loss (TEWL) for the whole body surface area was calculated to be 8.1 g/m2h. On the basis of measurements performed it was found that the total cutaneous insensible water loss can be estimated with a reasonable degree of accuracy by recording ER from only three easily accessible measurement points.

  18. Effects of ambient water quality on the endangered Lost River sucker in Upper Klamath Lake, Oregon

    Science.gov (United States)

    Martin, B.A.; Saiki, M.K.

    1999-01-01

    Populations of the Lost River sucker Deltistes luxatus have declined so precipitously in the Upper Klamath Basin of Oregon and California that this fish was recently listed for federal protection as an endangered species. Although Upper Klamath Lake is a major refuge for this species, fish in the lake occasionally experience mass mortalities during summer and early fall. This field study was implemented to determine if fish mortalities resulted from degraded water quality conditions associated with seasonal blooms of phytoplankton, especially Aphanizomenon flos-aquae. Our results indicated that fish mortality did not always increase as water temperature, pH, and un-ionized ammonia concentration increased in Upper Klamath Lake. Little or no mortality occurred when these water quality variables attained their maximum values. On the other hand, an inverse relation existed between fish mortality and dissolved oxygen concentration. High mortality (>90%) occurred whenever dissolved oxygen concentrations decreased to 1.05 mg/L, whereas mortality was usually low (< 10%) when dissolved oxygen concentrations equaled or exceeded 1.58 mg/L. Stepwise logistic regression also indicated that the minimum concentration of dissolved oxygen measured was the single most important determinant of fish mortality.

  19. Ni2+ toxicity in rice: effect on membrane functionality and plant water content.

    Science.gov (United States)

    Llamas, Andreu; Ullrich, Cornelia I; Sanz, Amparo

    2008-10-01

    The heavy metal nickel is an essential mineral trace nutrient found at low concentrations in most natural soils. However, it may reach toxic levels in certain areas and affect a number of biochemical and physiological processes in plants. Wilting and leaf necrosis have been described as typical visible symptoms of Ni(2+) toxicity. The plasma membrane (PM) of root cells constitutes the first barrier for the entry of heavy metals but also a target of their toxic action. This work studies the relationship between disturbances of membrane functionality and the development of the typical symptoms of Ni(2+) toxicity. Rice plants (Oryza sativa L. cv. Bahia) grown in nutrient medium containing 0.5mM Ni(2+) showed a significant decrease in water content as a consequence of the stress. Addition of Ni(2+) to the solution bathing the roots induced a concentration-dependent PM depolarization but the activity of the PM-H(+)-ATPase was not inhibited by the presence of Ni(2+) and the initial resting potential recovered in less than 1h. In the short term (hours), membrane permeability of root cells was not significantly affected by Ni(2+) treatments. However, in the long term (days) a drastic loss of K(+) was measured in roots and shoots, which should be responsible for the changes in the water content measured, since stomatal conductance and the transpiration rate remained unaffected by Ni(2+) treatment. The effects induced by Ni(2+) were not permanent and could be reverted, at least in part, by transferring the plants to a medium without Ni(2+).

  20. Large decrease in acute aquatic toxicity of linear alkylbenzene sulfonate in hard water and seawater by adding adsorbent.

    Science.gov (United States)

    Oya, Masaru; Takemoto, Yuka; Ishikawa, Yusuke

    2008-01-01

    LAS (Linear Alkylbenzene Sulphonate) shows relatively high aquatic toxicity in hard freshwater or seawater. In this paper, we studied the effect of adsorbent on the aquatic toxicity of LAS in hard freshwater and seawater. Daphnia magna and Artemia salina were used for acute aquatic toxicity test in freshwater and seawater, respectively. Kaolin was used as a model adsorbent and toxic surface tension (gamma(tox)) was used as an indicator of toxic condition. Results showed that the values of gamma(tox) of LAS to D. magna and A. salina were about 45-55 mN/m and 35-40 mN/m, respectively. Surface tension of LAS solution decreased and its aquatic toxicity increased with increasing the water hardness or the salinity. By adding adsorbent into the solutions, the surface activity and the aquatic toxicity were decreased greatly, and the effect of water hardness or salinity on surface tension and aquatic toxicity were removed. That is to say, the surface tension curve of soft freshwater corresponds with that of hard freshwater containing adsorbent and the surface tension curve at low salinity corresponds with that obtained for high salinity solutions containing the adsorbent. Therefore, our experimental data leads to the conclusion that the relatively high aquatic toxicity of LAS in concentrated solution of inorganic salts disappears in the presence of adsorbents. This is an important viewpoint in conducting environmental risk assessment of surfactants.

  1. 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

  2. Stability and toxicity of selected chlorinated benzophenone-type UV filters in waters.

    Science.gov (United States)

    Zhuang, Rensheng; Žabar, Romina; Grbović, Gorica; Dolenc, Darko; Yao, Jun; Tišler, Tatjana; Trebše, Polonca

    2013-01-01

    In our study, the transformation of two most widely used UV filters, benzophenone-3 (BP3) and benzophenone-4 (BP4), in chlorinated water with disinfection reagents sodium hypochlorite (NaClO) and trichloroisocyanuric acid (TCCA) was studied. Based on the HPLC/MS and UV-Vis analysis the formation of two different chlorinated products (5-chloro-2-hydroxy-4-methoxybenzophenone and 3,5-dichloro-2-hydroxy-4-methoxybenzophenone) was established. Identity of chlorinated products was confirmed by means of comparison of retention times with independently synthesized standards. Photostability study showed that dichloro-derivative in water is less stable then parent compounds, which is not the case for monochloro-derivatives. Toxicity of chlorinated compounds tested by Vibrio fischeri was found to be in the same range as that of the starting compounds. Preliminary testing of real water samples from swimming pools and sea swimming areas confirmed the presence of BP3 and its 3,5-dichloro derivative.

  3. Toxic cyanobacterial breakthrough and accumulation in a drinking water plant: a monitoring and treatment challenge.

    Science.gov (United States)

    Zamyadi, Arash; MacLeod, Sherri L; Fan, Yan; McQuaid, Natasha; Dorner, Sarah; Sauvé, Sébastien; Prévost, Michèle

    2012-04-01

    The detection of cyanobacteria and their associated toxins has intensified in recent years in both drinking water sources and the raw water of drinking water treatment plants (DWTPs). The objectives of this study were to: 1) estimate the breakthrough and accumulation of toxic cyanobacteria in water, scums and sludge inside a DWTP, and 2) to determine whether chlorination can be an efficient barrier to the prevention of cyanotoxin breakthrough in drinking water. In a full scale DWTP, the fate of cyanobacteria and their associated toxins was studied after the addition of coagulant and powdered activated carbon, post clarification, within the clarifier sludge bed, after filtration and final chlorination. Elevated cyanobacterial cell numbers (4.7 × 10(6)cells/mL) and total microcystins concentrations (up to 10 mg/L) accumulated in the clarifiers of the treatment plant. Breakthrough of cells and toxins in filtered water was observed. Also, a total microcystins concentration of 2.47 μg/L was measured in chlorinated drinking water. Cyanobacterial cells and toxins from environmental bloom samples were more resistant to chlorination than results obtained using laboratory cultured cells and dissolved standard toxins.

  4. A lab-on-chip cell-based biosensor for label-free sensing of water toxicants.

    Science.gov (United States)

    Liu, F; Nordin, A N; Li, F; Voiculescu, I

    2014-04-07

    This paper presents a lab-on-chip biosensor containing an enclosed fluidic cell culturing well seeded with live cells for rapid screening of toxicants in drinking water. The sensor is based on the innovative placement of the working electrode for the electrical cell-substrate impedance sensing (ECIS) technique as the top electrode of a quartz crystal microbalance (QCM) resonator. Cell damage induced by toxic water will cause a decrease in impedance, as well as an increase in the resonant frequency. For water toxicity tests, the biosensor's unique capabilities of performing two complementary measurements simultaneously (impedance and mass-sensing) will increase the accuracy of detection while decreasing the false-positive rate. Bovine aortic endothelial cells (BAECs) were used as toxicity sensing cells. The effects of the toxicants, ammonia, nicotine and aldicarb, on cells were monitored with both the QCM and the ECIS technique. The lab-on-chip was demonstrated to be sensitive to low concentrations of toxicants. The responses of BAECs to toxic samples occurred during the initial 5 to 20 minutes depending on the type of chemical and concentrations. Testing the multiparameter biosensor with aldicarb also demonstrated the hypothesis that using two different sensors to monitor the same cell monolayer provides cross validation and increases the accuracy of detection. For low concentrations of aldicarb, the variations in impedance measurements are insignificant in comparison with the shifts of resonant frequency monitored using the QCM resonator. A highly linear correlation between signal shifts and chemical concentrations was demonstrated for each toxicant.

  5. Water hardness reduces the accumulation and toxicity of uranium in a freshwater macrophyte (Ceratophyllum demersum).

    Science.gov (United States)

    Markich, Scott J

    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(3) L(-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(3) L(-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(-1)U at 20 mg CaCO(3 )L(-1) hardness, increasing to 547 μg L(-1) U at 400 mg CaCO(3) L(-1) hardness), cell surface binding affinity (log K=6.25 at 20 mg CaCO(3) L(-1) hardness, decreasing to log K=5.64 at 400 mg CaCO(3) L(-1) hardness) and accumulation (the concentration factor decreased from 63 at 20 mg CaCO(3) L(-1) hardness to 15 at 400 mg CaCO(3) L(-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(2)(2+), UO(2)OH(+), UO(2)(OH)(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(2+)/Mg(2+) and UO(2)(2+) (and/or UO(2)OH(+)) 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(2)(2+) (and/or UO(2)OH(+)) at the plant/water interface (boundary layer), and consequently, less U bound to physiologically active cell surface sites. In the absence of a biotic ligand model for U, the results of this study (together with

  6. Ambient Vibration Tests of an Arch Dam with Different Reservoir Water Levels: Experimental Results and Comparison with Finite Element Modelling

    Directory of Open Access Journals (Sweden)

    Sergio Vincenzo Calcina

    2014-01-01

    Full Text Available This paper deals with the ambient vibration tests performed in an arch dam in two different working conditions in order to assess the effect produced by two different reservoir water levels on the structural vibration properties. The study consists of an experimental part and a numerical part. The experimental tests were carried out in two different periods of the year, at the beginning of autumn (October 2012 and at the end of winter (March 2013, respectively. The measurements were performed using a fast technique based on asynchronous records of microtremor time-series. In-contact single-station measurements were done by means of one single high resolution triaxial tromometer and two low-frequency seismometers, placed in different points of the structure. The Standard Spectral Ratio method has been used to evaluate the natural frequencies of vibration of the structure. A 3D finite element model of the arch dam-reservoir-foundation system has been developed to verify analytically determined vibration properties, such as natural frequencies and mode shapes, and their changes linked to water level with the experimental results.

  7. 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

  8. 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)

  9. 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.

  10. Water management strategies against toxic Microcystis blooms in the Dutch delta.

    Science.gov (United States)

    Verspagen, Jolanda M H; Passarge, Jutta; Jöhnk, Klaus D; Visser, Petra M; Peperzak, Louis; Boers, Paul; Laanbroek, Hendrikus J; Huisman, Jef

    2006-02-01

    To prevent flooding of the Dutch delta, former estuaries have been impounded by the building of dams and sluices. Some of these water bodies, however, experience major ecological problems. One of the problem areas is the former Volkerak estuary that was turned into a freshwater lake in 1987. From the early 1990s onward, toxic Microcystis blooms dominate the phytoplankton of the lake every summer. Two management strategies have been suggested to suppress these harmful algal blooms: flushing the lake with fresh water or reintroducing saline water into the lake. This study aims at an advance assessment of these strategies through the development of a mechanistic model of the population dynamics of Microcystis. To calibrate the model, we monitored the benthic and pelagic Microcystis populations in the lake during two years. Field samples of Microcystis were incubated in the laboratory to estimate growth and mortality rates as functions of light, temperature, and salinity. Recruitment and sedimentation rates were measured in the lake, using traps, to quantify benthic-pelagic coupling of the Microcystis populations. The model predicts that flushing with fresh water will suppress Microcystis blooms when the current flushing rate is sufficiently increased. Furthermore, the inlet of saline water will suppress Microcystis blooms for salinities exceeding 14 g/L. Both management options are technically feasible. Our study illustrates that quantitative ecological knowledge can be a helpful tool guiding large-scale water management.

  11. Differential toxicity of drinking water disinfected with combinations of ultraviolet radiation and chlorine.

    Science.gov (United States)

    Plewa, Michael J; Wagner, Elizabeth D; Metz, Deborah H; Kashinkunti, Ramesh; Jamriska, Katherine J; Meyer, Maria

    2012-07-17

    Alternative technologies to disinfect drinking water such as ultraviolet (UV) disinfection are becoming more widespread. The benefits of UV disinfection include reduced risk of microbial pathogens such as Cryptosporidium and reduced production of regulated drinking water disinfection byproducts (DBPs). The objective of this research was to determine if mammalian cell cytotoxicity and genotoxicity varied in response to different chlorination protocols with and without polychromatic medium pressure UV (MPUV) and monochromatic low pressure UV (LPUV) disinfection technologies. The specific aims were to analyze the mammalian cell cytotoxicity and genotoxicity of concentrated organic fractions from source water before and after chlorination and to determine the cytotoxicity and genotoxicity of the concentrated organic fractions from water samples treated with UV alone or UV before or after chlorination. Exposure of granular activated carbon-filtered Ohio River water to UV alone resulted in the lowest levels of mammalian cell cytotoxicity and genotoxicity. With combinations of UV and chlorine, the lowest levels of cytotoxicity and genotoxicity were observed with MPUV radiation. The best combined UV plus chlorine methodology that generated the lowest cytotoxicity and genotoxicity employed chlorination first followed by MPUV radiation. These data may prove important in the development of multibarrier methods of pathogen inactivation of drinking water, while limiting unintended toxic consequences.

  12. [Studies on toxicity of four kinds of heavy metals in water by synchronous-scan fluorescence].

    Science.gov (United States)

    Duan, Jing-Bo; Liu, Wen-Qing; Zhang, Yu-Jun; Zhao, Nan-Jing; Wang, Zhi-Gang; Yin, Gao-Fang; Fang, Li; Liu, Jing

    2013-05-01

    Spectrofluorometry of chlorella pyrenoidosa was studied by three dimensional excitation-emission (3DEEM) fluorescence spectroscopy and synchronous scan fluorescence spectroscopy with Delta gamma = 20 nm in the stress of Hg+, Cd2+, Cu2+ and Zn2+. The conclusion from two kinds of Spectrofluorometry was the same: after 96h stress by heavy metals, the maximum fluorescence values reduced obviously, chlorophyll-a and chlorophyll-b in the photosynthetic system were seriously damaged by heavy metal. Further analysis of the correlations between heavy metal concentration and fluorescence quenching efficiency I0/I can conclude that the toxicity of heavy metal and the fluorescence quenching efficiency I0/I were positively correlated, and they all increased with the heavy metal concentration and stress time. For one kind of heavy metals, synchronous scan fluorometry is a sensitive method for its toxicity assessment. Compared to 3DEEM fluorescence spectroscopy, synchronous scan fluorescence spectroscopy is less time consuming and of higher selectivity. It is suitable to assess the toxicity of pollutions in water.

  13. Modeling removal of Cd, Cu, Pb, and Zn in acidic groundwater during neutralization by ambient surface waters and groundwaters

    Science.gov (United States)

    Paulson, A.J.; Balistrieri, L.

    1999-01-01

    Removal of Pb, Cu, Zn, and Cd during neutralization of acid rock drainage is examined using model simulations of field conditions and laboratory experiments involving mixing of natural drainage and surface waters or groundwaters. The simulations consider sorption onto hydrous Fe and Al oxides and particulate organic carbon, mineral precipitation, and organic and inorganic solution complexation of metals for two physical systems where newly formed oxides and particulate organic matter are either transported or retained along the chemical pathway. The calculations indicate that metal removal is a strong function of the physical system. Relative to direct discharge of ARD into streams, lower metal removals are observed where ARD enters streamwaters during the latter stages of neutralization by ambient groundwater after most of the Fe has precipitated and been retained in the soils. The mixing experiments, which represent the field simulations, also demonstrated the importance of dissolved metal to particle Fe ratios in controlling dissolved metal removal along the chemical pathway. Finally, model calculations indicate that hydrous Fe oxides and particulate organic carbon are more important than hydrous Al oxides in removing metals and that both inorganic and organic complexation must be considered when modeling metal removal from aquatic systems that are impacted by sulfide oxidation.Removal of Pb, Cu, Zn, and Cd during neutralization of acid rock drainage is examined using model simulations of field conditions and laboratory experiments involving mixing of natural drainage and surface waters or groundwaters. The simulations consider sorption onto hydrous Fe and Al oxides and particulate organic carbon, mineral precipitation, and organic and inorganic solution complexation of metals for two physical systems where newly formed oxides and particulate organic matter are either transported or retained along the chemical pathway. The calculations indicate that metal

  14. New Zealand risk management approach for toxic cyanobacteria in drinking water.

    Science.gov (United States)

    Kouzminov, Alexander; Ruck, John; Wood, Susanna A

    2007-06-01

    Cyanobacterial blooms are common seasonal phenomena occurring worldwide in fresh, estuarine and coastal waters, including those used for drinking-water supplies, recreation and stock watering. In New Zealand, the frequency of blooms and their geographic spread is likely to grow with increasing eutrophication and global climate change. The New Zealand Ministry of Health has recently developed national criteria for assessing and managing the risk of toxic cyanobacteria in drinking-water supplies. This paper investigates a cyanobacterial bloom incident in the summer 2002/03 in the Waikato River and hydro lakes, which are a major drinking-water supply for Hamilton City and many other smaller towns along the river. The procedures invoked by the Hamilton City Council and other authorities to deal with this bloom event are considered in terms of the best practice of the day and compared with the Drinking-Water Standards for New Zealand 2005. The presence of cyanobacteria has significant economic effects because of increases in water supply treatment costs or the need to use an alternative source, and there are also social effects from the disruption of recreational use of water bodies and loss of confidence in the quality of reticulated, treated water supplies. Notional evaluation of economic cost of monitoring regimes and control, based on the Waikato River cyanobacterial bloom incident, is also given. The multi-barrier and process-control risk management approach, reliant on good vertical communication systems between central and local government, is an advanced approach useful for any country that regularly experiences cyanobacterial problems.

  15. 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...

  16. Time dependent wettability of graphite upon ambient exposure: The role of water adsorption

    Science.gov (United States)

    Amadei, Carlo A.; Lai, Chia-Yun; Heskes, Daan; Chiesa, Matteo

    2014-08-01

    We report the temporal evolution of the wettability of highly ordered pyrolytic graphite (HOPG) exposed to environmental conditions. Macroscopic wettability is investigated by static and dynamic contact angles (SCA and DCA) obtaining values comparable to the ones presented in the literature. SCA increases from ˜68° to ˜90° during the first hour of exposure after cleaving, whereas DCA is characterized by longer-scale (24 h) time evolution. We interpret these results in light of Fourier transform infrared spectroscopy, which indicates that the evolution of the HOPG wettability is due to adsorption of molecules from the surrounding atmosphere. This hypothesis is further confirmed by nanoscopic observations obtained by atomic force microscope (AFM)-based force spectroscopy, which monitor the evolution of surface properties with a spatial resolution superior to macroscopic experiments. Moreover, we observe that the results of macro- and nanoscale measurements evolve in similar fashion with time and we propose a quantitative correlation between SCA and AFM measurements. Our results suggest that the cause of the transition in the wettability of HOPG is due to the adsorption of hydrocarbon contaminations and water molecules from the environment. This is corroborated by annealing the HOPG is vacuum conditions at 150°, allowing the desorption of molecules on the surface, and thus re-establishing the initial macro and nano surface properties. Our findings can be used in the interpretation of the wettability of more complicated systems derived from HOPG (i.e., graphene).

  17. Perinatal Toxicity and Carcinogenicity Studies of Styrene –Acrylonitrile Trimer, A Ground Water Contaminant

    Science.gov (United States)

    Behl, Mamta; Elmore, Susan A.; Malarkey, David E.; Hejtmancik, Milton R.; Gerken, Diane K.; Chhabra, Rajendra S.

    2015-01-01

    Styrene Acrylonitrile (SAN) Trimer is a by-product in the production of acrylonitrile styrene plastics. Following a report of a childhood cancer cluster in the Toms River section of Dover Township, New Jersey, SAN Trimer was identified as one of the groundwater contaminants at Reich Farm Superfund site in the township. The contaminants from the Reich Farm site’s ground water plume impacted two wells at the Parkway well field. The National Toxicology Program (NTP) studied the toxicity and carcinogenicity of SAN Trimer in rats exposed during their perinatal developmental period and adulthood. The chronic toxicity and carcinogenicity studies in F344/N rats were preceded by 7- and 18-week perinatal toxicity studies to determine the exposure concentrations for the 2-year studies. Subsequently, Fisher 344 pregnant dams were exposed to SAN Trimer containing diet at 400, 800, or 1600 ppm concentrations during gestation, nursing and weaning periods of offspring followed by two year of adult exposures to both male and female pups. There was no statistically significant evidence of carcinogenic activity following SAN-Trimer exposure; however, rare neoplasms in the brain and spinal cord were observed in males and to lesser extent in female rats. These incidences were considered within the range of historical background in the animal model used in the current studies. Therefore, the presence of a few rarely occurring CNS tumors in the treated groups were not judged to be associated with the SAN Trimer exposure. The major finding was a dose-related peripheral neuropathy associated with the sciatic nerves in females and spinal nerve roots in males and females thereby suggesting that SAN trimer is potentially a nervous system toxicant. PMID:24060431

  18. Perinatal toxicity and carcinogenicity studies of styrene-acrylonitrile trimer, a ground water contaminant.

    Science.gov (United States)

    Behl, Mamta; Elmore, Susan A; Malarkey, David E; Hejtmancik, Milton R; Gerken, Diane K; Chhabra, Rajendra S

    2013-12-06

    Styrene acrylonitrile (SAN) trimer is a by-product in the production of acrylonitrile styrene plastics. Following a report of a childhood cancer cluster in the Toms River section of Dover Township, New Jersey, SAN Trimer was identified as one of the groundwater contaminants at Reich Farm Superfund site in the township. The contaminants from the Reich Farm site's ground water plume impacted two wells at the Parkway well field. The National Toxicology Program (NTP) studied the toxicity and carcinogenicity of SAN Trimer in rats exposed during their perinatal developmental period and adulthood. The chronic toxicity and carcinogenicity studies in F344/N rats were preceded by 7- and 18-week perinatal toxicity studies to determine the exposure concentrations for the 2-year studies. Subsequently, Fisher 344 pregnant dams were exposed to SAN Trimer containing diet at 400, 800, or 1600ppm concentrations during gestation, nursing and weaning periods of offspring followed by two year of adult exposures to both male and female pups. There was no statistically significant evidence of carcinogenic activity following SAN-Trimer exposure; however, rare neoplasms in the brain and spinal cord were observed in males and to lesser extent in female rats. These incidences were considered within the range of historical background in the animal model used in the current studies. Therefore, the presence of a few rarely occurring CNS tumors in the treated groups were not judged to be associated with the SAN Trimer exposure. The major finding was a dose-related peripheral neuropathy associated with the sciatic nerves in females and spinal nerve roots in males and females thereby suggesting that SAN Trimer is potentially a nervous system toxicant.

  19. 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.

  20. 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....

  1. 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.

  2. BIOMONITORING OF AMBIENT CONCENTRATIONS OF CADMIUM,COPPER, LEAD AND ZINC IN THE COASTAL WETLAND WATER BY USING GILLS OF THE GREEN- LIPPED MUSSEL PERNA VIRIDIS

    Institute of Scientific and Technical Information of China (English)

    Chee Kong Yap; Ahmad Ismail; Abdul Rahim Ismail; Soon Guan Tan

    2006-01-01

    The distribution and concentrations of Cd, Cu, Pb and Zn were determined in the gills and remaining soft tissues of Perna viridis collected from 12 geographical sites ( 10 from the west and 2 from the east coastal waters) of Peninsular Malaysia. All samples showed that the levels of Cd, Pb and Zn were generally higher in the gill than those in the remaining soft tissues. These results could be due to the fact that gills are the first organ of metal accumulation and larger surface area with mucus sheets in the organ. Since the mussel gill is a better accumulator of Cd, Pb and Zn of ambient seawater than remaining soft tissue, it is a potential indicator of ambient levels of dissolved metals in the ambient seawater. However, further validations based on laboratory conditions are needed.

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

    Science.gov (United States)

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

    2007-03-15

    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.

  4. Realistic environmental mixtures of micropollutants in surface, drinking, and recycled water: herbicides dominate the mixture toxicity toward algae.

    Science.gov (United States)

    Tang, Janet Y M; Escher, Beate I

    2014-06-01

    Mixture toxicity studies with herbicides have focused on a few priority components that are most likely to cause environmental impacts, and experimental mixtures were often designed as equipotent mixtures; however, real-world mixtures are made up of chemicals with different modes of toxic action at arbitrary concentration ratios. The toxicological significance of environmentally realistic mixtures has only been scarcely studied. Few studies have simultaneously compared the mixture effect of water samples with designed reference mixtures comprised of the ratios of analytically detected concentrations in toxicity tests. In the present study, the authors address the effect of herbicides and other chemicals on inhibition of photosynthesis and algal growth rate. The authors tested water samples including secondary treated wastewater effluent, recycled water, drinking water, and storm water in the combined algae assay. The detected chemicals were mixed in the concentration ratios detected, and the biological effects of the water samples were compared with the designed mixtures of individual detected chemicals to quantify the fraction of effect caused by unknown chemicals. The results showed that herbicides dominated the algal toxicity in these environmentally realistic mixtures, and the contribution by the non-herbicides was negligible. A 2-stage model, which used concentration addition within the groups of herbicides and non-herbicides followed by the model of independent action to predict the mixture effect of the two groups, could predict the experimental mixture toxicity effectively, but the concentration addition model for herbicides was robust and sufficient for complex mixtures. Therefore, the authors used the bioanalytical equivalency concept to derive effect-based trigger values for algal toxicity for monitoring water quality in recycled and surface water. All water samples tested would be compliant with the proposed trigger values associated with the

  5. Water quality and aquatic toxicity data of 2002 spring thaw conditions in the upper Animas River watershed, Silverton, Colorado

    Science.gov (United States)

    Fey, D.L.; Wirt, L.; Besser, J.M.; Wright, W.G.

    2002-01-01

    This report presents hydrologic, water-quality, and biologic toxicity data collected during the annual spring thaw of 2002 in the upper Animas River watershed near Silverton, Colorado. The spring-thaw runoff is a concern because elevated concentrations of iron oxyhydroxides can contain sorbed trace metals that are potentially toxic to aquatic life. Water chemistry of streams draining the San Juan Mountains is affected by natural acid drainage and weathering of hydrothermal altered volcanic rocks and by more than a century of mining activities. The timing of the spring-thaw sampling effort was determined by reviewing historical climate and stream-flow hydrographs and current weather conditions. Twenty-one water-quality samples were collected between 11:00 AM March 27, 2002 and 6:00 PM March 30, 2002 to characterize water chemistry at the A-72 gage on the upper Animas River below Silverton. Analyses of unfiltered water at the A-72 gage showed a relation between turbidity and total-recoverable iron concentrations, and showed diurnal patterns. Copper and lead concentrations were related to iron concentrations, indicating that these elements are probably sorbed to colloidal iron material. Calcium, strontium, and sulfate concentrations showed overall decreasing trends due to dilution, but the loads of those constituents increased over the sampling period. Nine water-quality samples were collected near the confluence of Mineral Creek with the Animas River, the confluence of Cement Creek with the Animas River, and on the upper Animas River above the confluence with Cement Creek (three samples at each site). A total of six bulk water-toxicity samples were collected before, during, and after the spring thaw from the Animas River at the A-72 gage site. Toxicity tests conducted with the bulk water samples on amphipods did not show strong differences in toxicity among the three sampling periods; however, toxicity of river water to fathead minnows showed a decreasing trend

  6. 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.

  7. Synthesis of tin oxide nanospheres under ambient conditions and their strong adsorption of As(III) from water.

    Science.gov (United States)

    Zhang, Ge; Sun, Wuzhu; Liu, Lingmei; Yang, Weiyi; Xu, Zhengchao; Li, Qi; Shang, Jian Ku

    2015-11-07

    The development of highly efficient As(iii) adsorbents is critical to largely simplify the arsenic treatment process and lower its cost. For the first time, SnO2 nanospheres were demonstrated to possess a highly efficient As(iii) adsorption capability from water in a near neutral pH environment as predicted by the material criterion we recently developed for the selection of highly efficient arsenic adsorbents. These SnO2 nanospheres were synthesized by a simple and cost-effective hydrolysis process with the assistance of ethyl acetate under ambient conditions, which had a good dispersity, a narrow size distribution, a relatively large specific surface area, and a porous structure. A fast As(iii) adsorption was observed in the kinetics study on these SnO2 nanospheres, and their Langmuir adsorption capacity was determined to be ∼112.7 mg g(-1) at pH ∼7. The As(iii) adsorption mechanism on SnO2 nanospheres was examined by both macroscopic and microscopic techniques, which demonstrated that it followed the inner-sphere complex model. These SnO2 nanospheres demonstrated effective As(iii) adsorption even with exceptionally high concentrations of co-existing ions, and a good regeneration capability by washing with NaOH solution.

  8. Modeling removal of Cd, Cu, Pb, and Zn in acidic groundwater during neutralization by ambient surface waters and groundwaters

    Energy Technology Data Exchange (ETDEWEB)

    Paulson, A.J.; Balistrieri, L.

    1999-11-01

    Removal of Pb, Cu, Zn, and Cd during neutralization of acid rock drainage is examined using model simulations of field conditions and laboratory experiments involving mixing of natural drainage and surface waters or groundwaters. The simulations consider sorption onto hydrous Fe and Al oxides and particulate organic carbon, mineral precipitation, and organic and inorganic solution complexation of metals for two physical systems where newly formed oxides and particulate organic matter are either transported or retained along the chemical pathway. The calculations indicate that metal removal is a strong function of the physical system. Relative to direct discharge of ARD into streams, lower metal removals are observed where ARD enters streamwaters during the latter stages of neutralization by ambient groundwater after most of the Fe has precipitated and been retained in the soils. The mixing experiments, which represent the field simulations, also demonstrated the importance of dissolved metal to particle Fe ratios in controlling dissolved metal removal along the chemical pathway. Finally, model calculations indicate that hydrous Fe oxides and particulate organic carbon are more important than hydrous Al oxides in removing metals and that both inorganic and organic complexation must be considered when modeling metal removal from aquatic systems that are impacted by sulfide oxidation.

  9. EPISTEMOLOGIA AMBIENTAL

    OpenAIRE

    2012-01-01

    O livro Epistemologia Ambiental traz uma rica discussão sobre a questão ambiental, abordando teorias relevantes para o entendimento e interpretação da crise atual, orientando para a construção de novas racionalidades e a constituição de um saber ambiental. A obra vem compartimentada em cinco capítulos distribuídos em 240 páginas. 

  10. Influence of selected water quality characteristics on the toxicity of lambda-cyhalothrin and gamma-cyhalothrin to Hyalella azteca

    Science.gov (United States)

    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 Mississipp...

  11. 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 ...

  12. 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.

  13. Evaluation of acute copper toxicity to juvenile freshwater mussels (fatmucket, lampsilis siliquoidea) in natural and reconstituted waters

    Science.gov (United States)

    Wang, N.; Mebane, C.A.; Kunz, J.L.; Ingersoll, C.G.; May, T.W.; Arnold, W.R.; Santore, R.C.; Augspurger, T.; Dwyer, F.J.; Barniiart, M.C.

    2009-01-01

    The influence of dissolved organic carbon (DOC) and water composition on the toxicity of copper to juvenile freshwater mussels (fatmucket, Lampsilis siliquoidea) were evaluated in natural and reconstituted waters. Acute 96-h copper toxicity tests were conducted at four nominal DOC concentrations (0, 2.5, 5, and 10 mg/L as carbon [C]) in dilutions of natural waters and in American Society for Testing and Materials (ASTM) reconstituted hard water. Toxicity tests also were conducted in ASTM soft, moderately hard, hard, and very hard reconstituted waters (nominal hardness 45-300 mg/L as CaCO3). Three natural surface waters (9.5-11 mg/L DOC) were diluted to obtain a series of DOC concentrations with diluted well water, and an extract of natural organic matter and commercial humic acid was mixed with ASTM hard water to prepare a series of DOC concentrations for toxicity testing. Median effective concentrations (EC50s) for dissolved copper varied >40-fold (9.9 to >396 ??g Cu/L) over all 21 treatments in various DOC waters. Within a particular type of DOC water, EC50s increased 5- to 12-fold across DOC concentrations of 0.3 to up to 11 mg C/L. However, EC50s increased by only a factor of 1.4 (21 30 ??g Cu/L) in the four ASTM waters with wide range of water hardness (52-300 mg CaCO 3/L). Predictions from the biotic ligand model (BLM) for copper explained nearly 90% of the variability in EC50s. Nearly 70% of BLM-normalized EC50s for fatmucket tested in natural waters were below the final acute value used to derive the U.S. Environmental Protection Agency acute water quality criterion for copper, indicating that the criterion might not be protective of fatmucket and perhaps other mussel species. ?? 2009 SETAC.

  14. The isolation and characterization of lipopolysaccharides from Microcystis aeruginosa, a prominent toxic water bloom forming cyanobacteria.

    Science.gov (United States)

    Bláhová, Lucie; Adamovský, Ondřej; Kubala, Lukáš; Švihálková Šindlerová, Lenka; Zounková, Radka; Bláha, Luděk

    2013-12-15

    Massive toxic blooms of cyanobacteria represent a major threat to water supplies worldwide, yet serious gaps exist in understanding their complex toxic effects, including the role of lipopolysaccharides (LPS). The present comparative study focused on the levels and biological activities of LPS isolated from Microcystis aeruginosa, which is one of the most globally distributed toxic species. Using hot phenol extraction, LPS was isolated from 3 laboratory cultures and 11 natural water blooms. It formed 0.2-0.7% of the original dry biomass of the cyanobacteria, based on gravimetry. Additional analyses by commercial anti-LPS ELISA were correlated with gravimetry but showed concentrations that were about 7-times lower, which indicated either impurities in isolated LPS or the poor cross-reactivity of the antibodies used. LPS isolates from M. aeruginosa were potent pyrogens in the traditional Limulus amebocyte lysate (LAL)-test, but comparison with the PyroGene test demonstrated the limited selectivity of LAL with several interferences. The determined pyrogenicity (endotoxin units, EU) ranged from very low values in laboratory cultures (less than 0.003 up to 0.008-EU per 100 pg LPS) to higher values in complex bloom samples (0.01-0.078 EU per 100 pg of LPS), which suggested the role of bloom-associated bacteria in the overall effects. Potent pro-inflammatory effects of the studied LPS from both cultures and bloom samples were observed in a highly-relevant ex vivo human blood model by studying reactive oxygen species production in phagocytes as well as increased productions of interleukin 8, IL-8, and tumor necrosis factor α, TNF-α. LPS from M. aeruginosa seem to modulate several pathways involved in the regulation of both innate immunity and specific responses. In comparison to the standard pathogenic bacterial LPS (World Health Organization Escherichia coli O113:10 endotoxin; activity 1 EU per 100 pg), the studied cyanobacterial samples had pyrogenicity potencies

  15. Estimation of the toxicity of sulfadiazine to Daphnia magna using negligible depletion hollow-fiber liquid-phase microextraction independent of ambient pH

    Science.gov (United States)

    Liu, Kailin; Xu, Shiji; Zhang, Minghuan; Kou, Yahong; Zhou, Xiaomao; Luo, Kun; Hu, Lifeng; Liu, Xiangying; Liu, Min; Bai, Lianyang

    2016-12-01

    The toxicity of ionizable organic compounds to organisms depends on the pH, which therefore affects risk assessments of these compounds. However, there is not a direct chemical method to predict the toxicity of ionizable organic compounds. To determine whether hollow-fiber liquid-phase microextraction (HF-LPME) is applicable for this purpose, a three-phase HF-LPME was used to measure sulfadiazine and estimate its toxicity to Daphnia magna in solutions of different pH. The result indicated that the sulfadiazine concentrations measured by HF-LPME decreased with increasing pH, which is consistent with the decreased toxicity. The concentration immobilize 50% of the daphnids (EC50) in 48 h calculated from nominal concentrations increased from 11.93 to 273.5 mg L-1 as the pH increased from 6.0 to 8.5, and the coefficient of variation (CV) of the EC50 values reached 104.6%. When calculated from the concentrations measured by HF-LPME (pH 12 acceptor phase), the EC50 ranged from 223.4 to 394.6 mg L-1, and the CV decreased to 27.60%, suggesting that the concentrations measured by HF-LPME can be used to estimate the toxicity of sulfadiazine irrespective of the solution pH.

  16. Treatment of tunnel wash waters--experiments with organic sorbent materials. Part II: Removal of toxic metals.

    Science.gov (United States)

    Paruch, Adam M; Roseth, Roger

    2008-01-01

    In the first part of the article, the column and the bag experiments concerning removal of polycyclic aromatic hydrocarbons (PAHs) and nonpolar oil (NPO) from tunnel wash waters using organic sorbent materials have been described. This part presents the results of removal of toxic metals. The metals of concern (Al, As, Cd, Cr, Cu, Fe, Pb, Mo, Ni, and Zn) were selected based on the priority toxicant pollutants defined in surface water quality criteria. Concentrations of these metals in the collected effluents varied more than the concentrations of PAHs and NPO, and thus only metal contents were considered for statistical analyses. These analyses determined significant differences (P experiments revealed that the organic sorbents, and in particular their combination, removed toxic metals more effectively from wash water of road tunnel than from wash water of tunnel electrostatic filters. Among the investigated toxicants, Al and Fe showed the highest levels of reduction in the column experiment, 99.7% and 99.6%, respectively. The lowest reduction levels of 66.0% and 76.2% were found for Pb and Mo, respectively. The results of the bag experiment showed that even one day treatment of wash waters from tunnel electrostatic filters could reduce concentration of some toxicants by more than 70% (Al and Fe) and 80% (Cu).

  17. Association of respiratory complications and elevated serum immunoglobulins with drinking water arsenic toxicity in human.

    Science.gov (United States)

    Islam, Laila N; Nabi, A H M Nurun; Rahman, M Mahfuzur; Zahid, M Shamim H

    2007-10-01

    We assessed the relationship between chronic arsenic exposure through drinking water with respiratory complications and humoral immune response by measuring serum immunoglobulin profiles in the affected subjects (arsenicosis patients) living in the arsenic endemic rural villages of Bangladesh. The duration of exposure was determined through detailed history of the patients (n=125) and the levels of arsenic in the drinking water and urine samples were determined. The mean duration of exposure in the patients was 7.4+/-5.3 y, and the levels of arsenic in the drinking water and urine samples were 216+/-211 and 223+/-302 micro g/L, respectively, compared to 11+/-20 and 29+/-19 microg/L, respectively, in the unexposed subjects. There was high prevalence of respiratory complications like breathing problems including chest sound, asthma, bronchitis and cough associated with drinking water arsenic toxicity. Arsenicosis patients had significantly elevated levels of IgG (Pdiseases, rather it could be due to direct effects of arsenic. We found significant linear relationships between the levels of serum IgE and inorganic phosphorus (Pcaused respiratory complications, induced changes in the humoral as well as mucosal immune responses.

  18. Developmental Toxicity of Drinking Water Disinfection By-Products to Embryos of the African Clawed Frog (Xenopus laevis)

    Science.gov (United States)

    2005-06-10

    developmental toxicity tests with embryos of the South African clawed frog Xenopus laevis used to evaluate four individual DWDB; bromodichloromethane...SUBJECT TERMS Developmental toxicity; FETAX; water disinfection by-products; frogs ; Xenopus laevis; embryo malformations; embryo mortality...Disinfection By-Products to Embryos of the African Clawed Frog (Xenopus laevis) L. M. Brennan,1 M. W. Toussaint,1 D. M. Kumsher,1 W. E. Dennis,’ A. B

  19. Evaluation of chemical data from selected sites in the Surface-Water Ambient Monitoring Program (SWAMP) in Florida

    Science.gov (United States)

    Katz, B.G.; Collins, J.J.

    1998-01-01

    A cooperative study between the Florida Department of Environmental Protection (FDEP) and the U.S. Geological Survey was conducted to assess the integrity of selected water-quality data collected at 150 sites in the FDEP Surface-Water Ambient Monitoring Program (SWAMP) in Florida. The assessment included determining the consistency of the water-quality data collected statewide, including commonality of monitoring procedures and analytes, screening of the gross validity of a chemical analysis, and quality assurance and quality control (QA/QC) procedures. Four tests were used to screen data at selected SWAMP sites to estimate the gross validity of selected chemical data: (1) the ratio of dissolved solids (in milligrams per liter) to specific conductance (in microsiemens per centimeter); (2) the ratio of total cations (in milliequivalents per liter) multiplied by 100 to specific conductance (in microsiemens per centimeter); (3) the ratio of total anions (in milliequivalents per liter) multiplied by 100 to specific conductance (in microsiemens per centimeter); and (4) the ionic charge-balance error. Although the results of the four screening tests indicate that the chemical data generally are quite reliable, the extremely small number of samples (less than 5 percent of the total number of samples) with sufficient chemical information to run the tests may not provide a representative indication of the analytical accuracy of all laboratories in the program. In addition to the four screening tests, unusually low or high values were flagged for field and laboratory pH (less than 4.0 and greater than 9.0) and specific conductance (less than 10 and greater than 10,000 microsiemens per centimeter). The numbers of flagged data were less than 1 percent of the 19,937 water samples with pH values and less than 0.6 percent of the 16,553 water samples with specific conductance values. Thirty-four agencies responded to a detailed questionnaire that was sent to more than 60 agencies

  20. 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...

  1. 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 th

  2. Derecho Ambiental

    OpenAIRE

    2014-01-01

    Es indudable la relevancia para la vida del planeta proteger el ambiente. De ahí que a lo largo de las últimas decadas el derecho ambiental se ha consolidado como una nueva y vital rama del derecho público.

  3. Toxicity and metal speciation characterisation of waste water from an abandoned gold mine in tropical northern Australia.

    Science.gov (United States)

    Dam, Rick van; Hogan, Alicia; Harford, Andrew; Markich, Scott

    2008-09-01

    The decommissioned Mount Todd gold mine, located in the wet-dry tropics of northern Australia, consists of a large waste water inventory and an acid rock drainage problem, which has the potential to impact upon freshwater ecosystems of the Edith River catchment. The toxicity of retention pond 1 (RP1) water was determined using six local freshwater species (duckweed, alga, cladoceran, snail, hydra and a fish). RP1 water was very toxic to all species, with the percentage dilution of RP1 water inhibiting 10% of organism response (IC10), or lethal to 5% of individuals (LC5), ranging from 0.007 to 0.088%. The percentage dilution of RP1 water inhibiting 50% of organism response (IC50), or lethal to 50% of individuals (LC50), ranged from 0.051% to 0.58%. Based on chemical analyses and geochemical speciation modelling of the test waters, Cu, Zn and Al were the most likely toxic components at acidic dilutions (i.e. > or =1%), while Cu and Zn were the most likely toxic components at 0.1% RP1 water, where pH was 6.5. Species sensitivity distributions (SSDs) were used to predict dilutions of RP1 water that would protect or unacceptably affect the downstream aquatic ecosystems. A dilution ratio of 1 part RP1 water to 20000 parts Edith River water (0.005% RP1 water) was calculated to be required for the protection of at least 95% of species. This information can be used in conjunction with field chemical and biological data to better predict the ecological risks of RP1 waste water downstream of the Mount Todd mine.

  4. Alleviation of cadmium toxicity in Medicago sativa by hydrogen-rich water.

    Science.gov (United States)

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

    2013-09-15

    Hydrogen gas (H₂) induces plant tolerance to several abiotic stresses, including salinity and paraquat exposure. However, the role of H₂ 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 H₂ 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.

  5. Toxicity of fungicides to natural bacterial communities in wetland water and sediment measured using leucine incorporation and potential denitrification.

    Science.gov (United States)

    Milenkovski, Susann; Bååth, Erland; Lindgren, Per-Eric; Berglund, Olof

    2010-02-01

    We assessed potential toxicity of fungicides to natural bacterial communities from a constructed wetland, located in southern Sweden, and compared the sensitivity of two endpoints indicating bacterial activity, leucine incorporation, and potential denitrification, in detecting toxicity. The effects of eight fungicides (benomyl, carbendazim, carboxin, captan, cycloheximide, fenpropimorph, propiconazole, and thiram), two bactericides (bronopol and chlortetracycline) as controls, and one reference compound (3,5-dichlorophenol), were tested in a water-sediment microcosm set-up. Leucine incorporation was measured in both the water and sediment column, while potential denitrification was measured for the entire microcosm. The bactericides and the reference compound gave sigmoid concentration-response curves for both endpoints in all but one case. The fungicides thiram, captan, and benomyl, and to a lesser extent fenpropimorph and propiconazole had quantifiable toxic effects on leucine incorporation, with EC(50) values ranging from 3 to 70 mg l(-1), while carbendazim, carboxin, and cycloheximide had little effect at the investigated concentrations. Only thiram and captan inhibited potential denitrification; the other fungicides showed no quantifiable effect. A greater toxic effect on leucine incorporation was recorded for bacterial communities associated with the water column, compared to the sediment column, for all tested compounds. Leucine incorporation was the more sensitive method for toxicity assessment of bacterial communities, and also allowed for a rapid and simple way of comparing exposure in the sediment and water column, making it an attractive standard method for community based toxicological assays in aquatic environments.

  6. 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.

  7. The effects of water quality and age on the acute toxicity of copper to the Florida apple snail, Pomacea paludosa.

    Science.gov (United States)

    Rogevich, E C; Hoang, T C; Rand, G M

    2008-05-01

    Copper (Cu)-containing compounds have been used in Florida as fungicides, herbicides, and soil amendments, resulting in elevated Cu in the aquatic ecosystem. The Florida apple snail (Pomacea paludosa), a key species in south Florida, may be adversely affected by Cu. Water-quality parameters, such as hardness, dissolved organic carbon (DOC), pH, and alkalinity, affect metal bioavailability and toxicity in aquatic organisms; however, it is uncertain to what extent these factors affect Cu toxicity in the Florida apple snail. The research presented here characterized the acute (96-hour) toxicity of Cu in water to the Florida apple snail at various life stages and under different water-quality parameters. Cu was more toxic to juvenile than adult apple snails. There was no difference between the 96-hour LC(50) at pH 5.5 and 6.5; however, the 96-hour LC(50 )values at pH 7.5 and 8.5 were greater than at lower pHs. The decrease in Cu(2+) above pH 7, as predicted by the MINTEQ model, accounted for the pH effect. Cu toxicity decreased as DOC increased from 0.2 to 30 mg/L. Unlike other aquatic organisms, hardness had no effect on Cu toxicity to the Florida apple snail, suggesting another mechanism of toxicity. Whole-body tissue analysis indicated that the lethal body burden of 120-day-old snails exposed to Cu for 4 days was 30 mg/kg Cu dry weight. Multiple regression analysis indicated that Cu toxicity was a function of organism age, DOC, and pH.

  8. N-NITROSODIMETHYLAMINE AS A HAZARDOUS CHEMICAL TOXICANT IN DRINKING WATER

    Directory of Open Access Journals (Sweden)

    Sharma Veena

    2012-03-01

    Full Text Available Nitrosamines is a family of potent carcinogens, have been of concern for many decades due to their occurrence in foods, industrial workplace environments, and as groundwater contaminants. Human exposure to nitrosamines can result from formation of N nitroso compounds either in food during storage or preparation or in vivo, usually in the stomach. N-Nitrosodimethylamine is one of the main N-nitroso compound which is commonly found in drinking water and is a potent hepatotoxin, carcinogen and mutagen and it induces fibrosis and cirrhosis in liver. All identified health risks associated with N-Nitrosodimethylamine in drinking water incorporates all relevant routes of exposure from drinking water—namely, ingestion as well as skin absorption from showering and bathing. The toxicity produced by N-Nitrosodimethylamine is mediated by its reactive metabolites and not by the parent compound. Decontamination of N-Nitrosodimethylamine relies mostly on UV irradiation, but these methods are rather impractical and expensive when applied to municipal and wastewater treatment. N-Nitrosodimethylamine is reasonably anticipated to be a human carcinogen based on sufficient evidence of carcinogenicity in experimental animals. When administered orally, N-nitrosodimethylamine induced liver hemangiosarcomas, hepatocellular carcinomas, and kidney and lung tumors in mice. Reactive oxygen species have been implicated as causative agents in many degenerative diseases, and also in the promotion phase in carcinogenesis. Toxic effects of N-nitrosodimethylamine, a potent carcinogenic and mutagenic substance, were also proposed to be due to reactive oxygen species formed by its metabolic activation. The mechanism by which N-Nitrosodimethylamine produces cancer is well understood to involve biotransformation by liver microsomal enzymes, generating the methyldiazonium ion.

  9. 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...

  10. Water quality assessment in piracicamirim creek upstream and downstream a sugar and ethanol industry through toxicity tests with cladocerans

    Directory of Open Access Journals (Sweden)

    Rafael Grossi Botelho

    2012-08-01

    Full Text Available An environmental impact study was conducted to determine the Piracicamirim's creek water quality in order to assess the influence of effluents from a sugar industry in this water body. For this, toxicity tests were performed with a water sample upstream and downstream the industry using the microcrustaceans Daphnia magna, Ceriodaphnia dubia and Ceriodaphnia silvestrii as test organisms, as well as physical and chemical analysis of water. Results showed that physical and chemical parameters did not change during the sampling period, except for the dissolved oxygen. No toxicity was observed for D. magna and reproduction of C. dubia and C. silvestrii in both sampling points. Thus, the industry was not negatively impacting the quality of this water body.

  11. Assessment of water quality and toxicity of polluted Rivers Fez and Sebou in the region of Fez (Morocco).

    Science.gov (United States)

    Koukal, B; Dominik, J; Vignati, D; Arpagaus, P; Santiago, S; Ouddane, B; Benaabidate, L

    2004-09-01

    Water quality assessment in the region of Fez based on the physicochemical and ecotoxicological investigations is presented. The results indicate that sites located close to the most urbanized and industrialized areas are severely impaired. The major water quality problems are: low dissolved oxygen (DO), high turbidity, organic matter and ammonia contents, severe chromium and copper pollution and high acute and chronic toxicity. This results in the loss of the aquatic life which is still flourishing in the Fez River upstream from the Fez Medina. Remote sites downstream show signs of physicochemical recovery. However, even there, bioassays showed significant acute and chronic toxicity. Well water in the region of Fez has moderately poor water quality with nitrate and metal enrichments. Use of water for drinking or for agriculture from the rivers or from some wells without treatment may expose the population to health risk.

  12. [Toxicity and toxin profile of scavenging and carnivorous gastropods from the coastal waters of Okinawa Prefecture, Japan].

    Science.gov (United States)

    Taniyama, Shigeto; Takatani, Tomohiro; Sorimachi, Taiki; Sagara, Takefumi; Kubo, Hirofumi; Oshiro, Naomasa; Ono, Kaname; Xiao, Ning; Tachibana, Katsuyasu; Arakawa, Osamu

    2013-01-01

    From January to June 2009, a total of 64 gastropod specimens of 15 species were collected from the coastal waters of Okinawa Prefecture, Japan, and examined for toxicity by means of mouse bioassay. Among the specimens tested, 5 species, Nassarius glans, Nassariuscoronatus, Olivaannulata, Oliva concavospira and Zeuxis sp., were toxic. The toxicity scores of N. glans were very high; 39.6-461 MU/g in muscle, and 98.6-189 MU/g in viscera including digestive gland, followed by Zeuxis sp. (12.7 MU/g in whole body), N. coronatus (5.64-11.1 MU/g in whole body), O. annulata (10.8 MU/g in the whole body), O. concavospira (6.65 MU/g in the muscle). Liquid chromatography/mass spectrometry (LC-MS) revealed that the major toxic component was tetrodotoxin (TTX), which accounting for 13-82% of the total toxicity. As for the remaining toxicity in the case of N. glans, 4,9-anhydroTTX, 4-epiTTX and 11-oxoTTX were contributors. Moreover, Niotha albescens showed no toxicity (less than 10 MU/g) in mouse bioassay, but TTX (5.08 MU/g) was detected by LC-MS. Paralytic shellfish poison was not detected in any of the specimens by high-performance liquid chromatography with fluorometric detection (HPLC-FLD).

  13. 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.

  14. Degradation and aquatic toxicity of naphthenic acids in oil sands process-affected waters using simulated wetlands.

    Science.gov (United States)

    Toor, Navdeep S; Franz, Eric D; Fedorak, Phillip M; MacKinnon, Michael D; Liber, Karsten

    2013-01-01

    Oil sands process-affected waters (OSPWs) produced during the extraction of bitumen at the Athabasca Oil Sands (AOS) located in northeastern Alberta, Canada, are toxic to many aquatic organisms. Much of this toxicity is related to a group of dissolved organic acids known as naphthenic acids (NAs). Naphthenic acids are a natural component of bitumen and are released into process water during the separation of bitumen from the oil sand ore by a caustic hot water extraction process. Using laboratory microcosms as an analogue of a proposed constructed wetland reclamation strategy for OSPW, we evaluated the effectiveness of these microcosms in degrading NAs and reducing the aquatic toxicity of OSPW over a 52-week test period. Experimental manipulations included two sources of OSPW (one from Syncrude Canada Ltd. and one from Suncor Energy Inc.), two different hydraulic retention times (HRTs; 40 and 400 d), and increased nutrient availability (added nitrate and phosphate). Microcosms with a longer HRT (for both OSPWs) showed higher reductions in total NAs concentrations (64-74% NAs reduction, p100% v/v) independent of HRT. However, EC20s from separate Microtox® bioassays were relatively unchanged when comparing the input and microcosm waters at both HRTs over the 52-week study period (p>0.05), indicating that some sub-lethal toxicity persisted under these experimental conditions. The present study demonstrated that given sufficiently long HRTs, simulated wetland microcosms containing OSPW significantly reduced total NAs concentrations and acute toxicity, but left behind a persistent component of the NAs mixture that appeared to be associated with residual chronic toxicity.

  15. 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.

  16. 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.

  17. The chronic toxicity of sodium bicarbonate, a major component of coal bed natural gas produced waters

    Science.gov (United States)

    Farag, Aida M.; Harper, David D.

    2014-01-01

    Sodium bicarbonate (NaHCO3) is the principal salt in coal bed natural gas produced water from the Powder River Structural Basin, Wyoming, USA, and concentrations of up to 3000 mg NaHCO3/L have been documented at some locations. No adequate studies have been performed to assess the chronic effects of NaHCO3 exposure. The present study was initiated to investigate the chronic toxicity and define sublethal effects at the individual organism level to explain the mechanisms of NaHCO3 toxicity. Three chronic experiments were completed with fathead minnows (Pimephales promelas), 1 with white suckers (Catostomus commersoni), 1 with Ceriodaphnia dubia, and 1 with a freshwater mussel, (Lampsilis siliquoidea). The data demonstrated that approximately 500 mg NaHCO3/L to 1000 mg NaHCO3/L affected all species of experimental aquatic animals in chronic exposure conditions. Freshwater mussels were the least sensitive to NaHCO3 exposure, with a 10-d inhibition concentration that affects 20% of the sample population (IC20) of 952 mg NaHCO3/L. The IC20 for C. dubia was the smallest, at 359 mg NaHCO3/L. A significant decrease in sodium–potassium adenosine triphosphatase (Na+/K+ ATPase) together with the lack of growth effects suggests that Na+/K+ ATPase activity was shut down before the onset of death. Several histological anomalies, including increased incidence of necrotic cells, suggested that fish were adversely affected as a result of exposure to >450 mg NaHCO3/L.

  18. 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.

  19. Rapid Removal of Tetrabromobisphenol A by Ozonation in Water: Oxidation Products, Reaction Pathways and Toxicity Assessment.

    Directory of Open Access Journals (Sweden)

    Ruijuan Qu

    Full Text Available Tetrabromobisphenol A (TBBPA is one of the most widely used brominated flame retardants and has attracted more and more attention. In this work, the parent TBBPA with an initial concentration of 100 mg/L was completely removed after 6 min of ozonation at pH 8.0, and alkaline conditions favored a more rapid removal than acidic and neutral conditions. The presence of typical anions and humic acid did not significantly affect the degradation of TBBPA. The quenching test using isopropanol indicated that direct ozone oxidation played a dominant role during this process. Seventeen reaction intermediates and products were identified using an electrospray time-of-flight mass spectrometer. Notably, the generation of 2,4,6-tribromophenol was first observed in the degradation process of TBBPA. The evolution of reaction products showed that ozonation is an efficient treatment for removal of both TBBPA and intermediates. Sequential transformation of organic bromine to bromide and bromate was confirmed by ion chromatography analysis. Two primary reaction pathways that involve cleavage of central carbon atom and benzene ring cleavage concomitant with debromination were thus proposed and further justified by calculations of frontier electron densities. Furthermore, the total organic carbon data suggested a low mineralization rate, even after the complete removal of TBBPA. Meanwhile, the acute aqueous toxicity of reaction solutions to Photobacterium Phosphoreum and Daphnia magna was rapidly decreased during ozonation. In addition, no obvious difference in the attenuation of TBBPA was found by ozone oxidation using different water matrices, and the effectiveness in natural waters further demonstrates that ozonation can be adopted as a promising technique to treat TBBPA-contaminated waters.

  20. 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.

  1. 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.

  2. Water mediated eco-friendly green protocol for one-pot synthesis of -aminophosphonates at ambient conditions

    Indian Academy of Sciences (India)

    Santhosh Reddy Mandha; Manjula Alla; Vittal Rao Bommena

    2014-05-01

    Increasing environmental awareness and economic concerns have led to the consideration of highly efficient one-pot, three-component, green approaches for important organic synthons. We describe here a simple, elegant and high yielding protocol for the synthesis of -aminophosphonates in totally solvent-free, catalyst-free conditions by reacting aldehydes, amines and trimethyl phosphite at ambient temperature.

  3. Priority and emerging flame retardants in rivers: occurrence in water and sediment, Daphnia magna toxicity and risk assessment.

    Science.gov (United States)

    Cristale, Joyce; García Vázquez, Alejandro; Barata, Carlos; Lacorte, Silvia

    2013-09-01

    The occurrence, partitioning and risk of eight polybrominated diphenyl ethers (PBDEs), nine new brominated (NBFRs) and ten organophosphorus flame retardants (OPFRs) were evaluated in three Spanish rivers suffering different anthropogenic pressures (Nalón, Arga and Besòs). OPFRs were ubiquitous contaminants in water (ΣOPFRs ranging from 0.0076 to 7.2μgL(-1)) and sediments (ΣOPFRs ranging 3.8 to 824μgkg(-1)). Brominated flame retardants were not detected in waters, whereas ΣPBDEs ranged from 88 to 812μgkg(-1) and decabromodiphenyl ethane (DBDPE) reached 435μgkg(-1) in sediments from the River Besòs, the most impacted river. The occurrence of flame retardants in river water and sediment was clearly associated with human activities, since the highest levels occurred near urban and industrial zones and after wastewater treatment plants discharge. Daphnia magna toxicity was carried out for OPFRs, the most ubiquitous flame retardants, considering individual compounds and mixtures. Toxicity of nine tested OPFRs differed largely among compounds, with EC50 values ranging over three magnitude orders (0.31-381mgL(-1)). Results evidenced that these compounds act by non-polar narcosis, since their toxicity was proportional to their lipophilicity (Kow). Furthermore, their joint toxicity was additive, which means that single and joint toxicity can be predicted knowing their concentration levels in water using quantitative structure activity relationships (QSARs) and predictive mixture models. Based on these results, a risk assessment considering joint effect was performed calculating and summing risk quotients (RQs) for the water and sediment samples. No significant risk to D. magna (ΣRQs <1) was observed for any of the monitored rivers.

  4. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  6. Qualitative toxicity assessment of silver nanoparticles on the fresh water bacterial isolates and consortium at low level of exposure concentration.

    Science.gov (United States)

    Kumar, Deepak; Kumari, Jyoti; Pakrashi, Sunandan; Dalai, Swayamprava; Raichur, Ashok M; Sastry, T P; Mandal, A B; Chandrasekaran, N; Mukherjee, Amitava

    2014-10-01

    Silver nanoparticles (AgNPs) pose a high risk of exposure to the natural environment owing to their extensive usage in various consumer products. In the present study we attempted to understand the harmful effect of AgNPs at environmentally relevant low concentration levels (≤1ppm) towards two different freshwater bacterial isolates and their consortium. The standard plate count assay suggested that the AgNPs were toxic towards the fresh water bacterial isolates as well as the consortium, though toxicity was significantly reduced for the cells in the consortium. The oxidative stress assessment and membrane permeability studies corroborated with the toxicity data. The detailed electron microscopic studies suggested the cell degrading potential of the AgNPs, and the FT-IR studies confirmed the involvement of the surface groups in the toxic effects. No significant ion leaching from the AgNPs was observed at the applied concentration levels signifying the dominant role of the particle size, and size distribution in bacterial toxicity. The reduced toxicity for the cells in the consortium than the individual isolates has major significance in further studies on the ecotoxicity of the AgNPs.

  7. Arsenic toxicity in the water weed Wolffia arrhiza measured using Pulse Amplitude Modulation Fluorometry (PAM) measurements of photosynthesis.

    Science.gov (United States)

    Ritchie, Raymond J; Mekjinda, Nutsara

    2016-10-01

    Accumulation of arsenic in plants is a serious South-east Asian environmental problem. Photosynthesis in the small aquatic angiosperm Wolffia arrhiza is very sensitive to arsenic toxicity, particularly in water below pH 7 where arsenite (As (OH)3) (AsIII) is the dominant form; at pH >7 AsO4(2-) (As(V) predominates). A blue-diode PAM (Pulse Amplitude Fluorometer) machine was used to monitor photosynthesis in Wolffia. Maximum gross photosynthesis (Pgmax) and not maximum yield (Ymax) is the most reliable indicator of arsenic toxicity. The toxicity of arsenite As(III) and arsenate (H2AsO4(2-)) As(V) vary with pH. As(V) was less toxic than As(III) at both pH 5 and pH 8 but both forms of arsenic were toxic (>90% inhibition) at below 0.1molm(-3) when incubated in arsenic for 24h. Arsenite toxicity was apparent after 1h based on Pgmax and gradually increased over 7h but there was no apparent effect on Ymax or photosynthetic efficiency (α0).

  8. 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...

  9. Toxicity of neem pesticides on a fresh water loach, Lepidocephalichthys guntea (Hamilton Buchanan) of Darjeeling district in West Bengal.

    Science.gov (United States)

    Mondal, Debashri; Barat, Sudip; Mukhopadhyay, M K

    2007-01-01

    Static renewal bioassay tests were conducted to evaluate the acute toxicity of two neem based biopesticides, applied widely on tea plantation namely, Nimbecidine and Neem Gold either separately as well as, in combination to the fingerlings (mean body length- 4.46 +/- 0.15 cm; mean body weight- 0.49 +/- 0.15g) of a fresh water loach, Lepidocephalichthys guntea (Hamilton Buchanan) acclimatized to laboratory conditions prior to experiment. The 96 hours LC50 values for Nimbecidine and Neem Gold and the combination of the two were 0.0135 mgl(-1), 0.0525mgl(-1) and 0.0396 mgl(-1), respectively. The regular water quality analysis showed, that with increasing doses of biopesticides, dissolved oxygen level was lower and other parameters like pH, free carbon dioxide, total alkalinity total hardness, chloride ions of water increased. The fish under toxicity stress suffered several abnormalities such as erratic and rapid movement, body imbalance and surface floating responding proportionately to the increase in concentrations of the toxicant biopesticides. The 96 hours LC50 values proved Nimbecidine more toxic than Neem Gold and the combination of the two biopesticides.

  10. 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.

  11. Toxicity of Sulfide and Ammonium to Aedes triseriatus Larvae (Diptera: Culicidae) in Water-Filled Tree Holes and Tires.

    Science.gov (United States)

    Walker, Edward D

    2016-05-01

    Ammonium and sulfide in water of tree hole and tire habitats of Aedes triseriatus Say larvae could accumulate to toxic levels, limiting growth and production of larvae and adults. Both ions were detected in water samples taken in longitudinal series over 11 dates from 10 habitats of each type during the larval growth season, at concentrations suggestive of reducing conditions in these habitats. Ammonium was more concentrated overall in water of both habitat types, while sulfide was more concentrated in tires than in tree holes. Water of tree holes was more acidic, whereas water in tires tended to be more basic, an important difference relative to the tendency of ammonium to form the more toxic ammonia moiety under basic conditions. Oxygen saturation was low in both habitat types, indicative of hypoxic conditions such that aerobic respiration would be limited. First-and fourth-instar larvae were sensitive to ammonium and sulfide in acute dose-response assays, but LC50 values were above maximum concentrations observed under field conditions, suggesting that toxic effects of ammonium and sulfide on larvae are not acute, but could be chronic.

  12. Comparison of extracts and toxicities of organic compounds in drinking water concentrated by single and composite XAD resins.

    Science.gov (United States)

    Zhou, Xue; Xiang, Lunhui; Wu, Fenghong; Peng, Xiaoling; Xie, Hong; Wang, Jiachun; Yang, Kedi; Lu, Wenqing; Wu, Zhigang

    2013-12-01

    We compared extracts and toxicities of organic compounds (OCs) in drinking water concentrated by composite XAD-2/8 resin (mixed with an equal volume of XAD-2 and XAD-8 resins) with those extracted by single XAD-2 (non-polar) and XAD-8 (polar) resins. Drinking water was processed from raw water of the Han River and the Yangtze River in Wuhan section, China. The extraction efficiency of all resins was controlled at 30%. The types of extracted OCs were detected by gas chromatography-mass spectrometry, and the cytotoxicity and genotoxicity were assessed by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and comet assays, respectively, in human hepatoma HepG2 cells. Our results showed that XAD-2/8 extracted a larger variety of OCs, compared with XAD-8 and XAD-2. The cytotoxicity and genotoxicity of extracted OCs were in the order of XAD-8> XAD-2/8> XAD-2 at almost all tested concentrations after 24 h treatment (P < 0.05). Our findings suggest that single XAD resin selectively extracts either polar or non-polar OCs, which would lead to over- or under-estimation of the toxicity of drinking water. Nevertheless, composite resin extracts both polar and non-polar OCs, and could be utilized as a useful extraction technique to evaluate the level and toxicity of OCs in drinking water.

  13. Dynamics of an electrochemical biosensor for the detection of toxic substances in water

    Science.gov (United States)

    Simon, Laurent; Ospina, Juan

    2016-05-01

    A proposed analytical method focuses on electrolyte transport to the electrode of an electrochemical cell. The recombinant Escherichia coli whole-cell biosensor detects toxicity in water based on a set of biochemical reactors. Previous contributions elucidated the kinetics of product formation and validated a mathematical model for its diffusion in the chamber. This work introduces an approach to investigate the dynamics of the probe using Laplace transforms and an effective time constant. The transfer function between the electrolyte production and the total current revealed a faster response for larger electrode radii. Both the first-order and effective time constants increased with the chamber height and radius. Separation of variables yields closed-form solutions and helps estimate the kinetics of p-aminophenol generation. When the bacteria were exposed to phenol concentrations of 1.6, 8.3 and 16 ppm, the corresponding overall rate constants were 5.11x10-7, 1.13x10-6 and 1.99x10-6 (product concentration unit/s2), respectively. In addition to parameter estimation, the method can be applied to perform sensitivity analysis and aid manufacturers in meeting design specifications of biosensors.

  14. Heavy metals toxicity and bioaccumulation patterns in the body organs of four fresh water fish species

    Directory of Open Access Journals (Sweden)

    Safina Kousar and Muhammad Javed

    2014-04-01

    Full Text Available Various environmental pollutants, including metals can cause toxicological effects on aquatic animals especially fish species. Laboratory experiments were conducted to determine acute toxicity and bioaccumulation patterns of arsenic (As, nickel (Ni and zinc (Zn in 150-day old fish species (Labeo rohita, Cirrhina mrigala, Catla catla and Ctenopharyngodon idella, separately, in glass aquaria under constant water temperature (30oC, total hardness (300 mg L-1 and pH (7.5. Catla catla showed significantly (PNi>As. Among exposed fish species, Cirrhina mrigala exhibited significantly higher ability to amass Ni (146.8±149.1 μg g-1 and Zn (243.0±190.5 μg g-1, followed by Ctenopharyngodon idella, Labeo rohita and Catla catla at 96-h LC50. Liver showed higher tendency to accumulate Ni, followed by gills and kidney with significant differences while kidney showed higher tendency to accumulate As, followed by liver. Fins and scales exhibited significantly (P<0.05 least tendency to accumulate all the three metals. Accumulation of metals in different fish species is the function of their membrane permeability, which is highly species specific. Due to this reason different fish species showed different amount of metal accumulated in their bodies. This study also reveals that the metals, being conservative in nature have higher ability of biomagnifications.

  15. Drinking water obtaining by nanofiltration from waters contaminated with glyphosate formulations: process evaluation by means of toxicity tests and studies on operating parameters.

    Science.gov (United States)

    Saitúa, Hugo; Giannini, Fernando; Padilla, Antonio Perez

    2012-08-15

    Glyphosate formulations toxicity depends on all its components but commercial products only specify the active principle in their label. To treat contaminated waters and to verify if the unknown components which add toxicity have been removed represent a challenge. Nanofiltration and permeate analysis by toxicity tests with fish are an interesting alternative to evaluate the process. Permeates of solutions with concentrations five times above the lethal doses (48 mg/l) did not present toxicity, pointing that all toxic compounds were removed at the same time. Glyphosate rejection over an 80% despite its molecular weight is lower than membrane MWCO, this could be associated to a predominant Donnan exclusion mechanism, combined with dielectric exclusion due to the solute high charge density. Glyphosate concentration did not show any effect over rejection. It increased when pressure was incremented from 2.5 to 4 bar and then remained constant in a 4-10 bar range. Because of dissociation of the glyphosate and the surface charged of the membrane depend on pH value, the rejection increase from 72.5 to 92.5% when pH increase from 4 to 8.5. Studies with river water showed the same behavior with a slight decrease in rejection.

  16. Ambient intelligence

    OpenAIRE

    Sanders, David; Gegov, Alexander

    2006-01-01

    This paper considers some history and the state of the art of Ambient Intelligence and from that seeks to identify new topics and future work. Ubiquitous computing, communications, human-centric computer interaction, embedded systems, context awareness, adaptive systems and distributed device networks are considered.

  17. 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...

  18. Intravenous Toxicity Study of Water-soluble Ginseng Pharmacopuncture in SD Rats

    Directory of Open Access Journals (Sweden)

    Jun-Sang Yu

    2015-12-01

    Full Text Available Objectives: Radix Ginseng has been used for thousands of years to treat a wide variety of diseases. Radix ginseng has also been used as a traditional medicine for boosting Qi energy and tonifying the spleen and lungs. Traditionally, its effect could be obtained orally. Nowadays, a new method, the injection of herbal medicine, is being used. This study was performed to investigate the single-dose intravenous toxicity of water-soluble ginseng pharmacopuncture (WSGP in Sprague-Dawley (SD rats. Methods: All experiments were carried out at Biotoxtech, an institute authorized to perform non-clinical studies under the regulation of Good Laboratory Practice (GLP. At the age of six weeks, 40 SD rats, 20 male rats and 20 female rats, were allocated into one of 4 groups according to the dosages they would receive. The WSGP was prepared in the Korean Pharmacopuncture Institute under the regulation of Korea-Good Manufacturing Practice (K-GMP. Dosages of WSGP were 0.1, 0.5 and 1.0 mL/animal for the experimental groups, and normal saline was administered to the control group. The rat's general conditions and body weights, the results of their hematological and biochemistry tests, and their necropsy and histopathological findings were investigated to identify the toxicological effect of WSGP injected intravenously. The effect was examined for 14 days after the WSGP injection. This study was performed under the approval of the Institutional Animal Ethics Committee of Biotoxtech. Results: No deaths were found in this single-dose toxicity test on the intravenous injection of WSGP, and no significant changes in the rat's general conditions and body weights, the results on their hematological and biochemistry test, and their necropsy findings were observed during the test. The local area of the injection site showed minial change. The lethal dose was assumed to be over 1.0 mL/animal in both sexes. Conclusion: These results indicate that WSGP is safe at dosages up to

  19. Pelletized ponderosa pine bark for adsorption of toxic heavy metals from water

    Directory of Open Access Journals (Sweden)

    Tshabalala, M. A.

    2007-02-01

    Full Text Available 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(II, Zn(II, Cd(II, and Ni(II under both equilibrium and dynamic adsorption conditions. The experimental data for Cd(II and Zn(II showed a better fit to the Langmuir than to the Freundlich isotherm. The Cu(II data best fit the Freundlich isotherm, and the Ni(II data fitted both Freundlich and Langmuir isotherms equally. According to the Freundlich constant KF, adsorption capacity of pelletized bark for the metal ions in aqueous solution, pH 5.1 ± 0.2, followed the order Cd(II > Cu(II > Zn(II >> Ni(II; according to the Langmuir constant b, adsorption affinity followed the order Cd(II >> Cu(II ≈ Zn(II >> Ni(II. Although data from dynamic column adsorption experiments did not show a good fit to the Thomas kinetic adsorption model, estimates of sorption affinity series of the metal ions on pelletized bark derived from this model were not consistent with the series derived from the Langmuir or Freundlich isotherms and followed the order Cu(II > Zn(II ≈ Cd(II > Ni(II. According to the Thomas kinetic model, the theoretical maximum amounts of metal that can be sorbed on the pelletized bark in a column at influent concentration of ≈10 mg/L and flow rate = 5 mL/min were estimated to be 57, 53, 50, and 27 mg/g for copper, zinc, cadmium, and nickel, respectively. This study demonstrated the potential for converting low-cost bark residues to value-added sorbents using starting materials and chemicals derived from renewable resources. These sorbents can be applied in the removal of toxic heavy metals from waste streams with heavy metal ion concentrations of up to 100 mg/L in the case of Cu(II.

  20. Effect of water hardness on peracetic toxicity to zebrafish, Danio rerio, embryos

    Science.gov (United States)

    The use of peracetic acid (PAA) in aquaculture has been suggested as an alternative therapeutic agent as use of previous therapeutants becomes restricted. Few data are available concerning fish toxicity by PAA or factors that affect this toxicity. The aim of this study was to investigate the influ...

  1. Analytical and toxicity characterization of halo-hydroxyl-benzoquinones as stable halobenzoquinone disinfection byproducts in treated water.

    Science.gov (United States)

    Wang, Wei; Qian, Yichao; Li, Jinhua; Moe, Birget; Huang, Rongfu; Zhang, Hongquan; Hrudey, Steve E; Li, Xing-Fang

    2014-05-20

    Exposure to chlorination disinfection byproducts (DBPs) is potentially associated with an increased risk of bladder cancer. Four halobenzoquinones (HBQs) have been detected in treated drinking water and have shown potency in producing reactive oxygen species and inducing damage to cellular DNA and proteins. These HBQs are unstable in drinking water. The fate and behavior of these HBQs in drinking water distribution systems is unclear. Here we report the high-resolution mass spectrometry identification of the transformation products of HBQs as halo-hydroxyl-benzoquinones (OH-HBQs) in water under realistic conditions. To further examine the kinetics of transformation, we developed a solid-phase extraction with ultrahigh-performance liquid chromatography tandem mass spectrometry (SPE-UHPLC-MS/MS) method to determine both the HBQs and OH-HBQs. The method provides reproducible retention times (SD method, we confirmed that decrease of HBQs correlated with increase of OH-HBQs in both the laboratory experiments and several distribution systems, supporting that OH-HBQs were more stable forms of HBQ DBPs. To understand the toxicological relevance of the OH-HBQs, we studied the in vitro toxicity with CHO-K1 cells and determined the IC50 of HBQs and OH-HBQs ranging from 15.9 to 72.9 μM. While HBQs are 2-fold more toxic than OH-HBQs, both HBQs and OH-HBQs are substantially more toxic than the regulated DBPs.

  2. Toxic effect of selenium on the zooplankton, Daphnia magna and Daphnia pulicaria, in water and the food source (Chlamydomonas reinhardtii)

    Energy Technology Data Exchange (ETDEWEB)

    Boyum, K.W.

    1984-01-01

    Acute and chronic toxicity experiments were performed on the zooplankton, Daphnia magna and Daphnia pulicaria, to investigate the toxicity of selenium on these aquatic invertebrates. The acute 48 h LC/sub 50/ of sodium selenate for Daphnia magna and Daphnia pulicaria were 1.01 and 0.25 mg Se/1, respectively. The 48 h LC/sub 50/ of sodium selenite for D. magna and D. pulicaria were 0.45 and 0.006 mg Se/1, respectively. Chronic 28-day toxicity tests were performed on D. magna at 0.05, 0.10, 0.50, and 1.00 mg Se/1 as sodium selenate in the water and with two food types. One food type was algae raised in clean Lake Michigan water and the second treatment was algae raised in media with selenium concentrations corresponding to those in the water cited above. When compared to Daphnia fed selenium-free algae, D. magna fed selenium-laden algae had greater survival, a greater number of offspring produced, and a greater intrinsic growth rate, r, at the toxicant concentration in the water of 0.05, 0.10, and 0.50 mg Se/1. These parameters were, however, lower than those observed in the controls. Uptake of /sup 75/Se as sodium selenate in D. magna was reduced in the presence of selenium-laden algae and DL-selenomethionine, while L-methionine increased the uptake of /sup 75/Se. Selenium bound to an amino acid such as Dl-selenomethionine or organically bound within an algal food source appears to be preferentially incorporated thereby reducing the uptake of inorganic forms from the water.

  3. Effects of water hardness and alkalinity on the toxicity of uranium to a tropical freshwater hydra (Hydra viridissima).

    Science.gov (United States)

    Riethmuller, N; Markich, S J; Van Dam, R A; Parry, D

    2001-01-01

    In tropical Australian freshwaters, uranium (U) is of potential ecotoxicological concern, largely as a consequence of mining activities. Although the toxicity of uranium to Australian freshwater biota is comprehensive, by world standards, few data are available on the effects of physicochemical variables, such as hardness, alkalinity, pH and organic matter, on uranium speciation and bioavailability. This study determined the individual effects of water hardness (6.6, 165 and 330 mg l(-1) as CaCO3) and alkalinity (4.0 and 102 mg l(-1) as CaCO3), at a constant pH (6.0), on the toxicity (96 h population growth) of uranium to Hydra viridissima (green hydra). A 50-fold increase in hardness (Ca and Mg concentration) resulted in a 92% (two-fold) decrease in the toxicity of uranium to H. viridissima [i.e. an increase in the EC50 value and 95% confidence interval from 114 (107-121) to 219 (192-246) µg l(-1)]. Conversely, at a constant hardness (165 mg l-1 as CaCO3), the toxicity of uranium to H. viridissima was not significantly (P > 0.05) affected by a 25-fold increase in alkalinity (carbonate concentration) [i.e. EC50 values of 177 (166-188) and 171 (150-192) µg l(-1) at 4.0 and 102 mg l(-1) as CaCO3, respectively]. A knowledge of the relationship between water chemistry variables, including hardness and alkalinity, and uranium toxicity is useful for predicting the potential ecological detriment in aquatic systems, and can be used to relax national water quality guidelines on a site-specific basis.

  4. 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)

  5. Acute and chronic toxicity studies on partially purified hypoglycemic preparation from water extract of bark ofFicus bengalensis.

    Science.gov (United States)

    Gupta, S; Shukla, R; Prabhu, K M; Aggrawal, S; Rusia, U; Murthy, P S

    2002-01-01

    Acute and chronic toxicity studies were conducted to assess toxicity of a partially purified preparation from the water extract of the bark ofFicus bengalensis, which was demonstrated in our earlier studies to have significant hypoglycemic and hypocholesteroiemic effect on alloxan induced, mild and severe diabetes in rabbits. LD(50) of this preparation was found to be ∼1 gm/kg in rats when given orally. For chronic toxicity studies 3 doses of aqueous preparation were given to 3 groups of rats. First group received 5 times ED(50) (50 mg/kg), second group 10 times ED(50) (100 mg/kg) and the third group 15 times ED(50) (150 mg/kg) for 3 months. Fourth group which served as control was given water. After three months, blood was collected for studying biochemical and hematological parameters. Blood glucose, serum cholesterol, liver and kidney function tests, haemoglobin, total and differential leukocyte count were determined. Animals were sacrificed and histopathological examination of liver, heart and kidneys was carried out. Results of the study showed that partially purified preparation fromFicus bengalensis is not toxic by all the above mentioned parameters.

  6. Acute toxicity of drainage ditch water from a Washington State cranberry-growing region to Daphnia pulex in laboratory bioassays.

    Science.gov (United States)

    Wood, Barbara; Stark, John D

    2002-10-01

    High concentrations of organophosphorous insecticides resulting from cranberry bog applications were detected in the Grayland Drainage Ditch (GDD) system in Grayland, Washington State, during the 1994-1996 Washington State Department of Ecology Pesticide Monitoring Program. This drainage ditch system drains cranberry bogs and enters the Pacific Ocean via the North Cove and Supon Inlet. Concerns about the impact of these pesticides on human and environmental health led to this investigation of the potential impact on an indicator species, Daphnia pulex. To determine the toxic effects of multiple pesticides entering the GDD, standardized laboratory toxicity tests with D. pulex were conducted concurrently with the Washington State Department of Ecology pesticide sampling. Concentrations of three insecticides, diazinon, chlorpyrifos, and azinphosmethyl, were the highest ever detected in state waters. The GDD water was found to cause acute toxicity in 33% of the laboratory bioassays conducted. Regression analysis, however, detected a poor correlation between total insecticide detected and percentage mortality of D. pulex at the two drainage ditch sites studied, Grays Harbor County site and the Pacific County site. However, the relationship between mortality of D. pulex and detected concentrations of diazinon and chlorpyrifos were significant. Sampling schedules for chemical analysis and bioassay testing appear to be the primary reason that statistical analysis failed to correlate mortality with detected OP pesticide concentrations. Grab samples used in toxicity testing may over- or underestimate actual concentrations of contaminants present in the system being studied.

  7. Acute and subchronic toxicity study of the water extract from dried fruits of Piper nigrum L. in rats

    Directory of Open Access Journals (Sweden)

    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.

  8. Metales pesados y toxicidad de aguas del Río Aconcagua en Chile Heavy metals and toxicity of waters of the Aconcagua River in Chile

    OpenAIRE

    Hernán Gaete; Fernanda Aránguiz; Gabriela Cienfuegos; Marisol Tejos

    2007-01-01

    The toxicity of surface waters in a zone with mining activity in the Aconcagua River was determined through growth inhibition bioassays of Pseudokirchneriella subcapitata, and correlated with heavy metal concentrations. Results show that the waters near the discharge of the mining effluent displayed toxicity during all periods of study; the molybdenum and copper concentration exceeded the norms of water quality. The correlations between the concentrations of metals and the growth rate of P. s...

  9. Preliminary degradation test of toxic compounds dissolved in water using concentrated solar light. Tecnologia solar de concentracion para eliminacion mediante fotocatalisis de residuos industriales toxicos disueltos en agua

    Energy Technology Data Exchange (ETDEWEB)

    Blanco galvez, J.; Malato Rogriguez, S.

    1992-01-01

    The production and emission of hazardous chemicals wastes is a problem that is becoming more and more important in the industrialized world. Most of these wastes are toxic organic compounds appearing in low concentration in the water. solar photocatalytic water detoxification using interaction between ultraviolet light and TiO[sub 2] catalyst has therefore a strong potential in the industrial destruction of toxic organics in water. (Author)

  10. Comparison of diazinon toxicity to embryos of Xenopus laevis and Danio rerio; degradation of diazinon in water.

    Science.gov (United States)

    Modra, Helena; Vrskova, Dagmar; Macova, Stanislava; Kohoutkova, Jana; Hajslova, Jana; Haluzova, Ivana; Svobodova, Zdenka

    2011-06-01

    The aim of this study was to determine the toxic effect of diazinon (organophosphate insecticide) to embryos of Xenopus laevis and Danio rerio. The 96-h LC₅₀ values showed higher toxicity of diazinon for X. leavis in standard solution (9.84 mg/L) compared to the pond water (12.64 mg/L). Teratogenic index for diazinon was 1.3 and 1.6, respectively. The 96-h LC₅₀ diazinon values demonstrated similar sensitivity of embryos D. rerio (8.21-9.34 mg/L) and X. laevis in standard test solutions. Our results reflect that direct application of diazinon into the water can be associated with significant risks to aquatic organisms.

  11. Strategies for monitoring and managing mass populations of toxic cyanobacteria in recreational waters: a multi-interdisciplinary approach.

    Science.gov (United States)

    Tyler, Andrew N; Hunter, Peter D; Carvalho, Laurence; Codd, Geoffrey A; Elliott, J Alex; Ferguson, Claire A; Hanley, Nick D; Hopkins, David W; Maberly, Stephen C; Mearns, Kathryn J; Scott, E Marion

    2009-12-21

    Mass populations of toxin-producing cyanobacteria commonly develop in fresh-, brackish- and marine waters and effective strategies for monitoring and managing cyanobacterial health risks are required to safeguard animal and human health. A multi-interdisciplinary study, including two UK freshwaters with a history of toxic cyanobacterial blooms, was undertaken to explore different approaches for the identification, monitoring and management of potentially-toxic cyanobacteria and their associated risks. The results demonstrate that (i) cyanobacterial bloom occurrence can be predicted at a local- and national-scale using process-based and statistical models; (ii) cyanobacterial concentration and distribution in waterbodies can be monitored using remote sensing, but minimum detection limits need to be evaluated; (iii) cyanotoxins may be transferred to spray-irrigated root crops; and (iv) attitudes and perceptions towards risks influence the public's preferences and willingness-to-pay for cyanobacterial health risk reductions in recreational waters.

  12. Rapid removal of bacterial endotoxin and natural organic matter in water by dielectric barrier discharge plasma: Efficiency and toxicity assessment.

    Science.gov (United States)

    Zhang, Can; Fang, Zhendong; Liu, Wenjun; Tian, Fang; Bai, Miao

    2016-11-15

    Low-temperature plasma was used to control bacteria, endotoxins and natural organic matter (NOM) in water by a dielectric barrier discharge (DBD) device. Results indicate that DBD plasma has an obvious inactivation effect on various bacteria in water. The degree of inactivation from difficult to easy is as follows: Bacillus subtilis>Escherichia coli>Staphylococcus aureus. Activated ultrapure water treated using DBD plasma exhibited a sustained sterilization effect, but this sterilization effect decreased gradually after 1h. The total-endotoxin (free-endotoxin and bound-endotoxin) released by Escherichia coli during inactivation, as well as artificially simulated endotoxin in a control solution, was significantly controlled by DBD plasma. Both the metabolites that appeared after inactivation of microorganisms by plasma treatment, and the NOM in filtration effluent of a water treatment plant were well removed by DBD plasma if the treatment duration was sufficiently long. However, the acute toxicity increased significantly, and persisted for at least 2h, indicating that some long-life active substances were generated during the DBD process. Therefore, the removal of bacteria, endotoxins or NOM does not mean a safe water is produced. It is also important to eliminate the toxicity and byproducts produced during water treatment for the continuous promotion and industrial application of DBD plasma.

  13. Toxicity profiling of water contextual zinc oxide, silver, and titanium dioxide nanoparticles in human oral and gastrointestinal cell systems.

    Science.gov (United States)

    Giovanni, Marcella; Tay, Chor Yong; Setyawati, Magdiel Inggrid; Xie, Jianping; Ong, Choon Nam; Fan, Rongli; Yue, Junqi; Zhang, Lifeng; Leong, David Tai

    2015-12-01

    Engineered nanoparticles (ENPs) are increasingly detected in water supply due to environmental release of ENPs as the by-products contained within the effluent of domestic and industrial run-off. The partial recycling of water laden with ENPs, albeit at ultra-low concentrations, may pose an uncharacterized threat to human health. In this study, we investigated the toxicity of three prevalent ENPs: zinc oxide, silver, and titanium dioxide over a wide range of concentrations that encompasses drinking water-relevant concentrations, to cellular systems representing oral and gastrointestinal tissues. Based on published in silico-predicted water-relevant ENPs concentration range from 100 pg/L to 100 µg/L, we detected no cytotoxicity to all the cellular systems. Significant cytotoxicity due to the NPs set in around 100 mg/L with decreasing extent of toxicity from zinc oxide to silver to titanium dioxide NPs. We also found that noncytotoxic zinc oxide NPs level of 10 mg/L could elevate the intracellular oxidative stress. The threshold concentrations of NPs that induced cytotoxic effect are at least two to five orders of magnitude higher than the permissible concentrations of the respective metals and metal oxides in drinking water. Based on these findings, the current estimated levels of NPs in potable water pose little cytotoxic threat to the human oral and gastrointestinal systems within our experimental boundaries.

  14. Water adsorption isotherms on CH3-, OH-, and COOH-terminated organic surfaces at ambient conditions measured with PM-RAIRS.

    Science.gov (United States)

    Tu, Aimee; Kwag, Hye Rin; Barnette, Anna L; Kim, Seong H

    2012-10-30

    The water adsorption isotherms on methyl (CH(3))-, hydroxyl (OH)-, and carboxylic acid (COOH)-terminated alkylthiol self-assembled monolayers (SAMs) on Au were studied at room temperature and ambient pressure with polarization modulation reflection-absorption infrared spectroscopy (PM-RAIRS). PM-RAIRS analysis showed that water does not adsorb at all on the CH(3)-SAM/Au at subsaturation humidity conditions. In a dry Ar environment, the OH-SAM/Au holds at least 2 layer thick strongly bound water molecules which exhibit a broad O-H stretch vibration peak centered at ∼3360 cm(-1). The peak position implies that the strongly bound water layer on the OH SAM is more like a liquid than an ice. The additional uptake of water in humid environments is relatively weak, and the peak position changes very little. Unlike the OH-SAM/Au, the COOH-SAM/Au does not have strongly bound water layer. This seems to be due to the strong hydrogen bonding between terminal COOH groups in dry conditions. The weak interactions between water and carboxyl groups at low relative humidity (RH) and the solvation of dissociated carboxylic groups in high RH lead to a type III isotherm behavior, based on the BET categories, for water adsorption on the COOH-SAM/Au. The water spectra on the COOH-SAM at RH > 45% are centered at ∼3430 cm(-1) and very broad, indicating that the hydrogen-bonding network of water on the COOH-SAM is much different from that on the OH-SAM.

  15. 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.

  16. Concentrations, diffusive fluxes and toxicity of heavy metals in pore water of the Fuyang River, Haihe Basin.

    Science.gov (United States)

    Tang, Wenzhong; Duan, Shenghui; Shan, Baoqing; Zhang, Hong; Zhang, Wenqiang; Zhao, Yu; Zhang, Chao

    2016-05-01

    While the concentrations of heavy metals in pore water provide important information about their bioavailability, to date few studies have focused on this topic. In this study, pore water in river sediments collected from nine sampling sites (S1-S9) was examined to determine the concentrations, fluxes, and toxicity of heavy metals in the Fuyang River. The results showed that the average concentrations of Cr, Ni, Cu, As, Zn, and Pb in pore water were 17.06, 15.97, 20.93, 19.08, 43.72, and 0.56μgL(-1), respectively; these concentrations varied as the pore water depth increased. The diffusive fluxes of Cr, Ni, Cu, As, Zn, and Pb were in the following range: (-0.37) to 3.17, (-1.37) to 2.63, (-4.61) to 3.44, 0.17-6.02, (-180.26) to 7.51, and (-0.92) to (-0.29)μg(m(2)day)(-1), respectively. There was a potential risk of toxicity from Cu to aquatic organisms, as indicated by a value of the Interstitial Water Criteria Toxic Units that exceeded 1.0. Values of the Nemeraw Index were 2.06, 0.48, 0.11, 0.20, 1.11, 1.03, 0.99, 0.88, and 0.89 from S1 to S9, respectively. Only S1 was moderately polluted by heavy metals in pore water.

  17. Radiological and chemical toxicity due to ingestion of uranium through drinking water in the environment of Bangalore, India.

    Science.gov (United States)

    Mathews, Gladys; Nagaiah, N; Karthik Kumar, M B; Ambika, M R

    2015-06-01

    Groundwater samples collected from 96 bore wells in the study area (city of Bangalore) were analysed for concentration of natural uranium using laser-induced fluorimetry. The risk to the population of the region associated with radiological and chemical toxicity of uranium due to its ingestion through drinking water over a lifetime was estimated. The concentration of uranium was found to be in the range 0.136 to 2027.5 μg L(-1) with an average value of 92.42 μg L(-1). In the present study, about 61% of the samples show concentrations of uranium within the safe limit of 30 μg L(-1) as set by the world health organisation. The radiological risk estimated as lifetime cancer risk is in the range 4.3  ×  10(-7) to 6.4  ×  10(-3) with an average of 2.9  ×  10(-4). The chemical toxicity risk measured as lifetime average daily dose is found to range from 0.005 to 75.42 μg kg(-1) d(-1). The reference dose estimated as 1.12 μg kg(-1) d(-1) was used to assess the chemical toxicity. The results indicate that the chemical toxicity due to ingestion of uranium through drinking water is of more concern than the radiological toxicity. The present study, being the first of its kind in this region, will augment the database of uranium in groundwater.

  18. Acute and subchronic toxicity study of the water extract from the fruits of Piper chaba Hunter in rats

    Directory of Open Access Journals (Sweden)

    K Jaijoy

    2010-12-01

    Full Text Available Summary: The water extract from the fruits of Piper chaba Hunter was evaluated for acute and subchronic toxicity in both male and female rats. For the study of acute toxicity, a single oral dose of 5,000 mg/kg body weight was administered in rats (five females, five males. The results showed no signs of toxicity such as general behavior change, mortality, or change in gross appearance of internal organs. Subchronic toxicity was studied by daily oral doses (ten females, ten males of 300, 600 and 1,200 mg/kg body weight for consecutive 90 days. The satellite group was treated with the extract at the dose of 1,200 mg/kg/day for 90 days and kept for other 28 days after treatment. The results showed no abnormalities in treated groups as compared to the controls. Although significantly different, all of the values were within normal limits. Neither gross abnormalities nor histopathological changes were observed. The results suggest that P. chaba extract does not produce acute or subchronic toxicity in either female or male rats. Industrial relevance: Herbal medicines are popular and extensively used in the developing world. In many places, they offer a more wide available and more affordable alternative to pharmaceutical drugs and natural food supplements. The data of the acute and subchronic toxicity studies on medicinal plants or preparations derived from them should be obtained in order to increase the confidence in its safety to human, particularly for use in the development of pharmaceutical.

  19. The development of an aquatic toxicity index as a tool in the operational management of water quality in the Olifants River (Knsger National Park

    Directory of Open Access Journals (Sweden)

    V. Wepener

    1992-09-01

    Full Text Available The development of an aquatic toxicity index and its application is described. In this index the protection of aquatic life is always referred to in terms of toxic effects of different water quality variables to fish, as health indicators of the aquatic ecosystem. The final index score is produced by means of standard additive techniques as well as by using the water quality variable giving the lowest index score (minimum operator. The minimum operator is employed in order not to conceal important water quality information. The aquatic toxicity index development has been linked to toxicological data, international water quality standards and South African guidelines. The index provides valuable information concerning toxic effects of a specific variable on fish should the threshold level for normal maintanence of aquatic life be exceeded. This index is intended as an aid in the interpretation of water quality information in order to facilitate management decisions.

  20. Correlation Study of Toxicity of Substituted Phenols to River Bacteria and Their Biodegradability in River Water

    Institute of Scientific and Technical Information of China (English)

    XING YUAN; GUAN-GHUA LU; LI-MIN SU

    2005-01-01

    Objective To study the correlation of toxicity with biodegradability (BODT) in order to promote QSBR development and understand the degradation mechanism. Methods Toxicity of substituted phenols to river bacteria was determined by the turbidities that were measured using a spectrophotometer (UV-190) at 530 nm against a blank control. The biodegradability of substituted phenols was expressed as BODT and the DO concentrations were determined by the iodometric titration method. Results The BODT and toxicity(log 1/IC50) of 12 substituted phenols to bacteria from the Songhua River were determined respectively. The correlation of biodegradability with toxicity was developed: BODT=8.21 (±2.22) pKa -32.44 (±8.28) log 1/IC50 +89.04 (±38.20), n=12, R2=0.791, R2(adj)=0.745, SE=9.134, F=17.066, P=0.001. Conclusion The BODT of substituted phenols was influenced by their toxicity and the ionization constant pKa. The stronger the toxicity, the less readily the compound was degraded by river bacteria.

  1. A molecular-level approach for characterizing water-insoluble components of ambient organic aerosol particulates using ultra-high resolution mass spectrometry

    Directory of Open Access Journals (Sweden)

    A. S. Willoughby

    2014-04-01

    Full Text Available The chemical composition of organic aerosols in the atmosphere is strongly influenced by human emissions, and the effect these have on the environment, human health, and climate change is determined by the molecular nature of these chemical species. The complexity of organic aerosol samples limits the ability to study the chemical composition, and, therefore, the associated properties and the impacts they have. Many studies address the water-soluble fraction of organic aerosols, and have had much success in identifying specific molecular formulas for thousands of compounds present. However, little attention is given to the water-insoluble portion, which can contain most of the fossil material that is emitted through human activity. Here we compare the organic aerosols present in water extracts and organic solvent extracts (pyridine and acetonitrile of an ambient aerosol sample collected in a rural location that is impacted by natural and anthropogenic emission sources. A semi-quantitative method was developed using proton nuclear magnetic resonance spectroscopy to determine that the amount of organic matter extracted by pyridine is comparable to that of water. Electrospray ionization Fourier transform ion cyclotron resonance mass spectra show that pyridine extracts a molecularly unique fraction of organic matter compared to water or acetonitrile, which extract chemically similar organic matter components. The molecular formulas unique to pyridine were less polar, more aliphatic, and reveal formulas containing sulfur to be an important component of insoluble aerosol organic matter.

  2. Larvicidal activity of the water extract of Moringa oleifera seeds against Aedes aegypti and its toxicity upon laboratory animals.

    Science.gov (United States)

    Ferreira, Paulo M P; Carvalho, Ana F U; Farias, Davi F; Cariolano, Nara G; Melo, Vânia M M; Queiroz, Maria G R; Martins, Alice M C; Machado-Neto, Joaquim G

    2009-06-01

    In this work, biological effects of the water extract of Moringa oleifera seeds (WEMOS) were assessed on eggs and 3rd instar larvae of Aedes aegypti and on its toxicity upon laboratory animals (Daphnia magna, mice and rats). Crude WEMOS showed a LC50 value of 1260microg/mL, causing 99.2 +/- 2.9% larvae mortality within 24 h at 5200microg/mL, though this larvicidal activity has been lost completely at 80 masculineC/10 min. WEMOS did not demonstrate capacity to prevent egg hatching. After extensive dialyses of the crude WEMOS into watersoluble dialyzable (DF) and nondyalizable (NDF) fractions, only DF maintained its efficacy to kill larvae. Acute toxicity evaluations on daphnids (EC50 of 188.7microg/mL) and mice (LD50 of 446.5 mg/kg body weight) pointed out to low toxicity. Despite the thymus hypertrophy, WEMOS revealed to be harmless in orally and subacutelytreated rats. In conclusion, WEMOS has thermostable bioactive compounds against Ae. aegypti larvae with apparent molecular mass lower than 12 kDa and moderately toxic potential.

  3. 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.

  4. Population dynamics of toxic phytoplankton and bacterial flora in the waters of the low Adriatic sea; Dinamica di popolazione di fitoplancton tossico e flora batterica nel basso Adriatico

    Energy Technology Data Exchange (ETDEWEB)

    Caroppo, C.; Stabili, L.; Cavallo, R.A.; Pastore, M. [CNR, Ist. Sperimentale Talassografico Attlio Cerruti, Taranto (Italy); Marchiori, E. [Rome Univ., Rome (Italy). Dipt. di Chimica Organica; Bruno, M. [Istituto Superiore di Sanita' , Laboratorio di Igiene Ambientale, Rome (Italy)

    2000-07-01

    The coastal areas of the Southern Adriatic Sea, in particular the Apulian ones, may be considered an example of intact ecosystem and represent an ideal term of comparison to other marine ecosystems having higher levels of pollution (Northern Adriatic Sea). In order to evaluate the sanitary levels of this environment, four transect were investigated during two years monitoring (April 1995-March 1997) along the Otranto Channel coasts, by joint research groups of the Environmental Hygiene Laboratory of the Istituto Superiore di Sanita' and the Istituto Sperimentale Talassografico A. Cerruti of CNR in Taranto. The study underlines the phytoplanktic and bacterial population dynamics, and the detection of the microbiological water quality along the coast tract Brindisi-Lecce-Otranto-S. Maria di Leuca. The results acquired pointed out population dynamics of some potantially toxic species of Dinophysis genus and Pseudo-nitzschia delicatissima. These depended on the winter nutrient loads due to the ASW (Adriatic Superficial Waters) and to the LIW (Levantine Intermediate Waters). The bacterial community was mainly constituted by genera Aeromonas, Photobacterium, Cytophaga and Pseudomonas. Also the presence of Enterobacteriaceae family was relevant. Among the pathogenic vibrios the most frequently isolated species were Vibrio alginolyticus and Vibrio vulnificus. [Italian] Considerando che le zone del basso Adriatico, in particolare quelle pugliesi, costituiscono un biotopo ancora relativamente inalterato, esse sono state oggetto di un'indagine sperimentale condotta in 24 mesi di attivita' (aprile 1995-marzo 1997) lungo le coste del Canale di Otranto, ad opera di un gruppo congiunto del Laboratorio di Igiene Ambientale dell'Istituto Superiore di Sanita' e dei laboratori dell'Istituto Sperimentale Talassografico A. Cerruti del CNR di Taranto, ai fini di valutare lo stato di salute di questo ambiente, che fornisce, con buona probabilita', un

  5. Influence of dissolved organic carbon on toxicity of copper to a unionid mussel (Villosa iris) and a cladoceran (Ceriodaphnia dubia) in acute and chronic water exposures.

    Science.gov (United States)

    Wang, Ning; Mebane, Christopher A; Kunz, James L; Ingersoll, Christopher G; Brumbaugh, William G; Santore, Robert C; Gorsuch, Joseph W; Arnold, W Ray

    2011-09-01

    Acute and chronic toxicity of copper (Cu) to a unionid mussel (Villosa iris) and a cladoceran (Ceriodaphnia dubia) were determined in water exposures at four concentrations of dissolved organic carbon (DOC; nominally 0.5, 2.5, 5, and 10 mg/L as carbon [C]). Test waters with DOC concentrations of 2.5 to 10 mg C/L were prepared by mixing a concentrate of natural organic matter (Suwannee River, GA, USA) in diluted well water (hardness 100 mg/L as CaCO(3) , pH 8.3, DOC 0.5 mg C/L). Acute median effect concentrations (EC50s) for dissolved Cu increased approximately fivefold (15-72 µg Cu/L) for mussel survival in 4-d exposures and increased about 11-fold (25-267 µg Cu/L) for cladoceran survival in 2-d exposures across DOC concentrations from 0.5 to 10 mg C/L. Similarly, chronic 20% effect concentrations (EC20s) for the mussel in 28-d exposures increased about fivefold (13-61 µg Cu/L for survival; 8.8-38 µg Cu/L for biomass), and the EC20s for the cladoceran in 7-d exposures increased approximately 17-fold (13-215 µg Cu/L) for survival or approximately fourfold (12-42 µg Cu/L) for reproduction across DOC concentrations from 0.5 to 10 mg C/L. The acute and chronic values for the mussel were less than or approximately equal to the values for the cladoceran. Predictions from the biotic ligand model (BLM) used to derive the U.S. Environmental Protection Agency's ambient water quality criteria (AWQC) for Cu explained more than 90% of the variation in the acute and chronic endpoints for the two species, with the exception of the EC20 for cladoceran reproduction (only 46% of variation explained). The BLM-normalized acute EC50s and chronic EC20s for the mussel and BLM-normalized chronic EC20s for the cladoceran in waters with DOC concentrations of 2.5 to 10 mg C/L were equal to or less than the final acute value and final chronic value in the BLM-based AWQC for Cu, respectively, indicating that the Cu AWQC might not adequately protect the mussel from acute and

  6. Measured elemental carbon by thermo-optical transmittance analysis in water-soluble extracts from diesel exhaust, woodsmoke, and ambient particulate samples.

    Science.gov (United States)

    Wallén, Anna; Lidén, Göran; Hansson, Hans-Christen

    2010-01-01

    Elemental carbon has been proposed as a marker of diesel particulate matter. The objective of this study was to investigate if water-soluble carbonaceous compounds could be responsible for positive bias of elemental carbon using NIOSH Method 5040 with a thermo-optical carbon transmittance analyzer. Filter samples from eight different aerosol environments were used: pure diesel exhaust fume with a high content of elemental carbon, pure diesel exhaust fume with a low content of elemental carbon, pure biodiesel exhaust fume, pure woodsmoke, an urban road tunnel, an urban street canyon, an urban background site, and residential woodburning in an urban area. Part of each filter sample was analyzed directly with a thermo-optical carbon analyzer, and another part was extracted with water. This water-soluble extract was filtered to remove particles, spiked onto filter punches, and analyzed with a thermo-optical transmittance carbon analyzer. The ratio of elemental carbon in the water-soluble extract to the particulate sample measurement was 18, 12, and 7%, respectively, for the samples of pure woodsmoke, residential woodburning, and urban background. Samples with diesel particulate matter and ambient samples with motor exhaust detected no elemental carbon in the water-soluble extract. Since no particles were present in the filtered water-soluble extract, part of the water-soluble organic carbon species, existing or created during analysis, are misclassified as elemental carbon with this analysis. The conclusion is that in measuring elemental carbon in particulate aerosol samples with thermo-optical transmittance analysis, woodsmoke, and biomass combustion samples show a positive bias of elemental carbon. The water-soluble EC could be used as a simple method to indicate other sources, such as wood or other biomass combustion aerosol particles.

  7. Using Caffeine as a Water Quality Indicator in the Ambient Monitoring Program for Third Fork Creek Watershed, Durham, North Carolina

    OpenAIRE

    2015-01-01

    Caffeine has been suggested as a chemical indicator for domestic wastewater in freshwater systems, although it is not included in water quality monitoring programs. The Third Fork Creek watershed in Durham, NC, is highly urbanized, with a history of receiving untreated wastewater from leaking and overflowing sanitary sewers. The poor water quality originating in the Third Fork Creek watershed threatens its intended uses and jeopardizes drinking water, aquatic life, and recreational activities...

  8. A Potentiometric Flow Biosensor Based on Ammonia-Oxidizing Bacteria for the Detection of Toxicity in Water

    Directory of Open Access Journals (Sweden)

    Qianyu Zhang

    2013-05-01

    Full Text Available A flow biosensor for the detection of toxicity in water using the ammonia-oxidizing bacterium (AOB Nitrosomonas europaea as a bioreceptor and a polymeric membrane ammonium-selective electrode as a transducer is described. The system is based on the inhibition effects of toxicants on the activity of AOB, which can be evaluated by measuring the ammonium consumption rates with the ammonium-selective membrane electrode. The AOB cells are immobilized on polyethersulfone membranes packed in a holder, while the membrane electrode is placed downstream in the flow cell. Two specific inhibitors of the ammonia oxidation‒allylthiourea and thioacetamide‒have been tested. The IC50 values defined as the concentration of an inhibitor causing a 50% reduction in the ammonia oxidation activity have been measured as 0.17 μM and 0.46 μM for allylthiourea and thioacetamide, respectively. The proposed sensor offers advantages of simplicity, speed and high sensitivity for measuring toxicity in water.

  9. Are luminescent bacteria suitable for online detection and monitoring of toxic compounds in drinking water and its sources?

    Science.gov (United States)

    Woutersen, Marjolijn; Belkin, Shimshon; Brouwer, Bram; van Wezel, Annemarie P; Heringa, Minne B

    2011-05-01

    Biosensors based on luminescent bacteria may be valuable tools to monitor the chemical quality and safety of surface and drinking water. In this review, an overview is presented of the recombinant strains available that harbour the bacterial luciferase genes luxCDABE, and which may be used in an online biosensor for water quality monitoring. Many bacterial strains have been described for the detection of a broad range of toxicity parameters, including DNA damage, protein damage, membrane damage, oxidative stress, organic pollutants, and heavy metals. Most lux strains have sensitivities with detection limits ranging from milligrams per litre to micrograms per litre, usually with higher sensitivities in compound-specific strains. Although the sensitivity of lux strains can be enhanced by various molecular manipulations, most reported detection thresholds are still too high to detect levels of individual contaminants as they occur nowadays in European drinking waters. However, lux strains sensing specific toxic effects have the advantage of being able to respond to mixtures of contaminants inducing the same effect, and thus could be used as a sensor for the sum effect, including the effect of compounds that are as yet not identified by chemical analysis. An evaluation of the suitability of lux strains for monitoring surface and drinking water is therefore provided.

  10. Study on the toxicity of sodium bromide to different fresh water organisms. [Scenedesmus pannonicus; Daphnia magna; Poecilia reticulata; Oryzias latipas

    Energy Technology Data Exchange (ETDEWEB)

    Canton, J.H.; Wester, P.W.; Mathijssen-Spiekman, E.A.

    1983-08-01

    The toxicity of sodium bromide for fresh water organisms was tested using algae (Scenedesmus pannonicus), crustaceans (Daphnia magna) and fish (Poecilia reticulata and Oryzias latipes). Depending on the species tested, the acute toxicity varied from 44 to 5800 mg Br-/litre (EC50 values) and the No Observed Effect Concentrations (NOEC values) in the long-term tests varied from 7.8 to 250 mg Br-/litre. Bromide ion markedly impaired reproduction in both crustaceans and fish. Histologically no effects were observed in the long-term test with Oryzias, but in the reproduction test with Poecilia, hyperplasia of the thyroid, atrophy and degeneration of the musculature and regressive changes in the female reproductive tract were observed. As a criterion of water quality, 1 mg Br-/litre has been proposed, on the basis of reproductive performance in the Poecilia test. The concentrations found in surface water frequently exceed this value and sometimes reach levels at which acute effects on water organisms can be expected.

  11. Residues of organophosphate pesticides used in vegetable cultivation in ambient air, surface water and soil in Bueng Niam Subdistrict, Khon Kaen, Thailand.

    Science.gov (United States)

    Harnpicharnchai, Kallaya; Chaiear, Naesinee; Charerntanyarak, Lertchai

    2013-11-01

    Agricultural pesticide utilization is one of the important problems in rural and urban crop-cultivated areas, with the majority of pollutants dispersing via ambient air, water and other natural pathways. This study was therefore conducted in a specially selected village which is known to be a leading vegetable growing area in Khon Kaen Province. The aim of the study was to assess pesticide residues, and measure the seasonal fluctuations in organophosphate concentrations during 2010 in the environment of a risk area. Samples from selected sites were collected in two phases: Phase I was in summer (during March to May) and Phase II was in winter (during October to December). A total of 150 samples were analyzed using gas chromatography with flame photometric detection. The results showed that dicrotophos, chlorpyrifos, profenofos and ethion were found at the highest concentrations in soil and at the lowest concentrations in ambient air (pwater samples, the highest mean concentration of a pesticide was 1.3757 +/- 0.5014 mg/l for dicrotophos in summer and 0.3629 +/- 0.4338 mg/l for ethion in winter. The highest mean concentration of a pesticide in soil samples was 42.2893 +/- 39.0711 mg/kg ethion in summer and 90.0000 +/- 24.1644 mg/kg of ethion in winter.

  12. Interaction of Actinide Species with Microorganisms & Microbial Chelators: Cellular Uptake, Toxicity, & Implications for Bioremediation of Soil & Ground Water.

    Energy Technology Data Exchange (ETDEWEB)

    Hakim Boukhalfa

    2006-03-28

    Microorganisms influence the natural cycle of major elements, including C, N, P, S, and transition metals such as Mn and Fe. Bacterial processes can also influence the behavior of actinides in soil and ground water. While radionuclides have no known biological utility, they have the potential to interact with microorganisms and to interfere with processes involving other elements such as Fe and Mn. These interactions can transform radionuclides and affect their fate and transport. Organic acids, extruded by-products of cell metabolism, can solubilize radionuclides and facilitate their transport. The soluble complexes formed can be taken up by the cells and incorporated into biofilm structures. We have examined the interactions of Pu species with bacterial metabolites, studied Pu uptake by microorganisms and examined the toxicity of Pu and other toxic metals to environmentally relevant bacteria. We have also studied the speciation of Pu(IV) in the presence of natural and synthetic chelators.

  13. 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}.

  14. 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.

  15. 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.

  16. 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

  17. Treatment with coated layer double hydroxide clays decreases the toxicity of copper-contaminated water.

    Science.gov (United States)

    Blake, Deanne; Nar, Mangesh; D'Souza, Nandika Anne; Glenn, J Brad; Klaine, Stephen J; Roberts, Aaron P

    2014-05-01

    Copper is a common pollutant found in watersheds that exerts toxic effects on both invertebrates and vertebrates. Layer double hydroxide (LDH) clays are able to adsorb a wide range of contaminants through ion-exchange mechanisms. Coating LDH clays with various materials alters the aggregation of clay particles into the nano-size range, thus increasing relative surface area and offering great potential for contaminant remediation. The goal of this study was to determine if treatment with coated LDH clays decreases the toxicity of copper-containing solutions to Daphnia magna. Four LDH clays with different coatings used to alter hydrophobicity were as follows: used: Na(+) montmorillonite, Zn-Al LDH-nitrate, Zn-Al LDH-stearate, and Zn-Al LDH-carbonate. It was determined that coated LDH clays decreased copper toxicity by decreasing bioavailability and that smaller aggregate sizes decreased bioavailability the most. 96 h LC50 values increased by as much as 4.2 times with the treatment of the solutions with 100 mg/L LDH clay. Copper analysis of the clay and solutions indicated that the clays work by decreasing copper bioavailability by way of a binding mechanism. Coated LDH clays hold promise as a small-scale remediation tool or as an innovative tool for toxicity identification and evaluation characterization of metals.

  18. Kinetics of uranium uptake in soft water and the effect of body size, bioaccumulation and toxicity to Hyalella azteca

    Energy Technology Data Exchange (ETDEWEB)

    Alves, L.C. [Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1 (Canada); Aquatic Ecosystems Protection Research Division, Environment Canada, P.O. Box 5050, Burlington, ON L7R 4A6 (Canada); Borgmann, U. [Aquatic Ecosystems Protection Research Division, Environment Canada, P.O. Box 5050, Burlington, ON L7R 4A6 (Canada); Dixon, D.G., E-mail: dgdixon@uwaterloo.c [Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1 (Canada)

    2009-08-15

    The kinetics of uptake and the effect of body size on uranium (U) bioaccumulation and toxicity to Hyalella azteca exposed to water-only U concentrations in soft water were evaluated. The effect of body size on U bioaccumulation was significant with a slope of -0.35 between log body concentration and log body mass. A saturation kinetic model was satisfactory to describe the uptake rate, elimination rate and the effect of gut-clearance on size-corrected U bioaccumulation in H. azteca. The one-week lethal water concentrations causing 50% mortality for juvenile and adult H. azteca were 1100 and 4000 nmol U/L, respectively. The one-week lethal body concentration causing 50% mortality was 140 nmol U/g for juvenile H. azteca and 220 nmol U/g for adult H. azteca. One-week bioaccumulation studies that properly account for body-size and gut-clearance times can provide valuable data on U bioavailability and toxicity in the environment. - Uranium accumulation by Hyalella azteca approaches steady state after one week but is strongly dependent on body size.

  19. Kinetics of uranium uptake in soft water and the effect of body size, bioaccumulation and toxicity to Hyalella azteca.

    Science.gov (United States)

    Alves, L C; Borgmann, U; Dixon, D G

    2009-01-01

    The kinetics of uptake and the effect of body size on uranium (U) bioaccumulation and toxicity to Hyalella azteca exposed to water-only U concentrations in soft water were evaluated. The effect of body size on U bioaccumulation was significant with a slope of -0.35 between log body concentration and log body mass. A saturation kinetic model was satisfactory to describe the uptake rate, elimination rate and the effect of gut-clearance on size-corrected U bioaccumulation in H. azteca. The one-week lethal water concentrations causing 50% mortality for juvenile and adult H. azteca were 1100 and 4000 nmol U/L, respectively. The one-week lethal body concentration causing 50% mortality was 140 nmol U/g for juvenile H. azteca and 220 nmol U/g for adult H. azteca. One-week bioaccumulation studies that properly account for body-size and gut-clearance times can provide valuable data on U bioavailability and toxicity in the environment.

  20. The implementation of an aquatic toxicity index as a water quality monitoring tool in the Olifants River (Kruger National Park

    Directory of Open Access Journals (Sweden)

    V. Wepener

    1999-01-01

    Full Text Available Large sets of water quality data can leave water quality managers and decision-makers totally overwhelmed. In order to convey the interpretation of the data in a simplified and understandable manner, the water quality results from bi-monthly surveys undertaken at seven different sampling sites in the Letaba, Olifants, and Selati rivers over a two year period (February 1990 to April 1992 were reduced to index values, using a water quality index. The water quality index (Aquatic Toxicity Index or ATI revealed spatial and temporal trends. The higher index values, recorded for the sampling sites towards the eastern part of the Kruger National Park (KNP, revealed that the water quality was better than the quality measured in the Olifants River on the western bound-ary. The lowest index values were calculated for the Selati River, with index values consistently below 50. Index values indicate that the water quality in the Selati River was unsuitable for supporting normal physiological processes in fish. The water quality of the Selati River had an immediate impact on the water quality of the Olifants River directly below the confluence. Lower index values recorded at sites further downstream was also attributed to the influence of the Selati River since there are no known point sources of contaminants within the boundaries of the KNP. The index scores also elucidated temporal trends with lower scores evident during winter months. This was due to reduced flow in the Olifants River and a greater contribution of contaminated water from the Selati River. Index values increased following the first seasonal rains due to a dilution effect. Very low index values were recorded at certain sites during flood periods due to increased turbidity, reduced oxygen, and increased metal concentrations.

  1. Modulation of protein fermentation does not affect fecal water toxicity: a randomized cross-over study in healthy subjects.

    Directory of Open Access Journals (Sweden)

    Karen Windey

    Full Text Available OBJECTIVE: 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. DESIGN: 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. RESULTS: 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. CONCLUSION: This study does not support a role of protein fermentation in gut toxicity. The identified metabolites can provide new insight into colonic health. TRIAL REGISTRATION: ClinicalTrial.gov NCT01280513.

  2. Multi-linear regression analysis, preliminary biotic ligand modeling, and cross species comparison of the effects of water chemistry on chronic lead toxicity in invertebrates.

    Science.gov (United States)

    Esbaugh, A J; Brix, K V; Mager, E M; De Schamphelaere, K; Grosell, M

    2012-03-01

    The current study examined the chronic toxicity of lead (Pb) to three invertebrate species: the cladoceran Ceriodaphnia dubia, the snail Lymnaea stagnalis and the rotifer Philodina rapida. The test media consisted of natural waters from across North America, varying in pertinent water chemistry parameters including dissolved organic carbon (DOC), calcium, pH and total CO(2). Chronic toxicity was assessed using reproductive endpoints for C. dubia and P. rapida while growth was assessed for L. stagnalis, with chronic toxicity varying markedly according to water chemistry. A multi-linear regression (MLR) approach was used to identify the relative importance of individual water chemistry components in predicting chronic Pb toxicity for each species. DOC was an integral component of MLR models for C. dubia and L. stagnalis, but surprisingly had no predictive impact on chronic Pb toxicity for P. rapida. Furthermore, sodium and total CO(2) were also identified as important factors affecting C. dubia toxicity; no other factors were predictive for L. stagnalis. The Pb toxicity of P. rapida was predicted by calcium and pH. The predictive power of the C. dubia and L. stagnalis MLR models was generally similar to that of the current C. dubia BLM, with R(2) values of 0.55 and 0.82 for the respective MLR models, compared to 0.45 and 0.79 for the respective BLMs. In contrast the BLM poorly predicted P. rapida toxicity (R(2)=0.19), as compared to the MLR (R(2)=0.92). The cross species variability in the effects of water chemistry, especially with respect to rotifers, suggests that cross species modeling of invertebrate chronic Pb toxicity using a C. dubia model may not always be appropriate.

  3. Mixture effects of organic micropollutants present in water: towards the development of effect-based water quality trigger values for baseline toxicity.

    Science.gov (United States)

    Tang, Janet Y M; McCarty, Shane; Glenn, Eva; Neale, Peta A; Warne, Michel St J; Escher, Beate I

    2013-06-15

    In this study we propose for the first time an approach for the tentative derivation of effect-based water quality trigger values for an apical endpoint, the cytotoxicity measured by the bioluminescence inhibition in Vibrio fischeri. The trigger values were derived for the Australian Drinking Water Guideline and the Australian Guideline for Water Recycling as examples, but the algorithm can be adapted to any other set of guideline values. In the first step, a Quantitative Structure-Activity Relationship (QSAR) describing the 50% effect concentrations, EC50, was established using chemicals known to act according to the nonspecific mode of action of baseline toxicity. This QSAR described the effect of most of the chemicals in these guidelines satisfactorily, with the exception of antibiotics, which were more potent than predicted by the baseline toxicity QSAR. The mixture effect of 10-56 guideline chemicals mixed at various fixed concentration ratios (equipotent mixture ratios and ratios of the guideline values) was adequately described by concentration addition model of mixture toxicity. Ten water samples were then analysed and 5-64 regulated chemicals were detected (from a target list of over 200 chemicals). These detected chemicals were mixed in the ratios of concentrations detected and their mixture effect was predicted by concentration addition. Comparing the effect of these designed mixtures with the effect of the water samples, it became evident that less than 1% of effect could be explained by known chemicals, making it imperative to derive effect-based trigger values. The effect-based water quality trigger value, EBT-EC50, was calculated from the mixture effect concentration predicted for concentration-additive mixture effects of all chemicals in a given guideline divided by the sum of the guideline concentrations for individual components, and dividing by an extrapolation factor that accounts for the number of chemicals contained in the guidelines and for

  4. Effects of water hardness, alkalinity, and dissolved organic carbon on the toxicity of copper to the lateral line of developing fish.

    Science.gov (United States)

    Linbo, Tiffany L; Baldwin, David H; McIntyre, Jenifer K; Scholz, Nathaniel L

    2009-07-01

    Conventional water chemistry parameters such as hardness, alkalinity, and organic carbon are known to affect the acutely lethal toxicity of copper to fish and other aquatic organisms. In the present study, we investigate the influence of these water chemistry parameters on short-term (3 h), sublethal (0-40 microg/L) copper toxicity to the peripheral mechanosensory system of larval zebrafish (Danio rerio) using an in vivo fluorescent marker of lateral line sensory neuron (hair cell) integrity. We studied the influence of hardness (via CaCl2, MgSO4, or both at a 2:1 molar ratio), sodium (via NaHCO3 or NaCl), and organic carbon on copper-induced neurotoxicity to zebrafish lateral line neurons over a range of environmentally relevant water chemistries. For all water parameters but organic carbon, the reductions in copper toxicity, although statistically significant, were small. Increasing organic carbon across a range of environmentally relevant concentrations (0.1-4.3 mg/L) increased the EC50 for copper toxicity (the effective concentration resulting in a 50% loss of hair cells) from approximately 12 microg/L to approximately 50 microg/L. Finally, we used an ionoregulatory-based biotic ligand model to compare copper toxicity mediated by targets in the fish gill and lateral line. Relative to copper toxicity via the gill, we find that individual water chemistry parameters are less influential in terms of reducing cytotoxic impacts to the mechanosensory system.

  5. Acute toxicity of dispersed crude oil on the cold-water copepod Calanus finmarchicus: Elusive implications of lipid content.

    Science.gov (United States)

    Hansen, Bjørn Henrik; Jager, Tjalling; Altin, Dag; Øverjordet, Ida B; Olsen, Anders J; Salaberria, Iurgi; Nordtug, Trond

    2016-01-01

    In this investigation, acute toxicity data were used from two previously reported studies where cold-water copepods were exposed to mechanically dispersed (MD) and chemically (CD) dispersed oil. In one of these studies, concentration-dependent mortality was observed, whereas no apparent relationship between exposure concentration and mortality was found in the other. The only marked difference between the studies is that copepods in the first experiment displayed a lower lipid sac volume (on average) than in the second one. In this study additional biometric data on lipid content were utilized and observed effects and toxicokinetics modeling applied in order to investigate whether differences in sensitivity between copepod cohorts might be explained by differences in lipid content. Results suggest that although a considerable lipid sac might retard toxicokinetics, the observed differences in lipid volume are not sufficient to explain differences in toxicity. Further, there are no apparent indications that acute toxic stress leads to lipid depletion, or that acute increased mortality rate selectively affects lipid-poor individuals. It is conceivable that other potential explanations exist, but the causal relationship between lipid content and increased mortality frequency remains elusive.

  6. Discussion on Regularity of Toxic Action of Toxic Metals in Water%水体中有毒金属毒性作用的规律性探讨

    Institute of Scientific and Technical Information of China (English)

    史东丽

    2011-01-01

    讨论了水体中有毒金属毒性作用的基本规律,不同的动物对毒物的敏感性是不同的,但不同的鱼类对同一种有毒金属的敏感性大致是一样的,同一金属对不同年龄的各种水生物的毒性作用是不同的.有毒金属对生物联合毒性作用时没有明确的规律.%Basic law of toxic action of toxic metals in water was discussed. The sensitivity of different animals for poison is different, but the sensitivity of different kinds of fishes for the same toxic metal is roughly same, toxic actions of the same toxic metal for all kinds of aquatic animals with different ages are different. The biological joint toxic action of toxic metals still has not definite law.

  7. Maximum permissible concentrations for water, sediment and soil derived from toxicity data for nine trace metals

    OpenAIRE

    Plassche EJ van de; Polder MD; Canton JH

    1992-01-01

    In this report Maximum Permissible Concentrations (MPC) are derived for 9 trace metals based on ecotoxicological data. The elements are: antimony, barium, beryllium, cobalt, molybdenum, selenium, thallium, tin, and vanadium The study was carried out in the framework of the project "Setting integrated environmental quality objectives". For the aquatic environment MPCs could be derived for all trace elements. These values were based on toxicity data for freshwater as well as saltwater...

  8. Friction Behaviors of the Hot Filament Chemical Vapor Deposition Diamond Film under Ambient Air and Water Lubricating Conditions

    Institute of Scientific and Technical Information of China (English)

    SHEN Bin; SUN Fanghong

    2009-01-01

    The friction behavior of the hot filament chemical vapor deposition(HFCVD) diamond film plays a critical role on its applications in mechanical fields and largely depends on the environment. Studies on the tribological properties of HFCVD diamond films coated on Co-cemented tungsten carbide (WC-Co) substrates are rarely reported in available literatures, especially in the water lubricating conditions. In this paper, conventional microcrystalline diamond(MCD) and fine-grained diamond(FGD) films are deposited on WC-Co substrates and their friction properties are evaluated on a reciprocating ball-on-plate tribometer, where they are brought to slide against ball-bearing steel and copper balls in dry and water lubricating conditions. Scanning electron microscopy(SEM), atomic force microscopy(AFM), surface profilometer and Raman spectroscopy are adopted to characterize as-deposited diamond films;SEM and energy dispersive X-ray(EDX) are used to investigate the worn region on the surfaces of both counterface balls and diamond films. The research results show that the friction coefficient of HFCVD diamond films always starts with a high initial value, and then gradually transits to a relative stable state. For a given counterface and a sliding condition, the FGD film presents lower stable friction coefficients by 0.02-0.03 than MCD film. The transferred materials adhered on sliding interface are supposed to have predominate effect on the friction behaviors of HFCVD diamond films. Furthermore, the effect of water lubricating on reducing friction coefficient is significant. For a given counterpart, the stable friction coefficients of MCD or FGD films reduce by about 0.07-0.08 while sliding in the water lubricating condition, relative to in dry sliding condition. This study is beneficial for widespread applications of HFCVD diamond coated mechanical components and adopting water lubricating system, replacing of oil lubricating, in a variety of mechanical processing fields to

  9. 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...

  10. The effect of water hardness on the toxicity of uranium to a tropical freshwater alga Chlorella sp.

    Science.gov (United States)

    Charles, Amanda L; Markich, Scott J; Stauber, Jennifer L; De Filippis, Lou F

    2002-10-01

    Uranium (U) derived from mining activities is of potential ecotoxicological concern to freshwater biota in tropical northern Australia. Few data are available on the effects of water hardness (Ca and/or Mg), which is elevated in U mine wastewaters, on the toxicity and bioavailability of U to freshwater biota, particularly algae. This study determined the effect of water hardness (8, 40, 100 and 400 mg CaCO(3) x l(-1), added as calcium (Ca) and magnesium (Mg) sulphate) on the toxicity (72 h growth rate inhibition) of U to the unicellular green alga, Chlorella sp., in synthetic freshwater, at constant pH (7.0) and alkalinity (8 mg CaCO(3) x l(-1)), similar in chemical composition to sandy coastal streams in tropical northern Australia. A 50-fold increase in water hardness resulted in a 5-fold decrease (Phardness includes: (i) competition between U and Ca and/or Mg for binding sites on the cell surface; and (ii) a change in U speciation, and hence, bioavailability. Results showed that extracellular (cell-surface) and intracellular U concentrations significantly (Phardness increased from 8 to 400 mg CaCO(3)x l(-1). Calculation of U speciation using the geochemical model HARPHRQ showed that there were no significant (P>0.05) differences in the predicted speciation (% distribution) of U amongst the four water hardness levels. The reduction in U toxicity with increasing water hardness was most likely due to competition between U and Ca and/or Mg for binding sites on the algal cell surface. The minimum detectable effect concentrations of U were approximately 3 and 24 times higher (at 8 and 400 mg CaCO(3)x l(-1) hardness, respectively) than the national interim U guideline value (0.5 micro g x l(-1)) for protecting aquatic ecosystems. Overall, the results reinforce the need for a more flexible U guideline based on a hardness-dependent algorithm, which may allow environmental managers to relax the national guideline for U on a site-specific basis.

  11. Effects of herbicides and freshwater discharge on water chemistry, toxicity and benthos in a Uruguayan sandy beach.

    Science.gov (United States)

    Sauco, Sebastián; Eguren, Gabriela; Heinzen, Horacio; Defeo, Omar

    2010-01-01

    Environmental water chemistry analysis and microcosm toxicity bioassays (MTB) were performed to assess lethality of herbicides on the mole crab Emerita brasiliensis in a sandy beach affected by a freshwater discharge (Andreoni canal) from rice crops. A 5-yr macrocosm field sampling (MFS) was conducted to evaluate freshwater effects on population abundance. Propanil was only detected at the inner portion of the Andreoni canal (IAC), whereas quinclorac and clomazone were found at the IAC and at the canal mouth (CM). A major propanil metabolite was detected at the CM. Herbicides were undetectable at 13km from the CM. MTB showed an increased susceptibility to propanil with decreasing crab sizes. The MFS showed a drastic decrease in abundance towards the freshwater discharge, concurrently with decreasing salinities. The triad approach that included water analyses, toxicological experiments and long-term field sampling allowed rejecting relationships between herbicide exposure and mole crab lethal effects.

  12. 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

  13. 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.

  14. Waste water treatment plants as sources of polyfluorinated compounds, polybrominated diphenyl ethers and musk fragrances to ambient air

    Energy Technology Data Exchange (ETDEWEB)

    Weinberg, Ingo, E-mail: ingoweinberg@web.d [GKSS Research Centre Geesthacht, Max Planck Str. 1, 21502 Geesthacht (Germany); Leuphana University Lueneburg, Institute for Ecology and Environmental Chemistry, Scharnhorststr. 1, 21335 Lueneburg (Germany); Dreyer, Annekatrin; Ebinghaus, Ralf [GKSS Research Centre Geesthacht, Max Planck Str. 1, 21502 Geesthacht (Germany)

    2011-01-15

    To investigate waste water treatment plants (WWTPs) as sources of polyfluorinated compounds (PFCs), polybrominated diphenyl ethers (PBDEs) and synthetic musk fragrances to the atmosphere, air samples were simultaneously taken at two WWTPs and two reference sites using high volume samplers. Contaminants were accumulated on glass fiber filters and PUF/XAD-2/PUF cartridges, extracted compound-dependent by MTBE/acetone, methanol, or hexane/acetone and detected by GC-MS or HPLC-MS/MS. Total (gas + particle phase) concentrations ranged from 97 to 1004 pg m{sup -3} (neutral PFCs), water origin on emitted contaminant amounts. - Waste water treatment plants can be regarded as sources of musk fragrances, polyfluorinated compounds (PFCs) and polybrominated diphenyl ethers (PBDEs) to the atmosphere

  15. Influence of dissolved organic matter on nickel bioavailability and toxicity to Hyalella azteca in water-only exposures.

    Science.gov (United States)

    Doig, Lorne E; Liber, Karsten

    2006-03-10

    Dissolved organic matter (DOM) is known to reduce the bioavailability of metals in aquatic systems. This study evaluated the effects of DOM from various sources (e.g., Little Bear Lake sediment, Suwannee River, peat moss) and various DOM fractions (humic acids, HA; fulvic acids, FA) on the bioavailability of nickel (Ni) to Hyalella azteca, a common freshwater benthic invertebrate. In particular, this study was conducted to evaluate the effect of surficial sediment DOM on Ni bioavailability. Short-term (48 h) acute toxicity tests with H. azteca conducted in synthetic water demonstrated that the aqueous Ni concentrations required for lethality were greater than what could be significantly complexed by environmentally relevant concentrations of dissolved organic carbon (DOC: 0.6-30.4 mg/L). At Ni concentrations sublethal to H. azteca (500 microg/L), the bioavailability of Ni was significantly reduced in the presence of representative surface water DOC concentrations regardless of DOC source or fraction. DOC fraction (i.e., FA and HA) differentially affected Ni speciation, but had little or no effect on Ni accumulation by H. azteca. Tissue Ni was found to be strongly dependent upon the Ni(2+) concentration in the exposure solutions and the Ni:DOC ratio. Overall, the concentration of DOC played a greater role than either DOC source or fraction in determining Ni speciation and hence bioavailability and toxicity to H. azteca.

  16. Removal of toxic zinc from water/wastewater using eucalyptus seeds activated carbon: non-linear regression analysis.

    Science.gov (United States)

    Senthil Kumar, Ponnusamy; Saravanan, Anbalagan; Anish Kumar, Kodyingil; Yashwanth, Ramesh; Visvesh, Sridharan

    2016-08-01

    In the present study, a novel activated carbon was prepared from low-cost eucalyptus seeds, which was utilised for the effectively removal of toxic zinc from the water/wastewater. The prepared adsorbent was studied by Fourier transform infrared spectroscopy and scanning electron microscopic characterisation studies. Adsorption process was experimentally performed for optimising the influencing factors such as adsorbent dosage, solution pH, contact time, initial zinc concentration, and temperature for the maximum removal of zinc from aqueous solution. Adsorption isotherm of zinc removal was ensued Freundlich model, and the kinetic model ensued pseudo-second order model. Langmuir monolayer adsorption capacity of the adsorbent for zinc removal was evaluated as 80.37 mg/g. The results of the thermodynamic studies suggested that the adsorption process was exothermic, thermodynamically feasible and impulsive process. Finally, a batch adsorber was planned to remove zinc from known volume and known concentration of wastewater using best obeyed model such as Freundlich. The experimental details showed the newly prepared material can be effectively utilised as a cheap material for the adsorption of toxic metal ions from the contaminated water.

  17. Laboratory and modeling studies on the effects of water and soot emissions and ambient conditions on the formation of contrail ice particles in the jet regime

    Science.gov (United States)

    Wong, H.-W.; Beyersdorf, A. J.; Heath, C. M.; Ziemba, L. D.; Winstead, E. L.; Thornhill, K. L.; Tacina, K. M.; Ross, R. C.; Albo, S. E.; Bulzan, D. L.; Anderson, B. E.; Miake-Lye, R. C.

    2011-09-01

    Contrails and contrail-induced cirrus clouds are identified as the most uncertain components in determining aviation impacts on global climate change. Parameters affecting contrail ice particle formation immediately after engine exit plane (forcing. Despite this, detailed understanding of these parametric effects is still limited. In this paper, we present results from recent laboratory and modeling studies conducted to investigate the effects of water and soot emissions and ambient conditions on the near-field formation of contrail ice particles. The Particle Aerosol Laboratory (PAL) at the NASA Glenn Research Center and the Aerodyne microphysical parcel model for contrail ice particle formation were employed. Our studies show that exhaust water concentrations have a significant impact on contrail ice particle formation. When soot was introduced, ice particle formation was observed only when exhaust water concentration was above a critical level. When no soot or sulfuric acid was introduced, homogeneous ice particle formation was unfavorable. Soot particles were found to compete for water vapor condensation, and higher soot concentrations emitted into the chamber resulted in smaller ice particles being formed. Chamber conditions corresponding to higher altitude standard day conditions were found to favor ice particle formation as expected. The microphysical model captures experimental trends well, but discrepancies between the model and the experiments exist as the model predicts narrower ice particle size distributions and ice particle sizes nearly a factor of two larger than measured. These discrepancies are likely due to the lack of treatment of turbulent mixing in the model and particle loss and scatter during the experimental sampling process. Future measurement activities are planned to investigate other important parameters, such as soot surface properties and sulfuric acid concentrations, using the PAL and microphysical model.

  18. Comparing toxic air pollutant programs

    Energy Technology Data Exchange (ETDEWEB)

    Hawkins, S.C. [ECKENFELDER Inc., Greenville, SC (United States)

    1997-05-01

    This article compares state and federal toxic air pollutant programs. The Clean Air Act Ammendments created a program for the control of Hazardous Air Pollutants based on the establishment of control technology standards. State toxic programs can be classified into two categories: control technology-based and ambient concentration-based. Many states have opened to implement the MACT standards while enforcing their own state air toxics programs. Specific topics discussed include the following: the Federal air toxics program; existing state regulations; New Jersey Air Toxic Program; New York Toxics program.

  19. Metales pesados y toxicidad de aguas del Río Aconcagua en Chile Heavy metals and toxicity of waters of the Aconcagua River in Chile

    Directory of Open Access Journals (Sweden)

    Hernán Gaete

    2007-08-01

    Full Text Available The toxicity of surface waters in a zone with mining activity in the Aconcagua River was determined through growth inhibition bioassays of Pseudokirchneriella subcapitata, and correlated with heavy metal concentrations. Results show that the waters near the discharge of the mining effluent displayed toxicity during all periods of study; the molybdenum and copper concentration exceeded the norms of water quality. The correlations between the concentrations of metals and the growth rate of P. subcapitata varied in the different periods of the study; inverse and significant correlations with copper stand out in some periods.

  20. Characteristics and sources of water-soluble ionic species associated with PM10 particles in the ambient air of central India.

    Science.gov (United States)

    Deshmukh, Dhananjay K; Tsai, Ying I; Deb, Manas K; Zarmpas, Pavlos

    2012-11-01

    PM(10) aerosol samples were collected in Durg City, India from July 2009 to June 2010 using an Andersen aerosol sampler and analyzed for eight water-soluble ionic species, namely, Na(+), NH(4) (+), K(+), Mg(2+), Ca(2+), Cl(-), NO(3) (-) and SO(4) (2-) by ion chromatography. The annual average concentration of PM(10) (253.5 ± 99.4 μg/m(3)) was four times higher than the Indian National Ambient Air Quality Standard of 60 μg/m(3) prescribed by the Central Pollution Control Board, India. The three most abundant ions were SO(4) (2-), NO(3) (-), and NH(4) (+), with average concentrations of 8.88 ± 4.81, 5.63 ± 2.22, and 5.18 ± 1.76 μg/m(3), respectively, and in turn accounting for 27.1 %, 16.5 %, and 15.5 % of the total water-soluble ions analyzed. Seasonal variation was similar for all secondary ions i.e., SO(4) (2-), NO(3) (-), and NH(4) (+), with high concentrations during winter and low concentrations during monsoon. Varimax Rotated Component Matrix principal component analysis identified secondary aerosols, crustal resuspension, and coal and biomass burning as common sources of PM(10) in Durg City, India.

  1. 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

  2. Toxicity study of water transferred graphene-based nanostructures for cell culture substrate

    Science.gov (United States)

    Borghi, Fabricio; van der Laan, Tim; Ishaq, Musarat; Kumar, Shailesh; Ostrikov, Kostya

    2014-10-01

    Graphene has attracted enormous attention due to its unique physical and chemical properties. Early researches had focused on it electrical properties for device applications. Nowadays graphene has attracted increased interest in bio-medical applications, such as cell culture substrates. Substrates are critical for: investigating early stage development of cells, new drugs tests and tissue engineering. Benefits of graphene for this application are: it can be produced with desired structural morphology, its surface properties can be modified via plasma or chemical treatment (decorated with specific functional groups), and it can be transferred to a plethora of substrates (high influence of cells fate). Successful applications of graphene-based materials for bio-med applications are predominantly produced via chemical methods. When produced via Thermal CVD, the transfer to the desired substrate involves chemical treatment, potentially contaminating the graphene. In this work, we use a unique plasma produced graphene, transferred to glass via a chemical-free process, as cell culture substrates. This work aims graphene's bio-toxicity. Our results show that our material is non toxic, and cells morphology and proliferation indicates similar growth among all samples and the control.

  3. Ambient noise near the sea-route

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Ambient noise data measured in an experiment conducted in shallow water near a sea-route were analyzed. It was observed that, at low frequency, the horizontal correlation has an obvious difference from that predicted by the classical ambient noise model. The theoretical analyses show that this phenomenon is caused by wind noise together with the discrete shipping noise nearby. An ambient noise model was proposed to include the effects caused by both the noise sources. Data measured at different times verify that the proposed model can be used to forecast the ambient noise field in shallow water near the sea-route.

  4. Ambient noise near the sea-route

    Institute of Scientific and Technical Information of China (English)

    HE Li; LI ZhengLin; PENG ZhaoHui

    2009-01-01

    Ambient noise data measured in an experiment conducted in shallow water near a sea-route were analyzed. It was observed that, at low frequency, the horizontal correlation has an obvious difference from that predicted by the classical ambient noise model. The theoretical analyses show that this phenomenon is caused by wind noise together with the discrete shipping noise nearby. An ambient noise model was proposed to include the effects caused by both the noise sources. Data measured at different times verify that the proposed model can be used to forecast the ambient noise field in shal-low water near the sea-route.

  5. Two-dimensional titanium carbide for efficiently reductive removal of highly toxic chromium(VI) from water.

    Science.gov (United States)

    Ying, Yulong; Liu, Yu; Wang, Xinyu; Mao, Yiyin; Cao, Wei; Hu, Pan; Peng, Xinsheng

    2015-01-28

    Two dimensional (2-D) Ti3C2Tx nanosheets are obtained by etching bulk Ti3C2Tx powders in HF solution and delaminating ultrasonically, which exhibit excellent removal capacity for toxic Cr(VI) from water, due to their high surface area, well dispersibility, and reductivity. The Ti3C2Tx nanosheets delaminated by 10% HF solution present more efficient Cr(VI) removal performance with capacity of 250 mg g(-1), and the residual concentration of Cr(VI) in treated water is less than 5 ppb, far below the concentration (0.05 ppm) of Cr(VI) in the drinking water standard recommended by the World Health Organization. This kind of 2-D Ti3C2Tx nanosheet can not only remove Cr(VI) rapidly and effectively in one step from aqueous solution by reducing Cr(VI) to Cr(III) but also adsorb the reduced Cr(III) simultaneously. Furthermore, these reductive 2-D Ti3C2Tx nanosheets are generally explored to remove other oxidant agents, such as K3[Fe(CN)6], KMnO4, and NaAuCl4 solutions, by converting them to low oxidation states. These significantly expand the potential applications of 2-D Ti3C2Tx nanosheets in water treatment.

  6. Estimation of Acute Toxicity of Ammonium Sulphate to the Fresh Water Catfish,Heteropneustes fossilis——Ⅰ.Analysis of LC50 Values Determined by Various Methods

    Institute of Scientific and Technical Information of China (English)

    TarunK.Banerjee

    1993-01-01

    The acute toxic effects of ammonium sulphate to fresh-water catfish,Heteropneustes fossilis(H.fossilis)have been studied by determining LC50 values with 95% confidence limits,by the graphic method,the logistic method,the Spearman and Karber method and the trimmed Spearman-Karber method.The trimmed Spearman-Karber method was found the most ideal for ammonium salt toxicity test.The flaws in the trimmed Spearman-Karbr method are also discussed.

  7. Effect of arsenic contaminated irrigation water on Lens culinaris L.and toxicity assessment using lux marked biosensor

    Institute of Scientific and Technical Information of China (English)

    F. R. Sadeque Ahmed; Ian J. Alexander; Mwinyikione Mwinyihija; Ken Killham

    2012-01-01

    Contamination of irrigation water represents a major constraint to Bangladesh agriculture,resulting in elevated levels in the terrestrial systems.Lux bacterial biosensor technology has previously been used to measure the toxicity of metals in various environmental matrices.While arbuscular mycorrhizal fungi have their most significant effect on phosphorus uptake,but showed alleviated metal toxicity to the host plant.The study examined the effects of arsenic and inoculation with an arbuscular mycorrhizal fungus.Glomus mosseae,on lentil (Lens culinaris L.cv.Titore).Plants were grown with and without arbuscular mycorrhizal inoeulum for 9 weeks in a sand and terra-green mixture (50:50,V/V) and watered with five levels of arsenic (0,1,2,5,10 mg As/L arsenate).The results showed that arsenic addition above 1 mg/L significantly reduced percentage of mycorrhizal root infection.On further analysis a close relationship was established with the vegetative and reproductive properties of lentil (L.culinaris) plants compared to the percentage bioluminescence of the soil leachate.However,arbuscular mycorrhizal fungal inoculation reduced arsenic concentration in roots and shoots.Higher concentrations of arsenic (5,10 mg As/L arsenate) reduced the mycorrhizal efficiency to increase phosphorus content and nitrogen fixation.Therefore,this study showed that increased concentration of arsenic in irrigation water had direct implications to the lentil (L.culinaris) plants overall performance.Moreover the use of bioassay demonstrated that mycorrhiza and clay particle reduced arsenic bioavailability in soil.

  8. Development of a regression model to predict copper toxicity to Daphnia magna and site-specific copper criteria across multiple surface-water drainages in an arid landscape.

    Science.gov (United States)

    Fulton, Barry A; Meyer, Joseph S

    2014-08-01

    The water effect ratio (WER) procedure developed by the US Environmental Protection Agency is commonly used to derive site-specific criteria for point-source metal discharges into perennial waters. However, experience is limited with this method in the ephemeral and intermittent systems typical of arid climates. The present study presents a regression model to develop WER-based site-specific criteria for a network of ephemeral and intermittent streams influenced by nonpoint sources of Cu in the southwestern United States. Acute (48-h) Cu toxicity tests were performed concurrently with Daphnia magna in site water samples and hardness-matched laboratory waters. Median effect concentrations (EC50s) for Cu in site water samples (n=17) varied by more than 12-fold, and the range of calculated WER values was similar. Statistically significant (α=0.05) univariate predictors of site-specific Cu toxicity included (in sequence of decreasing significance) dissolved organic carbon (DOC), hardness/alkalinity ratio, alkalinity, K, and total dissolved solids. A multiple-regression model developed from a combination of DOC and alkalinity explained 85% of the toxicity variability in site water samples, providing a strong predictive tool that can be used in the WER framework when site-specific criteria values are derived. The biotic ligand model (BLM) underpredicted toxicity in site waters by more than 2-fold. Adjustments to the default BLM parameters improved the model's performance but did not provide a better predictive tool compared with the regression model developed from DOC and alkalinity.

  9. Study of radon concentration and toxic elements in drinking and irrigated water and its implications in Sungai Petani, Kedah, Malaysia

    Directory of Open Access Journals (Sweden)

    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.

  10. Portable Sensor for Rapid In Situ Measurement of Trace Toxic Metals in Water Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Water is one of the most crucial provisions that astronauts need to live and work in space, whether orbiting Earth, working at a lunar base or traveling to Mars. For...

  11. Comprehensive assessment of a chlorinated drinking water concentrate in a rat multigenerational reproductive toxicity study

    Science.gov (United States)

    Some epidemiological studies report associations between drinking water disinfection by-products (DBPs) and adverse reproductive and developmental effects, e.g., low birth weight, spontaneous abortion, stillbirth, and birth defects. To address concerns raised by these studies, w...

  12. Comprehensive Assessment of a Chlorinated Drinking Water Concentrate in a Rat Multigenerational Reproductive Toxicity Study##

    Science.gov (United States)

    Some epidemiological studies report associations between drinking water disinfection by-products (DBPs) and adverse reproductive and developmental effects, e.g., low birth weight, spontaneous abortion, stillbirth, and birth defects. To address concerns raised by these studies, w...

  13. Chemistry, Toxicity and Health Risk Assessment of Drinking Water Disinfection ByProducts

    Science.gov (United States)

    Disinfection byproducts (DBPs) are formed by the reaction of oxidizing chemicals (such as chlorine, ozone and chloramines) used to control waterborne pathogens with natural organic material and other substances in water. DBP mixture composition varies as a function of geographic ...

  14. Toxic metals in aquatic plants surviving in surface water polluted by copper mining industry.

    Science.gov (United States)

    Samecka-Cymerman, A; Kempers, A J

    2004-09-01

    Concentrations of the metals Al, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, V, and Zn, as well as the macronutrients N, P, K, Ca, Mg, and S were measured in water, sediments, and the aquatic macrophytes Potamogeton pectinatus and Myriophyllum spicatum, growing in surface water receiving sewages and solid wastes from a copper smelter and a copper ore processing factory located in the Legnica-Glogow copper district in Southwest Poland. The deposition of mineral wastes in this area belong to the largest repository in Europe. The plants were able to survive at heavily contaminated sites. The concentrations of Cd (up to 0.6-1.7 microg/L in water and up to 10.1-12.9 mg/kg in sediments), Cu (up to 29-48 microg/L in water and up to 4.6-5.6g/kg in sediments), Pb (up to 1.5-2.2 g/kg in sediments), and Zn (up to 167-200 microg/L in water and up to 1.4-1.8 g/kg in sediments) seriously exceeded background values. P. pectinatus was able to survive tissue concentrations (in mg/kg) of up to 920 Cu, 6240 Mn, 98 Co, and 59 Ni, while M. spicatum survived tissue concentrations up to 1040 Cu, 6660 Mn, and 57 Co for. Enrichment ratios of elements in plant tissue and in water were much higher than those between plant tissue and sediments.

  15. Degradation and toxicity depletion of RB19 anthraquinone dye in water by ozone-based technologies.

    Science.gov (United States)

    Lovato, María E; Fiasconaro, María L; Martín, Carlos A

    2017-02-01

    This research investigated the discoloration and mineralization of Reactive Blue 19 (RB19) anthraquinone dye by single ozonation, single UV radiation and ozonation jointed with UV radiation (O3/UV). The problem was approached from two points of view: with the objective of color removal or the mineralization of solution. In each case, the optimum operating conditions were different. Ozonation was the most effective treatment for color removal, while the combined O3/UV treatment was for mineralization. Major intermediates of the dye degradation were identified by gas chromatography/mass spectrometry and a degradation pathway was proposed. In addition, a clear decrease of the toxicity of the dye was achieved at the end of the experiments. The effect of initial dye concentration, pH, ozone dose, and UV radiation on the degradation of the dye and decrease of total organic carbon was investigated, in order to establish the optimal operating conditions to achieve discoloration, mineralization or a combination of both.

  16. Toxicity of magnesium pulses to tropical freshwater species and the development of a duration-based water quality guideline.

    Science.gov (United States)

    Hogan, Alicia C; Trenfield, Melanie A; Harford, Andrew J; van Dam, Rick A

    2013-09-01

    Six freshwater species (Chlorella sp., Lemna aequinoctialis, Amerianna cumingi, Hydra viridissima, Moinodaphnia macleayi, and Mogurnda mogurnda) were exposed to 4-h, 8-h, and 24-h Mg pulses in natural creek water. Magnesium toxicity to all species increased with exposure duration; however, the extent of increase and the nature of the relationship differed greatly between species. Based on median inhibitory concentrations (IC50s), and compared with continuous exposure data from a previous study, the increase in toxicity with increasing exposure duration from 4 h to continuous (72-144 h) ranged from approximately 2-fold for Chlorella sp. and H. viridissima to greater than 40-fold for A. cumingi. Moreover, the form of the relationship between Mg toxicity and duration ranged from linear or near-linear to exponential for different species. The life-stage at which M. macleayi was exposed was important, with cladocerans pulsed at the onset of reproductive maturity being approximately 4 times more sensitive (based on IC50s) than younger than 6-h-old neonates. Species sensitivity distributions were constructed for the 4-h, 8-h, and 24-h pulse durations, from which 99% species protection guideline values (95% confidence limits [CLs]) of 94 (6.4-1360) mg/L, 14 (0.5-384) mg/L, and 8.0 (0.5-144) mg/L Mg, respectively, were derived. These values were plotted against exposure duration (h) and polynomial interpolation used to derive a guideline value for any pulse duration within the range assessed.

  17. Effects of helium and ambient water vapor on tritium release from Li2TiO3

    Science.gov (United States)

    Kobayashi, Makoto; Uchimura, Hiromichi; Toda, Kensuke; Oya, Yasuhisa

    2014-12-01

    The effects of hydrogen isotopes in tritium recovery gas and the presence of helium on the tritium release behaviors were investigated for lithium meta-titanate (Li2TiO3) to develop a tritium migration model. The tritium trapping sites as oxygen vacancies and oxygen atoms with dangling bonds were formed by energetic tritium ion implantation. Isotope exchange processes with water vapor in purge gas enhanced the recovery of tritium adsorbed on the surface of Li2TiO3 and trapped in oxygen vacancies. Replacement of tritium as hydroxyl groups with hydrogen isotopes from purge gas was hardly occurred due to the higher trapping energy of tritium as hydroxyl groups. Helium implantation would induce the formation of helium bubbles, which would occupy irradiation damages, contributing to the decrease in the densities of trapping site for tritium. Consequently, the addition of hydrogen isotopes in the tritium recovery gas and the presence of helium in tritium breeding materials can contribute to the efficient tritium recovery for tritium breeding materials.

  18. Water quality benchmarking (WQB) and priority control screening (PCS) of persistent toxic substances (PTSs) in China: necessity, method and a case study.

    Science.gov (United States)

    He, Wei; Qin, Ning; Kong, Xiang-Zhen; Liu, Wen-Xiu; He, Qi-Shuang; Wang, Qing-Mei; Yang, Chen; Jiang, Yu-Jiao; Yang, Bin; Wu, Wen-Jing; Xu, Fu-Liu

    2014-02-15

    The priority control screening (PCS) and water quality benchmarking (WQB) of toxic chemicals in water are key steps to ensure the safety of drinking water and aquatic ecosystem that is the crucial goal of water environment management. Owing to the different levels of social-economic development in different countries and regions, the PCS and WQB of toxic chemicals must be determined in accordance with their specific water environment situations. However, in China, the PCS and WQB of toxic chemicals in water were mainly introduced from the other countries. A method for the PCS and WQB of toxic chemicals in water based on the ecological risks was proposed, and a platform named Bayesian Matbugs Calculator (BMC) was developed. As a case study, the WQB and PCS of sixty-nine PTSs based their ecological risks were performed on the basis of one-year monthly monitoring in Lake Chaohu. The results showed that the current national water quality criteria (WQC) would underestimate the toxicological risk to organisms in this aquatic ecosystem. It appears necessary to develop new WQC for the protection of aquatic organisms in Lake Chaohu. Four grades of priority control chemicals (PCCs) in Lake Chaohu were proposed. The highest priority was assigned to organonitrogen-phosphorus pesticides, including parathion, dichlorvos, malathion, omethoate, and di-n-butyl phthalate. However, the national "blacklist" of toxic compounds only covered 7 of 20 PCCs, indicating that the other 13 PCCs would not be controlled efficiently. Because the pollution pattern of PTSs in various water bodies might be quite different, we appealed to the governments to screen the regional PPC lists or develop a more comprehensive national list for aquatic ecosystem protection in China.

  19. Evaluation of using aluminum sulfate and water-soluble Moringa oleifera seed lectin to reduce turbidity and toxicity of polluted stream water.

    Science.gov (United States)

    Freitas, José Henrique Edmilson Souza; de Santana, Keissy Vanderley; do Nascimento, Ana Cláudia Claudina; de Paiva, Sérgio Carvalho; de Moura, Maiara Celine; Coelho, Luana Cassandra Breitenbach Barroso; de Oliveira, Maria Betânia Melo; Paiva, Patrícia Maria Guedes; do Nascimento, Aline Elesbão; Napoleão, Thiago Henrique

    2016-11-01

    Aluminum salts are used as coagulants in water treatment; however, the exposure to residual aluminum has been associated with human brain lesions. The water-soluble Moringa oleifera lectin (WSMoL), which is extracted with distilled water and isolated by chitin chromatography, has coagulant activity and is able to reduce the concentration of metal ions in aqueous solutions. This study evaluated the potential of using aluminum sulfate and WSMoL to reduce the turbidity and toxicity of water from the Cavouco stream located in Recife, Pernambuco, Brazil. The water sample used (called P1) was collected from the stream source, which was found to be strongly polluted based on physicochemical and water quality analyses, as well as ecotoxicity assays with Artemia salina and seeds of Eruca sativa and Lactuca sativa. The assays combining WSMoL and aluminum sulfate were more efficient than those that used these agents separately. Furthermore, the greatest reduction in turbidity (96.8%) was obtained with the treatment using aluminum sulfate followed by WSMoL, compared to when they were applied simultaneously (91.3%). In addition, aluminum sulfate followed by WSMoL treatment resulted in residual aluminum concentration (0.3 mg/L) that was much lower than that recorded after the treatment using only the salt (35.5 mg/L). The ecotoxicity of P1 was also strongly reduced after the treatments. In summary, the combined use of aluminum sulfate and WSMoL was efficient in promoting a strong reduction of turbidity and ecotoxicity of a polluted water sample, without resulting in a high residual aluminum concentration at the conclusion of the treatment.

  20. Toxicity of TiO2 nanoparticles to Escherichia coli: effects of particle size, crystal phase and water chemistry.

    Science.gov (United States)

    Lin, Xiuchun; Li, Jingyi; Ma, Si; Liu, Gesheng; Yang, Kun; Tong, Meiping; Lin, Daohui

    2014-01-01

    Controversial and inconsistent results on the eco-toxicity of TiO2 nanoparticles (NPs) are commonly found in recorded studies and more experimental works are therefore warranted to elucidate the nanotoxicity and its underlying precise mechanisms. Toxicities of five types of TiO2 NPs with different particle sizes (10∼50 nm) and crystal phases were investigated using Escherichia coli as a test organism. The effect of water chemistry on the nanotoxicity was also examined. The antibacterial effects of TiO2 NPs as revealed by dose-effect experiments decreased with increasing particle size and rutile content of the TiO2 NPs. More bacteria could survive at higher solution pH (5.0-10.0) and ionic strength (50-200 mg L(-1) NaCl) as affected by the anatase TiO2 NPs. The TiO2 NPs with anatase crystal structure and smaller particle size produced higher content of intracellular reactive oxygen species and malondialdehyde, in line with their greater antibacterial effect. Transmission electron microscopic observations showed the concentration buildup of the anatase TiO2 NPs especially those with smaller particle sizes on the cell surfaces, leading to membrane damage and internalization. These research results will shed new light on the understanding of ecological effects of TiO2 NPs.

  1. An in situ postexposure feeding assay with Carcinus maenas for estuarine sediment-overlying water toxicity evaluations

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Susana M. [Instituto de Ciencias Biomedicas de Abel Salazar (ICBAS), Departamento de Estudos de Populacoes, Largo Abel Salazar 2, 4099-003 Porto (Portugal); Centro Interdisciplinar de Investigacao Marinha e Ambiental, Laboratorio de Ecotoxicologia, Rua dos Bragas 289, 4050-123 Porto (Portugal); Moreira-Santos, Matilde [Instituto do Ambiente e Vida, Departamento de Zoologia da Universidade de Coimbra, Largo Marques de Pombal, 3004-517 Coimbra (Portugal); Guilhermino, Lucia [Instituto de Ciencias Biomedicas de Abel Salazar (ICBAS), Departamento de Estudos de Populacoes, Largo Abel Salazar 2, 4099-003 Porto (Portugal); Centro Interdisciplinar de Investigacao Marinha e Ambiental, Laboratorio de Ecotoxicologia, Rua dos Bragas 289, 4050-123 Porto (Portugal); Ribeiro, Rui [Instituto do Ambiente e Vida, Departamento de Zoologia da Universidade de Coimbra, Largo Marques de Pombal, 3004-517 Coimbra (Portugal)]. E-mail: rui.ribeiro@zoo.uc.pt

    2006-01-15

    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.

  2. Toxicity of TiO2 nanoparticles to Escherichia coli: effects of particle size, crystal phase and water chemistry.

    Directory of Open Access Journals (Sweden)

    Xiuchun Lin

    Full Text Available Controversial and inconsistent results on the eco-toxicity of TiO2 nanoparticles (NPs are commonly found in recorded studies and more experimental works are therefore warranted to elucidate the nanotoxicity and its underlying precise mechanisms. Toxicities of five types of TiO2 NPs with different particle sizes (10∼50 nm and crystal phases were investigated using Escherichia coli as a test organism. The effect of water chemistry on the nanotoxicity was also examined. The antibacterial effects of TiO2 NPs as revealed by dose-effect experiments decreased with increasing particle size and rutile content of the TiO2 NPs. More bacteria could survive at higher solution pH (5.0-10.0 and ionic strength (50-200 mg L(-1 NaCl as affected by the anatase TiO2 NPs. The TiO2 NPs with anatase crystal structure and smaller particle size produced higher content of intracellular reactive oxygen species and malondialdehyde, in line with their greater antibacterial effect. Transmission electron microscopic observations showed the concentration buildup of the anatase TiO2 NPs especially those with smaller particle sizes on the cell surfaces, leading to membrane damage and internalization. These research results will shed new light on the understanding of ecological effects of TiO2 NPs.

  3. Transformation of tamoxifen and its major metabolites during water chlorination: Identification and in silico toxicity assessment of their disinfection byproducts.

    Science.gov (United States)

    Negreira, Noelia; Regueiro, Jorge; López de Alda, Miren; Barceló, Damià

    2015-11-15

    The selective estrogen receptor modulator tamoxifen is the most commonly used drug for the treatment and prevention of breast cancer. Tamoxifen is considered as a pro-drug since it is known to exert its pharmacological effect through its major active metabolites, 4-hydroxy-tamoxifen and 4-hydroxy-N-desmethyl-tamoxifen, which are mainly excreted in the urine in the days following administration. In the present work, the reactivity of tamoxifen and its major active metabolites in free chlorine-containing water was investigated for the first time. Under the studied chlorination conditions, tamoxifen was fairly stable whereas its metabolites were quickly degraded. A total of thirteen chlorinated byproducts were tentatively identified by ultra-high performance liquid chromatography coupled to high-resolution hybrid quadrupole-Orbitrap tandem mass spectrometry. Time-course profiles of the identified byproducts were followed in real wastewater samples under conditions that simulate wastewater disinfection. A preliminary assessment of their acute aquatic toxicity at two trophic levels by means of quantitative structure-activity relationship models showed that the identified byproducts were up to 110-fold more toxic than the parent compounds.

  4. Laboratory and modeling studies on the effects of water and soot emissions and ambient conditions on the properties of contrail ice particles in the jet regime

    Directory of Open Access Journals (Sweden)

    H.-W. Wong

    2013-10-01

    Full Text Available Contrails and contrail-induced cirrus clouds are identified as the most uncertain components in determining aviation impacts on global climate change. Parameters affecting contrail ice particle formation immediately after the engine exit plane (< 5 s in plume age may be critical to ice particle properties used in large-scale models predicting contrail radiative forcing. Despite this, detailed understanding of these parametric effects is still limited. In this paper, we present results from recent laboratory and modeling studies conducted to investigate the effects of water and soot emissions and ambient conditions on near-field formation of contrail ice particles and ice particle properties. The Particle Aerosol Laboratory (PAL at the NASA Glenn Research Center and the Aerodyne microphysical parcel model for contrail ice particle formation were employed. Our studies show that exhaust water concentration has a significant impact on contrail ice particle formation and properties. When soot particles were introduced, ice particle formation was observed only when exhaust water concentration was above a critical level. When no soot or sulfuric acid was introduced, no ice particle formation was observed, suggesting that ice particle formation from homogeneous nucleation followed by homogeneous freezing of liquid water was unfavorable. Soot particles were found to compete for water vapor condensation, and higher soot concentrations emitted into the chamber resulted in smaller ice particles being formed. Chamber conditions corresponding to higher cruising altitudes were found to favor ice particle formation. The microphysical model captures trends of particle extinction measurements well, but discrepancies between the model and the optical particle counter measurements exist as the model predicts narrower ice particle size distributions and ice particle sizes nearly a factor of two larger than measured. These discrepancies are likely due to particle

  5. In vitro evaluation of the toxic effects and endocrine disrupting potential of oil sands processed water and naphthenic acids

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, X.; Wiseman, S.; Higley, E.; Jones, P.D.; Hecker, M.; Giesy, J.P. [Saskatchewan Univ., Saskatoon, SK (Canada); Gamel El Din, M.; Martin, J.W. [Alberta Univ., Edmonton, AB (Canada)

    2009-07-01

    Naphthenic acids (NAs) are the primary toxic constituents of oil sands process-affected waters (OSPW). This presentation reported on a series of in vitro studies that were initiated to evaluate potential endocrine modulating effects of OSPW and their constituent NAs. The H295R steroidogenesis bioassay was used to examine the impact of OSPW and NA on 52 steroidogenesis. In particular, dose-response and time course studies were conducted to evaluate the impact of OSPW and NAs on testosterone and estradiol production. Aromatase activity and transcript abundance of the key 11 steroidogenic enzymes were also quantified to complement analysis of hormone levels. The MVLN trans-activation assay was used to test the estrogenicity/anti-estrogenicity of OSPW and NAs. In vitro cell viability and apoptosis (live-dead) caused by OSPW and NAs was quantified by the MTS reduction and caspase-3/7 activity in H295R and MVLN cells.

  6. Modelling removal mechanisms of Pb, Cu, Zn and Cd in acidic groundwater during the neutralization by ambient surface and ground waters

    Science.gov (United States)

    Paulson, Anthony J.; Balistrieri, Laurie S.

    1999-01-01

    Removal of Pb, Cu, Zn, and Cd during neutralization of acid rock drainage is examined using model simulations of field conditions and laboratory experiments involving mixing of natural drainage and surface waters or groundwaters. The simulations consider sorption onto hydrous Fe and Al oxides and particulate organic carbon, mineral precipitation, and organic and inorganic solution complexation of metals for two physical systems where newly formed oxides and particulate organic matter are either transported or retained along the chemical pathway. The calculations indicate that metal removal is a strong function of the physical system. Relative to direct discharge of ARD into streams, lower metal removals are observed where ARD enters streamwaters during the latter stages of neutralization by ambient groundwater after most of the Fe has precipitated and been retained in the soils. The mixing experiments, which represent the field simulations, also demonstrated the importance of dissolved metal to particle Fe ratios in controlling dissolved metal removal along the chemical pathway. Finally, model calculations indicate that hydrous Fe oxides and particulate organic carbon are more important than hydrous Al oxides in removing metals and that both inorganic and organic complexation must be considered when modeling metal removal from aquatic systems that are impacted by sulfide oxidation.

  7. Chemistry of NOx on TiO2 Surfaces Studied by Ambient Pressure XPS: Products, Effect of UV Irradiation, Water, and Coadsorbed K(.).

    Science.gov (United States)

    Rosseler, Olivier; Sleiman, Mohamad; Montesinos, V Nahuel; Shavorskiy, Andrey; Keller, Valerie; Keller, Nicolas; Litter, Marta I; Bluhm, Hendrik; Salmeron, Miquel; Destaillats, Hugo

    2013-02-07

    Self-cleaning surfaces containing TiO2 nanoparticles have been postulated to efficiently remove NOx from the atmosphere. However, UV irradiation of NOx adsorbed on TiO2 also was shown to form harmful gas-phase byproducts such as HONO and N2O that may limit their depolluting potential. Ambient pressure XPS was used to study surface and gas-phase species formed during adsorption of NO2 on TiO2 and subsequent UV irradiation at λ = 365 nm. It is shown here that NO3(-), adsorbed on TiO2 as a byproduct of NO2 disproportionation, was quantitatively converted to surface NO2 and other reduced nitrogenated species under UV irradiation in the absence of moisture. When water vapor was present, a faster NO3(-) conversion occurred, leading to a net loss of surface-bound nitrogenated species. Strongly adsorbed NO3(-) in the vicinity of coadsorbed K(+) cations was stable under UV light, leading to an efficient capture of nitrogenated compounds.

  8. Water-gas shift reaction on metal nanoclusters encapsulated in mesoporous ceria studied with ambient-pressure X-ray photoelectron spectroscopy.

    Science.gov (United States)

    Wen, Cun; Zhu, Yuan; Ye, Yingchun; Zhang, Shiran; Cheng, Fang; Liu, Yi; Wang, Paul; Tao, Franklin Feng

    2012-10-23

    Metal nanoclusters (Au, Pt, Pd, Cu) encapsulated in channels of mesoporous ceria (mp-CeO(2)) were synthesized. The activation energies of water-gas shift (WGS) reaction performed at oxide-metal interfaces of metal nanoclusters encapsulated in mp-CeO(2) (M@mp-CeO(2)) are lower than those of metal nanoclusters impregnated on ceria nanorods (M/rod-CeO(2)). In situ studies using ambient-pressure XPS (AP-XPS) suggested that the surface chemistry of the internal concave surface of CeO(2) pores of M@mp-CeO(2) is different from that of external surfaces of CeO(2) of M/rod-CeO(2) under reaction conditions. AP-XPS identified the metallic state of the metal nanoclusters of these WGS catalysts (M@mp-CeO(2) and M/rod-CeO(2)) under a WGS reaction condition. The lower activation energy of M@mp-CeO(2) in contrast to M/rod-CeO(2) is related to the different surface chemistry of the two types of CeO(2) under the same reaction condition.

  9. Extraction-photometric determination of toxic aromatic hydroxy compounds in water

    Energy Technology Data Exchange (ETDEWEB)

    Korenman, Y.I.; Bortnikova, R.N.; Bolotov, V.M.; Taldykina, S.N.; Sel' manshchuk, N.N.; Tishchenko, Y.M.

    1980-09-01

    A rapid (1 hr) and accurate method with the use of simple equipment was developed to determine phenol and its derivatives in water. The method was tested on purified waste water from phenol-producing plants not containing other aromatic compounds and on water from the Oka River collected near Dzerzhinsk. The following conditions are recommended: 180 g of anhydrous Na/sub 2/SO/sub 4/ is added to 1 liter of water to be analyzed; this is acidified to pH 2 with HCl. Samples containing nitrophenols should be acidified to pH 0-0.5. An organic solvent with a distribution coefficient not below 30-40 (e.g., butyl acetate) is used to which 20 mol.% tributyl phosphate or camphor has been added. Under these conditions a 100-fold concentration is obtained.Further extraction with alkalinized aqueous solutions of the photometric reagent (p-nitroaniline or diazoticized sulfanilic acid) produces an additional three-fold concentration. Test data on determining phenol in aqueous solutions containing sodium sulfate with the use of butyl acetate plus 20 mol.% tributyl phosphate showed a high degree of concentration (about 330) and the possibility of determining phenol in maximum allowable concentrations (about 0.001 mg/liter).

  10. Copper toxicity in relation to surface water-dissolved organic matter: biological effects to Daphnia magna

    NARCIS (Netherlands)

    Kramer, K.J.M.; Jak, R.G.; Hattum, van B.; Hooftman, R.N.; Zwolsman, J.J.G.

    2004-01-01

    Water quality standards for copper are usually stated in total element concentrations. It is known, however, that a major part of the copper can be bound in complexes that are biologically not available. Natural organic matter, such as humic and fulvic acids, are strong complexing agents that may af

  11. The acute toxicity of major ion salts to Ceriodaphnia dubia: I. Influence of background water chemistry

    Science.gov (United States)

    The ions Na+, K+, Ca2+, Mg2+, Cl-, SO42-, and HCO3-/CO32- (referred to as “major ions”) are present in all fresh waters and are physiologically required by aquatic organisms, but can be increased to harmful levels by a variety of anthropogenic activities that speed ge...

  12. Does wastewater from olive mills induce toxicity and water repellency in soil?

    Science.gov (United States)

    Peikert, B.; Bandow, N.; Schaumann, G. E.

    2012-04-01

    Olive oil mill wastewater is the effluent generated by the olive oil extraction process. It is the main waste product of this industry mainly being produced in the Mediterranean Basin. Because proper treatment options are rare it is often disposed into the environment, e.g. fields or wadies. Due to its high concentration of fatty acids and phytotoxic phenolic compounds and its high chemical and biological oxygen demand, olive oil mill wastewater becomes a serious environmental problem. In this screening study we investigated long-term effects of olive oil mill wastewater application on soil properties in several locations in the West Bank and Israel. We determined wettability via water drop penetration time and the contact angle as well as general soil properties including pH, EC, carbon content, and we conducted thermogravimetrical analyses in order to characterize the impact of the waste water on the quality of soil organic matter. Our results show that application of olive oil mill wastewater has various effects. We determined contact angles between 110 and 120° and water drop penetration times up to 1367 s indicating significant reduction in wettability. Furthermore, soil carbon and nitrogen content and water extractable organic matter increased as well as electric conductivity, which could be pointed out as a fertilizing effect. In contrast soil pH was significantly reduced. Conducting thermal analyses we observed an increase in the labile and refractory carbon fraction. Probably first one is responsible for induced water repellency. As a consequence the reduced wettability negatively affects soil quality. It would therefore be promising to minimize the hydrophobizing impacts without losing fertilizing effects of the olive oil mill wastewater.

  13. A cost-effective and fast synthesis of nanoporous SiO 2 aerogel powders using water-glass via ambient pressure drying route

    Science.gov (United States)

    Bhagat, Sharad D.; Kim, Yong-Ha; Moon, Myung-Jun; Ahn, Young-Soo; Yeo, Jeong-Gu

    2007-07-01

    Considering the need for large-scale production of silica aerogel powders, the present research was aimed to develop a simple, cost-effective and rapid process based on water-glass precursor via ambient pressure drying (APD) route. It has been shown that the surface chemical modification of hydrogels can rapidly be carried out with extremely low doses (e.g. 5 g of hexamethyldisilazane ( HMDS) for 100 g of hydrogel) of HMDS by a co-precursor method which makes this process quite cost-effective. The surface modification in the aqueous phase essentially resulted in the displacement of the pore water and the simultaneous one-step solvent exchange using n-hexane converted the hydrogel into an organo-gel in 3 h and thus the total processing time of the aerogel powder production via APD could drastically be reduced to 5 h. The solvent n-hexane could be recollected during the drying stage and it does not add much to the material cost. The aerogel powders with tapping densities and specific surface areas in the range of 0.100-0.309 g/cm 3 and 473-776 m 2/g, respectively, could be synthesized using this novel route. The surface modification of the aerogel powders was explored by means of X-ray photoelectron spectroscopy (XPS) in conjunction with the Fourier transform infrared (FT-IR) spectroscopy. The textural investigations revealed that the aerogel powders with a wide variation in their pore size distributions and average pore diameters can easily be synthesized by varying the silica content in the sol.

  14. Occurrence of the Microcystins MC-LW and MC-LF in Dutch Surface Waters and Their Contribution to Total Microcystin Toxicity

    Directory of Open Access Journals (Sweden)

    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.

  15. Contribution of Colonic Fermentation and Fecal Water Toxicity to the Pathophysiology of Lactose-Intolerance

    Directory of Open Access Journals (Sweden)

    Karen Windey

    2015-09-01

    Full Text Available Whether or not abdominal symptoms occur in subjects with small intestinal lactose malabsorption might depend on differences in colonic fermentation. To evaluate this hypothesis, we collected fecal samples from subjects with lactose malabsorption with abdominal complaints (LM-IT, n = 11 and without abdominal complaints (LM-T, n = 8 and subjects with normal lactose digestion (NLD, n = 15. Lactose malabsorption was diagnosed using a 13C-lactose breath test. Colonic fermentation was characterized in fecal samples at baseline and after incubation with lactose for 3 h, 6 h and 24 h through a metabolomics approach using gas chromatography-mass spectrometry (GC-MS. Fecal water cytotoxicity was analyzed using a colorimetric assay. Fecal water cytotoxicity was not different between the three groups (Kruskall-Wallis p = 0.164. Cluster analysis of the metabolite patterns revealed separate clusters for NLD, LM-T and LM-IT samples at baseline and after 24 h incubation with lactose. Levels of 5-methyl-2-furancarboxaldehyde were significantly higher in LM-IT and LM-T compared to NLD whereas those of an unidentified aldehyde were significantly higher in LM-IT compared to LM-T and NLD. Incubation with lactose increased short chain fatty acid (SCFA concentrations more in LM-IT and LM-T compared to NLD. In conclusion, fermentation patterns were clearly different in NLD, LM-IT and LM-T, but not related to differences in fecal water cytotoxicity.

  16. Contribution of Colonic Fermentation and Fecal Water Toxicity to the Pathophysiology of Lactose-Intolerance.

    Science.gov (United States)

    Windey, Karen; Houben, Els; Deroover, Lise; Verbeke, Kristin

    2015-09-08

    Whether or not abdominal symptoms occur in subjects with small intestinal lactose malabsorption might depend on differences in colonic fermentation. To evaluate this hypothesis, we collected fecal samples from subjects with lactose malabsorption with abdominal complaints (LM-IT, n = 11) and without abdominal complaints (LM-T, n = 8) and subjects with normal lactose digestion (NLD, n = 15). Lactose malabsorption was diagnosed using a (13)C-lactose breath test. Colonic fermentation was characterized in fecal samples at baseline and after incubation with lactose for 3 h, 6 h and 24 h through a metabolomics approach using gas chromatography-mass spectrometry (GC-MS). Fecal water cytotoxicity was analyzed using a colorimetric assay. Fecal water cytotoxicity was not different between the three groups (Kruskall-Wallis p = 0.164). Cluster analysis of the metabolite patterns revealed separate clusters for NLD, LM-T and LM-IT samples at baseline and after 24 h incubation with lactose. Levels of 5-methyl-2-furancarboxaldehyde were significantly higher in LM-IT and LM-T compared to NLD whereas those of an unidentified aldehyde were significantly higher in LM-IT compared to LM-T and NLD. Incubation with lactose increased short chain fatty acid (SCFA) concentrations more in LM-IT and LM-T compared to NLD. In conclusion, fermentation patterns were clearly different in NLD, LM-IT and LM-T, but not related to differences in fecal water cytotoxicity.

  17. Graphene-Based Microbots for Toxic Heavy Metal Removal and Recovery from Water.

    Science.gov (United States)

    Vilela, Diana; Parmar, Jemish; Zeng, Yongfei; Zhao, Yanli; Sánchez, Samuel

    2016-04-13

    Heavy metal contamination in water is a serious risk to the public health and other life forms on earth. Current research in nanotechnology is developing new nanosystems and nanomaterials for the fast and efficient removal of pollutants and heavy metals from water. Here, we report graphene oxide-based microbots (GOx-microbots) as active self-propelled systems for the capture, transfer, and removal of a heavy metal (i.e., lead) and its subsequent recovery for recycling purposes. Microbots' structure consists of nanosized multilayers of graphene oxide, nickel, and platinum, providing different functionalities. The outer layer of graphene oxide captures lead on the surface, and the inner layer of platinum functions as the engine decomposing hydrogen peroxide fuel for self-propulsion, while the middle layer of nickel enables external magnetic control of the microbots. Mobile GOx-microbots remove lead 10 times more efficiently than nonmotile GOx-microbots, cleaning water from 1000 ppb down to below 50 ppb in 60 min. Furthermore, after chemical detachment of lead from the surface of GOx-microbots, the microbots can be reused. Finally, we demonstrate the magnetic control of the GOx-microbots inside a microfluidic system as a proof-of-concept for automatic microbots-based system to remove and recover heavy metals.

  18. ACUTE AND CHRONIC TOXICITY OF PHENYL QUINOLINE ON WATER FLEA DAPHNIA MAGNA

    Directory of Open Access Journals (Sweden)

    Hildebrando Ayala

    2012-06-01

    Full Text Available The aquatic ecotoxicological determination of phytonematicide products using the zooplanktonic cladoceran Daphnia magna is important for environmental risk assessment. Evaluations were made of the acute median lethal concentration (LC50 of phenyl quinoline on D. magna, that was 4.12 ug i.a. L-1 at 48 h of exposure. The chronic effects of phenyl quinoline in the mortality rate of the cladoceran D. magna at 17 d of exposure, with 0.18 ug ai L-1 of LOEC (Lowest Observed Effect Concentration and 0.072 ug ai L-1 of NOEC (No Observed Effect Concentration were determined. Evaluations of the chronic effect of phenyl quinoline on three parameters of growth of D. magna (total length, antenna length and caudal length to 17 d of exposure, only showed significant differences in length of the antenna between the control and 0.072 ug ai L-1 been this the value of LOEC and thus the lower concentration 0.0288 ug ai L-1, the NOEC value for phenyl quinoline. The ratio between acute and chronic toxicity (RAC for the relationship showed acute 48 h exposure on mortality NOEC 17 d a value of 57.22, and for the ratio of acute NOEC on of the length of the antenna to 17 d was a value of 143. The environmental risk assessment (ERA shows that the PEC (Probable Effect Concentration / PNEC (Predicted No-Effect Concentration for acute assay was 582 524 and for the PEC / PNEC for chronic test was 83 333 333. These results demonstrate that phenyl quinoline has a high impact on aquatic biota represented by the trophic level that belongs to D. magna, and therefore shows that the substance is a candidate for a comprehensive ecotoxicological assessment.

  19. Carcinogenicity and chronic toxicity of hydrazine monohydrate in rats and mice by two-year drinking water treatment.

    Science.gov (United States)

    Matsumoto, Michiharu; Kano, Hirokazu; Suzuki, Masaaki; Katagiri, Taku; Umeda, Yumi; Fukushima, Shoji

    2016-04-01

    The carcinogenicity and chronic toxicity of hydrazine monohydrate was examined by administrating hydrazine monohydrate in drinking water to groups of 50 F344/DuCrj rats and 50 Crj:BDF1 mice of both sexes for two years. The drinking water concentration of hydrazine monohydrate was 0, 20, 40 or 80 ppm (wt/wt) for male and female rats and male mice; and 0, 40, 80 or 160 ppm for female mice. Survival rates of each group of males and females rats and mice were similar to the respective controls, except female rats administered 80 ppm. Two-year administration of hydrazine monohydrate produced an increase in the incidences of hepatocellular adenomas and carcinomas in rats of both sexes along with hepatic foci. In mice, the incidences of hepatocellular adenomas and carcinomas were increased in females, and significantly increased incidences of hepatocellular adenomas in females administered 160 ppm were observed. Thus, hydrazine monohydrate is carcinogenic in two species, rats and mice. Additionally, non-neoplastic renal lesions in rats and mice and non-neoplastic nasal lesions in mice were observed.

  20. Water Spinach, Ipomoea aquatic (Convolvulaceae, Ameliorates Lead Toxicity by Inhibiting Oxidative Stress and Apoptosis.

    Directory of Open Access Journals (Sweden)

    Saikat Dewanjee

    Full Text Available Ipomoea aquatica (Convolvulaceae, an aquatic edible plant, is traditionally used against heavy metal toxicity in India. The current study intended to explore the protective role of edible (aqueous extract of I. aquatica (AEIA against experimentally induced Pb-intoxication.The cytoprotective role of AEIA was measured on mouse hepatocytes by cell viability assay followed by Hoechst staining and flow cytometric assay. The effect on ROS production, lipid peroxidation, protein carbonylation, intracellular redox status were measured after incubating the hepatocytes with Pb-acetate (6.8 μM along with AEIA (400 μg/ml. The effects on the expressions of apoptotic signal proteins were estimated by western blotting. The protective role of AEIA was measured by in vivo assay in mice. Haematological, serum biochemical, tissue redox status, Pb bioaccumulation and histological parameters were evaluated to estimate the protective role of AEIA (100 mg/kg against Pb-acetate (5 mg/kg intoxication.Pb-acetate treated hepatocytes showed a gradual reduction of cell viability dose-dependently with an IC50 value of 6.8 μM. Pb-acetate treated hepatocytes exhibited significantly enhanced levels (p < 0.01 of ROS production, lipid peroxidation, protein carbonylation with concomitant depletion (p < 0.01 of antioxidant enzymes and GSH. However, AEIA treatment could significantly restore the aforementioned parameters in murine hepatocytes near to normalcy. Besides, AEIA significantly reversed (p < 0.05-0.01 the alterations of transcription levels of apoptotic proteins viz. Bcl 2, Bad, Cyt C, Apaf-1, cleaved caspases [caspase 3, caspase 8 and caspase 9], Fas and Bid. In in vivo bioassay, Pb-acetate treatment caused significantly high intracellular Pb burden and oxidative pressure in the kidney, liver, heart, brain and testes in mice. In addition, the haematological and serum biochemical factors were changed significantly in Pb-acetate-treated animals. AEIA treatment restored

  1. Chemical comparison and acute toxicity of water accommodated fraction (WAF) of source and field collected Macondo oils from the Deepwater Horizon spill.

    Science.gov (United States)

    Faksness, Liv-Guri; Altin, Dag; Nordtug, Trond; Daling, Per S; Hansen, Bjørn Henrik

    2015-02-15

    Two Source oils and five field collected oil residues from the Deepwater Horizon incident were chemically characterized. Water accommodated fractions (WAFs) of the Source oils and two of the field-weathered oils were prepared to evaluate the impact of natural weathering on the chemical composition and the acute toxicity of the WAFs. Toxicity test species representing different tropic levels were used (the primary producer Skeletonema costatum (algae) and the herbivorous copepod Acartia tonsa). The results suggest that the potential for acute toxicity is higher in WAFs from non-weathered oils than WAFs from the field weathered oils. The Source oils contained a large fraction of soluble and bioavailable components (such as BTEX (benzene, toluene, ethyl benzene, xylenes) and naphthalene), whereas in the surface collected oils these components were depleted by dissolution into the water column as the oil rose to the surface and by evaporative loss after reaching the sea surface.

  2. Toxic effects of the herbicide Roundup in the guppy Poecilia vivipara acclimated to fresh water.

    Science.gov (United States)

    Harayashiki, Cyntia Ayumi Yokota; Varela, Antonio Sergio; Machado, Anderson Abel de Souza; Cabrera, Liziara da Costa; Primel, Ednei Gilberto; Bianchini, Adalto; Corcini, Carine Dahl

    2013-10-15

    Although it is believed that glyphosate-based herbicides are relatively nontoxic to humans, its broad use in agriculture and consequent contamination of aquatic systems is a concern. In the present study, reproductive (sperm quality) and biochemical parameters (acetylcholinesterase and glutathione S-transferase activity, lipoperoxidation, and antioxidant capacity against peroxyl radicals) were evaluated in adult guppies (Poecilia vivipara) acclimated to fresh water and exposed (96 h) to environmentally realistic concentrations of glyphosate (130 and 700 μg L(-1)) as the commercial formulation Roundup. Male guppies exposed to Roundup showed a poorer sperm quality, measured as reduced plasmatic membrane integrity, mitochondrial functionality, DNA integrity, motility, motility period and concentration of spermatic cells, than those kept under control condition (no Roundup addition to the water). Most of the spermatic parameters analyzed showed strong association to each other, which may help to understand the mechanisms underlying the observed reduction in sperm quality. Exposure to Roundup did not alter the biochemical parameters analyzed, though differences between genders were observed and deserve further investigations. Findings from the present study suggest that exposure to environmentally relevant concentrations of Roundup may negatively affect at long-term the reproduction of P. vivipara, with consequent changes in fish populations inhabiting environments contaminated with the herbicide.

  3. Causes of toxicity to Hyalella azteca in a stormwater management facility receiving highway runoff and snowmelt. Part II: salts, nutrients, and water quality.

    Science.gov (United States)

    Bartlett, A J; Rochfort, Q; Brown, L R; Marsalek, J

    2012-01-01

    The Terraview-Willowfield Stormwater Management Facility (TWSMF) features a tandem of stormwater management ponds, which receive inputs of multiple contaminants from highway and residential runoff. Previous research determined that benthic communities in the ponds were impacted by poor habitat quality, due to elevated sediment concentrations of metals and polycyclic aromatic hydrocarbons (PAHS), and salinity in the overlying water, but did not address seasonal changes, including those caused by the influx of contaminants with the snowmelt. In order to address this issue, water and sediment samples were collected from the TWSMF during the fall and spring, and four-week sediment toxicity tests were conducted with Hyalella azteca. The effects of metals and PAHs are discussed in a companion paper; the effects of road salt, nutrients, and water quality are discussed here. After exposure to fall samples, survival of Hyalella was reduced (64-74% of controls) at three out of four sites, but growth was not negatively affected. After exposure to spring samples, survival was 0-75% of controls at the two sites furthest downstream, and growth was significantly lower in four out of five sites when comparing Hyalella exposed to site water overlying site sediment versus control water overlying site sediment. Toxicity appeared to be related to chloride concentrations: little or no toxicity occurred in fall samples (200 mg Cl(-)/L), and significant effects on survival and growth occurred in spring samples above 1550 mg Cl(-)/L and 380 mg Cl(-)/L, respectively. Sodium chloride toxicity tests showed similar results: four-week LC50s and EC25s (growth) were 1200 and 420 mg Cl(-)/L, respectively. Although water quality and nutrients were associated with effects observed in the TWSMF, chloride from road salt was the primary cause of toxicity in this study. Chloride persists during much of the year at concentrations representing a significant threat to benthic communities in the TWSMF.

  4. 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 deve

  5. Earth Day 1990: Lesson Plan and Home Survey--K-6. Energy, Solid Waste/Recycling, Toxics, and Water, with Follow-up Activities and Action Guide.

    Science.gov (United States)

    Sly, Carolie; Ruskey, Abby

    The purpose of this K-6 curriculum is to provide teachers and other educators with classroom lessons and home surveys that are a starting point for understanding four significant environmental issues--water, toxics, energy, and solid waste/recycling. While each of these environmental issues is complex and has far-reaching implications, the lessons…

  6. Earth Day 1990: Lesson Plan and Home Survey--7-12. Energy, Solid Waste/Recycling, Toxics, Transportation, and Water with Fact Sheets and Action Guide.

    Science.gov (United States)

    Holm-Shuett, Amy; Shuett, Greg

    The purpose of this 7-12 curriculum is to provide teachers and other educators with classroom lessons and home surveys that are a starting point for understanding five significant environmental issues - water, toxics, energy, transportation, and solid waste/recycling. While each of these environmental issues is complex and has far-reaching…

  7. INVESTIGATION OF HYBRID OXIDATION PROCESSES (UV/TIO2/H2O2) FOR SELECTED ORGANIC MICROPOLLUTANTS ELIMINATION AND CHANGE OF WATER TOXICITY

    OpenAIRE

    2016-01-01

    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 ...

  8. 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

  9. Enslavement in the water body by toxic Aphanizomenon ovalisporum, inducing alkaline phosphatase in phytoplanktons.

    Science.gov (United States)

    Bar-Yosef, Yehonathan; Sukenik, Assaf; Hadas, Ora; Viner-Mozzini, Yehudit; Kaplan, Aaron

    2010-09-14

    The hepatotoxin cylindrospermopsin (CYN) produced by certain cyanobacteria, including Aphanizomenon ovalisporum (hereafter Aphanizomenon) [1], seriously affects lake water quality [2], but its biological role is not known. Strong correlation between Aphanizomenon abundance in Lake Kinneret, Israel, and alkaline phosphatase (APase) activity suggests that inorganic phosphate (Pi) limitation induces the PHO regulon and APase secretion [3]. Staining lake samples with DAPI [4] revealed a high level of polyphosphate bodies (PPB) in Aphanizomenon. Application of enzyme-labeled fluorescence (ELF-APase) [5] showed APase in various organisms, but not in Aphanizomenon. ELF-APase signals and extracellular APase activity in Aphanizomenon were detected only after exploiting PPB under prolonged Pi deprivation in cultures or toward the end of its autumn bloom. Pi deprivation of Aphanizomenon induces CYN production, high-affinity Pi uptake, and an internal, not external, APase. Addition of Aphanizomenon spent media or CYN to various phytoplanktons, including Chlamydomonas reinhardtii, induced genes typically upregulated under Pi limitation and a rise in extracellular APase activity, despite ample surrounding Pi. Coculturing Aphanizomenon with Chlamydomonas or with Debarya sp. showed positive ELF-APase signals, but not in Aphanizomenon. CYN producers promote Pi supply by inducing APase secretion by other phytoplanktons, possibly explaining their increased abundance despite reduced Pi supply from watersheds.

  10. Comparison of short-term chronic and chronic silver toxicity to fathead minnows in unamended and sodium chloride-amended waters.

    Science.gov (United States)

    Naddy, Rami B; Rehner, Anita B; McNerney, Gina R; Gorsuch, Joseph W; Kramer, James R; Wood, Chris M; Paquin, Paul R; Stubblefield, William A

    2007-09-01

    The chronic (early life stage [ELS]) and short-term chronic (STC) toxicity of silver (as silver nitrate) to fathead minnows (FHM) was determined concurrently in flow-through exposures (33 volume additions/d). Paired ELS (approximately 30 d) and STC (7 d) studies were conducted with and without the addition of 60 mg/L Cl (as NaCl). The paired studies in unamended water were later repeated using standard flow conditions (9 volume additions/d). The purpose of the paired studies was to determine if short-term chronic endpoints can be used to predict effects in ELS studies. For each experiment, a "split-chamber" design (organisms were held in a common exposure chamber) allowed the direct comparison between short-term and chronic exposures. It appeared that the chronic toxicity of silver was mitigated to some extent by NaCl addition. The maximum acceptable toxicant concentration for growth in the ELS study was 0.53 microg dissolved Ag/L under standard flow conditions. Early life stage and STC endpoints in all three studies typically agreed within a factor of two. Whole-body sodium and silver concentrations measured in individual fathead minnows during these studies showed an increase in silver body burdens and a decrease in sodium concentration. These results indicate that the STC study could be used as a surrogate test to estimate chronic toxicity and that the mechanism of chronic silver toxicity may be the same as for acute toxicity.

  11. Results of Water and Sediment Toxicity Tests and Chemical Analyses Conducted at the Central Shops Burning Rubble Pit Waste Unit, January 1999

    Energy Technology Data Exchange (ETDEWEB)

    Specht, W.L.

    1999-06-02

    The Central Shops Burning Rubble Pit Operable Unit consists of two inactive rubble pits (631-1G and 631-3G) that have been capped, and one active burning rubble pit (631-2G), where wooden pallets and other non-hazardous debris are periodically burned. The inactive rubble pits may have received hazardous materials, such as asbestos, batteries, and paint cans, as well as non-hazardous materials, such as ash, paper, and glass. In an effort to determine if long term surface water flows of potentially contaminated water from the 631-1G, 631-3G, and 631-2G areas have resulted in an accumulation of chemical constituents at toxic levels in the vicinity of the settling basin and wetlands area, chemical analyses for significant ecological preliminary constituents of concern (pCOCs) were performed on aqueous and sediment samples. In addition, aquatic and sediment toxicity tests were performed in accordance with U.S. EPA methods (U.S. EPA 1989, 1994). Based on the results of the chemical analyses, unfiltered water samples collected from a wetland and settling basins located adjacent to the CSBRP Operable Unit exceed Toxicity Reference Values (TRVs) for aluminum, barium, chromium, copper, iron, lead, and vanadium at one or more of the four locations that were sampled. The water contained very high concentrations of clay particles that were present as suspended solids. A substantial portion of the metals were present as filterable particulates, bound to the clay particles, and were therefore not biologically available. Based on dissolved metal concentrations, the wetland and settling basin exceeded TRVs for aluminum and barium. However, the background reference location also exceeded the TRV for barium, which suggests that this value may be too low, based on local geochemistry. The detection limits for both total and dissolved mercury were higher than the TRV, so it was not possible to determine if the TRV for mercury was exceeded. Dissolved metal levels of chromium, copper

  12. Reproductive Toxicity to Male Mice of Nose Only Exposure to Water- Pipe Smoke

    Directory of Open Access Journals (Sweden)

    Badreldin H. Ali

    2015-01-01

    Full Text Available Background/Aims: Water-pipe smoking (WPS is popular in the Middle East and is starting to gain popularity in several Western countries as well. It is widely and erroneously perceived to be less harmful than other forms of tobacco use. The reproductive adverse effects of cigarette smoking have been studied before with conflicting results, but data on the possible adverse reproductive effects of WPS are lacking. Here, we assessed the effects of nose-only exposure to mainstream WPS generated by commercially available honey-flavored "moasel" tobacco in mice. Methods: The duration of the session was 30 min/day for one month. Control mice were exposed to air. Twenty- four h after the last exposure, mice were killed and the testes and plasma removed for analysis. In testicular homogenates total protein, alkaline phosphatase activity, several indices of oxidative damage and Vascular Endothelial Growth Factor Receptor 2 (VEGFR2 were quantified. The plasma concentrations of leptin, testosterone, estrogen and luteinizing hormone (LH were also measured. Histological analysis of testes and lungs was also conducted. Results: WPS caused statistically significant decreases in the plasma concentrations of leptin, testosterone, and LH, and in the concentrations of total protein and the antioxidant indices measured. A statistically non - significant decrease in VEGFR2 protein in the WPS - exposed mice compared to the control mice was also found. The body and testicular weights of mice exposed to WPS, as well as their testicular alkaline phosphatase activity and light microscopic histology, and plasma estrogen concentration were all not significantly affected by WPS. Conclusion: Further studies on the functional implications of these findings in mice exposed to WPS for longer durations are warranted.

  13. Larvicidal activity of the water extract of Moringa oleifera seeds against Aedes aegypti and its toxicity upon laboratory animals

    Directory of Open Access Journals (Sweden)

    Paulo M.P. Ferreira

    2009-06-01

    Full Text Available In this work, biological effects of the water extract of Moringa oleifera seeds (WEMOS were assessed on eggs and 3rd instar larvae of Aedes aegypti and on its toxicity upon laboratory animals (Daphnia magna, mice and rats. Crude WEMOS showed a LC50 value of 1260µg/mL, causing 99.2 ± 2.9% larvae mortality within 24 h at 5200µg/mL, though this larvicidal activity has been lost completely at 80ºC/10 min. WEMOS did not demonstrate capacity to prevent egg hatching. After extensive dialyses of the crude WEMOS into watersoluble dialyzable (DF and nondyalizable (NDF fractions, only DF maintained its efficacy to kill larvae. Acute toxicity evaluations on daphnids (EC50 of 188.7µg/mL and mice (LD50 of 446.5 mg/kg body weight pointed out to low toxicity. Despite the thymus hypertrophy, WEMOS revealed to be harmless in orally and subacutelytreated rats. In conclusion, WEMOS has thermostable bioactive compounds against Ae. aegypti larvae with apparent molecular mass lower than 12 kDa and moderately toxic potential.Neste trabalho, o extrato aquoso das sementes de Moringaoleifera (EASMO foi avaliado quanto aos seus efeitos biológicos sobre ovos e larvas de Aedes aegypti no 3ºestágio de desenvolvimento e sua toxicidade sobre animais de laboratório(Daphnia magna, camundongos e ratos. O EASMO bruto revelou uma CL50 de 1.260 µg/mL, causando 99, 2 ± 2, 9% de mortalidade em 24 h na concentração de 5.200 µg/mL, embora o mesmo não tenha sido capaz de impedir a eclosão dos ovos. A atividade larvicida extinguiu-se após aquecimento do extrato a 80ºC/10 min. Diálises sucessivas do EASMO bruto resultaram em duas frações solúveis em água (Fração dializável, FD; Fração nãodializável, FND, dentre as quais apenas a FD mostrou ação larvicida. Testes de toxicidade aguda realizadosem dáfnias (CE50 de 188, 7 µg/mL e camundongos (DL50 de446,5 mg/kg de peso corpóreo evidenciaram baixa toxicidade. Apesar da hipertrofia tímica, o EASMO mostrou ser

  14. Testing Methods of Biological Toxicity Detection for Water Quality%水质的生物毒性检测方法

    Institute of Scientific and Technical Information of China (English)

    高小辉; 杨峰峰; 何圣兵; 戴鼎立; 陈雪初; 李玫芳

    2012-01-01

    水质生物毒性检测是水环境质量评价的重要内容.生物检测技术随着各学科间交叉发展的深入而产生了新的活力.该文综述了当前生物毒性检测技术的主要类型以及应用现状,并对未来的重点研究方向提出了一些建议,以期为水毒理学的持续发展提供科学参考.%Biological toxicity testing on water toxicity plays a significant role in water quality assessment. New technology of biological toxicity testing method has been put forward under the development of interdisciplinary infiltration. It was reviewed that the main types of biological toxicity testing and the present application situation in this paper. Meanwhile, some key directions in the future were raised, which could be contributed to the sustainable development of water toxicology detection.

  15. Influence of water quality on zinc toxicity to the Florida apple snail (Pomacea paludosa) and sensitivity of freshwater snails to zinc.

    Science.gov (United States)

    Hoang, Tham C; Tong, Xin

    2015-03-01

    The present study characterized the influence of water-quality characteristics on zinc (Zn) toxicity to the Florida apple snail (Pomacea paludosa) and the sensitivity of freshwater snails to Zn. Standard 96-h renewal acute toxicity tests were conducted with Zn and juvenile P. paludosa under 3 conditions of pH and alkalinity, water hardness, and dissolved organic carbon (DOC). Median lethal effect concentrations (96-h LC50s), no-observed- effect concentrations, lowest-observed-effect concentrations, LC10s, and LC20s were determined for each test. The results showed that Zn toxicity to P. paludosa decreased linearly with increasing hardness, pH, and DOC. A multiple linear regression model based on pH, hardness, and DOC was able to explain 99% of the observed variability in LC50s. These results are useful for the development of a biotic ligand model (BLM) for P. paludosa and Zn. Zinc acute toxicity data were collected from the literature for 12 freshwater snail species in a wide range of water-quality characteristics for species sensitivity distribution analysis. The results showed that P. paludosa is the second most sensitive to Zn. The present study also suggested that aqueous ZnCO3 and ZnHCO3 (-) can be bioavailable to P. paludosa. Therefore, bioavailability models (e.g., BLM) should take these Zn species into consideration for bioavailability when applied to snails.

  16. Chlorine dioxide as an alternative antifouling biocide for cooling water systems: Toxicity to larval barnacle Amphibalanus reticulatus (Utinomi).

    Science.gov (United States)

    Venkatnarayanan, Srinivas; Sriyutha Murthy, P; Kirubagaran, Ramalingam; Venugopalan, Vayalam P

    2017-01-19

    Chlorine dioxide (ClO2) is seen as an effective alternative to chlorine, which is widely used as an antifouling biocide. However, data on its efficacy against marine macrofoulants is scanty. In this study, acute toxicity of ClO2 to larval forms of the fouling barnacle Amphibalanus reticulatus was investigated. ClO2 treatment at 0.1mg/L for 20min elicited 45-63% reduction in naupliar metamorphosis, 70% inhibition of cyprid settlement and 80% inhibition of metamorphosis to juveniles. Increase in concentration to 0.2mg/L did not result in any significant difference in the settlement inhibition or metamorphosis. Treatment with 0.2mg/L of ClO2 elicited substantial reduction in the settlement of barnacle larvae compared to control. The study indicates the possibility of using ClO2 as an alternative antifouling biocide in power plant cooling water systems. However, more work needs to be done on the environmental effects of such switchover, which we are currently undertaking.

  17. WATER ENVIROMENTAL DIAGNOSTIC OF IPANEMA RIVER, SOROCABA / SP = DIAGNÓSTICO AMBIENTAL DO MEIO AQUÁTICO DO RIO IPANEMA, SOROCABA/SP

    Directory of Open Access Journals (Sweden)

    Fábio Henrique Bello

    2011-01-01

    Full Text Available The Ipanema river basin is inserted in the water resources management unit 10 (UGRHI's 10 - Sorocaba / Medium Tietê, specifically in the Sorocaba river basin. The Sorocaba river is the most important affluent on the mark left of Medium Tietê, draining an area of 5269 Km2, where the Ipanema river is one of its various affluents of the left mark. The UGRHI 10 covers thirty-four cities, of which eighteen are in the Sorocaba River basin. The development of this cities have grown pollution load released into the Sorocaba River basin, however, at ten years behind many tributaries of the Sorocaba river had good to excellent quality of water, which was reduced by virtue of receiving sewage in natura (no treatment, from land plots located on the outskirts of Sorocaba and other municipality on. The Ipanema river, whose waters are in the process of deterioration in due to the issue of the sewage emission, is a river located in the outskirts of various cities, among them Sorocaba and Araçoiaba da Serra. Thus, the water environmental diagnostic of the river can provide support to initiatives of protection of water ecosystems and water resources. This study was conducted across monthly campaigns in three sampling points along the Ipanema river by period of 2009, in order to understand possible spatial and seasonal variations in the quality of water through analysis of twelve parameters considered significant to measure the quality of the river, being 9 of them used to calculate de Water Quality Index (IQA and one of them used to calculate the trophic state index (IET. The Ipanema River’s water showed good quality of IQA and some parameters above those stipulated by the CONAMA 357/05 Resolution. = A bacia do rio Ipanema encontra-se inserida na unidade de gerenciamento de recursos hídricos 10 (UGRHI’s 10 – Sorocaba/Médio Tietê, especificamente na bacia do rio Sorocaba. O rio Sorocaba é o afluente mais importante da marquem esquerda do Médio Tiet

  18. Human cell toxicogenomic analysis linking reactive oxygen species to the toxicity of monohaloacetic acid drinking water disinfection byproducts.

    Science.gov (United States)

    Pals, Justin; Attene-Ramos, Matias S; Xia, Menghang; Wagner, Elizabeth D; Plewa, Michael J

    2013-01-01

    Chronic exposure to drinking water disinfection byproducts has been linked to adverse health risks. The monohaloacetic acids (monoHAAs) are generated as byproducts during the disinfection of drinking water and are cytotoxic, genotoxic, mutagenic, and teratogenic. Iodoacetic acid toxicity was mitigated by antioxidants, suggesting the involvement of oxidative stress. Other monoHAAs may share a similar mode of action. Each monoHAA generated a significant concentration-response increase in the expression of a β-lactamase reporter under the control of the antioxidant response element (ARE). The monoHAAs generated oxidative stress with a rank order of iodoacetic acid (IAA) > bromoacetic acid (BAA) ≫ chloroacetic acid (CAA); this rank order was observed with other toxicological end points. Toxicogenomic analysis was conducted with a nontransformed human intestinal epithelial cell line (FHs 74 Int). Exposure to the monoHAAs altered the transcription levels of multiple oxidative stress responsive genes, indicating that each exposure generated oxidative stress. The transcriptome profiles showed an increase in thioredoxin reductase 1 (TXNRD1) and sulfiredoxin (SRXN1), suggesting peroxiredoxin proteins had been oxidized during monoHAA exposures. Three possible sources of reactive oxygen species were identified, the hypohalous acid generating peroxidase enzymes lactoperoxidase (LPO) and myeloperoxidase (MPO), nicotinamide adenine dinucleotide phosphate (NADPH)-dependent oxidase 5 (NOX5), and PTGS2 (COX-2) mediated arachidonic acid metabolism. Each monoHAA exposure caused an increase in COX-2 mRNA levels. These data provide a functional association between monoHAA exposure and adverse health outcomes such as oxidative stress, inflammation, and cancer.

  19. Water treatment residual (WTR)-coated wood mulch for alleviation of toxic metals and phosphorus from polluted urban stormwater runoff.

    Science.gov (United States)

    Soleimanifar, Hanieh; Deng, Yang; Wu, Laying; Sarkar, Dibyendu

    2016-07-01

    Aluminum-based water treatment residual (WTR)-coated wood mulches were synthesized and tested for removal of heavy metals and phosphorus (P) in synthetic urban stormwater. WTRs are an industrial waste produced from coagulation in water treatment facilities, primarily composed of amorphous aluminum or iron hydroxides. Batch tests showed that the composite filter media could effectively adsorb 97% lead (Pb), 76% zinc (Zn), 81% copper (Cu) and 97% P from the synthetic stormwater (Pb = 100 μg/L, Zn = 800 μg/L, Cu = 100 μg/L, P = 2.30 mg/L, and pH = 7.0) within 120 min, due to the presence of aluminum hydroxides as an active adsorbent. The adsorption was a 2(nd)-order reaction with respect toward each pollutant. Column tests demonstrated that the WTR-coated mulches considerably alleviated the select pollutants under a continuous-flow condition over the entire filtration period. The effluent Pb, Zn, Cu, and P varied at 0.5-8.9%, 33.4-46.7%, 45.8-55.8%, and 6.4-51.9% of their respective initial concentrations with the increasing bed volume from 0 to 50. Synthetic precipitation leaching procedure (SPLP) and toxicity characteristic leaching procedure (TCLP) tests indicated that leached contaminants were all below the U.S. criteria, suggesting that the release of undesired chemicals under rainfall or landfilling conditions is not a concern during application. This study demonstrates that the WTR-coated mulches are a new, low-cost, and effective filter media for urban stormwater treatment. Equally important, this study provides a sustainable approach to beneficially reuse an industrial waste for environmental pollution control.

  20. Correlation between Charge State of Insulating NaCl Surfaces and Ionic Mobility Induced by Water Adsorption: A Combined Ambient Pressure X-ray Photoelectron Spectroscopy and Scanning Force Microscopy Study

    Energy Technology Data Exchange (ETDEWEB)

    Verdaguer, Albert; Jose Segura, Juan; Fraxedas, Jordi; Bluhm, Hendrik; Salmeron, Miquel

    2008-09-03

    In situ ambient pressure X-ray photoelectron spectroscopy (APPES) and scanning force microscopy were used to characterize the surface discharge induced by water layers grown on (001) surfaces of sodium chloride single crystals. The APPES studies show that both kinetic energy (KE) and full width at half-maximum (FWHM) of the Na 2s and Cl 2p core level peaks, monitored as a function of relative humidity (RH), mimic surface conductivity curves measured using scanning force microscopy. The KE position and FWHM of the core level peaks therefore are directly related to the solvation and diffusion of ions at the NaCl(100) surface upon adsorption of water.

  1. 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.

  2. Sediment-quality and water-toxicity data from 10 sites on the Westside Creeks and San Antonio River, San Antonio, Texas, 2014

    Science.gov (United States)

    Crow, Cassi L.; Wilson, Jennifer T.; Kunz, James L.

    2016-01-01

    Sediment samples and samples for water-toxicity testing were collected during 2014 from several streams in San Antonio, Texas known locally as the Westside creeks (Alazán, Apache, Martínez, and San Pedro Creeks) and from the San Antonio River. Samples were collected once during base-flow and again after periods of storm-water runoff (post-storm conditions) to determine baseline sediment- and water-quality conditions. Streambed-sediment samples were analyzed for selected constituents, including trace elements and organic contaminants such as pesticides, polychlorinated biphenyls (PCBs), brominated flame retardants, and polycyclic aromatic hydrocarbons (PAHs).

  3. Psicologia do Ambiente

    OpenAIRE

    Antunes, Dalila; Bernardo, Fátima; Palma-Oliveira, José-Manuel

    2011-01-01

    Na aplicação da Psicologia à área do AMBIENTE importa em primeiro lugar definir o que se entende, neste contexto, por ambiente. O conceito é entendido como toda a envolvente que rodeia o ser humano. Referimo-nos pois ao espaço físico e aos estímulos que nele existem (som, ar, paisagem…), dirigindo-se a Psicologia do Ambiente ao estudo e intervenção sobre a forma como o ambiente influencia o indivíduo ou grupos, e sobre o modo como o comportamento dos indivíduos e grupos influenciam o ambiente...

  4. Toxicity of chlorine dioxide to early life stages of marine organisms

    Energy Technology Data Exchange (ETDEWEB)

    Hose, J.E.; Di Fiore, D.; Parker, H.S.; Sciarrotta, T.

    1989-03-01

    With increasing interest in minimizing exposure to chlorine, many electric generating and water treatment plants are exploring the use of alternative biocides such as chlorine dioxide. Unlike chlorine, chlorine dioxide does not react with ambient organic compounds to form potentially carcinogenic trihalomethanes such as chloroform. However, the toxicity of chlorine dioxide to aquatic organisms has received little study. No information exists on chlorine toxicity to marine organisms. Furthermore, West Coast electric power stations usually discharge chlorine intermittently once or twice daily and substantial mixing of receiving water occurs between treatments. Therefore, this study sought to obtain information on chlorine dioxide toxicity using an exposure schedule typical of generating stations which discharge into the marine environment. Early life history stages of a plant, invertebrate and fish were tested since these stages are generally acknowledged to be most sensitive to toxicants and are the stages that are most likely to be exposed to the effluent.

  5. Choice of test organisms for determination of oil dispersant toxicity in marine waters. Auswahl von Testorganismen zur Bestimmung der Toxizitaet von Dispergatoren bei der Oelbekaempfung in marinen Gewaessern

    Energy Technology Data Exchange (ETDEWEB)

    Henke, G.A.

    1987-06-01

    Several marine organisms were investigated regarding their qualification for oil dispersant toxicity determination. Appropriate organisms were chosen for two different test procedures: Using mortality as a test criterion an acute toxicity test can be carried out very easy with larvae of the brine shrimp Artemia sp. The sensitivity for different dispersants ranges over several orders of magnitude. Another test indicator is the cell multiplication-inhibition test, conducted with the microalga Scrippsiella trochoidea, a representative of phytoplankton. The sensitivity for a common dispersant ranges a hundredfold higher than the acute toxicity test. Both test procedures are also practicable for other water-soluble substances, as well. One oil-spill dispersant efficiency test is proposed provisionally. (orig.) With 62 refs., 20 tabs., 11 figs.

  6. Acute Toxicity of Water-Accommodated Fraction and Chemically Enhanced WAF of Bunker C Oil and Dispersant to a Microalga Tetraselmis tetrathele.

    Science.gov (United States)

    Santander-Avanceña, Sheryll S; Sadaba, Resurreccion B; Taberna, Hilario S; Tayo, Gilma T; Koyama, Jiro

    2016-01-01

    This study assessed the toxicity of water-accommodated fraction (WAF) and chemically enhanced WAF (CEWAF) of bunker C oil and dispersant (DISP) to a microalga, Tetraselmis tetrathele. The 72-h median effective concentration (72-h EC50) of CEWAF and DISP were determined at 3.30% and 2.40%, respectively. The no observed effect concentration (NOEC) of CEWAF to T. tetrathele was at 2.0% and lowest observed effect concentration (LOEC) was at 3.0% while NOEC and LOEC of DISP to T. tetrathele were determined at 1.0% and 2.0%, respectively. The addition of dispersant to oil increased the amount of total PAH present in the CEWAF test solutions. DISP alone was highly toxic, and the toxicity of CEWAF was primarily caused by the presence of dispersant.

  7. 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...

  8. The biotic ligand model approach for addressing effects of exposure water chemistry on aquatic toxicity of metals: Genesis and challenges

    Science.gov (United States)

    A major uncertainty in many aquatic risk assessments for toxic chemicals is the aggregate effect of the physicochemical characteristics of exposure media on toxicity, and how this affects extrapolation of laboratory test results to natural systems. A notable example of this is h...

  9. 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.

  10. Ambient-temperature trap/release of arsenic by dielectric barrier discharge and its application to ultratrace arsenic determination in surface water followed by atomic fluorescence spectrometry

    Science.gov (United States)

    A novel dielectric barrier discharge reactor (DBDR) was utilized to trap/release arsenic coupled to hydride generation atomic fluorescence spectrometry (HGAFS). On the DBD principle, the precise and accurate control of trap/release procedures was fulfilled at ambient temperature, and an analytical m...

  11. Sun light degradation of 4-chloroaniline in waters and its effect on toxicity. A high performance liquid chromatography - Diode array - Tandem mass spectrometry study

    Energy Technology Data Exchange (ETDEWEB)

    Gosetti, Fabio, E-mail: fabio.gosetti@mfn.unipmn.i [University of Piemonte Orientale, DISAV Dipartimento di Scienze dell' Ambiente e della Vita, viale T. Michel 11, 15121 Alessandria (Italy); Bottaro, Michela; Gianotti, Valentina; Mazzucco, Eleonora; Frascarolo, Paolo; Zampieri, Davide; Oliveri, Caterina; Viarengo, Aldo; Gennaro, Maria Carla [University of Piemonte Orientale, DISAV Dipartimento di Scienze dell' Ambiente e della Vita, viale T. Michel 11, 15121 Alessandria (Italy)

    2010-02-15

    This paper studies the degradation reactions that 4-chloroaniline can naturally undergo in waters for the action of sun light. 10.00 mg L{sup -1} 4-chloroaniline aqueous solution, without any addition of organic solvent, are undergone to photoirradiation under conditions that simulate sun light. The degradation pathway, followed by HPLC-DAD-MS/MS methods, is complex since the pollutant gives rise to many photoproducts: the predominant species are characterized by m/z values of 217 (P5) and 218 (P6) and are compatible with dimeric structures of 4-chloroaniline. Vibrio fischeri tests indicate that the photoproducts of 4-chloroaniline are characterized by a toxicity level significantly greater than the precursor. - The study investigates the degradation of 4-chloroaniline in waters induced by the action of sun light, to evaluate a potential increase of toxicity due to the photodegradation effect.

  12. CHELATING PROPERTIES OF CARDIOSPERMUM HALICACABUM AGAINST THE TOXIC EFFECT OF CYPERMETHRIN IN THE QUANTIFICATION OF NUCLEIC ACIDS IN THE FRESH WATER FISH CIRRHINUS MRIGALA (HAMILTON

    Directory of Open Access Journals (Sweden)

    Vasantharaja C

    2013-01-01

    Full Text Available Among the pesticides the synthetic pyrethroids are commonly used because of their rapid biodegradability and non-persistent nature. The cypermethrin has a strong pescicidal activity in fresh water fish C. mrigala for all exposure periods (24h to 120h The acute toxicity value was found to be 150 µg/l and 1/5 as used for LC0 (30µg/l. Where observed on DNA and RNA content in selected tissues like gill, liver and kidney of fresh water fish. An overall decrease in nucleic acid was noted in (group 2 which is statistically significant. This indicates an evidence of inhibition of these nucleic acids in the selected organs by the toxicant problem Cardiospermum halicacabum exposed (group 3. Shows recovered by Cardiospermum halicacabum, Hence the pesticide intoxication has made a disturbance in normal functions of cells.

  13. 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.

  14. Molecular mechanisms of dust-induced toxicity in human corneal epithelial cells: Water and organic extract of office and house dust.

    Science.gov (United States)

    Xiang, Ping; Liu, Rong-Yan; Sun, Hong-Jie; Han, Yong-He; He, Rui-Wen; Cui, Xin-Yi; Ma, Lena Q

    2016-01-01

    Human corneal epithelial (HCE) cells are continually exposed to dust in the air, which may cause corneal epithelium damage. Both water and organic soluble contaminants in dust may contribute to cytotoxicity in HCE cells, however, the associated toxicity mechanisms are not fully elucidated. In this study, indoor dust from residential houses and commercial offices in Nanjing, China was collected and the effects of organic and water soluble fraction of dust on primary HCE cells were examined. The concentrations of heavy metals in the dust and dust extracts were determined by ICP-MS and PAHs by GC-MS, with office dust having greater concentrations of heavy metals and PAHs than house dust. Based on LC50, organic extract was more toxic than water extract, and office dust was more toxic than house dust. Accordingly, the organic extracts induced more ROS, malondialdehyde, and 8-Hydroxydeoxyguanosine and higher expression of inflammatory mediators (IL-1β, IL-6, and IL-8), and AhR inducible genes (CYP1A1, and CYP1B1) than water extracts (pdust presented greater suppression of superoxide dismutase and catalase activity than those of house dust. In addition, exposure to dust extracts activated NF-κB signal pathway except water extract of house dust. The results suggested that both water and organic soluble fractions of dust caused cytotoxicity, oxidative damage, inflammatory response, and activation of AhR inducible genes, with organic extracts having higher potential to induce adverse effects on primary HCE cells. The results based on primary HCE cells demonstrated the importance of reducing contaminants in indoor dust to reduce their adverse impacts on human eyes.

  15. DERECHO AMBIENTAL EN ARGENTINA

    OpenAIRE

    2014-01-01

    El objetivo de la presente publicación es brindar un panorama general, introductorio y actualizado del derecho ambiental argentino. Entendiendo que el derecho ambiental es un signo de nuestra era y que por la dinamicidad de la cuestión ambiental requiere de permanente actualización regularoria. La autora desarrolla en forma objetiva su postura en relación con la necesidad de hacer sostenible al derecho ambiental. Para luego analizar brevemente la situación actual del derecho vigente en Argent...

  16. 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

  17. Colour and toxic characteristics of metakaolinite-hematite pigment for integrally coloured concrete, prepared from iron oxide recovered from a water treatment plant of an abandoned coal mine

    Science.gov (United States)

    Sadasivam, Sivachidambaram; Thomas, Hywel Rhys

    2016-07-01

    A metakaolinite-hematite (KH) red pigment was prepared using an ocherous iron oxide sludge recovered from a water treatment plant of an abandoned coal mine. The KH pigment was prepared by heating the kaolinite and the iron oxide sludge at kaolinite's dehydroxylation temperature. Both the raw sludge and the KH specimen were characterised for their colour properties and toxic characteristics. The KH specimen could serve as a pigment for integrally coloured concrete and offers a potential use for the large volumes of the iron oxide sludge collected from mine water treatment plants.

  18. Acute toxicity of copper, lead, cadmium, and zinc to early life stages of white sturgeon (Acipenser transmontanus) in laboratory and Columbia River water.

    Science.gov (United States)

    Vardy, David W; Santore, Robert; Ryan, Adam; Giesy, John P; Hecker, Markus

    2014-01-01

    Populations of white sturgeon (Acipenser transmontanus) are in decline in North America. This is attributed, primarily, to poor recruitment, and white sturgeon are listed as threatened or endangered in several parts of British Columbia, Canada, and the United States. In the Columbia River, effects of metals have been hypothesized as possible contributing factors. Previous work has demonstrated that early life stage white sturgeon are particularly sensitive to certain metals, and concerns over the level of protectiveness of water quality standards are justified. Here we report results from acute (96-h) toxicity tests for copper (Cu), cadmium (Cd), zinc (Zn), and lead (Pb) from parallel studies that were conducted in laboratory water and in the field with Columbia River water. Water effect ratios (WERs) and sensitivity parameters (i.e., median lethal accumulations, or LA50s) were calculated to assess relative bioavailability of these metals in Columbia River water compared to laboratory water, and to elucidate possible differences in sensitivity of early life stage white sturgeon to the same concentrations of metals when tested in the different water sources. For Cu and Pb, white sturgeon toxicity tests were initiated at two life stages, 8 and 40 days post-hatch (dph), and median lethal concentrations (LC50s) ranged between 9-25 μg Cu/L and 177-1,556 μg Pb/L. LC50s for 8 dph white sturgeon exposed to Cd in laboratory water and river water were 14.5 and 72 μg/L, respectively. Exposure of 8 dph white sturgeon to Zn in laboratory and river water resulted in LC50s of 150 and 625 μg/L, respectively. Threshold concentrations were consistently less in laboratory water compared with river water, and as a result, WERs were greater than 1 in all cases. In addition, LA50s were consistently greater in river water exposures compared with laboratory exposures in all paired tests. These results, in combination with results from the biotic ligand model, suggest that the observed

  19. Ambient-Pressure X-ray Photoelectron Spectroscopy through Electron Transparent Graphene Membranes

    CERN Document Server

    Kraus, Jurgen; Gunther, Sebastian; Gregoratti, Luca; Amati, Matteo; Kiskinova, Maya; Yulaev, Alexander; Vlassiouk, Ivan; Kolmakov, Andrei

    2014-01-01

    Photoelectron spectroscopy (PES) and microscopy are highly demanded for exploring morphologically complex solid-gas and solid-liquid interfaces under realistic conditions, but the very small electron mean free path inside the dense media imposes serious experimental challenges. Currently, near ambient pressure PES is conducted using sophisticated and expensive electron energy analyzers coupled with differentially pumped electron lenses. An alternative economical approach proposed in this report uses ultrathin graphene membranes to isolate the ambient sample environment from the PES detection system. We demonstrate that the graphene membrane separating windows are both mechanically robust and sufficiently transparent for electrons in a wide energy range to allow PES of liquid and gaseous water. The reported proof-of-principle experiments also open a principal possibility to probe vacuum-incompatible toxic or reactive samples enclosed inside the hermetic environmental cells.

  20. Radiactividad y medio ambiente

    OpenAIRE

    Sánchez León, José Guillermo

    1993-01-01

    En los medios de comunicación frecuentemente aparecen noticias que hacen referencia a la radiactividad y al medio ambiente y, sin embargo, lo que es la radiactividad y como influye ésta sobre el medio ambiente suele ser poco conocido, incluso por personas de formación científica.

  1. DERECHO AMBIENTAL EN ARGENTINA

    Directory of Open Access Journals (Sweden)

    Silvia Nonna

    2014-05-01

    Full Text Available El objetivo de la presente publicación es brindar un panorama general, introductorio y actualizado del derecho ambiental argentino. Entendiendo que el derecho ambiental es un signo de nuestra era y que por la dinamicidad de la cuestión ambiental requiere de permanente actualización regulatoria. La autora desarrolla en forma objetiva su postura en relación con la necesidad de hacer sostenible al derecho ambiental. Para luego analizar brevemente la situación actual del derecho vigente en Argentina, haciendo un rápido y resumido recorrido desde la última reforma de la Constitución Nacional hasta la consideración especial de cada una de las nuevas normas de presupuestos mínimos de protección ambiental.

  2. 围压下磨料射流喷射套管及灰岩实验研究%Experimental study on abrasive water jet blasting casing and limestone under ambient pressures

    Institute of Scientific and Technical Information of China (English)

    黄中伟; 李根生; 史怀忠; 牛继磊; 宋先知; 邵尚奇

    2014-01-01

    在设计可承受围压的磨料射流喷射实验装置基础上,选取低孔低渗的石灰岩及套管试件,改变喷射压力、围压、喷嘴直径、喷射距离等因素,分析磨料射流切割套管及岩心的特性。结果表明,喷射压力、喷嘴直径等是影响磨料射流喷射效果的主要控制因素,喷射压力及喷嘴直径越大,喷射效果越好,射孔深度越深;射穿套管的时间对喷距及围压较为敏感,但岩样中的射孔深度对二者变化时的响应较小。%On the basis of the experimental device design for the abrasive water jet under ambient pressures, the low porosity and permeability limestone and the casing were selected to investigate the characteristics of casing cutting with abrasive water jet and sample core by changing the parameters of nozzle pressure drop, ambient pressure, nozzle diameter, and stand-off distance, etc. The results show that the nozzle pressure drop and nozzle diameter are the critical factors affecting the perfora-tion depth. The depth increases with the nozzle pressure drop and diameter going up. And the perforation time is more sensi-tive to the stand-off distance and ambient pressure. However, the perforation depth of the sample core has less response to the variation of the above two parameters.

  3. Nano-TiO{sub 2} enhances the toxicity of copper in natural water to Daphnia magna

    Energy Technology Data Exchange (ETDEWEB)

    Fan Wenhong, E-mail: fanwh@buaa.edu.cn [Department of Environmental Science and Engineering, School of Chemistry and Environment, Beihang University, Beijing 100191 (China); Cui Minming [Department of Environmental Science and Engineering, School of Chemistry and Environment, Beihang University, Beijing 100191 (China); Liu Hong; Wang Chuan [Research Center for Green Chemistry and Engineering, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Shi Zhiwei; Tan Cheng; Yang Xiuping [Department of Environmental Science and Engineering, School of Chemistry and Environment, Beihang University, Beijing 100191 (China)

    2011-03-15

    The acute toxicity of engineered nanoparticles (NPs) in aquatic environments at high concentrations has been well-established. This study demonstrates that, at a concentration generally considered to be safe in the environment, nano-TiO{sub 2} remarkably enhanced the toxicity of copper to Daphnia magna by increasing the copper bioaccumulation. Specifically, at 2 mg L{sup -1} nano-TiO{sub 2}, the (LC{sub 50}) of Cu{sup 2+} concentration observed to kill half the population, decreased from 111 {mu}g L{sup -1} to 42 {mu}g L{sup -1}. Correspondingly, the level of metallothionein decreased from 135 {mu}g g{sup -1} wet weight to 99 {mu}g g{sup -1} wet weight at a Cu{sup 2+} level of 100 {mu}g L{sup -1}. The copper was found to be adsorbed onto the nano-TiO{sub 2}, and ingested and accumulated in the animals, thereby causing toxic injury. The nano-TiO{sub 2} may compete for free copper ions with sulfhydryl groups, causing the inhibition of the detoxification by metallothioneins. - Research highlights: > This study demonstrates that, at a concentration generally considered to be safe in the environment, nano-TiO{sub 2} remarkably enhanced the toxicity of copper to Daphnia magna. > The copper was found to be adsorbed onto the nano-TiO{sub 2}, and ingested and accumulated in the Daphnia magna, thereby causing toxic injury. > The nano-TiO{sub 2} may compete for free copper ions with sulfhydryl groups, causing the inhibition of the detoxification mechanism of metallothionein. - The nano-TiO{sub 2} remarkably enhanced the toxicity of copper to Daphnia magna. The nano-TiO{sub 2} may compete for free copper ions with sulfhydryl groups, causing the inhibition of the detoxification mechanism of metallothionein.

  4. Assessing toxicity of copper, cadmium and chromium levels relevant to discharge limits of industrial effluents into inland surface waters using common onion, Allium cepa bioassay.

    Science.gov (United States)

    Hemachandra, Chamini K; Pathiratne, Asoka

    2015-02-01

    Toxicity of copper, cadmium and chromium relevant to established tolerance limits for the discharge of industrial effluents into inland surface waters was evaluated by Allium cepa bioassay. The roots of A. cepa bulbs exposed to Cu(2+) (3 mg L(-1)) individually or in mixtures with Cd(2+) (0.1 mg L(-1)) or/and Cr(6+) (0.1 mg L(-1)) exhibited the highest growth inhibition, mitotic index depression and nuclear abnormalities. Root tip cells exposed to Cr(6+) or Cd(2+) alone or in mixture displayed significant chromosomal aberrations in comparison to the controls. EC50s for root growth inhibition followed the order Cu(2+) < Cd(2+) < Cr(6+) indicating greater toxicity of copper. The results show that the industrial effluent discharge regulatory limits for these metals need to be reviewed considering potential cyto-genotoxicity to biological systems.

  5. The removal process of 2,2-dichloroacetamide (DCAcAm), a new disinfection by-product, in drinking water treatment process and its toxicity on zebrafish.

    Science.gov (United States)

    Lin, Tao; Zhou, Dongju; Yu, Shilin; Chen, Wei

    2016-09-01

    The removal process of 2,2-dichloroacetamide (DCAcAm), a new disinfection by-product (DBP) in conventional drinking water treatment plant (C-DWTP) and advanced DWTP (ADWTP) was studied with newly maximum formation potential (MFP) process. It was demonstrated that the advanced treatment displayed greater removal efficiency towards DCAcAm formation potential (MFP) than the conventional treatment. The hydrophilic natural organic matter and natural organic matter with molecular weight 10 kDa leaded to more DCAcAm formation, and the aromatic protein was inferred as one part of DCAcAm precursor. DCAcAm was found to cause delayed development and malformation to zebrafish embryos at embryonic growth stage. Compared with heart toxicity, it caused a significant neuron toxicity. It also could cause the acute DNA damage to adult zebrafish, which should be extremely cautioned.

  6. 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)

  7. Validation of a chronic dietary cadmium bioaccumulation and toxicity model for Hyalella azteca exposed to field-contaminated periphyton and lake water.

    Science.gov (United States)

    Golding, Lisa A; Borgmann, Uwe; Dixon, D George

    2011-11-01

    A model previously developed in the laboratory to predict chronic bioaccumulation and toxicity of cadmium to Hyalella azteca from a diet of periphyton was validated by comparing predictions with measurements of Cd in two exposure scenarios: laboratory-cultured H. azteca exposed for 28 d to field-contaminated water and periphyton, and Cd measured in field-collected H. azteca. In both exposure scenarios, model predictions of bioaccumulation were shown to be robust; however, effects on Cd bioaccumulation from complexation with dissolved organic carbon (DOC) and inhibition of Cd bioaccumulation by Ca²⁺ must be incorporated into the model to permit its wider application. The model predicted that 80 to 84% of Cd in H. azteca came from periphyton when H. azteca were chronically exposed to dissolved Cd in lake water at 2.63 to 3.01 nmol/L and periphyton at 1,880 to 2,630 nmol/g ash-free dry mass. Dietary Cd contributed markedly to the model-predicted decrease in 28-d survival to 74% at environmental Cd concentrations in food and water. In reality, survival decreased to 10%. The lower than predicted survival likely was due to the higher nutritional quality of periphyton used to develop the model in the laboratory compared with the field-collected periphyton. Overall, this research demonstrated that Cd in a periphyton diet at environmental concentrations can contribute to chronic toxicity in H. azteca.

  8. Acute toxicity over Ceriodaphnia silvestrii and Daphnia magna: Bioassays with water samples from a dam under the influence of uranium mine and with manganese

    Energy Technology Data Exchange (ETDEWEB)

    Ferrari, Carla R.; Nascimento, Heliana de Azevedo Franco do; Silverio, Emilia Gabriela Costa; Bruschi, Armando Luis; Roque, Claudio Vitor; Nascimento, Marcos Roberto L.; Bonifacio, Rodrigo Leandro, E-mail: carlarolimferrari@yahoo.com.br, E-mail: hazevedo@cnen.gov.br, E-mail: emiliagcsilverio@hotmail.com, E-mail: abruschi@cnen.gov.br, E-mail: cvroque@cnen.gov.br, E-mail: pmarcos@cnen.gov.br, E-mail: rodrigo@cnen.gov.br [Comissao Nacional de Energia Nuclear (LAPOC/CNEN-MG), Pocos de Caldas, MG (Brazil). Laboratorio de Pocos de Caldas; Rodgher, Suzelei [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Sao Jose dos Campos, SP (Brazil). Dep. de Engenharia Ambiental

    2015-07-01

    Treated effluents from uranium mine with acid mine drainage can impact receiving water bodies. AMD is relevant from the environmental view due to the large volume of effluents generated, known to affect aquatic biota. Studies show that one of the main problems of treated effluents released by UTM/INB on the catchment basin of Ribeirao das Antas is associated to high Mn values in water samples. In this context, acute 48-h toxicity tests with Mn were conducted with Ceriodaphnia silvestrii and Daphnia magna to determine the No Observed Effect Concentration (NOEC) and the Observed Effect Concentration (OEC) in laboratory bioassays and to verify the potential toxicity of the Mn in face of concentrations found in water samples from the Antas Dam, which receives treated effluents from UTM/INB. In this study, preliminary results of acute toxicity for C. silvestrii indicated OEC values between 9.0 and 10.0 mg Mn/L and NOEC < 3.0 mg Mn/L. For D. magna, OEC and NOEC concentrations were ≥ 30 mg Mn/L and ≤ 80 mg Mn/L, respectively. It was verified that Mn concentrations determined in environmental samples registered the highest value at 1.75 mg Mn/L, below the OEC concentrations recorded for both species. Since manganese occurs in the composition of the effluent that may contain other stable and radioactive elements, complementary ecotoxicological tests must be conducted, aiming at the assessment of synergistic and antagonistic effects of the chemical mixture that makes up the radioactive effluents that are treated and released at the Antas Dam. Such bioassays are underway in the Radioecology Laboratory at LAPOC/CNEN. (author)

  9. 水溶性塑料薄膜对斑马鱼的急性毒性%Acute Toxicity of Water-soluble Plastic Film on Zebra Fish

    Institute of Scientific and Technical Information of China (English)

    高世荣; 潘力军

    2011-01-01

    目的 研究水溶性塑料薄膜对斑马鱼的毒性,为其安全使用提供依据。方法 以具有代表性的水生动物斑马鱼为试验材科,采用静态法在室内测定水溶性塑料薄膜对斑马鱼的急性毒性并对其进行安全评价。结果 斑马鱼的24、48和96 h半数致死浓度(LC50)分别为2.75%、2.20%和2.20%。结论 水溶性塑料薄膜对斑马鱼有较强的毒性,应加强对其使用的管理。该研究为其安全使用提供了科学依据。%[Objective] To study the toxicity of water-soluble plastic film on zebra fish, provide the basis for its safe use. [Methods]The zebra fish what was the representative aquatic animal was used as the experimental materials, the acute toxicity of water-soluble plastic film on zebra fish was tested by static method in indoor environment, and the safety evaluation was conducted. [Results]24 h, 48 h and 96 h C50 of zebra fish was 2. 75% , 2. 20% and 2. 20% , respectively. [ Conclusion] The water-soluble plastic film has strong toxicity to zebra fish, and the management of its use should be strengthened. This research has provided the scientific basis for safety use.

  10. Determination of drugs in surface water and wastewater samples by liquid chromatography-mass spectrometry: Methods and preliminary results including toxicity studies with Vibrio fischeri

    Science.gov (United States)

    Farre, M.; Ferrer, I.; Ginebreda, A.; Figueras, M.; Olivella, L.; Tirapu, L.; Vilanova, M.; Barcelo, D.

    2001-01-01

    In the present work a combined analytical method involving toxicity and liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) was developed for the determination of pharmaceutical compounds in water samples. The drugs investigated were the analgesics: ibuprofen, ketoprofen, naproxen, and diclofenac, the decomposition product of the acetyl salicylic acid: salicylic acid and one lipid lowering agent, gemfibrozil. The selected compounds are acidic substances, very polar and all of them are analgesic compounds that can be purchased without medical prescription. The developed protocol consisted, first of all, on the use Microtox?? and ToxAlert??100 toxicity tests with Vibrio fischeri for the different pharmaceutical drugs. The 50% effective concentration (EC50) values and the toxicity units (TU) were determined for every compound using both systems. Sample enrichment of water samples was achieved by solid-phase extraction procedure (SPE), using the Merck LiChrolut?? EN cartridges followed by LC-ESI-MS. Average recoveries loading 1 l of samples with pH=2 varied from 69 to 91% and the detection limits in the range of 15-56 ng/l. The developed method was applied to real samples from wastewater and surface-river waters of Catalonia (north-east of Spain). One batch of samples was analyzed in parallel also by High Resolution Gas Chromatography coupled with Mass Spectrometry (HRGC-MS) and the results have been compared with the LC-ESI-MS method developed in this work. ?? 2001 Elsevier Science B.V. All rights reserved.

  11. Nickel and Copper Toxicity to Embryos of the Long-Spined Sea Urchin, Diadema savignyi.

    Science.gov (United States)

    Rosen, G; Rivera-Duarte, I; Colvin, M A; Dolecal, R E; Raymundo, L J; Earley, P J

    2015-07-01

    The sensitivity of long-spined sea urchins (Diadema savignyi) collected from Guam (Northern Marianas Islands), USA, to nickel and copper in seawater was explored using 48-h embryo-larval development toxicity tests. The median effective concentrations (EC50) averaged 94 µg L(-1) for nickel, and 19 µg L(-1) from a single exposure to copper, and suggest relatively high sensitivity of this species to nickel compared with other sea urchin genera, but similar sensitivity to copper. Ambient nickel and copper concentrations concurrently sampled from 16 near-shore locations around Guam were one to two orders of magnitude lower than those that would be expected to result in adverse effects to D. savignyi embryos. Although nationally recommended chronic ambient water quality criteria, currently 8.2 and 3.1 µg L(-1) for nickel and copper, respectively, were not exceeded, recently derived qualifying toxicity data should be considered for updating these criteria to ensure protectiveness of sensitive tropical species.

  12. Polycyclic aromatic hydrocarbon concentrations, mutagenicity, and Microtox® acute toxicity testing of Peruvian crude oil and oil-contaminated water and sediment.

    Science.gov (United States)

    Reátegui-Zirena, Evelyn G; Stewart, Paul M; Whatley, Alicia; Chu-Koo, Fred; Sotero-Solis, Victor E; Merino-Zegarra, Claudia; Vela-Paima, Elías

    2014-04-01

    The oil industry is a major source of contamination in Peru, and wastewater and sediments containing oil include harmful substances that may have acute and chronic effects. This study determined polycyclic aromatic hydrocarbon (PAH) concentrations by GC/MS, mutagenicity using TA98 and TA100 bacterial strains with and without metabolic activation in the Muta-ChromoPlate™ test, and Microtox® 5-min EC50 values of Peruvian crude oil, and water and sediment pore water from the vicinity of San José de Saramuro on the Marañón River and Villa Trompeteros on the Corrientes River in Loreto, Peru. The highest total PAH concentration in both areas was found in water (Saramuro = 210.15 μg/ml, Trompeteros = 204.66 μg/ml). Total PAH concentrations in water from San José de Saramuro ranged from 9.90 to 210.15 μg/ml (mean = 66.48 μg/ml), while sediment pore water concentrations ranged from 2.19 to 70.41 μg/ml (mean = 24.33 μg/ml). All water samples tested from Saramuro and Trompeteros sites, and one out of four sediment pore water samples from Trompeteros, were found to be mutagenic (P < 0.001). One sediment pore water sample in Saramuro was determined to have a measurable toxicity (Microtox EC50 = 335.1 mg/l), and in Trompeteros, the EC50 in water and sediment pore water ranged from 25.67 to 133.86 mg/l. Peruvian crude oil was mutagenic using the TA98 strain with metabolic activation, and the EC50 was 17.18 mg/l. The two areas sampled had very high PAH concentrations that were most likely associated with oil activities, but did not lead to acute toxic effects. However, since most of the samples were mutagenic, it is thought that there is a greater potential for chronic effects.

  13. Eco-toxicity and human estrogenic exposure risks from OH-initiated photochemical transformation of four phthalates in water: A computational study.

    Science.gov (United States)

    Gao, Yanpeng; An, Taicheng; Ji, Yuemeng; Li, Guiying; Zhao, Cunyuan

    2015-11-01

    Transformation products (TPs) of emerging organic contaminates (EOCs) in water are still rarely considered in environmental risk assessment, although some have been found to be concern. OH is believed as an important reactive species both in indirect phototransformation and advanced oxidation technology. Thus, eco-toxicity and human estrogenic exposure risks of four phthalates and TPs during the OH-initiated photochemical process were investigated using computational approach. Four phthalates can be degraded through OH-addition and H-transfer pathways. The OH-addition TPs were predominant for dimethyl phthalates, while H-transfer TPs were predominant for other three phthalates. Compared with phthalates, OH-addition TPs (o-OH-phthalates) were one level more toxic to aquatic organisms, and m-OH-phthalates exhibit higher estrogenic activity. Although H-transfer TPs were less harmful than OH-addition TPs, some of them still have aquatic toxicity and estrogenic activity. Therefore, more attentions should be paid to photochemical TPs and original EOCs, particularly those exhibiting high estrogenic activity to humans.

  14. Evaluation of underground water contamination of tubular wells, by fuels oil in Santo Andre City, Sao Paulo state: a contribution to the environmental management; Avaliacao da contaminacao da agua subterranea de pocos tubulares, por combustiveis fosseis, no municipio de Santo Andre, Sao Paulo: uma contribuicao a gestao ambiental

    Energy Technology Data Exchange (ETDEWEB)

    Mindrisz, Ana Copat

    2006-07-01

    The contamination of underground waters by hydrocarbons originated from gas stations has been object of increasing preoccupation in environmental organization all over the world. The organic compounds Benzene, Toluene, Ethylbenzene and Xylene (BTEX), present in these fuels, are extremely toxic to human health and could make impracticable the exploration of these contaminated waters by these kinds of pollutants and consequently the gasoline wells used for this purpose. In this work, it was carried out a diagnosis of the water quality with information and analyses, with the goals to snap shot the situation of the wells destined to domestic and commercial supply of water in the urban area of Santo Andre city, Sao Paulo state. There have been evaluated the presence of micron pollutants BTEX, after contamination due to leaks in fuel storage tanks close to the wells, in different places of the city. The physical chemistry parameters like color, turbidity and residual chlorine were also evaluated as well as trace elements, metals, anions like fluorine, sulphates, chlorine, nitrates and phosphates and bacteriological (total coliforms, thermo stable coliforms, heterotrophic bacteria). On definition of the sampling area, it was sought, at first, the evaluation of environmental contaminations historical series by gas stations, evaluating the set of information available at government environmental organizations and spatial representatively of the problem. For administration of the underground water quality it was adopted the methodology used by Companhia de Tecnologia de Saneamento Ambiental (CETESB), being accomplished a previous identification of contaminated potential areas and organizing a data base on landfills disposal and neglected places; registration of gas station services and, wells used by the population, industrial inventory with active and neglected maps taking into consideration the size and residues generation (such as SEMASA), prioritizing in this way the

  15. Acetylcholinesterase inhibition, antioxidant activity and toxicity of Peumus boldus water extracts on HeLa and Caco-2 cell lines.

    Science.gov (United States)

    Falé, P L; Amaral, F; Amorim Madeira, P J; Sousa Silva, M; Florêncio, M H; Frazão, F N; Serralheiro, M L M

    2012-08-01

    This work aimed to study the inhibition on acetylcholinesterase activity (AChE), the antioxidant activity and the toxicity towards Caco-2 and HeLa cells of aqueous extracts of Peumus Boldus. An IC(50) value of 0.93 mg/mL, for AChE inhibition, and EC(50) of 18.7 μg/mL, for the antioxidant activity, was determined. This activity can be attributed to glycosylated flavonoid derivatives detected, which were the main compounds, although boldine and other aporphine derivatives were also present. No changes in the chemical composition or the biochemical activities were found after gastrointestinal digestion. Toxicity of P. boldus decoction gave an IC(50) value 0.66 mg/mL for HeLa cells, which caused significant changes in the cell proteome profile.

  16. Acute toxicity of sodium bicarbonate, a major component of coal bed natural gas produced waters, to 13 aquatic species as defined in the laboratory

    Science.gov (United States)

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

    2014-01-01

    Water produced during coal bed natural gas (CBNG) extraction in the Powder River Structural Basin of Wyoming and Montana (USA) may contain concentrations of sodium bicarbonate (NaHCO3) of more than 3000 mg/L. The authors evaluated the acute toxicity of NaHCO3, also expressed as bicarbonate (HCO3−), to 13 aquatic organisms. Of the 13 species tested, 7 had a median lethal concentration (LC50) less than 2000 mg/L NaHCO3, or 1300 mg/L HCO3−. The most sensitive species were Ceriodaphnia dubia, freshwater mussels (Lampsilis siliquoidea), pallid sturgeon (Scaphirhynchus albus), and shovelnose sturgeon (Scaphirhynchus platorynchus). The respective LC50s were 989 mg/L, 1120 mg/L, 1249 mg/L, and 1430 mg/L NaHCO3, or 699 mg/L, 844 mg/L, 831 mg/L, and 1038 mg/L HCO3−. Age affected the sensitivity of fathead minnows, even within life stage. Two days posthatch, fathead minnows were more sensitive to NaHCO3 and HCO3− compared with 4-d-old fish, even though fish up to 14 d old are commonly used for toxicity evaluations. The authors recommend that ion toxicity exposures be conducted with organisms less than 24 h posthatch to ensure that experiments document the most sensitive stage of development. The results of the present study, along with historical and current research regarding the toxicity of bicarbonate, may be useful to establish regulatory standards for HCO3−.

  17. Diurnal depression in leaf hydraulic conductance at ambient and elevated [CO2] and reveals anisohydric water management in field-grown soybean

    Science.gov (United States)

    Diurnal cycles of photosynthesis and water use in field-grown soybean (Glycine max) are tied to light intensity and vapor pressure deficit (VPD). At high mid-day VPD, transpiration rates can lead to a decline in leaf water potential ('leaf) if leaf hydraulic conductance (Kleaf) is insufficient to su...

  18. 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.

  19. Synthesis of low polydisperse isotactic poly(N-isopropylacrylamide)s in environment-friendly and less toxic methanol-water mixtures by RAFT polymerization

    Indian Academy of Sciences (India)

    Chandra Sekhar Biswas; Kheyanath Mitra; Shikha Singh; Biswajit Ray

    2016-03-01

    Poly(N-isopropylacrylamide)s (PNIPAM) with low polydispersity and different isotacticity have been synthesized successfully in different compositions of environment-friendly and less toxic methanol-water mixtures by RAFT polymerization in the presence of 0.1 M Yttrium trifluoromethanesulfonate [Y(OTf)3]. The reactions were successful with high yield in the solvent compositions having mole-fraction of methanol (xm) at or above 0.31. Molecular weights were found to be in between 2.78*104-5.7*104 and polydispersity index (Mw/Mn=1.11 – 1.37) was close to unity. Isotacticity [meso diad (m), div] of the polymers increased from 55 to 86div with the increase in the xm value from 0.31 to 1.0. The lower critical solution temperature (LCST) of the formed PNIPAMs in water decreased with the increase in their isotacticity.

  20. Water and sodium intake habits and status of ultra-endurance runners during a multi-stage ultra-marathon conducted in a hot ambient environment: an observational field based study

    Science.gov (United States)

    2013-01-01

    Background Anecdotal evidence suggests ultra-runners may not be consuming sufficient water through foods and fluids to maintenance euhydration, and present sub-optimal sodium intakes, throughout multi-stage ultra-marathon (MSUM) competitions in the heat. Subsequently, the aims were primarily to assess water and sodium intake habits of recreational ultra-runners during a five stage 225 km semi self-sufficient MSUM conducted in a hot ambient environment (Tmax range: 32°C to 40°C); simultaneously to monitor serum sodium concentration, and hydration status using multiple hydration assessment techniques. Methods Total daily, pre-stage, during running, and post-stage water and sodium ingestion of ultra-endurance runners (UER, n = 74) and control (CON, n = 12) through foods and fluids were recorded on Stages 1 to 4 by trained dietetic researchers using dietary recall interview technique, and analysed through dietary analysis software. Body mass (BM), hydration status, and serum sodium concentration were determined pre- and post-Stages 1 to 5. Results Water (overall mean (SD): total daily 7.7 (1.5) L/day, during running 732 (183) ml/h) and sodium (total daily 3.9 (1.3) g/day, during running 270 (151) mg/L) ingestion did not differ between stages in UER (p  0.05 vs. CON pre-stage). Asymptomatic hyponatraemia (<135 mmol/L) was evident pre- and post-stage in n = 8 UER, corresponding to 42% of sampled participants. Pre- and post-stage urine colour, urine osmolality and urine/plasma osmolality ratio increased (p < 0.001) as competition progressed in UER, with no change in CON. Plasma volume and extra-cellular water increased (p < 0.001) 22.8% and 9.2%, respectively, from pre-Stage 1 to 5 in UER, with no change in CON. Conclusion Water intake habits of ultra-runners during MSUM conducted in hot ambient conditions appear to be sufficient to maintain baseline euhydration levels. However, fluid over-consumption behaviours were evident along competition

  1. Human Health Risk Assessment of Artisanal Miners Exposed to Toxic Chemicals in Water and Sediments in the Prestea Huni Valley District of Ghana

    Science.gov (United States)

    Obiri, Samuel; Yeboah, Philip O.; Osae, Shiloh; Adu-kumi, Sam; Cobbina, Samuel J.; Armah, Frederick A.; Ason, Benjamin; Antwi, Edward; Quansah, Reginald

    2016-01-01

    A human health risk assessment of artisanal miners exposed to toxic metals in water bodies and sediments in the PresteaHuni Valley District of Ghana was carried out in this study, in line with US EPA risk assessment guidelines. A total of 70 water and 30 sediment samples were collected from surface water bodies in areas impacted by the operations of artisanal small-scale gold mines in the study area and analyzed for physico-chemical parameters such as pH, TDS, conductivity, turbidity as well as metals and metalloids such as As, Cd, Hg and Pb at CSIR—Water Research Institute using standard methods for the examination of wastewater as outlined by American Water Works Association (AWWA). The mean concentrations of As, Cd, Hg and Pb in water samples ranged from 15 μg/L to 325 μg/L (As), 0.17 μg/L to 340 μg/L (Cd), 0.17 μg/L to 122 μg/L (Pb) and 132 μg/L to 866 μg/L (Hg), respectively. These measured concentrations of arsenic (As), mercury (Hg), cadmium (Cd) and lead (Pb) were used as input parameters to calculate the cancer and non-cancer health risks from exposure to these metals in surface water bodies and sediments based on an occupational exposure scenario using central tendency exposure (CTE) and reasonable maximum exposure (RME) parameters. The results of the non-cancer human health risk assessment for small-scale miners working around river Anikoko expressed in terms of hazard quotients based on CTE parameters are as follows: 0.04 (Cd), 1.45 (Pb), 4.60 (Hg) and 1.98 (As); while cancer health risk faced by ASGM miners in Dumase exposed to As in River Mansi via oral ingestion of water is 3.1 × 10−3. The hazard quotient results obtained from this study in most cases were above the HQ guidance value of 1.0, furthermore the cancer health risk results were found to be higher than the USEPA guidance value of 1 × 10−4 to 1 × 10−6. These findings call for case-control epidemiological studies to establish the relationship between exposure to the

  2. Human Health Risk Assessment of Artisanal Miners Exposed to Toxic Chemicals in Water and Sediments in the PresteaHuni Valley District of Ghana

    Directory of Open Access Journals (Sweden)

    Samuel Obiri

    2016-01-01

    Full Text Available A human health risk assessment of artisanal miners exposed to toxic metals in water bodies and sediments in the PresteaHuni Valley District of Ghana was carried out in this study, in line with US EPA risk assessment guidelines. A total of 70 water and 30 sediment samples were collected from surface water bodies in areas impacted by the operations of artisanal small-scale gold mines in the study area and analyzed for physico-chemical parameters such as pH, TDS, conductivity, turbidity as well as metals and metalloids such as As, Cd, Hg and Pb at CSIR—Water Research Institute using standard methods for the examination of wastewater as outlined by American Water Works Association (AWWA. The mean concentrations of As, Cd, Hg and Pb in water samples ranged from 15 μg/L to 325 μg/L (As, 0.17 μg/L to 340 μg/L (Cd, 0.17 μg/L to 122 μg/L (Pb and 132 μg/L to 866 μg/L (Hg, respectively. These measured concentrations of arsenic (As, mercury (Hg, cadmium (Cd and lead (Pb were used as input parameters to calculate the cancer and non-cancer health risks from exposure to these metals in surface water bodies and sediments based on an occupational exposure scenario using central tendency exposure (CTE and reasonable maximum exposure (RME parameters. The results of the non-cancer human health risk assessment for small-scale miners working around river Anikoko expressed in terms of hazard quotients based on CTE parameters are as follows: 0.04 (Cd, 1.45 (Pb, 4.60 (Hg and 1.98 (As; while cancer health risk faced by ASGM miners in Dumase exposed to As in River Mansi via oral ingestion of water is 3.1 × 10−3. The hazard quotient results obtained from this study in most cases were above the HQ guidance value of 1.0, furthermore the cancer health risk results were found to be higher than the USEPA guidance value of 1 × 10−4 to 1 × 10−6. These findings call for case-control epidemiological studies to establish the relationship between exposure to the

  3. Human Health Risk Assessment of Artisanal Miners Exposed to Toxic Chemicals in Water and Sediments in the Prestea Huni Valley District of Ghana.

    Science.gov (United States)

    Obiri, Samuel; Yeboah, Philip O; Osae, Shiloh; Adu-Kumi, Sam; Cobbina, Samuel J; Armah, Frederick A; Ason, Benjamin; Antwi, Edward; Quansah, Reginald

    2016-01-18

    A human health risk assessment of artisanal miners exposed to toxic metals in water bodies and sediments in the PresteaHuni Valley District of Ghana was carried out in this study, in line with US EPA risk assessment guidelines. A total of 70 water and 30 sediment samples were collected from surface water bodies in areas impacted by the operations of artisanal small-scale gold mines in the study area and analyzed for physico-chemical parameters such as pH, TDS, conductivity, turbidity as well as metals and metalloids such as As, Cd, Hg and Pb at CSIR-Water Research Institute using standard methods for the examination of wastewater as outlined by American Water Works Association (AWWA). The mean concentrations of As, Cd, Hg and Pb in water samples ranged from 15 μg/L to 325 μg/L (As), 0.17 μg/L to 340 μg/L (Cd), 0.17 μg/L to 122 μg/L (Pb) and 132 μg/L to 866 μg/L (Hg), respectively. These measured concentrations of arsenic (As), mercury (Hg), cadmium (Cd) and lead (Pb) were used as input parameters to calculate the cancer and non-cancer health risks from exposure to these metals in surface water bodies and sediments based on an occupational exposure scenario using central tendency exposure (CTE) and reasonable maximum exposure (RME) parameters. The results of the non-cancer human health risk assessment for small-scale miners working around river Anikoko expressed in terms of hazard quotients based on CTE parameters are as follows: 0.04 (Cd), 1.45 (Pb), 4.60 (Hg) and 1.98 (As); while cancer health risk faced by ASGM miners in Dumase exposed to As in River Mansi via oral ingestion of water is 3.1 × 10(-3). The hazard quotient results obtained from this study in most cases were above the HQ guidance value of 1.0, furthermore the cancer health risk results were found to be higher than the USEPA guidance value of 1 × 10(-4) to 1 × 10(-6). These findings call for case-control epidemiological studies to establish the relationship between exposure to the

  4. Architectural models of ambient-PRISMA in channel ambient calculus

    OpenAIRE

    Ali, Nour; Tuosto, Emilio

    2011-01-01

    peer-reviewed Ambient-PRISMA is an architectural approach for specifying aspect-oriented software architecture and generating code of distributed and mobile systems. Ambient-PRISMA lacks a precise semantics due to the fact that it is based only on a metamodel. In this paper, Ambient-PRISMA is mapped into a formal language called Channel Ambient Calculus, a process algebra for specifying mobile applications that provides channels and ambients as first-class citizens. We...

  5. Crystallization of perovskite film using ambient moisture and water as co-solvent for efficient planar perovskite solar cell (Conference Presentation)

    Science.gov (United States)

    Dubey, Ashish; Reza, Khan M.; Gaml, Eman; Adhikari, Nirmal; Qiao, Qiquan

    2016-09-01

    Smooth, compact and defect free morphology of perovskite is highly desired for enhanced device performance. Several routes such as thermal annealing, use of solvent mixtures, growth under controlled humidity has been adopted to obtain crystalline, smooth and defect free perovskite film. Herein we showed direct use of water (H2O) as co-solvent in precursor solution and have optimized the water content required to obtain smooth and dense film. Varying concentration of water was used in precursor solution of CH3NH3I and PbI2 mixed in γ-butyrolactone (GBL) and dimethylsulfoxide (DMSO). Perovskite films were crystallized using toluene assisted solvent engineering method using GBL:DMSO:H2O as solvent mixture. The amount of water was varied from 1% to 25%, which resulted in change in film morphology and perovskite crystallinity. It was concluded that an appropriate amount of water is required to assist the crystallization process to obtain smooth pin-hole free morphology. The change in morphology led to improved fill factor in the device, with highest efficiency 14%, which was significantly higher than devices made from perovskite film without adding water. We also showed that addition of up to 25% by volume of water does not significantly change the device performance.

  6. Using an interlaboratory study to revise methods for conducting 10-d to 42-d water or sediment toxicity tests with Hyalella azteca.

    Science.gov (United States)

    Ivey, Chris D; Ingersoll, Chris G; Brumbaugh, William G; Hammer, Edward J; Mount, Dave R; Hockett, J Russell; Norberg-King, Teresa J; Soucek, Dave; Taylor, Lisa

    2016-10-01

    Studies have been conducted to refine US Environmental Protection Agency, ASTM International, and Environment Canada standard methods for conducting 42-d reproduction tests with Hyalella azteca in water or in sediment. Modifications to the H. azteca method include better-defined ionic composition requirements for exposure water (i.e., >15 mg/L of chloride and >0.02 mg/L of bromide) and improved survival, growth, and reproduction with alternate diets provided as increased rations over time in water-only or whole-sediment toxicity tests. A total of 24 laboratories volunteered to participate in the present interlaboratory study evaluating the performance of H. azteca in 42-d studies in control sand or control sediment using the refined methods. Improved growth and reproduction of H. azteca was observed with 2 alternate diets of 1) ramped diatoms (Thalassiosira weissflogii) + ramped Tetramin or 2) yeast-cerophyll-trout chow (YCT) + ramped Tetramin, especially when compared with results from the traditional diet of 1.8 mg YCT/d. Laboratories were able to meet proposed test acceptability criteria and in most cases had lower variation in growth or reproduction compared with previous interlaboratory studies using the traditional YCT diet. Laboratory success in conducting 42-d H. azteca exposures benefited from adherence to several key requirements of the detailed testing, culturing, and handling methods. Results from the present interlaboratory study are being used to help revise standard methods for conducting 10-d to 42-d water or sediment toxicity exposures with H. azteca. Environ Toxicol Chem 2016;35:2439-2447. © 2016 SETAC.

  7. Using an interlaboratory study to revise methods for conducting 10-d to 42-d water or sediment toxicity tests with Hyalella azteca

    Science.gov (United States)

    Ivey, Chris D.; Ingersoll, Christopher G.; Brumbaugh, William G.; Hammer, Edward J.; Mount, David R.; Hockett, J. Russell; Norberg-King, Teresa J.; Soucek, Dave; Taylor, Lisa

    2016-01-01

    Studies have been conducted to refine US Environmental Protection Agency, ASTM International, and Environment Canada standard methods for conducting 42-d reproduction tests with Hyalella azteca in water or in sediment. Modifications to the H. azteca method include better-defined ionic composition requirements for exposure water (i.e., >15 mg/L of chloride and >0.02 mg/L of bromide) and improved survival, growth, and reproduction with alternate diets provided as increased rations over time in water-only or whole-sediment toxicity tests. A total of 24 laboratories volunteered to participate in the present interlaboratory study evaluating the performance of H. azteca in 42-d studies in control sand or control sediment using the refined methods. Improved growth and reproduction of H. azteca was observed with 2 alternate diets of 1) ramped diatoms (Thalassiosira weissflogii) + ramped Tetramin or 2) yeast–cerophyll–trout chow (YCT) + ramped Tetramin, especially when compared with results from the traditional diet of 1.8 mg YCT/d. Laboratories were able to meet proposed test acceptability criteria and in most cases had lower variation in growth or reproduction compared with previous interlaboratory studies using the traditional YCT diet. Laboratory success in conducting 42-d H. azteca exposures benefited from adherence to several key requirements of the detailed testing, culturing, and handling methods. Results from the present interlaboratory study are being used to help revise standard methods for conducting 10-d to 42-d water or sediment toxicity exposures with H. azteca.

  8. Toxicity of lithium to three freshwater organisms and the antagonistic effect of sodium.

    Science.gov (United States)

    Kszos, Lynn Adams; Beauchamp, John J; Stewart, Arthur J

    2003-10-01

    Lithium (Li) is the lightest metal and occurs primarily in stable minerals and salts. Concentrations of Li in surface water are typically toxicity of Li to common toxicity test organisms, we evaluated the toxicity of Li to Pimephales promelas (fathead minnow), Ceriodaphnia dubia, and a freshwater snail (Elimia clavaeformis). In the laboratory, the concentration of Li that inhibited P. promelas growth or C. dubia reproduction by 25% (IC25) was dependant upon the dilution water. In laboratory control water containing little sodium (approximately 2.8 mg l(-1)), the IC25s were 0.38 and 0.32 mg Li l(-1) and in ambient stream water containing approximately 17 mg Na l(-1), the IC25s were 1.99 and 3.33, respectively. A Li concentration of 0.15 mg l(-1) inhibited the feeding of E. clavaeformis in laboratory tests. Toxicity tests conducted to evaluate the effect of sodium on the toxicity of Li were conducted with fathead minnows and C. dubia. The presence of sodium greatly affected the toxicity of Li. Fathead minnows and Ceriodaphnia, for example, tolerated concentrations of Li as great as 6 mg l(-1) when sufficient Na was present. The interaction of Li and Na on the reproduction of Ceriodaphnia was investigated in depth and can be described using an exponential model. The model predicts that C. dubia reproduction would not be affected when animals are exposed to combinations of lithium and sodium with a log ratio of mmol Na to mmol Li equal to at least 1.63. The results of this study indicate that for most natural waters, the presence of sodium is sufficient to prevent Li toxicity. However, in areas of historical disposal or heavy processing or use, an evaluation of Li from a water quality perspective would be warranted.

  9. The PROCEL SANEAR program of energetic efficiency in environmental sanitation: water means energy; O programa PROCEL SANEAR de eficiencia energetica em saneamento ambiental: porque agua e energia

    Energy Technology Data Exchange (ETDEWEB)

    Pinheiro, Michel Goncalves; Barros, Denise Pereira; Moreira, Aurelio R.G.; Machado, Luciana D.L; Barreto, Marcus Paes; Coimbra, Claudia Maria; Perrone, Fernando; Soares, George Alves [ELETROBRAS, Brasilia, DF (Brazil); Capella, Paulo da Silva; Otero, Osvaldo [CEPEL, Rio de Janeiro, RJ (Brazil); Gomes, Airton Sampaio [Ministerio das Cidades (MCidades), Brasilia, DF (Brazil). Secretaria Nacional de Saneamento Ambiental

    2006-07-01

    The environmental sanitation sector accounts for 3% of all electric energy consumed. Along with the Electric System it is an important user of the hydro graphic basins. In 2003 ELETROBRAS created PROCEL SANEAR in order to promote the efficient use of energy and water in the environmental sanitation systems and by its consumers. This paper presents the Action Plan of PROCEL SANEAR 2006-2007 displaying its main ongoing actions: the implementation of projects of water and energy conservation selected by means of public hearings, the training of professionals with seminars for the high management and courses for the managers of sanitation services providers and the installation of equipment to implement laboratories of energy and water efficiency in sanitation. PROCEL SANEAR, a nationwide program, seeks to reach through its activities endurance and sustain ability aiming at minimizing isolated and discontinued actions. Thus, PROCEL SANEAR contributes to shift paradigms by causing service providers to prioritize the conservation of water and electric energy. (author)

  10. Suitability of seven species of soil-inhabiting invertebrates for testing toxicity of pesticides in soil pore water

    NARCIS (Netherlands)

    Ronday, R.; Houx, N.W.H.

    1996-01-01

    This study assessed the suitability of seven species of soil invertebrates for toxicologically testing pesticides in water. Requirements were that the organisms must survive in water, be easy to handle, be easy to breed, be sensitive to pesticides, and show unambiguous toxicological effects. The org

  11. Reuse/disposal of agricultural drainage water with high levels of salinity and toxic trace elements in central California.

    Science.gov (United States)

    Agricultural drainage waters in the western San Joaquin Valley of Central California contain high levels of salts, boron (B) and selenium (Se). Discharge of the drainage water directly into the Kesterson Reservoir in 1980's was hazardous to plants and wildlife. To investigate the plausibility of usi...

  12. Water and sodium intake habits and status of ultra-endurance runners during a multi-stage ultra-marathon conducted in a hot ambient environment: an observational field based study

    Directory of Open Access Journals (Sweden)

    Costa Ricardo JS

    2013-01-01

    Full Text Available Abstract Background Anecdotal evidence suggests ultra-runners may not be consuming sufficient water through foods and fluids to maintenance euhydration, and present sub-optimal sodium intakes, throughout multi-stage ultra-marathon (MSUM competitions in the heat. Subsequently, the aims were primarily to assess water and sodium intake habits of recreational ultra-runners during a five stage 225 km semi self-sufficient MSUM conducted in a hot ambient environment (Tmax range: 32°C to 40°C; simultaneously to monitor serum sodium concentration, and hydration status using multiple hydration assessment techniques. Methods Total daily, pre-stage, during running, and post-stage water and sodium ingestion of ultra-endurance runners (UER, n = 74 and control (CON, n = 12 through foods and fluids were recorded on Stages 1 to 4 by trained dietetic researchers using dietary recall interview technique, and analysed through dietary analysis software. Body mass (BM, hydration status, and serum sodium concentration were determined pre- and post-Stages 1 to 5. Results Water (overall mean (SD: total daily 7.7 (1.5 L/day, during running 732 (183 ml/h and sodium (total daily 3.9 (1.3 g/day, during running 270 (151 mg/L ingestion did not differ between stages in UER (p vs. CON. Exercise-induced BM loss was 2.4 (1.2% (p p > 0.05 vs. CON pre-stage. Asymptomatic hyponatraemia (n = 8 UER, corresponding to 42% of sampled participants. Pre- and post-stage urine colour, urine osmolality and urine/plasma osmolality ratio increased (p p  Conclusion Water intake habits of ultra-runners during MSUM conducted in hot ambient conditions appear to be sufficient to maintain baseline euhydration levels. However, fluid over-consumption behaviours were evident along competition, irrespective of running speed and gender. Normonatraemia was observed in the majority of ultra-runners throughout MSUM, despite sodium ingestion under benchmark recommendations.

  13. Ambient oxygen promotes tumorigenesis.

    Directory of Open Access Journals (Sweden)

    Ho Joong Sung

    Full Text Available Oxygen serves as an essential factor for oxidative stress, and it has been shown to be a mutagen in bacteria. While it is well established that ambient oxygen can also cause genomic instability in cultured mammalian cells, its effect on de novo tumorigenesis at the organismal level is unclear. Herein, by decreasing ambient oxygen exposure, we report a ∼50% increase in the median tumor-free survival time of p53-/- mice. In the thymus, reducing oxygen exposure decreased the levels of oxidative DNA damage and RAG recombinase, both of which are known to promote lymphomagenesis in p53-/- mice. Oxygen is further shown to be associated with genomic instability in two additional cancer models involving the APC tumor suppressor gene and chemical carcinogenesis. Together, these observations represent the first report directly testing the effect of ambient oxygen on de novo tumorigenesis and provide important physiologic evidence demonstrating its critical role in increasing genomic instability in vivo.

  14. 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.

  15. Radionuclide Transport Models Under Ambient Conditions

    Energy Technology Data Exchange (ETDEWEB)

    G. Moridis; Q. Hu

    2001-12-20

    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.

  16. Crisis ambiental y cristianismo

    OpenAIRE

    Felipe Cárdenas

    2008-01-01

    En el artículo se identifican y reconocen algunas opciones que se pueden desarrollar en el cristianismo en relación con la problemática ambiental. Se aborda el dilema bíblico suscitado por interpretaciones antiecológicas y ecológicas. Con base en una lectura de la Biblia, de testimonios cristianos, y en una rememoria de estructuras institucionales, como la parroquia, se analiza el valor que tiene el mensaje cristiano en lo referido a la mitigación de la crisis ambiental.This article identifie...

  17. The Prospective Toxic Effects of Some Heavy Metals Overload in Surface Drinking Water of Dakahlia Governorate, Egypt

    Directory of Open Access Journals (Sweden)

    YA Azab

    2011-09-01

    Full Text Available Background: The concentration of heavy metals in drinking water is very important.Objectives: To to evaluate the chemistry of some heavy metals in surface drinking water of Dakahlia Governorate, Egypt.Methods: 51 surface drinking water samples were collected from the main surface water stations and compact units in October 2009 and analyzed chemically. 26 water samples were analyzed by atomic absorption spectrophotometer for iron, manganese, lead, nickel, chromium, zinc, copper, cobalt, aluminum, and cadmium concentrations.Results: Aluminum concentration was slightly high in water sample of Bosat network. Cadmium concentration in samples of up-streams of shark and Mit-Khamis stations, networks of Mit-Antar, Demera, Bosat, Bilqas, El-satamony, El-Gamalia, Mit-asim and Bilqas station exceeded the permissible limits of Egyptian Ministry of Health (EMH, 2007 and World Health Organization (WHO, 2008. The nickel concentration in the network samples taken from Shoha, Bosat and El-Gamalia as well as up-stream of Bosat station exceeded the permissible limits. Also, lead concentrations of the network samples of Shoha, Mit-Antar, Demera and Nabaru exceeded the permissible limits.Conclusion: Regular chemical analysis of surface drinking water is required. Since these heavy metals are most likely originate from steel, plastics and batteries industries working in the region, we believe that activities of these industries must be stopped or at least limited in urban zones.

  18. Assessing plasma lipid levels, body weight, and hepatic and renal toxicity following chronic oral administration of a water soluble phytostanol compound, FM-VP4, to gerbils.

    Science.gov (United States)

    Wasan, K M; Najafi, S; Wong, J; Kwong, M; Pritchard, P H

    2001-01-01

    to controls. A significant increase in HDL cholesterol concentrations was observed in gerbils administered 2% FM-VP4 in their diet and 4% FM-VP4 in their drinking water compared to controls. No significant elevations in AST, ALT and creatinine concentrations were reported for all treatment groups compared to controls. These findings suggest that FM-VP4 significantly decrease plasma lipids and body weight with no apparent hepatic or renal toxicity.

  19. Bioaccumulation and toxicity assessment of irrigation water contaminated with boron (B) using duckweed (Lemna gibba L.) in a batch reactor system.

    Science.gov (United States)

    Türker, Onur Can; Yakar, Anıl; Gür, Nurcan

    2017-02-15

    The present study assesses ability of Lemna gibba L. using a batch reactor approach to bioaccumulation boron (B) from irrigation waters which were collected from a stream in largest borax reserve all over the world. The important note that bioaccumulation of B from irrigation water was first analyzed for first time in a risk assessment study using a Lemna species exposed to various B concentrations. Boron toxicity was evaluated through plant growth and biomass production during phytoremediation process. The result from the present experiment indicated that L. gibba was capable of removing 19-63% B from irrigation water depending upon contaminated level or initial concentration. We also found that B was removed from aqueous solution following pseudo second order kinetic model and Langmuir isotherm model better fitted equilibrium obtained for B phytoremediation. Maximum B accumulation in L. gibba was determined as 2088mgkg(-1) at average inflow B concentration 17.39mgL(-1) at the end of the experiment. Conversely, maximum bioconcentration factor obtained at lowest inflow B concentrations were 232 for L. gibba. The present study suggested that L. gibba was very useful B accumulator, and thus L. gibba-based techniques could be a reasonable phytoremediation option to remove B directly from water sources contaminated with B.

  20. Strong water-mediated friction asymmetry and surface dynamics of zwitterionic solids at ambient conditions: L-alanine as a case study

    Science.gov (United States)

    Segura, J. J.; Verdaguer, A.; Garzón, L.; Barrena, E.; Ocal, C.; Fraxedas, J.

    2011-03-01

    Water molecules strongly interact with freshly cleaved (011) surfaces of L-alanine single crystals at low relative humidity (below 10%) promoting diffusion of L-alanine molecules. Species mobility is enhanced above ˜40% leading to the formation of two-dimensional islands with long-range order through Ostwald ripening. Scanning force microscopy experiments reveal that both, islands and terraces, are identical in nature (composition and crystallographic structure) but a relevant friction asymmetry appearing upon water-surface interaction evidences that orientation dependent properties exist between them at the molecular level. We interpret this observation as due to water incorporation in the topmost surface crystal structure. Eventually, for high humidity values, surface dissolution and roughening occur.

  1. Identification, toxicity and control of iodinated disinfection byproducts in cooking with simulated chlor(am)inated tap water and iodized table salt.

    Science.gov (United States)

    Pan, Yang; Zhang, Xiangru; Li, Yu

    2016-01-01

    Chlorine/chloramine residuals are maintained in drinking water distribution systems to prevent microbial contamination and microorganism regrowth. During household cooking processes (e.g., soup making), the residual chlorine/chloramines in tap water may react with the iodide in iodized table salt to form hypoiodous acid, which could react with remaining natural organic matter in tap water and organic matter in food to generate iodinated disinfection byproducts (I-DBPs). However, I-DBPs formed during cooking with chloraminated/chlorinated tap water are almost completely new to researchers. In this work, by adopting precursor ion scan of m/z 127 using ultra performance liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry, many new polar I-DBPs formed during cooking with chloraminated/chlorinated tap water were detected and proposed with structures, of which 3-iodo-4-hydroxybenzaldehyde, 3-iodo-4-hydroxybenzoic acid, 3-iodo-4-hydroxy-5-methylbenzoic acid, diiodoacetic acid, 3,5-diiodo-4-hydroxybenzaldehyde, 3,5-diiodo-4-hydroxybenzoic acid, 2,6-diiodo-4-nitrophenol, 2,4-diiodo-6-nitrophenol, and 2,4,6-triiodophenol were confirmed with standard compounds. With the aid of ultra fast liquid chromatography/ion trap-time of flight-mass spectrometry, molecular formula identification of five new I-DBPs (C8H5O4I, C7H4NO4I, C8H5O5I, C7H4NO5I, and C8H6O3I2) was achieved. A developmental toxicity with a recently developed sensitive bioassay was conducted for the newly identified I-DBPs, suggesting that phenolic I-DBPs (except for iodinated carboxyphenols) were about 50-200 times more developmentally toxic than aliphatic I-DBPs. The major I-DBPs in a baseline simulated cooking water sample were determined to be from 0.72 to 7.63 μg/L. Polar I-DBPs formed under various disinfection and cooking conditions were compared, and suggestions for controlling their formation were provided.

  2. An Efficient, Simple and Green Zn(Phen2Cl2 Complex Catalyzed Synthesis of 4-H-Benzo[b]pyrans in Water at Ambient Temperature

    Directory of Open Access Journals (Sweden)

    E. Mosaddegh

    2011-01-01

    Full Text Available An efficient method for the synthesis of 4-H-benzo[b]pyrans has been developed by the use of Zn(Phen2Cl2(2 mol% as an ecofriendly catalyst. The mixture of an appropriate aldehyde, malononitrile and dimedone in the presence of the Zn(Phen2Cl2 as an inorganic catalyst in water at room temperature resulted excellent yields of the corresponding products in 5 min. Very short experimental time of the reaction, excellent yields, use of water as a green solvent, simple work-up and uses no extra catalyst and purification are the advantages of this method.

  3. Toxicity of surface waters from Benton Lake National Wildlife Refuge and Freezout Lake Wildlife Management Area, Montana, to mallard ducklings

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — We measured the growth and survival of captive mallard (Anas platyrhvnchos) ducklings housed in wire cages during a 28-day drinking water bioassay to assess...

  4. Public Health Strategies for Western Bangladesh That Address Arsenic, Manganese, Uranium, and Other Toxic Elements in Drinking Water

    OpenAIRE

    Frisbie, Seth H.; Mitchell, Erika J.; Mastera, Lawrence J.; Maynard, Donald M.; Yusuf, Ahmad Zaki; Siddiq, Mohammad Yusuf; Ortega, Richard; Dunn, Richard K.; Westerman, David S.; Bacquart, Thomas; Sarkar, Bibudhendra

    2008-01-01

    Background More than 60,000,000 Bangladeshis are drinking water with unsafe concentrations of one or more elements. Objectives Our aims in this study were to evaluate and improve the drinking water testing and treatment plans for western Bangladesh. Methods We sampled groundwater from four neighborhoods in western Bangladesh to determine the distributions of arsenic, boron, barium, chromium, iron, manganese, molybdenum, nickel, lead, antimony, selenium, uranium, and zinc, and to determine pH....

  5. Studies on alga pollution and its toxicity of municipal water supplies.%某市供水藻类污染及其毒性研究

    Institute of Scientific and Technical Information of China (English)

    吴静; 王玉鹏; 蒋颂辉; 朱惠刚

    2001-01-01

    Algae are the most frequently used biological monitoring indicators of waters eutrophication. In order to understand the status of algae pollution of municipal water supplies, monitoring of six times in a year for the main water supplies source algae in the city and the bioassay of toxic element extracted from lyophillized algal cell were performed. The results showed that the algae had polluted the water source at different level.4 species of the algae were identified. Extracts from lyophillized algal cell posed hepatotoxicity through injection of rat stomach. The LD50 was 68.39~114.02mg lyophillized algal cell per kilogram body weight. It is suggested that algae should be a regular monitoring index indicating water quality,in order to supply basis for chosing the water source reasonably.%藻类是反映水体富营养化最常用的生物监测指标.为弄清某城市供水水体的藻类污染状况,对该市主要供水水源的藻类进行了为期1年6次监测,并提取冷冻干藻细胞中的毒素成份进行生物学检测.结果发现,该市水源均受到藻类不同程度的污染,主要检测到4类藻.干藻细胞提取物经小鼠腹腔注射,发现具有肝毒性,其半数致死剂量为68.39~114.02mg干藻细胞/kg体重.建议今后将藻类作为水质监测的一个常规指标,为合理选择水源提供依据.

  6. Environmental process for elimination of phenolic water present in refinery gasoline tanks; Processo ambiental para eliminacao de agua fenolica presente em tanques de gasolina de refinarias de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Correa Junior, Bentaci; Pedroso, Osmar V.; Furlan, Luis T. [PETROBRAS, SP (Brazil). Refinaria de Paulinia

    2004-07-01

    Gasoline production in petroleum refineries usually implies carrying high phenol contents in water after treatment systems. Phenols are powerful bactericides and, therefore, harmful to microorganisms present in wastewater treatment plants and in rivers. Due to this reason, usually controlled phenolic water drainage is performed, enabling gasoline quality improvement, without jeopardizing the biological treatment. Increase of phenolic contents in the effluent, due to operational disarray during the drainage of gasoline tanks may cause inhibition or even mortality of the existing microorganisms in the wastewater treatment plants. Aiming at changing the traditional treatment logic of environmental demands at the 'end of pipe', sending the phenolic water to the sour water treatment systems was proposed and implemented, which in turn, is reutilized by the latter in the crude desalination of the Distillation Units, where the phenols are reincorporated to the crude oil, preventing negative consequences to the wastewater treatment plant. The implemented process has demonstrated that premises were correct, enabling to implement process flows quite higher than drainage flows, what has meant productivity gains and environmental improvement. (author)

  7. Toxicity of chromium (VI) to two mussels and an amphipod in water-only exposures with or without a co-stressor of elevated temperature, zinc, or nitrate

    Science.gov (United States)

    Wang, Ning; Kunz, James L.; Ivey, Chris D.; Ingersoll, Christopher G.; Barnhart, M. Christopher; Glidewell, Elizabeth A.

    2017-01-01

    The objectives of the present study were to develop methods for propagating western pearlshell (Margaritifera falcata) for laboratory toxicity testing and evaluate acute and chronic toxicity of chromium VI [Cr(VI)] to the pearlshell and a commonly tested mussel (fatmucket, Lampsilis siliquoidea at 20 °C or in association with a co-stressor of elevated temperature (27 °C), zinc (50 µg Zn/L), or nitrate (35 mg NO3/L). A commonly tested invertebrate (amphipod, Hyalella azteca) also was tested in chronic exposures. Newly transformed pearlshell (~1 week old) were successfully cultured and tested in acute 96 h Cr exposures (control survival 100%). However, the grow-out of juveniles in culture for chronic toxicity testing was less successful and chronic 28-day Cr toxicity tests started with 4 month-old pearlshell failed due to low control survival (39–68%). Acute median effect concentration (EC50) for the pearlshell (919 µg Cr/L) and fatmucket (456 µg Cr/L) tested at 20 °C without a co-stressor decreased by a factor of > 2 at elevated temperature but did not decrease at elevated Zn or elevated NO3. Chronic 28-day Cr tests were completed successfully with the fatmucket and amphipod (control survival 83–98%). Chronic maximum acceptable toxicant concentration (MATC) for fatmucket at 20 °C (26 µg Cr/L) decreased by a factor of 2 at elevated temperature or NO3 but did not decrease at elevated Zn. However, chronic MATC for amphipod at 20 °C (13 µg Cr/L) did not decrease at elevated temperature, Zn, or NO3. Acute EC50s for both mussels tested with or without a co-stressor were above the final acute value used to derive United States Environmental Protection Agency acute water quality criterion (WQC) for Cr(VI); however, chronic MATCs for fatmucket at elevated temperature or NO3 and chronic MATCs for the amphipod at 20 °C with or without elevated Zn or NO3 were about equal to the chronic WQC. The results indicate that (1) the elevated temperature

  8. Toxicity Effect of Hg2+ and Cr(Ⅵ)on Alga Growth in Eutrophic Water%Hg2+与Cr(Ⅵ)对富营养化水体中藻类生长