Controlling air toxics through advanced coal preparation

Energy Technology Data Exchange (ETDEWEB)

Straszheim, W.E.; Buttermore, W.H.; Pollard, J.L. [Iowa State Univ., Ames, IA (United States)

1995-11-01

This project involves the assessment of advanced coal preparation methods for removing trace elements from coal to reduce the potential for air toxic emissions upon combustion. Scanning electron microscopy-based automated image analysis (SEM-AIA) and advanced washability analyses are being applied with state-of-the-art analytical procedures to predict the removal of elements of concern by advanced column flotation and to confirm the effectiveness of preparation on the quality of quantity of clean coal produced. Specific objectives are to maintain an acceptable recovery of combustible product, while improving the rejection of mineral-associated trace elements. Current work has focused on determining conditions for controlling column flotation system across its operating range and on selection and analysis of samples for determining trace element cleanability.

Carcinogenic Air Toxics Exposure and Their Cancer-Related Health Impacts in the United States.

Science.gov (United States)

Zhou, Ying; Li, Chaoyang; Huijbregts, Mark A J; Mumtaz, M Moiz

2015-01-01

Public health protection from air pollution can be achieved more effectively by shifting from a single-pollutant approach to a multi-pollutant approach. To develop such multi-pollutant approaches, identifying which air pollutants are present most frequently is essential. This study aims to determine the frequently found carcinogenic air toxics or hazardous air pollutants (HAPs) combinations across the United States as well as to analyze the health impacts of developing cancer due to exposure to these HAPs. To identify the most commonly found carcinogenic air toxics combinations, we first identified HAPs with cancer risk greater than one in a million in more than 5% of the census tracts across the United States, based on the National-Scale Air Toxics Assessment (NATA) by the U.S. EPA for year 2005. We then calculated the frequencies of their two-component (binary), and three-component (ternary) combinations. To quantify the cancer-related health impacts, we focused on the 10 most frequently found HAPs with national average cancer risk greater than one in a million. Their cancer-related health impacts were calculated by converting lifetime cancer risk reported in NATA 2005 to years of healthy life lost or Disability-Adjusted Life Years (DALYs). We found that the most frequently found air toxics with cancer risk greater than one in a million are formaldehyde, carbon tetrachloride, acetaldehyde, and benzene. The most frequently occurring binary pairs and ternary mixtures are the various combinations of these four air toxics. Analysis of urban and rural HAPs did not reveal significant differences in the top combinations of these chemicals. The cumulative annual cancer-related health impacts of inhaling the top 10 carcinogenic air toxics included was about 1,600 DALYs in the United States or 0.6 DALYs per 100,000 people. Formaldehyde and benzene together contribute nearly 60 percent of the total cancer-related health impacts. Our study shows that although there are many

Carcinogenic Air Toxics Exposure and Their Cancer-Related Health Impacts in the United States.

Directory of Open Access Journals (Sweden)

Ying Zhou

Full Text Available Public health protection from air pollution can be achieved more effectively by shifting from a single-pollutant approach to a multi-pollutant approach. To develop such multi-pollutant approaches, identifying which air pollutants are present most frequently is essential. This study aims to determine the frequently found carcinogenic air toxics or hazardous air pollutants (HAPs combinations across the United States as well as to analyze the health impacts of developing cancer due to exposure to these HAPs. To identify the most commonly found carcinogenic air toxics combinations, we first identified HAPs with cancer risk greater than one in a million in more than 5% of the census tracts across the United States, based on the National-Scale Air Toxics Assessment (NATA by the U.S. EPA for year 2005. We then calculated the frequencies of their two-component (binary, and three-component (ternary combinations. To quantify the cancer-related health impacts, we focused on the 10 most frequently found HAPs with national average cancer risk greater than one in a million. Their cancer-related health impacts were calculated by converting lifetime cancer risk reported in NATA 2005 to years of healthy life lost or Disability-Adjusted Life Years (DALYs. We found that the most frequently found air toxics with cancer risk greater than one in a million are formaldehyde, carbon tetrachloride, acetaldehyde, and benzene. The most frequently occurring binary pairs and ternary mixtures are the various combinations of these four air toxics. Analysis of urban and rural HAPs did not reveal significant differences in the top combinations of these chemicals. The cumulative annual cancer-related health impacts of inhaling the top 10 carcinogenic air toxics included was about 1,600 DALYs in the United States or 0.6 DALYs per 100,000 people. Formaldehyde and benzene together contribute nearly 60 percent of the total cancer-related health impacts. Our study shows that although

Risk Assessment for Toxic Air Pollutants: A Citizen's Guide

Science.gov (United States)

... poisonous substances in the air that come from natural sources (for example, radon gas coming up from the ground) or from manmade sources (for example, chemical compounds given off by factory smokestacks) and can harm the environment or your health. Inhaling (or breathing) toxic air ...

Control of air toxics

International Nuclear Information System (INIS)

Livengood, C.D.

1995-01-01

For more than 10 years, Argonne National Laboratory has supported the US DOE's Flue Gas Cleanup Program objective by developing new or improved environmental controls for industries that use fossil fuels. Argonne's pollutant emissions research has ranged from experiments in the basic chemistry of pollution-control systems, through laboratory-scale process development and testing, to pilot-scale field tests of several technologies. The work on air toxics is currently divided into two components: Investigating measures to improve the removal of mercury in existing pollution-control systems applied to coal combustion; and, Developing sensors and control techniques for emissions found in the textile industry

Rethink potential risks of toxic emissions from natural gas and oil mining.

Science.gov (United States)

Meng, Qingmin

2018-09-01

Studies have showed the increasing environmental and public health risks of toxic emissions from natural gas and oil mining, which have become even worse as fracking is becoming a dominant approach in current natural gas extraction. However, governments and communities often overlook the serious air pollutants from oil and gas mining, which are often quantified lower than the significant levels of adverse health effects. Therefore, we are facing a challenging dilemma: how could we clearly understand the potential risks of air toxics from natural gas and oil mining. This short study aims at the design and application of simple and robust methods to enhance and improve current understanding of the becoming worse toxic air emissions from natural gas and oil mining as fracking is becoming the major approach. Two simple ratios, the min-to-national-average and the max-to-national-average, are designed and applied to each type of air pollutants in a natural gas and oil mining region. The two ratios directly indicate how significantly high a type of air pollutant could be due to natural gas and oil mining by comparing it to the national average records, although it may not reach the significant risks of adverse health effects according to current risk screening methods. The min-to-national-average and the max-to-national-average ratios can be used as a direct and powerful method to describe the significance of air pollution by comparing it to the national average. The two ratios are easy to use for governments, stakeholders, and the public to pay enough attention on the air pollutants from natural gas and oil mining. The two ratios can also be thematically mapped at sampled sites for spatial monitoring, but spatial mitigation and analysis of environmental and health risks need other measurements of environmental and demographic characteristics across a natural gas and oil mining area. Copyright © 2018 Elsevier Ltd. All rights reserved.

Current Status of Air Toxics Management and Its Strategies for Controlling Emissions in Taiwan

Directory of Open Access Journals (Sweden)

Wen-Tien Tsai

2016-04-01

Full Text Available Since the 1970s, hazardous air pollutants (HAPs, so-called air toxics, have been of great concern because they can cause serious human health effects and have adverse effects on the environment. More noticeably, some of them are known to be human carcinogens. The objective of this paper is to investigate the regulatory systems and human health effects of air toxics which have been designated by the Taiwan government under the Air Pollution Control Act. These toxic air pollutants include acutely toxic gas (i.e., ammonia, chlorine, fluorides, hydrochloric acid, hydrogen cyanide, hydrogen sulfide, nitric acid, phosphoric acid and sulfuric acid, gas containing heavy metals, and carcinogenic chemicals (including formaldehyde, vinyl chloride, asbestos and matter containing asbestos, dioxins and furans, volatile organic compounds, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls. In line with international concern about the carcinogenic risk and environmental persistence of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/PCDFs and heavy metals in recent years, the current status in monitoring and reducing the emissions of PCDDs/PCDFs from stationary sources was analyzed as a case study in the present study. Furthermore, the control strategies for reducing emissions of air toxics from stationary sources in Taiwan were also addressed.

Air toxics research in Finland

International Nuclear Information System (INIS)

Hahkala, M.

1994-01-01

Air toxics research in Finland has developed rapidly in recent years. Though they have no enormous environmental problems in Finland, the author feels that they have to increase their knowledge of more efficient energy production and control technology. Enormous emission sources are around them, but there are also huge markets for know-how and technology in the energy sector. Two Finnish national research programs will ensure the continuity of the development efforts concerning combustion technology and environmental aspects at both theoretical and practical levels

The potential impact of proposed hazardous air pollutant legislation on the US refining industry

International Nuclear Information System (INIS)

1989-11-01

The Administration has recently submitted a Clean Air Act Bill to Congress which would significantly modify the regulatory treatment of industrial hazardous air pollutants (air toxics). The adverse economic impacts of this legislation on the petroleum refining industry could be substantial. Depending on how EPA interprets the legislative language, the capital costs of compliance for the proposed bill could range from $1.3 to $15.0 billion. At the upper end of the range, costs of this order of magnitude would be over 2.5 times larger than the combined estimated cost of EPAs gasoline volatility (RVP) regulations and the proposed diesel sulfur content regulations. Potential compliance costs could be as much as $0.40 per barrel processed for large, complex refineries and as much as $0.50 per barrel for some small, simple refineries. For perspective, total refining costs, including a normal return on investment, are $4--5 per barrel. Because foreign refineries supplying the US will not be affected by the US air toxics regulations, US refineries may not be able to raise prices sufficiently to recover their compliance costs. For this reason, the air toxic legislation may put US refineries at an economic disadvantage relative to foreign competitors. Even under the best petroleum product market conditions, costs of $0.40 to $0.50 per barrel processed could reduce US Gulf refiner cash operating margins by as much as 29 percent. Under less favorable market conditions, such as the mid-80's when refiners were losing money, the hazardous air pollutant regulations could greatly increase US refiner operating losses and potentially lead to closure of some marginal refineries

Air toxics concentrations, source identification, and health risks: An air pollution hot spot in southwest Memphis, TN

Science.gov (United States)

Jia, Chunrong; Foran, Jeffery

2013-12-01

Southwest Memphis is a residential region surrounded by fossil fuel burning, steel, refining, and food processing industries, and considerable mobile sources whose emissions may pose adverse health risks to local residents. This study characterizes cancer and non-cancer risks resulting from exposure to ambient air toxics in southwest Memphis. Air toxics samples were collected at a central location every 6 days from June 5, 2008 to January 8, 2010. Volatile organic compounds (VOCs) were collected in evacuated stainless-steel canisters and aldehydes by DNPH cartridges, and samples were analyzed for 73 target compounds. A total of 60 compounds were detected and 39 were found in over 86% of the samples. Mean concentrations of many compounds were higher than those measured in many industrial communities throughout the U.S. The cumulative cancer risk associated with exposure to 13 carcinogens found in southwest Memphis air was 2.3 × 10-4, four times higher than the national average of 5.0 × 10-5. Three risk drivers were identified: benzene, formaldehyde, and acrylonitrile, which contributed 43%, 19%, and 14% to the cumulative risk, respectively. This is the first field study to confirm acrylonitrile as a potential risk driver. Mobile, secondary, industrial, and background sources contributed 57%, 24%, 14%, and 5% of the risk, respectively. The results of this study indicate that southwest Memphis, a region of significant income, racial, and social disparities, is also a region under significant environmental stress compared with surrounding areas and communities.

Validating potential toxicity assays to assess petroleum hydrocarbon toxicity in polar soil.

Science.gov (United States)

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

2012-02-01

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

Evolution of the Air Toxics under the Big Sky Program

Science.gov (United States)

Marra, Nancy; Vanek, Diana; Hester, Carolyn; Holian, Andrij; Ward, Tony; Adams, Earle; Knuth, Randy

2011-01-01

As a yearlong exploration of air quality and its relation to respiratory health, the "Air Toxics Under the Big Sky" program offers opportunities for students to learn and apply science process skills through self-designed inquiry-based research projects conducted within their communities. The program follows a systematic scope and sequence…

[Toxic fungi in Buenos Aires City and surroundings].

Science.gov (United States)

Romano, Gonzalo M; Iannone, Leopoldo; Novas, María V; Carmarán, Cecilia; Romero, Andrea I; López, Silvia E; Lechner, Bernardo E

2013-01-01

In Facultad de Ciencias Exactas y Naturales,Universidad de Buenos Aires there is a service called Servicio de Identificación de Hongos Tóxicos, directed by researchers of the Program of Medicinal Plants and Fungi Involved in Biological Degradation (PROPLAME-PRHIDEB, CONICET) that assist hospitals and other health establishments, identifying the different samples of fungi and providing information about their toxicity, so that patients can receive the correct treatment. The objective of the present study was to analyze all the cases received from 1985 to 2012. This analysis permitted the confection of a table identifying the most common toxic species. The information gathered revealed that 47% of the patients were under 18 years of age and had eaten basidiomes; the remaining 53% were adults who insisted that they were able to distinguish edible from toxic mushrooms. Chlorophyllum molybdites turned out to be the main cause of fungal intoxication in Buenos Aires, which is commonly confused with Macrolepiota procera, an edible mushroom. In the second place Amanita phalloides was registered, an agaric known to cause severe symptoms after a long period of latency (6-10 hours), and which can lead to hepatic failure even requiring a transplant to prevent severe internal injuries or even death, is not early and correctly treated.

National Air Toxics Assessment - 2005, EPA Region 2 (EPA.AIR.NATA99_R2)

Data.gov (United States)

U.S. Environmental Protection Agency — This data layer is based on the model results of the 1999 National-Scale Assessment (N-SA), a part of the National Air Toxics Assessment (NATA), conducted by EPA's...

National Air Toxics Assessment - 2002, EPA Region 2 (EPA.AIR.NATA99_R2)

Data.gov (United States)

U.S. Environmental Protection Agency — This data layer is based on the model results of the 1999 National-Scale Assessment (N-SA), a part of the National Air Toxics Assessment (NATA), conducted by EPA's...

National Air Toxics Assessment - 1999, EPA Region 2 (EPA.AIR.NATA99_R2)

Data.gov (United States)

U.S. Environmental Protection Agency — This data layer is based on the model results of the 1999 National-Scale Assessment (N-SA), a part of the National Air Toxics Assessment (NATA), conducted by EPA's...

Inhalation toxicity of indoor air pollutants in Drosophila melanogaster using integrated transcriptomics and computational behavior analyses

Science.gov (United States)

Eom, Hyun-Jeong; Liu, Yuedan; Kwak, Gyu-Suk; Heo, Muyoung; Song, Kyung Seuk; Chung, Yun Doo; Chon, Tae-Soo; Choi, Jinhee

2017-06-01

We conducted an inhalation toxicity test on the alternative animal model, Drosophila melanogaster, to investigate potential hazards of indoor air pollution. The inhalation toxicity of toluene and formaldehyde was investigated using comprehensive transcriptomics and computational behavior analyses. The ingenuity pathway analysis (IPA) based on microarray data suggests the involvement of pathways related to immune response, stress response, and metabolism in formaldehyde and toluene exposure based on hub molecules. We conducted a toxicity test using mutants of the representative genes in these pathways to explore the toxicological consequences of alterations of these pathways. Furthermore, extensive computational behavior analysis showed that exposure to either toluene or formaldehyde reduced most of the behavioral parameters of both wild-type and mutants. Interestingly, behavioral alteration caused by toluene or formaldehyde exposure was most severe in the p38b mutant, suggesting that the defects in the p38 pathway underlie behavioral alteration. Overall, the results indicate that exposure to toluene and formaldehyde via inhalation causes severe toxicity in Drosophila, by inducing significant alterations in gene expression and behavior, suggesting that Drosophila can be used as a potential alternative model in inhalation toxicity screening.

Potential fluoride toxicity from oral medicaments: A review.

Science.gov (United States)

Ullah, Rizwan; Zafar, Muhammad Sohail; Shahani, Nazish

2017-08-01

The beneficial effects of fluoride on human oral health are well studied. There are numerous studies demonstrating that a small amount of fluoride delivered to the oral cavity decreases the prevalence of dental decay and results in stronger teeth and bones. However, ingestion of fluoride more than the recommended limit leads to toxicity and adverse effects. In order to update our understanding of fluoride and its potential toxicity, we have described the mechanisms of fluoride metabolism, toxic effects, and management of fluoride toxicity. The main aim of this review is to highlight the potential adverse effects of fluoride overdose and poorly understood toxicity. In addition, the related clinical significance of fluoride overdose and toxicity has been discussed.

Potential fluoride toxicity from oral medicaments: A review

Directory of Open Access Journals (Sweden)

Rizwan Ullah

2017-08-01

Full Text Available The beneficial effects of fluoride on human oral health are well studied. There are numerous studies demonstrating that a small amount of fluoride delivered to the oral cavity decreases the prevalence of dental decay and results in stronger teeth and bones. However, ingestion of fluoride more than the recommended limit leads to toxicity and adverse effects. In order to update our understanding of fluoride and its potential toxicity, we have described the mechanisms of fluoride metabolism, toxic effects, and management of fluoride toxicity. The main aim of this review is to highlight the potential adverse effects of fluoride overdose and poorly understood toxicity. In addition, the related clinical significance of fluoride overdose and toxicity has been discussed.

Excretory nitrogen metabolism and defence against ammonia toxicity in air-breathing fishes.

Science.gov (United States)

Chew, S F; Ip, Y K

2014-03-01

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

Grandfather regulations, new source bias, and state air toxics regulations

International Nuclear Information System (INIS)

Levinson, Arik

1999-01-01

This paper uses plant-level data from the Census of Manufactures and the variation in toxic air pollution regulations across states to measure the effects of laws that are more stringent for new sources of pollution than for existing sources (so-called 'grandfather' regulations). Of particular interest is the resulting 'new source bias' and its effects on capital vintage and investment. Two industries are examined: commercial printing, which has a local product market; and paint manufacturing, which has a more national market. In general, there seem to be no statistically significant differences in capital vintage or investment between plants in states that grandfather new sources of pollution, plants in states that have no air toxics regulations, and plants in states that regulate both new and existing sources

Breathless: Schools, Air Toxics, and Environmental Justice in California

OpenAIRE

2005-01-01

Recent legislation on both federal and state levels has placed the intersection between children’s health and environmental justice on the forefront of public policy debate. This study looks at the intersection of air quality, children’s health, and school performance in the context of environmental equity in California. Information from the U.S. EPA’s National Air Toxics Assessment (NATA) is used to calculate a respiratory hazard ratio for each of California’s census tracts. These ratios ar...

Arabidopsis and the Genetic Potential for the Phytoremediation of Toxic Elemental and Organic Pollutants

OpenAIRE

Cobbett, Christopher S.; Meagher, Richard B.

2002-01-01

In a process called phytoremediation, plants can be used to extract, detoxify, and/or sequester toxic pollutants from soil, water, and air. Phytoremediation may become an essential tool in cleaning the environment and reducing human and animal exposure to potential carcinogens and other toxins. Arabidopsis has provided useful information about the genetic, physiological, and biochemical mechanisms behind phytoremediation, and it is an excellent model genetic organism to test foreign gene expr...

Notification: Background Investigation Services EPA’s Efforts to Incorporate Environmental Justice Into Clean Air Act Inspections for Air Toxics

Science.gov (United States)

Project #OPE-FY14-0017, March 7, 2014. The OIG plans to begin the preliminary research phase of an evaluation of the EPA's efforts to incorporate environmental justice into Clean Air Act (CAA) inspections for air toxics.

Race, deprivation, and immigrant isolation: The spatial demography of air-toxic clusters in the continental United States.

Science.gov (United States)

Liévanos, Raoul S

2015-11-01

This article contributes to environmental inequality outcomes research on the spatial and demographic factors associated with cumulative air-toxic health risks at multiple geographic scales across the United States. It employs a rigorous spatial cluster analysis of census tract-level 2005 estimated lifetime cancer risk (LCR) of ambient air-toxic emissions from stationary (e.g., facility) and mobile (e.g., vehicular) sources to locate spatial clusters of air-toxic LCR risk in the continental United States. It then tests intersectional environmental inequality hypotheses on the predictors of tract presence in air-toxic LCR clusters with tract-level principal component factor measures of economic deprivation by race and immigrant status. Logistic regression analyses show that net of controls, isolated Latino immigrant-economic deprivation is the strongest positive demographic predictor of tract presence in air-toxic LCR clusters, followed by black-economic deprivation and isolated Asian/Pacific Islander immigrant-economic deprivation. Findings suggest scholarly and practical implications for future research, advocacy, and policy. Copyright © 2015 Elsevier Inc. All rights reserved.

Pesticide Toxicity Index: a tool for assessing potential toxicity of pesticide mixtures to freshwater aquatic organisms

Science.gov (United States)

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

2014-01-01

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

Active prey selection in two pelagic copepods feeding on potentially toxic and non-toxic dinoflagellates

DEFF Research Database (Denmark)

Schultz, Mette; Kiørboe, Thomas

2009-01-01

Grazing on two red tide dinoflagellates, the potentially toxic Karenia mikimotoi and the non-toxic Gyrodinium instriatum, was examined in two species of marine copepods, Pseudocalanus elongatus and Temora longicornis. Both copepods cleared K. mikimotoi at rates that were a little lower but compar......Grazing on two red tide dinoflagellates, the potentially toxic Karenia mikimotoi and the non-toxic Gyrodinium instriatum, was examined in two species of marine copepods, Pseudocalanus elongatus and Temora longicornis. Both copepods cleared K. mikimotoi at rates that were a little lower...

Future research needs associated with the assessment of potential human health risks from exposure to toxic ambient air pollutants

DEFF Research Database (Denmark)

Möller, Lennart; Schuetzle, Dennis; Autrup, Herman

1994-01-01

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

Possible central nervous system oxygen toxicity seizures among US recreational air or enriched air nitrox open circuit diving fatalities 2004-2013.

Science.gov (United States)

Buzzacott, P; Denoble, P J

2017-01-01

The first diver certification programme for recreational 'enriched air nitrox' (EAN) diving was released in 1985. Concerns were expressed that many EAN divers might suffer central nervous system (CNS) oxygen toxicity seizures and drown. US fatalities on open-circuit scuba occurring between 2004-2013, where the breathing gas was either air or EAN, were identified. Causes of death and preceding circumstances were examined by a medical examiner experienced in diving autopsies. Case notes were searched for witnessed seizures at elevated partial pressures of oxygen. The dataset comprised 344 air divers (86%) and 55 divers breathing EAN (14%). EAN divers' fatal dives were deeper than air divers' (28 msw vs 18 msw, p < 0.0001). Despite this, of the 249 cases where a cause of death was established, only three EAN divers were considered to have possibly died following CNS oxygen toxicity seizures at depth (ppO2 132, 142 and 193 kPa). The analysis of recreational diving fatalities in the US over 10 years found just one death likely from CNS oxygen toxicity among EAN divers. A further two possible, although unlikely, cases were also found. Fears of commonplace CNS oxygen toxicity seizures while EAN diving have not apparently been realized.

EMISSIONS OF ORGANIC AIR TOXICS FROM OPEN ...

Science.gov (United States)

A detailed literature search was performed to collect and collate available data reporting emissions of toxic organic substances into the air from open burning sources. Availability of data varied according to the source and the class of air toxics of interest. Volatile organic compound (VOC) and polycyclic aromatic hydrocarbon (PAH) data were available for many of the sources. Data on semivolatile organic compounds (SVOCs) that are not PAHs were available for several sources. Carbonyl and polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofuran (PCDD/F) data were available for only a few sources. There were several sources for which no emissions data were available at all. Several observations were made including: 1) Biomass open burning sources typically emitted less VOCs than open burning sources with anthropogenic fuels on a mass emitted per mass burned basis, particularly those where polymers were concerned; 2) Biomass open burning sources typically emitted less SVOCs and PAHs than anthropogenic sources on a mass emitted per mass burned basis. Burning pools of crude oil and diesel fuel produced significant amounts of PAHs relative to other types of open burning. PAH emissions were highest when combustion of polymers was taking place; and 3) Based on very limited data, biomass open burning sources typically produced higher levels of carbonyls than anthropogenic sources on a mass emitted per mass burned basis, probably due to oxygenated structures r

Compressed breathing air - the potential for evil from within.

Science.gov (United States)

Millar, Ian L; Mouldey, Peter G

2008-06-01

Human underwater activities rely on an adequate supply of breathable compressed gas, usually air, free from contaminants that could cause incapacitation underwater or post-dive or longer-term health effects. Potentially fatal but well-known hazards are hypoxia secondary to steel cylinder corrosion and carbon monoxide (CO) poisoning due to contaminated intake air. Another phenomenon may be behind some previously unexplained episodes of underwater incapacitation and perhaps death: low-level CO poisoning and/or the effects of gaseous contaminants generated within the compressor, including toluene and other volatile compounds. Many low molecular weight volatile contaminants are anaesthetic and will be potentiated by pressure and nitrogen narcosis. In sub-anaesthetic doses, impaired judgement, lowered seizure threshold and sensitisation of the heart to arrhythmias may occur. Toxic compounds can be volatilised from some compressor oils, especially mineral oils, in overheated compressors, or be created de novo under certain combinations of temperature, humidity and pressure, perhaps catalysed by metal traces from compressor wear and tear. Most volatiles can be removed by activated carbon filtration but many filters are undersized and may overload in hot, moist conditions and with short dwell times. A compressor that passes normal testing could contaminate one or more cylinders after heating up and then return to producing clean air as the filters dry and the systems cool. The scope of this problem is very unclear as air quality is tested infrequently and often inadequately, even after fatalities. More research is needed as well as better education regarding the safe operation and limitations of high-pressure breathing air compressors.

An analysis of candidates for addition to the Clean Air Act list of hazardous air pollutants

Energy Technology Data Exchange (ETDEWEB)

Sonya Lunder; Tracey J. Woodruff; Daniel A. Axelrad [University of California, Berkeley, CA (United States). School of Public Health

2004-02-01

There are 188 air toxics listed as hazardous air pollutants (HAPs) in the Clean Air Act (CAA), based on their potential to adversely impact public health. This paper presents several analyses performed to screen potential candidates for addition to the HAPs list. We analyzed 1086 HAPs and potential HAPs, including chemicals regulated by the state of California or with emissions reported to the Toxics Release Inventory (TRI). HAPs and potential HAPs were ranked by their emissions to air, and by toxicity-weighted (tox-wtd) emissions for cancer and noncancer, using emissions information from the TRI and toxicity information from state and federal agencies. Separate consideration was given for persistent, bioaccumulative toxins (PBTs), reproductive or developmental toxins, and chemicals under evaluation for regulation as toxic air contaminants in California. Forty-four pollutants were identified as candidate HAPs based on three ranking analyses and whether they were a PBT or a reproductive or developmental toxin. Of these, nine qualified in two or three different rankings (ammonia (NH{sub 3}), copper (Cu), Cu compounds, nitric acid (HNO{sub 3}), N-methyl-2-pyrrolidone, sulfuric acid (H{sub 2}SO{sub 4}), vanadium (V) compounds, zinc (Zn), and Zn compounds). This analysis suggests further evaluation of several pollutants for possible addition to the CAA list of HAPs. 28 refs., 2 figs., 11 tabs.

Future research needs associated with the assessment of potential human health risks from exposure to toxic ambient air pollutants

DEFF Research Database (Denmark)

Möller, Lennart; Schuetzle, Dennis; Autrup, Herman

1994-01-01

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

POTENTIAL PATHOPHYSIOLOGICAL MECHANISMS OF ULTRAFINE PARTICLE TOXIC EFFECTS IN HUMANS

Directory of Open Access Journals (Sweden)

JASMINA JOVIĆ-STOŠIĆ

2008-03-01

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

Ionisation detectors as monitors of toxic compounds in air

International Nuclear Information System (INIS)

Leonhardt, J.W.

1994-01-01

Beta particles cause ionisation in gas mixtures. The ions produced provide information on the concentration and identity of trace compounds in ambient air. Modern ionisation detectors use ion mobilities to monitor toxic compounds. Chemical solvent, phosphororganic compounds, PCB and many other toxins can be detected using ion mobility detectors (IMD) in the ppb range or lower. Ion mobility detectors have large potential in industry and research because of their sensitivity, specificity, fast response and relatively low cost. Portable devices and fixed installations are possible. The paper discusses the following topics: (1) ionisation sources in IMD: 63 Ni, 3 H, photoionization and corona discharge, (2) basic principles of ion production, (3) ion collection in IMD, (4) design, gas supply, automatic identification and quantification of IMD data, and (5) selected applications. Advantages and problems with this new type of nuclear analytical instrument are also discussed. (author). 2 refs., 9 figs., 3 tabs

Hazardous air pollutant handbook: measurements, properties, and fate in ambient air

Energy Technology Data Exchange (ETDEWEB)

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

2002-07-01

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

Potential hazard by toxic substances in foods. Environmental protection

Energy Technology Data Exchange (ETDEWEB)

Unterhalt, B

1974-01-01

This paper reviews various toxic substances found in foods. These toxic substances include not only natural occurring toxins but also bacterial food poisons, pesticide residues, heavy metals, and food additives. The potential hazard of each toxic substance is discussed. 74 references.

Benzimidazole for the prevention of toxic effects of air pollutants on plants

Energy Technology Data Exchange (ETDEWEB)

Takaoka, I; Fukuda, M; Kitano, H; Shinohara, T

1974-02-02

Tobacco plants were sprayed with benzimidazole before being exposed to 30 ppM of photochemical oxidants for a period of two hours. The plants were observed 48 hours after exposure and found to have suffered no toxic effects from the oxidants. It may be concluded that benzimidazole is an effective agent for preventing the toxic effects of air pollutants, such as photochemical oxidants on plants.

Toxic and hazardous air pollutants from co-firing biomass fuels, fossil fuels, MSW and RDF

International Nuclear Information System (INIS)

Junge, D.C.

1991-01-01

Toxic and hazardous pollutants are defined and then are considered from the perspective of pollutants which enter the combustion process with the fuel (principally the metals and metallic compounds) and pollutants which are formed as products of incomplete combustion. Control strategies are reviewed through the entire process including fuel preparation and storage, combustion control and the application of air pollution control devices. Measurement techniques for specific toxic and hazardous air pollutants are discussed

Identifying inequitable exposure to toxic air pollution in racialized and low-income neighbourhoods to support pollution prevention

Directory of Open Access Journals (Sweden)

Suzanne Kershaw

2013-05-01

Full Text Available Numerous environmental justice studies have confirmed a relationship between population characteristics such as low-income or minority status and the location of environmental health hazards. However, studies of the health risks from exposure to harmful substances often do not consider their toxicological characteristics. We used two different methods, the unit-hazard and the distance-based approach, to evaluate demographic and socio-economic characteristics of the population residing near industrial facilities in the City of Toronto, Canada. In addition to the mass of air emissions obtained from the national pollutant release inventory (NPRI, we also considered their toxicity using toxic equivalency potential (TEP scores. Results from the unit-hazard approach indicate no significant difference in the proportion of low-income individuals living in host versus non-host census tracts (t(107 = 0.3, P = 0.735. However, using the distance-based approach, the proportion of low-income individuals was significantly higher (+5.1%, t(522 = 6.0, P <0.001 in host tracts, while the indicator for “racialized” communities (“visible minority” was 16.1% greater (t(521 = 7.2, P <0.001 within 2 km of a NPRI facility. When the most toxic facilities by non-carcinogenic TEP score were selected, the rate of visible minorities living near the most toxic NPRI facilities was significantly higher (+12.9%, t(352 = 3.5, P = 0.001 than near all other NPRI facilities. TEP scores were also used to identify areas in Toronto that face a double burden of poverty and air toxics exposure in order to prioritise pollution prevention.

Comparative In Vitro Biological Toxicity of Four Kinds of Air Pollution Particles.

Science.gov (United States)

Shin, Han-Jae; Cho, Hyun Gi; Park, Chang Kyun; Park, Ki Hong; Lim, Heung Bin

2017-10-01

Accumulating epidemiological evidence indicates that exposure to fine air pollution particles (APPs) is associated with a variety of adverse health effects. However, the exact physiochemical properties and biological toxicities of fine APPs are still not well characterized. We collected four types of fine particle (FP) (diesel exhaust particles [DEPs], natural organic combustion [NOC] ash, synthetic organic combustion [SOC] ash, and yellow sand dust [YSD]) and investigated their physicochemical properties and in vitro biological toxicity. DEPs were almost entirely composed of ultrafine particles (UFPs), while the NOC, SOC, and YSD particles were a mixture of UFPs and FPs. The main elements in the DEPs, NOC ash, SOC ash, and YSD were black carbon, silicon, black carbon, and silicon, respectively. DEPs exhibited dose-dependent mutagenicity even at a low dose in Salmonella typhimurium TA 98 and 100 strains in an Ames test for genotoxicity. However, NOC, SOC, and YSD particles did not show any mutagenicity at high doses. The neutral red uptake assay to test cell viability revealed that DEPs showed dose-dependent potent cytotoxicity even at a low concentration. The toxicity of DEPs was relatively higher than that of NOC, SOC, and YSD particles. Therefore, these results indicate that among the four FPs, DEPs showed the highest in vitro biological toxicity. Additional comprehensive research studies such as chemical analysis and in vivo acute and chronic inhalation toxicity tests are necessary to determine and clarify the effects of this air contaminant on human health.

Pilot study investigating ambient air toxics emissions near a Canadian kraft pulp and paper facility in Pictou County, Nova Scotia.

Science.gov (United States)

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

2017-09-01

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

Advanced combustor design concept to control NOx and air toxics

Energy Technology Data Exchange (ETDEWEB)

Eddings, E.G.; Pershing, D.W.; Molina, A.; Sarofim, A.F.; Spinti, J.P.; Veranth, J.

1999-03-29

stabilize slowly mixed flames which have the potential of producing ultra-low NOx levels with high carbon burnout. Also characterize the air toxic emissions from these flames; and Develop new char nitrogen model for use with a comprehensive combustion model that can be applied to the design and analysis of new and existing boilers.

Notification: Background Investigation Services New Assignment Notification: EPA’s Efforts to Incorporate Environmental Justice Into Clean Air Act Inspections for Air Toxics

Science.gov (United States)

The purpose of this memorandum is to notify you that the EPA OIG plans to begin the preliminary research phase of an evaluation of the U.S. EPA's efforts to incorporate environmental justice into Clean Air Act inspections for air toxics.

Evaluate the potential environmental toxicity of quantum dots on ciliated protozoa by microcalorimetry

International Nuclear Information System (INIS)

Xiao, Qi; Huang, Shan; Su, Wei; Li, Peiyuan; Liang, Zuocui; Ou, Jianzhen; Ma, Jianqiang; Liu, Yi

2012-01-01

Highlights: ► The toxic effects of QDs to T. thermophila BF 5 using a TAM air microcalorimeter. ► QDs were acutely toxic for T. thermophila BF 5 growth in a dose-dependent manner. ► The toxicity of different ligands-capped QDs on T. thermophila BF 5 was investigated. ► QDs could be ingested by cells and affect the morphology of T. thermophila BF 5 . - Abstract: In the present study, we evaluated the toxic effects of mercaptoacetic acid (MAA)-capped CdSe QDs and CdSe/ZnS QDs to particle-ingesting model ciliated protozoa Tetrahymena thermophila BF 5 (T. thermophila BF 5 ) by using a TAM air isothermal microcalorimeter. These results suggested that both MAA-CdSe QDs and MAA-CdSe/ZnS QDs were indeed acutely toxic for T. thermophila BF 5 growth in a dose-dependent manner, and the toxicities of both MAA-CdSe QDs and MAA-CdSe/ZnS QDs increased dramatically after UV irradiation due to the liberation of more toxic Cd 2+ , which indicated that the toxicity of MAA-CdSe/ZnS QDs was less than that of MAA-CdSe QDs. Furthermore, the toxicity of different ligands-capped CdSe/ZnS QDs on T. thermophila BF 5 was also investigated. The uptake of MAA-CdSe/ZnS QDs and adenosine 5′-monophosphate (AMP)-CdSe/ZnS QDs by cells and the morphological change during the process of T. thermophila BF 5 growth incubated with these QDs were further studied by fluorescence inverted microscopy.

Air toxic emissions from the combustion of coal: Identifying and quantifying hazardous air pollutants from US coals

Energy Technology Data Exchange (ETDEWEB)

Szpunar, C.B.

1992-09-01

This report addresses the key air toxic emissions likely to emanate from continued and expanded use of domestic coal. It identifies and quantifies those trace elements specified in the US 1990 Clean Air Act Amendments, by tabulating selected characterization data on various source coals by region, state, and rank. On the basis of measurements by various researchers, this report also identifies those organic compounds likely to be derived from the coal combustion process (although their formation is highly dependent on specific boiler configurations and operating conditions).

Air toxic emissions from the combustion of coal: Identifying and quantifying hazardous air pollutants from US coals

International Nuclear Information System (INIS)

Szpunar, C.B.

1992-09-01

This report addresses the key air toxic emissions likely to emanate from continued and expanded use of domestic coal. It identifies and quantifies those trace elements specified in the US 1990 Clean Air Act Amendments, by tabulating selected characterization data on various source coals by region, state, and rank. On the basis of measurements by various researchers, this report also identifies those organic compounds likely to be derived from the coal combustion process (although their formation is highly dependent on specific boiler configurations and operating conditions)

Evaluate the potential environmental toxicity of quantum dots on ciliated protozoa by microcalorimetry

Energy Technology Data Exchange (ETDEWEB)

Xiao, Qi [College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001 (China); State Key Laboratory of Virology, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Huang, Shan, E-mail: huangs@whu.edu.cn [College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001 (China); State Key Laboratory of Virology, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Su, Wei [College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001 (China); Li, Peiyuan [College of Pharmacy, Guangxi Traditional Chinese Medical University, Nanning 530001 (China); Liang, Zuocui; Ou, Jianzhen; Ma, Jianqiang [College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001 (China); Liu, Yi, E-mail: prof.liuyi@263.net [State Key Laboratory of Virology, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China)

2012-11-10

Highlights: Black-Right-Pointing-Pointer The toxic effects of QDs to T. thermophila BF{sub 5} using a TAM air microcalorimeter. Black-Right-Pointing-Pointer QDs were acutely toxic for T. thermophila BF{sub 5} growth in a dose-dependent manner. Black-Right-Pointing-Pointer The toxicity of different ligands-capped QDs on T. thermophila BF{sub 5} was investigated. Black-Right-Pointing-Pointer QDs could be ingested by cells and affect the morphology of T. thermophila BF{sub 5}. - Abstract: In the present study, we evaluated the toxic effects of mercaptoacetic acid (MAA)-capped CdSe QDs and CdSe/ZnS QDs to particle-ingesting model ciliated protozoa Tetrahymena thermophila BF{sub 5} (T. thermophila BF{sub 5}) by using a TAM air isothermal microcalorimeter. These results suggested that both MAA-CdSe QDs and MAA-CdSe/ZnS QDs were indeed acutely toxic for T. thermophila BF{sub 5} growth in a dose-dependent manner, and the toxicities of both MAA-CdSe QDs and MAA-CdSe/ZnS QDs increased dramatically after UV irradiation due to the liberation of more toxic Cd{sup 2+}, which indicated that the toxicity of MAA-CdSe/ZnS QDs was less than that of MAA-CdSe QDs. Furthermore, the toxicity of different ligands-capped CdSe/ZnS QDs on T. thermophila BF{sub 5} was also investigated. The uptake of MAA-CdSe/ZnS QDs and adenosine 5 Prime -monophosphate (AMP)-CdSe/ZnS QDs by cells and the morphological change during the process of T. thermophila BF{sub 5} growth incubated with these QDs were further studied by fluorescence inverted microscopy.

Potential air toxics hot spots in truck terminals and cabs.

Science.gov (United States)

Smith, Thomas J; Davis, Mary E; Hart, Jaime E; Blicharz, Andrew; Laden, Francine; Garshick, Eric

2012-12-01

Hot spots are areas where concentrations of one or more air toxics--organic vapors or particulate matter (PM)--are expected to be elevated. The U.S. Environmental Protection Agency's (EPA*) screening values for air toxics were used in our definition of hot spots. According to the EPA, a screening value "is used to indicate a concentration of a chemical in the air to which a person could be continually exposed for a lifetime ... and which would be unlikely to result in a deleterious effect (either cancer or noncancer health effects)" (U.S. EPA 2006). Our characterization of volatile organic compounds (VOCs; namely 18 hydrocarbons, methyl tert-butyl ether [MTBE], acetone, and aldehydes) was added onto our ongoing National Cancer Institute-funded study of lung cancer and particulate pollutant concentrations (PM with an aerodynamic diameter highways. In Phase 1 of our study, 15 truck terminals across the United States were each visited for five consecutive days. During these site visits, sorbent tubes were used to collect 12-hour integrated samples of hydrocarbons and aldehydes from upwind and downwind fence-line locations as well as inside truck cabs. Meteorologic data and extensive site information were collected with each sample. In Phase 2, repeat visits to six terminals were conducted to test the stability of concentrations across time and judge the representativeness of our previous measurements. During the repeat site visits, the sampling procedure was expanded to include real-time sampling for total hydrocarbon (HC) and PM2.5 at the terminal upwind and downwind sites and inside the truck cabs, two additional monitors in the yard for four-quadrant sampling to better characterize the influence of wind, and indoor sampling in the loading dock and mechanic shop work areas. Mean and median concentrations of VOCs across the sampling locations in and around the truck terminals showed significant variability in the upwind concentrations as well as in the intensity of

Arabidopsis and the Genetic Potential for the Phytoremediation of Toxic Elemental and Organic Pollutants

Science.gov (United States)

Cobbett, Christopher S.; Meagher, Richard B.

2002-01-01

In a process called phytoremediation, plants can be used to extract, detoxify, and/or sequester toxic pollutants from soil, water, and air. Phytoremediation may become an essential tool in cleaning the environment and reducing human and animal exposure to potential carcinogens and other toxins. Arabidopsis has provided useful information about the genetic, physiological, and biochemical mechanisms behind phytoremediation, and it is an excellent model genetic organism to test foreign gene expression. This review focuses on Arabidopsis studies concerning: 1) the remediation of elemental pollutants; 2) the remediation of organic pollutants; and 3) the phytoremediation genome. Elemental pollutants include heavy metals and metalloids (e.g., mercury, lead, cadmium, arsenic) that are immutable. The general goal of phytoremediation is to extract, detoxify, and hyperaccumulate elemental pollutants in above-ground plant tissues for later harvest. A few dozen Arabidopsis genes and proteins that play direct roles in the remediation of elemental pollutants are discussed. Organic pollutants include toxic chemicals such as benzene, benzo(a)pyrene, polychlorinated biphenyls, trichloroethylene, trinitrotoluene, and dichlorodiphenyltrichloroethane. Phytoremediation of organic pollutants is focused on their complete mineralization to harmless products, however, less is known about the potential of plants to act on complex organic chemicals. A preliminary survey of the Arabidopsis genome suggests that as many as 700 genes encode proteins that have the capacity to act directly on environmental pollutants or could be modified to do so. The potential of the phytoremediation proteome to be used to reduce human exposure to toxic pollutants appears to be enormous and untapped. PMID:22303204

Cleaning products and air fresheners: exposure to primary and secondary air pollutants

DEFF Research Database (Denmark)

Nazaroff, W.; Weschler, Charles J.

2004-01-01

Building occupants, including cleaning personnel, are exposed to a wide variety of airborne chemicals when cleaning agents and air fresheners are used in buildings. Certain of these chemicals are listed by the state of California as toxic air contaminants (TACs) and a subset of these are regulated...... by the US federal government as hazardous air pollutants (HAPs). California's Proposition 65 list of species recognized as carcinogens or reproductive toxicants also includes constituents of certain cleaning products and air fresheners. In addition, many cleaning agents and air fresheners contain chemicals...... that can react with other air contaminants to yield potentially harmful secondary products. For example, terpenes can react rapidly with ozone in indoor air generating many secondary pollutants, including TACs such as formaldehyde. Furthermore, ozone-terpene reactions produce the hydroxyl radical, which...

Toxic potential of palytoxin.

Science.gov (United States)

Patocka, Jiří; Gupta, Ramesh C; Wu, Qing-hua; Kuca, Kamil

2015-10-01

This review briefly describes the origin, chemistry, molecular mechanism of action, pharmacology, toxicology, and ecotoxicology of palytoxin and its analogues. Palytoxin and its analogues are produced by marine dinoflagellates. Palytoxin is also produced by Zoanthids (i.e. Palythoa), and Cyanobacteria (Trichodesmium). Palytoxin is a very large, non-proteinaceous molecule with a complex chemical structure having both lipophilic and hydrophilic moieties. Palytoxin is one of the most potent marine toxins with an LD50 of 150 ng/kg body weight in mice exposed intravenously. Pharmacological and electrophysiological studies have demonstrated that palytoxin acts as a hemolysin and alters the function of excitable cells through multiple mechanisms of action. Palytoxin selectively binds to Na(+)/K(+)-ATPase with a Kd of 20 pM and transforms the pump into a channel permeable to monovalent cations with a single-channel conductance of 10 pS. This mechanism of action could have multiple effects on cells. Evaluation of palytoxin toxicity using various animal models revealed that palytoxin is an extremely potent neurotoxin following an intravenous, intraperitoneal, intramuscular, subcutaneous or intratracheal route of exposure. Palytoxin also causes non-lethal, yet serious toxic effects following dermal or ocular exposure. Most incidents of palytoxin poisoning have manifested after oral intake of contaminated seafood. Poisonings in humans have also been noted after inhalation, cutaneous/systemic exposures with direct contact of aerosolized seawater during Ostreopsis blooms and/or through maintaining aquaria containing Cnidarian zoanthids. Palytoxin has a strong potential for toxicity in humans and animals, and currently this toxin is of great concern worldwide.

Potential enzyme toxicity of oxytetracycline to catalase

Energy Technology Data Exchange (ETDEWEB)

Zhenxing, Chi; Rutao, Liu; Zhang Hao, E-mail: Trutaoliu@sdu.edu.cn [School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment and Health, Shandong Province, 27 Shanda South Road, Jinan 250100 (China)

2010-10-15

Oxytetracycline (OTC) is a kind of widely used veterinary drugs. The residue of OTC in the environment is potentially harmful. In the present work, the non-covalent toxic interaction of OTC with catalase was investigated by the fluorescence spectroscopy, UV-vis absorption and circular dichroism (CD) spectroscopy at physiological pH 7.4. OTC can interact with catalase to form a complex mainly by van der Waals' interactions and hydrogen bonds with one binding site. The association constants K were determined to be K{sub 293K} = 7.09 x 10{sup 4} L mol{sup -1} and K{sub 311K} = 3.31 x 10{sup 4} L mol{sup -1}. The thermodynamic parameters ({Delta}H{sup o}, {Delta}G{sup o} and {Delta}S{sup o}) of the interaction were calculated. Based on the Foerster theory of non-radiative energy transfer, the distance between bound OTC and the tryptophan residues of catalase was determined to be 6.48 nm. The binding of OTC can result in change of the micro-environment of the tryptophan residues and the secondary structure of catalase. The activity of catalase was also inhibited for the bound OTC. This work establishes a new strategy to probe the enzyme toxicity of veterinary drug residues and is helpful for clarifying the molecular toxic mechanism of OTC in vivo. The established strategy can be used to investigate the potential enzyme toxicity of other small organic pollutants and drugs.

Potential enzyme toxicity of oxytetracycline to catalase

International Nuclear Information System (INIS)

Chi Zhenxing; Liu Rutao; Zhang Hao

2010-01-01

Oxytetracycline (OTC) is a kind of widely used veterinary drugs. The residue of OTC in the environment is potentially harmful. In the present work, the non-covalent toxic interaction of OTC with catalase was investigated by the fluorescence spectroscopy, UV-vis absorption and circular dichroism (CD) spectroscopy at physiological pH 7.4. OTC can interact with catalase to form a complex mainly by van der Waals' interactions and hydrogen bonds with one binding site. The association constants K were determined to be K 293K = 7.09 x 10 4 L mol -1 and K 311K = 3.31 x 10 4 L mol -1 . The thermodynamic parameters (ΔH o , ΔG o and ΔS o ) of the interaction were calculated. Based on the Foerster theory of non-radiative energy transfer, the distance between bound OTC and the tryptophan residues of catalase was determined to be 6.48 nm. The binding of OTC can result in change of the micro-environment of the tryptophan residues and the secondary structure of catalase. The activity of catalase was also inhibited for the bound OTC. This work establishes a new strategy to probe the enzyme toxicity of veterinary drug residues and is helpful for clarifying the molecular toxic mechanism of OTC in vivo. The established strategy can be used to investigate the potential enzyme toxicity of other small organic pollutants and drugs.

Potentials and limitations of hazard indices for the determination of risk potentials of disposed toxic wastes

International Nuclear Information System (INIS)

Kirchner, Gerald

1989-01-01

Hazard indices are often used for the determination of risk potentials arising from the geological disposal of toxic wastes. They are based on simplified models for the calculation of potential health effects caused by the wastes. The attractiveness of hazard indices lies in their simplicity which nevertheless results in reliable data on necessary isolation times and the most toxic nuclides of a waste. They also make possible comparisons of the potential risks of different wastes. After a discussion of the processes that control the behavior of toxic wastes in the environment after a failure of the geological barriers, a new hazard index is presented. Originally developed for nuclear wastes, it is the first which involves the joint consideration of the composition of a waste, the probability for transport of waste nuclides to man, their toxicity, and the time-dependent changes of the risk potentials which are caused by radioactive buildup and decay processes after the waste has entered the biosphere. The new hazard index makes possible the calculation of risk potentials at a given time of release and time period of concern thereafter. Sample calculations for different nuclear wastes show the importance of the model improvements on resulting time-dependent risk potentials. Applicability of the new hazard index to non-nuclear wastes is described. Potentials and limitations of comparative risk assessments using hazard indices are discussed. (author)

[Research progress on potential liver toxic components in traditional Chinese medicine].

Science.gov (United States)

Wu, Hao; Zhong, Rong-Ling; Xia, Zhi; Huang, Hou-Cai; Zhong, Qing-Xiang; Feng, Liang; Song, Jie; Jia, Xiao-Bin

2016-09-01

In recent years, the proportion of traditional Chinese medicine in scientific research and its clinical use increased gradually. The research result also becomes more and more valuable, but in the process of using traditional Chinese medicine, it also needs to pay more attention. With the gradual deepening of the toxicity of traditional Chinese medicine, some traditional Chinese medicines have also been found to have the potential toxicity, with the exception of some traditional toxicity Chinese medicine. Traditional Chinese medicine in the growth, processing, processing, transportation and other aspects of pollution or deterioration will also cause the side effects to the body. Clinical practice should be based on the theory of traditional Chinese medicine to guide rational drug use and follow the symptomatic medication, the principle of proper compatibility. The constitution of the patients are different, except for a few varieties of traditional Chinese medicines are natural herbs with hepatotoxicity, liver toxicity of most of the traditional Chinese medicine has idiosyncratic features. The liver plays an important role in drug metabolism. It is easy to be damaged by drugs. Therefore, the study of traditional Chinese medicine potential liver toxicity and its toxic components has become one of the basic areas of traditional Chinese medicine research. Based on the review of the literatures, this paper summarizes the clinical classification of liver toxicity, the pathogenesis of target cell injury, and systematically summarizes the mechanism of liver toxicity and toxic mechanism of traditional Chinese medicine. This paper provided ideas for the study of potential liver toxicity of traditional Chinese medicine and protection for clinical safety of traditional Chinese medicine. Copyright© by the Chinese Pharmaceutical Association.

Justice in the Air: Tracking Toxic Pollution from America's Industries and Companies to Our States, Cities, and Neighborhoods

OpenAIRE

Michael Ash; James Boyce; Grace Chang; Justin Scoggins; Manuel Pastor

2009-01-01

This new environmental justice study, (co-authored by PERI’s James Boyce, Michael Ash, & Grace Chang, along with Manuel Pastor, Justin Scoggins, & Jennifer Tran of the Program for Environmental and Regional Equity at the University of Southern California) examines not only who receives the disproportionate share of toxic air releases -- low-income communities and people of color -- but who is releasing them. Justice in the Air: Tracking Toxic Pollution from America's Industries and Companies ...

Potential fluoride toxicity from oral medicaments: A review

OpenAIRE

Rizwan Ullah; Muhammad Sohail Zafar; Nazish Shahani

2017-01-01

The beneficial effects of fluoride on human oral health are well studied. There are numerous studies demonstrating that a small amount of fluoride delivered to the oral cavity decreases the prevalence of dental decay and results in stronger teeth and bones. However, ingestion of fluoride more than the recommended limit leads to toxicity and adverse effects. In order to update our understanding of fluoride and its potential toxicity, we have described the mechanisms of fluoride metabolism, tox...

Toxic Potential of Carcinogenic Polycyclic Aromatic Hydrocarbons ...

African Journals Online (AJOL)

Toxic Potential of Carcinogenic Polycyclic Aromatic Hydrocarbons (cPAHs) and Heavy Metal in Crude Oil from Gokana Area, Rivers State, Nigeria. ... Considerable caution should be applied in exploration, exposure and distribution of the crude oil through protected and well maintained pipelines to avoid the possible ...

Projections of air toxic emissions from coal-fired utility combustion: Input for hazardous air pollutant regulators

International Nuclear Information System (INIS)

Szpunar, C.B.

1993-01-01

The US Environmental Protection Agency (EPA) is required by the 1990 CAAA to promulgate rules for all ''major'' sources of any of these HAPs. According to the HAPs section of the new Title III, any stationary source emitting 10 tons per year (TPY) of one HAP or 25 TPY of a combination of HAPs will be considered and designated a major source. In contrast to the original National Emission Standards for Hazardous Air Pollutants (NESHAP), which were designed to protect public health to ''an ample margin of safety,'' the new Title III, in its first phase, will regulate by industrial category those sources emitting HAPs in excess of the 10/25-TPY threshold levels, regardless of health risks. The trace elements normally associated with coal mineral matter and the various compounds formed during coal combustion have the potential to produce hazardous air toxic emissions from coal-fired electric utilities. Under Title III, the EPA is required to perform certain studies, prior to any regulation of electric utilities; these studies are currently underway. Also, the US Department of Energy (DOE) maintains a vested interest in addressing those energy policy questions affecting electric utility generation, coal mining, and steel producing critical to this country's economic well-being, where balancing the costs to the producers and users of energy with the benefits of environmental protection to the workers and the general populace remains of significant concern

Assessing the influence of traffic-related air pollution on risk of term low birth weight on the basis of land-use-based regression models and measures of air toxics.

Science.gov (United States)

Ghosh, Jo Kay C; Wilhelm, Michelle; Su, Jason; Goldberg, Daniel; Cockburn, Myles; Jerrett, Michael; Ritz, Beate

2012-06-15

Few studies have examined associations of birth outcomes with toxic air pollutants (air toxics) in traffic exhaust. This study included 8,181 term low birth weight (LBW) children and 370,922 term normal-weight children born between January 1, 1995, and December 31, 2006, to women residing within 5 miles (8 km) of an air toxics monitoring station in Los Angeles County, California. Additionally, land-use-based regression (LUR)-modeled estimates of levels of nitric oxide, nitrogen dioxide, and nitrogen oxides were used to assess the influence of small-area variations in traffic pollution. The authors examined associations with term LBW (≥37 weeks' completed gestation and birth weight variations) resulted in 2%-5% increased odds per interquartile-range increase in third-trimester benzene, toluene, ethyl benzene, and xylene exposures, with some confidence intervals containing the null value. This analysis highlights the importance of both spatial and temporal contributions to air pollution in epidemiologic birth outcome studies.

Chemical concentrations, exposures, health risks by census tract from National Scale Air Toxics Assessment (NATA)

Data.gov (United States)

U.S. Environmental Protection Agency — Chemical concentrations, exposures, health risks by census tract for the United States from National Scale Air Toxics Assessment (NATA). This dataset is associated...

Minimizing the water and air impacts of unconventional energy extraction

Science.gov (United States)

Jackson, R. B.

2014-12-01

Unconventional energy generates income and, done well, can reduce air pollution compared to other fossil fuels and even water use compared to fossil fuels and nuclear energy. Alternatively, it could slow the adoption of renewables and, done poorly, release toxic chemicals into water and air. Based on research to date, some primary threats to water resources come from surface spills, wastewater disposal, and drinking-water contamination through poor well integrity. For air resources, an increase in volatile organic compounds and air toxics locally is a potential health threat, but the switch from coal to natural gas for electricity generation will reduce sulfur, nitrogen, mercury, and particulate pollution regionally. Critical needs for future research include data for 1) estimated ultimate recovery (EUR) of unconventional hydrocarbons; 2) the potential for further reductions of water requirements and chemical toxicity; 3) whether unconventional resource development alters the frequency of well-integrity failures; 4) potential contamination of surface and ground waters from drilling and spills; and 5) the consequences of greenhouse gases and air pollution on ecosystems and human health.

Hazardous Air Pollutants

Science.gov (United States)

... Search Main menu Environmental Topics Air Bed Bugs Chemicals and Toxics Environmental Information by Location Greener Living Health Land, ... regulate toxic air pollutants, also known as air toxics, from categories of industrial facilities in two phases . About Hazardous Air Pollutants ...

Toxic Potential of Carcinogenic Polycyclic Aromatic Hydrocarbons ...

African Journals Online (AJOL)

DR. GODSON

the levels of PAHs and cPAHs in crude oil samples from Gokana area and using the data to determine the ... Exploration and production activities of petroleum in ... discharges of crude oil to the environment which ... equivalent concentration of cPAHs in the soil around ... in the crude oil and establish its potential toxicity risk.

Comprehensive assessment of toxic emissions from coal-fired power plants

International Nuclear Information System (INIS)

Brown, T.D.; Schmidt, C.E.; Radziwon, A.S.

1991-01-01

The Pittsburgh Energy Technology Center (PETC) of the US Department of Energy (DOE) has two current investigations, initiated before passage of the Clean Air Act Amendment (CAAA), that will determine the air toxic emissions from coal-fired electric utilities. DOE has contracted with Battelle Memorial Institute and Radian corporation to conduct studies focusing on the potential air toxics, both organic and inorganic, associated with different size fractions of fine particulate matter emitted from power plant stacks. Table 2 indicates the selected analytes to be investigated during these studies. PETC is also developing guidance on the monitoring of Hazardous Air Pollutants (HAPS) to be incorporated in the Environmental Monitoring plans for the demonstration projects in its Clean Coal Technology Program

Pollution of atmospheric air with toxic and radioactive particulate matter investigated by means of nuclear techniques

International Nuclear Information System (INIS)

Jagielak, J.

1978-01-01

The application of spectrometric methods of nuclear techniques to the investigations of atmospheric air pollution by toxic and radioactive elements and results of these investigations conducted in the highly industrialized and urbanized regions of Poland have been presented. The method of precipitation of the samples, the measurements and analysis of radiation spectra of alpha and gamma radiation emitted by isotopes present in the samples have been described. The concentrations of toxic metal dust in the air have been evaluated by neutron activation and X-ray fluorescence analysis. Appropriate methods of measurement, calibration of instrument and the discussion of results have been presented. The work presents the results of investigations performed in Siersza within the years 1973-1974 and in Warsaw in the period of 1975-1977, which have permitted to estimate the mean monthly values of concentration in the atmospheric air of the following radioisotopes: 7 Be, 54 Mn, 95 Zr, 103 Ru, 106 Ru, 125 Sb, 131 I, 137 Cs, 140 Ba, 141 Ce, 144 Ce, 226 Ra, Th-nat, U-nat and the following stable elements: Sc, Cr, Fe, Co, Zn, As, Se, Sb, W, Pb. The analysis of changes in concentration of each particular artificial radioisotope in the air for the region of Poland in connection with Chinese nuclear explosions have been given. On the basis of the performed environmental investigations the method of analysis of relations between the concentrations of particular elements present in the dust has been discussed. The applications of this method have been presented. The hazard to the population and the environment caused by the radioactive and toxic dust present in the atmospheric air has been estimated. (author)

Toxicity and elemental composition of particulate matter from outdoor and indoor air of elementary schools in Munich, Germany.

Science.gov (United States)

Oeder, S; Dietrich, S; Weichenmeier, I; Schober, W; Pusch, G; Jörres, R A; Schierl, R; Nowak, D; Fromme, H; Behrendt, H; Buters, J T M

2012-04-01

Outdoor particulate matter (PM(10)) is associated with detrimental health effects. However, individual PM(10) exposure occurs mostly indoors. We therefore compared the toxic effects of classroom, outdoor, and residential PM(10). Indoor and outdoor PM(10) was collected from six schools in Munich during teaching hours and in six homes. Particles were analyzed by scanning electron microscopy and X-ray spectroscopy (EDX). Toxicity was evaluated in human primary keratinocytes, lung epithelial cells and after metabolic activation by several human cytochromes P450. We found that PM(10) concentrations during teaching hours were 5.6-times higher than outdoors (117 ± 48 μg/m(3) vs. 21 ± 15 μg/m(3), P particle number), organic (29%, probably originating from human skin), and Ca-carbonate particles (12%, probably originating from paper). Outdoor PM contained more Ca-sulfate particles (38%). Indoor PM at 6 μg/cm(2) (10 μg/ml) caused toxicity in keratinocytes and in cells expressing CYP2B6 and CYP3A4. Toxicity by CYP2B6 was abolished with the reactive oxygen species scavenger N-acetylcysteine. We concluded that outdoor PM(10) and indoor PM(10) from homes were devoid of toxicity. Indoor PM(10) was elevated, chemically different and toxicologically more active than outdoor PM(10). Whether the effects translate into a significant health risk needs to be determined. Until then, we suggest better ventilation as a sensible option. Indoor air PM(10) on an equal weight base is toxicologically more active than outdoor PM(10). In addition, indoor PM(10) concentrations are about six times higher than outdoor air. Thus, ventilation of classrooms with outdoor air will improve air quality and is likely to provide a health benefit. It is also easier than cleaning PM(10) from indoor air, which has proven to be tedious. © 2011 John Wiley & Sons A/S.

Developmental toxicity of engineered nanomaterials

DEFF Research Database (Denmark)

Hougaard, Karin S.; Hansen, Jitka S.; Jackson, Petra

2016-01-01

Study of air pollution indicates that minute particles may adversely interfere with pregnancy and fetal development. As engineering of nanoparticles have emerged, so has concern that these might interfere with reproductive and developmental functions. This is because nanotechnology may potentially...... increase the overall particle burden in air and introduce particles with novel characteristics and surface reactivity. To evaluate safety for pregnant women, we have studied developmental toxicity of engineered nanoparticles (ENPs), following exposure of pregnant mice by inhalation (ENPs of titanium...

Acute aquatic toxicity and biodegradation potential of biodiesel fuels

International Nuclear Information System (INIS)

Haws, R.A.; Zhang, X.; Marshall, E.A.; Reese, D.L.; Peterson, C.L.; Moeller, G.

1995-01-01

Recent studies on the biodegradation potential and aquatic toxicity of biodiesel fuels are reviewed. Biodegradation data were obtained using the shaker flask method observing the appearance of CO 2 and by observing the disappearance of test substance with gas chromatography. Additional BOD 5 and COD data were obtained. The results indicate the ready biodegradability of biodiesel fuels as well as the enhanced co-metabolic biodegradation of biodiesel and petroleum diesel fuel mixtures. The study examined reference diesel, neat soy oil, neat rape oil, and the methyl and ethyl esters of these vegetable oils as well as various fuel blends. Acute toxicity tests on biodiesel fuels and blends were performed using Oncorhynchus mykiss (Rainbow Trout) in a static non-renewal system and in a proportional dilution flow replacement system. The study is intended to develop data on the acute aquatic toxicity of biodiesel fuels and blends under US EPA Good Laboratory Practice Standards. The test procedure is designed from the guidelines outlined in Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms and the Fish Acute Aquatic Toxicity Test guideline used to develop aquatic toxicity data for substances subject to environmental effects test regulations under TSCA. The acute aquatic toxicity is estimated by an LC50, a lethal concentration effecting mortality in 50% of the test population

Biodiesel and Cold Temperature Effects on Speciated Mobile Source Air Toxics from Modern Diesel Trucks

Science.gov (United States)

Speciated volatile organic compounds (VOCs) with a particular focus on mobile source air toxics (MSATs) were measured in diesel exhaust from three heavy-duty trucks equipped with modern aftertreatment technologies. Emissions testing was conducted on a temperature controlled chass...

Biodiesel and Cold Temperature Effect on Speciated Mobile Source Air Toxics from Modern Diesel Trucks

Science.gov (United States)

Speciated volatile organic compounds (VOCs) with a particular focus on mobile source air toxics (MSATs) were measured in diesel exhaust from three heavy-duty trucks equipped with modern aftertreatment technologies. Emissions testing was conducted on a temperature controlled chass...

Air Pollution Potential from Electroplating Operations.

Science.gov (United States)

Diamond, Philip

Measurements were made of emission rates from electroplating operations considered to have maximum air pollution potential. Sampling was performed at McClellan and additional data from a previous survey at Hill Air Force Base was used. Values obtained were extremely low. Based on existing Federal standards, no collectors are specifically required…

EXTRAN: A computer code for estimating concentrations of toxic substances at control room air intakes

International Nuclear Information System (INIS)

Ramsdell, J.V.

1991-03-01

This report presents the NRC staff with a tool for assessing the potential effects of accidental releases of radioactive materials and toxic substances on habitability of nuclear facility control rooms. The tool is a computer code that estimates concentrations at nuclear facility control room air intakes given information about the release and the environmental conditions. The name of the computer code is EXTRAN. EXTRAN combines procedures for estimating the amount of airborne material, a Gaussian puff dispersion model, and the most recent algorithms for estimating diffusion coefficients in building wakes. It is a modular computer code, written in FORTRAN-77, that runs on personal computers. It uses a math coprocessor, if present, but does not require one. Code output may be directed to a printer or disk files. 25 refs., 8 figs., 4 tabs

Up the stack : coal-fired electricity's toxic impact : an OCAA air quality report

International Nuclear Information System (INIS)

Rang, S.

2002-07-01

Ontario Power Generation (OPG) must report annually its releases and transfers of 268 chemicals to the federal National Pollutant Release Inventory (NPRI). Each OPG facility reports the amount of chemicals released to the air, land, water and injected under ground at the facility site. The facilities must also report the amount of chemicals that are transferred off-site for treatment, sewage, disposal, recycling or energy recovery. In 1999 and 2000, atmospheric releases from OPG's coal-fired plants accounted for a significant percentage of the total pollutants released for Ontario and Canada. OPG's facilities are often in the top 5 in Ontario and Canada for releases of various chemicals, including persistent toxic chemicals. In 1999, the Nanticoke coal-fired power plant on Lake Erie was ranked first in Canada for releases to the air. Data reported for the 1999 and 2000 reporting period for dioxins and furans, hexachlorobenzene, mercury, metals (chromium, nickel and arsenic), and acid gases such as hydrochloric acid, hydrogen fluoride, and sulphuric acid clearly indicates that OPG coal-fired plants are a leading source of air pollution in Canada and Ontario. The Ontario Clean Air Alliance suggests the data is sufficient to phase-out the use of coal for power generation in Ontario. It recommends conserving energy and replacing coal-fired power with renewable energy sources such as wind and water power. Converting coal facilities to high-efficiency natural gas units would also reduce the toxic impacts of OPG's coal-fired power plants. As an immediate first step, it was recommended that the government should ban non-emergency exports of coal-fired electricity during smog-alert periods in Ontario. 11 tabs

Toxic assessment of urban atmospheric particle-bound PAHs: Relevance of composition and particle size in Barcelona (Spain)

International Nuclear Information System (INIS)

Mesquita, Sofia Raquel; Drooge, Barend L. van; Reche, Cristina; Guimarães, Laura; Grimalt, Joan O.; Barata, Carlos; Piña, Benjamin

2014-01-01

Zebrafish embryotoxicity and dioxin-like activity levels were tested for particulate air samples from an urban background site in Barcelona (Spain). Samples were collected during 14 months, and maximal values for both biological activities corresponded to samples collected during late autumn months, correlating with elevated PAH levels. Vehicle and combustion emissions appeared as the potentially most toxic sources, whereas total PM mass and mineral content appeared to be poor predictors of the biological activity of the samples. Samples simultaneously collected at different particle size cut-offs (10, 2.5, and 1 μm) did not differ significantly in dioxin-like PAH levels and biological activity, indicating that the sub-micron particle fraction (PM 1 ) concentrated essentially all observed toxicity. Our results support the need for a tighter control on sub-micron particle emissions and show that total PM mass and, particularly, PM 10 , may not fully characterize the toxic potential of air samples. Highlights: • Dioxin-like activity was found in all air particle samples collected in Barcelona. • 50% of the samples showed different levels of fish embryotoxicity. • Toxic effects associated to PAHs and linked to vehicle and combustion emissions. • The toxicity was not correlated to PM mass or mineral content. • The sub-micron particle fraction PM 1 concentrated essentially all observed toxicity. -- In vivo toxic effects associated to sub-micron urban air particles from combustion and vehicle emissions

Air Toxics Emissions from Open Burning of Crop Residues in Southeast Asia

Science.gov (United States)

KIM Oanh, N. T.; Permadi, D. A.; Hopke, P. K.; Smith, K. R.; Nguyet, D. A.

2016-12-01

Agricultural crops production in Southeast Asia (SEA) increases annually to meet domestic consumption of growing population and also for export. Crop residue open burning (CROB) is commonly practiced by farmers to quickly dispose of huge amounts of the agricultural waste, such as rice straw, generated after each crop cycle. This CROB activity emits various toxic air pollutants as well as short-lived climate pollutants such as black carbon particles. Our study focused on quantifying the 2015 annual emissions of semi-volatile organic compounds including polycyclic aromatic hydrocarbons (PAHs), dioxins/furans (PCDD/PCDF), organochlorine pesticides (OCP), along with other conventional trace gases, particulate matter, and greenhouse gases from CROB in 10 major agricultural crop producing SEA countries. Crop production statistics and current field OB practices were gathered from our primary surveys and relevant secondary data sources. Emission factors for rice straw and maize residue burning were taken mainly from our measurements in Thailand while for other crops relevant published data were used. The best emission estimates of air toxics from CROB in SEA were 112 g-TEQ/yr of PCDD/PCDF, 33 t/yr of OCP, and 25 Gg/yr of total PAH of which the well-known carcinogenic benzo[a]pyrene was 0.3 Gg/yr. The CROB of rice production had the highest shares of emissions (33-95%) among considered 8 crop types. Indonesia was the top contributor to the total SEA emissions (30-45%) followed by Vietnam (16-26%), Thailand (6-22%) and Myanmar (5-18%). The spatial distributions of emissions, 0.1º x 0.1º, for each specie were prepared using MODIS land cover data. Temporally, higher emissions were observed in the harvesting months of the main rice crops. This emissions database can be used in regional air quality modeling studies to assess the impacts of CROB activity and to promote non-open burning alternatives.

Air conditioning systems as non-infectious health hazards inducing acute respiratory symptoms.

Science.gov (United States)

Gerber, Alexander; Fischer, Axel; Willig, Karl-Heinz; Groneberg, David A

2006-04-01

Chronic and acute exposure to toxic aerosols belongs to frequent causes of airway diseases. However, asthma attacks due to long-distance inhalative exposure to organic solvents, transmitted via an air condition system, have not been reported so far. The present case illustrates the possibility of air conditioning systems as non-infectious health hazards in occupational medicine. So far, only infectious diseases such as legionella pneumophila pneumonia have commonly been associated to air-conditioning exposures but physicians should be alert to the potential of transmission of toxic volatile substances via air conditioning systems. In view of the events of the 11th of September 2001 with a growing danger of large building terrorism which may even use air conditioning systems to transmit toxins, facility management security staff should be alerted to possible non-infectious toxic health hazards arising from air-conditioning systems.

Modeling the effects of reformulated gasoline usages on ambient concentrations of ozone and five air toxics

International Nuclear Information System (INIS)

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

1993-01-01

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

Development of Comparative Toxicity Potentials of TiO2 Nanoparticles for Use in Life Cycle Assessment

DEFF Research Database (Denmark)

Ettrup, Kim; Kounina, Anna; Hansen, Steffen Foss

2017-01-01

for TiO2 nanoparticles (TiO2-NP) for use in LCA. We adapted the USEtox 2.0 consensus model to integrate the SimpleBox4Nano fate model, and we populated the resulting model with TiO2-NP specific data. We thus calculated CTP values for TiO2 nanoparticles for air, water, and soil emission compartments...... in earlier studies. Assumptions, which were performed in those previous studies because of lack of data and knowledge at the time they were made, primarily explain such discrepancies. For future assessment of potential toxic impacts of TiO2 nanoparticles in LCA studies, we therefore recommend the use of our......Studies have shown that releases of nanoparticles may take place through the life cycle of products embedding nanomaterials, thus resulting in potential impacts on ecosystems and human health. While several life cycle assessment (LCA) studies have assessed such products, only a few of them have...

Criteria and air-toxic emissions from in-use automobiles in the National Low-Emission Vehicle program.

Science.gov (United States)

Baldauf, Rich W; Gabele, Pete; Crews, William; Snow, Richard; Cook, J Rich

2005-09-01

The U.S. Environmental Protection Agency (EPA) implemented a program to identify tailpipe emissions of criteria and air-toxic contaminants from in-use, light-duty low-emission vehicles (LEVs). EPA recruited 25 LEVs in 2002 and measured emissions on a chassis dynamometer using the cold-start urban dynamometer driving schedule of the Federal Test Procedure. The emissions measured included regulated pollutants, particulate matter, speciated hydrocarbon compounds, and carbonyl compounds. The results provided a comparison of emissions from real-world LEVs with emission standards for criteria and air-toxic compounds. Emission measurements indicated that a portion of the in-use fleet tested exceeded standards for the criteria gases. Real-time regulated and speciated hydrocarbon measurements demonstrated that the majority of emissions occurred during the initial phases of the cold-start portion of the urban dynamometer driving schedule. Overall, the study provided updated emission factor data for real-world, in-use operation of LEVs for improved emissions modeling and mobile source inventory development.

Proceedings: Second international conference on managing hazardous air pollutants, 1993

International Nuclear Information System (INIS)

Chow, W.; Levin, L.

1994-09-01

This volume contains the Proceedings of the Second International Conference on Managing Hazardous Air Pollutants, held in Washington, DC on July 13--15, 1993. This conference provided an important forum for sharing information and strategies at a critical time for electric utilities in the US and elsewhere. As mandated by the Clean Air Act Amendments of 1990, the US EPA is currently conducting a risk analysis of air toxic emissions from power plants which is expected in November 1995. This conference presented the results of recent research conducted by the EPA and others that may eventually be reflected in an assessment of power plant risks. New research in a number of areas will provide important inputs to a comprehensive and credible risk assessment. These research areas include the concentrations of toxic contaminants in fossil fuels, the development and testing of improved methods for measuring toxics in power plant emissions, the effectiveness of control devices in removing specific air toxics, the transport and dispersion of toxics through the air and other media, and the potential responses of the human body and environment to exposure to these pollutants. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database

Distribution of potentially toxic elements in urban soils of Bratislava; Distribucia potencialne toxickych prvkov v urbannych podach Bratislavy

Energy Technology Data Exchange (ETDEWEB)

Lahka, L.; Tatarkova, V.; Toth, R. [Univerzita Komenskeho, Prirodovedecka fakulta, Katedra geochemie, 84215 Bratislava (Slovakia)

2013-04-16

Potentially toxic elements naturally occur in soils, but their contents are increased in urban environment due to anthropogenic activities. The main sources of urban soil contamination with potentially toxic elements are chemical, energetic, building and blowing industry, engineering, traffic and municipal waste incineration plants. Contaminated urban soils can pose significant risks to human health trough dust inhalation, soil ingestion, and dermal contact. The primary objectives of the present study were: to assess concentrations of potentially toxic elements in soils of nursery schools, to investigate relationships between potentially toxic elements and physicochemical properties of soils, to identify the main possible sources. (authors)

Acute embryo toxicity and teratogenicity of three potential biofuels also used as flavor or solvent

Energy Technology Data Exchange (ETDEWEB)

Bluhm, Kerstin; Seiler, Thomas-Benjamin [RWTH Aachen University, Institute for Environmental Research, Worringerweg 1, 52074 Aachen (Germany); Anders, Nico [RWTH Aachen University, Aachener Verfahrenstechnik — Enzyme Process Technology, Worringerweg 1, 52074 Aachen (Germany); Klankermayer, Jürgen [RWTH Aachen University, Institut für Technische und Makromolekulare Chemie, Worringerweg 1, 52074 Aachen (Germany); Schaeffer, Andreas [RWTH Aachen University, Institute for Environmental Research, Worringerweg 1, 52074 Aachen (Germany); Chongqing University, College of Resources and Environmental Science, Chongqing 400715 (China); Nanjing University, State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing 210093 (China); Hollert, Henner, E-mail: Henner.Hollert@bio5.rwth-aachen.de [RWTH Aachen University, Institute for Environmental Research, Worringerweg 1, 52074 Aachen (Germany); Chongqing University, College of Resources and Environmental Science, Chongqing 400715 (China); Nanjing University, State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing 210093 (China); Tongji University, College of Environmental Science and Engineering and State Key Laboratory of Pollution Control and Resource Reuse, Shanghai 200092 (China)

2016-10-01

The demand for biofuels increases due to concerns regarding greenhouse gas emissions and depletion of fossil oil reserves. Many substances identified as potential biofuels are solvents or already used as flavors or fragrances. Although humans and the environment may be readily exposed little is known regarding their (eco)toxicological effects. In this study, the three potential biofuels ethyl levulinate (EL), 2-methyltetrahydrofuran (2-MTHF) and 2-methylfuran (2-MF) were investigated for their acute embryo toxicity and teratogenicity using the fish embryo toxicity (FET) test to identify unknown hazard potentials and to allow focusing further research on substances with low toxic potentials. In addition, two fossil fuels (diesel and gasoline) and an established biofuel (rapeseed oil methyl ester) were investigated as references. The FET test is widely accepted and used in (eco)toxicology. It was performed using the zebrafish Danio rerio, a model organism useful for the prediction of human teratogenicity. Testing revealed a higher acute toxicity for EL (LC{sub 50}: 83 mg/L) compared to 2-MTHF (LC{sub 50}: 2980 mg/L), 2-MF (LC{sub 50}: 405 mg/L) and water accommodated fractions of the reference fuels including gasoline (LC{sub 50}: 244 mg DOC/L). In addition, EL caused a statistically significant effect on head development resulting in elevated head lengths in zebrafish embryos. Results for EL reduce its likelihood of use as a biofuel since other substances with a lower toxic potential are available. The FET test applied at an early stage of development might be a useful tool to avoid further time and money requiring steps regarding research on unfavorable biofuels. - Highlights: • The demand for biofuels increases but their (eco)toxicological effects are unknown. • Acute fish embryo toxicity and teratogenicity of potential biofuels were evaluated. • Ethyl levulinate induced a higher acute toxicity compared to WAFs of gasoline. • Ethyl levulinate caused

Probing nanomechanical interaction at the interface between biological membrane and potentially toxic chemical.

Science.gov (United States)

Lim, Chanoong; Park, Sohee; Park, Jinwoo; Ko, Jina; Lee, Dong Woog; Hwang, Dong Soo

2018-04-12

Various xenobiotics interact with biological membranes, and precise evaluations of the molecular interactions between them are essential to foresee the toxicity and bioavailability of existing or newly synthesized molecules. In this study, surface forces apparatus (SFA) measurement and Langmuir trough based tensiometry are performed to reveal nanomechanical interaction mechanisms between potential toxicants and biological membranes for ex vivo toxicity evaluation. As a toxicant, polyhexamethylene guanidine (PHMG) was selected because PHMG containing humidifier disinfectant and Vodka caused lots of victims in both S. Korea and Russia, respectively, due to the lack of holistic toxicity evaluation of PHMG. Here, we measured strong attraction (Wad ∼4.2 mJ/m 2 ) between PHMG and head group of biological membranes while no detectable adhesion force between the head group and control molecules was measured. Moreover, significant changes in π-A isotherm of 1,2-Dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) monolayers were measured upon PHMG adsorption. These results indicate PHMG strongly binds to hydrophilic group of lipid membranes and alters the structural and phase behavior of them. More importantly, complementary utilization of SFA and Langmuir trough techniques are found to be useful to predict the potential toxicity of a chemical by evaluating the molecular interaction with biological membranes, the primary protective barrier for living organisms. Copyright © 2018 Elsevier B.V. All rights reserved.

"Air Toxics under the Big Sky": Examining the Effectiveness of Authentic Scientific Research on High School Students' Science Skills and Interest

Science.gov (United States)

Ward, Tony J.; Delaloye, Naomi; Adams, Earle Raymond; Ware, Desirae; Vanek, Diana; Knuth, Randy; Hester, Carolyn Laurie; Marra, Nancy Noel; Holian, Andrij

2016-01-01

"Air Toxics Under the Big Sky" is an environmental science outreach/education program that incorporates the Next Generation Science Standards (NGSS) 8 Practices with the goal of promoting knowledge and understanding of authentic scientific research in high school classrooms through air quality research. This research explored: (1)…

Defences against ammonia toxicity in tropical air-breathing fishes exposed to high concentrations of environmental ammonia: a review.

Science.gov (United States)

Ip, Y K; Chew, S F; Wilson, J M; Randall, D J

2004-10-01

In the tropics, air-breathing fishes can be exposed to environmental ammonia when stranded in puddles of water during the dry season, during a stay inside a burrow, or after agricultural fertilization. At low concentrations of environmental ammonia, NH(3) excretion is impeded, as in aerial exposure, leading to the accumulation of endogenous ammonia. At high concentrations of environmental ammonia, which results in a reversed NH(3) partial pressure gradient (DeltaP(NH3)), there is retention of endogenous ammonia and uptake of exogenous ammonia. In this review, several tropical air-breathing fishes (giant mudskipper, African catfish, oriental weatherloach, swamp eel, four-eyed sleeper, abehaze and slender African lungfish), which can tolerate high environmental ammonia exposure, are used as examples to demonstrate how eight different adaptations can be involved in defence against ammonia toxicity. Four of these adaptations deal with ammonia toxicity at branchial and/or epithelial surfaces: (1) active excretion of NH(4)(+); (2) lowering of environmental pH; (3) low NH(3) permeability of epithelial surfaces; and (4) volatilization of NH(3), while another four adaptations ameliorate ammonia toxicity at the cellular and subcellular levels: (5) high tolerance of ammonia at the cellular and subcellular levels; (6) reduction in ammonia production; (7) glutamine synthesis; and (8) urea synthesis. The responses of tropical air-breathing fishes to high environmental ammonia are determined apparently by behavioural adaptations and the nature of their natural environments.

Phytochemical constituents, antioxidant activity and toxicity potential of Phlomis olivieri Benth.

Directory of Open Access Journals (Sweden)

M.R. Delnavazi

2016-04-01

Full Text Available Background and objectives: Phlomis olivieri Benth. (Lamiaceae is a medicinal plant widely distributed in Iran. In the present study, we have investigated the phytochemical constituents, antioxidant activity and general toxicity potential of the aerial parts of this species. Methods: Silica gel (normal and reversed phases and Sephadex LH-20 column chromatographies were used for isolation of compounds from methanol-soluble portion (MSP of the total extract obtained from P. olivieri aerial parts. The structures of isolated compounds were elucidated using 1H-NMR, 13C-NMR and UV spectral analyses. Antioxidant activity and general toxicity potential of MSP were also evaluated in DPPH free radical-scavenging assay and brine shrimp lethality test (BSLT, respectively. Results: One caffeoylquinic acid derivative, chlorogenic acid (1, one iridoid glycoside, ipolamiide (2, two phenylethanoid glycosides, phlinoside C (3 and verbascoside (5, along with two flavonoids, isoquercetin (4 and naringenin (6 were isolated and identified from MSP. The MSP exhibited considerable antioxidant activity in DPPH method (IC50; 50.4 ± 4.6 µg/mL, compared to BHT (IC50; 18.7 ± 2.1 µg/mL, without any toxic effect in BSLT at the highest tested dose (1000 µg/mL. Conclusion: the results of the present study introduce P. olivieri as a medicinal plant with valuable biological and pharmacological potentials.

Potentially toxic elements in foodcrops: Triticum aestivum L., Zea mays L.

Science.gov (United States)

Bini, Claudio; Fontana, Silvia; Squizzato, Stefania; Minello, Fabiola; Fornasier, Flavio; Wahsha, Mohammad

2013-04-01

Soil is the basis of the ecosystems and of our system of food production. Crops can uptake heavy metals and potentially toxic elements from the soil and store them in the roots or translocate them to the aerial parts. Excessive content of these elements in edible parts can produce toxic effects and, through the food chain and food consumption, result in a potential hazard for human health. In this study soils and plants (spring wheat, Triticum aestivum L. and maize, Zea mays L.) from a tannery district in North-East Italy were analyzed to determine pedological characters, soil microbial indicators and the content of some major and micro-nutrients and potentially toxic elements (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Ni, P, Pb, S, Zn, V). The soils of the area are moderately polluted; Cr is the most important inorganic contaminant, followed by Ni, Cu and V. Factor analysis evidenced that the contaminants are in part anthropogenic and in part geogenic. Major anthropogenic origin was detected for Cr, Ni (from industrial activities), Zn, Cu, Cd (from agriculture practices). Biological Absorption Coefficient (BAC) from soil to plant roots and Translocation factor (TF) within the plant were calculated; major nutrients (K, P, S) and some micronutrients (Cu, Zn, Mg, Mn) are easily absorbed and translocated, whilst other nutrients (Ca, Fe) and potentially toxic elements or micronutrients (Al, Cd, Cr, Ni, Pb, V) are not accumulated in the seeds of the two considered species. However, the two edible species proved differently able to absorb and translocate elements, and this suggests to consider separately every species as potential PHEs transporter to the food chain and to humans. Cr concentrations in seeds and other aerial parts (stem and leaves) of the examined plants are higher than the values found for the same species and for other cereals grown on unpolluted soils. Comparing the Cr levels in edible parts with recommended dietary intake, besides other possible Cr sources

Mobility and Attenuation Dynamics of Potentially Toxic Chemical Species at an Abandoned Copper Mine Tailings Dump

Directory of Open Access Journals (Sweden)

Wilson Mugera Gitari

2018-02-01

Full Text Available Large volumes of disposed mine tailings abound in several regions of South Africa, as a consequence of unregulated, unsustainable long years of mining activities. Tailings dumps occupy a large volume of valuable land, and present a potential risk for aquatic systems, through leaching of potentially toxic chemical species. This paper reports on the evaluation of the geochemical processes controlling the mobility of potentially toxic chemical species within the tailings profile, and their potential risk with regard to surface and groundwater systems. Combination of X-ray fluorescence (XRF, X-ray diffraction (XRD, and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS techniques, show that the tailing profiles are uniform, weakly altered, and vary slightly with depth in both physical and geochemical properties, as well as mineralogical composition. Mineralogical analysis showed the following order of abundance: quartz > epidote > chlorite > muscovite > calcite > hematite within the tailings profiles. The neutralization of the dominant alumino-silicate minerals and the absence of sulfidic minerals, have produced medium alkaline pH conditions (7.97–8.37 at all depths and low concentrations of dissolved Cu (20.21–47.9 µg/L, Zn (0.88–1.80 µg/L, Pb (0.27–0.34 µg/L, and SO42− (15.71–55.94 mg/L in the tailings profile leachates. The relative percentage leach for the potentially toxic chemical species was low in the aqueous phase (Ni 0.081%, Cu 0.006%, and Zn 0.05%. This indicates that the transport load of potentially toxic chemical species from tailings to the aqueous phase is very low. The precipitation of secondary hematite has an important known ability to trap and attenuate the mobility of potentially toxic chemical species (Cu, Zn, and Pb by adsorption on the surface area. Geochemical modelling MINTEQA2 showed that the tailings leachates were below saturation regarding oxyhydroxide minerals, but oversaturated with Cu

A comparative assessment of the acute inhalation toxicity of vanadium compounds.

Science.gov (United States)

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

2016-11-01

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

Respiratory tract toxicity in rats exposed to Mexico City air.

Science.gov (United States)

Moss, O R; Gross, E A; James, R A; Janszen, D B; Ross, P W; Roberts, K C; Howard, A M; Harkema, J R; Calderón-Garcidueñas, L; Morgan, K T

2001-03-01

The rat has been used extensively as a health sentinel, indicator, or monitor of environmental health hazards, but this model has not been directly validated against human exposures. Humans in Mexico City show upper respiratory tract lesions and evidence of pulmonary damage related to their environmental inhalation exposure. In this study, male and female F344 rats were exposed (23 hr/day) in Mexico City to local Mexico City air (MCA)* for up to seven weeks. Controls were maintained at the same location under filtered air. Prior to these exposures, several steps were taken. First, the nasal passages of normal male rats shipped from the United States and housed in Mexico City were examined for mycoplasma infection; no evidence of infection was found. In addition, a mobile exposure and monitoring system was assembled and, with an ozone (O3) exposure atmosphere, was tested along with supporting histopathology techniques and analysis of rat nasal and lung tissues. Last, the entire exposure model (equipment and animals) was transported to Mexico City and validated for a three-week period. During the seven-week study there were 18 one-hour intervals during which the average O3 concentration of MCA in the exposure chamber exceeded the US National Ambient Air Quality Standard (NAAQS) of 0.120 ppm 03 (hourly average, not to be exceeded more than once per year). This prolonged exposure of healthy F344 rats to MCA containing episodically low to moderate concentrations of 03 (as well as other urban air pollutants) did not induce inflammatory or epithelial lesions in the nasal airways or lung as measured by qualitative histologic techniques or quantitative morphometric techniques. These findings agree with those of previous controlled O3 inhalation studies, but they are in contrast to reports indicating that O3-polluted MCA causes significant nasal mucosal injury in adults and children living in southwestern Mexico City. Taken together, these findings may suggest that human

An induced current method for measuring zeta potential of electrolyte solution-air interface.

Science.gov (United States)

Song, Yongxin; Zhao, Kai; Wang, Junsheng; Wu, Xudong; Pan, Xinxiang; Sun, Yeqing; Li, Dongqing

2014-02-15

This paper reports a novel and very simple method for measuring the zeta potential of electrolyte solution-air interface. When a measuring electrode contacts the electrolyte solution-air interface, an electrical current will be generated due to the potential difference between the electrode-air surface and the electrolyte solution-air interface. The amplitude of the measured electric signal is linearly proportional to this potential difference; and depends only on the zeta potential at the electrolyte solution-air interface, regardless of the types and concentrations of the electrolyte. A correlation between the zeta potential and the measured voltage signal is obtained based on the experimental data. Using this equation, the zeta potential of any electrolyte solution-air interface can be evaluated quickly and easily by inserting an electrode through the electrolyte solution-air interface and measuring the electrical signal amplitude. This method was verified by comparing the obtained results of NaCl, MgCl2 and CaCl2 solutions of different pH values and concentrations with the zeta potential data reported in the published journal papers. Copyright © 2013 Elsevier Inc. All rights reserved.

Nanoscale copper in the soil–plant system – toxicity and underlying potential mechanisms

Energy Technology Data Exchange (ETDEWEB)

Anjum, Naser A., E-mail: anjum@ua.pt [CESAM-Centre for Environmental and Marine Studies & Department of Chemistry, University of Aveiro, 3810-193 Aveiro (Portugal); Adam, Vojtech [Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno (Czech Republic); Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno (Czech Republic); Kizek, Rene [Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno (Czech Republic); Duarte, Armando C.; Pereira, Eduarda [CESAM-Centre for Environmental and Marine Studies & Department of Chemistry, University of Aveiro, 3810-193 Aveiro (Portugal); Iqbal, Muhammad [Department of Botany, Faculty of Science, Hamdard University, New Delhi 110062 (India); Lukatkin, Alexander S. [Department of Botany, Plant Physiology and Ecology, N.P. Ogarev Mordovia State University, Bolshevistskaja Str., 68. Saransk 430005 (Russian Federation); Ahmad, Iqbal, E-mail: ahmadr@ua.pt [CESAM-Centre for Environmental and Marine Studies & Department of Chemistry, University of Aveiro, 3810-193 Aveiro (Portugal); CESAM-Centre for Environmental and Marine Studies & Department of Biology, University of Aveiro, 3810-193 Aveiro (Portugal)

2015-04-15

Nanoscale copper particles (nano-Cu) are used in many antimicrobial formulations and products for their antimicrobial activity. They may enter deliberately and/or accidentally into terrestrial environments including soils. Being the major ‘eco-receptors’ of nanoscale particles in the terrestrial ecosystem, soil–microbiota and plants (the soil–plant system) have been used as a model to dissect the potential impact of these particles on the environmental and human health. In the soil–plant system, the plant can be an indirect non-target organism of the soil-associated nano-Cu that may in turn affect plant-based products and their consumers. By all accounts, information pertaining to nano-Cu toxicity and the underlying potential mechanisms in the soil–plant system remains scanty, deficient and little discussed. Therefore, based on some recent reports from (bio)chemical, molecular and genetic studies of nano-Cu versus soil–plant system, this article: (i) overviews the status, chemistry and toxicity of nano-Cu in soil and plants, (ii) discusses critically the poorly understood potential mechanisms of nano-Cu toxicity and tolerance both in soil–microbiota and plants, and (iii) proposes future research directions. It appears from studies hitherto made that the uncontrolled generation and inefficient metabolism of reactive oxygen species through different reactions are the major factors underpinning the overall nano-Cu consequences in both the systems. However, it is not clear whether the nano-Cu or the ion released from it is the cause of the toxicity. We advocate to intensify the multi-approach studies focused at a complete characterization of the nano-Cu, its toxicity (during life cycles of the least-explored soil–microbiota and plants), and behavior in an environmentally relevant terrestrial exposure setting. Such studies may help to obtain a deeper insight into nano-Cu actions and address adequately the nano-Cu-associated safety concerns in the �

Nanoscale copper in the soil–plant system – toxicity and underlying potential mechanisms

International Nuclear Information System (INIS)

Anjum, Naser A.; Adam, Vojtech; Kizek, Rene; Duarte, Armando C.; Pereira, Eduarda; Iqbal, Muhammad; Lukatkin, Alexander S.; Ahmad, Iqbal

2015-01-01

Nanoscale copper particles (nano-Cu) are used in many antimicrobial formulations and products for their antimicrobial activity. They may enter deliberately and/or accidentally into terrestrial environments including soils. Being the major ‘eco-receptors’ of nanoscale particles in the terrestrial ecosystem, soil–microbiota and plants (the soil–plant system) have been used as a model to dissect the potential impact of these particles on the environmental and human health. In the soil–plant system, the plant can be an indirect non-target organism of the soil-associated nano-Cu that may in turn affect plant-based products and their consumers. By all accounts, information pertaining to nano-Cu toxicity and the underlying potential mechanisms in the soil–plant system remains scanty, deficient and little discussed. Therefore, based on some recent reports from (bio)chemical, molecular and genetic studies of nano-Cu versus soil–plant system, this article: (i) overviews the status, chemistry and toxicity of nano-Cu in soil and plants, (ii) discusses critically the poorly understood potential mechanisms of nano-Cu toxicity and tolerance both in soil–microbiota and plants, and (iii) proposes future research directions. It appears from studies hitherto made that the uncontrolled generation and inefficient metabolism of reactive oxygen species through different reactions are the major factors underpinning the overall nano-Cu consequences in both the systems. However, it is not clear whether the nano-Cu or the ion released from it is the cause of the toxicity. We advocate to intensify the multi-approach studies focused at a complete characterization of the nano-Cu, its toxicity (during life cycles of the least-explored soil–microbiota and plants), and behavior in an environmentally relevant terrestrial exposure setting. Such studies may help to obtain a deeper insight into nano-Cu actions and address adequately the nano-Cu-associated safety concerns in the �

Monitoring of air toxics through air pathways in support of a No-Migration permit at a refinery land treatment facility

International Nuclear Information System (INIS)

Wineberry, W.T. Jr.; McReynolds, J.

1991-01-01

As part of Exxon's petition of the EPA for No-Migration variances, ambient concentrations of toxicants and carcinogens are required to be verified through onsite monitoring for comparison to the appropriate health based limits as well as for calibration of previously used atmospheric dispersion models. Ambient air around land treatment facilities us a very complex, dynamic system of interacting chemicals. Pollutants can be found in the gas phase, in the particulate phase, or in the aerosol phase. The complex nature of the dynamic air system around these facilities contributes to the complexity of the sampling and analytical selection for the identification and quantification for these chemicals. The selection of the proper sampling and analysis methods for a pollutant depends on many important interrelated factors, including compounds of interest, the level of detection required, the degree of specificity needed, and the purpose of the data collected. Other factors which may be as important as the above are cost, the accuracy and precision required, need for real-time versus long-term data, and the need for on-site or off-site analysis. Sampling time, sampling rate, the volume of air to be sampled and the acceptable risk level are also factors which must be considered when choosing a sampling method. The purpose of the ambient air monitoring program is to obtain a comparison of predicted concentration to those measured. This paper will focus on the ambient air monitoring program at Exxon's land treatment facility as part of a No-Migration variance to EPA's Land Ban Regulations. Ambient Air Monitoring data involving volatile, semi-volatile and metals/particulate matter less than ten microns (PM-10) will be presented

Arsenic: A Review of the Element's Toxicity, Plant Interactions, and Potential Methods of Remediation.

Science.gov (United States)

Hettick, Bryan E; Cañas-Carrell, Jaclyn E; French, Amanda D; Klein, David M

2015-08-19

Arsenic is a naturally occurring element with a long history of toxicity. Sites of contamination are found worldwide as a result of both natural processes and anthropogenic activities. The broad scope of arsenic toxicity to humans and its unique interaction with the environment have led to extensive research into its physicochemical properties and toxic behavior in biological systems. The purpose of this review is to compile the results of recent studies concerning the metalloid and consider the chemical and physical properties of arsenic in the broad context of human toxicity and phytoremediation. Areas of focus include arsenic's mechanisms of human toxicity, interaction with plant systems, potential methods of remediation, and protocols for the determination of metals in experimentation. This assessment of the literature indicates that controlling contamination of water sources and plants through effective remediation and management is essential to successfully addressing the problems of arsenic toxicity and contamination.

Cognitive Effects of Air Pollution Exposures and Potential Mechanistic Underpinnings.

Science.gov (United States)

Allen, J L; Klocke, C; Morris-Schaffer, K; Conrad, K; Sobolewski, M; Cory-Slechta, D A

2017-06-01

This review sought to address the potential for air pollutants to impair cognition and mechanisms by which that might occur. Air pollution has been associated with deficits in cognitive functions across a wide range of epidemiological studies, both with developmental and adult exposures. Studies in animal models are significantly more limited in number, with somewhat inconsistent findings to date for measures of learning, but show more consistent impairments for short-term memory. Potential contributory mechanisms include oxidative stress/inflammation, altered levels of dopamine and/or glutamate, and changes in synaptic plasticity/structure. Epidemiological studies are consistent with adverse effects of air pollutants on cognition, but additional studies and better phenotypic characterization are needed for animal models, including more precise delineation of specific components of cognition that are affected, as well as definitions of critical exposure periods for such effects and the components of air pollution responsible. This would permit development of more circumscribed hypotheses as to potential behavioral and neurobiological mechanisms.

Complex mixtures of dissolved pesticides show potential aquatic toxicity in a synoptic study of Midwestern U.S. streams

Science.gov (United States)

Nowell, Lisa H.; Moran, Patrick W.; Schmidt, Travis S.; Norman, Julia E.; Nakagaki, Naomi; Shoda, Megan E.; Mahler, Barbara J.; Van Metre, Peter C.; Stone, Wesley W.; Sandstrom, Mark W.; Hladik, Michelle L.

2018-01-01

Aquatic organisms in streams are exposed to pesticide mixtures that vary in composition over time in response to changes in flow conditions, pesticide inputs to the stream, and pesticide fate and degradation within the stream. To characterize mixtures of dissolved-phase pesticides and degradates in Midwestern streams, a synoptic study was conducted at 100 streams during May–August 2013. In weekly water samples, 94 pesticides and 89 degradates were detected, with a median of 25 compounds detected per sample and 54 detected per site. In a screening-level assessment using aquatic-life benchmarks and the Pesticide Toxicity Index (PTI), potential effects on fish were unlikely in most streams. For invertebrates, potential chronic toxicity was predicted in 53% of streams, punctuated in 12% of streams by acutely toxic exposures. For aquatic plants, acute but likely reversible effects on biomass were predicted in 75% of streams, with potential longer-term effects on plant communities in 9% of streams. Relatively few pesticides in water—atrazine, acetochlor, metolachlor, imidacloprid, fipronil, organophosphate insecticides, and carbendazim—were predicted to be major contributors to potential toxicity. Agricultural streams had the highest potential for effects on plants, especially in May–June, corresponding to high spring-flush herbicide concentrations. Urban streams had higher detection frequencies and concentrations of insecticides and most fungicides than in agricultural streams, and higher potential for invertebrate toxicity, which peaked during July–August. Toxicity-screening predictions for invertebrates were supported by quantile regressions showing significant associations for the Benthic Invertebrate-PTI and imidacloprid concentrations with invertebrate community metrics for MSQA streams, and by mesocosm toxicity testing with imidacloprid showing effects on invertebrate communities at environmentally relevant concentrations. This study documents the most

Toxic potential of organic constituents of submicron particulate matter (PM1) in an urban road site (Barcelona).

Science.gov (United States)

Mesquita, Sofia R; van Drooge, Barend L; Dall'Osto, Manuel; Grimalt, Joan O; Barata, Carlos; Vieira, Natividade; Guimarães, Laura; Piña, Benjamin

2017-06-01

Atmospheric particulate matter (PM) is a recognized risk factor contributing to a number of diseases in human populations and wildlife globally. Organic matter is a major component of PM, but its contribution to overall toxicity of PM has not been thoroughly evaluated yet. In the present work, the biological activity of organic extracts from PM1 (particles with less than 1 μm of aerodynamic diameter) collected from an urban road site in the centre of Barcelona (NE Spain) was evaluated using a yeast-based assay (AhR-RYA) and different gene expression markers in zebrafish embryos. Dioxin-like activity of the extracts correlated to primary emissions from local traffic exhausts, reflecting weekday/weekend alternance. Expression levels of cyp1a and of gene markers for key cellular processes and development (ier2, fos) also correlated to vehicle emissions, whereas expression of gene markers related to antioxidant defence and endocrine effects (gstal, hao1, ttr) was strongly reduced in samples with strong contribution from regional air masses with aged secondary organic species or with strong influence of biomass burning emissions. Our data suggest that the toxic potential of PM1 organic chemical constituents strongly depends on the emission sources and on the process of ageing from primary to secondary organic aerosols.

Potential for photoenhanced toxicity of spilled oil in Prince William Sound and Gulf of Alaska Waters

International Nuclear Information System (INIS)

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

2001-01-01

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

System approach for evaluation of air pollution toxic compounds in the 30-km area of nuclear power plants

International Nuclear Information System (INIS)

Shevtsova, O.V.; Zhigunova, L.N.; Makovskaya, N.A.; Pavlovich, E.L.

2012-01-01

The article shows the importance of a systematic approach to address environmental problems that arise during the construction of nuclear power plants, and identified the need to consider the transformation and biotransformation of primary pollutants and monitoring secondary pollutants. The basic pathways of pollutants in the air a 30-km zone of nuclear power plants established. The content of primary and secondary air pollutants identified. The evaluation of general toxic risk from primary pollutant and the calculation of the carcinogenic risk of secondary pollutants entering the body by inhalation are carried out. (authors)

Understanding environmental health inequalities through comparative intracategorical analysis: racial/ethnic disparities in cancer risks from air toxics in El Paso County, Texas.

Science.gov (United States)

Collins, Timothy W; Grineski, Sara E; Chakraborty, Jayajit; McDonald, Yolanda J

2011-01-01

This paper contributes to the environmental justice literature by analyzing contextually relevant and racial/ethnic group-specific variables in relation to air toxics cancer risks in a US-Mexico border metropolis at the census block group-level. Results indicate that Hispanics' ethnic status interacts with class, gender and age status to amplify disproportionate risk. In contrast, results indicate that non-Hispanic whiteness attenuates cancer risk disparities associated with class, gender and age status. Findings suggest that a system of white-Anglo privilege shapes the way in which race/ethnicity articulates with other dimensions of inequality to create unequal cancer risks from air toxics. Copyright © 2010 Elsevier Ltd. All rights reserved.

"The fairer the better?" Use of potentially toxic skin bleaching products.

Science.gov (United States)

Darj, Elisabeth; Infanti, Jennifer J; Ahlberg, Beth Maina; Okumu, Jecinta

2015-12-01

Skin bleaching is a widespread phenomenon in spite of their potentially toxic health effects. This study aimed to determine if such products are used in Sweden in particular by pregnant women, furthermore to explore immigrant women's view skin bleaching. 455 pregnant women completed a questionnaire, which were statistically analysed. Focus groups and individual interviews were conducted with immigrant women, content analysis was used to assess the data. Skin bleaching products were used by 2.6% of pregnant women, significantlly more by women born in non-European countries. Motivating factors were associated with the concept of beauty together with social and economic advantages. The women had low awareness of the potential health risks of the products. Regulations on the trade of skin bleaching products have not effectively reduced the availability of the products in Sweden nor the popularity of skin bleaching. There is need for further research especially among pregnant women and possible effects on newborns. Products should be tested for toxicity. Public health information should be developed and health care providers educated and aware of this practice, due to their potential negative health implications.

Chemical warfare agent and biological toxin-induced pulmonary toxicity: could stem cells provide potential therapies?

Science.gov (United States)

Angelini, Daniel J; Dorsey, Russell M; Willis, Kristen L; Hong, Charles; Moyer, Robert A; Oyler, Jonathan; Jensen, Neil S; Salem, Harry

2013-01-01

Chemical warfare agents (CWAs) as well as biological toxins present a significant inhalation injury risk to both deployed warfighters and civilian targets of terrorist attacks. Inhalation of many CWAs and biological toxins can induce severe pulmonary toxicity leading to the development of acute lung injury (ALI) as well as acute respiratory distress syndrome (ARDS). The therapeutic options currently used to treat these conditions are very limited and mortality rates remain high. Recent evidence suggests that human stem cells may provide significant therapeutic options for ALI and ARDS in the near future. The threat posed by CWAs and biological toxins for both civilian populations and military personnel is growing, thus understanding the mechanisms of toxicity and potential therapies is critical. This review will outline the pulmonary toxic effects of some of the most common CWAs and biological toxins as well as the potential role of stem cells in treating these types of toxic lung injuries.

Chemical mixtures in untreated water from public-supply wells in the U.S. - Occurrence, composition, and potential toxicity

Energy Technology Data Exchange (ETDEWEB)

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

2012-08-01

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

Role of forestry in mitigating global soil pollution from toxic heavy ...

African Journals Online (AJOL)

One of the challenges confronting environmental management is the pollution of land, air and water resources by toxic heavy metals.This review seeks to identify the plant species and their potentials for remediation, less cost effective methods to remediate contaminated soils, and the remediation capability of woody plants.

Potential carcinogenicity predicted by computational toxicity evaluation of thiophosphate pesticides using QSTR/QSCarciAR model.

Science.gov (United States)

Petrescu, Alina-Maria; Ilia, Gheorghe

2017-07-01

This study presents in silico prediction of toxic activities and carcinogenicity, represented by the potential carcinogenicity DSSTox/DBS, based on vector regression with a new Kernel activity, and correlating the predicted toxicity values through a QSAR model, namely: QSTR/QSCarciAR (quantitative structure toxicity relationship/quantitative structure carcinogenicity-activity relationship) described by 2D, 3D descriptors and biological descriptors. The results showed a connection between carcinogenicity (compared to the structure of a compound) and toxicity, as a basis for future studies on this subject, but each prediction is based on structurally similar compounds and the reactivation of the substructures of these compounds.

The Industrial Toxics Project: Targeting chemicals for environmental results

International Nuclear Information System (INIS)

Burch, W.M.

1991-01-01

In September, 1990, the Administrator of the US Environmental Protection Agency committed the Agency to a program of targeting chemicals for multi-media risk reduction activities through pollution prevention. The Industrial Toxics Project will place emphasis on obtaining voluntary commitments from industry to reduce releases of toxic chemicals to the air, water, and land with a goal of reducing releases nationwide by 33% by 1992 and 50% by 1995. An initial list of 18 chemicals have been selected based on recommendations from each Agency program. The chemicals selected are subject to reporting under the Toxic Chemical Release Inventory Program which will provide the basis for tracking progress. The chemicals are characterized by high production volume, toxicity and releases and present the potential for significant risk reduction through pollution prevention. This presentation will discuss the focus and direction of this new initiative

Chemical mixtures in untreated water from public-supply wells in the U.S. — Occurrence, composition, and potential toxicity

International Nuclear Information System (INIS)

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

2012-01-01

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

Elemental Composition of Two Rice Cultivars under Potentially Toxic an Aquept and Aquent

Directory of Open Access Journals (Sweden)

Adesola Olutayo OLALEYE

2009-12-01

Full Text Available Iron toxicity is a major nutrient disorder affecting rice production of wetland rice in the irrigated and rainfed ecosystem in West Africa sub-region. Little attention has been paid to evaluating nutrient contents of rice cultivars grown on such soils and their relationship to the iron toxicity scores, grain yield and dry matter yields. A pot experiment was conducted on two potentially Fe-toxic soils (Aeric Fluvaquent and Aeric Tropaquept. The experiment was a 2 x 2 x 4 factorial experiment with three replicates in arranged in a randomized fashion. The factors were two soil types, two rice cultivars (ITA 212 and tolerant (Suakoko 8 and four Fe 2+ levels (control, 1000, 3000 and 4000 mg L-1. The result showed that for both susceptible cultivar (ITA 212 and the relatively tolerant (Suakoko 8 cultivar, little or no differences were observed in their elemental composition with regards to micro and macro-nutrients. For the susceptible cultivar, results showed that none of the tissue nutrients significantly relates to iron toxicity scores (ITS, grain yield and dry matter yield on both soil types. However, for the tolerant cultivar, ITS was observed to be significantly related to tissue K and P contents on the two soil types respectively. Tissue Ca and Mg were observed to be significantly related to the dry matter yield (DMY on Aeric Tropquept. It could be concluded that for these rice cultivars grown on two potentially Fe-toxic soils, different tissue nutrients may trigger the manifestation of bronzing or yellowing symptoms of rice cultivars.

Potential Use of Chemoprotectants against the Toxic Effects of Cyanotoxins: A Review.

Science.gov (United States)

Guzmán-Guillén, Remedios; Puerto, María; Gutiérrez-Praena, Daniel; Prieto, Ana I; Pichardo, Silvia; Jos, Ángeles; Campos, Alexandre; Vasconcelos, Vitor; Cameán, Ana M

2017-05-23

Cyanobacterial toxins, particularly microcystins (MCs) and cylindrospermopsin (CYN), are responsible for toxic effects in humans and wildlife. In order to counteract or prevent their toxicity, various strategies have been followed, such as the potential application of chemoprotectants. A review of the main substances evaluated for this aim, as well as the doses and their influence on cyanotoxin-induced toxicity, has been performed. A search of the literature shows that research on MCs is much more abundant than research on CYN. Among chemoprotectants, antioxidant compounds are the most extensively studied, probably because it is well known that oxidative stress is one of the toxic mechanisms common to both toxins. In this group, vitamin E seems to have the strongest protectant effect for both cyanotoxins. Transport inhibitors have also been studied in the case of MCs, as CYN cellular uptake is not yet fully elucidated. Further research is needed because systematic studies are lacking. Moreover, more realistic exposure scenarios, including cyanotoxin mixtures and the concomitant use of chemoprotectants, should be considered.

Comparative study for toxic elements determination in air particulate reference material by INAA, CCT-ICP-MS, and ICP-MS

International Nuclear Information System (INIS)

Lim, J.M.; Lee, J.H.; Kim, K.H.; Moon, J.H.; Chung, Y.S.

2005-01-01

Although toxic elements are minor components in the atmospheric environment, they play a significant role as important marker for atmospheric science such as risk assessment, long-range transfer study, and source apportionment. Therefore, the techniques, which allow accurate and fast elemental analysis with a minimum pre-treatment, are very important. INAA has a main advantage of non-destruction of air particulate samples, while inductively Coupled plasma with mass spectrometry (ICP-MS) encounters the most significant difficulties in pre-treatment (digestion, fusion, and dilution) and polyatomic spectral interferences for interest toxic elements, Although INAA is still reference method, a number of factors (disadvantages of cost, complexity of the instruments, and scarcity of nuclear reactor) limit its applications. To date, the use of collision cell technology ICP-MS (CCT-ICP-MS) is recommended instead of typical ICP-MS for the analysis of the toxic elements; this is because CCT-ICP-MS technique prevents polyatomic spectral interferences despite of contamination and volatile effects. In this study, a number of toxic elements in reference material, NIST SRM 2783 (air particulate on filter media) were determined by INAA, CCT-ICP-MS, and ICP-MS. For both ICP methods, the filters were decomposed by microwave digestion with 5mL nitric acid. The analytical results by three methods were compared with certificated data; the INAA results showed the most accurate and precise data sets for all target elements among three methods. In detail, the deviation between analytical results and SRM's by INAA fell below 10% for all elements excluding As (14%), while those by CCT-ICP-MS were about 20%. For ICP-MS, the result does not agree with certificated data for several elements, because polyatomic spectral interference (due to 40 Ar 35 Cl, 40 Ar 23 Na, and 35 Cl 16 O) generate positive error of analytical result for As, Cu, and V. Based on our result, INAA is still one of the most

Silent Discharge Plasma Technology for the Treatment of Air Toxics and Other Applications

Energy Technology Data Exchange (ETDEWEB)

Rosocha, Louis A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chase, Peter J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gross, Michael P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

1998-09-21

Under this CRADA, the Los Alamos National Laboratory (LANL) and High Mesa Technologies, Inc. (HMT) carried out a joint project on the development of the silent discharge plasma (SDP) technology for the treatment of hazardous air pollutants and other hazardous or toxic chemicals. The project had two major components: a technology-demonstration part and a scale-up and commercialization part. In the first part, a small-scale, mobile SDP plasma processor, which was being developed under a CRADA with the Electric Power Research Institute (EPRI) was the mobile equipment was modified for higher capacity service and employed for an innovative remediation technologies demonstration on soil-vapor extraction off-gases at the McClellan Air Force Base near Sacramento, CA. The performance of the SDP system for the variety of volatile organic compounds (VOCs) encountered at the McClellan site was sufficiently promising to the project HMT and LANL worked together to formulate a scale-up strategy and commercialization/manufacturing plan, and to design a prototype scaled-up SDP unit. HMT and LANL are now in the final stages of completing a licensing agreement for the technology and HMT is in the process of raising funds to engineer and manufacture commercial prototype SDP equipment focused on stack-gas emissions control and environmental remediation. HMT, in collaboration with another Northern New Mexico business, Coyote Aerospace, has also been successful in receiving a Phase I Small Business Innovative Research (SBIR) award from the Army Research Office to develop, design, and construct a small non-thermal plasma reactor for laboratory studies ("Non-Thermal Plasma Reactor for Control of Fugitive Emissions of Toxic Gases")

Air toxics emission from an IGCC process

Energy Technology Data Exchange (ETDEWEB)

Mojtahedi, W; Hovath, A [Carbona Inc, Helsinki (Finland); Hinderson, A [Vattenfall Utveckling (Sweden); Nykaenen, J; Hoffren, H [Imatran Voima Oy, Vantaa (Finland); Nieminen, M; Kurkela, E [VTT, Espoo (Finland)

1997-10-01

The emissions of 12 toxic trace element from a coal-fired IGCC plant were calculated based on thermodynamic equilibrium in the gas phase and some of the results published. The theoretical calculations were extended to include some other fuels as well as mixture of some of these fuels. The combustion of the product gas in the gas turbine is also considered. These simulations correspond to gasification of the fuel at 850-1050 deg C (depending on the fuel) and 1823 bar pressure. The gas composition was taken from the measured data as far as possible. In the absence of experimental data, a computer code developed for the U-Gas gasifier was used to determine the fuel gas composition. The gas was then cooled to 550 deg C in the gas cooler and filtered at this same temperature and burned in the gas turbine with an air ratio of 3.2. The results of these simulations are compared with the measured data of an experimental program designed to measure the emissions of a few selected trace elements from a 15 MW,h pressurized fluidized bed gasification pilot plant. The pilot plant was equipped with an advanced hot gas cleanup train which includes a two fluidized-bed reactor system for high-temperature, high-pressure external sulfur removal and a filtration unit housing porous, rigid ceramic candle filters. The trace element concentrations in the fuel, bottom ash, and filter ash are determined and the results compared with EPA regulatory levels

Degradation study of pesticides by direct photolysis - Structural characterization and potential toxicity of photo products

International Nuclear Information System (INIS)

Rifai, A.

2013-01-01

Pesticides belong to the large family of organic pollutants. In general, they are intended to fight against crop pests. Distribution of pesticides in nature creates pollution in DIFFERENT compartments of the biosphere (water, soil and air) and can induce acute toxic effects on human beings of the terrestrial and aquatic living biomass. It is now shown that some pesticides are endocrine disruptors and are particularly carcinogenic and mutagenic effects in humans. Pesticides can undergo various processes of transformation in the natural life cycle (biodegradation, volatilization, solar radiation ...) or following applied in the sectors of natural water purification and treatment stations sewage treatment. The presence of degradation products of pesticides in our environment is even more alarming that their structures and potential toxicities generally unknown. Molecules belonging to two families of pesticides were selected for this study: herbicides, represented by metolachlor, and fungicides represented by procymidone, pyrimethanil and boscalid. The first part of the thesis focused on the development of an analytical strategy to characterize the structures of compounds from degradation by photolysis of pesticides. The second part focused on estimating the toxicity of degradation products using a test database in silico. Identification of degradation products was achieved through two complementary analysis techniques: the gas chromatography coupled to a mass spectrometer ''multi-stage'' (GC-MSn) and liquid chromatography coupled to a tandem mass spectrometer (LC-MS/MS). The estimation of the toxicity of the degradation products was performed using the TEST program QSAR recently developed to try to predict the toxicity of molecules. The strategy of the structural elucidation of degradation products of pesticides studied is based on studying of the mechanisms of fragmentation of parent molecules of the degradation products. The molar mass of parent

Influence of potentially confounding factors on sea urchin porewater toxicity tests

Science.gov (United States)

Carr, R.S.; Biedenbach, J.M.; Nipper, M.

2006-01-01

The influence of potentially confounding factors has been identified as a concern for interpreting sea urchin porewater toxicity test data. The results from >40 sediment-quality assessment surveys using early-life stages of the sea urchin Arbacia punctulata were compiled and examined to determine acceptable ranges of natural variables such as pH, ammonia, and dissolved organic carbon on the fertilization and embryological development endpoints. In addition, laboratory experiments were also conducted with A. punctulata and compared with information from the literature. Pore water with pH as low as 6.9 is an unlikely contributor to toxicity for the fertilization and embryological development tests with A. punctulata. Other species of sea urchin have narrower pH tolerance ranges. Ammonia is rarely a contributing factor in pore water toxicity tests using the fertilization endpoint, but the embryological development endpoint may be influenced by ammonia concentrations commonly found in porewater samples. Therefore, ammonia needs to be considered when interpreting results for the embryological development test. Humic acid does not affect sea urchin fertilization at saturation concentrations, but it could have an effect on the embryological development endpoint at near-saturation concentrations. There was no correlation between sediment total organic carbon concentrations and porewater dissolved organic carbon concentrations. Because of the potential for many varying substances to activate parthenogenesis in sea urchin eggs, it is recommended that a no-sperm control be included with every fertilization test treatment. ?? 2006 Springer Science+Business Media, Inc.

Chemical Compounds Toxic to Invertebrates Isolated from Marine Cyanobacteria of Potential Relevance to the Agricultural Industry

KAUST Repository

Essack, Magbubah

2014-10-29

In spite of advances in invertebrate pest management, the agricultural industry is suffering from impeded pest control exacerbated by global climate changes that have altered rain patterns to favour opportunistic breeding. Thus, novel naturally derived chemical compounds toxic to both terrestrial and aquatic invertebrates are of interest, as potential pesticides. In this regard, marine cyanobacterium-derived metabolites that are toxic to both terrestrial and aquatic invertebrates continue to be a promising, but neglected, source of potential pesticides. A PubMed query combined with hand-curation of the information from retrieved articles allowed for the identification of 36 cyanobacteria-derived chemical compounds experimentally confirmed as being toxic to invertebrates. These compounds are discussed in this review.

Chemical Compounds Toxic to Invertebrates Isolated from Marine Cyanobacteria of Potential Relevance to the Agricultural Industry

KAUST Repository

Essack, Magbubah; Alzubaidy, Hanin S.; Bajic, Vladimir B.; Archer, John A.C.

2014-01-01

In spite of advances in invertebrate pest management, the agricultural industry is suffering from impeded pest control exacerbated by global climate changes that have altered rain patterns to favour opportunistic breeding. Thus, novel naturally derived chemical compounds toxic to both terrestrial and aquatic invertebrates are of interest, as potential pesticides. In this regard, marine cyanobacterium-derived metabolites that are toxic to both terrestrial and aquatic invertebrates continue to be a promising, but neglected, source of potential pesticides. A PubMed query combined with hand-curation of the information from retrieved articles allowed for the identification of 36 cyanobacteria-derived chemical compounds experimentally confirmed as being toxic to invertebrates. These compounds are discussed in this review.

Chemical Compounds Toxic to Invertebrates Isolated from Marine Cyanobacteria of Potential Relevance to the Agricultural Industry

Science.gov (United States)

Essack, Magbubah; Alzubaidy, Hanin S.; Bajic, Vladimir B.; Archer, John A. C.

2014-01-01

In spite of advances in invertebrate pest management, the agricultural industry is suffering from impeded pest control exacerbated by global climate changes that have altered rain patterns to favour opportunistic breeding. Thus, novel naturally derived chemical compounds toxic to both terrestrial and aquatic invertebrates are of interest, as potential pesticides. In this regard, marine cyanobacterium-derived metabolites that are toxic to both terrestrial and aquatic invertebrates continue to be a promising, but neglected, source of potential pesticides. A PubMed query combined with hand-curation of the information from retrieved articles allowed for the identification of 36 cyanobacteria-derived chemical compounds experimentally confirmed as being toxic to invertebrates. These compounds are discussed in this review. PMID:25356733

Thermal oxidation for air toxics control

International Nuclear Information System (INIS)

Pennington, R.L.

1991-01-01

The Administration projects annual expenditures of $1.1 billion by 1995, increasing to $6.7 billion by 2005, in order to comply with the new Clean Air Act Title III hazardous air pollutant requirements. The Title III requirements include 189 hazardous air pollutants which must be reduced or eliminated by 2003. Twenty of the 189 listed pollutants account for approximately 75 percent of all hazardous air pollutant emissions. Ninety percent of these 20 pollutants can be effectively controlled through one or mote of the thermal oxidation technologies. This paper reports that the advantages and disadvantages of each thermal oxidation technology vary substantially and must be reviewed for each application in order to establish the most effective thermal oxidation solution. Effective thermal oxidation will meet MACT (maximum achievable control technology) emission standards

MONITORING THE AIR FOR TOXIC AND GENOTOXIC COMPOUNDS

Science.gov (United States)

A time-integrated sampling system interfaced with a toxicity-based assay is reported for monitoring volatile toxic industrial chemicals (TICs). Semipermeable membrane devices (SPMDs) using dimethyl sulfoxide (DMSO) as the fill solvent accumulated each of 17 TICs from the vapor p...

Identifying Toxic Impacts of Metals Potentially Released during Deep-Sea Mining—A Synthesis of the Challenges to Quantifying Risk

Directory of Open Access Journals (Sweden)

Chris Hauton

2017-11-01

Full Text Available In January 2017, the International Seabed Authority released a discussion paper on the development of Environmental Regulations for deep-sea mining (DSM within the Area Beyond National Jurisdiction (the “Area”. With the release of this paper, the prospect for commercial mining in the Area within the next decade has become very real. Moreover, within nations' Exclusive Economic Zones, the exploitation of deep-sea mineral ore resources could take place on very much shorter time scales and, indeed, may have already started. However, potentially toxic metal mixtures may be released at sea during different stages of the mining process and in different physical phases (dissolved or particulate. As toxicants, metals can disrupt organism physiology and performance, and therefore may impact whole populations, leading to ecosystem scale effects. A challenge to the prediction of toxicity is that deep-sea ore deposits include complex mixtures of minerals, including potentially toxic metals such as copper, cadmium, zinc, and lead, as well as rare earth elements. Whereas the individual toxicity of some of these dissolved metals has been established in laboratory studies, the complex and variable mineral composition of seabed resources makes the a priori prediction of the toxic risk of DSM extremely challenging. Furthermore, although extensive data quantify the toxicity of metals in solution in shallow-water organisms, these may not be representative of the toxicity in deep-sea organisms, which may differ biochemically and physiologically and which will experience those toxicants under conditions of low temperature, high hydrostatic pressure, and potentially altered pH. In this synthesis, we present a summation of recent advances in our understanding of the potential toxic impacts of metal exposure to deep-sea meio- to megafauna at low temperature and high pressure, and consider the limitation of deriving lethal limits based on the paradigm of exposure to

Investigation of the potential influence of production treatment chemicals on produced water toxicity

International Nuclear Information System (INIS)

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

1993-01-01

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

Hazard identification of contaminated sites. Ranking potential toxicity of organic sediment extracts in crustacean and fish

Energy Technology Data Exchange (ETDEWEB)

Karlsson, J.; Sundberg, H.; Aakerman, G.; Grunder, K.; Eklund, B.; Breitholtz, M. [Dept. of Applied Environmental Science (ITM), Stockholm Univ. (Sweden)

2008-09-15

Background, aim, and scope: It is well known that contaminated sediments represent a potential long-term source of pollutants to the aquatic environment. To protect human and ecosystem health, it is becoming common to remediate contaminated sites. However, the great cost associated with, e.g., dredging in combination with the large numbers of contaminated sites makes it crucial to pinpoint those sites that are in greatest need of remediation. In most European countries, this prioritization process has almost exclusively been based on chemical analyses of known substances; only seldom toxicity data has been considered. The main objective of the current study was therefore to develop a tool for hazard identification of sediment by ranking potential toxicity of organic sediment extracts in a crustacean and a fish. A secondary objective was to investigate the difference in potential toxicity between compounds with different polarities. Materials and methods Early life stages of the crustacean Nitocra spinipes and the fish Oncorhynchus mykiss, which represent organisms from different trophic levels (primary and secondary consumer) and with different routes of exposure (i.e. ingestion through food, diffusive uptake, and maternal transfer), were exposed to hexane and acetone fractions (semi-polar compounds) of sediment from five locations, ranging from heavily to low contaminated. Preliminary tests showed that the extracts were non-bioavailable to the crustacean when exposed via water, and the extracts were therefore loaded on silica gel. Rainbow trout embryos were exposed using nano-injection technique. Results and discussion Clear concentration-response relationships of both mortality and larval development were observed in all tests with N. spinipes. Also for rainbow trout, the observed effects (e.g., abnormality, hemorrhage, asymmetric yolk sac) followed a dose-related pattern. Interestingly, our results indicate that some of the locations contained toxic semi

Potential toxicity of superparamagnetic iron oxide nanoparticles (SPION

Directory of Open Access Journals (Sweden)

Neenu Singh

2010-09-01

Full Text Available Superparamagnetic iron oxide nanoparticles (SPION are being widely used for various biomedical applications, for example, magnetic resonance imaging, targeted delivery of drugs or genes, and in hyperthermia. Although, the potential benefits of SPION are considerable, there is a distinct need to identify any potential cellular damage associated with these nanoparticles. Besides focussing on cytotoxicity, the most commonly used determinant of toxicity as a result of exposure to SPION, this review also mentions the importance of studying the subtle cellular alterations in the form of DNA damage and oxidative stress. We review current studies and discuss how SPION, with or without different surface coating, may cause cellular perturbations including modulation of actin cytoskeleton, alteration in gene expression profiles, disturbance in iron homeostasis and altered cellular responses such as activation of signalling pathways and impairment of cell cycle regulation. The importance of protein–SPION interaction and various safety considerations relating to SPION exposure are also addressed.

Exposure, uptake, distribution and toxicity of nanomaterials in humans.

Science.gov (United States)

Holgate, Stephen T

2010-02-01

The last decade has witnessed an unprecedented explosion in nanotechnology to take advantage of the unique physicochemical properties that emerge at the nanoscale including quantum effects. However, the excitement generated by new applications of nanotechnology in products has not been matched by a parallel appreciation or understanding of their potential toxic effects in humans and the wider ecology. This review draws some parallels to what we already know about the toxicity of particles in the workplace and in association with air pollution, and then discusses what is known about the toxicology of nanomaterials in mammals including humans. The review identifies substantial gaps in knowledge and makes some recommendations for future research.

The relevance of national and international initiatives on toxic substances to the management of hazardous air pollutants in Canada

Energy Technology Data Exchange (ETDEWEB)

Buccini, J.

2001-03-30

The Canadian Council of Ministers of the Environment (CCME), seeking guidance on current and emerging national and international initiatives, activities, and programs that could impact on the management of hazardous air pollutants (HAPs) in Canada, commissioned the author to prepare this document. In this report, HAPs are defined as toxic substances subject to airborne transport as a significant route of environmental distribution and/or exposure. Heavy metals and persistent organic pollutants (POPs) were included in this definition. A model, known as toxics cycle, represented the four distinct stages of the process of selecting substances for risk assessment and management: problem identification and priority setting, risk assessment, risk management, and monitoring and evaluation. A large number of international activities were reviewed, such as research, hazard and risk assessment, risk management, and monitoring and surveillance programs. The present report only deals with the programs that had been identified in the National Air Issues Coordinating Committee-Other Air Issues (NAICC-A) of the CCME report published in 1999 and which had recent or foreseen impacts. Five bi-lateral and multi-lateral agreements on persistent toxic substances, as well as national, regional and global programs, activities, and initiatives concerning the assessment of the hazards and risks of chemicals and actions were reviewed. It was recommended that initiatives at all levels continue to be monitored and that Environment Canada continue to be the conduit of information at the international level. Issues and opportunities must be identified by all jurisdictions with regard to risk management. It was suggested by the author that risk assessment be conducted by Environment Canada and the attention of the HAP group be drawn on specific topics as required. 2 tabs., 1 fig.

Air layering and its potential in propagating Uapaca kirkiana : a fruit ...

African Journals Online (AJOL)

The potential to propagateUapaca kirkiana through air layering was investigated at Igumbilo forest, Tanzania. The objective was to determine the effect of time of setting air layers and use of indole-3-butyric acid (IBA) to promote rooting. Air layers were initiated on young shoots, 1- to 2-years old, growing on mature trees.

Safety Evaluation of Potential Toxic Metals Exposure from Street Foods Consumed in Mid-West Nigeria

Directory of Open Access Journals (Sweden)

O. C. Ekhator

2017-01-01

Full Text Available Objective. Street-vended foods offer numerous advantages to food security; nevertheless, the safety of street food should be considered. This study has investigated the level of potential toxic metal (Pb, Cd, Hg, Sb, Mn, and Al contamination among street-vended foods in Benin City and Umunede. Methods. Twenty street food samples were purchased from vendors at bus stops. Metals were analyzed with atomic absorption spectrophotometry. The methods developed by the US EPA were employed to evaluate the potential health risk of toxic metals. Results. The concentrations of the toxic metals in mg/kg were in the range of Pb (0.014–1.37, Cd (0.00–0.00017, Hg (0.00–0.00014, Sb (0.00–0.021, Mn (0.00–0.012, and Al (0.00–0.22. All the toxic metals except Pb were below permissible limit set by WHO, EU, and USEPA. The daily intake, hazard quotient, and hazard index of all toxic metals except for Pb in some street foods were below the tolerable daily intake and threshold value of 1, indicating an insignificant health risk. Total cancer risk was within the priority risk level of 1.0E-04 but higher than the acceptable risk level of 1E-06. Conclusion. Consumption of some of these street foods is of public health concern.

Environmental toxicity and radioactivity assessment of a titanium-processing residue with potential for environmental use.

Science.gov (United States)

Wendling, Laura A; Binet, Monique T; Yuan, Zheng; Gissi, Francesca; Koppel, Darren J; Adams, Merrin S

2013-07-01

Thorough examination of the physicochemical characteristics of a Ti-processing residue was undertaken, including mineralogical, geochemical, and radiochemical characterization, and an investigation of the environmental toxicity of soft-water leachate generated from the residue. Concentrations of most metals measured in the leachate were low; thus, the residue is unlikely to leach high levels of potentially toxic elements on exposure to low-ionic strength natural waters. Relative to stringent ecosystem health-based guidelines, only chromium concentrations in the leachate exceeded guideline concentrations for 95% species protection; however, sulfate was present at concentrations known to cause toxicity. It is likely that the high concentration of calcium and extreme water hardness of the leachate reduced the bioavailability of some elements. Geochemical modeling of the leachate indicated that calcium and sulfate concentrations were largely controlled by gypsum mineral dissolution. The leachate was not toxic to the microalga Chlorella sp., the cladoceran Ceriodaphnia dubia, or the estuarine bacterium Vibrio fischeri. The Ti-processing residue exhibited an absorbed dose rate of 186 nGy/h, equivalent to an annual dose of 1.63 mGy and an annual effective dose of 0.326 mGy. In summary, the results indicate that the Ti-processing residue examined is suitable for productive use as an environmental amendment following 10 to 100 times dilution to ameliorate potential toxic effects due to chromium or sulfate. Copyright © 2013 SETAC.

Defusing the Toxics Threat: Controlling Pesticides and Industrial Waste. Worldwatch Paper 79.

Science.gov (United States)

Postel, Sandra

The use of pesticides in agriculture and the discarding of industrial chemical waste into the air, soil, and water constitute two major pathways of human exposure to toxic substances. It is argued that these practices release hundreds of millions of tons of potentially hazardous substances into the environment each year. Speculation continues into…

Airborne uranium, its concentration and toxicity in uranium enrichment facilities

International Nuclear Information System (INIS)

Thomas, J.; Mauro, J.; Ryniker, J.; Fellman, R.

1979-02-01

The release of uranium hexafluoride and its hydrolysis products into the work environment of a plant for enriching uranium by means of gas centrifuges is discussed. The maximum permissible mass and curie concentration of airborne uranium (U) is identified as a function of the enrichment level (i.e., U-235/total U), and chemical and physical form. A discussion of the chemical and radiological toxicity of uranium as a function of enrichment and chemical form is included. The toxicity of products of UF 6 hydrolysis in the atmosphere, namely, UO 2 F 2 and HF, the particle size of toxic particulate material produced from this hydrolysis, and the toxic effects of HF and other potential fluoride compounds are also discussed. Results of an investigation of known effects of humidity and temperature on particle size of UO 2 F 2 produced by the reaction of UF 6 with water vapor in the air are reported. The relationship of the solubility of uranium compounds to their toxic effects was studied. Identification and discussion of the standards potentially applicable to airborne uranium compounds in the working environment are presented. The effectiveness of High Efficiency Particulate (HEPA) filters subjected to the corrosive environment imposed by the presence of hydrogen fluoride is discussed

An assessment of the potential toxicity of runoff from an urban roadscape during rain events.

Science.gov (United States)

Waara, Sylvia; Färm, Carina

2008-05-01

The potential negative impact of urban storm water on aquatic freshwater ecosystems has been demonstrated in various studies with different types of biological methods. There are a number of factors that influence the amount and bioavailability of contaminants in storm water even if it is derived from an area with a fairly homogenous land use such as a roadscape where a variation in toxicity during rain events might be expected. There are only a few previous investigations on the toxicity of highway runoff and they have not explored these issues extensively. The main objective of this study is therefore to characterize the potential toxicity of highway runoff during several rain events before it enters a detention pond in Västerås, Sweden, using laboratory bioassays with test organisms representing various functional groups in an aquatic ecosystem. The results are to be used for developing a monitoring program, including biological methods. The storm water was sampled before the entrance to a detention pond, which receives run-off from a highway with approximately 20,000 vehicles a day. The drainage area, including the roadscape and vegetated areas, is 4.3 ha in size. Samples for toxicity tests were taken with an automatic sampler or manually during storm events. In total, the potential toxicity of 65 samples representing 15 different storm events was determined. The toxicity was assessed with 4 different test organisms; Vibrio fischeri using the Microtox comparison test, Daphnia magna using Daphtoxkit-F agna, Thamnocephalus platyurus using the ThamnotoxkitF and Lemna minor, duckweed using SS 028313. Of the 65 samples, 58 samples were tested with DaphniatoxkitF agna, 57 samples with the Microtox comparison test, 48 samples with ThamnotoxkitF and 20 samples with Lemna minor, duckweed. None of the storm water samples were toxic. No toxicity was detected with the Lemna minor test, but in 5 of the 23 samples tested in comparison to the control a growth stimulation of

TOXIC LEADERSHIP: A SYSTEMIC APPROACH TO SHIFT FROM REACTIVE TO PROACTIVE SOLUTIONS

Science.gov (United States)

2017-03-01

AIR COMMAND AND STAFF COLLEGE AIR UNIVERSITY TOXIC LEADERSHIP: A SYSTEMIC APPROACH TO SHIFT FROM REACTIVE TO PROACTIVE SOLUTIONS...DISTRIBUTION A. Approved for public release: distribution unlimited. Toxic Leadership: A Systemic Approach to Shift From Reactive to Proactive Solutions 1...US military loses valuable personnel when it is too late to implement corrective action and after those toxic Toxic Leadership: A Systemic Approach

Human health and ecological toxicity potentials due to heavy metal content in waste electronic devices with flat panel displays

International Nuclear Information System (INIS)

Lim, Seong-Rin; Schoenung, Julie M.

2010-01-01

Display devices such as cathode-ray tube (CRT) televisions and computer monitors are known to contain toxic substances and have consequently been banned from disposal in landfills in the State of California and elsewhere. New types of flat panel display (FPD) devices, millions of which are now purchased each year, also contain toxic substances, but have not previously been systematically studied and compared to assess the potential impact that could result from their ultimate disposal. In the current work, the focus is on the evaluation of end-of-life toxicity potential from the heavy metal content in select FPD devices with the intent to inform material selection and design-for-environment (DfE) decisions. Specifically, the metals antimony, arsenic, barium, beryllium, cadmium, chromium, cobalt, copper, lead, mercury, molybdenum, nickel, selenium, silver, vanadium, and zinc in plasma TVs, LCD (liquid crystal display) TVs, LCD computer monitors and laptop computers are considered. The human health and ecotoxicity potentials are evaluated through a life cycle assessment perspective by combining data on the respective heavy metal contents, the characterization factors in the U.S. EPA Tool for the Reduction and Assessment of Chemical and other environmental Impacts (TRACI), and a pathway and impact model. Principal contributors to the toxicity potentials are lead, arsenic, copper, and mercury. Although the heavy metal content in newer flat panel display devices creates less human health toxicity potential than that in CRTs, for ecological toxicity, the new devices are worse, especially because of the mercury in LCD TVs and the copper in plasma TVs.

Pollution Assessment of Toxic and Potentially Toxic Elements in Agricultural Soils of the City Addis Ababa, Ethiopia.

Science.gov (United States)

Aschale, Minbale; Sileshi, Yilma; Kelly-Quinn, Mary; Hailu, Dereje

2017-02-01

Due to the significantly fast urban expansion and increased industrial activities, the soils in the farms in Addis Ababa are contaminated by some toxic and potentially toxic elements (As, V, Cr, Fe, Co, Ni, Cu, B, Ba, Sr, Zn, Mn, Pb and Cd) in varying degrees. The mean concentrations of Cr, Ni, As and B in most of the soil farms were found to be higher than the maximum recommended limits. The mean concentrations of Cd, Cu, Pb, Co, Ni and Mn were found to be higher than the background soil concentrations given for uncontaminated soils. Multivariate analyses coupled with correlation analysis were used to identify possible sources. The geo-accumulation index values for Cr, Mn and Pb indicated that the farm soils were unpolluted to moderately polluted as a result of anthropogenic activities. A comprehensive environmental management strategy should be formulated by the government to measure further pollution of the farmland soil.

REAL-TIME EMISSION CHARACTERIZATION OF ORGANIC AIR TOXIC POLLUTANTS DURING STEADY STATE AND TRANSIENT OPERATION OF A MEDIUM DUTY DIESEL ENGINE

Science.gov (United States)

An on-line monitoring method, jet resonance-enhanced multi-photon ionization (REMPI) with time-of-flight mass spectrometry (TOFMS) was used to measure emissions of organic air toxics from a medium-duty (60 kW)diesel generator during transient and steady state operations. Emission...

UV-visible degradation of boscalid--structural characterization of photoproducts and potential toxicity using in silico tests.

Science.gov (United States)

Lassalle, Yannick; Kinani, Aziz; Rifai, Ahmad; Souissi, Yasmine; Clavaguera, Carine; Bourcier, Sophie; Jaber, Farouk; Bouchonnet, Stéphane

2014-05-30

Boscalid is a carboximide fungicide mainly used for vineyard protection as well as for tomato, apple, blueberry and various ornamental cultivations. The structural elucidation of by-products arising from the UV-visible photodegradation of boscalid has been investigated by gas chromatography/multi-stage mass spectrometry (GC/MS(n) ) and liquid chromatography/tandem mass spectrometry (LC/MS/MS) couplings. The potential toxicities of transformation products were estimated by in silico calculations. Aqueous solutions of boscalid were irradiated up to 150 min in a self-made reactor equipped with a mercury lamp. Analyses were carried out using a gas chromatograph coupled with an ion trap mass spectrometer operated in both electron ionization (EI) and chemical ionization (CI) modes and a liquid chromatograph coupled with a quadrupole time-of-flight (Q-TOF) mass spectrometer operated in electrospray ionization (ESI) mode. Multiple-stage collision-induced dissociation (CID) experiments were performed to establish dissociation pathways of ions. The QSAR (Quantitative Structure-Activity Relationship) T.E.S.T. program allowed the estimation of the toxicities of the by-products. Eight photoproducts were investigated. Chemical structures were proposed not only on the interpretation of multi-stage CID experiments, but also on kinetics data. These structures led us to suggest photodegradation pathways. Three photoproducts were finally detected in Lebanon in a real sample of grape leaves for which routine analysis had led to the detection of boscalid at 4 mg kg(-1). With one exception, the structures proposed for the photoproducts on the basis of mass spectra interpretation have not been reported in previous studies. In silico toxicity predictions showed that two photoproducts are potentially more toxic than the parent compound considering oral rat LD50 while five photoproducts may induce mutagenic toxicity. With the exception of one compound, all photoproducts may

UV-visible degradation of boscalid- structural characterization of photoproducts and potential toxicity using in silico tests

International Nuclear Information System (INIS)

Rifai, A.; Jaber, F.; Lassalle, Y.; Kinani, A.; Souissi, Y.; Clavaguera, C.; Bourcier, S.; Bouchonnet, St.

2014-01-01

RATIONALE: Boscalid is a carboximide fungicide mainly used for vineyard protection as well as for tomato, apple, blueberry and various ornamental cultivations. The structural elucidation of by-products arising from the UV-visible photodegradation of boscalid has been investigated by gas chromatography/multi-stage mass spectrometry (GC/MSn) and liquid chromatography/tandem mass spectrometry (LC/MS/MS) couplings. The potential toxicities of transformation products were estimated by in silico calculations. METHODS: Aqueous solutions of boscalid were irradiated up to 150 min in a self-made reactor equipped with a mercury lamp. Analyses were carried out using a gas chromatograph coupled with an ion trap mass spectrometer operated in both electron ionization (EI) and chemical ionization (CI) modes and a liquid chromatograph coupled with a quadrupole time-of-flight (Q-TOF) mass spectrometer operated in electrospray ionization (ESI) mode. Multiple-stage collision-induced dissociation (CID) experiments were performed to establish dissociation pathways of ions. The QSAR (Quantitative Structure-Activity Relationship) T.E.S.T. program allowed the estimation of the toxicities of the by-products. RESULTS: Eight photoproducts were investigated. Chemical structures were proposed not only on the interpretation of multi-stage CID experiments, but also on kinetics data. These structures led us to suggest photodegradation pathways. Three photoproducts were finally detected in Lebanon in a real sample of grape leaves for which routine analysis had led to the detection of boscalid at 4 mg kg1. CONCLUSIONS: With one exception, the structures proposed for the photoproducts on the basis of mass spectra interpretation have not been reported in previous studies. In silico toxicity predictions showed that two photoproducts are potentially more toxic than the parent compound considering oral rat LD50 while five photoproducts may induce mutagenic toxicity. With the exception of one compound

THE IMPACT OF SHRINKING HANFORD BOUNDARIES ON PERMITS FOR TOXIC AIR POLLUTANT EMISSIONS FROM THE HANFORD 200 WEST AREA

International Nuclear Information System (INIS)

JOHNSON, R.E.

2005-01-01

This presentation (CE-580. Graduate Seminar) presents a brief description of an approach to use a simpler dispersion modeling method (SCREEN3) in conjunction with joint frequency tables for Hanford wind conditions to evaluate the impacts of shrinking the Hanford boundaries on the current permits for facilities in the 200 West Area. To fulfill requirements for the graduate student project (CE-702. Master's Special Problems), this evaluation will be completed and published over the next two years. Air toxic emissions play an important role in environmental quality and require a state approved permit. One example relates to containers or waste that are designated as Transuranic Waste (TRU), which are required to have venting devices due to hydrogen generation. The Washington State Department of Ecology (Ecology) determined that the filters used did not meet the definition of a ''pressure relief device'' and that a permit application would have to be submitted by the Central Waste Complex (CWC) for criteria pollutant and toxic air pollutant (TAP) emissions in accordance with Washington Administrative Code (WAC) 173-400 and 173-460. The permit application submitted in 2000 to Ecology used Industrial Source Code III (ISCIII) dispersion modeling to demonstrate that it was not possible for CWC to release a sufficient quantity of fugitive Toxic Air Pollutant emissions that could exceed the Acceptable Source Impact Levels (ASILs) at the Hanford Site Boundary. The modeled emission rates were based on the diurnal breathing in and out through the vented drums (approximately 20% of the drums), using published vapor pressure, molecular weight, and specific gravity data for all 600+ compounds, with a conservative estimate of one exchange volume per day (208 liters per drum). Two permit applications were submitted also to Ecology for the Waste Receiving and Processing Facility and the T Plant Complex. Both permit applications were based on the Central Waste Complex approach, and

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

Mercury and Air Toxic Element Impacts of Coal Combustion By-Product Disposal and Utilizaton

Energy Technology Data Exchange (ETDEWEB)

David Hassett; Loreal Heebink; Debra Pflughoeft-Hassett; Tera Buckley; Erick Zacher; Mei Xin; Mae Sexauer Gustin; Rob Jung

2007-03-31

The University of North Dakota Energy & Environmental Research Center (EERC) conducted a multiyear study to evaluate the impact of mercury and other air toxic elements (ATEs) on the management of coal combustion by-products (CCBs). The ATEs evaluated in this project were arsenic, cadmium, chromium, lead, nickel, and selenium. The study included laboratory tasks to develop measurement techniques for mercury and ATE releases, sample characterization, and release experiments. A field task was also performed to measure mercury releases at a field site. Samples of fly ash and flue gas desulfurization (FGD) materials were collected preferentially from full-scale coal-fired power plants operating both without and with mercury control technologies in place. In some cases, samples from pilot- and bench-scale emission control tests were included in the laboratory studies. Several sets of 'paired' baseline and test fly ash and FGD materials collected during full-scale mercury emission control tests were also included in laboratory evaluations. Samples from mercury emission control tests all contained activated carbon (AC) and some also incorporated a sorbent-enhancing agent (EA). Laboratory release experiments focused on measuring releases of mercury under conditions designed to simulate CCB exposure to water, ambient-temperature air, elevated temperatures, and microbes in both wet and dry conditions. Results of laboratory evaluations indicated that: (1) Mercury and sometimes selenium are collected with AC used for mercury emission control and, therefore, present at higher concentrations than samples collected without mercury emission controls present. (2) Mercury is stable on CCBs collected from systems both without and with mercury emission controls present under most conditions tested, with the exception of vapor-phase releases of mercury exposed to elevated temperatures. (3) The presence of carbon either from added AC or from unburned coal can result in mercury

Separation of special toxic substances from the air and incinerator of offgas streams, especially of radioactive iodine and polycyclic carbon hydrogens

International Nuclear Information System (INIS)

Nikoopour-Deylami, A.H.

1981-11-01

In the first part of the thesis, the adsorption of radioiodine and methyliodide on different kinds of active charcoal was studied. It was observed that untreated charcoal retains radioiodine sufficiently, while organic compounds as methyliodid could be adsorbed after pretreating with triethylenediamine even at high air velocities. In the presence of moisture in the air the efficiency dropped down to 30% of the original value. In the second part of the work an apparatus using sandfilter columns for the separation of toxic substances and thermochrome column for marking the temperature intervals was developed and posted at different places in athe filtering system of an incineration plant. After extraction of the polycyclic aromates with benzene from the column and chemical separation, the neutral fraction was split by a silicagel column and 14 toxic aromates identified by gas chromatography. It could be proven that 97 +- 2% of the polycyclic aromates were retained by the existing ceramic filter systems. (Author)

QUANTIFYING SUBGRID POLLUTANT VARIABILITY IN EULERIAN AIR QUALITY MODELS

Science.gov (United States)

In order to properly assess human risk due to exposure to hazardous air pollutants or air toxics, detailed information is needed on the location and magnitude of ambient air toxic concentrations. Regional scale Eulerian air quality models are typically limited to relatively coar...

Targeting Destructive Narcissism: A New Approach for Identifying and Eliminating Toxic Senior Leaders in the U.S. Air Force

Science.gov (United States)

2014-02-13

aspects of this phenomenon. Constructive narcissists are well-balanced, possess positive self - esteem , display empathy, have an aptitude for...toxicity, Schmidt developed five descriptive dimensions: 1) abusive supervision, 2) authoritative leadership, 3) narcissism, 4) self - promotion and...three core values of Integrity First, Service before Self , and Excellence in All We Do. While a majority of senior Air Force officers enforce the

Emissions of organic air toxics from open burning: a comprehensive review

Energy Technology Data Exchange (ETDEWEB)

Lemieux, P M [United States Environmental Protection Agency, NC (United States). Air Pollution Prevention and Control Division, National Risk Management Research Laboratory; Lutes, C C; Santoianni, D A [ARCADIS G and M, Durham, NC (United States)

2004-07-01

Emissions from open burning, on a mass pollutant per mass fuel (emission factor) basis, are greater than those from well-controlled combustion sources. Some types of open burning (e.g. biomass) are large sources on a global scale in comparison to other broad classes of sources (e.g. mobile and industrial sources). A detailed literature search was performed to collect and collate available data reporting emissions of organic air toxics from open burning sources. The sources that were included in this paper are: Accidental Fires, Agricultural Burning of Crop Residue, Agricultural Plastic Film, Animal Carcasses, Automobile Shredder Fluff Fires, Camp Fires, Car-Boat-Train (the vehicle not cargo) Fires, Construction Debris Fires, Copper Wire Reclamation, Crude Oil and Oil Spill Fires, Electronics Waste, Fiberglass, Fireworks, Grain Silo Fires, Household Waste, Land Clearing Debris (biomass), Landfills/Dumps, Prescribed Burning and Savanna/Forest Fires, Structural Fires, Tire Fires, and Yard Waste Fires. Availability of data varied according to the source and the class of air toxics of interest. Volatile organic compound (VOC) and polycyclic aromatic hydrocarbon (PAH) data were available for many of the sources. Non-PAH semi-volatile organic compound (SVOC) data were available for several sources. Carbonyl and polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofuran (PCDD/F) data were available for only a few sources. There were several known sources for which no emissions data were available at all. It is desirable that emissions from those sources be tested so that the relative degree of hazard they pose can be assessed. Several observations were made including: Biomass open burning sources typically emitted less VOCs than open burning sources with anthropogenic fuels on a mass emitted per mass burned basis, particularly those where polymers were concerned. Biomass open burning sources typically emitted less SVOCs and PAHs than anthropogenic sources on a mass

Glyphosate: environmental contamination, toxicity and potential risks to human health via food contamination.

Science.gov (United States)

Bai, Shahla Hosseini; Ogbourne, Steven M

2016-10-01

Glyphosate has been the most widely used herbicide during the past three decades. The US Environmental Protection Agency (EPA) classifies glyphosate as 'practically non-toxic and not an irritant' under the acute toxicity classification system. This classification is based primarily on toxicity data and due to its unique mode of action via a biochemical pathway that only exists in a small number of organisms that utilise the shikimic acid pathway to produce amino acids, most of which are green plants. This classification is supported by the majority of scientific literature on the toxic effects of glyphosate. However, in 2005, the Food and Agriculture Organisation (FAO) reported that glyphosate and its major metabolite, aminomethylphosphonic acid (AMPA), are of potential toxicological concern, mainly as a result of accumulation of residues in the food chain. The FAO further states that the dietary risk of glyphosate and AMPA is unlikely if the maximum daily intake of 1 mg kg(-1) body weight (bw) is not exceeded. Research has now established that glyphosate can persist in the environment, and therefore, assessments of the health risks associated with glyphosate are more complicated than suggested by acute toxicity data that relate primarily to accidental high-rate exposure. We have used recent literature to assess the possible risks associated with the presence of glyphosate residues in food and the environment.

Bioremediation of toxic and hazardous wastes by denitrifying bacteria

International Nuclear Information System (INIS)

Barraquio, Wilfredo L.

2005-01-01

This papers discusses the wastes coming rom domestic, industrial and agricultural sources are polluting the forests, rivers lakes, groundwater, and air and there are some measures like the physicochemical and biological measures are being utilized to remedy the destruction of resources; and of the measures, bioremediation offers great potential in cleaning up the environment of pollutants which is a cost-effective and environment-friendly technology that uses microorganisms to degrade hazardous substances into less toxic

Chemical mixtures in untreated water from public-supply wells in the U.S.--occurrence, composition, and potential toxicity.

Science.gov (United States)

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

2012-08-01

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

Potential hazards of compressed air energy storage in depleted natural gas reservoirs.

Energy Technology Data Exchange (ETDEWEB)

Cooper, Paul W.; Grubelich, Mark Charles; Bauer, Stephen J.

2011-09-01

This report is a preliminary assessment of the ignition and explosion potential in a depleted hydrocarbon reservoir from air cycling associated with compressed air energy storage (CAES) in geologic media. The study identifies issues associated with this phenomenon as well as possible mitigating measures that should be considered. Compressed air energy storage (CAES) in geologic media has been proposed to help supplement renewable energy sources (e.g., wind and solar) by providing a means to store energy when excess energy is available, and to provide an energy source during non-productive or low productivity renewable energy time periods. Presently, salt caverns represent the only proven underground storage used for CAES. Depleted natural gas reservoirs represent another potential underground storage vessel for CAES because they have demonstrated their container function and may have the requisite porosity and permeability; however reservoirs have yet to be demonstrated as a functional/operational storage media for compressed air. Specifically, air introduced into a depleted natural gas reservoir presents a situation where an ignition and explosion potential may exist. This report presents the results of an initial study identifying issues associated with this phenomena as well as possible mitigating measures that should be considered.

Meteorological air pollution potential for Santiago, Chile: Towards an objective episode forecasting.

Science.gov (United States)

Rutllant, J; Garreaud, R

1995-02-01

The geography and climate of the Santiago basin are, in general, unfavorable for the diffusion of air pollutants. Consequently, extreme events occur frequently during the high pollution season extending from April to August. The meteorological conditions concurrent with those extreme events are mainly associated with the leading edges of coastal lows that bring down the base of the semipermanent temperature inversion reducing the dirunal growth of the surface mixed layer. In order to produce an objective 12 to 24-hour episode forecast, a two-way multivariate discriminant analysis has been used in the definition of a meteorological air-pollution potential index (MAPPI), separating high and low meteorological air-pollution potential days. The same procedure has been applied in the selection of the most efficient predictors for the MAPPI objective forecast, based on 12 and 24 UTC radiosonde data at Quintero, about 100 km to the NW of Santiago. Results indicate about 70% correctly forecasted days, with satisfactory skill-scores relative to persistency. The strong persistency characterizing the most efficient predictors in the 12-hour objective forecast scheme, makes the prediction of the first and last days of any particular air-pollution potential episode particularly difficult. To overcome this problem, a new set of predictors based on continuous measurements near the level of the top of the temperature inversion layer (900 hPa during air-pollution episodes) is being tested. Preliminary results indicate that the time-integrated zonal wind component at that level is a reliable precursor for both the onset and the end of air-pollution potential episodes.

Characterization of air freshener emission: the potential health effects.

Science.gov (United States)

Kim, Sanghwa; Hong, Seong-Ho; Bong, Choon-Keun; Cho, Myung-Haing

2015-01-01

Air freshener could be one of the multiple sources that release volatile organic compounds (VOCs) into the indoor environment. The use of these products may be associated with an increase in the measured level of terpene, such as xylene and other volatile air freshener components, including aldehydes, and esters. Air freshener is usually used indoors, and thus some compounds emitted from air freshener may have potentially harmful health impacts, including sensory irritation, respiratory symptoms, and dysfunction of the lungs. The constituents of air fresheners can react with ozone to produce secondary pollutants such as formaldehyde, secondary organic aerosol (SOA), oxidative product, and ultrafine particles. These pollutants then adversely affect human health, in many ways such as damage to the central nervous system, alteration of hormone levels, etc. In particular, the ultrafine particles may induce severe adverse effects on diverse organs, including the pulmonary and cardiovascular systems. Although the indoor use of air freshener is increasing, deleterious effects do not manifest for many years, making it difficult to identify air freshener-associated symptoms. In addition, risk assessment recognizes the association between air fresheners and adverse health effects, but the distinct causal relationship remains unclear. In this review, the emitted components of air freshener, including benzene, phthalate, and limonene, were described. Moreover, we focused on the health effects of these chemicals and secondary pollutants formed by the reaction with ozone. In conclusion, scientific guidelines on emission and exposure as well as risk characterization of air freshener need to be established.

Potential risks of metal toxicity in contaminated sediments of Deule river in Northern France

International Nuclear Information System (INIS)

Lourino-Cabana, Beatriz; Lesven, Ludovic; Charriau, Adeline; Billon, Gabriel; Ouddane, Baghdad; Boughriet, Abdel

2011-01-01

Research highlights: → A historical environmental pollution is evidenced with reference to background levels. → Sedimentary trace metals partitioning is examined under undisturbed conditions. → Anoxia and diagenetic processes induce geochemical and mineralogical variabilities. → Do metals present in particles and pore waters exhibit a potential toxicity risk? → Behaviour of binding fractions contributes to trace metals scavenging. - Abstract: The aim of this paper was to evaluate the potential sediment cumulative damage and toxicity due to metal contamination in a polluted zone of Deule river (in northern France) from nearby two smelters. Metal-enrichment factors and geoaccumulation indices measured with sediment depth revealed that - compared to background levels either in local reference soils or in world rivers sediments/suspended particulate matter - Cd contributed to the highest pollution levels, followed by Zn, Pb and to a much lesser extent Cu and Ni. A comparison of the vertical distribution of AVS (acid volatile sulfides), SEM (simultaneously extracted metals), TMC (total metal concentrations), TOC (total organic carbon) and interstitial water-metal concentrations in the sediment allowed us to highlight the extent of toxicity caused by Cd, Pb, Zn, Ni and Cu and to raise the possibility of their association with certain geochemical phases. To assess the actual environmental impacts of these metals in Deule river, numerical sediment quality guidelines were further used in the present work. Sedimentary Pb, Zn, and Cd contents largely exceeded PEC (probable effect concentration) values reported as consensus-based sediment quality guidelines for freshwater ecosystems. As for risks of toxicity from pore waters, metal concentrations reached their maxima at the surficial layers of the sediment (1-3 cm) and IWCTU (Interstitial Water Criteria Toxicity Unit) observed for Pb and to a lesser extent Cd, violated the corresponding water quality data recommended

Dissolvable layered double hydroxide as an efficient nanosorbent for centrifugeless air-agitated dispersive solid-phase extraction of potentially toxic metal ions from bio-fluid samples

International Nuclear Information System (INIS)

Rajabi, Maryam; Arghavani-Beydokhti, Somayeh; Barfi, Behruz; Asghari, Alireza

2017-01-01

solid-phase extraction method was developed. • A new functionalized LDH nanosorbent was introduced. • The proposed method extends application of D-SPE in on-line systems. • Some potentially toxic heavy metals were quantified in different biological fluids. • Elimination of centrifugation and elution steps, are most advantages of the method.

Energy saving potential of natural ventilation in China: The impact of ambient air pollution

International Nuclear Information System (INIS)

Tong, Zheming; Chen, Yujiao; Malkawi, Ali; Liu, Zhu; Freeman, Richard B.

2016-01-01

Highlights: • Natural ventilation potential is affected largely by ambient air pollution in China. • NV hours of 76 Chinese cities based on weather and ambient air quality are estimated. • Cooling energy savings and carbon reductions of 35 major Chinese cities are estimated. • 8–78% of the cooling energy usage can be potentially reduced by NV. • Our findings provide guidelines to improve energy policies in China. - Abstract: Natural ventilation (NV) is a key sustainable solution for reducing the energy use in buildings, improving thermal comfort, and maintaining a healthy indoor environment. However, the energy savings and environmental benefits are affected greatly by ambient air pollution in China. Here we estimate the NV potential of all major Chinese cities based on weather, ambient air quality, building configuration, and newly constructed square footage of office buildings in the year of 2015. In general, little NV potential is observed in northern China during the winter and southern China during the summer. Kunming located in the Southwest China is the most weather-favorable city for natural ventilation, and reveals almost no loss due to air pollution. Building Energy Simulation (BES) is conducted to estimate the energy savings of natural ventilation in which ambient air pollution and total square footage at each city must be taken into account. Beijing, the capital city, displays limited per-square-meter saving potential due to the unfavorable weather and air quality for natural ventilation, but its largest total square footage of office buildings makes it become the city with the greatest energy saving opportunity in China. Our analysis shows that the aggregated energy savings potential of office buildings at 35 major Chinese cities is 112 GWh in 2015, even after allowing for a 43 GWh loss due to China’s serious air pollution issue especially in North China. 8–78% of the cooling energy consumption can be potentially reduced by natural

Microplastic potentiates triclosan toxicity to the marine copepod Acartia tonsa (Dana)

DEFF Research Database (Denmark)

Syberg, Kristian; Nielsen, Anne; Khan, Farhan

2017-01-01

Microplastics (MP) are contaminants of environmental concern partly due to plastics ability to sorb and transport hydrophobic organic contaminants (HOC). The importance of this "vector effect" is currently being debated in the scientific community. This debate largely ignores that the co-exposure......Microplastics (MP) are contaminants of environmental concern partly due to plastics ability to sorb and transport hydrophobic organic contaminants (HOC). The importance of this "vector effect" is currently being debated in the scientific community. This debate largely ignores that the co......-exposures of MP and HOC are mixtures of hazardous agents, which can be addressed from a mixture toxicity perspective. In this study, mixture effects of polyethylene microbeads (MP) and triclosan (TCS) (a commonly used antibacterial agent in cosmetics) were assessed on the marine copepod Acartia tonsa. Data...... indicated that MP potentiate the toxicity of TCS, illustrating the importance of understanding the mixture interaction between plastics and HOC when addressing the environmental importance of the vector effect....

[Air pollution and cardiovascular toxicity: known risks].

Science.gov (United States)

Kostrzewa, A; Filleul, L; Eilstein, D; Harrabi, I; Tessier, J F

2004-03-01

Review of studies about epidemiological and physiopathological knowledge of ambient air particles short-term cardio-vascular effects. CURRENTS AND STRONG POINTS: Many studies, in contrasted countries for pollution's sources, meteorological conditions or socio-demographical characteristics, have shown health effects due to ambient air particles. After having studied mainly the respiratory effects of particulate air pollution, epidemiologists are now interested in the cardio-vascular effects of ambient air particles. In fact, serious effects seem to exist in fragile people which can get to emergency department visits, hospitalisation and even death. In addition, studies have shown less serious effects, but likely to be frequent (cardiac symptoms, and stoppages for cardio-vascular causes, notably). The exact mechanism by which particles have cardio-vascular adverse health effects is unknown, but experimental and epidemiological studies have led to several hypotheses: local pulmonary effects seem to be followed by systemic effects, which would be responsible for effects on the electrical activity of the heart through cardiac autonomic dysfunction and effects on the blood supply to the heart. The objective of this work is to summarise epidemiological and physiopathological knowledge about the cardio-vascular effects of ambient air particles. To evaluate the real importance of cardio-vascular effects due to particulate air pollution and to identify their exact mechanism, a more precise knowledge of detailed causes of deaths and hospitalisations and a better knowledge of less serious effects, but likely to be frequent, is necessary. Equally, a detailed identification of fragile people is essential for developing preventive actions.

The use of sugar and alcohol industry waste in the adsorption of potentially toxic metals.

Science.gov (United States)

Santos, Oseas Silva; Mendonça, André Gustavo Ribeiro; Santos, Josué Carinhanha Caldas; Silva, Amanda Paulina Bezerra; Costa, Silvanio Silverio Lopes; Oliveira, Luciana Camargo; Carmo, Janaina Braga; Botero, Wander Gustavo

2016-01-01

One of the waste products of the industrial process of the sugar and alcohol agribusiness is filter cake (FC). This waste product has high levels of organic matter, mainly proteins and lipids, and is rich in calcium, nitrogen, potassium and phosphorous. In this work we characterized samples of FC from sugar and alcohol industries located in sugarcane-producing regions in Brazil and assessed the adsorption of potentially toxic metals (Cu(II), Cd(II), Pb(II), Ni(II) and Cr(III)) by this waste in mono- and multi-elemental systems, seeking to use FC as an adsorbent in contaminated environments. The characterization of FCs showed significant differences between the samples and the adsorption studies showed retention of over 90% of potentially toxic metals. In a competitive environment (multi-metallic solution), the FC was effective in adsorbing all metals except lead, but less effective compared to the mono-metallic solution. These results show the potential for use of this residue as an adsorbent in contaminated environments.

Bioaccumulation of potentially toxic trace elements in benthic organisms of Admiralty Bay (King George Island, Antarctica)

International Nuclear Information System (INIS)

Majer, Alessandra Pereira; Petti, Mônica Angélica Varella; Corbisier, Thais Navajas; Ribeiro, Andreza Portella; Theophilo, Carolina Yume Sawamura; Ferreira, Paulo Alves de Lima; Figueira, Rubens Cesar Lopes

2014-01-01

Highlights: • Toxic metals were released in the 2012 fire in the Brazilian base at Admiralty Bay. • Potentially toxic metals were measured in eight Antarctic benthos species. • The bioaccumulation of As, Cd and Pb was verified in the studied species. • The biomagnification of Cd is suggested for the studied Antarctic food web. - Abstract: Data about the concentration, accumulation and transfer of potentially toxic elements in Antarctic marine food webs are essential for understanding the impacts of these elements, and for monitoring the pollution contribution of scientific stations, mainly in Admiralty Bay due to the 2012 fire in the Brazilian scientific station. Accordingly, the concentration of As, Cd, Cu, Ni, Pb and Zn was measured in eight benthic species collected in the 2005/2006 austral summer and the relationship between concentration and trophic position (indicated by δ 15 N values) was tested. A wide variation in metal content was observed depending on the species and the element. In the studied trophic positions, it was observed bioaccumulation for As, Cd and Pb, which are toxic elements with no biological function. In addition, Cd showed a positive relationship between concentration and trophic level suggesting the possible biomagnification of this element

Leaching of the potentially toxic pollutants from composites based on waste raw material

Directory of Open Access Journals (Sweden)

Terzić Anja

2012-01-01

Full Text Available The disposal of the fly ash generated in coal based power-plants may pose a significant risk to the environment due to the possible leaching of hazardous pollutants, such as toxic metals. Also, there is a risk of leaching even when fly ash is built-in the construction composites. Fly ashes from various landfills were applied in several composite samples (mortar, concrete and brick without any physical or thermal pre-treatment. The leachability of the potentially toxic pollutants from the fly ash based products was investigated. The leaching behavior and potential environmental impact of the 11 potentially hazardous elements was tracked: Pb, Cd, Zn, Cu, Ni, Cr, Hg, As, Ba, Sb and Se. A detailed study of physico-chemical characteristics of the fly ash, with accent on trace elements and the chemical composition investigation is included. Physico/chemical properties of fly ash were investigated by means of X-ray fluorescence, differential thermal analysis and X-ray diffraction methods. Scanning electron microscope was used in microstructural analysis. The results show that most of the elements are more easily leachable from the fly ash in comparison with the fly ash based composites. The leaching of investigated pollutants is within allowed range thus investigated fly ashes can be reused in construction materials production.

[Air humidifier--benefit or risk?].

Science.gov (United States)

Fidler, A H

1989-12-01

Indoor air pollution has become an issue of growing importance for the scientific community. A recent publication of a report of the US Environmental Protection Agency (EPA) showed evidence that portable ultrasonic humidifiers may play a significant role as health hazards as far as indoor air pollution with heavy metal particles is concerned. Especially if the manufacturers' guidelines are not followed strictly and the device is operated with tap water, indoor particle concentrations may reach up to 50 times US outdoor standards for toxic particle concentration. This paper highlights potential risks and benefits of various types of humidifiers, both in private and hospital settings, emphasizing that risks of air humidification in certain situations might outweigh anticipated benefits. The health policy implication of these findings should lead to a more critical application of air humidification in the health care environment and in addition to that, promote better information of the customer about safe operation and useful indications of such devices.

Potentially toxic metal contamination of urban soils and roadside dust in Shanghai, China

International Nuclear Information System (INIS)

Shi Guitao; Chen Zhenlou; Xu Shiyuan; Zhang Ju; Wang Li; Bi Chunjuan; Teng Jiyan

2008-01-01

A detailed investigation was conducted to understand the contamination characteristics of a selected set of potentially toxic metals in Shanghai. The amount of Pb, Zn, Cu, Cr, Cd and Ni were determined from 273 soil/dust samples collected within urban area. The results indicated that concentration of all metals except Ni in soils was significant, and metal pollution was even severer in roadside dust. A series of metal spatial distribution maps were created through geostatistical analysis, and the pollution hotspots tended to associate with city core area, major road junctions, and the regions close to industrial zones. In attempt of identifying the source of metals through geostatistical and multivariate statistical analyses, it was concluded as follows: Pb, Zn and Cu mainly originated from traffic contaminants; soil Ni was associated with natural concentration; Cd largely came from point-sourced industrial pollution; and Cr, Ni in dust were mainly related to atmospheric deposition. - Human activities have led to high accumulation of potentially toxic metals in urban soils and roadside dust of Shanghai

Potentially toxic metal contamination of urban soils and roadside dust in Shanghai, China

Energy Technology Data Exchange (ETDEWEB)

Shi Guitao [Key Laboratory of Geographic Information Science of Ministry of Education, East China Normal University, Shanghai 200062 (China); Chen Zhenlou [Key Laboratory of Geographic Information Science of Ministry of Education, East China Normal University, Shanghai 200062 (China)], E-mail: gt_shi@163.com; Xu Shiyuan [Key Laboratory of Geographic Information Science of Ministry of Education, East China Normal University, Shanghai 200062 (China); Zhang Ju [School of Environment and Planning, Liaocheng University, Liaocheng 252059 (China); Wang Li; Bi Chunjuan [Key Laboratory of Geographic Information Science of Ministry of Education, East China Normal University, Shanghai 200062 (China); Teng Jiyan [Shanghai Chongming Dongtan National Nature Reserve, Shanghai 202183 (China)

2008-11-15

A detailed investigation was conducted to understand the contamination characteristics of a selected set of potentially toxic metals in Shanghai. The amount of Pb, Zn, Cu, Cr, Cd and Ni were determined from 273 soil/dust samples collected within urban area. The results indicated that concentration of all metals except Ni in soils was significant, and metal pollution was even severer in roadside dust. A series of metal spatial distribution maps were created through geostatistical analysis, and the pollution hotspots tended to associate with city core area, major road junctions, and the regions close to industrial zones. In attempt of identifying the source of metals through geostatistical and multivariate statistical analyses, it was concluded as follows: Pb, Zn and Cu mainly originated from traffic contaminants; soil Ni was associated with natural concentration; Cd largely came from point-sourced industrial pollution; and Cr, Ni in dust were mainly related to atmospheric deposition. - Human activities have led to high accumulation of potentially toxic metals in urban soils and roadside dust of Shanghai.

Speciation and mobility of potentially toxic elements in municipal solid waste incineration bottom ash

NARCIS (Netherlands)

Schollbach, K.; Alam, Q.; Florea, M.V.A.; Brouwers, H.J.H.

2017-01-01

Bottom ash (BA) is the main residue from municipal solid waste incineration (MSWI), which can have some applications in construction materials, but is mostly landfilled in many countries. The main problem is the high concentration of potentially toxic elements (PTEs), particularly in the fine

Environmentally induced epigenetic toxicity: potential public health concerns.

Science.gov (United States)

Marczylo, Emma L; Jacobs, Miriam N; Gant, Timothy W

2016-09-01

Throughout our lives, epigenetic processes shape our development and enable us to adapt to a constantly changing environment. Identifying and understanding environmentally induced epigenetic change(s) that may lead to adverse outcomes is vital for protecting public health. This review, therefore, examines the present understanding of epigenetic mechanisms involved in the mammalian life cycle, evaluates the current evidence for environmentally induced epigenetic toxicity in human cohorts and rodent models and highlights the research considerations and implications of this emerging knowledge for public health and regulatory toxicology. Many hundreds of studies have investigated such toxicity, yet relatively few have demonstrated a mechanistic association among specific environmental exposures, epigenetic changes and adverse health outcomes in human epidemiological cohorts and/or rodent models. While this small body of evidence is largely composed of exploratory in vivo high-dose range studies, it does set a precedent for the existence of environmentally induced epigenetic toxicity. Consequently, there is worldwide recognition of this phenomenon, and discussion on how to both guide further scientific research towards a greater mechanistic understanding of environmentally induced epigenetic toxicity in humans, and translate relevant research outcomes into appropriate regulatory policies for effective public health protection.

Bioaccessibility and Speciation of Potential Toxicants in Some Geogenic Sources of Atmospheric Particulate Matter

Science.gov (United States)

Morman, S. A.; Wolf, R. E.; Plumlee, G.; Reynolds, R. L.

2008-12-01

The correlation of exposure to particulate matter (PM) and increased morbidity and mortality was established in the 1970's. Research focused on elucidating mechanisms of action (i.e. particle size, composition, and biodurability), has generally examined anthropogenic sources such as solid or liquid combustion byproducts of fossil fuels, byproducts from the smelting of metal ores, and commercial/industrial mineral dusts (asbestos, crystalline silica. metal dusts). While many studies exist on agricultural exposures to inorganic dust, far fewer have examined health issues related to particulate matter contributions from rural, non-agricultural dusts or other geogenic sources. Geogenic PM (produced by natural processes such as volcanic ash, volcanic fog (vog), dusts from dry lakes or glacial deposits, smoke and windborne ash from wildfires, and dusts containing various soil pathogens) and geoanthropogenic PM (produced from natural sources by processes that are modified or enhanced by human activities such as dusts from lakebeds dried by human removal of water, dusts produced from areas that have undergone desertification as a result of human practices etc.) are increasingly recognized as potential agents of toxicity and disease, via both environmental and occupational exposures. Surface sediment on some dry lake beds may contribute significant amounts of mineral dusts to the atmospheric load. For example, Owens Lake (a dry lake in southern California) has been a major source of PM10 (particulate matter less than 10 micrometers) dust in the United States. Dusts from dry and drying saline lakes may contain high concentrations of metals, such as arsenic, with known human health toxicity. Wildfires, consuming over nine million acres in 2007, also contribute significant amounts of particulate matter in addition to their other hazards. Designed to estimate the bioaccessibility of metals in soils, dusts and other environmental materials by measuring the reactivity of the

Determination of nutrients and potentially toxic elements in Jatropha curcas seeds, oil and biodiesel using inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Maciel, P.B.; Barros de, L.L.S.; Duarte, E.C.M.; Harder, M.N.C.; Abreu, Jr.C.H.; Villanueva, F.C.A.

2013-01-01

Biodiesel is a renewable and biodegradable fuel that can be used in diesel engines as a replacement for fossil diesel. A suitable alternative is to produce it from Jatropha curcas, which has high quality oil concentration. Nevertheless, the presence of particular chemical elements above certain limits can affect the product quality, leading to vehicle engine problems and acting as air pollution source. The objective of this work is to develop a method for the simultaneous determination of B, Na, Mg, P, S, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Ba, and Pb in J. curcas seeds, oil and biodiesel using the inductively coupled plasma mass spectrometry (ICP-MS) technique. This material was evaluated because has been successfully employed in India for biodiesel production as well as in other places where there is an incentive to family farming, without affect the food chain. The oil was obtained from seeds via mechanical extraction and the biodiesel was achieved by oil transesterification. After optimization of the microwave digestion method for the different sample types, the samples were analyzed by ICP-MS. The certified reference material NIST SRM 1515 (apple leaves) and the recovery tests were carried out to ensure the accuracy of the proposed method, which made possible the quantification of several nutrients and potentially toxic elements in J. curcas seeds, oil and biodiesel, especially Na, K, Ca, Mg, P and S in biodiesel which are mandatory analyzed by Petroleum, Natural Gas and Biofuel National Agency (ANP). This work highlights the findings of the first study of potentially toxic and nutrient elements in the production chain steps seed-oil-biodiesel from J. curcas. (author)

An integrative view of cisplatin-induced renal and cardiac toxicities: molecular mechanisms, current treatment challenges and potential protective measures

Science.gov (United States)

Dugbartey, George J.; Peppone, Luke J.; de Graaf, Inge A.M.

2017-01-01

Cisplatin is currently one of the most widely-used chemotherapeutic agents against various malignancies. Its clinical application is limited, however, by inherent renal and cardiac toxicities and other side effects, of which the underlying mechanisms are only partly understood. Experimental studies show cisplatin generates reactive oxygen species, which impair the cell’s antioxidant defense system, causing oxidative stress and potentiating injury, thereby culminating in kidney and heart failure. Understanding the molecular mechanisms of cisplatin-induced renal and cardiac toxicities may allow clinicians to prevent or treat this problem better and may also provide a model for investigating drug-induced organ toxicity in general. This review discusses some of the major molecular mechanisms of cisplatin-induced renal and cardiac toxicities including disruption of ionic homeostasis and energy status of the cell leading to cell injury and cell death. We highlight clinical manifestations of both toxicities as well as (novel)biomarkers such as kidney injury molecule-1 (KIM-1), tissue inhibitor of metalloproteinase-1 (TIMP-1) and N-terminal pro-B-type natriuretic peptide (NT-proBNP). We also present some current treatment challenges and propose potential protective strategies with novel pharmacological compounds that might mitigate or prevent these toxicities, which include the use of hydrogen sulfide. PMID:27717837

CAirTOX: A compartment model for assessing the fate of and human exposure to toxic-chemical emissions to air

Energy Technology Data Exchange (ETDEWEB)

McKone, T.E.

1993-10-01

CAirTOX has been developed as a spreadsheet model to assist in making a risk assessment of toxic air emissions. With CAirTOX, one can address how contaminants released to an air basin can lead to contamination of soil, food, surface water, and sediments. The modeling effort includes a multimedia transport and transformation model, exposure scenario models, and efforts to quantify uncertainty in multimedia, multiple-pathway exposure assessments. The multimedia transport and transformation model is a steady-state, but non-equilibrium model that can be used to assess concentrations of contaminants released continuously to air. In Part 1, the authors describe the multimedia transport and transformation model used to determine the fate of air emissions. In Part 2, they describe inputs and data needs for CAirTOX and the development of a set of landscape factors, which can be used to represent regional air basin/water-shed systems in California. In Part 3, they describe the multiple-pathway exposure scenarios and exposure algorithms. In Part 4, they compare the HRA approach and results and the CAirTOX exposure equations. In Part 5, they consider model sensitivity and uncertainty to determine how variability and uncertainty in model inputs affects the precision, accuracy, and credibility of the model output.

Airborne persistent toxic substances (PTSs) in China: occurrence and its implication associated with air pollution.

Science.gov (United States)

Wang, Pu; Zhang, Qinghua; Li, Yingming; Matsiko, Julius; Zhang, Ya; Jiang, Guibin

2017-08-16

In recent years, China suffered from extensive air pollution due to the rapidly expanding economic and industrial developments. Its severe impact on human health has raised great concern currently. Persistent toxic substances (PTSs), a large group of environmental pollutants, have also received much attention due to their adverse effects on both the ecosystem and public health. However, limited studies have been conducted to reveal the airborne PTSs associated with air pollution at the national scale in China. In this review, we summarized the occurrence and variation of airborne PTSs in China, especially in megacities. These PTSs included polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), halogenated flame retardants (HFRs), perfluorinated compounds (PFCs), organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs) and heavy metals. The implication of their occurrence associated with air pollution was discussed, and the emission source of these chemicals was concluded. Most reviewed studies have been conducted in east and south China with more developed economy and industry. Severe contamination of airborne PTSs generally occurred in megacities with large populations, such as Guangzhou, Shanghai and Beijing. However, the summarized results suggested that industrial production and product consumption are the major sources of most PTSs in the urban environment, while unintentional emission during anthropogenic activities is an important contributor to airborne PTSs. It is important that fine particles serve as a major carrier of most airborne PTSs, which facilitates the long-range atmospheric transport (LRAT) of PTSs, and therefore, increases the exposure risk of the human body to these pollutants. This implied that not only the concentration and chemical composition of fine particles but also the absorbed PTSs are of particular concern when air pollution occurs.

Variable pore connectivity model linking gas diffusivity and air-phase tortuosity to soil matric potential

DEFF Research Database (Denmark)

Chamindu, Deepagoda; Møldrup, Per; Schjønning, Per

2012-01-01

information on soil functional pore structure, e.g., pore network tortuosity and connectivity, can also be revealed from Dp/Do–ψ relations. Based on Dp/Do measurements in a wide range of soil types across geographically remote vadose zone profiles, this study analyzed pore connectivity for the development...... of a variable pore connectivity factor, X, as a function of soil matric potential, expressed as pF (=log |−ψ|), for pF values ranging from 1.0 to 3.5. The new model takes the form of X = X* (F/F*)A with F = 1 + pF−1, where X* is the pore network tortuosity at reference F (F*) and A is a model parameter......- and intraaggregate pore regions of aggregated soils. We further suggest that the new model with parameter values of X* = 1.7 and A = 0 may be used for upper limit Dp/Do predictions in risk assessments of, e.g., fluxes of toxic volatile organics from soil to indoor air at polluted soil sites....

Using E-PRTR data on point source emissions to air and water—First steps towards a national chemical footprint

International Nuclear Information System (INIS)

Sörme, L.; Palm, V.; Finnveden, G.

2016-01-01

There is a great need for indicators to monitor the use and potential impacts of hazardous chemicals. Today there is a huge lack of data, methods and results and method development and studies should be given urgent priority. The aim of this paper was to develop and test an approach to calculate the potential environmental impacts of chemicals for a whole country using the E-PRTR (European Pollutant Release and Transfer Register) as a database and Sweden as an example. Swedish data from 2008 on emissions to air and water for 54 substances from point sources were retrieved from an open database. The data were transformed and aggregated using USEtox, a life-cycle impact assessment (LCIA) method for calculating potential human toxicity and ecotoxicity, both from industrial emissions directly and after input–output analysis (IO analysis) to reallocate emissions to product categories. Zinc to air and water contributed most to human toxicity followed by mercury to air. The largest contribution by industry to potential human toxicity came from the metal industry, followed by the paper and paper product industry. For potential ecotoxicity, zinc, fluoranthene and copper contributed the most. The largest contributions by industry came from the paper and paper products manufacturing sector, followed by the basic metals manufacturing sector. The approach used here can be seen as the first step towards a chemical footprint for nations. By adding data from other countries and other sources, a more complete picture can be gained in line with other footprint calculations. Furthermore, diffuse emissions from, for example, transport or emissions of pesticides could also be added for a more holistic assessment. Since the area of chemicals is complicated, it is probably necessary to develop and use several indicators that complement each other. It is suggested that the approach outlined here could be useful in developing a method for establishing a national chemical footprint

Using E-PRTR data on point source emissions to air and water—First steps towards a national chemical footprint

Energy Technology Data Exchange (ETDEWEB)

Sörme, L., E-mail: louise.sorme@scb.se [Statistics Sweden, Box 24300, SE-104 51 Sweden (Sweden); Palm, V. [Statistics Sweden, Box 24300, SE-104 51 Sweden (Sweden); KTH Royal Institute of Technology, Division of Environmental Strategies Research, SE-100 44 Stockholm (Sweden); Finnveden, G. [KTH Royal Institute of Technology, Division of Environmental Strategies Research, SE-100 44 Stockholm (Sweden)

2016-01-15

There is a great need for indicators to monitor the use and potential impacts of hazardous chemicals. Today there is a huge lack of data, methods and results and method development and studies should be given urgent priority. The aim of this paper was to develop and test an approach to calculate the potential environmental impacts of chemicals for a whole country using the E-PRTR (European Pollutant Release and Transfer Register) as a database and Sweden as an example. Swedish data from 2008 on emissions to air and water for 54 substances from point sources were retrieved from an open database. The data were transformed and aggregated using USEtox, a life-cycle impact assessment (LCIA) method for calculating potential human toxicity and ecotoxicity, both from industrial emissions directly and after input–output analysis (IO analysis) to reallocate emissions to product categories. Zinc to air and water contributed most to human toxicity followed by mercury to air. The largest contribution by industry to potential human toxicity came from the metal industry, followed by the paper and paper product industry. For potential ecotoxicity, zinc, fluoranthene and copper contributed the most. The largest contributions by industry came from the paper and paper products manufacturing sector, followed by the basic metals manufacturing sector. The approach used here can be seen as the first step towards a chemical footprint for nations. By adding data from other countries and other sources, a more complete picture can be gained in line with other footprint calculations. Furthermore, diffuse emissions from, for example, transport or emissions of pesticides could also be added for a more holistic assessment. Since the area of chemicals is complicated, it is probably necessary to develop and use several indicators that complement each other. It is suggested that the approach outlined here could be useful in developing a method for establishing a national chemical footprint

Dissolvable layered double hydroxide as an efficient nanosorbent for centrifugeless air-agitated dispersive solid-phase extraction of potentially toxic metal ions from bio-fluid samples

Energy Technology Data Exchange (ETDEWEB)

Rajabi, Maryam, E-mail: mrajabi@semnan.ac.ir; Arghavani-Beydokhti, Somayeh; Barfi, Behruz; Asghari, Alireza

2017-03-08

and tap water samples. - Highlights: • A novel centrifugeless dispersive solid-phase extraction method was developed. • A new functionalized LDH nanosorbent was introduced. • The proposed method extends application of D-SPE in on-line systems. • Some potentially toxic heavy metals were quantified in different biological fluids. • Elimination of centrifugation and elution steps, are most advantages of the method.

VirtualToxLab — A platform for estimating the toxic potential of drugs, chemicals and natural products

International Nuclear Information System (INIS)

Vedani, Angelo; Dobler, Max; Smieško, Martin

2012-01-01

The VirtualToxLab is an in silico technology for estimating the toxic potential (endocrine and metabolic disruption, some aspects of carcinogenicity and cardiotoxicity) of drugs, chemicals and natural products. The technology is based on an automated protocol that simulates and quantifies the binding of small molecules towards a series of proteins, known or suspected to trigger adverse effects. The toxic potential, a non-linear function ranging from 0.0 (none) to 1.0 (extreme), is derived from the individual binding affinities of a compound towards currently 16 target proteins: 10 nuclear receptors (androgen, estrogen α, estrogen β, glucocorticoid, liver X, mineralocorticoid, peroxisome proliferator-activated receptor γ, progesterone, thyroid α, and thyroid β), four members of the cytochrome P450 enzyme family (1A2, 2C9, 2D6, and 3A4), a cytosolic transcription factor (aryl hydrocarbon receptor) and a potassium ion channel (hERG). The interface to the technology allows building and uploading molecular structures, viewing and downloading results and, most importantly, rationalizing any prediction at the atomic level by interactively analyzing the binding mode of a compound with its target protein(s) in real-time 3D. The VirtualToxLab has been used to predict the toxic potential for over 2500 compounds: the results are posted on (http://www.virtualtoxlab.org). The free platform — the OpenVirtualToxLab — is accessible (in client–server mode) over the Internet. It is free of charge for universities, governmental agencies, regulatory bodies and non-profit organizations. -- Highlights: ► In silico technology for estimating the toxic potential of drugs and chemicals. ► Simulation of binding towards 16 proteins suspected to trigger adverse effects. ► Mechanistic interpretation and real-time 3D visualization. ► Accessible over the Internet. ► Free of charge for universities, governmental agencies, regulatory bodies and NPOs.

VirtualToxLab — A platform for estimating the toxic potential of drugs, chemicals and natural products

Energy Technology Data Exchange (ETDEWEB)

Vedani, Angelo, E-mail: angelo.vedani@unibas.ch [Biographics Laboratory 3R, Klingelbergstrasse 50, 4056 Basel (Switzerland); Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056 Basel (Switzerland); Dobler, Max [Biographics Laboratory 3R, Klingelbergstrasse 50, 4056 Basel (Switzerland); Smieško, Martin [Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056 Basel (Switzerland)

2012-06-01

The VirtualToxLab is an in silico technology for estimating the toxic potential (endocrine and metabolic disruption, some aspects of carcinogenicity and cardiotoxicity) of drugs, chemicals and natural products. The technology is based on an automated protocol that simulates and quantifies the binding of small molecules towards a series of proteins, known or suspected to trigger adverse effects. The toxic potential, a non-linear function ranging from 0.0 (none) to 1.0 (extreme), is derived from the individual binding affinities of a compound towards currently 16 target proteins: 10 nuclear receptors (androgen, estrogen α, estrogen β, glucocorticoid, liver X, mineralocorticoid, peroxisome proliferator-activated receptor γ, progesterone, thyroid α, and thyroid β), four members of the cytochrome P450 enzyme family (1A2, 2C9, 2D6, and 3A4), a cytosolic transcription factor (aryl hydrocarbon receptor) and a potassium ion channel (hERG). The interface to the technology allows building and uploading molecular structures, viewing and downloading results and, most importantly, rationalizing any prediction at the atomic level by interactively analyzing the binding mode of a compound with its target protein(s) in real-time 3D. The VirtualToxLab has been used to predict the toxic potential for over 2500 compounds: the results are posted on (http://www.virtualtoxlab.org). The free platform — the OpenVirtualToxLab — is accessible (in client–server mode) over the Internet. It is free of charge for universities, governmental agencies, regulatory bodies and non-profit organizations. -- Highlights: ► In silico technology for estimating the toxic potential of drugs and chemicals. ► Simulation of binding towards 16 proteins suspected to trigger adverse effects. ► Mechanistic interpretation and real-time 3D visualization. ► Accessible over the Internet. ► Free of charge for universities, governmental agencies, regulatory bodies and NPOs.

Potentially toxic concentrations of synthetic pyrethroids associated with low density residential land use

Directory of Open Access Journals (Sweden)

Stephen Marshall

2016-11-01

Full Text Available Trace organic compounds associated with human activity are now ubiquitous in the environment. As the population becomes more urbanised and the use of pesticides and person care products continues to increase, urban waterways are likely to receive higher loads of trace organic contaminants with unknown ecological consequences. To establish the extent of trace organic contamination in urban runoff, concentrations of emerging chemicals of concern were determined in sediments from 99 urban wetlands in and around Melbourne, Australia between February and April, 2015. As a preliminary estimation of potential risks to aquatic biota, we compared measured concentrations with thresholds for acute and chronic toxicity, and modelled toxic units as a function of demographic and land use trends. The synthetic pyrethroid insecticide bifenthrin was common and widespread, and frequently occurred at concentrations likely to cause toxicity to aquatic life. Personal care products DEET and triclosan were common and widely distributed, while the herbicides diuron and prometryn, and the fungicides pyrimethanil and trifloxystrobin occurred less frequently. Toxic unit modelling using random forests found complex and unexpected associations between urban land uses and trace organic concentrations. Synthetic pyrethroid insecticides were identified as emerging compounds of concern, particularly bifenthrin. In contrast with previous surveys, the highest bifenthrin concentrations were associated with lower housing and population density, implicating low-density residential land use in bifenthrin contamination. We discuss the implications for pesticide regulation and urban wetland management in a global context.

Evaluation of ameliorative potential of supranutritional selenium on enrofloxacin-induced testicular toxicity.

Science.gov (United States)

Rungsung, Soya; Khan, Adil Mehraj; Sood, Naresh Kumar; Rampal, Satyavan; Singh Saini, Simrat Pal

2016-05-25

The study was designed to assess the ameliorative potential of selenium (Se) on enrofloxacin-induced testicular toxicity in rats. There was a significant decrease in body weight and non-significant decrease in mean testicular weight of enrofloxacin treated rats. In enrofloxacin treated rats, total sperm count and viability decreased where as sperm abnormalities increased. Testicular histopathology revealed dose dependent dysregulation of spermatogenesis and presence of necrotic debris in seminiferous tubules which was marginally improved with Se. Enrofloxacin also produced a dose dependent decrease in testosterone level. The activity of testicular antioxidant enzymes decreased where as lipid peroxidation increased in a dose-dependent manner. Se supplementation partially restored oxidative stress and sperm damage and did not affect the plasma concentrations of enrofloxacin or ciprofloxacain. The results indicate that enrofloxacin produces a dose-dependent testicular toxicity in rats that is moderately ameliorated with supranutritional Se. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Air Quality – monitoring and modelling

Directory of Open Access Journals (Sweden)

Marius DEACONU

2012-12-01

Full Text Available Air pollution is a major concern for all nations, regardless of their development. The rapid growth of the industrial sector and urban development have lead to significant quantities of substances and toxic materials, mostly discharged into the atmosphere and having adverse effects both on human health and environment in general. Human society has to recognize that environment has only a limited capacity to process all of its waste without major changes. Each of us is a pollutant but also a victim of pollution. If monitoring of air pollutants is particularly important for assessing the air quality at any moment, by modelling the monitoring data spectacular results are obtained both through the factor analysis and identification of potential pollution mitigation measures. Latest equipment and techniques come and support these problems giving medium and long term solutions.

Evaluation of the Possible Sources and Controlling Factors of Toxic Metals/Metalloids in the Florida Everglades and Their Potential Risk of Exposure.

Science.gov (United States)

Li, Yanbin; Duan, Zhiwei; Liu, Guangliang; Kalla, Peter; Scheidt, Daniel; Cai, Yong

2015-08-18

The Florida Everglades is an environmentally sensitive wetland ecosystem with a number of threatened and endangered fauna species susceptible to the deterioration of water quality. Several potential toxic metal sources exist in the Everglades, including farming, atmospheric deposition, and human activities in urban areas, causing concerns of potential metal exposure risks. However, little is known about the pollution status of toxic metals/metalloids of potential concern, except for Hg. In this study, eight toxic metals/metalloids (Cd, Cr, Pb, Ni, Cu, Zn, As, and Hg) in Everglades soils were investigated in both dry and wet seasons. Pb, Cr, As, Cu, Cd, and Ni were identified to be above Florida SQGs (sediment quality guidelines) at a number of sampling sites, particularly Pb, which had a level of potential risk to organisms similar to that of Hg. In addition, a method was developed for quantitative source identification and controlling factor elucidation of toxic metals/metalloids by introducing an index, enrichment factor (EF), in the conventional multiple regression analysis. EFs represent the effects of anthropogenic sources on metals/metalloids in soils. Multiple regression analysis showed that Cr and Ni were mainly controlled by anthropogenic loading, whereas soil characteristics, in particular natural organic matter (NOM), played a more important role for Hg, As, Cd, and Zn. NOM may control the distribution of these toxic metals/metalloids by affecting their mobility in soils. For Cu and Pb, the effects of EFs and environmental factors are comparable, suggesting combined effects of loading and soil characteristics. This study is the first comprehensive research with a vast amount of sampling sites on the distribution and potential risks of toxic metals/metalloids in the Everglades. The finding suggests that in addition to Hg other metals/metalloids could also potentially be an environmental problem in this wetland ecosystem.

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.

High Time Resolution Measurements of VOCs from Vehicle Cold Starts: The Air Toxic Cold Start Pulse

Science.gov (United States)

Jobson, B. T.; Huangfu, Y.; Vanderschelden, G. S.

2017-12-01

Pollutants emitted during motor vehicle cold starts, especially in winter in some climates, is a significant source of winter time air pollution. While data exist for CO, NO, and total hydrocarbon emissions from federal testing procedures for vehicle emission certification, little is known about the emission rates of individual volatile organic compounds, in particular the air toxics benzene, formaldehyde, and acetaldehyde. Little is known about the VOC speciation and temperature dependence for cold starts. The US EPA vehicle emission model MOVES assumes that cold start emissions have the same speciation profile as running emissions. We examined this assumption by measuring cold start exhaust composition for 4 vehicles fueled with E10 gasoline over a temperature range of -4°C to 10°C in winter of 2015. The extra cold start emissions were determined by comparison with emissions during engine idling. In addition to CO and NOx measurements a proton transfer reaction mass spectrometer was used to measure formaldehyde, acetaldehyde, benzene, toluene, and C2-alkylbenzenes at high time resolution to compare with the cold start emission speciation profiles used in the EPA MOVES2014 model. The results show that after the vehicle was started, CO mixing ratios can reach a few percent of the exhaust and then drop to several ppmv within 2 minutes of idling, while NOx showed different temporal behaviors among the four vehicles. VOCs displayed elevated levels during cold start and the peak mixing ratios can be two orders higher than idling phase levels. Molar emission ratios relative to toluene were used to compare with the emission ratio used in MOVES2014 and we found the formaldehyde-to-toluene emission ratio was about 0.19, which is 5 times higher than the emission ratio used in MOVES2014 and the acetaldehyde-to-toluene emission ratios were 0.86-0.89, which is 8 times higher than the ones in MOVES2014. The C2-alkylbenzene-to-toluene ratio agreed well with moves. Our results

Surma eye cosmetic in Afghanistan: a potential source of lead toxicity in children.

Science.gov (United States)

McMichael, J R; Stoff, B K

2018-02-01

Surma is a traditional eye cosmetic used as an eyeliner for infants in Afghanistan, as well as in many other countries in Asia, the Middle East, and Africa. Surma has been reported to contain lead and to be a potential source of lead toxicity in children, which can lead to permanent damage to multiple organ systems. To our knowledge, assessment for lead in surma found in Afghanistan has not been performed. We determined the quantitative lead content of a convenience sample of 10 surma products acquired in Afghanistan. Analysis revealed that 70% of surma samples contained high levels of lead (range 35-83%). The remaining samples contained low levels of lead (range 0.04-0.17%). The majority of surma samples contained very high levels of lead, a troubling finding that could potentially correlate with lead toxicity in Afghan children. Making available lead-free surma alternatives and providing health education, for both healthcare professionals and the general population, in locations where surma use is prevalent and for those involved in care of refugees and immigrants from Afghanistan, may be strategies to prevent lead poisoning in children. What is Known: • Surma is a traditional cosmetic used as an eyeliner for infants in Afghanistan as well as in many countries in Asia, the Middle East, and Africa. • Surma has been reported to contain lead and to be a source of lead toxicity in children. What is New: • Assessment for lead content in surma found in Afghanistan has not been performed. • In this convenience sample of 10 surma products acquired in Afghanistan, 70% contained very high levels of lead.

Assessing potential dietary toxicity of heavy metals in selected vegetables and food crops.

Science.gov (United States)

Islam, Ejaz ul; Yang, Xiao-e; He, Zhen-li; Mahmood, Qaisar

2007-01-01

Heavy metals, such as cadmium, copper, lead, chromium and mercury, are important environmental pollutants, particularly in areas with high anthropogenic pressure. Their presence in the atmosphere, soil and water, even in traces can cause serious problems to all organisms, and heavy metal bioaccumulation in the food chain especially can be highly dangerous to human health. Heavy metals enter the human body mainly through two routes namely: inhalation and ingestion, ingestion being the main route of exposure to these elements in human population. Heavy metals intake by human populations through food chain has been reported in many countries. Soil threshold for heavy metal toxicity is an important factor affecting soil environmental capacity of heavy metal and determines heavy metal cumulative loading limits. For soil-plant system, heavy metal toxicity threshold is the highest permissible content in the soil (total or bioavailable concentration) that does not pose any phytotoxic effects or heavy metals in the edible parts of the crops does not exceed food hygiene standards. Factors affecting the thresholds of dietary toxicity of heavy metal in soil-crop system include: soil type which includes soil pH, organic matter content, clay mineral and other soil chemical and biochemical properties; and crop species or cultivars regulated by genetic basis for heavy metal transport and accumulation in plants. In addition, the interactions of soil-plant root-microbes play important roles in regulating heavy metal movement from soil to the edible parts of crops. Agronomic practices such as fertilizer and water managements as well as crop rotation system can affect bioavailability and crop accumulation of heavy metals, thus influencing the thresholds for assessing dietary toxicity of heavy metals in the food chain. This paper reviews the phytotoxic effects and bioaccumulation of heavy metals in vegetables and food crops and assesses soil heavy metal thresholds for potential dietary

Quantitative analysis of potentially toxic metals in alginates for dental use

Directory of Open Access Journals (Sweden)

A. S. BRAGA

2009-01-01

Full Text Available

Alginate is one the materials most employed in practice to make dental impressions. Substances like zinc, cadmium and lead silicate, which are included in several alginate brands with the aim of improving their physical, chemical and mechanical properties, are a source of serious concern as regards their toxicity. The most serious chronic effect of oral exposure to cadmium is renal toxicity. Assimilation of lead has deleterious effects on the gastrointestinal tract, hematopoietic system, cardiovascular system, central and peripheral nervous systems, kidneys, immune system, and reproductive system. Chronic oral exposures to zinc have resulted in hypochromic and microcyte anemia in some individuals. The aim of the present study was to measure the cadmium, lead and zinc contents of seven brands of alginate for dental use on sale in Brazil. The samples were weighed and placed in the Teflon cups of a closedsystem microwave oven. Aqua regia (4mL concentrated HCl:HNO₃, 3:1 v/v and hydrofluoric acid (2mL concentrated HF were added to the samples, which were then subjected to heating. The samples were then cooled to room temperature and diluted to 25 mL in deionized water in a volumetric glass flask. The samples were diluted in duplicate and analyzed against a reagent blank. The analyses were performed in an atomic absorption flame spectrophotometer. Neither lead nor cadmium was detected. Zinc contents ranged from 0.001% to 1.36% by weight. The alginates exhibited low contents of the metals under study and gave no cause for concern regarding toxicity; even so, it is advisable to monitor potentially toxic materials continually and to analyze their plasmatic levels in the professionals working with them. Keywords: Cadmium, lead, zinc, alginates, intoxication, irreversible hydrocolloid.

Study on the Potential Toxicity of a Thymoquinone-Rich Fraction Nanoemulsion in Sprague Dawley Tats

Directory of Open Access Journals (Sweden)

Maznah Ismail

2013-06-01

Full Text Available Toxicological studies constitute an essential part of the effort in developing an herbal medicine into a drug product. A newly developed thymoquinone-rich fraction nanoemulsion (TQRFNE has been prepared using a high pressure homogenizer. The purpose of this study was to investigate the potential acute toxicity of this nanoemulsion in Sprague Dawley rats. The acute toxicity studies were conducted as per the OECD guidelines 425, allowing for the use of test dose limit of 20 mL TQRFNE (containing 44.5 mg TQ/kg. TQRFNE and distilled water (DW as a control were administered orally to both sexes of rats on Day 0 and observed for 14 days. All the animals appeared normal, and healthy throughout the study. There was no observed mortality or any signs of toxicity during the experimental period. The effects of the TQRFNE and DW groups on general behavior, body weight, food and water consumption, relative organ weight, hematology, histopathology, and clinical biochemistry were measured. All the parameters measured were unaffected as compared to the control (DW group. The administration of 20 mL TQRFNE /kg was not toxic after an acute exposure.

Downward Movement of Potentially Toxic Elements in Biosolids Amended Soils

Directory of Open Access Journals (Sweden)

Silvana Irene Torri

2012-01-01

Full Text Available Potentially toxic elements (PTEs in soils are mainly associated with the solid phase, bound to the surface of solid components, or precipitated as minerals. For most PTEs, only a small portion is dissolved in the soil solution. However, there is an interest in following the fate of mobile PTEs in the environment, for a growing amount of evidence indicates that downward movement of PTEs may occur in biosolids amended soils, leading to groundwater contamination. Therefore, it is crucial to understand the factors that control the release of these elements after land application of biosolids, in order to overcome problems related to downward movement of PTEs in the soil profile.

Yellow phosphorus process to convert toxic chemicals to non-toxic products

Science.gov (United States)

Chang, S.G.

1994-07-26

The present invention relates to a process for generating reactive species for destroying toxic chemicals. This process first contacts air or oxygen with aqueous emulsions of molten yellow phosphorus. This contact results in rapid production of abundant reactive species such as O, O[sub 3], PO, PO[sub 2], etc. A gaseous or liquid aqueous solution organic or inorganic chemicals is next contacted by these reactive species to reduce the concentration of toxic chemical and result in a non-toxic product. The final oxidation product of yellow phosphorus is phosphoric acid of a quality which can be recovered for commercial use. A process is developed such that the byproduct, phosphoric acid, is obtained without contamination of toxic species in liquids treated. A gas stream containing ozone without contamination of phosphorus containing species is also obtained in a simple and cost-effective manner. This process is demonstrated to be effective for destroying many types of toxic organic, or inorganic, compounds, including polychlorinated biphenyls (PCB), aromatic chlorides, amines, alcohols, acids, nitro aromatics, aliphatic chlorides, polynuclear aromatic compounds (PAH), dyes, pesticides, sulfides, hydroxyamines, ureas, dithionates and the like. 20 figs.

Assessment of metal leachability and toxicity from sediment potentially stored on land

OpenAIRE

Baran, A; Tarnawski, M; Michalec, B

2015-01-01

The aim of this study was to assess the toxicity and metal leachability from three dredged bottom sediments potentially stored on land. Washing out was conducted at a sediment dry mass to water mass ratio of 1:10. The method relies on washing out pollutants from the examined sample using water with third degree of purity in static/quasi-dynamic conditions. The investigations comprised three 27-h washing out cycles, including leaching in static conditions (19 h) and shaking (8 h). Bottom sedim...

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

Oxidative potential of gas phase combustion emissions - An underestimated and potentially harmful component of air pollution from combustion processes

Science.gov (United States)

Stevanovic, S.; Vaughan, A.; Hedayat, F.; Salimi, F.; Rahman, M. M.; Zare, A.; Brown, R. A.; Brown, R. J.; Wang, H.; Zhang, Z.; Wang, X.; Bottle, S. E.; Yang, I. A.; Ristovski, Z. D.

2017-06-01

The oxidative potential (OP) of the gas phase is an important and neglected aspect of environmental toxicity. Whilst prolonged exposure to particulate matter (PM) associated reactive oxygen species (ROS) have been shown to lead to negative health effects, the potential for compounds in gas phase to cause similar effects is yet to be understood. In this study we describe: the significance of the gas phase OP generated through vehicle emissions; discuss the origin and evolution of species contributing to measured OP; and report on the impact of gas phase OP on human lung cells. The model aerosol for this study was exhaust emitted from a Euro III Common-rail diesel engine fuelled with different blends of diesel and biodiesel. The gas phase of these emissions was found to be potentially as hazardous as the particle phase. Fuel oxygen content was found to negatively correlate with the gas phase OP, and positively correlate with particle phase OP. This signifies a complex interaction between reactive species present in gas and particle phase. Furthermore, this interaction has an overarching effect on the OP of both particle and gas phase, and therefore the toxicity of combustion emissions.

Protective air lock

International Nuclear Information System (INIS)

Evans, H.W.

1976-01-01

A device suitable for preventing escape and subsequent circulation of toxic gases is described. An enclosure is sealed by a surrounding air lock, and an automatic mechanism partially evacuates the enclosure and air lock. The enclosure ventilating mechanism can be disconnected so that a relatively undisturbed atmosphere is created in the enclosure

Potential of extracellular microRNAs as biomarkers of acetaminophen toxicity in children

Energy Technology Data Exchange (ETDEWEB)

Yang, Xi, E-mail: Xi.Yang@fda.hhs.gov [Division of Systems Biology, National Center for Toxicological Research, Food and Drug Administration, 3900 NCTR Road, Jefferson, AR (United States); Salminen, William F., E-mail: Willie.Salminen@parexel.com [Division of Systems Biology, National Center for Toxicological Research, Food and Drug Administration, 3900 NCTR Road, Jefferson, AR (United States); Shi, Qiang, E-mail: Qiang.Shi@fda.hhs.gov [Division of Systems Biology, National Center for Toxicological Research, Food and Drug Administration, 3900 NCTR Road, Jefferson, AR (United States); Greenhaw, James, E-mail: James.Greenhaw@fda.hhs.gov [Division of Systems Biology, National Center for Toxicological Research, Food and Drug Administration, 3900 NCTR Road, Jefferson, AR (United States); Gill, Pritmohinder S., E-mail: PSGill@uams.edu [Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR (United States); Clinical Pharmacology and Toxicology Section, Arkansas Children' s Hospital, Little Rock, AR (United States); Bhattacharyya, Sudeepa, E-mail: SBhattacharyya2@uams.edu [Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR (United States); Clinical Pharmacology and Toxicology Section, Arkansas Children' s Hospital, Little Rock, AR (United States); Beger, Richard D., E-mail: Richard.Beger@fda.hhs.gov [Division of Systems Biology, National Center for Toxicological Research, Food and Drug Administration, 3900 NCTR Road, Jefferson, AR (United States); Mendrick, Donna L., E-mail: Donna.Mendrick@fda.hhs.gov [Division of Systems Biology, National Center for Toxicological Research, Food and Drug Administration, 3900 NCTR Road, Jefferson, AR (United States); Mattes, William B., E-mail: William.Mattes@fda.hhs.gov [Division of Systems Biology, National Center for Toxicological Research, Food and Drug Administration, 3900 NCTR Road, Jefferson, AR (United States); and others

2015-04-15

Developing biomarkers for detecting acetaminophen (APAP) toxicity has been widely investigated. Recent studies of adults with APAP-induced liver injury have reported human serum microRNA-122 (miR-122) as a novel biomarker of APAP-induced liver injury. The goal of this study was to examine extracellular microRNAs (miRNAs) as potential biomarkers for APAP liver injury in children. Global levels of serum and urine miRNAs were examined in three pediatric subgroups: 1) healthy children (n = 10), 2) hospitalized children receiving therapeutic doses of APAP (n = 10) and 3) children hospitalized for APAP overdose (n = 8). Out of 147 miRNAs detected in the APAP overdose group, eight showed significantly increased median levels in serum (miR-122, -375, -423-5p, -30d-5p, -125b-5p, -4732-5p, -204-5p, and -574-3p), compared to the other groups. Analysis of urine samples from the same patients had significantly increased median levels of four miRNAs (miR-375, -940, -9-3p and -302a) compared to the other groups. Importantly, correlation of peak serum APAP protein adduct levels (an indicator of the oxidation of APAP to the reactive metabolite N-acetyl-para-quinone imine) with peak miRNA levels showed that the highest correlation was observed for serum miR-122 (R = 0.94; p < 0.01) followed by miR-375 (R = 0.70; p = 0.05). Conclusion: Our findings demonstrate that miRNAs are increased in children with APAP toxicity and correlate with APAP protein adducts, suggesting a potential role as biomarkers of APAP toxicity. - Highlights: • Serum miR-122 and miR-375 levels were increased in children with APAP overdose. • Urine levels of miR-375 and miR-940 were increased in the APAP overdose group. • Peak serum miR-122 levels were correlated with peak serum APAP protein adducts.

Potential effects of salt-laden cooling air in the ALMR RVACS

International Nuclear Information System (INIS)

Hunsbedt, A.; Gordon, B.M.; Baston, V.F.; Steigerwald, R.F.

1992-01-01

The Advanced Liquid Metal Reactor (ALMR) concept has a totally passive safety-related decay heat removal system referred to as the Reactor Vessel Auxiliary Cooling System (RVACS) that rejects heat from the 471 MWt modular reactor to the atmosphere or ambient air by natural convection heat transfer. The system has no active components, requires no operator action to initiate, and thus is totally passive. The effects of operation of the RVACS in coastal environments where the air has high concentrations of air-borne sea-salt have been addressed. The potential for corrosion of the carbon steel and RVACS related structures have been evaluated and it was concluded that corrosion is not a problem. (author)

Control of aliphatic halogenated DBP precursors with multiple drinking water treatment processes: Formation potential and integrated toxicity.

Science.gov (United States)

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

2017-08-01

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

Organochlorine pesticides in soils of Mexico and the potential for soil-air exchange

International Nuclear Information System (INIS)

Wong, Fiona; Alegria, Henry A.; Bidleman, Terry F.

2010-01-01

The spatial distribution of organochlorine pesticides (OCs) in soils and their potential for soil-air exchange was examined. The most prominent OCs were the DDTs (Geometric Mean, GM = 1.6 ng g -1 ), endosulfans (0.16 ng g -1 ), and toxaphenes (0.64 ng g -1 ). DDTs in soils of southern Mexico showed fresher signatures with higher F DDTe = p,p'-DDT/(p,p'-DDT + p,p'-DDE) and more racemic o,p'-DDT, while the signatures in the central and northern part of Mexico were more indicative of aged residues. Soil-air fugacity fractions showed that some soils are net recipients of DDTs from the atmosphere, while other soils are net sources. Toxaphene profiles in soils and air showed depletion of Parlar 39 and 42 which suggests that soil is the source to the atmosphere. Endosulfan was undergoing net deposition at most sites as it is a currently used pesticide. Other OCs showed wide variability in fugacity, suggesting a mix of net deposition and volatilization. - Chemical profiles of residues and soil-air fugacities are used to assess the potential of soil as a source of organochlorine pesticides to the air of Mexico.

Toxicity of a metal(loid)-polluted agricultural soil to Enchytraeus crypticus changes under a global warming perspective: Variations in air temperature and soil moisture content

NARCIS (Netherlands)

Gonzalez Alcaraz, M.N.; van Gestel, C.A.M.

2016-01-01

This study aimed to assess how the current global warming perspective, with increasing air temperature (20 °C vs. 25 °C) and decreasing soil moisture content (50% vs. 30% of the soil water holding capacity, WHC), affected the toxicity of a metal(loid)-polluted agricultural soil to Enchytraeus

Biosorption: An Interplay between Marine Algae and Potentially Toxic Elements-A Review.

Science.gov (United States)

Bilal, Muhammad; Rasheed, Tahir; Sosa-Hernández, Juan Eduardo; Raza, Ali; Nabeel, Faran; Iqbal, Hafiz M N

2018-02-19

In recent decades, environmental pollution has emerged as a core issue, around the globe, rendering it of fundamental concern to eco-toxicologists, environmental biologists, eco-chemists, pathologists, and researchers from other fields. The dissolution of polluting agents is a leading cause of environmental pollution of all key spheres including the hydrosphere, lithosphere, and biosphere, among others. The widespread occurrence of various pollutants including toxic heavy metals and other emerging hazardous contaminants is a serious concern. With increasing scientific knowledge, socioeconomic awareness, human health problems, and ecological apprehensions, people are more concerned about adverse health outcomes. Against this background, several removal methods have been proposed and implemented with the aim of addressing environmental pollution and sustainable and eco-friendly development. Among them, the biosorption of pollutants using naturally inspired sources, e.g., marine algae, has considerable advantages. In the past few years, marine algae have been extensively studied due to their natural origin, overall cost-effective ratio, and effectiveness against a broader pollutant range; thus, they are considered a potential alternative to the conventional methods used for environmental decontamination. Herein, an effort has been made to highlight the importance of marine algae as naturally inspired biosorbents and their role in biosorption. Biosorption mechanisms and factors affecting biosorption activities are also discussed in this review. The utilization of marine algae as a biosorbent for the removal of numerous potentially toxic elements has also been reviewed.

Biosorption: An Interplay between Marine Algae and Potentially Toxic Elements—A Review

Science.gov (United States)

Bilal, Muhammad; Rasheed, Tahir; Raza, Ali; Nabeel, Faran

2018-01-01

In recent decades, environmental pollution has emerged as a core issue, around the globe, rendering it of fundamental concern to eco-toxicologists, environmental biologists, eco-chemists, pathologists, and researchers from other fields. The dissolution of polluting agents is a leading cause of environmental pollution of all key spheres including the hydrosphere, lithosphere, and biosphere, among others. The widespread occurrence of various pollutants including toxic heavy metals and other emerging hazardous contaminants is a serious concern. With increasing scientific knowledge, socioeconomic awareness, human health problems, and ecological apprehensions, people are more concerned about adverse health outcomes. Against this background, several removal methods have been proposed and implemented with the aim of addressing environmental pollution and sustainable and eco-friendly development. Among them, the biosorption of pollutants using naturally inspired sources, e.g., marine algae, has considerable advantages. In the past few years, marine algae have been extensively studied due to their natural origin, overall cost-effective ratio, and effectiveness against a broader pollutant range; thus, they are considered a potential alternative to the conventional methods used for environmental decontamination. Herein, an effort has been made to highlight the importance of marine algae as naturally inspired biosorbents and their role in biosorption. Biosorption mechanisms and factors affecting biosorption activities are also discussed in this review. The utilization of marine algae as a biosorbent for the removal of numerous potentially toxic elements has also been reviewed. PMID:29463058

Biosorption: An Interplay between Marine Algae and Potentially Toxic Elements—A Review

Directory of Open Access Journals (Sweden)

Muhammad Bilal

2018-02-01

Full Text Available In recent decades, environmental pollution has emerged as a core issue, around the globe, rendering it of fundamental concern to eco-toxicologists, environmental biologists, eco-chemists, pathologists, and researchers from other fields. The dissolution of polluting agents is a leading cause of environmental pollution of all key spheres including the hydrosphere, lithosphere, and biosphere, among others. The widespread occurrence of various pollutants including toxic heavy metals and other emerging hazardous contaminants is a serious concern. With increasing scientific knowledge, socioeconomic awareness, human health problems, and ecological apprehensions, people are more concerned about adverse health outcomes. Against this background, several removal methods have been proposed and implemented with the aim of addressing environmental pollution and sustainable and eco-friendly development. Among them, the biosorption of pollutants using naturally inspired sources, e.g., marine algae, has considerable advantages. In the past few years, marine algae have been extensively studied due to their natural origin, overall cost-effective ratio, and effectiveness against a broader pollutant range; thus, they are considered a potential alternative to the conventional methods used for environmental decontamination. Herein, an effort has been made to highlight the importance of marine algae as naturally inspired biosorbents and their role in biosorption. Biosorption mechanisms and factors affecting biosorption activities are also discussed in this review. The utilization of marine algae as a biosorbent for the removal of numerous potentially toxic elements has also been reviewed.

Commercial liquid bags as a potential source of venous air embolism in shoulder arthroscopy.

Science.gov (United States)

Austin, Luke; Zmistowski, Benjamin; Tucker, Bradford; Hetrick, Robin; Curry, Patrick; Williams, Gerald

2010-09-01

Venous air embolism is a rare but potentially fatal complication of arthroscopy. Fatal venous air embolism has been reported with as little as 100 mL of air entering the venous system. During liquid-only arthroscopy, avenues for air introduction into the joint are limited. Therefore, we hypothesized that commercially prepared 3-L saline-solution bags are a source of potentially fatal amounts of gas that can be introduced into the joint by arthroscopic pumps. Eight 3-L arthroscopic saline-solution bags were obtained and visually inspected for air. The air was aspirated from four bags, and the volume of the air was recorded. A closed-system pump was prepared, and two 3-L bags were connected to it. The pump emptied into an inverted graduated cylinder immersed in a water bath. Both bags were allowed to run dry. Two more bags were then connected and also allowed to run dry. The air was quantified by the downward displacement of water. The experiment was then repeated with the four bags after the air had been aspirated from them. This experiment was performed at three institutions, with utilization of three pump systems and two brands of 3-L saline-solution bags. Air was visualized in all bags, and the bags contained between 34 and 85 mL of air. Arthroscopic pumps can pump air efficiently through the tubing. The total volumes of gas ejected from the tubing after the four 3-L bags had been emptied were 75, 80, and 235 mL. When bags from which the air had been evacuated were used, no air exited the system. Because a saline-solution arthroscopic pump is theoretically a closed system, venous air embolism has not been a concern. However, this study shows that it is possible to pump a fatal amount of air from 3-L saline-solution bags into an environment susceptible to the creation of emboli. Evacuation of air from the 3-L bags prior to use may eliminate this risk.

Triphenyl phosphate-induced developmental toxicity in zebrafish: Potential role of the retinoic acid receptor

Energy Technology Data Exchange (ETDEWEB)

Isales, Gregory M.; Hipszer, Rachel A.; Raftery, Tara D. [Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC (United States); Chen, Albert; Stapleton, Heather M. [Division of Environmental Sciences and Policy, Nicholas School of the Environment, Duke University, Durham, NC (United States); Volz, David C., E-mail: volz@mailbox.sc.edu [Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC (United States)

2015-04-15

Highlights: • Triphenyl phosphate-induced toxicity in zebrafish embryos is enhanced in the presence of a retinoic acid receptor antagonist. • Triphenyl phosphate uptake or metabolism within zebrafish embryos is not altered in the presence of a retinoic acid receptor antagonist. • Triphenyl phosphate decreases expression of cytochrome P450 26a1 in zebrafish embryos. • Triphenyl phosphate inhibits retinoic acid-induced activation of human retinoic acid receptors. - Abstract: Using zebrafish as a model, we previously reported that developmental exposure to triphenyl phosphate (TPP) – a high-production volume organophosphate-based flame retardant – results in dioxin-like cardiac looping impairments that are independent of the aryl hydrocarbon receptor. Using a pharmacologic approach, the objective of this study was to investigate the potential role of retinoic acid receptor (RAR) – a nuclear receptor that regulates vertebrate heart morphogenesis – in mediating TPP-induced developmental toxicity in zebrafish. We first revealed that static exposure of zebrafish from 5–72 h post-fertilization (hpf) to TPP in the presence of non-toxic concentrations of an RAR antagonist (BMS493) significantly enhanced TPP-induced toxicity (relative to TPP alone), even though identical non-toxic BMS493 concentrations mitigated retinoic acid (RA)-induced toxicity. BMS493-mediated enhancement of TPP toxicity was not a result of differential TPP uptake or metabolism, as internal embryonic doses of TPP and diphenyl phosphate (DPP) – a primary TPP metabolite – were not different in the presence or absence of BMS493. Using real-time PCR, we then quantified the relative change in expression of cytochrome P450 26a1 (cyp26a1) – a major target gene for RA-induced RAR activation in zebrafish – and found that RA and TPP exposure resulted in a ∼5-fold increase and decrease in cyp26a1 expression, respectively, relative to vehicle-exposed embryos. To address whether TPP may

Harmonizing human exposure and toxicity characterization

DEFF Research Database (Denmark)

Fantke, Peter; Jolliet, O.; McKone, T.E.

2017-01-01

The UNEP-SETAC Life Cycle Initiative has launched a project to provide global guidance and build consensus on environmental life cycle impact assessment (LCIA) indicators. Human health effects from exposure to toxic chemicals was selected as impact category due to high relevance of human toxicity...... and harmonizing human toxicity characterization in LCIA. Building on initial work for the far-field and indoor air environments, and combining it with latest work on near-field consumer and occupational exposure assessment, dose-response and severity data, we aim at providing revised guidance on the development...... and use of impact factors for toxic chemicals. We propose to couple fate processes in consumer and occupational environments with existing environmental compartments and processes via a consistent and mass balance-based set of transfer fractions to quantify overall aggregated exposure to toxic substances...

Hazardous air emissions potential from a wood-fired furnace

International Nuclear Information System (INIS)

Hubbard, A.J.

1995-01-01

During the first week of April, 1991 the Wisconsin Department of Natural Resources (WDNR) conducted a series of air emissions tests of a small industrial wood-fired boiler in northern Wisconsin. The boiler was firing a virgin hogged wood/wood waste fuel with a moisture content of about 35 percent. The pollutants measured were particulates, nitrogen oxides (NOx), carbon monoxide (GO), total hydrocarbons (THC), benzene, formaldehyde (CHOH), polycyclic organic matter (POM, e.g. Benzo (a) pyrene), aldehydes, and trace metals (As, Ba, Cu, Pb, Mn, Ni, K, Se, Na, and Zn). For two and a half days continuous emissions data were recorded by laboratory-certified continuous emissions monitors for CO, NOx, 0-2, THC, and COq2 while the EPA reference method stack tests were being conducted for the other pollutants. In addition, a WDNR test team measured CO, 0-2, and flue gas temperature with a Rosemount portable combustion analyzer for several hours over the course of those two and a half days. The principal purpose behind the study was to evaluate the hazardous air emissions potential of a small industrial furnace firing a virgin wood fuel. To that end, it was hoped that a surrogate pollutant could be identified which would represent the levels of hazardous air emissions (e.g., benzene) present in the wood-fired furnace flue gases. If a readily monitorable pollutant could be identified, then a regulatory strategy of measuring one representative pollutant could be put in place to continually assess the hazardous emissions potential of virgin wood combustion. (UK)

Air Toxics Under the Big Sky: Examining the Effectiveness of Authentic Scientific Research on High School Students' Science Skills and Interest.

Science.gov (United States)

Ward, Tony J; Delaloye, Naomi; Adams, Earle Raymond; Ware, Desirae; Vanek, Diana; Knuth, Randy; Hester, Carolyn Laurie; Marra, Nancy Noel; Holian, Andrij

2016-01-01

Air Toxics Under the Big Sky is an environmental science outreach/education program that incorporates the Next Generation Science Standards (NGSS) 8 Practices with the goal of promoting knowledge and understanding of authentic scientific research in high school classrooms through air quality research. A quasi-experimental design was used in order to understand: 1) how the program affects student understanding of scientific inquiry and research and 2) how the open inquiry learning opportunities provided by the program increase student interest in science as a career path . Treatment students received instruction related to air pollution (airborne particulate matter), associated health concerns, and training on how to operate air quality testing equipment. They then participated in a yearlong scientific research project in which they developed and tested hypotheses through research of their own design regarding the sources and concentrations of air pollution in their homes and communities. Results from an external evaluation revealed that treatment students developed a deeper understanding of scientific research than did comparison students, as measured by their ability to generate good hypotheses and research designs, and equally expressed an increased interest in pursuing a career in science. These results emphasize the value of and need for authentic science learning opportunities in the modern science classroom.

Air Toxics Under the Big Sky: Examining the Effectiveness of Authentic Scientific Research on High School Students’ Science Skills and Interest

Science.gov (United States)

Delaloye, Naomi; Adams, Earle Raymond; Ware, Desirae; Vanek, Diana; Knuth, Randy; Hester, Carolyn Laurie; Marra, Nancy Noel; Holian, Andrij

2016-01-01

Air Toxics Under the Big Sky is an environmental science outreach/education program that incorporates the Next Generation Science Standards (NGSS) 8 Practices with the goal of promoting knowledge and understanding of authentic scientific research in high school classrooms through air quality research. A quasi-experimental design was used in order to understand: 1) how the program affects student understanding of scientific inquiry and research and 2) how the open inquiry learning opportunities provided by the program increase student interest in science as a career path. Treatment students received instruction related to air pollution (airborne particulate matter), associated health concerns, and training on how to operate air quality testing equipment. They then participated in a yearlong scientific research project in which they developed and tested hypotheses through research of their own design regarding the sources and concentrations of air pollution in their homes and communities. Results from an external evaluation revealed that treatment students developed a deeper understanding of scientific research than did comparison students, as measured by their ability to generate good hypotheses and research designs, and equally expressed an increased interest in pursuing a career in science. These results emphasize the value of and need for authentic science learning opportunities in the modern science classroom. PMID:28286375

Air Toxics Under the Big Sky: examining the effectiveness of authentic scientific research on high school students' science skills and interest

Science.gov (United States)

Ward, Tony J.; Delaloye, Naomi; Adams, Earle Raymond; Ware, Desirae; Vanek, Diana; Knuth, Randy; Hester, Carolyn Laurie; Marra, Nancy Noel; Holian, Andrij

2016-04-01

Air Toxics Under the Big Sky is an environmental science outreach/education program that incorporates the Next Generation Science Standards (NGSS) 8 Practices with the goal of promoting knowledge and understanding of authentic scientific research in high school classrooms through air quality research. This research explored: (1) how the program affects student understanding of scientific inquiry and research and (2) how the open-inquiry learning opportunities provided by the program increase student interest in science as a career path. Treatment students received instruction related to air pollution (airborne particulate matter), associated health concerns, and training on how to operate air quality testing equipment. They then participated in a yearlong scientific research project in which they developed and tested hypotheses through research of their own design regarding the sources and concentrations of air pollution in their homes and communities. Results from an external evaluation revealed that treatment students developed a deeper understanding of scientific research than did comparison students, as measured by their ability to generate good hypotheses and research designs, and equally expressed an increased interest in pursuing a career in science. These results emphasize the value of and need for authentic science learning opportunities in the modern science classroom.

Air compliance through pollution prevention at Air Force Materiel Command facilities.

Energy Technology Data Exchange (ETDEWEB)

Kolpa, R.; Ryckman, S.J. Jr.; Smith, A.E.

1999-03-19

Options for air compliance through pollution prevention (P2) have been identified at 14 facilities of the US Air Force Materiel Command, ranging from depots with significant light industrial activity to laboratories. Previous P2 efforts concentrated on reducing hazardous and solid wastes, with any reduction in air impacts generally being a collateral benefit. This work focused on reducing air emissions and air compliance vulnerabilities. P2 options were identified in three stages. First, potentially applicable P2 options were identified from Internet and published information. Attention was given to identifying the types of sources to which an option could be applied, the option's state of development, and constraints that could limit its application. Traditional P2 options involving technology or equipment changes and material substitution were considered. In addition, newer approaches based on administrative ''controls'' were considered. These included inserting P2 into operating permits in exchange for administrative relief, privatization, derating boilers, and reducing an installation's potential to emit and compliance vulnerability by separating sources not under the Air Force's ''common control.'' Next, criteria and toxic emissions inventories by source category were prepared from inventory data supplied by facilities. The major problems at this stage were differences in the levels of detail provided by facilities and in the categories used by different installations. Emitting categories were matched to P2 option categories to identify candidate options. Candidates were screened to account for local regulations and technical information about sources in the inventories. When possible, emission reductions were estimated to help facility personnel prioritize options. Some options identified are being actively pursued by facilities to determine their site-specific feasibility. Although much work has been

Differential embryotoxicity of the organic pollutants in rural and urban air particles

International Nuclear Information System (INIS)

Mesquita, Sofia R.; Drooge, Barend L. van; Oliveira, Eva; Grimalt, Joan O.; Barata, Carlos; Vieira, Natividade; Guimarães, Laura; Piña, Benjamin

2015-01-01

Airborne particulate matter (PM) is a recognized risk factor for human populations. Here we assessed the toxic potential of the organic constituents from PM collected in urban and rural sites during warm and cold periods of 2012/2013, and fractionated into 6 size fractions. The finest PM fraction (<0.5 μm) showed the highest biological activity (dioxin-like activity and fish embryotoxicity) in all samples, and the maximal activity was observed in rural samples from the cold period. Zebrafish embryo transcriptome analysis showed a strong induction of the AhR signaling pathway correlated to PAH concentrations. Oxidative stress-related genes and pancreatic and eye-lens gene markers appeared de-regulated in embryos exposed to urban extracts, whereas exposure to rural extracts affected genes implicated in basic cellular functions. The observed effects can be directly related to air pollution-related human disorders, suggesting different potential adverse outcomes for human populations exposed to air pollution from specific sources. - Highlights: • Embryotoxicity of airborne organic compounds collected in urban and rural areas. • Ultrafine particles (<0.5 μm) accumulated most of the observed toxicity. • Strong seasonal differences in rural areas, probably linked to wood combustion. • Rural and urban samples showed quantitative and qualitative differences in toxicity. • At least one independent toxic modes of action especially linked to urban emissions. - Quantitative and qualitative differences in embryotoxic effects of airborne particulate matter from urban and rural areas.

Air quality effects of alternative fuels. Final report

Energy Technology Data Exchange (ETDEWEB)

Guthrie, P.; Ligocki, M.; Looker, R.; Cohen, J.

1997-11-01

To support the Alternative Fuels Utilization Program, a comparison of potential air quality effects of alternative transportation fuels is being performed. This report presents the results of Phase 1 of this program, focusing on reformulated gasoline (RFG), methanol blended with 15 percent gasoline (M85), and compressed natural gas (CNG). The fuels are compared in terms of effects on simulated future concentrations of ozone and mobile source air toxics in a photochemical grid model. The fuel comparisons were carried out for the future year 2020 and assumed complete replacement of gasoline in the projected light-duty gasoline fleet by each of the candidate fuels. The model simulations were carried out for the areas surrounding Los Angeles and Baltimore/DC, and other (non-mobile) sources of atmospheric emissions were projected according to published estimates of economic and population growth, and planned emission control measures specific to each modeling domain. The future-year results are compared to a future-year run with all gasoline vehicle emissions removed. The results of the comparison indicate that the use of M85 is likely to produce similar ozone and air toxics levels as those projected from the use of RFG. Substitution of CNG is projected to produce significantly lower levels of ozone and the mobile source air toxics than those projected for RFG or M85. The relative benefits of CNG substitution are consistent in both modeling domains. The projection methodologies used for the comparison are subject to a large uncertainty, and modeled concentration distributions depend on meteorological conditions. The quantitative comparison of fuel effects is thus likely to be sensitive to alternative assumptions. The consistency of the results for two very different modeling domains, using very different base assumptions, lends credibility to the qualitative differentiation among these fuels. 32 refs., 42 figs., 47 tabs.

Addressing Geographic Variability in the Comparative Toxicity Potential of Copper and Nickel in Soils

DEFF Research Database (Denmark)

Owsianiak, Mikolaj; Rosenbaum, Ralph K.; Huijbregts, Mark A. J.

2013-01-01

Comparative toxicity potentials (CTP), in life cycle impact assessment also known as characterization factors (CF), of copper (Cu) and nickel (Ni) were calculated for a global set of 760 soils. An accessibility factor (ACF) that takes into account the role of the reactive, solid-phase metal pool...... findings stress the importance of dealing with geographic variability in the calculation of CTPs for terrestrial ecotoxicity of metals....

[Air contamination in the Autonomous City of Buenos Aires: the current risk or future climate change, a false option].

Science.gov (United States)

Abrutzky, Rosana; Dawidowski, Laura; Murgida, Ana; Natenzon, Claudia Eleonor

2014-09-01

Based on the theoretical framework of environmental risk, this article discusses the management of air quality in the Autonomous City of Buenos Aires in relation to current and potential impacts of toxic gases and global climate change on the health of the population. Information on historical and current management of the air was linked to the results of the South American Emissions, Megacities and Climate research project to assess danger, exposure, vulnerability and uncertainty as the dimensions of risk. By contextualizing public policies developed in recent decades on this subject, it was possible to identify emerging configurations of risk and uncertainties as accelerators of social vulnerability. On the one hand, the fact that there is a positive correlation between mortality, changes in temperature and air pollution was confirmed. On the other hand, it became clear that there is a disconnect between air quality management and health care management, while limitations were found in the proposed mitigation measures relating to emissions of greenhouse gases produced by fuel, revealing uncertainties regarding their efficacy.

Aerospace toxicology overview: aerial application and cabin air quality.

Science.gov (United States)

Chaturvedi, Arvind K

2011-01-01

Aerospace toxicology is a rather recent development and is closely related to aerospace medicine. Aerospace toxicology can be defined as a field of study designed to address the adverse effects of medications, chemicals, and contaminants on humans who fly within or outside the atmosphere in aviation or on space flights. The environment extending above and beyond the surface of the Earth is referred to as aerospace. The term aviation is frequently used interchangeably with aerospace. The focus of the literature review performed to prepare this paper was on aerospace toxicology-related subject matters, aerial application and aircraft cabin air quality. Among the important topics addressed are the following: · Aerial applications of agricultural chemicals, pesticidal toxicity, and exposures to aerially applied mixtures of chemicals and their associated formulating solvents/surfactants The safety of aerially encountered chemicals and the bioanalytical methods used to monitor exposures to some of them · The presence of fumes and smoke, as well as other contaminants that may generally be present in aircraft/space vehicle cabin air · And importantly, the toxic effects of aerially encountered contaminants, with emphasis on the degradation products of oils, fluids, and lubricants used in aircraft, and finally · Analytical methods used for monitoring human exposure to CO and HCN are addressed in the review, as are the signs and symptoms associated with exposures to these combustion gases. Although many agricultural chemical monitoring studies have been published, few have dealt with the occurrence of such chemicals in aircraft cabin air. However, agricultural chemicals do appear in cabin air; indeed, attempts have been made to establish maximum allowable concentrations for several of the more potentially toxic ones that are found in aircraft cabin air. In this article, I emphasize the need for precautionary measures to be taken to minimize exposures to aerially

Distribution and transfer of potentially toxic metal(loid)s in Juncus effusus from the indigenous zinc smelting area, northwest region of Guizhou Province, China.

Science.gov (United States)

Peng, Yishu; Chen, Jun; Wei, Huairui; Li, Shibin; Jin, Tao; Yang, Ruidong

2018-05-15

We collected samples (i.e., the aerial parts and roots of Juncus effusus and their growth media) in the indigenous zinc smelting area in the northwest region of Guizhou Province, China, and we measured and analyzed potentially toxic metal(loid)s (arsenic, As; cadmium, Cd; chromium, Cr; copper, Cu; mercury, Hg; lead, Pb and zinc, Zn) in these samples. The results include the following: First, there is a high concentration of one or more potentially toxic metal(loid)s in the slag and surrounding soil in the research area. This situation might be caused by metal(loid) damage or contamination due to the circumstances. Additionally, Juncus effusus in the indigenous zinc smelting area are contaminated by some potentially toxic metal(loid)s; since they are used for Chinese medical materials, it is especially significant that their As, Cd and Pb concentrations are greater than their limited standard values. Finally, both the bioconcentration factors and transfer factors for most potentially toxic metal(loid)s in Juncus effusus are less than 1 in the study area. Therefore, we suggest that Juncus effusus could be used for phytostabilization or as a pioneer plant for phytoremediation of potentially toxic metal(loid)s because it has a tolerance and exclusion mechanism for these metal(loid)s in the research district. Copyright © 2018 Elsevier Inc. All rights reserved.

Exposure information in environmental health research: Current opportunities and future directions for particulate matter, ozone, and toxic air pollutants

Energy Technology Data Exchange (ETDEWEB)

McKone, Thomas E.; Ryan, P. Barry; Ozkaynak, Haluk

2007-02-01

Understanding and quantifying outdoor and indoor sources of human exposure are essential but often not adequately addressed in health-effects studies for air pollution. Air pollution epidemiology, risk assessment, health tracking and accountability assessments are examples of health-effects studies that require but often lack adequate exposure information. Recent advances in exposure modeling along with better information on time-activity and exposure factors data provide us with unique opportunities to improve the assignment of exposures for both future and ongoing studies linking air pollution to health impacts. In September 2006, scientists from the US Environmental Protection Agency (EPA) and the Centers for Disease Control and Prevention (CDC) along with scientists from the academic community and state health departments convened a symposium on air pollution exposure and health in order to identify, evaluate, and improve current approaches for linking air pollution exposures to disease. This manuscript presents the key issues, challenges and recommendations identified by the exposure working group, who used cases studies of particulate matter, ozone, and toxic air pollutant exposure to evaluate health-effects for air pollution. One of the over-arching lessons of this workshop is that obtaining better exposure information for these different health-effects studies requires both goal-setting for what is needed and mapping out the transition pathway from current capabilities to meeting these goals. Meeting our long-term goals requires definition of incremental steps that provide useful information for the interim and move us toward our long-term goals. Another over-arching theme among the three different pollutants and the different health study approaches is the need for integration among alternate exposure assessment approaches. For example, different groups may advocate exposure indicators, biomonitoring, mapping methods (GIS), modeling, environmental media

Depth Profiling (ICP-MS Study of Toxic Metal Buildup in Concrete Matrices: Potential Environmental Impact

Directory of Open Access Journals (Sweden)

Ghada Bassioni

2010-10-01

Full Text Available This paper explores the potential of concrete material to accumulate toxic trace elements using ablative laser technology (ICP-MS. Concrete existing in offshore structures submerged in seawater acts as a sink for hazardous metals, which could be gradually released into the ocean creating pollution and anoxic conditions for marine life. Ablative laser technology is a valuable tool for depth profiling concrete to evaluate the distribution of toxic metals and locate internal areas where such metals accumulate. Upon rapid degradation of concrete these “hotspots” could be suddenly released, thus posing a distinct threat to aquatic life. Our work simulated offshore drilling conditions by immersing concrete blocks in seawater and investigating accumulated toxic trace metals (As, Be, Cd, Hg, Os, Pb in cored samples by laser ablation. The experimental results showed distinct inhomogeneity in metal distribution. The data suggest that conditions within the concrete structure are favorable for random metal accumulation at certain points. The exact mechanism for this behavior is not clear at this stage and has considerable scope for extended research including modeling and remedial studies.

Human Pluripotent Stem Cell-Based Assay Predicts Developmental Toxicity Potential of ToxCast Chemicals (ACT meeting)

Science.gov (United States)

Worldwide initiatives to screen for toxicity potential among the thousands of chemicals currently in use require inexpensive and high-throughput in vitro models to meet their goals. The devTOX quickPredict platform is an in vitro human pluripotent stem cell-based assay used to as...

Organochlorine pesticides in soils of Mexico and the potential for soil-air exchange

Energy Technology Data Exchange (ETDEWEB)

Wong, Fiona [Centre for Atmospheric Research Experiments, Science and Technology Branch, Environment Canada, 6248 Eighth Line, Egbert, Ontario L01 1N0 (Canada); Department of Chemistry, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario M1C 1A4 (Canada); Alegria, Henry A. [Department of Environmental Science, Policy and Geography, University of South Florida St. Petersburg, 140 7th Ave. S., St. Petersburg, FL 33701 (United States); Bidleman, Terry F., E-mail: terry.bidleman@ec.gc.c [Centre for Atmospheric Research Experiments, Science and Technology Branch, Environment Canada, 6248 Eighth Line, Egbert, Ontario L01 1N0 (Canada)

2010-03-15

The spatial distribution of organochlorine pesticides (OCs) in soils and their potential for soil-air exchange was examined. The most prominent OCs were the DDTs (Geometric Mean, GM = 1.6 ng g{sup -1}), endosulfans (0.16 ng g{sup -1}), and toxaphenes (0.64 ng g{sup -1}). DDTs in soils of southern Mexico showed fresher signatures with higher F{sub DDTe} = p,p'-DDT/(p,p'-DDT + p,p'-DDE) and more racemic o,p'-DDT, while the signatures in the central and northern part of Mexico were more indicative of aged residues. Soil-air fugacity fractions showed that some soils are net recipients of DDTs from the atmosphere, while other soils are net sources. Toxaphene profiles in soils and air showed depletion of Parlar 39 and 42 which suggests that soil is the source to the atmosphere. Endosulfan was undergoing net deposition at most sites as it is a currently used pesticide. Other OCs showed wide variability in fugacity, suggesting a mix of net deposition and volatilization. - Chemical profiles of residues and soil-air fugacities are used to assess the potential of soil as a source of organochlorine pesticides to the air of Mexico.

A question about the potential cardiac toxicity of escitalopram.

Science.gov (United States)

Howland, Robert H

2012-04-01

Previous reviews have focused on the potential cardiac toxicity of the racemic drug citalopram (Celexa(®)). Evaluating the safety of escitalopram (Lexapro(®)) is an important issue to consider, since it is the S-enantiomer of citalopram. Escitalopram has a small effect on the QTc interval. A prolonged QTc was seen in 2% to 14% of escitalopram overdose cases, without serious cardiac sequelae. The QTc prolongation effect of citalopram in beagle dogs has been attributed to the minor metabolite racemic didemethylcitalopram (DDCT). Whether the escitalopram minor metabolite S-DDCT has this effect is not known. Concentrations of S-DDCT are lower than DDCT, but for a broad range of doses of escitalopram and citalopram, the S-DDCT and DDCT concentrations are well below the QTc prolonging concentrations reported in dogs. There is no strong evidence from human and animal studies that the cardiac safety of escitalopram is significantly superior to that of citalopram. Copyright 2012, SLACK Incorporated.

Creating mechanisms of toxic substances emission of combustion engines

OpenAIRE

Jankowski Antoni; Kowalski Mirosław

2015-01-01

The paper analyses the mechanisms of creation of toxic exhaust gases, which mainly derived from inexact fuel metering and improper air-fuel mixture preparation. The paper describes the process of creating toxic components in the exhaust gases of piston engines during engine operation, and impact on the emission of these components determining the composition of the fuel mixture determined equivalence factor Φ. The principal mechanisms of formation of toxic exhaust gases, in particular nitroge...

Using GIS to study the health impact of air emissions.

Science.gov (United States)

Dent, A L; Fowler, D A; Kaplan, B M; Zarus, G M; Henriques, W D

2000-02-01

Geographical Information Systems (GIS) is a fast-developing technology with an ever-increasing number of applications. Air dispersion modeling is a well-established discipline that can produce results in a spatial context. The marriage of these two applications is optimal because it leverages the predictive capacity of modeling with the data management, analysis, and display capabilities of GIS. In the public health arena, exposure estimation techniques are invaluable. The utilization of air emission data, such as U.S. EPA Toxic Release Inventory (TRI) data, and air dispersion modeling with GIS enable public health professionals to identify and define the potentially exposed population, estimate the health risk burden of that population, and determine correlations between point-based health outcome results with estimated health risk.

Inorganic carbon acquisition in potentially toxic and non-toxic diatoms: the effect of pH-induced changes in the seawater carbonate chemistry

DEFF Research Database (Denmark)

Trimborn, S; Lundholm, Nina; Thoms, S

2008-01-01

. In terms of carbon source, all species took up both CO2 and HCO3-. K-1/2 values for inorganic carbon uptake decreased with increasing pH in two species, while in N. navis-varingica apparent affinities did not change. While the contribution of HCO3- to net fixation was more than 85% in S. stellaris......The effects of pH-induced changes in seawater carbonate chemistry on inorganic carbon (C-i) acquisition and domoic acid (DA) production were studied in two potentially toxic diatom species, Pseudo-nitzschia multiseries and Nitzschia navis-varingica, and the non-toxic Stellarima stellaris. In vivo...... activities of carbonic anhydrase (CA), photosynthetic O-2 evolution and CO2 and HCO3- uptake rates were measured by membrane inlet MS in cells acclimated to low (7.9) and high pH (8.4 or 8.9). Species-specific differences in the mode of carbon acquisition were found. While extracellular carbonic anhydrase (e...

Potential Medicinal Application and Toxicity Evaluation of Extracts from Bamboo Plants.

Science.gov (United States)

Panee, Jun

2015-06-01

Bamboo plants play a significant role in traditional Asian medicine, especially in China and Japan. Biomedical investigations on the health-benefiting effects as well as toxicity of different parts and species of bamboo have been carried out worldwide since the 1960s, and documented a wide range of protective effects of bamboo-derived products, such as protection against oxidative stress, inflammation, lipotoxicity, cancer, and cardiovascular disease. Some of these products may interfere with male and female reproductive function, thyroid hormone metabolism, and hepatic xenobiotransformation enzymes. The diversity of bamboo species, parts of the plants available for medicinal use, and different extraction methods suggest that bamboo has great potential for producing a range of extracts with functional utility in medicine.

Tolerance of plants to air pollutants. Shokubutsu no taiki osen taisei

Energy Technology Data Exchange (ETDEWEB)

Kondo, N.; Saji, H. (National Institute for Environmental Studies, Tsukuba (Japan))

1992-11-10

Attempts have been made to improve tolerance of plants to air pollutants by changing activities in detoxifying enzymes against toxic substances attributable to air pollutants, through gene manipulation. An air pollutant, absorbed in a plant through its stomata, produces toxic substances in the cells and damages the organism. Detailed discussions were given on the following: Stoma opening action and reaction; injuries attributable to air pollutants and detoxifying metabolism systems; ethylene and toxic enzymes of secondary toxic substances in an organism; different detoxifying mechanisms and active enzymes; and activation of detoxifying enzymes using genes. Pollution tolerance in plants is governed by inherent plant natures and environmental conditions. Plants that have two opposing functions of emerging damages from toxicity and preventing them with detoxifying capability are controlled with a complex and delicate balance. Changing pollution tolerance in plants may be possible by manipulating genes, but the importance is to elucidate what the tolerating enzymes are, and obtain their genes. Genes that could be used are very few in number. Expectations are placed on the future development. 122 refs., 4 figs.

Toxicity of plant essential oils to Tetranychus urticae (Acari: Tetranychidae) and Phytoseiulus persimilis (Acari: Phytoseiidae).

Science.gov (United States)

Choi, Won-Il; Lee, Sang-Geui; Park, Hyung-Man; Ahn, Young-Joon

2004-04-01

Fifty-three plant essential oils were tested for their toxicity against eggs and adults of Tetranychus urticae Koch as well as adults of Phytoseiulus persimilis Athias-Henriot, by using a filter paper diffusion bioassay without allowing direct contact. Responses varied according to oil type and dose, and mite species. In a plastic container (4.5 by 9.5 cm) bioassay at 14 x 10(-3) microl/ml air, caraway seed, citronella java, lemon eucalyptus, pennyroyal, and peppermint oils gave > 90% mortality against adult T. urticae, whereas 82 and 81% mortality was observed with sage and spearmint oils, respectively. With the exception of sage oil, the other six essential oils were highly effective against T. urticae eggs at 9.3 x 10(-3) microl/ml air. Against adult P. persimilis, these six test oils caused > 90% mortality at 7.1 x 10(-3) microl/ml air. Particularly peppermint oil at 4.7 x 10(-3) microl/ml air was highly toxic. In an acrylic cage (30 by 30 by 40 cm ) test, lemon eucalyptus, pennyroyal, peppermint, and spearmint oils were highly effective against adult T. urticae at 1.4 x 10(-3) microl/ml air. These results indicate that the mode of delivery of these essential oils was largely a result of action in the vapor phase via the respiratory system. The essential oils described herein merit further study as potential fumigants for T. urticae control.

Section 112 hazardous air pollutants Clean Air Act Amendments of 1990; potential impact of fossil/NUC

International Nuclear Information System (INIS)

Cronmiller, R.E.

1990-01-01

Control of hazardous air pollutants under the Clean Air Act (CAA) goes back several decades. Section 112 of the 1970 CAA as amended in 1977 served as the national statutory basis for controlling hazardous air pollutants until the most recent 1990 Amendments. Following severe criticism of the effectiveness of the Act to address hazardous air pollutant issues and a pile of seemingly never ending lawsuits challenging the regulatory process, the U.S. Congress has substantially rewritten Section 112 in the 1990 CAA Amendments. Many provisions heretofore requiring findings or regulatory decisions by the Environmental Protection Agency (EPA) Administrator are now automatic in the sense that the decisions have already been made by the US Congress legislatively. Thus, the new Section 112 has eliminated many of the existing regulatory obstacles, or safeguards; this will likely result in sweeping new regulatory programs mandating extensive controls on many industrial activities. A much needed study program to address fossil fuel fired steam electric generating units' hazardous air emissions and to identify control alternatives to regulate these emissions, if regulation is required, was incorporated into new Section 112. Because of this study, the regulatory fate of these units under the new Section 112 remains highly uncertain. An extensive regulatory program addressing hazardous air pollutants of these utility units under Section 112 would dwarf electric utility costs associated with the new acid rain control program. First, this paper identifies major provisions of the old law and the resulting regulatory status for both coal and nuclear power facilities before addressing the new Section 112 under the 1990 CAA Amendments and potential implications for electric utilities specifically

Air quality indicators from the Environmental Performance Index: potential use and limitations in South Africa

Directory of Open Access Journals (Sweden)

Rebecca M. Garland

2017-06-01

Full Text Available In responding to deteriorating air quality, many countries, including South Africa, have implemented national programmes that aim to manage and regulate ambient air quality, and the emissions of air pollutants. One aspect within these management strategies is effective communication to stakeholders, including the general public, with regard to the state and trend of ambient air quality in South Africa. Currently, information on ambient air quality is communicated through ambient mass concentration values, as well as number of exceedances of South African National Ambient Standards. However, these do not directly communicate the potential impact on human health and the ecosystem. To this end, the use of air quality indicators is seen as a potential way to achieve communication to stakeholders in a simplified, yet scientifically defensible manner. Air quality indicators and their source data from the Environmental Performance Index (EPI were interrogated to understand their potential use in South Africa. An assessment of four air quality indicators, together with their source data, showed improvements in air quality over the time period studied, though the input data do have uncertainties. The source data for the PM indicators, which came from a global dataset, underestimated the annual PM2.5 concentrations in the Highveld Priority Area and Vaal Triangle Airshed Priority Area over the time period studied (2009-2014 by ~3.7 times. This highlights a key limitation of national-scale indicators and input data, that while the data used by the EPI are a well-thought out estimate of a country’s air quality profile, they remain a generalised estimate. The assumptions and uncertainty inherent in such an ambitious global-wide attempt make the estimates inaccurate for countries without proper emissions tracking and accounting and few monitoring stations, such as South Africa. Thus, the inputs and resultant indicators should be used with caution until such

40 CFR 80.1005 - What acts are prohibited under the gasoline toxics program?

Science.gov (United States)

2010-07-01

... gasoline toxics program? 80.1005 Section 80.1005 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES Gasoline Toxics Violation Provisions § 80.1005 What acts are prohibited under the gasoline toxics program? No person shall: (a...

Dietary exposure to essential and potentially toxic elements for the population of Hanoi, Vietnam

DEFF Research Database (Denmark)

Marcussen, H.; Jensen, Bodil Hamborg; Petersen, Annette

2013-01-01

Knowledge of the dietary intake of essential and toxic elements in fast-developing Southeast Asian countries such as Vietnam is limited. Iron and Zn deficiency in Asia is a well-known problem and is partly due to rice constituting a major part of the diet. Dietary habits are changing...... and there is a need to build more knowledge so that authorities can give dietary recommendations. The aim of this study was to determine the total dietary intake of essential and potentially toxic elements and to assess the nutritional quality and food safety risks of the average Hanoi diet. 22 foods or food groups...... were identified and 14 samples of each food group were collected from markets and/or supermarkets in the period 2007-2009. Water spinach, water dropwort, watercress, water mimosa and pond fish are typically produced in wastewater-fed systems. Therefore, these samples were collected both at markets...

Lung inflammation caused by inhaled toxicants: a review

Directory of Open Access Journals (Sweden)

Wong J

2016-06-01

Full Text Available John Wong, Bruce E Magun, Lisa J Wood School of Nursing, MGH Institute of Health Professions, Boston, MA, USA Abstract: Exposure of the lungs to airborne toxicants from different sources in the environment may lead to acute and chronic pulmonary or even systemic inflammation. Cigarette smoke is the leading cause of chronic obstructive pulmonary disease, although wood smoke in urban areas of underdeveloped countries is now recognized as a leading cause of respiratory disease. Mycotoxins from fungal spores pose an occupational risk for respiratory illness and also present a health hazard to those living in damp buildings. Microscopic airborne particulates of asbestos and silica (from building materials and those of heavy metals (from paint are additional sources of indoor air pollution that contributes to respiratory illness and is known to cause respiratory illness in experimental animals. Ricin in aerosolized form is a potential bioweapon that is extremely toxic yet relatively easy to produce. Although the aforementioned agents belong to different classes of toxic chemicals, their pathogenicity is similar. They induce the recruitment and activation of macrophages, activation of mitogen-activated protein kinases, inhibition of protein synthesis, and production of interleukin-1 beta. Targeting either macrophages (using nanoparticles or the production of interleukin-1 beta (using inhibitors against protein kinases, NOD-like receptor protein-3, or P2X7 may potentially be employed to treat these types of lung inflammation without affecting the natural immune response to bacterial infections. Keywords: cigarette, mycotoxin, trichothecene, ricin, inflammasome, macrophage, inhibitors

Semivolatile organic compounds in residential air along the Arizona-Mexico border.

Science.gov (United States)

Gale, Robert W; Cranor, Walter L; Alvarez, David A; Huckins, James N; Petty, Jimmie D; Robertson, Gary L

2009-05-01

Concerns about indoor air quality and the potential effects on people living in these environments are increasing as more reports about the toxicities and the potential indoor air exposure levels of household-use chemicals and chemicals from housing and fumishing manufacture in air are being assessed. Gas chromatography/mass spectromery was used to confirm numerous airborne contaminants obtained from the analysis of semipermeable membrane devices deployed inside of 52 homes situated along the border between Arizona and Mexico. We also describe nontarget analytes in the organochlorine pesticide fractions of 12 of these homes; this fraction is also the most likely to contain the broadest scope of bioconcentratable chemicals accumulated from the indoor air. Approximately 400 individual components were identified, ranging from pesticides to a wide array of hydrocarbons, fragrances such as the musk xylenes, flavors relating to spices, aldehydes, alcohols, esters and phthalate esters, and other miscellaneous types of chemicals. The results presented in this study demonstrate unequivocally that the mixture of airborne chemicals present indoors is far more complex than previously demonstrated.

Grout disposal facility vault exhauster: Technical background document on demonstration of best available control technology for toxics

International Nuclear Information System (INIS)

Glissmeyer, J.A.; Glantz, C.S.; Rittman, P.D.

1994-09-01

The Grout Disposal Facility (GDF) is currently operated on the US Department of Energy's Hanford Site. The GDF is located near the east end of the Hanford Site's 200 East operations area, and is used for the treatment and disposal of low-level radioactive liquid wastes. In the grout treatment process, selected radioactive wastes from double-shell tanks are mixed with grout-forming solids; the resulting grout slurry is pumped to near-surface concrete vaults for solidification and permanent disposal. As part of this treatment process, small amounts of toxic particles and volatile organic compounds (VOCs) may be released to the atmosphere through the GDF's exhaust system. This analysis constitutes a Best Available Control Technology for Toxics (T-BACT) study, as required in the Washington Administrative Code (WAC 173-460) to support a Notice of Construction for the operation of the GDF exhaust system at a modified flow rate that exceeds the previously permitted value. This report accomplishes the following: assesses the potential emissions from the GDF; estimates air quality impacts to the public from toxic air pollutants; identifies control technologies that could reduce GDF emissions; evaluates impacts of the control technologies; and recommends appropriate emissions controls

Relationship of Indoor, Outdoor and Personal Air (RIOPA) study: study design, methods and quality assurance/control results.

Science.gov (United States)

Weisel, Clifford P; Zhang, Junfeng; Turpin, Barbara J; Morandi, Maria T; Colome, Steven; Stock, Thomas H; Spektor, Dalia M; Korn, Leo; Winer, Arthur; Alimokhtari, Shahnaz; Kwon, Jaymin; Mohan, Krishnan; Harrington, Robert; Giovanetti, Robert; Cui, William; Afshar, Masoud; Maberti, Silvia; Shendell, Derek

2005-03-01

The Relationship of Indoor, Outdoor and Personal Air (RIOPA) Study was undertaken to evaluate the contribution of outdoor sources of air toxics, as defined in the 1990 Clean Air Act Amendments, to indoor concentrations and personal exposures. The concentrations of 18 volatile organic compounds (VOCs), 17 carbonyl compounds, and fine particulate matter mass (PM(2.5)) were measured using 48-h outdoor, indoor and personal air samples collected simultaneously. PM2.5 mass, as well as several component species (elemental carbon, organic carbon, polyaromatic hydrocarbons and elemental analysis) were also measured; only PM(2.5) mass is reported here. Questionnaires were administered to characterize homes, neighborhoods and personal activities that might affect exposures. The air exchange rate was also measured in each home. Homes in close proximity (<0.5 km) to sources of air toxics were preferentially (2:1) selected for sampling. Approximately 100 non-smoking households in each of Elizabeth, NJ, Houston, TX, and Los Angeles, CA were sampled (100, 105, and 105 respectively) with second visits performed at 84, 93, and 81 homes in each city, respectively. VOC samples were collected at all homes, carbonyls at 90% and PM(2.5) at 60% of the homes. Personal samples were collected from nonsmoking adults and a portion of children living in the target homes. This manuscript provides the RIOPA study design and quality control and assurance data. The results from the RIOPA study can potentially provide information on the influence of ambient sources on indoor air concentrations and exposure for many air toxics and will furnish an opportunity to evaluate exposure models for these compounds.

Toxic Volatile Organic Compounds (VOCs in the Atmospheric Environment: Regulatory Aspects and Monitoring in Japan and Korea

Directory of Open Access Journals (Sweden)

Wen-Tien Tsai

2016-09-01

Full Text Available In the past decades, hazardous air pollutants (HAPs, so-called air toxics or toxic air pollutants, have been detected in the atmospheric air at low concentration levels, causing public concern about the adverse effect of long-term exposure to HAPs on human health. Most HAPs belong to volatile organic compounds (VOCs. More seriously, most of them are known carcinogens or probably carcinogenic to humans. The objectives of this paper were to report the regulatory aspects and environmental monitoring management of toxic VOCs designated by Japan and Korea under the Air Pollution Control Act, and the Clean Air Conservation Act, respectively. It can be found that the environmental quality standards and environmental monitoring of priority VOCs (i.e., benzene, trichloroethylene, tetrachloroethylene, and dichloromethane have been set and taken by the state and local governments of Japan since the early 2000, but not completely established in Korea. On the other hand, the significant progress in reducing the emissions of some toxic VOCs, including acrylonitrile, benzene, 1,3-butadiene, 1,2-dichloroethane, dichloromethane, chloroform, tetrachloroethylene, and trichloroethylene in Japan was also described as a case study in the brief report paper.

Potential of Annona muricata L. seed oil: phytochemical and nutritional characterization associated with non-toxicity

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L. C. Pinto

2018-03-01

Full Text Available The aim of this study was to evaluate the nutritional quality, phenolic compounds, fatty acid and antioxidant activity in vitro as well as a toxicological screening of A. muricata seed oil in vivo. The chemical composition and quantification of phenolic compounds were determined by the Adolfo Lutz Institute normative. The antioxidant activity was evaluated by DPPH, FRAP and ABTS methods. The oil was extracted by chloroform/ methanol and precipitated crude (AmPtO and supernatant oils (AmSO were obtained. The fatty acid profile was evaluated by gas chromatography and total compounds by HPLC-DAD. BALB/C mice received AmPtO and AmSO (0.5 and 1.0mL·Kg-1 for 14 days. Toxicity parameters were assessed. The major fatty acids in the oil were oleic (39.2% and linoleic (33%. HPLC-DAD suggested the presence of acetogenins (annonacin: 595 [M-H]-, with a greater presence in AmPtO. The AmPtO group showed toxicity, which may be related to the acetogenin content in AmPtO. The AmSO group showed no toxicity and this oil has potential for food or medicinal use.

Personal and ambient exposures to air toxics in Camden, New Jersey.

Science.gov (United States)

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

2011-08-01

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

U.S. EPA Environmental Quality Index - Air Domain

Science.gov (United States)

This is an invited presentation by Region 5, Air Office, who asked me to provide an overview of the Air Domain and health results associated with the Air Domain of the Environmental Quality Index. Region 5 is hosting an Air Toxics meeting for its member states (Ohio, Michigan, I...

Spatial and Temporal Dynamics of Potentially Toxic Cyanobacteria in the Riverine Region of a Temperate Estuarine System Altered by Weirs

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Jacqueline Martha Malazarte

2017-10-01

Full Text Available The effects of weirs on fish and other biological communities have garnered considerable study, whereas the effects of weirs on community composition of toxic cyanobacteria have not yet been well documented. In this study, temporal and spatial variations in species composition and the abundance of potentially toxic cyanobacteria were investigated in the riverine regions of the temperate Youngsan River estuary, where two weirs have recently been constructed. Four stations were sampled 0.5 m below the surface monthly along the channel of the upper river from May 2014 to April 2015 to explore cyanobacterial composition and abundance, while physicochemical and biological parameters were measured to elucidate possible mechanisms controlling these dynamics. Two stations were located upstream at free-flowing sites, and the other stations were located downstream at impounded sites near the weirs. Twenty-eight cyanobacterial species were identified, seven of which were potentially toxic: Microcystis sp., M. aeruginosa, M. flos-aquae, Dolichospermum sp., Aphanocapsa sp., Oscillatoria sp. and Phormidium sp. Microcystis sp. was the most abundant in June 2014 at the lowest station near the weir. Meanwhile, Phormidium sp. occurred at low abundance throughout the study period, except during the winter months, when its abundance was elevated. The interactive forward selection method highlighted dissolved inorganic nitrogen and zooplankton abundance as explanatory variables for this observed variation, but their effects on cyanobacterial growth are unclear. However, temperature was the major determinant for the temporal variation in cyanobacterial populations. Cluster analysis showed that the downstream stations near the weirs had a high similarity of potentially toxic cyanobacteria. Significantly higher abundance, especially of Microcystis sp., was also recorded at the impounded sites suggesting that the presence of weirs might affect variations in toxic

Semivolatile organic compounds in residential air along the Arizona - Mexico border

Science.gov (United States)

Gale, R.W.; Cranor, W.L.; Alvarez, D.A.; Huckins, J.N.; Petty, J.D.; Robertson, G.L.

2009-01-01

Concerns about indoor air quality and the potential effects on people living in these environments are increasing as more reports about the toxicities and the potential indoor air exposure levels of household-use chemicals and chemicals fromhousingandfurnishingmanufactureinairarebeingassessed. Gas chromatography/mass spectrometry was used to confirm numerous airborne contaminants obtained from the analysis of semipermeable membrane devices deployed inside of 52 homes situated along the border between Arizona and Mexico. We also describe nontarget analytes in the organochlorine pesticide fractions of 12 of these homes; this fraction is also the most likelytocontainthebroadestscopeofbioconcentratablechemicals accumulated from the indoor air. Approximately 400 individual components were identified, ranging from pesticides to a wide array of hydrocarbons, fragrances such as the musk xylenes, flavors relating to spices, aldehydes, alcohols, esters and phthalate esters, and other miscellaneous types of chemicals. The results presented in this study demonstrate unequivocally that the mixture of airborne chemicals present indoors is far more complex than previously demonstrated. ?? 2009 American Chemical Society.

1997 Toxic Hazards Research Annual Report

Science.gov (United States)

1998-05-01

evaluate the potential for CF 3I to produce reproductive toxicity and to provide additional information on the effect of CF 3I exposure on the...questions raised on the effects of CF 3I exposure following the recently completed acute and subchronic inhalation toxicity studies (Dodd et al., 1997a...individuals from potential toxic consequences resulting from exposure to combustion products of advanced composite materials (ACM), this laboratory has

Toxicity potentials from waste cellular phones, and a waste management policy integrating consumer, corporate, and government responsibilities

International Nuclear Information System (INIS)

Lim, Seong-Rin; Schoenung, Julie M.

2010-01-01

Cellular phones have high environmental impact potentials because of their heavy metal content and current consumer attitudes toward purchasing new phones with higher functionality and neglecting to return waste phones into proper take-back systems. This study evaluates human health and ecological toxicity potentials from waste cellular phones; highlights consumer, corporate, and government responsibilities for effective waste management; and identifies key elements needed for an effective waste management strategy. The toxicity potentials are evaluated by using heavy metal content, respective characterization factors, and a pathway and impact model for heavy metals that considers end-of-life disposal in landfills or by incineration. Cancer potentials derive primarily from Pb and As; non-cancer potentials primarily from Cu and Pb; and ecotoxicity potentials primarily from Cu and Hg. These results are not completely in agreement with previous work in which leachability thresholds were the metric used to establish priority, thereby indicating the need for multiple or revised metrics. The triple bottom line of consumer, corporate, and government responsibilities is emphasized in terms of consumer attitudes, design for environment (DfE), and establishment and implementation of waste management systems including recycling streams, respectively. The key strategic elements for effective waste management include environmental taxation and a deposit-refund system to motivate consumer responsibility, which is linked and integrated with corporate and government responsibilities. The results of this study can contribute to DfE and waste management policy for cellular phones.

Toxicity potentials from waste cellular phones, and a waste management policy integrating consumer, corporate, and government responsibilities.

Science.gov (United States)

Lim, Seong-Rin; Schoenung, Julie M

2010-01-01

Cellular phones have high environmental impact potentials because of their heavy metal content and current consumer attitudes toward purchasing new phones with higher functionality and neglecting to return waste phones into proper take-back systems. This study evaluates human health and ecological toxicity potentials from waste cellular phones; highlights consumer, corporate, and government responsibilities for effective waste management; and identifies key elements needed for an effective waste management strategy. The toxicity potentials are evaluated by using heavy metal content, respective characterization factors, and a pathway and impact model for heavy metals that considers end-of-life disposal in landfills or by incineration. Cancer potentials derive primarily from Pb and As; non-cancer potentials primarily from Cu and Pb; and ecotoxicity potentials primarily from Cu and Hg. These results are not completely in agreement with previous work in which leachability thresholds were the metric used to establish priority, thereby indicating the need for multiple or revised metrics. The triple bottom line of consumer, corporate, and government responsibilities is emphasized in terms of consumer attitudes, design for environment (DfE), and establishment and implementation of waste management systems including recycling streams, respectively. The key strategic elements for effective waste management include environmental taxation and a deposit-refund system to motivate consumer responsibility, which is linked and integrated with corporate and government responsibilities. The results of this study can contribute to DfE and waste management policy for cellular phones. 2010 Elsevier Ltd. All rights reserved.

First record of potentially toxic dinoflagellate, Alexandrium minutum Halim 1960, from Peruvian coastal

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Maribel Baylón

2015-04-01

Full Text Available Herein, we report the first record of the potentially toxic dinoflagellate Alexandrium minutum Halim 1960 from the Peruvian littoral. Alexandrium minutum produced the algae bloom in March 2006 and February 2009, in the Callao bay. Its identification was carried out by a morpho-taxonomic examination, detailing their plates with light and epifluorescence microscopy, moreover its quantification was realized in sedimentation chambers. This is the first report of A. minutum for Southeast Pacific. The characteristics in size, shape and thecal morphology were similarly to original descriptions of this species.

Potentially Toxic Elements and Health Risk Assessment in Farmland Systems around High-Concentrated Arsenic Coal Mining in Xingren, China

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Ying-ju Li

2018-01-01

Full Text Available The health risk of potentially toxic elements (PTEs via contamination of the food chain has attracted widespread concern. The aim of this study is to evaluate the effects of PTEs in environment and human body (fingernail, hair, and blood of people living in agricultural soil near arsenic coal mining areas in Xingren County (Guizhou, southwest China. 89 crop samples which included vegetables, rice, maize, and coix seed and their corresponding soils and 17 local surface water and biological tissue samples (41 × 3 in near arsenic coal mining areas were collected, and the concentrations of potentially toxic elements (As, Cd, Cu, Cr, and Pb in all the samples were determined. The health risk assessment methods developed by the United States Environmental Protection Agency were employed to explore the potential health hazards of PTEs in soils growing crops. Results showed that 4 toxic elements, Cd, Cu, As, and Cr, were found to have different degrees of contamination in soils in the studied area. The total concentration of toxic elements (As, Cr, Cu, and Pb in fingernail, hair, and blood samples were 90.50, 69.31, and 6.90 mg·kg−1, respectively. Fingernail samples from females were more likely to show exposure to trace metals compared to males. As the age of the subject increased, the concentration of As also increased in all three biological samples. The risk assessment for the mean hazard index value from the consumption of local food crops was 14.81, indicating that consumers may experience adverse, noncarcinogenic health effects. The estimated mean total cancer risk value of was 5.3 × 10−3, which was approximately 10 to 1000 times higher than the acceptable range of 10−6–10−4, indicating serious carcinogenic risks for local people consuming crops from the area. This study provides evidence that local residents in this study area may be at a high risk of disease caused from toxic element exposure.

Toxicity identification evaluations of produced-water effluents

International Nuclear Information System (INIS)

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

1997-01-01

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

Formaldehyde: a candidate toxic air contaminant. Final report

Energy Technology Data Exchange (ETDEWEB)

Frye, B.; Parker, T.

1988-03-01

Formaldehyde (HCHO) is a gas widely used in adhesives and resins, textiles, embalming fluids, fungicides, air fresheners, and cosmetics. It is directly emitted into the ambient outdoor air from vehicular and stationary sources, and is also produced in the atmosphere from other substances by photochemical smog processes. The International Agency for Research on Cancer (IARC) has determined that there is sufficient evidence for carcinogenicity of formaldehyde to animals, and limited evidence for carcinogenicity to humans. EPA classifies formaldehyde as a probable human carcinogen with a one in a million risk concentration of 0.08 ppb.

40 CFR 63.13 - Addresses of State air pollution control agencies and EPA Regional Offices.

Science.gov (United States)

2010-07-01

..., Louisiana, New Mexico, Oklahoma, Texas), Director, Air, Pesticides and Toxics, 1445 Ross Avenue, Dallas, TX..., Pesticides and Toxics Division, J.F.K. Federal Building, Boston, MA 02203-2211. EPA Region II (New Jersey...). Director, Air, Pesticides and Toxics Management Division, Atlanta Federal Center, 61 Forsyth Street...

Soil-based filtration technology for air purification: potentials for environmental and space life support application

Science.gov (United States)

Nelson, Mark; Bohn, Hinrich

Soil biofiltration, also known as Soil bed reactor (SBR), technology was originally developed in Germany to take advantage of the diversity in microbial mechanisms to control gases producing malodor in industrial processes. The approach has since gained wider international acceptance and seen numerous improvements, for example, by the use of high-organic compost beds to maximize microbial processes. This paper reviews the basic mechanisms which underlay soil processes involved in air purification, advantages and limitations of the technology and the cur-rent research status of the approach. Soil biofiltration has lower capital and operating/energetic costs than conventional technologies and is well adapted to handle contaminants in moderate concentrations. The systems can be engineered to optimize efficiency though manipulation of temperature, pH, moisture content, soil organic matter and airflow rates. SBR technology was modified for application in the Biosphere 2 project, which demonstrated in preparatory research with a number of closed system testbeds that soil could also support crop plants while also serving as soil filters with air pumps to push air through the soil. This Biosphere 2 research demonstrated in several closed system testbeds that a number of important trace gases could be kept under control and led to the engineering of the entire agricultural soil of Biosphere 2 to serve as a soil filtration unit for the facility. Soil biofiltration, coupled with food crop produc-tion, as a component of bioregenerative space life support systems has the advantages of lower energy use and avoidance of the consumables required for other air purification approaches. Expanding use of soil biofiltration can aid a number of environmental applications, from the mitigation of indoor air pollution, improvement of industrial air emissions and prevention of accidental release of toxic gases.

Toxic potential of the emerging contaminant nicotine to the aquatic ecosystem.

Science.gov (United States)

Oropesa, Ana Lourdes; Floro, António Miguel; Palma, Patrícia

2017-07-01

Nicotine is a "life-style compound" widely consumed by human populations and, consequently, often found in surface waters. This fact presents a concern for possible effects in the aquatic ecosystems. The objective of this study was to assess the potential lethal and sublethal toxicity of nicotine in aquatic organisms from different trophic levels (Vibrio fischeri, Pseudokirchneriella subcapitata, Thamnocephalus platyurus, and Daphnia magna). The bioassays were performed by exposing the organisms to concentrations of nicotine in a range of 0.5-1000 μg/L. Results showed that nicotine, at tested concentration, was not acutely toxic to V. fischeri and T. platyurus. On the contrary, this substance exhibited toxicity to P. subcapitata and Daphnia magna. Thus, concentrations of nicotine of 100 and 200 μg/L promoted an inhibition in the growth of P. subcapitata. In addition, a concentration of 100 μg/L nicotine acted on the reproduction of the crustacean D. magna, by decreasing the number of juveniles produced by female. On the other hand, the results showed that concentrations equal to or greater than 10 μg/L induced the production of daphnids male offspring, which may indicate that nicotine is a weak juvenoid compound of the D. magna endocrine system. Furthermore, the result showed that concentrations tested of this chemical have the capacity to revert the effect of fenoxycarb, a strong juvenoid chemical insecticide. The results of the study revealed that nicotine can induce several changes in some of the most important key groups of the aquatic compartment, which can compromise, in a short time, the balance of aquatic ecosystem. Finally, a preliminary environmental risk assessment of this stimulant was performed from the highest measured concentration in surface water and the no observable effect concentration value in the most sensitive species, i.e., D. magna. This process revealed that nicotine can produce an important risk to aquatic organisms.

Use of Segregation Indices, Townsend Index, and Air Toxics Data to Assess Lifetime Cancer Risk Disparities in Metropolitan Charleston, South Carolina, USA

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LaShanta J. Rice

2014-05-01

Full Text Available Background: Studies have demonstrated a relationship between segregation and level of education, occupational opportunities, and risk behaviors, yet a paucity of research has elucidated the association between racial residential segregation, socioeconomic deprivation, and lifetime cancer risk. Objectives: We examined estimated lifetime cancer risk from air toxics by racial composition, segregation, and deprivation in census tracts in Metropolitan Charleston. Methods: Segregation indices were used to measure the distribution of groups of people from different races within neighborhoods. The Townsend Index was used to measure economic deprivation in the study area. Poisson multivariate regressions were applied to assess the association of lifetime cancer risk with segregation indices and Townsend Index along with several sociodemographic measures. Results: Lifetime cancer risk from all pollution sources was 28 persons/million for half of the census tracts in Metropolitan Charleston. Isolation Index and Townsend Index both showed significant correlation with lifetime cancer risk from different sources. This significance still holds after adjusting for other sociodemographic measures in a Poisson regression, and these two indices have stronger effect on lifetime cancer risk compared to the effects of sociodemographic measures. Conclusions: We found that material deprivation, measured by the Townsend Index and segregation measured by the Isolation index, introduced high impact on lifetime cancer risk by air toxics at the census tract level.

40 CFR 80.1015 - Who is liable for violations under the gasoline toxics program?

Science.gov (United States)

2010-07-01

... gasoline toxics program? 80.1015 Section 80.1015 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES Gasoline Toxics Violation Provisions § 80.1015 Who is liable for violations under the gasoline toxics program? (a) Persons liable for...

40 CFR 80.810 - Who shall register with EPA under the gasoline toxics program?

Science.gov (United States)

2010-07-01

... gasoline toxics program? 80.810 Section 80.810 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES Gasoline Toxics General Information § 80.810 Who shall register with EPA under the gasoline toxics program? (a) Refiners and importers...

Hanging drop: an in vitro air toxic exposure model using human lung cells in 2D and 3D structures.

Science.gov (United States)

Liu, Faye F; Peng, Cheng; Escher, Beate I; Fantino, Emmanuelle; Giles, Cindy; Were, Stephen; Duffy, Lesley; Ng, Jack C

2013-10-15

Using benzene as a candidate air toxicant and A549 cells as an in vitro cell model, we have developed and validated a hanging drop (HD) air exposure system that mimics an air liquid interface exposure to the lung for periods of 1h to over 20 days. Dose response curves were highly reproducible for 2D cultures but more variable for 3D cultures. By comparing the HD exposure method with other classically used air exposure systems, we found that the HD exposure method is more sensitive, more reliable and cheaper to run than medium diffusion methods and the CULTEX(®) system. The concentration causing 50% of reduction of cell viability (EC50) for benzene, toluene, p-xylene, m-xylene and o-xylene to A549 cells for 1h exposure in the HD system were similar to previous in vitro static air exposure. Not only cell viability could be assessed but also sub lethal biological endpoints such as DNA damage and interleukin expressions. An advantage of the HD exposure system is that bioavailability and cell concentrations can be derived from published physicochemical properties using a four compartment mass balance model. The modelled cellular effect concentrations EC50cell for 1h exposure were very similar for benzene, toluene and three xylenes and ranged from 5 to 15 mmol/kgdry weight, which corresponds to the intracellular concentration of narcotic chemicals in many aquatic species, confirming the high sensitivity of this exposure method. Copyright © 2013 Elsevier B.V. All rights reserved.

Effects of UV irradiation on humic acid removal by ozonation, Fenton and Fe0/air treatment: THMFP and biotoxicity evaluation

International Nuclear Information System (INIS)

Wei, Ming-Chi; Wang, Kai-sung; Hsiao, Tung-En; Lin, I.-Chen; Wu, Hui-Ju; Wu, Yuh-Luan; Liu, Pey-Horng; Chang, Shih-Hsien

2011-01-01

Highlights: → Fe 0 /air rapidly and effectively removed HA within 9 min and its COD, biotoxicity and THMFP were low. → THMFP of ozonation-treated solution was much higher than those of Fenton-treated and Fe 0 /air-treated solutions. → UV irradiation during ozonation and Fenton oxidation enhanced HA removal, but did not reduce the THMFP of the treated solutions. → Fe 0 /air treatment with UV irradiation obviously increased the THMFP of the treated solution. → The relationship between biotoxicity and chloroform in the chlorinated solution was insignificant. - Abstract: Effects of UV irradiation on humic acid (HA) removal by Fe 0 /air, ozonation and Fenton oxidation were investigated. The trihalomethane forming potential (THMFP) and toxicity of treated solutions were also evaluated. The experimental conditions were ozone of 21 mg min -1 , H 2 O 2 of 8 x 10 -4 M, Fe 0 of 20 g L -1 , air flow of 5 L min -1 , and UVC of 9 W. Results indicated that Fe 0 /air rapidly removed HA color (>99%) and COD (90%) within 9 min. 51-81% of color and 43-50% of COD were removed by ozonation and Fenton oxidation after 60 min. Both UV enhanced ozone and Fenton oxidation removed HA, but the Fe 0 /air process did not. Spectrum results showed all processes effectively diminished UV-vis spectra, except for ozonation. The THMFP of Fe 0 /air-treated solution (114 μg L -1 ) was much lower than those of Fenton- (226 μg L -1 ) and ozonation-treated solutions (499 μg L -1 ). Fe 0 /air with UV irradiation obviously increased the THMFP of treated solution (502 μg L -1 ). The toxicity results obtained from Vibrio fischeri light inhibition test indicated that the toxicity of Fe 0 /air-treated solution (5%) was much lower than that of ozonation- (33%) and Fenton-treated solutions (31%). Chlorination increased the solution toxicity. The correlation between biotoxicity and chloroform in the chlorinated solution was insignificant.

Thermal Stress and Toxicity | Science Inventory | US EPA

Science.gov (United States)

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

Bisphenol A alternatives in thermal paper from the Netherlands, Spain, Sweden and Norway. Screening and potential toxicity

NARCIS (Netherlands)

Björnsdotter, Maria K.; Jonker, Willem; Legradi, Jessica; Kool, Jeroen; Ballesteros-Gómez, Ana

2017-01-01

Thermal paper contains potentially toxic additives, such as bisphenol A (BPA), as a common color developer. Because of its known endocrine disrupting effects, structural analogues to BPA, such as bisphenol S (BPS), D-8 and Pergafast 201, have been used as alternatives, but little is known about the

Danger in the Air: Air Pollution and Cognitive Dysfunction.

Science.gov (United States)

Cipriani, Gabriele; Danti, Sabrina; Carlesi, Cecilia; Borin, Gemma

2018-01-01

Clean air is considered to be a basic requirement for human health and well-being. To examine the relationship between cognitive performance and ambient pollution exposure. Studies were identified through a systematic search of online scientific databases, in addition to a manual search of the reference lists from the identified papers. Air pollution is a multifaceted toxic chemical mixture capable of assaulting the central nervous system. Despite being a relatively new area of investigation, overall, there is mounting evidence implicating adverse effects of air pollution on cognitive function in both adults and children. Consistent evidence showed that exposure to air pollution, specifically exposure to particulate matter, caused poor age-related cognitive performance. Living in areas with high levels of air pollution has been linked to markers of neuroinflammation and neuropathology that are associated with neurodegenerative conditions such as Alzheimer's disease-like brain pathologies.

Advances in developing a new test method to assess spray drift potential from air blast sprayers

Energy Technology Data Exchange (ETDEWEB)

Grella, M.; Gil, E.; Balsari, P.; Marucco, P.; Gallart, M.

2017-07-01

Drift is one of the most important issues to consider for realising sustainable pesticide sprays. This study proposes and tests an alternative methodology for quantifying the drift potential (DP) of air blast sprayers, trying to avoid the difficulties faced in conducting field trials according to the standard protocol (ISO 22866:2005). For this purpose, an ad hoc test bench designed for DP comparative measurements was used. The proposed methodology was evaluated in terms of robustness, repetitiveness and coherence by arranging a series of trials at two laboratories. Representative orchard and vineyard air blast sprayers in eight configurations (combination of two forward speeds, two air fan flow rates, and two nozzle types) were tested. The test bench was placed perpendicular to the spray track to collect the fraction of spray liquid remaining in the air after the spray process and potentially susceptible to drift out of the treated area. Downwind spray deposition curves were obtained and a new approach was proposed to calculate an index value of the DP estimation that could allow the differences among the tested configurations to be described. Results indicated that forward speed of 1.67 m/s allows better discrimination among configurations tested. Highest DP reduction, over 87.5%, was achieved using the TVI nozzles in combination with low air fan flow rate in both laboratories; conversely, the highest DP value was obtained with the ATR nozzles in combination with high air fan flow rate. Although the proposed method shows a promising potential to evaluate drift potential of different sprayer types and nozzles types used for bush and tree crops further research and tests are necessary to improve and validate this method.

SCANNING VOLTA POTENTIALS MEASUREMENTS OF METALS IN IRRADIATED AIR.

Energy Technology Data Exchange (ETDEWEB)

ISAACS, H.S.; ADZIC, G.; AND ENERGY SCIENCES AND TECHNOLOGY DEPARTMENT; JEFFCOATE, C.S.

2000-10-22

A method for direct dc measurement of the Volta potential is presented. High intensity synchrotron x-ray beams were used to locally irradiate the atmosphere adjacent to the metal surface and produce a conducting path between a sample and a reference probe. The direct measurements of potential in the ionized air could be made at probe heights of around 1 mm compared to less than 0.1 mm for the Kelvin probe. The measurements were similar to traditional Kelvin probe measurements, but had a poorer spatial resolution. In contrast to the Kelvin probe methods, the approach described allows observation of the current as a function of impressed voltage. Methods to improve the special resolution of the technique and applications to corrosion under coating will be presented.

Life-cycle-assessment of the historical development of air pollution control and energy recovery in waste incineration.

Science.gov (United States)

Damgaard, Anders; Riber, Christian; Fruergaard, Thilde; Hulgaard, Tore; Christensen, Thomas H

2010-07-01

Incineration of municipal solid waste is a debated waste management technology. In some countries it is the main waste management option whereas in other countries it has been disregarded. The main discussion point on waste incineration is the release of air emissions from the combustion of the waste, but also the energy recovery efficiency has a large importance. The historical development of air pollution control in waste incineration was studied through life-cycle-assessment modelling of eight different air pollution control technologies. The results showed a drastic reduction in the release of air emissions and consequently a significant reduction in the potential environmental impacts of waste incineration. Improvements of a factor 0.85-174 were obtained in the different impact potentials as technology developed from no emission control at all, to the best available emission control technologies of today (2010). The importance of efficient energy recovery was studied through seven different combinations of heat and electricity recovery, which were modelled to substitute energy produced from either coal or natural gas. The best air pollution control technology was used at the incinerator. It was found that when substituting coal based energy production total net savings were obtained in both the standard and toxic impact categories. However, if the substituted energy production was based on natural gas, only the most efficient recovery options yielded net savings with respect to the standard impacts. With regards to the toxic impact categories, emissions from the waste incineration process were always larger than those from the avoided energy production based on natural gas. The results shows that the potential environmental impacts from air emissions have decreased drastically during the last 35 years and that these impacts can be partly or fully offset by recovering energy which otherwise should have been produced from fossil fuels like coal or natural gas

Life-cycle-assessment of the historical development of air pollution control and energy recovery in waste incineration

International Nuclear Information System (INIS)

Damgaard, Anders; Riber, Christian; Fruergaard, Thilde; Hulgaard, Tore; Christensen, Thomas H.

2010-01-01

Incineration of municipal solid waste is a debated waste management technology. In some countries it is the main waste management option whereas in other countries it has been disregarded. The main discussion point on waste incineration is the release of air emissions from the combustion of the waste, but also the energy recovery efficiency has a large importance. The historical development of air pollution control in waste incineration was studied through life-cycle-assessment modelling of eight different air pollution control technologies. The results showed a drastic reduction in the release of air emissions and consequently a significant reduction in the potential environmental impacts of waste incineration. Improvements of a factor 0.85-174 were obtained in the different impact potentials as technology developed from no emission control at all, to the best available emission control technologies of today (2010). The importance of efficient energy recovery was studied through seven different combinations of heat and electricity recovery, which were modelled to substitute energy produced from either coal or natural gas. The best air pollution control technology was used at the incinerator. It was found that when substituting coal based energy production total net savings were obtained in both the standard and toxic impact categories. However, if the substituted energy production was based on natural gas, only the most efficient recovery options yielded net savings with respect to the standard impacts. With regards to the toxic impact categories, emissions from the waste incineration process were always larger than those from the avoided energy production based on natural gas. The results shows that the potential environmental impacts from air emissions have decreased drastically during the last 35 years and that these impacts can be partly or fully offset by recovering energy which otherwise should have been produced from fossil fuels like coal or natural gas.

Evaluation of potential toxicity from mercury in ayurvedic preparations

International Nuclear Information System (INIS)

Subramanian, Suresh; Maral, Anand; Mukherjee, Archana; Patankar, A.V.; Sarma, H.D.; Pillai, M.R.A.; Venkatesh, Meera

2003-01-01

Kajjali - which is a defined combination of purified elemental mercury and sulphur is used in Ayurvedic prescriptions. Kajjali is claimed to accelerate the therapeutic effects of various medicinal components. The exact role of Kajjali in this process is not as yet ascertained. Ayurveda literature claims that toxic effects of mercury are neutralised in the presence of sulphur. Mercury is known for its toxicity especially with respect to the nervous system and the amount of mercury used in the preparation of Kajjali is quite high. Hence, to study the pharmaco-kinetics of the preparation, bio-distribution studies using 203 Hg as a tracer in Kajjali were carried out in Wistar rats. (author)

Assessing the toxic effects of ethylene glycol ethers using Quantitative Structure Toxicity Relationship models

International Nuclear Information System (INIS)

Ruiz, Patricia; Mumtaz, Moiz; Gombar, Vijay

2011-01-01

Experimental determination of toxicity profiles consumes a great deal of time, money, and other resources. Consequently, businesses, societies, and regulators strive for reliable alternatives such as Quantitative Structure Toxicity Relationship (QSTR) models to fill gaps in toxicity profiles of compounds of concern to human health. The use of glycol ethers and their health effects have recently attracted the attention of international organizations such as the World Health Organization (WHO). The board members of Concise International Chemical Assessment Documents (CICAD) recently identified inadequate testing as well as gaps in toxicity profiles of ethylene glycol mono-n-alkyl ethers (EGEs). The CICAD board requested the ATSDR Computational Toxicology and Methods Development Laboratory to conduct QSTR assessments of certain specific toxicity endpoints for these chemicals. In order to evaluate the potential health effects of EGEs, CICAD proposed a critical QSTR analysis of the mutagenicity, carcinogenicity, and developmental effects of EGEs and other selected chemicals. We report here results of the application of QSTRs to assess rodent carcinogenicity, mutagenicity, and developmental toxicity of four EGEs: 2-methoxyethanol, 2-ethoxyethanol, 2-propoxyethanol, and 2-butoxyethanol and their metabolites. Neither mutagenicity nor carcinogenicity is indicated for the parent compounds, but these compounds are predicted to be developmental toxicants. The predicted toxicity effects were subjected to reverse QSTR (rQSTR) analysis to identify structural attributes that may be the main drivers of the developmental toxicity potential of these compounds.

Excess air in groundwater as a potential indicator of past environmental changes

International Nuclear Information System (INIS)

Aeschenbach-Hertig, W.; Beyerle, U.; Holocher, J.; Peeters, F.; Kipfer, R.

2002-01-01

Dissolved noble gases in groundwater are used to reconstruct paleotemperature, but also yield information about 'excess air', a component of dissolved gases in excess of solubility equilibrium, derived from dissolution of trapped air in the ground. A good characterization of the excess air component is necessary not only to obtain reliable noble gas temperatures, but also to investigate the potential of excess air as a proxy for past environmental conditions. Two excess air related quantities can be derived from groundwater noble gas data sets: The initial air/water ratio and the pressure exerted on the entrapped air. Under recharge conditions typical for many aquifers, the excess of dissolved gases, expressed by the relative Ne excess ΔNe, is mainly determined by the hydrostatic pressure on the entrapped air. Thus, we suggest that ΔNe is essentially a measure of the amplitude of water table fluctuations in the recharge area. Comparing data sets from three aquifers in temperate, humid latitudes and three aquifers in tropical, semi-arid regions, we find that ΔNe is generally higher in the tropical aquifers, possibly related to larger water table fluctuations in these aquifers characterized by deep unsaturated zones. Whereas ΔNe shows little temporal variation in the mid-latitude aquifers, there is a strong signal of higher ΔNe in the paleowaters of the tropical aquifers as compared to water recharged under modern climate conditions. This finding may indicate a higher variability of recharge in the past at the studied tropical sites. (author)

Ginkgolide A contributes to the potentiation of acetaminophen toxicity by Ginkgo biloba extract in primary cultures of rat hepatocytes

International Nuclear Information System (INIS)

Rajaraman, Ganesh; Chen, Jie; Chang, Thomas K.H.

2006-01-01

The present cell culture study investigated the effect of Ginkgo biloba extract pretreatment on acetaminophen toxicity and assessed the role of ginkgolide A and cytochrome P450 3A (CYP3A) in hepatocytes isolated from adult male Long-Evans rats provided ad libitum with a standard diet. Acetaminophen (7.5-25 mM for 24 h) conferred hepatocyte toxicity, as determined by the lactate dehydrogenase (LDH) assay. G. biloba extract alone increased LDH leakage in hepatocytes at concentrations ≥ 75 μg/ml and ≥ 750 μg/ml after a 72 h and 24 h treatment period, respectively. G. biloba extract (25 or 50 μg/ml once every 24 h for 72 h) potentiated LDH leakage by acetaminophen (10 mM for 24 h; added at 48 h after initiation of extract pretreatment). The effect was confirmed by a decrease in [ 14 C]-leucine incorporation. At the level present in a modulating concentration (50 μg/ml) of the extract, ginkgolide A (0.55 μg/ml), which increased CYP3A23 mRNA levels and CYP3A-mediated enzyme activity, accounted for part but not all of the potentiating effect of the extract on acetaminophen toxicity. This occurred as a result of CYP3A induction by ginkgolide A because triacetyloleandomycin (TAO), a specific inhibitor of CYP3A catalytic activity, completely blocked the effect of ginkgolide A. Ginkgolide B, ginkgolide C, ginkgolide J, quercetin, kaempferol, isorhamnetin, and isorhamnetin-3-O-rutinoside did not alter the extent of LDH leakage by acetaminophen. In summary, G. biloba pretreatment potentiated acetaminophen toxicity in cultured rat hepatocytes and ginkgolide A contributed to this novel effect of the extract by inducing CYP3A

Air quality impacts of increased use of ethanol under the United States’ Energy Independence and Security Act

Science.gov (United States)

Cook, Rich; Phillips, Sharon; Houyoux, Marc; Dolwick, Pat; Mason, Rich; Yanca, Catherine; Zawacki, Margaret; Davidson, Ken; Michaels, Harvey; Harvey, Craig; Somers, Joseph; Luecken, Deborah

2011-12-01

Increased use of ethanol in the United States fuel supply will impact emissions and ambient concentrations of greenhouse gases, "criteria" pollutants for which the U. S. EPA sets ambient air quality standards, and a variety of air toxic compounds. This paper focuses on impacts of increased ethanol use on ozone and air toxics under a potential implementation scenario resulting from mandates in the U. S. Energy Independence and Security Act (EISA) of 2007. The assessment of impacts was done for calendar year 2022, when 36 billion gallons of renewable fuels must be used. Impacts were assessed relative to a baseline which assumed ethanol volumes mandated by the first renewable fuels standard promulgated by U. S. EPA in early 2007. This assessment addresses both impacts of increased ethanol use on vehicle and other engine emissions, referred to as "downstream" emissions, and "upstream" impacts, i.e., those connected with fuel production and distribution. Air quality modeling was performed for the continental United States using the Community Multi-scale Air Quality Model (CMAQ), version 4.7. Pollutants included in the assessment were ozone, acetaldehyde, ethanol, formaldehyde, acrolein, benzene, and 1,3-butadiene. Results suggest that increased ethanol use due to EISA in 2022 will adversely increase ozone concentrations over much of the U.S., by as much as 1 ppb. However, EISA is projected to improve ozone air quality in a few highly-populated areas that currently have poor air quality. Most of the ozone improvements are due to our assumption of increases in nitrogen oxides (NO x) in volatile organic compound (VOC)-limited areas. While there are some localized impacts, the EISA renewable fuel standards have relatively little impact on national average ambient concentrations of most air toxics, although ethanol concentrations increase substantially. Significant uncertainties are associated with all results, due to limitations in available data. These uncertainties are

Radiomimetic toxicity of ozonised air

Energy Technology Data Exchange (ETDEWEB)

Brinkman, R; Lamberts, H B; Veninga, T S

1964-01-01

As little as 0.25 ppM O/sub 3/ for 30 min accelerated the effects of X-irradiation on sphering of circulating red blood cells in mice, rats, rabbits, and man. Such a result requires an ozone effect traversing the air--blood barrier. The 0.2 ppM O/sub 3/, 5 hr/day for 3 wk, produced ruptures of the nuclear envelope and extrusion of nuclear contents in post-mitotic nuclei of myocardial fibers of adult rabbits and mice. Again this effect has been attributed to X-rays. Mice exposed to 0.1 or 0.2 ppm O/sub 3/, 7 hr/day, for over 3 wk, had litters of normal size, but neonatal mortality in the first 3 wk was 6.8 and 7.5% as opposed to 1.6% for control.

40 CFR 80.820 - What gasoline is subject to the toxics performance requirements of this subpart?

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 16 2010-07-01 2010-07-01 false What gasoline is subject to the toxics... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES Gasoline Toxics Gasoline Toxics Performance Requirements § 80.820 What gasoline is subject to the toxics performance...

Antioxidants as potential medical countermeasures for chemical warfare agents and toxic industrial chemicals.

Science.gov (United States)

McElroy, Cameron S; Day, Brian J

2016-01-15

The continuing horrors of military conflicts and terrorism often involve the use of chemical warfare agents (CWAs) and toxic industrial chemicals (TICs). Many CWA and TIC exposures are difficult to treat due to the danger they pose to first responders and their rapid onset that can produce death shortly after exposure. While the specific mechanism(s) of toxicity of these agents are diverse, many are associated either directly or indirectly with increased oxidative stress in affected tissues. This has led to the exploration of various antioxidants as potential medical countermeasures for CWA/TIC exposures. Studies have been performed across a wide array of agents, model organisms, exposure systems, and antioxidants, looking at an almost equally diverse set of endpoints. Attempts at treating CWAs/TICs with antioxidants have met with mixed results, ranging from no effect to nearly complete protection. The aim of this commentary is to summarize the literature in each category for evidence of oxidative stress and antioxidant efficacy against CWAs and TICs. While there is great disparity in the data concerning methods, models, and remedies, the outlook on antioxidants as medical countermeasures for CWA/TIC management appears promising. Copyright © 2015 Elsevier Inc. All rights reserved.

Formal recycling of e-waste leads to increased exposure to toxic metals: an occupational exposure study from Sweden.

Science.gov (United States)

Julander, Anneli; Lundgren, Lennart; Skare, Lizbet; Grandér, Margaretha; Palm, Brita; Vahter, Marie; Lidén, Carola

2014-12-01

Electrical and electronic waste (e-waste) contains multiple toxic metals. However, there is currently a lack of exposure data for metals on workers in formal recycling plants. The objective of this study was to evaluate workers' exposure to metals, using biomarkers of exposure in combination with monitoring of personal air exposure. We assessed exposure to 20 potentially toxic metals among 55 recycling workers and 10 office workers at three formal e-waste recycling plants in Sweden. Workers at two of the plants were followed-up after 6 months. We collected the inhalable fraction and OFC (37-mm) fraction of particles, using personal samplers, as well as spot samples of blood and urine. We measured metal concentrations in whole blood, plasma, urine, and air filters using inductively coupled plasma-mass spectrometry following acid digestion. The air sampling indicated greater airborne exposure, 10 to 30 times higher, to most metals among the recycling workers handling e-waste than among the office workers. The exposure biomarkers showed significantly higher concentrations of chromium, cobalt, indium, lead, and mercury in blood, urine, and/or plasma of the recycling workers, compared with the office workers. Concentrations of antimony, indium, lead, mercury, and vanadium showed close to linear associations between the inhalable particle fraction and blood, plasma, or urine. In conclusion, our study of formal e-waste recycling shows that workers performing recycling tasks are exposed to multiple toxic metals. Copyright © 2014. Published by Elsevier Ltd.

Oxidative potential of subway PM2.5

Science.gov (United States)

Moreno, Teresa; Kelly, Frank J.; Dunster, Chrissi; Oliete, Ana; Martins, Vânia; Reche, Cristina; Minguillón, Maria Cruz; Amato, Fulvio; Capdevila, Marta; de Miguel, Eladio; Querol, Xavier

2017-01-01

Air quality in subway systems is of interest not only because particulate matter (PM) concentrations can be high, but also because of the peculiarly metalliferous chemical character of the particles, most of which differ radically from those of outdoor ambient air. We report on the oxidative potential (OP) of PM2.5 samples collected in the Barcelona subway system in different types of stations. The PM chemical composition of these samples showed typically high concentrations of Fe, Total Carbon, Ba, Cu, Mn, Zn and Cr sourced from rail tracks, wheels, catenaries, brake pads and pantographs. Two toxicological indicators of oxidative activity, ascorbic acid (AA) oxidation (expressed as OPAA μg-1 or OPAA m-3) and glutathione (GSH) oxidation (expressed as OPGSH μg-1 or OPGSH m-3), showed low OP for all samples (compared with outdoor air) but considerable variation between stations (0.9-2.4 OPAA μg-1; 0.4-1.9 OPGSH μg-1). Results indicate that subway PM toxicity is not related to variations in PM2.5 concentrations produced by ventilation changes, tunnel works, or station design, but may be affected more by the presence of metallic trace elements such as Cu and Sb sourced from brakes and pantographs. The OP assays employed do not reveal toxic effects from the highly ferruginous component present in subway dust.

Paraquat: model for oxidant-initiated toxicity

Energy Technology Data Exchange (ETDEWEB)

Bus, J.S.; Gibson, J.E.

1984-04-01

Paraquat, a quaternary ammonium bipyridyl herbicide, produces degenerative lesions in the lung after systemic administration to man and animals. The pulmonary toxicity of paraquat resembles in several ways the toxicity of several other lung toxins, including oxygen, nitrofurantoin and bleomycin. Although a definitive mechanism of toxicity of parquat has not been delineated, a cyclic single electron reduction/oxidation of the parent molecule is a critical mechanistic event. The redox cycling of paraquat has two potentially important consequences relevant to the development of toxicity: generation of activated oxygen (e.g., superoxide anion, hydrogen perioxide, hydroxyl radical) which is highly reactive to cellular macromolecules; and/or oxidation of reducing equivalents (e.g., NADPH, reduced glutathione) necessary for normal cell function. Paraquat-induced pulmonary toxicity, therefore, is a potentially useful model for evaluation of oxidant mechanisms of toxicity. Furthermore, characterization of the consequences of intracellular redox cycling of xenobiotics will no doubt provide basic information regarding the role of this phenomena in the development of chemical toxicity. 105 references, 2 figures.

Assessing the potential of random forest method for estimating solar radiation using air pollution index

International Nuclear Information System (INIS)

Sun, Huaiwei; Gui, Dongwei; Yan, Baowei; Liu, Yi; Liao, Weihong; Zhu, Yan; Lu, Chengwei; Zhao, Na

2016-01-01

Highlights: • Models based on random forests for daily solar radiation estimation are proposed. • Three sites within different air pollution index conditions are considered. • Performance of random forests is better than that of empirical methodologies. • Special attention is given to the use of air pollution index. • The potential of air pollution index is assessed by random forest models. - Abstract: Simulations of solar radiation have become increasingly common in recent years because of the rapid global development and deployment of solar energy technologies. The effect of air pollution on solar radiation is well known. However, few studies have attempting to evaluate the potential of the air pollution index in estimating solar radiation. In this study, meteorological data, solar radiation, and air pollution index data from three sites having different air pollution index conditions are used to develop random forest models. We propose different random forest models with and without considering air pollution index data, and then compare their respective performance with that of empirical methodologies. In addition, a variable importance approach based on random forest is applied in order to assess input variables. The results show that the performance of random forest models with air pollution index data is better than that of the empirical methodologies, generating 9.1–17.0% lower values of root-mean-square error in a fitted period and 2.0–17.4% lower values of root-mean-square error in a predicted period. Both the comparative results of different random forest models and variance importance indicate that applying air pollution index data is improves estimation of solar radiation. Also, although the air pollution index values varied largely from season to season, the random forest models appear more robust performances in different seasons than different models. The findings can act as a guide in selecting used variables to estimate daily solar

Potential environmental impacts of light-emitting diodes (LEDs): metallic resources, toxicity, and hazardous waste classification.

Science.gov (United States)

Lim, Seong-Rin; Kang, Daniel; Ogunseitan, Oladele A; Schoenung, Julie M

2011-01-01

Light-emitting diodes (LEDs) are advertised as environmentally friendly because they are energy efficient and mercury-free. This study aimed to determine if LEDs engender other forms of environmental and human health impacts, and to characterize variation across different LEDs based on color and intensity. The objectives are as follows: (i) to use standardized leachability tests to examine whether LEDs are to be categorized as hazardous waste under existing United States federal and California state regulations; and (ii) to use material life cycle impact and hazard assessment methods to evaluate resource depletion and toxicity potentials of LEDs based on their metallic constituents. According to federal standards, LEDs are not hazardous except for low-intensity red LEDs, which leached Pb at levels exceeding regulatory limits (186 mg/L; regulatory limit: 5). However, according to California regulations, excessive levels of copper (up to 3892 mg/kg; limit: 2500), Pb (up to 8103 mg/kg; limit: 1000), nickel (up to 4797 mg/kg; limit: 2000), or silver (up to 721 mg/kg; limit: 500) render all except low-intensity yellow LEDs hazardous. The environmental burden associated with resource depletion potentials derives primarily from gold and silver, whereas the burden from toxicity potentials is associated primarily with arsenic, copper, nickel, lead, iron, and silver. Establishing benchmark levels of these substances can help manufacturers implement design for environment through informed materials substitution, can motivate recyclers and waste management teams to recognize resource value and occupational hazards, and can inform policymakers who establish waste management policies for LEDs.

Sources of toxicity and exposure information for identifying chemicals of high concern to children

International Nuclear Information System (INIS)

Stone, Alex; Delistraty, Damon

2010-01-01

Due to the large number of chemicals in commerce without adequate toxicity characterization data, coupled with an ineffective federal policy for chemical management in the United States, many states are grappling with the challenge to identify toxic chemicals that may pose a risk to human health and the environment. Specific populations (e.g., children, elderly) are particularly sensitive to these toxic chemicals. In 2008, the Children's Safe Product Act (CSPA) was passed in Washington State. The CSPA included specific requirements to identify High Priority Chemicals (HPCs) and Chemicals of High Concern to Children (CHCCs). To implement this legislation, a methodology was developed to identify HPCs from authoritative scientific and regulatory sources on the basis of toxicity criteria. Another set of chemicals of concern was then identified from authoritative sources, based on their potential exposure to children. Exposure potential was evaluated by identifying chemicals detected in biomonitoring studies (i.e., human tissues), as well as those present in residential exposure media (e.g., indoor air, house dust, drinking water, consumer products). Accordingly, CHCCs were defined as HPCs that also appear in biomonitoring studies or relevant exposure media. For chemicals with unique Chemical Abstracts Service (CAS) numbers, we identified 2044 HPCs and 2219 chemicals with potential exposure to children, resulting in 476 CHCCs. The process of chemical identification is dynamic, so that chemicals may be added or subtracted as new information becomes available. Although beyond the scope of this paper, the 476 CHCCs will be prioritized in a more detailed assessment, based on the strength and weight of evidence of toxicity and exposure data. Our approach was developed to be flexible which allows the addition or removal of specific sources of toxicity or exposure information, as well as transparent to allow clear identification of inputs. Although the methodology was

Occurrence and potential toxicity of pyrethroids and other insecticides in bed sediments of urban streams in central Texas

Energy Technology Data Exchange (ETDEWEB)

Hintzen, Emily P. [Department of Environmental Studies, Baylor University, Waco, TX 76798 (United States); Lydy, Michael J. [Fisheries and Illinois Aquaculture Center, and Department of Zoology, Southern Illinois University, Carbondale, IL 62091 (United States); Belden, Jason B. [Department of Zoology, Oklahoma State University, 430 Life Science West, Stillwater, OK 74078 (United States)], E-mail: jbelden@okstate.edu

2009-01-15

Despite heavy insecticide usage in urban areas, only a few studies have investigated the impact of current-use insecticides on benthic invertebrates in urban streams. The objective of this study was to measure the presence and concentration of current-use pesticides in sediments of residential streams in central Texas. Additionally, toxicity of these sediments to Hyalella azteca was evaluated. Sediment samples were collected from several sites in urban streams over the course of a year, of which, 66% had greater than one toxic unit (TU) of insecticide. Bifenthrin was the greatest contributor accounting for 65% of the TUs, and sediment toxicity to H. azteca correlated with the magnitude of total insecticides and bifenthrin TUs. The results of this study further raise concerns over the environmental consequences posed by many current-use insecticides, especially pyrethroids, in urban settings. - This study examined the presence of insecticides in Texas stream sediments as a model for evaluating the potential impact of urban insecticide use in the Southern United States.

Occurrence and potential toxicity of pyrethroids and other insecticides in bed sediments of urban streams in central Texas

International Nuclear Information System (INIS)

Hintzen, Emily P.; Lydy, Michael J.; Belden, Jason B.

2009-01-01

Despite heavy insecticide usage in urban areas, only a few studies have investigated the impact of current-use insecticides on benthic invertebrates in urban streams. The objective of this study was to measure the presence and concentration of current-use pesticides in sediments of residential streams in central Texas. Additionally, toxicity of these sediments to Hyalella azteca was evaluated. Sediment samples were collected from several sites in urban streams over the course of a year, of which, 66% had greater than one toxic unit (TU) of insecticide. Bifenthrin was the greatest contributor accounting for 65% of the TUs, and sediment toxicity to H. azteca correlated with the magnitude of total insecticides and bifenthrin TUs. The results of this study further raise concerns over the environmental consequences posed by many current-use insecticides, especially pyrethroids, in urban settings. - This study examined the presence of insecticides in Texas stream sediments as a model for evaluating the potential impact of urban insecticide use in the Southern United States

40 CFR 80.910 - How does a refiner or importer apply for a toxics baseline?

Science.gov (United States)

2010-07-01

... for a toxics baseline? 80.910 Section 80.910 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES Gasoline Toxics Baseline Determination § 80.910 How does a refiner or importer apply for a toxics baseline? (a)(1) A refiner or importer...

Work-principle model for predicting toxic fumes of nonideal explosives

Energy Technology Data Exchange (ETDEWEB)

Wieland, Michael S. [National Institute of Occupational Safety and Health, Pittsburgh Research Center, P.O. Box 18070, Pittsburgh, PA 15236-0070 (United States)

2004-08-01

The work-principle from thermodynamics was used to formulate a model for predicting toxic fumes from mining explosives in underground chamber tests, where rapid turbulent combustion within the surrounding air noticeably changes the resulting concentrations. Two model constants were required to help characterize the reaction zone undergoing rapid chemical transformations in conjunction with heat transfer and work output: a stoichiometry mixing fraction and a reaction-quenching temperature. Rudimentary theory with an unsteady uniform concentration gradient was taken to characterize the combustion zone, yielding 75% for the mixing fraction. Four quenching temperature trends were resolved and compared to test results of ammonium nitrate compositions with different fuel-oil percentages (ANFO). The quenching temperature 2345 K was the optimum choice for fitting the two major components of fume toxicity: carbon monoxide (CO) and total nitrogen oxides (NO{sub X}). The resulting two-constant model was used to generate comparisons for test results of ANFO compositions with additives. Though respectable fits were usually found, charge formulations which reacted weakly could not be resolved numerically. The work-principle model yields toxic concentrations for a range of charge formulations, making it a useful tool for investigating the potential hazard of released fumes and reducing the risk of unwanted incidents. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

Potential of antioxidant and toxicity of some medical plants used by sub-ethnic communities of Bahau in East Kalimantan

Science.gov (United States)

Rohim, P.; Arung, E. T.; Kusuma, I. W.

2018-04-01

The purpose of this research is to assay the potential antioxidant and toxicity of several plants from Bahau, a sub-ethnic in East Kalimantan in regard to their utilization as traditional medicines. This research includes phytochemical analysis, DPPH radical and superoxide radical scavenging activity as well as toxicity assay using Artemiasalina shrimp larvae. The results of the extraction showed the highest yield was 2,91% obtained from avung tanaq (Ficus uncinata), while the lowest is 1.14% obtained from tevoqsalah (Saccharum sp.) species. The result of phytochemicals showed that all plants contain alkaloid and carbohydrate. While carotenoids, saponins, triterpenoids and steroids were absence in all plant extracts. The DPPH radical scavenging activity test showed that the lowest IC50 value of kayog kue (Dictamnus albus) by 23.96 μg/mL. The superoxide radical scavenging activity assay showed IC50 values of all extract samples were >100 μg/mL. The toxicity assay showed that LC50 values of all samples of extract tested were >1000 μg/mL. The present research suggested good potential activity of some plants from Bahau ethnic and further research oriented to wide uses of the plants as herbal products is needed.

Heme oxygenase-1 protects endothelial cells from the toxicity of air pollutant chemicals

International Nuclear Information System (INIS)

Lawal, Akeem O.; Zhang, Min; Dittmar, Michael; Lulla, Aaron; Araujo, Jesus A.

2015-01-01

Diesel exhaust particles (DEPs) are a major component of diesel emissions, responsible for a large portion of their toxicity. In this study, we examined the toxic effects of DEPs on endothelial cells and the role of DEP-induced heme oxygenase-1 (HO-1) expression. Human microvascular endothelial cells (HMECs) were treated with an organic extract of DEPs from an automobile engine (A-DEP) or a forklift engine (F-DEP) for 1 and 4 h. ROS generation, cell viability, lactate dehydrogenase leakage, expression of HO-1, inflammatory genes, cell adhesion molecules and unfolded protein respone (UPR) gene were assessed. HO-1 expression and/or activity were inhibited by siRNA or tin protoporphyrin (Sn PPIX) and enhanced by an expression plasmid or cobalt protoporphyrin (CoPPIX). Exposure to 25 μg/ml of A-DEP and F-DEP significantly induced ROS production, cellular toxicity and greater levels of inflammatory and cellular adhesion molecules but to a different degree. Inhibition of HO-1 enzymatic activity with SnPPIX and silencing of the HO-1 gene by siRNA enhanced DEP-induced ROS production, further decreased cell viability and increased expression of inflammatory and cell adhesion molecules. On the other hand, overexpression of the HO-1 gene by a pcDNA 3.1D/V5-HO-1 plasmid significantly mitigated ROS production, increased cell survival and decreased the expression of inflammatory genes. HO-1 expression protected HMECs from DEP-induced prooxidative and proinflammatory effects. Modulation of HO-1 expression could potentially serve as a therapeutic target in an attempt to inhibit the cardiovascular effects of ambient PM. - Highlights: • We examined the role of HO-1 expression on diesel exhaust particle (DEP) in endothelial cells. • DEPs exert cytotoxic and inflammatory effects on human microvascular endothelial cells (HMECs). • DEPs induce HO-1 expression in HMECs. • HO-1 protects against the oxidative stress induced by DEps. • HO-1 attenuates the proinflammatory effects

Heme oxygenase-1 protects endothelial cells from the toxicity of air pollutant chemicals

Energy Technology Data Exchange (ETDEWEB)

Lawal, Akeem O.; Zhang, Min; Dittmar, Michael [Division of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, 10833 Le Conte Avenue, CHS 43-264, Los Angeles, CA 90095 (United States); Lulla, Aaron [Division of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, 10833 Le Conte Avenue, CHS 43-264, Los Angeles, CA 90095 (United States); Molecular Toxicology Interdepartmental Program, University of California, Los Angeles (United States); Araujo, Jesus A., E-mail: JAraujo@mednet.ucla.edu [Division of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, 10833 Le Conte Avenue, CHS 43-264, Los Angeles, CA 90095 (United States); Molecular Toxicology Interdepartmental Program, University of California, Los Angeles (United States); Molecular Biology Institute, University of California, Los Angeles (United States)

2015-05-01

Diesel exhaust particles (DEPs) are a major component of diesel emissions, responsible for a large portion of their toxicity. In this study, we examined the toxic effects of DEPs on endothelial cells and the role of DEP-induced heme oxygenase-1 (HO-1) expression. Human microvascular endothelial cells (HMECs) were treated with an organic extract of DEPs from an automobile engine (A-DEP) or a forklift engine (F-DEP) for 1 and 4 h. ROS generation, cell viability, lactate dehydrogenase leakage, expression of HO-1, inflammatory genes, cell adhesion molecules and unfolded protein respone (UPR) gene were assessed. HO-1 expression and/or activity were inhibited by siRNA or tin protoporphyrin (Sn PPIX) and enhanced by an expression plasmid or cobalt protoporphyrin (CoPPIX). Exposure to 25 μg/ml of A-DEP and F-DEP significantly induced ROS production, cellular toxicity and greater levels of inflammatory and cellular adhesion molecules but to a different degree. Inhibition of HO-1 enzymatic activity with SnPPIX and silencing of the HO-1 gene by siRNA enhanced DEP-induced ROS production, further decreased cell viability and increased expression of inflammatory and cell adhesion molecules. On the other hand, overexpression of the HO-1 gene by a pcDNA 3.1D/V5-HO-1 plasmid significantly mitigated ROS production, increased cell survival and decreased the expression of inflammatory genes. HO-1 expression protected HMECs from DEP-induced prooxidative and proinflammatory effects. Modulation of HO-1 expression could potentially serve as a therapeutic target in an attempt to inhibit the cardiovascular effects of ambient PM. - Highlights: • We examined the role of HO-1 expression on diesel exhaust particle (DEP) in endothelial cells. • DEPs exert cytotoxic and inflammatory effects on human microvascular endothelial cells (HMECs). • DEPs induce HO-1 expression in HMECs. • HO-1 protects against the oxidative stress induced by DEps. • HO-1 attenuates the proinflammatory effects

[Investigation of potential toxic factors for fleece-flower root： from perspective of processing methods evolution].

Science.gov (United States)

Cui, He-Rong; Bai, Zhao-Fang; Song, Hai-Bo; Jia, Tian-Zhu; Wang, Jia-Bo; Xiao, Xiao-He

2016-01-01

In recent years, the rapid growth of reports on fleece-flower root-caused liver damages has drawn wide attention of both at home and abroad, however, there were rare literature on toxicology of fleece-flower root in ancient Chinese medicine. But why there are so many reports on toxicology of fleece-flower root now compared with the ancient literature? As a typical tonic medicine, the clinical utility of fleece-flower root was largely limited by its standardization and reliability of processing methods in ancient Chinese medicine. The ancient processing methods of fleece-flower root emphasized nine times of steaming and nine times of drying, while the modern processes have been simplified into one time of steaming. Whether the differences between ancient and modern processing methods are the potential cause of the increased events of fleece-flower root-caused liver damages. We will make deep analysis and provide new clues and perspectives for the research on its toxicity. This article, therefore, would discuss the affecting factors and key problems in toxicity attenuation of fleece-flower root on the basis of sorting out the processing methods of fleece-flower root in ancient medical books and modern standards, in order to provide the reference for establishing specification for toxicity attenuation of fleece-flower root. Copyright© by the Chinese Pharmaceutical Association.

High-throughput sequencing reveals microbial communities in drinking water treatment sludge from six geographically distributed plants, including potentially toxic cyanobacteria and pathogens.

Science.gov (United States)

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

2018-04-10

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

Associations between lifestyle and air pollution exposure: Potential for confounding in large administrative data cohorts.

Science.gov (United States)

Strak, Maciej; Janssen, Nicole; Beelen, Rob; Schmitz, Oliver; Karssenberg, Derek; Houthuijs, Danny; van den Brink, Carolien; Dijst, Martin; Brunekreef, Bert; Hoek, Gerard

2017-07-01

Cohorts based on administrative data have size advantages over individual cohorts in investigating air pollution risks, but often lack in-depth information on individual risk factors related to lifestyle. If there is a correlation between lifestyle and air pollution, omitted lifestyle variables may result in biased air pollution risk estimates. Correlations between lifestyle and air pollution can be induced by socio-economic status affecting both lifestyle and air pollution exposure. Our overall aim was to assess potential confounding by missing lifestyle factors on air pollution mortality risk estimates. The first aim was to assess associations between long-term exposure to several air pollutants and lifestyle factors. The second aim was to assess whether these associations were sensitive to adjustment for individual and area-level socioeconomic status (SES), and whether they differed between subgroups of the population. Using the obtained air pollution-lifestyle associations and indirect adjustment methods, our third aim was to investigate the potential bias due to missing lifestyle information on air pollution mortality risk estimates in administrative cohorts. We used a recent Dutch national health survey of 387,195 adults to investigate the associations of PM 10 , PM 2.5 , PM 2.5-10 , PM 2.5 absorbance, OP DTT, OP ESR and NO 2 annual average concentrations at the residential address from land use regression models with individual smoking habits, alcohol consumption, physical activity and body mass index. We assessed the associations with and without adjustment for neighborhood and individual SES characteristics typically available in administrative data cohorts. We illustrated the effect of including lifestyle information on the air pollution mortality risk estimates in administrative cohort studies using a published indirect adjustment method. Current smoking and alcohol consumption were generally positively associated with air pollution. Physical activity

Air Risk Information Support Center

Energy Technology Data Exchange (ETDEWEB)

Shoaf, C.R.; Guth, D.J. [Environmental Protection Agency, Washington, DC (United States)

1990-12-31

The Air Risk Information Support Center (Air RISC) was initiated in early 1988 by the US Environmental Protection Agency`s (EPA) Office of Health and Environmental Assessment (OHEA) and the Office of Air Quality Planning and Standards (OAQPS) as a technology transfer effort that would focus on providing information to state and local environmental agencies and to EPA Regional Offices in the areas of health, risk, and exposure assessment for toxic air pollutants. Technical information is fostered and disseminated by Air RISCs three primary activities: (1) a {open_quotes}hotline{close_quotes}, (2) quick turn-around technical assistance projects, and (3) general technical guidance projects. 1 ref., 2 figs.

Air toxics exposure from vehicle emissions at a U.S. border crossing: Buffalo Peace Bridge Study.

Science.gov (United States)

Spengler, John; Lwebuga-Mukasa, Jamson; Vallarino, Jose; Melly, Steve; Chillrud, Steve; Baker, Joel; Minegishi, Taeko

2011-07-01

The Peace Bridge in Buffalo, New York, which spans the Niagara River at the east end of Lake Erie, is one of the busiest U.S. border crossings. The Peace Bridge plaza on the U.S. side is a complex of roads, customs inspection areas, passport control areas, and duty-free shops. On average 5000 heavy-duty diesel trucks and 20,000 passenger cars traverse the border daily, making the plaza area a potential "hot spot" for emissions from mobile sources. In a series of winter and summer field campaigns, we measured air pollutants, including many compounds considered by the U.S. Environmental Protection Agency (EPA*) as mobile-source air toxics (MSATs), at three fixed sampling sites: on the shore of Lake Erie, approximately 500 m upwind (under predominant wind conditions) of the Peace Bridge plaza; immediately downwind of (adjacent to) the plaza; and 500 m farther downwind, into the community of west Buffalo. Pollutants sampled were particulate matter (PM) days. Other metals (beryllium, sodium, magnesium, potassium, titanium, manganese, cobalt, strontium, tin, cesium, and lanthanum) showed significant increases downwind as well. Sulfur, arsenic, selenium, and a few other elements appeared to be markers for regional transport as their upwind and downwind concentrations were correlated, with ratios near unity. Using positive matrix factorization (PMF), we identified the sources for PAHs at the three fixed sampling sites as regional, diesel, general vehicle, and asphalt volatilization. Diesel exhaust at the Peace Bridge plaza accounted for approximately 30% of the PAHs. The NPAH sources were identified as nitrate (NO3) radical reactions, diesel, and mixed sources. Diesel exhaust at the Peace Bridge plaza accounted for 18% of the NPAHs. Further evidence for the impact of the Peace Bridge plaza on local air quality was found when the differences in 10-minute average UFP counts and pPAH concentrations were calculated between pairs of sites and displayed by wind direction. With

Clean air and energy: from conflict to reconciliation

International Nuclear Information System (INIS)

Kolstad, C.D.; Schulze, W.D.; Williams, M.D.

1982-01-01

Unconstrained energy resource development in the Rocky Mountain west is likely to threaten the environment and the health and well-being of the people. Impacts may be associated with visibility degradation, toxic concentrations of gases, and deposition of acidic or toxic substances. Because the possible benefits of energy development in the region are very large, there is great concern that constraints imposed by air quality regulation may preclude the use of important resources or make unduly expensive energy produced from the region. The conflict between energy and clean air in the region is exacerbated by non-energy sources, such as copper smelters and urban areas, that already pose significant environmental threats. The hard policy question is not how to preserve clean air resources or how to develop energy but how to achieve and balance both goals. The effects and regulatory costs and benefits of air pollution control are discussed, and policy directions to protect air quality while pursuing energy development are presented

Interaction of arbuscular mycorrhizal symbionts with arsenic and other potentially toxic elements

International Nuclear Information System (INIS)

Khairuddin Abdul Rahim

2000-01-01

The response of arbuscular mycorrhizal (AM) symbionts to arsenic, and arsenic interactions with phosphorus and potentially toxic elements (PTEs) in soils from a former arsenic mine, the Devon Great Consols, were investigated. The objective was to determine whether AM associations ameliorate arsenic toxicity in Plantago lanceolata and Agrostis capillaris, plants commonly found at abandoned mines. An exploratory investigation indicated the richness in biodiversity of AMF that colonised plants growing at the site. Arsenic was found at high concentrations and was strongly associated with copper and iron. P. lanceolata was always colonised by AMF, while colonisation of A. capillaris was variable. There was no evidence in the field of soil pH or PTEs influencing AMF colonisation and spore density. There was no strong correlation between arsenic content in plant and available arsenic, obtained through various extraction methods. Spore germination and infectivity in the mine soils were strongly influenced by the AMF genotype and to a lesser extent by the soil environment. P. lanceolata and A. capillaris root growth was inhibited at arsenic concentrations of ≥50 μg g -1 in agar. Bioavailability experiments using mine soils and Terra-Green TM (calcined attapulgite) spiked with sodium arsenate gave no evidence that AMF-colonised plants translocated less arsenic to the shoots. Plants accumulated more arsenic in their roots than in their shoots, whether they were colonised by AMF or not. The A. capillaris genotype used in the present study translocated less of both arsenic and phosphorus to its shoots than P. lanceolata. High available phosphorus in Terra-Green TM protected plants against arsenic toxicity, at -1 As. There was evidence for inhibition by arsenic in AMF colonisation of roots. For quantifying AMF extra radical hyphae contribution to arsenic transportation from growth medium to plant using a compartmented pot system, the use of low phosphorus medium and a longer

Comparative toxicity of two azadirachtin-based neem pesticides to Daphnia pulex.

Science.gov (United States)

Goktepe, Ipek; Plhak, Leslie C

2002-01-01

Azadirachtin (AZA)-based pesticides (Neemix and Bioneem) demonstrated toxicity in 48-h nonrenewal toxicity assays using Daphnia pulex at levels that were comparable with several organophosphate pesticides. The median lethal concentration (LC50) values for the two neem pesticides were found to be 0.028 and 0.033 microl/ml, respectively. The LC50 value for nonformulated (95% pure) AZA was determined to be 0.382 microg AZA/ml. Neemix and Bioneem were exposed to air and northern sky daylight in a light box at 24 and 37 degrees C for 1, 3, 6, and 9 d. Standard 48-h acute toxicity tests were used to determine the effect of aging in these dry environmental conditions. Neemix and Bioneem were also fractionated into volatile and nonvolatile fractions, and the toxicity of each was tested. Compared with Neemix, Bioneem remained toxic longer when exposed to light and air at 37 degrees C, indicating that this pesticide may be less prone to environmental degradation. When fractionated, the nonvolatile fractions for both pesticides exhibited significantly lower LC50 values than the full formulations. These results suggest that, depending on the application rate and environmental fate, AZA-based pesticides may have direct adverse effects on aquatic organisms and that the toxicity and stability of formulated pesticides depend on factors other than only the AZA concentration.

Effect of Pre-Gamma Irradiation Induction of Metallothionein on potentially Radiation-Induced Toxic Heavy Metals Ions In Rats

International Nuclear Information System (INIS)

El-Shamy, El.

2004-01-01

Metallothionein, which is a cystein-rich metal binding protein, can act as free radical scavenger and involved in resistance to heavy metal toxicity. The induction of synthesis has been shown to protect organs from the toxic effect of radiation. This study aimed to stud the effects of pre-irradiation induction of by heavy metal (Zinc sulfate) on potentially gamma radiation-induced toxic heavy metals ions in rate liver and kidney tissues. Forty eight albino rats were included in this study. They were divided into eight groups each of six animals. Two control groups injected with saline. Two Zinc sulfate-treated groups injected with zinc sulfate, two Irradiated groups exposed to a single dose level (7 Gy) of whole body gamma irradiation and two combined zinc sulfate and irradiation groups injected with zinc sulfate and exposed to whole body gamma irradiation (at dose 7 Gy). Animals of all groups were sacrificed 24 and 48 hours after last either zinc sulfate dose or irradiation. Samples of liver and kidney's tissues were subjected to the following investigations: Estimation of tissue heavy Metals (Zinc, Iron and Copper), and tissue (MT). After irradiation, liver and kidney MT were increased approximately 10-fold and 2-fold respectively after irradiation. Accumulation of zinc and iron in both liver and kidney tissues were detected, while accumulation of copper only in the liver tissues. The pre-irradiation treatment with zinc sulfate (Zn SO4) resulted in highly significant decrease in zinc, iron, and copper levels in both liver and kidney tissues in comparison with irradiation groups. Conclusion, it can be supposed that pre-irradiation injection of ZnSO 4 exerted protective effect against the potentially radiation-induced toxic heavy metals ions through MT induction

USEtox fate and ecotoxicity factors for comparative assessment of toxic emissions in Life Cycle Analysis

DEFF Research Database (Denmark)

Andrew D, Henderson; Hauschild, Michael Zwicky; Van de Meent, Dik

2011-01-01

orders of magnitude. However, for an emission to air or soil, differences in chemical properties may decrease the CF by up to 10 orders of magnitude, as a result of intermedia transfer and degradation. This result brings new clarity to the relative contributions of fate and freshwater ecotoxicity...... with characteristic properties, this work provides understanding of the basis for calculations of CFs in USEtox. In addition, it offers insight into the chemical properties and critical mechanisms covering the continuum from chemical emission to freshwater ecosystem toxicity. For an emission directly to water......The USEtox model was developed in a scientific consensus process involving comparison of and harmonization between existing environmental multimedia fate models. For freshwater ecosystem toxicity, it covers the entire impact pathway, i.e., transforming a chemical emission into potential impacts...

Phytochemical constituents, antioxidant activity and toxicity potential of the essential oil from Ferula gummosa Boiss. roots

Directory of Open Access Journals (Sweden)

T. Saadattalab

2017-11-01

Full Text Available Background and objectives: Ferula gummosa Boiss. (Umbelliferae is a popular medicinal plant, which is known mostly for therapeutic uses of its oleo-gum-resin (Barijeh in Persian. In the present study, the essential oil of F. gummosa roots was investigated for its phytochemical constituents, antioxidant activity and toxicity potential. Methods: Phytochemical constituents of the essential oil (extracted by hydrodistillation method were analyzed using GC-MS. Antioxidant and toxicity properties of the oil were also evaluated in DPPH free radical-scavenging assay and brine shrimp lethality test, respectively. Results: Forty-two compounds, representing 87.7% of total oil, were identified by GC-MS analysis of the plant roots oil. The essential oil was characterized by a high concentration of monoterpene hydrocarbons (55.9%, mainly β-pinene (33.2%, β-phellandrene (8.0% and α-pinene (6.9%. In DPPH free radical-scavenging assay, the oil sample did not demonstrate any activity at the highest tested concentration (1.0 mg/mL. However, it was found very toxic in brine shrimp lethality test with LD50 value of 2.4 µg/mL. Conclusion: The results of this study introduced the F. gummosa roots oil as a source of monoterpene hydrocarbons, especially β-pinene. Considering the high yield of essential oil extraction (12.1% v/w, these compounds may be involved in anticonvulsant, antinociceptive and anti-inflammatory properties of F. gummosa root. Moreover, considerable toxicity of the root oil highlights it as an appropriate candidate for further mechanistic toxicological studies.

The potentiation effect makes the difference: Non-toxic concentrations of ZnO nanoparticles enhance Cu nanoparticle toxicity in vitro

Energy Technology Data Exchange (ETDEWEB)

Li, Lingxiangyu [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Fernández-Cruz, María Luisa; Connolly, Mona [Departamento de Medio Ambiente, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid 28040 (Spain); Conde, Estefanía; Fernández, Marta [Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Madrid 28040 (Spain); Schuster, Michael [Department of Chemistry, Technische Universität München, Garching 85747 (Germany); Navas, José María, E-mail: jmnavas@inia.es [Departamento de Medio Ambiente, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid 28040 (Spain)

2015-02-01

Here we examined whether the addition of a non-toxic concentration (6.25 μg/mL) of zinc oxide nanoparticles (ZnONPs: 19, 35 and 57 nm, respectively) modulates the cytotoxicity of copper nanoparticles (CuNPs, 63 nm in size) in the human hepatoma cell line HepG2. The cytotoxic effect of CuNPs on HepG2 cells was markedly enhanced by the ZnONPs, the largest ZnONPs causing the highest increase in toxicity. However, CuNPs cytotoxicity was not affected by co-incubation with medium containing only zinc ions, indicating the increase in toxicity might be attributed to the particle form of ZnONPs. Transmission electron microscopy (TEM) revealed the presence of CuNPs and ZnONPs inside the cells co-exposed to both types of NP and outflow of cytoplasm through the damaged cell membrane. Inductively coupled plasma mass spectrometry (ICP-MS) determined an increase in the concentration of zinc and a decrease in that of copper in co-exposed cells. On the basis of these results, we propose that accumulation of large numbers of ZnONPs in the cells alters cellular membranes and the cytotoxicity of CuNPs is increased. - Highlights: • ZnONPs at non-toxic concentrations increased the toxicity of CuNPs in vitro. • ZnONPs of larger size provoked a stronger synergistic effect with CuNPs. • The synergistic effect was attributed to the particle fraction of ZnONPs.

Toxicity of carbon nanotubes: A review.

Science.gov (United States)

Francis, Arul Prakash; Devasena, Thiyagarajan

2018-03-01

Carbon nanotubes (CNTs) are widely used in the aerospace, automotive, and electronics industries because of their stability, enhanced metallic, and electrical properties. CNTs are also being investigated for biomedical applications such as drug delivery systems and biosensors. However, the toxic potential of CNTs was reported in various cell lines and animal models. The toxicity depends on diverse properties of the CNTs, such as length, aspect ratio, surface area, degree of aggregation, purity, concentration, and dose. In addition, CNTs and/or associated contaminants were well known for oxidative stress, inflammation, apoptosis, pulmonary inflammation, fibrosis, and granuloma in lungs. The increased production of CNTs likely enhanced the possibility of its exposure in people. Studies on the toxicity of CNTs are mainly focused on the pulmonary effects after intratracheal administration, and only a few studies are reported about the toxicity of CNTs via other routes of exposure. So, it is essential to consider the chronic toxicity of CNTs before using them for various biomedical applications. This review focuses on the potential toxicities of CNTs.

Development of a health effects based priority ranking system for air emissions reductions from oil refineries in Canada

International Nuclear Information System (INIS)

McColl, S.; Gower, S.; Hicks, J.; Shortreed, J.; Craig, L.

2004-01-01

This paper presents the concept and methodologies behind the development of a health effects priority ranking tool for the reduction of air emissions from oil refineries. The Health Effects Indicators Decision Index- Versions 2 (Heidi II) was designed to assist policy makers in prioritizing air emissions reductions on the basis of estimated risk to human health. Inputs include facility level rankings of potential health impacts associated with carcinogenic air toxics, non-carcinogenic air toxics and criteria air contaminants for each of the 20 refineries in Canada. Rankings of estimated health impacts are presented on predicted incidence of health effects. Heidi II considers site-specific annual pollutant emission data, ambient air concentrations associated with releases and concentration response functions for various types of health effects. Additional data includes location specific background air concentrations, site-specific population densities, and the baseline incidence of different health effects endpoints, such as cancer, non-cancer illnesses and cardiorespiratory illnesses and death. Air pollutants include the 29 air toxics reported annually in Environment Canada's National Pollutant Release Inventory. Three health impact ranking outputs are provided for each facility: ranking of pollutants based on predicted number of annual cases of health effects; ranking of pollutants based on simplified Disability Adjusted Life Years (DALYs); and ranking of pollutants based on more complex DALYs that consider types of cancer, systemic disease or types of cardiopulmonary health effects. Rankings rely on rough statistical estimates of predicted incidence rates for health endpoints. The models used to calculate rankings can provide useful guidance by comparing estimated health impacts. Heidi II has demonstrated that it is possible to develop a consistent and objective approach for ranking priority reductions of air emissions. Heidi II requires numerous types and

Evaluate the potential toxicity of quantum dots on bacterial metabolism by microcalorimetry

Energy Technology Data Exchange (ETDEWEB)

Xiao, Qi [College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001 (China); State Key Laboratory of Virology, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Huang, Shan, E-mail: huangs@whu.edu.cn [College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001 (China); State Key Laboratory of Virology, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Su, Wei [College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001 (China); Li, Peiyuan [College of Pharmacy, Guangxi Traditional Chinese Medical University, Nanning 530001 (China); Liu, Yi, E-mail: prof.liuyi@263.net [State Key Laboratory of Virology, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China)

2013-01-20

Highlights: Black-Right-Pointing-Pointer Microcalorimeter was applied for the investigations of the toxic effects of QDs on bacteria. Black-Right-Pointing-Pointer The results indicate that the toxicity of these QDs may come from the toxic Cd{sup 2+} released. Black-Right-Pointing-Pointer The results indicate electrostatic interaction is the main force between bacteria and QDs. Black-Right-Pointing-Pointer The toxicity of these QDs can be varied efficiently by modifying with different ligands. - Abstract: Herein, we evaluated the toxic effects of mercaptoacetic acid (MAA)-CdSe quantum dots (QDs), MAA-CdSe/ZnS QDs and cysteamine (CA)-CdSe/ZnS QDs on the growth of both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) by microcalorimetry. Thermogenic curves of bacteria were recorded and bioeffects of QDs on bacteria were investigated. The results suggested that both MAA-CdSe QDs and MAA-CdSe/ZnS QDs inhibited the E. coli growth but stimulated the S. aureus growth with dose-dependent type. The inhibition or stimulation efficiency of QDs on E. coli or S. aureus growth all decreased dramatically after UV irradiation, which was due to the liberation of more toxic Cd{sup 2+}. In addition, MAA-CdSe/ZnS QDs and CA-CdSe/ZnS QDs affected the growth of E. coli and S. aureus differently. MAA-CdSe/ZnS QDs could not affect the growth of bacteria, while CA-CdSe/ZnS QDs inhibited the bacterial growth dramatically, which resulted from the negative charge on the surface of these bacteria.

Air pollution sources, impact and monitoring

International Nuclear Information System (INIS)

Qureshi, I.H.

1999-01-01

Improper management of socio-economic developmental activities has put a great stress on natural resources and eco-systems and has caused environmental degradation. Indiscriminate release of toxic substances into the atmosphere from power generation, industrial operations, transportation, incineration of waste and other operations has affected the quality of ambient air. Combustion of fossil fuel results in the emission of oxides of carbon, sulfur and nitrogen, particulate and organic compounds which affect the local, regional and global environment. Industrial operations release a wide variety of pollutants which directly affect the local environment. Operation of automobiles releases oxides of carbon, sulfur and nitrogen, hydrocarbons, traces of heavy metals and toxic polycyclic aromatic compounds whereas incineration of municipal waste releases particulate, acid fumes and photochemically reactive and odorous compounds. These air pollutants have varying impacts on health and environment. The intake of polluted air may produce various physiological disorders ranging from respiratory diseases to changes in blood chemistry. Therefore, the emission of pollutants should be controlled at the source and monitoring the levels of pollution should assess the quality of air. (author)

Potential petrophysical and chemical property alterations in a compressed air energy storage porous rock reservoir

Energy Technology Data Exchange (ETDEWEB)

Stottlemyre, J.A.; Erikson, R.L.; Smith, R.P.

1979-10-01

Successful commercialization of Compressed Air Energy Storage (CAES) systems depends on long-term stability of the underground reservoirs subjected to somewhat unique operating conditions. Specifically, these conditions include elevated and time varying temperatures, effective stresses, and air humidities. To minimize the requirements for premium fuels, it may be desirable to retain the thermal energy of compression. Porous media, e.g., sandstone, may hold promise as elevated temperature reservoirs. In this study, a reservoir composed of clean quartz sandstone and injection air temperatures of 300 to 575/sup 0/K are assumed. Numerical modeling is used to estimate temperature, stress, and humidity conditions within this reference porous media reservoir. A discussion on relative importance to CAES of several potential porous media damage mechanisms is presented. In this context, damage is defined as a reduction in intrinsic permeability (measure of air transport capability), a decrease in effective porosity (measure of storage capability), or an increase in elastic and/or inelastic deformation of the porous material. The potential damage mechanisms presented include: (1) disaggregation, (2) particulate plugging, (3) boundary layer viscosity anomalies, (4) inelastic microstructural consolidation, (5) clay swelling and dispersion, (6) hydrothermal mineral alteration, (7) oxidation reactions, and (8) well casing corrosion. These mechanisms are placed in perspective with respect to anticipated CAES conditions and mechanisms suggested are: (1) of academic interest only, (2) readily identified and controlled via engineering, or (3) potential problem areas requiring additional investigation.

Air Quality Monitoring Programme

DEFF Research Database (Denmark)

Kemp, K.; Palmgren, F.

The air quality in Danish cities has been monitored continuously since 1982 within the Danish Air Quality (LMP) network. The aim has been to follow the concentration levels of toxic pollutants in the urban atmosphere and to provide the necessary knowledge to assess the trends, to perform source...... apportionment, and to evaluate the chemical reactions and the dispersion of the pollutants in the atmosphere. In 2002 the air quality was measured in four Danish cities and at two background sites. NO2 and PM10 were at several stations found in concentrations above the new EU limit values, which the Member...

Global change impact on oxidative potential and toxicity of atmospheric particles from the East Mediterranean basin: the ARCHIMEDES initiative

Science.gov (United States)

Alleman, Laurent; Anthérieu, Sébastien; Baeza-Squiban, Armelle; Garçon, Guillaume; Lo Guidice, Jean-Marc; Hamonou, Eric; Öztürk, Fatma; Perdrix, Esperanza; Rudich, Yinon; Sciare, Jean; Sauvage, Stéphane

2017-04-01

Climate change (CC) has important social, economical and health implications, notably in accordance with variation in air pollution or microbiome modification and its related toxicity mechanisms. CC will have a strong influence on meteorology, inducing dryer and warmer conditions in some regions. The Mediterranean basin is foreseen as a hotspot for regional climate warming, favoring larger dust episodes, wild fire events, vegetation emissions and changes in air pollution physic-chemical characteristics due to enhanced photochemical reactivity. Increasing concentrations of biogenic volatile organic compounds (VOCs), ozone, and radicals will be associated with rising concentrations of secondary organic aerosols (SOA) and other oxidized aerosols. These expected changes in aerosol composition are currently studied within the international ChArMEx (Chemistry-aerosol Mediterranean Experiment) program, part of the interdisciplinary MISTRALS metaprogramme (Mediterranean Integrated STudies at Regional And Local Scales). According to the LIFE/MED-PARTICLES (LIFE) project, this might result in more adverse effects on health. However, toxicologists are far from having a detailed mechanistic knowledge of the quantitative causal relations between particles (PM) and health effects suggested by epidemiological evidences. Detailed toxicological studies looking at contrasted PM origins and chemical compositions are highly needed, particularly on strongly aged SOA suspected to increase the oxidative potential (OP) and to enhance the toxicity of airborne particles. Intensive researches onto the underlying mechanisms of inflammation started to describe the outlines of the intricate relationship between oxidative stress and inflammation. It is therefore, of great importance to better determine the OP of PM from contrasted surroundings, its relationship with CC through PM's physical, chemical and microbial characteristics, and its toxicological consequences within the lungs. Recently

Assessment of potential toxicity of a smokeless tobacco product (naswar) available on the Pakistani market.

Science.gov (United States)

Zakiullah; Saeed, Muhammad; Muhammad, Naveed; Khan, Saeed Ahmad; Gul, Farah; Khuda, Fazli; Humayun, Muhammad; Khan, Hamayun

2012-07-01

'Naswar' is a smokeless tobacco product (STP) widely used in Pakistan. It has been correlated with oral and oesophageal cancer in recent clinical studies. The toxic effects associated with STPs have been associated with trace level contaminants present in these products. The toxin levels of Pakistani naswar are reported for the first time in this study. A total of 30 Pakistani brands of naswar were tested for a variety of toxic constituents and carcinogens such as cadmium, arsenic, lead and other carcinogenic metals, nitrite and nitrate, and nicotine and pH. The average values of all the toxins studied were well above their allowable limits, making the product a health risk for consumers. Calculated lifetime cancer risk from cadmium and lead was 1 lac (100,000) to 10 lac (1,000,000) times higher than the minimum 10E-4 (0.00001) to 10E-6 (0.000001), which is the 'target range' for potentially hazardous substances, according to the US Environmental Protection Agency. Similarly, the level of arsenic was in the range of 0.15 to 14.04 μg/g, the average being 1.25 μg/g. The estimated average bioavailable concentration of arsenic is 0.125-0.25 μg/g, which is higher than the allowable standard of 0.01 μg/g. Similarly, the average minimum daily intake of chromium and nickel was 126.97 μg and 122.01 μg, as compared to allowable 30-35 μg and 35 μg, respectively; a 4-5 times higher exposure. However, beryllium was not detected in any of the brands studied. The pH was highly basic, averaging 8.56, which favours the formation of tobacco specific amines thus making the product potentially toxic. This study validates clinical studies correlating incidence of cancer with naswar use in Pakistan. This study shows that the production, packaging, sale and consumption of naswar should be regulated so as to protect the public from the health hazards associated with its consumption.

Assessment of market potential of compressed air energy storage systems

Science.gov (United States)

Boyd, D. W.; Buckley, O. E.; Clark, C. E., Jr.

1983-12-01

This report describes an assessment of potential roles that EPRI might take to facilitate the commercial acceptance of compressed air energy storage (CAES) systems. The assessment is based on (1) detailed analyses of the market potential of utility storage technologies, (2) interviews with representatives of key participants in the CAES market, and (3) a decision analysis synthesizing much of the information about market and technology status. The results indicate a large potential market for CAES systems if the overall business environment for utilities improves. In addition, it appears that EPRI can have a valuable incremental impact in ensuring that utilities realize the potential of CAES by (1) continuing an aggressive information dissemination and technology transfer program, (2) working to ensure the success of the first United States CAES installation at Soyland Power Cooperative, (3) developing planning methods to allow utilities to evaluate CAES and other storage options more effectively and more realistically, and (4) supporting R and D to resolve residual uncertainties in first-generation CAES cost and performance characteristics. Previously announced in STAR as N83-25121

Estimating Emissions of Toxic Hydrocarbons from Natural Gas Production Sites in the Barnett Shale Region of Northern Texas.

Science.gov (United States)

Marrero, Josette E; Townsend-Small, Amy; Lyon, David R; Tsai, Tracy R; Meinardi, Simone; Blake, Donald R

2016-10-04

Oil and natural gas operations have continued to expand and move closer to densely populated areas, contributing to growing public concerns regarding exposure to hazardous air pollutants. During the Barnett Shale Coordinated Campaign in October, 2013, ground-based whole air samples collected downwind of oil and gas sites revealed enhancements in several potentially toxic volatile organic compounds (VOCs) when compared to background values. Molar emissions ratios relative to methane were determined for hexane, benzene, toluene, ethylbenzene, and xylene (BTEX compounds). Using methane leak rates measured from the Picarro mobile flux plane (MFP) system and a Barnett Shale regional methane emissions inventory, the rates of emission of these toxic gases were calculated. Benzene emissions ranged between 51 ± 4 and 60 ± 4 kg h -1 . Hexane, the most abundantly emitted pollutant, ranged from 642 ± 45 to 1070 ± 340 kg h -1 . While observed hydrocarbon enhancements fall below federal workplace standards, results may indicate a link between emissions from oil and natural gas operations and concerns about exposure to hazardous air pollutants. The larger public health risks associated with the production and distribution of natural gas are of particular importance and warrant further investigation, particularly as the use of natural gas increases in the United States and internationally.

Potential impact of climate change on air pollution-related human health effects.

Science.gov (United States)

Tagaris, Efthimios; Liao, Kuo-Jen; Delucia, Anthony J; Deck, Leland; Amar, Praveen; Russell, Armistead G

2009-07-01

The potential health impact of ambient ozone and PM2.5 concentrations modulated by climate change over the United States is investigated using combined atmospheric and health modeling. Regional air quality modeling for 2001 and 2050 was conducted using CMAQ Modeling System with meteorology from the GISS Global Climate Model, downscaled regionally using MM5,keeping boundary conditions of air pollutants, emission sources, population, activity levels, and pollution controls constant. BenMap was employed to estimate the air pollution health outcomes at the county, state, and national level for 2050 caused by the effect of meteorology on future ozone and PM2.5 concentrations. The changes in calculated annual mean PM2.5 concentrations show a relatively modest change with positive and negative responses (increasing PM2.5 levels across the northeastern U.S.) although average ozone levels slightly decrease across the northern sections of the U.S., and increase across the southern tier. Results suggest that climate change driven air quality-related health effects will be adversely affected in more then 2/3 of the continental U.S. Changes in health effects induced by PM2.5 dominate compared to those caused by ozone. PM2.5-induced premature mortality is about 15 times higher then that due to ozone. Nationally the analysis suggests approximately 4000 additional annual premature deaths due to climate change impacts on PM2.5 vs 300 due to climate change-induced ozone changes. However, the impacts vary spatially. Increased premature mortality due to elevated ozone concentrations will be offset by lower mortality from reductions in PM2.5 in 11 states. Uncertainties related to different emissions projections used to simulate future climate, and the uncertainties forecasting the meteorology, are large although there are potentially important unaddressed uncertainties (e.g., downscaling, speciation, interaction, exposure, and concentration-response function of the human health studies).

In Vitro Toxicity of Aluminum Nanoparticles in Rat Alveolar Macrophages

Science.gov (United States)

2006-03-01

including intravenous, intramuscular , and subcutaneous injections, and including oral and ocular administration (Kreuter, 1991). NPs allow delivery of... NANOPARTICLES IN RAT ALVEOLAR MACROPHAGES THESIS Andrew J Wagner, 1st Lt, USAF AFIT/GES/ENV/06M-06 DEPARTMENT OF THE AIR FORCE AIR UNIVERSITY ORCE...TOXICITY OF ALUMINUM NANOPARTICLES IN RAT ALVEOLAR MACROPHAGES THESIS Presented to the Faculty Department of Systems and Engineering

CAirTOX, An inter-media transfer model for assessing indirect exposures to hazardous air contaminants

International Nuclear Information System (INIS)

McKone, T.E.

1994-01-01

Risk assessment is a quantitative evaluation of information on potential health hazards of environmental contaminants and the extent of human exposure to these contaminants. As applied to toxic chemical emissions to air, risk assessment involves four interrelated steps. These are (1) determination of source concentrations or emission characteristics, (2) exposure assessment, (3) toxicity assessment, and (4) risk characterization. These steps can be carried out with assistance from analytical models in order to estimate the potential risk associated with existing and future releases. CAirTOX has been developed as a spreadsheet model to assist in making these types of calculations. CAirTOX follows an approach that has been incorporated into the CalTOX model, which was developed for the California Department of Toxic Substances Control, With CAirTOX, we can address how contaminants released to an air basin can lead to contamination of soil, food, surface water, and sediments. The modeling effort includes a multimedia transport and transformation model, exposure scenario models, and efforts to quantify uncertainty in multimedia, multiple-pathway exposure assessments. The capacity to explicitly address uncertainty has been incorporated into the model in two ways. First, the spreadsheet form of the model makes it compatible with Monte-Carlo add-on programs that are available for uncertainty analysis. Second, all model inputs are specified in terms of an arithmetic mean and coefficient of variation so that uncertainty analyses can be carried out

Toxic emissions from mobile sources: a total fuel-cycle analysis for conventional and alternative fuel vehicles.

Science.gov (United States)

Winebrake, J J; Wang, M Q; He, D

2001-07-01

Mobile sources are among the largest contributors of four hazardous air pollutants--benzene, 1,3-butadiene, acetaldehyde, and formaldehyde--in urban areas. At the same time, federal and state governments are promoting the use of alternative fuel vehicles as a means to curb local air pollution. As yet, the impact of this movement toward alternative fuels with respect to toxic emissions has not been well studied. The purpose of this paper is to compare toxic emissions from vehicles operating on a variety of fuels, including reformulated gasoline (RFG), natural gas, ethanol, methanol, liquid petroleum gas (LPG), and electricity. This study uses a version of Argonne National Laboratory's Greenhouse Gas, Regulated Emissions, and Energy Use in Transportation (GREET) model, appropriately modified to estimate toxic emissions. The GREET model conducts a total fuel-cycle analysis that calculates emissions from both downstream (e.g., operation of the vehicle) and upstream (e.g., fuel production and distribution) stages of the fuel cycle. We find that almost all of the fuels studied reduce 1,3-butadiene emissions compared with conventional gasoline (CG). However, the use of ethanol in E85 (fuel made with 85% ethanol) or RFG leads to increased acetaldehyde emissions, and the use of methanol, ethanol, and compressed natural gas (CNG) may result in increased formaldehyde emissions. When the modeling results for the four air toxics are considered together with their cancer risk factors, all the fuels and vehicle technologies show air toxic emission reduction benefits.

Effect of negative air ions on the potential for bacterial contamination of plastic medical equipment.

Science.gov (United States)

Shepherd, Simon J; Beggs, Clive B; Smith, Caroline F; Kerr, Kevin G; Noakes, Catherine J; Sleigh, P Andrew

2010-04-12

In recent years there has been renewed interest in the use of air ionizers to control the spread of infection in hospitals and a number of researchers have investigated the biocidal action of ions in both air and nitrogen. By comparison, the physical action of air ions on bacterial dissemination and deposition has largely been ignored. However, there is clinical evidence that air ions might play an important role in preventing the transmission of Acinetobacter infection. Although the reasons for this are unclear, it is hypothesized that a physical effect may be responsible: the production of air ions may negatively charge items of plastic medical equipment so that they repel, rather than attract, airborne bacteria. By negatively charging both particles in the air and items of plastic equipment, the ionizers minimize electrostatic deposition on these items. In so doing they may help to interrupt the transmission of Acinetobacter infection in certain healthcare settings such as intensive care units. A study was undertaken in a mechanically ventilated room under ambient conditions to accurately measure changes in surface potential exhibited by items of plastic medical equipment in the presence of negative air ions. Plastic items were suspended on nylon threads, either in free space or in contact with a table surface, and exposed to negative ions produced by an air ionizer. The charge build-up on the specimens was measured using an electric field mill while the ion concentration in the room air was recorded using a portable ion counter. The results of the study demonstrated that common items of equipment such as ventilator tubes rapidly developed a large negative charge (i.e. generally >-100V) in the presence of a negative air ionizer. While most items of equipment tested behaved in a similar manner to this, one item, a box from a urological collection and monitoring system (the only item made from styrene acrylonitrile), did however develop a positive charge in the

Effect of negative air ions on the potential for bacterial contamination of plastic medical equipment

Directory of Open Access Journals (Sweden)

Kerr Kevin G

2010-04-01

Full Text Available Abstract Background In recent years there has been renewed interest in the use of air ionizers to control the spread of infection in hospitals and a number of researchers have investigated the biocidal action of ions in both air and nitrogen. By comparison, the physical action of air ions on bacterial dissemination and deposition has largely been ignored. However, there is clinical evidence that air ions might play an important role in preventing the transmission of Acinetobacter infection. Although the reasons for this are unclear, it is hypothesized that a physical effect may be responsible: the production of air ions may negatively charge items of plastic medical equipment so that they repel, rather than attract, airborne bacteria. By negatively charging both particles in the air and items of plastic equipment, the ionizers minimize electrostatic deposition on these items. In so doing they may help to interrupt the transmission of Acinetobacter infection in certain healthcare settings such as intensive care units. Methods A study was undertaken in a mechanically ventilated room under ambient conditions to accurately measure changes in surface potential exhibited by items of plastic medical equipment in the presence of negative air ions. Plastic items were suspended on nylon threads, either in free space or in contact with a table surface, and exposed to negative ions produced by an air ionizer. The charge build-up on the specimens was measured using an electric field mill while the ion concentration in the room air was recorded using a portable ion counter. Results The results of the study demonstrated that common items of equipment such as ventilator tubes rapidly developed a large negative charge (i.e. generally >-100V in the presence of a negative air ionizer. While most items of equipment tested behaved in a similar manner to this, one item, a box from a urological collection and monitoring system (the only item made from styrene

Pharmacophore modeling and in silico toxicity assessment of potential anticancer agents from African medicinal plants.

Science.gov (United States)

Ntie-Kang, Fidele; Simoben, Conrad Veranso; Karaman, Berin; Ngwa, Valery Fuh; Judson, Philip Neville; Sippl, Wolfgang; Mbaze, Luc Meva'a

2016-01-01

Molecular modeling has been employed in the search for lead compounds of chemotherapy to fight cancer. In this study, pharmacophore models have been generated and validated for use in virtual screening protocols for eight known anticancer drug targets, including tyrosine kinase, protein kinase B β, cyclin-dependent kinase, protein farnesyltransferase, human protein kinase, glycogen synthase kinase, and indoleamine 2,3-dioxygenase 1. Pharmacophore models were validated through receiver operating characteristic and Güner-Henry scoring methods, indicating that several of the models generated could be useful for the identification of potential anticancer agents from natural product databases. The validated pharmacophore models were used as three-dimensional search queries for virtual screening of the newly developed AfroCancer database (~400 compounds from African medicinal plants), along with the Naturally Occurring Plant-based Anticancer Compound-Activity-Target dataset (comprising ~1,500 published naturally occurring plant-based compounds from around the world). Additionally, an in silico assessment of toxicity of the two datasets was carried out by the use of 88 toxicity end points predicted by the Lhasa's expert knowledge-based system (Derek), showing that only an insignificant proportion of the promising anticancer agents would be likely showing high toxicity profiles. A diversity study of the two datasets, carried out using the analysis of principal components from the most important physicochemical properties often used to access drug-likeness of compound datasets, showed that the two datasets do not occupy the same chemical space.

Food plant toxicants and safety: risk assessment and regulation of inherent toxicants in plant foods.

NARCIS (Netherlands)

Essers, A.J.; Alink, G.M.; Speijers, G.J.A.; Alexander, J.; Bouwmeister, P.J.; Brandt, van den P.A.; Ciere, S.; Gry, J.; Herrman, J.; Kuiper, H.A.; Mortby, E.; Renwickn, A.G.

1998-01-01

The ADI as a tool for risk management and regulation of food additives and pesticide residues is not readily applicable to inherent food plant toxicants: The margin between actual intake and potentially toxic levels is often small; application of the default uncertainty factors used to derive ADI

APPLICATION OF JET REMPI AND LIBS TO AIR TOXIC MONITORING

Science.gov (United States)

The paper discusses three advanced, laser-based monitoring techniques that the EPA is assisting in developing for real time measurement of toxic aerosol compounds. One of the three techniques is jet resonance enhanced multiphoton ionization (Jet REMPI) coupled with a time-of-flig...

Toxic clinical hypoxic radiation sensitizers plus radiation-induced toxicity

International Nuclear Information System (INIS)

Richmond, R.C.

1984-01-01

The operational definition espoused twelve years ago that clinical hypoxic radiation sensitizers should be nontoxic interferes with the recognition and research of useful radiation sensitizers. Eight years ago the toxic antitumor drug cis-dichlorodiammineplatinum(II) was reported to be a hypoxic radiation sensitizer and the selective antitumor action of this drug was stressed as potentially creating tumor-targeted radiation sensitization. This rationale of oxidative antitumor drugs as toxic and targeted clinical sensitizers is useful, and has led to the study reported here. The antitumor drug cis-(1,1-cyclobutane-dicarboxylato)diammineplatinum(II), or JM-8, is being tested in clinical trials. Cells of S. typhimurium in PBS in the presence of 0.2mM JM-8 are found to be sensitized to irradiation under hypoxic, but not oxic, conditions. JM-8 is nontoxic to bacteria at this concentration, but upon irradiation the JM-8 solution becomes highly toxic. This radiation induced toxicity of JM-8 preferentially develops from hypoxic solution, and thus contributes to the rationale of hypoxic tumor cell destruction

Toxic potency and effects of diffuse air pollution

NARCIS (Netherlands)

Hamers, T.H.M.

2002-01-01

Diffuse air pollution consists of an omnipresent complex mixture of pollutants that is emitted from many widely dispersed sources as traffic, industries, households, energy plants, waste incinerators, and agriculture. It can be deposited in relatively remote areas as a result of

Nanomaterials and Retinal Toxicity

Science.gov (United States)

The neuroretina should be considered as a potential site of nanomaterial toxicity. Engineered nanomaterials may reach the retina through three potential routes of exposure including; intra­ vitreal injection of therapeutics; blood-borne delivery in the retinal vasculature an...

Using aquatic macroinvertebrate species traits to build test batteries for sediment toxicity assessment: accounting for the diversity of potential biological responses to toxicants.

Science.gov (United States)

Ducrot, Virginie; Usseglio-Polatera, Philippe; Péry, T Alexandre R R; Mouthon, Jacques; Lafont, Michel; Roger, Marie-Claude; Garric, Jeanne; Férard, Jean-François

2005-09-01

An original species-selection method for the building of test batteries is presented. This method is based on the statistical analysis of the biological and ecological trait patterns of species. It has been applied to build a macroinvertebrate test battery for the assessment of sediment toxicity, which efficiently describes the diversity of benthic macroinvertebrate biological responses to toxicants in a large European lowland river. First, 109 potential representatives of benthic communities of European lowland rivers were selected from a list of 479 taxa, considering 11 biological traits accounting for the main routes of exposure to a sediment-bound toxicant and eight ecological traits providing an adequate description of habitat characteristics used by the taxa. Second, their biological and ecological trait patterns were compared using coinertia analysis. This comparison allowed the clustering of taxa into groups of organisms that exhibited similar life-history characteristics, physiological and behavioral features, and similar habitat use. Groups exhibited various sizes (7-35 taxa), taxonomic compositions, and biological and ecological features. Main differences among group characteristics concerned morphology, substrate preferendum and habitat utilization, nutritional features, maximal size, and life-history strategy. Third, the best representatives of the mean biological and ecological characteristics of each group were included in the test battery. The final selection was composed of Chironomus riparius (Insecta: Diptera), Branchiura sowerbyi (Oligochaeta: Tubificidae), Lumbriculus variegatus (Oligochaeta: Lumbriculidae), Valvata piscinalis (Gastropoda: Valvatidae), and Sericostoma personatum (Trichoptera: Sericostomatidae). This approach permitted the biological and ecological variety of the battery to be maximized. Because biological and ecological traits of taxa determine species sensitivity, such maximization should permit the battery to better account

Air Quality Effects on Human Health and Approaches for Its Assessment through Microfluidic Chips.

Science.gov (United States)

Schulze, Frank; Gao, Xinghua; Virzonis, Darius; Damiati, Samar; Schneider, Marlon R; Kodzius, Rimantas

2017-09-27

Air quality depends on the various gases and particles present in it. Both natural phenomena and human activities affect the cleanliness of air. In the last decade, many countries experienced an unprecedented industrial growth, resulting in changing air quality values, and correspondingly, affecting our life quality. Air quality can be accessed by employing microchips that qualitatively and quantitatively determine the present gases and dust particles. The so-called particular matter 2.5 (PM2.5) values are of high importance, as such small particles can penetrate the human lung barrier and enter the blood system. There are cancer cases related to many air pollutants, and especially to PM2.5, contributing to exploding costs within the healthcare system. We focus on various current and potential future air pollutants, and propose solutions on how to protect our health against such dangerous substances. Recent developments in the Organ-on-Chip (OoC) technology can be used to study air pollution as well. OoC allows determination of pollutant toxicity and speeds up the development of novel pharmaceutical drugs.

Air Quality Effects on Human Health and Approaches for Its Assessment through Microfluidic Chips

Directory of Open Access Journals (Sweden)

Frank Schulze

2017-09-01

Full Text Available Air quality depends on the various gases and particles present in it. Both natural phenomena and human activities affect the cleanliness of air. In the last decade, many countries experienced an unprecedented industrial growth, resulting in changing air quality values, and correspondingly, affecting our life quality. Air quality can be accessed by employing microchips that qualitatively and quantitatively determine the present gases and dust particles. The so-called particular matter 2.5 (PM2.5 values are of high importance, as such small particles can penetrate the human lung barrier and enter the blood system. There are cancer cases related to many air pollutants, and especially to PM2.5, contributing to exploding costs within the healthcare system. We focus on various current and potential future air pollutants, and propose solutions on how to protect our health against such dangerous substances. Recent developments in the Organ-on-Chip (OoC technology can be used to study air pollution as well. OoC allows determination of pollutant toxicity and speeds up the development of novel pharmaceutical drugs.

Classification of baseline toxicants for QSAR predictions to replace fish acute toxicity studies.

Science.gov (United States)

Nendza, Monika; Müller, Martin; Wenzel, Andrea

2017-03-22

Fish acute toxicity studies are required for environmental hazard and risk assessment of chemicals by national and international legislations such as REACH, the regulations of plant protection products and biocidal products, or the GHS (globally harmonised system) for classification and labelling of chemicals. Alternative methods like QSARs (quantitative structure-activity relationships) can replace many ecotoxicity tests. However, complete substitution of in vivo animal tests by in silico methods may not be realistic. For the so-called baseline toxicants, it is possible to predict the fish acute toxicity with sufficient accuracy from log K ow and, hence, valid QSARs can replace in vivo testing. In contrast, excess toxicants and chemicals not reliably classified as baseline toxicants require further in silico, in vitro or in vivo assessments. Thus, the critical task is to discriminate between baseline and excess toxicants. For fish acute toxicity, we derived a scheme based on structural alerts and physicochemical property thresholds to classify chemicals as either baseline toxicants (=predictable by QSARs) or as potential excess toxicants (=not predictable by baseline QSARs). The step-wise approach identifies baseline toxicants (true negatives) in a precautionary way to avoid false negative predictions. Therefore, a certain fraction of false positives can be tolerated, i.e. baseline toxicants without specific effects that may be tested instead of predicted. Application of the classification scheme to a new heterogeneous dataset for diverse fish species results in 40% baseline toxicants, 24% excess toxicants and 36% compounds not classified. Thus, we can conclude that replacing about half of the fish acute toxicity tests by QSAR predictions is realistic to be achieved in the short-term. The long-term goals are classification criteria also for further groups of toxicants and to replace as many in vivo fish acute toxicity tests as possible with valid QSAR

Histopathological changes induced by acute toxicity of mercuric chloride on the air-breathing organ (branchial diverticulum) of the life-fish Heteropneustes (= Saccobranchus) fossilis (BLOCH)

Energy Technology Data Exchange (ETDEWEB)

Rajan, M.T. (Histochemistry and Histopathology Lab., Dept. of Zoology, Banaras Hindu Univ., Varanasi (India)); Banerjee, T.K. (Histochemistry and Histopathology Lab., Dept. of Zoology, Banaras Hindu Univ., Varanasi (India))

1993-01-01

Toxicity induced by 0.3 ppm (96 h LC[sub 50] value) mercuric chloride solution on the histomorphology of the innerlining of the air breathing organ (branchial diverticulum) of Heteropneustes fossilis has been described. The outer cell layers of the epithelial lining show cyclic necrosis leading to shedding with ultimate haemorrhage and drainage of blood into the lumen causing decrease in the number of blood islets. Simultaneously the epithelium regenerates causing hyperplasia of its cells and increased gas diffusion distance impairing normal aerial respiration. Also the number of foldings decreases and the secondary lamella like structures fuse together. This results in smoothening of the inner lining of the air sac. Later reappearance of the blood islets, secondary lamellae and foldings of the inner lining are observed along with the repair of the epithelium. Damage of the repaired inner lining follows again. (orig.)

Nasal biopsies of children exposed to air pollutants.

Science.gov (United States)

Calderón-Garcidueñas, L; Rodriguez-Alcaraz, A; Valencia-Salazar, G; Mora-Tascareño, A; García, R; Osnaya, N; Villarreal-Calderón, A; Devlin, R B; Van Dyke, T

2001-01-01

Southwest Metropolitan Mexico City (SWMMC) atmosphere is a complex mixture of air pollutants, including ozone, particulate matter, and aldehydes. Children in SWMMC are exposed chronically and sequentially to numerous toxicants, and they exhibit significant nasal damage. The objective of this study was to assess p53 accumulation by immunohistochemistry in nasal biopsies of SWMMC children. We evaluated 111 biopsies from 107 children (83 exposed SWMMC children and 24 control children residents in a pollutant-compliant Caribbean island). Complete clinical histories and physical examinations, including an ear-nose-throat (ENT) exam were done. There was a significant statistical difference in the upper and lower respiratory symptomatology and ENT findings between control and exposed children (p < 0.001). Control children gave no respiratory symptomatology in the 3 months prior to the study; their biopsies exhibited normal ciliated respiratory epithelium and were p53-negative. SWMMC children complained of epistaxis, nasal obstruction. and crusting. Irregular areas of whitish-gray recessed mucosa over the inferior and middle turbinates were seen in 25% of SWMMC children, and their nasal biopsies displayed basal cell hyperplasia, decreased numbers of ciliated and goblet cells, neutrophilic epithelial infiltrates, squamous metaplasia. and mild dysplasia. Four of 21 SWMMC children with grossly abnormal mucosal changes exhibited strong transmural nuclear p53 staining in their nasal biopsies (p 0.005, odds ratio 26). In the context of lifetime exposures to toxic and potentially carcinogenic air pollutants, p53 nasal induction in children could potentially represent. a) a checkpoint response to toxic exposures, setting up a selective condition for p53 mutation, or b) a p53 mutation has already occurred as a result of such selection. Because the biological significance of p53 nuclear accumulation in the nasal biopsies of these children is not clear at this point, we strongly

A New Potential Cause in the Development of Toxic Anterior Segment Syndrome: Fibrin Glue

Directory of Open Access Journals (Sweden)

Selçuk Sızmaz

2014-08-01

Full Text Available Objectives: To present a potential cause for toxic anterior segment syndrome (TASS. Materials and Methods: We report 4 cases of TASS that occurred following uneventful phacoemulsification and intraocular lens implantation. Results: The 4 cases were the first consecutive 2 cases of 2 different surgery days, 5 months apart. The most prominent sign of TASS was limbus-to-limbus corneal edema. Pain and/or intraocular pressure rise were also common. All surgical and presurgical procedures were checked after the first outbreak, whereas the second outbreak required further investigation. Fibrin glue remnants from preceding pterygium surgery with conjunctival autografting were found to be the potential cause. Despite intensive corticosteroid therapy, corneal edema did not resolve in 2 patients who underwent keratoplasty. Conclusion: TASS is a sight-threatening condition which requires thorough investigation for prevention of new cases. All steps must be carefully revised. (Turk J Ophthalmol 2014; 44: 280-3

Toxic metals in the atmosphere

International Nuclear Information System (INIS)

Munoz-Ribadeneira, F.J.; Mo, T.; Canoy, M.J.

1975-05-01

Methods used in Puerto Rico for monitoring toxic metals in the atmosphere are described. Air sampling machines are placed at heights from 15 to 25 ft above the surface and the tapes are subjected to neutron activation and γ spectroscopy. The concentrations of up to 33 elements can be determined with precision and sensitivity without destroying the tapes, which can then be used for analysis by other methods. (U.S.)

Diversity and dynamics of potentially toxic cyanobacteria and their ...

African Journals Online (AJOL)

Bloom–forming freshwater cyanobacteria pose human and livestock health problems due to their ability to produce toxins and other bioactive compounds. Some non-toxic cyanobacteria accumulate as buoyant surface dwelling scums and thick mats which affect the benthic fauna by degrading aquatic habitats and giving ...

HOUSEHOLD CHARACTERISTICS AND POTENTIAL INDOOR AIR POLLUTION ISSUES IN RURAL INDONESIAN COMMUNITIES USING FUELWOOD ENERGY

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Haryono Setiyo Huboyo

2016-03-01

Full Text Available Two rural communities using fuel wood energy in mountainous and coastal areas of Java island in Indonesia have been surveyed to know their household characteristics and the related potential indoor air pollution issues. By random sampling, we characterized fuel wood users only. The fuel wood use was mainly due to economic reason since some of the users were categorized as low-income families. Communities in the mountainous area were exposed to higher risk of indoor air pollution than those in coastal area due to their house characteristics and behavior during cooking. Both communities, however, were aware of indoor air pollution issues and indicated the sources. They also prioritized the factors to be controlled, which they perceived as the main cause of indoor air pollution problem.

The potentiation of zinc toxicity by soil moisture in a boreal forest ecosystem.

Science.gov (United States)

Owojori, Olugbenga J; Siciliano, Steven D

2015-03-01

Northern boreal forests often experience forest dieback as a result of metal ore mining and smelting. The common solution is to lime the soil, which increases pH, reducing metal toxicity and encouraging recovery. In certain situations, however, such as in Flin Flon, Manitoba, Canada, liming has yielded only moderate benefits, with some locations responding well to liming and other locations not at all. In an effort to increase the effectiveness of the ecorestoration strategy, the authors investigated if these differences in liming responsiveness were linked to differences in toxicity. Toxicity of metal-impacted Flin Flon soils on the oribatid mite Oppia nitens and the collembolan Folsomia candida was assessed, with a view toward identifying the metal of concern in the area. The effects of moisture content on metal sorption, uptake, and toxicity to the invertebrates were also investigated. Toxicity tests with the invertebrates were conducted using either Flin Flon soils or artificial soils with moisture content adjusted to 30%, 45%, 60%, or 75% of the maximum water-holding capacity of the soil samples. The Relative to Cd Toxicity Model identified Zn as the metal of concern in the area, and this was confirmed using validation tests with field contaminated soils. Furthermore, increasing the moisture content in soils increased the amount of mobile Zn available for uptake with the ion exchange resin. Survival and reproduction of both invertebrates were reduced under Zn exposure as moisture level increased. Thus, moisture-collecting landforms, which are often also associated with high Zn concentrations at Flin Flon, have, as a result, higher Zn toxicity to the soil ecosystem because of increases in soil moisture. © 2014 SETAC.

Fumigant toxicity of five essential oils rich in ketones against Sitophilus zeamais (Motschulsky

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J.M Herrera

2014-06-01

Full Text Available Essential oils (EOs and individual compounds act as fumigants against insects found in stored products. In fumigant assays, Sitophilus zeamais Motschulsky adults were treated with essential oils derived from Aphyllocladus decussatus Hieron, Aloysia polystachya Griseb, Minthostachys verticillata Griseb Epling and Tagetes minuta L , which are rich in ketones and their major components: a- thujone, R-carvone, S-carvone, (- menthone, R (+ pulegone and E-Z- ocimenone. M. verticillata oil was the most toxic ( LC50: 116.6 µl /L air characterized by a high percentage of menthone (40.1% and pulegone (43.7%. All ketones showed insecticidal activity against S. zeamais. However, pulegone (LC50: 11.8 µl/L air, R- carvone (LC50: 17.5 µl/L air, S-carvone (LC50: 28.1 µl/L air and E-Z-ocimenone (LC50: 42.3 µl/L air were the most toxic. These ketones are a,b-unsaturated carbonyl. This feature could play a fundamental role in the increase of insecticidal activity against S. zeamais.

Available online Efficiency potential of indirectly heated solar reforming with different types of solar air receivers

International Nuclear Information System (INIS)

Storch, Henrik von; Roeb, Martin; Stadler, Hannes; Sattler, Christian; Hoffschmidt, Bernhard

2016-01-01

Highlights: • A process for indirectly heated solar reforming of natural gas with air as heat transfer fluid is proposed. • Different solar receivers are modeled and implemented into the reforming process. • The overall efficiency of the process with different solar receivers is determined. • Optimum solar receiver characteristics for application in a solar reforming process are determined. - Abstract: In solar reforming, the heating value of natural gas is increased by utilization of concentrated solar radiation. Hence, it is a process for storing solar energy in a stable and transportable form that also permits further conversion into liquid fuels like methanol. This process has the potential to significantly decrease the natural gas consumption and the associated CO_2-emissions of methanol production with only few open questions to be addressed prior to commercialization. In the medium and long term, it has the potential to generate methanol as an environmentally friendly fuel for both transport as well as flexible electricity production in combined cycle gas turbines, when biogas is used as reactant. In a previous study the high potential of indirectly heated solar reforming with solar air receivers was shown; however, the efficiency is limited when using state of the art open volumetric receivers. Therefore, different types of air receivers are implemented into an indirectly heated solar reforming process and the overall efficiency potential is assessed in the present study. The implemented receivers are an open volumetric cavity receiver, a closed volumetric cavity receiver and a tubular cavity receiver. The open volumetric cavity receiver and tubular cavity receiver achieve the best results due to their capability of operating efficiently at temperatures well above 700 °C. For these receivers peak efficiencies up to 29% and 27% respectively are predicted. As the utilization of an open volumetric cavity receiver constitutes an open heat transfer

Preliminary Assessment of Health Risks of Potentially Toxic Elements in Settled Dust over Beijing Urban Area

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Dejun Wan

2016-05-01

Full Text Available To examine levels, health risks, sources, and spatial distributions of potentially toxic elements in settled dust over Beijing urban area, 62 samples were collected mostly from residential building outdoor surfaces, and their <63 μm fractions were measured for 12 potentially toxic elements. The results show that V, Cr, Mn, Co, Ni, and Ba in dust are from predominantly natural sources, whereas Cu, Zn, As, Cd, Sb, and Pb mostly originate from anthropogenic sources. Exposure to these elements in dust has significant non-cancer risks to children but insignificant to adults. Cancer risks of Cr, Co, Ni, As, and Cd via inhalation and dermal contact are below the threshold of 10−6–10−4 but As via dust ingestion shows a tolerable risk. The non-cancer risks to children are contributed mainly (75% by As, Pb, and Sb, and dominantly (92% via dust ingestion, with relatively higher risks mainly occurring in the eastern and northeastern Beijing urban areas. Although Cd, Zn, and Cu in dust are heavily affected by anthropogenic sources, their health risks are insignificant. Source appointments suggest that coal burning emissions, the dominant source of As, are likely the largest contributors to the health risk, and traffic-related and industrial emissions are also important because they contribute most of the Pb and Sb in dust.

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

Directory of Open Access Journals (Sweden)

Avazali Saririan Mobarakeh

2014-01-01

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

The effects of air pollution on the health of children.

Science.gov (United States)

Buka, Irena; Koranteng, Samuel; Osornio-Vargas, Alvaro R

2006-10-01

The present article is intended to inform paediatricians about the associations between ambient air pollution and adverse health outcomes in children within the context of current epidemiological evidence.The majority of the current literature pertains to adverse respiratory health outcomes, including asthma, other respiratory symptoms, and deficits in lung function and growth, as well as exposure to ambient levels of criteria air pollutants. In addition to the above, the present article highlights mortality, pregnancy outcomes, vitamin D deficiency and alteration in the immune system of children.Some of the data on the impact of improved air quality on children's health are provided, including the reduction of air pollution in former East Germany following the reunification of Germany, as well as the reduction in the rates of childhood asthma events during the 1996 Summer Olympics in Atlanta, Georgia, due to a reduction in local motor vehicle traffic. However, there are many other toxic air pollutants that are regularly released into the air. These pollutants, which are not regularly monitored and have not been adequately researched, are also potentially harmful to children.Significant morbidity and mortality is attributed to ambient air pollution, resulting in a significant economic cost to society. As Canada's cities grow, air pollution issues need to be a priority in order to protect the health of children and support sustainable development for future generations.

The Role of Plant–Microbe Interactions and Their Exploitation for Phytoremediation of Air Pollutants

Science.gov (United States)

Weyens, Nele; Thijs, Sofie; Popek, Robert; Witters, Nele; Przybysz, Arkadiusz; Espenshade, Jordan; Gawronska, Helena; Vangronsveld, Jaco; Gawronski, Stanislaw W.

2015-01-01

Since air pollution has been linked to a plethora of human health problems, strategies to improve air quality are indispensable. Despite the complexity in composition of air pollution, phytoremediation was shown to be effective in cleaning air. Plants are known to scavenge significant amounts of air pollutants on their aboveground plant parts. Leaf fall and runoff lead to transfer of (part of) the adsorbed pollutants to the soil and rhizosphere below. After uptake in the roots and leaves, plants can metabolize, sequestrate and/or excrete air pollutants. In addition, plant-associated microorganisms play an important role by degrading, detoxifying or sequestrating the pollutants and by promoting plant growth. In this review, an overview of the available knowledge about the role and potential of plant–microbe interactions to improve indoor and outdoor air quality is provided. Most importantly, common air pollutants (particulate matter, volatile organic compounds and inorganic air pollutants) and their toxicity are described. For each of these pollutant types, a concise overview of the specific contributions of the plant and its microbiome is presented. To conclude, the state of the art and its related future challenges are presented. PMID:26516837

Assessment of oral toxicity and safety of pentamethylchromanol (PMCol), a potential chemopreventative agent, in rats and dogs

International Nuclear Information System (INIS)

Lindeblad, Matthew; Kapetanovic, Izet M.; Kabirov, Kasim K.; Detrisac, Carol J.; Dinger, Nancy; Mankovskaya, Irina; Zakharov, Alexander; Lyubimov, Alexander V.

2010-01-01

lower levels is considered to be less likely to result in toxicity following 28 days of exposure. Sex-related differences were seen in rats. Male rats appeared to have greater sensitivity to nephrotoxicity, while female animals had a greater incidence of hepatoxicity and changes in hematological parameters evaluated, especially at a dose of 500 mg/kg/day, which correlated to the higher plasma drug levels in female rats. It appeared that dogs were generally more sensitive than rats to oral administration of PMCol. Further examination of the potential toxic effects of PMCol in longer term studies is required prior to understanding the full risks of PMCol administration as a chemopreventative agent.

Overview of direct air free cooling and thermal energy storage potential energy savings in data centres

International Nuclear Information System (INIS)

Oró, Eduard; Depoorter, Victor; Pflugradt, Noah; Salom, Jaume

2015-01-01

In the last years the total energy demand of data centres has experienced a dramatic increase which is expected to continue. This is why data centres industry and researchers are working on implementing energy efficiency measures and integrating renewable energy to overcome energy dependence and to reduce operational costs and CO 2 emissions. The cooling system of these unique infrastructures can account for 40% of the total energy consumption. To reduce the energy consumption, free cooling strategies are used more and more, but so far there has been little research about the potential of thermal energy storage (TES) solutions to match energy demand and energy availability. Hence, this work intends to provide an overview of the potential of the integration of direct air free cooling strategy and TES systems into data centres located at different European locations. For each location, the benefit of using direct air free cooling is evaluated energetically and economically for a data centre of 1250 kW. The use of direct air free cooling is shown to be feasible. This does not apply the TES systems by itself. But when using TES in combination with an off-peak electricity tariff the operational cooling cost can be drastically reduced. - Highlights: • The total annual hours for direct air free cooling in data centres are calculated. • The potential of TES integration in data centres is evaluated. • The implementation of TES to store the ambient air cold is not recommended. • TES is feasible if combined with redundant chillers and off-peak electricity price. • The cooling electricity cost is being reduced up to 51%, depending on the location

Projections of precipitation, air temperature and potential ...

African Journals Online (AJOL)

mabouelhaggag

Precipitation and air temperature records from 6 sites in Rwanda in the period from 1964 to 2010 are used for past/present climate assessment. Future climate projections (2010-2099) based on 3 general circulation models and 2 emission scenarios (A2 and B1) are used for climate projections. Precipitation, air temperature ...

New Jersey: Clean Air Communities (A Former EPA CARE Project)

Science.gov (United States)

Clean Air Communities (CAC) is the recipient of a Level II CARE cooperative agreement to implement recommendations by the state’s Environmental Justice Task Force and the Air Toxics Pilot Project to reduce environmental risks.

Creating mechanisms of toxic substances emission of combustion engines

Directory of Open Access Journals (Sweden)

Jankowski Antoni

2015-12-01

Full Text Available The paper analyses the mechanisms of creation of toxic exhaust gases, which mainly derived from inexact fuel metering and improper air-fuel mixture preparation. The paper describes the process of creating toxic components in the exhaust gases of piston engines during engine operation, and impact on the emission of these components determining the composition of the fuel mixture determined equivalence factor Φ. The principal mechanisms of formation of toxic exhaust gases, in particular nitrogen oxides, carbon monoxide and hydrocarbons, and also essential according to create each of toxic exhaust gases are the subject of the paper. Moreover, empirical relationships, by means of which it is possible to determine the time of creation of the individual components of toxic exhaust gases, are presented. For example, one of the mechanisms for prompt formation of nitrogen oxides and hydrocarbons graphic illustration of formation as a function of crank angle is described. At the conclusion, the summary and significance of information on creation mechanisms of toxic components in the exhaust gases of piston engines are presented.

Bioaccumulation Potential Of Air Contaminants: Combining Biological Allometry, Chemical Equilibrium And Mass-Balances To Predict Accumulation Of Air Pollutants In Various Mammals

Energy Technology Data Exchange (ETDEWEB)

Veltman, Karin; McKone, Thomas E.; Huijbregts, Mark A.J.; Hendriks, A. Jan

2009-03-01

In the present study we develop and test a uniform model intended for single compartment analysis in the context of human and environmental risk assessment of airborne contaminants. The new aspects of the model are the integration of biological allometry with fugacity-based mass-balance theory to describe exchange of contaminants with air. The developed model is applicable to various mammalian species and a range of chemicals, while requiring few and typically well-known input parameters, such as the adult mass and composition of the species, and the octanol-water and air-water partition coefficient of the chemical. Accumulation of organic chemicals is typically considered to be a function of the chemical affinity forlipid components in tissues. Here, we use a generic description of chemical affinity for neutral and polar lipids and proteins to estimate blood-air partition coefficients (Kba) and tissue-air partition coefficients (Kta) for various mammals. This provides a more accurate prediction of blood-air partition coefficients, as proteins make up a large fraction of total blood components. The results show that 75percent of the modeled inhalation and exhalation rate constants are within a factor of 2 from independent empirical values for humans, rats and mice, and 87percent of the predicted blood-air partition coefficients are within a factor of 5 from empirical data. At steady-state, the bioaccumulation potential of air pollutants is shown to be mainly a function of the tissue-air partition coefficient and the biotransformation capacity of the species and depends weakly on the ventilation rate and the cardiac output of mammals.

Assessment of indoor air quality related to potential vapor intrusion: Issues for former manufactured gas plants

International Nuclear Information System (INIS)

Rames, Antoine; Guillossou, Gaelle; Ronga-Pezeret, Sylvaine; Hulot, Corinne

2012-01-01

The indoor air quality of buildings on sites with soil or groundwater contaminated with volatile or semi-volatile compounds can be degraded by potential vapor intrusion (VI) from these environmental media. For sites of former manufactured gas plants (MGP), the compounds that must be considered are BTEX (benzene, toluene, ethylbenzene, and xylenes), 8 of the 16 polycyclic aromatic hydrocarbons (PAHs) generally studied, and, to a lesser degree, phenol and hydrogen cyanide. Given the plausibility of VI and in accordance with current recommendations of the French Ministry of the Environment, measurements of indoor air quality (and outdoor air, for additional analyses) were conducted on two occasions during the winter and summer of 2010. These measurements simultaneously used multiple air sampling devices (Summa canisters, Gore modules, air pumps coupled to various matrices; such as XAD2, silica gel, etc.). Phenol and hydrogen cyanide have not previously been quantified (limit of quantification between 0.12 and 2.00 μg/m 3 ). BTEX and PAHs were found ubiquitously at concentrations on the order of 1 to 10 μg/m 3 for BTEX and naphthalene and one to ten ng/m 3 for PAHs other than naphthalene) at all 14 MGP and both control sites, regardless of where onsite the air was sampled (office, basement or crawl space, or outdoors). These levels (the maximum considered) do not allow us to conclude that the indoor air is degraded according to the official French guidelines for managing potentially contaminated sites and soils. Thus, no excess health risk is expected for residents of these sites because of exposure to possible VI, which cannot be ruled out in view of the ubiquity of some compounds. (authors)

Life-cycle-assessment of the historical development of air pollution control and energy recovery in waste incineration

DEFF Research Database (Denmark)

Damgaard, Anders; Riber, C.; Fruergaard, Thilde

2010-01-01

Incineration of municipal solid waste is a debated waste management technology. In some countries it is the main waste management option whereas in other countries it has been disregarded. The main discussion point on waste incineration is the release of air emissions from the combustion...... impacts. With regards to the toxic impact categories, emissions from the waste incineration process were always larger than those from the avoided energy production based on natural gas. The results shows that the potential environmental impacts from air emissions have decreased drastically during...... of the waste, but also the energy recovery efficiency has a large importance. The historical development of air pollution control in waste incineration was studied through life-cycle-assessment modelling of eight different air pollution control technologies. The results showed a drastic reduction...

A zeta potential value determines the aggregate's size of penta-substituted [60]fullerene derivatives in aqueous suspension whereas positive charge is required for toxicity against bacterial cells.

Science.gov (United States)

Deryabin, Dmitry G; Efremova, Ludmila V; Vasilchenko, Alexey S; Saidakova, Evgeniya V; Sizova, Elena A; Troshin, Pavel A; Zhilenkov, Alexander V; Khakina, Ekaterina A; Khakina, Ekaterina E

2015-08-08

The cause-effect relationships between physicochemical properties of amphiphilic [60]fullerene derivatives and their toxicity against bacterial cells have not yet been clarified. In this study, we report how the differences in the chemical structure of organic addends in 10 originally synthesized penta-substituted [60]fullerene derivatives modulate their zeta potential and aggregate's size in salt-free and salt-added aqueous suspensions as well as how these physicochemical characteristics affect the bioenergetics of freshwater Escherichia coli and marine Photobacterium phosphoreum bacteria. Dynamic light scattering, laser Doppler micro-electrophoresis, agarose gel electrophoresis, atomic force microscopy, and bioluminescence inhibition assay were used to characterize the fullerene aggregation behavior in aqueous solution and their interaction with the bacterial cell surface, following zeta potential changes and toxic effects. Dynamic light scattering results indicated the formation of self-assembled [60]fullerene aggregates in aqueous suspensions. The measurement of the zeta potential of the particles revealed that they have different surface charges. The relationship between these physicochemical characteristics was presented as an exponential regression that correctly described the dependence of the aggregate's size of penta-substituted [60]fullerene derivatives in salt-free aqueous suspension from zeta potential value. The prevalence of DLVO-related effects was shown in salt-added aqueous suspension that decreased zeta potential values and affected the aggregation of [60]fullerene derivatives expressed differently for individual compounds. A bioluminescence inhibition assay demonstrated that the toxic effect of [60]fullerene derivatives against E. coli cells was strictly determined by their positive zeta potential charge value being weakened against P. phosphoreum cells in an aquatic system of high salinity. Atomic force microscopy data suggested that the

Identification of manganese as a toxicant in a groundwater treatment system: Addressing naturally occurring toxicants

International Nuclear Information System (INIS)

Goodfellow, W. Jr.; Sohn, V.; Richey, M.; Yost, J.

1995-01-01

Effluent from a groundwater remediation system at a bulk oil storage and distribution terminal has been chronically toxic to Ceriodaphnia dubia. The remediation system was designed in response to a hydrocarbon plume in the area of the terminal. The remediation system consists of a series of groundwater recovery wells and groundwater intercept trench systems with groundwater treatment and phased-separated hydrocarbon recovery systems. The groundwater treatment and petroleum recovery systems consist of oil/water separators, product recovery tanks, air strippers, filters, and carbon adsorption units. The characteristics of this effluent are low total suspended solids, total dissolved solids, and hardness concentrations as well as meeting stringent NPDES permit requirements for lead, copper, zinc, mercury, total petroleum hydrocarbons, and BTEX. Additional priority pollutant evaluations revealed no compounds of concern. Performance of a Toxicity identification Evaluation (TIE) indicated that manganese was the principle toxicant in the effluent. Manganese is a naturally occurring constituent in this groundwater source and is not added to the treatment system. This paper will present the results of the TIE with a discussion of treatability/control options for manganese control at this facility. Recommendations for addressing naturally occurring toxicants that are not a result of the facility's operations will also be presented

Potential for reducing air-pollutants while achieving 2 °C global temperature change limit target.

Science.gov (United States)

Hanaoka, Tatsuya; Akashi, Osamu; Fujiwara, Kazuya; Motoki, Yuko; Hibino, Go

2014-12-01

This study analyzes the potential to reduce air pollutants while achieving the 2 °C global temperature change limit target above pre-industrial levels, by using the bottom-up optimization model, AIM/Enduse[Global]. This study focuses on; 1) estimating mitigation potentials and costs for achieving 2 °C, 2.5 °C, and 3 °C target scenarios, 2) assessing co-benefits of reducing air pollutants such as NOx, SO2, BC, PM, and 3) analyzing features of sectoral attributions in Annex I and Non-Annex I groups of countries. The carbon tax scenario at 50 US$/tCO2-eq in 2050 can reduce GHG emissions more than the 3 °C target scenario, but a higher carbon price around 400 US$/tCO2-eq in 2050 is required to achieve the 2 °C target scenario. However, there is also a co-benefit of large reduction potential of air pollutants, in the range of 60-80% reductions in 2050 from the reference scenario while achieving the 2 °C target. Copyright © 2014 Elsevier Ltd. All rights reserved.

Potential CO{sub 2} reduction by implementing energy efficiency standard for room air conditioner in Malaysia

Energy Technology Data Exchange (ETDEWEB)

Mahlia, T.M.I.; Masjuki, H.H.; Choudhury, I.A.; Saidur, R. [Department of Mechanical Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia)

2001-09-01

This study attempts to predict the environmental impact of implementing an energy efficiency standard for room air conditioners in Malaysia. The ownership of room air conditioners has increased tremendously in this country. At present, there are about 528,792 room air conditioners in Malaysian households. In the year 2020, it will be about 1,511,276. The potential carbon dioxide reduction is based on the predicted electricity savings from implementing a minimum energy efficiency standard for room air conditioners. The electricity savings are calculated based on the predicted electricity consumption by a single air conditioner in the Malaysian household. The replacement of less efficient units of this appliance is reflected in reduced electricity consumption and emissions from power plants. The energy efficiency provisions of this regulation and agreement provide targets to save money, energy and, most importantly, to protect the environment. (Author)

Potential hepatic toxicity of buprofezin at sublethal concentrations: ROS-mediated conversion of energy metabolism.

Science.gov (United States)

Ji, Xiaotong; Ku, Tingting; Zhu, Na; Ning, Xia; Wei, Wei; Li, Guangke; Sang, Nan

2016-12-15

Buprofezin is known for its broad-spectrum action and environmental safety. The popularity of buprofezin has raised concerns about its potentially adverse effects on human health and risk to the environment. In this study, we first identified the liver as one of the major organs in which buprofezin accumulated, and we detected a severe oxidative stress response. Next, we demonstrated that sublethal concentrations of buprofezin promoted the conversion of energy metabolism from the aerobic tricarboxylic acid (TCA) cycle and oxidative phosphorylation to anaerobic glycolysis. Importantly, reactive oxygen species (ROS) generation partially accounted for the shunting of the energy metabolism through the buprofezin-mediated inhibition of cytochrome c oxidase activity. ROS directly perturbed the activities of several key TCA cycle enzymes, stimulated glycolysis, and indirectly disturbed the activity of the respiratory chain complex by altering mitochondrial DNA (mtDNA). These findings clarify the potential mechanisms of buprofezin toxicity and provide biomarkers for buprofezin-mediated hepatotoxicity at sublethal concentrations. Copyright © 2016 Elsevier B.V. All rights reserved.

Bioinformatics analysis to assess potential risks of allergenicity and toxicity of HRAP and PFLP proteins in genetically modified bananas resistant to Xanthomonas wilt disease.

Science.gov (United States)

Jin, Yuan; Goodman, Richard E; Tetteh, Afua O; Lu, Mei; Tripathi, Leena

2017-11-01

Banana Xanthomonas wilt (BXW) disease threatens banana production and food security throughout East Africa. Natural resistance is lacking among common cultivars. Genetically modified (GM) bananas resistant to BXW disease were developed by inserting the hypersensitive response-assisting protein (Hrap) or/and the plant ferredoxin-like protein (Pflp) gene(s) from sweet pepper (Capsicum annuum). Several of these GM banana events showed 100% resistance to BXW disease under field conditions in Uganda. The current study evaluated the potential allergenicity and toxicity of the expressed proteins HRAP and PFLP based on evaluation of published information on the history of safe use of the natural source of the proteins as well as established bioinformatics sequence comparison methods to known allergens (www.AllergenOnline.org and NCBI Protein) and toxins (NCBI Protein). The results did not identify potential risks of allergy and toxicity to either HRAP or PFLP proteins expressed in the GM bananas that might suggest potential health risks to humans. We recognize that additional tests including stability of these proteins in pepsin assay, nutrient analysis and possibly an acute rodent toxicity assay may be required by national regulatory authorities. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Vitamin D, Essential Minerals, and Toxic Elements: Exploring Interactions between Nutrients and Toxicants in Clinical Medicine

Science.gov (United States)

Schwalfenberg, Gerry K.; Genuis, Stephen J.

2015-01-01

In clinical medicine, increasing attention is being directed towards the important areas of nutritional biochemistry and toxicant bioaccumulation as they relate to human health and chronic disease. Optimal nutritional status, including healthy levels of vitamin D and essential minerals, is requisite for proper physiological function; conversely, accrual of toxic elements has the potential to impair normal physiology. It is evident that vitamin D intake can facilitate the absorption and assimilation of essential inorganic elements (such as calcium, magnesium, copper, zinc, iron, and selenium) but also the uptake of toxic elements (such as lead, arsenic, aluminum, cobalt, and strontium). Furthermore, sufficiency of essential minerals appears to resist the uptake of toxic metals. This paper explores the literature to determine a suitable clinical approach with regard to vitamin D and essential mineral intake to achieve optimal biological function and to avoid harm in order to prevent and overcome illness. It appears preferable to secure essential mineral status in conjunction with adequate vitamin D, as intake of vitamin D in the absence of mineral sufficiency may result in facilitation of toxic element absorption with potential adverse clinical outcomes. PMID:26347061

Twenty years of measurement of polycyclic aromatic hydrocarbons (PAHs) in UK ambient air by nationwide air quality networks.

Science.gov (United States)

Brown, Andrew S; Brown, Richard J C; Coleman, Peter J; Conolly, Christopher; Sweetman, Andrew J; Jones, Kevin C; Butterfield, David M; Sarantaridis, Dimitris; Donovan, Brian J; Roberts, Ian

2013-06-01

The impact of human activities on the health of the population and of the wider environment has prompted action to monitor the presence of toxic compounds in the atmosphere. Toxic organic micropollutants (TOMPs) are some of the most insidious and persistent of these pollutants. Since 1991 the United Kingdom has operated nationwide air quality networks to assess the presence of TOMPs, including polycyclic aromatic hydrocarbons (PAHs), in ambient air. The data produced in 2010 marked 20 years of nationwide PAH monitoring. This paper marks this milestone by providing a novel and critical review of the data produced since nationwide monitoring began up to the end of 2011 (the latest year for which published data is available), discussing how the networks performing this monitoring has evolved, and elucidating trends in the concentrations of the PAHs measured. The current challenges in the area and a forward look to the future of air quality monitoring for PAHs are also discussed briefly.

Air pollution damage to plants

Energy Technology Data Exchange (ETDEWEB)

Daly, G T

1974-01-01

The effects of the most important air pollutants on plants are described in detail. The include: smoke and particulates, sulfur dioxide, fluorides, peroxyacetyl nitrate, nitrogen oxides, and ozone. An attempt is made to show that plant injury by air pollution can be recognized and evaluated in the presence of effects from insect, fungal, bacterial, viral pathogens and the symptoms of nutrient and enviromental stress. All plants are more or less affected by toxic gases and metals absorbed from the air. For each plant and each pollutant there is a critical concentration above which damage occurs, and below which growth is normal.

Comparative assessment of button cells using a normalized index for potential pollution by heavy metals.

Science.gov (United States)

Moreno-Merino, Luis; Jiménez-Hernández, Maria Emilia; de la Losa, Almudena; Huerta-Muñoz, Virginia

2015-09-01

Many household batteries worldwide still end up in landfills or are incinerated due to inefficient collection and recycling schemes. Toxic heavy metals from improperly discarded button cells pose a serious risk to human health and the environment, as they can pollute air, soil and water. This paper analyses a series of button cells selected from batteries available on the retail market, and compares their polluting potential. A total of 64 batteries were subjected to chemical analyses of 19 elements - including metals and metalloids - , and energy density measurements. The samples were from four different brands of each of the four most common button cell technologies (alkaline, zinc-air, silver oxide and lithium). An energy-normalized index - the Weighted Potential Pollution Index (WPPI) - was proposed to compare the polluting potential of the different batteries. The higher the battery WPPI score, the greater the content in toxic elements and the lower the energy output. The results of the chemical composition and energy density varied depending on the construction technology of the button cells. However, significant differences in both variables were also found when comparing different brands within the same technology. The differences in WPPI values confirmed the existence of a significant margin to reduce the environmental impact of discarded button cells simply by avoiding the most polluting options. The choice of the battery with the most favourable WPPI produced a reduction in potential pollution of 3-53% for silver oxide batteries, 4-39% for alkaline, 20-28% for zinc-air and 12-26% for lithium. Comparative potential pollution could be assessed when selecting batteries using an energy-normalized index such as WPPI to reduce the environmental impact of improperly disposed button cells. Published by Elsevier B.V.

Pinus roxburghii plant needles as a three-season biomonitor for elemental air pollution monitoring along roadside

Energy Technology Data Exchange (ETDEWEB)

Daud, Muhammad; Wasim, Mohammad; Khalid, Nasir; Waheed, Shahida [Pakistan Institute of Nuclear Science and Technology, Islamabad (Pakistan). Chemistry Div.

2015-07-01

The present study deals with the determination of 36 elements in Pinus roxburghii plant needles to assess their potential as biomonitor for elemental air pollution monitoring. The elemental quantification was made by employing Instrumental Neutron Activation Analysis (INAA) and Atomic Absorption Spectrometric (AAS) techniques. The needles of Pinus roxburghii were collected in spring, summer and winter seasons from various sites in Islamabad. The method validation was performed by analyzing two certified reference materials i.e., Citrus leaves - NIST-SRM-1572 and IAEA-Soil-7. Pollution level was assessed by using three indicators: enrichment factor, pollution load index and average toxic element concentration. The results indicated that the needles of Pinus roxburghii plant had potential to monitor the extent of air pollution in the vicinity of high traffic areas.

Potential synergy between two renal toxicants: DTPA and uranium

International Nuclear Information System (INIS)

Muller, D.; Houpert, P.; Henge Napoli, M.H.; Paquet, F.; Muller, D.; Henge Napoli, M.H.; Metivier, H.

2006-01-01

At present, the most appropriate therapeutic approach to treat an accidental contamination with plutonium and uranium oxide mixture (MOX) is administration of diethylene-triamine-penta-acetate acid (DTPA) in order to accelerate plutonium excretion. As uranium and DTPA are both nephro-toxic compounds, the administration of DTPA after a contamination containing uranium could enhance the nephro-toxic effects of uranium. The aim of the present work was to study in vitro on a kidney proximal tubule cell line (LLC-PK 1 ) the cytotoxicity induced by increasing concentrations of uranium in presence of 3 different chemical forms of DTPA. The results showed that the DTPA used alone induced no cytotoxicity at the concentration used here (420 μM). However, this concentration of DTPA increased the cytotoxicity induced by uranium. This increase was maximal for uranium concentrations close to the lethal concentration for 50% of the cells and reached 37, 31 and 28% for anhydrous DTPA, Na 3 CaDTPA and Na 3 ZnDTPA, respectively. These results suggest that administration of DTPA could enhance the nephrotoxicity induced by uranium. (authors)

Viscous Potential Flow Analysis of Electroaerodynamic Instability of a Liquid Sheet Sprayed with an Air Stream

Directory of Open Access Journals (Sweden)

Mukesh Kumar Awasthi

2013-01-01

Full Text Available The instability of a thin sheet of viscous and dielectric liquid moving in the same direction as an air stream in the presence of a uniform horizontal electric field has been carried out using viscous potential flow theory. It is observed that aerodynamic-enhanced instability occurs if the Weber number is much less than a critical value related to the ratio of the air and liquid stream velocities, viscosity ratio of two fluids, the electric field, and the dielectric constant values. Liquid viscosity has stabilizing effect in the stability analysis, while air viscosity has destabilizing effect.

Toxicity of Carbon Nanotubes and Its Implications for Occupational and Environmental Health

Science.gov (United States)

Lam, Chiu-wing; James, John T.

2007-01-01

Carbon nanotubes (CNTs), which possess desirable electrical and mechanical properties, potentially have wide industrial applications. CNTs exist in two forms, single-wall (SW) and multi-wall (MW). There has been great concern that if CNTs enter the work environment as suspended respirable particulate matter (PM), they could pose an inhalation hazard. The results of recent rodent studies have collectively shown that CNTs can produce inflammation, epithelioid granulomas, fibrosis, and biochemical changes in the lungs. Studies in mice given equal amounts of test dusts showed that CNTs were more toxic than quartz and produced lesions that became progressively more pronounced. These results have led us to recommend that respirable CNT dust be considered a serious occupational health hazard, and that exposure limits be established in the expectation of expanded industrial applications. CNTs, which are totally insoluble and fibrous, would be expected to be more biopersistent than mineral fibers. Biopersistence is the key factor determining the long-term toxicity of mineral fibers and certainly of CNTs too. We have postulated that the electrical and fibrous properties of CNTs also play important roles in the toxicity of CNTs in the lungs. Recently, MWCNTs have been found in ultrafine PM aggregates in combustion streams of methane, propane, and natural-gas flames of typical stoves; indoor and outdoor fine (fuels, and fine PM has been reported to be a major contributor to the induction of cardiopulmonary diseases by pollutants. Given that manufactured SWCNTs and/or MWCNTs have elicited pathological changes in the lungs and heart, we have postulated that exposure to combustion-generated MWCNTs in fine PM in the air may play a significant role in air pollution-related cardiopulmonary diseases. Therefore, CNTs from manufacturing and combustion sources in the environment could have adverse effects on human health.

Engineered Nanoparticles as Potential Food Contaminants and Their Toxicity to Caco-2 Cells.

Science.gov (United States)

Mao, Xiaomo; Nguyen, Trang H D; Lin, Mengshi; Mustapha, Azlin

2016-08-01

Engineered nanoparticles (ENPs), such as metallic or metallic oxide nanoparticles (NPs), have gained much attention in recent years. Increasing use of ENPs in various areas may lead to the release of ENPs into the environment and cause the contamination of agricultural and food products by ENPs. In this study, we selected two important ENPs (zinc oxide [ZnO] and silver [Ag] NPs) as potential food contaminants and investigated their toxicity via an in vitro model using Caco-2 cells. The physical properties of ENPs and their effects on Caco-2 cells were characterized by electron microscopy and energy dispersive X-ray spectroscopic (EDS) techniques. Results demonstrate that a significant inhibition of cell viability was observed after a 24-h of exposure of Caco-2 cells to 3-, 6-, and 12-mM ZnO NPs or 0.5-, 1.5-, and 3-mM Ag NPs. The noticeable changes of cells include the alteration in cell shape, abnormal nuclear structure, membrane blebbing, and cytoplasmic deterioration. The toxicity of ZnO NPs, but not that of Ag NPs after exposure to simulated gastric fluid, significantly decreased. Scanning transmission electron microscopy shows that ZnO and Ag NPs penetrated the membrane of Caco-2 cells. EDS results also confirm the presence of NPs in the cytoplasm of the cells. This study demonstrates that ZnO and Ag NPs have cytotoxic effects and can inhibit the growth of Caco-2 cells. © 2016 Institute of Food Technologists®

Toxicity, sublethal effects, and potential modes of action of select fungicides on freshwater fish and invertebrates

Science.gov (United States)

Elskus, Adria A.

2012-01-01

Despite decades of agricultural and urban use of fungicides and widespread detection of these pesticides in surface waters, relatively few data are available on the effects of fungicides on fish and invertebrates in the aquatic environment. Nine fungicides are reviewed in this report: azoxystrobin, boscalid, chlorothalonil, fludioxonil, myclobutanil, fenarimol, pyraclostrobin, pyrimethanil, and zoxamide. These fungicides were identified as emerging chemicals of concern because of their high or increasing global use rates, detection frequency in surface waters, or likely persistence in the environment. A review of the literature revealed significant sublethal effects of fungicides on fish, aquatic invertebrates, and ecosystems, including zooplankton and fish reproduction, fish immune function, zooplankton community composition, metabolic enzymes, and ecosystem processes, such as leaf decomposition in streams, among other biological effects. Some of these effects can occur at fungicide concentrations well below single-species acute lethality values (48- or 96-hour concentration that effects a response in 50 percent of the organisms, that is, effective concentration killing 50 percent of the organisms in 48 or 96 hours) and chronic sublethal values (for example, 21-day no observed adverse effects concentration), indicating that single-species toxicity values may dramatically underestimate the toxic potency of some fungicides. Fungicide modes of toxic action in fungi can sometimes reflect the biochemical and (or) physiological effects of fungicides observed in vertebrates and invertebrates; however, far more studies are needed to explore the potential to predict effects in nontarget organisms based on specific fungicide modes of toxic action. Fungicides can also have additive and (or) synergistic effects when used with other fungicides and insecticides, highlighting the need to study pesticide mixtures that occur in surface waters. For fungicides that partition to

Potential hazards of toxic metals found in toothpastes commonly used in Nigeria.

Science.gov (United States)

Orisakwe, Orish Ebere; Okolo, Kenneth Obinna; Igweze, Zelinjo Nkeiruka; Ajaezi, Godwin Chukwuebuka; Udowelle, Nnaemeka Arinze

2016-01-01

Toothpastes have multi-functional configurations as oral care products. They can however constitute a pos- sible source, amongst others, of toxic metal exposure in public health. Indeed, the public health impact of personal hygiene and consumer products is largely unknown. To determine the level of toxic metals (lead, cadmium, cobalt, chromium, nickel) in toothpastes available in Nigeria, (home produced and imported), and assess the potential risk to the people. The samples of toothpastes commonly used in Nigeria were tested. Using a market basket protocol thirty five different brands of toothpaste were used. Samples were digest by addition of 10 mL mixture of conc. nitric and hydrochloric acids (HCl:HNO(3), 3:1), followed by heating to dryness. 20 mL deionized water was added, stirred and filtered. The filtrate was made up in standard volumetric flask and lead, cadmium, chromium, cobalt and nickel concentrations were determined using the atomic absorption spectrophotometry 205A. The daily intake of metals and target hazard quotient (THQ) were then calculated. Pepsodent and Flodent had the highest levels of lead at respectively 23.575 and 18.092 mg/kg while Colgate Herbal had the highest nickel of 18.535 mg/kg. The daily intake estimates of all imported toothpaste samples were below the stated upper limits (UL). All target hazard quotients were also found to be below one. Although the UL, THQ and daily intake rates were all normal, the high levels of lead in some of the tooth- pastes an important concern to public health suggesting that pre-marketing safety studies of toothpastes may be worthwhile for the regulatory authorities.

The potential DNA toxic changes among workers exposed to antimony trioxide.

Science.gov (United States)

El Shanawany, Safaa; Foda, Nermine; Hashad, Doaa I; Salama, Naglaa; Sobh, Zahraa

2017-05-01

Occupational exposure to antimony has gained much interest when specific toxic effects were noticed among workers processing antimony. Thus, the aim of the present work was to investigate the potential DNA oxidative damage occurring among Egyptian workers occupationally exposed to antimony trioxide. The study was conducted on 25 subjects exposed to antimony trioxide while working in the polymerization process of polyester in Misrayon and Polyester Fiber Company, KafrEldawwar, Beheira, Egypt. Urinary antimony levels were assessed using inductive coupled plasma-optical emission spectrometry (ICP-OES) and considered as a biological exposure index. DNA damage and total oxidant capacity (TOC) were assessed using ELISA. DNA damage was detected in the form of increased apurinic/apyrimidinic (AP) sites among antimony trioxide-exposed workers compared to control subjects, but it could not be explained by oxidative mechanisms due to lack of significant correlation between DNA damage and measured TOC. Antimony trioxide might have a genotoxic impact on occupationally exposed workers which could not be attributed to oxidative stress in the studied cases.

Reduction of Fumonisin Toxicity by Extrusion and Nixtamalization (Alkaline Cooking).

Science.gov (United States)

Voss, Kenneth; Ryu, Dojin; Jackson, Lauren; Riley, Ronald; Gelineau-van Waes, Janee

2017-08-23

Fumonisins are mycotoxins found in corn. They are toxic to animals and cause cancer in rodents and neural tube defects in LM/Bc mice. Reducing their concentrations in corn-based foods is therefore desirable. Chemical analysis or in vitro bioassays of food extracts might not detect toxic fumonisin reaction products that are unknown or unextractable from food matrices, thus potentially underestimating in vivo toxicity. The effectiveness of two common cooking methods, extrusion and nixtamalization (alkaline cooking), to reduce the toxicity of fumonisin-contaminated corn grits (extrusion) and whole kernel corn (nixtamalization) was shown by means of rat feeding bioassays using fumonisin-specific kidney effects as indicators of potential toxicity. A third bioassay showed that in contrast to fumonisin B 1 (FB 1 ), hydrolyzed fumonisin B 1 (HFB 1 ; formed from FB 1 during nixtamalization) did not cause neural tube defects in LM/Bc mice. The findings indicate that extrusion and nixtamalization reduce the potential toxicity of FB 1 -contaminated corn.

Potential impact of a US climate policy and air quality regulations on future air quality and climate change

Science.gov (United States)

Lee, Yunha; Shindell, Drew T.; Faluvegi, Greg; Pinder, Rob W.

2016-04-01

We have investigated how future air quality and climate change are influenced by the US air quality regulations that existed or were proposed in 2013 and a hypothetical climate mitigation policy that aims to reduce 2050 CO2 emissions to be 50 % below 2005 emissions. Using the NASA GISS ModelE2 general circulation model, we look at the impacts for year 2030 and 2055. The US energy-sector emissions are from the GLIMPSE project (GEOS-Chem LIDORT Integrated with MARKAL (MARKet ALlocation) for the Purpose of Scenario Exploration), and other US emissions data sets and the rest of the world emissions data sets are based on the RCP4.5 scenario. The US air quality regulations are projected to have a strong beneficial impact on US air quality and public health in year 2030 and 2055 but result in positive radiative forcing. Under this scenario, no more emission constraints are added after 2020, and the impacts on air quality and climate change are similar between year 2030 and 2055. Surface particulate matter with a diameter smaller than 2.5 µm (PM2.5) is reduced by ˜ 2 µg m-3 on average over the USA, and surface ozone by ˜ 8 ppbv. The improved air quality prevents about 91 400 premature deaths in the USA, mainly due to the PM2.5 reduction (˜ 74 200 lives saved). The air quality regulations reduce the light-reflecting aerosols (i.e., sulfate and organic matter) more than the light-absorbing species (i.e., black carbon and ozone), leading to a strong positive radiative forcing (RF) over the USA by both aerosols' direct and indirect forcing: the total RF is ˜ 0.04 W m-2 over the globe, and ˜ 0.8 W m-2 over the USA. Under the hypothetical climate policy, a future CO2 emissions cut is achieved in part by relying less on coal, and thus SO2 emissions are noticeably reduced. This provides air quality co-benefits, but it could lead to potential climate disbenefits over the USA. In 2055, the US mean total RF is +0.22 W m-2 due to positive aerosol direct and indirect forcing

Potential Impact of a US Climate Policy and Air Quality Regulations on Future Air Quality and Climate Change

Science.gov (United States)

Lee, Y. H.; Faluvegi, Gregory S.

2016-01-01

We have investigated how future air quality and climate change are influenced by the US air quality regulations that existed or were proposed in 2013 and a hypothetical climate mitigation policy that aims to reduce 2050 CO2 emissions to be 50% below 2005 emissions. Using the NASA GISS ModelE2 general circulation model, we look at the impacts for year 2030 and 2055. The US energy-sector emissions are from the GLIMPSE project (GEOS-Chem LIDORT Integrated with MARKAL (MARKet ALlocation) for the Purpose of Scenario Exploration), and other US emissions data sets and the rest of the world emissions data sets are based on the RCP4.5 scenario. The US air quality regulations are projected to have a strong beneficial impact on US air quality and public health in year 2030 and 2055 but result in positive radiative forcing. Under this scenario, no more emission constraints are added after 2020, and the impacts on air quality and climate change are similar between year 2030 and 2055. Surface particulate matter with a diameter smaller than 2.5 micron PM(sub 2:5) is reduced by 2 approximately µg/m(sup -3) on average over the USA, and surface ozone by approximately 8 ppbv. The improved air quality prevents about 91 400 premature deaths in the USA, mainly due to the PM(sub 2:5) reduction approximately (74 200 lives saved). The air quality regulations reduce the light-reflecting aerosols (i.e., sulfate and organic matter) more than the light-absorbing species (i.e., black carbon and ozone), leading to a strong positive radiative forcing (RF) over the USA by both aerosols' direct and indirect forcing: the total RF is approximately 0.04 W m(sup -2) over the globe, and approximately 0.8 W m(sup -2) over the USA. Under the hypothetical climate policy, a future CO2 emissions cut is achieved in part by relying less on coal, and thus SO2 emissions are noticeably reduced. This provides air quality co-benefits, but it could lead to potential climate disbenefits over the USA. In 2055, the US

Nail toxicity induced by cancer chemotherapy.

Science.gov (United States)

Gilbar, Peter; Hain, Alice; Peereboom, Veta-Marie

2009-09-01

To provide a comprehensive literature review of chemotherapy-induced nail toxicity, including clinical presentation, implicated drugs and approaches for prevention and management. A search of MEDLINE and EMBASE (1966-2008) databases was conducted using the terms (and variations of the terms) antineoplastic agents, nails, nail toxicity, onycholysis, and paronychia. Bibliographies from selected articles were reviewed for appropriate references. The retrieved literature was reviewed to include all articles relevant to the clinical presentation, diagnosis, incidence, prevention, and treatment of chemotherapy-induced nail toxicity. Nail toxicity is a relatively uncommon adverse effect linked to a number of chemotherapeutic agents. Clinical presentation varies, depending on which nail structure is affected and the severity of the insult. Nail changes may involve all or some nails. Toxicity may be asymptomatic and limited to cosmetic concerns, however, more severe effects, involving pain and discomfort can occur. Taxanes and anthracyclines are the antineoplastic drug groups most commonly implicated. It is suggested that the administration schedule may influence the incidence of nail abnormalities, for example reported cases linked to the weekly administration of paclitaxel.Before instituting chemotherapy, patients should be educated regarding potential nail toxicities and strategies for prevention implemented. Management includes appropriate nail cutting, avoiding potential irritants, topical, or oral antimicrobials, and possibly cessation or dose reduction of the offending agent. Cryotherapy, through the application of frozen gloves or socks, has been beneficial in reducing docetaxel-induced nail toxicity and may be effective for other drugs.

Summary of safety evaluation toxicity studies of glufosinate ammonium.

Science.gov (United States)

Ebert, E; Leist, K H; Mayer, D

1990-05-01

This article reviews the results of toxicity studies to evaluate the safety of the herbicide glufosinate ammonium (GLA) and its formulation (200 g/litre) in laboratory animals. The data show that GLA and its formulation are slightly toxic following oral exposure. In addition, the formulation induced GLA and its formulation are slightly toxic following oral exposure. In addition, the formulation induced slight dermal toxicity and eye irritation. Testing for teratogenicity in rats and rabbits indicated no teratogenic potential, and numerous mutagenicity tests showed GLA to be non-genotoxic. Chronic toxicity testing in rats and dogs yielded no-observable-effect levels of 2 and 5 mg/kg body weight/day, respectively. Oncogenicity studies in rats and mice revealed no carcinogenic potential. On the basis of these toxicity data it is concluded that this herbicide is safe under conditions of recommended use.

PRECOMBUSTION REMOVAL OF HAZARDOUS AIR POLLUTANT PRECURSORS

Energy Technology Data Exchange (ETDEWEB)

Unknown

2000-10-09

In response to growing environmental concerns reflected in the 1990 Clean Air Act Amendment (CAAA), the United States Department of Energy (DOE) sponsored several research and development projects in late 1995 as part of an initiative entitled Advanced Environmental Control Technologies for Coal-Based Power Systems. The program provided cost-shared support for research and development projects that could accelerate the commercialization of affordable, high-efficiency, low-emission, coal-fueled electric generating technologies. Clean coal technologies developed under this program would serve as prototypes for later generations of technologies to be implemented in the industrial sector. In order to identify technologies with the greatest potential for commercial implementation, projects funded under Phase I of this program were subject to competitive review by DOE before being considered for continuation funding under Phase II. One of the primary topical areas identified under the DOE initiative relates to the development of improved technologies for reducing the emissions of air toxics. Previous studies have suggested that many of the potentially hazardous air pollutant precursors (HAPPs) occur as trace elements in the mineral matter of run-of-mine coals. As a result, these elements have the potential to be removed prior to combustion at the mine site by physical coal cleaning processes (i.e., coal preparation). Unfortunately, existing coal preparation plants are generally limited in their ability to remove HAPPs due to incomplete liberation of the mineral matter and high organic associations of some trace elements. In addition, existing physical coal cleaning plants are not specifically designed or optimized to ensure that high trace element rejections may be achieved.

Teknologi Pengolahan Air Limbah Rumah Sakit

Directory of Open Access Journals (Sweden)

Prayitno - -

2012-05-01

Full Text Available Abstrak Air limbah rumah sakit mengandung polutan yang bersifat toksid, infeksius, bahkan radioaktif sehingga berpotensi menimbulkan dampak terhadap pencemaran lingkungan dan kesehatan masyarakat. Disamping itu dengan minimnya jumlah rumah sakit di Indonesia yang memiliki IPAL yaitu sebanyak 36%, dan yang memenuhi persyaratan IPAL sebesar 52% maka potensi dampak yang ditimbulkan akan semakin nyata. Pemilihan teknologi pengelolaan air limbah dengan demikian sangat penting. Makalah ini bertujuan untuk menganalisis aspek – aspek yang perlu dipertimbangkan dalam memilih jenis teknologi pengolalaan air limbah rumah sakit secara deskriptif. Dengan menggunakan pendekatan aspek teknis, aspek ekonomis dan aspek keberlanjutan terhadap beberapa teknologi pengolahan air limbah rumah sakit yang berkembangan saat ini, dapat direkomendasi bahwa kombinasi teknologi pengolahan biofilter anaerob – aerob dan ozonasi adalah  teknologi yang efektif dalam pengolahan air limbah rumah sakit.   Kata kunci: limbah rumah sakit, polutan, teknologi pengelolaan limbah Abstract Hospital wastewater contains pollutant which has been recognized toxic, infectious and radioactive that able to degrade environment and community health. In Indonesia, only 36% of hospital has wastewater treatment instrument (IPAL, and among them only 52% meet the national standard.  These situation potentially lead to pollution that threat environments. Promoting hospital water treatments therefore become significant. This reviews aims to analyze general aspect to choose proper technology for hospital water treatments. Using technical and  economical  aspects as well as sustainability perspective, it is recommended that combination of biofilter anaerob – aerob technology and ozonization is the effective strategy to manage and process hospital wastewater in Indonesia. Keywords: hospital wastewater, pollutant, wastewater threatment technology

Potential genotoxic effects of melted snow from an urban area revealed by the Allium cepa test.

Science.gov (United States)

Blagojević, Jelena; Stamenković, Gorana; Vujosević, Mladen

2009-09-01

The presence of well-known atmospheric pollutants is regularly screened for in large towns but knowledge about the effects of mixtures of different pollutants and especially their genotoxic potential is largely missing. Since falling snow collects pollutants from the air, melted snow samples could be suitable for evaluating potential genotoxicity. For this purpose the Allium cepa anaphase-telophase test was used to analyse melted snow samples from Belgrade, the capital city of Serbia. Samples of snow were taken at two sites, characterized by differences in pollution intensity, in three successive years. At the more polluted site the analyses showed a very high degree of both toxicity and genotoxicity in the first year of the study corresponding to the effects of the known mutagen used as the positive control. At the other site the situation was much better but not without warning signals. The results showed that standard analyses for the presence of certain contaminants in the air do not give an accurate picture of the possible consequences of urban air pollution because the genotoxic potential remains hidden. The A. cepa test has been demonstrated to be very convenient for evaluation of air pollution through analyses of melted snow samples.

Regional Air Transport in Europe: The Potential Role of the Civil Tiltrotor in Reducing Airside Congestion

Science.gov (United States)

Correnti, Vincenzo; Ignaccolo, Matteo; Capri, Salvatore; Inturri, Giuseppe

2006-01-01

The volume of air traffic worldwide is still in constant growth despite unfair events that sometimes occur. The demand for regional air transport is also increasing, thanks in part to the use of new vehicles purposely designed for short range flights which make this means of transport more attractive than in the past. This paper studies the possibility of using aircraft capable of vertical or short takeoff or landing (V/STOL), in particular the tiltrotor, in the regional air transport market and the impact on airport capacity that the use of this craft would have. With this in mind the advantages and disadvantages of using this vehicle are identified, as well as the changes to be made to the air transport system in order to exploit its full potential.

Nanoparticles: Their potential toxicity, waste and environmental management

International Nuclear Information System (INIS)

Bystrzejewska-Piotrowska, Grazyna; Golimowski, Jerzy; Urban, Pawel L.

2009-01-01

This literature review discusses specific issues related to handling of waste containing nanomaterials. The aims are (1) to highlight problems related to uncontrolled release of nanoparticles to the environment through waste disposal, and (2) to introduce the topics of nanowaste and nanotoxicology to the waste management community. Many nanoparticles used by industry contain heavy metals, thus toxicity and bioaccumulation of heavy metals contained in nanoparticles may become important environmental issues. Although bioavailability of heavy metals contained in nanoparticles can be lower than those present in soluble form, the toxicity resulting from their intrinsic nature (e.g. their size, shape or density) may be significant. An approach to the treatment of nanowaste requires understanding of all its properties - not only chemical, but also physical and biological. Progress in nanowaste management also requires studies of the environmental impact of the new materials. The authors believe Amara's law is applicable to the impact of nanotechnologies, and society might overestimate the short-term effects of these technologies, while underestimating the long-term effects. It is necessary to have basic information from companies about the level and nature of nanomaterials produced or emitted and about the expectation of the life cycle time of nanoproducts as a basis to estimate the level of nanowaste in the future. Without knowing how companies plan to use and store recycled and nonrecycled nanomaterials, development of regulations is difficult. Tagging of nanoproducts is proposed as a means to facilitate separation and recovery of nanomaterials.

A study of antioxidant activity, enzymatic inhibition and in vitro toxicity of selected traditional sudanese plants with anti-diabetic potential

Science.gov (United States)

2014-01-01

Background Diabetes mellitus is a chronic metabolic disease with life-threatening complications. Despite the enormous progress in conventional medicine and pharmaceutical industry, herbal-based medicines are still a common practice for the treatment of diabetes. This study evaluated ethanolic and aqueous extracts of selected Sudanese plants that are traditionally used to treat diabetes. Methods Extraction was carried out according to method described by Sukhdev et. al. and the extracts were tested for their glycogen phosphorylase inhibition, Brine shrimp lethality and antioxidant activity using (DPPH) radical scavenging activity and iron chelating activity. Extracts prepared from the leaves of Ambrosia maritima, fruits of Foeniculum vulgare and Ammi visnaga, exudates of Acacia Senegal, and seeds of Sesamum indicum and Nigella sativa. Results Nigella sativa ethanolic extract showed no toxicity on Brine shrimp Lethality Test, while its aqueous extract was toxic. All other extracts were highly toxic and ethanolic extracts of Foeniculum vulgare exhibited the highest toxicity. All plant extracts with exception of Acacia senegal revealed significant antioxidant activity in DPPH free radical scavenging assay. Conclusions These results highly agree with the ethnobotanical uses of these plants as antidiabetic. This study endorses further studies on plants investigated, to determine their potential for type 2 diabetes management. Moreover isolation and identification of active compounds are highly recommended. PMID:24885334

Air impacts of increased natural gas acquisition, processing, and use: a critical review.

Science.gov (United States)

Moore, Christopher W; Zielinska, Barbara; Pétron, Gabrielle; Jackson, Robert B

2014-01-01

During the past decade, technological advancements in the United States and Canada have led to rapid and intensive development of many unconventional natural gas plays (e.g., shale gas, tight sand gas, coal-bed methane), raising concerns about environmental impacts. Here, we summarize the current understanding of local and regional air quality impacts of natural gas extraction, production, and use. Air emissions from the natural gas life cycle include greenhouse gases, ozone precursors (volatile organic compounds and nitrogen oxides), air toxics, and particulates. National and state regulators primarily use generic emission inventories to assess the climate, air quality, and health impacts of natural gas systems. These inventories rely on limited, incomplete, and sometimes outdated emission factors and activity data, based on few measurements. We discuss case studies for specific air impacts grouped by natural gas life cycle segment, summarize the potential benefits of using natural gas over other fossil fuels, and examine national and state emission regulations pertaining to natural gas systems. Finally, we highlight specific gaps in scientific knowledge and suggest that substantial additional measurements of air emissions from the natural gas life cycle are essential to understanding the impacts and benefits of this resource.

Engineered Nanomaterials, Sexy New Technology and Potential Hazards

International Nuclear Information System (INIS)

Beaulieu, R.A.

2009-01-01

Engineered nanomaterials enhance exciting new applications that can greatly benefit society in areas of cancer treatments, solar energy, energy storage, and water purification. While nanotechnology shows incredible promise in these and other areas by exploiting nanomaterials unique properties, these same properties can potentially cause adverse health effects to workers who may be exposed during work. Dispersed nanoparticles in air can cause adverse health effects to animals not merely due to their chemical properties but due to their size, structure, shape, surface chemistry, solubility, carcinogenicity, reproductive toxicity, mutagenicity, dermal toxicity, and parent material toxicity. Nanoparticles have a greater likelihood of lung deposition and blood absorption than larger particles due to their size. Nanomaterials can also pose physical hazards due to their unusually high reactivity, which makes them useful as catalysts, but has the potential to cause fires and explosions. Characterization of the hazards (and potential for exposures) associated with nanomaterial development and incorporation in other products is an essential step in the development of nanotechnologies. Developing controls for these hazards are equally important. Engineered controls should be integrated into nanomaterial manufacturing process design according to 10CFR851, DOE Policy 456.1, and DOE Notice 456.1 as safety-related hardware or administrative controls for worker safety. Nanomaterial hazards in a nuclear facility must also meet control requirements per DOE standards 3009, 1189, and 1186. Integration of safe designs into manufacturing processes for new applications concurrent with the developing technology is essential for worker safety. This paper presents a discussion of nanotechnology, nanomaterial properties/hazards and controls

Toxicity of fluorescent tracers and their degradation byproducts

Directory of Open Access Journals (Sweden)

Philippe Gombert

2017-01-01

Full Text Available Tracer tests are frequently used to delineate catchment area of water supply springs in karstic zones. In the karstic chalk of Normandy, the main tracers used are fluorescent: uranine, sulforhodamine B, naphtionate, and Tinopal®. In this area, a statistical analysis shows that less than half of the injected tracers joins the monitored restitution points and enters the drinking water system where they undergo chlorination. Most of the injected tracers is absorbed in the rock matrix or is thrown out of the aquifer via karstic springs: then it can join superficial waters where it is degraded due to the sun and air action. The paper presents firstly the laboratory degradation of a first batch of fluorescent tracers in contact with chlorine, in order to simulate their passage through a water treatment system for human consumption. A second batch of the same tracers is subjected to agents of natural degradation: ultraviolet illumination, sunlight and air sparging. Most tracers is degraded, and toxicity and ecotoxicity tests (on rats, daphniae and algae are performed on degradation byproducts. These tests do not show any acute toxicity but a low to moderate ecotoxicity. In conclusion, the most used fluorescent tracers of the Normandy karstic chalk and their artificial and natural degradation byproducts do not exhibit significant toxicity to humans and the aquatic environment, at the concentrations generally noted at the restitution points.

Atmospheric deposition exposes Qinling pandas to toxic pollutants.

Science.gov (United States)

Chen, Yi-Ping; Zheng, Ying-Juan; Liu, Qiang; Song, Yi; An, Zhi-Sheng; Ma, Qing-Yi; Ellison, Aaron M

2017-03-01

The giant panda (Ailuropoda melanoleuca) is one of the most endangered animals in the world, and it is recognized worldwide as a symbol for conservation. A previous study showed that wild and captive pandas, especially those of the Qinling subspecies, were exposed to toxicants in their diet of bamboo; the ultimate origin of these toxicants is unknown. Here we show that atmospheric deposition is the most likely origin of heavy metals and persistent organic pollutants (POPs) in the diets of captive and wild Qinling pandas. Average atmospheric deposition was 199, 115, and 49 g·m -2 ·yr -1 in the center of Xi'an City, at China's Shaanxi Wild Animal Research Center (SWARC), and at Foping National Nature Reserve (FNNR), respectively. Atmospheric deposition of heavy metals (As, Cd, Cr, Pb, Hg, Co, Cu, Zn, Mn, and Ni) and POPs was highest at Xi'an City, intermediate at SWARC, and lowest at FNNR. Soil concentrations of the aforementioned heavy metals other than As and Zn also were significantly higher at SWARC than at FNNR. Efforts to conserve Qinling pandas may be compromised by air pollution attendant to China's economic development. Improvement of air quality and reductions of toxic emissions are urgently required to protect China's iconic species. © 2017 by the Ecological Society of America.

Functional traits of urban trees: Air pollution mitigation potential

DEFF Research Database (Denmark)

Grote, Rüdiger; Samson, Roeland; Alonso, Rocío

2016-01-01

In an increasingly urbanized world, air pollution mitigation is considered one of most important issues in city planning. Urban trees help to improve air quality by facilitating widespread deposition of various gases and particles through the provision of large surface areas as well as through...... are manifested depends on species-specific tree properties: that is, their "traits". We summarize and discuss the current knowledge on how such traits affect urban air pollution. We also present aggregated traits of some of the most common tree species in Europe, which can be used as a decision-support tool...... their influence on microclimate and air turbulence. However, many of these trees produce wind-dispersed pollen (a known allergen) and emit a range of gaseous substances that take part in photochemical reactions - all of which can negatively affect air quality. The degree to which these air-quality impacts...

Potentially toxic metals in rivers upstream of Pantanal Norte

Directory of Open Access Journals (Sweden)

Geizibel Campos de Magalhães

2016-11-01

Full Text Available Cuiabá (CBA and São Lourenço (SL rivers are considered strategic once they integrate regions, which are economically, socially and environmentally relevant for Brazil and the world. However, several activities developed in their watersheds may represent sources of metals and be a threat to the environmental quality. Thus, in this study we evaluated the spatial and temporal variability of potentially toxic metals in water and sediment and the relationship of their concentration with water quality parameters. Surface water samples were collected monthly in 15 points and bottom sediment in nine points distributed throughout both rivers from August 2012 to July 2013. Cr, Cu, Fe, Mn, Pb and Zn were determined in water by inducted coupled plasma optical emission spectrometry and in sediment by flame atomic absorption spectrometry. Fe, Mn, Pb and Cr had high concentrations in water and sediment but only Pb and Cr represent environmental risk. Fe and Mn were in higher concentrations in at the upper points of SL River and Cu and Pb in the urban area of both rivers. Temporally, the metal concentrations were associated with precipitation variation. The observed correlations amongst metal concentrations indicate common sources. Thus, the metals occurrence and concentrations in water and sediment of both rivers showed a natural contribution, as a reflex of soil type associated to the region's precipitation regimen as well as the anthropic contribution due to agricultural and cattle breeding activities, and disposal of untreated urban effluents.

Potential toxic effect of trifloxystrobin on cellular microstructure, mRNA expression and antioxidant enzymes in Chlorella vulgaris.

Science.gov (United States)

Shen, Yu-Feng; Liu, Lei; Gong, Yu-Xin; Zhu, Bin; Liu, Guang-Lu; Wang, Gao-Xue

2014-05-01

This study investigated the effects of trifloxystrobin that one strobilurin used widely in the world as an effective fungicidal agent to control Asian soybean rust on aquatic unicellular algae Chlorella vulgaris. We determined the potential toxic effect of trifloxystrobin on C. vulgaris, and found median inhibition concentration (IC(50)) value 255.58 (95% confidence interval, 207.81-330.29)μgL(-1). In addition, the algal cells were obviously depressed or shrunk at different concentrations by electron microscopy. In the study, a real-time polymerase chain reaction (PCR) assay showed changes in transcript abundances of three photosynthetic genes, psaB, psbC, and rbcL, and one energy gene, ATPs. The results showed that trifloxystrobin reduced the transcript abundances of the three genes and enhanced expression of ATPs after 48 and 96 h. The lowest abundances of psaB, psbC and rbcL transcripts in response to trifloxystrobin exposure were 58%, 79% and 60% of those of the control, respectively. For the potential toxic influences, trifloxystrobin could decrease the soluble protein and total antioxidant contents (T-AOC), and increase superoxide dismutase (SOD) and peroxidase (POD) activity with a gradual concentration-response relationship. Overall, the present study demonstrated that trifloxystrobin could affect the activities of antioxidant enzymes, disrupts photosynthesis in C. vulgaris, and damage cellular structure. Copyright © 2014 Elsevier B.V. All rights reserved.

Toxic vapor concentrations in the control room following a postulated accidental release

International Nuclear Information System (INIS)

Wing, J.

1979-05-01

An acceptable method is presented for calculating the vapor concentrations in a control room as a function of time after a postulated accidental release. Included are the mathematical formulas for computing the rates of vaporization and evaporation of liquid spills, the vapor dispersion in air, and the control room air exchange. A list of toxic chemicals and their physical properties is also given

Synthesis of a novel nanopesticide and its potential toxic effect on soil microbial activity

Science.gov (United States)

Liu, Wenjuan; Yao, Jun; Cai, Minmin; Chai, Hankuai; Zhang, Chi; Sun, Jingjing; Chandankere, Radhika; Masakorala, Kanaji

2014-11-01

A new nanopesticide, carboxymethyl-β-cyclodextrin-Fe3O4 magnetic nanoparticles-Diuron (CM-β-CD-MNPs-Diuron), was synthesized from an inclusion complex of CM-β-CD-MNPs as host and diuron as guest molecules. The transmission electron microscopy revealed it had an average diameter of 25 nm which is more or less the same as that of MNPs (average diameter 23 nm). The CM-β-CD grafting was confirmed by infrared spectroscopy, and the amount of CM-β-CD grafted on the surface of MNPs was determined to be 144.1 mg/g by thermogravimetry. The feasibility of using CM-β-CD-MNPs as a nanocarrier for loading diuron was verified by investigating the formation of inclusion complex. The complexation of CM-β-CD-MNPs with diuron followed the Langmuir adsorption isotherm. In this work, the potential toxic effect of CM-β-CD-MNPs-Diuron on soil microbial was evaluated by microcalorimetry, urease enzyme and real-time quantitative PCR (qPCR). The thermokinetic parameters were observed to decrease with increase in the loading of CM-β-CD-MNPs-Diuron in soil. The urease activity data showed that there was a significant effect ( p Diuron on the enzyme activity. The microcalorimetric analysis was in agreement with qPCR, confirming the toxic effect of this nanopesticide on microorganism in soil.

Transformation of toxic potential of Jatropha curcas (Ratanjyot into protein source: A mini-review

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Amit Shukla

2015-06-01

Full Text Available The production of animal largely depends on supplying of quality feed and proteinaceous supplement to the animals. Jatropha plant can grow in the barren lands, and are used as a source of biodiesel. Besides, the plant may act as a rich proteinaceous source. However, the antinutritional factors present in the seed and seed oil of the plant may hamper the availability and beneficial use of the plant. Curcin and phorbol esters are the major toxic compounds present in the plant; these toxic compounds cause to produce liver and kidney diseases. Detoxification of these toxic compounds by physical and chemical means converting to less toxic seed cake may serve the purpose of using this plant in future as a replacement of costly protein supplement for animals. Therefore, in modern world, it is recommended to utilize the protein source by neutralizing the antinutritional factors. This mini-review describes the updates on how J. curcas can be utilized as a supplementary source of protein for animals by decreasing its toxicity.

Australia’s first national level quantitative environmental justice assessment of industrial air pollution

International Nuclear Information System (INIS)

Chakraborty, Jayajit; Green, Donna

2014-01-01

This study presents the first national level quantitative environmental justice assessment of industrial air pollution in Australia. Specifically, our analysis links the spatial distribution of sites and emissions associated with industrial pollution sources derived from the National Pollution Inventory, to Indigenous status and social disadvantage characteristics of communities derived from Australian Bureau of Statistics indicators. Our results reveal a clear national pattern of environmental injustice based on the locations of industrial pollution sources, as well as volume, and toxicity of air pollution released at these locations. Communities with the highest number of polluting sites, emission volume, and toxicity-weighted air emissions indicate significantly greater proportions of Indigenous population and higher levels of socio-economic disadvantage. The quantities and toxicities of industrial air pollution are particularly higher in communities with the lowest levels of educational attainment and occupational status. These findings emphasize the need for more detailed analysis in specific regions and communities where socially disadvantaged groups are disproportionately impacted by industrial air pollution. Our empirical findings also underscore the growing necessity to incorporate environmental justice considerations in environmental planning and policy-making in Australia. (paper)

Comparative assessment of button cells using a normalized index for potential pollution by heavy metals

Energy Technology Data Exchange (ETDEWEB)

Moreno-Merino, Luis, E-mail: l.moreno@igme.es [Geological Survey of Spain, Environmental Geology Research Group, C/ Ríos Rosas 23, 28003 Madrid (Spain); Jiménez-Hernández, Maria Emilia; Losa, Almudena de la [Geological Survey of Spain, Environmental Geology Research Group, C/ Ríos Rosas 23, 28003 Madrid (Spain); Huerta-Muñoz, Virginia [Universidad Complutense de Madrid, Departamento de Geodinámica Externa, C/ José Antonio Novais, 12, Ciudad Universitaria, 28040 Madrid (Spain)

2015-09-01

Many household batteries worldwide still end up in landfills or are incinerated due to inefficient collection and recycling schemes. Toxic heavy metals from improperly discarded button cells pose a serious risk to human health and the environment, as they can pollute air, soil and water. This paper analyses a series of button cells selected from batteries available on the retail market, and compares their polluting potential. A total of 64 batteries were subjected to chemical analyses of 19 elements — including metals and metalloids — , and energy density measurements. The samples were from four different brands of each of the four most common button cell technologies (alkaline, zinc-air, silver oxide and lithium). An energy-normalized index — the Weighted Potential Pollution Index (WPPI) — was proposed to compare the polluting potential of the different batteries. The higher the battery WPPI score, the greater the content in toxic elements and the lower the energy output. The results of the chemical composition and energy density varied depending on the construction technology of the button cells. However, significant differences in both variables were also found when comparing different brands within the same technology. The differences in WPPI values confirmed the existence of a significant margin to reduce the environmental impact of discarded button cells simply by avoiding the most polluting options. The choice of the battery with the most favourable WPPI produced a reduction in potential pollution of 3–53% for silver oxide batteries, 4–39% for alkaline, 20–28% for zinc-air and 12–26% for lithium. Comparative potential pollution could be assessed when selecting batteries using an energy-normalized index such as WPPI to reduce the environmental impact of improperly disposed button cells. - Highlights: • We compare the polluting potential of button cells using an energy-normalized index. • This battery index considers both chemical

Comparative assessment of button cells using a normalized index for potential pollution by heavy metals

International Nuclear Information System (INIS)

Moreno-Merino, Luis; Jiménez-Hernández, Maria Emilia; Losa, Almudena de la; Huerta-Muñoz, Virginia

2015-01-01

Many household batteries worldwide still end up in landfills or are incinerated due to inefficient collection and recycling schemes. Toxic heavy metals from improperly discarded button cells pose a serious risk to human health and the environment, as they can pollute air, soil and water. This paper analyses a series of button cells selected from batteries available on the retail market, and compares their polluting potential. A total of 64 batteries were subjected to chemical analyses of 19 elements — including metals and metalloids — , and energy density measurements. The samples were from four different brands of each of the four most common button cell technologies (alkaline, zinc-air, silver oxide and lithium). An energy-normalized index — the Weighted Potential Pollution Index (WPPI) — was proposed to compare the polluting potential of the different batteries. The higher the battery WPPI score, the greater the content in toxic elements and the lower the energy output. The results of the chemical composition and energy density varied depending on the construction technology of the button cells. However, significant differences in both variables were also found when comparing different brands within the same technology. The differences in WPPI values confirmed the existence of a significant margin to reduce the environmental impact of discarded button cells simply by avoiding the most polluting options. The choice of the battery with the most favourable WPPI produced a reduction in potential pollution of 3–53% for silver oxide batteries, 4–39% for alkaline, 20–28% for zinc-air and 12–26% for lithium. Comparative potential pollution could be assessed when selecting batteries using an energy-normalized index such as WPPI to reduce the environmental impact of improperly disposed button cells. - Highlights: • We compare the polluting potential of button cells using an energy-normalized index. • This battery index considers both chemical

Coastal recirculation potential affecting air pollutants in Portugal: The role of circulation weather types

Science.gov (United States)

Russo, Ana; Gouveia, Célia; Levy, Ilan; Dayan, Uri; Jerez, Sonia; Mendes, Manuel; Trigo, Ricardo

2016-06-01

Coastal zones are under increasing development and experience air pollution episodes regularly. These episodes are often related to peaks in local emissions from industry or transportation, but can also be associated with regional transport from neighbour urban areas influenced by land-sea breeze recirculation. This study intends to analyze the relation between circulation weather patterns, air mass recirculation and pollution levels in three coastal airsheds of Portugal (Lisbon, Porto and Sines) based on the application of an objective quantitative measure of potential recirculation. Although ventilation events have a dominant presence throughout the studied 9-yrs period on all the three airsheds, recirculation and stagnation conditions occur frequently. The association between NO2, SO2 and O3 levels and recirculation potential is evident during summer months. Under high average recirculation potential and high variability, NO2 and SO2 levels are higher for the three airsheds, whilst for O3 each airshed responds differently. This indicates a high heterogeneity among the three airsheds in (1) the type of emission - traffic or industry - prevailing for each contaminant, and (2) the response to the various circulation weather patterns and recirculation situations. Irrespectively of that, the proposed methodology, based on iterative K-means clustering, allows to identify which prevailing patterns are associated with high recirculation potential, having the advantage of being applicable to any geographical location.

Comparative toxicity and endocrine disruption potential of urban and rural atmospheric organic PM1 in JEG-3 human placental cells

International Nuclear Information System (INIS)

Drooge, Barend L. van; Marqueño, Anna; Grimalt, Joan O.; Fernández, Pilar; Porte, Cinta

2017-01-01

Outdoor ambient air particulate matter and air pollution are related to adverse effects on human health. The present study assesses the cytotoxicity and ability to disrupt aromatase activity of organic PM 1 extracts from rural and urban areas at equivalent air volumes from 2 to 30 m 3 , in human placental JEG-3 cells. Samples were chemically analyzed for particle bounded organic compounds with endocrine disrupting potential, i.e. PAH, O-PAH, phthalate esters, but also for organic molecular tracer compounds for the emission source identification. Rural samples collected in winter were cytotoxic at the highest concentration tested and strongly inhibited aromatase activity in JEG-3 cells. No cytotoxicity was detected in summer samples from the rural site and the urban samples, while aromatase activity was moderately inhibited in these samples. In the urban area, the street site samples, collected close to intensive traffic, showed stronger inhibition of aromatase activity than the samples simultaneously collected at a roof site, 50 m above ground level. The cytotoxicity and endocrine disruption potential of the samples were linked to combustion products, i.e. PAH and O-PAH, especially from biomass burning in the rural site in winter. - Highlights: • Organic extracts of outdoor ambient air PM1 showed aromatase activity inhibition in exposed human placental JEG-3 cells. • Cytotoxicity and strongest endocrine disruption was observed in rural winter samples, while lowest inhibition was observed in urban background site 50 m above a busy street. • Cytotoxicity and aromatase activity inhibition in the samples were linked to combustion products, i.e. PAH and O-PAH, especially from biomass burning. - Organic extracts from ambient air PM 1 related to biomass burning are more cytotoxic and have stronger endocrine disruption potential than urban PM 1 .

Toxicological Considerations, Toxicity Assessment, and Risk Management of Inhaled Nanoparticles.

Science.gov (United States)

Bakand, Shahnaz; Hayes, Amanda

2016-06-14

Novel engineered nanoparticles (NPs), nanomaterial (NM) products and composites, are continually emerging worldwide. Many potential benefits are expected from their commercial applications; however, these benefits should always be balanced against risks. Potential toxic effects of NM exposure have been highlighted, but, as there is a lack of understanding about potential interactions of nanomaterials (NMs) with biological systems, these side effects are often ignored. NPs are able to translocate to the bloodstream, cross body membrane barriers effectively, and affect organs and tissues at cellular and molecular levels. NPs may pass the blood-brain barrier (BBB) and gain access to the brain. The interactions of NPs with biological milieu and resulted toxic effects are significantly associated with their small size distribution, large surface area to mass ratio (SA/MR), and surface characteristics. NMs are able to cross tissue and cell membranes, enter into cellular compartments, and cause cellular injury as well as toxicity. The extremely large SA/MR of NPs is also available to undergo reactions. An increased surface area of the identical chemical will increase surface reactivity, adsorption properties, and potential toxicity. This review explores biological pathways of NPs, their toxic potential, and underlying mechanisms responsible for such toxic effects. The necessity of toxicological risk assessment to human health should be emphasised as an integral part of NM design and manufacture.

Toxicological Considerations, Toxicity Assessment, and Risk Management of Inhaled Nanoparticles

Directory of Open Access Journals (Sweden)

Shahnaz Bakand

2016-06-01

Full Text Available Novel engineered nanoparticles (NPs, nanomaterial (NM products and composites, are continually emerging worldwide. Many potential benefits are expected from their commercial applications; however, these benefits should always be balanced against risks. Potential toxic effects of NM exposure have been highlighted, but, as there is a lack of understanding about potential interactions of nanomaterials (NMs with biological systems, these side effects are often ignored. NPs are able to translocate to the bloodstream, cross body membrane barriers effectively, and affect organs and tissues at cellular and molecular levels. NPs may pass the blood–brain barrier (BBB and gain access to the brain. The interactions of NPs with biological milieu and resulted toxic effects are significantly associated with their small size distribution, large surface area to mass ratio (SA/MR, and surface characteristics. NMs are able to cross tissue and cell membranes, enter into cellular compartments, and cause cellular injury as well as toxicity. The extremely large SA/MR of NPs is also available to undergo reactions. An increased surface area of the identical chemical will increase surface reactivity, adsorption properties, and potential toxicity. This review explores biological pathways of NPs, their toxic potential, and underlying mechanisms responsible for such toxic effects. The necessity of toxicological risk assessment to human health should be emphasised as an integral part of NM design and manufacture.

Ultra High Efficiency ESP for Fine Particulate and Air Toxics Control

International Nuclear Information System (INIS)

Srinivasachar, Srivats; Pease, Benjamin R.; Porle, Kjell; Mauritzson, Christer; Haythornthwaite, Sheila

1997-01-01

Nearly ninety percent of U.S. coal-fired utility boilers are equipped with electrostatic precipitators (ESP). Cost effective retrofittable ESP technologies are the only means to accomplish Department of Energy's (DOE) goal of a major reduction in fine particulate and air toxic emissions from coal-fired power plants. Particles in the size range of 0.1 to 5 (micro)m typically escape ESPs. Metals, such as arsenic, cadmium, lead, molybdenum and antimony, concentrate on these particles. This is the main driver for improved fine particulate control. Vapor phase emissions of mercury, selenium and arsenic are also of major concern. Current dry ESPs, which operate at temperatures greater than 280 F, provide little control for vapor phase toxics. The need for inherent improvement to ESPs has to be considered keeping in perspective the current trend towards the use of low sulfur coals. Switching to low sulfur coals is the dominant approach for SO 2 emission reduction in the utility industry. Low sulfur coals generate high resistivity ash, which can cause an undesirable phenomenon called ''back corona.'' Higher particulate emissions occur if there is back corona in the ESP. Results of the pilot-scale testing identified the ''low temperature ESP'' concept to have the biggest impact for the two low sulfur coals investigated. Lowering the flue gas temperature to 220 F provided the maximum impact in terms of decreased emissions. Intermediate operating temperatures (reduction from 340 to 270 F) also gave significant ESP performance improvement. A significant reduction in particulate emissions was also noted when the flue gas humidity was increased (temperature held constant) from the baseline condition for these moderately high resistivity ash coals. Independent control of flue gas humidity and temperature was an important and a notable element in this project. Mercury emissions were also measured as a function of flue gas temperature. Mercury emissions decreased as the flue gas

Car indoor air pollution - analysis of potential sources

Directory of Open Access Journals (Sweden)

Müller Daniel

2011-12-01

Full Text Available Abstract The population of industrialized countries such as the United States or of countries from the European Union spends approximately more than one hour each day in vehicles. In this respect, numerous studies have so far addressed outdoor air pollution that arises from traffic. By contrast, only little is known about indoor air quality in vehicles and influences by non-vehicle sources. Therefore the present article aims to summarize recent studies that address i.e. particulate matter exposure. It can be stated that although there is a large amount of data present for outdoor air pollution, research in the area of indoor air quality in vehicles is still limited. Especially, knowledge on non-vehicular sources is missing. In this respect, an understanding of the effects and interactions of i.e. tobacco smoke under realistic automobile conditions should be achieved in future.

Risk assessment of potentially toxic element pollution in soils and rice (Oryza sativa) in a typical area of the Yangtze River Delta

International Nuclear Information System (INIS)

Hang Xiaoshuai; Wang Huoyan; Zhou Jianmin; Ma Chengling; Du Changwen; Chen Xiaoqin

2009-01-01

Soil pollution with potentially toxic elements (PTEs) resulting from rapid industrial development has caused major concerns. Selected PTEs and their accumulation and distribution in soils and rice (Oryza sativa) collected from Changshu, east China, were analyzed to evaluate the potential health risk to the local population. The soils were primarily contaminated with Hg, followed by Cu, Cd, Pb, and Zn. The concentrations of Pb, Hg, and Cd of 46, 32, and 1 rice samples exceeded their national maximum allowable levels in foods, respectively. Spatial distributions of total Cr, Cu, Pb, Zn, and Cd in soils shared similar geographical trends. The risk assessment of PTEs through rice consumption suggests that the concentrations of Cu, Pb, and Cd in some rice samples exceed their reference oral dose for adults and children. In general, there was no target hazard quotient value of any individual element that was greater than 1, but hazard index values for adults and children were 1.726 and 1.523, respectively. - Industrial development has led to increased risk from potentially toxic elements in soils and rice.

Insecticide toxicity to Hyalella curvispina in runoff and stream water within a soybean farm (Buenos Aires, Argentina).

Science.gov (United States)

Mugni, H; Ronco, A; Bonetto, C

2011-03-01

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

HABIT, Toxic and Radioactive Release Hazards in Reactor Control Room

International Nuclear Information System (INIS)

Stage, S.A.

2005-01-01

1 - Description of program or function: HABIT is a package of computer codes designed to be used for the evaluation of control room habitability in the event of an accidental release of toxic chemicals or radioactive materials. 2 - Methods: Given information about the design of a nuclear power plant, a scenario for the release of toxic or radionuclides, and information about the air flows and protection systems of the control room, HABIT can be used to estimate the chemical exposure or radiological dose to control room personnel

Toxicity of sediments potentially contaminated by coal mining and natural gas extraction to unionid mussels and commonly tested benthic invertebrates

Science.gov (United States)

Wang, Ning; Ingersoll, Christopher G.; Kunz, James L.; Brumbaugh, William G.; Kane, Cindy M.; Evans, R. Brian; Alexander, Steven; Walker, Craig; Bakaletz, Steve

2013-01-01

Sediment toxicity tests were conducted to assess potential effects of contaminants associated with coal mining or natural gas extraction activities in the upper Tennessee River basin and eastern Cumberland River basin in the United States. Test species included two unionid mussels (rainbow mussel, Villosa iris, and wavy-rayed lampmussel, Lampsilis fasciola, 28-d exposures), and the commonly tested amphipod, Hyalella azteca (28-d exposure) and midge, Chironomus dilutus (10-d exposure). Sediments were collected from seven test sites with mussel communities classified as impacted and in proximity to coal mining or gas extraction activities, and from five reference sites with mussel communities classified as not impacted and no or limited coal mining or gas extraction activities. Additional samples were collected from six test sites potentially with high concentrations of polycyclic aromatic hydrocarbons (PAHs) and from a test site contaminated by a coal ash spill. Mean survival, length, or biomass of one or more test species was reduced in 10 of 14 test samples (71%) from impacted areas relative to the response of organisms in the five reference samples. A higher proportion of samples was classified as toxic to mussels (63% for rainbow mussels, 50% for wavy-rayed lampmussels) compared with amphipods (38%) or midge (38%). Concentrations of total recoverable metals and total PAHs in sediments did not exceed effects-based probable effect concentrations (PECs). However, the survival, length, or biomasses of the mussels were reduced significantly with increasing PEC quotients for metals and for total PAHs, or with increasing sum equilibrium-partitioning sediment benchmark toxic units for PAHs. The growth of the rainbow mussel also significantly decreased with increasing concentrations of a major anion (chloride) and major cations (calcium and magnesium) in sediment pore water. Results of the present study indicated that (1) the findings from laboratory tests were generally

Organochlorine pesticides in soils of Mexico and the potential for soil-air exchange.

Science.gov (United States)

Wong, Fiona; Alegria, Henry A; Bidleman, Terry F

2010-03-01

The spatial distribution of organochlorine pesticides (OCs) in soils and their potential for soil-air exchange was examined. The most prominent OCs were the DDTs (Geometric Mean, GM=1.6 ng g(-1)), endosulfans (0.16 ng g(-1)), and toxaphenes (0.64 ng g(-1)). DDTs in soils of southern Mexico showed fresher signatures with higher FDDTe=p,p'-DDT/(p,p'-DDT+p,p'-DDE) and more racemic o,p'-DDT, while the signatures in the central and northern part of Mexico were more indicative of aged residues. Soil-air fugacity fractions showed that some soils are net recipients of DDTs from the atmosphere, while other soils are net sources. Toxaphene profiles in soils and air showed depletion of Parlar 39 and 42 which suggests that soil is the source to the atmosphere. Endosulfan was undergoing net deposition at most sites as it is a currently used pesticide. Other OCs showed wide variability in fugacity, suggesting a mix of net deposition and volatilization. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Potential impact of a US climate policy and air quality regulations on future air quality and climate change

Directory of Open Access Journals (Sweden)

Y. Lee

2016-04-01

Full Text Available We have investigated how future air quality and climate change are influenced by the US air quality regulations that existed or were proposed in 2013 and a hypothetical climate mitigation policy that aims to reduce 2050 CO2 emissions to be 50 % below 2005 emissions. Using the NASA GISS ModelE2 general circulation model, we look at the impacts for year 2030 and 2055. The US energy-sector emissions are from the GLIMPSE project (GEOS-Chem LIDORT Integrated with MARKAL (MARKet ALlocation for the Purpose of Scenario Exploration, and other US emissions data sets and the rest of the world emissions data sets are based on the RCP4.5 scenario. The US air quality regulations are projected to have a strong beneficial impact on US air quality and public health in year 2030 and 2055 but result in positive radiative forcing. Under this scenario, no more emission constraints are added after 2020, and the impacts on air quality and climate change are similar between year 2030 and 2055. Surface particulate matter with a diameter smaller than 2.5 µm (PM2.5 is reduced by ∼ 2 µg m−3 on average over the USA, and surface ozone by ∼ 8 ppbv. The improved air quality prevents about 91 400 premature deaths in the USA, mainly due to the PM2.5 reduction (∼ 74 200 lives saved. The air quality regulations reduce the light-reflecting aerosols (i.e., sulfate and organic matter more than the light-absorbing species (i.e., black carbon and ozone, leading to a strong positive radiative forcing (RF over the USA by both aerosols' direct and indirect forcing: the total RF is  ∼ 0.04 W m−2 over the globe, and ∼ 0.8 W m−2 over the USA. Under the hypothetical climate policy, a future CO2 emissions cut is achieved in part by relying less on coal, and thus SO2 emissions are noticeably reduced. This provides air quality co-benefits, but it could lead to potential climate disbenefits over the USA. In 2055, the US mean total RF is +0.22�

New toxics, new poverty: a social understanding of the freebase cocaine/Paco in Buenos Aires, Argentina.

Science.gov (United States)

Epele, María E

2011-01-01

Included within the field of research on changes in drug use patterns and vulnerability are conditions of emergency related to economic crisis, wars, and political conflict. This study addresses the complex connections between the rapid propagation of freebase cocaine (FBC)-locally known as "pasta base" or "Paco" in Argentina and the normalization of the consequences of Argentina's 2001-2002 political-economic crisis. On the basis of the results of an ethnographic study carried out in three neighborhoods of the Greater Buenos Aires area between 2001 and 2005, this article aims to analyze how changes in the material and social living conditions are interrelated with the high toxicity of FBC/Paco and engender the emerging compulsion of its consumption and deterioration to the bodies, subjectivities, and social activities of active drug users from these shantytowns. By analyzing the changes in transactions directly or indirectly involving drugs-specifically those ranging from cocaine to FBC/Paco-we can argue how structural poverty, "new poverty," is not only associated with the expansion of FBC/Paco but is also shaped by its use, modes of consumption, associated health problems, and sufferings.

Comprehensive assessment of toxic chemical pollutants at Trombay region

International Nuclear Information System (INIS)

Sahu, S.K.; Saradhi, I.V.; Raghunath, R.; Pandit, G.G.; Puranik, V.D.

2006-04-01

Anthropogenic activities like industrial production and transportation, a wide range of chemical pollutants such as trace and toxic metals, pesticides, polycyclic aromatic hydrocarbons etc. eventually found their way into various environmental compartments. These pollutants get distributed among soil, water bodies, air and if left unattended can cause serious health risk to all exposed ecosystem components including human beings. These compounds may produce immediate toxicity to ecosystems or exhibit long term effects such as mutagenicity, carcinogenicity or biomagnify (concentrations of pollutant increase per unit body weight) in higher trophic organism of the food chain. Thus regular monitoring of these toxic chemicals in all the environmental matrices is unquestionably essential for reclaiming our natural resources. This report describes some of the activities of Environmental Assessment Division which are having direct relevance to the public health and regulatory bodies. Extensive studies were carried out in our laboratories for the Trombay site, over the years; on the organic as well as inorganic pollution in the environment to understand inter compartmental behaviour of these chemical pollutants. In this report attempt has been made to compare the data on various toxic chemical pollutants that are being monitored regularly at Trombay site and their levels are compared with existing regulations. For monitoring, methodologies have been standardized for characterization of toxic chemical pollutants using different analytical techniques. Regular sample collection from different environmental matrices has been done. Sample analysis has been carried out using different analytical instruments such as high performance liquid chromatograph, ion chromatograph, gas chromatograph, atomic absorption spectrophotometer, and differential pulse anodic stripping voltammetry. Major portion of the study covers Air quality monitoring of toxic chemical pollutants, as the other

Potential of roof-integrated solar collectors for preheating air at drying facilities in Northern Thailand

Energy Technology Data Exchange (ETDEWEB)

Roman, Franz; Nagle, Marcus; Leis, Hermann; Mueller, Joachim [Institute of Agricultural Engineering 440e, University of Hohenheim, Garbenstrasse 9, 70599 Stuttgart (Germany); Janjai, Serm [Department of Physics, Silpakorn University, Nakhon Pathom (Thailand); Mahayothee, Busarakorn [Department of Food Technology, Silpakorn University, Nakhon Pathom (Thailand); Haewsungcharoen, Methinee [Department of Food Engineering, Chiang Mai University, Chiang Mai (Thailand)

2009-07-15

Longan is one of the most widely cropped fruits in Northern Thailand, where a significant amount of the annual harvest is commercially dried and exported as a commodity. Liquefied petroleum gas is generally used as the energy source for heating the drying air, but concern is growing as fuel prices are expected to increase for the foreseeable future. Meanwhile, with the ample solar radiation in Thailand, the roofs of drying facilities could be adapted to serve as solar collectors to preheat the drying air, thus reducing the energy requirement from fossil fuels. In this study, a simulation program for a flat-plate solar air heater was used to estimate the potential to preheat drying air given the conditions of several longan drying facilities. Results showed that solar collectors can replace up to 19.6% of the thermal energy demand during the drying season. Bigger collectors and smaller air channels result in more useful heat, but attention has to be paid to costs and pressure drop, respectively. Annual monetary savings can reach up to THB 56,000 ({approx}US$ 1800 at US$ 1 THB 31). (author)