The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Peter Wilson - One of the best experts on this subject based on the ideXlab platform.
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it is time to develop ecological thresholds of toxicological concern to assist Environmental Hazard assessment
Environmental Toxicology and Chemistry, 2015Co-Authors: Scott E Belanger, Hans Sanderson, Michelle R Embry, Katie Coady, Dick Dezwart, Brianna Farr, Steve Gutsell, Marlies Halder, Robin Sternberg, Peter WilsonAbstract:The threshold of toxicological concern (TTC) concept is well established for assessing human safety of food-contact substances and has been reapplied for a variety of endpoints, including carcinogenicity, teratogenicity, and reproductive toxicity. The TTC establishes an exposure level for chemicals below which no appreciable risk to human health or the environment is expected, based on a de minimis value for toxicity identified for many chemicals. Threshold of toxicological concern approaches have benefits for screening-level risk assessments, including the potential for rapid decision-making, fully utilizing existing knowledge, reasonable conservativeness for chemicals used in lower volumes (low production volume chemicals (e.g., 1 t/yr) would in principle always require specific information because of the presumed higher exposure potential. The TTC approach has found particular favor in the assessment of chemicals used in cosmetics and personal care products, as well as other chemicals traditionally used in low volumes. Use of the TTC in Environmental safety is just beginning, and initial attempts are being published. Key questions focus on Hazard extrapolation of diverse taxa across trophic levels, importance of mode of action, and whether safe concentrations for ecosystems estimated from acute or chronic toxicity data are equally useful and in what contexts. The present study provides an overview of the theoretical basis for developing an ecological (eco)-TTC, with an initial exploration of chemical assessment and boundary conditions for use. An international collaboration under the International Life Sciences Institute Health and Environmental Sciences Institute has been established to address challenges related to developing and applying useful eco-TTC concepts. Environ Toxicol Chem 2015;9999:1–6. © 2015 SETAC
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it is time to develop ecological thresholds of toxicological concern to assist Environmental Hazard assessment
Environmental Toxicology and Chemistry, 2015Co-Authors: Scott E Belanger, Hans Sanderson, Michelle R Embry, Katie Coady, Dick Dezwart, Brianna Farr, Steve Gutsell, Marlies Halder, Robin M Sternberg, Peter WilsonAbstract:The threshold of toxicological concern (TTC) concept is well established for assessing human safety of food-contact substances and has been reapplied for a variety of endpoints, including carcinogenicity, teratogenicity, and reproductive toxicity. The TTC establishes an exposure level for chemicals below which no appreciable risk to human health or the environment is expected, based on a de minimis value for toxicity identified for many chemicals. Threshold of toxicological concern approaches have benefits for screening-level risk assessments, including the potential for rapid decision-making, fully utilizing existing knowledge, reasonable conservativeness for chemicals used in lower volumes (low production volume chemicals (e.g., 1 t/yr) would in principle always require specific information because of the presumed higher exposure potential. The TTC approach has found particular favor in the assessment of chemicals used in cosmetics and personal care products, as well as other chemicals traditionally used in low volumes. Use of the TTC in Environmental safety is just beginning, and initial attempts are being published. Key questions focus on Hazard extrapolation of diverse taxa across trophic levels, importance of mode of action, and whether safe concentrations for ecosystems estimated from acute or chronic toxicity data are equally useful and in what contexts. The present study provides an overview of the theoretical basis for developing an ecological (eco)-TTC, with an initial exploration of chemical assessment and boundary conditions for use. An international collaboration under the International Life Sciences Institute Health and Environmental Sciences Institute has been established to address challenges related to developing and applying useful eco-TTC concepts.
Constantini Samara - One of the best experts on this subject based on the ideXlab platform.
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assessment of the Environmental Hazard from municipal and industrial wastewater treatment sludge by employing chemical and biological methods
Ecotoxicology and Environmental Safety, 2005Co-Authors: I Mantis, Dimitra Voutsa, Constantini SamaraAbstract:Chemical analyses and toxicity testing were employed in conjunction to evaluate the Environmental Hazard from the wasted sludge generated during the biological treatment of urban and industrial wastewaters. Chemical analyses included determination of seven polychlorinated biphenyls (PCBs), 13 polycyclic aromatic hydrocarbons (PAHs), total organic carbon (TOC), and seven heavy metals (As, Cd, Cr, Cu, Pb, Mn, and Zn) in sludge and sludge leachates deriving from two standard leaching procedures: (a) the mild leaching test EN-12457-2 proposed by EC and (b) the relatively aggressive toxicity characteristic leaching procedure (TCLP) leaching test proposed by US EPA. Acute toxicity measurements were performed in aqueous sludge elutriates and leachates by using bioluminescence bacteria. The urban sludge was found to be more enriched with PAHs than the industrial sludge, however, at levels below the EU limits for sludge application. The total PCB content (Σ7PCBs) in both sludges, particularly in the industrial sludge, exceeded the proposed European limit for sludge use as soil amendment. With regards to their heavy metal content, both sludges met the requirements for use in agriculture. The urban sludge exhibited high ecotoxicity, while the industrial sludge with almost two times lower toxicity was classified as not toxic to slightly toxic. The EN and the TCLP leaching procedures resulted in different sludge characterizations both from chemical and from ecotoxicological points of view. The EN procedure appeared to be more sensitive to the potential Environmental risk from sludge disposal. The results of the study revealed the necessity for combining chemical with ecotoxicological criteria for integrated characterization of wasted sludge and the need for harmonization of the methods employed for waste classification.
Scott E Belanger - One of the best experts on this subject based on the ideXlab platform.
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it is time to develop ecological thresholds of toxicological concern to assist Environmental Hazard assessment
Environmental Toxicology and Chemistry, 2015Co-Authors: Scott E Belanger, Hans Sanderson, Michelle R Embry, Katie Coady, Dick Dezwart, Brianna Farr, Steve Gutsell, Marlies Halder, Robin Sternberg, Peter WilsonAbstract:The threshold of toxicological concern (TTC) concept is well established for assessing human safety of food-contact substances and has been reapplied for a variety of endpoints, including carcinogenicity, teratogenicity, and reproductive toxicity. The TTC establishes an exposure level for chemicals below which no appreciable risk to human health or the environment is expected, based on a de minimis value for toxicity identified for many chemicals. Threshold of toxicological concern approaches have benefits for screening-level risk assessments, including the potential for rapid decision-making, fully utilizing existing knowledge, reasonable conservativeness for chemicals used in lower volumes (low production volume chemicals (e.g., 1 t/yr) would in principle always require specific information because of the presumed higher exposure potential. The TTC approach has found particular favor in the assessment of chemicals used in cosmetics and personal care products, as well as other chemicals traditionally used in low volumes. Use of the TTC in Environmental safety is just beginning, and initial attempts are being published. Key questions focus on Hazard extrapolation of diverse taxa across trophic levels, importance of mode of action, and whether safe concentrations for ecosystems estimated from acute or chronic toxicity data are equally useful and in what contexts. The present study provides an overview of the theoretical basis for developing an ecological (eco)-TTC, with an initial exploration of chemical assessment and boundary conditions for use. An international collaboration under the International Life Sciences Institute Health and Environmental Sciences Institute has been established to address challenges related to developing and applying useful eco-TTC concepts. Environ Toxicol Chem 2015;9999:1–6. © 2015 SETAC
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it is time to develop ecological thresholds of toxicological concern to assist Environmental Hazard assessment
Environmental Toxicology and Chemistry, 2015Co-Authors: Scott E Belanger, Hans Sanderson, Michelle R Embry, Katie Coady, Dick Dezwart, Brianna Farr, Steve Gutsell, Marlies Halder, Robin M Sternberg, Peter WilsonAbstract:The threshold of toxicological concern (TTC) concept is well established for assessing human safety of food-contact substances and has been reapplied for a variety of endpoints, including carcinogenicity, teratogenicity, and reproductive toxicity. The TTC establishes an exposure level for chemicals below which no appreciable risk to human health or the environment is expected, based on a de minimis value for toxicity identified for many chemicals. Threshold of toxicological concern approaches have benefits for screening-level risk assessments, including the potential for rapid decision-making, fully utilizing existing knowledge, reasonable conservativeness for chemicals used in lower volumes (low production volume chemicals (e.g., 1 t/yr) would in principle always require specific information because of the presumed higher exposure potential. The TTC approach has found particular favor in the assessment of chemicals used in cosmetics and personal care products, as well as other chemicals traditionally used in low volumes. Use of the TTC in Environmental safety is just beginning, and initial attempts are being published. Key questions focus on Hazard extrapolation of diverse taxa across trophic levels, importance of mode of action, and whether safe concentrations for ecosystems estimated from acute or chronic toxicity data are equally useful and in what contexts. The present study provides an overview of the theoretical basis for developing an ecological (eco)-TTC, with an initial exploration of chemical assessment and boundary conditions for use. An international collaboration under the International Life Sciences Institute Health and Environmental Sciences Institute has been established to address challenges related to developing and applying useful eco-TTC concepts.
Bruce D Lindsey - One of the best experts on this subject based on the ideXlab platform.
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factors affecting temporal variability of arsenic in groundwater used for drinking water supply in the united states
Science of The Total Environment, 2015Co-Authors: Joseph D Ayotte, Marcel Belaval, Scott A Olson, Karen R Burow, Sarah M Flanagan, Stephen R Hinkle, Bruce D LindseyAbstract:Abstract The occurrence of arsenic in groundwater is a recognized Environmental Hazard with worldwide importance and much effort has been focused on surveying and predicting where arsenic occurs. Temporal variability is one aspect of this Environmental Hazard that has until recently received less attention than other aspects. For this study, we analyzed 1245 wells with two samples per well. We suggest that temporal variability, often reported as affecting very few wells, is perhaps a larger issue than it appears and has been overshadowed by datasets with large numbers of non-detect data. Although there was only a slight difference in arsenic concentration variability among samples from public and private wells (p = 0.0452), the range of variability was larger for public than for private wells. Further, we relate the variability we see to geochemical factors—primarily variability in redox—but also variability in major-ion chemistry. We also show that in New England there is a weak but statistically significant indication that seasonality may have an effect on concentrations, whereby concentrations in the first two quarters of the year (January–June) are significantly lower than in the second two quarters (July–December) (p
Emily R Garman - One of the best experts on this subject based on the ideXlab platform.
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weight of evidence approach for assessing removal of metals from the water column for chronic Environmental Hazard classification
Environmental Toxicology and Chemistry, 2019Co-Authors: Allen G Burton, Michelle L Hudson, Philippa Huntsman, Richard F Carbonaro, Kevin J Rader, Hugo Waeterschoot, Stijn Baken, Emily R GarmanAbstract:The United Nations and the European Union have developed guidelines for the assessment of long-term (chronic) chemical Environmental Hazards. This approach recognizes that these Hazards are often related to spillage of chemicals into freshwater environments. The goal of the present study was to examine the concept of metal ion removal from the water column in the context of Hazard assessment and classification. We propose a weight-of-evidence approach that assesses several aspects of metals including the intrinsic properties of metals, the rate at which metals bind to particles in the water column and settle, the transformation of metals to nonavailable and nontoxic forms, and the potential for remobilization of metals from sediment. We developed a test method to quantify metal removal in aqueous systems: the extended transformation/dissolution protocol (T/DP-E). The method is based on that of the Organisation for Economic Co-operation and Development (OECD). The key element of the protocol extension is the addition of substrate particles (as found in nature), allowing the removal processes to occur. The present study focused on extending this test to support the assessment of metal removal from aqueous systems, equivalent to the concept of "degradability" for organic chemicals. Although the technical aspects of our proposed method are different from the OECD method for organics, its use for Hazard classification is equivalent. Models were developed providing mechanistic insight into processes occurring during the T/DP-E method. Some metals, such as copper, rapidly decreased (within 96 h) under the 70% threshold criterion, whereas others, such as strontium, did not. A variety of method variables were evaluated and optimized to allow for a reproducible, realistic Hazard classification method that mimics reasonable worst-case scenarios. We propose that this method be standardized for OECD Hazard classification via round robin (ring) testing to ascertain its intra- and interlaboratory variability. Environ Toxicol Chem 2019;38:1839-1849. © 2019 SETAC.