The U.S. Environmental Protection Agency's (EPA) Integrated Risk Information System (IRIS) da... more The U.S. Environmental Protection Agency's (EPA) Integrated Risk Information System (IRIS) database, the authoritative source of U.S. risk assessment toxicity factors, currently lacks an oral reference dose (RfD) for copper. In the absence of such a value, various health‐based reference values for copper are available for use in risk assessment. We summarize the scientific bases and differences in assumptions among key reference values for ingested copper to guide selection of appropriate values for risk assessment. A comprehensive review of the scientific literature best supports the oral RfD of 0.04 mg/kg body weight/day derived by EPA from their Drinking Water Action Level. This value is based on acute gastrointestinal effects but is further supported by broader analysis of copper deficiency and toxicity.
The American Cleaning Institute® (ACI) is the industry trade association that represents the form... more The American Cleaning Institute® (ACI) is the industry trade association that represents the formulators of more than 90% of the consumer cleaning products in the United States. Recently, ACI set out to define and publish the ingredients used in its members’ products with the goal of identifying the publicly available hazard data for every ingredient and developing an associated exposure assessment and screening-level risk assessment. This presentation reviews the methodology used to develop the Ingredient Inventory for cleaning products, which was completed and published on ACI’s website in August 2012 (as the first stage in this multi-part study ). Over 900 products in the categories of laundry care, dish care, and hard surface cleaners were surveyed and all listed ingredients recorded. Data were captured using a rigorous set of quality assurance criteria, and naming was consolidated to eliminate redundancy and facilitate the search for hazard data. Over 800 unique ingredients were identified. Key tasks included consolidation of the ingredient list, resolving differences in ingredient naming, and developing a strategy for initial grouping into chemical classes. The presentation will include demonstration of the end product for the first phase of the effort, which is a web-based database that allows access to ingredient listings and basic identification information. This will form the basis for expansion to include hazard, fate and effects data for the nearly one thousand chemicals represented.
The American Cleaning Institute® (ACI) is the industry trade association that represents the form... more The American Cleaning Institute® (ACI) is the industry trade association that represents the formulators of more than 90% of the consumer cleaning products in the United States. Recently, ACI set out to define and publish the ingredients used in its members’ products with the goal of identifying the publicly available hazard data for every ingredient and developing an associated exposure assessment and screening-level risk assessment. This presentation reviews the methodology used to develop the Ingredient Inventory for cleaning products, which was completed and published on ACI’s website in August 2012 (as the first stage in this multi-part study ). Over 900 products in the categories of laundry care, dish care, and hard surface cleaners were surveyed and all listed ingredients recorded. Data were captured using a rigorous set of quality assurance criteria, and naming was consolidated to eliminate redundancy and facilitate the search for hazard data. Over 800 unique ingredients wer...
This document present a generalized protocol for conducting toxicity reduction evaluations (TREs)... more This document present a generalized protocol for conducting toxicity reduction evaluations (TREs) at municipal wastewater treatment plants (EETPs). This protocol is designed to provide guidance to municipalities in preparing TRE plants, evaluating the information generated during a technical basis for the selection and implementation of toxicity control methods. A TRE involves an evaluation of the municipal WWTP performance: an identification of the specific toxicants causing effluent toxicity; a review of the pretreatment and local limits programs; a characterization of the nature; variability and sources; and the evaluation, selection and implementation of the toxicity control options. Because of the broad scope of this protocol, it is to be expected that the specific considerations may to some extent warrant modifications and tailoring of the protocol approach for a given facility. The protocol has been developed based on current research and experience. TRE methods and procedure...
Tabulations of numerical concentration-based environmental benchmarks are commonly used to inform... more Tabulations of numerical concentration-based environmental benchmarks are commonly used to inform decisions on managing chemical exposures. Benchmarks are usually set at levels below which there is a low likelihood of adverse effects. Given the widespread use of tables of benchmarks, it is reasonable to expect that they are adequately reliable and fit for purpose. The degree to which a derived benchmark reflects an actual effect level or statistical randomness is critically important for the reliability of a numerical benchmark value. These expectations may not be met for commonly-used benchmarks examined in this study. Computer simulations of field sampling and toxicity testing reveal that small sample size and confounding from uncontrolled factors that affect the interpretation of toxic effects contribute to uncertainties that might go unrecognized when deriving benchmarks from data sets. The simulations of field data show that it is possible to derive a benchmark even when no toxicity is present. When toxicity is explicitly included in simulations, imposed effect threshold levels could not always be accurately determined. Simulations were also used to examine the influence of mixtures of chemicals on the determination of toxicity thresholds of chemicals within the mixtures. The simulations showed that data sets that appear large and robust can contain many smaller data sets associated with specific biota or chemicals. The sub-sets of data with small sample sizes can contribute to considerable statistical uncertainty in the determination of effects thresholds and can indicate that effects are present when they are absent. The simulations also show that less toxic chemicals may appear toxic when they are present in mixtures with more toxic chemicals. Because of confounding in the assignment of toxicity to individuals chemicals within mixtures, simulations showed that derived toxicity thresholds can be less than the actual toxicity thresholds. A set of best practices is put forward to guard against the potential problems identified by this work. These include conducting an adequate process of determining and implementing Data Quality Objectives (DQOs), evaluating implications of sample size, designing appropriate sampling and evaluation programs based on this information, using an appropriate tiered evaluation strategy that considers the uncertainties, and employing a weight of evidence approach to narrow the uncertainties to manageable and identified levels. The work underscores the importance of communicating the uncertainties associated with numerical values commonly included in tables for screening and risk assessment purposes to better inform decisions.
Decades of study indicate that copper oral exposures are typically not a human health concern. In... more Decades of study indicate that copper oral exposures are typically not a human health concern. Ingesting high levels of soluble copper salts can cause acute gastrointestinal symptoms and, in uncommon cases, liver toxicity in susceptible individuals with repeated exposure. This focused toxicological review evaluated the current literature since the last comprehensive reviews (2007–2010). Our review identified limitations in the existing United States and international guidance for determining an oral reference dose (RfD) for essential metals like copper. Instead, an alternative method using categorical regression analysis to develop an optimal dose that considers deficiency, toxicity, and integrates information from human and animal studies was reviewed for interpreting an oral RfD for copper. We also considered subchronic or chronic toxicity from genetic susceptibility to copper dysregulation leading to rare occurrences of liver and other organ toxicity with elevated copper exposure...
Abstract : The bioconcentration, elimination and metabolism of 14C-picric acid and 14C-picramic a... more Abstract : The bioconcentration, elimination and metabolism of 14C-picric acid and 14C-picramic acid were evaluated for rainbow trout (Salmo gairdneri) and American oysters (crassostrea virginica) continuously exposed to the compounds for 42 days followed by elimination for 14 days in clean waters. Acute toxicity was also determined for both compounds and species. Measurements of the uptake of both picric and picramic acid by rainbow trout showed that both compounds do not accumulate in the epaxial muscle tissues at levels above the mean exposure concentration in the water column. American oysters, however, do bioconcentrate both picric and picramic acid and/or their metabolites at significantly higher levels than exposure concentration levels. The uptake rate of both picric and picramic acid was biphasic. A well defined steady state was not reached during the 42-day exposure period for the compounds. The 42-day bioconcentration factor (BCF) for exposure to 0.45 mg/L picric acid was 65.5, while the 42-day BCF for exposure to 0.05 mg/L picric acid was 16.5. The 42-day BCFs for exposure to 0.24 and 0.02 mg/L picramic acid were 49.3 and 86.6, respectively. No statistically significant elimination of picric acid was observed for oysters during the 14-day elimination day study. Depuration of picramic acid from oysters was biphasic.
Effluents with extremely low or very high total dissolved solid concentrations require particular... more Effluents with extremely low or very high total dissolved solid concentrations require particular attention prior to performance of toxicity tests in order to ensure that possible artifacts are not evaluated as effluent toxicity. The low ionic strength of certain effluents such as cooling water condensates may not be physiologically acceptable. Resulting effects on aquatic test organisms may be due to the absence of necessary constituents rather than to the presence of deleterious compounds. Augmenting the sample prior to testing in order to increase the ionic strength of the effluent may be an acceptable alternative based on the discharge situation. Toxic effluents that contain high concentrations of total dissolved solids that are evaluated using marine or estuarine organisms also need to be closely examined to determine if the observed toxicity is a result of ionic imbalance. For example, an effluent that has an acceptable testing salinity but that is dominated by a single compound resulting in a significant deficiency of the remaining major ions and major trace ions may be toxic due only to this ionic imbalance. This paper will present, through the use of case studies, various techniques and procedures that have been used in the evaluation of low ionicmore » strength effluents in freshwater discharge situations and of high ionic strength effluents in estuarine or marine discharges.« less
The NPDES permitting process has been managed using a Water Quality Based Permitting Approach sin... more The NPDES permitting process has been managed using a Water Quality Based Permitting Approach since the US EPA`s 9 March 1984 National Policy Statement. Since that time, the regulating community has taken a phased approach to address environmental situations based on acute toxicity concerns followed more recently by chronic toxicity issues. The NPDES permit for individual discharges often combines the use of chemical specific limits and whole effluent toxicity either for monitoring or permit limits as a means to manage effluents. One of the major tools available to permittees is a Toxicity Reduction Evaluation (TRE), which is a strategy to characterize, identify, and control effluents that have the reasonable potential to exceed either chemical specific limits and/or are toxic to aquatic organisms. As the maturation of the program develops, more and more of the persistent acute toxicity problems identified during the NPDES permit process are being addressed successfully. However, the remaining NPDES permit issues often concern chronically toxic effluents or infrequently toxic effluents. Through the use of case studies, this paper presents modified strategies for addressing effluents that produce minimally chronic toxicity, that are infrequently toxic, or that have ephemeral toxicity. In these situations, toxicity often cannot be observed longmore » enough to confidently identify the toxicant or properly develop control strategies. This paper will also describe TREs in which the source of toxicity and/or the toxicant have changed during the course of the evaluation. This often is a result of the facility`s modifying its operational activities to address the original permit exceedance.« less
The U.S. Environmental Protection Agency's (EPA) Integrated Risk Information System (IRIS) da... more The U.S. Environmental Protection Agency's (EPA) Integrated Risk Information System (IRIS) database, the authoritative source of U.S. risk assessment toxicity factors, currently lacks an oral reference dose (RfD) for copper. In the absence of such a value, various health‐based reference values for copper are available for use in risk assessment. We summarize the scientific bases and differences in assumptions among key reference values for ingested copper to guide selection of appropriate values for risk assessment. A comprehensive review of the scientific literature best supports the oral RfD of 0.04 mg/kg body weight/day derived by EPA from their Drinking Water Action Level. This value is based on acute gastrointestinal effects but is further supported by broader analysis of copper deficiency and toxicity.
The American Cleaning Institute® (ACI) is the industry trade association that represents the form... more The American Cleaning Institute® (ACI) is the industry trade association that represents the formulators of more than 90% of the consumer cleaning products in the United States. Recently, ACI set out to define and publish the ingredients used in its members’ products with the goal of identifying the publicly available hazard data for every ingredient and developing an associated exposure assessment and screening-level risk assessment. This presentation reviews the methodology used to develop the Ingredient Inventory for cleaning products, which was completed and published on ACI’s website in August 2012 (as the first stage in this multi-part study ). Over 900 products in the categories of laundry care, dish care, and hard surface cleaners were surveyed and all listed ingredients recorded. Data were captured using a rigorous set of quality assurance criteria, and naming was consolidated to eliminate redundancy and facilitate the search for hazard data. Over 800 unique ingredients were identified. Key tasks included consolidation of the ingredient list, resolving differences in ingredient naming, and developing a strategy for initial grouping into chemical classes. The presentation will include demonstration of the end product for the first phase of the effort, which is a web-based database that allows access to ingredient listings and basic identification information. This will form the basis for expansion to include hazard, fate and effects data for the nearly one thousand chemicals represented.
The American Cleaning Institute® (ACI) is the industry trade association that represents the form... more The American Cleaning Institute® (ACI) is the industry trade association that represents the formulators of more than 90% of the consumer cleaning products in the United States. Recently, ACI set out to define and publish the ingredients used in its members’ products with the goal of identifying the publicly available hazard data for every ingredient and developing an associated exposure assessment and screening-level risk assessment. This presentation reviews the methodology used to develop the Ingredient Inventory for cleaning products, which was completed and published on ACI’s website in August 2012 (as the first stage in this multi-part study ). Over 900 products in the categories of laundry care, dish care, and hard surface cleaners were surveyed and all listed ingredients recorded. Data were captured using a rigorous set of quality assurance criteria, and naming was consolidated to eliminate redundancy and facilitate the search for hazard data. Over 800 unique ingredients wer...
This document present a generalized protocol for conducting toxicity reduction evaluations (TREs)... more This document present a generalized protocol for conducting toxicity reduction evaluations (TREs) at municipal wastewater treatment plants (EETPs). This protocol is designed to provide guidance to municipalities in preparing TRE plants, evaluating the information generated during a technical basis for the selection and implementation of toxicity control methods. A TRE involves an evaluation of the municipal WWTP performance: an identification of the specific toxicants causing effluent toxicity; a review of the pretreatment and local limits programs; a characterization of the nature; variability and sources; and the evaluation, selection and implementation of the toxicity control options. Because of the broad scope of this protocol, it is to be expected that the specific considerations may to some extent warrant modifications and tailoring of the protocol approach for a given facility. The protocol has been developed based on current research and experience. TRE methods and procedure...
Tabulations of numerical concentration-based environmental benchmarks are commonly used to inform... more Tabulations of numerical concentration-based environmental benchmarks are commonly used to inform decisions on managing chemical exposures. Benchmarks are usually set at levels below which there is a low likelihood of adverse effects. Given the widespread use of tables of benchmarks, it is reasonable to expect that they are adequately reliable and fit for purpose. The degree to which a derived benchmark reflects an actual effect level or statistical randomness is critically important for the reliability of a numerical benchmark value. These expectations may not be met for commonly-used benchmarks examined in this study. Computer simulations of field sampling and toxicity testing reveal that small sample size and confounding from uncontrolled factors that affect the interpretation of toxic effects contribute to uncertainties that might go unrecognized when deriving benchmarks from data sets. The simulations of field data show that it is possible to derive a benchmark even when no toxicity is present. When toxicity is explicitly included in simulations, imposed effect threshold levels could not always be accurately determined. Simulations were also used to examine the influence of mixtures of chemicals on the determination of toxicity thresholds of chemicals within the mixtures. The simulations showed that data sets that appear large and robust can contain many smaller data sets associated with specific biota or chemicals. The sub-sets of data with small sample sizes can contribute to considerable statistical uncertainty in the determination of effects thresholds and can indicate that effects are present when they are absent. The simulations also show that less toxic chemicals may appear toxic when they are present in mixtures with more toxic chemicals. Because of confounding in the assignment of toxicity to individuals chemicals within mixtures, simulations showed that derived toxicity thresholds can be less than the actual toxicity thresholds. A set of best practices is put forward to guard against the potential problems identified by this work. These include conducting an adequate process of determining and implementing Data Quality Objectives (DQOs), evaluating implications of sample size, designing appropriate sampling and evaluation programs based on this information, using an appropriate tiered evaluation strategy that considers the uncertainties, and employing a weight of evidence approach to narrow the uncertainties to manageable and identified levels. The work underscores the importance of communicating the uncertainties associated with numerical values commonly included in tables for screening and risk assessment purposes to better inform decisions.
Decades of study indicate that copper oral exposures are typically not a human health concern. In... more Decades of study indicate that copper oral exposures are typically not a human health concern. Ingesting high levels of soluble copper salts can cause acute gastrointestinal symptoms and, in uncommon cases, liver toxicity in susceptible individuals with repeated exposure. This focused toxicological review evaluated the current literature since the last comprehensive reviews (2007–2010). Our review identified limitations in the existing United States and international guidance for determining an oral reference dose (RfD) for essential metals like copper. Instead, an alternative method using categorical regression analysis to develop an optimal dose that considers deficiency, toxicity, and integrates information from human and animal studies was reviewed for interpreting an oral RfD for copper. We also considered subchronic or chronic toxicity from genetic susceptibility to copper dysregulation leading to rare occurrences of liver and other organ toxicity with elevated copper exposure...
Abstract : The bioconcentration, elimination and metabolism of 14C-picric acid and 14C-picramic a... more Abstract : The bioconcentration, elimination and metabolism of 14C-picric acid and 14C-picramic acid were evaluated for rainbow trout (Salmo gairdneri) and American oysters (crassostrea virginica) continuously exposed to the compounds for 42 days followed by elimination for 14 days in clean waters. Acute toxicity was also determined for both compounds and species. Measurements of the uptake of both picric and picramic acid by rainbow trout showed that both compounds do not accumulate in the epaxial muscle tissues at levels above the mean exposure concentration in the water column. American oysters, however, do bioconcentrate both picric and picramic acid and/or their metabolites at significantly higher levels than exposure concentration levels. The uptake rate of both picric and picramic acid was biphasic. A well defined steady state was not reached during the 42-day exposure period for the compounds. The 42-day bioconcentration factor (BCF) for exposure to 0.45 mg/L picric acid was 65.5, while the 42-day BCF for exposure to 0.05 mg/L picric acid was 16.5. The 42-day BCFs for exposure to 0.24 and 0.02 mg/L picramic acid were 49.3 and 86.6, respectively. No statistically significant elimination of picric acid was observed for oysters during the 14-day elimination day study. Depuration of picramic acid from oysters was biphasic.
Effluents with extremely low or very high total dissolved solid concentrations require particular... more Effluents with extremely low or very high total dissolved solid concentrations require particular attention prior to performance of toxicity tests in order to ensure that possible artifacts are not evaluated as effluent toxicity. The low ionic strength of certain effluents such as cooling water condensates may not be physiologically acceptable. Resulting effects on aquatic test organisms may be due to the absence of necessary constituents rather than to the presence of deleterious compounds. Augmenting the sample prior to testing in order to increase the ionic strength of the effluent may be an acceptable alternative based on the discharge situation. Toxic effluents that contain high concentrations of total dissolved solids that are evaluated using marine or estuarine organisms also need to be closely examined to determine if the observed toxicity is a result of ionic imbalance. For example, an effluent that has an acceptable testing salinity but that is dominated by a single compound resulting in a significant deficiency of the remaining major ions and major trace ions may be toxic due only to this ionic imbalance. This paper will present, through the use of case studies, various techniques and procedures that have been used in the evaluation of low ionicmore » strength effluents in freshwater discharge situations and of high ionic strength effluents in estuarine or marine discharges.« less
The NPDES permitting process has been managed using a Water Quality Based Permitting Approach sin... more The NPDES permitting process has been managed using a Water Quality Based Permitting Approach since the US EPA`s 9 March 1984 National Policy Statement. Since that time, the regulating community has taken a phased approach to address environmental situations based on acute toxicity concerns followed more recently by chronic toxicity issues. The NPDES permit for individual discharges often combines the use of chemical specific limits and whole effluent toxicity either for monitoring or permit limits as a means to manage effluents. One of the major tools available to permittees is a Toxicity Reduction Evaluation (TRE), which is a strategy to characterize, identify, and control effluents that have the reasonable potential to exceed either chemical specific limits and/or are toxic to aquatic organisms. As the maturation of the program develops, more and more of the persistent acute toxicity problems identified during the NPDES permit process are being addressed successfully. However, the remaining NPDES permit issues often concern chronically toxic effluents or infrequently toxic effluents. Through the use of case studies, this paper presents modified strategies for addressing effluents that produce minimally chronic toxicity, that are infrequently toxic, or that have ephemeral toxicity. In these situations, toxicity often cannot be observed longmore » enough to confidently identify the toxicant or properly develop control strategies. This paper will also describe TREs in which the source of toxicity and/or the toxicant have changed during the course of the evaluation. This often is a result of the facility`s modifying its operational activities to address the original permit exceedance.« less
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