- Email: [email protected]
Susceptibility and risk: an overview
Environmental Toxicology and Pharmacology 4 (1997) 187 – 188
Susceptibility and risk: an overview Harold Zenick a,*, Daniel L. Costa b b
a National Health and En6ironmental Effects Research Laboratory, Research Triangle Park, NC 27711, USA Pulmonary Toxicology Branch, Experimental Toxicology Di6ision, National Health and En6ironmental Effects Research Laboratory, Research Triangle Park, NC 27711, USA
Abstract This symposium on susceptibility and risk was the third in a series designed to bring together experts from diverse disciplines to discuss contemporary issues in risk assessment. The topic in 1996 was especially challenging since susceptibility is influenced by a myriad of factors including environmental, genetic, social and political elements. The delineation of the relative contribution of various ‘susceptibility’ factors has major implications for risk management options that may be applied in a regulatory context (risk prevention and risk reduction) or by the individual (risk avoidance). Current approaches to account for susceptibility in risk assessments (e.g. application of an uncertainty factor) have frequently been challenged as to their scientific basis and thus need periodic re-examination or update to maintain a credible foundation for the assessment process. The goal of this symposium was to gain a better understanding of the dimensions of the problem and to explore the directions that the risk assessment process might follow to better quantify the contribution of susceptibility in risk calculations. © 1997 Elsevier Science B.V. Keywords: Susceptibility; Risk assessment; Sensitive populations
Since our initial planning, the significance of this issue to the EPA has increased significantly. In 1995, the EPA announced an agency-wide policy to ensure that environmental risks to infants and children were explicitly and consistently evaluated in risk assessments, risk characterizations and environmental public health standards. Prior to that directive, the 1992 Clean Air Act Amendment contained both explicit and implicit language requiring standards to protect ‘sensitive’ groups (Table 1). In 1996, Congress passed two acts, namely the Food Quality Protection Act and the Safe Drinking Water Act, that require explicit consideration of susceptible populations in regulatory decision-making (Tables 2 and 3, respectively). The Agency is also expected to conduct research on this topic. Administrator Browner recently released an initiative to protect childrens’ health from environmental threats which is serving to focus and energize national attention on unusual risks of susceptible populations (Table 4). The Office of Research and Development (ORD) has * Corresponding author. 1382-6689/97/$17.00 © 1997 Elsevier Science B.V. All rights reserved. PII S 1 3 8 2 - 6 6 8 9 ( 9 7 ) 1 0 0 1 0 - 2
long-standing research programs to address the issue of identifying populations at unusually high risk and delineating the factors that contribute to that risk. Following the release of the 1993 NAS report, National Research Council, 1993 Pesticides in the Diets of Infants and Children, health effects and exposure research have intensified to improve understanding of risks for that population. It is anticipated that these programs will continue to be a prominent component of ORD’s research agenda. The sessions in the symposium, Susceptibility and Risk, were designed to capture a wide range of perspectives with the speakers helping to define the issues and current thinking on susceptibility and its incorporation into the risk assessment process. The reviewed contributions in this issue of the Journal reflect a frank, critical review of the current process and novel approaches, including their strengths and the inherent weaknesses. These are accompanied by more specific perspectives, reviews, and scientific reports which illustrate the complexity of the task and the advances being made to establish a credible scientific foundation for decision
188
H. Zenick, D.L. Costa / En6ironmental Toxicology and Pharmacology 4 (1997) 187–188
Table 1 Clean Air Act: language relevant to susceptible populations Section 108 directs the EPA to identify pollutants which ‘may reasonably be anticipated to endanger public health and welfare’ Section 109 requires the EPA to establish NAAQS for criteria air pollutants ‘allowing an adequate margin of safety… to protect the public health’ The legislative history of section 109 indicates that a primary standard is to be set at ‘the maximum permissible ambient air level… which will protect the health of any [sensitive] group of the population’ and specifically identifies bronchial asthmatics as a sensitive group to be protected.
Table 2 Food Quality Protection Act of 1996: pertaining to risk to infants and children (C) Exposure of infants and children—In establishing, modifying, leaving in effect, or revoking a tolerance or exemption for a pesticide chemical residue, the Administrator— (i) shall assess the risk of the pesticide chemical residue based on— (I) available information about consumption patterns among infants and children that are likely to result in disproportionately high consumption of foods containing or bearing such residue among infants and children in comparison to the general population; (II) available information concerning the special susceptibility of infants and children to the pesticide chemical residues, including neurological differences between infants and children and adults, and effects of in utero exposure to pesticide chemicals; and (III) available information concerning the cumulative effects on infants and children of such residues and other substances that have a common mechanism of toxicity; and (ii) shall — (I) ensure that there is a reasonable certainty that no harm will result to infants and children from aggregate exposure to the pesticide chemical residue; and (II) publish a specific determination regarding the safety of the pesticide chemical residue for infants and children.
Table 3 Safe Drinking Water Act 1996: relevant language pertaining to susceptible populations Section 103 (c) (I) Maximum contaminant levels — when proposing any national primary drinking water regulation, that includes a maximum contaminant level, the Administrator shall… publish, seek public comment on, and use… an analysis of… (V) The effects of the contaminant on the general population and on groups within the general population such as infants, children, pregnant women, the elderly, individuals with a history of serious illness, or other subpopulations that are identified as likely to be at greater risk of adverse health effects due to exposure to contaminants in drinking water than the general population.
Table 4 Administrator’s initiative to protect children’s health from environmental threats Selected actions The EPA will set public health and environmental standards to ensure that they protect children, under a new national policy, and review the most significant current standards to ensure that they protect children To ensure that the EPA applies the best science to its efforts to protect children, the Agency will identify and expand research on their unique susceptibility and exposure to environmental pollutants To ensure that children’s health is approached comprehensively, the EPA will address children’s total exposure to toxic chemicals
making. We hope that this collection will stimulate new thinking and innovative research on this increasingly important issue within the risk assessment paradigm.
References National Research Council, 1993. Pesticides in the Diets of Infants and Children. National Academy Press, Washington, DC.
Susceptibility and risk: an overview Harold Zenick a,*, Daniel L. Costa b b
a National Health and En6ironmental Effects Research Laboratory, Research Triangle Park, NC 27711, USA Pulmonary Toxicology Branch, Experimental Toxicology Di6ision, National Health and En6ironmental Effects Research Laboratory, Research Triangle Park, NC 27711, USA
Abstract This symposium on susceptibility and risk was the third in a series designed to bring together experts from diverse disciplines to discuss contemporary issues in risk assessment. The topic in 1996 was especially challenging since susceptibility is influenced by a myriad of factors including environmental, genetic, social and political elements. The delineation of the relative contribution of various ‘susceptibility’ factors has major implications for risk management options that may be applied in a regulatory context (risk prevention and risk reduction) or by the individual (risk avoidance). Current approaches to account for susceptibility in risk assessments (e.g. application of an uncertainty factor) have frequently been challenged as to their scientific basis and thus need periodic re-examination or update to maintain a credible foundation for the assessment process. The goal of this symposium was to gain a better understanding of the dimensions of the problem and to explore the directions that the risk assessment process might follow to better quantify the contribution of susceptibility in risk calculations. © 1997 Elsevier Science B.V. Keywords: Susceptibility; Risk assessment; Sensitive populations
Since our initial planning, the significance of this issue to the EPA has increased significantly. In 1995, the EPA announced an agency-wide policy to ensure that environmental risks to infants and children were explicitly and consistently evaluated in risk assessments, risk characterizations and environmental public health standards. Prior to that directive, the 1992 Clean Air Act Amendment contained both explicit and implicit language requiring standards to protect ‘sensitive’ groups (Table 1). In 1996, Congress passed two acts, namely the Food Quality Protection Act and the Safe Drinking Water Act, that require explicit consideration of susceptible populations in regulatory decision-making (Tables 2 and 3, respectively). The Agency is also expected to conduct research on this topic. Administrator Browner recently released an initiative to protect childrens’ health from environmental threats which is serving to focus and energize national attention on unusual risks of susceptible populations (Table 4). The Office of Research and Development (ORD) has * Corresponding author. 1382-6689/97/$17.00 © 1997 Elsevier Science B.V. All rights reserved. PII S 1 3 8 2 - 6 6 8 9 ( 9 7 ) 1 0 0 1 0 - 2
long-standing research programs to address the issue of identifying populations at unusually high risk and delineating the factors that contribute to that risk. Following the release of the 1993 NAS report, National Research Council, 1993 Pesticides in the Diets of Infants and Children, health effects and exposure research have intensified to improve understanding of risks for that population. It is anticipated that these programs will continue to be a prominent component of ORD’s research agenda. The sessions in the symposium, Susceptibility and Risk, were designed to capture a wide range of perspectives with the speakers helping to define the issues and current thinking on susceptibility and its incorporation into the risk assessment process. The reviewed contributions in this issue of the Journal reflect a frank, critical review of the current process and novel approaches, including their strengths and the inherent weaknesses. These are accompanied by more specific perspectives, reviews, and scientific reports which illustrate the complexity of the task and the advances being made to establish a credible scientific foundation for decision
188
H. Zenick, D.L. Costa / En6ironmental Toxicology and Pharmacology 4 (1997) 187–188
Table 1 Clean Air Act: language relevant to susceptible populations Section 108 directs the EPA to identify pollutants which ‘may reasonably be anticipated to endanger public health and welfare’ Section 109 requires the EPA to establish NAAQS for criteria air pollutants ‘allowing an adequate margin of safety… to protect the public health’ The legislative history of section 109 indicates that a primary standard is to be set at ‘the maximum permissible ambient air level… which will protect the health of any [sensitive] group of the population’ and specifically identifies bronchial asthmatics as a sensitive group to be protected.
Table 2 Food Quality Protection Act of 1996: pertaining to risk to infants and children (C) Exposure of infants and children—In establishing, modifying, leaving in effect, or revoking a tolerance or exemption for a pesticide chemical residue, the Administrator— (i) shall assess the risk of the pesticide chemical residue based on— (I) available information about consumption patterns among infants and children that are likely to result in disproportionately high consumption of foods containing or bearing such residue among infants and children in comparison to the general population; (II) available information concerning the special susceptibility of infants and children to the pesticide chemical residues, including neurological differences between infants and children and adults, and effects of in utero exposure to pesticide chemicals; and (III) available information concerning the cumulative effects on infants and children of such residues and other substances that have a common mechanism of toxicity; and (ii) shall — (I) ensure that there is a reasonable certainty that no harm will result to infants and children from aggregate exposure to the pesticide chemical residue; and (II) publish a specific determination regarding the safety of the pesticide chemical residue for infants and children.
Table 3 Safe Drinking Water Act 1996: relevant language pertaining to susceptible populations Section 103 (c) (I) Maximum contaminant levels — when proposing any national primary drinking water regulation, that includes a maximum contaminant level, the Administrator shall… publish, seek public comment on, and use… an analysis of… (V) The effects of the contaminant on the general population and on groups within the general population such as infants, children, pregnant women, the elderly, individuals with a history of serious illness, or other subpopulations that are identified as likely to be at greater risk of adverse health effects due to exposure to contaminants in drinking water than the general population.
Table 4 Administrator’s initiative to protect children’s health from environmental threats Selected actions The EPA will set public health and environmental standards to ensure that they protect children, under a new national policy, and review the most significant current standards to ensure that they protect children To ensure that the EPA applies the best science to its efforts to protect children, the Agency will identify and expand research on their unique susceptibility and exposure to environmental pollutants To ensure that children’s health is approached comprehensively, the EPA will address children’s total exposure to toxic chemicals
making. We hope that this collection will stimulate new thinking and innovative research on this increasingly important issue within the risk assessment paradigm.
References National Research Council, 1993. Pesticides in the Diets of Infants and Children. National Academy Press, Washington, DC.