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RISK CHARACTERIZATION OF PERSISTENT NEUROTOXIC CONTAMINANTS
Citation:
BIRNBAUM, L. S. RISK CHARACTERIZATION OF PERSISTENT NEUROTOXIC CONTAMINANTS. Presented at International Conference on Food Contaminants and Neurodevelopmental Disorders, Valencia, SPAIN, December 03 - 05, 2006.
Description:
Neurotoxicity is an adverse change in structure or function of the central and/or peripheral nervous system following exposure to a chemical, physical, or biological agent. Thousands of chemicals have been estimated to have neurotoxic potential. Many persistent and bioaccumulative environmental chemicals are reported to be neurotoxic, in addition to affecting other organ systems, in wildlife, laboratory animals, and people. These include many pesticides, industrial chemicals, and metals. Behavioral and cognitive alterations have been demonstrated, as have structural and molecular changes. Developmental neurotoxicity is of special concern, reflecting both differential sensitivity and susceptibility as compared to the adult organism. Multiple modes of action reflecting alterations in differentiation, morphology, and cellular signaling as well as homeostatic controls have been suggested. Some of the key persistent compounds which have been reported to be neurotoxic include the PCBs, dioxins, brominated flame retardants, perfluorinated chemicals, and methyl mercury, among others. A special concern is the appropriate dose metric for such PBTs. Another issue is the potential for interaction due to co-exposure to compounds which may impact the same response but involve different modes or mechanisms of action. The full characterization of neurotoxic risk involves an integration of hazard identification, exposure assessment, and dose/response analysis. Key assumptions and uncertainties must be described. A complete characterization of risk underlies the scientific process of risk assessment, while economic, societal, technological, and policy considerations also play a role in risk management. (This abstract does not reflect Agency policy.)