Evaluating Exposures to Chemical and Non-Chemical Stressors in a Cumulative Risk Assessment

摘要

Toxicological and epidemiological studies involving chemical mixtures (e.g., multi-pollutant exposures) have been increasing. Human health assessment of chemical and nonchemical mixture risk remains rare. Recently, there has been an increased emphasis on integrating nonchemicals (e.g., noise, microorganisms, psychosocial stress) into cumulative risk assessment (CRA). Due to limited evidence regarding the toxicity of and co-exposure to multiple chemical and nonchemical stressors, integration of chemical and nonchemical stressors is difficult. Another focus of CRA is on the identification of vulnerable populations. Some examples of why populations may be vulnerable include: higher exposures to one or more chemical stressor, differential toxicity due to nonchemical stressor exposure, and differential ability to recover from chemical or nonchemical stressor exposure due to genetics, lifestyle, or pre-existing disease. This presentation will illustrate how existing data can be used to 1) evaluate co-exposures to chemical and nonchemical stressors and 2) identify potentially vulnerable populations. It will also include a discussion of the uncertainties associated with CRAs of chemical and nonchemical stressors specifically regarding those related to combining data from various sources (e.g., national and local surveys) and situations with limited data on joint toxicity and/or exposure to these mixtures. Multiple case studies involving exposures to various chemical and nonchemical stressors will be used to aid this discussion. ~* The views expressed herein are those of the authors and do not necessarily reflect of the views or policies of the U.S. EPA.