The current practice of health risk assessment: Potential impact on standards for toxic air contaminants
- Division of McLaren/Hart Environmental Engineering Corp., Alameda, CA (USA)
Since the Bhopal incident, the public has placed pressure on regulatory agencies to set community exposure limits for the dozens of chemicals that may be released by manufacturing facilities. More or less objective limits can be established for the vast majority of these chemicals through the use of risk assessment. However, each step of the risk assessment process (i.e., hazard identification, dose-response assessment, exposure assessment, and risk characterization) contains a number of pitfalls that scientists need to avoid to ensure that valid limits are established. For example, in the hazard identification step there has been little discrimination among animal carcinogens with respect to mechanism of action or the epidemiology experience. In the dose-response portion, rarely is the range of plausible estimated risks presented. Physiologically based pharmacokinetic (PB-PK) models should be used to understand the difference between the tissue doses and the administered dose, as well as the difference in target tissue concentrations of the toxicant between rodents and humans. Biologically-based models like the Moolgavkar-Knudson-Venzon (MKV) should be developed and used, when appropriate. The exposure assessment step can be significantly improved by using more sensitive and specific sampling and analytical methods, more accurate exposure parameters, and computer models that can account for complex environmental factors. Whenever possible, model predictions of exposure and uptake should be validated by biological monitoring of exposed persons (urine, blood, adipose) or by field measurements of plants, soil, fish, air, or water. In each portion of an assessment, the weight of evidence approach should be used to identify the most defensible value. 129 refs.
- OSTI ID:
- 5837748
- Journal Information:
- Journal of the Air and Waste Management Association; (USA), Vol. 40:12; ISSN 1047-3289
- Country of Publication:
- United States
- Language:
- English
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AIR POLLUTION
RISK ASSESSMENT
BIOLOGICAL MODELS
COMPUTERIZED SIMULATION
DOSE-RESPONSE RELATIONSHIPS
MAN
MAXIMUM PERMISSIBLE EXPOSURE
METABOLISM
ANIMALS
MAMMALS
POLLUTION
PRIMATES
SAFETY STANDARDS
SIMULATION
STANDARDS
VERTEBRATES
560300* - Chemicals Metabolism & Toxicology