INTEGRATING TOXICOLOGY AND EPIDEMIOLOGY FOR RISK ASSESSMENT
Risk assessment (RA) is a tool of policy and regulation. Presently, RA policy is to assess individual chemicals in isolation. Use is allowed if exposures are below some estimated no effect concentration, or margin of exposure (MOE). The MOE does not usually account for measurement uncertainty and safety, or modulating factors such as: in utero and infant exposure; complex mixtures additivity and synergism; and polymorphisms. Default uncertainty factors exist, however, these are subjective, not empirical, and appear to be used arbitrarily, or only in legally enforceable Reference Dose (RfDs), or related standards, e.g., in the U.S. The MOEs are often reported as large, but the ignored uncertainty and safety factors may be even larger. Exploring this uncertainty quantitatively, by assessing potency variance within and between toxicological and epidemiological studies, found toxicologyepidemiology discordance, and in vitro – in vivo toxicology discordance. There is an apparent trend of increasing potency, with in vitro < in vivo < epidemiological. Contrasts in log units yielded one to four order of magnitude differences in means between these study types. In vitro data contrasts with epidemiology for DNT by 3 to 4 orders of magnitude and in vivo data contrasts with epidemiology for DNT by more than two orders of magnitude. The relation between log dose and study type changes with lipid weight versus wet weight basis.
Muir Tom Michalek Joel
Environment Canada – Retired. 70 Townsend Ave,Burlington,Ontario,Canada,L7T 1Y7 Department of Epidemiology and Biostatistics,University of Texas Health Science Center at San Antoni
国际会议
北京
英文
1-6
2009-08-24（万方平台首次上网日期，不代表论文的发表时间）