Risk analysis: Fundamental concepts, regulatory toxicology, and relative comparisons from radiation biology.

摘要

This talk uses fundamental concepts, and through usage reviews some definitions (which are underlined in the text) in the area of generalized risk analysis, methods currently used in regulatory toxicology to evaluate risk or hazard from carcinogenic and noncarcinogenic chemicals, and basic radiation physics and radiobiology as related to x and gamma photons. After a review of fundamentals, a suggested modification is made to use concepts which have been applied for decades in radiation protection as a template to reduce inaccuracies and uncertainties in hazard evaluations for nonradiological pollutants. A two-step process is proposed: first the relative potency of agent A with respect to the reference agent, B, is defined in terms of the treatments, T(sub A), and, T(sub B), which produce equal biological effect. Relative potency is then T(sub B)/T(sub A). This exercise yields a unitless hazard ranking. The second step is to couple the unitless hazard ranking to reference exposures which have been ''generally regarded as safe.'' Those reference exposures could be taken as the natural terrestrial radiation background, the toxicological equivalent of a reference meal comprised of common foodstuffs, or the toxicological equivalent of utility processes but otherwise pure drinking water. 37 refs., 6 figs., 4 tabs.