Cancer Models for B[α]P, Benzene, Benzidine, and Chromium

Abstract

Health standards are commonly based on only one group of rodents. Additional uncertainty (deriving from animals used as a surrogate for man and low‐dose extrapolations to environmental concentrations) cause inflated margins of safety to be incorporated into health standards. This paper demonstrates how more data and models can be used to produce more realistic and less expensive health criteria. The approach is to collect all available tumor studies for chemicals of interest. Next, common units of dose and response are used to merge data from multiple experiments. Then, an array of mathematical extrapolation models is fitted to the data, and the median model value at each dose of interest is used to compare relative toxicity between different compounds of interest. Finally, the relative toxicity factors can be coupled to a bench mark of human risk so that estimates for all chemicals have relative precision. In this fashion, decisions about control technology become standardized instead of varying by several orders of magnitude. The method works like a field horsepower ranking that is finally calibrated to a standard.