© 1992 Oxford University Press
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A Method for Quantitative Assessment of Reproductive Risks to the Human Male
Department of Experimental Radiotherapy, Box 66, University of Texas M. D. Anderson Cancer Center 1515 Holcombe Boulevard, Houston, Texas 77030
Received June 24, 1991; accepted January 2, 1992
There is a need for quantitative assessment of reproductive risks following human exposure to toxic agents. Current methods only estimate exposure levels that are unlikely to produce ap preciable risk; they do not address the magnitude of risk. The quantitative reproductive risk estimation (QRRE) approach presented here enables calculation of the increased incidence of infertility in a human population resulting from exposure of males to a toxic agent. The four steps involve (A) obtaining a dose-response curve in experimental animals for the effect of a toxicant on a measure of reproductive function; (B) applying an interspecies extrapolation factor (IEF) derived for a similar toxicant to relate doses in animals and humans that produce equivalent reproductive toxicity; (C) using human exposure and uptake levels, along with the IEF and the dose-response curve, to calculate impairment of the measure in humans; and (D) computing the increase in human infertility caused by that impairment. The QRRE method is used to compute reproductive risks from dibromochloropropane exposure.