Quantitative Risk Analysis for Quantal Reproductive and Developmental Effects

By Gaylor, David W.

Book Id: WPLBN0000052881
Format Type: PDF eBook:
File Size: 0.2 MB
Reproduction Date: 2005

Title:	Quantitative Risk Analysis for Quantal Reproductive and Developmental Effects
Author:	Gaylor, David W.
Volume:
Language:	English
Subject:	Government publications, United Nations., United Nations. Office for Disarmament Affairs
Collections:	Government Library Collection, Disarmament Documents
Historic Publication Date:
Publisher:	United Nations- Office for Disarmament Affairs (Unoda)


Citation APA MLA Chicago W. Gaylo, B. D. (n.d.). Quantitative Risk Analysis for Quantal Reproductive and Developmental Effects. Retrieved from http://gutenberg.us/

Description
Government Reference Publication

Excerpt
Introduction: In order to detect potential toxic effects with a limited number of animals, experimental studies typically employ doses that are higher than expected human exposure levels. Thus, high to low dose extrapolation is generally required. The following discussion of extrapolation of developmental toxicity data does not discount the possibility of a biological threshold below which no risk exists. One approach for setting acceptable levels for developmental toxicity risk has been the use of safety (uncertainty) factors. From a bioassay conducted at several dose levels (generally three or more), a supposedly safe dose for humans is determined by dividing the no-observed-effect level (NOEL) by a safety factor. Lehman and Fitzhugh suggested a safety factor of 100 (1). If the NOEL is taken to be a safe dose for the experimental animals, a safety factor of 10 is applied to allow for potentially higher sensitivities of humans compared to the experimental animals and another factor of 10 to allow for differerices in sensitivities among individuals. For irreversible effects, such as death or malformation, an additional safety factor of 10 is suggested (2). Even if a safety factor of 100 is adequate to account for interspecies and intraspecies differences in response, this does not necessarily result in a riskfree dose.