Review of Acute Human-Toxicity Estimates for Selected Chemical-Warfare Agents (1997)
Chapter: USE OF LOG-PROBIT ANALYSIS
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Evaluation of the Risk-Estimation Procedures Used in the CDEPAT Report
One of the Goals of the CDEPAT report was to provide dose-response information for various biological effects associated with acute exposure to chemical agents under investigation. Specifically, estimates of the proportion of individuals at risk as a function of exposure were based on log-probit analysis. In this chapter, the subcommittee evaluates this procedure for deriving human-toxicity estimates.
Use of Log-Probit Analysis
Log-probit analysis assumes that the density distribution among individuals exposed at the exposures that produce a specified biological effect (for example, death or some incapacitating condition) can be described by a lognormal distribution. In other words, it assumes that the distribution of the log-exposure that produces an effect among individuals is normal. The lognormal distribution is a common and generally accepted approach for describing biological effects. Other statistical distributions could be selected and used, but many notable differences would likely not be observed because of the small numbers of exposure groups and individuals or animals
