Assessment of reproductive risks.

In the regulatory process, the hazards posed by potentially toxic agents to the female and male reproductive systems and to developing young are evaluated by risk assessment procedures. In this paper, toxicity testing and the regulatory process are discussed, with emphasis on risk assessment. The suggested testing protocols of the Pesticide Assessment Guidelines (U.S. EPA) are presented as an example of testing that might be done to produce toxicity data for an agent. Protocols and end points that are utilized in testing for reproductive effects are described. Included are acute, subchronic, chronic, and short-term tests. The four components of reproductive risk assessment (hazard identification, dose-response assessment, exposure assessment, and risk characterization) are examined. Effects of dibromochloropropane on rabbit testicular parameters are used to demonstrate approaches that could be taken in doing a reproductive risk assessment. Research needs for screening methods, adequate dose-response testing, toxicokinetics, end point development, and extrapolation methods are identified. Finally, this paper discusses selected areas in which changes in reproductive risk assessment are anticipated, as well as the mechanism for influencing the nature and extent of those changes.

A review of the symposium on aneuploidy: etiology and mechanism.

A symposium titled "Aneuploidy: Etiology and Mechanisms" was held in Washington, D.C., in March, 1985. The stimulus for convening it was the growing concern that environmental agents with the capacity to induce aneuploidy can have detrimental effects on human health. Major components of the symposium were devoted to an analysis of human aneuploidy, mechanisms by which aneuploidy originates, and tests for the symposium, its conclusions, and major uncertainties in the field.