Aneuploidy: a report of an ECETOC task force.

Aneuploidy plays a significant role in adverse human health conditions including birth defects, pregnancy wastage and cancer. Although there is clear evidence of chemically induced aneuploidy in experimental systems, to date there are insufficient data to determine with certainty if chemically induced aneuploidy contributes to human disease. However, since there is no reason to assume that chemically induced aneuploidy will not occur in human beings, it is prudent to address the aneugenic potential of chemicals in the safety assessment process.

Pathology considerations for, and subsequent risk assessment of, chemicals identified as immunosuppressive in routine toxicology.

Several proposals have been made with the aim of assisting in the early identification of chemicals with immunotoxic potential. The Organisation for Economic Cooperation and Development is now likely to incorporate enhanced immunopathology into the test guideline for the 28-day rat study, which may be regarded as a Tier I investigation. However, no guidelines have yet been proposed either for how the new data generated will be evaluated, or for how a subsequent risk assessment will be made.

Evaluation of the neurotoxic potential of chemicals in animals.

This review provides a scientific view on how to evaluate effectively the neurotoxic potential of chemicals in order to provide adequate safeguards for human health. Detection of compounds that may cause direct, persistent, adverse effects on the nervous system should be given the most critical attention. Evaluation of the neurotoxic potential of a chemical should include descriptions of functional and morphological effects as well as the determination of the dose response, no-observed-effect level, time course and reversibility of effects.

The identification of chemicals with sensitizing or immunosuppressive properties in routine toxicology.

In the context of this paper, immunotoxicity is taken to encompass immunosuppression/immunopotentiation and allergy. Over the last 10 to 15 years, well characterized methods for the assessment of altered immune competence have been reported. This has led to proposals for tiered testing schemes.