Upcoming Special Issues
With the adoption of the acceptable daily intake (ADI) concept in chemical risk assessment, proposed by René Truhaut in the early 1960s, the focus of toxicity studies has shifted from analysis of dose-response relationships to determination of no-observed-adverse-effect-levels (NOAELs), on which the ADI is based. The ADI concept assumes the presence of thresholds of toxicity, the only exception being made for irreversible effects of mutagens, and neglects analysis of dose-response relationships. However, it is becoming increasingly clear that irreversible and cumulative effects are not confined to mutagens, but may also occur with nervous system poisons such as the neonicotinoid insecticides or sulfhydryl-reactive metals, the risks of which have been seriously underestimated, with disastrous consequences. Novel approaches to risk assessment, focused on identification and prevention of irreversible and cumulative effects of hazardous chemicals, are required to safeguard man and the environment.