Toxicological decisions and recommendations resulting from the safety assessment of pesticide residues in food

Deriving allowable daily intakes for systemic toxicants lacking chronic toxicity data

The lack of human toxicological data for most chemical compounds makes it difficult to quickly assess health risks associated with exposure to contaminants at hazardous waste sites. It would therefore be advantageous to have a technique for estimating acceptable daily intakes (ADIs) of potentially toxic substances based on more widely available animal toxicity data. This article focuses on the use of LD50 data to derive provisional ADIs, and it suggests multiplying oral LD50 values (expressed in mg/kg of body wt) by a factor in the range of 5 X 10(-6) to 1 X 10(-5) day-1 to convert them to such ADIs. It is emphasized that these interim ADI values are no substitute for toxicity testing, but that such testing would most likely result in higher ADI estimates.

The application of clinical toxicology

The objective of this review is to assess the role of clinical toxicology as it is practiced today and its possible future development. This includes the legal and ethical aspects of the subject and their application to man. The following issues are considered: extrapolation from animal to man; the logical sequence of the implementation of the stages that constitute good clinical practice; examples of the main invasive and noninvasive techniques employed in the clinical studies; the monitoring of the health of the employee in his working environment; chemically induced chronic disease states; and a retrospective consideration of specific examples of chemical hazards.

Overview of some aspects of quantitative risk assessment

Use of animal data to estimate the human risk from long-term exposure to low doses of environmental carcinogens poses a number of biological, toxicological, and statistical problems. One of the problems is that of extrapolating animal dose-response relations from the high-dose range, where animal test data are available, to the low doses that humans might encounter. Different mathematical models for extrapolation are summarized, and the procedures for an problems of estimating human risk on the basis of animal studies are evaluated.

Effects of feeding lindane to dogs for periods of up to 2 years

Lindane was administered to male and female Beagle dogs at dietary levels of 25, 50 and 100 ppm for 104 weeks, and of 200 ppm for 32 weeks. One death at 25 ppm and one at 200 ppm were not considered to be related to the test compound. At 100 and 200 ppm, SAP levels were raised and the livers were dark, friable and slightly enlarged but without any detected histopathological change. HVSA changes, possibly indicative of non-specific neuronal irritation, were recorded in the EEG tracings at 200 but not at 100 ppm. There were no other indications of an adverse effect of lindane. The negative findings at 50 ppm are consistent with a 'no-effect level' for this species of 1.25 mg/kg body weight, comparable with for the rat, and with proposed human ADI of 0.0125 mg/kg body weight.