Toxicokinetics epidemiological data

This chapter reviews physical and chemical properties and toxicokinetic, toxicologic, and epidemiologic data on ammonia. The Subcommittee on Submarine Escape Action Levels used the information to assess health risk to Navy personnel aboard a disabled submarine and to evaluate the submarine escape action levels (SEALs) proposed to avert serious health effects and substantial degradation in crew performance from short-term exposures (up to 10 d). The subcommittee also identifies data gaps and research relevant for determining the health risk attributable to exposure to ammonia. 

Risk assessment for humans is difficult due to limited toxicokinetic and toxicodynamic data available and the paucity of cases of human illness reported from consumption of food derived from heavily contaminated grains. Risk assessment from nondietary routes of exposure in humans is also complicated by lack of epidemiological data. 

The primary purpose of this chapter is to provide public health officials, physicians, toxicologists, and other interested individuals and groups with an overall perspective on the toxicology of methyl parathion. It contains descriptions and evaluations of toxicological studies and epidemiological investigations and provides conclusions, where possible, on the relevance of toxicity and toxicokinetic data to public health. 

Data from epidemiological studies, of sufficient quality, are generally preferred for estimating risks. When the evaluation is based on animal studies, the estimation of a human-equivalent dose should utilize toxicokinetic data for cross-species dose scaling if adequate data are available. Otherwise, a default procedure should be applied. The aim of the cross-species dose scaling is to define exposure levels for humans and animals that are expected to produce the same degree of effect, taking into account differences in scale between test animals and humans, such as size and life span. 

Lack of toxicologic, epidemiologic, and toxicokinetic data Few data available to assist in determining whether presence of some concentration of a chemical in body may have health effect... 

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