Bioavailability of Volatile Organics and Other Hydrocarbons from Environmental Media: Ingestion in Drinking Water.

摘要

The primary objectives of this project were to: (a) assess the roles of hepatic and pulmonary presystemic elimination in reducing the bioavailability of low levels of volatile organic chemicals (VOCs) found in drinking water supplies; (b) investigate gastrointestinal (GI) absorption pathways for VOCs; (c) characterize the influence of oil dosage vehicles on the absorption, pharmacokinetics (PK) and toxicity of VOCs, with emphasis on potential mechanisms by which corn oil acts. Substantial progress has been made towards achieving each of these objectives. Studies in unanesthetized, male Sprague-Dawley rats, contrasting the PK of equal doses of VOCs given orally as a single bolus and by constant intragastric (ig) infusion for up to 6 hours, revealed significantly lower peak blood levels and bioavailability in the ig groups. Blood concentrations of well metabolized VOCs, such as trichloroethylene (TCE) and 1,1-dichloroethylene, were so low that they were hardly detectable at low dosage levels in the ig animals. These findings suggest that the liver and lungs may be able to remove virtually all of the trace amounts of VOCs that are usually found in drinking water. Volatile organic chemicals (VOCs), Bioavailability, pharmacokinetics, presystemic elimination, absorption, lymphatic system, hepatotoxicity, dosage vehicles, drinking water contamination.