DNA binding of [14C]styrene in isolated rat hepatocytes

DNA adduct formation by 12 chemicals with populations potentially suitable for molecular epidemiological studies

DNA adduct formation, route of absorption, metabolism and chemistry of 12 hazardous chemicals are reviewed. Methods for adduct detection are also reviewed and approaches to sensitivity and specificity are identified. The selection of these 12 chemicals from the Environmental Protection Agency list of genotoxic chemicals was based on the availability of information and on the availability of populations potentially suitable for molecular epidemiological study. The 12 chemicals include ethylene oxide, styrene, vinyl chloride, epichlorohydrin, propylene oxide, 4,4'-methylenebis-2-chloroaniline, benzidine, benzidine dyes (Direct Blue 6, Direct Black 38 and Direct Brown 95), acrylonitrile and benzyl chloride. While some of these chemicals (styrene and benzyl chloride, possibly Direct Blue 6) give rise to unique DNA adducts, others do not. Potentially confounding factors include mixed exposures in the work place, as well the formation of common DNA adducts. Additional research needs are identified.

Review of the toxicology of styrene

Styrene is used in the production of plastics and resins, which include polystyrene resins, acrylonitrile-butadiene-styrene resins, styrene-acrylonitrile resins, styrene-butadiene copolymer resins, styrene-butadiene rubber, and unsaturated polyester resins. In 1985, styrene ranked in the top ten of synthetic organic chemicals produced in the U.S. This review focuses on various aspects of styrene toxicology including acute and chronic toxicity, carcinogenicity, genotoxicity, pharmacokinetics, effects on hepatic and extrahepatic xenobiotic-metabolizing enzymes, pharmacokinetic modeling, and covalent interactions with macromolecules. There appear to be many similarities between the toxicity and metabolism of styrene in rodents and humans. Needed areas of future research on styrene include studies on the molecular dosimetry of styrene in terms of both hemoglobin and DNA adducts. The results of such research should improve our ability to assess the relationship between exposure to styrene and surrogate measures of "effective dose", thereby improving our ability to estimate the effects of low-level human exposures.