Athione S -transferase activity, and lipid peroxidation was observed in liver and brain. Exposure to toluene, one of the gasoline constituents, both in vivo and in vitro, leads to reactive oxygen species formation in many tissues including brain tissue [36-38]. The study of Calder -Guzm et al [39] revealed that the aldehydes resulting from the oxidation of the methyl groups in the aromatic compou