Contamination of aromatic hydrocarbons in environmental samples after the Nakhodka oil spill

More than 6,200 kl of C-heavy oil, a type of fuel oil, was spilled from the Nakhodka into the Sea of Japan on January 2, 1997, and drifted to the sea coasts of eight prefectures in Japan. Monocyclic aromatic hydrocarbons (AHs) and polycyclic aromatic hydrocarbons (PAHs) in the oil, beach sand, sea water, fishes and air were determined for a period of almost one year after the oil spill. The concentration of naphthalene was the highest among the above compounds in the Nakhodka oil and its concentration in the air might have been high just after the spill. The concentrations of PAHs having less than four rings decreased in the oil and sand, while PAHs having four or more rings first increased and then decreased. A decreasing tendency was observed for benzo[a]pyrene in sea water. However, the concentration was higher at the seashores where the oil was still present than at seashores where the oil had been quickly removed. In addition, the Nakhodka oil showed indirect-acting mutagenicity in the Ames test using the S. typhimurium strains. PAHs contributed to the mutagenicity. (author)