20 巻 (2010) 2 号 p. 137-148
Polycyclic aromatic hydrocarbons (PAHs) concentrations in the bivalves were measured to elucidate the background levels of PAHs in the coastal waters of Japan. Seven species of bivalves, mainly Mytilus galloprovincialis and Septifer virgatus were collected in 64 sites. Eighteen kinds of PAHs having two to six rings were analyzed in 137 samples.
The range and median of ΣPAHs concentrations were 1.6-140 ng/g wet wt and 19 ng/g wet wt, respectively. There were no significant differences in the ΣPAHs concentrations among species. The high ΣPAHs concentrations sites were mainly observed in the Pacific coast of the south of Kanto region and around the Inland Sea.
Two concentration ratios (methylphenanthrene/phenanthrene and 4,5-methylenephenanthrene/methylphenanthrene) were examined in order to identify PAHs sources. Those results suggested the source of PAHs was mainly from combustion. And the sites where the influence of oil spill had been expected were observed in the coasts of Chugoku, Shikoku, and Kyushu regions.