Abstract
Shellfish and fish samples were collected at Rayong, Thailand a month and four months after an oil spill in 2013. Their polycyclic aromatic hydrocarbons（PAHs）and alkylated PAHs（alkPAHs）concentrations were analyzed due to their toxicity. While Σall PAHs concentrations in shellfish were almost lower than 200 ng/g except for Stn.1 at Samet Island, where they ranged from 28900 to 134000 ng/g. The diagnostic ratios of PAHs suggest that the sources of these PAHs in aquatic organisms were petrogenic. Σ PAH concentrations in fish and squid caught by set-net ranged from 3.74 to 5.31 ng/g. Benzo（a）pyrene, a carcinogenic PAH, was detected in oyster collected at Stn.1 ranging from 43.1 to 63.9 ng/g, which is a higher level than permitted by EU criteria. However, their levels were much less than the criteria in shellfish and fish from other stations.
