Polycyclic aromatic hydrocarbons are a group of organic pollutants composed of two or more benzene rings. These compounds are widely spread in the environment and among the ways these compounds enter the marine environment are the combustion of fossil fuels, oil spills, industrial and municipal wastewater. Pahs compounds are hydrophobic and tend to accumulate in sediments and aquatic bodies. Numerous studies have shown that some pahs compounds have carcinogenic and mutagenic properties. Bushehr coasts, in addition to being affected by oil pollution in the Persian Gulf, are also exposed to urban and industrial wastewater. In order to study the accumulation of polycyclic aromatic hydrocarbons in sediments and bivalves a. umbonella and determining the source of contamination on the shores of Bushehr from 5 stations, sampling was done. Sediment and bivalve samples were collected in aluminum foil and transported to the laboratory next to ice. Sediment and oyster samples were homogenized and their pahs compositions were analyzed by gc-ms. Also, the organic carbon content of all sediments and the amount of adipose tissue fat were calculated. The Bidkhoon station, which was affected by leaking furnace oil from worn-out vessels, showed the highest level of pollution. The stations located in Basatin estuary were in the next category and Bardestan station, which is further away from Assaluyeh industrial zone, showed the lowest level of pollution. In general, the level of pollution in the study area is on average compared to other parts of the world. Investigation of molecular ratios of PAHS compounds to determine the possible sources of PAHS compounds indicates the existence of petrogenic and pyrogenic sources in all studied stations. Total organic carbon content showed a positive correlation with sediment pahs. Also, a positive correlation was observed between the amount of adipose tissue fat and the concentration of pahs of bivalves as well as the concentration of pahs of se
