Study of Oil Pollution in the Coastal Sediments of Kharg Island in the Persian Gulf

More than 90% of Iranian crude oil is exported from Kharg Island in the Persian Gulf. In addition during the past 5 decades there have been extensive oil related activities in this island including crude oil extraction, storage and refinery. Therefore, coastal marine environment of the Kharg Island has been continuously exposed to large amounts of oily wastes and also oil discharges resulted from accidents. Thus, it is very important to have a good understanding about the extension of oil pollution in the coastal area of this island. However, the previous studies on the marine oil pollution of the Kharg Island are very limited. In this paper oil pollution in the coastal sediments of Kharg Island is discussed using the analysis of the concentrations of hydrocarbons in 14 sea bed surface sediment samples collected from water depths of 13-20 m around the Island. TPH (Total Petroleum Hydrocarbons) concentrations ranged between less than 1 and 133 μg/g and indicated low to moderate oil pollution. PAHs (Petroleum Aromatic Hydrocarbons) concentrations ranged from very low to large amounts and had a maximum of 3100 ng/g and indicated moderate to high PAH pollution in most of the samples. Several indexes were used for investigating the origin of aliphatic and aromatic hydrocarbons in the samples. Crude oil and the emissions from gas flares were found as the main sources for aliphatic and aromatic compounds in the samples, respectively.