Distribution and sources of polycyclic aromatic hydrocarbons in the surface sediments of Gorgan Bay, Caspian Sea

The level and source of 16 polycyclic aromatic hydrocarbons (PAHs) were investigated in the surface sediments from the Gorgan Bay, Caspian Sea. The sum of 16 PAHs (ΣPAH16) concentrations varied from 107.87 to 516.18 ng g−1 dry weight, with average value of 270.96 ± 150.47 ng g−1 dry weight. Ecological risk assessment of PAHs, indicated that adverse biological effects caused by acenaphthene, naphthalene, fluoranthene and Pyrene occasionally and frequently may take place in the sediments of Gorgan Bay. PAHs source identification demonstrated that the PAHs come from mixed and pyrogenic origin.