Seasonal variation of polycyclic aromatic hydrocarbons in the surface sediments of the southern Caspian Sea

The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in sediments from the southern Caspian Sea in fall 2015 and winter 2016. The sum of 16 PAH (ΣPAH) concentrations varied from 17.3 ± 3.05 to 926.7 ± 157.37 ng g− 1 dry weight and 14.3 ± 0.58 to 85.8 ± 4.41 ng g− 1 dry weight in fall and winter, respectively. There was no significant correlation between PAH and total organic carbon contents (p > 0.05). PAH source identification showed that the PAHs in the sediments originated from petroleum and petroleum combustion. When classified according to the pollution levels, sediments from the southern Caspian Sea could be considered to be low to moderately polluted with PAHs.