Determination and source identification of polycyclic aromatics hydrocarbons in Karaj River, Iran.

Sixteen priority polycyclic aromatic hydrocarbons (PAHs) were measured in six stations in Karaj River, which is the main resource of drinking water in Tehran. The single PAHs concentrations ranged from not detected to 2,327.8 ng L(-1), with a mean value of 31.5 ng L(-1). The total PAHs concentrations ranged from 25.6, in the spring, to 4,040.3 ng L(-1), in the summer. PAHs concentrations in different sampling stations were similar (p = 0.33-0.99), but strong relationships were detected between seasonal variations and total PAHs, BaP equivalent and carcinogen PAHs concentration (p = 0.010-0.037). Results showed that carcinogen PAHs comprised 7 %-92 % of detected PAHs in different sampling stations. The concentration of benzo(a)pyrene, as an indicator, was lower than the permissible limit of the World Health Organization; however, in some samples, carcinogen PAHs concentrations were higher than the permissible limits of the European Union and USA Environmental Protection Agency regulations for drinking water.