Probabilistic Ecological Risk Assessment of Typical PAHs in Coastal Water of Bohai Sea

Pollution status of 16 polycyclic aromatic hydrocarbons (PAHs) was investigated in coastal water of Bohai Sea, China, and ecological risks of the 4 typical PAHs (naphthalene, phenanthrene, fluoranthene, and benzo(a)pyrene) were assessed using probabilistic risk assessment approach. The average concentration of total 16 PAHs was 3504ng/L, and 3- and 4-ring PAHs were the dominant species. The probabilistic risks of the four typical PAHs were calculated using probability density function curve and joint probability distribution curve. The maximum acceptable ecological risks of 95% of the species being unaffected for the 4 compounds were 0.004, 0.035, 0.135, and 0.010, respectively. The joint ecological risk of the four PAHs was higher than the summation of their individual ecological risks, revealing that the summation of the calculated ecological risk of PAH mixtures underestimated their integrated ecological risks when they co-existed in aquatic environment.