Assessment of ecological risk and identification sources of polycyclic aromatic hydrocarbons at coastal sediments: A case study in Bushehr Province, Iran

Polycyclic aromatic hydrocarbons (PAHs) are stable and highly toxic environmental pollutants, which are produced mainly through combustion processes. The present study aimed to identify and determine PAHs compounds and their ecotoxicological effects in surface sediments of 20 stations in Bushehr province (Assaluyeh, Kangan, Khark, Emam Hasan, and Bushehr areas).

All sediment samples (0-5 cm) were collected from 20 sites of Persian Gulf costs (Bushehr province, Iran). The concentration of PAHs was determined by HPLC. Then, in order to identify the sources of PAHs, ƩLPAHs/ƩHPAHs, IP/ (IP+BP), PH/AN, and AN/(PH+AN) ratios were obtained. Sediment quality guidelines (SQGs) and sediment quality criteria (SQC) were used to measure the PAHs ecotoxicological effects in sediments.

Based on PAHs isomeric ratios, the contaminants of sediments originated from pyrogenic resources. ƩPAHs values (ng/g dw) in sediment samples ranged from ND to 49180. The toxic equivalent concentration (TEQ car) of PAHs raged from ND-7999 ngTEQ/g. Based on SQGs and SQC, the concentrations of ƩPAHs compounds in 10% and 6% of the sampling stations exceeded effects range median (ERM) and frequent effect level (FEL), respectively, indicating negative ecological risk effects.

Sampling stations sediments must be routinely checked for PAHs because may lead to a negative effect on the marine ecosystem, organisms, and humans.