بررسی هیدروکربن های پلی آروماتیک (PAH 16) در رسوبات و عضله دو نوع ماهی کفال سالینس و سفید دریای خزر

Background and purpose: Polycyclic aromatic compounds (PAHs) are considered as priority organic compounds pollutants worldwide due to their high toxicity. Presence of oil wells has made petroleum hydrocarbon as one of the sources of pollution in the Caspian Sea. These are the pollutants of soil and water which are very dangerous and lethal for the aquatic ecosystem. The purpose of this study was to determine the 16PAHs (as oil pollution) in the sediments and two commercial fish in the Caspian Sea. Materials and methods: In this study, 32 sediment samples were collected from 8 stations at eight transects at 10 meter depth during four seasons. Also, 34 samples of Liza saliens (n=17) and Rutilus frisii kutum (n=17) were taken from the south of Caspian Sea. The samples were extracted using Soxhlet execrator with organic solvents and then analyzed using GC-FID (Shimadzu-14 A) instruments. Results: Concentration of 16PAHs in sediment in most stations was lower than critical level (NOAA standard). Applying different PAHs ratios, it was found that PAHs originated predominantly from the pyrogenic source either from the combustion of grass, wood and coal (majority of the samples) or from petroleum combustion (harbor area). The mean concentration of PAHs in Liza. s and R. frisii kutum were observed 2460 ± 60 and 2710 ± 56 µg/kg dw, respectively and 990 ± 33 µg/kg dw for sediment. In general, concentrations of PAHs in edible tissue of two species were higher than their corresponding sediment concentrations reflecting their great bioavailability (242-3880 µg/kg dw). The highest concentrations were observed in some ports of the southern Caspian Sea (Anzali, Nowshahr, and Amirabad), probably due to intensive shipping activities. Conclusion: The distribution pattern of PAHs was similar for fish and sediments, particularly for sediments characterized by high contamination level, and they were dominated by the high molecular weight PAHs (4-6-rings) which have high ecological risks.