Fecal sterols and pahs in sewage polluted marine environment along the eastern Red Sea coast, South of Jeddah, Saudi Arabia

摘要

Water and sediment samples were takes near the sewage discharge point on the eastern Red Sea Coast of Jeddah and analyzed for PAH and fecal sterols like coprostanol, cholesterol and cholestanol. PAH were estimated spectrofluorometrically and then further analyzed by GC-MS. Sterols were derivatized by BSTFA into their corresponding trimethyl silyl derivatives and then analyzed by gas chromatography and quantified with standard sterols. PAH ranged from 1.5 to 6.5 μg l~(-1) in eight stations. Concentration of coprostanol in water samples showed a maximum of 8.2 μg l~(-1) at station XVUI and minimum 0.1 μg l~(-1) at station 10C. The analysis of the sediment samples indicated much higher values for fecal sterols. It was found to be 785 μg l~(-1) m sediment and 6.5 μg l~(-1) in the water samples at station ⅩⅧ. PAH did not show any distinct increase in the sediment samples. According to Grimaldt equation the value of r~* (5β / 5β + 5α) was determined. Out of a total of sixteen samples, fourteen samples had a value of 0.7 or higher than 0.7. This indicate a definite and a positive sewage contamination infecting almost the whole area studied. The GC-MS of the PAH indicate the presence of phenanthrene, benzophenone and 2,4-diisoprophyl naphthalene, methylnaphthalene, and 9-H-methylene flourene. Present study infers that the sewage; either untreated or partially treated is dumped into the sea.