Persistent Organic Pollutants in Soil Samples from Industrial Vicinity East of Zarqa City, Jordan

Abstract

The levels of 13 Polyaromatic hydrocarbons (PAHs) and 12 Polychlorinated biphenyls (PCBs) were   determined in 23 soil samples collected from the vicinity of the Jordan petroleum refinery and Al-Hussein thermal power stations in Zarqa region. The total concentrations of PAHs were  ranged between 0.94 µg/kg  (site 13) and 191 µg/kg (site 19), while none of the samples was containing any of the studied PCBs. Recoveries of PAHs and PCBs were found between 82 -106% and 91-114% respectively. Precision of the method for both PAHs and PCBs, calculated as relative standard deviation (RSD) was ranged between 0.6 – 7%. The limit of detection for PAHs and PCBs were between 0.006- 0.070 µg/kg and 0.149-0.330 µg/kg respectively. The total estimated cancer risks of exposure to PAHs in the soil samples were ranged from 8.56 × 10^-9 to 5.53 × 10^-6. By multiplying these numbers of cancer risks of exposure to soil sample-PAHs by 10⁶, it is possible to determine the maximum theoretical number of cancer cases per million of people. The maximum estimated cancer risks cases determined in this study (6 out of million) are well within the acceptable range of excess cancer risk specified by the US Environmental Protection Agency. In general, the studied area shows very low pollution level.