Sources and Cancer Risk Exposure of Polycyclic Aromatic Hydrocarbons in Soils from Industrial Areas in Southeastern, Nigeria

Abstract

This study investigated the cancer risk exposure of Polycyclic Aromatic Hydrocarbons (PAHs) in Soils from industrial areas in South Eastern States of Nigeria. PAHs concentrations in soil samples from study sites ranged from below the limits of detection (0.01±0.00) in Ishiagu to 2.67±0.02 in Akwuuru. Total PAHs (∑PAHS) concentrations in most crop samples had values 13, 9.55, 22.12 <0.01, 5.85 Mg/kg for Abia, Imo, Anambra, Ebonyi and Enugu Soils respectively. The diagnostic ratios indicated both pyrolytic and petrogenic sources of pollution suggesting that there is no point source of pollution in the industrialized areas. The secondary evaluation on carcinogenic PAHs in soil for Akwuuru and Osisioma showed significant dominance above other soils analyzed for the different states. Estimated daily intake of PAHs in soils was within the interval of 2.54819E-06mg/kg/body to 8.57844E-05 mg/kg/body (Adults) and 2.67993E-06 mg/kg/body to 9.02193E-05 mg/kg/body for children. The summation of the Incremental Life Time Cancer Risk for Oral, Inhalation and Dermal routes for Soils fell at the upper limit of the tolerable range(10^-6-10^-4).Values were: 4.40E-04, 2.69E-05,9.07E-4, BDL and 2.37 E04 and 4.25E-04,2.60E-05,8.70E-04, BDL, 2.29E-04 for Adults and Children in Abia, Imo, Anambra, Ebonyi and Enugu Soils respectively. These values do not indicate carcinogenic risk due to PAHs although levels of PAHs in children were higher than in Adults suggesting that children are at greater risk compared to adults since they have a longer period of exposure.