Assessment of Polycyclic Aromatic Hydrocarbons (PAH) Concentration in Sediments and Soils around Ibadan, Southwestern Nigeria

摘要

The concentrations of polycyclic aromatic hydrocarbons (PAHs) in sediments and surface soils under different land use patterns were studied using a High Performance Liquid Column-Fluorescence Detector (HPLC-FD) and Gas Chromatography-Mass Spectrometry (GC-MS) systems. Two sets of separate samples were collected. Set A involved ten surface soil samples and set B contained five top soil and two sediment samples. The results show that the sum of 15US Environmental Protection Agency (EPA) priority pollutant PAHs are present. The concentration of PAHs in the sediment and surface soils range from 1.68 to 919 μg kg -1 and 1.76 to 2926.68 μg kg -1 respectively. The results show also that the low molecular weights are more than the high molecular weight, and the calculated ratios of PHen/ANth , FllTH/PYR, and FLth/ (FLth+PYr) exceed the background values, all these suggest that the PAHs are more of petrogenic sources. These results show more of petrogenic origin than pyrogenic and others of mixed nature. The average PAH-homologue concentrations are 3 rings >4 rings>5 rings 2 rings. PAHs concentrations are higher in engine oil impregnated soil, incinerated soils and stream sediments as against a non - oil industrialized areas. Most of the PAHs like benzo[a] anthracene, chrycene, benzo [b] fluoranthene, benzo[ ghi] perylene have properties that are carcinogenic, toxic, mutagenic and teratogic and are therefore dangerous to health. The public is advised not to take in food that are derived from such contaminated surface soils