EVALUATION OF POLYCYCLIC AROMATIC HYDROCARBONS IN SOIL OF SELECTED URBAN AREAS OF DELTA STAT NIGERIA (original) (raw)

Sixteen Polycyclic aromatic hydrocarbons (PAHs) grouped as endocrine disruption substances (EDSs) were determined for their concentrations, sources and human health risk. Naphthalene (Nap), acenaphthylene (Acy), acenaphthene (Ace), fluorine (Flu), phenanthrene (Phe), anthracene (Ant), fluoranthene (Flt), pyrene (Pyr), chrysene (Chr), benzo(a)anthracene (B[a]a), benzo(b)fluoranthene (B[b]f), benzo(k)fluoranthene (B[k]f), benzo(a)pyrene (B[a]p), indeno(1,2,3-cd)perylene (I[123-cd]p), benzo(ghi) perylene (B[ghi]p) and dibenzo(a,h) anthracene (D[ah]a) were analyzed in three urban soils of Agbor, Asaba and Issele-Ukwu, at 0-15 and 16-30 cm depth in wet and dry seasons. After extraction using ultrasonication with hexane and dichloromethane and clean-up, PAHs concentration was measured using gas chromatography equipped with mass spectrometer. The concentrations of Ʃ16 PAHs ranged from 178.0 to 787.0 µg/kg and 105.1 to 437.7 µg/kg in wet season and dry season respectively. PAHs concentrations varied significantly (p<0.05) between sites, soil profile and seasons. The Incremental Lifetime Cancer Risk values obtained were relatively above the tolerable target risk levels of 10-6 set by the US.EPA, this suggest a potential for human mutagenic and carcinogenic risk in the study area. Source estimates ratios suggest that PAHs were from petroleum, coal, biomass combustion and traffic origin.