PUBLIC HEALTH IMPLICATION OF PAH AND TRACE HEAVY METALS IN SOIL SAMPLES FROM A PETEROLEUM REFINING AREA

Abstract

The concentration of polyaromatic hydrocarbon and heavy metals in soil samples from vicinity around a petroleum refinery in Nigeria was investigated in an attempt to elucidate its public health implication. Soil samples were collected from three stations around the refinery; Ifie, Ijala and Ubeji which are in close proximity to the Refinery. Soil samples collected were digested and extracted for PAHs and Heavy metals using standard methods while analysis was carried out using a Gas Chromatograph and an Atomic Absorption Spectrophotometer respectively. Health impact of the concentrations of PAH and heavy metals were estimated using the chronic daily intake and the hazard quotient. Results showed varying concentrations of PAH and Heavy metals in soil samples from the vicinities close to Warri refinery. The concentrations of the heavy metals followed the sequence; Zn>Cu>Mn>Pb>Cr>Ni>Cd, while the predominant PAHs were Benzo (a) anthracene, pyrene and chrysene. Ubeji station had the highest PAH and heavy metal concentrations in soil samples. Health risk assessment of heavy metals showed that there were no potential noncarcinogenic effects from exposure through accidental ingestion, dermal contact and inhalation because estimates were below the safety threshold. However, health risks assessment of PAH in soil samples indicated that there is a potential for carcinogenic effects upon dermal exposure to PAH. This study highlights the environmental pollution problems and public health concerns of petroleum refining, particularly the potential hazards of to the health of individuals residing in areas close to the refinery.