SPATIO-TEMPORAL OCCURRENCE, SOURCES, AND HUMAN HEALTH RISK OF 16-POLYCYCLIC AROMATIC HYDROCARBONS IN ANTHROPOGENIC VECTORED SOILS

Abstract

This study determined the spatiotemporal distribution, sources, and human health hazards of sixteen polycyclic aromatic hydrocarbons (PAHs) in land-use soils. PAHs were determined by a gas chromatography-mass spectrometer (GC-MS). Total PAHs concentrations ranged from 125.3 to 2587.16 µgkg-1 showing concentrations in the order of topsoil < subsoil and wet season > dry season. PAHs occurrence exceeded the DPR-EGAPSIN target and intervention value in 33.3% and 11% of the samples. This study established variable concentrations of HPAHs relative to LPAHs with a predominance of carcinogenic 5-ring PAHs. The highest concentrations of total PAHs were at Warri military checkpoint. The cancer risk for infants was higher than for adults, and permissible target values, thus signifying human on-spot exposure risk. The results established that the source of PAHs is pyrogenic and petrogenic low-temperature combustion of petroleum fractions and high-temperature combustion of wood, grass, biomass, diesel, and vehicular traffic particulate emissions. The results demonstrated considerable concentration variation and potential for ecological and human health exposure risks. The results show PAHs exposures risk in military checkpoints and related catchments elsewhere.