Determination of polyaromatic hydrocarbons and some selected heavy metals in an aluminium recycling contaminated soil of Atuwara-Igbheren, Sango-Ota, Ogun State

Polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs), both carcinogenic and hazardous, are common environmental contaminants. Soil samples were taken from three sites using a soil auger, air dried, and digested with the AODC method. HMs concentrations were measured using atomic absorption spectrophotometry, while PAHs were extracted with the USEPA method and analyzed by gas chromatography mass spectrophotometry. Descriptive and inferential statistics were applied to the data. HMs’ mean concentrations in mg/kg were copper (Cu) (255 ± 33-356 ± 22), lead (Pb) (48 ± 4-213 ± 62), Mn (77 ± 10-101 ± 3), Na (49 ± 8-63 ± 19), and cadmium (Cd) (0.51 ± 0.05-4 ± 3), with Cu > Pb > Mn > Na > Cd. Cu, Pb, and Cd levels exceeded Dutch target values. PAHs concentrations ranged from 147,290 ± 120,340 to 265,090 ± 184,321 µg/kg, with six out of seven carcinogenic PAHs detected. Dibenzo[a,h]anthracene had the highest concentration (26,053 ± 18,465 µg/kg). All PAH levels exceeded the Dutch guideline of 50 µg/kg.