Human health risk assessment of the levels of dioxin-like polychlorinated biphenyls (PCBs) in soils from mechanic workshops within Nekede mechanic village, Imo State, Nigeria

Dioxin-like polychlorinated biphenyls (DL-PCBs) are a class of persistent toxic substances with high potential to accumulate in the soil as an organic pollutant and bioaccumulate humans. The study determined level human health risk twelve (12) DL-PCBs soils from mechanic workshops within Nekede village (NMV), Imo State. In this study, samples (0–15 cm depth) were collected at four different sampling points village. At each point, composite consisting 10 sub-samples pre-cleaned pet bottles using auger labelled SA, SB, SC, SD. control sample was taken 500 metres away where there no form auto-mechanic activities. Sample analysis conducted Agilent GC 6890 N coupled MS 5970B determine levels DL-PCBs. data analysed SPSS version 23. results revealed that mean concentration 12 DL-PCB congeners (Σ12PCBs) ranged 0.31–16.31 µg kg−1, which significantly higher than (0.006–0.087 kg−1). PCB-126 major contributor (58.99%) while least PCB-157 (0.0040%) Σ12 TEQ. sum total LCR (adults 1.29 × 101, children 4.42 101) HQs 6.68 102, 2.29 103) above acceptable limit (LCR = 10−4, HQ 1); indicating very adverse effect on humans especially children.