Waste disposal on dumpsites has resulted in significant vanadium pollution of the soil and ecosystem. This study assessed the pollution status and potential ecological risk of vanadium in some selected waste dumpsites in southeastern Nigeria. In this study, the soil samples were taken from the active waste dumpsites using a stainless-steel soil auger at a depth of 0 - 20 cm. Five sub-samples were taken from each sample location. A control sample was taken from an area devoid of industrial activities and waste dumps. Soil samples were air-dried at room temperature, pulverized with an agate mortar and pestle, and stored using appropriately labeled polythene bags prior to analysis. Vanadium analysis was conducted using an FS240AA atomic absorption spectrophotometer, and the data generated was analysed using IBM SPSS version 20.0 and Ms-Excel 2007. The mean vanadium concentrations in the studied waste dumpsites were found to be in the following order: Okpuno-Egbu dumpsite > Nekede dumpsite > Enyimba dumpsite > Rice-mill dumpsite. Acceptable potential ecological risk indices were observed in the Rice-mill, Enyimba, and Okpuno-Egbu dumpsites, while Nekede dumpsite recorded a high potential ecological risk. Furthermore, the pollution load index revealed that all the studied dumpsites were heavily polluted. Statistical analysis revealed no significant variations in vanadium concentrations in the studied dumpsites (p>0.05). Additionally, there was a strong and positive correlation between the dumpsites of Enyimba/Nnewi (r = 0.634), Nekede/Nnewi (r = 0.615), and Nekede/Rice-mill (r = 0.842). This indicated that the metal found in the dumpsites is of the same origin.

Dioxin-like polychlorinated biphenyls (DL-PCBs) are a class of persistent toxic substances with a high potential to accumulate in the soil as an organic pollutant and bioaccumulate in humans. The study determined the level and human health risk of twelve (12) DL-PCBs in soils from mechanic workshops within Nekede mechanic village (NMV), Imo State. In this study, soil samples (0-15 cm depth) were collected at four different sampling points within Nekede mechanic village. At each sampling point, composite samples consisting of 10 subsamples were collected with pre-cleaned pet bottles using soil auger and were labeled SA, SB, SC, SD. Control sample was taken 500 metres away from the mechanic village where there was no form of auto-mechanic activities. Sample analysis was conducted using Agilent GC 6890N coupled with Agilent MS 5970B to determine the levels of DL-PCBs. The data were analyzed using SPSS version 23. The results revealed that the mean concentration of 12 DL-PCB congeners (Σ12PCBs) in soil ranged from 0.31-16.31 µg kg − 1 , which was much higher than that in the control sample (0.006-0.087 µg kg − 1 ). PCB-126 was the major contributor (58.99%) while the least contributor was PCB-157 (0.0040%) of the Σ12 DL-PCBs TEQ. The estimated LCR (adults 1.29×10 1 , children 4.42×10 1 ) and HQs (adults 6.68×10 2 , children 2.29×10 3 ) were above the acceptable risk limit (LCR = 10 − 4 , HQ = 1); indicating a very high adverse effect of DL-PCBs on humans especially children.

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