Risk Assessment of Poisonous Metals in Water and Soil at Two Abandoned Lead-Zinc Mines at Yonov, Benue State

Aim: The study was aimed at determining the risk assessment of toxic metal concentration in soil and water at two abandoned Lead-Zinc mines Yonov District, Logo, Benue State, Nigeria.

Study design: comparative cross-sectional study.

Place and duration of study: This study was carried out at the Bruce Powel Toxicology & Biodiversity Laboratory, Animal and Environmental Biology Department, University of Port Harcourt, Analysis at Giolee Global Services Limited Port Harcourt, Nigeria from 16th July to 30th October 2019.

Methodology: Eighteen composite water and soil samples were collected and analyzed using Atomic Absorption Spectrophotometer.

Results: The mean concentration of Lead (Pb) was higher than that of Zinc (Zn) in all eighteen samples, while, Mercury (Hg) and Cadmium (Cd) were below detection limit in all samples. Mean concentration for Pb in soil samples in the order SiteII>Site I (1.29±0.134 mg/kg>1.26±0.04mg/kg) >control 0.82±0.06 mg/kg. Zn was higher in site I, 0.70±0.10 mg/kg than site II 0.66±0.04mg/kg, and control 0.42±0.02mg/kg. Pb values in water was similar in both sites at 0.46±0.04/0.02 mg/L, while control 0.02±0.001mg/kg. Zn was higher in site II 0.05±0.01mg/L than site I 0.04±0.01Mg/L, control was 0.004±0.00 mg/L. Health risk assessment showed that Estimated daily intake of metals, hazard quotient, hazard index were all less than 1, Carcinogenic risk was within the stipulated ranged of 10-6 to 10-4.

Conclusion: Ecological and health risk indices revealed non-contamination by Poisonous metals, however, routine assessment is recommended to forestall any sudden change in the concentration that may result to deleterious effects on human health.