Evaluating the Spatial Distribution of Some Toxic Substances Concentration with the Microbial Contamination of Wetland Water, Sediment and Fishes, and Their Potential Health Hazards

Abstract

This study evaluated the impact of anthropogenic factors on the accumulation of toxic materials in wetland. The wetland was micro-zoned into five sub-regions, namely; NDE, ISN, ISS, UGS and BUR. Sediment, water and fishes (catfish and tilapia) were sampled from each locality. Heavy metals (Cd, Cr, Cu, Ni, Fe, Pb and Zn) and total petroleum hydrocarbon (TPH) of the samples were determined. The pollution indices (Bioaccumulation quotient “BQ”, contamination factor “CF”, geoaccumulation index “Igeo”, enrichment factor “EF” and Pollution load index “PLI”) and potential health risks (Metal Pollution Index “MPL”, Estimated Daily Intake “EDI”, Total Health hazard quotient “THQ” and Hazard index “HI”) of the water, sediment and fish flesh were calculated appropriately. The results revealed that the wetland fishes contained viable bacteria which ranged between 1362.0 cfu/g and 2634.3 cfu/g. Heavy metal level ranking in the sediment and water was Fe > Zn > Cu > Pb > Ni > Cr > Cd. Spatially, the heavy metals concentration in the water, sediment and fish followed the order: BUR > UGS > ISN > ISS > NDE. The TPH concentration in water, sediment and fishes differed significantly across the five sub-regions (p≤ 0.05), and its value ranged from 3.44 mg/kg to 99.38 mg/kg for the catfish, 2.08 mg/kg to 83.73 mg/kg for the tilapia, 25.34 mg/kg to 718.87 mg/kg for the sediment and 0.016 mg/kg to 1.099 mg/kg for the water. Spatial ranking of the TPH levels in the fish flesh was BUR > UGS > ISN > NDE > ISS; sediment TPH level ranked BUR > UGS > NDE > ISN > ISS; and the water TPH level ranked BUR > UGS > ISN > ISS > NDE. Human health risks associated with the consumption of the wetland fish ranked thus BUR > UGS > ISN > NDE > ISS. It was evident from the results that anthropogenic actions from resulting poor regional planning had significant effect on environmental health. The results called for environmental protection for public interest in order to prevent disease epidemics.