Land Use Contributions to Heavy Metals/Metaloids Pollution in the Tano Basin, Ghana, and Its Associated Health Risks to Dependant Communities

Abstract

Increased anthropogenic activities are suspected to have contributed to the Tano basin heavy metal/metalloids water quality. However, data on land use contribution to the basin’s heavy metal/metalloids pollution are limited. The study assessed the contribution of land use to the basin’s heavy metals/metalloids pollution by assessing the levels of heavy metals/metalloids in 36 water samples taken from the source/control and experimental sites along the basin. Atomic absorption spectrophotometer was used to analysis samples. Metals/metalloids concentrations in water samples from the basin’s source and the physicochemical parameters were compared with the corresponding concentrations in samples from the experimental sites. Significantly, higher heavy metal/metalloids concentrations and physicochemical levels were identified in the experimental sites than the source/control site. Heavy metal/metalloids levels at the source were as follows: As (0.001 ± 0.11 mg/L) < Cd (0.003 ± 0.34 mg/L) < Zn (0.011 ± 0.97 mg/L) but Pb, Hg, and Cr were not detected. The corresponding levels in the experimental sites were As (0.014 ± 0.88 mg/L) < Hg (0.051 ± 0.76 mg/L) < Cd (0.056 ± 0.45 mg/L) < Zn (0.166 ± 1.95 mg/L) < Cr (0.299 ± 0.42 mg/L) < Pb (0.428 ± 0.44 mg/L). Control water pH was slightly acidic (5.38 ± 3.4) but the experimental sites were near neutrality (7.35 ± 2.1). Noncarcinogenic and carcinogenic risks were detected for water consumption by children and adults in the experimental but none in the control. Land use activities identified were industrial, agricultural, and commercial. Enforcement of buffer zone protection laws is recommended.