Ecological and human health risks associated with metals in water from Anka Artisanal Gold Mining Area, Nigeria

Toxic metals are deleterious to the environment. In this study, risks associated with metals in water from Anka area, Nigeria were unraveled. A total of 104 water samples were collected. The concentrations of metals were determined using high performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS), while cations and anions were analyzed using inductively coupled plasma optical emission spectrometry (ICP-OES). Results revealed that the mean concentration of heavy metals in groundwater are Cu: 4.16 mg/l; Zn: 4.23 mg/l; Pb: 0.05 mg/l; Fe: 0.52 mg/l. For surface water, the mean concentration of Cr, Ni, Cu, As, Pb, and Zn is 0.06 mg/l, 6.53 mg/l, 5.92 mg/l, 0.06 mg/l, and 6.45 mg/l, respectively. Average concentrations of Cr, Co, Ni, Cu, Pb, and Zn in mine water are 0.12 mg/l, 2.11 mg/l, 0.66 mg/l, 4.44 mg/l, 2.72 mg/l, and 11.82 mg/l, respectively. Generally, metals in the samples are above recommended drinking water quality standards. Samples were extremely contaminated and released by geogenic and aggravated by mining. The metals pose great ecological risk but do not pose non-carcinogenic health risk while they pose carcinogenic health risk in both through oral and dermal contact with contaminated water. Children are more prone to health risks than adults.