Evaluation of Heavy Metals in Drinking Water Resources in the Department of Nyan, Province of Logone Oriental in Chad

Abstract

The present research work was carried out in the Department of Nyan, Province of Logone Oriental. It allowed the quantification of heavy metal contents in well, borehole and river water intended for human consumption. Samples from these water sources were collected and submitted for laboratory analysis. Structural quality indicators such as pH, temperature, electrical conductivity, turbidity, dissolved oxygen and sulphate ions were measured first. The sample was acidified and the measurement is then performed on the metals, i.e. barium, calcium, iron, magnesium, manganese, copper, chromium, aluminium, lead, strontium, tin, zirconium and titanium. The results of the quality indicators showed that well and borehole waters have an acidic pH; their average measured values are 5.34±0.24 and 5.48±0.15 respectively. Well water and that of rivers have high turbidity values averaging 43.40±1.21 NTU and 47.56±1.5 NTU respectively. With respect to metals, some have values above the WHO drinking water standards. These include iron, which has high values in well water (7.890±0.016 mg/L) and river water (0.866±0.003 mg/L), manganese in well water (0.093±0.001 mg/L), aluminum in well water (5.614±0.009 mg/L) and river water (1.211±0.008 mg/L). Based on these results, consumption of these water sources would expose communities to mild or chronic health risks.