The present study was aimed at bridging the gaps in the knowledge concerning heavy metals (Pb, Cd, Cr, Ni, Zn, Cu, Mn and Fe) concentrations in the groundwaters of the Ntem watershed in Yaoundé. Representative groundwater samples (25 numbers) were collected from five (05) hand-dug wells and their metal concentrations were assessed as per standards procedures and the deterministic interpolation techniques were used to perform the spatial distribution of heavy metal concentration maps. The ranges of concentrations of these metals in groundwaters were: Pb (0.11–0.34 mg/L > 0.025 mg/L); Cd (0.00–0.08 mg/L > 0.005 mg/L); Cr (0.12–1.33 mg/L > 0.05 mg/L) and Ni (0.11–0.46 mg/L > 0.05 mg/L). Besides, the average metal concentrations in groundwaters of the sampling sites were in general higher than the prescribed World Health Organization (WHO) norms. The risks assessment indicated that the concerned population are considered unsafe and are therefore exposed to non-cancerogenic and cancerogenic effects on health. The occurrence of more than permissible levels of heavy metals in the representative groundwaters and their spatial distribution indicate that there is a potential threat of these contaminants to the public health in the Ntem watershed.
- anthropogenic activities
- deterministic interpolation techniques
- urban pollution
- First received 2 June 2016.
- Accepted in revised form 26 October 2016.
- © IWA Publishing 2016