Heavy metals pollution profiles in streams serving the Owabi reservoir

Abstract

Water samples from five sampling points on four rivers, Owabi, Akyeampomene, Pumpunase and Sukobri, representing the main streams serving the Owabi reservoir were analysed for some pollution indicators using standard methods. Heavy metals (Zn, Cu, Mn, Cu, Pb and As) concentrations and some physical parameters of the water samples were determined. Electrical conductivity and pH of waters from all the streams were found to be within the acceptable limits of the World Health Organization (WHO). All the streams showed high turbidity values above WHO limits. Of the heavy metals determined in the water samples, Fe, Mn, Zn and Cu concentrations in all the streams were within the acceptable WHO limits, whiles Pb and As appeared to be higher than the acceptable limits in all the streams. The highest concentrations of most of the heavy metals were recorded at the Kronum site on Owabi stream. There was a statistically significant positive correlation between pH and some metals at all the sample points (p = 0.05). The results showed that all the streams were polluted and must be treated before consumption. It was also recommended that, human activities within the catchments should be monitored closely to minimise their polluting impacts on the water quality.

Key words: Heavy metals, Owabi, pollution, water quality, WHO.