Evaluation of health risks associated with trace metal exposure in water from the Barekese reservoir in Kumasi, Ghana

Abstract

Reservoirs play a pertinent role in providing potable water to humans and aquatic animals. Exposure to trace metal pollution in water may threaten aquatic ecosystem and human health. In this study, total and dissolved trace metals pollution and health risk they posed to humans in water sampled from the Barekese reservoir in Kumasi were investigated. Levels of Hg, As, Ni, and Cr in the water exceeded the WHO and USEPA stipulated limits. Arsenic and Cd recorded the highest non-carcinogenic health risk to humans. Hazard quotients (HQs) ≫1 were recorded for an adult (HQ = 9.05) and a child (HQ = 21.11) via oral exposure to dissolved As in water samples. High HQ values of 40.10 and 17.20 for a child and an adult respectively were recorded through oral exposure for As. HQ of 1.41 was estimated for a child’s risk via dermal exposure to total Cd in water from the reservoir. Cancer risks of 1.63 × 10⁻⁵ and 2.33 × 10⁻⁶ were respectively recorded for a child and an adult oral exposure to dissolved As, suggesting possible adverse effects. The study concludes that anthropogenic activities within the Barekese catchment are deteriorating its water quality.

Keywords:

• artisanal mining
• carcinogenic
• non-carcinogenic
• metal
• water quality

Acknowledgments

The authors of this study are grateful to the Ghana Water Company Limited at Barekese for their kind courtesies and for permitting the use of their resources for this study.