The Assessment of Heavy Metals Pollution in the Nyabarongo River Sediments – Case Study: Mageragere Sector

Abstract

The accumulation of heavy metals in rivers’ sediments near industrial wastes and mining activities has been a serious issue in developing countries including Rwanda and it has caused different environmental impacts on aquatic and terrestrial lives. Environmental studies have reported heavy metals pollution (lead, manganese, copper, zinc, nickel, iron,and cadmium) in major Rwandese rivers such as Mpazi, Rusine, and Nyabugogo. The increasein heavy metal concentrations in the environment results in abnormal enrichment,which in turn, affects the surrounding environment. This study aimed to investigatethe heavy metals in Nyabarongo sediments, Mageragere sector using both X-ray fluorescence (XRF) and Atomic Absorption Spectrometer (AAS) instruments. Sediments samples were collected systematically on four sampling stations and the results showed that the Cadmium (Cd), Lead (Pb), and Manganese (Mn)concentrationsamong the investigated heavy metals areabove the Rwanda Standard Board (RSB) and World Health Organization (WHO) guidelinesfor soils and sediments, meaning that those metals arethe measure pollutantsin the sediments of Nyabarongo River and the study has recommendedthe people around the river to reinforce the erosion control measuresand not to use Nyabarongo water for domestic use and animal farming activities because of the concentration of heavy metals it contains that are toxic to animals, plants and micro-organisms