Heavy metals found at Umzimvubu River Estuary in the Eastern Cape, South Africa

Abstract

The aim of this research was to detect and measure the concentration of heavy metals found in the water and silt of the Mzimvubu River at Port St Johns in the Eastern Cape. The water from this river estuary is used by the people and animals of that area and is suspected to cause several health conditions. The objective of the research was to undertake a pilot analysis for heavy metals. Atomic Absorption Spectroscopy (AAS) was selected as a tool to determine the concentration of the heavy metals present in the water and sediment samples. Water and sediment samples were collected at the river mouth and 5 kilometers upstream, near the R61 bridge, on either side of the river. The atomic absorption spectrophotometer used to measure the heavy metal concentrations was a Varian Spectra AA 100 equipped with a single slot burner. Measurements were carried out in triplicate. Throughout the study it was evident that there are heavy metals such as lead, cadmium, zinc and nickel in the Umzimvubu River. The bio-accessibility of lead is a concern in view of the fact that it was found in high concentrations. Cadmium contamination was found to be in lower concentrations compared to the South African guidelines. Zinc and nickel were not severe since both were within the WHO and SADWAF guidelines. Therefore, it is concluded that the Umzimvubu River is an intimidation to many living organisms since it contains high concentrations of Lead, significantly higher than the South African guidelines. Severe damage in physical condition could be experienced by the human and animal populations in close proximity to the river. Further and more detailed studies are recommended, including bio-accessibility and bio-accumulation studies.

Key words: Mzimvubu river, heavy metals, atomic absoption spectroscopy.