Environmental analysis of heavy metal pollution in Mtondia dumpsite, Kilifi County, Kenya.

Abstract

Dumping and open burning of waste with no regard to environmental implications is a common occurrence in Kenya. In several health surveys in communities close to dump sites, a wide range of human health problems, such as respiratory symptoms, allergies, irritation of the skin, and gastrointestinal problems, have been reported. The issue of heavy metal pollution brought about by the dump sites has become of concern in recent studies. Heavy metal contamination occurs when their concentrations exceed the recommended limits in the soil, water, or plant resources and have negative effects on humans or animals. The accumulation of heavy metals in agricultural soils is of great concern due to food safety issues, potential health risks, and detrimental effects on the soil’s ecosystems. The samples were obtained through random sampling and analysed in the laboratory using the Energy Dispersive X-ray Fluorescence (EDXRF) technique. The EDXRF technique software was used to calculate the qualitative and quantitative aspects of the heavy metals. SPSS version 22 was used to calculate Pearson's correlation coefficient. It was observed that the soil and plants sampled from the dumpsite recorded higher levels of heavy metals than the control samples. This showed that the soils at the dumpsite were more polluted with heavy metals as compared to those at the farms. The mean concentrations of the heavy metals in soil during the dry season followed the trend Zn>Mn>Pb>Cu>Ni>Co>Cr>As. In conclusion, it was observed that the resources (soil, plants, water, and fish) were indeed polluted with various heavy metals. However, the levels do not exceed the permissible limits set by the WHO and FAO.