Urban livestock and potential human health risks in Eldoret town, Kenya

Abstract

Urban agriculture is increasing in many urban areas in developing countries including Kenya. This is posing a danger of food contamination from heavy metals. This study assessed concentrations of heavy metals lead (Pb) and cadmium (Cd) in liver and kidney samples from Eldoret slaughterhouse. A total of 404 samples in duplicates comprising of kidney and liver tissues from randomly selected carcasses were analyzed for the heavy metals using standard procedures. Mean Pb (liver) and Cd (liver) concentrations were 0.16±0.07mg/kg and 0.021±0.026mg/kg, while Pb (kidney) and Cd (kidney) were 0.11±0.06mg/kg and 0.031±0.045mg/kg, respectively. The maximum concentrations of 0.33mg Pb/kg liver and 0.44mg Cd/kg kidney were those of animal samples from urban areas. The human health risk assessment was estimated by comparing the heavy metals exposure rates with the Provisional Tolerable Weekly Intake (PTWI). The calculations, demonstrated that the concentrations of the metals (Cd and Pb) in the animal livers and kidneys were much lower than the PTWI values and accordingly there is no risk for the human consumption of these organs in Eldoret town. However, since there is no established 'no effect level' for Pb in animals or humans, exposure to increased levels of Pb in foods resulting from direct human activity has to be avoided. Dietary intake levels should not exceed those considered acceptable by the tolerable limits.

Keywords: Heavy metals, urban agriculture, contamination, health risks