Temporal lead contamination and health risks of geophagia in Eldoret Municipality, Kenya

Abstract

In Kenya, geophagic soils have been commercialised and are currently packaged and sold in supermarkets or sold in open markets where they are exposed for long periods to environments with high probability of contamination such as vehicular lead. This study assessed concentration levels of lead (Pb) at source (Gituro quarry, Eldoret) and temporal Pb contamination of exposed geophagic soils sold in open markets in Eldoret Municipality. The results showed that mean Pb levels in the soil samples were all above naturally occurring levels indicating contamination from environmental sources. Lead concentration was lowest at source, and ranged from 31.5 mg/kg – 41 mg/kg with a mean of 32.5±2.2 mg/kg - 37.5±2.1 mg/kg. Exposed soils had highest Pb concentration at Langas site with a range of 57.5 mg/kg - 98.0 mg/kg while Huruma, Municipal market (1), and Municipal market (2) sites ranged from 46.5 mg/kg - 73.5 mg/kg Pb, 36.5 mg/kg - 84.5 mg/kg Pb and 55.0 mg/kg - 66.0 mg/kg Pb respectively. Regression of Pb levels with time gave strong positive relationships indicating temporal Pb accumulation. Health risk assessment showed that geophagia is a potential health hazard especially for soils exposed over a longer time in the open market. Geophagic soils sold at the open markets should be avoided.