Arsenic in Groundwater Sources and Skin Cancer Prevalence in Meru County, Kenya

Natural contamination of groundwater by arsenic (As) derived from the Earth’s crust is a common global phenomenon. The World Health Organization (WHO) has set a safe limit of 10 μg/L for As in drinking water. Arsenic toxicity causes serious human health problems, especially dermal lesions and skin cancers. Other associated effects include lungs, bladder, prostate, liver, and kidney cancers; cardiovascular diseases; diabetes mellitus; encephalopathy; and adverse pregnancy outcomes. This study investigated the levels of arsenic in groundwater sources and the 5-year prevalence of skin cancer in Meru County, Kenya. Four springs and twenty-five water boreholes were analysed for arsenic using inductively coupled plasma-optical emission spectrometry (ICP-OES). The As levels ranged from <2.94 to 85.4 ± 8.3 μg/L. All the four springs were found to be free from As contamination whereas eight boreholes (32%) had >10 μg/L As. Most of the affected springs were in Buuri sub-county, and the same area had a high prevalence of skin cancers, with 8 per 100,000 persons five times higher than the national prevalence. The findings showed an underlying potential health risk of As-induced cancers from the use of contaminated groundwater, and follow-up epidemiological studies are recommended. Mitigation and remediation measures against chronic As exposure are necessary to safeguard inhabitants of this region.