Assessment of the Impact of Groundwater Fluoride on Human Health in Makindu District, Makueni County, Kenya

Abstract

Assessment of human exposure to the naturally occurring fluoride in groundwater in Kenya has not being exhaustive in terms of geographical coverage and the media. There is need to have representative data and information on the extent of human exposure to fluoride and its impact on human health. This study investigated the extent of human exposure to fluoride and its impact on human health in Makindu District, and evaluated the potential risk of using ground water contaminated by fluoride ion (F-). The study used, an ex post facto design and the data collection tools used were interviews, questionnaires, key informants and observation. The research involved three key-informants, two dentists and one health officer, a sample of 286 respondents from Makindu Location and 112 respondents from Kiboko Location were interviewed and observed. The data collected was analyzed using the Ms-Exel and the Statistical Package for Social Sciences (SPSS). Majority, 80% and 68% respectively, of the respondents in Makindu Location and Kiboko Location relied on tap water from springs whereas those who relied on boreholes were 10% and 21% respectively. Raw water from Makindu Spring, the main source of drinking water for Makindu Town, had fluoride concentration of 1.1 mg/L, which is below the WHO maximum allowable value of 1.5 mg/L. All the three boreholes covered during the study had fluoride concentration above the WHO maximum allowable value with Kiboko Borehole having the highest concentration of 4.2 mg/L followed by Makindu Boys Borehole with concentration of 2.85 mg/L. This implied that the population that relied on boreholes as a source of water was exposed to health risk associated with high fluoride. 38.4% and 33.3% of the respondents, respectively from Kiboko Location and Makindu Location, had moderately to severely mottled enamel, an indication of the impact of fluoride in water. To mitigate for the health impact of high fluoride, use of alternative sources of potable water as well as defluoridation is recommended. In addition, educating the community on dangers of using water with excess fluoride is recommended in order to ensure good health.