Health effects of mercury amongst artisanal gold miners in Lorgorien area, Trans-mara District, Kenya

Abstract

Gold occurs in a number of places within the gold-bearing greenstone rocks in western Kenya. From 1995, prospecting has been active in Lorgorien by licensed gold mining companies coupled with the influx of artisanal miners. Artisanal gold mining (AGM) using mercury (Hg) is of great environmental health concern. Mercury is one of the priority toxic elements of global consideration and its abusive discharge into ecosystems by miners poses serious health problems. The study was prompted by widespread use of mercury by small-scale gold miners in Lorgorien and lack of information on the effects of mercury to human health. This study examined the associated health problems of mercury (Hg) used by artisanal miners of gold in Lorgorien mine area, Transmara District, Kenya. Small scale gold mining contributes positively to social and economic development of Lorgorien Township. Mercury is used to purify gold and has been characterized by improper handling, unintentional spill and dumping into rivers and waterways. The health effects of mercury remain poorly studied in Kenya, and especially in Lorgorien area. The main objectives of the study were to; determine the community's knowledge on mercury problems, examine health effects associated with artisanal gold mining and to find out other factors that compromise the health of artisanal gold miners in the study area. The study was carried out in Lorgorien gold mining licensed area (Moyoi and Masurura locations). The study utilized a descriptive analytical study design. Data were collected using semi-structured questionnaires administered to 196 systematically sampled households by two clinicians and two research assistants. In-depth interviews with key informants, observation checklist, water and sediments sampling and health records from Lorgorien Sub-District Hospital were also used in the study. Data collected were cleaned, entered and analyzed using Statistical Package for Social Statistics (SPSS) version 16 for both descriptive and inferential statistics. Descriptive statistics that included frequencies, percentages and means were used to analyze data. Binomial test, Correlation and Regression tests were used to assess the null hypothesis at a significance level of 0.05. The study found out that mercury is widely used in the processing of gold. Majority of the miners (64%) indicated low awareness to mercury toxicity and identified some measures to reduce toxicity. Precautionary measures on how to mitigate negative effects of mercury were found out to be use of protective equipments, outdoor blowtorching and use of tailing ponds. Findings of the study revealed a statistically significant P-value (0.001) thus rejecting the null hypothesis. Hence, the study concluded that the health problems associated with mercury released by artisanal gold mining are widespread in the study area. The study recommends scaling up campaign to bolster awareness on what mercury does to human health and on-site training of miners on safe and healthy mining practices.