Environmental and health problems associated with artisanal mining in kenya: a case study of macalder mines in Migori.

Abstract

In order to understand the risk of heavy metal contamination in soil and water and their association with health problems among communities practicing artisanal gold mining, a cross-sectional study was carried out in the Macalder mines in Migori County, Western Kenya. In order to collect information on heavy metal concentration in the soils and water in mines and surrounding area, a total of 150 soil samples and 150 water samples were randomly collected from the house-holds, the Macalder mines area and River Kuja which was the main source of drinking water for most of the study respondents. Data from the questionnaire survey and key informant interviews was analyzed using descriptive statistics. An elemental analysis for mercury, lead and arsenic was carried out using the X-ray fluorescence spectrometry (XRF) technique. The household surveys showed the average household size was 7 people, and 50% of the respondents reported arti-sanal mining as their main source of livelihood. The binomial tests proved that there is no relationship between occupation and illness as the results of the logistic regression were all tending towards the probability of 1 (Chest infections-0.9907, miscarriages- 0.993, tuberculosis-0.991, anaemia 0.405, malaria-0.0144). The miners and non-miners had minimal knowledge on the dangers associated with the use of mercury or any illnesses linked to mercury. None of the miners reported using any personal protective equipment. The levels of mercury, lead and arsenic in soil and water study samples were compared against the acceptable safe levels recommended by the World Health Organization and United States Environment Protection Agency. The levels of lead and arsenic were highest in soil samples from River Kuja and the Macalder mines, with lead quantities being 1.05 and ix 5200 times, and arsenic quantities being 1.97 and 7300 times above the WHO/US-EPA acceptable levels respectively. The levels of mercury, lead and arsenic in soil and water study samples were compared against the acceptable safe levels rec-ommended by the World Health Organization and United States Environment Protection Agency. Levels of arsenic, lead and mercury from the household were either within the WHO and US-EPA acceptable levels or undetectable. Levels of lead in River Kuja were above acceptable levels in both soil and water samples. Arsenic had acceptable levels in the water but unsafe levels in the soil samples. The Macalder mines had unacceptable levels of lead and arsenic in both soil and water samples, creating an occupational risk for the mineworkers. It is interesting to note that mercury, which is the main input for the amalgamation process was undetectable in all the soil and water samples. The data shows an increased risk of exposure to the heavy metals among the miners in Macalder mines and River Kuja compared to exposure acquired at the households. To allow safe mining processes, there should be precautionary steps such as rehabilitation of the mines, use of personal protective equipment and education on the dangers of exposure to toxic elements like mercury, which is used, in the mining process. Also, artisan-mining policies that have well organized laws of operation to reduce the occupational risks should be implemented.