Elemental mercury exposure in men, women, and children from a Bolivian community engaged in artisanal gold mining

Artisanal gold mining is attractive to economically disadvantaged communities because it requires little capital investment and uses relatively simple equipment.  The prevailing method involves the addition of elemental mercury to pulverized rock to form a gold-mercury amalgam which is then further processed to remove the mercury.  Exposure to elemental mercury or its amalgam happens primarily by inhalation of the vapor and places workers at risk of adverse health effects, particularly to the central nervous system and kidneys.  The concentration of mercury from spot urine samples was used to assess individual exposure in men (n=89), women (n=24), and children (n=21) who reside and work in an area of Bolivia involved in artisanal gold mining. Participants also responded to questionnaires.  Results were categorized as ACCEPTABLE (less than 7 µg/L urine), CAUTION (7-25 µg/L urine), and HEALTH ALERT (> 25 µg/L urine).  While over half of the participants had acceptable levels of mercury exposure, 17% of the men (n=11/89), 25% of the women (n=6/24), and 25% of the children (n=5/21) were found to have levels placing them in the HEALTH ALERT range. 22% (14/63) of adults reporting occupational contact with mercury were in the HEALTH ALERT range compared with 13% (3/23) among those without such exposure.  We are currently engaged in analysis to determine the geospatial, environmental, and workplace factors associated with mercury exposure. These findings will be used to develop interventions in collaboration with the community, the mining cooperatives, and PLAGBOL, a Bolivian organization seeking to minimize exposures to environmental toxicants.