Mercury Exposure, Cardiovascular Health, and Pulmonary Function in a Small-Scale Gold Mining Community in Northeast Ghana.

Abstract

Small-scale gold mining is practiced globally in low and middle-income countries and is a vital component of the Ghanaian economy. Miners and non-miners in artisanal and small-scale gold mining (ASGM) communities may be highly exposed to elemental mercury (Hg), a toxicant used to isolate gold, as well as silica dust generated during the mining process. With the exception of a few studies, the scientific literature lacks research on how ASGM communities are exposed to Hg, how Hg exposures impact blood pressure (BP), and how ASGM impacts pulmonary function. The objective of this research is to increase the understanding of Hg exposure via multiple media and its impacts on BP, and to assess pulmonary function in an ASGM community. Residents in northeast Ghana from an ASGM community, Kejetia, and a comparison subsistence farming community, Gorogo, were surveyed in May through July 2011 on mining and medical histories and practices. Participants had BP (systolic and diastolic) measured, performed spirometry, and provided urine, hair, and household soil samples. Data were collected from 97 adults from 54 households in Kejetia and 75 adults from 26 households in Gorogo. Total mean specific gravity-adjusted urinary Hg, hair Hg, and household soil Hg were higher among Kejetia miners than Kejetia non-miners, and Gorogo participants. Close to one-third of Kejetia participants had urinary Hg concentrations >10 µg/L and household soil Hg above the Canadian health guideline of 6.6 µg/g Hg. Urinary and hair Hg were not significantly associated with systolic or diastolic BP for Kejetia or Gorogo participants, but follow trends found in other studies. Abnormal lung function was elevated above the expected 5% in healthy populations for percent predicted FEV1 (15.0%) and FEV1/FVC (22.0%). Percent predicted FEV1, FVC and FEV1/FVC were not significantly different between Kejetia and Gorogo or by mining status in Kejetia. Biomass fuel use showed some associations with adverse respiratory symptoms and reduced pulmonary function. This research adds to our understanding of how miners and non-miners in ASGM communities may be exposed to Hg and serves as a basis for further research on pulmonary function and Hg’s cardiovascular impacts among small-scale gold miners.