Title: Mercury exposure, blood pressure and lung function in a small-scale gold mining community in northeast Ghana
Authors and Affiliations: Mozhgon Rajaee1, Allison K. Yee1, Rachel Long1, Thomas G. Robins1, Mark L. Wilson2, Elisha P. Renne3, Niladri Basu1
1 Department of Environmental Health Sciences, University of Michigan, School of Public Health, Ann Arbor, USA
2 Department of Epidemiology, University of Michigan, School of Public Health, Ann Arbor, USA
3Department of Anthropology, University of Michigan, Ann Arbor, USA
Abstract: There are a number of health risks that may result from artisanal and small-scale gold mining (ASGM), including the use of elemental mercury and exposure to respirable silica dust. There is increasing concern about potential cardiovascular effects of mercury exposure, though little is known about mercury-associated cardiovascular effects in ASGM communities despite the exposure risk. Exposure to respirable silica and biomass cooking fuels, which may adversely affect pulmonary function and respiratory symptoms, is another concern. In 2011, we conducted a cross-sectional study with adults (≥ 18 years old) in anASGM site (Kejetia; 97 adults from 54 households, including 71 current miners and 26 current non-miners) and a nearby subsistence farming site (Gorogo; 75 adults from 27 households, all current non-miners) in Ghana. Participants provided hair and urine samples to measure organic and elemental mercury exposure, respectively, and had blood pressure (systolic, diastolic) measured. Adults were interviewed on household characteristics and occupational and medical histories and were given a standard spirometry test to measure their forced expiratory volume in one second (FEV1) and forced vital capacity (FVC).Urinary Hg levels were elevated in Kejetia, particularly among current miners, compared to Gorogo and U.S. reference values. Urinary Hg was significantly associated with a decrease in diastolic BP (p = 0.024) for Kejetia miners while adjusting for sex, age, BMI, smoking status and pack years, hair Hg and biomass cooking fuel use. Urinary and hair Hg were not significantly associated with systolic BP for Kejetia miners or non-miners, or Gorogo.Abnormal lung function was observed at elevated rates in Kejetia miners and Gorogo for FEV1 (11.3% and 20.4%, respectively) and the FEV1/FVC ratio (11.3% and 28.9%, respectively), compared to a U.S. reference population (5%).Common adverse respiratory symptoms in Kejetia miners included chest tightness (53.5%), usual phlegm production (41.4%), usual cough (29.6%), chronic phlegm production (25.4%) and dyspnea (23.1%), which were also elevated in Kejetia non-miners.These results suggest a negative impact on cardiovascular and respiratory health that further research will help to expound.