Mercury Exposure Biomarkers and Neurologic Measure Differences between Registered and Unregistered ASGM Miners in Ghana

摘要

Workers within artisanal and small-scale gold mining (ASGM) communities are amongst the highest Hg-exposed groups worldwide. While formalization of this sector has been suggested as a means to reduce exposures and improve health and safety, we are unaware of empirical evidence that supports this notion. The objective of this study was to compare mercury exposure profiles and neurologic measures among miners working in licensed versus un-licensed ASGM sites. To achieve this, 404 small-scale miners were recruited in 2014 from 9 mining sites in Tarkwa (Ghana), of which 5 were licensed and 4 were not licensed. Miners were interviewed, performed a range of neurologic tests and surveys, and urine and hair samples were taken for measurements of total Hg content in a subset (n=316). Sociodemographic characteristics of miners from the two groups were relatively similar (33.8 yrs old, 92% male, 29% completed high school, 66% living with a partner). Those currently working in an un-licensed mine have higher mean levels of total Hg in urine (110.7 vs 16.0 ug/L; p<0.001) and hair (4.5 vs. 2.0 ug/g; p=0.09) compared to workers from the licensed mines. A range of other information was collected showing differences between these groups of miners such as work history and injury episodes, and these will be discussed. Neurological measures (e.g., gait, peripheral outcomes) are being finalized. These findings advance our understanding of mercury exposure (and other differences) amongst ASGM workers especially important differences between miners working in a licensed versus and un-licensed site.