A systematic review on the management and treatment of mercury in artisanal gold mining

Highlights: • Many interventions try to remove mercury in artisanal gold mining. • This review found social, technical, environmental aspects must be considered. • A systematic review determined barriers involved with current solutions. • Removing mercury in AGM requires a comprehensive approach. • Technology, education, mineralogy, and government support are needed. Artisanal gold mining (AGM) continues to be a pervasive global health issue. While there are various problems associated with AGM, mercury exposure is the primary hazard contributing to adverse health effects in exposed human populations. Over the last several decades, many interventions have been developed and implemented to curb mercury emissions and releases, notwithstanding a comprehensive review of context specific effectiveness. A systematic review was conducted in order to specifically assess the impact of current mercury interventions within the AGM sector worldwide. To aid in this review, a resource pool of information on AGM and mercury, treatment and management of emissions and releases, and interventions was assembled through a search conducted via multiple search engines. This search determined that there have been many strategies used to reduce or eliminate mercury, through interventions or programs focusing on education, processing centers, or mercury alternative techniques. Education has focused on environment or health awareness or more specifically on cleaner or alternative techniques. Processing centers offered artisanal miners rudimentary equipment for grinding and amalgamation that extract less than 30% of the gold as an exchange for their tailings. Some techniques reduced mercury releases including retorts, mill leaching, vat-leaching, and others replaced mercury from the process such as magnets, direct smelting, sluices, and borax. There are both positive and negative outcomes associated with every intervention. Novel and comprehensive strategies—including mercury removal technology, miner education on mercury hazards, economic gains, and policy—are needed to address mercury public health issues associated with AGM.