Quantifying mercury use in artisanal and small-scale gold mining for the Minamata Convention on Mercury's national action plans: Approaches and policy implications

Establishing quantitative baseline estimates of mercury use in artisanal and small-scale gold mining is necessary to meet the requirements of the Minamata Convention on Mercury which aims to reduce and, where possible, eliminate mercury emissions. As part of this obligation, countries use baseline estimates to measure progress in reducing mercury emissions and releases. However, mercury baseline estimation methods vary widely resulting in high levels of uncertainty in estimates. Using artisanal and small-scale gold mining National Action Plans and baseline reports from 25 countries, we synthesize methods and data sets used to estimate mercury emissions and releases, demonstrating the range of techniques and quality of data used for these methods. National Action Plans often fail to report the quantitative uncertainty when reporting quantitative baseline estimates, and when reported, uncertainty often exceeds target reduction goals. Improved data transparency can increase the usefulness of such estimates in decision making, indicating areas in which more quantitative and qualitative data is needed for developing appropriate policies. This work demonstrates the limitations of quantitative baseline estimates as reported in National Action Plans and emphasizes the importance of a holistic understanding of the ASGM sector for policy decisions.