March 2019: The UN Environment Programme (UNEP) has published an update to the 2013 Global Mercury Assessment that includes the most recent information available for global emissions to air, releases to water and transport of mercury in atmospheric and aquatic environments.

The report reflects progress made by the scientific community, national authorities and organizations to better understand: mercury cycling; atmospheric mercury emissions; mercury levels in air; atmospheric transport and fate; releases to water; and the cycling and methylation of mercury in the aquatic environment. The 2018 Assessment also includes new sections on observed mercury levels in biota, and observed mercury levels and trends in humans.

The assessment highlights a number of policy-relevant findings, some of which are highlighted below.

  • A new global inventory of mercury emissions to air from anthropogenic sources in 2015 quantifies global emissions from 17 key sectors at approximately 2,220 tonnes.
  • Actions to reduce emissions have resulted in modest decreases in emissions in North America and the EU, while increased economic activity, particularly in Asia, and the use and disposal of mercury-added products have more than offset efforts to reduce mercury emissions.
  • Stationary combustion of fossil fuels and biomass is responsible for about 24% of global emissions, primarily from coal burning.
  • The majority of mercury emissions in 2015 occurred in Asia, followed by South America and Sub-Saharan Africa.
  • Emissions from artisanal and small-scale gold mining (ASGM) account for almost 38% of the global total and are the main contributor to emissions from South America and Sub-Saharan Africa.
  • Human activities have increased total atmospheric mercury concentrations by about 450% above natural levels.
  • ASGM introduced about 1,220 tonnes of mercury into terrestrial and freshwater environments in 2015. Global releases of anthropogenic mercury from other sources (waste treatment, ore mining and processing and energy) to aquatic environments totaled about 580 tonnes in 2015.
  • Climate change and changes in terrestrial and aquatic ecosystem processes are playing increasingly important roles in the mercury cycle, affecting the distribution, chemical interactions and biological uptake of mercury in the environment.

The Assessment underscores that all people are exposed to some amount of mercury through, for example: consumption of fish, shellfish and marine mammals; and exposure to elemental and inorganic mercury in occupational settings, such as ASGM.

The assessment refers to mercury as the chemical element in all forms, in contrast to the Minamata Convention, which distinguishes mercury from mercury compounds. The 2018 assessment is the fourth such assessment undertaken by UNEP, and the second produced by UNEP in collaboration with the Arctic Monitoring and Assessment Programme (AMAP). [Publication: Global Mercury Assessment 2018] [Publication Landing Page]