While mercury emission from industrialized countries has been reduced during the last decade, communities in developing countries are facing increasing health and environmental risks linked to exposure to mercury, according to new studies by the United Nations Environment Programme (UNEP).
According to UNEP anthropogenic sources are responsible for about 30% of annual emissions of mercury to air, another 10% comes from natural geological sources, and the rest (60%) is from ‘re-emissions’ of previously released mercury that has built up in surface soils and oceans. Mercury is contaminating soils and rivers, and much of human exposure to mercury is through the consumption of contaminated fish. UNEPs Global Mercury Assessment 2013 Report
Mercury poisoning leads to sensory impairment, disturbed sensation and a lack of co-ordination, kidney lung and brain disfunction and even death.
Figure: Estimates of annual anthropogenic mercury emissions
from different continents/regions, 1990-2005.
Source: UNEP, Global Mercury Assessment 2013, UNEP, Geneva, 2013
The new UNEP report said parts of Africa, Asia and South America could see increasing emissions of mercury into the environment, with artisanal and small-scale gold mining emissions being the major source of emissions to air, at 727 tons per year globally in 2010, followed by coal burning. The original studies and reports: UNEP, Global Mercury Assessment 2013, UNEP, Geneva, 2013
Sub-Saharan Africa’s emissions were in the 168-154 tons/year range, 16.1% of the global average of 1,960 tons/year (range 1,010-4,070), topped only by East and Southeast Asia, with a range of 395-1,690 tons/year, or 39.7% of the total. After South Africa came South America, with an emission range of 128- 465 tons/ year (12.5% of the total), according to UNEP’s Global Mercury Assessment 2013.
The GMA report reiterated that much human exposure to mercury is through the consumption of contaminated fish, making aquatic environments the critical link to human health. UNEP reports that man-made emissions have caused the amount of mercury in the top 100 metres of the world’s oceans to double during the last 100 years. Along with a parallel UNEP publication "Mercury; Time to Act", the new assessment will be formally presented at the International Negotiating Committee on Mercury (INC5), taking place in Geneva this week (January 13- January 18).
Another scientific report published a few days ago by Sunderland and Selin (see below) projects the historical trends into the future. The authors come to the alarming conclusion, that inputs of mercury to ecosystems are expected to increase substantially in the future, in part due to growth in the legacy reservoirs of mercury in oceanic and terrestrial ecosystems. Seawater mercury concentration trajectories in areas such as the North Pacific Ocean that supply large quantities of marine fish to the global seafood market are projected to increase by more than 50% by 2050. Their report concludes, that aggressive anthropogenic emission reductions are needed to reduce MeHg exposures and associated health impacts on humans and wildlife and protect the integrity of one of the last wild-food sources globally.
Elsie M. Sunderland, Noelle E. Selin, Future trends in environmental mercury
concentrations: implications for prevention strategies
, Environmental Health, 12:2 (2013). doi: 10.1186/1476-069X-12-2 Related studies:
R.P. Mason, A.L. Choi, W.F. Fitzgerald, C.R. Hammerschmidt, C.H.Lamborg, A.L. Soerensen, E.M. Sunderland, Mercury biogeochemical cycling in the ocean and policy implications
, Environ. Res., 119 (2012) 101–117. doi: 10.1016/j.envres.2012.03.013
Chad R. Hammerschmidt, Katlin L. Bowman, Vertical methylmercury distribution in the subtropical North Pacific Ocean
, Mar. Chem., 132–133 (2012) 77–82. doi: 10.1016/j.marchem.2012.02.005
F. Wang, R. Macdonald, D. Armstrong, G. Stern, Total and methylated mercury in the Beaufort Sea: The role of local and recent organic matter remineralization
, Environ. Sci. Technol., 46 (2012) 11821–11828. doi: 10.1021/es302882d
D. Cossa, L.-E. Heimburger, D. Lannuzel, S.R. Rintoul, E.C.V. Butler, A.R. Bowie, B. Averty, R.J. Watson, T. Remenyi, Mercury in the Southern Ocean
, Geochim. Cosmochim. Acta, 75 (2011) 4037–4052. doi: 10.1016/j.gca.2011.05.001
E. Pacyna, J. Pacyna, K. Sundseth, J. Munthe, K. Kindbom, S. Wilson, F. Steenhuisen, P. Maxson, Global emission of mercury to the atmosphere from anthropogenic sources in 2005 and projections to 2020
, Atmos. Environ., 44 (2010) 2487–2499. doi: 10.1016/j.atmosenv.2009.06.009
D. Cossa, B. Averty, N. Pirrone, The origin of methylmercury in open Mediterranean waters
, Limnol. Oceanogr., 54 (2009) 837–844. doi: 10.4319/lo.2009.54.3.0837
E.M. Sunderland, D.P. Krabbenhoft, J.W. Moreau, S.A. Strode, W.M. Landing, Mercury sources, distribution, and bioavailability in the North Pacific Ocean: Insights from data and models
, Global Biogeochem Cycles, 23 (2009) GB2010. doi: 10.1029/2008GB003425
D.G. Streets, Q. Zhang, Projections of global mercury emissions in 2050
, Environ. Sci. Technol., 43/8 (2009) 2983–2988. doi: 10.1021/es802474j
J.L. Kirk, V. St Louis, H. Hintelmann, I. Lehnherr, B. Else, L. Poissant, Methylated mercury species in marine waters of the Canadian High and Sub Arctic
, Environ. Sci. Technol., 42 (2008) 8367–8373. doi: 10.1021/es801635m
E.M. Sunderland, R. Mason, Human impacts on open ocean mercury concentrations
, Global Biogeochem. Cycles, 21 (2007) GB4022. doi: 10.1029/2006GB002876
R.P. Mason, W. Fitzgerald, Alkylmercury species in the equatorial Pacific
, Nature, 347 (1990) 457–459. doi: 10.1038/347457a0
Related information UNEP: Reducing Risk from Mercury BRI
- Report: Mercury in the Global Environment: Patterns of Global Seafood
Mercury Concentrations and their Relationship with Human Health Zero Mercury Working Group - Report: Mercury Contamination, Exposures and Risk: A New Global Picture Emerges, December 2012 Related EVISA Resources Link database: Mercury exposure through the diet Link database: Environmental cycling of mercury Link database: Toxicity of Organo-mercury compounds Link database: Research projects related to organo-mercury compounds Related EVISA News January 14, 2013: United Nations Global Mercury Treaty: Fifth and final session December 9, 2012: Mercury in fish more dangerous than previously believed; Scientists urge for effective treaty ahead of UN talks June 17, 2012: Factors Affecting Methylmercury Accumulation in the Food Chain January 25, 2012: New Report Shows High Levels of Mercury in Terrestrial Ecosystems December 19, 2011: Anthropogenic Mercury Releases Into the Atmosphere from Ancient to Modern Time October 15, 2011: Mercury pollution in the Great Lakes region -- nearly forgotten, but not gone January 21, 2011: Arctic Mercury Cycling May Be Linked to Ice Cover August 16, 2010: Methylmercury: What have we learned from Minamata Bay? June 28, 2010: New Study Examines Why Mercury is More Dangerous in Oceans
August 21, 2009: USGS Study Reveals Mercury Contamination in Fish Nationwide May 3, 2009: Ocean mercury on the rise February 11, 2009: Mercury in Fish is a Global Health Concern June 17, 2009: 'Surprisingly High Levels' of Methylmercury Contamination found in Groundwater October 30, 2008: Precautionary approach to methylmercury needed
March 11, 2007: Methylmercury contamination of fish warrants worldwide public warning October 9, 2006: Linking atmospheric mercury to methylmercury in fish August 16, 2006: Mercury pollution threatens health worldwide, scientists say June 8, 2006: Methylmercury in fish: Can you cook it out ? February 17, 2006: Study shows link between clear lakes and methylmercury contamination in fish
last time modified: January 14, 2013