There are several forms of mercury that exist naturally in the environment, with the most common being metallic mercury, mercuric chloride, mercuric sulphide, and methyl mercury.
Some micro-organisms can produce organic mercury, particularly methylmercury, from other mercury forms. Methylmercury can accumulate in living organisms and reach high levels in fish and marine mammals via a process called biomagnification (i.e. concentrations increase in the food chain).
Methymercury contamination of fish and fish-eating mammals is a global public health concern.
RELEVANT ZMWG work
1. October 2013
Civil society organisations from 9 countries, participated in the ZMWG hair testing project in order to ascertain mercury levels in women of child bearing age and to raise awareness about reducing exposure to mercury, a dangerous neurotoxin. Samples were collected from rural and urban women. The study results revealed that women of childbearing age in several countries have mercury levels of concern, most likely due to high consumption of mercury-contaminated fish. Overall, nearly one-quarter (24%) of the samples exceeded the widely recognized U.S. Environmental Protection Agency (EPA) guideline of 1 microgram per gram (µg/g).
In 4 of the 9 countries a high percentage (defined as more than 20%) of all samples from women of child bearing age exceeded this threshold, specifically:
- 64% of those tested in Spain;
- 71% of those tested in Japan;
- 36% of those tested in Mauritius; and
- 23% of those tested in Côte d’Ivoire.
The report is available here: ASSESSING HAIR MERCURY LEVELS OF WOMEN OF CHILDBEARING AGE IN 9 COUNTRIES: A CIVIL SOCIETY PILOT PROJECT
Available in Spanish from Ecologistas en Accion at: http://www.ecologistasenaccion.org/article26617.html, http://tinyurl.com/nghjs2b
2.December 2012 - In preparation for INC 5, in January 2013, ZMWG is undertaking a series of Communication activities:
Two Global ZMWG Webinars were carried out on 4th December 2012.
On the 4th December 2012, the Zero Mercury Working Group, in cooperation with scientists from the Biodiversity Research Institute (BRI) and with other prominent scientists, organised a global webinar to release new findings that demonstrated extensive mercury contamination of seafood and summarized recent studies that show health effects from methylmercury occurring below the level that was considered “safe” just a few years ago. Scientists highlighted new research and explained why current government “safety limits” should be strengthened worldwide. The reports were released accompanied by a press release on the 4th December 2012. . This came ahead of the final round of United Nations negotiations, scheduled in January 2013, for a global mercury treaty.
Press Release - 4 December 2012 - Evidence shows mercury threat underestimated ahead of UN treaty talks
Also from colleagues around the world - SDPI Pakistan, AWHHE- Armenia, EeA- Spain, EEB/ZMWG FR version
3.In 2009, and before going to the 25th session of the UNEP Governing Council (February 2009), ZMWG published a report after having carried out a study of fish tested in different locations around the world. The study shows that internationally accepted exposure levels for methylmercury are exceeded, often by wide margins, in each country and area covered. According to the report, “Mercury in Fish: An Urgent Global Health Concern”, the risk is greatest for populations whose per capita fish consumption is high, and in areas where pollution has elevated the average mercury content of fish. In cultures where fish-eating marine mammals are part of the traditional diet, mercury in these animals can add substantially to total dietary exposure. In addition, the study shows that methylmercury hazards still exist where these dietary and local pollutant levels are less prevalent.
In cultures where fish-eating marine mammals are part of the traditional diet, mercury in these animals can add substantially to total dietary exposure. In addition, the study shows that methylmercury hazards still exist where these dietary and local pollutant levels are less prevalent.
[10 February 2009]