Tag Archives: Methyl Mercury

Eating predatory fish linked to methylmercury in humans

I belong to an international network called International POPs Elimination Network which has obtained small grants to fund research for its global CSO members.  Their ambit widened to toxics which fall under the categories for all the UN conventions on Chemicals & Wastes, because of the recognized interlinkages among issues.

 While for Pacific Islands the emphasis is on improving management of chemicals and wastes rather than technical expertise with regard to industrial byproduts, there are still not many Pacific CSOs who follow these multilateral environmental agreements.

I was happy with the  emphasis during the Health Conference on research to gather data to support policy-making

First, there is the same issue mentioned by Dr Maoate in his keynote speech i.e. translating European terms into Cook Islands maori.  I tend to characterize bad chemicals as vairaku kino, that is “bad medicine”. We have  had advisory  fact sheets about mercury   translated into maori by former Parliamentary translator.  We decided to coin the phrase “mecurio” for mercury because the periodic table of elements has not been translated.

The second point I would like to reinforce  is the targeting specific populations with regard to interventions.

My third point is focus on minimizing risks to human health and environment from methlymercury

UN Environmental Program has an initiative called Strategic Approach to International chemicals Management (SAICM) which provides a forum for industry, academia, practitioners, government policymakers and negotiations; and civil society organisations or NGOs.   Under SAICM, one of the current emphases is to engage the health sector in effective, safe management of chemicals and waste, starting at international level with WHO and working successively down through regional, subregional and national levels. 

Brain damage resulting from methylmercury exposure in utero has similar social consequences to those characterized earlier in the Conference with regard to exposure to alcohol.  So the key message is about reducing exposure to toxics that will have lifelong impacts on a person’s life.

The  United States Geological Service or USGS carried out a ground-breaking study in 2009.  The aim was to find the origins of methylmercury in the North Pacific Ocean, and how it gets into fish.

It was estimated that 75% of human exposure to mercury globally was from fish or shellfish, but nobody knew how it got there.  It was further estimated that about 40% of U.S. exposure was from Pacific fish, but there were no research results available.

In 2009, the USGS published its findings in a report entitled “Mercury Sources, Distribution & Bioavailability in the North Pacific Ocean: Insights from Data & Models”.  The complex methylation process was explained

US Environmental Protection Authority (US EPA) commented that one unexpected finding was the significance of long-range transport by large ocean circulation currents from the west to the east.  Typically it was though that emissions were due to land-based combustion activity but this particular study concluded that emissions originated near Asia.


Some sceptics dispute this; and others have commented that radionucleoide technology can be used to determine from which continent the combustion source originated. 

 An important point for the Cook Islands is that “global deposition” explains why islands so far from the continents should be affected when there are no  nearby sources such industrial processes or coal-based power stations.

 In Europe, PRTRs (“pollutant release and transfer registers”) were set up to monitor pollutant releases under a regional convention called the Aarhus Convention.   Air quality monitoring is also carried outin the Arctic.  Perhaps the Pacific region could do with a similar monitoring system.



In a report produced jointly by IPEN and Biodiversity Research Institute entitled Global Mercury Hotspots, alarming levels of mercury were found in humans in 14 countries. “Fish and human hair from around the world regularly exceeded health advisory levels,” said Dr. David Evers, Executive Director at the Biodiversity Research Institute (BRI). “The results demonstrate the need for a mercury treaty that mandates true reductions of mercury emissions not just to air, but also to land and water as well.”


As a Cook Islands public-interest NGO, ISACI took part in this IPEN-BRI project that analyzed mercury in hair and fish samples from 14 countries. Far from industrial sources and with little economic activity other than fishing and aquaculture for black pearls, the Cook Islands hair samples showed comparatively high levels of mercury. The most likely explanation for this result is that mercury is easily transported by wind and sea to remote, pristine environments where it enters the food chain.


“I am glad that a Pacific Islands country participated in this project,” said Lowell Alik, General Manager of the Marshall Islands Environmental Protection Authority at a presentation to governments on 16th January 2013. “But I also wonder what the levels in Marshall Islands might be, if we took part in a similar study. I have seen the film about the terrible health impacts of mercury contamination on the Minamata community in Japan, and I think our people would want to know.”


The dangers of mercury poisoning have been known for centuries. Exposure to high levels of mercury can permanently damage the brain and kidneys. Mercury can also be passed from a mother to her developing foetus and this can result in brain damage, reduced intelligence and mental retardation. Unless there is a meaningful effort to curb these sources, global mercury pollution looks likely to increase.


Some countries at the negotiations have pushed to eliminate obligations to reduce or eliminate mercury releases to land and water. Without such big reductions, global levels of methyl mercury (the organic form of mercury that pollutes fish and sea food) will increase. This is particularly important for Small Island states (SIDS) who main source of protein is fish.


Reversal of marine pollution has been successful in regions like the Baltic Sea, and Chesapeake Bay. “Clean-up of mercury in the Pacific Ocean would need large reductions by global emitters of their mercury emissions to air and releases to water and land,” said Imogen Ingram from ISACI. “Only then will contamination of our migratory fish be reduced.  SIDS may find that the UN Convention of the Law of the Sea, in particular its London Protocol dealing with marine pollution, may be the long-term solution that the Mercury Convention has not provided.”


Given that many foreign countries are fishing under licence in the Pacific, and exporting large volumes of fish to the global market, it is likely that consumers in the big countries of the world would also like to know.


Imogen Ingram

Island Sustainability Alliance CIS Inc. (“ISACI”)