28 Sep 2017 Story Chemicals & waste

Une conférence historique démontre au monde entier l'étendue de la menace posée par le mercure

As the mercury falls in Geneva with the advent of autumnal chills, the world is for the first time gathering to deal with the rising health impacts of the toxic chemical.

The Minamata Convention on Mercury, which entered into force last month, is holding its first conference of the parties from 24 to 29 September in the Swiss city. The goal is to protect people and the environment – by accelerating action on controlling mercury emissions from industry, banning new mercury mining, and reducing mercury use in artisanal and small-scale gold mining.

“The Minamata Convention shows that our global work to protect our planet and its people can continue to bring nations together,” says UN Environment Executive Director Erik Solheim. “Together, we are cleaning up our act.”

This concerted international action under the convention, which has 128 signatories and 76 ratifications, is an intensification of previous efforts such UN Environment’s Global Mercury Partnership. And it comes not a moment too soon.

Human activities have doubled the amount of mercury in the top 100 metres of the oceans in the last 100 years, and we continue to release an estimated 2,960 tonnes every year. We are poisoning our planet, and so ourselves. The very name of the convention, taken from the worst mercury poisoning disaster in history, highlights the damage that the neurotoxin can cause.

In May 1956, following decades of dumping of industrial wastewaters into Minamata Bay, Japan, villagers who ate fish and shellfish from the waters suffered convulsions, psychosis, loss of consciousness and coma. The poisoning claimed the lives of 900 people, with 2,265 people eventually certified as suffering from mercury poisoning.

While there has not been a repeat of such a dramatic and localized incident, problems persist today across the globe. Several new reports released this year demonstrate the far-reaching and insidious nature of the health threat – which is particularly grave for unborn children and infants.

Multiple threats

A study from IPEN, UN Environment and the Biodiversity Research Institute found mercury levels in women from four Pacific Islands, with a diet rich in fish, up to 11 times greater than the 1 ppm (parts per million) threshold for negative health effects.  The study, which analyzed hair samples from women of child-bearing age, found that 96 per cent of the women sampled exceeded the 1 ppm threshold.

“The information revealed to us that Pacific Island women appear to be at significant threat of mercury contamination through their food chain,” IPEN researcher Lee Bell says. “This shows there is a global deposition of mercury to oceans, and that where people eat a lot of fish they are being impacted by those mercury emissions.”

The problem is bioaccumulation. As inorganic mercury in our air, soil and water enters the oceans, aquatic microbes convert it to methylmercury – a form readily absorbed by sea life. At every step in the food chain, methylmercury loads increase until they reach levels as much as half a million times higher than in the water. And at the top of that food chain, more often than not, is us.

“What it tells us is that we need to dramatically alter and reduce mercury pollution and emission sources,” Bell says. “So we need to ensure that all countries who have ratified the Minamata Convention endeavour to take very strong action to reduce their mercury emissions as soon as possible.”

Mercury is also a major problem in artisanal and small-scale gold mining, where miners employ it to separate gold from ore – giving off toxic fumes when it is burned away.

According to UN Environment’s new report, Global Mercury Supply, Trade and Demand, artisanal and small-scale gold mining has steadily increased (along with the spot price of gold) since about 2000. To meet the demand for gold, new mercury supply chains have emerged since 2011 in Mexico and Indonesia, with their combined mercury mining production estimated at 800-1100 tonnes in 2015.

A new report from the UN Environment-hosted International Environmental Technology Centre, the Global Mercury Waste Assessment, shows that mercury waste management is an additional part of the toxic puzzle.

The review of 30 countries finds many continue to manage mercury waste as part of municipal or industrial waste, and dispose of it as mixed waste in landfills or at open dumping sites – creating another route of exposure.

Multiple solutions

The Convention’s work on addressing these sources, and many others besides, is particularly crucial given mercury’s persistence once released to the environment.

“When mercury is emitted into the environment it can cycle and can impact health and ecosystems for a long time – so the sooner we reduce emissions the more those long-term impacts will be reduced,” Ken Davis of UN Environment’s Global Mercury Partnership says.

Other moves are afoot to address mercury – as well as other sources of pollution to the air, water, and land. Today, UN Environment is releasing a new report, Towards a Pollution-Free Planet, at the Minamata meeting. It lays out the scale of the challenge and points to solutions, which the UN Environment Assembly will take up later this year.

The assembly, set for early December at the UN Environment headquarters in Nairobi, will serve as a platform for governments, the private sector and civil society to bring the latest insights on how to achieve a pollution-free planet. It represents a critical opportunity to drive bold global commitments to beat pollution.

“The Minamata Convention and the UN Environment Assembly show that world is ready, willing and able to end the mercury menace,” says Claudia TenHave, who heads up the Minamata Convention’s secretariat. “Now we need to put in the work.”   

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