Obama re-ignites stalled talks on global mercury rules

After years of deadlock, an international deal to reduce global mercury levels is imminent after the US dropped its Bush-era opposition to the proposed new rules and pledged to take a "leading role" in efforts to deliver a legally binding agreement to cut use of the toxic metal.

No formal treaty has been signed, but the US, India and China along with representatives from 137 other countries all agreed last week to press for an agreement at negotiations later this year.

The US – one of the world's largest exporters of the metal – had been opposed to measures that would curtail global trade of mercury, with the Bush administration repeatedly blocking international efforts to limit its use.

But, in a sign of things to come, Barack Obama last December co-sponsored a bill to ban exports of elemental mercury by 2013 and introduce rules governing the storage of the metal from 2010.

The EU also took similar action last year with an export ban that will become effective from 2011.

Now the US has dropped its opposition to even tighter international rules, with Nancy Sutley, chair of the White House council on environmental quality, insisting the country "will play a leading role in working with other nations to craft a global, legally binding agreement that will prevent the spread of mercury into the environment".

The UN-backed treaty will aim to tackle all parts of Mercury trade and will work to reduce both supply and demand.

Under the proposals, signatories to the deal will reduce the supply of mercury from mines, while on the demand side they will invest in identifying alternative materials that can be used in products such as thermometers and industrial processes like paper manufacture.

The treaty will also seek to cut mercury emissions from coal-fired power plants, which are responsible for about half of the world's mercury pollution, and reduce the use of mercury in small-scale gold mining where an estimated 10 million miners and their families are exposed to dangerous mineral vapours.

In a clear nod towards talks to agree an international deal on climate change by the end of the year, Achim Steiner, UN under-secretary general, said the mercury agreement underlined the fact that effective global environmental regulations could be delivered.

"Only a few weeks ago nations remained divided on how to deal with this major public health threat, which touches everyone in every country of the world," he said. "Today we are united on the need for a legally binding instrument and immediate action towards a transition to a low-mercury world."

Mercury often ends up contaminating waterways where it affects fish and enters the food chain. This can ultimately lead to illness, particularly among the elderly and newborn children.

In Sweden, for example, around 50,000 lakes have pike with mercury levels exceeding international health limits. Women of child-bearing age are advised not to eat pike, perch, turbot and eel at all, while the rest of the population are advised to only eat it once a week.