Heavy metal blunder: First international mercury treaty too weak, scientists say

Graphic: Justin Ladia

Over 140 United Nations member states agreed to a treaty to reduce mercury emissions on Geneva. The treaty has been under negotiation for four years. Named the Minamata Convention on Mercury after a Japanese city that was hit hard by mercury pollution in the mid-20th century, it is the first legally binding international agreement to reduce mercury emissions. But some activists and non-governmental organizations (NGOs) are arguing that the treaty is not strict enough.

The treaty was adopted on Saturday, Jan. 19, after a week of talks and an evening of negotiations. It will be signed later this year in Minamata. Then it must be ratified by 50 nations before it comes into effect. It will be another three to four years before that happens.

The agreement will ban certain products containing mercury and require countries with small-scale gold mining operations to draw up national plans to reduce mercury emissions. Coal plants will be required to install the best available technologies to control mercury emissions. Specific thresholds and caps were not agreed upon, and will be discussed at the first meeting once the treaty enters into force.

Mercury is a toxic metal that usually reaches humans through contaminated fish. It can cause nerve damage, kidney damage, memory loss, and linguistic impairment. Children and pregnant women are especially vulnerable to mercury poisoning. The two largest sources of mercury emissions are coal and small-scale (artisanal) gold mining. Since mercury is present in coal, it is released in large amounts by coal-fired power plants. It is used in artisanal gold mining operations to separate the metal from its ore. This use, largely unregulated throughout the world, accounts for 35 per cent of the total global mercury emissions per year.

Mercury is a particular concern for Canada because the Arctic is hit especially hard by mercury pollution. A report from the United Nations Environment Program (UNEP) says that approximately 200 tonnes of mercury are retained by the Arctic each year.

According to Sarah Beattie, a master’s student at the University of Manitoba who studies the cycle of mercury in the Arctic, the metal evaporates into the atmosphere in warmer regions and moves toward the poles, where it condenses out of the atmosphere and is deposited into the ocean, on the snow cover, or onto the sea ice.

“Since mercury is an element, it will never be removed from the environmental system entirely. It can only be converted into safer, less toxic species.”

According to UNEP, once it has been deposited, the mercury can circulate for centuries at a time, and any reduction in mercury emissions would take years or decades to be felt.

Beattie said that strict emission regulations should be implemented, with specific numbers given upfront.

“My opinion is that we will only see Arctic mercury concentrations decrease if all countries (including Canada) sign this treaty, and if the restrictions within this treaty are properly enforced.”

Beattie is not alone in expressing concerns about the treaty. Several NGOs have complained that it is too lenient and too open-ended.

“We hope that many of the provisions in this treaty can still be improved, but as it stands now the treaty offers only vague or no options for controlling emissions from the world’s worst sources of mercury pollution,” said Joe DiGangi, senior science advisor for the International Persistent Organic Pollutant Elimination Network (IPEN), a coalition of NGOs. “Countries that do not want to do this can escape quite easily.”

IPEN, along with some Japanese activists, takes issue with the treaty’s name, saying that its restrictions would not have prevented the health issues in Minamata.

“Water pollution resulting in contaminated sediment and fish caused the Minamata tragedy, but the treaty contains no obligations to reduce mercury releases to water and no obligations to clean up contaminated sites,” said Japanese activist Takeshi Yasuma in an interview with the CBC.

Supporters of the treaty have called it a first step, and hope that it will become stronger over time.