Liquid mercury
Image via Cameroon Chemical Company

Occasionally I come across a surprising anachronism which I thought was an issue resolved long ago. The continued lack of voting rights for women in a some countries (Saudi Arabia, Vatican City); the ongoing controversy regarding Pluto’s status (“dwarf planet” vs. “planet” vs. “Kuiper belt object”), things like that. As it turns out, another anachronism has been existing outside my horizons for completely inexplicable reasons: As of January 2013, the world’s first legally binding international treaty on mercury will aim to reduce the global emissions levels, production and the use of mercury in household products and in industrial processes.

Mercury is found in products ranging from electrical switches to amalgam dental fillings and even facial creams, and large amounts of the heavy metal are released from small-scale gold mining, coal-burning power plants, metal smelters and cement production.

It’s like finding out I live next door to a mountain range I never before noticed. Yes, I know all about mercury in fish, but for some reason I have been telling myself that the mercury in the seas was the result of old industrial fallout, not from continuing run-off into the world’s waterways, or from the estimated 200 tonnes that end up in Arctic every year, ready to melt into the oceans.

I remember as a child learning that a broken thermometer was a household disaster, the scurrying silver pearls to be gathered with a slip of paper into a jar and turned over to a pharmacist for disposal. For even if mercury has a number of interesting chemical properties, and even though the first emperor of China, Qín Shǐ Huáng Dì  was killed by drinking a mercury and powdered jade mixture formulated by Qin alchemists who intended to give him eternal life, it has been general knowledge for over 50 years that mercury is not a healthy element once ingested. 

The images of Minamata mercury victims during the 1960s are probably why I thought this was a poison long since under strict controls – how could we let something this toxic race, quicksilver, through our homes, through the air, through the seas? No matter, I have no excuse for this blind spot in my knowledge.

The Minamata Convention on Mercury is due to be signed in October in Minamata, Japan, so emblematic of mercury poisoning. It’s a beginning.

More:

New Scientist article

World Health Organization document – Exposure to Mercury