Brandon Nichols knows first hand what it's like to get poisoned by mercury.
"I got mercury poisoning two or three times," he told CBC news. "I got some serious headaches."
The University of British Columbia grad student had been in South America, researching small scale gold mining operations in Ecuador and their use of mercury.
Mercury is widely used by the miners because it bonds with gold, allowing it to be more easily separated from the ore hauled out of countless mines dotting the countryside.
The widespread use of the toxic liquid metal is creating a long lasting environmental hazard that starts with ore processing and travels all the way up the food chain. But much of it is hidden in remote corners of the developing world so it's receiving little attention.
Nichols shot hours of video as he researched mining and processing techniques. Now he's working on ways to reduce the use of mercury and its largely unregulated use in those remote places.
"If you were ever going to try and clean this up, I don't know how you would," he says, describing how rudimentary workshops have become mini toxic waste sites.
"These guys, they splash it around. The walls are contaminated, the floor, the miner. Essentially every square inch of the place is covered in mercury."
He says the workers compound the problem when they then return home, covered with the invisible poison which then contaminates their homes and families.
The biggest risk to human health occurs when the workers burn off the mercury in order to release the gold from the amalgam. This creates an invisible toxic gas but few take even basic precautions to protect themselves or others.
Nichols says he found one exhaust vent spewing toxins between a school and a restaurant in Portovelo, Ecuador.
A recent conference at the University of British Columbia brought together experts from around the world battling to cut down on the use of mercury in mining.
Susan Keane, deputy director of health programs at the Natural Resources Defence Council in Washington, D.C., says about 1,400 tonnes of mercury is used by miners each year.
"Mercury use from small scale gold mining is the largest source of mercury pollution in the world."
Developing countries in South America, Asia and Africa are the biggest users.
Paleah Black Moher is a toxicologist with Simon Fraser University who's seen the problems first hand.
"I just did a study in Burkina Faso in February and found some of the highest exposures of elemental mercury ever recorded. So, it's pretty phenomenal."
Neurological time bomb
She says mercury concentrates in the human brain and over time creates neurological problems, especially if children are exposed. It can lower IQ and cause people to lose control of their extremities. It can also cause genetic defects which can be passed onto future generations.
The best known example of widespread contamination took place in Japan starting in the 1950s. The mercury was dumped into the water by industry and absorbed by fish and shellfish. More than 2,000 people who ate seafood from the area came down a severe form of mercury poisoning which came to be called Minamata disease.
Fixing the problem won't be easy
One small step is to protect miners exposed to mercury during processing.
At his lab at UBC, mining engineering Prof. Marcello Veiga has been working on devices to prevent workers from being poisoned.
He has a range of simple tools that can be easily made or bought in developing countries and are designed to capture most of the toxic gas created when mercury amalgams are burned off.
"Everywhere we go we just take this and show them how simple it can be for them to save their own lives."
He is one of the leading experts on the problem as the past chief technical adviser on mercury for the United Nations Industrial Development Organization.
Poverty and mining
Worldwide an estimated 15 million people, many of them women and children, work in small scale gold mining and processing using mercury.
Veiga says it's been tough to counter the toxic metal's use because even though they often make only a few dollars a day, mining is sometimes the only way to put food on the table.
"It's going up every year because the poverty in rural areas is increasing, gold prices are still good and it's a big opportunity for the poor."
He says the other key part of the solution is a global treaty called the Minamata Convention.
It's designed to cut the production and use of mercury and has made its way through the United Nations. But the convention isn't in effect yet because not enough countries, including Canada, have ratified it.
As a centre of mining expertise, Veiga encourages more action on mercury pollution, and says Canada should ratify the treaty.
"We have a big responsibility here as Canadians to show them how to do this in a proper way."