Study: Mercury levels in environment pose significant risk

A professor at Peterborough’s Trent University agrees with a study published in a Swedish science journal claiming that methylmercury levels in the environment pose global health concerns.

The study, which was published Thursday in the environmental magazine Ambio, claims mercury levels in the environment are posing serious global health risks. Dr. Holger Hintelmann explains the effects of mercury contamination:

“It mostly affects mammals,” he says. “Methylmercury is a neurotoxin, so it acts on the brain.”

Although Hintelmann says people do not become “acutely ill” from the mercury levels found in fish, long-term exposure may cause developmental problems in children and impair motor skills of adults.

Despite the fact that elevated mercury levels are being found in some fish, Hintelmann, who chairs Trent’s chemistry department, is not advocating that people abstain from seafood.

“The trick is to choose which fish to eat that are low enough in mercury so that they are safe for consumption,” Hintelmann states in a March 8 press release. “Those fish exist almost everywhere, and it is therefore important to educate fish-eating populations to select safe fish.”

Hintelmann says fish which eat vegetation generally contain lower levels of mercury than their counterparts which eat other fish.

“Predatory fish – northern pike, walleye, the larger lake trout – have the highest levels (of mercury),” he says.

 

Elevated mercury levels found in the environment are caused mainly by burning fossil fuels. Methylmercury contained in industrial emissions fall back to Earth where it infects fish.

 

Hintelmann says methylmercury has posed a problem for Ontario’s lakes.

“It’s fair to say that 50 per cent of the lakes have mercury advisories,” he says.

The report – called The Madison Declaration on Mercury Pollution – examines 33 findings from five studies. The basis of the report was formulated in August in Madison, Wisconsin, at the eighth annual Conference on Mercury as a Global Pollutant.

Some key features of the report include:

- The revelation that there is more mercury falling from the sky than during the Industrial Revolution.

- There is little known about the effect of mercury in marine ecosystems.

- Evidence shows methylmercury is toxic to humans, fetuses being particularly vulnerable.

- We are seeing increased levels of mercury in fish-eating species even in remote areas of Earth.