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Site C hearings: Dam raises concerns about mercury-contaminated fish

Contaminated fish were a concern brought up at yesterday’s Site C hearing.

Contaminated fish were a concern brought up at yesterday’s Site C hearing.

“Health Canada identified methyl mercury contamination of fish as potentially one the most important biophysical human health effects resulting from this project,” said Yota Hatziantoniou from Health Canada.

She also said that fetuses, young children and women of childbearing age are most vulnerable to the toxin, which affects the developing nervous system. Research indicates it may interfere with the development of fine motor function and cognitive skills in children.

For example, a regular 163 gram serving of a can of tuna for a woman of childbearing age before the Site C project could safely be consumed at eight servings a week, but would go down to two servings per week during operations, according to Hatziantoniou.

There is a risk that local fish could become contaminated with methylmercury, but that it is unlikely to pose a threat to the health of people who continue to consume it as long as they stick to Health Canada guidelines, according to Randy Barker from the Azimuth Consulting Group.

He said that methylmercury concentrations in Site C reservoirs would peak at about three to four times the present level. He added that depending on the species, this peak would occur between three and eight years after the building of the dam and would return to normal between about 20 to 25 years after construction.

However, according to B.C. Hydro calculations, concentrations of methyl mercury in fish will remain low enough for human consumption, even during peak methyl mercury concentrations.

Hydro acknowledged that effective communication was important to avoid any public health problems. Siobhan Jackson, who spoke on behalf of the organization, said this is especially true in the case of First Nations, as local fish make up a large portion of their diet.