Ontario Premier Kathleen Wynne says more research is needed before the province can consider a cleanup of the 50-year-old mercury contamination near Grassy Narrows First Nation in northwestern Ontario.

She was responding to the public release on Monday of a report on human and ecological health at Grassy Narrows that was commissioned by the province and the First Nation. Reed Paper in Dryden, Ont. dumped mercury in the English-Wabigoon River beginning in 1962 until the province ordered it to stop in 1970.

The new report shows the amount of mercury currently in some lakes is twice the threshold level that should trigger a clean-up under Canadian guidelines. It also shows rising contamination levels in some waterways that are the main source of fish, a staple food, for people at Grassy Narrows.

"There are a lot of difficult questions," Wynne said. "The scientists have said to us there are questions about how to actually do the cleanup because moving the sediment at the bottom can actually cause further damage. So we have to be very careful."

Community leaders said the remediation needs to be done before another generation suffers the effects of mercury poisoning.

Grassy Narrows First Nation Deputy Chief Randy Fobister is calling for immediate action on a new report that says the mercury in the English-Wabigoon River system should be remediated. (freegrassy.net) "The shaking, the tremors, are even starting to show in the youth," said Grassy Narrows Deputy Chief Randy Fobister.

Mercury contamination has been a fact of life in Grassy Narrows since before the 46-year-old was born.

"Even before I was on council that was the discussion — the river needs to be cleaned up," Fobister said. "It needs to be cleaned up. There is no other way."

After 50 years of contamination, Grassy Narrows community activist Judy DaSilva said removing the mercury "feels like an impossible dream."

It's a dream she continues to pursue because the lives of her community members depend on it, she said.

"It feels very urgent because we are losing our family members and also seeing some of our children having difficulties," DaSilva said.

Aside from the scientific questions about the risks and benefits of remediation, Wynne said there are other complicating factors for decision makers to work out.

"The challenge is to find the balance among all of these things, among the health of the community, the environment and the economy," Wynne said.

The premier did commit to one of the 40 recommendations in the new report — working with Grassy Narrows First Nation to find that balance.​