Aboriginal leaders in northwestern Ontario are calling for a public inquiry after an international health expert said people living in the area are still showing effects of mercury poisoning.

Dr. Masazumi Harada, a world-renowned neurologist, said Thursday that the conditions of people exposed to mercury three decades ago have stayed the same or worsened.

During the 1970s, a paper plant dumped tonnes of mercury into the river systems that run through communities home to the White Dog and Grassy Narrows First Nations.

Ron McDonald
Ron McDonald

Harada's report, released earlier this week, says at least nine residents show symptoms of Minimata disease, or methylmercury poisoning, which can include partial paralysis, dementia, impaired balance, impaired speech and blurred vision.

"Everything that has gone wrong in my community is all pointing back to mercury," said Ron McDonald, chief of White Dog First Nations.

"We need our government to come forward to the table and speak to us, and stop denying that there is a problem."

Health Canada disputes report

Health Canada disputed the report by Harada, who tested residents in 1975 and retested them two years ago.

The department countered that blood mercury levels in people are in steady decline. It suggested the symptoms found by Harada could be associated with different disorders such as diabetes, multiple sclerosis and alcoholism.

$17 million in compensation paid

Between 1962 and 1970, a pulp mill operated by Dryden Chemicals dumped about 9,000 kilograms of mercury into the English-Wabigoon river system. Both communities sit along the 480-kilometre system, which runs across the Ontario-Manitoba border.

Testing showed people had high levels of mercury in their blood, which was blamed for birth defects in children.

In the mid-1980s, the bands received a compensation package of almost $17 million from the company and provincial and federal governments.

They're still advised not to eat fish from the river.