McGill University has cleared one of its former professors of wrongdoing, saying the scientist did not collude with the asbestos industry or doctor any data in decades of research into the safety of the substance.

John Corbett McDonald, an expert in occupational health, studied the medical effects of asbestos on Quebec miners and mill workers from 1966 until the late 1990s.

McDonald and his team published a series of studies between 1971 to 1998, the centrepiece of which was used by an asbestos lobby group to promote use of the mineral overseas and had been cited by the federal government in its previously pro-industry stance.

McDonald affirmed that the chrysotile form of asbestos, which was mined in Quebec until recently, is "essentially innocuous" at certain levels, and advocated for its export to the Third World.

The studies were partly funded by the Quebec Asbestos Mining Association, from which McDonald and other researchers at the McGill School of Occupational Health received payments totalling almost a million dollars from 1966 to 1972.

CBC News investigation earlier this year disclosed the funding, prompting calls for an investigation into McDonald's work.

'Data was collected in a proper way'

McGill has always maintained that McDonald acknowledged the financial support, but the university nonetheless launched an internal review.

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John Corbett McDonald's asbestos research findings from studies conducted last century at McGill University were thrown into question earlier this year. (CBC)

On Wednesday, dean of medicine David Eidelman said the six-month probe by the Montreal university's research integrity officer found no evidence of scientific misconduct, including rigged data analyses or conclusions.

"We're not here to discuss Dr. McDonald's opinions, but rather whether the data he collected was collected in a proper way. In fact, his data was collected in a proper way, and he was quite open about the fact that he accepted money from asbestos companies, as did all researchers at the time," Eidelman said.

McDonald has also testified against bans and stricter regulations on asbestos at various government hearings around the world, and once worked for Imperial Tobacco while at McGill — even trying to hide it. Eidelman said McGill's review did not consider those actions.

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Dean of medicine David Eidelman says McGill's review did not consider McDonald's testimony at government hearings into asbestos. (CBC)

The 17-page report was written by former dean of medicine Abe Fuks. Critics had been wary of the review process since it began, saying there were too many possible links between the people involved and McDonald, who retired from McGill in the late 1980s but was still an emeritus professor.

CBC News documentary also pointed to the long-standing ties between McGill and the asbestos industry, citing claims that the industry sought to use the public university to burnish its image.

In a statement on its website, McGill says "Prof. Fuks also concludes that his review of relevant information 'lends no credence' to allegations that McGill colluded with the asbestos industry in promoting the use of asbestos."

Canadian industry dead

More than 50 countries ban the mining and use of asbestos because it causes cancer, in particular a form of malignancy known as mesothelioma.

The World Health Organization says 107,000 people around the world die annually from ongoing workplace exposure to asbestos. It is still used in many developing countries in everything from roofing tiles to cement pipes and boiler insulation, and even Canada imported $2.6 million worth of asbestos brake pads last year.

As recently as 2010, Canada was producing 150,000 tonnes of asbestos annually, all of it in Quebec, and exporting 90 per cent — worth about $90 million — to developing countries.

The domestic industry is all but dead now, however, following the Quebec government's decision to cancel a loan to the country's last remaining mine.