They accuse the federal agency of hobnobbing and sharing research with a sector that is pursuing profits with little regard for people's health or sufferings.
"The industry lied about addiction, lied about the risks of its products, lied about light and mild cigarettes, and lied about marketing to children," fumed Garfield Mahood, executive director of the Non-Smokers' Rights Association.
He is among 44 doctors, nurses and health advocates who signed an open letter to Health Minister Tony Clement demanding answers.
Health Canada appears to be undermining what many medical specialists agree is a crucial need to marginalize the tobacco industry and expose its tactics, Mahood said.
Adding insult to injury, says the letter, is the fact that several Health Canada officials have pulled out of a national conference starting Sunday in Edmonton on how to reduce smoking.
Rita Smith, a spokeswoman for Clement, says Health Canada takes part in U.S. tobacco conferences to gather data used to help cut smoking rates to historic lows. Fifteen per cent of Canadians now smoke, down from 30 per cent in 1985, she said.
That said, tobacco use remains a primary cause of preventable death in Canada - killing about 37,000 people a year.
Seven Health Canada officials went to the Tobacco Science Research Conference in Charlotte, North Carolina, presenting findings on such topics as "Nicotine Trends in Canadian cigarettes from 1968-2005."
"Our scientists have been attending this conference for the past 10 years," Smith said.
Officials will continue to go to such events, she insisted, despite the damning findings of fact made against American tobacco giants last year. U.S. District Judge Gladys Kessler pounded the industry in a case brought by the Department of Justice.
"This is a science-based ministry," Smith said. "The scientists here have processes that they use to develop programs which have actually brought smoking prevalence rates down to a fraction of what they were before.
"Attending a wide variety of conferences is one of the tools at their disposal."
Smith stressed that 25 Health Canada staff would attend the Edmonton conference, adding that some pulled out when a workshop was cancelled. Ottawa is also funding $175,000 of related costs.
Smith denied that the U.S. conference had anything to do with reduced attendance in Edmonton.
But a conference organizer who didn't wish to be named said the workshop had to be cancelled after Health Canada staff said they couldn't attend.
"It caused a great deal of turmoil for the schedulers and left some holes in the program," said the organizer.
Joanna Cohen, a public health sciences professor at University of Toronto, has studied the extent to which tobacco companies have historically used industry research conferences to distort the scientific record while forging links with universities to gain respectability.
"It's a completely inappropriate forum for Health Canada to share their research findings," she said of the North Carolina gathering.
If the department feels they need to be there to gather information, they could have confined themselves to sending an observer, she said.