OTTAWA -- The majority of food cans found in major Canadian retail stores contain bisphenol A, or BPA, a chemical linked to health concerns, says a new study conducted by six non-profit groups from Canada and the United States.

The groups surveyed 192 cans of food from major retailers on both sides of the border and found 67 per cent had BPA in the epoxy resin of the can lining or lid.

Among cans purchased in Canada, 18 of 21 -- or 86 per cent -- contained BPA, according to the study released Wednesday.

The research builds on previous studies by the U.S.-based Breast Cancer Fund, one of the survey sponsors, which indicated food packaging is a major source of BPA leaching into food and ultimately into humans.

"It is likely that people are exposed to BPA from canned foods at levels that are compromising our health," stated Wednesday's report.

Advocates say bisphenol A exposure in even tiny amounts has been linked to increased risk of breast and prostate cancer, infertility, type-2 diabetes, obesity, asthma and behavioural changes including attention-deficit disorder.

Health Canada has another take.

"BPA from food packaging is not a health risk to people, including newborns and children," states a fact sheet from the federal department.

The European Food Safety Agency also maintains that BPA in food packaging is a low risk for consumers and last September a French court overturned that country's export ban on BPA-based "food contact materials" -- although domestic French sales are still prohibited.

What is certain is that BPA, which can mimic the hormone estrogen and is not naturally occurring, is found in the urine of most North Americans, according to the Atlanta-based Centers for Disease Control and Prevention.

The agency also says on its web site that: "Finding a measurable amount of BPA in the urine does not imply that the levels of BPA cause an adverse health effect."

Nonetheless, concerns about the chemical's effects on developing children spurred the Canadian government to ban BPA in plastic baby bottles in 2008 and the chemical was listed as a toxic substance in Canada in 2010.

Groups such as the Breast Cancer Fund and Environmental Justice are counting on health-conscious consumers to continue to push BPA out of the marketplace.

"It shouldn't be a buyer-beware situation for shoppers every time they set foot in the canned food aisle," Janet Nudelman of the Breast Cancer Fund said in a news release.

"National brands need to get BPA out of food can linings and fully disclose the identity and safety of any BPA alternatives they're using. Consumers deserve protection from the toxic effects of this hormonally active chemical and the likelihood of exposure to equally toxic alternatives."

Despite the absence of a scientific consensus on BPA's health impacts, food producers and packagers are taking note.

Campbell Soup Co. announced this week that it has begun removing BPA resins from some of its cans and that the company's full line of products will be BPA-free by the middle of next year. Nestle has made similar commitments.