Canada’s tar sands development, in the Alberta province, has been linked to environmental contaminants in wildlife and increasing incidences of cancer in indigenous communities, a new report released this week said.

“This report confirms what we have always suspected about the association between environmental contaminants from [tar] sands production upstream and cancer and other serious illnesses in our community,” Mikisew Cree First Nation (MCFN) Chief Steve Courtoreille said in a press release Monday. “We are greatly alarmed and demand further research and studies are done to expand on the findings of this report.”

Tar sands oil, or bitumen, has been pegged by critics as among the dirtiest fuels on earth. The substance is as thick as peanut butter and must be diluted with toxic chemicals in order to be transported through pipelines.

Elevated levels of arsenic, cadmium, mercury, selenium and polycyclic aromatic hydrocarbons (PAHs) were found in a variety of animals that indigenous groups depend on for food — such as moose, muskrats, ducks, beavers and fish, according to the report. Indigenous populations are especially vulnerable to these impacts because of the close link between their livelihoods and the environment.

People in First Nations communities have responded to what they believe is the increasing presence of toxins in traditional food sources by resorting to store-bought alternatives — a change which has negatively affected their health, the report said.

Alberta’s Athabasca tar sands represents the largest reservoir of tar sands in the world that is suitable for large-scale surface mining — and is a major boon to the Canadian economy. But some First Nations communities and environmentalists say they are concerned about toxic chemicals that could hurt their health and the environment that many indigenous groups still depend on. Further complicating the matter, critics have said regulators responsible for ensuring the safety of oil sands development are too closely tied with the industry.

The study, conducted by University of Manitoba and University of Saskatchewan researchers and First Nations in Alberta, is the first of its kind to draw an association between tar sands and declines in community health in Fort Chipewyan, Alberta. A January survey had suggested that Alberta residents’ illnesses may be linked to the development but noted that most area doctors were afraid to speak out about any such connection.

Athabasca Chipewyan First Nation Chief Allan Adam criticized the government and tar sands industry for failing to conduct such a study in the past.

“It’s frustrating to be constantly filling the gaps in research and studies that should have already been done," Adam said. "This demonstrates the lack of respect by industry and government to effectively address First Nations’ concerns.”

Many participants in the study said they had already decided not to eat locally caught fish because of concerns over heavy metals, which the government has issued advisories on. Their increased consumption of store-bought foods means their diets include much higher amounts of fats, sugars and salts than is deemed healthy. The report said that trend is expected to continue as tar sands development expands and the availability of safe-to-consume wildlife declines.

The indigenous people interviewed for the report said they were worried about the well-being of their community, and viewed themselves as less healthy than their parents. They cited neurological, respiratory, circulatory and gastrointestinal illnesses as increasing along with tar sands — also referred to as "oil sands" — production but said they were most worried about the escalating cancer crisis.

Of the 94 participants in the study, more than 20 percent had been diagnosed with some form of cancer. The risks increased with age and were most frequently found in women, the report said.

“For the first time, we showed that upstream development and environmental decline are affecting cancer occurrence,” the study said. “Thus cancer occurrence increased significantly with participant employment in oil sands and with increased consumption of traditional foods and locally caught fish.”

The Canadian Association of Petroleum Producers was not available for comment, but when similar concerns were raised in February, the organization said in a release that “Canada’s oil sands producers are deeply concerned about suggestions oil sands development is affecting people’s health, most specifically resident First Nations. Safety is our industry’s top priority and oil sands development must occur in a manner that keeps people safe, and benefits their overall quality of life.”

The report, "Environmental and Human Health Implications of Athabasca Oil Sands," was partially funded by Canada’s federal department of health, Health Canada, and was reviewed by federal scientists and other health and environmental agencies.

First Nations groups said they pushed for the report because they believe some provincial and federal health officials are masking the growing problem.

“One thing most striking … is that both province and federal government’s refuse to do anything about (the high rates of cancer). Even though the pressure is escalating,” Adam told the Vancouver Observer. “We are being brainwashed by the Conservative government that everything is OK. It’s not.”