– In the Cree language, the word “Athabasca” means “a place where grass is everywhere.” Here in northern Alberta, the Athabasca River slices through forests of spruce and birch before spilling into a vast freshwater delta and Lake Athabasca.

But 100 miles upstream, the boreal forest has been peeled back by enormous strip mines, where massive shovels pick up 100 tons of earth at a time and dump it into yellow trucks as big as houses.

The tarry bitumen that is extracted is eventually shipped to refineries, many in the United States, to be processed into gasoline, diesel and other fuels. But the leftover polluted slurry remains in miles-long impoundments, some high above the banks of the river. Air cannons sound periodically to keep migratory birds from landing on the toxic ponds.

Oil sands production, as the procedure is called, is booming in northeastern Alberta. And it is expected to grow far larger if the Obama administration issues a federal permit for the Keystone XL pipeline from the province.

Debate in the United States over the pipeline has largely focused on whether the oil sands would contribute to climate change, or that oil might spill along the pipeline route. But in northeastern Alberta, the effect of the mining plays out in more complicated ways.

Oil sands are exploited by injecting high-pressure steam into the earth or by strip mining to extract the sticky bitumen, which is then washed away from clay and sand, swiftly heated and diluted with chemicals before being shipped to refineries.

Economic growth, at a cost

The petroleum industry has funneled billions of dollars into Canada’s national, provincial and local economies and employs thousands of people in places with few other jobs. But the oil sands boom may also be polluting the air and water, and is stoking fear that it is damaging the health of those in its arc.

“From everything I hear from the indigenous peoples, their thinking seems to be ‘It’s a choice between whether we starve to death or are poisoned to death,’ ” said Dr. John O’Connor, a general practitioner who has worked here since 1993.

In Fort Chipewyan, a village of 1,100 people on the north shore of Lake Athabasca, cancer and autoimmune diseases such as lupus have taken a heavy toll on its mostly indigenous Cree, Dene and Metis population during the last 20 years. In 2009, the provincial government found that cancer rates over a 12-year period were 30 percent higher than normal for such a small community (51 cancers in 47 individuals vs. an expected 39 cancers).

Three weeks ago, government scientists told villagers that they had found high levels of mercury in the eggs of migratory birds that nest downstream from oil sands production. Fishermen say pickerel and northern pike in the lake show bulging eyes and other deformities.

Three studies by independent scientists have shown rising concentrations of pollutants, including carcinogens, in nearby waterways.

Industry officials and the Alberta government insist that chemicals detected in area waterways are naturally occurring, not the result of pollution.

They also say they are taking full safety precautions to protect communities tucked into a vast wilderness. Some of the indigenous people, known as the First Nations, have hunted and fished here for thousands of years.

The oil industry is funding a government-run system to monitor possible pollution. Reclamation efforts, meanwhile, can take years, if not decades. Of the thousands of acres mined during 40 years of oil sands extraction in Alberta, only 247 acres have been restored to land resembling unmined areas.