Pollution From Canadian Oil Sands Vapor Is Substantial, Study Finds
An oil sands strip mine, north of Fort McMurray, Alberta. While Canada’s economy depends heavily on resources like the oil sands, the new prime minister, Justin Trudeau, has made climate change a priority on his agenda. CreditIan Willms for The New York Times
OTTAWA — The amount of pollution created by vapor from Canada’s oil sands, which contributes to climate change, ranks on par with most major cities in North America, according to a new study by the country’s environmental regulator that was published on Wednesday.
While the connection between the oil sands’ carbon emissions and climate change is well documented, the study, which was funded by the regulator, Environment and Climate Change Canada, and appeared in Nature, is the first to track the vapor produced in the process and the extent of the pollution that results. It also adds the particularly weighty voice of the Canadian government to the debate.
In recent months, the government, under the leadership of the new prime minister, Justin Trudeau, has reversed course on global climate change. While the country’s economy depends heavily on resources like the oil sands, Mr. Trudeau has made climate change a priority on his agenda.
The study was published just as several major oil sands operations were trying to reopen after being evacuated because of a massive wildfire in the Fort McMurray, Alberta area. Earlier efforts to restart operations were abandoned after the fire swung north and reached the perimeter of Suncor’s and Syncrude’s large mines and plants. Large fire breaks prevented any damage, however.
The study takes a close look at what happens to the tarlike bitumen of the oil sands. Vapor from the bitumen is released into the air when it is dug up in open pit mines and later as the oil is separated out.
Once in the atmosphere and exposed to sunlight, those vapors mix with other chemicals to become particles known as secondary organic aerosols, or S.O.A.s. Those aerosols, which form a major component of smog, are considered a risk to human health.
John Liggio, a scientist with the air quality research division of Environment and Climate Change Canada, said the rate at which the oil sands created those particles was unexpected.
“The chemistry tells us this should happen,” said Mr. Liggio, who is based in Toronto. “We were surprised by the extent. It’s greater than Houston.”
The concentration of oil refineries around Houston makes it a particularly large source of the particles. But Mr. Liggio said the oil sands were rivaled by only the largest metropolitan areas, like Los Angeles, in North America when it came to creating the particles. Vehicle exhaust and electrical generation are the main sources of the particles in cities.
The paper found that the rate of particle production related to the Deepwater Horizon spill in the Gulf of Mexico was about the same as that of the oil sands. “But the spill lasted only for a few months; the oil sands has been operated for decades,” Mr. Liggio said. He added that the oil sands vapor also converts more easily into polluting particles than fumes from lighter grades of oil.
Shao-Meng Li, another Environment Canada scientist and co-author of the study, said the S.O.A. particles tended to lower temperatures by reflecting energy back toward the sun. All atmospheric particles, he said, are know to harm cardiovascular and respiratory health.
“This is all new information for us,” said Terry Abel, the director of oil sands at the Canadian Association of Petroleum Producers. “It’s one more piece of information about what’s happening in the environment in and around these facilities.” He said more research would be needed to determine the impact of the particles.
The study was based on data gathered by specialized instruments on aircraft that flew around the major oil sands sites north of Fort McMurray. The researchers want to focus their future efforts on determining how and where most of the vapor is released. Other scientists are also studying the effects of the particles after they make their inevitable descent back to earth.
The researchers on the study also want to look at whether oil sands projects that use underground injections of steam to release the bitumen are any better than those that use open-pit mining. While Mr. Liggio said limiting emissions from the plants that process the oils sands after they were dug up might be possible, what could be done with those mines was less clear.
“You can’t build a huge bubble over a huge open pit mine,” he said.