The research, published in Science, found the oil operations are releasing vast quantities of compounds that can cause localized air pollution and form damaging particles that can travel across the continent.

By Nicholas Kusnetz

Canada’s tar sands have gained infamy for being one of the world’s most polluting sources of oil, thanks to the large amounts of energy and water use required for their extraction. A new study says the operations are also emitting far higher levels of a range of air pollutants than previously known, with implications for communities living nearby and far downwind.