The enclosed in-situ mining techniques used in many newer tar sands/oil sands extraction operations are less unsightly on the surface than first-generation open-pit mines, but are still releasing toxins to the atmosphere, the first scientific study of the subject indicates.

Because in-situ mines—which inject steam into bitumen formations to liquefy the hydrocarbons and force them to the surface through drilled wells—don’t create the vast pits and tailing ponds of conventional recovery, “they are often described as more environmentally friendly,” the Canadian Press’ Bob Weber writes in iPolitics.

University of Ottawa researcher Jennifer Korosi set out to test that claim, taking sediment core samples from a lake bed near an in-situ bitumen recovery facility near Cold Lake, AB.

“The cores revealed polycyclic aromatic hydrocarbons beginning in 1985, about the same time as oil sands development in the area began,” Weber writes. Levels of the carcinogenic compounds, while still too low to have likely environmental impacts, are now more than double those in 1985, according to Kerosi’s findings, released this week. 

“There are certain PAH compounds that we know are released by forest fires, from traffic emissions, and we don’t see those compounds increasing,” Korosi told CP. “We have a number of different ways we can fingerprint hydrocarbons to know where they’re coming from and, consistently, the different metrics were suggesting a petroleum-based source.”

Researchers last year demonstrated that airborne pollution from tar sands/oil sands operations travels hundreds of kilometres downwind across Canada’s prairie provinces.

Korosi would like to see increased government monitoring of steam-injection in-situ bitumen production.