Dirty sands


Mining of oil sands in Canada accounts for as much pollution as a mid-size city, say researchers. Using satellite remote sensing observations, the Canadian team found high levels of sulfur dioxide and nitrogen dioxide across an area of 1,500 sq km around the mines. The air pollutants can lead to acid rain.

Oil sands are deposits of sand, clay and water saturated with bitumen, a viscous oil. They are mined and processed to extract bitumen, an energy intensive exercise, which is then refined and diluted to turn it into oil. About two tonnes of the sands are required to produce one barrel of oil (159 litres). The sands contribute to 40 per cent of Canada's oil production.


Down To Earth, March 2012