Acid rain
While overall pollution levels have dropped, it was found that oil sands pollution has increased by 20% since 2009. Tar sands facilities were found to be among the top four highest polluters of volatile organic compounds (VOCs)- a major air contaminant. VOCs and other air contaminants are set to increase in the future as a result of continued output from the oil sands. Oil sands pollution is not only set to increase VOCs, but also, acid rain. Acid rain is rain that has been contaminated by airborne chemicals, making it acidic. Two major causes of acid rain are sulphur dioxide and nitrogen oxide. Acid rain can cause damage to soil, water, wildlife, plants and buildings. Additionally, the airborne particles that cause acid rain can also contribute to smog. In recent years progress has been made in reducing acid rain, however, Alberta's oil sands may soon set back this progress.