The World Health Organization (WHO) has reported that air pollution caused the deaths of 7 million people in 2012.

According to WHO, air pollution is “the world’s largest single environmental health risk”— one in eight global deaths were linked with air pollution. The largest number of related deaths were in South East Asia and the WHO’s Western Pacific region, mainly in low- and middle-income countries.

Risks associated with air pollution, including heart disease, stroke, respiratory problems and cancer, pose a greater threat than previously thought. The majority of air pollution deaths were linked with cardiovascular diseases - in total, 40 percent of deaths related to outdoor pollution were due to heart disease.