The most severely affected countries include India, Pakistan, China, Bangladesh, Madagascar, and Kenya where up to a quarter of all deaths were caused by pollution. Most of these deaths happened through heart diseases, stroke, lung cancer and chronic obstructive pulmonary disease.
Based largely on 2015 data from the Global Burden of Disease, the report estimates that at least 9 million premature deaths were caused during the year by diseases from toxic exposure.
"Pollution is more than an environmental challenge".
Philip Landrigan, a professor at the Icahn School of Medicine in New York City, who jointly led the worldwide research, said: "Pollution is much more than an environmental challenge - it is a profound and pervasive threat that affects many aspects of human health and wellbeing". It is also one-and-a-half times higher than the number of people killed by smoking and over six times the number of people dying in road accidents.
The largest number of deaths related to pollution in that year was in India with 2.5 million deaths, and China 1.8 million deaths.
The report said that pollution in low-income and middle-income countries caused by industrial emissions, vehicular exhaust, and toxic chemicals has particularly been overlooked in both the worldwide development and the global health agendas.
While Canada has one of the lower death rates due to pollution compared with places like India and Somalia, Environmental Defence program manager Muhannad Malas says it is one of the few developed nations that doesn't have enforceable, legally binding national standards for air quality.
Dr Penny Woods, chief executive of the British Lung Foundation, said: "Air pollution is reaching crisis point worldwide, and the United Kingdom is faring worse than many countries in western Europe and the US".
Almost 25% of all deaths in India in 2015 were caused by pollution; Pakistan, China, Bangladesh, and Kenya too reported that one in four deaths were caused by pollution.