Around seven million people across the world died as a result of air pollution exposure in 2012, according to a report of World Health Organization(WHO) released on Tuesday.

The report said the seven million deaths, one in eight of total global deaths confirmed that air pollution is now the world's largest single environmental health risk, and reducing air pollution could save millions of lives.

In particular, the new data reveal a stronger link between both indoor and outdoor air pollution exposure and cardiovascular diseases, such as strokes and ischemic heart disease, as well as between air pollution and cancer.

The report said that low- and middle-income countries in South-East Asia and Western Pacific Regions had the largest air pollution-related burden in 2012, with a total of 3.3 million deaths linked to indoor air pollution and 2.6 million deaths related to outdoor air pollution.

According to the report, for the deaths related to outdoor pollution, 40 percent were heart disease, and 40 percent were stroke, 11 percent were chronic obstructive pulmonary disease(COPD), six percent were lung cancer and three percent were acute lower respiratory infections in children.

While the proportion of the same diseases caused by indoor pollution were 26 percent, 34 percent, 22 percent, six percent and 12 percent, respectively.

After analyzing the risk factors and taking into account revisions in methodology, WHO estimates indoor air pollution was linked to 4.3 million deaths in 2012 in households cooking over coal, wood and biomass stoves.