More must be done to reduce air pollution, leading health officials have warned after a new report suggested that pollution claims the lives of millions of people every year.
Around the globe seven million people died in 2012 as a result of air pollution, according to new estimations from the World Health Organisation (WHO).
The body said that air pollution is "the world's largest single environmental health risk".
A new WHO report suggests there is a link between air pollution and heart disease, respiratory problems and cancer.
Many of the deaths in 2012 occurred in low and middle-income countries in south east Asia and the western Pacific region, where about 3.3m died as a result of indoor air pollution and 2.6m deaths were related to outdoor air pollution, WHO said.
The body said that reducing air pollution could save millions of lives.
"Cleaning up the air we breathe prevents non communicable diseases as well as reduces disease risks among women and vulnerable groups, including children and the elderly," said Dr Flavia Bustreo, WHO's assistant director-general for family, woman and children's health.
"Poor women and children pay a heavy price from indoor air pollution since they spend more time at home breathing in smoke and soot from leaky coal and wood cook stoves."
Dr Maria Neira, director of WHO's department for Public Health, Environmental and Social Determinants of Health, added: "The risks from air pollution are now far greater than previously thought or understood, particularly for heart disease and strokes.
"Few risks have a greater impact on global health today than air pollution; the evidence signals the need for concerted action to clean up the air we all breathe."