In 2012, seven million people died of air pollution exposure, according to new estimates published on Tuesday (25 March) by the World Health Organisation (WHO). Air pollution now is the cause behind one in eight global deaths, and is now the world’s largest single health risk.

The new data reveal a stronger link between both indoor and outdoor air pollution exposure and cardiovascular diseases, such as strokes, ischaemic heart disease, and cancer. In addition, air pollution also plays a role in the development of respiratory diseases, including acute respiratory infections.

The new estimates are based on assessment of human exposure to air pollutants through improved measurements and technology, enabling scientists to make a more detailed analysis of health risks from a wider demographic spread, which now includes rural as well as urban areas, the WHO said.

“Cleaning up the air we breathe prevents noncommunicable diseases as well as reduces disease risks among women and vulnerable groups, including children and the elderly,” said Dr Flavia Bustreo, assistant director-general for Family, Women and Children’s Health at the WHO.

The health organisation estimates that indoor air pollution was linked to 4.3 million deaths in 2012 in households with cooking over coal, wood and biomass stoves. The new estimate is explained by better information about pollution exposures among the estimated 2.9 billion people living in homes using wood, coal or dung as their primary cooking fuel, as well as evidence about air pollution's role in the development of cardiovascular disease and cancers.

As air pollution is often a by-product of unsustainable policies in sectors such as transport, energy, waste management and industry, according to the WHO, healthier strategies would be both more economical in the long term, due to healthcare cost savings, as well as create climate gains.