Air pollution from cooking fires to auto fumes has contributed to an estimated seven million deaths worldwide in 2012, the UN health agency says.
“Air pollution, and we’re talking about both indoors and outdoors, is now the biggest environmental health problem, and it’s affecting everyone, both developed and developing countries,” said Maria Neira, the World Health Organisation’s public and environmental health chief.
Globally, pollution was linked to one in eight deaths in 2012, new WHO research found.
The biggest pollution-related killers were heart disease, stroke, pulmonary disease and lung cancer.
The hardest hit regions were Southeast Asia, which includes India and Indonesia, and the Western Pacific, ranging from China and South Korea to Japan and the Philippines.
Together, they accounted for 5.9 million deaths.
The toll included 4.3 million deaths due to indoor air pollution, caused mainly by cooking over coal, wood and biomass stoves.
The toll from outdoor pollution was 3.7 million, with sources ranging from coal heating fires to diesel engines.
Many people were exposed to both indoor and outdoor pollution, the WHO said, and due to that overlap, separate death toll attributed to the two sources cannot simply be added together, hence the figure of seven million deaths.
The new figure is “shocking and worrying”, Neira told reporters.
When WHO last released an estimate for deaths related to air pollution, in 2008, the agency had put the figure related to outdoor pollution at 1.3 million, while the number blamed on indoor pollution was 1.9 million.
But a change in research methods makes comparison difficult between the 2008 estimate and the 2012 figures, Neira said.
“The risks from air pollution are now far greater than previously thought or understood, particularly for heart disease and strokes,” said Neira.
WHO says about 2.9 billion people in poor nations live in homes that use fires as their principle method of cooking and heating.
Carlos Dora, the WHO’s public and environmental health co-ordinator, said that turned homes into “combustion chambers”.
Simple measures to stem the impact include so-called “clean cook stoves”, which are a low-tech option, as well as improved ventilation, he said.
With air pollution having sparked a recent scare in France, leading to restrictions on car use and the temporary scrapping of public transport fees in Paris, Dora said such measures could be applied in the longer term.
“The air is a shared resource. In order to breathe clean air, we have to have interventions in the areas that pollute air,” he said.
The WHO said it planned by the end of this year to release a ranking of the world’s 1600 most polluted cities.