Some 92 percent of the planet's population live in areas where air quality levels exceed the World Health Organization's (WHO) limits, according a new air quality model from the agency.
Around 3 million deaths every year are connected to exposure to outdoor air pollution, the WHO said in a news release on Tuesday, and the figures rise when indoor pollution – such as that caused by heating a home with an open fire fueled by charcoal or coal, for example – is taken into account. In 2012, 6.5 million deaths were connected to both outdoor and indoor pollution together, the agency said.
Countries in the developing world are bearing the brunt of deaths connected to air pollution, with the WHO saying that almost 90 percent occur in low and middle income countries.
"Air pollution continues take a toll on the health of the most vulnerable populations – women, children and the older adults," said Flavia Bustreo, assistant director general at the WHO. "For people to be healthy, they must breathe clean air from their first breath to their last."
But impact of air pollution isn't restricted to developing nations. For instance, a report released earlier this year stated that exposure to outdoor air pollution was linked to roughly 40,000 deaths every year in the U.K.
The report, a joint effort between the Royal College of Paediatrics and Child Health and the Royal College of Physicians, also found that air pollution had been linked to wide range of diseases from cancer to asthma, heart disease and diabetes.
As well as being linked to death and disease, the report stated that exposure to outdoor air pollution cost the U.K. economy over £20 billion ($25.95 billion) every year.
The WHO said its new model was based on data from ground station monitors, satellite measurements and air transport models. It was developed together with the University of Bath, in England.
"This new model is a big step forward towards even more confident estimates of the huge global burden of more than 6 million deaths – 1 in 9 of total global deaths – from exposure to indoor and outdoor air pollution," Maria Neira, WHO director, Department of Public Health, Environmental and Social Determinants of Health, said.
"More and more cities are monitoring air pollution now, satellite data is more comprehensive, and we are getting better at refining the related health estimates," Neira added.