BBC: Outdoor air pollution is estimated to contribute to more than two-and-a-half million deaths each year, a study has suggested.
It calculated that, each year, 470,000 people died as a result of ozone and 2.1 million deaths were linked to fine particulate matter.
Air pollution increased respiratory and heart disease risks, with the young, elderly and infirm most vulnerable.
The findings appear in the Environmental Research Letters journal.
"Epidemiological studies have shown that ozone and...