"LONDON -- Air pollution kills about 7 million people worldwide every year, with more than half of the fatalities due to fumes from indoor stoves, according to a new report from the World Health Organization published Tuesday.

The agency said air pollution is the cause of about one in eight deaths and has now become the single biggest environmental health risk.

"We all have to breathe, which makes pollution very hard to avoid," said Frank Kelly, director of the environmental research group at at King's College London, who was not part of the WHO report."

Maria Cheng reports for the Associated Press March 24, 2014. [2]