World Health Organization declares air pollution a carcinogen

Thursday, October 17, 2013, 5:39 PM -

The World Health Organization has officially recognized air pollution is a cancer-causing agent, adding it to its official list of known carcinogens.

The announcement was made Thursday at a conference in Switzerland.

Researchers at W.H.O. say the more people are exposed to damaging air particulates, the higher their risk of developing lung and bladder cancers.

Experts estimate that air pollution led to more than 220,000 lung cancer deaths globally in 2010 alone.

In some places -- like Beijing, China -- air pollution is a persistent problem.

The city's air quality index regularly exceeds 500 micrograms. On January 12, 2013, the particulate level skyrocketed to 755 micrograms -- setting a new record.

The World Health Organization recommends a maximum daily level of 20 micrograms.

According to the US Environmental Protection Agency, levels higher than 300 micrograms per cubic meter are considered "hazardous."

With files from CNN