世卫组织：地球上90%的人呼吸被污染的空气

Nine out of 10 people on the planet are breathing polluted air, the World Health Organization says, with indoor pollution a major and generally unrecognized problem.

The latest report by the WHO says air pollution kills 7 million people every year with marginalized populations in such places as Africa and Asia, who bear the brunt.

Dirty air, both in and out of doors, leads strokes, heart disease, lung cancer and such chronic respiratory diseases as asthma.

While most people associate air pollution with outdoor sources such as factory emissions and cars, the WHO report says indoor pollution causes close to 4 million deaths a year.

"Three-billion people around the world...almost half of the world global population...are still relying on very polluting fuels for cooking or heating or lighting the house," Dr. Neira says.

They include kerosene, wood, and other solid fuels instead of cleaner sources such as electricity and gas.

Dr. Neira announced WHO will convene the first-ever global conference on air pollution at the end of October in Geneva, looking to come up with interventions and solutions.