Ahead of the International Day of Clean Air, here’s a look at what causes air pollution, what it does to people and how the world can rein it in.

Despite improvements in air quality in past decades, 156 million Americans still breathe in too much soot or ozone, says the annual State of the Air report from the American Lung Association.

A new study finds a strong relationship between exposure to air pollution and the risk of developing dementia, while air quality regulations are being weakened in the U.S.

The researchers created a model to look at levels of air pollution called PM2.5 – also sometimes called particle pollution or particulate matter pollution – and levels of antibiotic resistance ...