Millions rely on cheap cloth masks that may provide little protection against deadly air pollution

Author

Richard E. Peltier

Associate Professor of Environmental Health Sciences, University of Massachusetts Amherst

Republish this article

We believe in the free flow of information. We use a Creative Commons Attribution NoDerivatives licence, so you can republish our articles for free, online or in print.

Read this article in French and English

Anyone who has stepped off an airplane in one of the major cities of the developing world has encountered profound and noxious air pollution. In New Delhi, Jakarta, Accra, Kathmandu and many other cities, diesel exhaust and burning garbage foul the air. The most serious concern is particulate matter (PM) – microscopic particles, much smaller than a human hair, usually produced when chemicals from fuel combustion react in the atmosphere. Once these particles form, winds can transport them over long distances. Read more.