Answer to Question #4549 Submitted to "Ask the Experts"

Q

I am going to protest military training in Australia where US and Australian troops will be using depleted uranium ammunition. I've heard the dust can become airborne for 10s of kilometres. Is there a danger? Do I need to buy a respirator? Do you know of an affordable respirator that will effectively filter the dust?

A

There should be no danger to you from airborne depleted uranium, and it is therefore unnecessary for you to purchase or to wear a respirator. You may wish to learn more about the potential hazards of depleted uranium by consulting the Health Physics Society depleted uranium fact sheet. This brief fact sheet will also refer you to other websites by reputable organizations, such as the United Nations, which provide in-depth information about depleted uranium and its potential hazards.

Please note that while it is true that airborne dust can be transported many kilometers, only a miniscule fraction of dust released to air at or near the surface of the earth would travel long distances, a fact that is supported by a very large body of both theoretical and empirical studies. Most of the material would fall to earth very close to the point of release and would constitute no hazard to nearby personnel, let alone those at kilometer distances. For uranium-bearing dusts to constitute a meaningful inhalation hazard, the quantity inhaled would have to be relatively large, and the particle sizes would have to be in the so-called respirable range, i.e., on the order of 1 micrometer or so in diameter.

Ronald L. Kathren
Professor Emeritus of Pharmaceutical Sciences
Washington State University at Tri-Cities