Different physics?

I read Frank de Haan's letter on depleted uranium (DU) munitions and followed his advice to read some of the many websites devoted to this topic (C&EN, March 27, page 3). The more I read, the more I began to wonder if the laws of physics really differ by latitude or longitude.

For three years in the late 1970s, I was commander of a combat-loaded tank on alert for combat in Fulda, West Germany. In every one of the thousands of tanks on alert was a combat load of 63 rounds of cannon ammunition: 40 of these were "kinetic" rounds-solid-shot projectiles made of tungsten carbide and depleted uranium that destroy enemy tanks with 1-mile-per-second muzzle velocity and enough impact to drill through more than a foot of armor plate. I could believe that firing them might create a hazard on impact, but the sites also say just being in a combat-loaded tank is a radiation hazard.

My crew and I spent months at a stretch surrounded by DU rounds in a 57-ton steel enclosure-every available space inside a tank is crammed with ammo and equipment. So why are DU rounds lethal to crews in Iraq but not in Cold War Germany? Is physics different north of the 40th parallel?

Neil Gussman
Philadelphia