Do our new bombs cause cancer?

Civilian casualties always make for bad press. Perhaps as damaging to the war effort is having to back off a target because it's too close to a school or hospital. So the Pentagon is always looking for new ways to pinpoint their deadly assaults, causing as little collateral damage as possible. Unfortunately, the newest weapon may cause cancer.

The Air Force Research Laboratory's latest attempt at precision death is called Dense Inert Metal Explosive (DIME). It's designed to be just as deadly as a conventional bomb, but keep its destructive radius at a minimum.

DIME has a carbon fiber casing which turns into dust upon explosion. Most bomb casing turn into deadly shrapnel that can kill bystanders up to 2,000 feet away.

Also, DIME's casing is filled with explosives and tungsten powder. The tungsten's micro-shrapnel is as deadly as regular shrapnel, but because it's so small it's dragged to a halt within 25 feet. It's "a smaller but deadlier footprint - a 12-gauge compared to a rifle" writes David Hambling of Defense Tech.

There's only one problem: research in February of 2006 suggests tungsten is highly carcinogenic. Scientists implanted 92 rats with simulated tungsten shrapnel. Within 5 months all had developed a rare form of cancer called rhabdomyosarcoma.

"The military needs to hold up on this conversion to tungsten alloy weapons until more is known," says University of Arizona toxicologist Mark Witten.