No adverse health effects are expected from such contact. Unfired depleted uranium munitions are encased in thin metal jackets that seal in alpha and beta particles. The amount of gamma emissions from depleted uranium (DU) is very low and falls well below regulatory health and safety limits. Similarly, depleted uranium panels used in tank armor pose no health risk because the depleted uranium is sealed inside several inches of regular steel armor. Alpha radiation, which is the major concern for internalized depleted uranium, is not an external concern because alpha radiation does not penetrate the outer layers of skin. The second source of radiation is from the depleted uranium rounds stored on board the tank. While soldiers are exposed to an increased level of radiation from the stored munitions, the cumulative exposure levels for tank crewmembers are within applicable guidelines. Since depleted uranium munitions are only used in combat, only forward-deployed vehicles are routinely uploaded with depleted uranium munitions.  While it is impossible to evaluate all potential exposure scenarios, each of the major weapon systems have been fully evaluated and all of the routine exposures are well within exposure guidelines. In fact, radiation levels measured inside the turret of an Abrams Heavy Armor Tank are below background levels measured outside the turret because armor shields the tank occupants from cosmic and terrestrial radiation sources. Crewmembers have their overall radiation exposure reduced by working inside the tank.  The most frequently cited example of radiation exposure is holding a bare penetrator rod. The penetrator rods in the 120mm, 105mm and 30mm rounds are shielded which prevents direct contact with the actual penetrator rod of intact rounds. But even when holding a bare penetrator rod, an individual could hold the rod for 250 hours before reaching the extremity or skin limit of 50 rem.