As they decay, uranium atoms, whether natural or depleted, give off small amounts of radiation, like sources of natural background radiation in the environment. DU and its decay products give off radiation that could potentially cause exposure inside the body as well as externally. While DU gives off alpha particles, the decay products give off beta and gamma particles as they decay even more. However, the alpha radiation does not penetrate the outer, dead layer of skin, and so uranium must be first taken into the body for alpha particles to be a concern. Beta radiation is screened out by normal military clothing, but could be a concern if uranium were first taken into the body, or protective clothing (such as gloves) was not worn. Gamma radiation, which is penetrating, must be considered even without internal exposure to uranium, but the doses of it from DU are small. Research indicates that exposures to alpha and beta particles would be below occupational guidelines.