Ionizing radiation through the photoelectric effect and the Compton effect. Either of those interactions will cause the ejection of an electron from an atom at relativistic speeds, turning that electron into a beta particle (secondary beta particle) that will ionize many other atoms. Since most of the affected atoms are ionized directly by the secondary beta particles, photons are called indirectly ionizing radiation. Photon radiation is called gamma rays if produced by a nuclear reaction, subatomic particle decay, or radioactive decay within the nucleus. It is otherwise called x-rays if produced outside the nucleus. The generic term photon is therefore used to
Optical radiation of the spectrum, from UV to IR, can produce thermal injury to the surface layers of the skin, including the eye. When it comes from natural sources, this sort of thermal injury might be called a sunburn. However, thermal injury from infrared radiation could also occur in a workplace, such as a foundry, where such radiation is generated by industrial processes. At the other end of this range, UV light has enough photon energy that it can cause direct effects to protein structure in tissues, and is well established as carcinogenic in humans. Occupational exposures to UV light occur in