REN R360 Lecture Notes - Ultraviolet, Genotoxicity, Electromagnetic Spectrum
Document Summary
Smoking and driving are much more dangerous then exposures to low levels of radiation. The electromagnetic spectrum is divided into three segments with visible light in the middle. The other two segments are referred to as ionizing and nonionizing, based on their biological activity and span a wide range of wave lengths. The ionizing portion of the spectrum includes gamma rays and ultraviolet radiation. Ionizing radiation is given off by decaying radioisotopes or radionuclide, typically as beta particles or gamma rays. Ionizing radiation is genotoxic and can act as a carcinogens. Nonionizing radiation is not energetic enough to disrupt electrons and hence is not thought to be genotoxic. The radio-frequency range of the nonionizing-radation spectrum can heat tissues. 2) studies of patients receiving diagnostic and therapeutic radiation, also high dose by typically intermittent. 3) studies of occupational cohorts, typically with protracted exposures. Ionizing radiation produces two kinds of cell injury, one immediate and other delayed.