Non-Ionizing Radiation (US Department of Labor)
"Non-ionizing radiation is described as a series of energy waves composed of oscillating electric and magnetic fields traveling at the speed of light. Non-ionizing radiation includes the spectrum of ultraviolet (UV), visible light, infrared (IR), microwave (MW), radio frequency (RF), and extremely low frequency (ELF). Lasers commonly operate in the UV, visible, and IR frequencies."
Radiation Therapy- National Cancer Institute( National Cancer Institute)
"Radiation therapy (also called radiotherapy) is a cancer treatment that uses high doses of radiation to kill cancer cells and stop them from spreading. At low doses, radiation is used as an x-ray to see inside your body and take pictures, such as x-rays of your teeth or broken bones. Radiation used in cancer treatment works in much the same way, except that it is given at higher doses."
How Does Nuclear Radiation Harm the Body? (Live Science)
"There's been some reported evidence that radioactive iodine and cesium are being released into the environment from the malfunctioning nuclear reactors in Japan, said Kathryn Higley, director of the Oregon State University department of nuclear engineering and radiation health physics."