Many types of radiation can be found in the workplace and in our environment. Many radiations are naturally-occurring, for example, radon, radium, uranium, and the sun (ultraviolet rays). Man-made radiations include X-rays, CAT scans and magnetic resonance imaging (MRI). There are 2 broad types of radiation of concern: electromagnetic and nuclear. Electromagnetic radiation is the way power is broadcast through the air. Nuclear radiation comes either naturally occurring or man-made sources.
The human body is ill-equipped to protect itself against radiation and cannot even detect it with its natural sensing mechanisms. Depending on the level of exposure, radiation can pose a health risk. It can adversely affect individuals directly exposed, as well as their descendents. Radiation can affect cells of the body, increasing the risk of cancer or harmful genetic mutations that can be passed on to future generations; or if the dosage is large enough to cause massive tissue damage, it may lead to death within a few weeks of exposure.
The main concern here is the hazard associated with radioactive materials. After usage, these radioactive materials become waste, and as these waste decay, they give off energy (radiation) that can be very harmful to humans and other living organisms.
The 2 main categories of electromagnetic radiation are ionizing radiation and non-ionizing radiation (see Figure). These 2 categories are generally used to show the effect of radiation wavelength and energy on living organisms.
All matter is composed of atoms. Atoms have a nucleus of protons and neutrons, and electrons spin in orbit around the nucleus. When ionization occurs, there is an energy transfer that changes the normal electrical balance in an atom. Atoms that have an unstable nucleus become radioactive from the emission of particles from the nuclei. Some elements are naturally radioactive, and others, like isotopes, become radioactive after bombardment with neutrons or other particles. Click here for more information on types of ionizing radiation.
The type of radiation, the radiation energy, and the substance being irradiated are factor in the total amount of radiation absorbed in a tissue. High-energy radiation will penetrate and produce effects deep into the body, while low-energy radiation has its maximum effect on the surface of the body.
Non-ionizing radiation has longer wavelengths and lower frequencies. Non-ionizing radiation includes radio, television, radar, microwave, infrared (IR), visible light, and ultraviolet (UV) areas of the electromagnetic spectrum. Some of the hazards associated with non-ionizing radiation are:
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