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Radiation hormesis is the conjecture that a low level of ionizing radiation (i.e., near the level of Earth's natural background radiation) helps "immunize" cells against DNA damage from other causes (such as free radicals or larger doses of ionizing radiation), and decreases the risk of cancer. The theory proposes that such low levels activate ...
Radioactive contamination can be due to a variety of causes. It may occur due to the release of radioactive gases, liquids or particles. For example, if a radionuclide used in nuclear medicine is spilled (accidentally or, as in the case of the Goiânia accident, through ignorance), the material could be spread by people as they walk around.
Warning sign next to a transmitter with high field strengths. While the most acute exposures to harmful levels of electromagnetic radiation are immediately realized as burns, the health effects due to chronic or occupational exposure may not manifest effects for months or years. [17] [18] [4] [19]
Ionizing radiation is generally harmful and potentially lethal to living things but can have health benefits in radiation therapy for the treatment of cancer and thyrotoxicosis. Its most common impact is the induction of cancer with a latent period of years or decades after exposure.
Background radiation is from naturally radioactive materials and cosmic radiation from space. [5] The embryo and fetus are considered highly sensitive to radiation exposure. [8] Complications from radiation exposure include malformation of internal organs, reduction of IQ, and cancer formation. [8]
Radiation is often categorized as either ionizing or non-ionizing depending on the energy of the radiated particles. Ionizing radiation carries more than 10 electron volts (eV), which is enough to ionize atoms and molecules and break chemical bonds. This is an important distinction due to the large difference in harmfulness to living organisms.
The WHO stresses that the percentages stated in that section of their report are relative risk increases of developing these cancers, not absolute risk increases, since the lifetime absolute baseline risk of developing thyroid cancer in females is 0.75% and the radiation-induced cancer risk is now predicted to increase that 0.75% to 1.25%, with ...
The economic cost, for example of adding a barrier against radiation, must also be considered when applying the ALARP principle. Computed tomography, better known as CT scans or CAT scans have made an enormous contribution to medicine, however not without some risk. The ionizing radiation used in CT scans can lead to radiation-induced cancer. [13]