Search results
Results from the WOW.Com Content Network
The most widely accepted model posits that the incidence of cancers due to ionizing radiation increases linearly with effective radiation dose at a rate of 5.5% per sievert; [1] if correct, natural background radiation is the most hazardous source of radiation to general public health, followed by medical imaging as a close second.
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.
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.
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]
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.
Ionizing radiation may be used to treat other cancers, but this may, in some cases, induce a second form of cancer. [74] Radiation can cause cancer in most parts of the body, in all animals, and at any age, although radiation-induced solid tumors usually take 10–15 years, and can take up to 40 years, to become clinically manifest, and ...
The classification of mobile phone signals as "possibly carcinogenic to humans" by the World Health Organization (WHO) — "a positive association has been observed between exposure to the agent and cancer for which a causal interpretation is considered by the Working Group to be credible, but chance, bias or confounding could not be ruled out ...
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 ...