- Industry: Government
- Number of terms: 33950
- Number of blossaries: 0
- Company Profile:
United States Department of Health and Human Services, Radiation Emergency Medical Management
The property of certain nuclides of emitting radiation by spontaneous transformation of their nuclei. Various units of (radio)activity have been used including curie (1 ci = 3.7 x 1010 disintegrations per second) and becquerel ( 1 bq = 1 disintegration per second). (mettler fa jr, upton ac: medical effects of ionising radiation, 3rd ed. Philadelphia, pa: saunders elsevier, 2008, page 552)
Industry:Medical devices
An exposure to radiation that occurred in a matter of minutes rather than in longer, continuing exposure over a period of time. See also chronic exposure, exposure, fractionated exposure.
Industry:Medical devices
The acute radiation syndrome (ars) is also known as radiation sickness. A person exposed to radiation will develop ars only if the radiation dose was high, penetrating (e.g., x-rays or gamma rays), encompassed most or all of the body, and was received in a short period of time. Clinical severity of the four subsyndromes of ars (hematopoietic, cutaneous, gastrointestinal, and neurovascular) will vary with dose and host factors (e.g., young or old age, immunosuppression, and medical co-morbidity--especially extensive trauma and burns).
Industry:Medical devices
A nuclear weapon explosion that is high enough in the air to keep the fireball from touching the ground. Because the fireball does not reach the ground and does not pick up any surface material, the radioactivity in the fallout from an air burst is relatively insignificant compared with a surface burst. For more information, see chapter 2 of cdc’s fallout report (pdf - 32.24 mb).
Industry:Medical devices
The initial kinetic energy of the primary ionising particles (photoelectrons, compton electrons, positron/negatron pairs from photon radiation, and scattered nuclei from fast neutrons) produced by the interaction of the incident uncharged radiation in a small volume of air, when it is irradiated by an x-ray beam. Unit of measure is gray. See also kerma.
Industry:Medical devices
Means making every reasonable effort to maintain exposures to ionising radiation as far below the dose limits as practical. This is a key principle in radiation protection and safety.
Industry:Medical devices
(image) the nucleus of a helium atom, made up of two neutrons and two protons with a charge of +2. Certain radioactive nuclei emit alpha particles. Alpha particles generally carry more energy than gamma rays or beta particles, and deposit that energy very quickly while passing through tissue. Alpha particles can be stopped by a thin layer of light material, such as a sheet of paper, and cannot penetrate the outer, dead layer of skin. Therefore, they do not damage living tissue when outside the body. When alpha-emitting atoms are inhaled or swallowed, however, they are especially damaging because they transfer relatively large amounts of ionising energy to living cells. See also beta particles, gamma rays, neutron, x-ray.
Industry:Medical devices
A silvery metal; it is a man-made element whose isotopes am-237 through am-246 are radioactive. Am-241 is formed spontaneously by the beta decay of plutonium-241. Trace quantities of americium are widely used in smoke detectors and as neutron sources in neutron moisture gauges.
Industry:Medical devices
Assigned protection factor (apf) means the workplace level of respiratory protection that a respirator or class of respirators is expected to provide to employees enrolled in a continuing, effective respiratory protection program. (source: assigned protection factors for the revised respiratory protection standard, 2009. Osha. U.s. department of labour publication no. 3352-02 2009.)
Industry:Medical devices
The smallest particle of an element that can enter into a chemical reaction.
Industry:Medical devices
