Infrared radiation Health Dictionary

The term applied to the nausea, vomiting and loss of appetite which may follow exposure to RADIATION – for example, at work – or the use of RADIOTHERAPY in the treatment of cancer and other diseases. People exposed to radiation at work should have that exposure carefully monitored so it does not exceed safety limits. Doses of radiation given during radiotherapy treatment are carefully measured: even so, patients may suffer side-effects. The phenothiazine group of tranquillisers, such as CHLORPROMAZINE, as well as the ANTIHISTAMINE DRUGS, are of value in the prevention and treatment of radiation sickness.... radiation sickness

Energy in the form of waves or particles. Radiation is mainly electromagnetic and is broadly classi?ed as ionising and non-ionising. The former can propel ions from an atom; these have an electrical charge and can combine chemically with each other. Ionisation occurring in molecules that have a key function in living tissue can cause biological damage which may affect existing tissue or cause mutations in the GENES of germ-cell nuclei (see GAMETE; CELLS). Non-ionising radiation agitates the constituent atoms of nuclei but is insu?ciently powerful to produce ions.

Ionising radiation comprises X-RAYS, GAMMA RAYS and particle radiation. X-rays are part of the continuous electromagnetic-wave spectrum: this also includes gamma rays, infra-red radiation, ultraviolet light and visible light. They have a very short wavelength and very high frequency, and their ability to penetrate matter depends upon the electrical energy generating them. X-rays that are generated by 100,000 volts can pass through body tissue and are used to produce images – popularly known as X-rays. X-rays, generated at several million volts can destroy tissue and are used in RADIOTHERAPY for killing cancer cells. Gamma rays are similar to X-rays but are produced by the decay of radioactive materials. Particle radiation, which can be produced electrically or by radioactive decay, comprises parts of atoms which have mass as well as (usually) an electrical charge.

Non-ionising radiation includes ultraviolet light, radio waves, magnetic ?elds and ULTRASOUND. Magnetic ?elds are used in magnetic resonance imaging (MRI) and ultrasound, which is inaudible high-frequency sound waves, and is used for both diagnoses and treatment in medicine.... radiation

Harmful ultraviolet radiation from depletion of the ozone layer may affect general health and cause skin cancers, cataracts and immune deficiency. The protection offered by antioxidant nutrients can play a part in reducing the incidence of lens cataract. Until scientific medicine discovers effective treatment it would appear that Vitamins A, E, and Evening Primrose oil have a role to play in protection of the eyes and skin. Horsetail, rich in silica, is believed to delay progression of cataract when taken internally.

Topical. Creams to prevent burning: Vitamin E, Evening Primrose, Houseleek, Aloe Vera. Honey. Most creams contain Vitamin E which acts as a filter and moisturiser.

Diet. Foods rich in beta-carotene, Vitamins C and E.

Supplements. Vitamins A and E.

Note: Use of sunglasses and sun screens on sunny days to avoid burning. Wearing of a hat. ... ozone radiation

Hazards from radiation may arise from external sources of radiation or from radioactive materials taken into the body. The effects depend on the dose, the duration of exposure, and the organs exposed.

With some forms of radiation, damage occurs when the radiation dose exceeds a certain limit, usually 1 sievert (Sv) (see radiation unit). This damage may include radiation dermatitis, cataracts, organ failure (which may occur many years later), or radiation sickness.

For other types of radiation damage, the risk that damage will occur increases with increasing doses of radiation. Cancer caused by radiation-induced mutation is the major example of this type of damage. Radioactive leaks from nuclear reactors can cause a rise in mutation rates, which may lead to an increase in cancers, such as leukaemias; to birth defects; and to hereditary diseases. Cancer usually develops years after exposure. Radiation damage can be controlled by limiting exposure. People exposed to radiation at work have their exposure closely monitored to ensure that it does not exceed safe limits. People of reproductive age or younger should have their reproductive organs shielded when having X-rays or radiotherapy.There is no evidence of radiation hazards with visual display units (VDUs).... radiation hazards

measures designed to limit the dose of harmful radiation to patients and workers. Medical exposure to radiation is governed in the UK by the Department of Health and Social Care under the Ionising Radiation (Medical Exposures) Regulations 2000 (IRMER). A guiding theme of protection is the ALARA principle (“as low as reasonably achievable”).... radiation protection

see radioembolization.... selective internal radiation therapy

Several different internationally agreed units (called units) are used to measure ionizing radiation. For example, the roentgen (R) measures the amount of radiation in the air, and the becquerel is the unit of spontaneous activity of a radioactive source such as uranium. For medical purposes, the most commonly used units are the gray (Gy) and the sievert (Sv).

The gray is the unit of radiation that is actually absorbed by any tissue or substance as a result of exposure to radiation. 1 Gy is the absorption of 1 joule of energy (from gamma radiation or X-rays) per kilogram of irradiated matter. The gray supersedes an older unit called the rad (1 Gy = 100 rads).

Because some types of radiation affect biological organisms more than others, the sievert is used as a measure of the impact of an absorbed dose. It uses additional factors, such as the kind of radiation and its energy, to quantify the effects on the body of equivalent amounts of different types of absorbed energy. The sievert replaces an older unit, the rem (1 Sv=100 rems).... radiation unit