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A hot particle is a microscopic piece of radioactive material, which can become lodged in living tissue and deliver a concentrated dose of radiation to a small area. A controversial theory proposes that hot particles within the body are vastly more dangerous than external emitters delivering the same dose of radiation in a diffused manner. Other researchers claim that there is little or no difference in risk between internal and external emitters. The theory has gained most prominence in debates over the health effects of nuclear accidents, dirty bombs or fallout from atomic weapons, all of which can spread hot particles through the environment. The current ICRP risk model for radiation exposure is derived from studies of victims of external radiation, and detractors claim it does not adequately estimate the risk of hot particles. == Attributes == Hot particles contained in far-traveled nuclear fallout range in size from 10 nanometers to 20 micrometers, whereas those present in local fallout may be much larger (100 micrometers to several millimeters). Hot particles can be identified by a Geiger counter, or by autoradiography, ''i.e.'', fogging X-Ray film. Their age and origin can be determined by their isotopic signature. Due to their small size, hot particles may be swallowed, inhaled or enter the body by other means. Once lodged in the body, cells very near the hot particle may absorb much of its radiation, and be bombarded in a very sustained and concentrated fashion. By contrast, an external radioactive source delivering the same total amount of radiation over the whole body would give a relatively minute dose to any one cell.〔(Hot particle dosimetry and radiobiology—past and present )〕〔(The Hot Particle Problem )〕〔Hot particles and lung cancer statistics - An old paper, suggesting 1/2000 chance of lung cancer per hot particle induced lesion. http://docs.google.com/viewer?a=v&q=cache:lSp0zqeNobsJ:docs.nrdc.org/nuclear/nuc_77030001a_17.pdf+Health+effects+of+alpha-emitting+particles+in+the+respiratory+tract.+EPA+Office+of+Radiation+Programs+1976.&hl=en&gl=ca&pid=bl&srcid=ADGEESj_RgQY9NjJ8sCkPRZRNDZQDsf0O8CPDHwriViiUkzLJ0dxQRRucDBfnyo6Ju8ZtzBGxkdr8DVv8n55IeaKqj3ERjZodH6UNsYY7gHUrjUqMO3udeynngeZyM8aLqbsAmWrmKvu&sig=AHIEtbQhH5iElPIJhpsxZedOyMBEHic0Ag〕〔Some paper suggests a 1 in 10 to 1 in 2 chance for a lesion per hot particle inhaled - http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/28/061/28061202.pdf〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Hot particle」の詳細全文を読む スポンサード リンク
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