b'\n_START_ARTICLE_\nStr\xc3\xa5lskydd\n_START_SECTION_\nRiskbed\xc3\xb6mningar\n_START_PARAGRAPH_\nVid studiet av risk som funktion av str\xc3\xa5ldos fann en internationell kommitt\xc3\xa9 att f\xc3\xb6r h\xc3\xb6ga doser var risken direkt proportionell mot dosen. Detta g\xc3\xa4llde ned till doser d\xc3\xa4r ingen risk kunde m\xc3\xa4tas. Som ansats till str\xc3\xa5lskyddsarbetet beslutade man d\xc3\xa4rf\xc3\xb6r att \xc3\xa4ven f\xc3\xb6r l\xc3\xa5ga doser, d\xc3\xa4r risken \xc3\xa4r s\xc3\xa5 liten att man inte kan hitta den genom m\xc3\xa4tningar, skall man betrakta den som proportionell mot dosen. F\xc3\xb6r dessa l\xc3\xa5ga str\xc3\xa5ldoser, under c:a 200 mSv, g\xc3\xa4ller att om det finns n\xc3\xa5gra h\xc3\xa4lsoeffekter s\xc3\xa5 \xc3\xa4r de i varje fall s\xc3\xa5 l\xc3\xa5ga att man inte kan hitta dem. Denna s.k. LNT-modell (Linear No Treshold) \xc3\xb6verskattar d\xc3\xa4rf\xc3\xb6r riskerna._NEWLINE_P\xc3\xa5st\xc3\xa5endet \xe2\x80\x9ddet finns inga s\xc3\xa4kra gr\xc3\xa4nsv\xc3\xa4rden\xe2\x80\x9d, som f\xc3\xb6rekommer i debatten \xc3\xa4r allts\xc3\xa5 en felaktig tolkning av m\xc3\xa4tresultaten. Gr\xc3\xa4nsv\xc3\xa4rdena f\xc3\xb6r joniserande str\xc3\xa5lning \xc3\xa4r i verkligheten mycket s\xc3\xa4krare \xc3\xa4n de flesta kemiska gr\xc3\xa4nsv\xc3\xa4rden._NEWLINE_Den franska Vetenskapsakademien (Acad\xc3\xa9mie des Sciences) och den franska akademien f\xc3\xb6r medicin (Acad\xc3\xa9mie nationale de M\xc3\xa9decine) publicerade 2005 en rapport (samtidigt som rapporten BEIR VII publicerades I USA) d\xc3\xa4r en tr\xc3\xb6skelv\xc3\xa4rdesmodell f\xc3\xb6rordades framf\xc3\xb6r LNT-modellen:_NEWLINE_In conclusion, this report raises doubts on the validity of using LNT for evaluating the carcinogenic risk of low doses (< 100 mSv) and even more for very low doses (< 10 mSv). The LNT concept can be a useful pragmatic tool for assessing rules in radioprotection for doses above 10 mSv; however since it is not based on biological concepts of our current knowledge, it should not be used without precaution for assessing by extrapolation the risks associated with low and even more so, with very low doses (< 10 mSv), especially for benefit-risk assessments imposed on radiologists by the European directive 97-43._NEWLINE_The Health Physics Society gjorde ett st\xc3\xa4llningstagande i fr\xc3\xa5gan 1996, vilket uppdaterades i juli 2010:_NEWLINE_In accordance with current knowledge of radiation health risks, the Health Physics Society recommends against quantitative estimation of health risks below an individual dose of 5 rem (50 mSv) in one year or a lifetime dose of 10 rem (100 mSv) above that received from natural sources. Doses from natural background radiation in the United States average about 0.3 rem (3 mSv) per year. A dose of 5 rem (50 mSv) will be accumulated in the first 17 years of life and about 25 rem (250 mSv) in a lifetime of 80 years. Estimation of health risk associated with radiation doses that are of similar magnitude as those received from natural sources should be strictly qualitative and encompass a range of hypothetical health outcomes, including the possibility of no adverse health effects at such low levels._NEWLINE_Nuclear Regulatory Commission i USA "accepts the LNT hypothesis as a conservative model for estimating radiation risk" men noterar att "public health data do not absolutely establish the occurrence of cancer following exposure to low doses and dose rates \xe2\x80\x94 below about 10,000 mrem (100 mSv). Studies of occupational workers who are chronically exposed to low levels of radiation above normal background have shown no adverse biological effects."_NEWLINE_Nya forskningsresultat om mekanismerna kring DNA repair, publicerade 2011 i Proceedings of the National Academy of Sciences of the United States, "casts considerable doubt on the general assumption that risk to ionizing radiation is proportional to dose"._NEWLINE_Mot detta talar en ny rapport, som studerat leukemi hos barn och joniserande str\xc3\xa5lning, b\xc3\xa5de naturlig bakgrundsstr\xc3\xa5lning och annan str\xc3\xa5lning._NEWLINE_Str\xc3\xa5ls\xc3\xa4kerhet m\xc3\xa5ste hanteras med omd\xc3\xb6me. Risker fr\xc3\xa5n l\xc3\xa5gdosstr\xc3\xa5lning \xc3\xa4r sv\xc3\xa5ra att bed\xc3\xb6ma. Joniserande str\xc3\xa5lning kan skapa oro och detta f\xc3\xa5r inte ge upphov till \xc3\xa5ngest som inneb\xc3\xa4r st\xc3\xb6rre skada \xc3\xa4n en ok\xc3\xa4nd risk fr\xc3\xa5n viss l\xc3\xa5gdosstr\xc3\xa5lning._NEWLINE_Svenska myndigheters diskussioner \xc3\xa5r 2010 kring att s\xc3\xa4nka gr\xc3\xa4nsv\xc3\xa4rdet f\xc3\xb6r radon fr\xc3\xa5n 200 till 100 Bq/m\xc2\xb3 \xc3\xa4r ett exempel p\xc3\xa5 n\xc3\xa5got som kan ha skapat st\xc3\xb6rre skada \xc3\xa4n nytta. Det b\xc3\xb6r dels relateras till att radonrisken framf\xc3\xb6r allt ber\xc3\xb6r tobaksr\xc3\xb6kare, dels att man i Schweiz f\xc3\xb6r n\xc3\xa4rvarande planerar att s\xc3\xa4nka riktv\xc3\xa4rdet fr\xc3\xa5n 1000 till 300 Bq/m\xc2\xb3.'