Abstract

C. Knüsli  "Ionizing Radiation: Medical Risks – New Aspects"

Since its detection ionising radiation [IR] has been recognised as a major human health risk inducing a broad variety of biological cellular changes. Characteristically, high IR doses are associated with deterministic whereas lower IR doses are related to stochastic effects respectively. Biological research establishing reliable biomarkers in low dose IR is still limited in contrast to higher dose and dose-rate IR. Radioprotection concepts have been developed and respective measures were widely implemented in the medical fields and in occupational exposure in the nuclear industry. According to the current recommendations of the International Commission on Radiological Protection (ICRP publication 103; 2007) the risk for lethal cancer disease in adults amounts to 5.5%/Sievert. Carcinogenicity is the hallmark of IR, however lethal IR impact of noncancer – e.g. cardiovascular – diseases has been shown to be in the same order as death to radioinduced malignancy. Modern epidemiological studies on nuclear workers, on populations exposed to fallout from nuclear power plant accidents, on natural background irradiation as well as radiodiagnostic studies confirm the dose response relationship of low dose IR and its detrimental health impacts. These studies corroborate the Linear No Threshold [LNT] concept and underline the usefulness of collective dose calculations. The latter allow extrapolations of health risks in large populations exposed to low doses of ionising radiation. Current scientifically based understanding calls for acceptance of risk estimations at doses as low as 1 mSv and below and therefore asks for a revision of the ICRP-recommendations which are outdated one decade after their effective date.