[en] The 23rd Annual Meeting of the European Society for Radiation Biology was held in Dublin, Eire, 23-26 September 1990. Papers presented were grouped into two themes:- (a) Promoting areas where new developments in cell and molecular biology are fundamentally altering concepts of radiation action (papers on radiation induced mutagenesis and transformations, dosimetry and risk, DNA damage and repair, low dose/low dose rate effects, and non-ionising radiation). (b) Areas where radiobiological information is directly important to the topic (papers on food irradiation, diagnostic imaging, environmental radiation, radiotherapy, and the oxygen effect). (UK)

[en] Neutral filter elution, viral reactivation and the plasmid reconstitution assay are discussed in relation to DNA repair in human tumour cells. The authors demonstrate that radioresistant cells do not necessarily perform well in repair assays, suggesting that processes other than repair are more important in the determination of radiosensitivity, or that current assays do not measure processes critical to the survival of a cell following radiation. (UK)

[en] Medical Radiology accounts for up to 5% of health care costs and 40% of population radiation dose. For this reason, a rational approach to radiodiagnostic investigations is mandatory. Quality control, reduction of patient radiation dose by improved technology and well defined medical indications for the radiological studies are the key factors to achieve optimization of image quality and patient exposure. (author)

[en] Insult from ionizing radiation is always in the form of individual structured tracks. At cell level possible responses are limited by numbers and variety of tracks and on time intervals between them. Most situations of practical concern in radiation protection are characterized by single tracks well separated in time from any other tracks in the same cell. A wide variety of initial molecular damage is possible, at the level of DNA, due to the traversal of just a single track. Therefore no dose-threshold can be expected for such molecular damage. A crucial question is how the cell may respond to such damage, received in isolation, and how this response may be modified by additional uncorrelated damage elsewhere in the same cell but received a considerable time earlier or later. (author)

[en] This paper discusses a 40-year overview to radioactivity in the environment, compares several Global sources of radionuclides, and suggests public involvement in a coordinated approach to evaluate comparative risks from living with environmental radioactivity. (author)

[en] The author demonstrates that to calculate the risk of leukemia in populations exposed to environmental plutonium, it is necessary (a) to estimate the amount of plutonium which is concentrated from the environment by the population at risk (b) to calculate the radiation dose received by target cells for leukemia within the bone-marrow uptake (c) to derive the leukaemogenic risk of these deposits, using risk estimates derived from human experience. It is pointed out that there is uncertainty at all stages and therefore current estimates of risk should be regarded with caution. (UK)

[en] This outline survey reviews the subject of food irradiation under the following headings:- brief history, the process (sources, main features of a food processing facility, interaction of radiation with food, main applications of the technology, packaging) consumer concerns (safety, nutritional changes, labelling, detection), international use of food irradiation and legal aspects. (UK)

[en] The progression of normal cells to the fully malignant phenotype is considered in outline, with particular reference to human cells and the role played by oncogenes and suppressor genes and by viruses and the cellular mechanisms by which HPV contributes to immortality, differentiation and carcinogenesis. (UK)

[en] Syrian hamster embryo (SHE) cells were neoplastically transformed by different types of ionizing radiation (γ-rays, α-particles or carbon ions). Transformed and tumor cell lines (derived from nude mice tumors) were analysed for alterations of the oncogenes c-Ha-ras and c-myc, i.e. RFLPs, gene amplifications, activation by point mutation, gene expression, and for cytological changes. In addition, the chromosome number and the numbers of micronuclei per cell have been determined in a series of cell lines. (author)

[en] The mean plutonium concentration measured in children's teeth samples from the U.K. was found to be 4.8 mBq.kg^-1, ash, with a median of 3.6 mBq.kg^-1, ash, and a range of 0.2 -21 mBq.kg^-1, ash. These values are consistent with the results of other studies on plutonium in humans worldwide. Approximately 75% of the samples analysed to date had a concentration of less than 5.0 mBq.kg^-1, ash. No correlation with mean annual rainfall was found, nor did there appear to be any correlation with linear distance from Sellafield. The origin of the detected plutonium could not be established directly because of the ultra-low levels involved. (author)