Exposure ionising radiation

PM 77 Fitness of equipment used for medical exposure to ionising radiation... 

COP23 Ionising radiations (part 3) Exposure to radon. 

L7 Ionising radiations (part 4) Dose limitation — restriction of exposure. 

In order to compare exposures to radon decay-products with those to other forms of ionising radiation, it is useful to assess the effective dose equivalent expressed in sieverts (Sv). A conversion coefficient of 15 Sv per J h m"3, equivalent to 5.5 mSv per WLM, has been recommended (UNSCEAR, 1982). With this conversion factor, the... 

The first member of the series, methyl vinyl ether (MVE) provided an interesting lesson, because although it can be polymerised cationically by chemical initiators, its exposure to ionising radiations produces only a radical polymerisation. Desai et al. 

The intensity of ionising radiation at the earth s surface is not high enough to significantly affect plastics, hence radiation exposure tests are only required in connection with applications in nuclear plant and possibly where radiation is used for sterilisation or to induce crosslinking. 

It has been known for many years that homolytic fusion of the 0-0 bond in H2O2 will yield the hydroxyl free radical OH. This may be produced by exposure of H2O2 solutions to heat or ionising radiation and hence may be formed, for example, after accidental or therapeutic exposure to radiation (e.g. during cancer therapy) ... 

When bone is treated with ionising radiation, free radicals are trapped in the crystal lattice of the bone (Gordy etal., 1955) and consequently can be detected by EPR spectroscopy. Prior to its application for the identification of irradiated food, the technique was used to date archaeological specimens (Ikeya and Miki, 1980) and as an in-vivo dosimeter to determine the level of human exposure to radiation (Pass and Aldrich, 1985). 

All three principles apply to the protection of workers and the public. However, to protect patients during the medical use of ionising radiation only justification and optimisation apply. Dose limits are not applicable to medical exposure, but guidance levels which show what is achievable by good practice may be established for use by medical practitioners. Dose limits are also inapplicable to interventions, which are concerned with reducing exposure. 

The ionising Radiations Regulations 1999 SI no 3232 and the ionising radiation (medical exposure) Regulations 2000. 

NRC (1990). Health Effects of Exposure to Low Levels of Ionising Radiation. US National Research Coundl Report BEIR V, National Academy Press, Washington, DC. 

It is clear that exposure of biological material to ionising radiation leads to a loss of function due to the modification of critical structures. Results of former space experiments suggest that the biological effect of space radiation could be enhanced under microgravity. 

Biological Effects of Ionising Radiation, (BEIR) VI Report The Health Effects of Exposure to Indoor Radon, 1998, US Environmental Protection Agency, Washington DC, USA. 

The data presented here demonstrate that the induction of differentiation by DMSO in the human promyelocytic leukaemia cells, HL-60, along the granulocytic lineage does not retard the ability of these cells to repair DNA lesions induced by exposure to either ionising radiation or treatment with the mono-functional methylating agent, DMS. This is consistent with our previous observation that post-mitotic primary muscle cell nuclei undergoing terminal differentiation are as efficient as their pro-... 

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