Low dose radiation risks.

Abstract

The 20th L H Gray Conference held in 2002 took as its general title ‘‘Radiation Cancer Analysis and Low Dose Risk Estimation’’. The purpose of the meeting was to bring together experts from a broad spectrum of disciplines, including epidemiologists, modellers, statisticians and radiation biologists to discuss new insights in radiation-induced carcinogenesis and the implications for low dose radiation risk. The findings of the Conference are also especially timely for the large number of staff in the healthcare professions who are concerned with the diagnostic uses of ionizing radiation. The Ionising Radiation (Medical Exposure) Regulations 2000 [1] and the extensive Guidance Notes to these regulations recently published [2] rely heavily on the linear-no-threshold (LNT) model of radiation induced cancer, especially with regard to the principles of Justification and Optimization. Therefore it is important to be aware of the latest findings, both for and against the model, and the degree of confidence that can be attached to it. A major aim of the Conference was to look at the extent to which multistage cancer models can bridge the gap between mechanistic information such as in vitro dose responses and epidemiological information from which risks are estimated with an LNT approach. Four broad areas of research provided the majority of the papers; 1) cancer modelling, 2) basic mechanisms and bystander effects, 3) radon exposure and lung cancer risks, and 4) cancer after radiotherapy.