The effects of ionising radiation: Some studies in physics and biology.
thesisposted on 19.11.2015, 09:18 by Monty Winston. Charles
This thesis summarises the authors contributions to the field of ionising radiation effects by reviewing a number of studies in physics and biology made over the past 20 years. These studies relate primarily to aspects of radiological protection and chapters I and II provide some background and an historical introduction to this important branch of radiation research. Chapter III deals with work on two-dimensional multilayer structures and in particular their utilisation as long-spacing pseudo crystals for the dispersion of low energy X-radiation. Chapter IV deals with investigations of the gas gain and energy resolution of gas proportional counters and their utilisation for the study of energy deposition processes. Chapter V deals with the development of defensible radiological protection criteria for, and the measurement of doses to, superficial tissues such as the skin, eye and gonads. Enphasis has been placed upon the need for parallel developments in the understanding of both the necessary radiobiology and physics. Studies in radiobiology and morphology can identify the origin and depth of target cells while fundamental physics developments may be necessary for the production of appropriate radiation detectors. The superficial tissues may be subjected to high localised radiation exposures from poorly penetrating radiations such as alpha, beta and low energy X-radiation. Chapter VI reviews the use of animal models for the investigation of the effects of non-uniform skin exposure such as those which arise when the skin is subjected to radioactive particle exposures. The discussion is framed in terms of the limitations of current recommendations of the International Commission on Radiological Protection (ICRP) for skin dose limitation. The rationale of much of the authors work has been to carry out fundamental research in order to identify weaknesses in ICRP recommendations and, where they exist, to provide information to strengthen or underwrite revised radiological protection criteria. Such new data have been produced, for both stochastic and nonstochastic biological effects, through extensive multi-disciplinary collaborative research programmes, which are described. Chapter VII deals with the development of biological dosimetry techniques, particularly those capable of providing information on the uniformity of radiation exposures. The development of skin and hair as monitors of skin dose, and as indicators of the uniformity of whole body exposures, is particularly appropriate to the need for dose assessments in unscheduled exposures which have been underlined by the Chernobyl reactor accident. Chapter VIII deals with the evaluation of radiation risks from human radiation exposure experience. Particular emphasis is laid on the importance of the Japanese bomb survivor data and the controversy regarding radiation risks which has arisen in recent years following the need to revise the survivors radiation doses. The authors original estimates of revised risks and more recent analyses of the latest Japanese epidemiology data are presented. More than 80 publications are referred to, the majority of which are included as copies at the end of each chapter, together with suggestions for further reading. A list of the authors major publications and curriculum vitae are also included.