Radiation Exposure And Occupational Risks

The aim of radiation protection standards is to make the radiation workplace as safe as is humanly possible. The gradual evolution over the last 20 years has been towards a more precise definition of the limits for occupational exposure. These have been created not only in terms of short-term effects but also more importantly in terms of long-term risks involving such problems as the potential for carcinogenesis and genetic change. In the United States the National Committee for Radiation Protection has recom mended that 5 rems (50 mSv) should remain as the maximum permissible dose equiva lent for total body exposure. This would represent the sum of internal and external ex posure and should be regarded as the upper limit allowed. The community of radiation users is required to conduct its operations in such a man ner that the absolute value of the individual's dose equivalent in rems does not exceed his age in years. There should be additional limits for tissues and organs based on short term effects. Therefore, individual organs are limited to dose equivalents low enough to ensure that the dose threshold values are not exceeded.

This book is the seventh in a series of titles from the National Research Council that addresses the effects of exposure to low dose LET (Linear Energy Transfer) ionizing radiation and human health. Updating information previously presented in the 1990 publication, Health Effects of Exposure to Low Levels of Ionizing Radiation: BEIR V, this book draws upon new data in both epidemiologic and experimental research. Ionizing radiation arises from both natural and man-made sources and at very high doses can produce damaging effects in human tissue that can be evident within days after exposure. However, it is the low-dose exposures that are the focus of this book. So-called “late” effects, such as cancer, are produced many years after the initial exposure. This book is among the first of its kind to include detailed risk estimates for cancer incidence in addition to cancer mortality. BEIR VII offers a full review of the available biological, biophysical, and epidemiological literature since the last BEIR report on the subject and develops the most up-to-date and comprehensive risk estimates for cancer and other health effects from exposure to low-level ionizing radiation.

This book reevaluates the health risks of ionizing radiation in light of data that have become available since the 1980 report on this subject was published. The data include new, much more reliable dose estimates for the A-bomb survivors, the results of an additional 14 years of follow-up of the survivors for cancer mortality, recent results of follow-up studies of persons irradiated for medical purposes, and results of relevant experiments with laboratory animals and cultured cells. It analyzes the data in terms of risk estimates for specific organs in relation to dose and time after exposure, and compares radiation effects between Japanese and Western populations.

Jointly published by three international organizations with mandates relating to occupational health and ionizing radiation - the ILO, IAEA and WHO - the publication will be useful for national authorities, trade unions, employers and other parties with an interest in ensuring an equitable approach to workers' compensation.

The present Safety Guide provides general guidance on the establishment of an effective radiation protection programme for occupational exposure, appropriate for the sources of radiation likely to be encountered in a range of industries, medical institutions, educational and research establishments and nuclear fuel cycle facilities. The report further provides the necessary guidance to meet the requirements as laid down in Safety Series No. 115, International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (1996).