Preface This report of the National Academy of Sciences National Researeh Council Advisory Committee on the Biological Effeets of fonizing Radtations (BEIR Committee) deals with the sci- entific basis for the extablishinent of radiation toxicological agents: nor have we attempted to explore in detail technological matters such as sustained engineering performance of power reactors, large-scale waste disposal, or the problemof catastropnic accidents. Neverthe- protection standards atul encompasses a review and re-evaluaiion of existing scientific less. we have felt it urzent to call attention to human populations. The present basis of radiation protection is essentially the establishment of sinwzle upper limits for individual and population average expusures with the understand- acceptance fained on the basis of providing society with the services that it needs at a mini- knowledge concerning radiation exposure of ing that anybioluvical risks should be offset by commensurate benefits and that these risks should be kept as low as practicable. It has become apparent that these current concepts of radiation protection may net be adequate in a future ave of é cale ise at clear energy. Inadejue becuuse there is the po- tential for radiation exposure uf entire popula- tions and such exposure may be an alternative to other types af hazards as. for example. the substicucion of radivactive contaminants from nuclear pawer Tor the ce tion products from fossil Tuet plants. pmus there is a “need somehowto make comin risons of biological risks and benedts not oniv for radiation but for the alternative options. Inihts report it has not been pus side for us ta deal with critical interacting ars such as socie-cconomics, energy Needs, and comparative cfects of other these issues because ultimately, decisions will have to be made involving them, and public muinrisk to health and the environment. The BEIR Committee has endeavored to en- sure that no sources of relevant knowledge or expertise were overluvked in its study and toward this end hus e-tablished and maintained jaigan with appropriate nattonal ard international erganizations, and has solicited the opinions and course J ividual setentists The Committee wish €X: appreciation to inuse who serve he $ itees. ard tothe many organizations and iduais who have cooperated by providing wpoints and infermation. The members oi the Committee and Subcommittzes fivicuals, noi 25 representatives of their organi Coapters IV througn VIE rear vorts of the respective Subcomnm have been modified by the Commi tr bers of the Committe: approve the substance of the report if not necessarily each specific aera.