Lessons Learned from Joint Working Group Report on Assessment and Management of Cancer Risks from Radiological and Chemical Hazards

Abstract

Regulation of radiological hazards to humans is greatly simplified by the existence of the InternationalCommission on Radiological Protection (ICRP). The average RBE values or radiation weighting factorsrecommended by the ICRP are based on non-human data. The ICRP has a lso indicated that "the standard ofenvironmental control needed to protect man to the degree currently thought desirable wi ll ensure that otherspecies are not put at risk.'. This statement appears to be suppo1ted by technical publications from otherorganizations. Two published objections by AECB staff to the scientific technical background of the ICRPstatement do not offer any good reason to reject this ICRP statement.A brief summary is given of the joint working group report on the topic indicated in the title. It is noted thatregulators of cancer-causing chemicals have in general paid less attention to natural sources than have theregulators of radiological hazards. Most non-human species are exposed to about I millisieve,t (mSv) equivalentdose of radiation per year from natural sources. Caribou and organisms living underground are noted as exampleswhere radiation exposures from natural sources are considerably higher.The natural biota is in general remarkably resistant. both in the laboratory and in field snidies, to the effects ofhigh doses of radiation. A recent review by the International Atomic Agency concluded that dose rates below theequivalent of 400 mSv per year are unlikely to alter the survival of non-human species.It is recommended that caution and common sense be applied in any future research on radiological protection ofnon-human species in the environment in Canada. Many of the proposed U.S. regulations to control chemical andradiation in the environment are not cost-effective. It is to be hoped that efforts to protect non-human speciesfrom potential radiological hazards in Canada do not slide into a similar kind of irrational quagmire.