１　引言１９９０年国际辐射防护委员会（ＩＣＲＰ）在ＩＣＲＰ６０号出版物中发表了新的建议，以替代１９７７年发表的建议和在ＩＣＲＰ年报中发表的增补声明。新建议书中一个重要的变化是对辐射诱导癌症危险的评估进行了修正，新的癌症危险估计要比１９７７年发表的高３～ 1 Introduction In 1990, the International Commission on Radiological Protection (ICRP) published a new proposal in I-CRP60 publication to replace the recommendations issued in 1977 and the supplemental statements published in the ICRP annual report. An important change in the new Recommendation is the revision of the assessment of radiation-induced cancer risk. The new cancer risk is estimated to be 3 to 3 times higher than published in 1977,