广西壮族自治区环境天然贯穿辐射水平调查研究

INVESTIGATION OF ENVIRONMENTAL NATURAL PENETRATING RADIATION LEVEL IN GUANGXI ZHUANGZU AUTONOMOUS REGION

本文报道了1987—1988年广西壮族自治区环境天然贯穿辐射水平的调查方法及其结果。全区以25×25 km 网格均匀布点,共布设测量网格点360个,各类加密点599个。调查结果表明:(1)全区原野天然γ辐射剂量率按面积、人口和测点加权平均值分别为63.4、65.3和62.8 nGy·h^(-1)。;(2)道路的天然γ辐射剂量率按测点平均值为54.9 nGy·h^(-1);(3)建筑物室内天然γ辐射剂量率按人口和测点加权平均值分别是97.6和91.7 nGy·h^(-1);(4)宇宙射线电离成分所致空气吸收剂量率按人口和测点加权平均值,室外分别是28.9和29.5 nGy·h^(-1),室内分别为25.2和25.8 nGy·h^(-1);(5)天然贯穿辐射剂量率(不包括中子成分)按人口和测点加权平均值,室外分别为94.3和92.3nGy·h^(-1),室内分别为122.8和117.5 nGy·h^(-1);(6)天然γ辐射、宇宙射线和天然贯穿辐射所致的我区人均年有效剂量当量分别是0.54、0.23和0.77 mSv,全区居民集体年有效剂量当量分别为1.98、0.84和2.82×10~4人·Sv;(7)我区主要旅游区(点)的天然γ辐射大部分属于正常本底水平。首次发现“花山-姑婆山”天然γ辐射高本底区,面积约500 km^2,其原野和建筑物室内的天然γ辐射剂量率分别为20.5和27.8 nGy·h^(-1)。

The methods and results of the investigation on natural penetrating radiation level inGuangxi from 1987 to 1988 are presented.360 25×25 km-grid measuring points were set unformlyup all over the region,with 599 densely measuring points of different types added.The results showthat:(1)The area-weighted,population-weighted and point-weighted average value of natural γradiation dose rate for field is 63.4,65.3 and 62.8 nGy·h^(-1),respectively;(2)The point-weightedaverage value of natural γ radiaton dose rate for road is 54.9nGy·h^(-1);(3)The population-weightedand point-weighed average value of natural γ radiaton dose rate inside buildings is 97.6 and 91.7nGy·h^(-1),respectively;(4)The population-weighted and point-weighted average value of the dose rateouside buildings from cosmic ray is 28.9 and 29.5nGy·h^(-1),and inside buildings is 25.2 and 25.8nGy·h^(-1),respectively;(5)The population-weighted and point-weighted average value of naturalpenetrating radiation dose rate outside buildings is 94.3 and 92.3n Gy·h^(-1),inside buildings is 122.8 and 117.6nGy·h^(-1),resPectively;(6)The annual individual effective dose equivalent from natural γradiation,cosmic ray and natural penetrating radiation is 0.54,0.23 and 0.77 mSv,respectively;and correspondingly,the annual collective effective dose equivalent is 1.98,0.84 and 2.82×10~4man·Sv,respectively.(7)The natural γ radiation of most major place for travel in the region isnearly normal background level.An abnormal background area near“Huashan-Guposhan”was foundof natural γ radiation dose rate for field and inside building to be 20.5 to 27.8 nGy·h^(-1),respectively.