云南省环境天然贯穿辐射水平调查研究

INVESTIGATION OF ENVIRONMENTAL NATURAL PENETRATING RADIATION LEVEL IN YUNNAN PROVINCE

本文报道云南省环境天然贯穿辐射水平调查的方法和结果。全省以２５ｋｍ×２５ｋｍ网格均匀布点，共布设网格点６３０个，各类加密点９５５个。调查结果表明：（１）云南省原野γ辐射剂量率按面积、人口和网格点的加权均值分别为６６．０、６４．８和６６．７ｎＧｙ·ｈ￣（－１）；（２）道路γ辐射剂量率按网格点平均值为６３．２ｎＧｙ·ｈ￣（－１）；（３）室内γ辐射剂量率按人口和网格点加权均值分别为９１．４和９３．１ｎＧｙ·ｈ￣（－１）；（４）宇宙射线电离成分（不包括中子）所致空气吸收剂量率按网格点和人口加权均值，室内分别为４０．６和３９．９ｎＧｙ·ｈ￣（－１），室外分别为４５．６和４５．１ｎＧｙ·ｈ￣（－１）；（５）天然贯穿辐射剂量率，按网格点和人口加权均值，室内分别为１３３．７和１３１．３ｎＧｙ·ｈ￣（－１），室外分别为１１２．３和１０９．７ｎＧｙ·ｈ￣（－１）；（６）天然γ辐射、宇宙射线和天然贯穿辐射所致居民人均年有效剂量当量分别为０．５１、０．３６和０．８８ｍＳｖ，所致全省居民集体年有效剂量当量分别为１．７、１．２和２．９×１０￣４人·Ｓｖ。

The methods and results of the investigation on natural penetrating radiation levelin Yunna Province are presented.630 25 km×25 km-grid measuring points were set uniformly up all over the province,with 955 densely measuring points of different types added.Theresults show that:(1)The area-weighted, population-weighted and point-weighted averagevalue of naturalγ radiation dose rate for field is 66.0,64.8 and 66.7 nGy·h￣(-1) ,respectively;(2)The point-weighted average value of natural γ radiaton dose rate for road is 63.2 nGy·h￣(-1);(3)The population-weighted average and point-weighted value of natural γ radiaton doserate inside buildings is 91.4 and 93.1nGy·h￣(-1),respectively;(4)The point-weighted andpopulation-weighted average value of the dose rate inside buildings from cosmic ray is 40.6and 39.9 nGy·h￣(-1),and outside buildings is 45.6 and 45.1nGy·h￣(-1),respectively;(5)The point-weighted and population-weighted average value of natural penetrating radiation doserate inside buildings is 133.7 and 131.3 nGy·h￣(-1),outside buildings is 112.3 and 109.7 nGy·h￣(-1),respectively;(6)The annual effective dose equivalent from natural γ radiation,cosmicray and natural penetrating radiation is 0.51,0.36 and 0.88 mSv,respectively;and correspondingly,the annual collective effective dose equivalent is 1.7,1.2 and 2.9×10￣4man· Sv,respectively.