四川省环境天然贯穿辐射水平调查研究

INVESTIGATION OF ENVIRONMENTAL NATURAL PENETRATING RADIATION LEVEL IN SICHUAN PROVINCE

本文报道了四川省环境天然贯穿辐射水平调查研究的方法和结果。川东盆地按２５ｋｍ×２５ｋｍ网格均匀布设４１８个网格点，川西山地高原地区按５０ｋｍ×５０ｋｍ网格均匀布设９８个网格点，合计５１６个网格点。在城镇布设人口加密点３５５个。在核设施、矿山和大熊猫保护区加密布点分别为１４６、１５９和７１个。调查结果表明：（１）四川省原野γ辐射剂量率（离地１ｍ高处的空气吸收剂量率，下同）以５１６个网格点（下同）按面积、人口和网格点（以下简称测点）加权平均值分别为６２，８、６２．５和６４．６ｎＧｙ·ｈ￣（－１）；（２）道路γ辐射剂量率按测点平均值为６３．０ｎＧｙ·ｈ￣（－１）；（３）室内γ辐射剂量率按人口、测点加权平均值分别为９１．６和９２．１ｎＧｙ·ｈ￣（－１）；（４）宇宙射线电离成分（不包括中子成分）所致空气吸收剂量率按测点和人口加权平均值，室内分别为３３．５和３１．２ｎＧｙ·ｈ￣（－１），室外分别为３９．６和３３．５ｎＧｙ·ｈ￣（－１）；（５）天然贯穿辐射（γ辐射十宇宙射线）剂量率按测点和人口加权平均值，室内分别为１２２．５和１１７．９ｎＧｙ·ｈ￣（－１），室外分别为１０２．１和９６．７ｎＧｙ·ｈ￣（－１）；（６）宇宙射?

The methods and results of investigation on natural penetrating radiation level inSichuan Province are reported. 418 25 km × 25 km-grid measuring points were set up uni-formly in the east of Sichuan and 98 50 km×50 km-grid in the mount area of West Sichuan,totally 516 grid points, with 355 densely measuring points of different types added. The re-sults show that: (1)The area-weighted,population-weighted and point-weighted average val-ue of natural γ radiation dose rate for field is 62.8,62. 5 and 64. 6 nGy·h￣(-1),respectively;(2)The point-weighted average value of natural γ radiaton dose rate for road is 63. 0 nGy·h￣(-1);(3)The population-weighted and point-weighted average value of natural γ radiaton dose rateinside buildings is 91. 6 and 92. 1 nGy·h￣(-1),respectively;(4)The point-weighted and popula-tion-weighted average value of the dose rate inside buildings from cosmic ray is 33. 5 and31. 2 nGy·h￣(-1),and outside buildings is 39. 6 and 33. 5 nGy·h￣(-1),respectively;(5)The point-weighted and population-weighted average value of natural penetrating radiation dose rate in-side buildings is 122. 5 and 117. 9 nGy·h￣(-1),outside buildings is 102. 1 and 96.7 nGy·h￣(-1),respectively;(6)The annual effective dose equivalent from cosmic ray,natural γ radiationand natural penetrating radiation is 0.26,0. 51 and 0.77 mSv,respectively; and correspond-ingly, the annual collective effective dose equivalent is 2. 59×10￣4,5. 09×10￣4 and 7. 68×10￣4man·Sv,respectively.