河北省环境天然贯穿辐射水平调查研究

INVESTIGATION OF ENVIRONMENTAL NATURAL PENETRATING RADIATION LEVEL IN HEBEI PROVINCE

本文报道了1985—1987年河北省环境天然贯穿辐射剂量水平的调查方法及其结果。全省以25×25km网格均匀布点,共布设网格点285个,各类加密测点204个。结果表明:(1)原野天然γ辐射剂量率按测点、按面积和按人口加权的平均值分别为5.59、5.51和5.31×10^(-3)Gy·h^(-1);(2)道路的天然γ辐射剂量率按测点平均为5.11×10^(-8)Gy·h^(-1);(3)建筑物室内天然γ辐射剂量率按测点和按人口加权的平均值分别为9.39和9.17×10^(-8)Gy·h^(-1);(4)宇宙射线电离成分所致空气吸收剂量率按测点和按人口加权的平均值,室内分别为3.05和2.80×10^(-8)Gy·h^(-1),室外分别为3.38和3.11×10^(-8)Gy·h^(-1);(5)天然贯穿辐射剂量率(不包括中子成分)按测点和按人口加权的平均值,室内分别为12.44和11.97×10^(-8)Gy·h^(-1),室外分别为8.97和8.42×10^(-8)Gy·h^(-1),(6)天然γ辐射、宇宙射线和天然贯穿辐射所致的我省人均年有效剂量当量分别为0.50、0.25和0.75mSv,全省集体年有效剂量当量分别为2.7,1.3和4.0×10~4人·Sv。 首次发现“计马石”天然γ辐射异常本底区,该测点的原野、道路、建筑物室内的天然γ辐射剂量率分别为20.92、19.77和27.93×10^(-8)Gy·h^(-1)。

The methods and results of the investigation on naturalpenetrating radiation level in Hebei Province from 1985 to 1987 arepresented. 285 25×25 km-netted measuring points were set unformly upall over the porvince, with 204 densely measuring points of differentypes added. The results show that: (1) The point-weighted,area-weighted and population-weighted average value of natural γradiation dose rate for field is 5.59, 5.51 and 5 .31×10^(-8) Gy. h^(-1),respectively; (2) The point-weighted average value of natural γradiaton dose rate for road is 5.11×10^(-8) Gy. h^(-1); (3) Thepoint-weighed and population-weighted average value of natural γradiaton dose rate inside buildings is 9.39 and 9.17×10^(-8) Gy. h^(-1),respectively; (4) The point-weighted andpopulation-weighted averagevalue of the dose rate inside buildings from cosmic ray is 3.05 and 2.80×10^(-8) Gy. h^(-1), and outside buildings is 3.38 and 3.11×10^(-8) Gy.h^(-1),rsepectively;(5) The point-weighted and population-weighted averagevalue of natural penetrating radiation dose rate inside buildings is 12.44and 11.97×10^(-8) Gy. h^(-1), outside buildings is 8.97 and 8.42×10^(-8) Gy.h^(-1), respectively; (6) The annual effective dose equivalent from naturalγradiation, cosmic ray and natural penetrating radiation is 0.50, 0.25,and 0.75 mSv, respectively; and correspondingly, the annual collectiveeffective dose equivalent is 2.7, 1.3 and 4.0×10~4 man. Sv, respectively.An abnormal background area near 'Jimashi', was found of natualγradiation dose rate for field, road and inside buildings to be 20.92,19.77 and 27.93×10^(-8) Gy. h^(-1), respectively.