测试环境采编刊群
1985年 · 第05卷第Z1期
测试环境采编刊群
This paper presents the results of investigation on natural environmental radiation and the estimation of dose to population in Beijing area. The average absorbed dose rates in air from terrestrial gamma radiation are 6.06×10-8Gy·h-1, 8.9×l0-8Gy·h-1 and 4.91×10-8Gy·h-1 for outdoors, indoors and roads, respectively. The ratio of the indoor-to-outdoor absorbed dose rates in air is about 1.47. The average annual effective dose equivalent to population is 0.77mSv and the annual collective effective dose equivalent is 7.1×10-3man·Sv.
The exposure rates from natural radiation measured from August 1982 to January 1984 with a FD-71 Scintillation Radiometer in Shanxi Province are reported in this paper. The average absorbed dose rate in air of 1,842 open field sites was (10.78±1.41)×10-8Gy·h-1. The mean value of area-weighted outdoor absorbed dose rates in air was 6.8×10-8Gy·h-1. The average absorbed dose rate in air from natural external radiation of 3,446 indoor sites was (14.02±2.09)×10-8Gy·h-1 and the indoor area-weighted dose rate from natural radiation was 10.48×10-8Gy·h-1. The annual individual average effective dose equivalant to population in this province was 0.88 mSv, and the annual collective dose equivalent was 21,626.83 man.Sv.
In this paper the results of measurement of environmental radiation levels in Inner Mongolia Autonomous Region and the calculated doses to population are reported. The dose rates in air were measured by a FD-71 scintillation radiometer and a high pressure ionization chamber. The results showed that the average values of outdoor and indoor gamma radiation dose rates were (6.9±1.3)×10-8Gy·h-1 and (10.6±1.9)×10-8Gy·h-1, respectively, i.e., the indoor exposure was higher than that of outdoors by a factor of 1.5. The individual total annual effective dose equivalent from terrestrial gamma radiation and cosmic rays averaged 91.5×10-5Sv, and the annual collective effective dose equivalent was estimated to be 1.74×104man·Sv.
In this paper the results of measurement of environmental penetrating radiation in Liaoning Province and estimation of population dose are reported. The results showed that the average values of outdoor and indoor absorbed dose in air were 10.0×10-8Gy·h-1 and 12.7×l0-8Gy·h-1, respectively. The indoor exposure was higher than that of outdoors by a factor of 1.46 for terrestrial gamma radiation. The annual average effective dose equivalent of the population in this province was 79.82×10-5Sv, and the annual collective effective dose equivalent was 28.85×103man·Sv.
In this paper the results of measurement of environmental gamma radiation in Jilin Province and the calculated population doses are reported. The exposure rates were measured by FD-71 portable scintillation radiometers. The retults showed that the average values of outdoor and indoor exposure rates were 7.7×10-8G·h-1 and 10.9×10-8Gy·h-1, respectively. The annual effective dose equivalent of the environmental gamma radiation to the inhabitants in this province was about 620 µSv.
The external natural radiation level in Heilongjiang Province was measured by using China-made FD-71 scintillation radiometers and RSS-111 high pressure ionization chambers. The doses of external radiation to population were also calculated.
The population-weighted average value of the absorbed dose rate from terrestrial γ-radiation was 7.2×10-8Gy·h-1 for outdoors, and 10.8×10-8Gy·h-1 for indoors. The population-weighted average absorbed dose rate in air from cosmic rays was 3.3×10-8Gy·h-1.
The annual population-weighted average effective dose equivalent and the annual collective effective dose equivalent from the environmental γ-radiation were 620μSv and 20.1×103 man·Sv, respectively. The corresponding figures from cosmic rays were 260µSv and 8.7×103 man·Sv, respectively.
The environmental radiation field in Shanghai area is relatively uniform with a variance within 5.5%. The average level of terrestrial gamma radiation is about 7.13×10-8Gy·h-1 and the contribution of cosmic radiation is approximately of a constant value of about 2.9×10-8Gy·h-1; thus, the total external exposure level of natural radiation is about 10.1×10-8Gy·h-1. The annual collective effective dose equivalent to the population is 10,755 man·Sv and the annual effective dose equivalent (weighted average per capita) is 0.91 mSv.
In this paper the results of investigation of terrestrial gamma radiation level in Jiangsu Province are reported and the population doses due to this radiation are estimated. The sketch map of the geographical distribution of the terrestrial gamma radiation level is given.
In this investigation FD-71 portable scintillation counters and RSS-111 high pressure ionization chambers were used.
The results showed that the terrestrial gamma absorbed dose rates in air for indoors and outdoors were 10.7×10-8Gy/h and 6.5×10-8Gy/h (weithted values) respectively. The indoors-to-outdoors ratio was 1.65. The total (indoor plus outdoor) annual effective dose equivalent from terrestrial gamma radiation, averaged over the population in this province, was 6.0×10-4Sv. The collective annual effective dose equivalent was 3.6×104 man·Sv. Therefore, the absorbed dose to population in Jiangsu Province is in the range of the normal background.
Using FD-71 scintillation radiometers calibrated with RSS-111 high pressure ionization chamber, the external exposure levels from natural radiation in Zhejiang Province were measured, and the sketch of geographical distribution of terrestrial γ-radiation levels was drawn. The calculated dose equivalent to the population is given, and the hazard to the human body is discussed. The results showed that the average values of absorbed dose rates in air from γ-radiation for outdoors and indoors were (9.3~2.9)×10-8Gy·h-1 and (13.2±3.2)×10-8Gy·h-1, respectively. The average value of the annual effective dose equivalent was about 1,090 μSv to the population and the annual collective effective dose equivalent was 4.30×104 man·Sv.
The absorbed dose rates in air lm above the ground from natural radiation and terrestrial gamma radiation in Anhui Province were surveyed. One measurement was made in every area of 90 km2. The absorbed dose rates in air from terrestrial radiation range from 54 to 99 nGy·h-1 with an average of 70 nGy·h-1. The ratios of indoors-to-outdoors and of roads-to-outdoors are 1.5 and 0.9 respectively. The annual effective dose equivalent from external radiation is 0.68~1.05 mSv. The population-weighted average values for mountain area, plain, hilly land, and the Changjiang River basin as well as the annual collective effective dose equivalent were calculated.
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