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Objective To compare the cosmic radiation doses to air crew (including pilots and flight attendants) between polar route and non-polar route flights. Methods A typical polar flight route (Beijing-New York) was selected and compared with non-polar route, non-polar route was selected as control group. Optically stimulated luminescence (OSL) dosimeter and CR-39 solid track detector were used to measure the cosmic radiation dose to air crew. Results The annual mean effective dose to air crew from polar route and non-polar route was (5.79 ± 0.92)mSv/a and (2.14 ± 0.64)mSv/a, respectively.The 1000 h effective dose to air crew was (3.10 ± 0.27)mSv/kh and (2.21 ± 0.46)mSv/kh,respectively. There was significant difference between the two groups in either annual mean effective dose (t=30.25, P＜0.05) or 1000 h effective dose (t =7.60, P＜0.05). The doses of pilot groups were higher than that of flight attendants for either polar route ( t = 7.96, P ＜0.05) or non-polar route (t=4.70, P ＜ 0.05). Conclusions The effective dose to air crew from galactic cosmic radiation during polar route fight might be higher than that of non-polar route fight, however, it did not exceed 20 mSv/year,which is the limit of national standard.
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Objective To estimate the dose to non-uranium miners from external exposure.Methods Ore samples of non-uranium mines were collected in site and analyzed with gamma spcetrometry,then annual dose to the miners was estimated based on the measured radioactivities of radionuclides.Results Thirty-two ore samples in thirteen mines in seven provinces were collected and analyzed.Among them,radioactivity concentrations in two samples were higher than others,and the annual doses from external exposure to the radionuclides in the two ore samples were estimated to be higher than 1 mSv/a.Conclusions Gamma spectrometry is fit for determining the radionuclides concentrations and its results can be used for estimating dose from external exposure in non-uranium mines.
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Objective To establish a method for estimating internal dose from aerosol inhalation in non-uranium miners.Methods Aerosol samples in a tunnel in Dongchuan Copper Mine in Yunnan Province were collected by portable high flux air sampler.Radionuclides collected at the sampler filters were analyzed by the gamma spectrometry.Annual committed effective dose due to inhalation of the aerosol dust was estimated using the formula provided by ASTM.Results Radionuclides collected in two aerosol samples were anlayzed,the annual committed effective doses due to inhalation of 1 μm and 5 μm aerosol were estimated.Conclusions The method of using high flux air sampling and gamma spectrometry is explored to estimate the dose from aerosol inhalation.
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Objective To develop the software for the assessment of radionuclide concentration and doses from atmospheric dispersion. Methods Based on procedures for radionuclide atmospheric dispersion and dose assessment in IAEA publications (safety series reports No. 19), a parameter database was constructed using Microsoft Access, and the dispersion model and dose assessment methods were computerized using Microsoft Visual Basic 6.0, then we got the dose assessment software for radionuclide atmospheric dispersion. Results Atmospheric radionuclide concentration and public effective dose in a year could be estimated rapidly with the present software. Conclusion The present software provides a practical and rapid tool for evaluation and assessment the influence of radionuclide atmospheric dispersion, which can be used in the evaluation of atmospheric radionuclide concentration in routine monitoring or nuclides/radiological emergency, and also can be used as the screening evaluation in environmental surveillance.
