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Objective:To monitor and analyze the activity concentrations of 7Be and 210Pb in atmospheric aerosol in Beijing from 2017 to 2020. Methods:Totally 1 074 atmospheric aerosol samples were collected by high flow air sampler (SnowWhite) including 275 in spring, 266 in summer, 262 in autumn and 271 in winter and subjected to analysis by low background high-purity germanium gamma-ray spectrometery (ORTEC) to determine the activity concentrations of 7Be and 210Pb. Results:The activity concentrations of 7Be in atmospheric aerosol were from 0.56 to 14.84 mBq/m 3, with an avearage of 6.84 mBq/m 3, and from 0.01 to 9.37 mBq/m 3 for 210Pb, with an avearage 3.19 mBq/m 3. The differences in activity concentrations of 7Be and 210Pb in atmospheric aerosol among differernt seasons were statistically significant ( F=32.66, 93.93, P<0.05). Activity concentration of 7Be was highest in spring, followed by autumn, and lowest in summer and winter. Activity concentration of 210Pb ranged from winter, autumn, spring to summer in descending order. Conclusions:The activity concentrations of 7Be and 210Pb in atmospheric aerosol in Beijing from 2017 to 2020 fluctated within the range of normal level.
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Objective To investigate the variation patterm in activity concentration of 210Pb in atmospheric aerosol in Qindao and evaluate its internal radiation effect to human body.Methods 210Pb activity concentration of aerosol samples was measured by high purity germanium(HPGe) γ spectrometer for purpose of ascertaining its variation in aerosol in Qingdao from April 2015 to March 2016.Results 210Pb activity concentration in aerosol varied from 0.06 to 1.61 mBq/m3 and the mean of (0.70 ± 0.50) mBq/m3,slightly higher than the UNSECAR 1988 report recommended value of O.50 mBq/m3.In this study,210Pb activity concentration in aerosol was high from December 2015 to February 2016 and low from August to November.Radiation dose assessment revealed that the annual committed effective dose to adults delivered by 210Pb was 6.35 × 10-6 Sv.The monthly variation in activity concentration variation of 210Pb in atmospheric aerosol in Qingdao was similar as in Xiamen.Conclusions Activity concentration of 210Pb in atmospheric aerosols in Qingdao varied largely dependent on atmospheric environmental pollution.210Pb contributed less to the adult annual committed effective dose.However,more attention should be drawn to the long-term radiation effects to aduhs due to the 210Pb potentially deposited in lungs.
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The species of bromine and iodine in aerosol samples were extracted using ultra-pure water-ultrasonic method with different time in-length and pressurizing decomposition with dilute ammonia, respectively. The efficiency of extraction and the stability of bromine and iodine species were compared under different extraction) conditions. Results showed that(1) the efficiency of extraction using pressurizing decomposition, which might destroy some unknown form of organic iodine, was relatively higher than the one by ultrasonic method;(2) I~- was unstable in added standard cellular blank filter during ultrasonic assisted extraction for long time;(3) The optimum condition was ultra-pure water-ultrasonic assisted extraction for 5 min. Moreover), the suitability of glass microfiber filter(GF) and cellular filter(CF) during extraction for bromine and iodine) species in aerosol was also compared, which indicated that GF is favorable for species analysis than CF under different kinds of extraction conditions. Based upon the extraction results, HPLC-ICP-MS approach was developed to analyze bromine and iodine) species in atmospheric aerosol. The total iodine, bromine and species in the aerosol samples collected in Hefei were then determined accordingly. The levels of total bromine and iodine) in Hefei aerosols were 883 and 231 pmol/m~3, respectively. Br~- was found to be dominant species with 68%, while BrO_3~- was undetectable. 70% of total iodine occurred as unidentified forms including soluble organic) iodine and insoluble iodine.