Analysis of variations in activity concentrations of 7Be, 137Cs and 210Pb in the air in Beijing
10.3760/cma.j.cn112271-20230911-00084
- VernacularTitle:北京市空气中 7Be、 137Cs和 210Pb活度浓度变化情况分析
- Author:
Lifan LI
1
;
Xuebo FAN
;
Huiping LI
;
Qingyun LIU
;
Xuya LYU
;
Hui LIU
Author Information
1. 中国原子能科学研究院，北京 102413
- Keywords:
Air;
Beijing;
Activity concentration;
Meteorological parameters;
Correlation
- From:
Chinese Journal of Radiological Medicine and Protection
2024;44(8):669-674
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To discusses the variations of 7Be, 137Cs and 210Pb activity concentrations in the air in Beijing from March 16, 2021 to March 31, 2023, and their correlation with temperature, precipitation, relative humidity, barometric pressure, PM10 (only limited to 137Cs) and other meteorological parameters. Methods:A total of 60 aerosol samples were collected using the HRHA01-SFS1000/A ultra-large flowair sampler in the automatic radiation monitoring station. The activity concentrations of 7Be, 137Cs and 210Pb in the aerosol samples were measured by GMX-60 low background anti-Compton high purity germanium gamma spectrometer. Pearson correlation coefficient was used to show the correlation of the relevant parameters. Results:The seasonal mean values of 7Be activity concentration were spring 4.31 mBq/m 3, summer 3.53 mBq/m 3, autumn 3.09 mBq/m 3 and winter 2.45 mBq/m 3, respectively, ranging from 1.17 to 7.79 mBq/m 3, with the overall mean of (3.36±1.33) mBq/m 3. The activity concentration of 137Cs ranged from 0.39 to 8.49 μBq/m 3, with an average of (0.59±1.47) μBq/m 3. The average activity concentrations of 210Pb were spring 0.53 mBq/m 3, summer 0.44 mBq/m 3, autumn 0.72 mBq/m 3 and winter 0.75 mBq/m 3, respectively, ranging from 0.21 to 1.36 mBq/m 3, with an average of (0.56±0.26) mBq/m 3. The activity concentration of 7Be was correlated with temperature and pressure ( r=0.38, -0.40), the activity concentration of 137Cs was correlated with precipitation ( r=-0.41), and the activity concentration of 210Pb was correlated with temperature and pressure ( r=-0.31, 0.37). The variation of 137Cs activity concentration in the air showed an obvious seasonal pattern, and the peak value generally appears in spring of each year (March to May), which was related to the frequent spring dust in Beijing. The activity concentration of 210Pb in the air was affected by coal combustion heating in winter, and has a peak value during November to March. Conclusions:The activity concentrations of 7Be, 137Cs and 210Pb in the air in Beijing are within the normal range, showing a seasonal trend.
