Indoor radon concentration and its changing trend in northeastern China / 中国辐射卫生

@#<b>Objective</b> To investigate the indoor radon concentration and its changing trend in northeastern China. <b>Methods</b> We measured indoor radon levels cumulatively for over three months by solid state nuclear track detection in a total of 261 houses in multi-story or high-rise buildings in Shenyang, Changchun, Harbin, Heihe, and Yichun in northeastern China. The measurement lasted one year in Changchun for seasonal changes. <b>Results</b> The average indoor radon concentration in the five cities was 88 Bq/m³, ranging from 12 to 558 Bq/m³. The indoor radon concentrations were ≤ 100 Bq/m³ in 75.1% of the houses, and ≤ 300 Bq/m³ in 97.7% of the houses. The indoor radon concentration increased with the age of buildings. The indoor radon concentration was highest in winter, and it was higher in summer than in autumn and spring. <b>Conclusion</b> The indoor radon concentration in northeastern China increased compared with the data of 1980s and 1990s. It is highest in the winter heating season, and higher in summer than in spring and autumn. Indoor radon exposure deserves attention.

Investigation and analysis of indoor radon concentration of urban residents in Shiyan, China / 中国辐射卫生

@#<b>Objective</b> To monitor the indoor radon concentration of urban residents in Shiyan, China, and to analyze the related influencing factors. <b>Methods</b> From April to July, 2019, RSKS standard detectors were used to measure the indoor radon concentration of 125 households in Shiyan, and the results were analyzed. <b>Results</b> The indoor radon concentration of residents in Shiyan showed a skewed distribution, ranging from 13.8 to 145 Bq/m³, and <i>M</i> (<i>P</i>₂₅,<i>P</i>₇₅) was 38.3 (29.0,62.0) Bq/m³. The estimated annual effective dose of radon and radon daughters from inhalation was 0.52-5.50 mSv, and <i>M</i> (<i>P</i>₂₅,<i>P</i>₇₅) was 1.45 (1.10, 2.36) mSv, which was consistent with literature. Building structure (<i>H</i> = 14.10, <i>P</i> < 0.001), floor (<i>H</i> = 24.41, <i>P</i> < 0.001), and geographical region (<i>H</i> = 8.963, <i>P</i> < 0.05) were influencing factors of indoor radon concentration, and the differences were significant. <b>Conclusion</b> The indoor radon concentration of urban residents in Shiyan is lower than the national standard limit. However, in daily life, it is still necessary to take appropriate measures to reduce the concentration of indoor radon as much as possible.

Indoor radon level and distribution characteristic in Zhuhai city / 中华放射医学与防护杂志

Objective To analyze the indoor radon level and distribution characteristic in different geological background by studying the indoor radon level in three typical areas in Zhuhai City.Methods The region of investigation includes three districts:granite area in Zhuhai District,granite area in Doumen District and the Quaternary sedimentary area in Doumen District.Activated charcoal adsorption method was used to measure the indoor radon concentrations.In some sampling sites,solid state nuclear track detectors were used at the same time for the indoor radon measurement.Results The average indoor radon level included 80 buildings was (66.0 ± 49.8) Bq/m3 using activated charcoal adsorption method and the maximum value was 1078.5 Bq/m3.The results of 23 sampling sites show that the average indoor radon level using solid state nuclear track detectors was (88.8 ± 49.1) Bq/m3,and (69.5 ± 37.7) Bq/m3 by activated charcoal adsorption method.The indoor radon concentration was (73.6 ± 61.0),(87.5 ± 58.3) and (48.6 ± 22.6) Bq/m3 in granite area in Zhuhai District,granite area in Doumen District and the Quaternary sedimentary area in Doumen District,respectively.Conclusions The surface lithology of an area has a certain impact on the indoor radon level.The indoor radon level in granite area in Zhuhai District and Doumen District is apparently higher than that in the Quaternary sedimentary area in Doumen District.The study of indoor radon level and distribution characteristic should be discussed in combination with geological background of area.