Levels and distribution of indoor radon concentrations in Shenzhen, China / 中华放射医学与防护杂志

ABSTRACT

Objective To investigate the levels and distribution of radon in dwellings in Shenzhen cities of China.Methods A total of 108 low-,multi-,middle-and high-rise buildings were selected.Indoor radon concentrations were measured by using solid track detector.Results The arithmetic mean of indoor radon concentrations in Shenzhen was 64 Bq/m3,and geometric mean was 58 Bq/m3,in range of 15 to 155 Bq/m3.The average indoor radon concentration in Bao'an district was 50 Bq/m3 with the lowest value,and that in Pingshan new district was 87 Bq/m3 with the highest value.There were 12 measuring points where indoor radon concentrations were higher than 100 Bq/m3 in Shenzhen,accounting for 11.1％ of the total number.Shapiro-Wilk test showed that the frequency distribution of indoor radon concentration in Shenzhen follows lognormal distribution (P ＞ 0.05).The indoor radon concentrations showed a downward trend from 1990 to 2015.The indoor radon concentration decreases with the elevated floors except 10th and above floors.Conclusions The indoor radon concentrations in Shenzhen increased by 35％,compared to the previous investigations.It is recommended that efforts continue to improve radioactive materials standards about building material and to enhance the natural ventilation in high-rise buildings in order to lower the radiation hazards from radon.