Survey of radon concentrations and dose estimation in 87 greenhouses in China

Radon (²²²Rn) is a major natural radiation source and the second leading cause of lung cancer after smoking. Greenhouses, as semi-enclosed environments, may accumulate elevated levels of radon, potentially increasing lung cancer risk among workers. Radon concentrations were measured in 90 greenhouses across 28 cities in China using CR-39 detectors, with exposure durations mainly for three months, and in a few cases, for one or two months. Information on greenhouse type, ventilation type, and irrigation water sources was also collected. A total of 416 measurements from 87 greenhouses were obtained. The results showed an arithmetic mean radon concentration of 166 Bq/m³, a geometric mean of 106 Bq/m³, and a range of 11-2326 Bq/m³. 12% of the measurements exceeded 300 Bq/m³, and 1% exceeded 1000 Bq/m³. Factors such as regional differences, greenhouse type, ventilation type and irrigation water source influence radon concentrations in greenhouses. The mean annual effective dose for greenhouse workers was 1.46 mSv, with a range of 0.1-20.4 mSv. The findings of this study indicate substantial regional variations in radon levels in greenhouses across China. Attention should be paid to greenhouses with elevated radon concentrations and to the health of workers. Improving ventilation efficiency and optimizing greenhouse design can reduce radon accumulation.