²²²Rn concentrations in drinking water samples from Beijing City, China, were determined based on a simple method for the continuous monitoring of radon using a radon-in-air monitor coupled to an air-water exchanger. A total of 89 water samples were sampled and analyzed for their ²²²Rn content. The observed radon levels ranged from detection limit up to 49 Bq/L. The calculated arithmetic and geometric means of radon concentrations in all measured samples were equal to 5.87 and 4.63 Bq/L, respectively. The average annual effective dose from ingestion of radon in drinking water was 2.78 μSv, and that of inhalation of water-borne radon was 28.5 μSv. It is concluded that it is not the ingestion of waterborne radon, but inhalation of the radon escaping from water that is a substantial part of the radiological hazard. Radon in water is a big concern for public health, especially for consumers who directly use well water with very high radon concentration.

Introduction Radon (²²²Rn or ²²²radon) is a radioactive gas emitted from building materials, foundations, and soil. Children are especially susceptible to radon exposure, underscoring the need to assess indoor radon levels in kindergartens. This study monitored radon concentrations in 37 Beijing kindergartens from June to October 2023. Methods A random sample of 37 kindergartens was selected from 18 administrative districts in Beijing. The indoor radon concentration was measured using the solid track accumulation method, with radon detectors continuously monitored over a 3-month period. Results The mean indoor radon level in 37 kindergartens, observed at 252 monitoring points, was 84.3 Bq/m³, with values varying from 12.9 to 263.5 Bq/m³. About 20.2% of points showed radon levels between 100.0 and 200.0 Bq/m³, while 2.4% exceeded 200.0 Bq/m³. Notably, radon levels were significantly elevated on the ground floor compared to the upper floors. Conclusion Indoor radon levels in 37 kindergartens remained below the national standard limit of 300.0 Bq/m³ for buildings (GB/T 16146-2015). Nonetheless, 18.9% of the kindergartens exceeded the 100.0 Bq/m³ limit set for new constructions. It is advised to improve radon monitoring in kindergartens and consider developing a national standard for maximum permissible radon levels in such facilities.

The wearing method of personal dosemeters for medical staff changed from under to outside the operator’s protective apron in April 2020. We measured the radiation dose H_p(10) for medical staff in Beijing from September 2020 to October 2021. The study population consisted of 3291 medical staff. All participants were divided into three groups. After excluding unusually low doses, the collected data higher than the detection limit involved 811 (7.8%) of 10 395 readings from 479 (14.6%) of 3291 staff. The mean equivalent dose was 1.4 mSv/3 months, with an SD of 2.3 mSv. The calculated average annual effective doses of radiation workers in the three groups after the interventional procedures from September 2020 to October 2021 ranged from 0.47 to 0.63 mSv/year, with median values of 0.32, 0.23 and 0.26 mSv/year, respectively.