Objective To investigate the radon activity concentrations in subways of Nanning City and assess the average annual effective doses for subway staff and passengers due to radon exposure. Methods Sixty-three stations across the subway lines 2, 3, and 5 were selected as study sites. Radon activity concentrations were measured using the scintillation counting method with scintillation vials. Results The radon activity concentrations in subway lines 2, 3, and 5 were 7.9-24.4, 12.0-26.2, and 12.6-18.2 Bq/m³, respectively. The average radon activity concentrations for these three lines were (17.4 ± 4.6), (19.1 ± 4.1), and (14.6 ± 1.7) Bq/m³, respectively. Statistical analysis using SPSS 26.0 software revealed a significant difference in radon activity concentrations among these stations (P<0.01). Considering the data in previous research, the average radon activity concentration across all stations in the subway lines of Nanning City was determined to be 17.4 Bq/m³. The estimated average annual effective dose due to radon exposure was 0.131 mSv for subway staff and 0.033 mSv for passengers. Conclusion The radon activity concentrations in the subway lines of Nanning City were significantly lower than the national standard limit (400 Bq/m³). The annual effective doses from radon exposure for both subway staff and passengers were below the limits specified in the Basic Standards for Protection Against Ionizing Radiation and for the Safety of Radiation Sources (GB18871—2002). The health impact of radon and its progeny on subway staff and passengers in the subway lines of Nanning City was extremely low and can be considered negligible.

Objective:To establish an atomic absorption spectrophotometry and flame method for the determination of sodium,potassium,magnesium and calcium ions in compound sodium acetate ringer injection.Methods:The A3AFG-12 A3 atomic absorption spectrophotometer,XS205DU and XP6 electronic balances were used.Cesium chloride was used as the ionization inhibitor for the determination of sodium and potassium ions,and lanthanum chloride was used as the ionization inhibitor for the determination of magnesium and calcium ions.The contents of sodium,potassium,magnesium and calcium were determined at 589.3,766.5,285.2 and 422.7 nm,respective-ly,and the methodol was verified.Results:Four ions had good linear relationships in the concentration range of 0.15-1.20,0.2-1.6,0.05-0.4,and 1.014-5.069 μg·mL-1,and the correlation coefficients were r=0.999 6,r=0.999 3,r=0.999 6,r=0.999 0,respectively.The average recoveries were 98.5％,98.1％,93.2％and 95.0％,respectively.The contents of sodium,potassium,magnesium and calcium ions in 5 batches of injection samples were measured in the range of 3.186-3.221,0.155-0.160,0.023-0.026 and 0.056-0.059 mg·mL-1,respectively.Conclusion:The established method has high reproducibility and accuracy,and is suitable for the determination of sodium,potassium,magnesium and calcium in compound sodium acetate ringer injection.