Atmospheric radon level in Beijing

Objective: To analyze and estimate the atmospheric radon level in Beijing through continuous measurement. Methods: Long term and continuous measurement has been carried out by using ERMB1 (ERM: Electrostatic Radon Monitors), which can supply hourly radon concentration. Results: The annual average concentration of atmospheric radon in 2003 was (14.1 ± 5.5) Bq/m3, the maximum was 40.4 Bq/m3 in October and the minimum was 2.7 Bq/m3 in May. For monthly average, the maximum was (18.5 ± 5.0) Bq/m3 in November and the minimum was (9.9 ± 4.1) Bq/m3 in May. For diurnal variation, the highest frequency could be described as the maximum appeared during 6:00-8:00 and that the minimum appeared during 16:00-18:00. Conclusion: The atmospheric radon level in Beijing was higher than the world average and the national average as well. For monthly average, the maximum appeared in November and the minimum appeared in May. Typical diurnal variation was observed as well.(authors)