||Atmospheric processes studies and radiation dose assessment based on 7Be, 210Pb and 210Po around Xiamen Island
men, Wu ,
Lin, Jing ,
Wang, Fenfen ,
Yin, MingduanZheng, Jian
Proceedings of the 18th Workshop on Environmental Radioactivity
320 , 2017-12
The activities of 7Be, 210Pb and 210Po in the aerosol of Xiamen City from August 2014 to July 2015 were measured. The trace pair of 7Be and 210Pb was used to study the atmospheric transport processes. 7Be activities varied relatively larger, even though in the same month, especially during September 2014 to June 2015. In August-September 2014 and June-July, 2015, 7Be level was relatively low and showed a small variation range. Compared with 7Be, the variations of 210Pb and 210Po were in a small range. During November 2014 to March 2015, 210Pb and 210Po were both in a high level with larger variation. But on the contrary, they are both in a very low level in the other month. The discussion of the source of atmospheric masses suggested that the convective mixing and removal processes were the main controlling factors for 7Be, 210Pb and 210Po in the atmosphere. The strong removal scavenging processes, such as rainfall precipitation and the conversion of land-sea breeze, which can decrease activities of 7Be, 210Pb and 210Po in a very short time. The low-level of 210Pb and 7Be may be due to the intrusion of the surface oceanic air mass. Based on the data of 210Pb and 210Po, the average residence time of aerosol in Xiamen city was estimated to be 21~188d with an average of 87d. Radiation dose assessment revealed that the total committed effective dose derived from 7Be, 210Pb and 210Po is 5.3μSv, which is three orders of magnitude lower than the natural background radiation.