Atmospheric deposition fluxes of ⁷Be, ²¹⁰Pb and ²¹⁰Po at Xiamen, China

Abstract

The atmospheric deposition fluxes of ⁷Be, ²¹⁰Pb and ²¹⁰Po at Xiamen were measured. The samples were collected from March 2004 to April 2005 and the sampling period was one month. The ⁷Be and ²¹⁰Pb activity were measured using HPGe γ-spectrometer after concentration using Fe(OH)₃ co-precipitation method. The ²¹⁰Po was counted with an α-spectrometer after the sample was digested and spontaneous plated onto a silver planchet. At Xiamen, the atmospheric deposition fluxes of ⁷Be varied between 0.11 and 2.93 Bq·m⁻²·d⁻¹ and the average was 1.64 Bq·m⁻²·d⁻¹; ²¹⁰Pb fluxes varied between 0.04 and 0.85 Bq·m⁻²·d⁻¹, and the average was 0.51 Bq·m⁻²·d⁻¹; ²¹⁰Po fluxes varied between 0.002 and 0.133 Bq·m⁻²·d⁻¹, and the average was 0.061 Bq·m⁻²·d⁻¹. There were positive correlations between the deposition fluxes of ⁷Be, ²¹⁰Pb or ²¹⁰Po and the amount of precipitation. The residence time of aerosols varied between 6.0 and 54.0 days with a mean of 27.1 days, which were calculated by ²¹⁰Po/²¹⁰Pb fluxes ratios.