About AAQR

Aims and Scope

Articles online
For contributors
Call for Papers
Guideline for the
Special Issue Proposal
Subscription
Information

Advertising

Contact Us
 
Search for  in   Search  Advanced search  

 

Volume 9, No. 2, June 2009, Pages 187-197 PDF(242 KB)  
doi: 10.4209/aaqr.2009.01.0004   

Beryllium-7 Aerosols in Ambient Air

Constantin Papastefanou

Atomic and Nuclear Physics Laboratory, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece

 

Abstract

 

The aerodynamic size distribution of 7Be aerosol particles in ambient air was determined by using 1-ACFM and high-volume (HVI) cascade impactors, 20 m above the ground on the roof of the Faculty of Science building, Aristotle University of Thessaloniki at Thessaloniki Greece (40o38’N, 22o58’E) from November 2006 to June 2008. The activity concentration of 7Be aerosols was determined by gamma spectrometry (Eγ = 0.477 MeV). The activity size distribution of 7Be-aerosols was largely associated with submicron aerosol particles in the accumulation mode (0.4-2.0 μm). The activity median aerodynamic diameter, AMAD varied from 0.76-1.18 μm (average 0.90 μm), indicating post-condensation growth either in the upper atmosphere or after mixing into the boundary layer. The geometric standard deviation, σg varied from 1.86-2.77 (average 2.24). The activity size distribution of 7Be-aerosols peaked in the 0.7-1.1 μm size range in the 65% of the measurements carried out by the 1-ACFM cascade impactor. In estimating lifetimes of 7Be-aerosols in ambient air, a mean residence time of about 8 days averaged for atmospheric aerosols of 0.90 μm AMAD size.

 

 

Keywords: Beryllium-7; Radioactive aerosols; Aerosol impactors; 1-ACFM; AMAD; Residence time.

 

 

Copyright © 2009-2014 AAQR All right reserved.