Characterization of ambient aerosols in Northern T

Authors: N Tippayawong P Pengchai A Lee

Publish Date: 2006/10/01

Volume: 3, Issue: 4, Pages: 359-369

PDF Link

Abstract

The present study examines variation of ambient aerosol mass and number concentrations in Chiang Mai Thailand during winter Aerosol particle samples were collected and measured at four different sites representative of urban industrial residential and rural areas during daytime between December 2003 and January 2004 Average 10 h particulate matter PM mass concentrations were found to be in the range of 75–290 ì g/m3 with average value of 149 ± 45 ì g/m3 Urban and industrial areas appeared to have higher PM loading than residential and rural areas Number concentration and size distribution of particles in the range of 03–100 ìm did not exhibit any marked variation between sites Relatively stable number concentrations were reported Temporal variation of number concentrations was not clearly significant No short term peak observed during rush hours During sampling period the average number concentration for 03–05 05–10 10–50 and 50–100 ìm were 660 × 106 118 × 106 211 × 105 and 112 × 104/m3 respectively Particles with diameter smaller than 10 ìm accounted for over 90 of the total number concentration Concentrations of major metals were determined by atomic absorption spectrophotometer Pb Fe Al Si Cr Cd Ni Zn and flame photometer K Na and Ca Data obtained were used to identify probable sources via a multivariate analysis Si Na Fe Ca Al and K were the six dominant elements in the airborne PM Principle component analysis was carried out and major sources of airborne PM in Chiang Mai were determined namely 1 long distance sources such as sea spray earth soil and industrial combustion 2 shortdistance sources such as crustal resuspension vehicular related emissions and vegetation burning and 3 the unknown distance sources with low influence of traffic emissions

Keywords: