Sulfate Formation in Incense Burning Particles : A Single-Particle Mass Spectrometric Study

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

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Original languageEnglish
Pages (from-to)718-725
Journal / PublicationEnvironmental Science and Technology Letters
Issue number9
Online published26 Aug 2022
Publication statusPublished - 13 Sept 2022


Incense burning is a common ritual in Asian communities, and it emits massive amounts of particles. These particles can undergo atmospheric aging upon exposure to sunlight and other pollutants. In this work, we observed sulfate formation in fresh incense particles upon exposure to SO2, using a single-particle aerosol mass spectrometer (SPAMS). Analysis of the positive mass spectra classified the particles as K-type and OC-type. In both dark and light experiments, SO2 uptake and oxidation were found preferentially in OC-type particles over K-type particles. Sulfate formation, as represented by the number fraction of sulfate-containing particles (FS), under dark was likely due to gaseous oxidants. FS increased with UV, mainly attributable to photosensitization reactions. While more sulfate formed at higher relative humidity (RH) under dark, sulfate formation under light was independent of RH. The increase in FS due to photochemistry was more effective under lower RH, where the photoactive compounds were more concentrated and likely generated more photo-oxidants. This effect outweighed that due to reduced SO2 dissolution. Since incense burning particles contain organic photosensitizers that have also been found in biomass burning particles, our findings could shed light on the potential of biomass burning particles to trigger sulfate formation.

Research Area(s)

  • Aerosol photochemistry, Biomass burning, Incense burning, Single particles, SO2uptake, Sulfate

Citation Format(s)

Sulfate Formation in Incense Burning Particles: A Single-Particle Mass Spectrometric Study. / Liang, Zhancong; Zhou, Liyuan; Infante Cuevas, Rosemarie Ann et al.
In: Environmental Science and Technology Letters, Vol. 9, No. 9, 13.09.2022, p. 718-725.

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review