Water-soluble Ions in PM2.5 on the Qianhu Campus of Nanchang University, Nanchang City: Indoor-Outdoor Distribution and Source Implications

Hong Huang,Shujuan Xue,Chenglong Yu,Fangxu Zhu,Pokeung Tsang,Junji Cao,Changwei Zou

doi:10.4209/aaqr.2011.11.0219

Abstract

Ambient PM2.5 was sampled in three indoor environments (a common office, a photocopy room and a student dormitory) and one outdoor environment (a rooftop) on a campus of Nanchang University in Nanchang city, China, on June 5–20, 2009. Analysis by ion chromatograph showed the indoor-outdoor differences and relationships of water-soluble ions. The indooroutdoor distributions indicated that chemicals and household garbage contributed most to the generation of water-soluble ions indoors. The indoor-outdoor relationships of water-soluble ions in PM2.5 in the common office and student dormitory were unrelated or weak, which indicated that the ions were produced indoors rather than carried in from outdoors. Correlations between various water-soluble ions in indoor and outdoor PM2.5 are discussed here, and it is suggested that the photocopier machine contributed little to the water-soluble ions indoors. Ion balance calculations indicated that the anions and cations in the photocopy room and outdoor environment shared an origin, but part of the anions and cations in the common office room and student dormitory originated indoors. The linear regression slopes (anion/cation) are all lower than 1, with the anion deficits probably affected by the absence of data on F − , PO4 3− , NO2 − , CO3 2− and organic acid salt.

Highlights

Aerosol particles have many disadvantageous impacts on the global climate, atmospheric environment and even human health (Shine et al, 1999; Polichetti et al, 2009; Jahn et al, 2011), there is still some uncertainty and complexity about them
Ambient PM2.5 was sampled in three indoor environments and one outdoor environment on a campus of Nanchang University in Nanchang city, China, on June 5–20, 2009
The indoor-outdoor relationships of water-soluble ions in PM2.5 in the common office and student dormitory were unrelated or weak, which indicated that the ions were produced indoors rather than carried in from outdoors

Summary

Introduction

Aerosol particles have many disadvantageous impacts on the global climate, atmospheric environment and even human health (Shine et al, 1999; Polichetti et al, 2009; Jahn et al, 2011), there is still some uncertainty and complexity about them. Fine particles (PM2.5) have received much more attention than coarse particle (PM10) (Yang et al, 2005; Feng et al, 2007; Li et al, 2008; Li et al, 2009), as fine particles can travel more deeply into the human lungs, reaching the alveolar region of the respiratory system They take along higher contributions of toxic species harming health, higher contributions of light absorption species and light scattering species that affect visibility and the climate more than coarse particles (Kok et al, 2006; Polichetti et al, 2009).

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