Carbonyl Levels and Personal Exposures in Large Shopping Malls of Nanchang, China

Abstract

Ambient levels of carbonyl compounds and their possible sources, diurnal variations, and personal exposure were investigated in four types of large shopping malls (including department store, supermarket, and bookstore and furniture store) in urban district of Nanchang, China. Eighteen out of the twenty target carbonyls were detected in summer samples while only fifteen carbonyls were detected in winter samples. The descending order of total mean concentration was furniture store (102.2 ± 22.9 µg m⁻³)>supermarket (84.2 ± 15.7 µg m⁻³)>department store (79.0 ± 21.1 µg m⁻³)>book store (68.6 ± 14.5 µg m⁻³). A significant correlation between the concentration of the low molecular-weight (LMW) carbonyl compounds (<C₅) and ozone was found in summer. The diurnal curve exhibited a higher peak at the morning hour and a lower peak at the evening hour except for acetaldehyde, which peaked at the afternoon hour in winter. The indoor concentrations of LMW carbonyl compounds were found to be higher than their outdoor counterparts with only a few exceptions. For some high molecular weight (HMW) carbonyls (≥C₅) especially for benzaldehyde and p-tolualdehyde which might have stronger outdoor source (e.g., vehicle exhaust), had resulting in the Indoor/Outdoor ratios below 1. The personal exposures showed that large shopping malls in Nanchang were important microenvironments for exposure to formaldehyde and acetaldehyde.

Keywords:

• Cancer risk
• Carbonyl compound
• Concentration
• Exposure
• Shopping mall

Acknowledgments

This work was financially supported by the National Natural Science Foundation of China (Grants 41003057 and 41203076), the Natural Science Foundation of Jiangxi Province of China (20122BAB213017), the Foundation of Jiangxi Educational Committee (GJJ11166), and the Innovation Fund of Nanchang Hangkong University (EA200901291).

Notes

N: number of samples. Mean: Total arithmetic mean (incluing summer and winter). SD: Standard deviation. Nd: Not detected.

Department store, including The First Department store of Nanchang (D1) and Tianhong Department store (D2). Supermarket, including Wal-Mart supermarket (S1) and Hongkelong supermarket (S2). Bookstore, including Xinhua bookstore (B1) and New Oriental bookstore (B2). Furniture store, including Luding International furniture store (F1) and Guanghui furniture store (F2).

^a Only one sample.

^b Three samples average.

^c Two samples average.

^d Four samples average.

R: Pearson coefficient.

Min.: minimum; Max.: maximum; Ave.: average.

Note. Inspire rate is 0.63 m³/h for exposure calculation and the inkalation unit risk estimates of formaldehyde and acetaldehyde were 1.3 × 10⁻⁵ and 2.2 × 10⁻⁵ (µg/m³)⁻¹, respectively according to EPA exposure factors (U.S. EPA 1992).

^a carbonyl concentration (µg /m³).

^b exposures (µg /day).

^c Arith. mean of indoor carbonyl concentrations in the eight targeted shopping mall.

^d Estimated value according the figures in the corresponding paper.

^e Arith. mean of indoor carbonyl concentrations in the 37 small-and medium-sized commercial buildings.

^f The exposure time of 2 h in the original literature was converted to be 8 h for the convenient comparison.