Characteristics of Particulate Matter during Haze and Fog (Pollution) Episodes over Northeast China, Autumn 2013

Hujia Zhao,Yang Li,Yunfei Wu

doi:10.4209/aaqr.2014.08.0158

Abstract

Mass concentrations of particulate matter (PM), including PM1.0, PM2.5 and PM10, were measured from October 13 th to November 30 th 2013 at eight sites in Northeast China to evaluate their variations during pollution periods. Five major pollution periods were identified during the autumn of 2013. The maximum daily average PM2.5 concentrations were 437 ± 85 µg/m 3 and 322 ± 50 µg/m 3 in Harbin and Shenyang, respectively. The minimum was 75 ± 28 µg/m 3 in Dandong. The presence of finer particles was significantly related to visibility degradation during pollution periods. Wind speeds had a negative correlation with PM concentrations, while high relative humidity (RH) favored the formation of haze in Northeast China. Visibility on non-hazy days was approximately 2.5–3.0 times greater than that on hazy days. During hazy days, the PM1.0:PM2.5 ratios were 0.89 ± 0.04, 0.85 ± 0.04 and 0.91 ± 0.04 at Anshan, Shenyang and Dandong, respectively. These results show that PM1.0 was the dominant particle pollutant in Northeast China during periods of pollution. High RH and low wind speeds during hazy days may favor the accumulation of atmospheric pollutants. The results of this study provide useful information toward recognizing air pollution episode characteristics in Northeast China.

Highlights

Particulate matter (PM) pollution exerts an important influence on human health (NRC, 1998; Pope et al, 2009), visibility (Ghim et al, 2005; Che et al, 2007) and climate (Okada et al, 2001; IPCC, 2013; Wang, 2013)
Mass concentrations of particulate matter (PM), including PM1.0, PM2.5 and PM10, were measured from October 13th to November 30th 2013 at eight sites in Northeast China to evaluate their variations during pollution periods
Wind speeds had a negative correlation with PM concentrations, while high relative humidity (RH) favored the formation of haze in Northeast China

Summary

Introduction

Particulate matter (PM) pollution exerts an important influence on human health (NRC, 1998; Pope et al, 2009), visibility (Ghim et al, 2005; Che et al, 2007) and climate (Okada et al, 2001; IPCC, 2013; Wang, 2013). In China, haze is usually viewed as an atmospheric pollution phenomenon caused by large numbers of aerosol particles in the atmosphere, with visibility < 10 km when ambient relative humidity (RH) is below 90% (CMA, 2003; Sun et al, 2006). The formation of haze is closely related to meteorological factors, as well as to particulate matter in the atmosphere (Hu et al, 2002; Wang et al, 2003), especially. In China, haze episodes often occur in developed regions such as the North China Plain (NCP) (Sun et al, 2013; Zhang et al, 2013; Che et al, 2014), the Yangtze River Delta (YRD) (Che et al, 2009; Deng, 2011; Du et al, 2012; Yang et al, 2012; Cheng et al, 2013) and the Pearl River Delta (PRD) (Lü et al, 2009; Yue et al, 2010; Zhang et al, 2012)

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Conclusion