Characterization of polycyclic aromatic hydrocarbon (PAHs) source profiles in urban PM2.5 fugitive dust: A large-scale study for 20 Chinese cites
Graphical abstract
Introduction
Fugitive dust is a major fraction of particulate matter (PM) that originates from a variety of open sources, such as paved and unpaved roadways, vehicular track-out, non-vegetated areas, material storage piles, and construction-related activities (Amato et al., 2011; Bhaskar and Sharma, 2008; Cao et al., 2008; Diego et al., 2009; Zhang et al., 2014). It is the most prevalent component in urban PM (Yu et al., 2013; Chen et al., 2007; Ajmone-Marsan et al., 2008). According to the statistic, fugitive dust accounts for ~20% of PM with aerodynamic diameters <2.5 μm (PM2.5) in most Chinese cities (Cao et al., 2012). Due to its heterogeneous origins, fugitive dust composites of a complex organic and inorganic mixture on outdoor ground surfaces. The mixture can physically contribute to atmospheric pollution through resuspension and transportation. Quantities and compositions of inorganic and organic materials, such as elements, ions, and carbon fractions, in PM2.5 were often measured to evaluate adverse effects and to conduct source apportionments (Cao et al., 2008; Shen et al., 2016; Zhang et al., 2014; Sun et al., 2019). Comparatively, important toxic organic contaminants of polycyclic aromatic hydrocarbons (PAHs) in PM2.5 fugitive dust have not been thoroughly discussed.
Numerous epidemiological studies confirmed that PAHs are a critical class of organic pollutants in fugitive dust formed from incomplete combustion or pyrolysis of organic materials (Hussain et al., 2015; Manoli et al., 2004; Han et al., 2009; Wang et al., 2018; Zeng et al., 2018). Additionally, 16 PAHs have been identified as priority control pollutants by the United States Environmental Protection Agency (U.S.EPA) due to their health impacts. Both short-term and long-term exposures to particular PAHs, including benz[a]anthracene, benzo[a]pyrene, benzo[b]fluoranthene, benzo[j]fluoranthene, benzo[k]fluoranthene, chrysene, dibenz[a,h]anthracene, and indeno[1,2,3-c,d]pyrene, can impair lung function and even cause cancer (Kim et al., 2013; Diggs et al., 2011). The importance of PAHs in fugitive dust has been widely recognized. The concentration and chemical composition of PAHs in fugitive dust were greatly affected by anthropogenic activities, including the emissions from local transportation, industry and even air pollution transmission and deposition (Yang et al., 1999; Murakami et al., 2005; Han et al., 2009). The concentrations of PAHs in fugitive dust vary greatly depending on geographical location, energy infrastructure, and urban pollution. The concentrations of PAHs in PM2.5 fugitive dust in an industrial city in Korea (Lee and Dong, 2011) were 2–8 times higher than those collected in Delhi, India (Agarwal et al., 2009), Birmingham, UK (Smith et al., 1995), and Niteroi, Brazil (Netto et al., 2006). Previous studies revealed that fugitive dust PAHs in urban areas mainly originate from cooking, smoking, mining, metal working, and oil refining (Kong et al., 2015; Martuzevicius et al., 2011; Han et al., 2009; Iwegbue and Obi, 2016; Lannerö et al., 2008; Armstrong et al., 2004; See et al., 2006).
Due to rapid urbanization in recent decades, the numbers of construction work and traffic flow have been increasing in most Chinese urban cities that have considerably stressed the environments, particularly causing contaminations on fugitive dusts. Construction sites and roadways are hot-spot sources for urban fugitive fine-particle PAHs, and their pollution levels and health impacts should be investigated. In this study, PAHs profiles in PM2.5 fugitive dusts were investigated in 20 Chinese cities, where can be defined as seven regions (northwest China [NWC], the North China Plain [NCP], northeast China [NEC], central China [CC], south China [SC], southwest China [SWC], and east China [EC]) of the country. The objectives of this study are 1) to investigate the PAHs profiles in PM2.5 fugitive dust over 20 Chinese cities; 2) to identify the potential pollution sources for both road dust (RD) and construction dust (CD), and 3) to evaluate the potential toxicological impacts and cancer risks for adults and children.
Section snippets
Sample locations and collections
Urban fugitive dust PM2.5 samples were collected in 20 Chinese cities across seven regions, including (i) NWC: Xi'an, Lanzhou, and Yinchuan; (ii) the NCP: Beijing, Tianjin, Baoding, Shijiazhuang, Handan, and Taiyuan; (iii) NEC: Harbin, Changchun, and Shenyang; (iv) CC: Wuhan and Changsha; (v) SC: Guangzhou; (vi) SWC: Chongqing, Chengdu, and Kunming; and (vii) EC: Nanjing and Shanghai (Fig. 1). According to geography, the NWC, NCP, NEC, and CC were grouped as northern and central regions of
Spatial distribution of PAHs in urban PM2.5 fugitive dust
The total concentrations of target PAHs (ΣPAHs) in the RD and CD PM2.5 samples collected in the seven Chinese regions were showed in Fig. 1. The levels of ∑PAHsRD varied from 2.09 to 81.22 μg·g−1 with a geometric mean of 21.59 μg·g−1. In contrast, the ∑PAHsCD ranged from 0.38 to 106.34 μg·g−1 with an average of 22.82 μg·g−1. The results illustrate that the PAHs were more abundant in Chinese fugitive dust, compared with those of Dhanbad, India (3.5 μg·g−1) (Suman et al., 2016), Niteroi City,
Conclusion
The present study proves the high abundances of PAHs in urban fugitive dusts in the seven regions in China. The five-to-six-rings PAHs comprised a significant proportion of RD, and four-rings PAHs were prevalent in CD, indicating that pyrogenic sources were main contributors to PAHs. The PAHs levels varied substantially across the regions in relation to local and regional pollution sources. The highest ∑PAHsRD and ∑PAHsCD were found in NCP, 10 times higher than those in SC. In comparison, the
Acknowledgment
This research is supported by the National Project of Causes and Treatment of Heavy Air Pollution (DQGG0105-01); Ministry of Science and Technology of the People's Republic of China (2013FY112700), a grant from SKLLQG, Chinese Academy of Sciences (SKLLQG1616).
References (64)
- et al.
Pattern, sources and toxic potential of PAHs in the agricultural soils of Delhi, India
J. Hazard. Mater.
(2009) - et al.
Metals in particle-size fractions of the soils of five European cities
Environ. Pollu.
(2008) - et al.
Sources and variability of inhalable road dust particles in three European cities
Atmos. Environ.
(2011) - et al.
Assessment of fugitive road dust emissions in Kanpur, India. A note
Transp. Res. Part D: Transp. Environ.
(2008) - et al.
Composition of higher molecular weight organic matter in smoke aerosol from biomass combustion in Amazonia
Chemos
(1995) - et al.
Size-differentiated source profiles for fugitive dust in the Chinese Loess Plateau
Atmos. Environ.
(2008) - et al.
Polycyclic aromatic hydrocarbons in the urban atmospheric particulate matter in the city of Naples (Italy)
Atmos. Environ.
(1999) - et al.
Distribution, origin, and potential toxicological significance of polycyclic aromatic hydrocarbons (PAHs) in sediments of Kaohsiung Harbor, Taiwan
Mar. Pollut. Bull.
(2011) - et al.
n-Alkanes and polycyclic aromatic hydrocarbons in total suspended particulates from the southeastern Tibetan Plateau: concentrations, seasonal variations, and sources
Sci. Total Environ.
(2014) - et al.
Nature, distribution and origin of polycyclic aromatic hydrocarbons (PAHs) in the sediments of Olbia harbor (Northern Sardinia, Italy)
Mar. Pollut. Bull.
(2005)