Polycyclic aromatic hydrocarbons in the atmosphere of Shanghai, China

Abstract

Shanghai is the largest industrial and commercial city in China, and its air quality has been concerned for several years. However, scarce study had been made on the seasonal levels of atmospheric polycyclic aromatic hydrocarbons (PAHs), together with their gas-particle partitioning and potential emission sources. Based on an intensive sampling campaign at urban and suburban areas in Shanghai during four seasons of [2005][2006], this study presented the measurement of PAH concentrations in both particulate and gaseous phases, as well as seasonal and spatial variability. The results showed that the annual PAH levels (gas + particle) were 167 ± at the suburban site. Gaseous PAHs (>70%) dominated the total PAH mass at both sites, while particulate PAHs contributed more than 90% of the toxic power according to benzo(a)pyreneequivalent carcinogenic parameter. Different seasonal trend of PAH concentrations was observed between the two sites, and it may be explained by complicated factors such as sampling heights, local/regional emission sources, and climatic conditions. The gas-particle partitioning of PAHs in all samples was calculated, and strong linear correlations between log K p and log P o L were observed, with shallower slopes (m r ) at the suburban site than the urban one and in warm season than the cold months, indicating the different equilibrium conditions of PAHs in spatial and seasonal scales in Shanghai. The slope (m r = −0.96) and correlation coefficient (R 2 = 0.81) for four-ring PAHs were closest to theoretical equilibrium conditions among compounds with various aromatic rings. Finally, the potential PAH sources were estimated based on principal factor analysis with multiple linear regressions. Ground volatilization dominated the PAH pollutions at both sites, while vehicles and coal consumption were the other main emission sources, which totally contributed 32.0% (suburban) to 49.2% (urban) of PAH mass in Shanghai atmosphere. The effects of wood and biomass burning were also detected, but their contributions to PAHs were negligible. Environ Monit Assess (2011) 172:235-247

Polycyclic Aromatic Hydrocarbons in the Atmosphere of Two Subtropical Cities in Southeast China: Seasonal Variation and Gas/Particle Partitioning

“…7). These results are similar to the ones reported by Chen et al (2011) and Gaga et al (2012). In particular, Phe contributed more than half of the total PAH concentrations in summer suggesting the strong volatilization fluxes of this compound from soil, road dust and atmospheric particles probably due to the high ambient temperature.…”

“…3 reveals that the seasonal trends in PAH concentrations were different between the gas and particle phases. The average concentrations of particle phase PAHs at four sites in the two cities were higher in fall-winter than in spring-summer, which is similar to the results reported in other areas without domestic heating in winter (Yang et al, 2010;Chen et al, 2011;Lai et al, 2011;Zhao et al, 2011). Thus, the high particle phase PAH concentrations measured in fall-winter might not result from additional local fossil fuel usage for domestic heating purposes.…”

“…Expanding car ownership, heavy traffic, and low-grade gasoline have made vehicles the leading source of air pollution in this area as in many other major cities in China. Although PAHs may be contributed from many sources, vehicle exhausts are considered to be the primary source in the major cities of Southeast China (Li et al, 2006;Liu et al, 2010;Chen et al, 2011;Zhao et al, 2011). Several studies conducted in the Xiamen area during the last decade focused primarily on the particulate phase PAHs (Hong et al, 2007;Wu et al, 2009Wu et al, , 2010Wu et al, , 2012, while extremely limited data are available concerning the gaseous phase distribution of these compounds Zhao et al, 2011).…”

Exchange of polycyclic aromatic hydrocarbons across the air-water interface in the Bohai and Yellow Seas

“…This value was comparable to results from coastal cities in China, e.g., Beijing, Shanghai, and Xiamen, as well as the Gosan station on Jeju Island, Korea (Zhao et al, 2010;Chen et al, 2011;Ma et al, 2011;Choi et al, 2012). It should be noted that the value would be lower if the tworing PAH naphthalene were taken into account or be higher if sampling in cold seasons.…”

Atmospheric polycyclic aromatic hydrocarbons in rural and urban areas of northern China

“…As illustrated in Table 2, the average total PAH concentration at NAEO was similar to the background site Mountain (MT). Waliguan (the Global Climate Observing System of the World Meteorological Organization in tropical zone) (Cheng, 2006) and rural site in Italy (Perrone et al, 2012), and also higher than the high mountain regions in Europe (Fernandez et al, 2002), MT Taishan (Li et al, 2010), while lower than those found in other urban or suburban sites such as Guangzhou (Li et al, 2006), Shanghai (Chen et al, 2011), Beijing (Zhou et al, 2005), Hong Kong , Seoul in Korea (Park et al, 2002). Eastern China is a significant source of atmospheric PAHs (Zhang et al, 2011).…”