Levels, sources and health risks of carbonyls and BTEX in the ambient air of Beijing, China

Abstract

The atmospheric concentrations of carbonyls and BTEX (benzene, toluene, ethylbenzene, m,p-xylene and o-xylene) were measured simultaneously at a same sampling site in Beijing from September 2008 to August 2010. The average concentrations of the total measured carbonyls during autumn, winter, spring, and summer were 37.7, 31.3, 39.7, 50.5 μg/m 3 , respectively, and maximal values for their diurnal variations usually happened at noontime. In contrast to carbonyls, the average concentrations of the total measured BTEX during the four seasons were 27.2, 31.

Seasonal, diurnal and nocturnal variations of carbonyl compounds in the semi-urban environment of Orléans, France

“…In winter, the obvious elevation of carbonyl concentrations that appeared during the traffic rush hours of 17:00-19:00 implied that vehicular exhaust might be the primary source of carbonyls in winter. The results were in agreement with Pang and Mu (2006) and Zhang et al (2012) investigated the seasonal variation of atmospheric carbonyls in Beijing city. It should be noted that the time of increment of carbonyl concentrations began in the morning (8:00, UTC) in spring and summer, and much earlier than that in autumn.…”

“…To evaluate their influence on human health as well as atmospheric chemistry, field measurements of atmospheric carbonyls have been carried out in different areas, including urban (Cheng et al 2014;Lü et al 2010;Weng et al 2009;Pang and Mu 2006;Pang and Lee 2010;Xu et al 2010;Zhang et al 2012;Feng et al 2005;Ho et al 2002;Nguyen et al 2001;Possanzini et al 2002), rural (Xie et al 2008;Villanueva-Fierro et al, 2004;Wiedinmyer et al 2001;Solberg et al 2001;Shepson et al 1991;Cheng et al 2014) and remote areas (Singh et al 2004;Zhou and Mopper 1993;Wagner et al 2001;De Serves 1994). In comparison with urban areas, however, investigations on atmospheric carbonyls in rural or semi-urban areas are still sparse.…”

Serious BTEX pollution in rural area of the North China Plain during winter season

“…It is evident that the outdoor concentrations of BTEX compounds (25.8-236.0 μg/m 3 ) in this study were at least a factor of 3 higher than those reported in Chinese cities or rural areas (Zhong et al, 2005;Guo et al, 2003Guo et al, , 2006Wang and Zhao, 2008;Ling et al, 2011;Zhang et al, 2012;Li et al, 2014), indicating that the pollution levels of BTEX in this rural area of the NCP are indeed very serious in winter. The indoor pollution levels of BTEX (254.5-1552.9 μg/m 3 ) were found to be more serious, a factor of 1.26 higher than the outdoor levels.…”

“…The absorption tube was connected to a six-port valve as a loop and BTEX enriched in the absorption tube were injected into a separation column (SE-30, 20 m × 0.53 mm × 1.0 μm), after heating for 40 sec in an oven kept at 300°C, and detected by a gas chromatograph equipped with a Photo Ionization Detector (GC-PID, GC4400, East &West Analytical Instruments, Inc., China) with N 2 as carrier gas. The details on the preparation of the absorption tube as well as sampling and analysis procedures have been described in our previous publications (Liu et al, 2009(Liu et al, , 2013Zhang et al, 2012 Fig. 1 shows the time series of outdoor ambient levels of each BTEX compound and wind speed during the sampling days.…”

Ambient air benzene at background sites in China's most developed coastal regions: Exposure levels, source implications and health risks

“…To date, a systematic health risk assessment for benzene exposure has not been undertaken in China, and very few health risk studies are available with a focus on urban environments (Zhou et al, 2011;Zhang et al, 2012a;Li et al, 2014). The results of previous studies in urban areas cannot be regarded as representative of those in the whole developed coastal regions because field measurements were conducted at sites close to emission sources, and conducted over very short time spans.…”