A Spatial-Temporal Resolved Validation of Source Apportionment by Measurements of Ambient VOCs in Central China

Abstract

Understanding the sources of volatile organic compounds (VOCs) is essential in the implementation of abatement measures of ground-level ozone and secondary organic aerosols. In this study, we conducted offline VOC measurements at residential, industrial, and background sites in Wuhan City from July 2016 to June 2017. Ambient samples were simultaneously collected at each site and were analyzed using a gas chromatography–mass spectrometry/flame ionization detection system. The highest mixing ratio of total VOCs was measured at the industrial site, followed by the residential, and background sites. Alkanes constituted the largest percentage (>35%) in the mixing ratios of quantified VOCs at the industrial and residential sites, followed by oxy-organics and alkenes (15–25%).The values of aromatics and halohydrocarbons were less than 15%. By contrast, the highest values of oxy-organics accounted for more than 30%. The model of positive matrix factorization was applied to identify the VOC sources and quantify the relative contributions of various sources. Gasoline-related emission (the combination of gasoline exhaust and gas vapor) was the most important VOC-source in the industrial and residential areas, with a relative contribution of 32.1% and 40.4%, respectively. Industrial process was the second most important source with a relative contribution ranging from 30.0% to 40.7%. The relative contribution of solvent usage was 6.5–22.3%. Meanwhile, the relative contribution of biogenic emission was only within the range of 2.0–5.0%. These findings implied the importance of controlling gasoline-related and industrial VOC emissions in reducing the VOC emissions in Wuhan.

Volatile organic compounds: A proinflammatory activator in autoimmune diseases

“…However, there are differences in the sources that contribute to VOC emission across regions in China. In the cities of Langfang and Xiamen, paint solvents constitute the highest contributing factor to VOC emission (62), while vehicular exhaust and combustion are the primary sources of VOCs in Wuhan City (63). In another study (59), it was reported that about 40 VOCs were observed in more than 50% of air samples collected from residences of pregnant women in Northeastern British Columbia, a region of natural gas exploitation, while four VOCs were detected in more than 50% of the water samples tested.…”

“…Although inflammation causes oxidant injury, the reverse response is possible since inflammation and oxidative stress are mutually causal (76). Studies show that the pathogenic autoreactive antibodies/autoreactive T cells against ROSinduced VOC stays in the blood for years before the development of the active disease, making it a chronic condition if not detected at the preclinical stage (63). The Dichloromethane Induces IFN-related genes as part of the immune response which was then followed by the apoptosis pathway (human promyelocytic leukemia HL60 cells)…”

Spatiotemporal variation, sources, and secondary transformation potential of volatile organic compounds in Xi'an, China

“…The T / B ratio is clearly different for various source profiles (Table S5). In industrial source emission studies, the ratio of T / B ranged from 1.4 ± 0.8 to 5.8 ± 3.4 by different industry type and process unit (Mo et al, 2015;Shi et al, 2015). In traffic source emission studies, the ratio of T / B ranged from 0.9 ± 0.6 to 2.2 ± 0.5 by different vehicle type and fuel composition (Qiao et al, 2012;Dai et al, 2013;Wang et al, 2013;Yao et al, 2013;Zhang et al, 2013; Mo et al, 2016;Yao et al, 2015a;Deng et al, 2018).…”

Research progresses on VOCs emission investigationsviasurface and satellite observations in China

“…[17][18][19] Offline observations refer to the collection of air samples at the sampling sites using sampling devices and then the analysis of the samples brought to the laboratory, e.g., Shen et al collected 359 offline samples at three different sites and sent the samples to the central laboratory for analysis. 20 Fig. 1 shows the online observation sites and offline sampling sites in China reported in published studies in the past two decades.…”

“…3 shows PMF results for major chinese cities from recent studies. 7,20,21,[70][71][72][73][74][75][76] Li et al found that solvent usage (42%) accounted for the highest proportion of China's VOCs emission inventory. 77 However, in the PMF results of major cities such as Beijing (4.3%), 70 Hangzhou (14.3%), 74 Wuhan (10.9%), 20 Chengdu (9.3%), 75 and Xi'an (10.6%), 21 the proportion of solvent usage sources was relatively low.…”