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The long-term and high temporal resolution measurement of ambient volatile organic compounds (VOCs) was continuously performed in urban Beijing in 2016. Historical VOC data were compiled and compared with our results. A positive matrix factorization (PMF) model was used to determine potential emission sources. The backward trajectories and the concentration, ozone formation potential (OFP), and secondary organic aerosol potential (SOAP) of VOCs in the air masses from different regions were used to estimate the VOC chemical behaviour and transport-direction contributions. A health assessment, including the carcinogenic risk and non-carcinogenic risk of specific hazardous VOC species, was performed, while the point estimate approach was used for risk apportionment based on emission sources. In this study, the average (±standard deviation, Std) concentration of total observed VOCs (TVOCs) was 101.5 ± 65.2 μg/m3, ranging from 21.4 to 439.1 μg/m3. The VOC concentration in Beijing had decreased but was still higher than that in other Chinese cities according to compiled reported VOC data. Combustion-related sources were the primary sources of VOC pollution in urban Beijing. VOC contributions were increasingly coming from the northwestern regions instead of solely from regions to the south of Beijing according to the VOC concentration, OFP, and SOAP data. A potential health risk from VOCs should be considered for residents living in Beijing. The results of this study are expected to provide basic data for efficient VOC emission management and public health protection in Beijing.

Observations of volatile organic compounds (VOCs) are a prerequisite for evaluating the effectiveness of government efforts targeting VOC pollution. Here, based on the one-year online VOC measurement in 2018 in Beijing, systematic analyses and model simulation were conducted to illuminate VOC characteristics, emission sources, regional hotspots and behaviours in response to O

In 2015, comprehensive observations were carried out in Chengdu, Sichuan Province, China, to elucidate the seasonal variation characteristics of the concentrations, chemical compositions, and the sources of PM

To clarify the aerosol hygroscopic growth and optical properties of the Pearl River Delta (PRD) region, integrated observations were conducted in Heshan City of Guangdong Province from October 19 to November 17, 2014. The concentrations and chemical compositions of PM2.5, aerosol optical properties and meteorological parameters were measured. The mean value of PM2.5 increased from less than 35 (excellent) to 35-75 μg/m3 (good) and then to greater than 75 μg/m3 (pollution), corresponding to mean PM2.5 values of 24.9, 51.2, and 93.3 μg/m3, respectively. The aerosol scattering hygroscopic growth factor (f(RH = 80%)) values were 2.0, 2.12, and 2.18 for the excellent, good, and pollution levels, respectively. The atmospheric extinction coefficient (σext) and the absorption coefficient of aerosols (σap) increased, and the single scattering albedo (SSA) decreased from the excellent to the pollution levels. For different air mass sources, under excellent and good levels, the land air mass from northern Heshan had lower f(RH) and σsp values. In addition, the mixed aerosol from the sea and coastal cities had lower f(RH) and showed that the local sources of coastal cities have higher scattering characteristics in pollution periods.