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Ambient carbonyls were continuously observed in the field during a heavy ozone pollution episode in Chengdu, China from August 4 to August 19, 2019, and the pollution characteristics, atmospheric photochemical reactivity, human health risk, and sources of carbonyls were analyzed. Fifteen carbonyls were quantified with average total mixing ratios of 20.38 ppbv Formaldehyde (9.86 ppbv), acetone (4.41 ppbv), and acetaldehyde (3.57 ppbv) were the three most abundant carbonyls. During the heavy ozone pollution episode, the concentration of carbonyls was found to be higher on pollution days than on the clean days, and relatively higher in the daytime, especially at noon on the pollution days. This was influenced by the intensity of photochemical reactions and precipitation. The “weekend effect” with the concentration of carbonyls was higher on the weekends than on the weekdays was pointed out. Formaldehyde, acetaldehyde and hexaldehyde were the dominant oxidative species during the observation. The carcinogenic and non-carcinogenic risk values of formaldehyde and acetaldehyde were higher on pollution days than on clean days, and these values were higher compared with those of other cities in China and abroad. Long-term exposure to these compounds should therefore be avoided. Diagnostic ratios and correlation analysis together with backward trajectory analysis showed that primary emission and secondary formation accounted 66%–76% and 24%–34% of carbonyls in Chengdu, respectively, with primary emission being the main sources of carbonyls, and carbonyls from the surrounding cities and emission from natural sources also had a significant contribution to the carbonyls in Chengdu.
Jiemeng Bao; Hong Li; Zhenhai Wu; Xin Zhang; Hao Zhang; Yunfeng Li; Jun Qian; Junhui Chen; Liqun Deng. Atmospheric carbonyls in a heavy ozone pollution episode at a metropolis in Southwest China: Characteristics, health risk assessment, sources analysis. Journal of Environmental Sciences 2021, 113, 40 -54.
AMA StyleJiemeng Bao, Hong Li, Zhenhai Wu, Xin Zhang, Hao Zhang, Yunfeng Li, Jun Qian, Junhui Chen, Liqun Deng. Atmospheric carbonyls in a heavy ozone pollution episode at a metropolis in Southwest China: Characteristics, health risk assessment, sources analysis. Journal of Environmental Sciences. 2021; 113 ():40-54.
Chicago/Turabian StyleJiemeng Bao; Hong Li; Zhenhai Wu; Xin Zhang; Hao Zhang; Yunfeng Li; Jun Qian; Junhui Chen; Liqun Deng. 2021. "Atmospheric carbonyls in a heavy ozone pollution episode at a metropolis in Southwest China: Characteristics, health risk assessment, sources analysis." Journal of Environmental Sciences 113, no. : 40-54.
Vehicular exhaust is one of the important contribution sources of secondary organic aerosol (SOA) in urban areas. Long-chain alkanes and aromatic hydrocarbons are included in gaseous organic pollutants of vehicle emissions, representative of diesel and gasoline vehicles respectively. In this work, the SOA production from individual anthropogenic volatile organic compounds (AVOCs) (n-dodecane, 1,3,5-trimethylbenzene) and mixed AVOCs (n-dodecane + 1,3,5-trimethylbenzene) was studied with a large-scale outdoor smog chamber. Results showed that the SOA formation from the mixed AVOCs was enhanced compared to the predicted SOA mass concentration based on the SOA yield of individual AVOCs. According to the results of mass spectrometry analysis with electrospray ionization time-of-flight mass spectrometry (ESI-ToF-MS), interaction occurred between intermediate products from the two precursors, which could be the main reason for the enhanced SOA production from the mixed AVOC reaction system. The study results could improve our understanding about the contribution of representative precursors from vehicular exhaust to the formation of SOA in urban areas. This study also indicates that further studies on SOA chemistry from the mixed VOC reaction system are needed, as the interactions between them and the effect on SOA formation can give us a further understanding of the SOA formed in the atmosphere.
Junling Li; Hong Li; Kun Li; Yan Chen; Hao Zhang; Xin Zhang; Zhenhai Wu; Yongchun Liu; Xuezhong Wang; Weigang Wang; Maofa Ge. Enhanced secondary organic aerosol formation from the photo-oxidation of mixed anthropogenic volatile organic compounds. Atmospheric Chemistry and Physics 2021, 21, 7773 -7789.
AMA StyleJunling Li, Hong Li, Kun Li, Yan Chen, Hao Zhang, Xin Zhang, Zhenhai Wu, Yongchun Liu, Xuezhong Wang, Weigang Wang, Maofa Ge. Enhanced secondary organic aerosol formation from the photo-oxidation of mixed anthropogenic volatile organic compounds. Atmospheric Chemistry and Physics. 2021; 21 (10):7773-7789.
Chicago/Turabian StyleJunling Li; Hong Li; Kun Li; Yan Chen; Hao Zhang; Xin Zhang; Zhenhai Wu; Yongchun Liu; Xuezhong Wang; Weigang Wang; Maofa Ge. 2021. "Enhanced secondary organic aerosol formation from the photo-oxidation of mixed anthropogenic volatile organic compounds." Atmospheric Chemistry and Physics 21, no. 10: 7773-7789.
Nitrous acid (HONO), as a key reservoir of hydroxyl radical (OH), plays a significant role in atmospheric chemistry. To study the sources and atmospheric influence of HONO, continuous observations of HONO and relevant air pollutants were performed from June to July 2019 at an urban site in Beijing. A comparative study on the ambient levels, diurnal variation, the sources in daytime and nighttime, and the formation mechanisms were investigated for a haze pollution period (Period I) and an ozone pollution period (Period II). The average hourly HONO concentrations during Period I, Period II, and the whole observation period, were 0.58 ± 0.23, 0.54 ± 0.19 and 0.44 ± 0.24 ppb, respectively. The emission from vehicle exhaust was an important source of nocturnal HONO formation. During the nighttime, compared with the homogeneous reaction of NO with OH, the heterogeneous conversion from NO2 was the dominant pathway for HONO formation. The heterogeneous conversion frequency was 0.0075 h−1 during Period I, higher than that during Period II (0.0028 h−1), suggesting a higher conversion potential to HONO formation during the haze episode. Based on the analysis of HONO budget, it was found that the daytime unknown source Punknown during Period II was higher than that during Period I. Correlation analysis implied that the photo-enhanced NO2 conversion on the aerosol surface might be a potential source for daytime HONO. Without HONO constraint, the Observation-Based Model (OBM) would largely underestimate the averaged daytime atmospheric oxidative capacity (24%), OH production rate (57%), and net O3 production rate (20%). The study results further demonstrated the necessity for clarifying the formation mechanism of HONO to improve the understanding of the influence of HONO to atmospheric chemical processes.
Yunfeng Li; Xuezhong Wang; Zhenhai Wu; Ling Li; Chuhan Wang; Hong Li; Xin Zhang; Yingnan Zhang; Junling Li; Rui Gao; Likun Xue; Abdelwahid Mellouki; Yangang Ren; Qingzhu Zhang. Atmospheric nitrous acid (HONO) in an alternate process of haze pollution and ozone pollution in urban Beijing in summertime: Variations, sources and contribution to atmospheric photochemistry. Atmospheric Research 2021, 260, 105689 .
AMA StyleYunfeng Li, Xuezhong Wang, Zhenhai Wu, Ling Li, Chuhan Wang, Hong Li, Xin Zhang, Yingnan Zhang, Junling Li, Rui Gao, Likun Xue, Abdelwahid Mellouki, Yangang Ren, Qingzhu Zhang. Atmospheric nitrous acid (HONO) in an alternate process of haze pollution and ozone pollution in urban Beijing in summertime: Variations, sources and contribution to atmospheric photochemistry. Atmospheric Research. 2021; 260 ():105689.
Chicago/Turabian StyleYunfeng Li; Xuezhong Wang; Zhenhai Wu; Ling Li; Chuhan Wang; Hong Li; Xin Zhang; Yingnan Zhang; Junling Li; Rui Gao; Likun Xue; Abdelwahid Mellouki; Yangang Ren; Qingzhu Zhang. 2021. "Atmospheric nitrous acid (HONO) in an alternate process of haze pollution and ozone pollution in urban Beijing in summertime: Variations, sources and contribution to atmospheric photochemistry." Atmospheric Research 260, no. : 105689.
Ground-level ozone (O3) has become the principal air pollutant in Beijing during recent summers. In this context, an investigation of ambient concentrations and variation characteristics of O3 and its precursors in May and June from 2014 to 2017 in a typical urban area of Beijing was carried out, and the formation sensitivity and different causes of heavy O3 pollution (HOP, daily maximum 8-h O3 (MDA8h O3)>124 ppbv) were analyzed. The results showed that the monthly assessment values of the O3 concentrations (the 90th percentile MDA8h O3 within one month) were highest in May or June from 2014 to 2017, and the values presented an overall increasing trend. During this period, the number of O3 pollution days (MDA8h O3 > 75 ppbv) also showed an increasing trend. During the HOP episodes, the concentrations of volatile organic compounds (VOCs), nitrogen oxides (NOX), and carbon monoxide (CO) were higher than their respective mean values in May and June, and the meteorological conditions were more conducive to atmospheric photochemical reactions. The HOP episodes were mainly caused by local photochemical formation. From 2014 to 2017, O3 formation during the HOP episodes shifted from VOC and NOX mixed-limited to VOC-limited conditions, and O3 formation was most sensitive to anthropogenic VOCs. Six categories of VOC sources were identified, among which vehicular exhaust contributed the most to anthropogenic VOCs. The VOC concentrations and OFPs of anthropogenic sources have decreased significantly in recent years, indicating that VOC control measures have been effective in Beijing. Nevertheless, NOX concentrations did not show an evident decreasing trend in the same period. Therefore, more attention should be devoted to O3 pollution control in May and June; control measure adjustments are needed according to the changes in O3 precursors, and coordinated control of VOCs and NOX should be strengthened in long-term planning.
Xin Zhang; Hong Li; Xuezhong Wang; Yujie Zhang; Fang Bi; Zhenhai Wu; Yuhong Liu; Hao Zhang; Rui Gao; Likun Xue; Qingzhu Zhang; Yizhen Chen; Fahe Chai; Wenxing Wang. Heavy ozone pollution episodes in urban Beijing during the early summertime from 2014 to 2017: Implications for control strategy. Environmental Pollution 2021, 285, 117162 .
AMA StyleXin Zhang, Hong Li, Xuezhong Wang, Yujie Zhang, Fang Bi, Zhenhai Wu, Yuhong Liu, Hao Zhang, Rui Gao, Likun Xue, Qingzhu Zhang, Yizhen Chen, Fahe Chai, Wenxing Wang. Heavy ozone pollution episodes in urban Beijing during the early summertime from 2014 to 2017: Implications for control strategy. Environmental Pollution. 2021; 285 ():117162.
Chicago/Turabian StyleXin Zhang; Hong Li; Xuezhong Wang; Yujie Zhang; Fang Bi; Zhenhai Wu; Yuhong Liu; Hao Zhang; Rui Gao; Likun Xue; Qingzhu Zhang; Yizhen Chen; Fahe Chai; Wenxing Wang. 2021. "Heavy ozone pollution episodes in urban Beijing during the early summertime from 2014 to 2017: Implications for control strategy." Environmental Pollution 285, no. : 117162.
Understanding the formation mechanisms of secondary air pollution is very important for the formulation of air pollution control countermeasures in China. Thus, a large-scale outdoor atmospheric simulation smog chamber was constructed at Chinese Research Academy of Environmental Sciences (the CRAES Chamber), which was designed for simulating the atmospheric photochemical processes under the conditions close to the real atmospheric environment. The chamber consisted of a 56-m3 fluorinated ethylene propylene (FEP) Teflon film reactor, an electrically-driven stainless steel alloy shield, an auxiliary system, and multiple detection instrumentations. By performing a series of characterization experiments, we obtained basic parameters of the CRAES chamber, such as the mixing ability, the background reactivity, and the wall loss rates of gaseous compounds (propene, NO, NO2, ozone) and aerosols (ammonium sulfate). Oxidation experiments were also performed to study the formation of ozone and secondary organic aerosol (SOA), including α-pinene ozonolysis, propene and 1,3,5-trimethylbenzene photooxidation. Temperature and seed effects on the vapor wall loss and SOA yields were obtained in this work: higher temperature and the presence of seed could reduce the vapor wall loss; SOA yield was found to depend inversely on temperature, and the presence of seed could increase SOA yield. The seed was suggested to be used in the chamber to reduce the interaction between the gas phase and chamber walls. The results above showed that the CRAES chamber was reliable and could meet the demands for investigating tropospheric chemistry.
Junling Li; Hong Li; Xuezhong Wang; Weigang Wang; Maofa Ge; Hao Zhang; Xin Zhang; Kun Li; Yan Chen; Zhenhai Wu; Fahe Chai; Fan Meng; Yujing Mu; Abdelwahid Mellouki; Fang Bi; Yujie Zhang; Lingyan Wu; Yongchun Liu. A large-scale outdoor atmospheric simulation smog chamber for studying atmospheric photochemical processes: Characterization and preliminary application. Journal of Environmental Sciences 2021, 102, 185 -197.
AMA StyleJunling Li, Hong Li, Xuezhong Wang, Weigang Wang, Maofa Ge, Hao Zhang, Xin Zhang, Kun Li, Yan Chen, Zhenhai Wu, Fahe Chai, Fan Meng, Yujing Mu, Abdelwahid Mellouki, Fang Bi, Yujie Zhang, Lingyan Wu, Yongchun Liu. A large-scale outdoor atmospheric simulation smog chamber for studying atmospheric photochemical processes: Characterization and preliminary application. Journal of Environmental Sciences. 2021; 102 ():185-197.
Chicago/Turabian StyleJunling Li; Hong Li; Xuezhong Wang; Weigang Wang; Maofa Ge; Hao Zhang; Xin Zhang; Kun Li; Yan Chen; Zhenhai Wu; Fahe Chai; Fan Meng; Yujing Mu; Abdelwahid Mellouki; Fang Bi; Yujie Zhang; Lingyan Wu; Yongchun Liu. 2021. "A large-scale outdoor atmospheric simulation smog chamber for studying atmospheric photochemical processes: Characterization and preliminary application." Journal of Environmental Sciences 102, no. : 185-197.
PM2.5 level has decreased significantly in Beijing in recent years due to the strict air quality control measures taken in Jingjinji Region and the surrounding areas. However, the variation characteristics of the concentrations of PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) in Beijing in recent years are still not so clear. In order to understand the pollution status of PM2.5-bound PAHs in Beijing, fifteen PAHs were measured in a typical urban area of Beijing from 1 March to 20 March 2018. The average mass concentration of the 15 PAHs was 21 ng/m3 and higher in the nighttime than that in the daytime. The proportion of 4-ring PAHs in 15 PAHs was highest (43%), while 6-ring PAHs was lowest (10%). The levels of PAHs were higher during heavy pollution episodes than those in non-heavy pollution episodes, and the proportions of 5- and 6-ring PAHs were increased during a heavy pollution episode. PAHs posed obvious carcinogenic risks to the exposed populations, and the risk was higher during heavy pollution episodes than the average value of the whole monitoring period. The main sources of PAHs were traffic emissions and coal/biomass burning. Air masses from the south-southeast had a great influence on the PM2.5 levels during a heavy pollution episode. It is recommended that not only the PM2.5 levels but also the PAHs levels bounded in PM2.5 should be controlled to protect human health in Beijing.
Mei Luo; Yuanyuan Ji; Yanqin Ren; Fuhong Gao; Hao Zhang; Lihui Zhang; Yanqing Yu; Hong Li. Characteristics and Health Risk Assessment of PM2.5-Bound PAHs during Heavy Air Pollution Episodes in Winter in Urban Area of Beijing, China. Atmosphere 2021, 12, 323 .
AMA StyleMei Luo, Yuanyuan Ji, Yanqin Ren, Fuhong Gao, Hao Zhang, Lihui Zhang, Yanqing Yu, Hong Li. Characteristics and Health Risk Assessment of PM2.5-Bound PAHs during Heavy Air Pollution Episodes in Winter in Urban Area of Beijing, China. Atmosphere. 2021; 12 (3):323.
Chicago/Turabian StyleMei Luo; Yuanyuan Ji; Yanqin Ren; Fuhong Gao; Hao Zhang; Lihui Zhang; Yanqing Yu; Hong Li. 2021. "Characteristics and Health Risk Assessment of PM2.5-Bound PAHs during Heavy Air Pollution Episodes in Winter in Urban Area of Beijing, China." Atmosphere 12, no. 3: 323.
Based on ambient air quality data of the four key cities (Nanning, Liuzhou, Guilin, and Beihai) in Guangxi, China, along with an analysis of the main emission sources, topographic features, weather conditions, and backward trajectories, the variation of main air pollutants and pollution episodes in the four cities were studied. Results showed that air pollution was most serious in Liuzhou and Guilin, followed by Nanning and Beihai. PM2.5 was the dominant pollutant in each city, followed by O3, PM10, and NO2. Concentrations of SO2 and CO did not exceed their National Ambient Air Quality Standard Grade II limit values. In the cities, the concentrations of PM2.5, PM10, NO2, and SO2 were high during fall and winter and low during spring and summer, while the concentrations of O3 were high during fall and low during the other seasons. Concentrations of CO were low during summer and high during the other seasons in Nanning and Liuzhou, while they were high during spring and winter and low during summer and fall in Guilin and Beihai. In these cities, pollution episodes resulted mainly from stagnant accumulation and showed characteristics of regional pollution. However, pollution levels and durations for each city were different due to differences in main pollution sources, local geography, and weather conditions. The influences of air masses on the four cities were similar. They were mainly influenced by local emission sources in the spring, while during autumn, long-distance transportation from Hunan and Hubei was significant. In winter, air pollution in Nanning and Beihai was mostly affected by local emission sources, and that in Liuzhou and Guilin was mainly affected by long-distance transportation from the south and northeast of Guangxi.
Jing-Ying Mao; Zhi-Ming Chen; Zong-Kai Jiang; Zhao-Yu Mo; Hong-Jiao Li; Fan Meng; Bei Chen; Hui-Jiao Ling; Hong Li. A Comparative Study on Air Pollution Characteristics in Four Key Cities during 2013 in Guangxi Province, China. Sustainability 2021, 13, 1612 .
AMA StyleJing-Ying Mao, Zhi-Ming Chen, Zong-Kai Jiang, Zhao-Yu Mo, Hong-Jiao Li, Fan Meng, Bei Chen, Hui-Jiao Ling, Hong Li. A Comparative Study on Air Pollution Characteristics in Four Key Cities during 2013 in Guangxi Province, China. Sustainability. 2021; 13 (4):1612.
Chicago/Turabian StyleJing-Ying Mao; Zhi-Ming Chen; Zong-Kai Jiang; Zhao-Yu Mo; Hong-Jiao Li; Fan Meng; Bei Chen; Hui-Jiao Ling; Hong Li. 2021. "A Comparative Study on Air Pollution Characteristics in Four Key Cities during 2013 in Guangxi Province, China." Sustainability 13, no. 4: 1612.
To better evaluate the variations in concentration characteristics and source contributions of atmospheric volatile organic compounds (VOCs) during continuous haze days and non-haze days, hourly observations of atmospheric VOCs were conducted using a continuous on-line GC-FID (Airmo VOC GC-866) monitoring system during 1–15 March 2019, in urban areas of Beijing, China. The results showed that the total VOC concentrations during haze days and non-haze days were 59.13 ± 31.08 μg/m3 and 16.91 ± 7.19 μg/m3, respectively. However, the average O3 concentrations during the two haze days were lower than those of non-haze days due to the extremely low concentrations at night instead of the reported lower photochemical reaction in daytime. The ratio of OH radical concentration during haze and non-haze days indicating that the rate of photochemical reaction during haze days was higher than those of non-haze days from 13:00–19:00. The stable air conditions and the local diesel emission at night were the main reasons for the decreased O3 concentrations during haze days. Six major sources were identified by positive matrix factorization (PMF), namely, diesel exhaust, combustion, gasoline evaporation, solvent usage, gasoline exhaust, and the petrochemical industry, contributing 9.93%, 25.29%, 3.90%, 16.88%, 35.59% and 8.41%, respectively, during the whole observation period. The contributions of diesel exhaust and the petrochemical industry emissions decreased from 26.14% and 6.43% during non-haze days to 13.70% and 2.57%, respectively, during haze days. These reductions were mainly ascribed to the emergency measures that the government implemented during haze days. In contrast, the contributions of gasoline exhaust increased from 34.92% during non-haze days to 48.77% during haze days. The ratio of specific VOC species and PMF both showed that the contributions of gasoline exhaust emission increased during haze days. The backward trajectories, potential source contribution function (PSCF) and concentration weighted trajectory (CWT) showed that the air mass of VOCs during haze days was mainly affected by the short-distance transportation from the southwestern of Hebei province. However, the air mass of VOCs during non-haze days was mainly affected by the long-distance transportation from the northwest.
Lihui Zhang; Xuezhong Wang; Hong Li; Nianliang Cheng; Yujie Zhang; Kai Zhang; Lei Li. Variations in Levels and Sources of Atmospheric VOCs during the Continuous Haze and Non-Haze Episodes in the Urban Area of Beijing: A Case Study in Spring of 2019. Atmosphere 2021, 12, 171 .
AMA StyleLihui Zhang, Xuezhong Wang, Hong Li, Nianliang Cheng, Yujie Zhang, Kai Zhang, Lei Li. Variations in Levels and Sources of Atmospheric VOCs during the Continuous Haze and Non-Haze Episodes in the Urban Area of Beijing: A Case Study in Spring of 2019. Atmosphere. 2021; 12 (2):171.
Chicago/Turabian StyleLihui Zhang; Xuezhong Wang; Hong Li; Nianliang Cheng; Yujie Zhang; Kai Zhang; Lei Li. 2021. "Variations in Levels and Sources of Atmospheric VOCs during the Continuous Haze and Non-Haze Episodes in the Urban Area of Beijing: A Case Study in Spring of 2019." Atmosphere 12, no. 2: 171.
In order to clarify the influence of primary emission and secondary formation on the organic compositions of fine aerosols during the atmospheric pollution process in summer in Beijing, an intensive field measurement were carried out at an urban site in Beijing from July 1 to July 30, 2017. Inorganic ions (SO42−, NO3−, and NH4+) and organic compounds (OM) were the most important components of PM2.5 throughout the whole sampling period, with inorganic ions having the highest concentrations during the polluted period and OM having the highest concentration during the clean period. The apportioned quantitatively primary and secondary sources accounted for an average 86 ± 12% of the measured organic carbon (OC) at the urban site, based on positive matrix factorization modeling and the tracer-based method. Coal combustion was an important primary source for OC in the polluted episode, and biomass burning was the main contributor during the clean period. β-Caryophyllene SOC (secondary OC) was the main secondary contributor for OC during summertime in Beijing. The significant amount of SOC enhanced with an increased ozone and acidification indicated that the atmospheric oxidants and the in-situ acidity of particles were important factors in the formation of SOC during period of high pollution in Beijing.
Yan Qin Ren; Jie Wei; Yuan Yuan Ji; Zhen Hai Wu; Fang Bi; Rui Gao; Xue Zhong Wang; Hong Li. Chemical composition of fine organic aerosols during a moderate pollution event in summertime in Beijing: Combined effect of primary emission and secondary formation. Atmospheric Environment 2020, 246, 118167 .
AMA StyleYan Qin Ren, Jie Wei, Yuan Yuan Ji, Zhen Hai Wu, Fang Bi, Rui Gao, Xue Zhong Wang, Hong Li. Chemical composition of fine organic aerosols during a moderate pollution event in summertime in Beijing: Combined effect of primary emission and secondary formation. Atmospheric Environment. 2020; 246 ():118167.
Chicago/Turabian StyleYan Qin Ren; Jie Wei; Yuan Yuan Ji; Zhen Hai Wu; Fang Bi; Rui Gao; Xue Zhong Wang; Hong Li. 2020. "Chemical composition of fine organic aerosols during a moderate pollution event in summertime in Beijing: Combined effect of primary emission and secondary formation." Atmospheric Environment 246, no. : 118167.
Biomass burning and dust storm have significant impacts on air pollution, aerosol properties and potential human health. In order to investigate the influences of them on the chemical component and sources of aerosols, PM2.5 are collected in spring and summer in Beijing. There are two special periods in the whole campaign. (1) Event I, from 16 to 18 April. Air quality is extremely poor during this period mainly affected by biomass burning. (2) Event II, from 4 to 5 May, the biggest dust storm happened on 4 May. In addition, we choose a relative clean period as (3) Event III, from 24 to 29 July, with the lowest PM2.5 levels (16–31 μg m−3) in the whole campaign. Contributions of NO3−, SO42−, and NH4+ to PM2.5 in Event I are 22.1%, 11.3%, and 8.3%, respectively, and decreased dramatically to 2.4%, 5.4%, and 0.9% in Event II, suggesting secondary aerosols are more significant in haze period. Both ratios of phytane & pristane and PAHs to OC in Event I and II are comparable, indicating contribution of local primary organic aerosols from fossil fuel combustions to PM2.5 are not significant differences between polluted and dust period. In contrast, ratio of levoglucosan to OC is much higher in Event I and ratio of trehalose to OC is much higher in Event II, suggesting the contribution of regional primary organic aerosols from biomass burning to PM2.5 is important during polluted period, while contribution of regional primary organic aerosols from dust to PM2.5 is significant in dust storm. Based on the organic markers, this work also estimates the source apportionment of PM2.5. Dust and biomass burning are the main contributors in polluted period, while vehicle and cooking are the main contributors in clean period.
Yanqin Ren; Jie Wei; Zhenhai Wu; Yuanyuan Ji; Fang Bi; Rui Gao; Xuezhong Wang; Gehui Wang; Hong Li. Chemical components and source identification of PM2.5 in non-heating season in Beijing: The influences of biomass burning and dust. Atmospheric Research 2020, 251, 105412 .
AMA StyleYanqin Ren, Jie Wei, Zhenhai Wu, Yuanyuan Ji, Fang Bi, Rui Gao, Xuezhong Wang, Gehui Wang, Hong Li. Chemical components and source identification of PM2.5 in non-heating season in Beijing: The influences of biomass burning and dust. Atmospheric Research. 2020; 251 ():105412.
Chicago/Turabian StyleYanqin Ren; Jie Wei; Zhenhai Wu; Yuanyuan Ji; Fang Bi; Rui Gao; Xuezhong Wang; Gehui Wang; Hong Li. 2020. "Chemical components and source identification of PM2.5 in non-heating season in Beijing: The influences of biomass burning and dust." Atmospheric Research 251, no. : 105412.
The pollution characteristics of surfactant substances in fine particles (PM2.5) in spring were studied in the Beibu Gulf Region of China, 68 samples of PM2.5 were collected at Weizhou Island in Beihai City from March 12 to April 17, 2015. The Anionic Surfactant Substances (ASS) and Cationic Surfactant Substances (CSS) in the samples were analyzed using Byethyl Violet Spectrophotometry and Disulfide Blue Spectrophotometry, respectively. Combined with the data from backward trajectory simulation, the effects of air pollutants from remote transport on the pollution characteristics of surfactant substances in PM2.5 in the Beibu Gulf Region were analyzed and discussed. The results showed that the daily mean concentrations of ASS and CSS in spring in the Beibu Gulf Region were 165.20 pmol/m3 and 8.05pmol/m3, and the variation ranges were 23.21–452.55 pmol/m3 and 0.65–31.31 pmol/m3, accounting for 1.82‰ ± 1.65‰ and 0.12‰ ± 0.11‰ of the mass concentration of PM2.5, respectively. These concentrations were lower than those in comparable regions around the world. There was no clear correlation between the concentrations of ASS and CSS in PM2.5 and the mass concentrations of PM2.5. Tourism and air transport had a positive contribution on the concentrations of ASS. The concentration of surfactant substances in PM2.5 was significantly impacted by wind speed and wind direction. Atmospheric temperature, air pressure and precipitation had little effect on the concentrations of surfactant substances. Surfactant substances in PM2.5 significantly impacted visibility. Results also showed that the main sources of surfactant substances were from the southern China and Southeast Asia.
ZhengZheng Zhang; Hong Li; Hongyan Liu; Yingchen Bai; Jinjuan Li; Guorui Zhi; Yanting Yu; Wenjun Li; Hao Zhang; Fan Meng. A preliminary study on pollution characteristics of surfactant substances in fine particles in the Beibu Gulf Region of China. Journal of Environmental Sciences 2020, 102, 363 -372.
AMA StyleZhengZheng Zhang, Hong Li, Hongyan Liu, Yingchen Bai, Jinjuan Li, Guorui Zhi, Yanting Yu, Wenjun Li, Hao Zhang, Fan Meng. A preliminary study on pollution characteristics of surfactant substances in fine particles in the Beibu Gulf Region of China. Journal of Environmental Sciences. 2020; 102 ():363-372.
Chicago/Turabian StyleZhengZheng Zhang; Hong Li; Hongyan Liu; Yingchen Bai; Jinjuan Li; Guorui Zhi; Yanting Yu; Wenjun Li; Hao Zhang; Fan Meng. 2020. "A preliminary study on pollution characteristics of surfactant substances in fine particles in the Beibu Gulf Region of China." Journal of Environmental Sciences 102, no. : 363-372.
Twenty-three atmospheric volatile halogenated hydrocarbons (VHHs) were detected in a typical urban area of Beijing, China from 24 August to 4 September, 2012. The mean and range in daily mass concentrations of the 23 VHHs were 30.53 and 13.45–76.33 µg/m3, respectively. Seven of those VHHs were controlled ozone-depleting substances in China, with a mean of 12.95 µg/m3, accounting for 42.43% of the total. Compared with other national and international cities, the concentrations of the selected 11 VHHs in this study were relatively higher. Dichloroethane had the highest mass concentration, followed by difluorochloromethane. Maxima of total VHHs occurred within the period 8:30–9:00 a.m., while minima occurred during 1:30–2:00 p.m. Source apportionment suggested that the main sources of VHHs in the study area were solvents usage and industrial processes, leakage of chlorofluorocarbons banks, refrigerants, and fumigant usage. Among the selected 7 VHHs, trichloromethane, tetrachloromethane, 1,2-dichloroethane, and 1,4-dichlorobenzene posed potential carcinogenic risks to exposed populations, while none of the selected 11 VHHs posed appreciable non-carcinogenic risks to exposed populations. The carcinogenic risks from atmospheric VHHs in Beijing are higher than in other Chinese cities, indicating that it is necessary to implement immediate control measures for atmospheric VHHs in Beijing.
Yuanyuan Ji; Linghong Xu; Hong Li; Chuhan Wang; Dongyao Xu; Lei Li; Hao Zhang; Jingchun Duan; Yujie Zhang; Xuezhong Wang; Weiqi Zhang; Fang Bi; Yizhen Chen; Yanting Yu; Lingshuo Meng. Pollution Characteristics and Health Risk Assessment of Summertime Atmospheric Volatile Halogenated Hydrocarbons in a Typical Urban Area of Beijing, China. Atmosphere 2020, 11, 1021 .
AMA StyleYuanyuan Ji, Linghong Xu, Hong Li, Chuhan Wang, Dongyao Xu, Lei Li, Hao Zhang, Jingchun Duan, Yujie Zhang, Xuezhong Wang, Weiqi Zhang, Fang Bi, Yizhen Chen, Yanting Yu, Lingshuo Meng. Pollution Characteristics and Health Risk Assessment of Summertime Atmospheric Volatile Halogenated Hydrocarbons in a Typical Urban Area of Beijing, China. Atmosphere. 2020; 11 (10):1021.
Chicago/Turabian StyleYuanyuan Ji; Linghong Xu; Hong Li; Chuhan Wang; Dongyao Xu; Lei Li; Hao Zhang; Jingchun Duan; Yujie Zhang; Xuezhong Wang; Weiqi Zhang; Fang Bi; Yizhen Chen; Yanting Yu; Lingshuo Meng. 2020. "Pollution Characteristics and Health Risk Assessment of Summertime Atmospheric Volatile Halogenated Hydrocarbons in a Typical Urban Area of Beijing, China." Atmosphere 11, no. 10: 1021.
Biogenic volatile organic compounds (BVOCs) in the atmosphere play important roles in the formation of ground-level ozone and secondary organic aerosol (SOA) in global scale and also in regional scale under some condition due to their large amount and relatively higher reactivity. In places with high plant cover in the tropics and in China where air pollution is serious, the effect of BVOCs on ozone and secondary organic aerosols is strong. The present research aims to provide a comprehensive review about the emission rate, emission inventory, research methods, the influencing factors of BVOCs emissions, as well as their impacts on atmospheric environment quality and human health in recent years in Asia based on the summary and analysis of literatures. It is suggested to use field direct measurement method to obtain the emission rate and model method to calculate the emission amount. Several recommendations are given for future investigation and policy development on BVOCs emission.
Xiaoxiu Lun; Ying Lin; Fahe Chai; Chong Fan; Hong Li; Junfeng Liu. Reviews of emission of biogenic volatile organic compounds (BVOCs) in Asia. Journal of Environmental Sciences 2020, 95, 266 -277.
AMA StyleXiaoxiu Lun, Ying Lin, Fahe Chai, Chong Fan, Hong Li, Junfeng Liu. Reviews of emission of biogenic volatile organic compounds (BVOCs) in Asia. Journal of Environmental Sciences. 2020; 95 ():266-277.
Chicago/Turabian StyleXiaoxiu Lun; Ying Lin; Fahe Chai; Chong Fan; Hong Li; Junfeng Liu. 2020. "Reviews of emission of biogenic volatile organic compounds (BVOCs) in Asia." Journal of Environmental Sciences 95, no. : 266-277.
Rainfall samples were collected from three observation sites in Guilin from 2013 to 2017, and the chemical composition characteristics of precipitation and the contribution made by different ion sources were analyzed when atmospheric pollutants levels were reduced. The results showed that acid gas emissions and atmospheric pollutant concentrations continued to decline during the study period. However, the change in the volume-weighted mean pH at the three sites suggested that acid rain pollution was not alleviated and began to deteriorate after 2015. The continuing downward trend for alkaline neutralizing ions (Ca2+, NH4+) in precipitation indicated that the reduction in alkaline neutralizing substances in the atmosphere was an important factor that led to the deterioration in acid rain across Guilin. The principal component analysis and spearman correlation analysis indicated five sources of ions in precipitation. Quantitative assessment of these five sources indicated that fossil fuel combustion contributed the most ions concentration in precipitation at the three sites, followed by agriculture, terrestrial (crustal) sources, marine sources, and biomass burning. Long-distance airflow might affect the acidity, the electrical conductivity (EC), and ion concentrations in precipitation across Guilin. The airflow trajectory from the west and southeast directions corresponded to higher acidity and ion concentrations. According to the current air pollution control strategy planned by Guilin, reducing atmospheric coarse particles and NH3 at the same time may potentially lead to further deteriorations in acid rain contents. Therefore, Guilin needs to develop more reasonable pollution prevention measures that synergistically control atmospheric pollutants and acid rain pollution.
Ling Li; Hong Li; Liang Peng; Yongshan Li; Yi Zhou; Fahe Chai; Zhaoyu Mo; Zhiming Chen; Jingying Mao; Wenxing Wang. Characterization of precipitation in the background of atmospheric pollutants reduction in Guilin: Temporal variation and source apportionment. Journal of Environmental Sciences 2020, 98, 1 -13.
AMA StyleLing Li, Hong Li, Liang Peng, Yongshan Li, Yi Zhou, Fahe Chai, Zhaoyu Mo, Zhiming Chen, Jingying Mao, Wenxing Wang. Characterization of precipitation in the background of atmospheric pollutants reduction in Guilin: Temporal variation and source apportionment. Journal of Environmental Sciences. 2020; 98 ():1-13.
Chicago/Turabian StyleLing Li; Hong Li; Liang Peng; Yongshan Li; Yi Zhou; Fahe Chai; Zhaoyu Mo; Zhiming Chen; Jingying Mao; Wenxing Wang. 2020. "Characterization of precipitation in the background of atmospheric pollutants reduction in Guilin: Temporal variation and source apportionment." Journal of Environmental Sciences 98, no. : 1-13.
Benzene homologues are important chemical precursors to the formation of ground-level ozone and secondary organic aerosol (SOA) in the atmosphere, in addition, some toxic species are harmful to human health. Strict countermeasures have been taken to fight air pollution since 2013, and total amount control of volatile organic compounds is being promoted in China at present. Therefore, it is important to understand the pollution situation and the control status of ambient benzene homologues in China. This paper reviews research progress from published papers on pollution characteristics, atmospheric photochemical reactivity, health risk assessment and source identification of ambient benzene homologues in recent years in China, and also summarizes policies and countermeasures for the control of ambient benzene homologues and the relevant achievements. The total ambient levels of benzene, toluene, ethylbenzene and xylenes (BTEX) shows a declining tendency from 2001 to 2016 in China. The mass concentrations of BTEX are generally higher in southern regions than in northern regions, and they present vertical decreasing variation characteristics with increasing altitude within the height range of about 5500 m. Toluene has the highest ozone formation potential and SOA formation potential both in urban areas and background areas, while benzene poses an obvious carcinogenic risk to the exposed adult populations in urban areas. Source identification of ambient benzene homologues suggested that local governments should adopt differentiated control strategies for ambient benzene homologues. Several recommendations are put forward for future research and policy-making on the control of ambient benzene homologues in China.
Yuanyuan Ji; Fuhong Gao; Zhenhai Wu; Lei Li; Dandan Li; Hao Zhang; Yujie Zhang; Jian Gao; Yingchen Bai; Hong Li. A review of atmospheric benzene homologues in China: Characterization, health risk assessment, source identification and countermeasures. Journal of Environmental Sciences 2020, 95, 225 -239.
AMA StyleYuanyuan Ji, Fuhong Gao, Zhenhai Wu, Lei Li, Dandan Li, Hao Zhang, Yujie Zhang, Jian Gao, Yingchen Bai, Hong Li. A review of atmospheric benzene homologues in China: Characterization, health risk assessment, source identification and countermeasures. Journal of Environmental Sciences. 2020; 95 ():225-239.
Chicago/Turabian StyleYuanyuan Ji; Fuhong Gao; Zhenhai Wu; Lei Li; Dandan Li; Hao Zhang; Yujie Zhang; Jian Gao; Yingchen Bai; Hong Li. 2020. "A review of atmospheric benzene homologues in China: Characterization, health risk assessment, source identification and countermeasures." Journal of Environmental Sciences 95, no. : 225-239.
Abdelwahid Mellouki; Christian George; Fahe Chai; Yujing Mu; Jianmin Chen; Tao Wang; Hong Li. Preface. Journal of Environmental Sciences 2020, 95, 1 .
AMA StyleAbdelwahid Mellouki, Christian George, Fahe Chai, Yujing Mu, Jianmin Chen, Tao Wang, Hong Li. Preface. Journal of Environmental Sciences. 2020; 95 ():1.
Chicago/Turabian StyleAbdelwahid Mellouki; Christian George; Fahe Chai; Yujing Mu; Jianmin Chen; Tao Wang; Hong Li. 2020. "Preface." Journal of Environmental Sciences 95, no. : 1.
The uptake of dinitrogen pentoxide (N2O5) on aerosols affects the nocturnal removal of NOx and particulate nitrate formation in the atmosphere. This study investigates N2O5 uptake processes using field observations from an urban site in Beijing during April–May 2017, a period characterized by dry weather conditions. For the first time, a very large N2O5 uptake rate (k(N2O5) up to ~0.01 s−1) was observed during a sand storm event, and the uptake coefficient (γ(N2O5)) was estimated to be 0.044. The γ(N2O5) in urban air masses was also determined and exhibited moderate correlation (r = 0.68) with aerosol volume to surface ratio (Va/Sa), but little relation to aerosol water, nitrate, and chloride, a finding that contrasts with previous results. Several commonly used parameterizations of γ(N2O5) underestimated the field-derived γ(N2O5). A new parameterization is suggested for dry conditions, which considers the effect of Va/Sa, temperature, and relative humidity.
Men Xia; Weihao Wang; Zhe Wang; Jian Gao; Hong Li; Yutong Liang; Chuan Yu; Yuechong Zhang; Peng Wang; Yujie Zhang; Fang Bi; Xi Cheng; Tao Wang. Heterogeneous Uptake of N2O5 in Sand Dust and Urban Aerosols Observed during the Dry Season in Beijing. Atmosphere 2019, 10, 204 .
AMA StyleMen Xia, Weihao Wang, Zhe Wang, Jian Gao, Hong Li, Yutong Liang, Chuan Yu, Yuechong Zhang, Peng Wang, Yujie Zhang, Fang Bi, Xi Cheng, Tao Wang. Heterogeneous Uptake of N2O5 in Sand Dust and Urban Aerosols Observed during the Dry Season in Beijing. Atmosphere. 2019; 10 (4):204.
Chicago/Turabian StyleMen Xia; Weihao Wang; Zhe Wang; Jian Gao; Hong Li; Yutong Liang; Chuan Yu; Yuechong Zhang; Peng Wang; Yujie Zhang; Fang Bi; Xi Cheng; Tao Wang. 2019. "Heterogeneous Uptake of N2O5 in Sand Dust and Urban Aerosols Observed during the Dry Season in Beijing." Atmosphere 10, no. 4: 204.
To evaluate the influence of the implementation of emission reduction measures on air quality during the 2015 China Victory Day Parade, the characteristics of organic aerosols in particulate matter with a diameter less than 2.5 μm (PM2.5) were analyzed from 11 August to 10 September 2015 in Beijing, China. The average concentration of PM2.5 decreased by 64% during the 2015 China Victory Day Parade compared with that before the event. Local emissions were the main PM2.5 sources during the 2015 China Victory Day Parade; cooking and traffic emission were two significant contributors. During the 2015 China Victory Day Parade, the average concentrations of levoglucosan and dehydroabietic acid decreased by 31% and 12%, respectively, indicating the significant effects of regional air pollution controls on air quality. 17α(H), 21β(H)-30-Norhopane and 17α(H), 21β(H)-hopane concentrations decreased continuously throughout the entire study period, suggesting the significant effect of the “odd-even” traffic restrictions implemented. Similarly, o-phthalic acid, succinic acid, and 2,3-dihydroxy-4-oxopentanoic acid (DPA) concentrations also significantly decreased during the Parade, with reductions of 63, 50, and 61%, respectively, compared with before the event. Photochemical oxidation played an important role in the formation of o-phthalic acid, while the formation of DPA was influenced by both photochemical oxidation and liquid-phase chemical reactions. The lung cancer risk, caused by inhalation exposure to polycyclic aromatic hydrocarbons, to the exposed populations decreased by 40% during the 2015 China Victory Day Parade, the enhanced control measures implemented during Parade Blue would also have positive influence on the human health.
Yanqin Ren; Hong Li; Fan Meng; Gehui Wang; Hao Zhang; Ting Yang; Wenjun Li; Yuanyuan Ji; Fang Bi; Xuezhong Wang. Impact of emission controls on air quality in Beijing during the 2015 China Victory Day Parade: Implication from organic aerosols. Atmospheric Environment 2018, 198, 207 -214.
AMA StyleYanqin Ren, Hong Li, Fan Meng, Gehui Wang, Hao Zhang, Ting Yang, Wenjun Li, Yuanyuan Ji, Fang Bi, Xuezhong Wang. Impact of emission controls on air quality in Beijing during the 2015 China Victory Day Parade: Implication from organic aerosols. Atmospheric Environment. 2018; 198 ():207-214.
Chicago/Turabian StyleYanqin Ren; Hong Li; Fan Meng; Gehui Wang; Hao Zhang; Ting Yang; Wenjun Li; Yuanyuan Ji; Fang Bi; Xuezhong Wang. 2018. "Impact of emission controls on air quality in Beijing during the 2015 China Victory Day Parade: Implication from organic aerosols." Atmospheric Environment 198, no. : 207-214.
Continuous observation of isoprene, α-pinene and β-pinene was carried out in a typical urban area of Beijing from March 2014 to February 2015, using an AirmoVOC online analyzer. Based on the analysis of the ambient level and variation characteristics of isoprene, α-pinene and β-pinene, the chemical reactivity was studied, and their sources were identified. Results showed that the concentrations of isoprene, α-pinene and β-pinene in the urban area of Beijing were lower than those in richly vegetated areas; the concentrations of isoprene were at a moderate level compared with those of previous studies of Beijing. Concentrations of isoprene, α-pinene and β-pinene showed different seasonal, monthly, daily and diurnal variations, and all of the three species showed higher level at night than those in the daytime as a whole, the variations of isoprene, α-pinene and β-pinene mainly influenced by emission of sources, photochemical reaction, and meteorological parameters. Isoprene was the largest contributor to the total OFP values than α-pinene and β-pinene. α-Pinene was the largest contributor to the total SOAFP values than isoprene and β-pinene in autumn, while isoprene was the largest one in other seasons. Isoprene, α-pinene and β-pinene were derived mainly from biological sources; and α-pinene level were also affected by industrial sources. To reduce the concentrations of isoprene, α-pinene and β-pinene, it is necessary to scientifically select urban green plant species, and more strict control measures should be taken to reduce the emission of α-pinene from industrial sources, such as artificial flavors and resins synthesis processes.
Xi Cheng; Hong Li; Yujie Zhang; Yuping Li; Weiqi Zhang; Xuezhong Wang; Fang Bi; Hao Zhang; Jian Gao; Fahe Chai; Xiaoxiu Lun; Yizhen Chen; Junyi Lv. Atmospheric isoprene and monoterpenes in a typical urban area of Beijing: Pollution characterization, chemical reactivity and source identification. Journal of Environmental Sciences 2018, 71, 150 -167.
AMA StyleXi Cheng, Hong Li, Yujie Zhang, Yuping Li, Weiqi Zhang, Xuezhong Wang, Fang Bi, Hao Zhang, Jian Gao, Fahe Chai, Xiaoxiu Lun, Yizhen Chen, Junyi Lv. Atmospheric isoprene and monoterpenes in a typical urban area of Beijing: Pollution characterization, chemical reactivity and source identification. Journal of Environmental Sciences. 2018; 71 ():150-167.
Chicago/Turabian StyleXi Cheng; Hong Li; Yujie Zhang; Yuping Li; Weiqi Zhang; Xuezhong Wang; Fang Bi; Hao Zhang; Jian Gao; Fahe Chai; Xiaoxiu Lun; Yizhen Chen; Junyi Lv. 2018. "Atmospheric isoprene and monoterpenes in a typical urban area of Beijing: Pollution characterization, chemical reactivity and source identification." Journal of Environmental Sciences 71, no. : 150-167.
Size-fractioned atmospheric aerosol particles were collected during a typical heavy air pollution event in Beijing. The organic and inorganic components on the surfaces of the samples were analyzed using time-of-flight secondary ion mass spectrometry (TOF-SIMS). The variation characteristics of the surface chemical composition and influencing factors were studied, and the possible sources of these chemical compositions were identified through principal component analysis. The results showed that inorganic components such as crustal elements and sulfate, and organic components such as aliphatic hydrocarbons and oxygen-containing organic groups were present. Some surface components, such as polycyclic aromatic hydrocarbons, heavy metals and fluorides may exert adverse effects on human health. The species and relative percentages of the chemical components varied with particle size, diurnal and pollution progress. During a heavy pollution event, the species and relative percentages of secondary components such as oxygen-containing organic groups and sulfurous compounds increased, indicating that particles aged during this event. The surface chemical composition of the aerosol particles was affected mainly by emissions from coal combustion and motor vehicles. In addition, air pollution, meteorological factors, and air mass transport also exerted a significant effect on the surface chemical composition of aerosol particles.
Wenjun Li; Hong Li; Jinjuan Li; Xueli Cheng; ZhengZheng Zhang; Fahe Chai; Hao Zhang; Ting Yang; Pengli Duan; Defeng Lu; Yizhen Chen. TOF–SIMS surface analysis of chemical components of size–fractioned urban aerosols in a typical heavy air pollution event in Beijing. Journal of Environmental Sciences 2018, 69, 61 -76.
AMA StyleWenjun Li, Hong Li, Jinjuan Li, Xueli Cheng, ZhengZheng Zhang, Fahe Chai, Hao Zhang, Ting Yang, Pengli Duan, Defeng Lu, Yizhen Chen. TOF–SIMS surface analysis of chemical components of size–fractioned urban aerosols in a typical heavy air pollution event in Beijing. Journal of Environmental Sciences. 2018; 69 ():61-76.
Chicago/Turabian StyleWenjun Li; Hong Li; Jinjuan Li; Xueli Cheng; ZhengZheng Zhang; Fahe Chai; Hao Zhang; Ting Yang; Pengli Duan; Defeng Lu; Yizhen Chen. 2018. "TOF–SIMS surface analysis of chemical components of size–fractioned urban aerosols in a typical heavy air pollution event in Beijing." Journal of Environmental Sciences 69, no. : 61-76.