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06%, 59.90%, 11.79%, and 54.50%, respectively. The content of the VOCs in different types of coatings varied substantially. The main components and OFP contributors were alcohols and ethers for water-based coatings, benzene series and esters for solvent-based coatings, and esters, alcohols, and ethers for UV coatings. The average value of the coating samples could meet the current mandatory national standards, but 12% of the solvent-based wood coating samples and 42% of the solvent-based OEM coating samples did not meet the standards. In addition, except for the benzene series of the water-based wood coatings, the contents of harmful substances in other coating samples were up to the standards.During the National Traditional Games of Ethnic Minorities (NTGEM) 2019, air quality in Zhengzhou was analyzed to evaluate the impact of pollution prevention and control measures on Zhengzhou. Ground-observed meteorological and pollutant data as well as the chemical compositions of volatile organic compounds (VOCs) were investigated. The results showed that the six parameters of pollutants in the safeguard period in 2019 indicated a downward trend as compared with that during the same time in 2018, and the average concentrations of PM2.5 and PM10 were decreased by 16.2% and 25.1%, respectively. However, the average concentration of O3 was only reduced by 3.7%. The daily proportions of primary pollutants of O3 increased to 90% during the NTGEM, and the ozone pollution was severe in this period. Meanwhile, the concentration of total volatile organic compounds (TVOCs) in the safeguard period was 26.21×10-9, which was significantly lower than that during the historical period. Six emission sources of the VOCs were identified using PMF model, including vehicle exhaust (28%), LPG evaporation (21%), combustion source (16%), industrial emissions (15%), solvent utilization (15%), and biogenic VOCs (5%). During the NTGEM period, the control of combustion sources and industrial sources was evident.In this study, according to the activity levels of volatile organic compounds (VOCs) sources and source profiles, a 2016-based inventory of the speciation emission of the VOCs was established and the ozone formation potential (OFP) were estimated in Zhengzhou. The results showed that the total VOCs emission in Zhengzhou in 2016 was 96215.3 t. https://www.selleckchem.com/products/su5402.html The highest emission source was on-road mobile source (29.7%) followed by solvent use sources (28.1%). The species that contributed the highest emission was alkanes (29.8%) followed by aromatics (29.0%). The OFP in Zhengzhou in 2016 was 341291.0 t with the highest contributing source as on-road mobile (30.5%) followed by solvent use source (28.8%). Moreover, the light duty gasoline vehicle, use of interior wall coatings, vehicle surface coating, gas station loading and unloading, and manufacture of non-metallic mineral were the major secondary emission sources of OFP, which needed to be controlled for reducing ozone pollution in Zhengzhou. For VOCs species group, the higher contribution groups were aromatics (42.8%) and alkenes (38.9%). The sources that produced m/p-xylene, propylene, ethylene, and other species should be paid more attention.To understand the trends and characteristics of air pollution in Baoding in recent years, an analysis of air quality and air pollutant concentrations in Baoding from 2013 to 2018 was carried out. The results showed that 1 from 2013 to 2018, the comprehensive index of Baoding dropped from 11.6 to 6.6, the days of severe pollution decreased from 114 days to 27 days, and cumulative concentration of pollutants during severe pollution decreased from 57.34% to 20.59%. This indicated that the air quality of Baoding city has improved year on year from 2013 to 2018. Not only has the number of heavy pollution days and the annual average concentration of pollutants decreased, but also the proportion of cumulative concentrations of pollutants during heavy pollution has decreased. the difference between the average concentration level of Baoding city and "2+26" Cities is getting smaller and smaller. ② Summer ρ(O3-8h) increased year on year. In 2017 and 2018, the heavy pollution days caused by O3 accounted for 17.0% and 14tion increased as compared to that during the high pollution season in 2017, indicating that the coal combustion was still one of the pollution sources that Baoding city needed to control. In summary, Baoding should strengthen the management and control of motor vehicles in autumn, and gradually change from the original coal control measures to a combination of coal control and diesel control in winter; in the future, the focus of air pollution prevention and control should be strengthened toward O3 pollution.To evaluate the effect of emergency emission reduction measures during the heavy air pollution episodes in Beijing, Tianjin, Hebei, and its surrounding areas, a scenario simulation method was used. The concentrations of PM2.5, PM10, SO2, NO2, CO, and O3-8h, air quality index (AQI), characteristics of heavy air pollution, and climate and meteorological factors were analyzed using the observation data available from October to December 2019. The 24 h, 72 h, and 144 h prediction results of NAQPMS model were analyzed. The uncertainties of the assessment and model prediction were discussed. The results showed that the average PM2.5 concentration in Beijing, Tianjin, and its surrounding 26 cities ("2+26" cities) from October to December 2019 was 64 μg ·m-3, indicating a decrease of 10 μg ·m-3 as compared with that during the same period in 2018. There were 4 occurrences of regional heavy air pollution episodes, with the average PM2.5 concentration of 156 μg ·m-3 of affected cities. The value of evaluation on meteorological condition index of PM2.5 pollution (EMI) of "2+26" cities ranged from -15.6%-16.8%. The meteorological conditions of 12 cities, including Beijing, Tianjin, and Shijiazhuang, deteriorated as compared with those during the same period in 2018, and the changes ranged from 3.2%-16.8%. However, the emergency emission reduction measures effectively reduced the occurrence of regional heavy air pollution episodes, the peak concentration of PM2.5 was decreased significantly, and no severe regional pollution episode occurred. The daily PM2.5 concentrations reduced by 2% to 9% in Beijing, Shijiazhuang, Baoding, Tangshan, and other cities during a typical heavy air pollution period. The quarterly average concentrations of PM2.5 in the "2+26" cities reduced by 1 to 3 μg ·m-3. The regional emergency emission reduction measures have played an active role in protecting the health of the people and improving the quality of ambient air.
