The chemical composition of Beijing aerosol was measured during summer and winter. Two distinct episodes were identified. Water-soluble potassium (K(+)) increased significantly during the firework episode in winter with an episode to non-episode ratio of 4.97, whereas the biomass burning (BB) episode in summer was characterized by high episode to non-episode ratios of levoglucosan (6.38) and K(+) (6.90). The BB and firework episodes had only a minor influence on the water-soluble OC (organic carbon) to OC ratio. Based on separate investigations of episode and non-episode periods, it was found that: (i) sulfate correlated strongly with both relative humidity and nitrate during the typical winter period presumably indicating the importance of the aqueous-phase oxidation of sulfur dioxide by nitrogen dioxide, (ii) oxalate and WSOC during both winter and summer in Beijing were mainly due to secondary formation, and (iii) high humidity can significantly enhance the formation potential of WSOC in winter.
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http://dx.doi.org/10.1016/j.envpol.2013.10.037 | DOI Listing |
Environ Monit Assess
August 2024
School of Chemistry and Life Sciences, Hanoi University of Science and Technology, No. 1 Dai Co Viet, Hanoi, 100000, Vietnam.
Every year, Hanoi suffers from several episodes (periods with daily concentration of PM higher than 50 µg m during at least two consecutive days). These episodes are of health concern because of the high concentration of PM and/or PM and the presence of PM-bound toxic components, such as, PAHs. In this study, the concentrations of PAHs bound to PM and PM in night-time and day-time samples during episode and non-episode periods in December 2021 were determined.
View Article and Find Full Text PDFEnviron Sci Process Impacts
May 2024
Environmental Change Research Centre, University College London, Gower Street, London WC1E 6BT, UK.
Fifty-two consecutive PM samples from December 2021 to February 2022 (the whole winter) were collected in the center of Chongqing, a humid metropolitan city in China. These samples were analysed for the 16 USEPA priority polycyclic aromatic hydrocarbons (16 PAHs) to explore their composition and sources, and to assess their cancer risks to humans. The total concentrations of the 16 PAHs (ng m) ranged from 16.
View Article and Find Full Text PDFHuan Jing Ke Xue
March 2024
School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China.
Tropospheric ozone (O) is mainly produced through a series of photochemical reactions of nitrogen oxides (NO) and volatile organic compounds (VOCs). The reaction process presents complex non-linear relationships. In this work, datasets of atmospheric ozone and volatile organic compounds (VOCs) observed during the summer of 2018 in Nanjing were used.
View Article and Find Full Text PDFFront Cardiovasc Med
March 2023
Heart Center, Department of Cardiovascular Medicine, Zhejiang Provincial People's Hospital (Affiliated People's Hospital, Hangzhou Medical College), Hangzhou, China.
Background: Previous studies have shown that patients with a history of atrial fibrillation (AF) have a higher risk of developing coronary slow flow (CSF). However, whether AF episode status affects the incidence of CSF has not been confirmed. This study investigated the correlation between AF episode status and the incidence of CSF.
View Article and Find Full Text PDFInt J Environ Res Public Health
November 2022
School of Atmosphere and Remote Sensing, Wuxi University, Wuxi 214105, China.
Recently released hourly particular matter (PM:PM and PM) and gaseous pollutants (SO, NO, CO, and O) data observed in Qingdao, Hangzhou, and Xiamen from 2015 to 2019 were utilized to reveal the current situation of air pollution over eastern coastal China. The PM pollution situation over the three metropolises ameliorated during studied period with the concentrations decreasing about 20-30%. Gas pollutants, excepting SO, generally exhibit no evident reduction tendencies, and a more rigorous control standard on gaseous pollutants is neededEven for the year 2018 with low pollution levels among the study period, these levels (<10% of PM, <6% of PM, and <15% of O) surpass the Grade II of the Chinese Ambient Air Quality Standard (CAAQS) over these metropolises of eastern coast China.
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