Significant Reductions in Secondary Aerosols after the Three-Year Action Plan in Beijing Summer

Li, Yan; Lei, Lu; Sun, Jiaxing; Gao, Yueqi; Wang, Peng; Wang, Siyu; Zhang, Zhaolei; Du, Aodong; Li, Zhijie; Wang, Zifa; Kim, Jin Young; Kim, Hwajin; Zhang, Hongliang; Sun, Yele

doi:10.1021/acs.est.3c02417

Cited by 14 publications

(7 citation statements)

References 65 publications

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“…A detailed analysis of PM 2.5 compositions reveals that the decreased contribution of sulfate offsets the increased contribution of nitrate (Figure S11a in Supporting Information ), leading to the relatively stable ratio of secondary aerosols with typhoon influence in cities near mountains. Such decreased contribution of sulfate agrees with the recent findings that sulfate has the largest declined rate compared to other pollutants (Y. Li et al., 2023; Zheng et al., 2018). MERRA2 also captures the higher ratios of secondary aerosols in typhoon‐induced episodes than in no‐typhoon episodes but shows a slight decrease in ratios in typhoon‐induced episodes between the first and second 4 years (Figure S11b in Supporting Information ).…”

Section: Changes During 2014–2021 and The Implicationssupporting

confidence: 92%

“…Such decreased contribution of sulfate agrees with the recent findings that sulfate has the largest declined rate compared to other pollutants (Y. Li et al, 2023;Zheng et al, 2018). MERRA2 also captures the higher ratios of secondary aerosols in typhoon-induced episodes than in no-typhoon episodes but shows a slight decrease in ratios in typhoon-induced episodes between the first and second 4 years (Figure S11b in Supporting Information S1).…”

Section: Changes During 2014-2021 and The Implicationssupporting

confidence: 89%

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Impacts of Northward Typhoons on Autumn Haze Pollution Over North China Plain

Lin,

Ding,

Huang

et al. 2024

JGR Atmospheres

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Although air quality in China has improved substantially over recent years, haze pollution events still occur frequently, especially over the North China Plain (NCP). Previous studies showed that typhoons are conducive to regional pollution events in eastern China; however, the underlying mechanism and quantitative understanding of the typhoons' impact on haze pollution remain unclear there. Here, based on ground‐based and satellite observations, reanalysis data, and model simulations, we show that northward typhoons approaching China are essential for autumn haze pollution over NCP. Elevated relative humidity levels and enhanced pollution accumulation, caused by northward typhoons and the corresponding high‐pressure systems, are responsible for the pollution enhancements over NCP. Compared with episodes without typhoon influence, cities near Taihang and Yan Mountain suffer from heavier haze pollution when typhoons approach, with PM2.5 concentrations increasing from 87.1 to 106.4 μg m−3. More water vapor from the Yellow and Bohai Seas and pollutants from eastern China are transported to these cities by typhoon‐induced southeasterly wind anomalies, facilitating the chemical formation of aerosols there. In addition, by the block of mountains, these southeasterly wind anomalies also lead to stronger local accumulation over cities and an elevation of pollutants along the mountains. What is more, with the implementation of emission reduction, the relative changes of PM2.5 concentrations between typhoon‐induced episodes and no‐typhoon episodes increase. This work highlights the importance of understanding the impact of synoptical weather on PM2.5 transport, accumulation, and formation processes in haze pollution mitigation in eastern China.

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Section: Changes During 2014–2021 and The Implicationssupporting

confidence: 92%

Section: Changes During 2014-2021 and The Implicationssupporting

confidence: 89%

Impacts of Northward Typhoons on Autumn Haze Pollution Over North China Plain

Lin,

Ding,

Huang

et al. 2024

JGR Atmospheres

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“…26 The ambient temperature and relative humidity were obtained from the measurements on the Beijing 325 m meteorological tower. The detailed information on the sampling site is presented in Li et al 27 The gym HR-AMS data were analyzed with ToF-AMS HR Analysis 1.26 software in Igor Pro. The mass concentrations of NR-PM 1 species were determined using the previously calibrated ionization efficiency, 28 relative ionization efficiencies, and composition dependent collection efficiency.…”

Section: Methodsmentioning

confidence: 99%

“…The ambient temperature and relative humidity were obtained from the measurements on the Beijing 325 m meteorological tower. The detailed information on the sampling site is presented in Li et al…”

Section: Methodsmentioning

confidence: 99%

Particulate Siloxane and Cigarette Smoke Organic Aerosol in a Gym

Sun,

Li,

You

et al. 2024

Environ. Sci. Technol. Lett.

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Understanding the composition and concentration of pollutants in the gym environment is crucial for evaluating the potential health risks associated with physical exercise. Here submicron aerosol composition in a basement gym was characterized by a highresolution aerosol mass spectrometer. Our results showed higher fraction of organic aerosol (OA) in particulate matter indoors (50%) than outdoors (40%). Positive matrix factorization identified two distinct gym-related OA factors, i.e., siloxane OA (SiOA) and cigarette smoke OA (CSOA). Unexpectedly high concentrations of particulate siloxane, up to 6 μg m −3 and contributing 7−11% of OA were observed, and the variations of SiOA were strongly correlated with carbon dioxide emissions from human activities. The source of SiOA is likely from the lubricant of silicone polymers used in fitness equipment during exercise. Additionally, the presence of CSOA in the gym, on average contributing 6−7% of OA, is primarily linked to outdoor transport during ventilation. Our results highlight the significance of thorough investigations of air quality across different gyms with varying equipment, human occupancy, and ventilation conditions which is pivotal for implementing effective measures that ensure healthy indoor air quality and minimize potential health risks associated with exercise in gyms.

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“…In recent years, the Chinese Government has shifted its focus toward improving air quality, achieving notable success in reducing NO x emissions. − A model-based analysis indicates a 15% decline in NO x deposition over the China Sea Coastal region . The NO x emission inventory in Southeast Asia also shows a slight decreasing trend from 2013 to 2019 .…”

Section: Introductionmentioning

confidence: 99%

Increase in Agricultural-Derived NH_x and Decrease in Coal Combustion-Derived NO_x Result in Atmospheric Particulate N–NH₄⁺ Surpassing N–NO₃^– in the South China Sea

Zhang,

Li,

Zhang

et al. 2024

Environ. Sci. Technol.

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The atmospheric deposition of anthropogenic active nitrogen significantly influences marine primary productivity and contributes to eutrophication. The form of nitrogen deposition has been evolving annually, alongside changes in human activities. A disparity arises between observation results and simulation conclusions due to the limited field observation and research in the ocean. To address this gap, our study undertook three field cruises in the South China Sea in 2021, the largest marginal sea of China. The objective was to investigate the latest atmospheric particulate inorganic nitrogen deposition pattern and changes in nitrogen sources, employing nitrogen-stable isotopes of nitrate (δ 15 N−NO 3 − ) and ammonia (δ 15 N−NH 4 + ) linked to a mixing model. The findings reveal that the N−NH 4 + deposition generally surpasses N−NO 3 − deposition, attributed to a decline in the level of NO x emission from coal combustion and an upswing in the level of NH x emission from agricultural sources. The disparity in deposition between N−NH 4 + and N−NO 3 − intensifies from the coast to the offshore, establishing N−NH 4 + as the primary contributor to oceanic nitrogen deposition, particularly in ocean background regions. Fertilizer (33 ± 21%) and livestock (20 ± 6%) emerge as the primary sources of N−NH 4 + . While coal combustion continues to be a significant contributor to marine atmospheric N−NO 3 − , its proportion has diminished to 22 (Northern Coast)−35% (background area) due to effective NO x emission controls by the countries surrounding the South China Sea, especially the Chinese Government. As coal combustion's contribution dwindles, the significance of vessel and marine biogenic emissions grows. The daytime higher atmospheric N−NO 3 − concentration and lower δ 15 N−NO 3 − compared with nighttime further underscore the substantial role of marine biogenic emissions.

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Significant Reductions in Secondary Aerosols after the Three-Year Action Plan in Beijing Summer

Cited by 14 publications

References 65 publications

Impacts of Northward Typhoons on Autumn Haze Pollution Over North China Plain

Impacts of Northward Typhoons on Autumn Haze Pollution Over North China Plain

Particulate Siloxane and Cigarette Smoke Organic Aerosol in a Gym

Increase in Agricultural-Derived NH_x and Decrease in Coal Combustion-Derived NO_x Result in Atmospheric Particulate N–NH₄⁺ Surpassing N–NO₃^– in the South China Sea

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Significant Reductions in Secondary Aerosols after the Three-Year Action Plan in Beijing Summer

Cited by 14 publications

References 65 publications

Impacts of Northward Typhoons on Autumn Haze Pollution Over North China Plain

Impacts of Northward Typhoons on Autumn Haze Pollution Over North China Plain

Particulate Siloxane and Cigarette Smoke Organic Aerosol in a Gym

Increase in Agricultural-Derived NHx and Decrease in Coal Combustion-Derived NOx Result in Atmospheric Particulate N–NH4+ Surpassing N–NO3– in the South China Sea

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Product

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Increase in Agricultural-Derived NH_x and Decrease in Coal Combustion-Derived NO_x Result in Atmospheric Particulate N–NH₄⁺ Surpassing N–NO₃^– in the South China Sea