Unexpected air pollution with marked emission reductions during the COVID-19 outbreak in China

Science, Год журнала: 2020, Номер 369(6504), С. 702 - 706

Опубликована: Июнь 17, 2020

Air pollution epidemic The lockdown enforced in most cities China response to the outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) resulted virtual absence motor vehicle traffic and sharply reduced manufacturing activity for several weeks. Le et al. report some anticipated unanticipated effects that this had on air there, including unexpectedly high levels particulate matter abundances haze formation areas. This natural experiment will help assessment mitigation strategies. Science , issue p. 702

Язык: Английский

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Impact of city lockdown on the air quality of COVID-19-hit of Wuhan city

The Science of The Total Environment, Год журнала: 2020, Номер 742, С. 140556 - 140556

Опубликована: Июнь 30, 2020

Язык: Английский

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Volatile Organic Compounds (VOCs) as Environmental Pollutants: Occurrence and Mitigation Using Nanomaterials

International Journal of Environmental Research and Public Health, Год журнала: 2021, Номер 18(24), С. 13147 - 13147

Опубликована: Дек. 13, 2021

Volatile organic compounds (VOCs) comprise various chemicals which are released as gases from different liquids or solids. The nature and impact of the health effects dependent on VOCs concentrations and, also, exposure time. present in household, industrial commercial products, but their accumulation air water has primarily gained attention. Among VOCs, trichloroethylene vinyl chloride most toxic carcinogenic compounds. In order to improve indoor quality, can be removed via efficient approaches involving nanomaterials, by using techniques such adsorption, catalysis photocatalysis. recent years, development manufacturing procedures, characterization testing processes resulted growth na-nomaterials obtaining applications, creating great possibilities also a tremendous prov-ocation applying them for highly removal. This review is intended contrib-ute improvement awareness knowledge potential that nanomaterials have removal, outdoor environment, worldwide sources.

Язык: Английский

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Enhanced secondary pollution offset reduction of primary emissions during COVID-19 lockdown in China

EarthArXiv (California Digital Library), Год журнала: 2020, Номер unknown

Опубликована: Апрель 13, 2020

To control the spread of 2019 novel coronavirus (COVID-19), China imposed nationwide restrictions on movement its population (lockdown) after Chinese New Year 2020, leading to large reductions in economic activities and associated emissions. Despite such decreases primary pollution, there were nonetheless several periods heavy haze pollution East China, raising questions about well-established relationship between human air quality. Here, using comprehensive measurements modeling, we show during COVID lockdown driven by enhancements secondary pollution. In particular, NOx emissions from transportation increased ozone nighttime NO3 radical formation, these increases atmospheric oxidizing capacity turn facilitated formation particulate matter. Our results, afforded tragic natural experiment COVID-19 pandemic, indicate that mitigation depends upon a coordinated balanced strategy for controlling multiple pollutants.

Язык: Английский

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Explosive Secondary Aerosol Formation during Severe Haze in the North China Plain

Environmental Science & Technology, Год журнала: 2021, Номер 55(4), С. 2189 - 2207

Опубликована: Фев. 4, 2021

Severe haze events with exceedingly high-levels of fine aerosols occur frequently over the past decades in North China Plain (NCP), exerting profound impacts on human health, weather, and climate. The development effective mitigation policies requires a comprehensive understanding formation mechanisms, including identification quantification sources, formation, transformation aerosol species. Haze evolution this region exhibits distinct physical chemical characteristics from clean to polluted periods, as evident increasing stagnation relative humidity, but decreasing solar radiation well explosive secondary formation. latter is attributed highly elevated concentrations precursor gases reflected by rapid increases particle number mass concentrations, both corresponding nonequilibrium processes. Considerable new knowledge has been acquired understand processes regulating particularly light progress elucidating mechanisms. This review synthesizes recent advances highlighting several critical chemical/physical processes, that is, growth driven photochemistry aqueous chemistry interaction between atmospheric stability. Current challenges future research priorities are also discussed.

Язык: Английский

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The Synergistic Role of Sulfuric Acid, Bases, and Oxidized Organics Governing New‐Particle Formation in Beijing

Geophysical Research Letters, Год журнала: 2021, Номер 48(7)

Опубликована: Март 22, 2021

Abstract Intense and frequent new particle formation (NPF) events have been observed in polluted urban environments, yet the dominant mechanisms are still under debate. To understand key species governing processes of NPF we conducted comprehensive measurements downtown Beijing during January–March, 2018. We performed detailed analyses on sulfuric acid cluster composition budget, as well chemical physical properties oxidized organic molecules (OOMs). Our results demonstrate that fast clustering (H 2 SO 4 ) base triggered events, OOMs further helped grow newly formed particles toward climate‐ health‐relevant sizes. This synergistic role H , species, is likely representative environments where abundant usually co‐exist, with moderately low volatility when produced high NO x concentrations.

Язык: Английский

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Continuous and comprehensive atmospheric observations in Beijing: a station to understand the complex urban atmospheric environment

Big Earth Data, Год журнала: 2020, Номер 4(3), С. 295 - 321

Опубликована: Июль 2, 2020

Due to profound impact on climate and human health, air quality has attracted attention from all levels of the civil society. The key step in provision required tools for society tackle complex problem is characterize it a comprehensive manner with long-term perspective. Here, we describe continuous observation station its accompanying state-of-the-art instrumentation that was established investigate urban atmospheric environment rapidly developing Chinese Megacity. station, located downtown Beijing, aims study by identifying major pollutants processes determining their formation loss mechanisms. A few hundreds parameters are continuously measured instruments, including trace gas concentrations, aerosol particle size distributions, mass covering chemical composition molecules micrometer-sized particles. This produced long-term, big data around 1×1011 bytes per year. In this paper, provide an overview facilities used, workflow observations examples results 2018 2019 basis establishing modern other megacities.

Язык: Английский

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Source–Receptor Relationship Revealed by the Halted Traffic and Aggravated Haze in Beijing during the COVID-19 Lockdown

Environmental Science & Technology, Год журнала: 2020, Номер 54(24), С. 15660 - 15670

Опубликована: Ноя. 23, 2020

The COVID-19 outbreak greatly limited human activities and reduced primary emissions particularly from urban on-road vehicles but coincided with Beijing experiencing "pandemic haze," raising the public concerns about effectiveness of imposed traffic policies to improve air quality. This paper explores relationship between local vehicle winter haze in before during lockdown based on an integrated analysis framework, which combines a real-time emission inventory, situ quality observations, localized numerical modeling system. We found that decreased substantially pandemic, its imbalanced abatement NOx (76%, 125.3 Mg/day) volatile organic compounds (VOCs, 53%, 52.9 led significant rise atmospheric oxidants areas, resulting modest increase secondary aerosols due inadequate precursors, still offset emissions. Moreover, enhanced oxidizing capacity surrounding regions increased particles relatively abundant was transported into mainly responsible for aggravated pollution. recommend mitigation should focus accelerating VOC reduction synchronously controlling regional sources release benefits control.

Язык: Английский

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Aerosol–photolysis interaction reduces particulate matter during wintertime haze events

Proceedings of the National Academy of Sciences, Год журнала: 2020, Номер 117(18), С. 9755 - 9761

Опубликована: Апрель 16, 2020

Significance Aerosol–radiation interaction (ARI) not only constitutes one of the major uncertainties in climate prediction, but also significantly deteriorates particulate matter (PM) pollution during heavy haze events. However, modification photolysis caused by aerosol absorbing and/or scattering solar radiation (referred to as aerosol–photolysis or API) changes atmospheric oxidizing capability and influences secondary formation. The synergetic effect API ARI on PM is quantitatively assessed a persistent episode from modeling perspective study. results reveal that hinders formation substantially mitigates ARI. Future research radiative forcing essential improve understanding effect.

Язык: Английский

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The promotion effect of nitrous acid on aerosol formation in wintertime in Beijing: the possible contribution of traffic-related emissions

Atmospheric chemistry and physics, Год журнала: 2020, Номер 20(21), С. 13023 - 13040

Опубликована: Ноя. 7, 2020

Abstract. Secondary aerosols are a major component of PM2.5, yet their formation mechanisms in the ambient atmosphere still unclear. Based on field measurements downtown Beijing, we show that photolysis nitrous acid (HONO) may promote organic and nitrate winter which is supported by fact mass concentrations linearly increase as function HONO consumed from early morning to noon. The increased content also leads ammonium particulate matter through enhancing neutralization sulfate ammonia. We further illustrate during pollution events over 50 % be related traffic-related emissions, including direct emissions via reaction between OH vehicle-emitted NO. Overall, our results indicate play an important role oxidative capacity turn contribute haze Beijing. mitigation NOx vehicles effective way reduce secondary severe

Язык: Английский

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