Non-agricultural sources dominate the atmospheric NH3 in Xi'an, a megacity in the semi-arid region of China

Wu, Chengdong; Wang, Gehui; Li, Jin; Li, Jianjun; Cao, Cong; Ge, Shuangshuang; Xie, Yuning; Chen, Jianmin; Liu, Shijie; Du, Wei; Zhao, Zhu‐Yu; Cao, Fang

doi:10.1016/j.scitotenv.2020.137756

Cited by 59 publications

(29 citation statements)

References 60 publications

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“…The data was observed at 95% confidence level indicating a strong relation between PM 2.5 and COVID-19 spreading and deaths. Therefore, the above authors have concluded that their results underscore the importance of continuing to enforce existing air pollution regulations to protect human health under COVID-19 pandemic (Wu et al 2020a , b , c ). Similar observations are also observed in cities of China, India, Britain, Italy, and the Netherlands etc.…”

Section: Covid-19 Severity Under High Air Pollutionmentioning

confidence: 92%

“…Particulate matters are “a complex mixture of extremely small particles and liquid droplets, made up of acids, organic chemicals, metals, and soil or dust particles” (Li et al 2018 ). A very recent study in the United States indicates that an elevation of only 1 μg m −3 in PM 2.5 is associated with a rise in 8% COVID-19-induced death rate (Wu et al 2020a , b , c ). The data was observed at 95% confidence level indicating a strong relation between PM 2.5 and COVID-19 spreading and deaths.…”

Section: Covid-19 Severity Under High Air Pollutionmentioning

confidence: 99%

“…Most of the aerosols found in the air are resulted from the anthropogenic activities that produced fine, very fine and ultra-fine particles. They are also produced following gas-to-particle conversion processes (Li et al 2020 ; Wu et al 2020a ). If the quantity of aerosols increases to large quantities, it increases the level of air pollution.…”

Section: Covid-19 Severity Under High Air Pollutionmentioning

confidence: 99%

“…The COVID-19 disease had positive effects on the selfregeneration process of nature. Air, water and noise pollution were reduced in many parts of the planet because of the stationary activity of humans (Wang et al 2020a). Humans are now off the street and self-locked inside home to avoid SARS-CoV-2 infection (Paital et al 2020a, b).…”

Section: Introductionmentioning

confidence: 99%

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Air pollution by NO2 and PM2.5 explains COVID-19 infection severity by overexpression of angiotensin-converting enzyme 2 in respiratory cells: a review

2020

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Many major cities that witnessed heavy air pollution by nitrogen dioxide (NO 2) and particulate matter (PM) have experienced a high rate of infection and severity of the coronavirus disease pandemic (COVID-19). This phenomenon could be explained by the overexpression of the angiotensin converting enzyme 2 (ACE-2) on epithelial cell surfaces of the respiratory tract. Indeed, ACE-2 is a receptor for coronaviruses including the severe acute respiratory syndrome coronavirus 1 and 2 (SARS-CoV), and ACE-2 is overexpressed under chronic exposure to air pollution such as NO 2 and PM 2.5. In this review, we explain that ACE-2 acts as the sole receptor for the attachment of the SARS-CoV-2 via its spike protein. The fact that respiratory and vascular epithelial cells express ACE-2 has been previously observed during the 2003 epidemic of the SARS-CoV-1 in China, and during the 2012 Middle East respiratory syndrome in Saudi Arabia. High ACE-2 expression in respiratory epithelial cells under air pollution explains the positive correlation between the severity in COVID-19 patients and elevated air pollution, notably high NO 2 and PM 2.5 levels. Specific areas in India, China, Italy, Russia, Chile and Qatar that experience heavy air pollution also show high rates of COVID-19 infection and severity. Overall, we demonstrate a link between NO 2 emissions, PM 2.5 levels, ACE-2 expression and COVID-19 infection severity. Therefore, air pollution should be reduced in places where confirmed cases of COVID-19 are unexpectedly high.

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Section: Covid-19 Severity Under High Air Pollutionmentioning

confidence: 92%

Section: Covid-19 Severity Under High Air Pollutionmentioning

confidence: 99%

Section: Covid-19 Severity Under High Air Pollutionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Air pollution by NO2 and PM2.5 explains COVID-19 infection severity by overexpression of angiotensin-converting enzyme 2 in respiratory cells: a review

2020

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“…Their study and an earlier study from Felix et al (2014) highlighted the importance of fossil fuel related sources (e.g., vehicular exhaust, NH 3 slip from Selective Catalytic Reduction (SCR) equipped power plants, and coal combustion) based on isotope-based source apportionment of δ 15 N(NH 4 + ) and δ 15 N(NH 3 ) values, respectively. Thereafter a number of studies suggested that fossil fuel related sources may be an important source of NH 4 + and NH 3 in urban atmosphere in China based on source apportionment of δ 15 N(NH 4 + ) values (Liu et al, 2018;Pan et al, 2018a;Wu et al, 2019a;Wu et al, 2019b;Bhattarai et al, 2020;Wu et al, 2020;Xiao et al, 2020;Zhang et al, 2020c) and δ 15 N(NH 3 ) values (Chang et al, 2016;Chang et al, 2019;Bhattarai et al, 2020;Zhang et al, 2020a;Zhang et al, 2020b), respectively.…”

Section: Introductionmentioning

confidence: 99%

δ15N-stable isotope analysis of NHx: An overview on analytical measurements, source sampling and its source apportionment

Bhattarai

Pan

Tian

et al. 2021

Front. Environ. Sci. Eng.

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Agricultural sources and non-agricultural emissions contribute to gaseous ammonia (NH 3) that plays a vital role in severe haze formation. Qualitative and quantitative contributions of these sources to ambient PM 2.5 (particulate matter with an aerodynamic equivalent diameter below 2.5 µm) concentrations remains uncertain. Stable nitrogen isotopic composition (δ 15 N) of NH 3 and NH 4 + (δ 15 N(NH 3) and δ 15 N(NH 4 +), respectively) can yield valuable information about its sources and associated processes. This review provides an overview of the recent progress in analytical techniques for δ 15 N(NH 3) and δ 15 N(NH 4 +) measurement, sampling of atmospheric NH 3 and NH 4 + in the ambient air and their sources signature (e.g., agricultural vs. fossil fuel), and isotope-based source apportionment of NH 3 in urban atmosphere. This study highlights that collecting sample that are fully representative of emission sources remains a challenge in fingerprinting δ 15 N(NH 3) values of NH 3 emission sources. Furthermore, isotopic fractionation during NH 3 gas-to-particle conversion under varying ambient field conditions (e.g., relative humidity, particle pH, temperature) remains unclear, which indicates more field and laboratory studies to validate theoretically predicted isotopic fractionation are required. Thus, this study concludes that lack of refined δ 15 N(NH 3) fingerprints and full understanding of isotopic fractionation during aerosol formation in a laboratory and field conditions is a limitation for isotope-based source apportionment of NH 3. More experimental work (in chamber studies) and theoretical estimations in combinations of field verification are necessary in characterizing isotopic fractionation under various environmental and atmospheric neutralization conditions, which would help to better interpret isotopic data and our understanding on NH x (NH 3 + NH 4 +) dynamics in the atmosphere.

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Impact of Lockdown on Air Quality in Megacities of India During COVID-19 Pandemic

Khobragade

Ahirwar²

2022

Society of Earth Scientists Series

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Non-agricultural sources dominate the atmospheric NH3 in Xi'an, a megacity in the semi-arid region of China

Cited by 59 publications

References 60 publications

Air pollution by NO2 and PM2.5 explains COVID-19 infection severity by overexpression of angiotensin-converting enzyme 2 in respiratory cells: a review

Air pollution by NO2 and PM2.5 explains COVID-19 infection severity by overexpression of angiotensin-converting enzyme 2 in respiratory cells: a review

δ15N-stable isotope analysis of NHx: An overview on analytical measurements, source sampling and its source apportionment

Impact of Lockdown on Air Quality in Megacities of India During COVID-19 Pandemic

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