Impacts of the COVID-19 economic slowdown on ozone pollution in the U.S.

Campbell, Patrick; Tong, Daniel; Tang, Youhua; Baker, Barry; Lee, Pius; Saylor, Rick; Stein, Ariel; Ma, Siqi; Lamsal, L. N.; Qu, Zhen

doi:10.1016/j.atmosenv.2021.118713

Cited by 25 publications

(33 citation statements)

References 44 publications

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“…These studies suggest that the increases in surface ozone could be due to a weakening of a titration effect on ozone in accordance with 2020 meteorological conditions and relative levels of NO x versus VOC reductions. Campbell et al (2021) and Parker et al (2022) also show increases up to about +40% for near-surface ozone concentrations in spring-summer 2020 over the US in urban environments. Campbell et al (2021) further describe the complex nature of the BL chemistry (NO x limited vs. VOC limited) whereby the widespread emission decreases in the US in 2020 in a general sense led to increases of BL ozone in urban areas, but widespread decreases in rural regions.…”

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confidence: 93%

“…A result was unprecedented decreases in Northern Hemisphere (NH) pollution including important ozone precursors nitrogen oxides (NO x = nitric oxide [NO] + nitrogen dioxide [NO 2 ]) and Volatile Organic Compounds (VOCs). The decreases in pollution and subsequent changes in tropospheric ozone, particularly in the NH, has led to a large number of published articles on this subject (e.g., Bauwens et al., 2020 ; Bouarar et al., 2021 ; Bray et al., 2021 ; Campbell et al., 2021 ; Elshorbany et al., 2021 ; Jensen et al., 2021 ; Keller et al., 2021 ; Liu et al., 2020 ; Miyazaki et al., 2021 ; Pakkattil et al., 2021 ; Sicard et al., 2020 ; Stavrakou et al., 2021 ; Steinbrecht et al., 2021 ). These studies have shown numerous cases of large reductions in NO 2 , VOCs, and other pollutants in the troposphere including free‐tropospheric ozone during spring‐summer 2020 that reached 5%–10% deficits or greater throughout the NH, particularly in urban environments.…”

Section: Introductionmentioning

confidence: 99%

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NASA Satellite Measurements Show Global‐Scale Reductions in Free Tropospheric Ozone in 2020 and Again in 2021 During COVID‐19

Ziemke

Kramarova

Frith

et al. 2022

Geophysical Research Letters

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In early 2020, soon after the beginning of the global COronaVIrus Disease 2019 (COVID-19) pandemic, extensive international efforts were taken in attempt to reduce the spread of the virus. These efforts included lockdowns and reduced activities of many private and public businesses, schools, and travel. A result was unprecedented decreases in Northern Hemisphere (NH) pollution including important ozone precursors nitrogen oxides (NO x = nitric oxide [NO] + nitrogen dioxide [NO 2 ]) and Volatile Organic Compounds (VOCs). The decreases in pollution and subsequent changes in tropospheric ozone, particularly in the NH, has led to a large number of published articles on this subject (e.g.,

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mentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

NASA Satellite Measurements Show Global‐Scale Reductions in Free Tropospheric Ozone in 2020 and Again in 2021 During COVID‐19

Ziemke

Kramarova

Frith

et al. 2022

Geophysical Research Letters

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“…Campbell et al. ( 2021 ) used the NOAA forecasting system and observations to examine 2020 changes and found a complex pattern of increases and decreases, depending on location and time of year. Jing and Goldberg ( 2022 ) examined mean 2020 NO 2 and O 3 changes for the Chicago region and found no significant change in mean O 3 concentrations, which they attributed to the presence of hotter than normal conditions.…”

Section: Introductionmentioning

confidence: 99%

“…Some studies have identified small reductions in free tropospheric O 3 concentrations over the Northern Hemisphere (Chang et al, 2022;Steinbrecht et al, 2021), which reverses the earlier trends (Gaudel et al, 2020). Campbell et al (2021) used the NOAA forecasting system and observations to examine 2020 changes and found a complex pattern of increases and decreases, depending on location and time of year. Jing and Goldberg (2022) examined mean 2020 NO 2 and O 3 changes for the Chicago region and found no significant change in mean O 3 concentrations, which they attributed to the presence of hotter than normal conditions.…”

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confidence: 99%

NO_x and O₃ Trends at U.S. Non‐Attainment Areas for 1995–2020: Influence of COVID‐19 Reductions and Wildland Fires on Policy‐Relevant Concentrations

2022

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Surface ozone (O 3 ) is formed from photochemical reactions of nitrogen oxides (NO x = NO + NO 2 ) and volatile organic compounds (VOCs). O 3 has serious health impacts up to and including premature mortality (Bell et al., 2004;Di et al., 2017). In the U.S., reductions in NO x and VOCs over the past several decades have reduced peak O 3 concentrations considerably (Simon et al., 2015), but at present, there are still more than 100 million Americans living in areas that do not meet the O 3 standard (American Lung Association (ALA), 2020). For O 3 , the U.S. National Ambient Air Quality Standards (NAAQS) is based on the annual fourth highest maximum daily 8-hr average (MDA8) concentration. To be in compliance with the 2015 8-hr O 3 standard, each monitor in a region must have a 3-year average of the fourth highest MDA8 of 70 ppb or less. Using data from 2018 to 2020, the U.S. Environmental Protection Agency (EPA) reports that there are 52 regions in the U.S. that are considered non-attainment areas (NAAs) for the 2015 standard (https://www.epa.gov/air-trends/air-quality-design-values). Most of these NAAs are in large metropolitan areas. However, some areas have relatively low emissions but are downwind of a major metropolitan area. Simon et al. (2015) report downward trends for U.S. anthropogenic NO x and VOCs emissions of 39% and 14%, respectively, for 2002-2011. Hidy and Blanchard (2015) report a near linear relationship between peak

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“…Zeng et al ( 2018 ) found that the reduction ratio of the VOCs to NO x concentrations should not be lower than 0.73 to control O 3 pollution. During the Level I Response period, traffic restrictions decreased NO x emission more than it reduced VOCs emission, thereby resulting in a higher VOC/NO x ratio and increased O 3 production (Brancher, 2021 ; Campbell et al, 2021 ). Shanghai, Wuhan, and Tangshan had different levels of traffic development, so the different changes in the precursors of O 3 (i.e., in VOCs and NO x ) would directly result in different increases of the O 3 concentration among three cities.…”

Section: Discussionmentioning

confidence: 99%

Diverse spillover effects of COVID-19 control measures on air quality improvement: evidence from typical Chinese cities

Zhao

Wang

Zhang

et al. 2022

Environ Dev Sustain

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The COVID-19 prevention and control measures are taken by China’s government, especially traffic restrictions and production suspension, had spillover effects on air quality improvement. These effects differed among cities, but these differences have not been adequately studied. To provide more knowledge, we studied the air quality index ( AQI ) and five air pollutants (PM 2.5 , PM 10 , SO 2 , NO 2 , and O 3 ) before and after the COVID-19 outbreak in Shanghai, Wuhan, and Tangshan. The pollution data from two types of monitoring stations (traffic and non-traffic stations) were separately compared and evaluated. We used monitoring data from the traffic stations to study the emission reduction caused by traffic restrictions. Based on monitoring data from the non-traffic stations, we established a difference-in-difference model to study the emission reduction caused by production suspension. The COVID-19 control measures reduced AQI and the concentrations of all pollutants except O 3 (which increased greatly), but the magnitude of the changes differed among the three cities. The control measures improved air quality most in Wuhan, followed by Shanghai and then Tangshan. We investigated the reasons for these differences and found that differences in the characteristics of these three types of cities could explain these differences in spillover effects. Understanding these differences could provide some guidance and support for formulating differentiated air pollution control measures in different cities. For example, whole-process emission reduction technology should be adopted in cities with the concentrated distribution of continuous process enterprises, whereas vehicles that use cleaner energy and public transport should be vigorously promoted in cities with high traffic development level.

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Impacts of the COVID-19 economic slowdown on ozone pollution in the U.S.

Cited by 25 publications

References 44 publications

NASA Satellite Measurements Show Global‐Scale Reductions in Free Tropospheric Ozone in 2020 and Again in 2021 During COVID‐19

NASA Satellite Measurements Show Global‐Scale Reductions in Free Tropospheric Ozone in 2020 and Again in 2021 During COVID‐19

NO_x and O₃ Trends at U.S. Non‐Attainment Areas for 1995–2020: Influence of COVID‐19 Reductions and Wildland Fires on Policy‐Relevant Concentrations

Diverse spillover effects of COVID-19 control measures on air quality improvement: evidence from typical Chinese cities

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Impacts of the COVID-19 economic slowdown on ozone pollution in the U.S.

Cited by 25 publications

References 44 publications

NASA Satellite Measurements Show Global‐Scale Reductions in Free Tropospheric Ozone in 2020 and Again in 2021 During COVID‐19

NASA Satellite Measurements Show Global‐Scale Reductions in Free Tropospheric Ozone in 2020 and Again in 2021 During COVID‐19

NOx and O3 Trends at U.S. Non‐Attainment Areas for 1995–2020: Influence of COVID‐19 Reductions and Wildland Fires on Policy‐Relevant Concentrations

Diverse spillover effects of COVID-19 control measures on air quality improvement: evidence from typical Chinese cities

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Product

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NO_x and O₃ Trends at U.S. Non‐Attainment Areas for 1995–2020: Influence of COVID‐19 Reductions and Wildland Fires on Policy‐Relevant Concentrations