Air Quality Implications of COVID-19 in California

Abstract

The COVID-19 pandemic has significantly affected human health and the economy. The implementation of social distancing practices to combat the virus spread, however, has led to a notable improvement in air quality. This study compared the surface air quality monitoring data from the United States Environmental Protection Agency (U.S. EPA)’s AirNow network during the period 20 March–5 May in 2020 to those in 2015–2019 from the Air Quality System (AQS) network over the state of California. The results indicated changes in fine particulate matter (PM2.5) of −2.04 ± 1.57 μg m−3 and ozone of −3.07 ± 2.86 ppb. If the air quality improvements persist over a year, it could potentially lead to 3970–8900 prevented premature deaths annually (note: the estimates of prevented premature deaths have large uncertainties). Public transit demand showed dramatic declines (~80%). The pandemic provides an opportunity to exhibit how substantially human behavior could impact on air quality. To address both the pandemic and climate change issues, better strategies are needed to affect behavior, such as ensuring safer shared mobility, the higher adoption of telecommuting, automation in the freight sector, and cleaner energy transition.

Modeling the impact of COVID-19 on air quality in southern California: implications for future control policies

“…Similar findings, i.e., reduced PM 2.5 and NO 2 concentrations, are also reported for China (e.g., Chu et al, 2021;Le et al, 2020;Liu et al, 2020;Marlier et al, 2020;Shi and Brasseur, 2020;Miyazaki et al, 2020b), India (e.g., Pathakoti et al, 2020;Sharma et al, 2020), and Europe (e.g., Chen et al, 2020;Menut et al, 2020;Sicard et al, 2020;Ordóñez et al, 2020) based on surface and/or satellite observations. For O 3 , the concentrations either increased or slightly decreased during the pandemic, depending on the region (Bekbulat et al, 2020;Huang et al, 2021;Pan et al, 2020;Zhao et al, 2020). Most of the above studies, however, are limited to comparing observations with and without lockdown measures, which correspond to different time periods under different meteorological conditions.…”

“…For example, Archer et al (2020) compared the observed concentrations at all available ground monitoring sites in the US between April 2020 and the prior 5 years (2015)(2016)(2017)(2018)(2019) and found statistically significant decreases in NO 2 concentrations at more than 65 % of the monitoring sites, with an average drop of 2 ppb. Pan et al (2020) compared the surface air quality monitoring data in California during the period 20 March-5 May 2020 with those in 2015-2019 and found that PM 2.5 in 2020 exhibited a notable decrease, which could result from emission reductions associated with the COVID-19 lockdown. Similar findings, i.e., reduced PM 2.5 and NO 2 concentrations, are also reported for China (e.g., Chu et al, 2021;Le et al, 2020;Liu et al, 2020;Marlier et al, 2020;Shi and Brasseur, 2020;Miyazaki et al, 2020b), India (e.g., Pathakoti et al, 2020;Sharma et al, 2020), and Europe (e.g., Chen et al, 2020;Menut et al, 2020;Sicard et al, 2020;Ordóñez et al, 2020) based on surface and/or satellite observations.…”

“…Pan et al (2020) compared the surface air quality monitoring data in California during the period 20 March-5 May 2020 with those in 2015-2019 and found that PM 2.5 in 2020 exhibited a notable decrease, which could result from emission reductions associated with the COVID-19 lockdown. Similar findings, i.e., reduced PM 2.5 and NO 2 concentrations, are also reported for China (e.g., Chu et al, 2021;Le et al, 2020;Liu et al, 2020;Marlier et al, 2020;Shi and Brasseur, 2020;Miyazaki et al, 2020b), India (e.g., Pathakoti et al, 2020;Sharma et al, 2020), and Europe (e.g., Chen et al, 2020;Menut et al, 2020;Sicard et al, 2020;Ordóñez et al, 2020) based on surface and/or satellite observations. For O 3 , the concentrations either increased or slightly decreased during the pandemic, depending on the region (Bekbulat et al, 2020;Huang et al, 2021;Pan et al, 2020;Zhao et al, 2020).…”

The global impacts of COVID-19 lockdowns on urban air pollution

“…Brazil: (Dantas et al, 2020;Krecl et al, 2020;Nakada and Urban, 2020;Siciliano et al, 2020a) Other: (Mendez-Espinosa et al, 2020;Pacheco et al, 2020;Zalakeviciute et al, 2020;Zambrano-Monserrate and Ruano, 2020) Europe Multiple countries: (Baldasano, 2020;Collivignarelli et al, 2020;Filippini et al, 2020;Gautam, 2020a;Giani et al, 2020;Gualtieri et al, 2020;Higham et al, 2020;Ljubenkov et al, 2020;Sicard et al, 2020;Tobías et al, 2020;Martorell-Marugán et al, 2021) Oceania Australia: (Fu et al, 2020) New Zealand: (Patel et al, 2020) Africa Morocco: (Ass et al, 2020;Otmani et al, 2020) This includes the "discussed but not corrected" and "not discussed or corrected" categories in Figure 2. (Zheng et al, 2020), and Tianjin (Dai et al, 2020), China.…”

Remote-Working Carbon-Saving Footprint: Could COVID-19 Pandemic Establish a New Working Model with Positive Environmental Health Implications?

“…15 Of note, a separate study, that confirmed reductions in ozone (O 3 ) and PM 2.5 in California (USA), has estimated thousands of air pollution-related premature deaths prevented annually in California, due to an assumed persistence of the ongoing air quality improvement. 16 Therefore, it becomes obvious that the improvement of the urban air quality can be easily controlled by simple interventions, and proper traffic management. Remote-working, since it drastically reduces the number of vehicles moving in the cities, may serve as an indirect traffic management control measure.…”