key: cord-0933025-wuce2xss authors: Chen, Kevin L.; Henneman, Lucas R.F.; Nethery, Rachel C. title: Differential Impacts of COVID-19 Lockdowns on PM [Formula: see text] across the United States date: 2021-10-07 journal: Environ Adv DOI: 10.1016/j.envadv.2021.100122 sha: 1469c4e7613de96b81066f15aa6a05af2c74a661 doc_id: 933025 cord_uid: wuce2xss The COVID-19 pandemic has induced large-scale behavioral changes, presenting a unique opportunity to study how air pollution is affected by societal shifts. At 455 PM [Formula: see text] monitoring sites across the United States, we conduct a causal inference analysis to determine the impacts of COVID-19 lockdowns on PM [Formula: see text]. Our approach allows for rigorous confounding adjustment with highly spatio-temporally resolved effect estimates. We find that, with the exception of the Southwest, most of the US experienced increases in PM [Formula: see text] compared to concentrations expected under business-as-usual. To investigate possible drivers of this phenomenon, we use a regression model to characterize the relationship of various factors with the observed impacts. Our findings have immense environmental policy relevance, suggesting that mobility reductions alone may be insufficient to substantially and uniformly reduce PM [Formula: see text]. as government-imposed stay-at-home orders, in response to the rapid spread 18 of the virus. The unprecedented actions taken to curb the spread of COVID-19 19 have created a unique "quasi-experiment" that can be leveraged to study 20 the effect of large-scale behavioral change on air quality. 21 Exposure to fine particle matter, PM 2.5 , has been shown to have signif- Table 212 A.2. across counties within each US region to obtain the results displayed in Table 332 2. The values in Table 2 Additionally, we note that total PM 2.5 is only one aspect of air pollution 366 that is relevant to human health. While we report lockdown-attributable Our study has found that the impacts of the 2020 COVID-19 lockdowns 378 on PM 2.5 levels vary dramatically across the US, with strong regional trends. In the Midwestern and Southern regions, we unexpectedly observe consistent Gard-411 ner, Association between mobility patterns and COVID-19 transmission 412 in the USA: a mathematical modelling study More-418 land Timing of Commu-422 nity Mitigation and Changes in Reported COVID-19 and Community Statewide COVID-19 Stay Orders and Population Mobility in the United States, World Medical & 429 Health Epidemiology of fine particulate air pollution and hu-432 man health: biologic mechanisms and who's at risk?, Environmental 433 The impact of PM2.5 437 on the human respiratory system Fine Particulate Air Pollution and Hospital Ad-442 mission for Cardiovascular and Respiratory Diseases Impact of lockdown measures to combat covid-19 on air quality over 480 western europe Estimating lockdown-induced european NO2 changes using satellite and 489 surface observations and air quality models, Atmospheric Chemistry and 490 Impacts of the COVID-19 lockdown 494 on air pollution at regional and urban background sites in northern 495 italy Changes in air quality and human mobility in the USA during the COVID-19 pandemic Environmental Protection Agency, Our Nation's Air COVID-19 US state policy database Air Quality System Data Mart Google Earth Engine: Planetary-scale geospatial analysis for everyone Synthetic control methods 516 for comparative case studies: Estimating the effect of Californias to-517 bacco control program Generalized Synthetic Control Method: Causal Inference with 520 Interactive Fixed Effects Models Matrix Completion Methods for Causal Panel Data Models Effects of COVID-19 lockdown on global 527 air quality and health The short-term impacts of COVID-19 lock-531 down on urban air pollution in china Protecting 535 privacy in Facebook mobility data during the COVID-19 response American Community Survey 5-Year 539 National Emissions 541 Inventory NCHS urban-rural classification scheme for 547 counties Environmental Benefits Map-549 ping and Analysis Program Community Edition Acute and Chronic Effects of Particles on Hospital 552 Admissions Assessment of the health impacts of particulate matter char-556 acteristics a system-561 atic analysis for the global burden of disease study Changes in U.S. air pollution during the 565 COVID-19 pandemic Changes in criteria air pollution levels in 570 the US before, during, and after covid-19 stay-at-home orders: Evidence 571 from regulatory monitors