Nonuniform impacts of COVID-19 lockdown on air quality over the United States.

ABSTRACT: Most of the state governments in United States (U.S.) issued lockdown or business restrictions amid the COVID-19 pandemic in March 2020, which created a unique opportunity to evaluate the air quality response to reduced economic activities. Data acquired from 28 long-term air quality stations across the U.S. revealed widespread but nonuniform reductions of nitrogen dioxide (NO₂) and carbon monoxide (CO) during the first phase of lockdown (March 15-April 25, 2020) relative to a pre-lockdown reference period and historical baselines established in 2017-2019. The reductions, up to 49% for NO₂ and 37% for CO, are statistically significant at two thirds of the sites and tend to increase with local population density. Significant reductions of particulate matter (PM_2.5

SUBMITTER: Chen LA 

PROVIDER: S-EPMC7373013 | biostudies-literature | 2020 Nov

REPOSITORIES: biostudies-literature