Impact of Covid-19 Lockdown on Ambient Air Pollution (PM2.5, PM10, and Ozone) and Respiratory Health (Asthma and COPD): Analyzing Regional Trends and Sociodemographic Disparities in North Carolina from 2020-2022

Abstract

"The coronavirus disease 2019 (COVID-19) pandemic prompted unprecedented public health interventions. Yet, limited empirical research has examined how state-mandated lockdowns affected environmental conditions and respiratory health among vulnerable populations, including young children with asthma and chronic obstructive pulmonary disease (COPD) and older adults with chronic comorbidities. Existing literature demonstrates that air pollution, particularly particulate matter (PM) in the form of PM2.5 and PM10, and ground-level ozone (O3), is strongly associated with exacerbations of asthma and COPD; however, few studies have evaluated these relationships within the context of rapid, crisis-driven reductions in human activity. This study addresses this gap by investigating the environmental and health impacts of North Carolina’s 51-day COVID-19 lockdown, a period characterized by dramatic declines in traffic volume and industrial emissions. Using a retrospective, cross-sectional, quantitative observational design, secondary data were obtained from the U.S. Environmental Protection Agency (EPA) Air Quality System and the North Carolina Disease Event Tracking and Epidemiologic Collection Tool (NC DETECT). Daily ambient concentrations of PM2.5 and PM10, as well as ozone, were analyzed in conjunction with regional emergency department (ED) visits for asthma and COPD from 2020 to 2022. Descriptive analyses, Poisson regression, and time-series assessments were used to examine pollutant trends during the lockdown, stratified by demographic and socioeconomic indicators. Results show a statistically significant decline in ambient ozone concentrations during the 51-day lockdown period, coinciding with documented reductions in vehicular traffic and industrial activity. Although PM2.5 and PM10 displayed variable patterns across regions, overall ozone reductions aligned with decreased asthma- and COPD-related ED visits during the same period. These findings provide compelling evidence that short-term behavioral and structural changes can yield rapid and measurable improvements in air quality and associated health outcomes. Additionally, the results highlight the potential of targeted policy interventions, whether in response to crises or as part of environmental planning, to mitigate air pollution and reduce respiratory health disparities among communities that disproportionately bear the burden of chronic respiratory diseases. This study contributes to the literature by empirically demonstrating the intersection of environmental regulation, community health, and crisis-responsive policy design. The observed improvements in air quality and respiratory outcomes during the lockdown highlight opportunities for sustainable, equity-focused strategies to protect populations most vulnerable to pollution-related morbidity."