Disclosure: This study was funded by the National Institute of Environmental Health Sciences. Chen does not make any relevant financial disclosures.
Exposure to air pollution and nitrogen dioxide can affect the severity of COVID-19 and associated mortality, researchers reported in the American Journal of Respiratory and Critical Care Medicine.
“Long-term and short-term exposure to air pollution increases the risk of severe COVID-19 illness, including hospitalizations and deaths from SARS-CoV-2 infection. Improving air quality and reducing personal exposure to air pollution could be beneficial in preventing severe consequences from COVID-19,” Zhanghua Chen, PhD Assistant Professor of Population and Public Health Sciences in the Division of Preventive Medicine at USC’s Keck School of Medicine, Healio said.
Chen and colleagues conducted a large, multiracial, population-based cohort study involving 74,915 people (mean age 42.5 years; 54% female; 66% Hispanic) diagnosed with COVID-19 from March through August 2020 at Kaiser Permanente Southern California Using patients’ residential address histories, researchers estimated 1-year and 1-month average exposure to pollutants in ambient air, including particulate matter (PM2.5), nitrogen dioxide (NO2) and ozone prior to COVID-19 diagnosis.
“It is hypothesized that air pollution increases the risk of severe COVID-19 disease through its direct effect on pneumonia and altered immune response to viral infection, as well as through the adverse effect on other comorbidities associated with severe COVID-19 disease such as obesity can increase. Diabetes and cardiovascular disease,” Chen told Healio. “Although ecological analyzes have shown some association between long-term exposure to air pollution, including particulate matter and nitrogen dioxide, and COVID-19 mortality by averaging data from large geographic areas and heterogeneous populations, there is an urgent need for evidence, supported by cohort studies suggest linking exposure to air pollution at an individual level and risk of serious COVID-19 outcomes, adjusting for variations in individual confounders such as socioeconomic characteristics and disease history.”
Overall, the hospitalization rate was 6.3%, intensive ventilator support 2.4%, ICU admission 1.5%, and mortality 1.5%.
Average 1 year PM2.5 and 1 month NO2 The exposures, after adjusting for sociotypical characteristics and comorbidities, were associated with the severity of COVID-19 infection, according to the researchers. For every 1 standard deviation increase in 1-year PM2.5the association for hospitalization (OR = 1.24; 95% CI, 1.16-1.32), intensive ventilatory support (OR = 1.33; 95% CI, 1.2-1.47) and admission remained the same ICU (OR = 1.32; 95% CI, 1.16-1.51). For 1 month NO2the association also persisted for hospitalization (OR = 1.12; 95% CI, 1.06-1.17), intensive ventilatory support (OR = 1.18; 95% CI, 1.1-1.27), and admission the intensive care unit (OR = 1.21; 95% CI, 1.11). -1.33), according to the results.
Regarding mortality, researchers reported associations between mortality and 1-year PM2.5 (HR = 1.14; 95% CI, 1.02-1.27) and 1-month NO2 (HR=1.07; 95% CI, 0.98-1.16).
Looking ahead, “besides testing personal intervention tools, some key concerns regarding COVID-19 now are the new variants and the long COVID,” Chen told Healio. “It will be important for future research to investigate whether exposure to air pollution also increases the incidence and severity of COVID-19 for new virus variants, and whether air pollution could also have adverse effects on long-COVID.”