While exposure to smog is a known risk factor for preterm birth and low-birth weight, new research suggests it also may heighten risk of COVID-19 infection for pregnant low-income women.
Scientists at Columbia University Mailman School of Public Health analyzed the COVID test results for more than 3,300 pregnant women in New York and also assessed their long-term exposure to fine particulate matter known as PM2.5.
They found that poorer women in neighborhoods with higher levels of PM2.5 air pollution were 60% more likely to test positive for COVID-19.
"COVID-19 has exposed and exacerbated existing health disparities. Low-income pregnant people may have been more likely to test positive for the virus and be symptomatic due to more exposure on the job or inability to isolate, as well as heightened exposure to a range of environmental pollutants," study co-author Joan Casey said in a Columbia news release. She's an assistant professor of environmental health sciences.
All women who delivered a baby at Columbia University Irving Medical Center between March and December 2020 were tested for COVID. The research team estimated PM2.5 exposure using location-specific air pollution data for 2018 and 2019 at the homes of the study participants. They adjusted the results based on income level and neighborhood-level status.
The study found no association between PM2.5 and ever testing positive for COVID-19 for the study group as a whole. However, the odds of a positive COVID test were 60% higher for each 1 microgram per cubic meter of air increase in long-term PM2.5 in study participants who had Medicaid, the publicly funded insurance program for the poor.
While only 22% of those testing positive reported symptoms, 69% of symptomatic individuals used Medicaid, the study found.
COVID can cause pregnancy complications. Pregnant women who are infected with COVID-19 are more likely to experience significant respiratory symptoms and to die than non-pregnant COVID patients, the researchers noted. They are also more likely to experience adverse pregnancy outcomes, including preterm delivery, preeclampsia and possibly stillbirth.
Previous studies have found higher long-term PM2.5 concentrations to be associated with a risk of acute respiratory infection in the general population.
The findings were recently published in the American Journal of Epidemiology.
Nationwide Children's Hospital has tips for a healthy pregnancy.
SOURCE: Columbia University Mailman School of Public Health, news release, Sept. 6, 2022