New research from UCLA has found that U.S. counties with higher exposures to poor air quality, historically, saw higher county-level COVID-19 mortality rates in 2020, according to a news release from the university.
The research also found that preventative measures – like stay home orders and masking – reduced the risk of COVID-19 by 15% and 8%, respectively, but did not reduce the increase of incidence in counties with poor air quality, which saw a 7.6% increase in in COVID-19 risk with a one-unit increase of 2.5 micrometers (µm) in atmospheric particulate matter, or PM2.5.
“This is evidence that long-term exposure to poor air quality increased the risk of COVID-19, during each surge, and cumulatively, in the United States,” said Zuo-Feng Zhang, MD, PhD, UCLA Fielding School of Public Health (FSPH) distinguished professor of epidemiology and associate dean for research. “And although both state-level implementation of facemasks mandates and stay home orders were effective in preventing the spread of COVID-19, no clear effects were observed in terms of long-term exposure to fine particulate matter. “
The research – “Long-Term Exposure to PM2.5, Facemask Mandates, Stay Home Orders and COVID-19 Incidence in the United States” - is being published in International Journal of Environmental Research and Public Health.
“The burden of environmental risks is grossly unequal in the US and globally,” said Jody Heymann, MD,PhD, UCLA Distinguished Professor of Public Health, Public Policy, and Medicine. “This study raises profound concerns about one more way that elevated exposure to air pollutants likely has serious consequences for the health of all people in the U.S.”
Fine particulate matter, defined as inhalable pollutant-derived particles with a diameter equal to or less than 2.5 micrometers, has been linked to heart and lung diseases, including asthma. The risks are severe, despite the tiny size of the particles, authors said.
Some 3,096 counties across the United States were included in the study; as of 12 September 2020, the average COVID-19 incidence in the U.S. was 2.6%, with a median of 1.27%. Counties with COVID-19 incidence greater than the national median had higher average fine particulate matter concentrations, earlier occurrences of the first case, more tests performed, and were less likely to reopen.
Higher population densities, higher proportions of African American and Hispanic residents, a larger percentage of people living in poverty, higher populations with less than a high school education, and fewer owner-occupied properties were found in the counties with increased incidences of COVID-19.
