Short-term exposure to common air pollutants may heighten the odds of Covid-19 infection in young adults, researchers found in what’s billed as a first-of-its-kind study of the age group now considered primarily responsible for spreading the respiratory disease.
The study, recently published online in the Journal of the American Medical Association, looked at 425 students and others in their mid-20s within an existing cohort who tested positive for the novel coronavirus.
Despite “relatively low levels of air pollution exposure,” the Swedish researchers tied higher daily levels of airborne particles and black carbon to increased risk of infection in the range of 6 to 7 percent. While no such association was found for exposure for another class of pollutants known as nitrogen oxides, the results support “the broad public health benefits of reducing ambient air pollution levels,” write the authors, who work at the Stockholm-based Karolinska Institutet and other organizations in Sweden and Italy.
Since first surfacing in late 2019 and then spreading worldwide, the Covid-19 pandemic has claimed more than 6.2 million lives globally, with almost a million of those deaths in the United States, according to data from the World Health Organization and the U.S. Centers for Disease Control and Prevention.
The connection between air pollution and susceptibility to respiratory diseases like asthma and influenza is already well-established. Accordingly, the possible nexus with vulnerability to the coronavirus has garnered close scientific and media attention; it was one factor cited in EPA Administrator Michael Regan’s decision almost a year ago to launch a new review of the agency’s ambient air quality standards for soot and other types of particulate matter (Greenwire, June 11, 2021).
In general, however, the more publicized studies have explored the potential connection between long-term air pollution exposure and Covid-19 deaths across populations that may number in the tens of thousands or millions of people (Greenwire, Aug. 13, 2020).
While the disease is far more likely to kill older people or those with pre-existing health problems, young adults are now considered the “major spreader” of the virus, the study says. “To our knowledge, this is the first report of individual-level, short-term exposure to air pollution” linked to Covid-19 infection in that demographic group, the authors add.
Taking together the findings of other research, the authors also speculate that higher levels of short-term air pollution play a role in producing symptoms among those infected with the virus rather than contributing to its transmission.