Airborne pollutant exposure increases COVID19 infections: Study
Rajeev Choudhury
Confirming long time impression that long term exposure to air pollutants leads to increased susceptibility to respiratory infections, researchers from Italy claim that an increase of one microgram per cubic meter in the annual average exposure to PM2.5 leads to a 5.1% increase in the rate of COVID19 cases among the adult population.
The study led by Professor Giovanni Veronesi of the University of Insubria, Varese and published in the journal Occupational & Environmental Medicine, recently tried to ascertain the relationship between long-term exposure to airborne pollutants and the incidence of COVID19 up to March 2021 in a prospective study of residents in Varese city in northern Italy.
During the study, the researchers tracked 62,848 residents of the city who were aged 18 years or more as of 31 December 2019, and tracked their exposure to air pollutants using the Flexible Air quality Regional Model (FARM) chemical transport model and found that 4,408 people in the study group were affected by COVID19.
The researchers estimated that the annual average PM2.5 exposure among the study group was found to be 12.5 micrograms per cubic meter.
In single-pollutant multivariate models, the researchers found that an increase of one microgram per cubic meter of PM2.5 led to a 5.1% increase in the rate of COVID19 (95% CI 2.7% to 7.5%), resulting in 294 additional cases per 100 000 person-years.
The relation was confirmed by several sensitivity analyses, including bi-pollutant models, seasonal versus annual average exposure, pandemic period and after excluding individuals living in residential homes, they said.
“Our findings provide the first solid empirical evidence for the hypothesised pathway linking long-term exposure to air pollution with the incidence of COVID19 and deserve future generalisation in different contexts,” the researchers observed.
The researchers concluded that the efforts to further reduce air pollution levels by the government can help to mitigate the public health burden of COVID19.
