New York, Jul 10 (IANS): Long-term exposure to fine particulate matter (PM2.5) was associated with more than three times the odds of being ventilated and twice the likelihood of a stay in ICU due to Covid-19, finds a study.
The greater the exposure, the greater the risk, revealed researchers from the Henry Ford Hospital in Detroit, US.
While it is not clear how air pollutants contribute to more severe disease, it is possible that long-term exposure to air pollution may impair the immune system, leading both to increased susceptibility to viruses and to more severe viral infections, they said.
Further, the fine particles in air pollution may also act as a carrier for the virus, increasing its spread.
"Our study calls attention to the systemic inequalities that may have led to the stark differences in Covid-19 outcomes along racial and ethnic lines," said Anita Shallal from the hospital.
"Communities of colour are more likely to be located in areas closer to industrial pollution, and to work in businesses that expose them to air pollution," she added.
The study was conducted in Detroit -- the 12th most polluted city in the US, measured by year-round PM2.5, according to the American Lung Association.
The team analysed data from 2,038 adults with Covid-19 admitted in hospitals between March 12 and April 24, 2020. Patients were followed until May 27, 2020.
They found that patients who were male, black, obese, or had more severe long-term health conditions were much more likely to be mechanically ventilated and admitted to the ICU. So too were patients living in areas with higher levels of PM2.5 and lead paint.
"The key takeaway is that living in a more polluted neighbourhood is an independent risk factor for severity of Covid-19 disease," Shallal said.
"Urgent further research is needed to guide policy and environmental protection, to minimise the impact of Covid-19 in highly industrialised communities that are home to our most vulnerable residents," she noted.
The study will be presented at the 2021 European Congress of Clinical Microbiology and Infectious Diseases to be held online between July 9 and 12.