Long-term exposure to air pollution may increase COVID-19 death risk, say scientists

A new analysis of more than 3,000 counties in US has found that people with long-term exposure to fine-particle pollutants may be more likely to die from COVID-19, findings which may make policymakers reexamine harms of air pollution and help reduce deaths during pandemic.

research, published in journal Science vances, investigated impact of long-term exposure to PM 2.5 pollutants -- tiny particles in air that are two and one half microns or less in width -- on COVID-19 mortality rates in 3089 counties in US, "covering 98 per cent of population." It found that "higher historical exposure" to se particulate pollutants is associated with greater county-level COVID-19 mortality rates after accounting for several area-level risk factors.

While study could t provide insights into mechanism underlying relationship, scientists, including those from Harvard University in US, believe chronic exposure to PM 2.5 may cause over production of ACE-2 receptor in lungs, which vel coronavirus uses to enter host cells.

y believe prolonged exposure to air pollution may also impair people's immune system.

"Chronic exposure to PM2.5 causes alveolar ACE-2 receptor overexpression and impairs host defences. This could cause a more severe form of COVID-19 in ACE-2–depleted lungs, increasing likelihood of poor outcomes, including death," scientists wrote in study.

Citing limitations of study, scientists said y were unable to just for individual-level risk factors such as , race, and smoking status as such data were unavailable.

"This approach leaves us unable to make conclusions regarding individual-level associations," scientists said.

However, researchers said analyses provide strong justification for follow-up investigations as more and higher-quality COVID-19 data become available.

"Research on how modifiable factors may exacerbate COVID-19 symptoms and increase mortality risk is essential to guide policies and behaviours to minimize fatality related to pandemic," y ted in research.

Im Credits: PTI