Nov. 23, 2022 -- New research links air pollution to respiratory infections and the diminished immune systems of many older adults.

The study, published in Nature Medicine, found that inhaled particles accumulated in immune cells in lymph nodes associated with the lungs. That weakened the cells’ resistance to respiratory infections.

Previously, the weakened immune systems in older people have been considered part of aging.

And the COVID-19 pandemic drove home the point about the vulnerability of older people, with those over 75 suffering a death rate 80 percent higher than younger adults. Flu and other lung infections disproportionately strike old people, as well.

Researchers looked at tissue from 84 dead donors aged 11 to 93. All were non-smokers. 

“When we looked at people’s lymph nodes, we were struck by how many of the nodes in the lung appeared black in color, while those in the GI tract and other areas of the body were the typical beige color,” says Donna Farber, PhD, at Columbia University, who led the study.

The blackened lymph nodes were “clogged with particles from airborne pollutants,” she said. 

“These immune cells are simply choked with particulates and could not perform essential functions that help defend us against pathogens,” Farber said. “Pollution undoubtedly plays a role in creating more dangerous respiratory infections in elderly individuals and is another reason to continue the work in improving air quality.”

Show Sources

Nature Medicine: “Inhaled particulate accumulation with age impairs immune function and architecture in human lung lymph nodes”


Columbia University: “Decades of Air Pollution Undermine the Immune System”

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