The immune defenses of the lungs can wane with age, leaving the elderly more vulnerable to lung damage and severe bouts of respiratory infections. New research reveals one reason this happens: inhaling particulate matter from pollution It outperforms the business over timeweakens the immune system in the lungs, researchers report online Nov. 21 in Nature medicine.
Air pollution is a The main cause of disease and early death disproportionately worldwide Affect poor and marginalized communities (SN: 7/30/20). Particulate matter – a type of pollution emitted from vehicle exhaust, power plants, wildfires and other sources – has been linked to health harms including Diseases of the respiratory, cardiovascular and neurological systems (SN: 9/19/17).
In the new study, researchers from Columbia University analyzed lung immune tissue from 84 organ donors between the ages of 11 and 93. Donors were non-smokers or had no history of heavy smoking. The research team found that as people age, the lymph nodes in the lungs — which filter foreign material and contain immune cells — become overloaded with particles, making them deeply squeaky.
“if it was [lymph nodes] “You pile up with a lot of stuff, and then they can’t do their job,” says Elizabeth Kovacs, a cell biologist who studies inflammation and injury at the University of Colorado Anschutz Medical Campus in Aurora.
Lymph nodes are home to a host of immune cells, including macrophages. These cytosolic Pac-Mans devour pathogens and other debris, including particles. Filled with pollutants, macrophage production of cytokines and proteins secreted by cells to activate other immune cells decreased. The cells also showed signs of an impaired ability to eat more.
Older adults have accumulated so much debris, the new study suggests, that “they may not be able to accumulate more,” impairing their ability to process inhaled substances, says Kovacs, who was not involved in the research.
The research team writes that pollution is “a persistent and growing threat to the health and livelihood of the world’s population.” Their work found that the threat includes a “persistent and pervasive effect” on respiratory immunity with advancing age.