Macrophages are key immune cells: the microplastics that we breathe reduce their ability to get rid of pathogens and harmful cells.
The microplastics that we breathe and end up in the lungs they worsen the functionality of the macrophagesthe brush cells of the human body in charge of eliminating damaged pathogens and cells. This was verified by a study published on the occasion of the 2025 International Conference of the American Thorancic Society (Here all the abstracts of the event): long -term damage to these fundamental immune cells they can increase the risk of infections and forms of cancernot only to the lungs but to the whole organism.
A breath of air and plastic
Scientific research has now agreed to consider inhalation one of the main entrance routes of microplastics into the human body. Once penetrated in the body, the microplastics bring damage in many ways: they trigger inflammation and oxidative stress processes, they clog the blood vessels, alter the functions of the mitochondria and encourage cell death processes.
Bocconi difficult to digest
Adam Soloff, associate professor of cardioatoracic surgery at the University of Pittsburgh (United States) and first author of the new study, has now revealed another damage inflicted by microplastics: the ability to negatively alter the functioning of the macrophages, the most abundant immune cells in the lungs, which normally incorporate the pathogens, get rid of the dead cells and maintain the cellular balance.
Soloff has studied the effects of microplastics on macrophages both in vitroby cultivating the immune cells alongside fragments of polystyrene (polystyrene) of different thickness, both in the body of mice who had ingested plastic particles. After 24 hours of “forced coexistence” in tube with microplastics, macrophages have proven less capable of surrounding and destroying other foreign microorganisms, such as bacteria. A biological process called phagocytosisfundamental for innate or non -specific immunity, the first line of defense to an infection.
The macrophages struggled to incorporate and digest in vitro plastic, and the macrophages of the mice have retained, without being able to destroy them, plastic particles even for a week, after the initial inhalation. Microplastics have been identified also in other organs rodents, such as liver, spleen, colon, kidneys and brain.
«After passing through the lungs, the microplastics spread systematically and negatively alter the functionality of the macrophages. They can have negative effects on any organ and contribute to numerous diseases, “explains Soloff. In addition to making infections more vulnerable, the little efficiency of macrophages could encourage the onset of tumors.
A drug to strengthen macrophages
Finally, scientists have shown that the acodesin, a drug already used in the treatment of a form of leukemia, partially restores the functionality of the macrophages damaged by microplastics, and could be used in populations particularly at risk of pollution from microplastics to reduce the incidence of lung diseases.
