Air pollution exposure may raise risk of meningioma brain tumour, new research finds

Time of India

10-07-2025

Breathing polluted air daily may do more harm than we thought—especially to your brain. A new Danish study published in Neurology has found a potential link between long-term air pollution exposure and a higher risk of developing meningioma, a typically non-cancerous but serious type of brain tumour.
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The research followed nearly four million adults over 21 years and revealed that exposure to ultrafine particles—like those from traffic and diesel fumes—was associated with increased tumour risk. These findings add to growing evidence that air pollution doesn't just affect your lungs and heart—it may impact brain health too.
Meningioma brain tumour development linked to air pollution in large-scale study
A new large-scale
has found that people exposed to higher levels of air pollution over long periods may face an increased risk of developing meningioma—a type of brain tumour that is typically non-cancerous but can still cause serious health problems.
Published in Neurology, the medical journal of the American Academy of Neurology, the study followed nearly four million Danish adults over a span of 21 years. Researchers tracked the development of tumours of the central nervous system and found that approximately 16,600 participants were diagnosed during that period—of which 4,600 cases were meningioma.
What is meningioma brain tumour and why is it a concern?
Meningiomas are the most common type of primary brain tumour.
While usually benign (non-cancerous), they can grow large enough to press on nearby brain tissue, nerves, or blood vessels, potentially leading to neurological symptoms such as headaches, vision problems, or seizures. Because they grow slowly, they can go unnoticed for years.
Ultrafine particles in air pollution linked to higher brain tumour risk
To estimate long-term pollution exposure, researchers assessed air quality in participants' neighborhoods—particularly traffic-related emissions, diesel exhaust, and ultrafine particles such as those found in smoke and vehicle fumes.
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The analysis revealed a clear link between higher air pollution levels and increased risk of meningioma, especially in those exposed to ultrafine particles. However, no strong connection was observed between air pollution and more aggressive or cancerous tumours, such as gliomas.
According to lead study author
, a senior scientist at the Danish Cancer Institute, these findings add to the growing understanding that air pollution doesn't just harm the lungs and heart—but may also affect the brain.
'While research on the health effects of ultrafine particles is still in its early stages, these findings point to a possible link between traffic-related ultrafine particle exposure and the development of meningioma,' said Hvidtfeldt in a statement.
How can air pollution affect brain health?
Although the study does not establish direct causation, it strengthens the growing body of evidence suggesting that airborne pollutants can cross the blood-brain barrier, potentially triggering inflammation or damage to brain tissue.
Previous research has found that ultrafine particles, due to their small size, may penetrate deeply into the lungs, enter the bloodstream, and reach the brain, where they may contribute to neurodegenerative diseases or cognitive decline.
Other known risk factors for meningiomas brain tumour
While the exact cause of meningioma is still unclear, other recognised risk factors include:
Radiation exposure, especially during childhood
Hormonal factors (more common in women)
Genetic conditions such as Neurofibromatosis type 2 (NF2)
This study sheds new light on the possible role of environmental triggers like air quality in meningioma development.
While the findings are significant, researchers noted several limitations. Pollution exposure was estimated based on outdoor air quality in residential areas and did not account for time spent indoors or at work, where pollution levels can differ. The authors emphasised that more detailed studies are needed to confirm these results and explore whether reducing air pollution could help lower the risk of developing brain tumours.