Study: Long-Term Air Pollution Exposure May Trigger Brain Tumours

New Delhi: Air pollution is already known to have serious effects on the heart and lungs, but new research suggests it may also increase the risk of developing meningioma—a common, usually noncancerous tumor that forms in the membranes surrounding the brain and spinal cord.

The findings, published in the journal Neurology, are based on a large-scale study conducted in Denmark. While the study does not prove that air pollution directly causes meningioma, it does show a significant association between long-term exposure to certain air pollutants and an increased risk of developing the tumor.

Researchers looked closely at pollutants commonly linked to traffic, such as nitrogen dioxide and ultrafine particles. These types of pollution are especially concentrated in urban environments. The study found that individuals who were exposed to higher levels of these air pollutants had a greater likelihood of developing meningioma over time.

“Air pollution has already been shown to have harmful effects on various organs, particularly the heart and lungs. Ultrafine particles are small enough to cross the blood-brain barrier, which may allow them to directly impact brain tissue,” said Ulla Hvidtfeldt, a doctoral researcher at the Danish Cancer Institute in Copenhagen.

“Our findings suggest that long-term exposure to traffic-related air pollution could contribute to the development of meningioma. This adds to the growing evidence that air pollution doesn’t just affect the cardiovascular or respiratory system but may also impact brain health,” she added.

The study involved nearly 4 million Danish adults with an average age of 35. Participants were tracked over a period of 21 years. During that time, 16,596 individuals were diagnosed with central nervous system tumors, of which 4,645 were cases of meningioma.

Interestingly, the study did not find a strong connection between air pollution and more aggressive brain tumors, such as gliomas. Still, the results raise important questions about how environmental factors like air quality may influence brain health over the long term.

“More research is needed to confirm our findings,” Hvidtfeldt said. “But if improving air quality can reduce the risk of brain tumors, even slightly, it could lead to significant public health benefits.”