Air pollution linked to common brain tumors

2025-07-11 08:08:00, Shëndeti CNA

People who breathe more polluted air are at greater risk of developing a common brain tumor, a new study suggests.

Several different types of air pollutants, including particulate matter and nitrogen dioxide, appear to increase the risk of meningiomas — tumors that form in the layers of tissue covering the brain and spinal cord, researchers reported July 9 in the journal Neurology.

“Various types of air pollution have been shown to have negative effects on health, and ultrafine particles are small enough to cross the blood-brain barrier and can directly affect brain tissue,” lead researcher Ulla Hvidtfeldt, a senior scientist at the Danish Cancer Institute in Copenhagen, Denmark, said in a press release.

"Our study suggests that long-term exposure to air pollution from traffic and other sources may play a role in the development of meningioma and adds to the growing evidence that air pollution can affect the brain - not just the heart and lungs," she added.

More than 170,000 people are diagnosed with meningioma in the United States each year, according to the Cleveland Clinic. Symptoms include headaches, dizziness, nausea, vision changes, hearing loss, seizures, memory problems, muscle weakness or paralysis, and changes in behavior or personality.

Meningiomas can be treated with surgery, radiotherapy or chemotherapy, says the Cleveland Clinic.

For the new study, researchers followed nearly 4 million adults in Denmark over a 21-year period. During that time, about 16,600 of them developed brain or spinal cord tumors, including more than 4,600 who developed meningiomas.

Using people's addresses, the research team assessed their long-term exposure to air pollution. The results showed that people with the highest exposure to air pollution had three times the rate of meningioma compared to those with the lowest exposure - 0.2% of the population versus 0.06%.

Moreover, the risk increased with increasing exposure to various air pollutants. For example, people had a 21% higher risk of meningioma for every four micrograms per cubic meter increase in exposure to fine particulate matter, or airborne particles with a diameter of 2.5 microns. By comparison, a human hair is 50 to 70 microns in diameter.

Likewise, they had a:

12% increase in risk for every 8.3 Ug/m3 increase in nitrogen dioxide.

10% higher risk for each increase of 5,747 particles/cm3 for ultrafine particles with a diameter of less than 0.1 micrometer.

3% higher risk for every 0.4 Ug/m3 increase in carbon in the air.

However, the researchers did not find strong links between air pollutants and more aggressive brain tumors.

"While research on the health effects of ultrafine particles is still in its early stages, these findings indicate a possible link between exposure to traffic-related ultrafine particles and the development of meningioma," said Hvidtfeldt.

The researchers noted that the study design cannot prove a direct cause-and-effect relationship between air pollutants and meningioma, but only an association.

"More research is needed to confirm these results, but if cleaning our air can help reduce the risk of brain tumors, this could make a real difference to public health," Hvidtfeldt added./ CNA