Nov. 14 (UPI) -- Researchers at McGill University in Montreal have for the first time linked nano-particles in air pollution to increased risk for brain cancer.
In a study published Wednesday in the journal Epidemiology, researchers report that a one-year increase in pollution exposure of 10,000 nano-particles per cubic centimeter raised the risk of brain cancer by more than 10 percent. Nano-particles, or ultra-fine particles, are commonly found in vehicle exhaust, particularly that produced diesel cars and trucks.
"Any time you burn anything, these small particles are produced," study co-author Scott Weichenthal, an epidemiologist, told UPI. "These particles are so small the can get into our bloodstream and into our brains."
And once there, they can do significant damage.
Weichenthal and his colleagues assessed the relationship between air pollution and brain cancer in two Canadian cities -- Toronto and Montreal -- but he noted that the "types and levels of air pollution" in most major cities across North America -- including the United States -- are "similar."
Pollution levels in the two Canadian cities ranged from 6,000 to nearly 100,000 nano-particles per cubic centimeter. According to Weichenthal, people living with pollution levels measuring at 50,000 nano-particles per cubic centimeter have a 50 percent higher risk of brain cancer than those living in environments with 15,000 nano-particles per cubic centimeter in the air.
The presence of toxic nano-particles from air pollution in human brains was first observed in a study published in 2016 in the journal Proceedings of the National Academy of Sciences.
Earlier this year, a review of existing research published in the journal Chest also concluded that air pollution may cause damage to virtually every organ and cell in the human body.
The McGill-based team performed their analysis using the medical records and pollution exposure of 1.9 million adult Canadians from 1991 to 2016, using data from the Canadian Census Health and Environment Cohorts as well as the Canadian Cancer Registry.
Thankfully, Weichenthal said, brain cancer remains relatively rare, but he and his colleagues wrote that the findings suggest an increase in pollution exposure roughly equivalent to moving from a quiet city street to a busy one leads to one extra case of brain cancer for every 100,000 people exposed.
"That risk is significant when it's viewed within the context of large urban areas like Toronto, Montreal or New York City," Weichenthal said. The findings are a reminder that "everyone should take measures to reduce their exposure to environmental pollutants," he added.