Study Links Air Pollution Nanoparticles To Brain Cancer For First Time

MONTREAL (CBS Local) -- Tiny particles produced by motor traffic have been linked to brain cancer for the first time, according to a new study from Canadian researchers.

The study, published in the journal Epidemiology, found that higher exposures of ultra-fine particles (UFPs), which are produced by fuel burning, particularly in diesel vehicles, significantly increase people's chances of getting the deadly cancer.

Specifically, it found that a one-year increase in pollution exposure of 10,000 nanoparticles per cubic centimeters – the approximate difference between quiet and busy city streets – increased the risk of brain cancer by more than 10 percent.

The pollution levels in the cities studied -- Toronto and Montreal -- ranged from 6,000/cm3 to 97,000/cm3.

"I think [Toronto and Montreal] are typical of major cities," he said. "I wouldn't expect the nanoparticles to be any less harmful anywhere else," said Scott Weichenthal, at McGill University in Canada, who led the study.

The research analyzed the medical records and pollution exposure of 1.9 million adult Canadians across the country from 1991 to 2016.

"Brain cancers are rare but often fatal. When you multiply these small risks by lots of people, all of a sudden there can be lots of cases," said Weichenthal.

Although previous work has shown that nanoparticles can get into the brain and that they can carry carcinogenic chemicals, this is the first study to suggest a relationship with the incidence of brain tumors.

Weichenthal says regulatory action to reduce combustion-related nanoparticles could have an important public health impact in Canada and globally.

"At an individual level, it is always a good idea to reduce your exposure to pollutants," he said. "But the more important actions are at a regulatory level, where you can take action that reduces everyone's exposure -- that is where the real benefits come in."