A new study from European researchers found breathing polluted air diminishes cognitive abilities.
Scientists have known for a while that reduced lung function can have harmful effects on our brains, and they've thought that pollution hinders our cognitive response through this lung connection.
What's interesting about this latest study, which comes from a coalition of German and Swiss researchers, is they've found pollutants can hurt brain function independently of a connection to the lungs.
"Our findings disprove the hypothesis that air pollution first decreases lung function and this decline, in turn, causes cognitive impairment by releasing stress signals and humoral mediators into the body," said Mohammad Vossoughi, a PhD student at the Leibniz Institute for Environmental Medicine.
The result raises questions about how air pollution has such direct effects on the brain, and Vossoughi is careful to emphasize the need for future research. But he postulated that pollutants and particulate matter – small particles of smoke and dust from engines and exhaust - impact the central nervous system through our sense of smell.
Researchers culled data from a previous study on aging that involved 834 German women. They tested the association between impaired lung function and cognitive decline.
Cars and trucks, of course, are a leading source of these pollutants. Estimates indicate that pollution spewed from vehicles kills about 53,000 people in the United States every year, according to research from MIT. That's more than the approximately 33,000 who die in car accidents.
As European researchers further examine the causes of that direct link, their counterparts in Canada could suggest a solution. University of Toronto researchers released a paper on car pollution earlier this month that suggests 25 percent of the vehicles on the road are responsible for 90 percent of the pollution.
It's not only the cars' fault. It's how they're driven.
"How you drive, hard acceleration, age of vehicle, how the car is maintained – these are things we can influence that can all have an effect on pollution," said Greg Evans, the study's author.