Air pollution risk: beyond breathing problems

Researchers studied the effects of particulate matter and nitrogen dioxide (NO2) - two common air pollutants. Keystone

Swiss and German researchers have found that air pollution may impair cognitive function directly - independently of respiratory effects.

Scientists already know that air pollution can harm lungs, and that breathing problems, in turn, can cause cognitive deficits. But if people exposed to air pollution develop cognitive deficits, is this a direct result of impaired breathing? Or could pollutants harm the nervous system in some other way?

In a study of over 800 older women, researchers from the Swiss Tropical and Public Health Institute in Basel and the Leibniz Research Institute for Environmental Medicine (IUF) in Düsseldorf, Germany found evidence supporting the latter theory: air pollution appeared to harm the subjects’ cognition independently of lung function.

Specifically, the subjects’ visuo-spatial cognition – their ability to process information about the nature and position of objects – was impaired. To determine this, the researchers administered a battery of tests typically used to diagnose Alzheimer’s disease.

According to IUF researcher Tamara Schikowski, one possible explanation for these results could be that particulate matter and other pollutants enter the central nervous system through the nose.

“This is the first time this research has been done, and the first time these results have been shown,” Schikowski told swissinfo.ch from Denver, Colorado, where she is presenting the findings at the 2015 American Thoracic Society meeting. “Further studies with larger cohorts are needed to validate our results.”