Dangers at the stoplight

Red lights may prevent deadly auto accidents, but waiting at one poses a different kind of hazard to your health. Car exhausts emit harmful pollutants, known as nanoparticles, which have been linked to heart and lung disease.

When researchers from the University of Surrey in England analyzed drivers’ exposure to these pollutants at various points in their typical daily commutes, they found the motorists were exposed to 29 times more air pollution at red lights than when they were moving. While the process of braking for a stoplight, idling, and accelerating away composed a mere 2 percent of total driving time, it accounted for 25 percent of the drivers’ overall exposure to nanoparticles.

To help limit that exposure, the scientists advised motorists to keep their car windows closed and leave ample distance between their vehicle and the one in front at traffic lights. Lead author Prashant Kumar says those on the sidewalk should also be wary of busy junctions. “Pedestrians regularly crossing such routes, should consider whether there might be other paths less dependent on traffic light crossings.”