Waiting at a red light during your commute isn't just frustrating if you're running late. It can be hard on your health, too.
A new study has found that waiting at stoplights and then accelerating increases your exposure to pollutants. Researchers studied commuters in the United Kingdom, where the average round trip commute each day is about an hour or more, and found that congested intersections became hot spots when vehicles accelerated after idling.
A fairly short time was spent waiting for red lights to turn green, but these moments had an outsized effect on exposure to pollutants: The concentration of harmful particles was 29 times higher at stoplights than when people were driving down the road, the researchers found. Although the drivers spent just 2% of their time at traffic intersection lights, that time accounted for 25% of their exposure to air pollutants.
Inhaling the tiny particles that accumulate inside of tail pipes of cars can aggravate respiratory disorders like asthma and chronic obstructive pulmonary disease. Worse, the particles also affect your cardiovascular system, says Kerry E. Kelly, an air quality researcher at the University of Utah. "The most dramatic effects are relationships between fine particulate matter and increased incidents of heart attacks and strokes," she says.
Given that Salt Lake's air quality is already a cause for concern, it's important for motorists to limit their exposure to pollutants during their commutes. The U.K. researchers recommend that people idling at lights keep their windows up and turn off fans that draw air from outside.
Kelly also suggests trying to vary the time you commute or your route to avoid traffic congestion. "Pay attention to traffic reports and try to limit the amount of times [you're] at lights," she says.