Surprisingly Large Effects From Breathing Traffic Fumes Inside Your Car

Most of us tend to think we are protected from traffic-induced air pollution when we are in our cars. Unfortunately, that is not the case.

Both short- and long-term exposure to air pollution have been linked to a wide range of diseases, including strokes, chronic obstructive pulmonary disease, lung cancer, diabetes, obesity and even Alzheimer’s, according to the World Health Organization. Indeed, research has shown that chronic exposure to air pollution can impact nearly every organ in the body.

Now, scientists from the University of Washington have shown that breathing unfiltered air from inside your car can result in significant spikes in blood pressure, which last for over 24 hours.

“The magnitude of the effect, about 4.5 mmHg in diastolic blood pressure during a two-hour morning drive and still almost 4 mmHg higher the next morning, was surprisingly large,” Joel Kaufman, a professor at the Environmental & Occupational Health Sciences, Medicine, and Epidemiology Department at the University of Washington, told Newsweek.

“These are the size of effects from things like salt in the diet that are well-known to increase blood pressure. Elevated blood pressures are risk factors for heart disease, stroke, and kidney disease.”

These spikes in blood pressure lasted for over 24 hours after the exposure. “We tested for up to 24 hours, and found the increase persisted through that period,” Kaufman said. “We did not test after that.”

In their study, published in the journal Annals of Internal Medicine, Kaufman and his team drove 16 individuals, aged between 22 and 45, through traffic in Seattle for three days between 2014 and 2016 to determine the effects of on-road pollutant exposure and blood pressure. On two of the days, on-road air was allowed into the vehicle. On the third day, the vehicle was equipped with higher efficiency particulate air (HEPA) filtration. On each day, blood pressure was measured before, during and after the drive.

“The study approach allowed us to separate out effects of stress and noise from effects of air pollution,” Kaufman said. “The filters primarily removed particle pollution.”

Unfortunately, Kaufman said that “not very many” cars on the road today use these filters. “Some manufacturers may use them, and some aftermarket devices may be available,” he said. “We have not tested these.”

So what should you do to protect yourself from traffic-induced air pollution?

“Roll up your windows, have a good cabin air filter, and put the climate setting on recirculate,” Kaufman said. “If in public transit, it’s not a bad idea to wear an effective mask, like an N95, that you might want to do for other reasons anyway to protect yourself from respiratory diseases.”