Taking your car to work every day not only leads to frustration in traffic, but new research shows it can directly raise your blood pressure and risk of heart disease.
A novel study has found exposure to air pollution from car exhaust during peak rush hour drives can significantly increase blood pressure in healthy adults. The concerning effects lasted up to 24 hours after exposure.
The research highlights growing worries around unregulated ultrafine particulate matter from brakes and tires as an emerging public health threat similar to second-hand smoke. Here’s what commuters need to know to protect themselves.
Simulating Rush Hour Exposure in Cars
The pioneering experiment was conducted by researchers at the University of Washington, led by Dr. Joel D. Kaufman, Professor of Epidemiology.
His team wanted to closely investigate how a typical commute during peak traffic in urban areas might affect cardiovascular health. They created a unique real-world simulation where participants were driven around downtown Seattle across three separate rides spaced three weeks apart.
“We literally drove people around measuring their blood pressure before, during and after driving them next to other cars in traffic,” said Dr. Kaufman.
The rides deliberately occurred in morning rush hour between 9:30-11:30 AM near heavy traffic areas. A key aspect was randomly using a car with a standard air filter plus high-efficiency particulate (HEPA) filter on some drives. For others, all protective filtration was removed allowing full exposure.
Neither the driver nor passengers knew which filtration state the car was in beforehand, making it a controlled blind experiment. This reduced potential bias in the results.
Air Pollution Has Same Impact as Salt or Smoking
The results showed breathing in air pollution directly from car exhaust substantially raised blood pressure to concerning levels.
Peak effects occurred after one hour driving unfiltered, increasing diastolic pressure by 4.7 mm/Hg on average. Alarmingly, some retained higher blood pressure 24 hours later.
“The findings add more evidence supporting that exposure to traffic pollution particles increases cardiovascular disease risk,” said Dr. Robert D. Brook, Professor of Medicine at Wayne State University, who studies pollution and hypertension but wasn’t directly involved in the research.
Dr. Kaufman emphasized, “It’s a complex system, and it appears somewhere in those mechanisms, traffic pollution interferes with blood pressure similar to smoking or salt.”
What Exactly Are We Breathing from Cars?
Vehicle exhaust includes various gases like nitrogen dioxide, carbon dioxide and carbon monoxide. But much focus is now on particulate matter, specifically ultrafine particles under 0.1 micrometers emitting from brakes, tires and fuel combustion.
“Ultrafines may be especially important for blood pressure,” noted Dr. Kaufman. Unlike larger pollutants, these minuscule particles can penetrate deep into lungs and enter the bloodstream, triggering inflammation linked to cardiovascular disease.
While the U.S. EPA regulates PM10 and PM2.5 particulates under 10 and 2.5 micrometers, they don’t monitor these ultrafine particles. Though growing data shows they likely pose the biggest health risk for commuters.
“The unregulated pollutant most reduced using car filtration in our experiment appears to be ultrafine particles. Exposure levels were extremely high on the road and nearly eliminated when a HEPA system was added,” explained Dr. Kaufman. “That points to ultrafines from traffic causing the blood pressure increases we measured.”
Everyday Exposure Similar to Pack-a-Day Smoker
Dr. Panagis Galiatsatos, a lung specialist at Johns Hopkins, said research continually shows air pollution has a sizable impact on health like second-hand smoke.
“Economically and politically there are ways to promote cleaner, safer cars to win this battle. Find advocacy groups promoting air quality rights – it’s a very winnable public health fight,” he told Healthline.
Dr. Brook similarly said in a 2020 published study that particulate pollution contributes to 8.9 million early deaths globally each year.
“Reducing exposure to traffic – an everyday source of particles for billions – is key to protecting cardiovascular health worldwide,” he explained.
While more research is warranted, Dr. Kaufman said the experiment adds compelling evidence tying car pollution to increased cardiovascular disease risk. Participants were healthy young adults, indicating even they aren’t immune to impact.
“It has effects similar to adding more dietary salt or being a pack-a-day smoker. For the average commuter, you are getting a lot more exposure over years,” he warned.
Protect Yourself: Limit Exposure, Use Air Filters
Until stronger policies and electric vehicles cut traffic emissions, experts advise individuals to use available precautions. These include:
- Closing windows and setting cars to recirculate interior air during heavy traffic
- Using central air conditioning over opening windows
- Checking daily air quality data and limiting outdoor activities on high smog days
- Using portable HEPA filters and air purifiers at home, especially bedrooms
- Choosing cycling routes away from congested roads with heavy stop-start traffic when possible
- Advocating locally and federally for stricter clean air laws around vehicle emissions and environmental regulations
In the future, Dr. Kaufman plans to study whether antioxidants like omega-3 fatty acids could potentially counteract effects of particle pollution on cardiovascular health for frequent commuters. But right now limiting exposure remains key.
For individuals feeling helpless against pollution, he reminds “traffic is made up of individuals. If 100,000 people stop driving, there are 100,000 less cars emitting fumes.”
Small personal choices when stacked together can drive positive change. Your health and the planet will thank you.