Exposure to diesel exhaust affects the ability to think.
Diesel exhaust has long been linked to health risks such as lung cancer, heart attacks, kidney damage, and blood clotting. Semi-trucks, commercial vehicles, and even some personal-use trucks are fueled by diesel; the exhaust from these vehicles contains nitrogen oxide, volatile organic compounds, and dangerous particulate matter. This is a health concern not only for the trucks’ drivers, but also for those in other occupations that take place mostly on the road, such as taxi drivers, bike messengers, delivery van drivers, and motorcycle police officers.
A new study conducted by respiratory experts at the University of British Columbia and the University of Victoria, in Canada, suggests that diesel exhaust also affects our ability to think clearly. In this study, the first of its kind, the team exposed human test subjects to real-world levels of traffic exhaust in a carefully calibrated exposure booth, then used an MRI to measure brain activity. The images showed that air containing diesel exhaust altered the brain’s connectivity network and impacted regions devoted to memory. Even a few moments of breathing diesel-polluted air, the study found, lowers cognitive performance and could trigger symptoms of depression.
“We know that altered functional connectivity in the DMN [the brain’s default mode network] has been associated with reduced cognitive performance and symptoms of depression, so it’s concerning to see traffic pollution interrupting these same networks,” said Dr. Jodie Gawryluk, the study’s first author, in a press release.
But there’s good news: The researchers found that these changes in brain function were temporary; brain function returned to normal once participants stopped breathing the polluted air. However, the researchers warn that effects could be longer lasting if exposure is prolonged. If you are on the road for work, here are steps you can take to protect yourself:
For Bike, Scooter, Moped, and Motorcycle Riders
- Choose your route carefully. If possible, ride on less-trafficked streets or greenways.
- Avoid biking near industrial areas, such as ports.
- If your schedule is flexible, try to ride during off-peak hours; you may find that an hour or even half-hour adjustment in your commute makes a big difference in how much vehicular traffic is on the road.
- Wear a well-fitting, high quality mask.
For Car, Van, and Truck Drivers
- If you are stuck in traffic, keep your windows rolled up and set your A.C. to “recirculate.” Once free of traffic, open the windows to allow in fresh air.
- Periodically wipe down the interior of your vehicle to eliminate pollution grime that accumulates on surfaces and continues to pollute your air.
- Shut off your vehicle’s engine at traffic lights, to help reduce pollution overall.
- Check your air filters regularly; a saturated filter offers no protection at all.
- If your job regularly exposes you to diesel exhaust—whether from vehicles, ships, trains, or cargo handlers—consider wearing a mask.
For Fleet Owners and Managers
Truck fleet owners and managers can be proactive about keeping their employees safer and protecting the communities they serve. According to the EPA, best practices include:
- Reduce idling time and ensure drivers respect state-required idling limits.
- Designate routes that avoid polluting vulnerable populations, such schools, hospitals, and nursing homes.
- Invest in proper maintenance. Check vehicles daily to ensure they aren’t smoking or burning off excess gas. Change filters regularly.
- Consider upgrading ventilation systems where diesel-powered vehicles are serviced or stored indoors.
- Upgrade your fleet with lower- or zero-emission vehicles.
As with most environmental issues, there is no single broad-stroke solution to reducing diesel pollution and mitigating exposure—at least until zero-emission vehicles replace all the combustion vehicles on the road. For now, it is very important that individuals protect themselves from prolonged exposure to diesel fumes and that employers and fleet owners do everything possible to protect their workers and communities.