Freeway drivers breathe dirtier air than previously thought Quotes: "Rush hour just got a lot worse. A new study finds that freeway pollution is twice as toxic than air just off the roadway. And air during the morning commute is worse than during the drive home. ...... Then, the researchers examined the mix of particles sucked into the cars through their intake systems or open windows. The pollution found included unburnt gasoline, diesel soot and tiny specks of metals that come off brake pads. Not all the particles are equally as bad, but the researchers discovered that the types of particles inhaled by drivers on the freeway during morning rush hour were the more harmful kind. Breathing the particles they found is twice as likely to cause reactions in our airways that can cause chronic inflammation and may lead to higher risk of asthma, heart disease, even dementia and diabetes. ...... But there are things drivers can do to reduce their exposure. Rolling up the windows and recirculating the air can cut the concentration of particle pollution inside the car by half to three-quarters, Fruin found in a previous study. Newer cars are better, because they are more tightly sealed, which minimizes the amount of outside air that can seep in. Replacing your air filter regularly is also a good idea. And, of course, avoiding freeways during rush hour, or taking public transit is best." End quotes. I would add to the last paragraph: If everyone gets out of ICE vehicles and into EVs this would eliminate the vast majority of the pollution particles. Until then, use your re-circulation feature on your AC. If you are fortunate enough to have Bio-Weapon Defense Mode--use it! What's a 200-300 dollar HEPA filter versus you and your loved ones lungs?