Research shows that pollution inside of your vehicle can be 5-6 times the concentration of outside air. As your vehicle is moving along, outside air is drawn in through the HVAC system, it then passes through the cabin air filter where contaminates are removed. If you live in an area with unhealthy levels of pollution like we have in the Laurel, Beltsville and Columbia area, then your cabin air filter works even harder to remove pollutants such as dust, pollen, smog and mold spores from entering the inside of your vehicle.
Parking under trees can further hasten the deterioration of this critical component. I have seen these filters clogged with leaves, pine needles and even rodent droppings. Cabin filters are a tremendous help for people with allergies since they do trap pollen, mold spores and other allergens.