INVESTIGATORS: Why rush hour air can hurt your health

It's common knowledge that poor diet, lack of exercise and smoking play a part in causing heart disease, but now, there is something else to be concerned about: rush hour air. It can be a hazard for healthy people with no cardiovascular disease. VIEW PHOTOS

Researchers say invisible particles from an automobile's exhaust can be inhaled and end up in the blood stream. Those tiny assassins maybe a hundred times smaller than the thickness of a human hair. Over time, they can damage your arteries raising your risk for a heart attack or stroke.

One study in California looked at the health impact of commuters who spent a lot of time in heavy traffic. "They actually found the longer the commute the more likely people were to have calcified arteries, " said Dr. Steve Smalley, a Cardiologist from Regions Hospital in St. Paul.

By no means is the air in the Twin Cities on par with Los Angeles smog. But, the more we learn about those noxious little pollutants, the more we understand there's a risk of harm no matter what the level.

Rush hour air test

The Minnesota Pollution Control Agency is constantly checking air quality. But it's two dozen monitoring stations in the metro give only a general picture of what we're breathing. They don't detect the pollution levels inside your car. So the Fox 9 Investigators conducted a rush hour air test.

Jake Swanson, is a professor from Minnesota State University, Mankato, who's done a lot of research on this issue, helped us set up and conduct the test.

We used special devices which measured air particle contamination outside and inside our news vehicle as we drove in rush hour. The devices were loaned to us by TSI Incorporated.

The outside sensor, which looks like an antenna taped to our back window, detected more particle pollution in heavier traffic.

But what was in the air that we were breathing inside the vehicle? There was about 50% less of the pollutants inside, as there were outside. That's because the ventilation system blocked out some of the bad stuff. As we turn on the air recirculation mode, the levels dropped even more.

But when we used the defroster, the particle levels inside jump to nearly the same as what's outside.

How often should you change the cabin air filter?

Many newer vehicles come with cabin air filters to trap dust, pollen and other impurities.

Many people think you should change the filter regularly. But our professor told us otherwise.

In our road test, we compared air quality in our test vehicle with a cabin filter installed and then again with it removed. There was little difference in terms of particle pollution in either scenario.

When we pulled out the filter from the compartment below the glove box, it had a brownish color on parts of it. That discoloration means those itsy bitsy toxins, the ones that are potentially bad for our health, are still sneaking into the passenger cabin.

The solution, according to Professor Swanson, is to install a super high efficiency filter that will trap those bad actors. Or don't change the filter so often. The more gunk it collects the harder it is for those ultra-fine particles to get through.

Avoid the toxic soup

On the day of our test, we didn't detect any widespread pollution at alarming levels.

But there were pockets of concern. The Lowry tunnel for example, was showing nearly 200,000 particles per cubic centimeter of air. That's more like a bad smog day in LA.

"That starts to be a concentration where I as an individual I don't want to breathe that all day long." said Swanson.

We saw similar levels driving behind a diesel truck.

Contrary to what you might think, our test found fewer particles in the air when rush hour traffic was crawling, as opposed to moving quickly. Engines produce more pollution at higher speeds.

Heart experts, including dr. Smalley, say you should try to reduce your exposure to this toxic soup.

Stay off busy highways when you can. And don't exercise outdoors near lots of traffic.

Since bad air tends to hang over busy roads, our test found things were much cleaner just 3 blocks away. Think about that the next time you're doing any physical activity outside or choosing a place to live.