The American Lung Association’s 'State of the Air' report for 2017 lists Denver as the 11th most ozone-polluted city in the country.

Now we know the pollution that we are creating down here is being pushed up the slope and contaminating our fresh mountain air.

The National Center for Atmospheric Research (NCAR) just released a new report commissioned as part of a major field project in the summer of 2014 led by Dr. Gabi Pfister and Dr. Frank Flocke: The Front Range Air Pollution and Photochemistry Experiment (FRAPPÉ) .

The research was conducted jointly by NCAR and NASA, taking detailed measurements from the ground and from aircraft.

In this new report, NCAR scientists have now concluded that automobile traffic, and local oil and gas operations are the two main sources of our ozone pollution.

The report says those two sources contribute, on average, 60 to 80 percent of the total local ozone production in the region.

NCAR says that all of northeast Colorado is out of compliance with the EPA ozone standard of 70 parts per billion, and that on some days, more than half of that pollution is produced right here on the Colorado Front Range.

The study also concludes that ozone is frequently pushed up into the foothills, and even remote mountain areas, including Rocky Mountain National Park. Scientists have found damage caused by ozone on the sensitive and unique vegetation in Rocky Mountain National Park.

The study shows that ozone pollution also spills over the Divide into the mountain valleys near Granby, but it does not track too far west. Steamboat Springs is often listed as one of the cleanest ozone cities in America by the American Lung Association.

NCAR says ground-level ozone is created when the sun bakes other pollutants, creating an invisible but harmful pollutant that can lead to increased asthma attacks and other respiratory ailments, producing symptoms that include coughing, trouble breathing, and chest pain. It also can be damaging to vegetation, including crops.

"And you can talk to a lot of people that have asthma or an other respiratory problem, and they are very aware of this. They have to go and check the air quality forecast daily. They are affected by this ozone pollution," said NCAR scientist Dr. Gabi Pfister, one of the lead scientists in this report.

Pfister also said she believes most people will be surprised to learn of the amount of ozone pollution in Colorado's precious mountains.

“But shouldn't it be incentive enough that we want to live in an area, that we breathe clean and healthy air? I mean I don’t want to go out on a bad pollution day and breathe the air because I know that it damages my health, it damages our ecosystems. Don’t we want to do it for ourselves, no matter if you go to the mountains or not?" said Pfister.

The Front Range of Colorado has to work harder than other cities to reduce ground-level ozone. We are susceptible to temperature inversions that pool our pollutants in large concentrations. Our location next to the mountains means that easterly winds trap pollutants in our area. And because of our elevation, we have less atmosphere up here to filter out the solar radiation that creates the ozone.