At first glance, the gardens before me are a refreshing contrast to their concrete surroundings. But closer inspection reveals pockmarks dotting many of the plants’ leaves. The spots resemble the furious punctuation marks I made as a child, grinding the lead into the paper so hard that it would leave an indentation.

But the tip of a pencil isn’t responsible for the specks that litter the plants’ leaves. Ozone is.

Rather than protecting us from harmful UV rays, as it does when high in the stratosphere, ozone at the Earth’s surface is an air pollutant.

Surface ozone damages many plants, including valuable crops, and irritates people’s lungs. Along the Front Range ozone pollution is particularly high.

To raise awareness about this regional problem Danica Lombardozzi, a project scientist at the National Center for Atmospheric Research (NCAR), and Kateryna Lapina of CU’s Mechanical Engineering Department planted “Ozone Gardens.” These public gardens have plants like the cutleaf coneflower, snap bean, and milkweed that readily show symptoms from high ozone levels.

“The idea behind the gardens is to educate people about surface ozone pollution,” says Kateryna, “which many people are not aware of.”

“Because the plants react in such a way they make it easier to see the results of ozone pollution.”

Danica shows me another plant damaged by ozone pollution where the green of the leaf has bronzed; it shimmers a little in the sunlight.


The ozone garden project is now beginning its second year. The four gardens are in public locations, including the entrance to NCAR’s Mesa Laboratory and CU’s Natural History Museum, so that everyone can see the effects ozone pollution has on these plants.

Ozone pollution is high along the Front Range in part because of our gloriously sunny days. Ozone forms when pollution from combustion reactions — think of car exhaust, power plants and forest fires — reacts in the presence of sunlight.in public locations, including the entrance to NCAR’s Mesa Laboratory and CU’s Natural History Museum, so that everyone can see the effects ozone pollution has on these plants.

Because ozone forms from these other pollutants, “it’s something you can control in your everyday life,” says Kateryna. “How many times you drive your car, when you mow the lawn or fill your gas tank.”

“There are some really easy steps that people can take to really help reduce ozone concentrations,” adds Danica. “For example, re-fueling in the evening when there’s less sunlight rather than in the middle of the day.”

Those small changes could have big impact, given the consequences ozone pollution has on crops.

“High ozone levels reduce crop yield,” explains Danica. “So, what does that mean for our ability to produce food in the future?”

In Asia, one study estimated that each year the loss in three crops – wheat, rice and soybean – to ozone damage is enough to feed 94 million people.

“You can predict very high losses every year in the US,” adds Kateryna.

For Danica and Kateryna, the ozone gardens are a project of passion.

“The gardens are educational,” says Kateryna. “They show people that we have a large-scale air quality problem in the Front Range and then inspire people to make lifestyle changes.”

“They make an invisible problem visible.”

Check out the gardens at CU’s Natural History Museum and Mountain Research Station or NCAR’s Mesa Laboratory Main Entrance and Cafeteria Patio.

If you can’t make it there, follow the gardens’ progress with Danica’s posts on UCAR’s Sci Ed blog and see their feature from Colorado Public Radio.

By Roni Dengler

Posted by Science Buffs

A CU Boulder STEM Blog

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