Hiking In The Ozone, And Learning About It Too
On a warm afternoon in Boulder, a small group of residents and scientists walked alongside South Boulder Creek.
"Today, we are here to talk about our regional air quality," said Jennelle Freeston, the volunteer coordinator for Boulder's Open Space and Mountain Parks.
The group had gathered as part of an educational effort to teach area residents more about ground level ozone, the most serious air pollutant on the Front Range. Because the area has so much pollution, scientists from NASA and the National Center for Atmospheric Research are currently flying planes to learn more about what causes the pollution and how it moves through the atmosphere.
With low-flying planes likely to capture resident attention, NCAR also seized the opportunity to help them learn -- and capture some additional air quality data en route. In collaboration with the University of Colorado's Cooperative Institute for Research in Environmental Sciences, they created a set of hikes at Boulder Open Space and Rocky Mountain National Park.
"While we are hiking we are going to be taking our air quality readings," said Freeston, rallying the group down the trail. At periodic stops along the way, Freeston asked the group some questions -- did they know what caused ozone here? (Answer: mostly burning fossil fuels, energy production, and agriculture).
In addition to learning about ozone themselves, the hikers were also gathering information to help scientists learn about it. To do this, they carried two different instruments. Freeston and another hiker had a CairClip, a pollution monitor about the size of a 35 mm film canister that measured ozone and the pollutant NO2, attached to their waists.
The other instrument, called an M-Pod, is also wearable. It connects to a smart phone and measures a wide range of pollutants, including ozone and volatile organic compounds, or VOCs.
Along the way, Freeston read her ozone measurements out loud.
"44 parts per billion, 37 parts per billion. … now mine says 52, and it's flashing."
The flashing indicated that ozone had passed a threshold, air quality going from good to moderate. Over 100 parts per billion means the air is unhealthy for sensitive groups, like people who are exercising or who have asthma or other respiratory diseases. Freeston, who has led a number of the educational hikes, said the worst her monitor has picked up has been around 90 parts per billion.
"Breathing in ozone at higher levels is like getting a sunburn on your lungs," Freeston said, and the group of hikers collectively winced at the image. Thirty million Americans have asthma, she said, and are extra vulnerable to high ozone levels. One way to avoid exposure is to exercise early or late in the day, when the sun is not strong and ozone, which is formed by a reaction with the sun, is not as high.
Nick Masson, a research assistant at the University of Colorado, also came along for the hike. He works on developing instruments like the M-Pod, and cautioned that while the devices are convenient, they are not as accurate as scientists hope -- yet.
"A lot of this technology has really just come out in the last two to three years," said Masson. The benefits, though, are many. The instruments are cheap, less than $1,000 each rather than $20,000 per instrument, like standard air quality measurement devices. And, they're portable, allowing scientists, and citizens, to measure air quality even where there are no preexisting monitors.
Right now, the Environmental Protection Agency is working with the CairClips to see how accurate they are compared to existing air quality monitors.
"So we are trying to really determine how well they work compared to our reference methods," said Russell Long, a research chemist with the EPA.
While Long does not believe the tiny instruments will completely replace full-sized monitors, he does think they could be used to identify areas that may have pollution problems, or places where scientists or regulators want to learn more about pollution but cannot afford an expensive monitor.
During the hike, questions came from the group about the monitors. Do they have GPS? What will the data be used for?
The sensors do record location data, and the National Center for Atmospheric Research plans to use the pollution information collected from the hikes along with the data they collected from flights, balloons, vans, and other monitoring efforts during their summer research project.
As the hikers neared the trailhead parking lot, they brainstormed ways to limit their own contribution to the Front Range ozone problem. "Carpool," one shouted out. "Ride your bike," suggested another. "Write your legislator to tighten air quality regulations," offered a third.
Then, after filling out a survey, most of the hikers got in their vehicles and drove away, each now aware, if they had not been before, that they were contributing a tiny bit to the Front Range ozone problem.
Oil & Gas
All Tech Considered