Ozone levels on rise in NWA, testing shows

Northwest Arkansas had its first brush with higher-than-recommended ozone levels in the air at ground level in 2023, state monitoring shows.

High ozone levels can adversely affect people with respiratory conditions such as asthma, according to the federal Environmental Protection Agency.

State monitoring stations in Fayetteville and Springdale would have to report finding more than 0.07 parts per million of ozone for three consecutive years before passing the EPA’s recommended threshold, said Tim Conklin, executive director of the Northwest Arkansas Regional Planning Commission. The 2023 readings were the region’s first year above the threshold, he said.

The 0.07 threshold is not based on a single sample either, Conklin said. The level is determined using a formula based on averages and peak levels.

If the region exceeds the threshold in each of the next two years, Northwest Arkansas communities would become eligible for federal money to address the rise, Conklin said. The region would also have to take ozone mitigation into more account in planning projects such as transportation improvements.

Communities in the region are at work on projects to improve air quality and reduce emissions including ozone, Conklin said. For example, Bentonville is setting up a program using grants from nonprofit sources to help residents afford electric bicycles.

The biggest challenge in curbing ozone emissions is the growth of the region, Conklin said.

“More people, more emissions,” he said. “We have more emissions each and every year because we have 100,000 people move in per decade.”

Ozone is produced indirectly, according to the EPA. A variety of chemicals emitted by cars, power plants and a variety of industries combine in the air and are converted into ozone by sunlight. High concentrations of ozone at ground level tend to occur in urban areas on sunny days, according to the agency.

Kevin Stewart is director for environmental health advocacy and public policy at the American Lung Association. He said in a statement Friday high levels of ozone are of concern to high-risk groups such as children, senior citizens and people with asthma and chronic obstructive pulmonary disease, also known as COPD.

Central Arkansas has encountered high-ozone days before but does not exceed the current EPA threshold, said Casey Covington, executive director of Metroplan, the regional planning commission’s equivalent in Central Arkansas. The highest concentrations of ozone in Arkansas are in West Memphis, part of the Memphis metro area, he said.

“If there is a high concentration of ozone on a given day there are things you can do,” Covington said in a phone interview. “Even getting people to mow their yards at a different time of day can help.”

The biggest effect of exceeding the EPA’s levels is on planning of transportation projects, Covington said. Planners have to show their projects take the increased level and mitigating it into consideration, he said. Another effect is on recruiting new business.

Higher ozone levels can also have environmental effects, particularly on sensitive plants during growing season, according to the EPA.