Running counter to national trends, ozone pollution levels in seven counties in Wyoming have worsened this year, according to the annual “State of the Air 2016” report from the American Lung Association (ALA), which was released on Wednesday.

Citing rapid growth of oil and natural gas development in some of the identified counties, ALA’s report called out the Wyoming counties for drops in their grades for ozone despite the national trend of lower ozone levels.

Wyoming’s Department of Environmental Quality (DEQ) did not review the ALA data in advance, and it is now reviewing the report and will have a reaction later, a Cheyenne-based DEQ spokesperson told NGI on Thursday.

“We follow all the standards and really have only one area of nonattainment [with federal standards] and that is for ozone in the Sublette County area,” said Keith Guille, a DEQ spokesperson. “That’s the winter ozone phenomenon, and we haven’t exceeded the [federal 70 ppb] standard there for the past five winters [2012-2016].”

Guille said the state also is considered a leader in the control, application and guidance of minor source controls for oil/gas operations. “The U.S. Environmental Protection Agency has used a lot of what we do, as well as Colorado, in what it puts out for minor source regulations,” he said.

ALA reported that Campbell County, a center of oil/gas growth, had its ozone slip from a “B” grade last year to a “D” now, and Laramie County, where there is also big growth in oil/gas activity, had its “A” grade drop to a “C.”

“Air emissions from oil and gas sources are identified as precursors to the formation ozone,” the ALA report said. “Ozone pollution health effects include asthma attacks, hospital admissions and premature deaths.”

ALA said the problem is focused in the oilfields and other unpopulated areas. Laramie County, where ozone levels have worsened, includes the city of Cheyenne, which the report ranked “as one of the cleanest cities for short-term and for year-’round particle pollution,” an ALA spokesperson said.

Wyoming’s counties also saw some deterioration in particulate matter levels, according to the ALA report, which cited Sublette County as showing improvement in ozone pollution levels only to receive a failing “F” grade for “dangerous levels of short-term particle pollution,” which is supposed to carry serious health effects risks from residents in the area.

Besides the two counties mentioned for worsening ozone levels, the five others are: Albany, Fremont, Sweetwater, Teton and Uinta counties. Sublette saw improvement from “F” to “C.” All eight counties assessed passed the year-’round annual average particle pollution tests, but Sublette had the failure on the short-term particulate pollution.

ALA annually publishes a national air quality report card, using data from federal, state, local and tribal sources on the two most widespread types of pollution — ozone, or “smog,” and fine particulate matter pollution.