As ozone increases, so do doctor visits for residents in Wyo. county

Posted: Apr 17, 2013

Written by

Scott Streater, Greenwire
Sublette County

A new health study has found that spikes in ground-level ozone concentrations in a heavily drilled county in west-central Wyoming result in more people visiting doctor's offices with respiratory complaints.

The 32-page study, conducted primarily by researchers with the Centers for Disease Control and Prevention and the Wyoming Department of Health, measured daily ozone concentrations in Sublette County, Wyo., between 2008 and 2011 and found that increases in ozone concentrations had adverse health impacts for residents.

The goal of the study was to evaluate associations between short-term changes in ground-level ozone and adverse acute respiratory effects, and the researchers found that even modest increases in the maximum daily ozone level measured over an eight-hour period led to increases in local health clinic visits in Sublette County.

High concentrations of ground-level ozone can trigger asthma attacks and inflame the conditions of those suffering from bronchitis and emphysema. Ozone pollution is particularly dangerous to children and the elderly.

Sublette County and portions of neighboring Lincoln and Sweetwater counties in the Upper Green River Basin are currently in violation of the federal health-based standard for ozone concentrations, which is 75 parts per billion.

The study suggests that for every 10 ppb increase in ozone, there was a 3 percent increase in local health clinic visits between 2008 and 2011 in Sublette County.

"The results of this study suggest an association of ground-level ozone with clinic visits for adverse respiratory-related effects the day following elevations of ground-level ozone in Sublette County," according to the study. "Improved awareness and education of the public and providers of the adverse respiratory-related health effects from ground-level ozone in Sublette County should continue."

While ozone levels "vary day to day and from place to place depending on the weather and pollution amounts and types," the study underscores the health impacts of ozone, mainly that it makes it difficult for some people to breathe deeply and vigorously, leading to coughing and sore or scratchy throats, said Kerry Pride, a CDC epidemiologist assigned to the Wyoming Department of Health and the lead author of the study.

The study results were not a surprise to Pride and the state health officials who worked on the study, given the known health impacts of ozone. "Our findings for Sublette County were very similar to what other studies across the country and internationally have found," Pride said.

But the results underscore the urgency to address Sublette County's wintertime ozone problem, which is marked by stagnant air that allows pollution emitted mostly by drilling operations to collect in the lower atmosphere and then be converted into ozone by sunlight and heat reflecting off snowpack on the ground.

Indeed, the high ozone and related health impacts were measured primarily in the winter and early spring months, between February and April, according to the study.

State officials say that in addition to the weather conditions, emissions of nitrogen oxides from compressor engines and generators at oil and natural gas drilling sites are likely the primary man-made contributor to the problem.

Sublette County is home to the massive Pinedale Anticline and Jonah Infill oil and gas fields in the Upper Green River Basin.

The Wyoming Department of Environmental Quality has been working on solutions for years. The DEQ last month released a multipronged plan to address ozone in the Upper Green River Basin that includes a mixture of short-term measures designed to be implemented and completed by August and longer-term strategies that include adopting new rules that would require industry in the basin to better report emissions of all pollutants that contribute to the formation of ozone (E&ENews PM, March 14).

And the DEQ's air quality division this week announced it would continue for a third year conducting on-site inspections of oil and natural gas operations statewide in an effort to ensure that emissions from compressors and generators meet permitted limits (EnergyWire, April 12).

"The weight has always been on us to help reduce these ozone levels," said Keith Guille, a Wyoming DEQ spokesman.

The problem is that ozone is almost always a summertime problem, when pollution from automobile tailpipes and industry smokestacks mix in the sunlight and heat to form ozone. The region's almost unique wintertime ozone problem makes it tough to develop effective strategies to reduce ozone, Guille said.

"In urban areas with summer ozone, they already have [computer] modeling that can tell you if you reduce, say, NOx emissions from automobiles by a certain amount, you can reduce ozone levels by x amount," he said. "We just don't have that."

But the new study comes at a time when federal and state regulators are evaluating several large oil and gas drilling projects in or near the region.

The Bureau of Land Management, for example, is evaluating the Continental Divide-Creston Natural Gas Development Project near the Upper Green River Basin. The project would be among the nation's largest natural gas fields, where developers say as many as 9,000 natural gas wells covering 1.1 million acres of mostly federal land in south-central Wyoming could be developed over the next 15 years (Greenwire, Dec. 7, 2012).

Some environmental groups, including the Wyoming Outdoor Council, have expressed concern that emissions from this project could drift into the Upper Green River Basin.

If a large-scale expansion of oil and gas drilling in the region is approved, federal and state regulators need to ensure they include protections against exacerbating the area's ozone problem, said Bruce Pendery, program director and staff attorney for the Wyoming Outdoor Council.

"Hopefully, this [study] will lead to a little more effort to reduce the emissions of so-called ozone precursors," Pendery said. "I think everyone wants to move in that direction. But the question is, how fast are they going to do it and how much urgency will they feel? We hope this study will contribute to a sense of urgency that this is a priority."

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