Scientists in Colorado study winter ozone pollution
BOULDER, Colorado ” Ozone pollution is typically associated with hot, summer days, but scientists in Boulder, Colorado say it can develop in the dead of winter when the sun reacts with emissions from natural gas fields.
Scientists at the National Oceanic and Atmospheric Administration in Boulder studied ozone levels around two major natural gas fields in southwestern Wyoming and found the pollutant formed quickly on cold days last February under certain conditions.
The finding suggests the hazards of ground-level zone pollution could be more geographically and seasonally prevalent than previously thought.
“Rapid production of wintertime ozone is probably occurring in other regions of the western United States, in Canada, and around the world,” said Russell Schnell, lead author of a paper on the study published Sunday in the journal Nature Geosciences.
Schnell said the wintertime ozone levels in the Wyoming gas fields can quickly reach levels more than twice the 75 parts per billion the Environmental Protection Agency has set as a health threshold, leaping from 30 parts per billion to as high as 160 parts per billion in just four hours. That’s far higher than typical levels in metro Denver on a high-ozone summer day.
“It’s unbelievable,” Schnell said. “It just goes straight up as the sun comes up.”
The NOAA study found that ozone formed in the cold when emissions from gas drilling combined with a temperature inversion that trapped air ” and the chemicals ” close to the ground. Snow reflected enough sunlight to start the chemical reactions needed to form ozone.
Oil and gas companies are adding new emission controls to drilling rigs and making other changes to reduce air pollution in southwestern Wyoming.
Colorado has toughened regulations on energy companies as the state tries to bring a stretch along the Front Range into compliance with federal ozone standards.
Ground-level ozone, a key component of smog, forms when the sun bakes pollutants such as vehicle exhaust and vapors from everything from paint. It is a health risk for children and people with respiratory problems.