Winter ozone problem returns to western Wyoming gas fields

CHEYENNE (AP) — Itchy eyes and scratchy throats blamed on high levels of wintertime ozone have returned to western Wyoming's gas patch for the first time in six years, and so too has finger-pointing over who's responsible for fouling the air.

The ozone results from atmospheric chemical reactions that occur in just the right mix of cold temperatures, sunlight, snow on the ground and air pollution....