The Wyoming Department of Environmental Quality declared another ozone action day for the Upper Green River Basin for both Thursday and Friday.
Regulators warned the weather conditions could generate high levels of ozone, an air pollutant that blossoms when sun reacts with emissions from industrial activities.
Emissions mixed with cold temperatures, a lack of wind and snow cover can concoct higher concentrations of ground-level ozone.
Regulators asked industry and residents to take steps to minimize emissions containing volatile organic compounds and nitrogen oxides.
Individuals can help keep precursor ozone emissions at bay by not idling vehicles or overfilling gas tanks. Companies must limit natural gas production or construction activities during the day.
Thursday’s announcement marked the third time this season Wyoming Department of Environmental Quality called for an ozone action day. The season typically runs from January until March.
The pollutant can cause lung damage or other health conditions. The state’s air quality specialists recommended individuals with chronic respiratory ailments or older adults and children “limit strenuous or extended outdoor activities, especially in the afternoon and evening.”