ការព្យាករណ៍គុណភាពខ្យល់
ទិន្នន័យគុណភាពខ្យល់ផ្តល់ដោយ៖ the Colorado Department of Environmental Protection (colorado.gov)
Note that the measurements for O3 (ozone), CO (carbon monoxide), NO2 (nitrogen dioxide) and SO2 (sulfur dioxide) are taken from the station: Welby, Colorado