Nitrogen Dioxide: More about the data

Nitrogen dioxide trends are based on hourly data collected by the continuous the continuous ambient monitoring stations operated by Alberta Environment and the airshed organizations. This data can be obtained directly from the Clean Air Strategic Alliance (CASA) Data Warehouse.

In 2007 there were 36 Alberta Environment and airshed zone stations monitoring nitrogen dioxide (excluding portables). Twenty-five stations are included in the analysis for this indicator. The other stations do not have adequate data for trend analysis. Only those stations with five or more years of consecutive data are included in the analysis. Trends that are statistically significant (α=0.05) are represented with an asterisk.

Current nitrogen oxide concentrations are posted on Alberta Environment's interactive air quality website.