The Calgary Region Airshed Zone enjoys collaborating and learning from all the Airsheds in Alberta. This blog post was written by Fort Air Partnership which encompasses Lamont County, Fort Saskatchewan, Bruderheim, Gibbons, Elk Island, and Redwater.
Cold Weather Impacts Air Quality
Most of the time, local air quality in the Fort Air Partnership (FAP) Airshed is of low risk to health as indicated by the Air Quality Health Index (AQHI). However, the AQHI rating can rise to a medium or high health risk when there is an occurrence of a weather phenomenon called a temperature inversion.
Normally, warm air sits near the ground and air rises easily, carrying away polluting substances. During a temperature inversion, cold air is trapped near the ground by warm air several hundred meters above it. The warm air acts like a lid and polluting substances can’t rise and disperse as readily. This leads to a higher AQHI rating. Some sources of polluting substances, like industrial emissions and wetlands, stay fairly constant throughout the year no matter what the season. But in the winter, fireplaces, wood stoves, home heating and idling vehicles contribute to higher concentrations. A temperature inversion traps a build-up of these substances near the ground until wind, a snowstorm or some other weather change sweeps them away. Fortunately, temperature inversions that cause high or very high AQHI ratings are rare. In our Airshed, only six hours of high or very high AQHI ratings due to inversions were recorded throughout 2017.
What you can do?
People can reduce their impact on air quality by not idling vehicles when parked, avoiding excessive fireplace or wood stove use, and using energy efficient products. People can also keep track of current and forecast local AQHI levels on our website and, if levels are high, adjust their outdoor activities accordingly.
Fort Air Partnership 2017 Results & Five Year Trends Released
Our 2017 regional air quality monitoring results show that FAP’s six stations that collect data used to calculate an hourly and forecast Air Quality Health Index (AQHI) in and around Alberta’s Industrial Heartland registered low risk readings most of the time.
In total across the network, 43,014 hours of AQHI readings were recorded in 2017. Of that total, 57 hours (or less than 0.2% of total hours monitored) were in the high or very high risk AQHI category. These were due mainly to forest fire smoke or winter temperature inversions.
During 2017, there were 146 occasions across FAP’s nine monitoring stations where air quality measurements exceeded Alberta’s Ambient Air Quality Objectives. Two-thirds (67%) of these exceedances involved high concentrations of Respirable Particulate Matter (PM2.5). The PM2.5 exceedances were caused mainly by forest fire smoke and winter temperature inversions.
Five year trends of both AQHI and exceedances show fluctuations. This can be attributed to variances in annual seasonal events like forest fires, weather patterns and FAP’s transition over the last five years to a regional monitoring network that more accurately monitors air quality where people live.
For more information on Fort Air Partnership, www.fortair.org