canadasvoice:Environment Canada issued a special air quality statement for the city of Calgary at 5:34 p.m. Thursday.
High levels of air pollution developed due to a temperature inversion.
Although this is not a frequent occurrence in Calgary it does sometimes happen as a chinook is unfolding. At first warmer air will ride over the heavier, cold air on the surface causing pollutants, which normally get carried away on rising air currents, to get trapped at ground level.
West winds are expected to surface later Thursday evening, dispersing the pollutants and improving air quality.
Until then, air pollution levels will remain high and some people may experience increased coughing, throat irritation, headaches or shortness of breath. Children, seniors, and those with cardiovascular or lung disease, such as asthma, are especially at risk.
Environment Canada says exposure to air pollution is particularly a concern for children, the elderly, and those who have underlying medical conditions such as lung or heart disease….More
Source – Global News