Edmontonians are dealing with dense fog and poor air quality that has blanketed the region.

Environment Canada has issued two alerts for much of central and northern Alberta, including the Edmonton region.

Poor air quality is expected to continue throughout the week, according to the alert updated Tuesday night.

Fog was still thick on Wednesday morning.

"Conditions may improve slightly Wednesday afternoon, though areas of poor visibility will likely linger throughout the day," reads the advisory that was updated at 3:55 p.m.

Dozens of flights were cancelled or delayed at Edmonton International Airport as fog engulfed the Edmonton region Tuesday.

A spokesperson for EIA told CBC News that all departures were cancelled for Tuesday night, but conditions were improving and 14 flights were still scheduled to land, adding that the cancellations and delays appear to be a ripple effect from earlier in the day.

Ethan Williams, a weather and climate reporter and presenter for CBC News based in Regina, told CBC Edmonton News at 11 host Sandra Batson that the conditions are being caused by an inversion effect.

"As you go higher up in the atmosphere the temperature is actually getting warmer, instead of colder, and that is creating kind of a cap, almost, a boundary layer on the atmosphere which is allowing those fog particles to develop," Williams said.

While the fog may clear up in some areas Wednesday, the poor air quality will continue for days due to stagnant weather conditions causing pollutants at the surface to build up, Environment Canada said in its advisory.

The air quality is expected to be worse overnight and in the early morning hours, Environment Canada said in the special weather statement.

As of 8:15 p.m. MT Tuesday, the air quality health index in Edmonton was at 8, which is considered high risk, and can be a health concern or people with heart or breathing problems, those with diabetes, children and the elderly.