Earlier Thursday, Alberta Health Services had issued an advisory for areas east of the city but expanded that when the smoke started to drift into the city itself.
AHS said in a news release that while there is a noticeable smell of smoke in Medicine Hat, air quality monitoring being done by a mobile unit has shown no significant health risk.
However, people with sensitivities and pre-existing respiratory conditions such as chronic obstructive pulmonary disease, heart problems and asthma could be impacted.
On Wednesday, officials in Cypress County declared a state of emergency and ordered nine homes evacuated due to the fire, which started Monday.
They said at the time that air quality in the area had deteriorated to the point that it was considered "a serious life safety hazard."
The cause of the fire at the Westar landfill remains unknown but officials said it is not possible to extinguish it yet.
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