Asthma deaths prompt Alta. probe

The deaths of four people from asthma attacks within a two-week period in July have prompted an Alberta Health investigation.

Three of the deaths occurred in Edmonton. The fourth was in northern Alberta.The victims were a man and a woman in their 50s and two men in their 20s.

"At this point in time, there is no commonality that's found between the four cases," Dr. Marcia Johnson, the acting medical officer of health for Alberta Health Services in Edmonton, said Monday.

Officials have only conducted a preliminary investigation at this point.

The deaths occurred in the second and third weeks of July. Some of the deaths werelinked directly to asthma; inother cases, the asthma wasaggravated by other underlying medical conditions.

Johnson would provide no further details about the cases.

There are 10 to 20 asthma deaths for every million people each year in Canada, Johnson said, which makes the chance of death from an attack relatively rare.

Still, health officials warn that asthma can worsen quite quickly, and people with the condition need tomonitor their symptoms closely.

"Although asthma can be controlled, it has to be taken seriously and it has to be respected as something to be taken care of and watched," Johnson said.

Poor air quality in Edmonton last week caused by smoke from forest fires in B.C.led to a rise in respiratory complaints at local emergency rooms, particularly on Thursday.

Monday's air quality was rated from good to fair, and the number of medical cases has dropped with the improved air quality.But health officials are stillonalertas some patients might take longer to develop symptoms after the initial exposure to bad air.