A Canadian study found that thunderstorms can trigger asthma attacks, and fungus may be the culprit, according to the results of a study published in Chest (March 2003). Examining 4 years of records from the Children?s Hospital of Eastern Ontario, researchers from the University of Ottawa Health Research Institute compared the pattern of asthma attacks with daily data on weather, airborne allergies, and pollution collected at a nearby airport.
Robert E. Dales, MD, lead author, noted that emergency room visits appeared to jump after severe thunderstorms, yet the link has neither been well established nor explained. Hospital visits for asthma were 15% more frequent on days with thunderstorms than on other days. Dales said that the cause appeared to be fungal spores more commonly found in air samples on those days, while other allergens, like pollen, were not.