The death toll in the Australian state of Victoria from a rare phenomenon called "thunderstorm asthma" has risen to at least 8. More than 8,500 people were treated at area hospitals, including one who remains in a critical condition.
The incident began at about 6:30 p.m. on November 22 when emergency services in the state of Victoria started receiving a sharp increase in people who suffered from respiratory symptoms. It coincided with heavy rain and a thunderstorm that hit the area.
Over the next few hours, hospitals across the region treated more than 8,500 people in connection with the event, which flooded emergency lines with thousands of calls and overwhelming the health system as they struggled to treat the victims. Melbourne, Geelong and nearby areas were the worst hit areas.
The Victoria Department of Health & Human Services confirmed on Tuesday that two patients who were earlier described as critical had died, raising the death toll to eight. Seven other patients remain hospitalized for a variety of respiratory and related conditions, including a man who is in a critical condition at a Melbourne hospital.
The phenomenon happens during a thunderstorm when downdrafts of cold air concentrate pollens and mold spores before sweeping them into the high humidity of clouds. They are then broken down into small, respirable fragments which are released through rain. They can then cause severe asthma attacks as the allergens are highly concentrated.
People who never experienced an asthma attack before can also be affected by the phenomenon if they have a history of allergic rhinitis. And while thunderstorms have long been linked to increases in asthma attacks, especially during the grass flowering season, the scale of the emergency in Victoria was unprecedented.