Australia thunderstorm asthma risk raised to 'moderate'
Locals in an Australian state hit by a thunderstorm asthma outbreak last year have been warned of a "moderate" health risk this week.
Nine people died in Melbourne last November after rain and wind triggered asthma attacks brought on by pollen.
On Sunday, authorities asked people in Victoria to plan for asthma conditions, although they may not eventuate.
It is the first warning since an alert system was introduced following a review into last year's event.
There are three tiers in the classification system - low, moderate and high.
More than 8,000 people were treated in hospital during last year's outbreak. The strain on health resources was akin to a disaster event such as a major bushfire, authorities said.
"The number of people affected and the severity of the consequences suggest this thunderstorm asthma event was without international precedent," the review found in April.
Thunderstorm asthma typically occurs in spring when rye grass pollen gets wet, breaks into smaller pieces and enters people's lungs, causing them breathing problems.