The Environmental Protection Agency (EPA) has advised that the air quality in Melbourne and Geelong will continue to be poor over the weekend.
The poor air quality is believed to be the result of calm weather conditions combined with a build up of urban pollution as well as wood and heater smoke.
While the event is not as dramatic as the thunderstorm asthma which occurred last November, the pollution may exacerbate heart and lung conditions and cause coughing and irritated eyes.
"Thunderstorm asthma was pollen, which of course isn't a pollutant -- it's a naturally occurring event," Dr Anthony Boxshall from the EPA told Nine News.
"This is way less dramatic than that but if you're an asthmatic it is important that we get the information out to stick to our asthma management plan."
The EPA identified those believed to be at risk include people over 65, children 14 years and younger, pregnant women and those with existing heart or lung conditions.
These groups have been advised to limit their time spent outdoors.
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