The air quality in Melbourne is the worst it has been in five years because of smoke haze from last weekend's grassfires.
Four hundred and thirty two fires broke out last weekend but very calm winds since then mean the smoke has remained blanketed over the city and the suburbs.
The Environment Protection Agency (EPA) says the at Footscray, Deer Park, Alphington and Richmond was poor or very poor today and only two areas, Dandenong and Traralgon are listed as being good.
The last time the concentration of particulates was this high was in February 2009 around the time of the Black Saturday fires.
Victoria's chief health officer Dr Rosemary Lester says people with heart or lung conditions need to continue to take precautions until the smoke clears.
"It is important that those at-risk groups minimise their outdoor activity," she said.
"They should take their medication strictly as prescribed by their doctor and people with asthma should follow their personal asthma plan.
"Because of the very still conditions I believe they expect that it might last for another few days yet."
The EPA says Melbourne's air quality is usually ranked amongst the best in the world, only just behind Canada.
© ABC 2014
10:33 EST Areas of fog have swallowed up parts of Melbourne for the fourth morning in a row, with one more to go.