A council spatial air quality report shows the highest levels of PM10 (particles less than 10 microns in diameter) were found in areas of dense residential land use which also had residential land use up-wind.
Environmental resource scientist Jono Conway says in the report Mosgiel failed the national standard about eight times a year and experienced cold, still days and temperature inversions.
The National Environmental Standard requires the average daily PM10 level not to exceed 50mcg per cubic metre in a 24-hour period more than once a year by 2013.
Emissions across Mosgiel on an average winter's day were caused mainly by domestic heating appliances, with the western areas of town experiencing higher densities of emissions, Mr Conway said.
The southeastern quarter of Mosgiel had large open areas of parks, schools and retirement facilities and industrial and commercial emissions were low in the town, apart from one large discharge to the northeast which contributed 7% of PM10 emissions.
The study showed there was considerable variation in air quality across Mosgiel during winter evenings, Mr Conway said.
"The peak areas tend to be in residential areas and towards the north and west of the town, due to clusters of residential land use and the prevailing wind."
Cr Bryan Scott said Mosgiel's air quality needed to be put in perspective.
The times when it had exceeded the national standard were not frequent compared with Arrowtown or Milton, which had been over the limit about 29 and 19 times respectively so far this year .
Up to July 19, Mosgiel had exceeded the national standard four times.
Regional council chief executive Graeme Martin said the air quality standards were being reviewed by the Government, but in the meantime the council should continue doing all it could to ensure people were aware of the issue.
"Mosgiel remains one of the areas likely to get through . . . without stronger regulatory measures."
Cr Louise Croot said there was markedly higher use of wood and coal in the problem areas, so the message to reduce coal use and use dry wood should be continued.
