Timaru has the worst air pollution in Oceania, according to World Health Organisation figures.
The organisation measures pollution by the amount of particulate matter, known as PM10, in the atmosphere.
The matter can come from sources including sand, sea spray, construction dust and soot.
Timaru mayor Damon Odey said Timaru's location was a factor.
"PM10 is made up of many things including dust and airborne salt particles and of course we're right on the side of the ocean there," he said.
"You've got to compare apples with apples." - Damon Odey
The regional council was running an educational programme about wood-burning, Mr Odey said.
"In 2014 we exceeded our allowance something like 45 times, last year we were down to about 22, so we are making progress.
"We do also have an older demographic in this town, so we realise some people on fixed incomes just can't pull out their log burner out and chuck a new one in.
"So there's a balance around making sure that they do the best with the appliance they've got and as they reach certain ages look at phasing them out to new ultra-low emission burners."