Air pollution in Invercargill and Gore caused seven air quality exceedances between them in the 2024 monitoring season.
Environment Southland said, in a statement, the exceedances began late in the season, with the first one not until July 14 in Invercargill, with a 24-hour average PM10 concentration recorded at 51.6mcg per cubic metre.
Invercargill’s highest recording came just two days later with a reading of 69.5mcg/cum.
The season runs from May 1 to the end of August.
Environment Southland air and terrestrial team leader Dr Nick Talbot said the first four exceedances, between July 14-20, came during a particularly cold snap.
"We know it was a winter of cold temperatures and many days had low wind speeds, allowing pollution from home heating to become trapped between inversion layers," Dr Talbot said.
Particulates from air pollution could easily get into the lungs, he said.
"We are not saying people should avoid home heating during the winter period. However, there are ways to reduce their impacts on winter air quality. These include burning dry wood, upgrading to cleaner heating sources and being more aware of how they operate their burners."
Among the exceedances this winter were two in Gore, ending its four-year period of no exceedances.
"Unusually high concentrations in the early morning added to the afternoon and evening peak concentrations we typically see from home heating. Combined, these brought the 24-hour average over the limit of 50mcg/cum."
Niwa conducted research for Environment Southland to track air pollution across the Gore airshed this season using 28 sensors.
This data will help to identify which areas have the highest and lowest areas of air pollution and may indicate the need for further monitoring sites in the town. The results are expected next month.
This year there was a reduction in public complaints about domestic burning, with a total of 13, and a rise for outdoor burning, which totalled 49, up from 39 last year.
