Oamaru’s air quality is relatively good compared to the rest of the district, says Gavin Palmer, Otago Regional Council director of engineering, hazards and science.
Air quality in Otago is monitored by the Otago Regional Council who follow the National Environment Standards (NES) set by the Government in 2004.
The NES standards set a limit of PM10 emissions (air particles produced from primarily from household fires), which is the main cause of air pollution, to 50 micrograms per cubic metre of air.
In September 2005, areas where air quality could reach high levels were identified and classed as airsheds based on previous monitoring, as well as climatic and topographical features.
Mr Palmer said out of the 13 towns in Otago that had been monitored, Palmerston was the only one not to exceed the NES limit and the next best towns had been Oamaru and Lawrence, which had 2-3 exceedances during the winters they were monitored.
Relatively speaking, North Otago had good air quality when compared to Alexandra, Milton and Cromwell, which regularly had more than 30 exceedances a day, he said.
“This is not to say that air quality is good every hour of the day.
“It is well-recognised that during evening hours and some morning hours, under certain weather conditions, there may be excessively smoky conditions due, primarily, to the extensive use of solid fuel domestic heating appliances.”
Currently, there is a continuous air quality monitor in Palmerston, which will be removed later this year.
In Oamaru, a monitor was installed at the end of June 2008 and ran every day until September 2009.
There are nine towns where the air quality is continuously monitored and there is one monitor that gets rotated every two years around other towns.
In the case of Oamaru, once the pattern of air quality was established, the regional council decided to move onto another town, Mr Palmer said.
Permanent monitoring takes place in other towns either because they have more challenging air quality environments or the Ministry for the Environment has required them to be monitored.
Otago is required to meet the NES, which state there should be no more than one day a year over 50µg/m3 by 2020.
“We would like to see all air quality meet the Otago Goal Level of having no days over 35µg/m3.”
North Otago Asthma Society educator Debbie Hulls said she did not think the air quality in Oamaru was worse than anywhere else, however the quality of the air did have an impact on asthma sufferers, especially “cold dry nights when the smoke’s hanging around”.
Southern District Health Board (SDHB) medical director of women’s, children’s and public health Marion Poore said although all areas identified as airsheds (including Oamaru) had air quality that was deemed to pose an increased risk of respiratory illness, air quality in North Otago was generally pretty good.
By RUBY HARFIELD