Central Otago households have been commended for their vigilance over what they are burning to keep warm over winter.

There were just 16 instances last year in Central Otago where the national PM10 standard was exceeded in Alexandra (4) and Arrowtown (12). 

PM10 and PM 2.5 refer to particles of less than 10 micrometres and fine particles of less than 2.5 micrometres in the air we breathe. 

From 2017 to 2021, the number of exceedances has steadily fallen from 57 to 31- the average for those five years

However, home heating emissions around parts of Otago continue to exceed national standards in some places, according to the Otago Regional Council’s (OCR) annual air quality report for the 2022 calendar year.

Monitoring in Alexandra and Arrowtown showed 16 exceedances of particulate matter 10 (PM10) during the winter months last year.

“Around Otago, the main source of particulate matter is home heating emissions in winter,” ORC land team leader Ben Mackey said.

“Recent research provides evidence that air pollution is dangerous at lower concentrations than previously thought and supports the lowering of existing guidelines.

“The limit for PM10 is an average of 50 micrograms per cubic metre over 24 hours, with the maximum in Alexandra … 89 on one day.”

Ben said while the ORC monitors in particular areas where air quality is degraded, “everyone should be aware of what they are burning as it can have an impact”.

Long-term exposure to particulate matter can contribute to the risks of developing cardiovascular and respiratory conditions or exacerbating preexisting conditions

ORC has implemented work programmes as part of its air quality strategy to improve quality in targeted towns leading to the long-term reduction in PM10 concentrations in Alexandra, Cromwell and Clyde.

Continued vigilance over what households burn is encouraged.