Air quality in pollution hot spots continues to improve

Alexandra's air pollution problem is not made worse by the level of air pollution in Clyde, and...

Alexandra's air pollution problem. Photo: Lynda Van Kempen.

Air quality in Otago’s key pollution hot spots is improving, although more remains to be done, the latest regional data shows.

Otago Regional Council (OCR) staff presented the most recent particulate monitoring data, from last year, to councillors during their environmental science and policy committee meeting in Balclutha yesterday.

Although home heating emissions in some parts of the province continued to exceed national standards, the figures revealed an overall downwards trend was continuing.

Collectively, monitoring in Alexandra, Arrowtown and Mosgiel showed 17 exceedances of particulate matter 10 (PM10) during the winter months last year.

That was down from 31 during 2021, and 57 in 2017, the report said.

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

ORC land team leader Ben Mackey said Otago had several towns where air quality was considered degraded during winter, including Alexandra, Arrowtown, Clyde, Cromwell and Milton.

"Around Otago the main source of particulate matter is home heating emissions in winter.

"There were 17 instances last year where the national PM10 standard was exceeded — in Alexandra (4), Arrowtown (12) and Mosgiel (1), with none in Dunedin Central."

The ORC had implemented work programmes to improve quality in targeted towns as part of its Air Quality Strategy 2018, which led to the long-term reduction.

New standards, taking account of lower particulate sizes and concentrations, were expected to be adopted soon, Mr Mackey said.

Councillors at yesterday’s meeting reacted positively to the latest results.

Cr Michael Laws said, given housing growth in Dunstan, the reduction was unexpected, and should be celebrated.

However, Cr Bryan Scott cautioned against the council "patting [itself] on the back too soon", as the number of exceedances remained high in places.

"There’s still a long way to go."

The ORC would run its Burn Dry, Breath Easy programme once more this winter, Mr Mackey said.