Timaru's position as Canterbury's smoggiest city remains.
The monitoring station at Anzac Square yesterday recorded an average particulate matter rate of 131 micrograms per cubic metre of air, nearly three times the recommended maximum level set by the World Health Organisation of 50mcg per cubic metre.
It is the 25th such instance this year, well up on the same time last year, when the town had recorded 20. Christchurch was the second-worst city in the region, with 18 high-pollution nights so far.
It appears Timaru is also running close to Alexandra (29 so far) and Milton (25), the two worst air-sheds in the country last year.
Otago Regional Council environmental science director John Threlfall said all of those areas had clear, wind-free winters, cold night temperatures, and poorly insulated homes.
"That means the particulate matter hangs in the air longer, and builds up over the evening.
"Otago and Canterbury appear to be in a ‘who is the smoggiest competition'. It's not the sort of competition that either side wants to win."
National environmental standards mean towns will be allowed to have only three such nights by 2016, or face possible central government restrictions on getting consents for development.
Environment Canterbury (ECan), along with the Energy Efficiency Conservation Authority, launched a new Clean Heat scheme this year. So far, there have been more than 80 completed conversions to cleaner forms of heating this year, with several dozen more expressions of interest.
ECan spokeswoman Katherine Trought said it had been a challenge to educate Timaru people about the risks.
"It can be as simple as making sure you're burning your wood properly," she said. "If you're not sure, even checking your chimney outside could give you an idea."
Ms Trought said the education campaign, which included a website about facts on air pollution, letscleartheair.co.nz, had got a good response from the public, but more awareness was needed.
"We do inventories every three years and, every time, it shows the bulk of particulate pollution is caused by poor home heating. It really is as simple as that."
Ms Trought said ECan would keep co-operating with the Timaru District Council over the next year. "There will be a review of its progress, but this is a significant commitment we have made."
In Timaru, ECan still allows woodburners to be installed, but they must be low-emission models.
A $500 subsidy applies to woodburners and pellet fires approved by ECan for Timaru.
Timaru district councillor Steve Earnshaw, who has campaigned for the city to clean up its air in the past, said it was "disappointing, but not surprising".
"We won't really see the effects of the programme until a year or so down the line. But I'm encouraged that more people are becoming aware of the issues. That's progress. Now, we have to start doing something about it," he said.
- The Timaru Herald