Smoky air usually marks the onset of winter in Hawke’s Bay, with our reliance on wood-burners for home heating. But this year a colder than average month of May has resulted in well-above-average smoke (or PM10) levels in the air for this time of year, especially in Hastings.
Hawke's Bay Regional Council scientists say that it could get worse, with weather predictions for more anticyclones this winter – meaning chilly nights and calm, frosty mornings.
So far this winter PM10 levels have exceeded the National Environmental Standards for air quality on 13 days in Hastings. Last year Hastings exceeded the standard 13 times for the whole winter.
“It’s the worst start to winter air quality since Hawke's Bay Regional Council started full-time monitoring of PM10 levels in 2003,” says air quality scientist, John Phillips.
A graph of the latest air quality in Hastings and Napier is live on this website so people can check each day.
Hastings is the most affected by air pollution from household woodburners because of the strong inversion layers there in winter. Napier’s PM10 levels are measured at Council’s Marewa Park monitoring site and exceeded the standard for the first time last night, although there are likely to be pockets of Napier that have exceeded it before now.
The National Environmental Standards, put in place by central government, require regional councils to reduce PM10 levels in polluted areas to acceptable levels by 2013 or they won’t be allowed to issue air discharge consents for major industries, even though industry is not the cause of the problem.
PM10 levels in Hastings will need to be reduced by 79%, and Napier by 55%. Hawke's Bay Regional Council is having to consider what policy approach is needed to reduce the air pollution during winter in these cities to meet the National Standards.
What can people do to reduce smoke in the air?
While some heating sources are less polluting than others, much of the pollution arises from poor operation of woodburners. There are ways that people can reduce the amount of smoke coming from their home fires.
Council data shows that the peak smoky times are early in the evening when people start their wood burners, and then later in the evening when people stoke fires up with wood and ‘bank them down’ before going to bed.
“Set your wood burner so the fire starts quickly and builds up flame and heat rather than smoke. That will reduce the amount of smoke in the night air,” says Mr Phillips.
“Damping down woodburners overnight is also extremely inefficient. By starving the fire of oxygen, it releases a lot of smoke outside and clogs your chimney with soot.”
The new generation of NES-compliant woodburners cannot be damped down, but they still need to be started quickly and operated with dry wood to work efficiently. “With slow starts and damp wood they can be almost as polluting as older-style woodburners.”
Ways to reduce smoke pollution of the air are -
- Start the fire quickly, with plenty of dry kindling and a good draft to get a hot flame going.
- Use only dry wood in home heating burners.
- Never use treated wood or driftwood, as burning these releases harmful substances that damage your burner and your health.
- Have an insulated, dry home and close curtains before it gets dark.
- If your burner is past its useful life, replace it with an NES compliant model or consider alternatives like pellet burners or heat pumps.
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