Students, scientists, citizens study Arrowtown’s ailing air

Arrowtown may be known for its picturesque autumn scenery, but in winter this tiny Central Otago town has a problem.

Arrowtown may be known for its picturesque autumn scenery, but in winter this tiny Central Otago town has a problem.

That’s why NIWA scientists are this week launching a project in Arrowtown in a bid to better understand what can be done to improve the town’s poor air quality.

NIWA air quality researchers are kicking off an air quality study in Arrowtown that will empower the community to assess their local air quality, then develop and evaluate solutions.

NIWA air quality scientists are recruiting households to install sensors so they can study the air quality inside and outside their homes in much greater detail. 

The sensors will test for smoke and record when people are using home heating. Participants will have the sensors for two to four weeks after which they will be given an assessment of the heating and air quality in their homes.

Data needed to solve air quality problem

Scientist Dr Ian Longley says Arrowtown’s persistent air quality problem is due to wood burning, cooking, calm winds preventing smoke dispersing and polluted air from outside entering and becoming trapped inside homes.

“Domestic wood burners are a major source of air pollutants in urban areas during winter. However, until recently, little scientific evidence had been gathered to show how smoke levels in New Zealand towns are influenced by the weather, topography, buildings and home-heating behaviour.”

It's that kind of evidence that Dr Longley says is needed for regional councils to design effective intervention strategies.

Recent analysis by NIWA has shown that about 800,000 New Zealanders are exposed to fine particles in the air that exceed World Health Organisation guidelines every winter, the majority of which is due to home heating emissions.

Dr Longley says the impact is greatest in towns across Southland, Otago and Canterbury, but home heating emissions degrade air quality on winter nights in many towns and cities across the country.

“Our research, based on deploying dense networks of sensors around the streets and in homes in Rangiora, Alexandra and Gisborne has revealed how little protection is provided by staying indoors, with fine particles which can affect people’s health, often found in higher concentrations inside than out.”

The amount of fine particles inhaled on winter nights depends not just on the number of homes burning solid fuel and emission rating of their burner, but also the thermal efficiency of homes, fuel quality and how burners are used, Dr Longley says.

NIWA is developing a programme, called CONA—or Community Networks for Air—that empowers communities to assess their air quality, then develop and evaluate solutions.

Improving air quality collectively

On Thursday evening Dr Longley will launch the project in Arrowtown at a public meeting at Athenaeum Hall starting at 7pm. The project is being run in conjunction with the Cosy Homes Trust, Otago Regional Council and Southern District Health Board. It includes helping homeowners access subsidies to improve insulation and to change old, non-complaint wood burners for new, low emission ones.

NIWA is also keen to recruit households that take up heating or insulation subsidies, so they can study air quality before and after the intervention.

The project also involves Arrowtown School pupils participating in a high-tech study, measuring and mapping air quality across the town and sharing their findings with the community and online.

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