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Assessing air quality issues in New Zealand towns in winter: Community Observation Networks for Air (CONA)

Please note that this project is on hold currently due to COVID-19 restrictions and will resume as soon as possible.

Poor air quality is a problem during winter in many New Zealand regions. Air pollution can have a significant detrimental effect on human health.    

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. Regional councils need that evidence to design effective intervention strategies.

NIWA's Community Observation Networks for Air (CONA) research projects work with communities to tackle the air pollution issues relevant for them. We take our sensors, distribute them in the community and try to answer the questions that the participants have around the impacts of air pollution on their health.

CONA studies in Arrowtown in 2019, Alexandra in 2018 and Rangiora in 2015-17 have proven that the technologies and methodologies used by NIWA to monitor and track the behaviour of air pollutants are reliable and provide valuable data to support mitigation efforts by local authorities.

Read more about our previous CONA projects.

Read more about wood burning, smog and its impact on air quality in Burning wood, not quite as cosy as it seems.

In 2019 CONA focused on Arrowtown

Arrowtown has a persistent problem with air quality in winter 

Winter brings high levels of air pollution to Arrowtown and other Otago towns, and being inside may offer only limited protection. Causes include:

  • Wood burning, cooking and smoking inside houses.
  • Calm winds preventing smoke from dispersing.
  • Polluted air from outside entering and getting trapped inside homes.

NIWA scientists are working with households to better understand the problem

Last winter, NIWA scientists worked with Arrowtown households to host air quality sensors. Households who joined our research received a personalised assessment of the heating and air quality in your home.

Participants were given a pack of our small sensors to place in their home for 2 to 4 weeks. The sensors silently tested for smoke in the home and recorded when people were using heating.

After the sensors were removed we provided an assessment of how much smoke was in each home and what was causing it. All results were also anonymised and added to summary results, available on this website.

This project was run in conjunction with Otago Regional Council, Southern District Health Board and the Cosy Homes Trust. Some of the households we recruited also took up home insulation and/or heating subsidies, which enabled us to assess the effect on air quality of changing a heating source or improving insultation.

Other resources

Dr Ian Longley’s presentation from his talk on air quality in Arrowtown on 9th May 2019 is available:

Download the Arrowtown air quality presentation. [PDF3MB]

CONA: where to next?

As well as the Arrowtown work, we are currently supporting a program to reduce wood smoke in Rocky Mountain towns with the Idaho Department of Environmental Quality and the University of Montana. Read our Community observations network for air - Montana and Idaho blog.

Other communities interested in participating can contact NIWA’s Air Quality Team by emailing

NIWA Contacts

Principal Scientist - Air Quality
Page last updated: 
17 April 2020
Research subject: Air Quality