NIWA reveals Arrowtown air quality standards breached every time temperature plummets

The first month of data from NIWA’s air quality monitoring project in Arrowtown reveals that air quality has already breached the national standard eight times this winter, including six times in the week from 19 to 26 June – in fact every time the air temperature dropped below freezing. “Concentrations of airborne particles at the Otago Regional Council monitoring site were particularly high on Wednesday 19 June, with a daily average of 108 micrograms per cubic metre. That’s more than double the national standard of 50, with hourly concentrations peaking at 314 micrograms per cubic metre,” says project leader NIWA air quality scientist Dr Ian Longley. “NIWA’s data is now showing how widespread this contamination is across the town.”
The data comes from 22 air sensors called ODINs that were designed, built and installed by NIWA across the town either on power poles or outside volunteers’ homes. Two ODINs were also put up at Arrowtown School. The sensors take measurements every minute and transmit their data to NIWA’s computers through the mobile phone network. Maps of average air quality are now being created and are available, along with animations for each night, on NIWA’s website. Dr Longley, NIWA technician Ayushi Kachhara, and Francisco Barraza (University of Otago) are now looking at the data to see what else they can tell us about Arrowtown’s air quality.
“Early indications are that Arrowtown’s air quality isn’t uniform and that smoke moves around the town in a complex way,” says Dr Longley.
In addition, 21 households have participated in the project by hosting an indoor air quality monitor to detect how much smoke from outdoors is getting into their homes. Dr Longley says anonymised data from these devices should be available soon. The devices will be passed on to other residents who have signed up to host them. Year 8 students at Arrowtown School have also joined the project team under the guidance of teacher Kelly Scoles. They have been the first to see the data from the ODIN monitors, and, aided by a weekly video link with the NIWA team, have been learning how to create charts and calculate statistics to summarise the data. Their work will also be released through the project website.
Cosy Homes Trust, Otago Regional Council and Southern District Health Board are working together to improve Arrowtown’s environment and air quality and to help households make their homes warmer and healthier. This includes helping home owners access subsidies to improve the insulation in their homes and to change old, non-compliant wood burners for new, ultra-low emission wood burners. NIWA’s air quality research in Arrowtown follows successful pilot studies in Rangiora and Alexandra in 2017 and 2018, all under the umbrella of “Community Observation Networks for Air (CONA)”. The Arrowtown work will continue all winter and a repeat of the project in winter 2020 is being considered.