NIWA launches biggest-ever scientific air quality campaign

NIWA is looking at the long-term effects of motorways and wood smoke on air quality. Scientists are assessing the impacts of Auckland’s southern motorway on air quality in a surrounding neighbourhood. They are doing this to understand more about the health effects of air pollution.

NIWA scientists, along with Kim Dirks from Auckland University and Simon Kingham from Canterbury University, are gathering a picture of the long-term and seasonal variations of concentrations of air pollutants. They have analysed emissions from the motorway, their dispersion downwind, and the penetration of outdoor air into the indoor environment. Emissions from other sources (local roads and domestic woodburning) were monitored upwind of the motorway.

The scientists gathered their outdoor air-quality data by:

• car
• bike
• lampposts (sampling tubes on lampposts)
• air quality monitoring stations.

NIWA designed and mounted a mobile air-quality system in a late model Ford Falcon. A quarter-century-old bike had a basket on the front containing measuring equipment. Sampling tubes were positioned on lampposts, and three air-quality monitoring stations were strategically positioned within the one square kilometre study area.

“We chose a 1 kilometre radius site in Otahuhu. It’s a flat neighbourhood which allows us to concentrate on the effects of dispersion, and it’s a very typical New Zealand layout, with small sections and low density houses – it means that we can apply our results to other locations across New Zealand,” says NIWA air quality scientist, Dr Ian Longley.

Woody Pattinson, a Canterbury University PhD student, became part of this living, breathing reality, experiment as he rented a house in the area and monitored the outdoor and indoor air quality of his surroundings.

One of the aims of this work is to find out how we might reduce the number of people exposed to health-endangering concentrations of air pollution close to motorways. International research shows that the impact of major roads is significant up to one or two hundred metres distance and possibly further.

In New Zealand, there is a risk that National Environmental Standards for air quality (and World Health Organisation WHO guidelines) might be breached alongside major roads.

“These findings will help clarify and identify locations where the impacts of transport emissions are significant,” says Dr Longley.

Poor air quality can have very serious long-term health effects for those with pre-existing respiratory conditions, e.g., chronic bronchitis, asthma, and cardiovascular conditions.

The scientists are also investigating the significance of wood smoke in the area to compare its impact with emissions from traffic.