New Zealand’s air pollution stocktake finds continued improvement in most towns

Regional and unitary councils support the health of their communities and ecosystems by monitoring and managing air quality.

The latest stocktake of air quality monitoring results from councils presented by the Land, Air, Water Aotearoa (LAWA) project highlights meaningful improvements and underscores the importance of reducing pollution where possible.

Teresa Aberkane, LAWA Air Quality Science Lead and Senior Air Quality Analyst at Environment Canterbury, advises that scientists have observed marked improvements in air quality in many parts of New Zealand.

“Almost three-quarters of the 45 monitoring sites with sufficient data show a positive trend in reducing particulate matter (PM10) levels over a 10-year period. This achievement is a testament to the efforts of communities who have responded to regional and unitary councils monitoring and managing air quality.

“In 2023, the National Environmental Standards for Air Quality (NES-AQ) for daily average PM10 concentrations were met at around 80% of monitored sites across the country. Looking at the small number of sites that did not meet the PM10 standard, it’s heartening that the majority are improving.

"Targeted interventions and ongoing public awareness campaigns about the impacts of burning wood and coal for home heating have contributed to improvements," said Ms Aberkane.

Tamsin Mitchell, Scientist with the LAWA project and Senior Air Quality Scientist at Greater Wellington explains air quality matters because it has an impact on public health. 

"Clean air is vital to our well-being. New Zealand research shows that breathing air containing microscopic particles under 2.5 µm (PM2.5) from home fires — even at low levels — and nitrogen dioxide gas (NO2) from traffic exhaust does considerable harm to many people, including children.  

“While there have been significant improvements, challenges persist in certain areas, particularly during winter," said Ms Mitchell. 

Towns such as Tokoroa, Kaiapoi, and Timaru continue to experience high levels of PM2.5 due to smoke from home heating, local weather conditions, and the terrain. 

The most air-friendly form of home heating is a heat pump or other electric source. People using log burners this winter are encouraged to burn good dry wood to save money and create less pollution. 

Dry wood burns more efficiently by producing more heat and less smoke, in turn reducing harmful emissions. 

Transport initiatives, such as increasing active travel and public transport options, cleaner vehicle emission standards and zero emission vehicles will reduce levels of NO2 as well as climate-warming gases. 

LAWA Chair Dr Tim Davie said it’s important that the public can access air quality information.

"Through the LAWA project, we aim to make air quality data accessible and understandable to everyone. We provide real-time data from around 60 active and 85 historical monitoring sites across New Zealand.

"Our interactive website allows users to explore air quality trends, understand the main contributors to pollution in their area, and see how their actions can make a difference,” said Dr Davie.

The LAWA Air Quality topic presents regulatory data against the New Zealand NES-AQ and non-regulatory data collected proactively by some councils against guidelines set internationally.

Dr Davie advised that revising the NES-AQ as part of the Resource Management Act replacement will help ensure that domestic air quality regulations provide a balanced level of health protection for New Zealanders based on the best available science.

“As central government takes a fresh look at the NES-AQ set in 2004, we look forward to the opportunity for any changes to reflect the latest scientific understanding of the health impacts from air pollution.

"The LAWA project supports the expansion of PM2.5 and NO2 monitoring across more sites where this makes sense. These pollutants have been identified as having significant health impacts, and enhancing our monitoring network will provide better data to inform public health interventions,” said Dr Davie.