Improvements to the motor vehicle fleet are helping to reduce air pollutant emissions in New Zealand, according to a new report.

The Ministry for the Environment and Stats NZ’s latest three-yearly update about air quality in Aotearoa, Our Air 2024, brings together recently updated Stats NZ indicator data, as well as insights from research literature.

The report shows that air pollutant levels have decreased at most monitoring sites over the last eight years.

However, some sites showed worsening air quality, while pollutant levels at sites where air quality improved were at times above levels in World Health Organization  guidelines.

MfE’s deputy secretary – Strategy, Stewardship and Performance, Natasha Lewis, said emissions from motor vehicles (as well as aviation, shipping and rail) were lower in 2019 than in 2012 for all monitored pollutants, except sulphur dioxide.

“Air pollutants from motor vehicle exhaust emissions are reducing per kilometre as a result of vehicle emissions standards, lower-emissions vehicles and improvements in engine technology and fuel quality,” she said.

The report also showed New Zealand’s vehicle fleet reached its largest size to date in 2022. Annual kilometres travelled by motorists have also increased over recent decades.

Road vehicles contribute significantly to different types of air pollution and were the largest source of nitrogen oxides (39%) in 2019.

The study said the impacts of air pollution from motor vehicles are much higher than previously understood, causing health issues for thousands of people each year along with substantial socio-economic costs.

The report showed that air pollution from motor vehicles is still associated with a high number of hospitalisations, premature deaths and substantial social costs.

“The burden of health impacts caused by air pollution is also greater for some areas and population groups than for others,” Lewis said.

“Children, the elderly, pregnant people and people with cardiovascular or respiratory disease are more vulnerable to the impacts of pollution than others.”