Air slowly getting cleaner, but health impacts of breathing pollution worse than previously thought

Air pollution is slowly getting better in most places, as New Zealanders gradually switch to cleaner cars and heat pumps.

But the air we breathe is still regularly exceeding World Health Organisation guidelines, and contributing to thousands of premature deaths a year.

The Our Air 2024 report is the first major update to national air quality data since 2021.

All sites monitored by the national network of researchers tested above World Health Organisation guidelines for PM2.5 between 2020 and 2023, it says. These are fine, airborne particles small enough to be inhaled and enter the bloodstream.

The 2024 report says the health impacts of traffic pollution are worse than previously reported, because researchers have a better understanding of how nitrogen dioxides and other tiny airborne particles affect people's health, and are monitoring more sites than they were.

It says diesel-powered vehicles have an outsized impact on pollution levels from traffic, and both traffic and pollution from home fires remains a major factor in many urban areas.

Air quality experts who've seen the report said New Zealand's remote, windy location meant it should have some of the best air quality in the world, but gains were slow and at current rates it would be decades before parts of the country met world health guidelines.

Independent specialists Dr Ian Longley and Dr Guy Coulson also said there were wins worth celebrating - such as a significant drop in nitrogen dioxide (from traffic) levels in Auckland's Queen Street due to the substantial reduction in traffic along the busy street where they said many people were exposed to polluted air.

The report says human-made air pollution is contributing to thousands of deaths a year with the main contributors being vehicles and home fires for heating.

However, monitoring focuses on urban areas where most people live and pollution is more likely, meaning there'll be places where air is cleaner that don't feature in reports.

More to come...