“PM10 trends decreased at 30 out of 41 local government monitoring sites, while trends for PM2.5 decreased at 12 out of 16 sites. Nitrogen dioxide (NO2) trends decreased at 99 out of 114 NZ Transport Agency Waka Kotahi monitoring sites between 2014 and 2023,” environment and agricultural statistics senior manager Stuart Jones said.

PM10 and PM2.5 are particles that can be suspended in the air and are less than 10 micrometres and 2.5 micrometres in diameter, respectively. They are primarily formed by residential wood burning, dust from unsealed roads, and industrial and construction activities. NO2 is a gas primarily formed through burning fossil fuels.

“PM10 can be breathed into lungs and PM2.5 is small enough to enter the blood stream. Concentrations of particles, gas, and liquid in air can be harmful to human health and contribute to health issues such as cardiovascular and respiratory health problems and increased mortality,” Jones said.

Visit the Stats NZ website to read this news story in full and view the indicators published today:

• Air pollutant trends decrease at most monitoring sites over the last eight years
• PM10 concentrations (air quality): Data to 2023
• PM2.5 concentrations (air quality): Data to 2023
• Nitrogen dioxide concentrations: Data to 2023
• Sulphur dioxide concentrations: Data to 2023
• Carbon monoxide concentrations: Data to 2023
• Ground-level ozone concentrations: Data to 2023