Nitrogen dioxide

Traffic-related air pollution is measured at three core sites and is supplemented by a regional network of low cost nitrogen dioxide (NO2) passive diffusion tubes. (A picture of NO2 tube site can be seen here). Air pollution levels from traffic vary considerably across the region and so a larger monitoring network is needed to capture representative regional and local trends. Some sites are also part of NZTA’s national monitoring network. The passive tubes are a manual monitoring method and data is only available as monthly averages after the tube has been analysed in a laboratory.

Core sites

Benchmarking & Resources has more information on the guidelines and standards used for the following summary tabs.

Annual summary

Annual NO2 summary results are shown in the map and table. Annual averages are only reported for sites with more than 75% data capture.

Map usage: drag and scroll on the map to move and zoom in on areas of interest, hover on the site circles to see more information, and use the selection box ( ) to subset the map and table data to that area.

Table usage: click on sites in the table to highlight them on the map, and click on table headers or the arrows next to them () to sort the data by that column – holding the shift key allows sorting over multiple columns.