Air quality – how are we tracking?

High pollution nights have been recorded this month in Christchurch, Ashburton, Timaru and Kaiapoi – but the region is still on track to improve on last year’s results.

Environment Canterbury monitored eight airsheds in 2017 as part of the region’s programme to ensure we meet national air quality standards.  During winter 2017, the Canterbury region experienced a combined total of 45 days, across the eight airsheds, when winter pollution exceeded the National Environmental Standards for Air Quality (NESAQ).

The air monitoring sites are located in Rangiora in the north through to Waimate in the south, with Timaru experiencing the highest number of days exceeding the required limit during the 2017 winter period.

“Timaru had 17 days last winter when air pollution exceeded the national environmental standards.  While this is really good progress compared with the 2016 levels of 27, it still needs to come down further which is why we are concentrating on working with residents and the Timaru District Council, to try and reduce air pollution levels this winter.  On a typical winter’s day in Timaru, 95% of the pollution comes from home heating - burning wood and coal. Industry and transport are the two other main contributors,” said Katherine Trought, Environment Canterbury air quality director.

“Most winter air pollution comes from the burning of wood and coal for home heating in all airsheds except Washdyke, which is in an industrial area and rarely breaches the NESAQ.”

“From 1 September 2020, all Canterbury airsheds must have no more than one high pollution day per year. While many towns still breach the NESAQ there are fewer days now in Christchurch, Kaiapoi, Ashburton and Timaru. It is important for the health of our communities that we continue to reduce these high pollution days across the region.

“Environment Canterbury has a plan in place to help ensure the region meets the national environmental standards for air quality. This is an extensive programme of activities that varies from location to location to take account of local conditions and it includes changes to consent provisions for home heating sources through to helping households reduce emissions through better wood burning. In addition, Environment Canterbury provides subsidies for low-income households replacing log burners with cleaner forms of heating. People wanting to know more about this can contact Environment Canterbury,” said Trought.

Five main air contaminants are measured as part of the NESAQ monitoring programme. These include:

  • Particulate matter (PM10) (which are very fine particles as well as coarse particles)
  • Sulphur dioxide
  • Carbon monoxide
  • Nitrogen Dioxide and
  • Ozone

Of these five contaminants PM10 is the main concern and regularly breaches the National Environmental Standards for Air Quality while the other contaminants no longer breach the NESAQ. The main source of PM10 in Canterbury’s towns and cities is from burning wood for home heating. Other main sources include industry and transport.

Read the full report about air quality in Canterbury in 2017.