Nelson region

Air Quality

Air quality in Nelson is generally good except during cold still nights when air particulates, mainly emitted from home heating get trapped and build up. Nelson has four reqularly monitored airsheds.

Nelson’s air story
Air quality in Nelson is generally good except during cold and still weather conditions which can occur during the winter. Nelson's location is at the head of Tasman Bay and is flanked by hills on three sides. The hills deflect much of the prevailing wind and as a result Nelson's weather is characterised by low wind speeds and calm conditions usually occurring during winter and often lasting days or weeks on end. During the winter period most air particulate discharges come from home heating fires such as enclosed wood burners (smoke). Where still conditions occur the smoke builds up until the weather conditions change and the wind increases. Other sources of particulates include industrial processes such as boilers, motor vehicles and from natural sources such as airborne sea salt and dust particles.
The particulates from this smoke (and from sea salt, dust and cars) are known as PM₁₀ and these tiny particles can get deep in to our lungs and cause health issues for some people.
We all have a role to play in achieving cleaner, healthier air to breathe and Nelson City Council has been working with the community to improve air quality. There have been significant improvements since the early 2000s.
Nelson has defined four separate air quality management areas (airsheds) and has a permanent PM₁₀ monitoring station in each. You can find information for all current and previously monitored sites here and see how they compare from year to year, and against the national guidelines.
Annual average PM₁₀ concentrations in most airsheds are below national guidelines. During still, cold days in winter, daily average PM₁₀ concentrations can exceed national guidelines. Nelson City
Council has worked with the community to develop the Nelson Air Quality Plan which includes measures to manage all of these contaminants and meet national health-based guidelines.
The National Environmental Standards for air quality require no more than one day per year when the measured PM₁₀ is greater than 50ug/m³.

Regional Summary

PM₁₀and PM_2.5at towns in this region

The most significant air pollutant in New Zealand are small airborne particles in our air (known as particulate matter). Particulate pollutants are of most concern in New Zealand because of their high concentrations in some of our towns. Exposure to high levels of airborne particle pollutants has the potential to cause respiratory and cardiovascular issues. View a factsheet on why air quality is important here.

PM₁₀ is the main concern in the Nelson urban area, particularly during the winter period when cold still conditions prevent dispersion and allow the particulate matter to build up. Exposure to PM₁₀ can have short and long term health effects. The Council reports on annual and daily PM₁₀ concentrations each year for four sites. Trends are reported for our two longer record sites at St Vincent St (Nelson South) and Blackwood St (Tahunanui).

PM monitoring history at towns in this region

Annual average
Highest daily average
Exceedance

Showing:

PM₁₀

What is this showing me?

The graph enables you to view the annual average and highest daily average concentrations of PM₁₀ and number of exceedance days for the year selected. The results are compared to the relevant air quality standard or guideline (denoted by the red horizontal line). See this factsheet for more information about the PM₁₀ measurements, and the standards and guidelines used to report on.

Values above the standard or guideline shown can be a cause for concern as short- or long-term exposure to high PM₁₀ can have health impacts. See this factsheet about why air quality is important and factors that influence air quality.

The trends in the table below indicate whether the PM₁₀ concentrations have been improving, showing no measurable change, or declining over the 10-years prior to the year selected. (For towns that have more than one monitoring site, a representative site is shown).

Data table PM₁₀

Towns	10-year Trend	annual average (µg/m³)	Highest daily average (µg/m³)	2nd highest daily average (µg/m³)	Number of exceedances

PM_2.5

What is this showing me?

The graph enables you to view the annual average and highest daily average concentrations of PM_2.5 and number of exceedance days for the year selected. The results are compared to the World Health Organization guidelines (denoted by the red horizontal line). See this factsheet for more information about the PM_2.5 measurements, and the standards and guidelines used to report on.

Values above the guidelines can be a cause for concern as short- and long-term exposure to high PM_2.5 values can have health impacts. See this factsheet about why air quality is important and factors that influence air quality.

Any trends in the table below indicate whether the PM_2.5 concentrations have been improving, showing no measurable change, or declining over the 10-years prior to the year selected. (For towns that have more than one monitoring site, a representative site is shown).

Data table PM_2.5