Air Pollution

What causes air pollution?

Air pollution comes from many sources, some produced by human activities, including burning fuels such as diesel, petrol, wood, gas and oil, and from natural sources such as windblown dust, pollen and sea salt. The burning process releases chemicals and small particles (particulates) into the air that are harmful to humans and lead to brown hazes and unpleasant odours.

PM₁₀ are particles less than 10 microns in diameter and PM2.5 are less than 2.5 microns in diameter.

What drives air pollution in Nelson?

Nelson has a settled coastal climate and is surrounded by hills, which can result in periods of calm weather, with little wind to dissipate smoke away from chimneys.

During winter when Nelson has clear and calm skies, the air near the ground can be colder than the air above, which is referred to as a meteorological ‘inversion’ in the atmosphere. This temperature inversion forms a layer that can trap smoke from domestic fires, factories and vehicle exhausts, holding it near to ground.

The result of this still, clear weather pattern is that smoke concentrations during winter months can be much higher than normal for a city of this size.

During spring and summer periods, natural sources such as sea salt, pollen and dust can comprise a significant proportion of fine particles.

Air quality in Nelson can also be affected by chemical pollution not related to burning. Standards are in place for these pollutants and their levels are monitored.

What are we doing about it?

Nelson Air Quality Plan

Nelson City Council has an operative Air Quality Plan, which places controls on activities affecting air pollution. Plan rules prohibit outdoor burning in urban areas, the use of open fires and the installation of enclosed burners in houses that do not already have an enclosed burner. In 2016 Nelson City Council made changes to the rules around the use of woodburners in the city to allow for a limited number of ultra-low emission wood burners (ULEB’s) to be installed in Airshed B2 (1,000 ULEB’s) and Airshed C (600 ULEB’s). Council is also working with industry to reduce its contribution to air pollution through the resource consents process.

Other measures

Nelson City Council established the Good Wood scheme to encourage people to buy and burn dry, untreated timber.

Burn Bright

The Burn Bright pages are full of hints and tips for getting better performance from your wood burner and keeping your home warm for less money.

Smoke patrols and pollution reporting

Council runs smoke patrols and educational campaigns over winter. Be a helpful neighbour: If you see excessive air pollution that doesn’t look quite right, contact us at 0800 NO POLLUTE and we’ll look into it for you

Home heating advice

Council also runs a community education programme to improve how people operate their woodburners. Council’s Eco-Design Advisor provides a free service giving advice on heating options and keeping our homes warm.