Air Pollution
Air Pollution – what is it?
Breathing clean air is important for our health and wellbeing. Emissions from human and natural activities can degrade the quality of our air, impacting on our health and our quality of life. Poor air quality also affects the health of plants and animals. The main air contaminants in urban areas are particulate matter (particles suspended in the air) and gases such as nitrogen dioxide.
Air pollution comes from many sources, some from natural sources such as windblown dust, pollen and sea salt. Some are produced by human activities, including burning fuels such as diesel, petrol, wood, gas and oil, The burning process releases chemicals and small particles (particulates) into the air that are harmful to humans and our ecosystems (plants and animals), and can reduce visibility.
Health impacts can occur as a result of both short and long-term exposure to particulates. Long-term exposure to PM2.5 (the smallest particles) has the greatest health impacts as these tiny particles can penetrate deep into our lungs. Health impacts of particulate pollution can include people dying earlier than they otherwise would and being hospitalised with cardiovascular and respiratory problems. People with existing heart or lung diseases, as well as children and older adults, are the most likely to be affected by exposure to particle pollution.
PM consists of small airborne particles, including solid matter and liquid droplets, that are small enough to be inhaled. PM2.5 refers to particles with a diameter of less than 2.5 micrometres and PM10 refers to particles with a diameter of less than 10 micrometres, which is the major air pollutant monitored in New Zealand.
What causes 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 still winter days, the colder temperature forms an inversion layer that can trap smoke from domestic fires, factories, and vehicle exhausts, holding it near to ground. The result 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
We measure both PM10 and PM2.5 in Nelson South and in Tāhunanui because these are the areas that have the highest concentrations of particulates. We continue to monitor PM10 in Airsheds Stoke and Nelson North. We are reviewing the air quality monitoring network and modernising our equipment to improve efficiency and ensure best use of monitoring resources. This is likely to result in a better understanding of PM2.5 by moving to continuous monitoring for Nelson South and Tāhunanui.
Nelson Air Quality Plan
We continue to implement the Nelson Air Quality Plan to limit emissions from both domestic and industrial sources, and to ensure air quality is improving where this is necessary and is not degrading elsewhere. This includes ensuring only solid fuel burners that comply with regulations can be installed in our airsheds, and programmes such as the ‘good wood’ scheme continue to promote the use of quality firewood to reduce the particulates being discharged to air. We continue to require industries that discharge contaminants to air to obtain resource consents – which include conditions requiring action to be taken to improve the quality of these discharges
What you can you do
Best burning practices
- The Best practice burning tips are full of hints and tips for getting better performance from your wood burner and keeping your home warm for less money.
Pollution reporting
- 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
