Air is made up of two main gases (nitrogen and oxygen), with small amounts of carbon dioxide and other gases.
Air can be contaminated by:
Air is polluted when contaminants are in air for long enough, and at concentrations high enough, to affect humans, plants, animals, property, or amenity values (visibility and odour).
Contaminants come from many sources. Some are natural, such as geothermal emissions, but many are human-made. In the Waikato region, human-made emissions are mostly from:
Air pollution can happen on a:
In the Waikato region the main contaminants of our air are fine particles (PM10), contained in contaminants such as smoke. We measure local PM10 levels in selected airshed(external link) and compare it against the national environmental standards for air quality(external link) set by the Ministry for the Environment. For PM10 the standard is 50 micrograms of PM10 per cubic metre of air (50 µg/m3) as a 24-hour average. It allows one day per 12 month period when concentrations can be greater than 50 µg/m3.
When this standard is exceeded in an airshed two or more times in a 12-month period, we are required to follow the Ministry’s regulations and publicly notify the breach and put in place restrictions on fireplace use. Industrial discharges may also be affected.
Triggered by Regulation 24A of the Resource Management (National Environmental Standards for Air Quality) Regulations 2004, the following open fire place bans are now in place in the Waikato region.
A domestic solid-fuel burning open fire –
(a) means an appliance or a structure inside a domestic building that can burn solid-fuel but cannot effectively control the rate of air supply to the combustion zone; and
(b) to avoid doubt, includes a fireplace to which paragraph (a) applies that has a cover or doors that cannot effectively control the rate of air supply to the combustion zone i.e. any fire where the combustion chamber is not totally enclosed e.g. brick or masonary fireplaces, visors, open hearths, Jetmaster fireplaces.
Over a 5-year period (2008 to 2013) Putaruru, Taupō, Te Kuiti and Tokoroa regularly exceeded the national environmental standards for PM10 and were classified as polluted airsheds under Regulation 16D and 17(4) of the Resource Management (National Environmental Standards for Air Quality) Regulations 2004. While Putaruru and Tokoroa remain classified as polluted, Te Kuiti and Taupō have since met the criteria under Regulation 17(4) of the standards for being re-classified as non-polluted as of 10 December 2016 and 31 July 2018 respectively.
Under Regulation 17, the standards require us to assess all resource consent applications for substantial discharges of PM10 into polluted airsheds to determine whether offsets will be necessary.
Air pollution can damage our health and reduce our enjoyment of life. It can affect our health by causing:
Air pollution can also cause:
Air contaminants that cause health effects in humans can also affect other living things. A few air contaminants are so dangerous that accidental releases can cause serious injury or death.
Many tourists visiting the Waikato region are attracted by our clean, green image. Poor visibility, odours, dust and other air pollution problems may damage our tourism industry.
Air quality in the Waikato region is generally good, but some areas are more prone to air pollution because of:
In most inland towns air pollution is a problem in the winter because the local climate is cold and calm with frequent inversion layers that trap air contaminants close to the ground.
We all contribute to air pollution and we are all affected by it.