Working to improve air quality in our region
Community and Public Health provides a supporting role to Environment Canterbury for monitoring and policy responses to ambient air quality issues and improvements.
Air pollution and air quality in New Zealand
New Zealand research suggests that ambient air pollution is responsible for an estimated 970 premature deaths each year in people over 30 years of age, approximately 400 of which are from vehicle emissions. Fine particles are produced in the combustion of fuel pose greater health risks than previously thought – these are known as PM10 and PM2.5. Harmful gases also affect air quality such as carbon monoxide, sulphur dioxide, benzene and nitrogen dioxide.
There are several different sources of air pollution:
- Area sources including home heating, outdoor burning, dust from construction , livestock and landfills..
- Transport sources such as cars, truck, buses, motorcycles, boats and shipping, as well as dust from unsealed roads.
- Many industrial processes release air pollutants as well as from heating commercial or public buildings like schools and hospitals.
- Natural sources include wind-blown dust, pollen, sea salt, volcanic and geothermal activity, and ash from wildfires.
Children, elderly people and those with respiratory diseases are more vulnerable to air pollution and areas of high deprivation have greater excess mortality from air pollution. The infographic below shows the health impacts of air pollutants ranging from coughing and throat irritation to respiratory and cardiovascular disease and cellular and genetic damage.
Winter air quality issues in Christchurch
Temperature inversions exacerbate air quality problems in Christchurch during the cooler months, especially when people are burning wood or coal to heat their homes. Cooling near the ground’s surface on clear nights leads to cold air near the ground being overlaid by a layer of warm air – the opposite of the normal temperature gradient. This warm air acts as a lid – trapping pollutants and allowing them to build up. The surrounding hills and valleys act as additional barriers.
These inversion events are responsible for peak PM concentrations at many of the monitoring sites in Christchurch residential areas. Most of the air pollution under these conditions is from human activities.
Contact your local CPH office for further information:
Ph: +64 3 364 1777
Fax: +64 3 379 6125
Ph: +64 3 687 2600
Fax: +64 3 688 6091
Ph: +64 3 768 1160
Fax: +64 3 768 1169
For additional information, contact:
ECAN Winter Air Pollution Forecast
Ph: +64 3 353 9004
Call to reduce home-heating emissions due to air quality concerns
Land Air Water Aotearoa media release: 22nd June 2020
The team at LAWA are encouraging people to help keep the air in our towns and cities healthy by using clean home-heating methods as temperatures drop.
An increase in the number of people working from home due to COVID-19, combined with cooler weather, means we could see an increase in home heating emissions this winter. Breathing polluted air can lead to lung and heart problems with vulnerable populations most affected.
LAWA Air Quality Lead and Environment Canterbury Air Quality Analyst Teresa Aberkane explained that New Zealand towns and cities recorded below average levels of air pollution during COVID-19 Alert Level 4 lockdown, but things may have been different if lockdown happened over winter.
“Traffic pollution dropped significantly during lockdown at roadside locations which you would expect with fewer vehicles on the road. This is good news but cars are not our primary air quality polluters. New Zealand’s dominant source of PM10 and PM2.5 air pollution comes from people burning wood and coal to heat their homes. If lockdown had coincided with winter rather than during a dry autumn, we could have seen record particulate matter exceedances,” said Ms Aberkane.
It is important for people to stay warm in their homes over the cooler months, and there are different home heating methods available to suit different circumstances, that contribute less pollution. The cleanest home heating appliances include heat pumps, pellet burners, or ultra-low emission burners. The next best alternatives are electric, gas, or oil heaters.
Clean heating may not always be an option. To reduce emissions from wood burners, people should:
- only burn dry, non-treated wood from a trusted supplier; and
- use an efficient burning technique.
Canterbury Regional Air Plan
Community and Public Health has a joint work plan with Environment Canterbury around common areas of interest, including air quality.
One example of this collaboration was the review of the Regional Air Plan. A joint Health Impact Assessment (HIA) of the Air Plan was done to assess the potential impact of proposed plan changes on population health.
The HIA revealed that air quality is closely linked with housing, heating, and energy use, and these factors need to be considered when dealing with unintended health consequences. The HIA recommendations included the carefully phased introduction of home heating changes along with supporting measures, such as targeted heating and insulation subsidies.