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.

Environment Canterbury is responsible for monitoring of Canterbury air quality.

Ministry for the Environment develops national indicators and strategies on air quality.

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.

• Find out more about the health effects of some common air pollutants (Ministry for the Environment).

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.

Documents

• Our air 2021 (Ministry for the Environment 2021).
• Changes in Aotearoa’s air quality during the 2020 social restriction response to the COVID-19 pandemic: A summary (Ministry for the Environment 2021).
• Authorised wood burners list (Ministry for the Environment 2021).
• Review of the Air Quality National Environmental Standard (Ministry for the Environment 2019).
• Canterbury Air Regional Plan (Environment Canterbury 2017).
• Airshed progress report 2012 (Ministry for the Environment 2014).
• Review of evidence on health aspects of air pollution (World Health Organisation 2013).
• Clean Healthy Air for All New Zealanders: The National Air Quality Compliance Strategy to Meet the PM10 standard (Ministry for the Environment 2011).
• Revised National Environmental Standards for Air Quality: Evaluation under Section 32 of the Resource Management Act (Ministry for the Environment 2011).

Links

• Air Quality (Ministry for the Environment).
• Environment Canterbury.
• Air Quality in Canterbury (LAWA).
• Vehicle Exhaust Emissions (NZTA).

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.

• Read the Health Impact Assessment of the Canterbury Regional Air Plan.
• Read the CDHB Submission on the Proposed Canterbury Regional Air Plan.
• Read the Canterbury Air Regional Plan – released in October 2017.