In a 2013 survey, 90 percent of New Zealanders surveyed considered New Zealand’s air quality to be adequate, good, or very good. The remaining 10 percent said it was bad, very bad, or didn’t know (Hughey, Kerr, & Cullen, 2013).
Another survey asked people in Auckland, Wellington, Porirua, Hutt, Christchurch, and Dunedin areas whether they felt their local air quality was or was not a problem. Results showed that in Wellington, 79 percent of respondents were satisfied with air quality, compared with 49 percent in Christchurch (Nielsen, 2013).
Objective information on the state of New Zealand’s air can be obtained from the routine air quality monitoring that is carried out across the country by regional councils and unitary authorities. These agencies are responsible for monitoring and managing air quality within their regions. Monitoring can occur at peak sites (locations where concentrations are expected to be high), background sites (locations where concentrations are expected to be low), or sites that are between these limits.
With the assistance of a technical advisory group, we selected these pollutants because they are associated with significant health and environmental effects. Their concentrations are measured using annual averages and short-term levels to represent their long- and short-term effects.
Comparing concentrations to guidelines and standards
We compared annual concentrations with the World Health Organization (WHO) long-term guidelines. These guidelines are the recommended maximum concentrations that should not be exceeded to provide a set level of protection against the long-term health effects from exposure. In cases where WHO guidelines do not exist (eg for arsenic and benzo(a)pyrene), we used the Ministry for the Environment’s 2002 Ambient Air Quality Guidelines.
For comparing daily and hourly monitoring data, we used New Zealand’s National Environmental Standards for Air Quality (NESAQ) (Resource Management Regulations, 2004). In a few cases, where WHO guidelines and NESAQ differ (eg for sulphur dioxide), we report against both. These also represent the recommended maximum concentrations that should not be exceeded to provide a set level of protection against the short-term health effects from exposure.