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4 Ambient Air Quality Guidelines and Standards

In October 2004, the Ministry for the Environment introduced the National Environmental Standards (NES) for air quality. The NES includes five standards for ambient (outdoor) air quality. These and other New Zealand guidelines are described in table 1 below.

The criteria applied to TSP, 60 µg/m3 (seven-day average), was previously applied by the Ministry of Health. This has been superseded by the Ministry for the Environment Ambient Air Quality Guidelines but is useful for analysing the results of the monitoring data.

Table 1: National environmental standards, guidelines and regional targets3

Air pollutant National environmental standards 2004 Ministry for the Environment Ambient Air Quality Guidelines 2002 and other Averaging period National environmental standards permissible excess
Carbon monoxide 10 mg/m3   8-hour average One 8-hour period in a 12-month period
  30 mg/m3 1-hour average
Nitrogen dioxide   100 µg/m3 24-hour average  
200 µg/m3   1-hour average 9 hours in a 12-month period
Sulfur dioxide   120 µg/m3 24-hour average  
350 µg/m3   1-hour average 9 hours in a 12-month period
570 µg/m3   1-hour average Not to be exceeded at any time
Benzene        
– Year 2002   10 µg/m3 Annual average  
– Year 2010   3.6 µg/m3 Annual average  
1,3-Butadiene   2.4 µg/m3 Annual average  
Fine particulate (PM10)   20 µg/m3 Annual average  
50 µg/m3   24-hour average One 24-hour period in a 12-month period
Total suspended particulate (TSP)   60 µg/m3 (Ministry of Health) 7-day average  
Lead   0.2 µg/m3 3-month average