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National environmental standard for PM10 – Peak daily levels

Monitoring peak daily levels of PM10 in an airshed provides an understanding of the intensity of air pollution to which people are being exposed. The national environmental standard for air quality set an acceptable daily level for PM10 of 50 μg/m3 and requires continuous monitoring throughout the year in areas where PM10 is likely to breach the standard.

Current situation

In 2010, peak daily levels of PM10 in the 44 monitored airsheds ranged from 27 to 148 μg/m3. The three highest daily levels of PM10 were recorded in the Timaru, Otago 1 and Otago 2, airsheds. Nine of the top 10 airsheds that recorded the highest daily PM10 levels in New Zealand are located in the South Island.


Highest 24-hour PM10 concentration in airsheds, 2010

Highest 24-hour PM<sub>10</sub> concentration in airsheds, 2010

Read table of data of this graph

North Island airsheds South Island Airsheds
Auckland 51 Ashburton 79
Hamilton City 30 Blenheim 67
Hastings 85 Christchurch 101
Helensville 32 Geraldine 58
Kaitaia 27 Gore 70
Kumeu 43 Invercargill 96
Lower Hutt 29 Kaiapoi 98
Matamata 40 Nelson A 59
Napier 71 Nelson B 52
Ngaruawahia 29 Otago 1 133
Porirua 30 Otago 2 119
Putaruru 53 Otago 3 76
Rotorua 84 Otago 4 54
Taihape 37 Rangiora 91
Taumarunui 55 Reefton 99
Taupo 55 Richmond 69
Te Kuiti 56 Timaru 148
Tokoroa 99 Waimate 97
Turangi 32
Upper Hutt 32
Waiheke Island 27
Waihi 45
Wainuiomata 62
Wairarapa 67
Wellington 32
Whangarei 50

Data sources: Auckland Council, Bay of Plenty Regional Council, Environment Canterbury, Environment Southland, Greater Wellington Regional Council, Hawke's Bay Regional Council, Horizons Regional Council, Marlborough District Council, Nelson City Council, Northland Regional Council, Otago Regional Council, Tasman District Council, Waikato Regional Council, West Coast Regional Council.

Trend

The highest national recorded daily PM10 level has shown an improving trend by steadily dropping from 198 μg/m3 in 2005, to 148 μg/m3 in 2010. Levels can vary largely from year-to-year due to meteorological variation and this trend may have been influenced by such variation.

The airsheds recording the highest number of exceedances from 2005 to 2010 remained fairly consistent. Four airsheds – Christchurch, Kaiapoi, Otago 1 and Timaru – consistently appeared in the top 10 list from 2005 to 2010.

Airsheds with the 10 highest 24-hour average PM10 levels, 2005-2010

Rank 2005 2006 2007 2008 2009 2010
1 Invercargill (198) Timaru (190) Otago 1(2) (168) Rotorua (162) Otago 2(3) (145) Timaru (148)
2 Kaiapoi (152) Christchurch (184) Auckland (137) Otago 1(2) (150) Otago 1(2) (137) Otago 1(2) (133)
3 Christchurch (147) Kaiapoi (161) Reefton (129) Otago 2(3) (141) Timaru (134) Otago 2(3) (119)
4 Hastings (145) Otago 1(2) (149) Timaru (128) Invercargill (110) Rotorua (126) Christchurch (101)
5 Timaru (109) Rangiora (138) Christchurch (120) Timaru (109) Reefton (91) Tokoroa (99)
6 Otago 1(2) (103) Ashburton (136) Nelson B (112) Hastings (105) Nelson A (89) Reefton (99)
7 Tokoroa (102) Hastings (132) Rotorua (111) Putaruru (98) Waimate (89) Kaiapoi (98)
8 Rangiora (99) Rotorua (116) Nelson A (110) Ashburton (90) Auckland (88) Waimate (97)
9 Otago 2(3) (98) Nelson A (111) Rangiora (107) Christchurch (87) Kaiapoi (86) Invercargill (96)
10 Nelson A (96) Nelson B (107) Kaiapoi (104) Kaiapoi (86) Christchurch (85) Rangiora (91)

Notes:

  1. The number in brackets after each airshed is the airshed’s highest 24-hour average PM10 level.
  2. From 2006, Otago 1 monitoring results are the combination of Alexandra and Arrowtown results. From 2008, Otago 1 monitoring results also include results from Clyde and Cromwell.
  3. From 2008, Otago 2 monitoring results are the combination of Mosgiel and Milton. Before 2008, Otago 2 monitoring results are for Mosgiel only.

Move to information on the trends in airshed exceedances and concentrations.

 

Last updated: 2 August 2011