Executive Summary
Air quality monitoring for carbon monoxide (CO), nitrogen dioxide (NO2), sulphur dioxide (SO2), ozone (O3), benzene and benzo(a)pyrene (BaP) has been carried out in a number of locations in New Zealand. This report summarises the results of this monitoring for the years 1992 to 2002 and identifies areas and contaminants of concern. Results are compared to the ambient air quality guidelines and the air quality categories - excellent, good, acceptable, alert, and action (MfE and MoH, 2002).
Air quality monitoring of CO has been carried out in Auckland, Waikato, Hawkes Bay, Bay of Plenty, Wellington, Canterbury, Otago and Nelson. For the majority of the time, concentrations of CO are 'excellent' or 'good' in most of these locations. However, the guideline values are regularly exceeded at the Khyber Pass Road traffic site and at residential monitoring sites in Christchurch. Long-term monitoring for CO at Queen Street in Auckland and St Albans in Christchurch indicates concentrations of this contaminant have decreased between 1992 and 2001.
Concentrations of NO2 have been monitored in Auckland, Waikato, Hawkes Bay, Wellington, Canterbury and Nelson. In addition, survey type monitoring has been carried out in Taranaki, Bay of Plenty and Otago. For the majority of the time, concentrations of NO2 are 'excellent' or 'good' in these locations. The main exception is the Khyber Pass Road monitoring site in Auckland, where NO2 concentrations regularly exceed guideline values. No guideline value exceedences for NO2 (24-hour average) have been measured at residential air quality monitoring sites.
Ambient air quality monitoring for SO2 has been carried out in a number of locations within Canterbury, Auckland and Hawkes Bay. In addition, survey type monitoring has been carried out in Taranaki, Bay of Plenty and Otago. Concentrations of SO2 are 'excellent' or 'good' in most locations. No guideline exceedences for SO2 were measured during the period of 1992 to 2002.
Air quality monitoring for O3 has been carried out at a number of locations within Auckland and at two sites on the outskirts of Christchurch. Two exceedences of the eight-hour guideline value occurred at Musick Point in Auckland during October 2002. In other locations, guideline values have not been exceeded, although a large proportion of the data were within the 'acceptable' category and in Auckland up to 15% of the data were in the 'alert' air quality category.
Concentrations of benzene have been monitored in Auckland, Christchurch, Hamilton, Dunedin, Nelson, the Bay of Plenty and on the West Coast. Annual average concentrations have been within the current guideline value of 10 µgm-3 (annual average) and 2010 guideline (3.6 µgm-3) at most 'residential' sites. Guideline exceedences have been recorded at Khyber Pass Road in Auckland and at Riccarton Road in Christchurch. However, these were peak traffic sites that are not typically representative of a person's potential annual exposure.
Measurements of BaP have been carried out in Christchurch during 1999. Data show strong correlations with PM10 concentrations and indicate that the annual average BaP concentrations are at least 4 ngm-3, more than 10 times the guideline value concentration. Based on these results, it is likely that BaP concentrations also exceed ambient air quality guideline values in areas where elevated PM10 concentrations occur as a result of solid fuel burning for domestic home heating.
