Quantifying air pollution sources is crucial for developing effective measures to reduce emissions and improve air quality. This technical report on carbon monoxide (CO), nitrogen oxides (NOx), sulphur dioxide (SO2), ozone, benzene and benzo(a)pyrene summarises what we currently know about the main sources of air pollutants in New Zealand towns and cities. Other reports in this series summarise monitoring concentrations and potential health effects.
Many councils have prepared emission inventories for urban areas in their regions and we now have a reasonable picture of the main emission sources. Domestic fires and vehicles contribute the greatest quantity of air pollutant in New Zealand, although industry can cause localised air pollution.
It is important to recognise that inventories are estimates of emissions from different sources. Usually they provide an averaged value for an area or whole airshed. Some of the inventories presented in this report are not directly comparable because different methodologies have been used. Despite this need to compare datasets cautiously, inventory information will assist in identifying sources and locations where action is required to reduce emissions. This report will also assist in developing appropriate national environmental standards for air quality.
I would like to thank all those councils and others that have contributed data and provided feedback.
Ministry for the Environment