Air quality is a critically important aspect of environmental health in New Zealand. Air pollutants include fine particulate matter and toxic gases such as nitrogen dioxide. Sources of outdoor air pollution include vehicle emissions, industrial processes, power stations and home heating, as well as natural sources. Indoor air quality can be affected by tobacco smoke, as well as fuels used for cooking and heating. Human health effects from poor air quality (indoor and outdoor/ambient air) include respiratory problems, particularly in the young and old and in people with pre-existing medical problems.
In 2007, 23 of the 40 monitored airsheds in New Zealand exceeded the national environmental standard for air quality for small particulate matter (PM10). This included 15 of the 17 South Island airsheds. The airsheds with the highest number of exceedance days in 2007 were Otago 1, Timaru, Rotorua, Nelson A, Richmond and Reefton.
In 2005, the two monitored sites in Auckland (at Khyber Pass Road and Penrose) exceeded the national environmental standards for nitrogen dioxide.
Almost 1 in 10 children were exposed to second-hand tobacco smoke in the home in 2006/07, as were 1 in 15 non-smoking adults aged 15 years and over. The following areas had significantly higher rates of children exposed to second-hand smoke in the home compared to the national average: Waikato DHB, and the combined area of Northland, Tairawhiti, Hawke’s Bay, Lakes and Whanganui DHBs.
In 2007, there were high hospitalisation rates for respiratory disease among children aged 0–4 years in the following DHBs: Northland, Counties Manukau, Lakes, Bay of Plenty, Tairawhiti, Hawke’s Bay, Whanganui, Hutt Valley, Wairarapa and Canterbury.