Lives are being saved as the quality of air in New Zealand improves through technology that reduces vehicle pollutants and as fewer homes burn wood or coal.
A report published today said there was an 8 per cent fall in the concentration of PM10 – very small airborne particles 10 micrometres or less in diameter – between 2006 and 2012.
PM10 particles are associated with health problems ranging from respiratory irritation to cancer.
A model estimated that deaths from exposure to man-made PM10 were down 14 per cent because of the drop in PM10 concentrations.
Hospital admissions were down an estimated 15 per cent, and days with restricted activity were down an estimated 9 per cent.
The figures were in the 2014 air domain report produced by the Ministry for the Environment and Statistics New Zealand.
It is the first report in a new environmental reporting series. Other aspects of the environment to be covered will be atmosphere and climate, fresh water, land and the marine environment.
"Good outdoor air quality is fundamental to our wellbeing. On average, a person inhales about 14,000 litres of air every day, and the presence of contaminants in this air can adversely affect people's health," the report said.
"People with pre-existing respiratory and heart conditions, diabetes, the young and older people are particularly vulnerable."
Today's report said estimated emissions from road transport fell by between 25 and 49 per cent for a range of pollutants from 2001 to 2012.
That was mainly because of technological advances in vehicles and fuel, with vehicle use up 11 per cent.
The decrease in estimated emissions may have contributed to the fall in PM10 concentrations.
Despite the improvement, road transport continued to be a problem, with high levels of nitrogen dioxide and benzene in some places during peak traffic, the report said.
From 1996 to 2013, there was a 25 per cent fall in the number of households burning wood or coal for heating, which was also likely to have contributed to the fall in PM10 concentrations.
Burning wood and coal was still associated with air-quality issues, including high levels in some places of the finer PM2.5 particles, arsenic from burning treated timber, and the hydrocarbon benzo(a)pyrene.
New Zealand's average national PM10 concentration was the seventh lowest of 32 Organisation for Economic Co-operation and Development countries in 2011, while 48 out of 55 monitoring sites met World Health Organisation long-term guidelines in 2012, the report said.
The worst results came from two sites where PM10 levels were between 21 and 40 per cent above the WHO guidelines.
Guidelines were also exceeded at some times in some places for PM2.5 particles, nitrogen dioxide and sulphur dioxide.
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