Masterton ranks as one of the worst towns in Oceania for air pollution, according to a world database just released.

Figures released by the World Health Organisation (WHO) uses 2012 data which shows the town crosses the line for one of two measures of air quality.

Annual levels of PM10 particles and the smaller PM2.5 particles are used to measure air quality -- these are so small that they can get into the lungs, potentially causing serious health problems. Masterton has a PM10 particle reading of 14 and a PM2.5 particle reading of 12.

The WHO guidelines state that levels of 20 and 10 micrograms per cubic metre respectively are considered safe.


Timaru is the worst in Oceania, with a PM10 annual mean level of 28 micrograms per cubic metre, and a PM2.5 level of 15 micrograms per cubic metre.

Christchurch was the worst of New Zealand's major cities, while air in Wellington and Auckland was found to be much cleaner.

Air pollution is an enduring winter problem for Masterton, with the standards for PM10 breached on 13 days, and PM2.5 exceeded on 34 days, in 2014. The most common complaint to Greater Wellington is for smell, out of 133 notifications relating to discharges to the air in Wairarapa in 2013 and 2014.

Odour accounted for 69 notifications, while 46 related to smoke.

In 2013, a Victoria University PhD student published a study which showed arsenic featured in the air pollution in winter months in Masterton -- most likely from people burning treated timber.

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