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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