Media Release
8 May 2014
Hawke’s Bay Air Quality Science Informs WHO Review
Hawke’s Bay is doing as well as, if not better than, many other towns and cities in New Zealand in terms of air quality,
says Hawke’s Bay Regional Council scientists in response to a report from the World Health Organisation.
The United Nations public health arm has released a report of outdoor air quality in 1600 cities across 91 countries. Subsequent news reports have stated that many smaller centres have worse air quality than metropolitan Auckland.
The World Health Organisation (WHO) used figures supplied by the Ministry for the Environment based on data supplied by
regional councils. These figures are the annual mean concentrations of fine particulate matter, which are particles
smaller than 10 micrometres per cubic metre of air (ie PM10).
HBRC air scientist Dr Kathleen Kozyniak says that annual mean PM10 concentrations for both Napier and Hastings are lower
than the MfE’s Ambient Air Quality Guideline value of 20 micrograms per cubic metre. They rank similarly to Auckland at
14 and 15 micrograms per cubic metre respectively.
Dr Kozyniak says that HBRC was advised last year that WHO would be collecting data, and councils had the opportunity to
verify their monitoring information.
“On the whole there has been a pleasing decrease in PM10 concentrations in our two cities since monitoring began in
2005/6,” says Dr Kozyniak.
“From 2010 to 2012 we saw Hastings concentrations drop from 17 to 15 micrograms per cubic metre and Napier’s from 15 to
14 micrograms per cubic metre. Having said that, there was a blip upward in concentrations last year in both cities for
a number of possible reasons, such as the light winds we had last winter. I’m aware there was a similar pattern in other
NZ centres’ air quality too.”
Dr Kozyniak says that weather plays a part in air quality.
“Hawke’s Bay’s winters may be blessed with days of fine blue skies and calm conditions in winter but, although they
cheer the heart, these are conditions which trap smoke close to the ground. Some of the centres listed in the news
report have windier and wetter conditions which help to clear the air.”
Hawke’s Bay Regional Council has conducted emissions inventories (2005 and 2010, another is due next year) which
indicate that domestic fire emissions contribute more than 90% of the wintertime concentrations of PM10.
HBRC’s Heatsmart Programme Manager, Mark Heaney, says that council’s Heatsmart scheme for upgrading older model wood
burners to more efficient modern burners or heat pumps means that people can expect to see PM10 concentrations
progressively decrease.
“The quality of the air in Napier and Hastings during winter still needs to improve and we all have to work towards
that. It has been encouraging to advise a lot of people over the past few months on the choices they can make for home
heating and how to take advantage of the Council’s funding assistance package.”
Below are graphs for Napier and Hastings average winter only concentrations, as compared to the annual average quoted by WHO. These graphs are adjusted to take account of the variation in weather between winters. Overall the trend
is downward, but with a blip last year.
Napier
Hastings
Note – micrograms per cubic metre are shown as µgm-3