Source: New Zealand Herald, 28 September 2016
New Zealand has some of the cleanest and safest air on the
planet, a new World Health Organisation report suggests.
The report analysed data from more than
100 nations, comparing exposure to ambient air pollution and
related death and illness.
It showed New Zealand was either in the top five or 10 nations
with the best results for concentrations of PM2.5 - a key measure
of air pollution - along with rates of deaths, disease and illness
that could be attributed to pollution.
However, Associate Professor Simon Hales of Otago University's
Department of Public Health questioned whether the report's methods
accurately reflected rates in smaller countries such as New
"Their estimates of PM2.5 exposure use data from satellites,
which are excellent for large countries with little surface air
pollution monitoring data, but do not perform so well at local
scale in small countries like New Zealand," Hales said.
The resolution of their data is of the order of 10km, which was
too coarse for most New Zealand urban areas, he said.
"The study authors did not assess health impacts of exposures
below 5.9 μg/m3.'
"Again, this makes sense if exposures are high, as in countries
with a lot of heavy industry or using biomass for heating and
"It is not so appropriate for New Zealand, since we know from
epidemiological studies of mortality that the comparatively low
levels of exposure do have a substantial health impact here.
"We can and should reduce levels of exposure still further."
A 2014 report by Parliamentary Commissioner
for the Environment Dr Jan Wright found the state of New Zealand's
air was generally good, as could be expected in a windswept
maritime country with a small population and little heavy
Air quality was poorer in some towns and cities during cold,
calm days in winter, but even in these places air quality was high
on most days, she found.
What the WHO report found
New Zealand had the one of the lowest annual median
concentrations of PM2.5 (particulate matter under 2.5 micrometres
in diameter), with a rate of five micrograms per cubic metre of
air, across urban and rural areas.
This was equalled only by the Solomon Islands, Kiribati and
Brunei Darussalam; and lower than other low-rating nations
including Sweden (6μg/m3), Fiji (6μg/m3), Australia (6μg/m3),
Canada (7μg/m3), Finland (7μg/m3), Iceland (8μg/m3), Estonia
(8μg/m3) and Liberia (8μg/m3).
At the other end of the spectrum, nations with the highest
amounts were Saudia Arabia (108μg/m3), Qatar (103μg/m3), Egypt
(93μg/m3) and Kuwait (75μg/m3).
The data, as at 2012, showed New Zealand as having one of the
lowest rates of death attributable to ambient air pollution, with
0.3 (age-standardised) deaths per 100,000 people.
Australia and Sweden had only slightly better rates, with 0.2
deaths per 100,000 people.
This compared withhigh rates per 100,000 people in Turkmenistan
(89) Afghanistan (81), Egypt (64), Mali (62) and China (60).
New Zealand listed 20 deaths attributable to air pollution,
including four to stroke, three to lung cancer and 13 to ischemic
In terms of rates of years of life lost to air pollution, New
Zealand had a figure of six per 100,000 people - a level only
higher than the Solomon Islands (zero years), Sweden (three),
Micronesia (four) and Australia (five).
Countries with the highest rates were Turkmenistan (3120)
Afghanistan (2456 years) Tajikistan (2346) and Uzbekistan
Global picture not so pretty
More concerning was that the data confirmed that 92 per cent of
the world's population lived in places where air quality levels
exceed WHO limits.
About three million deaths each year were linked to exposure to
outdoor air pollution, and indoor air pollution could be just as
In 2012, an estimated 6.5 million deaths were associated with
indoor and outdoor air pollution together.
Nearly 90 per cent of air-pollution-related deaths occur in low-
and middle-income countries, with nearly two out of three occurring
in Southeast Asia and western Pacific regions.
Ninety-four per cent were due to non communicable diseases -
notably cardiovascular diseases, stroke, chronic obstructive
pulmonary disease and lung cancer.
Air pollution also increased the risks for acute respiratory
"Air pollution continues take a toll on the health of the most
vulnerable populations - women, children and the older adults,"
said WHO assistant director-general Dr Flavia Bustreo.
"For people to be healthy, they must breathe clean air from
their first breath to their last."
Major sources of air pollution included inefficient modes of
transport, household fuel and waste burning, coal-fired power
plants, and industrial activities.
However, not all air pollution originated from human activity:
air quality could also be influenced by dust storms, particularly
in regions close to deserts.