ARC cooks the books on air pollution

By OWEN McSHANE

Aucklanders are puzzled. The Auckland Regional Council tells us that Auckland's air is polluted - filthier than the air of London and New York.

Many of us do not believe it. How come the regional council's figures are so contrary to common sense? The answer is simple. They cooked the books.

And they have persuaded others, including the Parliamentary Commissioner for the Environment. A graph in his latest report, Creating Our Future: Sustainable Development for New Zealand, shows Auckland's levels of carbon monoxide from motor vehicles, from 1992 to 1998, significantly exceed international guidelines.

The commentary below the graph explains: "In Auckland, carbon monoxide concentrations are higher than in London and other larger cities".

The graph is sourced from a paper by G.W. Fischer, of the National Institute of Water and Atmosphere (Niwa). But on the first page, Mr Fischer explains that: "The data are also only peak values. That is, the numbers represent the highest value found anywhere in the city, at any time of year."

In reality, the median value for levels of carbon monoxide over the whole five-year period is only about 7 per cent of the international guidelines. And this average is from the most polluted site in the region.

Mr Fischer's paper concludes: "New Zealand is still a very clean place, especially in comparison to other countries."

Yet the regional council insists that Auckland is more polluted than London.

When someone compares Auckland with London, we first have to ask "what is Auckland?" and "what is London?"

If you tell me that Manhattan Island has a higher residential density than Los Angeles City, you are right. But if you then tell me that the New York metropolitan region has a higher density than greater Los Angeles, you are wrong. Los Angeles is a very high-density region.

So what Auckland is the regional council measuring? Wellsford? Pukekohe? Piha?

They are drawing on three highly polluted monitoring sites - Queen St, Khyber Pass Rd and some short-term readings in Dominion Rd.

The regional council's Queen St monitor used to be sited in the middle of a Queen St block, near Tisdalls sports store. But a few years ago, it was moved across the road, close to traffic lights at Wyndham St.

The peak readings naturally increased and the regional council tells us that carbon monoxide in Auckland is increasing.

These peaks occur from 11pm to 3am on Fridays and Saturdays, when there are few people around. What causes the high readings?

First, Queen St runs down a gully, which is further contained by a canyon of high buildings. Auckland's nights are comparatively calm. And the midnight hours are when the boy racers come out to play. So if Mayor John Banks gets the boy racers out of Queen St, the street's air pollution problems will probably disappear with them.

The other dirty site is in Khyber Pass. Niwa's office is on the corner of Mountain Rd and its sampling pipe hangs out the window, sucking up air from the traffic lights.

A couple of London's many monitoring sites appear to carry similar traffic levels to Queen St and Khyber Pass. Sure enough, the highest level of nitrogen dioxide (the other major exhaust pollutant) at Camden peaks at 207g/m3, which is lower than at Khyber Pass, which peaks at 277g/m3.

On the other hand, the level at Tower Hamlets (294g/m3) is higher than at Khyber Pass. The average levels at both London sites (Camden 71g/m3 and Tower Hamlets 74g/m3) are higher than at Khyber Pass, at only 58g/m3.

The recommended ambient guideline for nitrogen dioxide is way up there at 200g/m3. So our average reading of 58g/m3 at Khyber Pass suggests most Aucklanders have little to worry about - except their bureaucrats.

At the congested monitoring sites in London, traffic is mostly idling or moving slowly. There are no nearby traffic lights and these London sites are flat.

When the traffic lights at the Khyber Pass site turn green, the traffic has to accelerate and climb uphill, which increases the load on the engine and produces more pollution right below Niwa's intake pipe.

It is not surprising that this monitoring site records such high levels of exhaust pollution.

Why do these analysts in the regional council want us to believe that Auckland is one of the most polluted cities in the world?

Why are they telling potential tourists that Auckland is filthier than London, New York and Hong Kong?

Who knows? But we do know that the regional council will soon be the owners and operators of a train system and it needs as many passengers as possible. One way to increase patronage is to increase the cost of driving a motor car.

The regional council coyly calls it "travel demand management". Shafting the competition is more like it.

In a briefing paper to the regional council, Kevin Rolfe, an air quality management specialist, recommended the way to solve this non-existent crisis was to introduce a series of measures including:

* Restricting the age of imported vehicles.

* Making cleaner fuels.

* Providing remote carbon monoxide sensing sites at roadsides.

* Running a refit programme.

* Legislating accelerated vehicle retirement.

* Funding a diesel engine rebuilding programme.

These are hugely expensive programmes. Can Auckland afford to spend hundreds of millions of dollars solving a non-existent problem?

Why should South Auckland workers suffer higher motoring costs because of Queen St boy racers?

Why not do what other responsible regulators do and generate a daily exposure-related air pollution index, so that drivers can avoid the most polluted parts of town?

That would empower motorists rather than punish them.

Niwa wrote the Ministry of Transport report which claimed, with astonishing precision, that air pollution was causing 399 premature deaths in New Zealand a year. Its own measurements tell it that its office is sitting on top of one of the most polluted sites in Auckland.

So why do they keep working there? Do they have so little faith in their own work?

Or do they know something we don't?

* Owen McShane, of Kaiwaka, is a research consultant and public policy analyst.

nzherald.co.nz/environment