LA motors cleaner than ours

By MARTIN JOHNSTON

Auckland vehicles puff out toxic carbon monoxide gas at a rate nearly two-thirds higher than those in Los Angeles, a study shows.

The finding has prompted fresh demands for mandatory controls on excessive exhaust emissions, but the Government is not convinced.

Preliminary results from an Auckland roadside study in April show carbon monoxide (CO) comprised 0.71 per cent of the fumes coming out of vehicles' exhaust pipes.

Similar surveys in the United States in 2001 showed that the invisible, toxic gas was 0.44 per cent of vehicle fumes in Los Angeles and 0.34 per cent in Denver.

"The simple message is to tune your vehicles," said Dr Gavin Fisher, a National Institute of Water and Atmospheric Research scientist involved in the Auckland study.

The Clean Air Society president said last night that the research also highlighted the need for New Zealand to introduce US or European-style vehicle emission controls.

"A lot of countries do have regulation at warrant-of-fitness time. If carbon monoxide levels are too high they require you to fix it, including places like Brazil."

The Niwa-Auckland Regional Council study checked more than 30,000 vehicles as they passed 14 sites in the region, including a motorway onramp. Researchers aimed infrared and ultraviolet light beams across the roads and measured the amounts of CO arriving at the other side after the beams had passed through the exhaust.

An electronic board 50m down the road from each site told drivers about the quality of their vehicle's exhaust. Number plates were photographed to allow further factors like vehicle age and type of fuel to be linked to emissions levels.

The worst 10 per cent of vehicles created 50 per cent of the emissions.

The study also found that the average level of hydrocarbons was 331 parts per million (compared with 125 in Los Angeles) and average level of nitrogen oxides 602 parts per million (411 in Los Angeles).

While carbon monoxide poisoning can be fatal, Dr Fisher notes that at lower levels, from which people recover, it can cause headaches, learning disabilities in children, and drowsiness.

"Nitrous oxides cause breathing difficulties for people, especially asthmatics," he said.

An estimated 399 New Zealanders aged over 30 die prematurely every year from inhaling tiny, non-gas particles in vehicle exhaust.

Council chairwoman Gwen Bull said that while driver education helped reduce emissions, the only way to obtain a real reduction from the worst polluters was to regulate, "to ensure that they must clean up their act. This is only fair on everyone else".

The Government will this year consider whether to impose emission screening on secondhand, imported vehicles and, "if necessary", regularly on all vehicles.

Associate Transport Minister Judith Tizard said she would recommend to the Cabinet that warrant-of-fitness emission tests be introduced as a voluntary, educational measure. They should become mandatory only when there was sufficient research to support them.

"We've got to balance this against people's ability to get to work and all the things we need cars, trucks and vans for."

She was concerned but not surprised that Auckland vehicles compared badly with those in the two American cities.

Auckland's rating

City Av CO level, 2001

Los Angeles 0.44%

Denver 0.34%

Auckland 0.71%