Science

Air pollution worst inside cars: research

Tuesday, 2 September, 2008
Dan Gaffney

Commuters inside slow-moving cars are exposed to far higher levels of air pollution in peak traffic times than those using any other form of transport, new research has revealed.

Car drivers and passengers face pollution levels inside their vehicles that are two to three times higher than those experienced by pedestrians and cyclists in the open air, the study has found.

Comparing all forms of transport, train travellers breathe the cleanest air and pollution levels inside buses are second lowest, despite public transport vehicles such as buses accounting for the bulk of vehicle emission pollution in Australia's major cities.

The news comes as the NSW Government this week announced plans for a cycling "blueprint" to promote cycling and improving cycling facilities as part of a balanced transport system.

The NSW Minister for Environment and Climate Change, Verity Firth said the Premier's Council on Active Living would start work on a new bike plan for NSW: "It makes sense to encourage more people to consider cycling as an environmentally friendly and healthy means of transportation, particularly for short trips," Ms Firth said.

"It is often assumed incorrectly that cyclists and pedestrians are exposed to higher air-pollution levels than motor vehicle occupants because they are physically unprotected," says the study's author, Dr Chris Rissel from Sydney University. "Yet cyclists tend reduce their pollutant exposure by taking side streets and moving out from behind motor vehicles during traffic stoppages."

Typical vehicle emission pollutants include carbon monoxide, nitrogen dioxide, volatile organic compounds such as benzene and toluene, and tiny smog particles less than 2.5 microns in diameter. Exposure to these pollutants has been linked to diseases and adverse outcomes such as cancer, asthma, emphysema, leukaemia, reduced fertility and low birth-weight. One of Australia's foremost environmental health experts,

Professor Tony McMichael from the Australian National University, has stated that there are as many or even more deaths caused by urban air pollution as by car crashes.

"Around 12,000 Sydneysiders are now cycling to work each day, and we should encourage even more to do so by providing continuous bicycle routes with well-maintained surfaces" according to UNSW risk and safety expert Dr Julie Hatfield. "Cycling to work has health benefits over and above the health benefits of cycling for recreation".

Cycling also has a host of health, economic and environmental benefits, Professor Hatfield notes. The value of cycling to the national health system is calculated to be approximately $227 million a year. As well, cyclists reduce the community costs of traffic congestion ($64 million a year) and greenhouse gas emissions ($9.3 million a year). Higher cycling rates will increase those savings.

"Just one person who switches from driving to cycling to work during the week over a 10km trip each way saves around 1.3 tonnes of greenhouse gas emissions a year," said Ms Firth. "And cycling doesn't just help reduce pollution, it also cuts down on traffic congestion and gets people fit. Last year, NSW residents purchased around 430,000 new bicycles, outstripping the number of new vehicles registered in the same period by 75,000."

Drs Chris Rissel and Julie Hatfield will speak at a forthcoming cycling safety seminar.

A place for bicycles: strategies for promoting safety
When: Friday 5th September 2008.
Where: Sydney Park Pavilion, Euston Rd, Alexandria
Contact: Henny Oentojo, UNSW, 02 9385 7953; or Julie Hatfield, UNSW, 0425 356 484
UNSW's Injury Risk Management Research Centre is hosting the seminar with support from the Motor Accidents Authority of NSW and the City Sydney Council.

Media contact: Dan Gaffney - UNSW - 0411 156 015