Sydney risks falling short of its air pollution targets for photochemical smog and ozone, as growing population and traffic congestion erodes the gains made by the switch to unleaded petrol in the 1980s. While the city's air is usually cleaner now than it has been for more than 20 years, a new report from the NSW Department of Environment, Climate Change and Water suggests the respite could be temporary. ''Previous and current strategies have been effective in reducing pollutants,'' the report said. ''However, gains have been reduced due to growth in emissions sources, and further reductions in the future will be affected by the impacts of climate change.'' Most indicators of Sydney's air quality have been improving steadily since the 1990s, when University of Technology research contended that air in Sydney could contain more carcinogens than a person would inhale if they smoked 10 cigarettes a day. The main driver of the improvement was the switch to unleaded petrol and other changes to vehicle emissions standards. Lead levels have fallen to the extent that regular monitoring was phased out in 2004, while other potentially toxic compounds such as sulfur dioxide and carbon monoxide are also declining. But, using the Intergovernmental Panel on Climate Change's estimates of future temperature rises, the department report found that the number of days when air pollution from ozone exceeded guidelines over a four-hour period would rise 40% from 2021, and 92% from 2051. South-west Sydney, around Campbelltown and Liverpool, would be worst hit by high ozone levels, which can damage lung tissue. The south-west is more heavily affected by air pollution mainly because the prevailing sea breeze is north-easterly. ''Reducing ground-level ozone pollution in the Sydney and Illawarra regions presents a challenge,'' the report said. The Australian Government's plan to achieve further improvements requires the number of kilometres people travel in private vehicles to peak by 2021. ''Realistically this is pretty unlikely,'' said the director of the Total Environment Centre, Jeff Angel, from the state's Clean Air Forum yesterday. ''The idea that people in Sydney would rather drive a car than catch public transport is just a destructive, self-perpetuating myth that leads to reduced priority being given to public transport,'' he said. ''The only answer is to continue curbing the sprawl of Sydney, with more high-density housing around better rail links.'' The Environment Minister, Frank Sartor, said the Government would spend $1.8 million on research into ways of stopping particle emissions. These include muzzling the exhausts of 'non-road' diesel-powered cranes, forklifts and bulldozers, and a trial of two hybrid diesel-electric buses. "There is increasing scientific evidence to suggest that even low levels of air particle pollution can have impacts on human health," Mr Sartor said. The Government is also expanding its monitoring of air pollution and dust in the Hunter Valley.


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