Secretary for Environment, Transport and Works Sarah Liao admitted air pollution control ``as a whole'' has not been successful, although the government had effectively controlled levels of emissions.

Speaking at the Legislative Council's Public Accounts Committee, Democratic Alliance for the Betterment and Progress of Hong Kong legislator Lau Kwong-wah argued the government is wasting public funds as it has spent more than HK$1.4 billion since 1999, but air pollution had only gotten worse.

In defending the government's efforts to reduce roadside pollution, Liao said diesel vehicles were only one source of pollution. Other causes included the rapid industrial development of Pearl River Delta and emissions from local factories.

``We have tried our best to combat pollution by controlling the source of pollution,'' Liao said, but air quality improvements had not met their targets.

Admitting that air pollution is getting worse, Liao said ``the improvement in air pollution as a whole is not successful.''

However, Liao argued that the territory's dense urban population as well as high-rise buildings blocked the wind speed, thus reducing the ability to dilute pollutants.

The Hong Kong Observatory reported in January that wind speeds decreased at a rate of 1.69 kilometres per hour (0.47 metres per second) per decade between 1986 and 2004. This is the result of high density urban development. ``We are effectively reducing the source of pollution, otherwise the situation will be even worse,'' Liao said, adding the government will closely monitor the emissions of factories and power plants.

University of Hong Kong Professor of Community Medicine Anthony Hedley Monday criticized the government for its lack of urgency in tackling air pollution, saying the SAR had gone ``backwards, not forward, in the past two years.''

``The intervention [of government] has not matched the severity of the problem,'' Hedley said.

Most of the environment control measures like converting mini-buses to liquefied petroleum gas (LPG) are voluntary, which caused many delays, Hedley said.

He said a ``radical approach'' should be adopted to solve the problem.

``We should stop building roads and encourage cleaner forms of transportation such as the MTR,'' he said.

``And the government should increase penalties for violaters.''

Regarding the cross-border measures in combating regional air pollution, Hedley described as ``toothless'' the government's efforts to urge mainland authorities to take quicker action, saying timetables for improvements were far too long.

``The government has not established a suitable dialogue with the mainland. They do not understand the nature of pollution and the approach does not match the severity and urgency of the problem,'' Hedley said.

The regional air strategy took form in late 1999 when the Guangdong and the SAR governments commissioned a study to determine the major sources of air pollution in the Pearl River Delta.

chester.yung@singtaonewscorp.com