Despite an improvement in roadside air quality, there has been little reduction in air pollution generally,  Secretary for Environment, Transport & Works Dr Sarah Liao says.

Dr Liao told the Legislative Council this afternoon that this was a reflection of poor regional air quality.

She said the average concentrations of air pollutants recorded at roadside air quality monitoring stations had fallen over the past five years.

This indicated that the measures implemented to reduce motor-vehicle emissions over the past few years had improved roadside air quality, she added.

However, there had been little reduction in the concentrations of pollutants in the surrounding air generally. 

Pollutants come from Pearl River Delta

"This reflects that the problem of regional air quality has not improved much in relative terms, and its impact on the air quality in Hong Kong is particularly serious under certain meteorological conditions," Dr Liao said.

She said the pollutants in the air in Hong Kong came from emission sources in Hong Kong and other areas of the Pearl River Delta region.

To improve regional air quality, the Government and the Guangdong Provincial Government have drawn up a Regional Air Quality Management Plan.

Impact of air pollution on health studied 

Dr Liao said the Environmental Protection Department, the University of Hong Kong and the Chinese University of Hong Kong carried out a study in 2002 on the correlation between air pollution in Hong Kong and its impact on health. 

The study made use of the air quality data from 1995 to 2000 and the data on daily admissions at 12 public hospitals of the Hospital Authority to assess the correlation between air pollution and respiratory and cardiovascular illnesses in Hong Kong.

According to the study, the admission to hospital of 3,770 patients with respiratory illness and 3,970 patients with cardiovascular illness in 2000 could have been related to air pollution.