Cheung Chi-fai, SCMP – Updated on Feb 02, 2009
Hong Kong should increase the number of air-quality monitoring stations, particularly at the roadside, and incorporate a measurement of very fine particles to give the public a better picture of the health risk it faces, a critic says.
The issue has been raised as the government plans to consult the public on the air-quality objectives review early this year amid pressure for it to adopt the World Health Organisation’s highest standards.
But the Environmental Protection Department said there was no need to enlarge the monitoring network, although it was willing to consider expanding its fine-particles measurements and publish them online.
The city has 14 air-quality monitoring stations – 11 measuring background readings and three roadside readings of five pollutants.
The stations measuring background readings reflect the regional pollution, and the roadside ones – in Causeway Bay, Mong Kok and Central – gauge pollution posing a direct threat to people on the streets.
Only four general and one roadside station measure the level of fine particles – known as PM-2.5 – which overseas research has found to pose a greater health threat.
Last year, the annual reading of fine particles at roadside level in Central reached 41 micrograms per cubic metre of air, four times the WHO standard.
“It is worth studying the issue, given our unique city environment does not favour dispersion of pollutants,” said Alexis Lau Kai-hon, the manager of the Environmental Central Facility at the University of Science and
Technology.
However, Choy So-yuk, a North Point-based district councillor and a member of the Council for Sustainable Development, said it was far more important for the government to improve roadside air quality than to build
more stations.
“Everybody knows the air quality in North Point is far worse than in Central, even without a monitoring station,” she said.
Ms Choy said officials should focus more on getting rid of the wall effect in the city by cutting building heights, and increasing the number of green areas in busy parts of the city.