Cheung Chi-fai, SCMP – Mar 26, 2009
Local politicians in Wan Chai want more pedestrian flyovers, traffic-free streets and further greening of the area after a study they commissioned found particulate matter in the district’s air at levels nearly five times higher than recommended under the most stringent world standards.
The joint Wan Chai District Council/Neighbourhood Advice-Action Council study measured fine particle concentrations – known as PM 2.5 – at 15 locations in the district between December and January and found none of the readings met World Health Organisation air quality guidelines.
Conducted by Polytechnic University experts, the study also discovered that up to 72 per cent of particles found in the tested air were very fine ones capable of infiltrating directly into lungs and blood systems, causing even greater health threats than more coarse “fine” particles.
The highest reading recorded was 140 micrograms of fine particles per cubic metre in Causeway Road, compared to the WHO standard of 25 micrograms per cubic metre. Even in the city’s largest open space, Victoria Park, the reading was 30 micrograms per cubic metre. Study readings were largely in line with official air quality monitoring in Yee Wo Street, which measures only coarser “fine” particles, the study said.
Daniel Chan Wai-tin, an engineering professor in charge of the study, said the chosen locations were representative of the commercial and tourism district characterised by heavy vehicular and pedestrian traffic and high-rise buildings.
He said the high pollution readings were mainly attributable to emissions from vehicles and the poor pollutant dispersion capabilities of the built environment.
The wall effect created by the concrete jungle had blocked the dispersion of pollutants once made possible by natural inflow of sea breeze, and increased pollution in the district, Professor Chan said.
To ease the pollution, Professor Chan recommended more pedestrian flyovers and subways to separate traffic from commuters, and more planting of vegetation throughout the district.
Wan Chai District Council chairman Suen Kai-cheong said the study’s findings would be useful in discussions by councillors and community members relating to ways to reduce air pollution.
“The findings will provide us with some objective and scientific evidence that might help persuade different parties to come to a consensus on certain projects beneficial to the air quality that requires some changes,” he said.
The study will be submitted to the government for reference.