A government plan to set up a low-emission zone in busy districts, including Central, Causeway Bay and Mong Kok, is unlikely to get off the ground before the current administration ends its term in mid-2012.
In an attempt to improve air quality, officials proposed last year that only public buses with emission levels of Euro IV and above should enter such areas.
But with only 160 buses currently meeting that standard, the Environmental Protection Department now proposes looking at an option of fitting Euro II and Euro III buses with a filter that could meet Euro IV emission standards.
However, as Undersecretary for the Environment Dr Kitty Poon Kit told lawmakers yesterday, a study of fitting a catalyst reduction device - said to be effective in cutting nitrogen oxide emissions by 60 per cent in buses - would take up to a year, and would not start until next year.
Cyd Ho Sau-lan of Civic Act-up told a joint meeting of the Legislative Council's environment and transport panels: 'The present political administration - including you and me - will step down by mid-2012. We will not have enough time to assess funding even if you manage to table a plan by then.'
The joint panel's chairwoman, Audrey Eu Yuet-mee, pressed Poon on any plan the government might have so that it could be passed to the next administration, but she could give no answer.
Poon said it was still not known if the catalyst reduction device - which costs more than HK$100,000 - could be added to buses in Hong Kong. It has been installed in single-decker buses in London and Belgium, but tests have to be done for its efficiency in Hong Kong, where most buses are heavy double-deckers that operate in hot and humid summer conditions.
Some bus companies said earlier there may not be enough space for the device and it might not be compatible with the engines.
As of March, Euro II buses made up about 70 per cent of the 5,800-strong fleet for Kowloon Motor Bus, New World First Bus and Citybus combined. If all the 2,360 buses entering the three busy areas have to meet the Euro IV emission standard, there would be a shortfall of 2,200 buses. And even if entry to the zones was lowered to Euro III standard, there would still be a shortfall of about 1,200 buses.