Hong Kong's clean-air targets will be toughened for the first time in a quarter of a century from 2014, but they will still fall short of World Health Organisation standards.
Environmentalists criticised the long delay in adopting the new objectives and accused the government of taking a half-hearted approach to implementing more than 20 measures identified to improve air quality.
The Executive Council endorsed the new air quality targets, first put out for public consultation in 2009, yesterday. The Legislative Council must now approve changes to the Air Pollution Control Ordinance.
Secretary for the Environment Edward Yau Tang-wah said there was an urgent need to update air quality objectives, which had not changed since 1987. 'But we have to understand that the ultimate WHO guidelines are a distant target. Even the European Union cannot fully adopt all of them,' Yau said.
'Given the surrounding environment of Hong Kong, we cannot set a goal that is unachievable.'
The new objectives, which lay down atmospheric concentration limits for seven pollutants, are between 10 per cent and 64 per cent more stringent than existing ones.
Yau said the government could not implement the full WHO guidelines at this stage as regional pollution was beyond its control. Instead, targets for three of the seven pollutants will be based on the WHO's interim targets, which are intended to help territories with high levels of pollution move towards the full targets.
For the first time, the air quality standards will include a measure of airborne particles smaller than 2.5 microns in diameter (PM2.5), which are more harmful than larger particles as they can penetrate deep into people's lungs. But the standards will be in line with the loosest of the three WHO interim targets for PM2.5, angering environmentalists.
A total of 22 measures - including phasing out heavily polluting vehicles, promoting hybrid or electric vehicles, and increasing the use of natural gas - had been identified by the government to help achieve the new standards, and Yau said most of them were being implemented.
The steps could extend Hongkongers' average life expectancy by a month, officials said earlier.
There will be a three-year transitional period after 2014 to allow construction projects that begin earlier to continue under the old guidelines so they will not be delayed, Yau said.
The delay in implementation has meant some key projects, such as the Hong Kong-Zhuhai-Macau bridge, have had their environmental impact assessments approved under the old air-quality guidelines.
The Airport Authority says it will apply the new guidelines when it carries out the environmental impact assessment on the proposed third runway at Chek Lap Kok, and adopt mitigation measures.
Mike Kilburn, head of environmental strategy at think tank Civic Exchange, said he was 'extremely disappointed' with the two-year delay in implementing the policy.
Dr Man Chi-sum, chief executive of environmental group Green Power, said that as well as setting new standards, the government must thoroughly implement the package of measures it set out to help meet the target. 'Many of the measures are only being half-heartedly executed.'
Hahn Chu Hon-keung, senior environmental affairs manager at Friends of the Earth (Hong Kong), said the government had failed to set a timetable to reach the WHO's highest targets and had set the target for PM2.5 at the lowest possible level.