The government has rejected claims that its seven-year clean-air plan, released yesterday, is nothing but a rehash of the previous administration's ideas.
Critics have said the road map - billed as the most comprehensive plan yet to improve Hong Kong's air quality - features very few new ideas or measures.
Undersecretary for the environment Christine Loh Kung-wai defended the strategy.
"[The plan] shows the strong intensity and determination of the government and what our priorities are," Loh said.
One new measure, outlined by Secretary for Transport and Housing Professor Anthony Cheung Bing-leung, aims to plug a loophole in prosecuting operators of smoky vessels. Cheung said plans for a law to introduce the Ringelmann chart would be presented to the legislature later this year.
The chart tracks the colour of smoke from white through shades of grey to black. Any vessel with smoke darker than a particular shade for more than three minutes would be liable to prosecution. Current law makes emitting dark smoke an offence only if it is proved to be a nuisance.
But aside from this initiative, critics say most of the measures have been announced by the previous administration.
Angus Wong, policy advocacy manager of World Green Organisation, was disappointed with the plan.
"It is old wine, new bottles, to some extent. But I don't think they could come up with something drastically new," he said.
He called on officials to implement all those previous measures and then consider addressing planning shortcomings that have trapped air pollutants in the city.
Professor Wong Tze-wai, an air pollution expert at Chinese University, said officials should be given time to do their work.
"We should not pour cold water on them right now," he said.
Measures outlined in the road map include cleaner fuel for ships, retrofitting buses with emission controls, and better research into air pollution.
The government has promised to introduce legislation to require cleaner fuel for local vessels this year and ocean-going ships in port next year.
Loh said it had also initiated talks with Guangdong on a similar requirement for berthed ships at the province's ports.
By the turn of the decade, she said, the Pearl River Delta region, including Hong Kong and Macau, could be turned into an emission-control area requiring even cleaner fuel.
About 1,400 old franchised buses will be retrofitted with selective catalytic reduction devices by 2016, in an attempt to lower nitrogen dioxide emissions.
Talks are still continuing with commercial diesel truck operators on phasing out old vehicles under a HK$10 billion scheme
On building up air science, Loh said local universities were exploring research to gauge the health impacts of air pollution.
She said environment officials would also be sent to Geneva to learn from air experts of the World Health Organisation.
Permanent secretary for development Wai Chi-sing said the bureau would build a city-wide cycling network and incorporate air-flow assessment in government works projects in the future.
Undersecretary for food and health Professor Sophia Chan Siu-chee said health officials would provide professional advice on the impact of air pollution by tracking international trends and standards.