For cleaner air, marine emissions should be Hong Kong's next target

The long-anticipated tougher air quality standards are finally in effect in Hong Kong, acting as a benchmark for assessing the impact new development projects will have on air quality. Although the new air quality objectives fall short of World Health Organisation recommended levels, it is still a change for the better.

Another breakthrough has been the introduction of the air quality health index to more accurately track pollution levels and alert the public to the health risks.

Meanwhile, last month, the Legislative Council passed the amendment to the Air Pollution Control (Air Pollutant Emission) (Controlled Vehicles) Regulation to phase out old, polluting diesel commercial vehicles. The result may take some time to show, but it is undoubtedly a strong policy that will help the city reduce its roadside emissions.

So the past year has marked a number of milestones for air policy in Hong Kong. Yet people are still unhappily gazing up and seeing our city shrouded in smog, more aware now than ever of the terrible health consequences of pollution. Only last October, the WHO classified air pollution as a cause of cancer, signifying the attention for action it deserves.

It's now time for the Hong Kong government to step up its efforts. Cargo and passenger marine vessels in our waters have become the biggest source of sulphur dioxide and respirable suspended particulate emissions, according to the 2011 data in the government's Air Pollutant Emission Inventory report. There must be no delay in tightening the cap on the sulphur content of locally supplied marine diesel and requiring ocean-going vessels to switch to low-sulphur fuel while at berth.

In the long run, an emission control area should be set up in the waters of the Pearl River Delta.