Ships caused a larger percentage of emissions in Hong Kong in 2010 than 2009.
Air pollution produced by marine vessels in Hong Kong worsened in 2010 compared with the previous year, despite a general improvement in pollution levels, according to a new report by the Environmental Protection Department (EPD).
Vessels emitted 16,900 tonnes of sulfur dioxide (SO2) in 2010, up 9.7 percent from 2009, while nitrous oxide (NOX) emissions from ships rose 8.3 percent to 35,000 tonnes.
Emissions of respirable suspended particulates (RSP) from vessels also rose, though ships produced less volatile organic compounds and carbon monoxide than in 2009.
Overall, emissions, particularly SO2, fell significantly as stiffer regulations on power plants took effect, but the South China Morning Post reports that officials acknowledged pollution problems continue to be serious.
Andrew Lai Chi-wah, Deputy Director of Environmental Protection, Hong Kong
We have done less in cleaning up the ships and vehicles than with power plants
"We understand that people may not feel that they are breathing cleaner air despite the reductions," said Andrew Lai Chi-wah, deputy director of environmental protection.
"Indeed, we have done less in cleaning up the ships and vehicles than we did with power plants."
"We are stepping up measures in these aspects."
The government is negotiating with the shipping industry in an effort to get ships and ferries to use lower-sulfur diesel, but Lai said the ports of Shekou and Yantian in nearby Guangdong need to agree on clean diesel requirements so that vessels don't just shift to those ports.
Overall, in 2012 marine vessels accounted for 48 percent of SO2 emission, 32 percent of NOX, 16 percent of carbon monoxide, 36 percent of respirable suspended particulates, and 11 percent of volatile organic compounds.
The EPD noted that it altered its methodology in collecting data on vessel emissions to conform to methods used at the Port of Los Angeles and other "advanced places," which resulted in higher estimates.
Last month Hong Kong said it was introducing an incentive program for vessels to use cleaner fuel when berthing in its waters, while a joint study by Hong Kong-based think tank Civic Exchange and Hong Kong University called for policymakers to introduce a regional Emissions Control Area (ECA) for Hong Kong and the Pearl River Delta (PRD) area.