HONG KONG (Bloomberg) — Hong Kong, the world's second-busiest port, plans to tighten exhaust emission standards on ships to improve the city's air quality.The administration will table rules in the city legislature on July 11 that if allowed to stand will bring marine air emissions standards in line with international guidelines, the government said in an e-mailed statement yesterday.

The regulation will also impose controls marine fuel quality and ship incineration, the statement said.

In 2006, 3,297 cruise ships arrived in Hong Kong, Eva Cheng, Hong Kong's secretary for transport and housing, told lawmakers yesterday. Time spent in Hong Kong's harbour was estimated at 32,000 hours, she said.

Air pollution costs Hong Kong about HK$21.2 billion ($2.7 billion) a year in hospital admissions and lost productivity, according to a study released last year by three Hong Kong universities and a research group.

Hong Kong's government, facing mounting criticism it isn't doing enough to tackle pollution, in October announced plans to enforce emission caps on power companies and give tax breaks for cleaner vehicles.