Hong Kong has suffered the most from ship emissions in the Pearl River Delta, with locals accounting for 75 per cent of deaths related to sulphur dioxide released from vessels, a think tank found. The air quality at Kwai Chung and Tsim Sha Tsui could be worst-hit by ship pollutants, researchers behind a five-year study by Civic Exchange suggest. The think tank, founded by Christine Loh Kung-wai, now environment undersecretary, urged the city's administration to be more proactive in tightening restrictions and to seek support from its mainland counterparts. The city's popular ship routes were partly to blame, because some vessels passed through Hong Kong waters on the way to twin ports in Shenzhen, the group said in its report. "With so many ships berthing at the terminal in Kwai Chung, it's like a small power plant," said Simon Ng Ka-wing, Civic Exchange's head of transport and sustainability research. According to the Civic Exchange report, jointly issued with the University of Science and Technology and the University of Hong Kong, the city saw 385 of the 519 deaths directly related to sulphur dioxide from ship emissions in the region. The number of deaths in the inner Pearl River Delta region was 93, while that in the outer region was 42. Dr Lai Hak-kan, an HKU research assistant professor who contributed to the report, said the figures were probably an underestimate, as the researchers had not taken long-term health effects of sulphur dioxide into account. The chemical can cause cancer and diseases in heart and blood vessels. Ng said emissions from ships, mainly containers, were harmful although they accounted for only 18 per cent of sulphur dioxide in the city's air. As it was released at a lower level, it could reach the residential areas easily. The think tank suggested the government seek support from the central government and apply to the International Maritime Organisation to set up an emission control area, which would require ships to switch to 0.1 per cent sulphur fuel when they are within 100 nautical miles of Hong Kong. It said such a move could reduce deaths related to sulphur dioxide by 91 per cent. It also suggested the government make it compulsory that ships switch their fuel to 0.5 per cent sulphur at berth. This suggestion follows the Fair Winds Charter which saw 18 shipping lines agree to do so two years ago. The pact will end in December. Roberto Giannetta, secretary of the Hong Kong Liner Shipping Association, said it would cost a shipping line US$2 million a year to switch from conventional bunker fuel to low-sulphur clean fuel. He said it was uncommon for ships in Hong Kong to use low-sulphur fuel because it was not available in the city.