April 5 (Bloomberg) -- Ships burning black sludge known as bunker oil are under rising scrutiny in Hong Kong as the city seeks to fix a mounting smog problem at home and meet the demands of leaders in Beijing to deliver cleaner air.
Vessels calling at North Sea and Baltic ports must use fuel containing no more than 1 percent sulfur to cut emissions estimated to cause at least 60,000 deaths a year worldwide. Ships steaming into Hong Kong are free to burn less costly 3.5 percent sulfur oil. Bloomberg's Paul Allen reports. (Source: Bloomberg)