Container ships from China laden with cargo for the rest of the world disperse more than toys, televisions and other exports. They are also a serious, often neglected, emitter of pollution from the cheap fuel allowed under Chinese rules, according to a new report from the Natural Resources Defense Council, a United States-based environmental advocacy group.
Except when they approach and dock at ports that require cleaner fuel, such as in the United States or Europe, oceangoing ships plying trade through Chinese ports usually use cheap “bunker” oil, a grade of fuel that is heavy in sulfur and leaves a dense trail of fine soot, ozone and nitrogen- and sulfur-based pollutants, said the report, which was released on Tuesday.
“Regulation of air emissions from ships is virtually nonexistent today in China and the rest of the developing world,” the report said.
“With ships allowed to burn fuel with much higher sulfur levels than permitted in on-road diesel, one container ship cruising along the coast of China emits as much diesel fuel pollution as 500,000 new Chinese trucks in a single day,” an accompanying summary of the report said.
Freda Fung, a consultant in Hong Kong who was one of the report’s four co-authors, said in an interview that the estimate referred to PM 2.5: the soup of small-particle pollution that hangs over many Chinese cities, causing breathing problems and public ire.
The shipping pollution is a significant contributor to overall pollution and to poor health in some of China’s biggest cities, Ms. Fung said. China has seven of the world’s 10 busiest ports, with Shanghai at the top of the list, and about a quarter of the world’s container volume passes through the country’s 10 busiest ports, the report said. Other big port cities in China include Shenzhen, Qingdao and Tianjin, and nearly all of the port equipment uses diesel, also heavy in pollutants.
“Since Chinese port cities are among the most densely populated with the busiest ports in the world,” the report said, “air pollution from ships and port activities likely contributes to much higher public health risks than are found in other port regions.”
The damage is difficult to quantify given the other sources of contaminants and the complexities of tracking health. But soot from bunker fuel and low-grade diesel exhaust tends to be especially harmful because it is so fine and carries dozens of chemical contaminants, some of which can travel through the air for many thousands of miles.
The result is “a toxic stew of cancer-causing diesel exhaust and black carbon that chronically plagues China’s growing port regions,” Barbara Finamore, the Asia director of the Natural Resources Defense Council, said in an email. One study cited in the report estimated that in 2008, air pollutants from ocean and river vessels had caused about 1,200 premature deaths in Hong Kong.
Stricter standards in North America, especially California, and Western Europe mean that when ships approach and stop at ports there, they switch their engines to cleaner diesel that has much less sulfur, Ms. Fung said. The International Maritime Organization has also set fuel sulfur standards for seas off North America and parts of Europe.
But bunker oil is “the cheapest fuel, so whenever possible the ship operators prefer to use it, unless they’re required to use a different fuel,” Ms. Fung said.
Stung by public alarm about pollution, China has introduced tougher fuel and vehicle standards on its roads. Ms. Fung said she hoped the same pressure would encourage the government to introduce more stringent rules for ships. Hong Kong, with its own distinctive laws and government, has used the incentive of reduced port fees to encourage ships stopping there to use cleaner fuel and was developing proposed mandatory restrictions, she said.
Shenzhen, the large port on mainland China near Hong Kong, has developed plans to discourage use of the dirtiest diesel by ships docking there, Ms. Fung said. But other mainland Chinese ports have been slower to act, and without concerted international action, ship operators are likely to keep switching their vessels to bunker fuel on the open seas after they leave regulated ports and waters, she said.
“If Shenzhen follows, eventually I hope there’ll be a chain reaction for the other major ports in China,” she said.