Ocean-going vessels produce greater quantities of sulfur oxide air pollutants than all the world's cars, trucks and buses combined, according to a study released Thursday.
The report by the International Council on Clean Transportation calls for international regulators to move aggressively to curb emissions from "bunker fuel" used by freight vessels that contains an average 27,000 parts per million of sulfur. U.S. standards for diesel trucks and other vehicles limit sulfur fuels to just 15 parts per million to protect public health. One kind of sulfur oxide, sulfur dioxide, can quickly kill if too much is inhaled rapidly. Chronic exposure to lower levels has been linked to respiratory problems.
The report is especially relevant for Southern California. More than 40% of retail goods imported to the U.S. arrive on ships that dock at Los Angeles and Long Beach, often after passing coastal communities in Santa Barbara and Ventura counties.
"International ships are one of the world's largest, virtually uncontrolled source of air pollution," said Alan C. Lloyd, president of the International Council on Clean Transportation and former secretary of the California Environmental Protection Agency. "Air pollution from diesel trucks and buses in Europe, Japan, and the U.S. has declined steadily for over a decade. At the same time, air pollution from international ships is rising virtually unchecked."
The council comprises about 20 scholars and current or former air-quality and transportation regulators from the U.S., South America, Asia and Europe. They include Margo Oge, head of the U.S. Environmental Protection Agency's office of transportation and air quality. A spokesman said the EPA had yet to review the report.
The authors relied on peerreviewed air pollution studies, their own work and government pollution and freight data, according to the council's executive director, Drew Kodjak.
The report found that in 2001, heavy-duty diesel trucks, buses and cars burned more than a billion metric tons of fuel, and emitted 2.2 million metric tons of sulfur oxide. The same year, ocean-going vessels burned 280 million tons of fuel, far less, but emitted 3.4 million metric tons of sulfur oxide, about 17% of the global total.
Ships are also responsible for 3.6 million to 6.5 million metric tons of nitrogen oxide, another pollutant.
