Pollution off the starboard bow.

From Barbie dolls to the latest consumer gadgets, most of the goods stocking North American store shelves arrive by ship. Large marine vessels such as container ships and oil tankers are one of the least-regulated sources of air pollution in the United States. As these ships make their way to and from their ports of call, a steady stream of toxic filth is released from their smokestacks.

Ship engines release significant amounts of nitrogen oxides (NOx), diesel particulates and sulfur into the atmosphere. NOx contributes to the formation of low-level ozone, which plays a role in increased risk of respiratory disease, airborne allergies and asthma. Carcinogenic diesel emissions from-all sources are responsible for about 70 percent of the cancer risk associated with Southern California's polluted air.

With more than 60,000 ship calls annually at U.S. ports, the impacts on air pollution are enormous. The Santa Barbara County Air Pollution Control District found that even without a port in the county, air-quality gains from reducing car and truck emissions would be wiped out by passing ships commuting to the nearby ports of Los Angeles and Long Beach. "Just one container ship traveling one mile produces NOx emissions equaling 25,000 cars traveling the same distance," explains Anthony Fournier of the District.

The San Francisco Bay Area-based Bluewater Network has sued the Environmental Protection Agency (EPA) twice, claiming that it failed to effectively regulate NOx emissions from large ships. Bluewater asserted that the EPA's standards violated the Clean Air Act's requirement to "achieve the greatest degree of emission reduction." The agency's 2003 standard wouldn't actually improve air quality, the group said, since new ship engines already meet the guidelines. Bluewater says the problem is with older ships, which actually make up most of the global fleet. The EPA argues that it should be allowed to postpone consideration of stricter standards until 2007 to be able to evaluate advances in technology.

"These ships run on the dirtiest fuel available," says Martin Wagner, the Earthjustice attorney who is representing Bluewater. "EPA's failure to regulate their emissions undermines the efforts of coastal communities from Los Angeles to Boston to protect public health and meet federal clean air standards."

At press time, the case is being decided by the U.S. Court of Appeals for the District of Columbia. CONTACT: Bluewater Network, [phone], www.bluewaternetwork.org; Earthjustice, [phone], www.earthjustice.org.