LONG BEACH - More than a year after California was rebuffed in federal court for pursuing emission rules on freight ships, federal authorities are pushing to adopt similar restrictions that could prevent up to 33,000 premature deaths annually in the U.S. and Canada.

In a meeting with the public Thursday in Long Beach, the U.S. Environmental Protection Agency rolled out a proposed law requiring ships to use cleaner fuels within 200 miles of the U.S. and Canadian coastline by 2020.

The "clean-air buffer zone" proposal, expected to be finalized through an international treaty in October, would help slash toxic emissions in and around busy seaports like Long Beach and Los Angeles, where ship emissions are blamed for health problems like cancer, heart disease and asthma.

Under the measure, exhaust from cargo ships could drop by as much as 80 percent, saving billions in health-care costs annually, said Debbie Jordan, an EPA administrator who attended Thursday's hearing at the Westin hotel.

The rule would apply to all large freight ships visiting U.S. seaports and would be phased in incrementally over the coming decade.

EPA rulemakers believe the law could prevent the premature deaths of at least 13,000 and possibly up to 33,000 U.S. and Canadian residents - primarily those in urban areas near busy ports - by 2030. The EPA is continuing studies to pinpoint the number deaths from heart disease, cancer and other problems related to diesel particulates and other port pollution.

Wilmington resident Juan Garibay said the rule is long overdue.

"For decades...our communities have been facing a public health crisis at the expense of the international trade industry," said Garibay, who also belongs to an environmental organization called Coalition for a Safe Environment.

In the ports of Long Beach and Los Angeles, which air quality regulators list as the largest source of toxic emissions in the state, freight ships spewed some 434,000 tons of carbon dioxide - a greenhouse gas - into local skies in 2007 alone, according to a survey by the South Coast Air Quality Management District.

Freight ships visiting here are also blamed for emitting more than 1,000 annual tons of diesel particulate matter - a toxic pollutant believed linked to cancer, asthma and heart disease.

Costs to industry for cleaner fuels are estimated to increase by $1.8 billion by 2020, which the EPA believes will be passed onto consumers in the form of minimally higher prices on consumer goods like televisions, computers and food.

A bushel of grain, for example, would rise by about 3 cents, while a new pair of tennis shoes might rise by a penny, according to EPA estimates.

Despite costs to retrofit ships and purchase cleaner fuels, the rule is supported by a coalition of West Coast shippers who had successfully sued California when the state tried to adopt a 24-mile "buffer zone" in 2007. Their objection was that only a few ports would be under those restrictions, and they favored rules on a national or international level.

That rule was upheld on appeal, leading state regulators to push the White House for new rules, which it did in March.

"When fully implemented, the regulation will provide maximum public health benefits at the earliest possible date while maintaining competitive parity for the maritime industry," said T.L. Garrett, vice president of the Pacific Maritime Shipping Association.

Specifically, ships would have to burn diesel fuel with sulfur content no higher than 1,000 parts per million.

Currently, ships burn a cheap, sludge-like fuel known as bunker fuel that contains sulfur content as high as 27,000 parts per million. By comparison, diesel fuel used by cars and trucks in the United States can contain sulfur content no higher than 15 parts per million.

Sulfur spewed into the air contributes to smog, acid rain and health problems.

Final approval for the EPA's proposal is required by the International Maritime Organization, which governs rules in international waters, and is expected in the fall.

The Coast Guard and EPA will be in control of enforcement, although penalties for noncompliance have not been finalized.