It hasn’t been a good week for owners and operators of ocean-going vessels in and around California. But the bad news for shippers is good news for millions of asthma and allergy sufferers along the California coast.

The U.S.Environmental Protection Agency announced it will approve new tough new rulesthat crack down on diesel-powered trucks, buses and marine vessels.

The new plan is designed to roll back pollution levels in the South Coast and San Joaquin Valley areas and help prevent 3,500 annual premature deaths in California alone, the EPA said.

Meanwhile, the toughest ship-pollution controls in the world got tougher yesterday when theCalifornia Air Resources Board voted to extend the state’s “clean-fuel zone” out beyond the Channel Islands. The extension covers an area that shippers were using heavily to avoid California’s tougher rules that applied closer to shore.

The clean-fuel rules require ocean-going vessels using the waters to substitute cleaner fuels for the “bunker fuel” they have typically used and which results in heavy particle pollution.

Shippers who avoided the current clean-fuel zones were saving as much as $6,000 per round trip by diverting away from the coast and burning the cheaper, dirtier fuel.