A $2.25 million agreement has settled a class-action lawsuit filed on behalf of people affected when a railroad derailment and chemical spill sent a toxic cloud over Superior and Duluth, Minn.

About 22,000 people were evacuated after a tanker car from a Burlington Northern Railroad Co. train plunged into the Nemadji River June 30, 1992, spilling chemicals that produced the toxic cloud. The chemicals included the carcinogen benzene.Timothy Thornton, an attorney representing the railroad, said Monday's agreement meant checks would be mailed before Christmas to about 1,500 people.

In addition to the $2.25 million settlement of lawsuits resulting from the spill, the railroad will set aside about $500,000 for a "20-year fund" for reimbursement of those who believe the spill left them at risk of cancer or some other disease. Unused money in the trust fund, which is expected to grow, will be turned over to the community, a BN spokesman said.

Mr. Thornton previously had arranged settlements costing slightly more than $2 million between the company and about 28,000 people. He said the latest agreement raises the total to about 29,500.

He said he doubted the 20-year fund would ever be used.

But William Harper, the attorney who filed the class-action suit, disagreed.

"I know of two death cases because of liver failure," he said. "To say that everything is great is to literally stick your head in the sand."

Mr. Harper said he knew of an 18-month-old baby affected with a disease caused by benzene.

Mr. Thorton disputed any definite link between benzene exposure from the spill and illnesses.

"The chance of that is less than zero," he said, adding that sickness linked with benzene has "developed in people who work around benzene eight hours a day, five days a week in a 20-year career."

He said the settlement would cause the railroad to make more careful checks of track conditions. The National Transportation Safety Board preliminarily has found that inadequate inspection was the probable cause of the derailment.

Of the $2.25 million settlement, $750,000 will go to attorneys for fees and expenses, and the rest will go to the persons who sued the railroad.