Ed Boyer, a professor of emergency medicine at the University of Massachusetts Medical School in Worcester who is leading the team treating the man, said he was doing well after suffering burns on his arm and leg. Boyer said it was the only non-military occupational exposure to mustard gas in the United States he had ever heard of.

"What is stunning to everyone is it is still so potent after all this time," said Boyer, a medical toxicologist who studies mustard gas.

The Coast Guard said blister agents -- a group of chemicals that includes mustard gas -- were found in one area of the ESS Pursuit today, and the Coast Guard, the EPA, and other federal, state, and local agencies were developing a decontamination plan for the boat.

Read the complete story at The Boston Globe.