SCIENCE / MEDICINE : Contaminant Blamed for Ailment

A contaminant found in mussels apparently caused an unusual and irreversible long-term memory loss in 14 people in Canada in late 1987, scientists reported last week. A toxin called domoic acid produced by a common seaweed appears to have destroyed brain cells, leaving 13 of the victims permanently disabled.

While no other cases are believed to have occurred, the incident led to changes in the way mussels are labeled and tested in Canada and prompted an extensive testing program for domoic acid in Maine, which produces 85% of mussels in the United States.

Domoic acid apparently creates hyperactivity in brain cells and “makes the cells almost commit suicide,” said Dr. Neil Cashman, a neurologist and co-author of one of two studies on the mussel contamination published in the New England Journal of Medicine.

In one study, the toxin caused a variety of symptoms, including vomiting, abdominal cramps, diarrhea and severe headaches; 25% of those affected suffered short-term memory losses.

The research could have implications for understanding such devastating brain disorders as Alzheimer’s disease and Lou Gehrig’s disease, which some scientists suspect may involve a toxin, Cashman said.