MAJURO -- Marshall Islanders who were exposed to American hydrogen bomb test fallout in the 1950s continue to suffer psychological distress, a Harvard-based expert told the nuclear claims tribunal in Majuro this week.

Dr. Robert J. Lifton, an authority on the psychological impact of radiation exposure, was beamed live into Majuro from the U.S. east coast on Wednesday to give testimony in support of Utrik Atoll's claim for hardship compensation before the nuclear claims tribunal.

Utrik Islanders were doused with radioactive fallout from the 1954 bravo hydrogen bomb test at Bikini. They have experienced a high incidence of thyroid tumors and cancer and other health disorders as a result of their fallout exposure.

The islanders are seeking a multi-million dollar compensation settlement to clean up residual radiation on Utrik and for hardships suffered as a result of the U.S. testing program, told AFP.

The U.S. tested 67 nuclear weapons at Bikini and Enewetak Atolls between 1946 and 1958. Utrik is about 400 kilometers (250 miles) downwind.

Using video teleconferencing equipment at the college of the Marshall islands, Lifton presented testimony and answered questions at the Utrik hearing, which started more than a week ago before a panel of judges.

The tribunal is a U.S.-funded but locally-based organization set up to review compensation claims and issue awards.

It has already awarded more than one billion dollars to Bikini and Enewetak for cleanup costs and the suffering of Islanders, but has run out of compensation funds.

The Marshall Islands government is appealing to the U.S. Congress to consider additional recompense. Lifton, who has studied the psychological impact of atomic bombings on survivors in Hiroshima and Nagasaki, said many people who fight in wars or are exposed to radiation or were survivors of the atomic bombings have what is known as "post traumatic stress disorder."

But while the problems of a war veteran may be relatively short term and will decline over time, those exposed to radiation or other "invisible contamination" retain a life-long fear that "doesn't go away", Lifton said.

The fear of radiation exposure is very real and documented in numerous studies, he said.

"Any group exposed to significant radiation, especially from bombs, will experience some fear," Lifton said.

A well-designed education program can help to alleviate some of the psychological distress for the Utrik people, but "the fear of radiation won't go away," he said.

Looking at other groups of radiation victims -- he named American "atomic veterans" and those exposed to the Chernobyl nuclear power plant catastrophe in 1986 -- there is "no evidence that the fear of invisible contamination goes away," he said.

Interviews with numerous Utrik residents showed the deep fear of staying on the Atoll that they fear is radioactive. People are deeply connected to their land on Utrik but have an equally deep fear of living there, he said. "It is the deepest ambivalence," he said. "There is no clear solution."