Vanderbilt radiation experts help determine safety of Alaskan seafood

Vanderbilt researchers are two of the authors of a research study released today that revealed seafood from the area close to the Aleutian Islands in Alaska currently is not threatened by radioactive materials resulting from underground nuclear tests carried out at Amchitka Island between 1965 and 1971.

Vanderbilt Professor and Chair of Civil and Environmental Engineering David S. Kosson directed the geophysical research for the independent study. He and Michael Stabin, assistant professor of radiology and radiological sciences, conducted much of the laboratory analysis, which revealed that the levels of radionuclides in the area are presently far below any human health food safety standard. Radionuclides are atoms that emit radiation and can accumulate in the muscle tissue and bones.

“The results are very reassuring, not only because approximately one-third of the fish sold commercially in the U.S. come from the broader marine region affected by the area we studied, but because our evidence showed no indications of damage to the ecosystem in the area,” Kosson said.

At the same time, Kosson cautioned that the geophysical research he directed suggests that the situation requires continued monitoring.

“Our remote sensing studies of the island’s rock substructure show that any nuclear material from the nuclear test shot cavities will actually take longer than we previously thought,” Kosson said. “That means that the area should continue to be monitored well into the future.”

The study was commissioned by the U.S. Department of Energy, along with the State of Alaska, the U.S. Fish and Wildlife Service and the Aleutian/Pribilof Islands Association. The research was planned and conducted by The Consortium for Risk Evaluation with Stakeholder Evaluation (CRESP), an independent university consortium, to find out whether three tests of nuclear bombs exploded in Amchitka Island some 40 years ago have resulted in dangerous levels of radioactivity in the fish and wildlife of the area.

Although Kosson did not accompany other researchers to Amchitka last summer to collect the samples, he was a member of the project leadership team that designed and oversaw the implementation of the overall study. He was also responsible for overseeing the geophysical studies providing insights into the potential pathways and timeframes over which radionuclides may travel from the nuclear test locations into the marine environment.

In addition, Kosson and Stabin, working with graduate student Derek Favret, and research staff member Rossane Delapp, spent a good part of the last year in their Vanderbilt laboratory evaluating samples for the presence of radionuclides.

Studying the area around Amchitka Island presents significant logistical and safety challenges. The expedition force of Aleut hunters and fishers and researchers from six universities braved high winds and cold seas during the short period of time each summer when the weather permits the area to be reached with any assurance of arriving in one piece.

The expedition produced data for one of the most extensive single-point-in-time studies of radiation in a defined marine environment ever conducted.

“We sent them into danger with every protection we could reasonably devise, but the fact that the expedition was executed safely and successfully is quite extraordinary,” said Charles W. Powers, CRESP principal investigator and professor of environmental and occupational medicine, University of Medicine and Dentistry of New Jersey (UMDNJ) “And then we found that the challenge of analyzing our data proved every bit as difficult as the expedition itself.”

A significant challenge of the research was to analyze samples for a sufficiently long period of time to determine the levels of radionuclides were present, since some degree of radioactivity is always present. Researchers then had to determine whether the radionuclides resulted from the nuclear tests, or perhaps came from fallout or naturally occurring sources.

Kosson, who is head of the CRESP Remediation Center of Expertise, said that some of the solutions they found to difficulties posed by the analysis of the samples will help CRESP in other studies in the future.

“I am excited by the fact that we were able, within the very short single season of work, to add so significantly to the geophysical understanding of Amchitka and its marine department,” Kosson said. “I worked with excellent teams from four good research universities.”

In addition to Vanderbilt and Rutgers, researchers participating in the study came from the University of Alaska, the University of Alberta, the University of Medicine and Dentistry of New Jersey, the University of Pittsburgh, and the University of Washington.