Alaskan scientists are expressing concern over the volume of radioactive contamination reaching the state’s coastal waters from Japan’s meltdown-plagued Fukushima Daiichi nuclear power plant.Radiation has been detected in northern Alaska and along the west coast of North America, raising concerns over contamination in fish and wildlife.

Douglas Dasher, a researcher at the University of Alaska, Fairbanks, Marine Science Institute, told the Canadian Broadcasting Corp. that he fears radiation in Alaskan waters could reach levels once caused by Cold War atomic testing.

“The levels they are projecting in some of the models are in the ballpark of what they saw in the North Pacific in the 1960s,” he said.

But others believe the current lack of coordinated measurement of the radiation means it will be impossible to know if and when contamination reaches levels that are dangerous for humans and wildlife.

“The general concern was, is the food supply safe? And I don’t think anyone can really answer that definitively,” said the university’s professor emeritus John Kelly.

Official statements from Japanese and American officials have assured that radiation will be dissipated to insignificant levels by the time it reaches Alaska and other parts of North America.

But a previously top secret memo from the U.S. Atomic Energy Commission said that was not necessarily the case from atomic testing contamination.

The 1955 memo said that “dissipation of radioactive fallout in ocean waters is not a gradual spreading out of the activity from the region with the highest concentration to uncontaminated regions, but that in all probability the process results in scattered pockets and streams of higher radioactive materials in the Pacific.”

It went on to caution that tuna had been living in, or had passed through such pockets of high contamination, or were feeding on plant and animal life that had been exposed in those areas.