A provocative new study released this week suggests as many as 14,000 Americans may have died as a result of exposure to radioactive particles blown here from Japan after the Fukushima nuclear reactor meltdown in March. But even though the report is gaining some attention, experts say there is no scientific basis for its claims.
The study, published in the International Journal of Health Services, was based on mortality data from the Centers for Disease Control and Prevention and compared death rates before and after the cloud of radioactive air rising out of the crippled reactor hit U.S. shores.
Joseph Mangano, the lead author of the new report, says the number of deaths in the spring of 2011 was 4.46 percent higher than in the previous spring and the most likely cause was the higher levels of radiation.
Mangano also found an increase of 2.34 percent in the winter of 2011 compared to the previous year, but he called that increase “standard,” as opposed to the beginning of a trend. Mangano said he couldn’t prove that the higher than expected death rate was due to radiation, but he said he believed it was the leading contender. He was unable to point to any studies showing how low levels of radiation in the U.S. would cause death.
While U.S. deaths did rise in 2011, radiation doesn't make sense as the cause, experts say.
“There’s nothing in the radiation health effects research to substantiate those claims,” said Bernadette Burden, a spokesperson for the CDC.
Radiation expert Andrew Maidment said that the levels of radiation that blew over the U.S. were too low to have caused any deaths – especially in such a short period of time following the disaster.
“For acute radiation sickness you would need much higher levels of radioactivity,” said Maidment, an associate professor of radiology and chief of the physics section in the department of radiology at the University of Pennsylvania. “The levels they are talking about we see naturally occurring across the country.”
What Maidment means is that normal radiation levels vary from region to region around the nation. And though the levels rose in certain areas as a result of the cloud of particles coming from the reactor, those levels still weren’t the highest measured around the U.S. so, they’re still within the norm for the U.S.
Cancers typically associated with lower levels of radiation take years to develop, Maidment explained. “With leukemia, you’re talking about five to seven years,” he said. “And there’s a 10 to 20 year delay for solid tumors. I know of no mechanism that could get you instantaneous mortality from radiation at lower levels.”
Dr. Robert L. Brent agreed. “The exposure of the USA population was extremely small and could not account for any acute lethal effects of radiation,” said Brent, a member of the National Counsel for Radiation Protection and distinguished professor of pediatrics, radiology and pathology at the Jefferson Medical College and the Dupont Hospital for Children.
"The authors indicated that SIDS (Sudden Infant Death Syndrome) was increased according to the mortality figures the authors obtained from the CDC," said Brent. "To infer that SIDS can be produced by low or high exposures to protracted radiation is naïve. That is not even a remote possibility."
So, how can you explain the rise in U.S. deaths following the reactor disaster?
There’s something called biological variability, Brent said. “For example, if you look at reports from the CDC on birth defects, you might find in a particular month a single case of Down Syndrome. The next month there might be seven. That’s biological variability.”
You can’t assume that a bump in the death rate was caused by a particular factor just because the timing was right, Brent said. “It has to be biologically plausible before you think about linking the two.”
Some associations are just the result of chance, experts said.
Maidment said it’s always possible that the events in Japan made some people in the U.S. very worried. “One thing we do know is that stress correlates with mortality,” he added. “It might be interesting to see if there was an increase in mortality after other highly stressful events, such as 9/11.”
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