Satellite image captured March 14, 2011 shows a view of the Fukushima Daiichi nuclear plant. Explosions at the plant following a 9.0-magnitude earthquake and subsequent tsunami resulted in the worst nuclear disaster since Chernobyl.
Credit: AFP
SYDNEY: The nuclear accident at Japan's Fukushima Daiichi power plant earlier this year released one-tenth the amount of radioactivity as the 1986's Chernobyl disaster. Based on these statistics, about 1,000 extra cancer-related deaths can be expected from the accident, says a U.S. scientist.
The findings, published this week in the Bulletin of the Atomic Scientists, are presented as part of a special issue reflecting on the Japanese nuclear disaster six months on.
The study by Frank N. von Hippel, an expert in nuclear arms control and energy at Princeton University in New Jersey, confirmed that resulting cancer-related deaths would be lower than Chernobyl.
In 1986 a sudden surge in power destroyed the nuclear power plant at Chernobyl, Ukraine, in the former USSR. About 16,000 Chernobyl-caused cancer deaths are projected during the lifetime of those who were exposed in Belarus, Ukraine, and western Russia, and farther afield in lesser-exposed parts of Europe, according to the study.
While the toll of cancer in Japan should be lower, Von Hippel warned, however, that the psychological impact could be severe and should be closely be monitored.
"It is well known that there is a special dread associated with exposure to ionizing radiation," the report states. "This may be due to the invisibility of the damage and the long latency of cancer and genetic defects."
Radioactive material released
A 9.0-magnitude Tohuku earthquake and subsequent tsunami rocked Japan on 11 March 2011, causing hydrogen explosions at four reactors at the Fukushima Daiichi Nuclear Power Station. The hydrogen explosions were indicators that the fuel cladding had failed and released radioactive materials such as cesium-137 and iodine-131 into the atmosphere.
Cesium-137 has a 30-year half-life and has been the principle source of radiation around the Chernobyl site for more than 25 years. It now comprises the major radioactive contaminant around Fukushima.
Using the documented after effects from Chernobyl and comparing the extent of the two incidents, von Hippel found that the area in Japan contaminated with Cesium-137 at the same levels that forced evacuation around Chernobyl, is about one-tenth the size.
The cancer toll
A replicated study of the cancer consequences of the Fukushima Daiichi accident has not yet been conducted, but the report makes a preliminary order-of-magnitude estimate.
"Out of the two million people who live within an 80-kilometre radius of the Fukushima plant, about one million live in areas contaminated with cesium-137 to levels greater than 1 curie per square kilometre," the report stated.
It continued: "Scaling to the six million people in areas contaminated to similar levels by the Chernobyl accident, one might expect around 1,000 extra cancer deaths related to the Fukushima Daiichi accident, that is, a 0.1 % incidence rate."
Additionally, one of the most visible and undeniable health consequences of Chernobyl was an influx in mostly-non-fatal thyroid cancers.
But according to von Hippel, the number of thyroid cancer cases in Japan will be less than 1% of those resulting after Chernobyl.
This is due in part, he reports, to action taken by the Japanese Government in terms of evacuation and stopping people from consuming contaminated milk.
Disaster profiles differed
Peter Burns, former head of the Australian Radiation Protection and Nuclear Safety Agency, said the number of people exposed and the level of dose in Japan was much smaller than Chernobyl, especially since much of the contaminants ended up in the Pacific Ocean.
He said the profiles of the disasters are quite different, with Chernobyl affecting a greater number of people in several populations differently, including recovery workers, early and late evacuees, and people who continued to live in the contaminated zone.
Gauging the long-term health consequences of the Fukushima disaster will be difficult, he added. "It depends how many people are allowed to go back to contaminated areas, and what the government is willing to mark as an acceptable dose."
"It is very early to be making estimates, though it can be helpful when assessing remediation options," he commented. "Compared to the roughly 25,000 people who died in the tsunami, the number of people who will die from cancer is very small."
Burns also cautioned against the potential psychological impact.
"A lot of the effects of Chernobyl were the psychological effects of taking people out of their homes and putting them into camps, where they were removed from their livelihoods ... and their whole social structure was taken away," he said.
