Five men at a nuclear research facility near Tokyo were exposed to uranium and plutonium when they accidentally ripped a plastic bag holding the material.
The accident occurred at the Oarai Research and Development Center outside Tokyo where the men were researching improving nuclear fuel.
One opened a container holding a mixture of uranium and plutonium, but ripped the double plastic bag holding the powdered material inside.
The men were all wearing protective masks and clothes, but were tested as a precaution. Soon after, the Japan Atomic Energy Agency (JAEA) reported that three of the men had been found with 24 becquerels of plutonium-239 in their nasal passages.
A becquerel is measured as a single atomic nucleus in a material decaying per second. The highest level found in Fukushima Prefecture after the 2011 disaster was 15 becquerels per square metre.
Later, when tested by a different machine, one of the researchers registered a level of 22,000 becquerels.
Inhaled as dust, just 454g of plutonium-239 could cause cancer in two million people. While that sounds alarming, it’s well short of other biological agents such as anthrax or botulism.
Still, no one is sure what will happen to the unfortunate researchers, because as far as security offical Ishikawa Keiji can recall, “no one has inhaled plutonium at this level”.
Another worker registered up to 14,000 becquerels of radioactive materials in his lungs.
One official assured the Japanese newspaper The Asahi Shimbun that “the amount is not enough to cause acute radiation damage”, but admitted 22,000 becquerels “is a situation that cannot be easily brushed aside”.
All anyone could say was that “future health-related problems were a high possibility”.
The men were all injected with medicine to help their bodies discharge the radioactive materials.
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