A group of scientists studying the effects of radiation on wooly aphids after the nuclear accident in Fukushima discovered some abnormality in the growth of the insects. The group headed by Shinichi Akimoto, professor of entomology at Hokkaido University, conducted the study in Yamakiya district, which is one of the planned evacuation zones in Fukushima. The annual cumulative dose of radiation in the area is presently anywhere between 9.2 to 42.5 millisieverts, which is well over the permissible annual dose of 1 millisievert set by ICRP.
About 10 percent of the sample wooly aphids collected by the group showed different kinds of maldevelopment, including missing antenna. Such incidence rate is more than 10 times the usual rate.
"There's no doubt that there were some sort of an outside cause that triggered mutation at DNA level," said Akimoto. He points out that since living creatures become deformed from having their DNAs damaged by radiation, it is likely that the insects were affected by the accident.
In order to verify the cause, Akimoto's group will conduct studies in areas that have not been affected by radiation and make comparisons between the results.
A research group from University of the Ryukyus has also done a study on the effects of the nuclear accident on a kind of butterfly, and found that there were some genetic abnormalities. Professor Akimoto says that aside from deformation, there may also be other effects such as abnormal behavior or shortened lifespan for the insects.
<Hokkaido Shimbun August 16, 2012>