The consequences of the nuclear disaster at Fukushima five years ago surfaced in a terrible way in serious mutations in butterflies. This discovery is owing to the tireless work of the Japanese researcher Chiyo Nohara, who died a few months ago.
The Japanese editorial team at swissinfo.ch met her at a conference in Switzerland in 2014.
“I had nothing to do with Fukushima before that,” Nohara recalled in the below interview, which took place at a symposium on “Effects of Radiation on Genetics” in Geneva, when she was already seriously ill.
“After the nuclear accident, I worried about it constantly, as if my daughter were living there. I wanted to go straight to Fukushima to see with my own eyes what happened there.”
That desire was the catalyst for her decision to devote herself to researching butterflies.
Nohara had little to do with sciences originally. At Aichi University, a few hundred kilometres south of Tokyo, she was a professor teaching public administration auditing. Later she switched to environmental studies and moved to the southern island of Okinawa, where she taught at the Ryukyu University.
In May 2011 the researchers collected male butterflies which had suffered radioactive contamination in the towns of Fukushima and Motomiya, about 60 kilometres northwest and west respectively from the nuclear power station. They could ascertain on the spot that their wings were smaller than those of the same species in places farther away.
Back in Okinawa, they bred a first generation of contaminated butterflies in the laboratory.
They noted delays in development in pupation and hatching and a high rate of abnormalities. The closer to the nuclear power station the fathers had been found, the more likely it was that their offspring would show abnormalities.
The second-generation young showed not only similar mutations to their parents, but also had completely abnormal body parts, such as a forked antenna.
Additionally, the team researched the effects of radiation by artificially contaminating healthy butterflies from Okinawa and feeding them with radioactive creeping wood sorrel to contaminate them internally.
Here too they identified falling survival rates, a reduction in the wing size and physical abnormalities.
The interview was done on November 29, 2014
swissinfo.ch: Why did you travel to Fukushima two months after the nuclear accident to collect samples?
Chiyo Nohara: Actually, there was still a danger of further accidents at the nuclear power station, from aftershocks for example. But I was absolutely determined to collect contaminated butterflies that had wintered as larvae in Fukushima.
In Chernobyl, an investigation of organisms didn’t take place until five years after the accident. I wanted to avoid that.
At the end of May, I visited various places with Professor Otaki and two other researchers. We wanted to compare our samples against those from Tokyo and other cities.
Read more at The butterfly effect of Fukushima