The accident at Fukushima Dai-ichi Nuclear Power Plant in japan following the March 12, 2011 earthquake and tsunami caused a massive release of radioactive materials to the environment that butterflies have shown symptoms of mutation and malformation, sending signals that the local human population may have to face the impact.
A research team has shown that the accident caused physiological and genetic damage to the pale grass blue Zizeeria maha, a common lycaenid butterfly in Japan. When the team collected the first-voltine adults in the Fukushima area in May 2011, some of which showed relatively mild abnormalities.
The first offspring from the first-voltine females showed more severe abnormalities, which were inherited by the following second generation. Adult butterflies collected in September 2011 showed more severe abnormalities than those collected in May. It has been established now that artificial radionuclides from the Fukushima Nuclear Power Plant caused physiological and genetic damage to this species.
The leakage of radioactive materials from the Fukushima Dai-ichi Nuclear Power Plant (NPP) to environment due to the earthquake may produce produce long-term destruction of ecosystems and cause chronic diseases, the team said.
Another fear is a possible increase in the incidence of cancers. Since the exposure of animals and humans is relatively lower than the butterflies, one of the concerns is the possible inheritance of the adverse effects by the offspring.
“We use the pale grass blue butterfly Zizeeria maha (Lepidoptera, Lycaenidae) as an indicator species to evaluate the environmental conditions. A reliable rearing method has been established for this species. Butterflies are generally considered useful environmental indicators… this species is particularly suitable for this purpose because it is widespread in Japan, including the Fukushima area, and because its wing colour patterns are sensitive to environmental changes,’ said the report by researchers.
The sample of adult butterflies appeared morphologically and behaviorally normal, but mild morphological abnormalities were detected in some individuals. The male forewing size (from the base to the apical end) was different among populationsand was significantly reduced in the Fukushima population in comparison with the Tsukuba population, said the report.