Nuclear Butterflies? 'Abnormal' Butterfly Population Found in Japan

Rumors of "nuclear butterflies" have emerged after scientists from Japan reported "abnormalities" in the country's butterfly population. They have suggested that the issue could be a result of the Fukushima nuclear disaster last year.

A study has been published in online journal, "Scientific Reports," where researchers claim "artificial radionuclides" from the Fukushima plant caused "physiological and genetic damage" to pale grass blue butterflies.

Butterflies have been analyzed, along with numerous other insects and wildlife, since just two months following the nuclear disaster in Japan, sparked by last year's devastating earthquake and tsunami. The recent report claims that from 121 insects collected just two months following the fallout a much higher proportion of them had unusually small wings than normal; 12 percent of them.

Another sample group was collected six months following the disaster. In that group scientists claim that 28 percent of butterflies had "abnormal" traits. The percentage doubled when the offspring of those butterflies were examined.

The study reports: "At the time of the accident, the populations of this species were overwintering as larvae and were externally exposed to artificial radiation. It is possible that they ate contaminated leaves during the spring and were thus also exposed to internal radiation."

A widespread panic was sparked following the disaster, but in the months following the tsunami many of the initial fears were allayed. The overall effects on human health were considered minimal, and the precautions implemented for Japanese inhabitants in the aftermath far exceeded those put in place following the Chernobyl nuclear disaster, which was a far worse incident.

Nevertheless there have been increased radioactive levels detected in various tests conducted over the past year. Excessive levels of radioactive cesium have been detected in seafood off the Fukushima coast, and there have been incidences of bluefin tuna being caught off the coast of San Diego that had higher than normal levels of radioactive cesium – although the levels were still far below what would be considered dangerous for humans.