The nuclear meltdown at Fukushima in March 2011 released huge amounts of radiation into the surrounding environment. Here's the first evidence that people exposed to the radiation could suffer serious health problems like the survivors of other intense nuclear catastrophes.
Japanese researchers say they've conclusively proven that butterfly specimens collected in Fukushima shortly after the disaster show both "physiological and genetic damage" owing to exposure. What's worse, the abnormalities seem have gotten increasingly worse over time; butterflies collected in September 2011 show more severe defects than those collected just two months after the meltdown. The researchers note that in the past these types of mutations have been linked to human illness:
In the case of the Chernobyl accident, changes in species composition and phenotypic aberration in animal sand an increase in the incidence of thyroid and lymph cancers in humans have been reported. Similarly, an increase in the incidence of cancers has been reported for atomic bomb survivors in Hiroshima and Nagasaki, Japan.
The researchers, of course, are hesitant to say that people exposed to radiation are doomed. As they point out, the effects of low-dose radiation "are still a matter of debate."