Butterfly larvae fed leaves contaminated with radioactive cesium from the Fukushima nuclear disaster had a higher rate of death and development abnormalities than larvae that got leaves from a location farther from the accident. The result, published May 15 in Scientific Reports, suggests there are health risks associated with ingesting a diet polluted with radioactive cesium, at least for this species of butterfly. The same risks may also apply to other animals living close to where the accident occurred, the scientists say.