Are ‘Mutated’ Daisies Really Caused by Fukushima Radiation?

Radiation from damaged power plant may be responsible for odd flowers, but there could be other forces at work.

A picture of malformed daisies uploaded to Twitter from Japan is going viral, causing many people to speculate that radiation from the damaged Fukushima nuclear power plant, which was rocked by a 2011 tsunami is to blame for the oddity.

“Frightening. Fukushima daisies go viral as nuclear radiation is blamed for deformities,” one twitter user noted.

But plant scientists aren’t so sure. It’s possible the radiation could be involved, but there are a number of other explanations as well, they say.

Twitter user @san_kaido first shared the picture in late May, from Nasushiobara City. That’s about 173 kilometers southwest of the Fukushima Daiichi power plant, which was disabled by the March 2011 tsunami and leaked radiation into the environment.

The radiation at the site where the stretched-looking Shasta daisies were photographed was 0.5 μSv/h, wrote @san_kaido, an account set up in the Tochigi Prefecture Nasu district to disseminate information about radiation and Fukushima. That might sound scary, but that level is considered only slightly above normal and is classified as safe for “medium to long term habitation.”

It’s possible the flower deformity could have been induced by radiation, says Jeffrey J. Doyle, a professor of plant biology at Cornell University. However, “this is a pretty common mutation in daisies that I’ve seen sporadically in various places not associated with radioactivity,” he says.

There are many factors that can cause the oddity, Doyle says, from chemicals to diseases, a hormone imbalance, or random mutations to inherited genes. This particular malformation has been seen in numerous species of the world’s 20,000 members of the daisy family, from Holland to Idaho.

He's not ruling out a role for Fukushima: “It wouldn’t surprise me to find mutations of all types, including this one, in places that have higher than average levels of mutagenic agents, such as a radioactive site or toxic waste dump.”

But this single plant is not enough to make a connection. If many other plants were found in the immediate area with mutations, that would provide more evidence of a possible link, he says.

Even if radiation levels were 10 times what was reported at the site, “the dose rate would be highly unlikely to induce a significantly higher level of mutations,” says Edwin Lyman, a senior scientist with the Union of Concerned Scientists. “But at areas closer to the release site, local dose rate levels were much higher at the time of the accident and possibly could have caused high additional mutation rates in flora in highly contaminated areas.”

Beth Krizek, a plant biologist at the University of South Carolina, agrees that radiation is a possible cause of the flower oddity, but says there are many other possible explanations.

“It’s not that rare,” Krizek says of the odd daisies. “You could occasionally see this just in plants growing in your garden.”

That being said, it’s likely that the nuclear disaster has been impacting wildlife in Japan, scientists reported in the Journal of Heredity in 2014. As in the aftermath of the Chernobyl nuclear disaster in 1986, scientists have observed higher mortality rates among birds, insects, and plants in the immediate vicinity of the radioactive leaks.

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