At first glance, the story looks credible. And scary. The information comes from a physician, Janette Sherman MD, and epidemiologist Joseph Mangano, who got their data from the Centers for Disease Control and Prevention's Morbidity and Mortality Weekly Reports—a newsletter that frequently helps public health officials spot trends in death and illness.
Look closer, though, and the credibility vanishes. For one thing, this isn't a formal 
scientific study and Sherman and Mangano didn't publish their findings in a peer-reviewed journal, or even on a science blog. Instead, all of this comes from an essay the two wrote for Counter Punch, a political newsletter. And when Sci Am's Moyer holds that essay up to the standards of scientific research, its scary conclusions fall apart.
...why did the authors choose to use only the four weeks preceding the Fukushima disaster? Here is where we begin to pick up a whiff of data fixing. ... While it certainly is true that there were fewer deaths in the four weeks leading up to Fukushima than there have been in the 10 weeks following, the entire year has seen no overall trend. When I plotted a best-fit line to the data, Excel calculated a very slight decrease in the infant mortality rate. Only by explicitly excluding data from January and February were Sherman and Mangano able to froth up their specious statistical scaremongering.
You can see that data all plotted out nicely by Moyer over at Sci Am. How did these numbers get so heinously distorted? It's hard to say. But there should be some important lessons here. In particular, this is a good reminder that human beings do not always behave the way some economists think we do. We're not totally rational creatures. And profit motive is not the only factor driving our choices.