As many as 1,300 people could eventually die from cancers caused by radiation exposure from last year's nuclear disaster at the Fukushima Daiichi power plant in Japan, and another 2,500 could get nonlethal cancers, according to a new analysis by researchers at Stanford University.
In March, a professor at Oxford University said the "radiation at Fukushima has caused no loss of life and is unlikely to do so, even in the next 50 years." But Mark Jacobson, coauthor of the Stanford report, says that's not the case.
"There's not going to be zero deaths," Jacobson says. "It's not going to be tens of thousands either, but it's not a trivial thing."
The study says that a worst case scenario could see upwards of 1,300 cancer cases, but more conservative estimates outlined in the study say there could be several hundred.
"That range uncertainty is primarily a function of three things: The dose of radiation received, where the population was concentrated, and figuring out exactly what the population was being exposed to," he says. One thing that was difficult for the researchers to measure, for instance, was whether people were exposed to iodine in a liquid or gaseous state--which can cause thyroid cancer. "We had to do several different estimates for that," he says.
Although almost all of the victims are expected to be from Japan, Jacobson says there could be a few isolated cancer cases in other nearby countries.
Jacobson and coauthor Jon Ten Hoeve used global weather and atmosphere data, as well as nuclear emission estimates from the Comprehensive Nuclear Test Ban Treaty Organization to create the model. He says the weather conditions in the aftermath of the earthquake that caused the meltdown could have saved many lives.
"In one sense, it was a lucky incident because of where the location was—only 19 percent of the [radiation] made it over land," he says. "It could have been a lot worse if the winds had blown differently."
Curiously, more people may have died during the evacuation process than from the radiation. About 600 elderly or injured people have been estimated to die during evacuation.
"I can't imagine not evacuating, that just wouldn't make sense," he says. But according to their model, the evacuation was likely to have prevented just 245 radiation deaths.
Jacobson says people who were living in the area could suffer from thyroid cancer or leukemia, and that children are most likely to be at risk, because the radiation dosages were likely to affect smaller bodies harder.
"It's not going to just be the elderly getting sick," he says. "Smaller people are more susceptible to some of these cancers--there's the concern that many of these cases could be in children."
Jason Koebler is a science and technology reporter for U.S. News & World Report. You can follow him on Twitter or reach him at firstname.lastname@example.org