by Susanne Rust, California Watch
New research suggests that the cancer and death toll from Fukushima may be higher than previously claimed.
According to a team of Stanford University researchers, most of these deaths will likely occur in Japan, but there could be as many as 30 casualties from radiation exposure in North America.
These numbers are in addition to the roughly 600 people who died as result of the evacuation near Fukushima after the plant’s meltdown in March 2011.
The new estimates stand in stark contrast to others, including the United Nations Science Committee on the Effects of Atomic Radiation, which suggested there would be no deaths as a result of the radioactive release.
Mark Jacobson, co-author of the study and an environmental and civil engineer at Stanford University, said he didn't have any expectations when he started looking into the issue but wasn't surprised that the claim of "zero health impacts" was not correct.
"I am very familiar with the health impacts of air pollutants and particulate matter," Jacobson said. "If you reduce the concentration you'll have fewer health impacts. Why should this be any different?"
To get a handle on how the radiation was distributed, Jacobson and Ten Hoeve, another Stanford researcher, used a 3-D global atmospheric model they actively use to track and trace pollutants across the globe. The model is based on more than 20 years of research collected by Jacobson, who is particularly interested in the migration of pollutants from mainland Asia to California.
So, when the Fukushima disaster happened, he figured he'd throw radiation into the analysis and build a model that could track the released iodine and cesium.
Not surprisingly, it moved around in similar fashion to other pollutants, with iodine behaving like a gas and cesium like a particulate. With prevailing westerly winds, only about 19 percent of the fallout made it to land, and the rest drifted out to sea.
The researchers then combined that information with a standard health-effects model, which is used by public health researchers to estimate exposure to radioactivity.
They found that the number of deaths would likely range between 15 and 1,300, with a best estimate of 130, while the number of people acquiring cancer as a result would range between 24 and 2,500, with a best estimate of 180.
Most deaths and cancer cases are likely to occur in Japan, but there may be a few in mainland Asia and as far away as North America.
"These worldwide levels are relatively low," Hoeve said in a press statement. He said these numbers should "serve to manage the fear in other countries that the disaster had an extensive global reach."
The research appears in Tuesday's journal Energy and Environmental Science.
Paul Carroll, program director of the Ploughshares Fund, an antinuclear organization, said he thought the casualties seemed a little low and stressed that this kind of epidemiological data is highly uncertain.
"It is extremely difficult to predict the long-term effects of radiation, especially when you start factoring in things like different types of radiation, at different levels, at constant low levels, on different people," he said.
"It's the difference between death by a thousand cuts or death by a guillotine," he explained. "So much of our data is based on large doses of exposure to radiation, not the constant, low levels. Which cut eventually killed the person? The 999th or the 1,000th?"
Jacobson agreed that the epidemiological data is the most uncertain, which is why their projected ranges were so wide.
But he said one of the reasons the deaths may seem so low is that only about 19 percent of the fallout found its way to land; the rest went out to sea.
If the same accident had happened at Diablo Canyon, Jacobson said, 45 percent of the radiation would find its way to land. Therefore, despite the fact that the population density around Diablo Canyon is a fourth of that around the Japanese power plant, the death rate would be 25 percent higher.
Jacobson said one of the most important factors, however, in keeping deaths from climbing in a disaster like this is a swift government response. And it is likely, in large part, the Japanese government's response that prevented Fukushima from becoming Chernobyl, where nothing was done to remove people from the surrounding area.
Susanne Rust is an investigative journalist for California Watch.