Fukushima: Seven years on ... The thyroid cancer mystery

A Fukushima woman and her children who have been evacuated from their home lie in a school gymnasium that serves as a temporary shelter in Iwaki, about 20 km from the stricken nuclear power plant, just an hour after the first hydrogen explosion on March 12, 2011. Rob Gilhooly photo.

Today marks the 7th anniversary since the devastating earthquakes and tsunami hit northern Japan, claiming up to 21,000 lives and triggering the second-worst nuclear disaster in history.

The multiple meltdowns and explosions at three of the reactors at the Fukushima No. 1 Nuclear Power Plant, which is located in the heart of the tsunami-hit region, resulted in the contamination of a wide area of land and sea and caused the evacuation of some 160,000 residents living near the plant.

Naturally, one of the biggest fears from nuclear "fallout" is the impact on health, most crucially the effect of radionuclides, such as radioactive iodine and caesium. Studies following the A-bombs of Hiroshima and Nagasaki, the Nevada nuclear tests and the 1986 Chernobyl nuclear disaster, among others,  showed an increase in prevalence of a variety of of cancers among survivors and residents. Of those cancers, thyroid cancer has been shown to be a concern, particularly because it has been shown to impact people under 18 the most -- including babies and unborn foetuses.

In the case of the Chernobyl nuclear disaster, even the most conservative estimates -- including those made by US cancer expert Robert Peter Gale, who treated emergency workers who were irradiated (some of whom eventually died) by the explosion and massive release of radionuclides at ONE reactor at the Chernobyl plant -- say more than 6,000 cases of thyroid cancers were found among children and adolescents as  a result of ingesting large amounts of iodine.*** Since the Nevada tests, which were carried out  between 1952 and 1957,  up to 270,000 of the 170 million US residents alive at the time of those experiments developed extra thyroid cancers, according to Gale's 2013 book "Radiation."

In the case of  Fukushima, tests on some 380,000 people who were under 18 at the time of the nuclear disaster  have found some 200 "extra"** thyroid cancers (39 of them "suspected" cancers).

According to cancer experts, this is 10s of times more than the normally occurring thyroid cases in Japan's general population.

What is perplexing about the finds in Fukushima is that while in other historical cases such as Chernobyl, extra thyroid cancers believed to be tied to the radiation emitted by the nuclear plant did not begin to show up in residents until around a decade after the disasters, in Fukushima they started to show up just a few years after the disasters.

This has led scientists to believe they are not connected to the disaster itself.

One of them is Imperial College London cancer expert Geraldine Thomas. In one interview with Dr. Thomas I was told about something known as the "screening effect," where extensive tests on patients turn up "suspected" thyroid nodes/lumps that "almost certainly will be treated, even though treatment might not be required." What this means is that, many people who have lumps on their thyroids that are not necessarily tied to radiation and quite possibly not even to cancer go through life completely unaware that they exist. They are, in many cases, harmless. However, the moment they are tested and the lumps revealed, the "natural" result is that they will be treated, possibly through a surgical procedure that might actually have not been required (and potentially be of even more danger to the patient than the lump itself).

Kenji Shibuya, a public health specialist at University of Tokyo, is another specialist who would seem to agree with Thomas. According to a report in Science magazine, Shibuya said after the first thyroid cancers were detected back in 2011 that the extensive screenings were leading to an “overdiagnosis and overtreatment,” of dozens of children who were having their thyroids removed, perhaps unnecessarily. 

Further clouding the issue is how/where the relevant radionuclide -- iodine-131 -- was dispersed following the Fukushima nuclear disaster. While government data showing where these radionuclides were dispersed was sadly lacking -- an issue I discuss in my book Yoshida's Dilemma -- it is widely believed that prevailing winds took them out to sea. Gale says in his book that even if that was not the case and the winds had taken them inland, the Japanese diet -- which is high in iodine due to the widespread consumption of fish, seaweed and other iodine-rich marine products --  "the danger would not have been as grave as one might think."

"The danger to people from iodine-131 released in the  Chernobyl reactor meltdown ... was strikingly dissimilar from that released in the Fukushima explosions," Gale writes.

A major difference between the two is how quickly and efficiently the Japanese cut the food supply chain after the disaster, adds Thomas. "While Chernobyl children continued to consume contaminated milk and other dairy produce, Japanese children ate uncontaminated food brought in from elsewhere," she says.

A final word on this point: As reported in my book, independent tests of soil from rice paddies by local farmers and other residents living inland from the nuclear plant, showed fairly large deposits of radionuclides INCLUDING  iodine. Are we to believe, then that these were already present in the soil? 

Nonetheless, scientists such as Thomas are adamant that the occurrence of cancers among Fukushima residents will not take place for another three years at least.

And yet, I have personally interviewed residents, nuclear plant workers and disaster first respondents who have developed cancers that they believe, or have been told, were a result of the nuclear disaster.  As one of the lawyers representing some of those first respondents (who are in the process of suing Fukushima plant operator TEPCO)* says, his clients were shown to be healthy and fit before the disasters. "So why are they getting cancer and other illnesses? That can only be because they were exposed to radiation. It can’t just be a coincidence.”   

 Thomas, Gale and other (often pro-nuclear) cancer experts seem to be in agreement about one thing: while it is impossible to incontrovertibly link nuclear plant radiation to cancers,  it is also impossible to say that link does not exist. (No experiments to date have revealed a DNA marker connecting the two, according to Thomas). If science has been unable to provide 100 percent verification in this regard, does it make sense to assume that thyroid or other cancers that occur 10 years or more after a nuclear disaster are connected but those occurring under 10 years are not? It seems ludicrous to say something unprovable suddenly becomes provable at a certain point, and that point is 10 years, even if we have historical "evidence" suggesting that is the case. 


*His clients are US sailors and other navy officials who were taking part in relief operations following the March 11 2011 disasters. They claim that their illnesses -- including thyroid and other cancers -- were the result of a plume of radiation from the Fukushima plant that passed over their boats when anchored in the Pacific Ocean about 100 miles northwest of the plant.

**"extra" indicates "in addition" to what would be normally found in the population.

***If discovered at an early stage aught thyroid  cancer is often cured by removing the thyroid gland. In the case of the 6,000 cases following Chernobyl, most were not life-threatening. Indeed, according to a 2006 UN report, there were just 15 childhood thyroid cancer deaths believed to be attributable to the Chernobyl disaster.