I was very moved after hearing the heartfelt testimonies of teacher Yoshiko Aoki, high-school student Moe Harada, and a group of students dialling in from Fukushima to the OECD NEA risk communication workshop in Paris. I previously shared with you their Stories from Tomioka town, Fukushima. But I felt that I needed to do more – I wanted to honour the last plea the students made before they hung up:

“Everyone should try to know the real facts about Fukushima.”

I have tried to do just that. I looked for information on the areas that were so painful for the teacher, Ms Aoki to see: where inhabitants of Tomioka town are still barred from entering. Although coming back to their homes in 2017 was cause for happiness and an opportunity to finally begin to heal for Aoki and more than a thousand others, the existence of these off-limit areas sounded from her account like wounds in the town itself.

“There are barriers in our town, where people are forbidden to go.”

In this piece write about my attempt to understand the kind of risks the authorities were protecting their people from with such extreme measures.

The areas denoted by yellow in the map here are estimated by the officials to yield a total dose of between 20 to 50 mSv/year. In these areas, businesses are allowed but habitation is largely prohibited.

These levels, although notably higher than the typical global range of 1 to 13 mSv/year, are not exceptional. They are in the same class with natural background in Kerala, India, where total doses can reach 40 mSv/year. No increase in cancer rates in the area have been observed.

The pink ‘difficult to return’ area is described as yielding an estimated dose of ‘above 50 mSv/year.’

Looking at the more detailed dose survey map of Fukushima coast, the measurement points with ambient radiation levels yielding more than 83 mSv/year – see orange and red dots in the map below – number only eight all in all. The one red dot, more than 166 mSv/year, is found very near the power plant. But none of these eight are located in Tomioka town, which is the area around the dark blue dot on the lower edge of the coast.

In the larger Fukushima area, the yellow (33-83 mSv/year) points represent a narrow band among a sea of darker greens and blues (dark greens yielding ambient doses of below 16 mSv/year and blues below 4 mSv/year).

There are factors other than ambient radiation to consider, but the potential ingestion of radioactive caesium, for instance, is unlikely to result in a very large dose. Studies in Chernobyl find that caesium does not accumulate anywhere in the body, and thanks to its long half-life, decay happens infrequently – its fate is much like that of the small amount of radioactive potassium we ingest in bananas and other foods.

The surveys of Tomioka town itself (see zoomed in map below) are all green or blue, which means the ambient radiation are at levels below 33 mSv/year.

But even if the ‘difficult to return’ areas would yield a total dose of well over 50 mSv/year, what would the size of the actual risk be?

Let’s assume, for the sake of argument, that the exposures in these off-limits areas would reach or surpass 100 mSv/year. This magnitude of background levels are naturally found in Ramsar, Iran, as well as at a famous Guarapari beach in Bazil, where people come for the supposed healing properties of the black radioactive sand.

After decades of epidemiological radiation research, scientific reviews can’t confirm discernible health effects from radiation below 100 mSv (UNSCEAR, McLean et al 2017). Although the correlations between 100-200 mSv are noisy enough to show both positive and negative correlations, at least in cases where exposures are acquired over a short period of time (such as among atomic bomb survivors), it is possible to determine a slight increase in cancer risk at doses above 100 mSv/year.

Common scientific estimate consider there to be a 5 % increase in cancer incidence with an exposure of 1000 mSv, or 1 Sievert (likely in a shorter time-frame than a year – but let’s assume, for a cautious estimate, for it to be per year).

By going back to live in the pink ‘difficult to return’ areas of Fukushima, in other words, the population there could perhaps have an increase in life-time cancer incidence of about 0.5 % (on top of the baseline life-time cancer risk of 40 %).

It’s fear, not level of risk, that is keeping people out of Fukushima

It’s startling to realize that a government would deny people the right to their homes for such a small increase in risk. What if should apply the same logic to other industrial pollutants – like particulate matter in air? The pollution from burning fossil fuels and wood, as well as traffic exhausts has long been known to cause serious health effects, including increased risk of cancers, heart disease, and respiratory illnesses.

Fukushima prefecture has relatively good air quality. If people from Fukushima would decide to move 200 km south to live in the relatively clean megacity of Tokyo, their risk of premature death due to air pollution would increase by about 1.8 %, on average. If they were unlucky enough to pick the areas in Tokyo with the most polluted air (Kuki or Koshigaya), however, their risk of death would go up by almost 5 % – the equivalent of 1000 mSv/year radiation exposure.

The air quality on the Fukushima coast just a few km from Tomioka town, as I am writing this, is well below the WHO recommended limit: PM2.5 concentration of 10 of μg/m3, equivalent to an Air Quality Index or AQI of 42. At this level, the WHO concludes that no increase in long-term mortality is observed.

The large aggregation of stations in the Tokyo area in the bottom of the map shows that, unfortunately, even a relatively clean metropolis regularly crosses that air pollution limit (yellow stations above).

Should we see these areas, or indeed, most of Tokyo, barred off with metal fences as has been done with the northern parts of Tomioka town? Moving to Tokyo would triple the populations’ increase in risk of death, compared to moving them back to the remaining off-limits zones in Fukushima.

Considering the risks are larger, how come are the people allowed to move to Tokyo, but not allowed back on their ancestral lands?

To put this in further perspective still – the whole of Japan is a country where the air quality is good.

Merely crossing the sea over to South Korea or China would change the risk profile dramatically: 9-15 % increase in risk of premature death due to air pollution is the norm rather than the exception. In China and India particularly, there are places far worse affected, where the increases in risk is calculated in tens or hundreds of percents compared to areas of low particulate pollution, found commonly enough in places like the Nordics, France, Spain, Portugal, Canada, and large parts of the US.

Air pollution is a silent killer. Our industries impose the population to harmful emissions which cause an increase in heart and vascular disease, lung cancer, chronic obstructive pulmonary disease and respiratory infections. These effects are something far far worse and far-reaching than the possible small increase in risk due to radiation around the Fukushima nuclear plant. Yet the residents of Fukushima have been subjected to wrenching changes, and their life choices are still heavily dictated by regulations. These regulations are set by exaggerated caution due to fear, not by a realistic assessment of the context of risks.

By focusing blindly on making sure that radiation exposures remain extremely low, the people in charge have disregarded larger real risks, which they have imposed on their own citizens in the process.

I can only imagine what might have gone through Ms Aoki’s mind when she spoke to us in Paris, but in effect, her words sadly and accurately describe the conclusion I have found. As she so strikingly put it:

it’s people who destroyed Tomioka town.

The consequences of the Daiichi nuclear accident have not been about the effects of the radioactivity on the body – but about the actions of people, tragically changing the lives of those living in parts of Fukushima prefecture like the Tomioka town.

The high-school student from Tomioka town, Ms Harada, who was eight years old at the time of the accident, told us:

“I want to be able to live in my home town without the fear of radiological risk.”

This is what we should to give these children: the freedom from fear, and from the kind of damaging decisions that can result from it.

We can’t allow our policies, governments, and regulatory agencies to continue reacting out of fear, and considering risks of radiation in a vacuum. It is a fundamental principle of bioethics that all medical students are taught throughout the world: that it may be better not to do something, or even to do nothing, than to risk causing more harm than good.

We must hold our government and regulatory bodies accountable to the same basic principle of ‘first, do no harm‘ – for the sake of the public they are supposed to be protecting.

For further articles on radiation, you can read my pieces: Radiation and Cancer Risk – What Do We Know? and Radiation Exposures at a Glance. More on nuclear power found under Climate and Energy.

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