It’s getting “hot” in here…Nature in the Fukushima Nuclear Exclusion Zone


Here Adam Hart writes about his latest scientific travels, making a TV documentary in Japan

On March 11th 2011 there was a magnitude 9 earthquake off the Pacific coast of Japan. As would be expected in a country well-used to dealing with such events, the active reactors at the coastal Fukushima Daiici Nuclear Power Plant were automatically shut down. No drama. Unfortunately, it is rarely possible to plan for every eventuality….

A series of events were triggered by the earthquake that led to a major nuclear disaster. A tsunami was generated that devastated Pacific coastal areas but also disabled the emergency generators that provided power to the cooling pumps that were keeping the reactors from overheating. Without effective cooling, the reactors went into meltdown, leading to hydrogen explosions and the consequent release of radioactive material. It was the worst nuclear incident since the 1986 Chernobyl disaster.

Fukushima is a human tragedy but not because of the deaths associated with the disaster itself; currently there are no fatalities associated with radiation exposure although such effects can take time to become apparent. It is a disaster because of the mass evacuation of people from the area surrounding the nuclear reactor. The initial evacuation zone extended for 20km from the reactor, and affected hundreds of thousands of people. Former residents are still not permitted to live in much of the area.

Against this background, I found myself sitting slightly nervously at Heathrow Airport.  I was heading out to spend a week in the Exclusion Zone filming and assisting with a documentary being made about wildlife living there. Having never been to Japan before I jumped at the chance but I also can’t pretend that a risk assessment that explicitly requires you to carry a personal Geiger counter wasn’t just a little bit exciting…

Crammed into the “World Traveller” section, I took off at 2pm, flew for nearly 12 hours and landed late-morning the next day, which was a little confusing if I’m honest. Since Paul (the producer, camera operator, director and everything else combined), was arriving 4 hours after me, I booked myself into a Capsule Hotel at the airport. For just 3 pounds an hour I could relax in a very comfortable but slightly coffin-like pod, lulled to sleep by the gentle sound of waves. How these aren’t everywhere is beyond me – they are brilliant.

After a refreshing sleep, I met Paul from his plane and we set off north in our slightly-too-small hire car, accompanied with the usual assortment of bags and cases that are inevitable for a filming expedition. Driving in Japan is easy; they drive on the left, the road system is logical and even the toll booths proved easy because of our fabulous grasp of the Japanese language (all hail the wonder of Google Translate).

Our first night was spent in a slightly odd set up…we had the upper rooms of a house owned by a farmer but he neither seemed to be expecting us nor willing to open the door to us. We had a local “fixer” who was also due to stay the night as well but she was an hour away. Ever resourceful, we solved the problem in the way that many such problems are solved. We skulked around the tiny Japanese village drinking quite a lot of the beer we had thoughtfully bought earlier.

We eventually made it into the house. My room was bare and cold but the bedding comfortable and clean. There were rather more shield bugs in the room than I would like though, and I say that as someone that doesn’t mind the odd insect here and there. Glamourous location shooting this was not…

We bonded with our host (who turned out to be a fascinating man of prominent local political importance) over a series of increasingly bizarre alcoholic drinks, or more accurately an increasingly bizarre assortment of animals pickled within the drinks. Personally the dead snake in the last bottle didn’t really appeal but I can vigorously recommend Giant Hornet (Vespula mandarinia) sake.


Jetlag conquered, we woke up to a glorious day – sunny and warm, with clear skies. Breakfast regrettably was not part of our accommodation package but luckily we had bought some snacks to go with our beers the day before. So it was that day 1 began with a nutritious breakfast of a Snickers and a half-tube of Pringles. We were staying around 5km out from the exclusion zone but a main road through the zone is now open, albeit only in the day. Lining this road, the 114, are a series of Geiger counters, which can also be seen throughout the region. Through these and our own Geiger counters, we rapidly learnt that while background radiation within the zone is high, and in places, very high, the levels are not terrifying. Sections of the 114 reached 4.5 microsieverts per hour. This is 45 times a normal background reading but around the same level as you are exposed to during a plane flight, which of course can last for 10-12 hours.  We did find regions where readings taken close the ground exceeded 17 microsieverts and some “hot” areas reach 30 or more on the ground but if you minimise your exposure then your cumulative dose can be kept well within safe limits.
Of course, the major problem for organisms within the zone is that they cannot minimise their exposure. They are there 24/7 and this exposes them to levels of ionising radiation (the kind that damages DNA) that are unacceptable for us and harmful to them.

So what are the effects of radiation on the organisms within the zone? Well, unsurprisingly, “it’s complicated”. Ionising radiation is always harmful but those effects are not always immediately apparent. The ecosystem looks “normal” – in fact the region looking stunning, bathed in bright autumnal colours. The absence of humans has been great for the macaques, which have taken over the deserted towns, and for the wild boar whose images fill up any camera trap you choose to put out. We even saw salmon spawning in the rivers. But first impressions do not tell the whole story. Research here and at Chernobyl show that birds and mammals have smaller brains, they suffer more cataracts and in general animals are less common, less fit and less diverse.

There is a more subtle effect of the radiation and it is noticeable when you take a turn over branches on the forest floor, open your eyes and take a lovely deep breath. What you see are very few invertebrates and what you don’t smell is that rich decaying fungal smell of a healthy forest floor. Radiation is affecting the decomposers that keep a forest functioning correctly. Trying to tell some of these bigger picture ecological stories was one of the reasons I was there.

After our first night we decided to find better lodgings by the way…we checked into a hotel, ate food that wasn’t out of a packet and drinks that were clear of any wildlife. We set fire to most of our dinner on our table-top BBQ mind you, but that’s for a different blog, along with the story of how two mature men were reduced to a fit of giggles after buying a basket-full of drinks with names like “9% Hard” (highly alcoholic pink grapefruit juice – amazing).

Most of the week was spent filming in the Zone or navigating the far from clear permit system to gain access to different locations. Even though I only spent a week there, and didn’t exactly visit the usual tourist sites, I saw and experienced enough of Japan to know that I very much want to go back. Next time though I might visit somewhere that doesn’t require a pocket Geiger counter…
This documentary will air sometime next year – watch this space!

Adam Hart, Professor or Science Communication

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