Following the reactor accidents in Fukushima as a result of the earthquake and tsunami, there is uncertainty about the specific effects of the disaster in Japan. In an interview with Dr. Thomas Jung, radiation biologist, professor and director of the Federal Office for Radiation Protection (Department for Radiation Effects and Radiation Risk), we get to the bottom of fundamental questions about consequences for health and nutrition.
After the reactor accidents in Japan, is there also a danger from radioactivity for us in Germany?
Jung: In Germany, the radiation exposure will not be so high that it could be dangerous to health. In about two weeks, depending on the weather, we will be able to measure a minimal increase in general radioactivity. However, this will not be harmful to health. The usual annual radiation exposure in Germany is two to three millisieverts (0.002 sievert), which generally exists due to natural radiation sources. The reactor accident in Japan will not significantly increase this radiation exposure: At present, we expect an additional exposure at most in the range of a few microsieverts (1 microsievert = 0.000001 sievert) in Germany – based on the radiation dose for the entire coming year. In comparison, a long-haul flight over the North Atlantic route, for example, has an exposure of about 50 microsieverts.
Would it then be excessive to take iodine tablets as a precaution?
Jung: It would not only be exaggerated, but even contraindicated in the current and expected situation in Germany, to take iodine tablets to protect oneself from radioactive iodine. The high doses of iodine required for effective iodine blockade of the thyroid gland (2 x 65mg potassium iodide emergency tablets for adolescents from 13 years of age and adults up to 45 years of age, instead of the recommended daily dose of 0.2mg iodine) carry a high risk of metabolic derailment. The normal human organism and especially that of an already overactive thyroid gland are overstimulated by the short-term high amount of iodine. This can provoke life-threatening circulatory disorders. Therefore, ingestion should only be carried out on official instructions and, if possible, under medical supervision.
Do you assume that many people actually take iodine hastily out of fear?
Jung: Despite the danger posed by uncontrolled intake of iodine tablets, there are reports of a Europe-wide buy-up of iodine tablets in pharmacies. So, at present, we in Germany should be more afraid of incidents due to medication side effects caused by exaggerated precautions than of radioactivity. We therefore strongly advise against taking iodine tablets on our own. Also, when traveling abroad to Japan, it is important to consult a doctor and not simply self-medicate with iodine.
How would iodine prophylaxis work in an emergency?
Jung: For iodine prophylaxis, it is sufficient to take it a few hours before the radioactive cloud arrives. However, we do not currently expect such a cloud. We also do not expect that in countries such as Thailand or Vietnam, which are several 100 kilometers away from Japan, there will still be a high dose of radioactivity that would justify taking iodine tablets. The filtering effect of the atmosphere will greatly dilute the radioactive material. In an actual emergency, which is by no means present or expected in Europe at this time, those affected would have to take two emergency tablets of 65mg potassium iodine each. This would be requested by the authority in case of emergency.
What foods could be contaminated by radioactivity in Japan?
Jung: The foodstuffs that can be found on the supermarket shelves so far have not yet been affected by the radioactivity, as they were imported before the accident. So there is no need to worry here. In addition, it is currently winter in Japan, so that hardly any grain such as rice or fruit is grown there anyway. The contaminated area in Japan around the nuclear power plants is currently still affected by the natural disaster, so that exports of foodstuffs from there are not to be expected for the time being. Fish and seafood are the foods that could potentially be at risk. However, since new guidelines and limits for the most accurate food controls were developed and implemented in the wake of the Chernobyl disaster, we can now draw on these experiences and standards.All food that could be dangerous is carefully checked before import. Fish, for example, are broken down into their exact composition using special radiochemical methods and measuring equipment to see what radioactive substances may be present.
Do pregnant women need to pay special attention?
Young: Even today, some mushrooms, such as truffles, are radioactively contaminated as a result of the reactor accident in Chernobyl. So is meat from wild boar. However, these products are closely controlled before they enter the market, so they should not pose any danger. More dangerous are self-collected mushrooms or meat from wild boar that has not been tested for radioactivity – pregnant women should most likely avoid these. In Japan, contamination with radioactive material will have similar consequences – we will have to see if the mushrooms there also tend to accumulate the radioactive cesium.
Where else can you travel without fear of radioactivity?
Young: I would only advise against traveling to the greater Tokyo area and the disaster area. The people there have been affected by a severe natural disaster and, accordingly, the area does not represent an area suitable for travel at the moment. On the other hand, one can travel to other countries such as the Pacific coast of South America or Southeast Asia in general without any problems and without fear of radiation.
How can you notice radioactive radiation?
Jung: Humans have no sensory organs for radioactivity. That is just the uncanny thing about it. Radiation can only be detected with the help of measuring devices. Only when one has been exposed to large amounts of radiation, such as the people who were directly affected by the Chernobyl disaster on site as relief workers in 1986, can one develop acute radiation syndrome, with nausea, vomiting and bloody diarrhea, which can lead to death.
What would be done if such a reactor accident happened in Europe?
Jung: In principle, what is being done in Japan is the same course of action we would take in Europe. With the difference that citizens must be informed comprehensively and more widely about the situation. If high radiation levels are expected, it is important to quickly evacuate the area within a radius of 20 kilometers around the power plant and more. However, exactly where to evacuate depends on the regional situation. Later, possibly even further – one must always weigh up whether the dangers posed by an evacuation are higher than those posed by radioactive contamination at the respective distance. In addition, one must quickly decide whether iodine tablets should be distributed and in which areas. In general, in a radioactive emergency, people should first stay indoors, as there is less radiation exposure there than outside. Evacuation and taking iodine tablets should be done only on official instructions and not independently. The discipline of the Japanese in evacuating despite the tremendous exposure to natural and now impending nuclear disaster has certainly helped to avoid further casualties. The interview was conducted by Julia Völker, MD.
