Rianne Teule | Greenpeace blog

Last week the World Health Organisation released its first preliminary analysis of the Japanese people’s exposure to radiation after the Fukushima nuclear disaster, and the renowned German Max Planck Institute released its own report warning of the global risks of the next nuclear accident.  Both reports underline the need for better measures in Japan and across the world to protect the public from nuclear risks.

The Max Planck Institute stated that nuclear meltdowns “may occur once every 10 to 20 years (based on the current number of reactors) — some 200 times more often than estimated in the past.  The World Health Organisation (WHO) – based on a preliminary assessment – concluded that the radiation impacts in most of Japan are very small, though in some areas radiation exposure is ”relatively high”. Also last week, the Japanese operator of the crippled Fukushima plant said that the amount of radioactivity released in the accident is larger than previously estimated.

These stories got a different spin in the media, depending on which outlet covers them. Some chose a headline like ”Fukushima Radiation below permitted levels”, as if nothing extraordinary happened when the Fukushima reactors melted down. Others opted for a more balanced headline like “WHO releases mixed Fukushima radiation report”, but still struggled with the interpretation of the numbers. The WHO report confirmed that a large part of the population in Fukushima prefecture has been exposed to radiation levels between 1 – 50 millisievert in the past year (1 mSv is the internationally accepted maximum allowable dose for members of the public). This seems harmless, as many have started to believe that only above 100 mSv does the risk of cancer increase (see for example “The Children of Fukushima wait for UN study”).

In fact, there is no safe dose of radiation: any increase in radiation exposure increases cancer risks, the International Commission on Radiological Protection says. Hence when a large population (as in Fukushima) is exposed to radiation between 1-50 mSv, an increase in cancer and other health risks is expected. These health risks are hard to identify in scientific studies, as they are often hard to distinguish against the background of health risks due to other causes.

No nuclear spin can hide that a large population in Japan is still being exposed to higher levels of radiation than is normal. The WHO report is merely a first indication of how the public has been exposed, but in no way an evaluation of the health impacts of the radiation from the Fukushima disaster. The full impact of the disaster will only become known in time. Until then, much more emphasis needs to be placed on protecting the people in the contaminated areas. Not only the people in the highest exposure areas need to be protected, but measures need to be put in place to keep the radiation exposure of all people as low as possible.

Reporters and municipal staff in white protective suits walk along the "flower tunnel" in Tomioka, Fukushima Prefecture, inside the nuclear disaster exclusion zone on April 19.