The annual dose due to nuclear testing peaked in 1963 at 300 microsieverts 0

Children of the 1960s, this information has escaped probably, but you are the generation that has suffered most from the air nuclear tests. Impossible, answer you, since they have been replaced by underground fire from 1961. But forget the frenzy that swept the world during the cold war, between 1954 and 1958, and in 1961 and 1962 essentially. In 1961, the former Soviet Union realized the most powerful shooting ever released with a record explosion with a capacity of 50 million tons in Novaya Zemlya! Either 2,500 times greater than those of Hiroshima and Nagasaki, knowing that a nuclear weapon power is expressed in tons of conventional explosive TNT (trinitrotoluene) type.

The following year, the USSR and the United States were 118 shots amounting to 170 million tonnes of TNT, 40 of the power dropped between July 16, 1945 and the last atmospheric test in 1980. Between the first test of the American bomb in the desert of New Mexico, which will be three weeks later the bombardments of the Japanese cities of Hiroshima and Nagasaki (6 and 9 August 1945) and the last Chinese launch, the total power sent into the air by the five world nuclear powers (ex-USSR, USA, United Kingdom, France and China) reached 440 million tons!

However these "small experiments" have may have occurred on isolated sites, they are acting in deserts or Islands lost as Mururoa, they did in no less released billions of radioactive particles. As the famous "fungus" could be up to 50 kilometers into the stratosphere, some are back quietly by gravity across the globe, others travelling with the prevailing winds over thousands of kilometres. In the fission of heavy atoms such as uranium-235 or plutonium-239, some of the dispersed radionuclides have a life that is little more than a few days, and to forget quickly, but others, such as strontium-90 (29 years), americium-241 (433 years), or even the plutonium 239 (24,000 years!) are so-called "long life".

Compensation for victims

While the Ministry of defence in France at the end of a long struggle to recognize the right of compensation for the victims of the 210 nuclear tests carried out by the France in the Sahara and Polynesia, the Institute of radiation protection and nuclear safety (IRSN) unveils the results of a study on the impact of nuclear testing on the metropolis. It took until 2003, following a controversy raised by the discovery of a significant radioactivity to the cesium 137 in the soils of the Black Mountain in the Aude region in theory saved by the fallout from Chernobyl, the Ministry of the environment asked the IRSN to shed light on this subject. In operator and modeling more than 40.000 measurements carried out between 1961 and 1978, the IRSN could thus calculate that the generation the most exposed to fallout from atmospheric testing is that of children born in 1961. Over the first seventeen years of their lives, they have absorbed a radioactive dose cumulative 1.5 millisievert (mSv) average, and up to 5 mSv for the inhabitants of the regions "watered". A child of 1961 a likely received one dose in thyroid 40 times greater than that of a child born in 1970. "The annual dose due to nuclear testing peaked in 1963 at 300 microsieverts (0.3 mSv) in France, said the Institute, or a same order of magnitude than that of the year 1986, due to the impact of the accident at Chernobyl."

The IRSN is able in part to this calculation by the analysis of the peaks of activity found on plants. After each shot, the radioactivity of the leaf of lettuce progressed, up to 100 becquerels at the height of 1963! Other measures allow to see the same phenomenon for milk, and the IRSN notes that after the first trials, "all foods are met in a continuous and sustainable manner by cesium-137 and strontium 90". By converting these data to the human stomach, especially, the IRSN concludes that atmospheric testing were finally weighed for 0.3 mSv.

One millisievert per year

Children of the 1960s, rest assured, this amount remains low with the average dose received by a French of today. It is estimated at 3.3 mSv per year. Radiation due to testing and even the fallout from Chernobyl became virtually undetectable. And currently, the tolerable annual regulatory "artificial" radioactivity is set for a millisievert per year for the public.

The French metropolis were finally not been exposed to great danger because of the tests, the IRSN admits as cesium-137 always present in the soil of the territory did not exist before 1945 and proves a posteriori how further atmospheric testing could be dangerous. Prohibited in the air and water by a first partial international agreement in 1963, it took fifty years of fierce fighting pacifists for the prohibition of all tests, including underground, under the 1996 nuclear test ban treaty. Although it is applied, this Treaty is still waiting for official ratification of China and the United States.