Exposure from atmospheric nuclear testing

Until the Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space, and Under Water, signed in Moscow on August 5th 1963, almost all nuclear explosions (fissions and fusions) to test weapons were carried out in the atmosphere, mostly in the northern atmosphere, e.g., in the former Soviet Union at Semipalatinsk in Kazakhstan 456 tests were carried out between 1949 and 1989 [http://www. nato.int/science/e/grants]; after the treaty almost all explosions have been conducted underground. The two time periods of most intense atmosphere tests were 1952-1958 and 1961-1962 (see Figure A.13). The total number of atmospheric tests was 543 and the total yield estimated is 440 megatons (189 megatons from fission) [UNSCEAR, 2000].

The total collective effective dose resulting from weapon tests to date is 3 x 107manSv; 7 x 106manSv will be delivered within the first 250 years (until 2200); the remainder, due to the long life of the C14 radionuclide produced, in the next 10,000 years. The annual average effective dose varies both with time (decreasing thanks to the ban treaty) and with location: in the northern hemisphere the dose is higher than in the southern. The average effective dose estimated for the year 1999 is 5.87 mSv in the northern hemisphere, 2.68 mSv in the southern and 5.51 globally (see Figure A.14).

Atmospheric tests czn:;:! Underground tests

Atmospheric tests czn:;:! Underground tests

I I I I | I I I I | I I I I | I I I I | I I I I | I I I I | I I I I | I I I I | I I I I | I I I I | I I I I | 1943 1950 1955 196(1 1965 1970 I'>75 I9S0 1985 1990 1995 2000

Figure A.13. Number of weapons tests per year.

I I I I | I I I I | I I I I | I I I I | I I I I | I I I I | I I I I | I I I I | I I I I | I I I I | I I I I | 1943 1950 1955 196(1 1965 1970 I'>75 I9S0 1985 1990 1995 2000

Figure A.13. Number of weapons tests per year.

Average annual effective dose (mSv)

Year

Northern Hemisphere

Southern Hemisphere

World

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