We calculated a concentration budget for Cs'", using its 

 vertical distribution in different areas (Figs. 1,2,3). For the 

 period from the beginning of nuclear exercises and extending 

 up to 1978, the total input of Cs'" on the Earth's surface was 

 estimated as 1,740 and 1,150 Bq/m' for the 

 latitudes 60-70°N and 70-80°N, respectively (Vakulovsky 

 etui. 1985). 



Accounting for radioactive disintegration, the concentration 

 of Cs'" could decrease by no less than twice; therefore, the 

 maximum estimated amount of Cs'" on the Earth's surface in 



the above-mentioned areas should not exceed 1,370 and 

 575 Bq/m- . Amounts of Cs'" in the seawater, calculated on the 

 basis ofthis investigation, are 2 10 Bq/m"forthe Gulf of Anadyr 

 and 120 Bq/m' for the Chukchi Sea and the northern Bering 

 Sea. 



The average concentrations of Cs' " in the Chukchi and the 

 Bering Seas are 10-50 times lower than in the Black Sea 

 (Buesseler. 1987; Nikitin et al. 1988) and in the Barents, the 

 Greenland, and the Kara Seas, where local sources of radioactive 

 pollution are situated. 



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