regions of the ocedn, and the gradual purification of the air by fall- 

 out of aerosols as they move over the water body. Especially persistent 

 fields of high levels of regional pollution are created in areas with 

 limited water exchange, for example in the internal seas. 



Zonality of distribution and the latitude effect . --As has been 

 shown, using radioactive products as an example, finely dispersed 

 aerosols are transferred and precipitate from the atmosphere in the 

 zonal direction, forming latitudinal zones of intensive pollution at the 

 parallels where the sources of atmospheric pollution are located 

 (Karol', Malakhov, 1965; Nelepo, 1970). As a result, in the temperate 

 latitudes of the northern, and to a lesser extent of the southern 

 hemispheres, there are maxima of precipitation and pollution, while at 

 the equator and in the polar regions there are minima. This global 

 picture has been produced on the basis of observed data on the 

 continental surface; however, there is every reason to extrapolate it to 

 the World Ocean as well. 



Atmospheric flux of chemical pollutants is primarily concentrated 

 in the northern hemisphere, particularly at 30-70°N, where the main 

 industrial zones are located and where most of the substances are 

 produced which pollute the troposphere and subsequently precipitate into 

 the ocean. According to some calculations, some 90% of all atmospheric 

 pollution is accounted for by these regions (Duce et al., 1974). If we 

 consider the zonality of the transfer of tropospheric aerosols noted 

 above and the restriction of the maximum precipitation to the middle 

 latitudes of the northern hemisphere, we can speak of the existence of a 

 latitude effect in the large-scale distribution of chemical pollutants 

 in the ocean with its maximum in the temperate latitudes of the northern 

 hemisphere (see figure). 



These considerations have been confirmed as yet only by the results 



of studies of artificial radioactivity (Popov, Patin, 1966), plus some 



information on chemical pollution of the waters of the North Atlantic 

 (Simonov et al ., 1974). 



The mosaic nature of distribution . --Analysis of this phenomenon as 

 applicable to artificial radionuclides has shown (Popov, Patin, 1966) 

 that it cannot be explained by analytic errors in the determination of 

 impurities in the sea water alone. This heterogeneity is characteristic 

 for all trace elements in the marine medium, and its causes are probably 

 related to the peculiarities of turbulent mixing of masses of water and 

 the overall specifics of the behavior of trace quantities of substances 

 in complex heterogeneous systems such as sea water. In this connection, 

 we must recall the processes of sorption, hydrolysis and complex 

 formation, which lead to the complicated and "anomalous" behavior of 

 many tr^ice impurities under conditions of great dilution in aqueous 

 solutions. 



Localization in the surface film . --This feature of the 

 microstructure of the field of pollution is related to the physical- 

 chemical and ecologic peculiarities of the thin surface film at the 

 division boundary between the water and the atmosphere, where many 



411 



