Our concerns with marine pollution are a part of a much largerand perhaps much 

 more important problem— a quantification of the ability of the oceans to accept a 

 portion of the wastes of human societies. The peoples of the world utilize about three 

 billion tons per year of minerals, food, and forest products. If this tonnage were com- 

 pressed into a cube, each edge of the cube would be a kilometer long. (In addition, 

 about 20 billion tons of carbon dioxide are released to the atmosphere through the 

 combustion of oil, coal, and other fossil fuels.) Since the solid and liquid materials 

 are generally not accumulated but are disposed, the identification of sites to accom- 

 modate these wastes is of paramount importance, especially if we wish to maintain 

 environmental resources. The use of the oceans as disposal space has been accepted 

 throughout history. Yet extreme care must be exercised in regulating the amounts 

 and types of discharges such that the resources of the oceans are kept in renewable 

 states. 



Previous investigations of marine pollution problems provide guidance about the 

 possible disposal of benign and toxic wastes to the sea. Clearly, economic and social 

 considerations are involved. But the development of scientific protocols for assess- 

 ment of assimilative capacities of marine waters can proceed upon the basis of past 

 experience. It is with this view in mind that 1 will review some of the more important 

 events in marine pollution and in marine chemistry, and I will then present some 

 concepts used in determining assimilative capacities. 



THE SPRINGBOARD - RADIOACTIVE POLLUTION 



In the early 1950s, many scientists were concerned about the ability of the oceans 

 to accept artificially produced radionuclides and especially about the biological 

 effects of radiation. The mood of the period is well expressed in the following para- 

 graph (Revelle and Schaefer, 1957): 



Among the variety of questions generated by the introduction of radioactive 

 materials into the sea, there are few to which we can give precise answers. We can, 

 however, provide conservative answers to many of them, which can serve as a basis 

 of action pending the results of detailed experimental studies. The large areas of 

 uncertainty respecting the physical, chemical, and biological processes in the sea 

 lead to restrictions on what can now be regarded as safe practices. These will 

 probably prove to be too severe when we have obtained greater knowledge. It is 

 urgent that the research required to formulate more precise answers be vigorously 

 pursued. 



The regulatory measures that limit the introduction of radionuclides to the oceans 

 have been formulated over the past decades with the goal of protecting human 

 health. Perhaps the largest amounts of radioactivity introduced today come from the 

 nuclear reprocessing plant at Windscale, United Kingdom. The materials enter the 

 Irish Sea through a pipeline from the various facilities. United Kingdom environ- 

 mental scientists have developed protocols to regulate such discharges on the basis of 

 the "critical pathways" technique. Herein, radionuclides that are ingested through 

 the consumption of algae, fish, and shellfish or the cumulative gamma radiation of 

 which is emitted from sediments in beach areas and which may achieve levels capable 

 of jeopardizing human health are monitored. The surveillances are carried out on the 

 consumed foods or their basic components and at the beach areas of concern. 

 Supported by assessments prepared by the International Commission on Radio- 

 logical Protection (ICRP), permissible body burdens of given radionuclides have 

 been evolved based upon their toxicity. A "critical population" is identified con- 

 sisting of those individuals receiving the highest radiation dose rates, either from 

 food consumption or from beach exposure. The acceptable levels are conservative, 

 with many built-in maximizing assumptions such as those of a lifetime consumption 

 of the radionuclide in question and the proviso that the living materials eventually 

 eaten come only from the area adjacent to the Windscale outfall. 



