4. MARINE CONTAMINANTS 



Effects on the Ocean of Atmospheric 

 Circulation of Gases and Particulate Matter 



The transport of materials from 

 the continents to the marine environ- 

 ment takes place primarily through 

 wind, river, or glacial systems. The 

 activities of man have added two 

 other paths: (a) introduction, both 

 by intent and by accident, from ships 

 and domestic and industrial sewage 

 outfalls, and (b) introduction by man 

 of materials to the atmosphere, with 

 subsequent impact upon the oceans. 

 The latter path will be emphasized 

 here. 



Aerial transport can result in the 

 rapid and widespread dispersal of 

 solids, liquids, and gases. For ex- 

 ample, radioactive debris in the 

 troposphere from the Chinese nuclear 

 device tested in 1965 fell back to 

 earth in a latitudinal band following 

 its transport in the jet streams; these 

 materials circled the world twice with 

 an average velocity of 16 meters per 

 second. 



The ocean acts as a reservoir for 

 the dissolved phases introduced to 

 it and maintains them for periods 

 of the order of centuries to thousands 

 of millenia. Thus, the impacts of man 

 upon the seas, if measurable today, 

 will also be measurable many, many 

 generations into the future. 



There are probably three major re- 

 sponses by the environment to such 

 impingements by man: alteration of 

 its physical nature, alteration of cli- 

 mate, and alteration in the constitu- 

 tion of communities of organisms. 

 Although some of the changes are 

 quite difficult to detect today, none- 

 theless, on the basis of our knowl- 

 edge of the types and amounts of 

 materials being dispersed to the air, 

 there is hope for some predictions. 



Impact of Man-Made Materials 



Managing the discharge of mate- 

 rials to the atmosphere will take on 

 greater importance with time as both 

 population and the material and en- 

 ergy utilizations per capita increase 

 in the world. We have successfully 

 managed, so far, the releases of 

 radioactivity to the environment from 

 nuclear reactors. On the other hand, 

 we have had serious problems with 

 the disposition of pesticides to our 

 surroundings; clear-cut impacts on 

 the communities of birds have been 

 felt. The definition of critical prob- 

 lems in atmospheric release of solids 

 and gases such that appropriate ac- 

 tions can be taken by policymaking 

 bodies is clearly the end-point of the 

 considerations presented here. 



Metals — The identification of the 

 materials from fuel combustion and 

 from industrial production is incom- 

 plete, especially with regard to the 

 latter category. Metals such as mer- 

 cury and arsenic, which have volatile 

 forms, are entering the atmosphere — 

 and subsequently the oceans — as a 

 result of mining and extractive metal- 

 lurgical, industrial, and agricultural 

 operations. High concentrations of 

 atmospheric mercury accompany the 

 smog in the San Francisco Bay region. 

 High arsenic contents of Japanese 

 rain waters have been attributed to 

 the smelting of sulfide ores and fuel 

 combustion. The flow of such sub- 

 stances through our surroundings is 

 poorly defined. About 2.5 percent 

 of the total production of gasoline 

 is lost by evaporation during trans- 

 fer processes, from production site to 

 vehicles and to storage tanks and 

 through vaporization from the auto- 

 mobile gas tank and carburetor. This 

 amounts to several million tons per 



year throughout the world. Again, 

 the subsequent activities of this gas- 

 oline in the air are as yet undeter- 

 mined. 



Chemicals — Volatile synthetic or- 

 ganic chemicals are dispersed about 

 the atmosphere and their impacts are 

 still described inadequately. The 

 losses of dry-cleaning fluids and 

 freon, though not necessarily the 

 most important emissions, are none- 

 theless illustrative of the types of 

 material flows that should be studied. 

 The evaporation of dry-cleaning sol- 

 vents must be of the same order of 

 magnitude as their production — sev- 

 eral hundred thousand tons per year. 

 The most widely used substance is 

 perchloroethylene. 



A similar amount of dichloro- 

 difluoro-methane (Freon-12) enters 

 the air following its use as a propel- 

 lant in the bombs containing shaving 

 cream, deodorants, paints, and so on. 

 Do such materials retain their iden- 

 tity before entering the oceans or 

 are they degraded as atmospheric 

 gases? The gas chromatograms of 

 liquid air condensates from the at- 

 mosphere contain many unidentified 

 peaks, perhaps volatile synthetic or- 

 ganic compounds. A systematic in- 

 vestigation of possible inputs, based 

 on production figures and field ob- 

 servations, would be most rewarding. 



Fuels — The greatest single source 

 of man-introduced materials to the 

 environment encompasses the prod- 

 ucts resulting from combustion of 

 the fossil fuels — coal, oil, and natural 

 gas. Since 1850, the amounts burned 

 have doubled about every fifteen to 

 twenty years. Carbon dioxide is the 

 principal gas released in such proc- 

 esses; its rate of increase at the pres- 



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