Ill. SPECIFIC MARINE POLLUTANTS 
Man’s activities have generated a number of pollutants in the 
marine environment. Among the specific pollutants are chlorinated 
hydrocarbons, heavy metals, municipal wastes, solid materials, carbon 
dioxide, petroleum, radioactivity, and thermal discharges. 
Major Characteristics of Pollutants 
In order to assess the potential of a pollutant to damage a marine 
ecosystem, several factors must be determined: quantity, toxicity, 
persistence, and mobility. A pollutant must be present in sufficient 
quantity to have a deleterious effect. Toxicity determines the critical 
quantity or concentration of a pollutant necessary to produce detvi- 
mental effects. Persistence allows concentrations to build up over a 
period of time until critical levels are reached. Mobility is important 
as a product released on land will remain there if it is not very mobile. 
Volatility is also an aspect of mobility since the atmosphere is an 
important medium through which some pollutants enter the ocean. 
Major Classes of Pollutants 
Nearly any substance can become a marine pollutant if its use is 
not controlled. However, it is not the intent of this study to list every 
possible contaminant but to consider only those of major or potentiaily 
major significance. These are the pollutants that must be considered 
in formulating a policy of ocean resource utilization. These pollutants, 
in the absence of a policy or other controls, will ultimately determine 
the extent to which the ocean’s resources can be developed. To sup- 
plement the following discussion a table of harmful substances found 
in the oceans is included in Appendix I. 
Chlorinated hydrocarbons.—There are two major types of chlorinated 
hydrocarbons found in marine ecosystems. The most widespread is 
p,p’-DDE which is a derivative of the insecticide p,p’-DDT. DDE 
has very low toxicity to insects, vertebrates, and almost all other 
forms of life, and has never been used as a biocide. It is, however, a 
persistent (non-degradable) compound and has been found in oceans 
and rainwater throughout the world. Though the toxicity of DDE is 
low it poses other problems as are discussed later. 
PCB compounds (polychlorinated biphenyls) are also widespread 
marine pollutants. These compounds are industrial products and are 
not used as pesticides. There is recent evidence that PCB compounds 
may also result from the breakdown of DDT.! PCB is extensively 
used by industry in manufacturing various paints, plastics, adhesives, 
coating compounds, electrical equipment, and many other products.” 
The usefulness of the chlorinated biphenyl compounds derives fror 
their chemical stability which also ensures that they will persist Tee 
after the manufactured products disintegrate 
1 Moilanen, K. W. and D. G. Crosby. in a An Unrecognized Source of Polychlorinated Biphenyl 
(Maugh, T. H. Tl). Science, v. 180, 1973: 578-579 
se een Company. Technical Bulletins O/PL-311A, O/PL-306, and O-FF/1: Monsanto Companys 
ous. 
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