10 
By feeding on infected animals, a transmittance to man may again 
occur. The nematode, Anisakis, for instance, which may be ingested 
from poorly cooked herrings causes tumorous-like growths in the 
stomach and intestines of man. In Holland several persons were 
recently reported to have become seriously ill and many died from 
the attack of this parasite.” 
In most communities, an inseparable part of municipal waste is 
derived from industrial activity. Such wastes may contain heavy 
metals which may build up to toxic levels in the food chain. Polluted 
runoff from streets may also be added to the municipal waste. Clearly, 
control of municipal waste is a necessary step to enhance and preserve 
the ocean resource. 
Solid materials—In addition to municipal sludge, a number of 
solid materials are carried into the oceans. These range from harmful 
microscopic particles carried by rivers to barge loads of dredge spoil 
and construction wastes dumped directly into the oceans. The U.S. 
has recently passed legislation to limit the dumping of solid wastes 
into the oceans, but the effects of previous dumping and the materials 
carried by river systems still remain a problem. 
Spoil from channel dredging accounts for most of the solid material 
disposed of in the sea. This can pose a pollution problem by disturbing 
the equilibrium of the water-sediment interface, allowing new chem- 
ical reactions to occur. For example, when reduced (oxygen-deficient) 
sediments are dredged, sulfides may be released, causing the oxygen 
level in nearby waters to drop, thereby endangering marine life. 
Among the smaller particles that are now being found polluting the 
open ocean are bits of plastic, as well as small balls of polystyrene, 
the crumbly plastic foam widely used for packing, drinking cups, 
and insulating material. These bits of indigestible plastic have been 
found in ten species of larval, juvenile, and adult fish. It has been sug- 
gested that ingestion of plastic particles could cause intestinal block- 
age and mortality, but to date evidence in support of this hypothesis 
is lacking. Plastics, predominantly polyethylene, have also been found 
floating in the Sargasso Sea in concentrations of about 300 grams/ 
square kilometer.” 
Microscopic asbestos fibers are another contaminant which may 
cause cancer. Asbestos is widely used in the food and beverage in- 
dustry as a filter for soft drinks, beer, liquor, and edible oils and is 
used by some municipalities for filtration of water supplies. Once the 
increasing amounts of asbestos fibers have reached the oceans they 
are less of a direct hazard to man. Very little is known about the pos- 
sible effects of asbestos fibers on marine life. The quantities reaching 
the oceans are probably insignificant at this time except possibly in 
local areas where asbestos is extensively used or processed. An ex- 
ample of local contamination, although in fresh water, is Lake Superior 
where asbestos resulting from the processing of taconite (a low grade 
iron ore) has recently been detected. This resulted in a statement from 
the Environmental Protection Agency on June 15, 1973, advising 
residents of Duluth, Minnesota, and other north shore towns that 
‘Drudence ‘dictates that an alternative source of drinking water be 
14 Foyn, E. Municipal wastes. In Impingement of Man on the Oceans (Hood, D. W. ed.). New York, 
Wiley-Interscience, 1971: 457. 
18 Carpenter, E. J. and K. L. Smith. Plastics on the Sargasso Sea surface. Science, v. 175, 1972: 1240-1241. 
