circulation during the summer months and therefore might accumulate 
larger quantities of contaminant than other coastal areas. 
A theoretical study of the dilution of contaminant by turbulent 
mixing processes has been made. The results of the study provide the 
means of evaluating the effects of changing environmental parameters 
and of various disposal methods on the dilution of a contaminant. Be- 
cause of the assumptions made all estimates of concentration at a given 
distance and time are probably higher by at least a factor of ten than 
would actually exist in practice. Even with these conservative assump- 
tions calculations show that given a rate of disposal of 100 curies per 
year of uncontained waste into water 30 meters deep with a current of 
5 miles per day, the maximum concentration of waste which will appear 
one kilometer (approximately 5/8 miles) from the disposal site will be 
2 x 1077 uc/ml, a concentration that is lower than the maximum permis- 
sible concentration of Sr 90 in drinking water. Sr 90 has the lowest 
MPC value of all radioisotopes listed. In addition, the relationships 
between both relative concentration and time after release and distance 
from the disposal site, under the unlikely condition that no current will 
aid in diffusive mixing, have been developed. 
In arriving at recommended disposal rates the interaction of a 
contaminant with suspended solids and bottom sediments has been neg- 
lected. It was found impossible to make a quantitative estimate of the 
magnitude of this reaction. Neglecting this factor puts a certain factor 
of safety in the recommendations, as sorption onto bottom sediments 
within the disposal area will provide additional containment, thus allow- 
ing for further destruction of the contaminant by radioactive decay. In 
the case of disposal into areas productive in commercially important 
shellfish (oysters, clams, etc.) the sorption onto bottom deposits may 
become a potential hazard rather than a safety factor. This situation 
has been eliminated by selecting areas in which no shell fisheries occur. 
The return of radioactive wastes to man by ingestion of contam- 
inated marine food products is considered to be the most likely poten- 
tial source of hazard that could result from disposal into coastal waters. 
An estimate has been made of the maximum permissible concentration 
of each of several radioisotopes in sea water, below which contamina- 
tion of marine food products will not lead to greater than allowable in- 
take by humans whose sole source of protein is fish. This estimate 
was derived from the maximum permissible concentration of the iso- 
topes in drinking water, from which was computed the maximum 
weekly intake of each of the isotopes; the weekly ingestion rate of fish, 
taken as 1.5 kg, a value that is high compared with the per capita value 
for this country but has been taken on the assumption that some indi- 
viduals obtain all of their protein from fish; and the extent to which 
marine organisms can concentrate the various isotopes within them- 
selves above the level in their environment. The most hazardous iso- 
tope in the list is Sr 90, for which the maximum permissible concen- 
tration in sea water is 8 x 10-7 uc/ml, which by coincidence is identical 
with the MPC value for drinking water. 
