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HW-80991
between Ringold and Richland are shown in Figure 9.
The seasonal varia-
tion is affected by the amount of ps2 released from the reactors, the feeding
habits and metabolism of the fish, and flow rate of the river which determines the effective dilution of the reactor effluent.
The concentration of p32
in whitefish starts to decrease late in the year and, due to cold water and
“limited feeding, continues to decrease until spring.
As the temperature of
the river water rises in the spring, the fish eat larger quantities of food
organisms that have accumulated p?? and this results in an increased deposition of p?? in the fish.
The trend is reversed in mid-spring by the high
flow rates of the Columbia which afford greater dilution of effluent and thus
lower concentrations of p? in the food organisms.
As the high flows recede
in early summer and water temperatures rise further, the p?? content in
fish again increases and reaches a maximum in late fall.
The average con-
centration of p% in whitefish sampled downstream from the reactors during
1963 was 420 pe/g of flesh, and the sample with the highest concentration
contained 2800 pc/g.
The annual average zn°° concentration in whitefish was
38 pce/g of flesh and the maximum was 120 pc/g in samples collected at
Ringold.
If whitefish were eaten at the rate of one meal per week (about 25 lb/
year), the intake in 1963 would have been approximately 4.8 uc of p? and
0.43 uc of zn®°,
The resulting exposure would have been about 100 mrems
to the GI tract, 40 mrems to the total body and 30% of the MPRI for bone.
In order to determine the consumption of locally caught fish more
accurately, a number of fishermen were asked to estimate the quantities and
kinds of fish they ate each year.
This survey was carried out by personnel
of the State of Washington, Department of Game.
The data obtained thus far
show that the individuals who probably ingest the largest amounts of p%2 a re
fishermen who claim to eat bass, crappie, perch, and catfish at a frequency
of 3 to 5 times a week.
This number of fish meals implies an annual con-
sumption of about 90 lb (in contrast with the 25 lb of whitefish used as a ref-
erence amount in the preceding paragraph) but the average p? content of the
species involved is lower than in the whitefish. An intake of 7 uc of P°“
during 1963 is estimated for an individual that claimed to eat some 200 meals
of fresh fish caught from the Burbank Area.