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HW-80991
The reported consumption of 200 meals of local fish per year is used
as a basis for calculating the maximum intake of radionuclides from this
source.
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This same individual is also assumed to consume each day over -
2 qts of water from the Pasco system, and about 1 qt of milk, 1/2 lb of beef,
and nearly 1/2 lb of fresh leafy vegetables (in season), all produced onirrigated farms of the Riverview District.
The composite exposure from these
sources is illustrated in Figures 21, 22, 23, and 24.
They amount to about
15% of the appropriate limit for the GI tract, 50% of the limit for the bone,
1% of the limit for the thyroid, and 25% of the limit for the total body.
The
estimated exposure to the total body includes an increment of 50 mr received
from the river bank while catching the fish.
It also includes a contribution
from ingested sr?9 that is unrealistically high (20 mrems) in relation to
1 year's intake, because it assumes an accumulation of sr? in the body that
would only be gained over several decades.
The maximum thyroid dose is postulated to have occurred in a small
child, rather than an adult, because of the relatively small mass ( 2 g versus
20 g for an adult) in which the ingested yi31 accumulates.
On the basis of a
daily intake of 1 liter of milk from a farm of the Riverview District, 0.8 liter
of water from the Pasco system, and 50 g of fresh leafy vegetables, the intake
131
of I
for the year is estimated at about 6700 pc which would deliver a dose
of about 115 mrems—about 7.5% of Radiation Protection Guide for individuals.
B.
The Average Tri-City Resident
The vast majority of people who live in Richland, Pasco, and Kennewick
obtain their food from local stores (rather than directly from farms) and do
not eat fish caught from the Columbia River.
The principal sources of radio-
nuclides to these people are world-wide fallout (present to some extent in nearly
all foodstuffs throughout the country) and drinking water pumped from the
Columbia River.
Thecontribution from fallout is almost entirely associated with grO
and pst and is assumed to be the samefor all three cities.
The gr? intake
is estimated from dietary surveys made elsewhere in the United States and
reported by the Federal Radiation Council) but adjusted on the basis of the $r90