UL
LIC
NaAllVUildt
ACHAeEMY
OT
sclence’s
Effects of Ionizing Radiation
for the purpose.
LOommittee
(BEIR III Report)
on
the
b1010g1Cal
has been selected
Selection of any of the earlier documents would make rather little
difference in the magnitude of the genetic effects estimates.
From Table IV-2 of the 1979 BEIR III Report, we get an estimate
of from 5-75 genetic effects in the first generation per rem per
million live births.
This range may be appropriately scaled for
dose or for population size by simple proportionality.
Specific Genetic Risk Estimates
The population dose estimates described allow calculation of an
average 30 year population dose for the entire population of
the atoll.
The 180 people assumed to go back to Enjebi constitute
about 40% of the total weighting the Enjebi/Northern Islands and
the Southern Islands/Northern Islands dose estimates accordingly,
we get ((5.6x0.4)+(0.23x0.6))=2.38 average individual dose
integrated over 30 years, or 79 mrem per year (notably, well below
the FRC guide for the general population average).
The dose
proportional adjustment factor
is then 2.38/,,
and the range of
risk from BEIR III is (2.38x5) to (2.38x7S5), or 11.9 to 178.5 per
million live births.
AS a minimum estimate, we assumed the present population might
just replace itself in 30 years; i.e., 453 births.
The risk, then,
would be
(11.9
to 178.5)x453/1,000,000 = 0.0054
to 0.081
additional
cases.
Assuming a 10.7% spontaneous risk, we would expect 48.5
cases to occur naturally during the same period.
Thus the upper
bound risk in this case is that the normally expected 48.50
cases arising during the next 30 years might conceivably increase
to as much as 48.56, an increment of less than two tenths of one
percent.
‘
Assumption of the higher number of 1000 births in the next 30 years
simply increases the absolute numbers proportionately:
The risk
becomes (11.9 to 178.5)x1,000/1,000,000 = 0.012 to 0.18 additional
cases in 30 years, against a spontaneous total of 107 cases.
To provide an upper limit to credible risk of genetic ill health
we might consider a child born to a couple born on Enjebi eight
years after the return, they would receive as much as 4.9 rem in
30 years, and the risk to a child born to them at age 30 would be
a