Date, On Exposures
The work of Henriques* suggests that at the depth of U.Uu9 mm in
iiving porcine skin (maximm thickness of epidermis) that “l4uu_/3uu
roentgen-equivalent—beta" (delivered over short periods of time so that
they may be assumed to be instantaneous) is required to produce recognizable transepidermal injury.
The curve of biological damage rises
go on to develop chronic radiation dermatitis persisting for months,
The preceding discussion suggests that, using the gamma dose rates
listed in these criteria, which are based on an estimated 10 roentgen
infinity gamma dose, as high as 2,000 reps might be delivered to the
‘basal layer of the epidermis over a period of time covered by the
lifetime of the radioactive material.
There have been instances where the calculated infinity gamma dose
in areas where personnel were present around the Nevada Test Site have
reached 12-15 roentzgens but there have been no Imown cases of beta
burns in these areas.
The number of persons involved in these areas cf
highest contamination was relatively small, perhaps a few dozen, and with
an observed duration of fallout of about one hour it is possible that
they were not in a positicn to receive the full fallout.
Likewise,
minute areas of the skin may have been so affected yet not detected or
reported.
In other areas encompassing some 2,000 people the infinity
gamma dose was about eight roentgens and no instances of beta injury
appeared.
*Op,. cits
re
the epidermis may be expected to exfoliate and in the majority of cases
=
rather sharply so that at a dose of just under 2000 rep (at 0.09 m),