Evening star., 1959-06-29
Radiation Dosoqe

contributing writer. Lillian
Levy. in your June IL issue.
I win assume that the re-
porting is accurate. as the
Star Is usually extremely
careful.
The story stated that DR..
Visscher took sharp issue
with the recent raise In the
maximum permissible (radi-
alton dosel level recon-
mended by the U. s. National
Committee on Radiation
Protection and Measure
ments." The NCRP has not
recommended any increase
In permissible dose levels.
This is q misunderstanding
of the committees recent
recommendations, that un-
fortunately have been incor.
rectly reported in some news
paper articles. DR.. Visscher
may have used these for his
technical references rather
than the technical reports
themselves.
The NCRP and the Inter.
national Commission on Ra-
biological Protection have
worked Jointly in developing
the recent recommendations
on internal radiation dose.
Their numerical recommen-
dations are identical In every
respect. Both bodies have in
dicated that for the same
maximum permissible dose
that was recommended some
three years ago, 1t has been
found that the human body
can accept twice as much
Strontium-90 without ex-
ceeding the permissible dose
level.
The confusion arises, in
part, because maximum per-
missible body burdens and
maximum permissible con-
centrations Of radioactive
material In air and water
are not maximum permissible
doses. The maximum permis-
sible dose Is q measure Of the
radiation dose actually re-
ceived by the body. Maximum
permissible body burdens
and maximum permissible
concentrations refer to meas
ures of the amount of radio
active elements that can be
taken into the body without
causing the body to exceed its
maximum permissible dose.
These are values which can
be accepted over the adult
lifetime Of an individual
without causing him to ex-
coed his maximum permis-
sible dose. I would like to
emphasize again that there
has been no change in the
maximum permissible dose
since 1t was lowered three
years ago by both the U. s.
National Committee and the
international Commission.
DR.. Visscher also implied
that there may be some re-
lationship between the set
ting Of maximum permis-
Sible concentrations mot
maximum permissible dose)
and the Russian tests last
year. Actually. most Of the
values set in the recently re-
leased report by the National
Committee were arrived at
several years ago and there
was no relationship between
the timing Of the recent re-
lease and any other events,
other than the normal prob
lens of completing a report.
The full details Of this
problem are contained in the
report of the NCRP, entitled
Maximum Permissible Body
Burdens and Maximum Per-
missible Concentrations of
Radionuclides in Air and in
Water for Occupational Ex-
poSure." This report was is
sued on June 5, 1859. as Ma
tional Bureau Of Standards
Handbook SO.
I would like to compliment
The Star upon its very care
full and objective reporting
Of this very complicated
problem relative to permis-
sible dose levels. There has
been no evidence of attempt
ing to sensationalize some
thing that is basically not
sensational.
Lauriston s. Taylor,
Chairman, Nationa q !
Committee on Radia-
tton Protection and
Measurements.