monet Original Message----- .
From: Richard Wilson [mailto:wilson@huhepl.harvard.edu]
Sent: Sunday, November 25, 2001 11:48 AM

To: ocas@cdc.gov

Subject: irep

To CDC and NIOSH
Dear Sirs,

Ihave been looking at the procedure and calculation laid out in the
computer program:
http://216.82.51.38/irep_niosh/

This program is hard to find although it is easy to use.

NONE of the search engines seem to find it. | only found it by calling

Dr Owen Hoffman. | strongly urge making it clearly linked on the NIOSH
website, the NCI website, the SENES website and as many others as you
can think of. The public comment period mentioned in the Federal
Register documents of October 6th 2001 should be extended until at least
90 days after that is done.

| have made comments earlier in this procedure in the proper manner.
They were not acknowledged. I have no evidence that any one person has
ever looked at them. The lack of acknowledgement is common in
Federal,Agencies such as EPA, NIOSH, OSHA. This is a lamentable
failure and makes a mockery of the Freedom of Information act. Other
agencies, NRC, NASA, routinely issue a document listing all comments and
the agency comments thereon. I therefore make them again. My opinion
can of course be discounted as only one of many. But it seems not even
to have been included in an uncertainty analysis. The procedure is
seriously flawed in its selection and use of data and uncertainties. 1

detail the most egregious of these below.

(1) By only using a formula fitted to the Hiroshima/Nagasaki data from
RERF including an extrapolation (really an interpolation between the
lowest point and zero) to low doses that is linear without a theshold, a
huge assumption is made. | have urged that this assumption be
explicitly stated and the enormous uncertainties inherent in the use of
the asumption be included in the DEFAULT uncertainty model used in the
public version of the program. It is not.

(2). It is stated that using a linear-quadratic fit to the data

automatically takes account of a dose rate correction factor. This is
wrong. The two factors, low dose extrapolationa nd low dose rate for

the same dose are funadmentally distinct and should be separated. Doses
at Hiroshima and Nagasaki were almost instantaneous. Those of DOE and

1


other industry exposures were over a long period. There is no way the
former can mimic the latter without an assumtion which MUST BE and HAS
NOT BEEN carefuly articulated. Data from the Techa River accident and
from the Mayak occupational cohort suggest a dose rate reduction factor
of three FOR LEUKEMIA. No other direct data exist. These should be
accepted as a start and any uncertainty around that value. (For solid
cancers we have no direct data). Whoever chose the Dose rate reduction
factors was an extreme pessimist. | address this further below.

(3) Professional organisations who have studied this carefully argue
that we do not know what the effect is of a cumulative dose less than 20
Rems. (e.g official statement by the Health Physics Society} Some
scientists argue for low dose linearity, some for a threshold and
others for hormesis. The formulae should take this into account. They
do not.

(4) It seems that the procedure used is the procedure used, very
reasonably, by public health authorities for a cautious protection of
public health. In such a procedure one deliberately takes ALL
uncertainties and errs "on the safe side.” BUt these tables are NOT

for protection of public health. Whatever has happened has happened.
“What is done we never, never, can undo". These tables are explicitly
for compensation. Unless there is a SPECIFIC statement that the
compensation is to be done in a VERY generous way (some of the words
already propose compensation at a 0.01 % probability so it could be
argued that we need no more generosity), the low dose calculation should
be considered more carefully.

As an example try finding POC for some who developes a rare cancer (eg
leukemia) at a young age. (40) The model which is based on
Hiroshima/Nagasaki data with a linear no threshold extrapolation to
zero, gives a high figure for someone who has always kept his exposure
at the allowable radiation exposure limit.

POC for a reare cancer is an even higher figure for an exposure of 20
Rems, which is the number below which the Health physics Society say we
know nothing.

At the very least NIOSH should say loudly and in large bold letters, in

each and every document and webpage that these tables do not necessarily
represent the truth but a guess of some people that is appropriate for
whatever particlar action NIOSH is contemplating and may have no
relevance to any other action contempated by NIOSH or any other agency
or person

I would be happy to go over these arguments with you carefully on an
appropriate occasion.

Richard Wilson
Mallinckrodt Research Professor of Physics
Harvard University