[ RadSafe ] Please Critique This Reply by Rosalie Bertell

Wed Feb 21 14:56:51 CST 2007

Dr. Bertell,

Schlein et al. are referring to ICRP 1954 (1988).  However, ICRP
Publication 54, pg. 7 states that the model being referred to is the one
described in ICRP Publication 30 (1979).  ICRP Publication 30 used the
model published in 1966 by the ICRP's Task Group on Lung Dynamics
(TGLD).  According to ICRP Publication 66 (1994, pg. 4), the publication
of the 1966 model stimulated extensive research on the deposition,
retention, clearance, and translocation of inhaled aerosols to other
tissues in the body of experimental animals and humans.  The model was
found wanting in many cases, one case being that research on deposition
of inhaled aerosols had extended the particle size range beyond that of
the 1966 model.  Therefore, in 1984, the ICRP created a special Task
Group to propose either revisions to the 1966 model or propose a new
model.  The Task Group opted to improve the ICRP 30 model, and so you
get the ICRP 66 model which can now handle aerosol particles in the
submicrometer range (thanks to 25 or so years of research).

The 1984 decision to revise/update the model had nothing to do with the
1991 Gulf War.

J.L. Anderson
NIOSH

-----Original Message-----
From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] On
Behalf Of Rosalie Bertell
Sent: Wednesday, February 21, 2007 11:57 AM
To: m.schouwenburg at tudelft.nl; 'Roger Helbig'
Cc: 'radsafelist'
Subject: RE: [ RadSafe ] Please Critique This Reply by Rosalie Bertell

Dear Mr. Marcel Schouwenburg,

Thank you for this reference. My source was the Handbook of Health
Physics and Radiological Health, Third Edition, Edited by Bernard
Schleien, Lester A. Slaback, Jr. and Brian Kent Birky, Lippincott
Williams and Wilkins, Philadelphia,1998.  on page 12-13, it is stated:

"The model is intended for use with aerosol with AMADs between 0.2 and
10 micron and with geometric standard deviation less than 4.5.
Provisional estimates of deposition further extending the size range are
given in the dashed lines of Figure12.3. ... The model does not apply to
aerosols with AMADs less than 01. micron. (Courtesy ICRP from
Publication  54, 1987)".

Could you please explain why ICRP 66 (1994) changed this limit. This
should have been promulgated by 1998. My understanding is that when
particles are of AMADs less than 0.1 micron they behave like a gas. They
freely enter through the cell walls, the lung-blood barrier, the blood
brain barrier and cross the placenta. The other major problem is that
are too small for the kidney filter. Was this decision made after the
first Gulf War for some reason?

Dr. Rosalie Bertell

-----Original Message-----
From: Marcel Schouwenburg [mailto:m.schouwenburg at tudelft.nl]
Sent: Wednesday, February 21, 2007 6:12 AM
To: Roger Helbig
Cc: radsafelist; Rosalie Bertell
Subject: Re: [ RadSafe ] Please Critique This Reply by Rosalie Bertell

Daer Mrs/Ms Bertelli,

The ICRP Respiratory Tract Model can be apllied to particles with a
diameter < 0.1 micron. For this purpose the model describes a.o.
fractional deposition in various compartments of the respiratory tract
for particles down to a an Activity Median Thermodynamic Diameter, AMTD
(to be used in stead of the AMAD because of the small particle size) of
0.001 micron. So, the model can also be used for particles in a DU
aerosol with a size between
0.001 micron and 0.1 micron. 

Reference
ICRP-66 (1994), Human Respiratory Tract Model for Radiological
Protection.
ICRP-Publication 66, Annals of the ICRP 24(1-3), Elsevier Science LTD,
Oxford, pp. 49-54.

With kind regards,

Marcel Schouwenburg
Head / Lecturer Training Centre Delft, Health Physicist, expert level 2
RadSafe Moderator & Listowner National Centre for Radiation Protection
(Dutch abbr. NCSV)

Delft University of Technology
Faculty of Applied Sciences / Reactor Institute Delft Mekelweg 15 NL -
2629 JB  DELFT The Netherlands
T: +31 (0)15 27 86575
F: +31 (0)15 27 81717
M: +31 (0)6 419 83 145
E: m.schouwenburg at tudelft.nl <mailto:m.schouwenburg at iri.tudelft.nl> 

Roger Helbig wrote: 

----- Original Message -----
From: "Rosalie Bertell"  <mailto:rosaliebertell at greynun.org>
<rosaliebertell at greynun.org>
To: "'Roger Helbig'"  <mailto:rhelbig at california.com>
<rhelbig at california.com>
Sent: Tuesday, February 20, 2007 8:45 AM
Subject: RE: Nichols Publish the Truth??????

Dear Roger,

My guess is that you are sending the estimates by the physicists who use
the ICRP Respiratory Model methodology. This is only valid down to
particles of aerodynamic diameter of
0.1 micro. DU aerosol has been shown to coalesce into particles of
aerodynamic diameter between 0.001 and 0.1 micron (nano particles).
Therefore they miss some of the most serious effects.

Dr. Rosalie Bertell.

_______________________________________________
You are currently subscribed to the RadSafe mailing list

Before posting a message to RadSafe be sure to have read and understood
the RadSafe rules. These can be found at:
http://radlab.nl/radsafe/radsaferules.html

For information on how to subscribe or unsubscribe and other settings
visit:
http://radlab.nl/radsafe/

_______________________________________________
You are currently subscribed to the RadSafe mailing list

Before posting a message to RadSafe be sure to have read and understood
the RadSafe rules. These can be found at:
http://radlab.nl/radsafe/radsaferules.html

For information on how to subscribe or unsubscribe and other settings
visit: http://radlab.nl/radsafe/