In-Reply-To: <C9E3F3C4-5E33-4718-81BE-4DB81683C9DE**At_Symbol_Here**uvm.edu>
Allan:
You raise an interesting point. However, it does need ela
boration. By focusing on the nasal epithelium and cancer you are implying c
oncern for nasal cancers occurring in humans as a result of low level expos
ures to formaldehyde.
In my opinion, there is limited epidemiological evi
dence for formaldehyde causing nasal cancer in humans. There is a large bod
y of evidence indicating formaldehyde is a nasal carcinogen in rats and mic
e exposed for several years to from 2 to 15 ppm formaldehyde for 35 hours p
er week. Much of that data was developed at what was then called the Chemic
al Industry Institute of Toxicology (CIIT). The CIIT team also developed an
extraordinarily large data base on the mechanisms of action of formaldehyd
e in rodents (persistent nasal injury, cell death, compensatory cell
proliferation, weak mutagenicity and tumor development, all threshold expos
ure-response phenomena) and associated modeling to aid in inter-speci
es extrapolation.
In recent years, concern has been raised, based on
epidemiological evidence, for formaldehyde causing leukemia. In my pro
fessional opinion, that evidence is very weak. Moreover, in my opinion, it
lacks biological plausibility because inhaled formaldehyde does not get to
the bone marrow and reach concentrations beyond those that are naturally pr
esent.
In the interest of full disclosure I served as the
President of CIIT from 1988 - 1999. I am proud of the numerous contribution
s my colleagues made to understanding the toxicity and carcinogenicity of f
ormaldehyde, all of which has been reported in the peer-reviewed literature
. Unfortunately, there are some individuals who would like to ignore that r
igorous science base and exaggerate the health effects of low level exposur
es to formaldehyde. I do think it is relevant to remind everyone that the h
uman body always contains formaldehyde-- a fact of life!!
I feel strongly that knowledge of how a speci
fic chemical has been classified as to carcinogenic hazard must always be c
omplemented with knowledge of exposure and the potency of the chemical for
causing cancer at those levels of exposure. I am dismayed that sometimes th
e carcinogen classification , ie, it is a human carcinogen or it is a likel
y human carcinogen, of a chemical is used to scare folks. A result is that
folks become numb from being told they live in a sea of carcinogenic chemic
als and start to ignore real hazards that exist in a sea of trivial hazards
.
Thanks for allowing me to elaborate on my ear
lier comment.
Roger
--
Roger O. McClellan, DVM, MMS, DSc(Honorary), D
ipl-ABT, Dipl-ABVT, Fellow-ATS
Advisor, Toxicology and Human Health Risk Analysis <
BR>13701 Quaking Aspen Place NE
Albuquerque, NM 87111
Tel: 505-296-
7083
Fax: 505-296-9573
E-mail: roger.o.mcclellan**At_Symbol_Here**att.net
-------------- Original message from List Moderator <ecgr
ants**At_Symbol_Here**UVM.EDU>: --------------
> From: "Allan Astrup Jense
n"
> Date: December 4, 2009 3:31:28 AM EST
> Su
bject: RE: [DCHAS-L] Paraformaldehyde - carcinogen or not?
> > Ju
st to refresh the memory of some folks, recall formaldehyde is present in t
he 1 carbon metabolic cycle so our bodies contain lots of formaldehyde. I u
nderstand that formaldehyde has been measured in exhaled breath at 1-2 ppb.
> The dose does make the poison!!
>
> OK, Roger, but
the internal exposures are not gaseous hitting mucous tissues of
> t
he nose!
>
> Yours truly,
> Allan Astrup Jensen
&g
t;
> Technical Vice President
> Secretariat for Quality Manag
ement and Metrology
>
> FORCE Technology, Br=C3=B8ndby
&g
t; Park All=C3=A9 345
> 2605 Br=C3=B8ndby
> Denmark
>
;
> Phone: +45 43 26 70 00
> Direct: +45 43 26 70 81
>
Mobile: +45 40 94 10 22
> Fax: +45 43 26 70 11
> e-mail: aaj
**At_Symbol_Here**force.dk
> www: www.forcetechnology.com
>
>
>
===
>
> From: "David Bunzow" <
BR>> Date: December 4, 2009 6:11:48 AM EST
> Subject: RE: [DCHAS-
L] Paraformaldehyde - carcinogen or not?
>
> =E2=80=A6which i
s why the Delaney clause never made good toxicological sense. We live,
> therefore we die.
> David
>
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