Allan Astrup Jensen

Technical Vice President
Secretariat for Quality Management and Metrology

FORCE Technology, Br=F8ndby
Park All=E9 345
2605 Br=F8ndby
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

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From: DCHAS-L Discussion List [mailto:DCHAS-L**At_Symbol_Here**list.uvm.edu] On Behalf Of roger.o.mcclellan**At_Symbol_Here**ATT.NET
Sent: 4. december 2009 18:05
To: DCHAS-L**At_Symbol_Here**LIST.UVM.EDU
Subject: Re: [DCHAS-L] 2 RE: [DCHAS-L] Paraformaldehyde - carcinogen or not?
Importance: High

Allan:

   You raise an interesting point. However, it does need elaboration. By focusing on the nasal epithelium and cancer you are implying concern for nasal cancers occurring in humans as a result of low level exposures to formaldehyde.

    In my opinion, there is limited epidemiological evidence for formaldehyde causing nasal cancer in humans. There is a large body of evidence indicating formaldehyde is a nasal carcinogen in rats and mice exposed for several years to from 2 to 15 ppm formaldehyde for 35 hours per week. Much of that data was developed at what was then called the Chemical Industry Institute of Toxicology (CIIT). The CIIT team also developed an extraordinarily large data base on the mechanisms of action of formaldehyde in rodents (persistent nasal  injury, cell death, compensatory cell proliferation, weak mutagenicity and tumor development, all threshold exposure-response phenomena) and associated  modeling to aid in inter-species extrapolation.

    In recent years, concern has been raised, based on epidemiological evidence, for formaldehyde causing leukemia. In my professional 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 present.

    In the interest of full disclosure I served as the President of CIIT from 1988 - 1999. I am proud of the numerous contributions my colleagues made to understanding the toxicity and carcinogenicity of formaldehyde, all of which has been reported in the peer-reviewed literature. Unfortunately, there are some individuals who would like to ignore that rigorous science base and exaggerate the health effects of low level exposures to formaldehyde. I do think it is relevant to remind everyone that the human body always contains formaldehyde-- a fact of life!!

     I feel strongly that knowledge of how a specific chemical has been classified as to carcinogenic hazard must always be complemented with knowledge of exposure and the potency of the chemical for causing cancer at those levels of exposure. I am dismayed that sometimes the carcinogen classification , ie, it is a human carcinogen or it is a likely 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 chemicals and start to ignore real hazards that exist in a sea of trivial hazards.

     Thanks for allowing me to elaborate on my earlier comment.

          Roger

--
Roger O. McClellan, DVM, MMS, DSc(Honorary), Dipl-ABT, Dipl-ABVT, Fellow-ATS

Advisor, Toxicology and Human Health Risk Analysis
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