From: russ@wpg.com (Russell Lawrence)
Subject: Re: Mercury in dental fillings?
Organization: WP Group
Date: Sat, 15 Aug 1992 12:07:09 GMT


BEN PRICKRIL writes:
bp> -Preliminary studies in humans indicate that both fertility and 
bp> brain function may be altered due to exposure to dental amalgam 
bp> mercury.  
bp> ... [other alleged hazards deleted]

Russell Lawrence writes:
rl> Please post your references.  I'm intimately familiar with most of the
rl> anti-amalgam studies on the market, and without exception, every one of
rl> the anti-amalgam studies I've seen is seriously flawed.

bp> Mercury vapor release.
bp>   -Svare, C.W. et al. (1981) J. Dent. Res. 60, 1668-1671.

This study used a Jerome Gold Film Mercury Detector which was 
designed and calibrated to measure the mercury in a cubic meter 
of air...  not the volume of air in the human oral cavity.  This
led to readings that were off by several orders of magnitude.

In 1984, Svare amended his position:

   "I think it's not appropriate to use, perhaps, mouth level mercury
    levels diagnostically in terms of what the effect might be on a 
    particular individual... it has certain inherent errors in it
    because the exposure that you get from your amalgams can be rather
    continuous or it may be rather intermittent.  That is, a person
    may not generate these levels more than four or five minutes
    during the day".  Svare, Carl. "Dental Amalgam related mercury
    vapor exposure". _Workshop on Biocompatibility of Metals in Dentistry_,
    ADA/NIDR/NIH pp 320-321.  Cited in Dodes, John.  "Amalgam Toxicity" :
    A Review of the Literature.   Operative Dentistry. Winter, 1988. p 35

bp>   -Vimy, M.J., and Lorscheider, F.L. (1985) J. Dent. Res. 64, 1069-1071.

The abstract for this study states, "Measurements were made with a 
Jerome Hg Detector both before and ten minutes after chewing".  Again,
this particular device is incapable of accurately measuring mercury
levels in the oral cavity. (see above).

You'll find detailed criticism of the Jerome test method in Langan, Fan,
and Hoos.  "The Use of Mercury in Dentistry: a critical review of the
recent literature". JADA, Dec, 1987. 

bp>   -Patterson, J.E. et al. (1985) Bull. Environ. Contam. Toxicol. 34,
bp>    459-468.
bp>   -Gross, M.J. and Harrison, J.A. (1989) J. Appl. Electrochem. 19, 301-310
bp>
bp> Mercury absorption by body tissue.
bp>   -Vimy, M.J., and Lorscheider, F.L. (1990) J. Trace Elem. Exper. Med.
bp>    3, 111-123.
bp> 
bp>   -World Health Organization (1991) Environmental Health Criteria 118,
bp>    Inorganic Mercury. p. 36, WHO, Geneva.
bp>   -Clarkson, T.W. et al. (1988) In: Biological Monitoring of Toxic Metals
bp>    (Clarkson, T.W. and others, eds.) pp.199-246.
bp>   -ibid., pp.247-260.
bp>   -Nylander, M., et al. (1987) Swed. Dent. J. 11, 179-187.
bp>   -Aposhian et al. (1992) FASEB J. 6, 2472-2476.
bp> 
bp> Effect of dental amalgum on fertility and organ function.
bp> 
bp>   -Society of Toxicology Annual Meeting (1992) Symposium: Toxicity
bp>    assessment of mercury vapor from dental amalgams. The Toxicologist
bp>    12, 6-7.
bp> 
bp> Ben Prickril, Univ. of Georgia (404)542-3486
bp> prickril@bscf.uga.edu  

Hmm.  You've caught me off guard with most of these.  I'll have to do some
more research. :-)   I vaguely recall reading a Vimy paper that was
published around 1990, possibly dealing with the same study as the
paper mentioned above.  The one that comes to mind was widely criticized
in dental circles because of the small number of subjects used in the
study.

Both the Dodes and Langan papers explain why mercury amalgams present
little or no threat vis-a-vis elemental and mythl mercury.  

-- 
Russell Lawrence, WP Group, New Orleans (504) 443-5000
russ@wpg.com   uunet!wpg!russ