| Comment Record |
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Commentor |
Mr. Bernard Windham |
Date/Time |
2001-01-16 13:18:36 |
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Organization |
Mr. Bernard Windham |
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Category |
Individual |
| Comments for FDA General |
| Questions |
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1. General Comments
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Dental Amalgam Fillings is the Number One Source of Mercury in People and Exposure Exceeds Government Health Standards for Inorganic mercury(vapor)
Bernard Windham- Chemical Engineer
Government agencies and medical studies have found that the number one source of mercury in people is from dental amalgam fillings(ref 2-20). Exposure from fillings amounts to from 50 to 90 percent of exposure, with the average being about 80 % of total exposure(5-9,12-15,19,20). The studies found that mercury amalgams are unstable due to mercury's low vapor pressure and galvanic action, leaking mercury vapor continuously into the lungs and saliva at levels exceeding health standards.
Mercury exposure of most people with fillings was found to exceed government health standards and levels found to cause adverse health effects(see below).
The tolerable daily exposure level for mercury developed in a report for Health Canada is .014 micrograms/kilogram body weight(ug/kg) or approximately 1 ug/day for average adult(2). The U.S. EPA Health Standard for elemental mercury exposure(vapor) is 0.3 micrograms per cubic meter of air(1). The U.S. ATSDR health standard(MRL) for mercury vapor is 0.2 ug/ M3 of air, and the MRL for methyl mercury is 0.3 ug/kg body weight/day(4). For the average adult breathing 20 M3 of air per day, this amounts to an exposure of 4 or 6 ug/day for the 2 elemental mercury standards. The EPA health guideline for methyl mercury is 0.1 ug/kg body weight per day or 7 ug for the average adult(1).
The range of mercury exposure levels found in people with amalgam fillings by
the World Health Organization Scientific Panel on Mercury was 3 to 70 micrograms per day(3), with other medical studies finding up to 500 ug/day in gum chewers or people who grind their teeth(6,11,16,17,18) or some with large numbers of fillings. The average amount absorbed was above 10 ug/day (ref. 3-18). The average mercury exposure for a Canadian adult with amalgam fillings was found in the Health Canada study to be 9 ug/day(2). In a large German study with 20,000 tested subjects at a University Medical Clinic, the average exposure from fillings was over 10 ug/day and over 50 % of all those with 6 or more amalgam fillings had daily exposure exceeding the EPA health guideline(6).
Studies have consistently found modern high copper non gamma-two amalgams have greater release of mercury vapor than conventional silver amalgams (21,22,23). Recent studies have concluded that because of the high mercury release levels of modern amalgams, mercury poisoning from amalgam fillings is widespread throughout the population(17,22,18,6).
Common levels found in persons with amalgam fillings are over 10 times the Health Canada TDE, and more than the EPA health standard for mercury vapor. Thus persons with amalgam fillings have levels of intraoral mercury vapor and body exposure levels higher than the level considered to have significant health risk.
The studies found that Total mercury intake is proportional to the number and extent of amalgam surfaces, but other factors such as chewing gum and drinking hot liquids influence the intake significantly increasing exposure as much as 500%. ).
A World Health Organzation Scientific Panel concluded that a safe level of mercury exposure below which no adverse effects occur has never been established(3)
References
(1) U.S. Environmental Protection Agency(EPA), 1996, Integrated Risk Information System, National Center for Invironmental Assessment,Cincinnati, Ohio(& web).
(2) Mark Richardson, Environmental Health Directorate,Health Canada, Assessment of Mercury Exposure and Risks from Dental Amalgam, 1995, Final Report.
(3) World Health Organization(WHO),1991, Environmental Health criteria 118, Inorganic Mercury, WHO, Geneva;
(4)Agency for Toxic Substances and Disease Registry, U.S. Public Health Service, Toxicological Profile for MercuryMarch, 1999; & Apr 19,1999 Media Advisory, New MRLs for toxic substances, MRL:elemental mercury vapor/inhalation/chronic & MRL: methyl mercury/ oral/acute; & http://atsdr1.atsdr.cdc.gov:8080/97list.html.
(5) A.Kingman et al, National Institute of Dental Research, Mercury concentrations in urine and blood associated with amalgam exposure in the U.S. military population, Dent Res, 1998, 77(3):461-71.
(6) Dr. P.Kraub & M.Deyhle, Universitat Tubingen- Institut fur Organische Chemie, Field Study on the Mercury Content of Saliva, 1997 (20,000 people tested for mercury level in saliva and health status/symptoms compiled) http://www.uni-tuebingen.de/KRAUSS/amalgam.html;
(7) A. Engqvist et al, Speciation of mercury excreted in feces from individuals with amalgam fillings, Arch Environ Health, 1998, 53(3):205-13; & Dept. of Toxicology & Chemistry, Stockholm Univ., National Institute for Working Life, 1998. (www.niwl.se/ah/1998-02.html)
(8) J.A.Weiner et al,The relationship between mercury concentration in human organs and predictor variables,138(1-3):101-115,1993; & An estimation of the uptake of mercury from amalgam fillings, Sci Total Environmet,v168,n3,1995.
(9) M.J.Vimy and F.L. Lorscheider, Faculty of Medicine, Univ. Of Calgary, July 1991. (Study findings) & J. Trace Elem. Exper. Med., 1990,3, 111-123.
(10) B.Arnold, Eigenschaften und Einsatzgebiete des Chelatbildners:DMPS,Z. Umweltmedizin, 1997,5(1):38-; & Diagnostik un Monitorung von Schwermetallbelastungen,I,II,ZWR, 1996,105(10):586-569 & (11):665-
(11) L.Barregard et al, People with high mercury uptake from their own dental amalgam fillings, Occup Envir Med, 1995, 52:124-128.
(12) L.Bjorkman et al, Mercury in saliva and feces after removal of amalgam fillings, Toxicol Appl Pharmacol 1997, 144(1): 156-162.
(13) Berglund A, Molin M, Mercury levels in plasma and urine after removal of all amalgam restorations: the effect of using rubber dams, Dent Mater 1997 Sep;13(5):297-304;
& M.Molin et al, kinetics of mercury in blood and urine after mercury removal
J Dent Research, 1995, 74:420-
(14) Zander, D; Ewers U, Freier I, Brockhaus A, Studies on Human Exposure to Mercury. III: DMPS Induced Mobilization of Mercury in Subjects With and Without Amalgam Fillings. Zentrablatt Fur Hygiene und Umweltmedizin, 192:5, Feb 1992, p447-54
(15) J.Begerow et al, Long Term Mercury Excretion in Urine after Removal of Amalgam Fillings, Int Arch Occup Health 66: 209-212.
(16) G.Sallsten et al, long term use of chewing gum and mercury exposure from dental amalgam, J Dental Research, 1996, 75(1):594-598.
(17) I.Skare, Mass Balance and Systemic Uptake of Mercury Released from Dental Fillings, Water, Air, and Soil Pollution, 80(1-4):59-67, 1995.
(18) B.Windham, Anotated Bibliography of Exposure and Health Effects from
Amalgam Fillings, 2000(over 600 references & 60,000 clinical replacement cases).
(19) Halbach, 1995,Estimation of mercury dose .., Int.Archieves of Occupational
& Environmental Health, 67:295-300; & G. Sandborgh-Englund, Pharmacokinetics of mercury from dental amalgam, Gotab(Stockholm), 1998, 1-49.
(20) H.V.Aposhian, Envir.Health Perspectives, Vol 106,Supp 4, Aug, 1998; &
H.V. Aposhian et al, FASEB J, 6: 2472-2476, 1992.
(21) J Pleva, Mercury- A Public Health Hazard, Reviews on Environmental Health, 1994, 10:1-27.
(22) C. Toomvali, Studies of mercury vapor emission from different dental amalgam alloys, LIU-IFM-Kemi-EX 150,1988; & A.Berglund,A study of the release of mercury vapor from different types of amalgam alloys, J Dent Res, 1993, 72: 939-946; & D.B.Boyer, Mercury vaporization from corroded dental amalgam Dental Materials, 1988, 4:89-93; & V.Psarras et al, Mercury vapour releases from dental amalgams, Swed Dent J,1994, 18:15-23; & L.E.Moberg, Long term corrosion studies of amalgams and Casting alloys in contact, Acta Odontal Scand 1985, 43:163-177;
(23) H. Lichtenberg, Mercury vapor in the oral cavity in relation to the number of amalgam fillings and chronic mercury poisoning, Journal of Orthomolecular Medicine, 1996, 11:2, 87-94.
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