From the international Amalgam Mailing list :


IV.  Health Effects from Dental Personnel Exposure to Mercury Vapor

1. Dentists and dental personnel who work with amalgam are chronically
exposed to mercuryvapor.
(1,6-12,32,34,36,72,122,123,124,171,172,173,240,249]
Studies note that carpeting in dental offices should be avoided as it is a
major repository of mercury[188].  
Mercury levels in urine of dental personnel average about 2 times that of
controls(123,124,171,249) and was 43 nmol/liter for a population surveyed in
Sweden(171), which is above the Swedish occupational exposure guideline.

2. Drilling old amalgam fillings with only a saliva extractor and no other
precautions produces mercury vapor levels 2 to 15 times occupational
threshold limit values(30 micrograms/cubic meter)[120,219].

3. The average dental office exposure affects the body mercury level
approximately the same as having 19 amalgam fillings[123,124,173].
Dentists were found to score significantly worse than a comparable control
group on neurobevaioral tests of motor speed, visual scanning, visuomotor
coordination, concentration, verbal memory, visual memory, and visuomotor
coordination speed(249). 

4. Both dental hygienists and patients get high doses of mercury vapor when
dental hygienists polish or use ultrasonic scalers on amalgam surfaces(240).
Pregnant women or pregnant hygienist especially should avoid these
practices during pregnancy or while nursing since maternal mercury exposure
has been shown to affect the fetus and to be related to birth defects, SIDS,
etc. (38,61) and breast milk contains up to 6 times higher mercury than in
the mother's blood(20). 

5. Body burden increases with time and older dentists have median mercury
urine levels about 4 times those of controls, as well as higher brain and
body burdens(13,34, 70-74,122]. Some older dentists have mercury levels
in some parts of the brain as much as 80 times higher than normal
levels(14,34).  

6. Dentists and dental personnel experience significantly higher levels of
neurological, memory, musculoskeletal, mood, and behavioral problems, which
increase with years of exposure(13,34,49, 69-74,88,122,188,246,247,248,249].

7. Female dental technicians who work with amalgam have significantly
reduced fertility and lowered probability of conception(3,24,38, 121], and
their children have significantly lower average IQ compared to the general
population(13). The level of mercury excreted in urine is
significantly higher for female dental assistants than
dentists(171,172,173,247). Several dental assistants have been diagnosed
with mercury toxicity and some have died of related health
effects(245,246,247,248).

8. Many homes of dentists have been found to have high levels of mercury
contamination used by dentists bringing it home on shoes and clothes[187].

9. Some studies have found increased risk of lung, kidney, brain, and CNS
system cancers among dental workers(14,34, 143].

10. Autopsies of former dental staff found levels of mercury in the
pituitary gland averaged over 10 times that of controls(99), as well as
higher levels in the occipital cortex and renal cortex and thyroid.

                            References
1. Sandra Denton MD; Proceedings of the First International Conference on   
Biocompatibility, 1988
3. Gordon - Pregnancy in Female Dentists- a Mercury Hazard. Proceedings of  
Intl conference on Mercury Hazards in Dental Practice Sept. 2-4 Glasgow
1981
6 Schulein,T.M.; Reinhardt, J.W. and Chan K.C. Survey of  Des Moines area   
dental offices for Mercury vapour. Iowa  Dent. J. 70(1):35-36 1984

7 JonesDW, Sutton EJ, and Milner EL Survey of Mercury vapour in dental
offices in Atlantic Canada.Can. Dent.  Assoc. J. 4906:378-395, 1983
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