Page 48 - Spring2018

Dental also called “silver” fillings, which are 50 percent exposure. 46

amalgam mercury. In fact, the first dental amalgam was After calomel was removed from use,
placed in 1830 in the U.S. Dental amalgams another source of mercury took its place. Thi-
in pregnant are still being used and are the filling of choice merosal (ethylmercury) was first used in vac-
mothers is for poorer children on the Medicaid program. cines in the 1930s and the amounts increased
the largest The American Dental Association continues to beginning in 1989, with a sharp rise in 1990 as
endorse amalgam fillings as “safe, affordable new vaccines were added to the schedule. This
source of and durable.” 47 increase closely coincided with a dramatic in-
mercury to Proposition 65, passed by the state of Cali- crease in autism spectrum disorder (now at one
in thirty-six children), a rise in attention deficit
the fetus and fornia in 1986, lists mercury as a reproductive disorder, and a steady rise in the prevalence of
toxin and a cause of birth defects. Thus, in
young infants. California products that use mercury and cause developmental disability. 9

significant mercury exposure must provide Before 1989, the maximal dose of thimero-
warnings to the public of the known health risk. sal by age two was 200 micrograms (mcg) but
Use of dental amalgam by dentists in California by the 1990s, it rose to 237.5 mcg. In the early
requires such a warning. Several other states 2000s, companies started to remove thimerosal
have passed similar laws requiring warnings from the vaccines. However, it is still present in
by dentists about the known health risks related the flu vaccine, which the CDC recommends to
to use of dental amalgam. Dental amalgam has pregnant women and children over six months of
been documented by tests at medical labs to be age. The dangers of thimerosal were dismissed
the largest source of mercury exposure for most by experts who claimed that ethylmercury is
people who have several amalgam fillings, with quickly removed from the body. Studies show
exposure levels as much as ten times the average that it quickly clears the blood but is not excreted
from the body. Instead it is deposited in organs
for those without amalgam fillings. 48 and tissues, including the brain.
Dental amalgam in pregnant mothers is Thimerosal is used as a preservative in
the largest source of mercury to the fetus and multi-dose vials of vaccine. If single-dose vials
young infants. It readily crosses the placenta were normally in use, it would not be necessary.
49
and also the blood-brain barrier. In order to In 1999 when two pharmaceutical companies
50
minimize the chances of autism, developmental offered to supply thimerosal-free vaccines, the
disability, lower IQ and physical defects, women CDC rejected this offer and allowed the vaccine
of reproductive age and those contemplating industry to sell its existing stocks which were
pregnancy would be well advised to have their not exhausted until 2003.
9
mercury amalgams removed by a dentist who is That mercury can affect fertility is well
trained in such procedures as soon as possible known since mercury was commonly used as a
before pregnancy occurs. spermicide in birth control products. Potential
51
In the late 1940s, when the mercury etiol- effects can be seen from effects on wildlife.
ogy of acrodynia was clarified, the possibility Some Florida panthers that eat birds and animals
of multiple sclerosis (MS) as an adult form of that eat fish, frogs and turtles containing very
acrodynia was also considered. No general low levels of mercury (about one part per mil-
and widespead source of mercury was then lion) have died from chronic mercury poisoning.
recognized. However, in 1966, Baasch, a Swiss Since mercury is an estrogenic chemical and a
neurologist, recognized the possibility of amal- reproductive toxin, the majority of the remain-
gam fillings being such a source. He concluded ing panthers cannot reproduce. The average
that a mercury amalgam etiology could explain male Florida panther has estrogen levels as high
the known facts about MS and that additional as females due to the estrogenic properties of
protective or aggravating factors in the environ- mercury. 52
ment could play a role. Lead was also considered
as a possible contributing factor because of its WHY IS MERCURY SO DEADLY?
widespread occurrence, known demyelinat- Mercury severely affects humans because
ing activity and some reports of MS after lead this heavy metal has diffuse and widespread

46 Wise Traditions SPRING 2018