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Public Water Fluoridation
Substances
MCL's/MCLG's
revisited
"The difficult
problem is to determine what is the greatest good
and whether the several goods are compatible or whether
one will destroy the others.” Wallace Stegner
Although
hydrofluorosilicic acid is NSF certified, the product
doesn't comply with ANSI/NSF standard 60 general requirement
3.2.1.
Fluorine should not
be confused with fluoride, although in the early fluoridation
literature the words were used interchangeably. Fluorine
is an element. Fluoride denotes that fluorine has
combined with other elements and formed a compound,
e.g. hydrofluosilicic acid (H2SiF6) sodium silicofluoride
(NaSiF6) sodium fluoride (NaF) and calcium fluoride
(CaF2).
Hydrofluorosilicic acid (H2SiF6)
is one of the most commonly chosen chemical used to
fluoridate public water supplies.
Some of the contaminants reported
as present in fluorine bearing substances hydrofluosilicic
acid and other silicofluorides used in fluoridation
programs include arsenic, barium, beryllium,
cadmium, chromium, crystalline silica, fluorine, hydrogen
fluoride, iron, iodine, lead, lead 210, mercury, phosphorous,
polonium 210, radon 222, selenium, silica and silver.
Some specific agents used or present in phosphate/hydrofluorosilicic
acid processing include oil based de foamers, dioxins,
polymers, petroleum products, naphthalene, chlorides,
sulfides and synspar.
"Traditionally,fluorspar
has been considered to be vital to the Nation's national
security and economy. It is used directly or indirectly
to manufacture such products as aluminum, gasoline.
insulating foams, refrigerants, steel, and uranium
fuel. Hydrofluoric acid (HF) was consumed in the manufacture
of uranium tetrafluoride, which was used in the process
of concentrating uranium isatope 235 for use as nuclear
fuel and in fission explosives. It also was used in
stainless steel pickling, petroleum alkylation, glass
etching, treatment of oil and glass wells and as a
feedstock in the manufacture of a group of inorganic
fluorine chemicals that include chlorine trifluoride,
lithium fluoride, sodium fluoride, sulfur hexafluoride,
tungstun hexafluoride and others used in diaelectrics,
metallurgy, wood preservatives, herbacides, mouthwashes,
decay-preventing dentrifices and water fluoridation."
A
Congressional investigation also revealed the following:
* EPA confirmed that
the two compounds used almost exclusively in the U.S.
for fluoridation have never, ever been studied for
their effect on health or behavior.
* NSF International, the
private organization certifying fluoridation chemicals,
confirmed that it is doing so in violation of its
own standard requiring manufacturers to submit any
available published and unpublished toxicological
studies on both the fluoride compound and any contaminants
contained in the product. NSF disclosed in the investigation
that they have no such studies on file
see
Doe vs Rumsfeld
Fluorine
should not be confused with fluoride, although in
the early fluoridation literature the words were used
interchangeably. Fluorine is an element. Fluoride
denotes that fluorine has combined with another element
and formed a compound, e.g. sodium fluoride (NaF)
and calcium fluoride (CaF2).
Hydrofluorosilicic
acid (H2SiF6) is
one of the most commonly chosen chemical used to fluoridate
Utah's public water supplies.
The Very Best of 101
Fluoride Questions SLVHD
Is there a difference
between natural fluoride and the fluoride used in
"artificial fluoridation"?
No. There is
no such thing as artificial fluoride. Fluoride is
found in a natural mineral form and cannot be artificially
created. The appropriate term "adjusted"
fluoridation more accurately describes the process.
In the fluoridation process, natural fluoride from
the environment is used to adjust the existing natural
level of fluoride to the recommended level of 1 ppm
for preventing tooth decay.
Is fluoride a fertilizer?
No. Fluoride is not a fertilizer.
Fluoride is a mineral that is obtained from rocks
and minerals in the environment. Phosphate, which
is a fertilizer, is often found in the same rocks
and minerals as fluoride. During the phosphate fertilizer
manufacturing process, fluoride is collected separately
from the phosphate.
because
fluorosilicic acid is a byproduct of the phosphate
fertilizer industry and is not manufactured for itself
alone..
As "Process water"
cannot be discharged into the environment, it is often
recycled back into the wet scrubbers. Wet scrubbers
are installed in the phosphate fertilizer stacks in
an effort to prevent toxic gases from releasing into
the atmosphere. Fluoridation chemicals are a waste
product from the wet scrubbers. Process water is radioactive
The CDC's
ATSDR ToxFAQ's outlines the toxicity.
Both the Davis
County Health Department and the Salt Lake Valley
Health Department have claimed fluoride
is not a fertilizer. Fluoride is a mineral that is
obtained from rocks and minerals in the environment.
Although that is true so is it true that the
fluoridating chemical used in most public water supplies
is an industrial waste by product.
Although the Utah Health Department
suggests otherwise, The CDC
concedes fluoridation chemicals are by-products
of the phosphate fertilizer industry. The CDC states
that most of the available literature on fluoride
toxicity concerns sodium fluoride. That is not the
chemical used in our public water supplies. The Epa
called for research referring to fluoridation chemicals
as regulated contaminants.
A Salt Lake area lab made a sample
analysis of the fluosilicic acid used in both Davis
and Salt Lake Counties. Among other contaminants,
arsenic and lead is present.
Fluorine
recovery in the fertilizer industry - a review.
by H.F.J. Denzinger, H.J. Konig and G.E.W.
Kruger outlines the process for the recovery.
The AWWA is the organization
that recommends the level of fluoride that can be
added to public water supplies. An AWWA
Standards Committee on Fluorides is listed. Their
relationships are outlined and the EPA's response
to a long standing problem is stated.
Aren't all fluoridation chemicals
the same? Are public water fluoridation chemicals
the same fluoridation
chemicals that are found in toothpaste or prescribed
by the dentist? The CDC
(Center for Disease Control) refers to specific fluorine
chemicals. The CDC's affiliate group, the
ATSDR (Agency for Toxic Substances and Disease
Registry) says something slightly different.
The
FDA, the organization that regulates medicines
and additives, has never approved industrial-grade
fluoridation chemicals for human consumption. It has
not been listed as an essential nutrient. In response
to a congressional hearing asking if they had approved
or rejected fluoridation drugs meant for injestion,
the FDA replied no.
What about an overfeed
of the fluoridation chemical? How much is too much?
Below
is a basic chemistry lesson.
Fluorine ( F2)
Fluorine (F2) is an extremely reactive,
poisonous and corrosive gas. It reacts with every
other element except two noble gases (helium and neon).
It even reacts with asbestos. Except for some emissions
from volcanoes, fluorine gas does not occur freely
in nature.
Hydrogen fluoride (HF).
When dry, hydrogen fluoride is a
gas. It is a common pollutant produced in many industries,
particularly metallurgical processes like iron, zinc
and aluminum smelting. It is also produced when coal
is burned, or when many natural materials containing
fluoride (such as clays and rocks) are subjected to
high temperatures. For example it is released in both
the brick and ceramic industries. Like fluorine, hydrogen
fluoride is also very reactive and even attacks glass,
which is a definite telltale sign of hydrogen fluoride
pollution. In solution it forms the acid hydrofluoric
acid. This acid is extremely toxic. When it comes
in contact with human flesh it quickly eats through
the flesh and the bone. Once the hydrogen fluoride
gets into the bloodstream it usually proves fatal,
because, when it reaches the heart muscle it interferes
with the calcium levels there resulting in heart failure.
Sodium fluoride (NaF).
Sodium fluoride is a white crystalline
solid. It is not very reactive chemically, but it
is highly toxic. About a teaspoonful will kill an
adult. It readily dissolves in water and when it does
the positive sodium ions (Na+) and the negative fluoride
ions (F-) go their separate ways. To all intents and
purposes a solution of sodium fluoride can be treated
as two separate solutions - a solution of sodium ions
(which have distinct properties) and a solution of
fluoride ions (which have distinct properties). This
explains why people talk of "fluoride" without
mentioning its partner ion. In other words when water
is fluoridated with sodium fluoride, there is little
concern about the addition of the sodium ion to the
water, it is the fluoride ion which confers the properties
being sought by promoters, or those we wish to avoid
as opponents. This also explains why it is when scientists
list the ions in water they list the positive ions
and negative ions separately. They do not partner
up until the water is evaporated.
Organofluorine compounds.
Today the chemical industry is making
more and more organofluorine compounds which are used
as solvents, propellants, refrigerants, (e.g the CFCs
or chlorinated fluorcarbons), plastics (e.g. teflon),
pharmaceuticals (e.g. prozac) and pesticides. The
problem with these organofluorine compounds along
with their organochlorine cousins, is that they produce
very dangerous byproducts when burned, are fat soluble,
are highly persistent in the environment, resist detoxification
in our bodies, frequently interfere with hormonal
signals, accumulate in our fat and are transferred
to the fetus during pregnancy.
So just like the organochlorine
compounds, which were often exploited for their "apparent"
non-toxicity and their persistence, it is their very
persistence which is coming back to haunt us as well
as their more subtle toxicity.
In this connection, of particular
concern are the perfluorinated octanyl compounds or
PFOs e.g. PFOA (perfluorinated octanoic acid). These
substances comprise a chain of 8 carbons completely
saturated with fluorine at all positions (this is
what the prefix "per" means) except the
terminal group. These substances are being found throughout
the environment and in human tissues throughout the
world (See a recent discussion of this topic entitled
"Fluorine Persists" by Stephen Ritter in
C &EN, June 14, 2004). The PFOs are thought to
be strong endocrine disrupters (i.e. they interfere
with various hormonal signals in both animals and
humans). One example is perfluorinated octanyl sulfonate
(PFOS) which was manufactured by 3M corporation (skotchguard)
but which it voluntarily ceased manufacturing in May,
2000.
The fluorine atom is very small
and so when pharmaceutical companies develop a therapeutically
active molecule (i.e. a drug) they will often put
fluorine into the molecule in place of an hydrogen
atom and usually at a place where the molecule is
normally metabolized because the C-F bond is much
more stable to enzymatic attack than a C-H bond. They
do this in order to increase the time the body takes
to metabolize the drug and thus enable the prescription
of smaller doses. This is where we get into a highly
contentious issue among those opposed to fluoridation.
Some have assumed that the fluorine present in these
drugs (such as prozac) represent another source of
fluoride in our daily lives. However, this would only
be the case if the drug is actually metabolized at
the C-F bond. However, for most pharmaceuticals, this
is unlikely. Other sites in the molecule are more
likely to be attacked and the excreted water soluble
metabolites are thus likely to still contain the fluorine
atom covalently attached to the molecule. However,
this is not always the case as has been demonstrated
for some of the fluorinated anesthetics and propellants.
To resolve the issue for drugs like prozac we need
to have confirmation from the drug companies (and/or
the FDA) that based upon mass balance studies all
the fluorine can be accounted for in the excreted
water soluble metabolites for the drug in question.
Sulfuryl fluoride (SO2F2)
In the case of sulfuryl fluoride
the fluorine atoms are covalently attached to the
sulfur atom. The S-F fluorine bond is far less stable
than the carbon-fluorine bond. In fact, it is rapidly
attacked by water producing hydrogen fluoride. Sulfuryl
fluoride has been used as a fumigant against insects
which attack wooden structures. Presumably, the hydrogen
fluoride released kills the insects. Recently, DOW
Agrochemicals has sort permission from the US EPA
to use sulfuryl fluoride as a fumigant on foodstuffs.
The concern on this issue is twofold. Firstly, direct
exposure to applicators, warehouse workers and local
residents to sulfuryl fluoride which is extremely
toxic. Secondly, is the concern about the increased
exposure to inorganic fluoride, particularly children,
that a further increase of fluoride residues on the
foodstuffs that this practice would cause. On January
23, 2004, the US EPA granted DOW permission to use
sulfuryl fluoride as a fumigant on food along with
increased fluoride tolerance levels on about 40 foodstuffs.
This decision is currently being appealed by the Fluoride
Action Network and the group Beyond Pesticides.
Hexafluorosilicic acid or
hydrofluorosilicic acid or H2SiF6.
This substance is usually generated
in the wet scubbing sytems of the phosphate fertilizer
industry and shipped as a 23% solution to communities
fluoridating their water. However, when it is diluted
( approximately 180,000 gallons to one) at the public
water works the substance is attacked by the water
and yields fluoride ion. To what extent this process
goes to completion by the time the water reaches the
consumer is under debate. Urnansky and Schock (2000)
argue based upion theoretical assumptions that the
process will be complete and that there will be no
fluoride left aattached to silicon. Masters and Coplan
argue based upon a Ph.D thesis from Germany (Westendorf,
1974) that at neutral pH two fluoride atoms are still
attached to the silicon and moreover the hexafluorosilicate
ion is more active biologically than the free fluoride
ion. Masters and Coplan (1999, 2000) have also found
an association between blood levels in children in
both Massachusetts (1999) and New York (2000) and
the use of the silicon fluorides (H2SiF6 and Na2SiF6)
as fluoridating agents but not sodium fluoride. Thus,
they have argued that it is some silcon fluoride complex
which facilitates the uptake of lead (from other environmental
sources) into children's blood and not the free fluoride
ion itself.
There are approximately 100 elements
which make up all the matter in our world and the
rest of the universe. However, there are millions
of different substances which we call compounds. These
are all built up from combinations of the 100 elements.
Fluorine is one of those elements. The difference
between different elements is they have different
atoms. These atoms are all made of three fundamental
particles called protons, neutrons and electrons which
are held together by positive and negative charges.
The only thing we need to know about charges is that
like charges repel and unlike charges attract.
The protons are positively charged,
the neutrons have no charge and the electrons are
negatively charged (the magnitude of the charge on
the electron is equal to the charge on the proton
-but opposite in sign). The protons and neutrons are
located in the center of the atom (called the nucleus)
and a simplified view of the structure of the atom
is to consider the electrons rotating around the nucleus
like planets around the sun. Instead of gravity we
have the electrostatic attraction of the combined
positive charge of the protons in the nucleus holding
onto the negatively charged electrons circulating
around.
The key player in chemical matters
is the electron. In chemistry nothing ever happens
to the nucleus. At no time in a chemical reaction
do we change the number of protons or neutrons in
the nucleus. Changes which occur in the nucleus are
covered in a separate branch of science called nuclear
physics. In chemical reactions atoms change partners
by rearranging their electrons. This can happen in
two different ways: 1) electrons either move from
one atom (or group of atoms) to another (as in ionic
bonding and oxidation reactions) or 2) share themselves
(in pairs) between atoms (covalent bonding).
The constancy of the nucleus, despite
changes with the electrons, allows us to uniquely
define each atom. Thus the number of protons (the
atomic number) in the nucleus defines each atom and
hence each element, since all the atoms of the same
element have the same number of protons. This numbering
game is remarkably simple and systematic. Here we
will ignore the number of neutrons present, since
they only add mass to the atom and do not change the
chemistry in anyway.
The first element, hydrogen, (atomic
number 1) has one proton and one electron in its (isolated)
atom. The second element, helium, (atomic number 2)
has two protons and two electrons, and the third,
lithium (atomic number 3) has 3 protons and 3 electrons
and so on all the way up to uranium (atomic number
92) which has 92 protons and 92 electrons. Now, it
couldn't get much more simple than that, could it?
If you can count up to 92 you now know all the building
blocks of our universe (apart from man made elements).
Fluorine has an atomic number of
nine. Thus it has nine protons in its nucleus and
nine electrons circulating around. Again, I have ignored
the neutrons, which only serve to add mass to the
atom.
The elements can be divided into
two major groups: metals and non-metals. The difference
between these two groups lies in the properties of
their atoms and these properties are determined by
the activity of their electrons. Metal atoms have
a tendency to lose electrons and non-metals a tendency
to gain electrons. This represents a huge divide in
chemistry.
An atom which has lost electrons
is called a positive ion. Thus metal atoms form positive
ions (or cations). The number of positive charges
it has will depend upon the number of electrons it
loses, thus for sodium we have the Na+ ion (meaning
that the sodium atom has lost one electron) and for
calcium we have the ion Ca2+ (meaning that the calcium
atom has lost two electrons) and for aluminum we have
the ion Al3+ (meaning that the aluminum atom has lost
three electrons) and so on.
Metal atoms form positive ions when
their atoms combine with non-metals atoms.
Non-metals have atoms which want
to gain electrons. They can gain electrons in two
ways. Some non metals can combine with metals and
form negative ions (or anions). This is called ionic
bonding (the transfer of electrons from metal atoms
to non-metal atoms). Only a few non-metals can do
this, but ALL of them can gain electrons in another
way, and that is by sharing electrons with another
non-metal atom. This sharing of electrons between
non-metal atoms is called covalent bonding. The result
of covalent bonding is the formation of molecules,
i.e. groups of atoms held together by covalent bonds.
To be precise a covalent bond is formed when two atoms
share two electrons, one electron coming from each
atom. A covalent bond is represented in chemical textbooks
as a single line between two atomic symbols (e.g.
H-H). Each covalent bond represents a gain of one
electron to each atom. They gain by sharing, thus
non-metal atoms are more sensible than many people!
Groups of atoms held together by covalent bonds are
called molecules.
Those with access to a chemistry
text might wish to take a look at the Periodic Table
which usually can be found on the inside of the cover.
You will note that the metals (about 80 of the100
elements are metals) appear on the left hand side
of the table and the non-metals on the right. You
will also note that elements appear in order of their
atomic numbers in rows and columns. The number of
the vertical column gives valuable clues as to the
number of electrons involved in both ion formation
and the number of covalent bonds formed when non-metal
atoms combine.
Ionic compounds and covalent compounds
(ions and molecules) represent another huge divide
in chemistry. Most of "inorganic chemistry"
is dominated by the behavior of various ions, whereas
most of "organic chemistry" (the chemistry
of carbon) is dominated by the behavior of various
molecules.
When we talk about the "reactivity"
of elements we are referring to the readiness with
which they seek to lose or gain electrons. The more
reactive ones want to gain or lose electrons more
than the less reactive ones.
The fluorine atom is the most reactive
of all the non-metal atoms. It wants to gain one electron.
When fluorine combines with metals, it forms ionic
compounds which contain the negatively charged ion
F-. When it combines with atoms of non-metals (including
itself) it forms molecules with fluorine forming one
covalent bond per atom.
When a fluorine atom reacts with
a sodium atom ( a reactive metal) it forms an "ion
pair" called sodium fluoride (NaF). Actually
it doesn't stop as a pair but forms a whole latticework
(an ionic lattice) with each fluoride ion surrounded
by six sodium ions and each sodium ion surrounded
by six fluoride ions in a three dimensional array.
The end result is a crystal whose shape reflects this
regular internal arrangement: this three dimensional
array of alternating positive and negative ions. This
explains why it is that all ionic compounds are high
melting point solids. It takes a lot of energy to
separate the ions from the lattice, unless the substance
is dissolved in water in which case the ions are separated
rather easily (see NaF below).
As already indicated, fluorine can
also gain one electron by combining with another non-metal
atom. The simplest example is the fluorine molecule
itself (F2) which consists of two fluorine atoms connected
with one covalent bond (i.e. F-F). Another example
is the molecule hydrogen fluoride (HF) which consists
of one hydrogen atom combined with one fluorine atom
with one covalent bond (H-F). Yet another example
is Silicon tetrafluoride (SiF4) which consists of
one silicon atom attached to four fluorine atoms with
silicon forming four single covalent bonds. The number
of covalent bonds formed depends upon the number of
electrons the atom desires and this in turn is dependent
upon its position in the Periodic Table. Both carbon
and silicon are in group IV of the periodic table
and want to form four covalent bonds. Thus carbon
forms a similar molecule to silicon tetrafluoride
called carbon tetrafluoride CF4.
The compounds containing carbon
are called organic compounds and compounds containing
carbon covalently bonded to fluorine are called organofluorine
compounds.
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