Transcript Fluorine Presentation

Created by:
Josh Sugay and Paige Parker
Symbol: F
Atomic Number: 9
Atomic Weight: 18.9984
Group Number: 17
Group Name: Halogen
Ground State Electron Configuration:
[He]2s22p5
Oxidation State: -1
•It is the most electronegative and
reactive of all elements.
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Due to its high electronegativity, it does not
naturally occur in the elemental state.
Instead it exists as the monovalent anion
fluoride F-.
It forms soluble compounds with monovalent
cations such as Na+ K+ and with multivalent
cations such as Ca2+, Mg2+, and Al2+.
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Fluoride is found
mainly in our teeth
and bone.
It can displace the OH
group on
hydroxyapatite
crystals forming
fluoroapatite which
hardens tooth enamel
and stabilizes bone
mineral.
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20-25% of fluoride is absorbed by the stomach.
◦In the stomach, it depends on the formation of
HF prior to its assimilation into the blood.
Conditions of higher gastric acidity promote
fluoride absorption from the stomach.
75-80% is absorbed by the small intestine.
◦Absorption from the small intestine is pHindependent. The majority of fluoride
absorption occurs in the small intestine via
passive diffusion quite possibly through
membrane channels.
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In the fasted state, fluoride in the form of
fluoridated water or sodium fluoride tablets,
the absorption is 100%.
However, when fluoride is found in food
sources, or taken with food, the absorption
varies from 50-80%.
Part of the reduction in fluoride absorption is
caused by insoluble complex formation with
cations in the alkaline small intestine, usually
Ca2+ or Mg2+.
Aluminum from certain antacids has also been
shown to form an insoluble complex.
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Dietary proteins contribute to high gastric
acidity thus increasing fluoride absorption.
Dietary fats stimulate fluoride absorption from
the stomach by delaying gastric emptying time.
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Absorbed fluoride enters the plasma where the
concentration under usual intake ranges from
10-20μg/L.
It is quickly taken from the plasma into tissue in
exchange with other anions (hydroxyl, citrate, and
carbonate ions)
95% of total body fluoride is found in bones and
teeth.
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90% of fluoride excretion occurs in the urine.
Only under heavy sweating is a considerable
amount lost in sweat.
Some have suggested a homeostatic
mechanism for fluoride by way of skeletal
uptake and urinary excretion in order to
prevent high amounts of fluoride in the
plasma.
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Fluoride can activate enzymes by way of Gproteins as in the activation of adenylate
cyclase and polyphosphoinositide
phosphodiesterase which are involved in
platelet activation
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C. BROM, J. BROM & W. KONIG. Immunology 1991:
73(3):287-292
“It may be possible that NaF acts on a regulatory factor
which enhances the exchange of GDP for GTP, as was
recently isolated and characterized for rasP21
proteins.”
“Therefore, we conclude that the addition of NaF
modulates the interaction between the thrombin
receptor and the G proteins. It was postulated that two
GTPases were stimulated by thrombin in membranes
of human platelets. However, it may be also possible
that different signal transduction pathways, including
different G-proteins, are involved in the cell activation
by NaF and thrombin.”
Life Stage
Age
Males (mg/day)
Females (mg/day)
Infants
0-6 months
0.01
0.01
Infants
7-12 months
0.5
0.5
Children
1-3 years
0.7
0.7
Children
4-8 years
1.0
1.0
Children
9-13 years
2.0
2.0
Adolescents
14-18 years
3.0
3.0
Adults
19 years and older
4.0
3.0
Pregnancy
all ages
-
3.0
Breastfeeding
all ages
-
3.0
Age Group
UL (mg/day)
Infants 0-6 months
0.7
Infants 7-12 months
0.9
Children 1-3 years
1.3
Children 4-8 years
2.2
Children 9-13 years
10.0
Adolescents 14-18 years
10.0
Adults 19 years and older
10.0
Food
Serving
Fluoride (mg)
Tea
100 ml (3.5 fluid ounces)
0.1-0.6
Grape juice
100 ml (3.5 fluid ounces)
0.02-0.28
Canned sardines (with
bones)
100 g (3.5 ounces)
0.2-0.4
Fish (without bones)
100 g (3.5 ounces)
0.01-0.17
Chicken
100g (3.5 ounces)
0.06-0.10
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Adding fluoride in the water.
Two main forms NaF and Hydrofluorosilicic
acid, which is a waste product in fertilizer
industries
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From 1901 to 1933, fluoride, already a naturally occurring
substance in water, was studied thoroughly, and it was
determined to be safe and to have the ability to protect teeth
enamel against decay, especially in children.
From 1933-1945 fluoridation was confirmed to be safe and efficient
in fighting against dental caries and decay. Set an effective range
of 0.7-1.2ppm.
Early 1960s fluoridation was occurring if 40 countries, protecting
300 million people.
For more than 50 years fluoridation has been responsible for
reducing cavities as much as 60% in children and 35% in adults.
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In 1989 the Centers of Disease Control and Prevention
has set a goal of 75% of the US population to have
fluoridation in communities by the year 2000. The
current level is 62.1%.
In 1999 the Centers of Disease Control and Prevention
put water fluoridation as one of the top 10 public
health achievements in the 20th century
Source: The Massachusetts Coalition for Oral Health
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Dental Fluorosis
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Kidney Damage
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Neural and Hormonal interferences
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White spots to brown/black stains
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Increased in porosity of enamel
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Endoplasmic Reticulum(ER) stress on
ameloblasts
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Terms:
ameloblasts – cells from which tooth enamel develops
amelogenin – protein responsible for forming the matrix in which
enamel is formed
Fluorosis – hypermineralization of enamel due to retention of
amelogenin proteins by F. Thus the enamel does not mature and
the surface and subsurface becomes porous. (Allen K, et al.)
A study by Kubota, et al. concluded that exposure to NaF induces
ER stress response to both enamel proteins and ameloblasts.
Ameloblasts are the most susceptible to high dosage exposure to
fluorine.
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32% of American Children now have some
form of dental fluorosis and 2%-4% have
moderate to severe fluorosis (CDC 2005).
Rate of bone fractures among children with
fluorosis is higher than bone fracture rate
among children with no fluorosis (AlarconHerrera MT, et al.)
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Kidney is 2nd in having the most concentration
of F in the body. Pineal gland has the most.
Kidneys of healthy adults excrete
approximately 50% of an ingested dose of F.
Individuals with kidney disease only excrete
10-20%. Thus, increasing susceptibility of F
poisoning (Johnson, et al)
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Study in China detected evidence of kidney
and liver disturbances in children drinking
water with as little as 2ppm of F.
210 children living in areas of 0.61-5.69ppm.
>2ppm were found to have high levels of Nacetyl-beta-D-glucosaminidase (NAG) and
gamma-GT in the urine which are indicators of
kidney damage. Also high levels of lactic
dehydrogenase in blood which is a marker for
liver damage (Lui JL, et al).
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Pineal gland contains the highest concentration
of fluoride in the body ~300ppm.
Responsible for regulation of melatonin. Study
in The Effect of Fluoride on the Physiology of the
Pineal Gland shows that animals treated with
fluoride have lower levels of circulating
melatonin. Lead to earlier onset of puberty.
Further investigations needed to apply to
humans.
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Hypothyroidism
Fluoride is used to treat hyperthyroidism with
doses as low as 2mg/day.
Cause fatigue, muscle pains, weight gain, hair
loss and increased LDL.
Secondary hyperparathyroidism (skeletal
fluorosis)
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"Up to now EPA, under the Safe Drinking Water Act,
has regulated fluoride in order to prevent children
from having teeth which looked like they had been
chewing brown shoe polish and rocks... EPA in
response to new studies, which only confirmed the old
studies, and some flat out political preasure, has
decided to raise the standard to 4 mg/L. This increase
will allow 40% of all children to have teeth gross
enough to gag a maggot."
-Paul Price, EPA Drinking Water Analyst, October 31,
1985
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Fluoridation in communities has made a huge
impact in helping with dental health, though it
needs to be monitored closely and revised to
prevent fluoride toxicity.