Transcript COMMUNITY WATER FLUORIDATION - Tennesse Department Of Health

A Tennessee Perspective
on Community Water
Fluoridation
David E. Brumley, DDS, MPH
South Central Region
November 16, 2006
Community Water Fluoridation
Centers for Disease Control and Prevention
Community water fluoridation is one of
ten great public health achievements
of the 20th century.
MMWR April 2, 1999, Vol. 48 (12)
Community Water Fluoridation
What is water fluoridation?
• Small amounts of fluoride are present naturally in
all water sources.
• Water fluoridation is the precise adjustment of
the natural fluoride concentration in a public
water supply up to the level recommended for
preventing tooth decay.
• The USPHS has established the optimal
concentration for fluoride in water supplies in a
range of 0.7 to 1.2 parts per million.
Historical Perspective
• At the turn of the 20th century, Dr. Fredrick S. McKay
moved from Philadelphia to Colorado Springs, Colorado
and opened a dental practice.
• He noticed that many of his patients exhibited a peculiar
condition referred to along the Continental Divide as
‘Colorado Brown Stain.’
• In 1908, he initiated a study and found that this
condition was prevalent among long-term residents who
were born in the area. It was also endemic to other
communities along the Continental Divide.
• Dr. McKay and Dr. G.V. Black wrote the first detailed
clinical description of mottled enamel which is now
termed fluorosis.
Historical Perspective
• In 1928, Dr. McKay discovered the agent in the drinking water
that caused mottled enamel also inhibited dental caries.
• In 1931, Dr. McKay sent samples of this water to an Alcoa
chemist named H.V. Churchill who identified the causative agent
as fluoride.
• In the 1930s, Dr. McKay and Dr. H. Trendley Dean of the
USPHS collaborated to explore the possibility of adjusting the
level of fluoride in drinking water to reduce dental caries.
• In the 1940s, four classic studies were begun which proved the
benefits of adding fluoride to community water supplies.
 Grand Rapids, MI – Muskegon, MI
 Newburgh, NY – Kingston, NY
 Evanston, IL – Oak Park, IL
 Brantford, Ontario – Sarnia, Ontario
When Fluoridation is Discontinued
City or
Town
Initiated
Fluoridation
Discontinued Number of
Fluoridation Years without
Fluoridation
Antigo,
Wisconsin
1949
1960
5.5
Wick,
Scotland
1971
1979
5.0
Percent
Increase in
Caries Rates
70%-200%
Primary 40%
Permanent 27%
Galesburg,
Illinois
Naturally Fl
water source
1959
switched to
non-Fl
water source
2.0
38%
Bristol
Crossville
Cookeville
Cleveland
Chattanooga
Cowan
Lawrenceburg
Nashville
Paris
Milan, Tennessee
• In March 1951, Milan became the first city in Tennessee
and the second city in the Southeast to adjust the level
of fluoride in its community water supply for the
prevention of dental caries.
• As a result, five years later in 1956, the six-year-old
Milan children had a 57 percent reduction in dental
caries in their permanent teeth compared to the 1951
same-age cohort.
• In addition, when compared to their counterparts in
Humboldt and Trenton – two neighboring nonfluoridated
cities – the 1956 Milan six-year-olds had a 62 percent
and 70 percent reduction in dental caries, respectively.
Systemic Effect of Drinking Fluoridated Water
• 97 percent of tooth enamel is composed of hydroxyapatite.
• When fluoridated water is ingested, the fluoride ion (F-)
readily replaces the hydroxyl ion (OH-) during enamel
formation of the tooth.
• Hydroxyapatite Ca5(PO4)5OH then becomes a compound
called fluorapatite Ca5(PO4)3F.
• Fluorapatite at the enamel surface is less soluble and more
resistant to acids produced by cariogenic bacteria.
Community Water Systems
>50 water treatment chemicals used for:
•
•
•
•
•
•
•
Disinfection
Absorption
Dechlorination
Algae control
Oxidation
Metal coagulation
Water softening
•
•
•
•
•
•
•
Filtration
pH control
Iron control
Coagulation
Corrosion control
Decolorization
Fluoridation
Water Fluoridation Chemicals
• Sodium Fluoride (NaF)
–
–
–
–
Crystalline powder
Relatively constant (low) solubility
pH 7.6
Saturator Systems
• Sodium Fluorosilicate (Na2SiF6)
–
–
–
–
Crystalline powder
Solubility varies with water temperature
pH 3.5
Dry-feed Systems
• Fluorosilicic Acid (H2SiF6)
–
–
–
–
Liquid
Infinite solubility
pH 1.2
Venturi Systems
Community Water Fluoridation
Is it safe?
• Acute fatal poisoning (CLD) in adults requires the
ingestion of 2.5 - 5.0 grams of fluoride in a 2 - 4 hour
time frame.
• In drinking fluoridated water at 1.0 ppm, an adult would
have to drink 660 gallons in 2 - 4 hours to reach the
lower limit of a fatal dose.
• A 10kg child (12 - 18 months of age) would have to drink
85 gallons of fluoridated water (1.0 ppm) in 2 - 4 hours to
reach the lower limit of a fatal dose.
Community Water Fluoridation
What are the costs?
$0.50 per person
Average annual cost of water fluoridation in the U.S.
Systems serving 2,000 or less =
$0.77 - $1.16 per person per year
Systems serving 2,000 - 20,000 =
$0.21 - $0.95 per person per year
Systems serving  100,000 =
$0.12 - $0.21 per person per year
In most communities, every $1 invested in fluoridation saves
$38 to $80 in dental treatment costs.
Community Water Fluoridation
Status
Healthy People 2010 Goal
75%
States Currently Meeting Goal = 24
States range from:
2.3% (Utah) to 100% (Kentucky, Rhode Island, South
Dakota, & the District of Columbia)
CDC Fluoridation Status, 2002
Community Water Fluoridation
Status
• 10 states, Puerto Rico, and the District of Columbia
mandate statewide fluoridation through legislation.
– California, Connecticut, Delaware, Georgia, Illinois,
Minnesota, Nebraska, Nevada, Ohio, South Dakota
• Kentucky mandates statewide fluoridation through
administrative regulation.
• Tennessee has a voluntary process with an emphasis
on education rather than legislative mandate.
Community Water Fluoridation
Status
Tennessee
United States
(2005)
(2002)
Percentage of total
population receiving
fluoridated water
89.7%
60.5%
Percentage of
population on public
water system receiving
fluoridated water
96.0%
67.3%
Healthy People 2010 Goal
75.0%
Public Water System
Source: http://apps.nccd.cdc.gov/gisdoh/waterfluor.aspx
Total Population
Source: http://apps.nccd.cdc.gov/gisdoh/waterfluor.aspx
Number of water systems starting fluoridation, by year, Tennessee, 1950-2005
16
14
Number of Water Systems
12
10
8
6
4
2
0
1950
1955
1960
1965
1970
1975
1980
1985
1990
1995
2000
2005
Tennessee’s
Water Systems
532
Approved Systems
214
Fluoridating Systems
118
Consecutive Systems
332
Fluoridated Systems
Tennessee’s 50-Year Fluoridated Cities
Milan
Cookeville
Nashville
Kingsport
Brownsville
Cowan
Murfreesboro
Linden
Cleveland
Lawrenceburg Woodbury
Lebanon
Germantown
Crossville
Lewisburg
Ripley
Bristol
Union City
Springfield
Hartsville
Chattanooga
Oak Ridge
Shelbyville
Paris
Winchester
Dresden
Tennessee’s Largest
Non-Fluoridating Systems
System
County
Population
South Blount
Lincoln County #1
Poplar Grove
Ocoee
Blount
Lincoln
Tipton
Bradley
30,725
16,643
16,043
13,313
Pleasant View
Watts Bar
First Utility District
Cheatham
Rhea
Tipton
11,846
9,001
8,479
County Wide
First Utility District
Mount Pleasant
Crockett
Carter
Maury
8,258
6,951
6,220
1996-97 East
Tennessee Dental
Health Survey
15 ETR counties
62 communities
65 schools
17,256 children
http://apps.nccd.cdc.gov/MWF/Index.asp
http://www.ada.org/public/topics/fluoride/facts/