1. Abstract
According to the Salt Lake Valley Health Department1 the optimal level of
fluoride is 0.7 to 1.2 ppm in drinking water. In 2003 the State of Utah
started adding fluoride to tap water1. At present the state has about 50% of
the population receiving fluoride treated water with the aim of reaching the
1 ppm fluoride level2. It has also been reported that some counties are
considering cutting back to about 0.7 ppm2.The acidity of many foods and
drinks leads to tooth decay. This study examined the pH and fluoride
content of domestic water in Utah as well as areas in Nevada and
California. Fluoride levels ranged from <0.05 – 0.94 ppm. The pH values
for these samples ranged from 6.26-8.16. The fluoride levels and pH in
bottled water and other drinks were also studied because many people in
Utah do not drink tap water, particularly in regions of high water hardness
or areas where taste and / or odor can be off-putting. The pH values ranged
from 2 to 8, the most acidic being colas, energy and citrus-based drinks.
Fluoride values varied from <0.02 to1.34 ppm. Five loose leaf tea samples
were also analyzed and found to be in the range 0.26-1.03 ppm. . Instant
Coffees showed fluoride ranges from < 0.1 and 0.34 ppm.
Introduction
Fluoride is universally recognized to help build stronger tooth enamel, stop
or reverse the tooth decay process and prevent loss of important minerals.
Tooth enamel is primarily fluorapatite. This mineral is developed prior to
teeth breaking through the gums and continues be replenished by dietary
fluoride throughout the lifetime of the teeth3. The Fluoride Ion-Selective
Electrode couples with Total Ionic Strength Adjustments Buffers (TISAB
II) has been used to measure fluoride in water samples since 1968,
providing a versatile tool for chemical speciation studies of fluoride4.
Dentists have concerns about the acidity of many drinks consumed in most
people’s diets and one asked this team to investigate drinks as part of this
study 5. Flow Injection Analysis (FIA) mode was employed via a Chemflow
FIP-3 flowcell, which enabled up to 120 injections per hour. This study
shows data on samples in two categories, firstly domestic water and
secondly a wide range of beverages including loose leaf tea samples
because it has been reported that camellia plants are known to concentrate
fluoride from the environment6.
Experimental
pH measurements were made with a Thermo Scientific Orion 4-star
pH/ISE meter and a Thermo Scientific Ross Ultra glass pH combination
electrode. Fluoride measurements were made with a Thermo Scientific
Orion Fluoride Ion Selective Electrode. All fluoride samples and standards
were treated with equal volumes of TISAB II (29.30 grams of sodium
acetate (UNIVAR), 29.0 g of sodium chloride (NHD), 6 g of trisodium
citrate dehydrate, (BHD), 2 g of CDTA (ALDRICH) and 8.2 mL of glacial
acetic acid (BHD) per 1000 mL water. The pH was adjusted to 5.5 using
10M sodium hydroxide prior to being made to volume). Ultra pure water
was used for all prepared solutions: Barnstead, E-pure; 17.9 megaohms.
Sodium Fluoride: ScholAR Chemistry, Sodium Hydroxide Pellets:
J.T.Baker, AR.
FIA measurements were made using a Chemflow FIP-3 flowcell wall-jet
configuration and a MicroLab FS-522 in conjunction with a Dell laptop. 60
µL injection volumes with a Reodyne injection valve were used. Flow rates
of 2 - 5 mL per minute were employed via a Gilson peristaltic pump.
Results and Discussion
Table 1 shows samples and data from 2011 to 2016. The fluoride
concentrations and pHs found in city / county water supplies from various
sites in Utah, Nevada, and California. The locations are indicated in the top
part of the Table 1. The fluoride and pH values for beverage samples are
also shown in the lower part of Table 1.
The results reported for domestic water show that only modest percentage of
the water supply samples fall in the range 0.7-1.2 These results indicate that
none or very little fluoridation has occurred, with most values near the 0.2
ppm example value for Farmington creek water which may be used as an
estimate of background levels..
The beverage samples generally showed quite low fluoride concentrations
with a few notable exceptions. Arrowhead bottled water contained 0.47 ppm
in 2011 and 1.05 ppm in 2012 suggesting it may be filtered tap water. Coke
products contained between < 0.05 and 0.59 ppm fluoride suggesting some
fluoridated water. Beverage pH values ranged from 2 to 8. Tea samples
ranged between 0.26 and 1.34 ppm. On its label, the low-fluoride tea claims
to be made from very young leaves from the top of the plant. These leaves
apparently had little time to accumulate fluoride from the environment. The
bottled cold teas show significant fluoride levels and the highest being 1.34
ppm. Energy drinks generally had low fluoride when not based on tea. The
acidity of these samples is generally quite low and similar to other
commercial soft drinks. Instant Coffees ranged from < 0.1 and 0.34
ppm.and pH 4.4 – 4.9.
Acknowledgements
SLCC Chemistry Department and students, Chris Peak, Sara Ranquist, Sydney
Richards, Rajan Kochambilli, Darren Saunders, Lacey Walker, Adam Dastrup
References
1. Salt Lake Valley Health Department, www.slvhealth.org , 2010.
2. National Center for Chronic Disease Prevention and Health Promotion,
apps.nccd.cdc.gov, 2010.
3. Frieden, E. Biochemistry of the Essential Ultratrace Elements, Plenum
Press, New York, 1984.
4. Frant , M. S. and Ross, J. W. Jr, Use of a Total Ionic Strength Adjustment
Buffer for Electrode Determination of Fluoride in Water Supplies, Anal.
Chem. 40 (7) ;1169-1171, 1968.
5. Sorensen, C. O. , private communication, 2010.
6. Fung K.F., Zhang Z.Q., Wong J.W.C., and Wong M.H. Fluoride contents in
tea and soil from tea plantations and the release of fluoride into tea liquor
during infusion. Environ Pollut 1999: 104: 197–205.
Conclusion
It seems that many of Utah’s counties and cities need to better monitor and
adjust their fluoridation methods to meet the fluoride levels for optimum dental
health. Dental practitioners are deservedly concerned with colas, energy drinks
and citrus-based drinks, which are highly acidic, and with loose teas and
instant coffees, may present a risk of over-fluoridation when made with
fluoridated tap water. The Chemflow FIP-3 flowcell was found to be ideal with
injection rates up to 120 per hour. In the future an expanded survey will be
conducted to determine the fluoride levels in more domestic water locations.
An analysis of the chemical content of Fluoride additive to water sources may
be done to see if it releases free F- ions. Also, an analysis of these samples for
water hardness may shed further light on the potential health effects of
consuming these domestic and commercial products.
Table 1. Water and Beverage Data
Analysis of Dental Parameters, Fluoride and pH, in Utah's waters and drinks.
Peter Iles, Alan Abbinanti, Sarah Moore, Ashley Rihm, Tyler Fullmer, Kenny Robbins, William Ballard, Tallon Nielsen, Laura Dalby,
Lourdes Peralta, Ryan Holcomb, Neil Bastian, Luther Giddings, Mary Alvarez and Ron Valcarce
Salt Lake Community College 4600 South Redwood Rd. Salt Lake City Utah, 84130
Location [ F-] ppm pH Location [ F-] ppm pH Location [ F-] ppm pH
Battle Mountain, NV 0.81 7.31 LDS Hospital 0.49 8.07 Sugarhouse 0.56 7.88
Beaver County 0.17 7.88 Lehi, Utah County 0.23 7.83 Suisun City, CA 0.90 8.16
Beck St Warm Springs 1.59 6.95 Magna 0.41 8.06 Taylorsville Campus 0.92 7.90
Bountiful City 0.69 7.78 Millard County 0.10 7.63 Taylorsville City 0.54 8.16
Davis County 0.52 7.77 Millcreek 0.46 7.75 Truckee, CA 0.76 7.35
Draper 0.86 7.88 Millcreek, UT 0.85 7.90 Washington County 0.23 7.86
Draper, UT 0.94 7.83 Morgan 0.04 6.26 West Valley City 0.89 7.90
Emigration canyon 0.35 7.54 Murray 0.29 7.85 West Wendover, NV 0.78 8.06
Fort Douglas 0.47 7.82 Murray 0.58 7.90
Farmington Creek,
Farmington, UT
0.22
Herriman 0.90 7.67 Park city 0.10 7.67 Holladay, UT 0.32
Herriman 0.75 8.00 Redwood SLCC 0.54 8.07 North Salt Lake, UT 0.43
Jordan Campus 0.20 7.00 Roseville, CA 0.86 6.51 Park City, UT 0.27
Juab County 0.08 8.00 Salt Lake City 0.47 7.98 Rose Park, UT 0.38
Kaysville 0.62 7.76 Sandy 0.68 7.74 Snyderville, UT 0.25
Kaysville City 0.04 7.75 South Salt Lake Well 0.16 8.04 Tooele, UT 0.24
Kaysville Water w/filter 0.39 6.73 St. George 0.18 7.90
Kearns City 0.74 7.85 St. George 0.19 8.00
Beverage [ F-] ppm pH Beverage [ F-] ppm pH Beverage [ F-] ppm pH
Aquafina Bottled Water 0.03 5.96 Arrowhead Bottled Water 0.47 8.16 Kirkland Bottled Water 0.03 8.16
Smart Water <0.05 7.42 Arrowhead Water 1.05 8.22
Beverage [ F-] ppm pH Beverage [ F-] ppm pH Beverage [ F-] ppm pH
Amp Cherry Energy <0.05 3.04
Maverik: Get Rev'd
(Grape)
0.21 2.95 NOS: Zero 0.04 2.47
AMP: Mixed Berry <0.02 2.65
Maverik: Get Rev'd Extra
Strength
0.31 2.89 Red Bull: Original 0.10 3.17
AMP: Sugar Free Citrus <0.02 2.59 Monster: Absolute Zero 0.04 3.44 Red Bull: Sugar Free 0.03 3.20
Five Hour Energy: Extra Strength <0.02 2.57 Monster: Low Carb <0.02 3.44 Rockstar: Original <0.02 2.60
Five Hour Energy: Lemon Lime <0.02 2.56 Monster: Zero Ultra <0.02 3.42 Rockstar: Zero Carb 0.09 3.17
Full Throtle: Citrus <0.02 2.84 NOS: Regular <0.02 3.14
Xyience: Xenergy (Frost
Berry Blast)
<0.02 2.85
Beverage [ F-] ppm pH Beverage [ F-] ppm pH Beverage [ F-] ppm pH
A & W Root Beer 0.04 4.69 Coke Zero 0.31 2.96 Mountain Dew 0.39 3.45
Barq's Root Beer 0.14 4.29 Diet Dr. Pepper 0.15 3.30 Ocean Spray Apple Juic <0.05 3.88
Caffeine Free Diet Coke 0.31 3.22 Kirkland Vita Rain Mango 0.01 2.72 Pepsi Max <0.05 3.00
Coke from Mexico <0.05 2.40 Mello Yello 0.15 3.14 Regular Coca Cola 0.22 2.38
Coke from USA 0.59 2.38 Minute Maid Lemonade 0.07 2.57 Schwepps GingerAle 0.01 2.94
Beverage [F-]ppm pH Beverage [F-]ppm pH Beverage [F-]ppm
Lipton: Herbal Peppermint Tea 0.04 7.01
Stash: Chai Spice Black
Tea
0.74 4.54
Rishi organic green tea,
“Jade Cloud”
0.26
Lipton: Peach Mango White Tea * 0.77 Brisk raspberry iced tea 0.71
Rishi organic white tea,
“Silver Needle Jasmine”
0.35
Lipton: Pure Green Tea 1.34 4.76 Pure Leaf iced tea 0.89
Monster: Rehab Tea &Pink Lemonade 0.12 4.00
Rishi organic black tea,
“China Breakfast”
1.03
Beverage [F-] ppm pH Beverage [F-] ppm pH Beverage [F-] ppm pH
Maxwell House Instant Coffee Original 0.1 4.41
Starbuck’s Instant
Colombia
<0.1 4.93 Folger’s Instant Classic 0.12 4.66
Taster’s Choice Instant House Blend 0.34 4.62
Western Family Instant
Classic Blend
0.21 4.74
* Storage spoiled sample