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ORIGINAL ARTICLE
The effect of water filter pitchers on the mineral concentration of
tap water
Loai Wadea Hazzazi BDS, MS
1,2
| Armando E. Soto-Rojas DDS, MDPH
3
|
E. Angeles Martinez-Mier DDS, MSD, PhD
2
|
Hani M. Nassar BDS, MSD, PG Cert., MHPE, PhD
4
| George J. Eckert MAS
5
|
Frank Lippert PhD
2
1
Department of Oral Biology, Faculty of
Dentistry, King Abdulaziz University, Jeddah,
Saudi Arabia
2
Department of Biomedical and Applied
Sciences, Indiana University School of
Dentistry, Indianapolis, Indiana, USA
3
Department of Dental Public Health and
Dental Informatics, Indiana University School
of Dentistry, Indianapolis, Indiana, USA
4
Department of Restorative Dentistry, Faculty
of Dentistry, King Abdulaziz University,
Jeddah, Saudi Arabia
5
Department of Biostatistics and Health Data
Science, Indiana University School of Medicine,
Indianapolis, Indiana, USA
Correspondence
Loai Wadea Hazzazi, Indiana University
School of Dentistry, Oral Health Research
Institute, Department of Biomedical and
Applied Sciences, 415 Lansing St, Indianapolis,
IN 46202, USA.
Email: loai.hazzazi@gmail.com
Abstract
Objectives: To investigate the effect of water filter pitchers on the concentration of
different minerals in tap water.
Methods: Nine water filter pitchers (A–I) were chosen based on consumer prefer-
ences and Amazon reviews. Each filter was tested for its ability to modify the con-
centrations of fluoride, calcium, magnesium, potassium, and sodium in tap water.
Tap water samples were collected before and after filtration, at various intervals
(1, 5, 10, 30, 50, 75, and 100 L) during filtration, and analyzed using an ion-
specific electrode (fluoride) and atomic absorption spectrometry (other minerals).
Statistical analyses were conducted to compare filtered and unfiltered water min-
eral concentrations.
Results: Water filter pitcher effect: Filters F (p< 0.001) and G (p=0.030)
decreased fluoride concentrations. All filters except I (p=0.235) and H
(p=0.717) decreased calcium concentrations (p< 0.01). Filters E (p=0.018), D
(p=0.014), and G (p=0.010) decreased magnesium concentrations. Filters I
(p=0.028) and D (p=0.009) increased potassium concentrations. Filter A
(p=0.002) increased sodium concentrations, while C (p=0.034) decreased
sodium concentrations. Effect of filter aging: All filters affected mineral concen-
trations over time but to varying extents. Filter G had the most pronounced effect
on reducing mineral concentrations compared to all others. No filter was able to
completely remove fluoride from tap water, contrary to the claims made by three
manufacturers.
Conclusions: The present study highlighted that water filter pitchers vary greatly
in their ability to affect mineral concentrations in tap water during their use. Fur-
ther research is needed to develop more effective water treatment solutions.
KEYWORDS
dental caries, drinking water, fluoride, trace elements, water filter pitcher, water filtration, water
purification
INTRODUCTION
Community water fluoridation (CWF) involves the con-
trolled addition of fluoride to public drinking water at
concentrations ranging from 0.7 to 1.2 mg/L, a practice
strongly endorsed by the Centers for Disease Control and
Prevention (CDC) due to its proven effectiveness in pre-
venting dental caries [1]. Since its implementation in the
United States in 1945, numerous longitudinal studies
have consistently demonstrated the significant role of
Received: 7 June 2024 Revised: 5 September 2024 Accepted: 18 October 2024
DOI: 10.1111/jphd.12649
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided
the original work is properly cited.
© 2024 The Author(s). Journal of Public Health Dentistry published by Wiley Perio dicals LLC on behalf of American Association of Public Health Dentistry.
J Public Health Dent. 2024;1–8. wileyonlinelibrary.com/journal/jphd 1
CWF in reducing the prevalence of dental caries across
populations [2]. Presently, approximately 75% of the
U.S. population benefits from fluoridated public drinking
water [3]. There is an extensive body of literature on lon-
gitudinal preventive effects of CWF on dental caries. A
systematic review concluded that CWF is effective in pre-
venting the prevalence of dental caries in children with a
35% reduction in decayed, missing, and filled deciduous
teeth (dmf) and a 26% reduction in permanent teeth
decayed, missing, filled and treated, compared to non-
fluoridated areas. Additionally, the review identified a
15% increase in caries-free children in their deciduous
dentition and a 14% increase in their permanent dentition
due to CWF [4]. Moreover, CWF is cost-effective, pro-
viding substantial economic benefits through reduced
dental treatment costs and improved oral health
outcomes.
However, public confidence in tap water safety has
been shaken by incidents such as the lead poisoning crisis
in Flint, Michigan [5, 6]. This has led to a notable shift
towards bottled water consumption and the widespread
adoption of water filtration and purification systems
(WFPS) in households [7, 8]. Between 2013 and 2018,
bottled water consumption surged, particularly among
Black and Hispanic populations, reflecting growing con-
cerns about the quality and safety of tap water [9]. This
trend is further highlighted by a study showing that
15.1% of U.S. adults consider their tap water unsafe,
39.0% believe bottled water is safer, and 25.9% dislike
the taste of tap water. These negative perceptions are
most common among younger adults, Non-Hispanic
Black and Hispanic individuals, those with lower educa-
tion and income, and renters. As a result, these groups
are more likely to consume bottled water and sugar-
sweetened beverages (SSBs) instead of tap water [10].
While improving public perceptions of tap water
safety and taste could help reverse this trend, the growing
reliance on bottled water carries unintended conse-
quences. One significant concern is the potential loss of
the benefits provided by CWF, which is crucial for pre-
venting dental caries. For instance, a study conducted in
Indianapolis, Indiana, found that only two of 92 sampled
bottled water brands had fluoride levels comparable to
CWF, raising concerns about the dental health implica-
tions of widespread bottled water use [11]. The introduc-
tion of water filtration systems further complicates the
landscape.
The WFPS market in the U.S. has nearly doubled
over the past 5 years and is expected to continue growing,
driven by consumer concerns about tap water safety and
the desire for improved water quality [12]. The market
offers a wide array of options, ranging from cost-effective
water pitchers and tap-mount filters to advanced reverse
osmosis and whole-house systems.
Among consumers, water filter pitchers stand out as a
popular choice due to their simplicity, affordability, and
portability. The CDC defines water filter pitchers as
“pitchers that are filled from the top and have built-in fil-
ters that water must pass through before being poured
out for drinking or other use.”These filters often feature
replacement cartridges filled with activated carbon and
ion-exchange resin [13]. Some manufacturers describe a
three-step filtration process: an initial mesh barrier to
capture debris, activated carbon granules to enhance
taste by removing mercury and chlorine, and ion
exchange resin to trap copper, zinc, and cadmium
ions [14]. However, despite their widespread use, there is
limited research on the impact of these filtration systems
on fluoride concentrations in tap water.
At present, the American Dental Association (ADA)
has granted its Seal of Acceptance to only two water filter
pitchers and one tap-mount filter, deeming them effective
at filtration without fluoride removal [15]. Nonetheless,
the absence of ADA endorsement does not preclude
other WFPS from effectively maintaining fluoride levels,
as the ADA’s Seal of Acceptance program remains vol-
untary. Research on WFPS’s impact on fluoride concen-
trations in tap water is scant, outdated, and yielded
conflicting results, with no dedicated studies assessing the
effects of water filter pitchers on fluoride concentrations
in tap water [16–20].
Therefore, the focus of this study was to provide evi-
dence on the effect of water filter pitchers commercially
available in the USA on fluoride concentration in tap
water. Beyond fluoride, other minerals in water, such as
calcium and magnesium, play vital roles in oral health.
Calcium and magnesium, for instance, can enhance tooth
strength through remineralization [21–24]. Additionally,
research suggests that calcium may partially compensate
for inadequate fluoride levels in tap water for caries pre-
vention [25]. A study involving school children also
found an inverse relationship between caries experience
and salivary potassium, while salivary sodium showed a
positive association with dental caries [26]. Therefore,
understanding how these filters affect not only the reten-
tion of fluoride, but also other beneficial minerals is
essential for overall oral health.
The study tested several hypotheses regarding the
effectiveness of water filter pitchers in reducing fluoride,
calcium, magnesium, sodium, and potassium concentra-
tions in tap water. The null hypotheses (H
0
) were as fol-
lows: (a) there is no difference between water filter
pitchers in their ability to reduce the fluoride concentra-
tion in tap water; (b) there is no difference between water
filter pitchers in their ability to reduce the concentrations
of calcium, magnesium, sodium, and potassium in tap
water; (c) the ability of water filter pitchers to reduce the
fluoride concentration in tap water does not change dur-
ing their use; and (d) the ability of water filter pitchers to
reduce the concentrations of calcium, magnesium,
sodium, and potassium in tap water does not change dur-
ing their use.
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MATERIALS AND METHODS
Selection of water filter pitchers
Due to the extensive and competitive water filter market,
which features numerous established and emerging com-
panies, we focused on studying the most commonly used
water filter pitchers among U.S. consumers for this study.
We utilized online platforms like Amazon, a widely
trusted source for consumer purchases, to determine
which water filter pitchers are the most popular and
highly reviewed. Additionally, we referred to consumer
guides to ensure our study focused on filters predomi-
nantly used by the U.S. population. Local department
stores were avoided due to their potential regional exclu-
sivity, as Amazon provides broader accessibility across
the country. After conducting our search, nine water fil-
ter pitcher models (N=9) were selected for this study.
In our selection process, we explored different models
offered by each brand and included these variations in
our study. Details displayed on the outer packaging and
accompanying information, as well as any claims regard-
ing the filter’s ability to remove fluoride, were recorded.
Upon purchase, relevant information for each filter was
documented, including the maintenance required
(e.g., filter material/pad renewal) and the expected dura-
tion of optimal performance before deterioration
(Table 1). Among the nine pitchers studied, one model
(PUR) has received the ADA Seal of Acceptance, indi-
cating their efficacy in filtering water without removing
beneficial fluoride [15].
The study was conducted from October 2023 to
January 2024 and the filters were stored at ambient con-
ditions at the Oral Health Research Institute (OHRI) of
the Indiana University School of Dentistry.
Water filtration and sample collection
Due to the potential for fluctuations in tap water fluoride
concentrations, fluoride levels in the water were analyzed
in a prior study, confirming that the fluoride levels are
approximately 0.7 mg/L [27]. Subsequently, for each
pitcher filter, the pitcher was removed from the package,
and the filter was installed in the pitcher. Cleaning
instructions for the filter and the procedure of running
water for a specified duration before using the filter were
followed in accordance with the manufacturers’instruc-
tions, as outlined in Table 1. Water sample collection
commenced immediately after the recommended running
time for each filter. Samples (20 mL) were collected after
1, 5, 10, 30, 50, 75, and 100 L of water had passed
through the filter. Additionally, unfiltered tap water was
collected immediately prior to and after each pitcher has
been studied. Consequently, nine samples were collected
for each filter test and stored under ambient conditions
until analysis. This process was repeated for each filter.
Fluoride analysis
The fluoride concentration of all samples was determined
by using a fluoride ion-specific electrode (Orion #96–
909-00) as described by Martínez-Mier et al. [28]. For
each water sample, 1 mL of total ionic strength adjust-
ment buffer II (Fisher Scientific) was added to a 1 mL ali-
quot of the water sample in a fluoride-free polyethylene
vial (7-mL vial; Fisher Scientific). After that, the solution
was mixed using a vortex mixer and placed under the
electrode. Finally, the millivolt reading of each sample
was compared to a standard curve to obtain the fluoride
content values.
Calcium, magnesium, potassium, and sodium
analyses
Mineral contents were determined using an atomic
absorption spectrometer (ICE 3000 series-Thermo,
England) equipped with background correction
(a deuterium lamp) as well as cathode lamps at a wave-
length of 422.7, 285.2, 589.0, and 766.5 nm suitable for
the analysis of calcium, magnesium, sodium, and potas-
sium, respectively. The applied concentration of the stan-
dard solutions covered the measurement range of the
analytical method, which was characterized by the linear-
ity of the calibration curve [29, 30]. All samples were pre-
pared for analysis using polyethylene vials (7-mL vial;
Fisher Scientific). For calcium analysis, 1 mL of lantha-
num chloride was added to all samples. All water samples
were tested at a volume to ensure that all measured con-
centrations fell in the measurement range that was deter-
mined previously (calcium—0.25; magnesium and
potassium—0.05; sodium—0.20 mL).
Statistical analysis
Mineral concentrations of the unfiltered water samples
collected immediately prior to and after filtration were
averaged. For the purpose of comparing filters to unfil-
tered samples, all filtered samples were averaged. Differ-
ences in mineral concentrations between filtered and
unfiltered water were tested for each filter using one-
sample t-tests. One-way analysis of variance (ANOVA)
was used to compare the tested filters for differences in
percent changes in each mineral. A two-sided 5% signifi-
cance level was used for all tests.
RESULTS
The average concentrations of each mineral in unfiltered
tap water during the experimental phase were as follows:
1.1 fluoride, 62.2 calcium, 28.4 magnesium, 9.6 potas-
sium, and 36.0 ppm sodium.
THE EFFECT OF WATER FILTER PITCHERS ON THE MINERAL CONCENTRATION OF TAP WATER 3
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Filter characteristics
The most common filtration mechanism was activated car-
bon (six filters), followed by ion exchange (three filters), used
alone or in combination with activated carbon (Table 1).
Filters used up to five stages of filtration. Filter replacement
intervals varied between every 25–30 to every 150 gallons
(95–114 to 568 L). Filters C, F, and G claimed to remove
fluoride to at least 98.4%, whereas other filters either made
no claim to that effect or stated that they did not affect
water fluoride concentrations. Only filter G claimed to
remove calcium, magnesium, potassium, and sodium.
Figures 1–5show the mineral concentrations by water
filter pitchers and amount of water filtration volume. To
allow for better comparisons of filter effects on mineral
concentrations, unfiltered water samples were set at
100% and mineral concentrations of filtered samples were
calculated in comparison to unfiltered samples.
TABLE 1 Studied water filter pitchers and their characteristics.
Code Brand Product/model Filtration process
Filter
replacement Pre-use instruction
Effect on
fluoride*
Effect on calcium,
potassium,
magnesium, and
sodium*
A Brita Everyday
pitcher,
standard filter,
(36050)
Activated carbon granules
Ion exchange resin
Every 40
gallons/151
liters
Rinse 15 s with cold
water
Fill then empty the
pitcher 3 times before use
Does not
remove
fluoride
“Preserves
certain healthy
minerals in water”
B Pure 7 cup pitcher
filtration
system
Activated carbon granules
Ion exchange resin
Every 40
gallons/151 L
Rinse 15 s with cold
water
Fill then empty the pitcher
one time before use
Does not
remove
fluoride
“Preserves certain
healthy minerals in
water”
C Epic
water
filter
Pure water
filtration jug
Proprietary blend of water
filtration media within
three activated coconut
carbon
Every 150
gallons/every
2–5 months
Fill then empty the
pitcher twice before use
Removes
more than
98.4% of
fluoride
No statement about
removal/retention
D Drink
Soma
Soma 10 cup
pitcher
Activated coconut shell
carbon
Charcoal
Every 40
gallons/every
2 months
Soak the filter with cold
water for 15 min then
rinse for 10 s
No statement
about fluoride
removal/
retention
No statement about
removal/retention
E Clear
2
O Gravity
water filtration
pitcher
(GRP200)
Nano alumina fibers onto
microglass filaments
creating a non-woven filter
media with a strong
electropositive charge (+)
that removes sub 1-micron
contaminants via electro-
adsorption, not just
mechanical filtration
Every 60
gallons
Rinse few seconds with
cold water
Fill then empty the
pitcher 3 times before use
No statement
about fluoride
removal/
retention
“Preserves certain
healthy minerals in
water”
F Clearly
filtered
Gravity-Fed
Water Pitcher
model
(CF-PRF)
3 stages of filtrations
First stage: woven mesh
screening layer
Second stage: granulated
coconut carbon layer
Third stage: proprietary
composite shell
Every 100
gallons
Priming the filter by
attaching the filter to a
priming bag and running
the water till it fills the
bag then forcing the
water out of the filter (to
be repeated three times)
Removes
more than
99.54% of
fluoride
(no information
provided)
G Zero
water
10 cup ready-
pour pitcher
5 stages ion exchange Every 25–30
gallons
Clean with warm water
and soap then rinse
Removes
more than
99% of
fluoride
Removes
calcium, potassium,
magnesium, and
sodium up to 100%
H Brita Stream model
(36238)
Activated carbon
Proprietary dual-layer
filtration technology
Every 40
gallons/151 L
Rinse 15 s with cold
water
Fill then empty the pitcher
one time before use
Does not
remove
fluoride
“Preserves certain
healthy minerals in
water”
I Brita Long last
+
model (OB06)
Patented pleated filter and
proprietary active filtering
agents in a housing, made
without BPA
Every 120
gallons/every
6 months
Rinse 15 s with cold
water
Fill then empty the pitcher
one time before use
Does not
remove
fluoride
“Preserves certain
healthy minerals in
water”
*Information gleaned from product packaging or manufacturer’s website.
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Both filters F (p< 0.001) and G ( p=0.030), resulted
in a significant decrease in fluoride concentrations. All fil-
ters, except I (p=0.235) and H (p=0.717), resulted in a
significant decrease in calcium concentrations (p< 0.01).
Filters E (p=0.018), D (p=0.014), and G ( p=0.010)
demonstrated a significant decrease in magnesium concen-
trations. Filters I (p=0.028) and D ( p=0.009) were
notable for significantly increasing potassium concentra-
tions. Moreover, filter A (p=0.002) showed an increase
in sodium concentrations, while C (p=0.034) signifi-
cantly decreased sodium concentrations.
Effect of filter aging
Fluoride
Filter F had the biggest impact as fluoride concentrations
did not return to baseline values during the experimental
phase (Figure 1). Filters C and G exhibited significant
reductions in fluoride concentrations initially, but both
did not show an effect after 100 or 50 L, respectively.
Calcium
Filter G had the biggest impact as calcium concentration
did not return to baseline values during the experimental
phase (Figure 2). Filter F showed an initial reduction in
calcium concentration followed by sudden increase but
failed to return to baseline after 50 L of water filtration.
All other filters resulted in an initial decrease in calcium
concentration followed by a gradual increase, before
reaching baseline values or values close to it.
Magnesium
Filter G had the biggest impact as magnesium concentra-
tions did not return to baseline values during the experi-
mental phase (Figure 3). Filters A, B, and D showed a
significant reduction in magnesium concentration ini-
tially, but did not show an effect after 30, 50, and 30 L,
respectively.
Potassium
Filter A initially increased potassium concentrations, but
then displayed a gradual decrease over time (Figure 4).
Similarly, D exhibited a significant fluctuation, with
potassium levels rising sharply before declining rapidly.
Filters C, D, and G showed similar trends, with potas-
sium levels initially dropping before experiencing a sud-
den surge and subsequent stabilization.
Sodium
Filter G had the biggest impact on sodium concentration;
however, concentrations returned to baseline values after
75 L (Figure 5). Filter B exhibited fluctuations in sodium
levels, but these stabilized and returned to baseline values
after 50 L. Filter F initially experienced a decrease in
sodium levels, followed by a gradual increase, but subse-
quently dropped again, failing to return to baseline
values after 50 L.
FIGURE 1 Fluoride concentration as a function of water filter
pitcher and filtration volume. [Color figure can be viewed at
wileyonlinelibrary.com]
FIGURE 2 Calcium concentration as a function of water filter
pitcher and filtration volume. [Color figure can be viewed at
wileyonlinelibrary.com]
FIGURE 3 Magnesium concentration as a function of water filter
pitcher and filtration volume. [Color figure can be viewed at
wileyonlinelibrary.com]
THE EFFECT OF WATER FILTER PITCHERS ON THE MINERAL CONCENTRATION OF TAP WATER 5
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DISCUSSION
According to the National Health and Nutrition Exami-
nation Survey (NHANES) 2007–2010 data [7], 33.7% of
US adults use water treatment devices, including carbon
filters, fiber filters, reverse osmosis units, neutralizers,
chemical feed pumps, disinfection and softeners, and
water filter pitchers. Although there are no specific data
on water filter pitchers alone, they are likely the most
used form of filtration along with faucet-mount filters
due to their comparatively low cost [31]. The change in
mineral content after filtration has a major effect on
drinking water. Therefore, the objective of the present
study was to assess the impact of commercially available
water filter pitchers on fluoride, calcium, potassium,
magnesium, and sodium concentrations. To the authors’
knowledge, this study is the first of its kind.
The results of the present study demonstrated that all
filters affected the concentrations of at least some of the
tested minerals in tap water to varying extents, thereby
rejecting the null hypotheses a and b. Notably, Filter G
emerged as the filter with the most pronounced impact
(Figures 1–5). Filters F and C also displayed significant
effects on fluoride, calcium, and sodium concentrations.
In contrast, Filters A, B, and D exhibited diverse impacts
on potassium and magnesium, with fluctuations observed
throughout the filtration process, thus also rejecting the
null hypotheses c and d. The interpretation of the present
data is further complicated by the recommendations for
filter replacement (Table 1). Users may also not be aware
that filter replacement is warranted unless an indicator
signals to the users that it is time to do so. For example,
filter G affected fluoride concentrations for approxi-
mately half of its usage period (25–30 gallons), resulting
in users being inconsistently exposed to fluoride. Filter C
maintained its effectiveness in reducing fluoride concen-
trations longer than Filter G before eventually surpassing
baseline levels. However, given that Filter C has a longer
recommended replacement interval, its overall impact on
fluoride exposure is likely to be less significant compared
to Filter G.
The present results diverge from Jobson et al. [32]
findings, where activated carbon filters significantly
removed fluoride. The discrepancy may stem from differ-
ences in the number of water filter pitchers tested and the
volume of water filtered. The present study investigated
up to 100 L of water passing through a filter, whereas
their study only tested up to 100 mL.
In contrast, Buzalaf et al. [33] findings were similar to
the present ones. They found that most domestic acti-
vated carbon water filters do not remove fluoride. How-
ever, their study tested both new and old filters and
collected only two samples of filtered and unfiltered
water for analysis.
Konno [34] demonstrated that hollow-fiber mem-
brane filters or activated carbon filters used for domestic
water filtration do not significantly remove fluoride from
tap water. Although all filters in our study employed acti-
vated carbon, known to absorb chlorine, lead, and other
contaminants, some brands incorporated ion exchange
resins or other filtration media. Interestingly, we
observed some filters exhibiting simultaneous increases in
one element and decreases in another. For instance, Fil-
ter G showed a trend where calcium concentrations
increased while sodium concentrations decreased over
time. Similarly, Filter F displayed a gradual rise in
sodium levels, accompanied by a notable reduction
in potassium. We hypothesize that this phenomenon may
be attributed to the proprietary materials utilized in these
filters, acting as ion exchange materials.
The observed phenomena of filters exhibiting simulta-
neous changes in different elements, such as Filters G
and F, present intriguing implications in the context of
water filtration. Filter G displayed an increase in calcium
concentrations over time, coinciding with a decrease in
sodium concentrations, suggesting a complex interplay
between the filtration mechanism and the chemical
composition of the filtered water. Similarly, Filter F
FIGURE 5 Sodium concentration as a function of water filter
pitcher and filtration volume. [Color figure can be viewed at
wileyonlinelibrary.com]
FIGURE 4 Potassium concentration as a function of water filter
pitcher and filtration volume. [Color figure can be viewed at
wileyonlinelibrary.com]
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demonstrated a unique pattern, with sodium concentra-
tions gradually increasing after the initial filtration, while
potassium concentrations sharply dropped after filtering
a certain volume of water. Lastly, several filters exhibited
mineral concentrations that were initially lower but even-
tually higher than baseline values after 100 L of tap water
passed through (e.g., Figure 1, C; Figure 4, G). There are
multiple reasons that we believe are causing these effects
on the minerals. One, the minerals were initially trapped
inside the filter and then leached out again. Second, the
filter became saturated. Third, it simply stopped working.
These findings underscore the importance of understand-
ing the dynamic interactions between filtration systems
and the diverse array of minerals present in water. Fur-
ther investigation into the underlying mechanisms driving
these changes is warranted to optimize water filtration
technologies and ensure the delivery of safe and nutri-
tiously balanced drinking water.
In the present study, we focused on water filter
pitchers, which are popular among consumers due to
their portability and built-in filtration systems. These fil-
ters are designed to remove undesirable contaminants
such as heavy metals, lead, chlorine, and per- and poly-
fluoroalkyl substances (PFAS), aiming to enhance water
taste and odor. While most of the brands we examined
claimed to preserve fluoride along with other healthy
minerals in the water, the present data on three filters
(C, F, and G) is in contrast to these claims. Additionally,
the impact of these filters on other minerals essential for
oral health, including calcium, magnesium, potassium,
and sodium was investigated. However, obtaining
detailed information from the brands’websites proved
challenging, as they often grouped these minerals under a
generic category of “healthy minerals”without providing
specific details. According to the authors’knowledge, no
prior study investigated the effect of the pitcher water fil-
ters on the presently studied minerals. Thus, a compari-
son to previous studies is not possible. Moreover, some
filters employed additional filtration processes beyond
activated carbon, such as filtration media or screening
barriers. Due to proprietary reasons, these processes were
not disclosed, posing a challenge in interpreting the fluc-
tuations observed in our results. Furthermore, the water
samples were collected from a previously tested
water source in Indianapolis with a known fluoride level.
This presents a limitation of the study, as water from
other cities may have different fluoride levels.
The present study had several strengths. First, it
focused solely on popular water filter pitchers and com-
pared different commercial brands. Second, the filters’
aging effects on fluoride removal were investigated by
tracking changes over time. Lastly, besides fluoride, we
assessed other beneficial minerals in water, which some
brands do not provide information on filtering. However,
we also acknowledge that the present study also had limi-
tations, including a relatively small sample size of only
nine filter brands, a single 100 L observation for each
filter brand, and limited access to unique filtration media
blends, making it challenging to explain discrepancies in
results.
For future research, it is imperative to conduct larger-
scale studies involving a wider range of water filter
brands to further validate our findings. Additionally,
exploring the long-term effects of water filtration systems
on fluoride and mineral levels in tap water could provide
valuable insights into their efficacy and durability over
time. Moreover, investigating the specific mechanisms
underlying the observed changes in mineral levels, partic-
ularly those related to ion exchange features and proprie-
tary filtration media, would enhance our understanding
of how different filters impact water composition. Fur-
thermore, studies focusing on the potential health impli-
cations of altered mineral levels in filtered water,
particularly in relation to dental and overall health out-
comes, would be beneficial. Lastly, transparency from
manufacturers regarding the composition and perfor-
mance of water filtration systems is crucial for consumers
to make informed decisions about their water treatment
options.
The shift from fluoridated tap water to bottled water
carries significant economic consequences, notably the
potential wastage of resources. The present study advo-
cates for scientifically supported, cost-effective water fil-
tration alternatives that enhance public trust in tap water
safety while preserving important minerals.
Additionally, the present study serves as a valuable
resource for dental care providers and policymakers. It
provides guidance on advising patients about their water
consumption patterns and the benefits of specific filters.
For manufacturers and policymakers, the present study
emphasizes the importance of continual innovation in
water filtration technologies and maintaining transpar-
ency about product features. This approach ensures that
consumers can make well-informed decisions that sup-
port their health and environmental sustainability. These
insights encourage a more informed public and drive
industry advancements to better meet consumer needs.
In conclusion, our study provides current evidence on
the varying effects of water filter pitchers on the concen-
trations of fluoride and other minerals in tap water.
While some filters effectively removed fluoride as
claimed, others did not, and certain filters exhibited unex-
pected changes in mineral concentrations during their
usage. Consumers should carefully research the capabili-
ties and limitations of water filter pitchers, particularly
regarding their impact on fluoride and essential mineral
concentrations. Regular filter replacement is crucial, and
users should choose filters with clear replacement indica-
tors to ensure consistent performance. It is important to
balance the removal of contaminants with the retention
of other beneficial minerals like calcium and magnesium.
Consumers should seek detailed information from manu-
facturers about filter technologies and monitor their
water quality regularly.
THE EFFECT OF WATER FILTER PITCHERS ON THE MINERAL CONCENTRATION OF TAP WATER 7
17527325, 0, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/jphd.12649 by Frank Lippert - Indiana University School Of , Wiley Online Library on [21/11/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License
CONFLICT OF INTEREST STATEMENT
The authors declare no conflicts of interest.
ORCID
Loai Wadea Hazzazi https://orcid.org/0000-0003-4702-
1813
Armando E. Soto-Rojas https://orcid.org/0000-0002-
7893-7528
E. Angeles Martinez-Mier https://orcid.org/0000-0002-
5389-0209
Hani M. Nassar https://orcid.org/0000-0002-6241-1118
George J. Eckert https://orcid.org/0000-0001-7798-
7155
Frank Lippert https://orcid.org/0000-0003-1944-2960
REFERENCES
1. Chandra S, Chandra S. Textbook of community dentistry. Ch 7.
New Delhi: Jaypee Brothers Medical Publishers (P) Ltd; 2002.
p. 1017.
2. U.S. Department of Health and Human Services Federal Panel on
Community Water Fluoridation. U.S. Public health service recom-
mendation for fluoride concentration in drinking water for the pre-
vention of dental caries. Public Health Rep. 2015;130(4):318–31.
3. Centers for Disease Control and Prevention. Fluoridation Stat [Inter-
net]. 2018 https://www.cdc.gov/fluoridation/statistics/2018stats.htm
4. Iheozor-Ejiofor Z, Worthington HV, Walsh T, O’Malley L,
Clarkson JE, Macey R, et al. Water fluoridation for the prevention of
dental caries. Cochrane Database Syst Rev [Internet]. 2015;2015(9):
CD010856. https://doi.org/10.1002/14651858.CD010856.pub2
5. Allaire M, Wu H, Lall U. National trends in drinking water qual-
ity violations. Proc Natl Acad Sci. 2018;115(9):2078–83.
6. Ruckart PZ, Ettinger AS, Hanna-Attisha M, Jones N, Davis SI,
Breysse PN. The Flint water crisis: a coordinated public health
emergency response and recovery initiative. J Public
Health Manag Pract. 2019;25(1):S84–90.
7. Rosinger AY, Herrick KA, Wutich AY, Yoder JS, Ogden CL.
Disparities in plain, tap and bottled water consumption among US
adults: National Health and nutrition examination survey
(NHANES) 2007–2014. Public Health Nutr. 2018;21(8):1455–64.
8. Levêque JG, Burns RC. Predicting water filter and bottled water
use in Appalachia: a community-scale case study. J Water Health.
2017;15(3):451–61.
9. Rosinger AY, Patel AI, Weaks F. Examining recent trends in the
racial disparity gap in tap water consumption: NHANES 2011–
2018. Public Health Nutr. 2021;11:1–7.
10. Park S, Onufrak SJ, Cradock AL, Patel A, Hecht C, Blanck HM.
Perceptions of water safety and tap water taste and their associa-
tions with beverage intake among U.S. adults. Am J Health Pro-
mot. 2023;37(5):625–37.
11. Almejrad L, Levon JA, Soto-Rojas AE, Tang Q, Lippert F. An
investigation into the potential anticaries benefits and contribu-
tions to mineral intake of bottled water. J Am Dent Assoc. 2020;
151(12):924–934.e10.
12. Water Filter Market Size & Share Analysis. Industry research report—
growth trends [Internet]. 2024. https://www.mordorintelligence.com/
industry-reports/global-water-purifier-filter-market
13. Centers for Disease Control and Prevention. Home water treat-
ment: Water filters [Internet]. https://www.cdc.gov/healthywater/
drinking/home-water-treatment/water-filters/step3.html
14. Brita. How do Brita filters work? [Internet]. https://www.brita.
com/better-water/how-do-brita-filters-work/
15. American Dental Association. PUR Pitcher/Dispenser ADA Seal
of Acceptance [Internet]. https://www.ada.org/en/resources/research/
science-and-research-institute/ada-seal-of-acceptance/product-search/
a065e000007A361AAC/pu r-pitcher-dispenser
16. Ong Y, Williams B, Holt R. The effect of domestic water filters on
water fluoride content. Br Dent J. 1996;181(2):59–63.
17. Lindemeyer R, Fitz L, Pikarski J. Fluoride: surprising factors in
bottled water. Pa Dent J Harrisb. 1996;63(1):13–7.
18. Tate W, Chan J. Fluoride concentrations in bottled and filtered
waters. Gen Dent. 1994;42(4):362–6.
19. Tate WH, Snyder R, Montgomery EH, Chan JT. Impact of source
of drinking water on fluoride supplementation. J Pediatr. 1990;
117(3):419–21.
20. Brown MD, Aaron DMDG. The effect of point-of-use water con-
ditioning systems on community fluoridated water. Pediatr Dent.
1991;13(1):35–8.
21. García-Godoy F, Hicks MJ. Maintaining the integrity of the
enamel surface. J Am Dent Assoc. 2008;139:25S–34S.
22. Cardoso A, de Sousa E, Steiner-Oliveira C, Parisotto T, Nobre-
dos-Santos M. A high salivary calcium concentration is a protec-
tive factor for caries development during orthodontic treatment.
J Clin Exp Dent. 2020;12:e209–14.
23. Arvin E, Bardow A, Spliid H. Caries affected by calcium and fluo-
ride in drinking water and family income. J Water Health. 2018;
16(1):49–56.
24. Azarpazhooh A, Limeback H. Clinical efficacy of casein deriva-
tives. J Am Dent Assoc. 2008;139(7):915–24.
25. Bruvo M, Ekstrand K, Arvin E, Spliid H, Moe D, Kirkeby S,
et al. Optimal drinking water composition for caries control in
populations. J Dent Res. 2008;87(4):340–3.
26. Benghasheer HF, Hussein AS, Hassan MIA. Salivary sodium and
potassium in relation to dental caries in a group of multiracial
school children. E-J Dent. 2013;3(1):307–12.
27. Tamayo-Cabeza G, Lippert F. Evaluation of fluoride and calcium
concentrations in drinking water from public water fountains on a
university campus. Gen Dent. 2022;70:41–5.
28. Martínez-Mier EA, Cury JA, Heilman JR, Katz BP, Levy SM,
Li Y, et al. Development of gold standard ion-selective electrode-
based methods for fluoride analysis. Caries Res. 2011;45(1):3–12.
29. Gątarska A, Ciborska J, To
nska E. Natural mineral bottled waters
available on the polish market as a source of minerals for the con-
sumers. Part 2: the intake of sodium and potassium. Rocz Panstw
Zakl Hig. 2016;67(4):373–82.
30. Gątarska A, To
nska E, Ciborska J. Natural mineral bottled waters
available on the polish market as a source of minerals for the con-
sumers. Part 1. Calcium and Magnesium Rocz Panstw Zakl Hig.
2016;67(1):1–8.
31. Hobson WL, Knochel ML, Byington CL, Young PC, Hoff CJ,
Buchi KF. Bottled, filtered, and tap water use in Latino and non-
Latino children. Arch Pediatr Adolesc Med. 2007;161(5):457–61.
32. Jobson MD, Grimm SE, Banks K, Henley G. The effects of water
filtration systems on fluoride. Washington, D.C.: Metropolitan
area. J Dent Child. 2000;67(5):350–4.
33. Buzalaf MA, Levy FM, Rodrigues MH, Bastos JR. Effect of
domestic water filters on water fluoride content and level of the
public water supply in Bauru, Brazil. J Dent Child (Chicago, III).
2003;70(3):226–30.
34. Konno H. Neither hollow-fibre membrane filters nor activated-
charcoal filters remove fluoride from fluoridated tap water. J Can
Dent Assoc. 2008;74(5):7.
How to cite this article: Hazzazi LW,
Soto-Rojas AE, Martinez-Mier EA, Nassar HM,
Eckert GJ, Lippert F. The effect of water filter
pitchers on the mineral concentration of tap water.
J Public Health Dent. 2024. https://doi.org/10.
1111/jphd.12649
8HAZZAZI ET AL.
17527325, 0, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/jphd.12649 by Frank Lippert - Indiana University School Of , Wiley Online Library on [21/11/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License
