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Article

Evaluation of Fluoride Concentration in Commercially Available Bottled Water in Romania—A Potential Risk Factor for Dental Fluorosis

by
Eugeniu Mihalas
1,
Laura Gavrila
1,*,
Ana Sirghe
1,†,
Vasilica Toma
1,†,
Yllka Decolli
2,* and
Carmen Savin
1
1
Department of Paediatric Dentistry, Faculty of Dental Medicine, “Grigore T. Popa” University of Medicine and Pharmacy Iasi, 16 Universitatii Str., 700115 Iasi, Romania
2
Department of Endodontics, Faculty of Dental Medicine, “Grigore T. Popa” University of Medicine and Pharmacy Iasi, 16 Universitatii Str., 700115 Iasi, Romania
*
Authors to whom correspondence should be addressed.
†
Authors with equal contribution as the first author.
Appl. Sci. 2023, 13(13), 7563; https://doi.org/10.3390/app13137563
Submission received: 29 May 2023 / Revised: 24 June 2023 / Accepted: 25 June 2023 / Published: 27 June 2023
(This article belongs to the Section Applied Dentistry and Oral Sciences)
Review Reports Versions Notes

Abstract

:
Fluoride (F) ions actively participate in the dental enamel remineralisation process and inhibit the activity of cariogenic bacteria of the oral biofilm. However, increased systemic intake of F during critical periods of amelogenesis can lead to dental fluorosis (DF). The necessity of our study stemmed from the growing consumption of bottled water, as water is one of the primary sources of F in humans, and labelling F concentration is optional. Our aim was to evaluate the F concentration in bottled natural mineral or spring still waters available on the market in Iasi, Romania. We purchased forty different brands of still bottled water from the major grocery stores and tested them using an ion-selective electrode method. The reliability of the data was assessed by the intraclass correlation coefficient (ICC), while the differences between the obtained and labelled F values were examined using a paired samples t-test. The tested F levels ranged between 0.0338 and 4.6262 milligrams per litter (mg/L). The majority of the samples, around 85% recorded F values ranging from 0.232 to 0.0338 mg/L, offering slight or no benefit in caries prevention. Another 10% of the samples had F values ranging between 0.3 and 0.4 mg/L and could provide a dental health benefit. A percentage of 5% of the tested samples recorded F levels above the optimal level of 0.7 mg/L, as set by the American Dental Association (ADA) and the United States Department of Health and Human Services (U.S. HHS). This elevated F concentration poses a potential risk for DF in infants and toddlers, indicating that regular consumption of these samples may be unsafe.

1. Introduction

Fluorine is a common element found in the Earth’s crust. Fluorides (Fs) are naturally present in soil, rocks and water worldwide, with higher concentrations in areas where previous pyroclastic activity or geological elevation has occurred [1,2]. Additionally, Fs are widely used in various industrial processes [2,3]. Moreover, Fs play a significant role in oral and skeletal health [3,4]. It is well-known that fluoride (F) ions actively participate in the remineralisation of tooth enamel and inhibit the metabolic activity of cariogenic bacteria of the oral biofilm [4,5,6]. Considering the above-mentioned characteristics, historically, F has been the first attempt in dental practice used for preventive purposes [7]. Toothpastes, mouth rinses and topical gels have been developed over the years, showing significant results. Thus, the effect of F is primarily achieved through topical application, which is further enhanced when combined with good oral hygiene [5,8]. Low levels of F in plaque and saliva help prevent the demineralisation of healthy enamel and promote the remineralisation of previously demineralised enamel [4,5,6,7]. The application of topical gels or varnishes containing high levels of F results in the formation of a temporary layer resembling calcium fluoride on the surface of the enamel [9]. This layer releases F when the pH decreases due to acid production, enabling it to contribute to enamel remineralisation or affect bacterial metabolism [6,9]. The primary sources of systemic F exposure include the diet (water and food), as well as fluoride-containing oral hygiene or dental products such as toothpaste, mouthwash, dental floss, gels, foams, varnishes, silver diamine fluoride (SDF), slow-release F beads [3,5,7,9,10,11].
While Fs have played a crucial role in promoting oral health over the past 60 years and continue to be an important tool in the fight against dental caries in both children and adults, excessive systemic intake of F during critical periods of dental enamel formation (amelogenesis) can result in dental fluorosis (DF) [5,9,10]. The optimal dose of F intake is recommended to be 0.05 mg F/kg body weight (bw)/day [6,12].
Ameloblasts are the cells responsible for the process of amelogenesis. Amelogenesis comprises four main stages: pre-secretory, secretory, transition, and maturation [11]. During the secretory stage, ameloblasts secrete enamel proteins into the enamel matrix [13]. Some studies suggest that chronic exposure to F at this stage can reduce matrix biosynthesis or disturb vesicular transport in secretory ameloblasts, resulting in a slight reduction in enamel thickness [11,14]. Furthermore, late secretory ameloblasts may detach from the surface and form subameloblastic cysts, leading to the clinical manifestation of shallow occlusal pits, which are often observed in severe forms of DF [11,14]. In addition, F exposure during this stage has been linked to the development of accentuated perikymata, which is a clinical sign of a mild form of DF [11]. During the transition and maturation stages, the enamel extracellular matrix undergoes enzymatic modification, enabling the continued deposition of minerals required for the development of mature enamel [14]. Chronic F exposure during the maturation stage can lead to the retention of amelogenin proteins, potentially delaying the final mineralisation of the enamel matrix [11,13]. This delay in mineralisation can contribute to the development of subsurface hypomineralisation, which is one of the characteristic features of DF [11]. As a result, enamel affected by DF exhibits specific characteristics, such as enlarged intercrystalline spaces within the hydroxyapatite structure. These spaces are filled with residual proteins and water [13]. These alterations are specific to hypomineralised enamel and are clinically manifested by increased porosity (subsurface hypomineralisation), reduced translucency, and increased opacity [2]. Additionally, the excess of F adversely affects the bond strength of both conservative [15] and orthodontic materials [16].
Four primary risk factors consistently linked to DF are the use of fluoridated drinking water, F supplements, F toothpaste, and the consumption of infant formulas before the age of 6 years [8,10]. Thereby, children under the age of 4 are susceptible to DF affecting their permanent incisors and first molars. This is because the calcification and maturation of these teeth take place during this age range [8,10]. Similarly, premolars and second molars undergo calcification and maturation between the ages of 4 and 6. However, the risk of DF becomes less significant after 6 years of age [4,8,10].
Drinking water is one of the primary sources of F for the human body, supplying approximately 2/3–4/5 of the daily F requirement [17,18]. The F content in streams and lakes typically ranges between 0.1 and 0.3 mg/L, in atmospheric precipitation between 0.1 and 0.2 mg/L, in groundwater between 0.1 and 10 mg/L, and in oceans and seawater between 1.2 and 1.4 mg/L [19].
In the European Union (EU), the F concentration in bottled mineral waters can vary significantly. For example, in Portugal, the concentration can reach as high as 14 mg/L, while in Bulgaria, it can be as high as 5 mg/L, and in France, it reaches approximately 8.5 mg/L [20]. Regular consumption of water with high F concentrations, as mentioned earlier, can significantly increase the risk of DF in children [10,21].
The European Academy of Paediatric Dentistry (EAPD) states that bottled drinking water is widely consumed in many countries, even in those with community water fluoridation, potentially resulting in decreased consumption of fluoridated tap water. When appropriately fluoridated, bottled water could present an extra alternative for preventing dental caries in the population. Nonetheless, additional research is needed to explore the impact of bottled waters containing F on dental caries and DF [8].
The objective of our study was to optimise preventive measures for DF by evaluating one of the primary sources of F, namely natural mineral or spring waters, and assessing the accessibility of the obtained data at the community level. Specifically, our study aimed to determine the concentration of F in bottled water available in the Romanian market using the direct potentiometric technique with a F ion-selective electrode (ISE). Additionally, we aimed to evaluate the level of accuracy and grade of labelling of F values on the bottle labels.

2. Materials and Methods

Samples were collected from different bottled drinking waters between April and June 2022. The selection criteria included: plain spring/mineral water, packaged in plastic or glass bottles up to 2 L in size, and purchased before the expiration date indicated on the label. We also made sure to include samples from the same brand but sourced from different springs of origin. The bottled waters were obtained from major supermarkets and grocery stores in Romania.
In order to perform F content readings, the combination ISE was used (HI-4110 F Combination ISE Electrode, Hanna Instruments, Woonsocket, RI, USA). The manufacturer’s instructions were followed, and direct calibration and measurement technique was utilised [22]. The HI-4110 is a potentiometric device, specifically designed for the rapid determination of free F ions in various samples, including water, soft drinks, wine, emulsified foods, and plating and pickling acids. The electrode functions as a sensor or ionic conductor. Furthermore, the HI-4110 has a reference electrode incorporated and requires the use of an electrolyte fill solution of 1.7 M KNO3 + 0.7 M KCl (HI-7075 Electrolyte Solution, Hanna Instruments, Woonsocket, RI, USA). This F ISE HI-4110 was connected to a research-grade benchtop ISE meter (HI 5222-02 pH/mV/ISE/Temperature Bench Meter, Hanna Instruments, Woonsocket, RI, USA), which allowed us to measure F directly in mg/L. The ISE HI 4110 meter determines the concentration of the sample by a direct reading after calibrating the meter with standards [23]. Usually, the meter is calibrated with two or more freshly made standards if the measurement range of the samples is linear. If the measurement range is non-linear, additional calibration standards are required. After calibration, the samples are read directly. Thus, we performed a five-point calibration of the HI 5222-02 meter. F calibration standards ranging in concentration from 0 to 1.0 mg/L F were prepared using 10 mg/L F standard with incorporated total ionic strength adjustment buffer (TISAB) II (HI 4010-10 10 mg/L F Standard with TISAB II, Hanna Instruments, Woonsocket, RI, USA) and double distilled water (Chemical Company, Iasi, Romania). The F concentration range of the calibration standards was chosen based on the estimative F concentration of the samples. TISAB II is formulated for water sample analysis to provide samples and standards with a constant ionic strength and pH background, which stabilises the solutions’ activity coefficient and allows the concentration to be measured directly. It also enables the measurement of the total real F concentration by de-complexing metal (i.e., Al+3, Fe+3)-F complexes that could be found in the sample.
Plastic beakers were used for both the calibration standards and the sample solutions. The solutions were stirred at the same rate using a magnetic stirrer (HI 180, Hanna Instruments, Woonsocket, RI, USA) and identical-sized TFE-coated stir bars. The purchased samples were kept in their original sealed containers at room temperature until examination. Prior to the direct measurement technique of the F concentration, the samples were prepared by adding TISAB II solution (HI-4010-00, Hanna Instruments, Woonsocket, RI, USA) in a 1:1 ratio.
The samples were analysed twice, and the intraclass correlation coefficient (ICC) was used to measure the reliability of the obtained values [24]. A paired samples t-test was used to evaluate the differences between the obtained and labelled F values. A p-value of <0.05 was considered statistically significant. The data were analysed using SPSS (IBM SPSS Statistics for Windows, Version 26.0. Armonk, NY, USA: IBM Corp; 2019). The design of the study was approved by the Research Ethics Committee of the “Grigore T. Popa” University of Medicine and Pharmacy Iasi, Romania.

3. Results

Forty bottles of still natural mineral or spring water from different brands were identified and purchased at the major grocery stores in Romania, including Carrefour, Kaufland, Lidl, Profi and Auchan. The volume of the bottles ranged from 250 millilitres to 2 L, and the majority of samples were packaged in plastic bottles. However, three brands (Aura, Acqua Panna and Voss) were packaged in glass bottles. Out of the total purchased bottles, 67.5% (n = 27) were of Romanian origin, while the remaining 32.5% (n = 13) were imported from countries such as Italy, France, Spain, Norway, Bulgaria and Fiji. Additionally, 45% (n = 18) of the purchased water bottles were from the list of officially recognised waters in Romania (Table 1).
The F content was listed on 17.5% (n = 7) of the bottles, out of which only 7.5% (n = 3) were of Romanian brand. Furthermore, data regarding the safety of use in infants and/or children under 7 years of age were marked on 17.5% (n = 7) of the bottles. Among them, the statement “product not recommended for regular consumption by infants and children under 7 years of age” appeared on the labels of two bottles, representing 5% of the total. Both of these bottles originated from Bulgaria and had a high F concentration indicated on the label (Table 1).
Most of the brands sampled in our study had a low F concentration. Based on our determinations, the F content in the water samples ranged between 0.0338 and 4.6262 mg/L, with a mean (±SD) of 0.3155 (±0.9086). We observed the highest levels of F (>1.5 mg/L) in only 5% (n = 2) of the samples, specifically the Alcalia (4.66 mg/L) and Devin (3.71 mg/L) brands from Bulgaria. Furthermore, the higher level of F (≥0.3 mg/L) was found in 10% (n = 4) of the samples, including the Vittel kids (0.314 mg/L) and Vittel (0.313 mg/L) brands from Italy, as well as Simplu Carrefour (0.305 mg/L) and Proxi Profi (0.3 mg/L) brands from Romania. Excluding these six brands, the remaining 85% (n = 34) of them had a low F concentration (<0.3 mg/L).
The accuracy of the method was confirmed by comparing the first and second readings of the samples. An obtained ICC of 0.983 indicates excellent reliability of measurements. In addition, there were no statistically significant differences in the F values between the obtained and the labelled values (p = 0.304).

4. Discussion

The appropriate daily intake of F varies based on age and body weight, similar to other nutrients [3,6]. When used and consumed appropriately, F is considered safe and has preventive effects against dental caries [6,25]. Dietary reference intakes for F have been established by the Food and Nutrition Board of the U.S. Institute of Medicine since 1997 [11]. These reference intakes encompass all sources of F, including fluoridated water, foods, beverages, fluoride dental products, and dietary fluoride supplements. The optimal dose is set at 0.05 mg F/kg bw/day [6,12,26]. Additionally, to prevent DF and potential adverse effects associated with high doses of F, a tolerable upper intake level of 0.1 mg F/kg bw/day has been established [6].
Thus, for children aged up to 6 years who are most susceptible to developing DF, the recommended adequate daily intake of F is set as follows [6,11,12]:
  • Infants 0–6 months (weighing approximately 7 kg): 0.01 mg/day;
  • Infants 7–12 months (weighing approximately 9 kg): 0.5 mg/day;
  • Children 1–3 years (weighing approximately 13 kg): 0.7 mg/day;
  • Children 4–8 years (weighing approximately 22 kg): 1.0 mg/day.
As mentioned earlier, exceeding the recommended daily doses of F during critical stages of amelogenesis can result in DF [2]. Clinically, teeth affected by DF may exhibit a range of manifestations. These can vary from thin white lines at the incisal edge to more prominent and thicker white lines, patchy cloudy areas, yellow or light brown discoloration and even eruption pits [11]. Additionally, severe DF can result in compromised tooth strength due to poorly mineralised deeper enamel, leading to chipping and brown staining [2,11]. While mild DF may offer some resistance to dental decay due to higher F levels, severely fluorosed teeth are more susceptible to decay due to surface irregularities or loss of the protective layer [11]. Moreover, excessive F intake has been associated with other health issues, including skeletal fluorosis, neurological toxicity, endocrine disruption and a potential decrease in IQ when exposed during prenatal and/or early life stages [21].
The fluoridation of community drinking water for the purpose of preventing tooth decay is considered one of the ten most important achievements in the field of public health in the 20th century in the U.S. and other countries worldwide [2,9,11]. However, despite the decrease in the prevalence of dental caries, there has been an increase in DF worldwide [27]. The prevalence of DF in adolescents aged 12–15 years in the U.S. has increased from 23% to 41%, almost doubling since 1987 [17]. Conversely, in the population of Western Europe, only 3% consumes artificially or naturally fluoridated water [28]. Ireland has the highest proportion, with a rate of 73%, followed by Spain at 11%, the United Kingdom (UK) at 10% and Serbia at 3% [28].
Data on the prevalence of DF at the European level are inconsistent due to the use of different clinical indices and evaluation methods. According to Cochran et al. [29], who utilised the standardised photo evaluation method and the Thylstrup & Fejerskov (TF) index, the prevalence of DF ranges from 5% to 30% in different countries. The specific prevalence rates are as follows: Ireland at 30%, Holland at 26%, Iceland at 21%, the UK at 17%, Greece at 12%, Finland at 8% and Portugal at 5%.
There is no national program for the fluoridation of drinking water in Romania, and as far as we know, there is no updated information regarding the prevalence of DF. However, in a specific region, namely the Danube Delta Biosphere Reserve, a prevalence of 2% has been reported in children between the ages of 6 and 12, and 7.42% in adults aged 18–50 [30].
A significant portion of the EU population prefers bottled water as their primary source of hydration [8,31]. Recent statistics indicate that bottled water accounts for 48% of the market share among other non-alcoholic beverages [31]. According to the latest data from the non-profit trade association Natural Mineral Waters Europe (NMWE), 63% of consumers prefer to drink still bottled water [31].
In 2019, the average per capita consumption of bottled water in the EU was 118 L. Among the EU countries, the top five largest consumers of bottled water were Italy with 200 L per capita, Germany with 168 L, Portugal with 140 L, Hungary with 139 L, and Spain with 135 L. Romania ranked in the middle with an average consumption of 106 L per capita [31]. These data indicate an increase in water consumption at the EU level compared to previously available data. Furthermore, when considering specific social groups that are prone to higher daily water intake, such as athletes or individuals living in regions/countries with tropical or dry climates, it becomes even more important to closely monitor the daily F intake from water.
Romania is known for its abundant underground water resources, boasting over 2000 springs and holding 60% of the mineral water reserves in Europe [32]. The country’s natural mineral water production accounts for more than 12% of the total production in Eastern Europe but represents only approximately 3% of the production registered in the EU [32]. More than 75% of the natural mineral water deposits intended for bottling in Romania are managed by the National Mineral Water Society [32,33]. The official list of recognised natural mineral waters in Romania is published annually, by order of the president of the National Agency for Mineral Resources (ANRM). According to the ANRM, the list comprises 78 trade names of bottled water in 2023 [33]. Additionally, in the market, both imported and domestic brands can be found, including those that are unrecognised or in the process of recognition.
According to Romanian legislation, the labelling requirements for natural mineral or spring water, state that only mineral waters with a F concentration higher than 1.5 mg/L are required to have the following warning on the label: “Contains more than 1.5 mg/L fluorides: product not recommended for the regular consumption of infants and children under 7 years old”. However, indicating the F concentration on the bottle label is optional [34]. There is no comprehensive “map of the distribution of F” in groundwater in Romania. Instead, there have been sporadic studies indicating the presence of regions with high F content in both ground and drinking water, containing up to 2.75 mg/L of F [18], exceeding the maximum safe limit of 1.5 mg/L set by the EU Parliament and Council [35].
The World Health Organisation (WHO) has established a water quality target for F at a value of 1.5 mg/L, which represents the maximum level without observed adverse effects [1]. However, it is important to consider the volume of water consumed and F intake from other sources when setting national standards [1].
The optimal level of F in drinking water to prevent tooth decay and minimise the risk of DF is recommended to be 0.7 mg/L. This recommendation is supported by the American Dental Association (ADA) and United States Department of Health and Human Services (U.S. HHS) for both tap water fluoridation and bottled water that has F added [6,17].
Conversely, the U.S. Environmental Protection Agency (U.S. EPA) has set the maximum allowable level of naturally occurring F in drinking water at 4 mg/L. If the F concentration exceeds this level, defluoridation processes are required to reduce the F content [6,17]. Additionally, the U.S. EPA has established a secondary maximum contaminant level of 2.0 mg/L for F in drinking water. If the naturally occurring F level exceeds this value, water suppliers are required to notify consumers [6]. The purpose of this notification is to inform families that regular consumption of water with natural F levels greater than 2 mg/L by infants and young children may lead to the development of moderate to severe DF in their developing teeth [6]. This measure aims to raise awareness and help parents make informed decisions regarding the water consumed by their children. Thus, based on these recommendations and our findings, we do not recommend the regular use of bottled water brands such as Alcalia and Devin, which have high F content in infants, toddlers and children. Moreover, we advise against consuming brands with F content above 0.7 mg/L during pregnancy and in infants aged 3 or younger. To further reduce the risk of DF in children, we support the Environmental Working Group (EWG), a U.S. non-profit organisation, recommendation to use filtered tap water for preparing infant formula [36]. If tap water is not fluoridated, a carbon filter can be used to remove impurities, and if it is fluoridated, a reverse osmosis filter can be used to remove the F [1,36]. It is important to note that if bottled water is used for infants, it should be F-free.
The Canadian Paediatric Society (CPS) has put forth a different recommendation regarding the F content in drinking water compared to the WHO, ADA and U.S. HHS. According to the CPS, the appropriate amount of F in tap or bottled drinking water is around 0.3 mg/L [25]. They believe this level is sufficient to prevent dental caries while avoiding the risk of DF. The CPS also advises that children under the age of 3 should not consume water with F levels ≥ 0.7 mg/L. These recommendations are based on the understanding that most toothpaste products contain F, and children under 3 years old tend to swallow toothpaste instead of spitting it out, leading to increased daily F intake beyond the recommended dose of 0.7 mg for children aged 1–3 years [6,8,10].
To our knowledge, the last Romanian study focusing on this subject dates back to 2004 when Totolici et al. [20] stated that only one of the 19 mineral waters investigated revealed a concentration nearing 1 mg/L of F. The F content of bottled mineral or spring drinking water in our study exhibited a wide range, varying from 0.0338 to 4.6262 mg/L. These findings are consistent with studies conducted in other countries worldwide, including Bangkok, Thailand (0.01–0.89 mg/L); Fortaleza, Brazil (0.07–0.63 mg/L); Thessaloniki, Greece (0.05–4.8 mg/L); Suzhou Urban Area, China (0–0.120 mg/L); Indianapolis, U.S. (0.02–1.22 mg/L); and Victoria, Australia (<0.1–1.6 mg/L) [26,37,38,39,40,41].
According to Nasman et al. [42], the estimated individual F exposure from drinking water can be categorised into four groups: very low (<0.3 mg/L); low (0.3–0.69 mg/L); medium (0.7–1.49 mg/L); and high (≥1.5 mg/L). Based on this classification, we can categorise the bottled water samples from our study as follows: 85% (n = 34) with a very low concentration of F, 10% (n = 4) with a low concentration, and 5% (n = 2) with a high concentration of F (Table 1).
Based on our findings, where 85% of the evaluated waters had a F concentration below 0.3 mg/L, we consider their regular consumption to be safe for children and toddlers over 1 year of age. However, it is crucial to take into account the recommended daily adequate intakes of F for infants and toddlers under 1 year of age. For infants aged 0–6 months, the recommended intake is 0.01 mg/day, and for those aged 7–12 months, it is 0.5 mg/day [6]. Therefore, we recommend selecting water with the lowest possible F concentration for mixing infant formulas or preparing other types of food. This will help ensure that the F intake remains within the appropriate range for optimal dental health in this age group.
It has been suggested that F concentrations are lower in water packaged in glass containers compared to water at the source, due to the binding of F to the glass [41]. In our study, three of the brands were packaged in glass bottles, but none of them had recorded F levels on the label. As a result, it was not possible to directly compare the F concentration at the source with those specific brands. Nonetheless, based on the understanding that F levels may be lower in water packaged in glass containers, it can be recommended that individuals seeking even lower F concentrations consider opting for bottled water in glass containers.
Several limitations need to be considered in the interpretation of our data. Firstly, we only sampled still bottled water as it is consumed more frequently. Additionally, our sampling was based on specific brands and water sources, without considering potential variations within production batches. It is important to note that our study was geographically limited to one city, and therefore, the findings may not be representative of all bottled waters available in Romania. Furthermore, individual preferences of brands or types of bottled water were not taken into consideration. Moreover, flavoured drinking water bottles were not included in the study, along with electrolyte/sport water, soft drinks and other beverages that are available in the market.
Our study provides additional information on the safety of using natural mineral or spring waters, particularly in relation to the nutrition of infants, toddlers, and children who are more susceptible to the negative effects of increased F intake. Based on our findings, we recommend limiting the regular consumption of bottled waters with F concentration above 0.7 mg/L to occasional use.
The results of our study can contribute to the development of a guide for parents and specialists in the field regarding the intake amount of F from bottled water. It also underlines the importance of monitoring the daily intake of F from other sources.
A potential future research direction could consist of the evaluation of F concentrations in tap water and other beverages. Additionally, the relationship between F content in bottled waters, dental caries and DF prevalence could be examined throughout future clinical studies.

5. Conclusions

The present study identified that the F concentration in the bottled natural mineral or spring still water available on the market at the time of testing in Romania ranged between 0.0338 and 4.6262 mg/L.
The F content was listed on only 17.5% of the samples, highlighting the lack of routine reporting by the manufacturers of F levels on the labels.
According to the Romanian legislation regarding F content, which is in line with WHO regulations, the statement “product not recommended for regular consumption by infants and children under 7 years of age” was present on the label of 5% of the samples that registered F levels above 1.5 mg/dL. These were the only samples with a F concentration above 1.5 mg/L in our study.
The differences between the F levels listed on the label of bottled waters and those obtained in laboratory analysis were not statistically significant.

Author Contributions

Conceptualisation, E.M. and L.G.; Methodology, E.M., Y.D. and C.S.; Software, E.M. and A.S.; Validation, V.T. and C.S.; Formal Analysis, C.S.; Investigation, E.M., L.G. and Y.D.; Resources, E.M.; Data Curation, Y.D. and L.G.; Writing—Original Draft Preparation, E.M., L.G. and Y.D.; Writing—Review and Editing, E.M., L.G. and C.S.; Visualisation, E.M. and A.S.; Supervision and Project Administration, E.M., C.S. and A.S. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the “Grigore T. Popa” University of Medicine and Pharmacy Iasi, based on grant number 7373/30.04.2020.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Additional data that support our findings are available from the corresponding authors upon reasonable request.

Conflicts of Interest

The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.

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Table
Table 1. Fluoride (F) concentration of commercially available bottled water in Romania.
Table 1. Fluoride (F) concentration of commercially available bottled water in Romania.
Brand/Trade NameSource, Place and Country of OriginLabelled F Concentration (mg/L)Measured F Concentration (mg/L)Labelled Data about Safeness of Use in Infants
Alcalia **C-5, Velingrad, Bulgaria4.234.66Not
Devin **Spring Nr 5, Devin, Bulgaria3.693.71Not
Vittel kids **Grande Source, Vittel, FranceN/A0.314N/A
Vittel **Grande Source, Vittel, FranceN/A0.313N/A
Simplu, CarrefourParcului I, Azuga, Prahova, RomaniaN/A0.305N/A
Proxi, ProfiF7 Aqua, Carei, Satu Mare, RomaniaN/A0.3N/A
Fiji **Yaqara, Viti Levu, Fiji N/A0.232N/A
AquaviaA1, Bologa, Cluj, RomaniaN/A0.171N/A
Vreau din Romania, Kaufland *F6 ISPIF, Zacamant Boholt,
Hunedoara, Romania		N/A0.148N/A
Borsec *Faget Borsec, Borsec, RomaniaN/A0.14N/A
SanBenedetto
baby bottle **		Spring Antica Fonte Della Salute, Italy0.10.131N/A
Evian **Cachat, Evian- SAEME, FranceN/A0.126N/A
Voss **N-4730, Vatnestrom, NorwayN/A0.118N/A
Biborteni Batani *F1 SNAM, Biborteni Batani,
Covasna, Romania		N/A0.115N/A
Carpatina *C1, Domogled-Baile Herculane,
Caraș-Severin, Romania		N/A0.11N/A
Aqua Carpatica *Spring Haja, Paltinis, Suceava, RomaniaN/A0.108N/A
Zizin *F1 bis, F2, F4, Izv 1, Zizin, Brasov, RomaniaN/A0.105N/A
Artesia *FH Artezia 3, Sansimion, Harghita, RomaniaN/A0.103N/A
AuraSpring Ursoanea, Ocna de Fier,
Caras-Severin Romania		N/A0.1N/A
Peppa Pig my water **M7, Thesi Miloniana, Chania, GreeceN/A0.1N/A
Cheile Bicazului *FH1, Bicazul Ardelean, Neamt, RomaniaN/A0.0978N/A
DeceneuF1, Sindrilita, Ifov, RomaniaN/A0.0835N/A
SanBenedetto **Spring Benedicta, Scorze (Venice), Italy0.10.0799Safe
Acqua Panna **Scarperia e San Piero, Florence, ItaliyN/A0.0787N/A
Aqua Carpatica Kids *Spring Bajenaru, Paltinis, Suceava, RomaniaN/A0.0761N/A
Solan de Cabras **Solan de Cabras, Beteta (Cuenca), SpainN/A0.0755Safe
Dorna Izvorul Alb * White Spring, Dorna Candrenilor,
Suceava, Romania		N/A0.072N/A
Keia Izvorul Zaganului Junior *Spring Zaganului, Cheia, Prahova, RomaniaN/A0.072N/A
Izvorul Muntelui *Spring Muntelui, Bicaz-Chei, Neamt, Romania0.060.069N/A
Perla Harghitei *F1, F2 SNAM, Sancraieni, Harghita, RomaniaN/A0.065N/A
Perla Harghitei *FH Artezia 2, Sansimion, Harghita, RomaniaN/A0.0635N/A
AzugaParcului III, Azuga, Prahova, RomaniaN/A0.0584N/A
Aquatique *Spring Busteni, Busteni, Prahova, Romania0.060.0509Safe
Bucovina *C7, Dorna Candrenilor, Suceava, Romania0.030.0461Safe
Izvorul Minunilor *Spring Minunilor, Stana de Vale,
Bihor, Romania		N/A0.0448Safe
CarreffourUrechea, Azuga, Prahova, RomaniaN/A0.0421N/A
AuchanS3E1, Cheia Prahova, RomaniaN/A0.0406N/A
Glaceau smartwater **K-76, Zalaszentgrot, HungaryN/A0.0406N/A
Apa Craiului *Spring 5, Galgoaie, Arges, RomaniaN/A0.0373N/A
Izvorul dintre BraziS4, Cheia, Prahova, RomaniaN/A0.0338N/A
* From official list of natural mineral waters recognised in Romania by ANRM law No. 116/2023. ** Imported brand. N/A—no available data.
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Mihalas, E.; Gavrila, L.; Sirghe, A.; Toma, V.; Decolli, Y.; Savin, C. Evaluation of Fluoride Concentration in Commercially Available Bottled Water in Romania—A Potential Risk Factor for Dental Fluorosis. Appl. Sci. 2023, 13, 7563. https://doi.org/10.3390/app13137563

AMA Style

Mihalas E, Gavrila L, Sirghe A, Toma V, Decolli Y, Savin C. Evaluation of Fluoride Concentration in Commercially Available Bottled Water in Romania—A Potential Risk Factor for Dental Fluorosis. Applied Sciences. 2023; 13(13):7563. https://doi.org/10.3390/app13137563

Chicago/Turabian Style

Mihalas, Eugeniu, Laura Gavrila, Ana Sirghe, Vasilica Toma, Yllka Decolli, and Carmen Savin. 2023. "Evaluation of Fluoride Concentration in Commercially Available Bottled Water in Romania—A Potential Risk Factor for Dental Fluorosis" Applied Sciences 13, no. 13: 7563. https://doi.org/10.3390/app13137563

APA Style

Mihalas, E., Gavrila, L., Sirghe, A., Toma, V., Decolli, Y., & Savin, C. (2023). Evaluation of Fluoride Concentration in Commercially Available Bottled Water in Romania—A Potential Risk Factor for Dental Fluorosis. Applied Sciences, 13(13), 7563. https://doi.org/10.3390/app13137563

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