PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of jodddLink to Publisher's site
 
J Dent Res Dent Clin Dent Prospects. 2013 Winter; 7(1): 1–7.
Published online Feb 21, 2013. doi:  10.5681/joddd.2013.001
PMCID: PMC3593199
Fluoride Concentration of Drinking Waters and Prevalence of Fluorosis in Iran: A Systematic Review
Saber Azami-Aghdash, 1 Morteza Ghojazadeh, 2 Fatemeh Pournaghi Azar, 3 Mohammad Naghavi-Behzad, 4 Mostafa Mahmoudi, 5 and Zahra Jamali 6 , 7 *
1Tabriz Health Services Management Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
2Associate Professor, Liver and Gastrointestinal Disease Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
3Assistant Professor, Department of Operative Dentistry, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran
4Medical Philosophy and History Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
5Assistant Professor, Department of Oral & Maxillofacial Pathology, Faculty of Dentistry, Birjand University of Medical Sciences, Birjand, Iran
6Dental and Periodontal Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
7Assistant Professor, Department of Oral Medicine, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran
*Corresponding Author; z.jamali55/at/gmail.com
Received December 25, 2012; Accepted January 31, 2013.
Background and aims
The aim of the present study was to systematically review fluoride concentration of drinking waters and prevalence of fluorosis in Iran through systematically evaluating results of studies conducted in this regard.
Materials and methods
In this systematic review study, the required data was collected using keywords including drinking water fluoride, fluoride concentration, Fluorosis, dent*, Iran*, and their Persian equivalents through PubMed, ScienceDirect, IranMedex, SID, MEDLIB, and Magiran databases. Out of 617 articles, 29 articles were finally considered after excluding the remaining articles which were not related to the study objectives. Following precise studying and extraction, the relevant data were summarized in extraction tables and analyzed manually. Excel 2007 software was used to draw diagrams.
Results
4434 samples of surface, ground, and tap water resources collected within 236 months during all seasons in 17 provinces of Iran were used in 29 articles determining fluoride concentrations of drinking water. Average fluoride concentration was estimated to be 0.43 ± 0.17 ppm with zero and 3.06 as minimal and maximal values. The least concentration was seen in tap water. Fluoride concentration of only three provinces was in accordance with the global standard. According to estimations, prevalence of fluorosis was 61% with only 1% as severe fluorosis.
Conclusion
Despite lower than standard concentrations of fluoride in drinking water, a relatively high level of fluorosis was seen in Iran.
Keywords: Concentration, drinking waters, fluoride, fluorosis, prevalence
At present, fluoride concentration of drinking water and the dental caries are regarded as one of the most common health problems and main concerns of dentists,1 since low fluoride concentration of the consumed water, i.e. less than the standard rate (1.2-6 ppm), results in caries,2 and if progressed, fluorosis.3 According to World Health Organization, standard rate of fluoride of drinking water is 0.5–1 ppm.4 Studies conducted at different parts of the world reported variable concentrations of water fluoride and fluorosis,5-7 such that it was 0.19 ppm in South Africa study with prevalence rate of 47% for fluorosis.3 According to World Health Organization, highest rate of prevalence of fluorosis is seen in China and India.6 Studies conducted in Iran reported different fluoride concentrations of water and prevalence of fluorosis.8-11 Although different policies including adding of fluoride to drinking water, use of fluoride-contained toothpastes and mouthwashes are made when there is insufficient fluoride concentration in drinking waters, there is controversies among experts in this regard.2,4 Standard value of water fluoride varies according to ecological and social conditions.5,8 In Iran, standard values should be identified for every region considering their ecological conditions since Iran has different weather and the temperature varying +50°C to −20°C in some regions.8 Although there are several studies conducted at different parts of Iran, there is not any comprehensive study evaluating fluoride concentration of waters of different resources and prevalence of fluorosis, according to results of articles review. Therefore, the present study aimed at systematically evaluating the studies published on fluoride concentration of different water sources as well as prevalence of fluorosis and providing a clear and comprehensive viewpoint from status of fluoride found in drinking waters and prevalence rate of fluorosis.
In this systematic review study, the relevant data was collected using keywords including “drinking water fluoride,” “fluoride concentration,” “fluorosis,” “dent*”, “Iran*” and their Persian equivalents through PubMed, ScienceDirect, IranMedex, SID, MEDLIB, and Magiran databases. Articles published from 1990 to 2012, articles reporting fluoride concentration of drinking water and prevalence of fluorosis, and articles published in both Persian and English languages were regarded as inclusion criteria of the study. Articles presented at conferences as well as papers evaluating fluoride in resources other than water, e.g. tea, agricultural products, soil, etc., were excluded from the study. Following database searching, some authentic journals were manually searched in order to identify and cover more published articles. After excluding those articles relating weakly to the study objectives and selecting main articles, references of the selected articles were researched to being assured of identification and evaluation of the available articles and find more related articles. Out of 617 articles, 29 completely related articles were finally considered and the remaining not properly related to the study objecttives was excluded. The selected articles were completely and exactly evaluated (Figure 1). There were two articles published in English-language journals. Following extraction of the relevant data, they were initially summarized in extraction table and analyzed manually. Excel 2007 software was used to draw diagrams.
Figure 1
Flowchart of the study selection process.
In this study, out of 617 articles, 29 articles completely related to the study objectives were finally selected, exactly studied, and the relevant data extracted (Tables (Tables11 & 2).
Table 1
Table 1
Extraction table for fluoride concentration of drinking waters in Iran
Table 2
Table 2
Extraction table for prevalence of fluorosis in Iran
Time interval of the evaluated articles varied from 1991 to 2009. Generally, the studies covered 17 Iranian provinces. SPANDS sampling method was used to sample water in all studies within 236 months during the study period. It should be noted that 16, 12, 11, and 8 studies were conducted in spring, summer, fall, and winter, respectively. Resources used in 8, 17, 4, and studies included well water, urban and rural tap water, ground waters (spring and duct), and surface waters (river and pond). The evaluated studies considered 4434 samples of different water resources of the country. Also, 3727 students ranging 7-16 years old were studied to evaluate prevalence of fluorosis.
To determine fluorosis severity, Dean Index was used in all studies. Figure 2 shows the mean fluoride concentration of waters in different evaluated resources based on the different years.
Figure 2
Mean fluoride concentration of different resources waters evaluated in the studies based on year.
As seen, the highest rate of fluoride concentration of different water resources is attributed to the year 2002.
The average fluoride concentration of drinking waters was 0.43 ± 0.17 ppm with zero and 3.06 as its minimal and maximal values obtained for Kermanshah and Khorasan Razavi provinces, respectively.
Figure 3 demonstrates mean fluoride concentration of waters based on the different water resource. According to Figure 3, drinking waters of well has the highest mean concentration of the studied waters. The least one belongs to urban and rural tap waters. As mentioned, Iran has different ecological condifmean range of fluoride concentration in waters of provinces. Figure 4 demonstrates fluoride concentration of drinking waters in every province. As seen on the figure, Yazd and Mazandaran provinces have the highest and lowest rates of fluoride concentration. Tehran is regarded as a province with low fluoride concentration. As seen, only three provinces are at the standard range recommended by World Health Organization.
Figure 3
Mean fluoride concentration of different resources waters evaluated in the studies based on the understudy water resource.
Figure 4
Mean fluoride concentration of different resources waters evaluated in the studies based on the understudy provinces.
Figure 5 shows prevalence of fluorosis among samples of the evaluated studies based on its severity. According to Figure 5, there is normal fluorosis in about 39% of the samples and severe fluorosis was seen in only about 1% of the samples.
Figure 5
Prevalence of fluorosis based on its severity among the understudy samples in the evaluated studies
In 4434 samples evaluated in the conducted studies, average fluoride concentration was estimated 0.43 ± 0.17 ppm with zero and 3.06 as minimal and maximal values. The highest and lowest concentrations were seen in well, and urban and rural tap waters, respectively. Out of 3727 studied students, only 1% suffered from severe fluorosis.
Mean scores obtained from the studies conducted in Iran (0.43 ± 0.17 ppm) is less than standard values of 0.7 ppm for tropical and 1.2 ppm for cold regions recommended by World Health Organization. Therefore, appropriate plans and policies should be designed and executed to standardize fluoride concentration of different water resources of Iran. According to results of the study, most interventions should focus on increasing fluoride of drinking water since fluoride insufficiency leads to caries.12 Although fluoride concentration in drinking waters of Iran is less than standard values and their fluoride content should be increased, its disadvantages should also be considered in planning and policy makings, as increasing fluoride concentration above the permitted level would lead to undesirable disorders and complications such as mental disability, change of human chromosome structure, renal damages, and osteomalacia.13-15 Additionally, the results of global studies have demonstrated that the higher the fluoride concentration of drinking waters, the higher the prevalence rate of fluorosis in the population.16-18 According to recent reports provided by experts of Iran Fluoride Scientific Association, exceeding fluoride concentration of drinking waters from 0.7 mg/l may increase disadvantages rather than desirable effects of caries prevention.19 Reviewing studies conducted on measurement of drinking water fluoride in the US demonstrated that adding fluoride to drinking waters was not only useless but entailed certain disadvantages and economical costs.20 By precise evaluation of drinking water fluoride and its comparison with standards, authorities and experts should make appropriate decisions and offer proper plans to exactly adjust fluoride concentration of drinking waters.
Fluoride concentration of drinking waters of every province is demonstrated in Figure 4. According to this figure, fluoride concentrations of drinking waters of only three provinces are in accordance with standards defined by World Health Organization. Also, high fluoride concentration is seen in drinking water of provinces located at tropical regions where the water is mainly supplied by wells and ground waters. Necessary actions should be taken to reduce fluoride concentration in these regions. On the contrary, provinces located at cold and mountainous regions have low concentrations of fluoride. Water in these provinces is mainly supplied by surface and river waters. The regions require policies to increase fluoride level of drinking water.
In researches evaluated in this study, 3727 subjects were studied considering fluorosis. Generally, about 2274 cases (61%) suffered from different degrees of fluorosis. Of these, only 38 students (1%) experienced severe fluorosis. According to reports, the prevalence of fluorosis with fluoride concentration of 0.19 ppm was 47% in South Africa.22 Considering fluoride concentration found in the present study, it can be stated that the prevalence of fluorosis in South Africa is higher than Iran. The study conducted on 12-15 year-old students in Khuzestan reported prevalence rate of fluorosis about 51%, which is just below the average value calculated for the country. The results of the present study are in accordance with those of the Hormozgan province.23 Despite low fluoride concentration in drinking waters of Iran, high prevalence rate of fluorosis is seen in this study. Other resources including foodstuff, tea, and toothpastes may be regarded as the most important and justifiable sources of high fluoride dose thath individual receive. Further studies are warranted in order to identify main factors resulting in high prevalence of fluorosis.
Lack of meta-analyses of the extracted data due to different ways of data presentation is regarded as one of the drawbacks of the present study. It is recommended to use the same specific procedures in presenting the results of such studies. This was the reason why it was not possible to statistically evaluate the relationship between fluoride concentration and prevalence of fluorosis in this study.
The results of the present study demonstrate that although average fluoride concentration in drinking waters of Iran is less than recommended standards, it is still higher than standard level in some regions. Generally, there are different concentrations of water fluoride in Iran due to variable ecological conditions of the country. Considering different effects of variable concentrations of fluoride, setting uniform policies for all regions of the country may result in undesirable complications. Therefore, appropriate policies should be made based on regional conditions as well as specific fluoride concentrations. Also, high prevalence of fluorosis in Iran was noted in spite of low fluoride concentrations, which may have resulted from fluoride uptake from other resources.
  • Damle SG. Textbook of Pediatric Dentistry. 3rd ed. India: ARYA (Medi) Publishing House; 2006.
  • Zimmers A. Caries preventive effects of fluoride products when used in conjunction with fluoride dentifrice. Caries Res. 2001;35:18–21. [PubMed]
  • Douki Zbidi N, Zouiten S, Hajjami H, Baccouche C. Different treatment of fluorosis stains. Dental News. 2003;10:45–9.
  • Seppä L. The future of preventive programs in countries with different systems for dental care. Caries Res. 2001;35 Suppl 1:26–9. [PubMed]
  • Nagendra Rao CR. Fluoride and environment—a review, 2003. Available at: http://www.yorku.ca/bunchmj/ICEH/proceedings/Rao_N_ICEH_papers_386to399.pdf.
  • Bo Z, Mei H, Yongsheng Z, Xueyu L, Xuelin Z, Jun D. Distribution and risk assessment of fluoride in drinking water in the west plain region of Jilin province, China. Environ Geochem Health. 2003;25:421–31. [PubMed]
  • Singh B, Gaur S, Garg VK. Fluoride in drinking water and human urine in southern haryana, India. J Hanzard Mater. 2007;144:147–51. [PubMed]
  • Dindar Loo K, Ali Pour V, Farshid Far GhR. Chemical quality of drinking water in Bandar Abbas. Journal of Hormozgan University of Medical Sciences 2006;10:57-62. [In Persian]
  • WHO Guidelines for Drinking Water Quality. Second Addendum to Third Edition. Volume 1 Recommendations. Available from: http://www.who.int/water_sanitation_health/dwq/secondaddendum20081119.pdf.
  • Asghari Moghadam A, Jomeyri R, Mohammadi A. Source of high fluoride in groundwater of basaltic lavas of Bazargan-Poldasht Plains and its ill effects on human health. Journal of Enviromental Studies 2007;33:25-32. [In Persian]
  • Rahimzadeh H, Kargar M, Dadban Y, Birami S. Fluoride Level in Drinking Water Resources of Gorgan Rural Regions, 1385. Medical Laboratory Journal 2008;1:45-8. [In Persian]
  • Pizzo G, Piscopo MR, Pizzo I, Giuliana G. Community water fluoridation and caries prevention: a critical review. Clin Oral Invest. 2007;11:189–93. [PubMed]
  • World Health Organization. Fluoride in Drinkingwater, Background document for development of WHO Guidelines for Drinking-water Quality, 2004.Available at: http://www.who.int/water_sanitation_health/dwq/chemicals/fluoride.pdf.
  • Institute national de santé publique du Québec. Water fluoridation: an analysis of the health benefits and risks, 2007. Available from: www.inspq.qc.ca/pdf/publications/705-Water Fluoration.pdf (Accessed April 2011).
  • American Dental Association. Fluoridation Facts, 2005. Available from http://www.adacatalog.org (Accessed April 2011).
  • Xiang Q. Relationships between daily total fluoride intake and dental fluoroisis and dental caries. Journal of Nanjing Medical University. 2009;23:33–9.
  • Palmer C, Wolfe SH; American Dietetic Association. Position of the American Dietetic Association: the impact of fluoride on health. J Am Diet Assoc 2005;105:1620-8. [PubMed]
  • Narbutaite J, Vehkalahti M, Mil Hiuviene S. Dental fluorosis and dental caries among 12-yr-old children from high-and low-fluoride areas in Lithuania. Eur J oral Sci. 2007;115:137–42. [PubMed]
  • Dobaradaran S, Mahvi AH, Dehdashti S. Fluoride content of bottled drinking water available in Iran. Fluoride 2008;40:93-4. [In Persian]
  • Carton RJ. Review of the 2006 United States National Research Council report: Fluoride in drinking water. Fluoride. 2006;39:163–72.
  • Almasi H, Mostafaie GR, Iranshahi L. Fluor concentration of drinking water of Kashan in 1999. Feyz, Kashan University of Medical Sciences & Health Services 2002;6:37-43. [In Persian]
  • Grobleri SR, Louw AJ, Van Kotze TJ. Dental fluorosis and caries experience in relation to three different drinking water fluoride levels in South Africa. Oral and Dental Research Institute, University of Stellenbosch Faculty of Dentistry. Tygerberg, South Africa. Int J Paediatr Dent. 2001;11:372–9. [PubMed]
  • Davari A, Ezoddini Ardakani F, Majidi M, Abdollahi Alibeyk F. The prevalence of fluorosis in students 15-12 years old, Aghda, Yazd. Scientific Quarterly of Yazd Health School 2005;4:27-35. [In Persian]
  • Azimi AA, Bid Hendi QR, Hashemi H, Maham Y. Concentration of fluoride in drinking water supply surface water sources in Tehran. Journal of Environmental Studies 2003;29:35-40. [In Persian]
  • Hosseinpour Feizi MA, Mosaferi M, Dastgiri S, Mehdipour M, Khosha A. Analysis of fluoride and some quality parameters of drinking water in East Azerbaijan province. Tabriz University of Medical Sciences Journal. 2012;33:35-50. [In Persian]
  • Mohseni Sajadi M, Afyuni M, Khademi H, Mohseni Movahed SA, Ayubi S. Spatial variability of fluoride in groundwater and soils in some areas of Arak Plain. Journal of Water and Soil 2011;25:1033-41. [In Persian]
  • Sahargahi B, Por Mahr R, Razaei M, Naderi MR, Sherzadi A, Mohammadi B, et al. Comparative of Eslamabad city drink water flouride concentration with 80 decade standards. Kermanshah University of Medical Science Journal 2012;16:84-5. [In Persian]
  • Khademi H, Talab M. Relationship of fluorosis and dental caries with drink water fluoride concentration. Research in Medical Science 2001;5:213-5. [In Persian]
  • Mirghaffari N, Shariatmadari H. Fluoride distribution in groundwater, soil and some crops in Isfahan region. JWSS - Isfahan University of Technology 2007;11:43-51. [In Persian]
  • Javan G, Mostaghni E, Jafari S, Amini B, Hematei Nejad B. Dental fluorosis and urinary fluoride in 10-12 years old adolescents of Bushehr port. Iranian South Med J 2005;8:165-71. [In Persian]
  • Rajaei Q, Mehdinejad MH, Hesari Motlagh S. A Survey of chemical quality of rural drinking water of Birjand and Qaen Plains, Iran. Health Care Research 2012;7:737-45. [In Persian]
  • Shahriari T, Azizi M, Sharifzadeh G, Hajiani M, Zeraatkar V, Aliabadi R. Evaluation of fluorine concentration in drinkingwater sources in South Khorasan (2008-2009). Journal of Birjand University of Medical Sciences 2010;17:33-41. [In Persian]
  • Pooreslami H, Khazaeli P, Masoodpoor H. Fluoride Content of Drinking Waters in Kerman/Iran. Journal of Kerman University of Medical Sciences 2008;15:235-42. [In Persian]
  • Basir L, Khaneh Masjedi M, Haghighi M, Neamatiasl S. Comparative investigation on the prevalence of fluorosis and DMFT and their relations with the amount of fluoride in all the three drinking water resources (Maroon, Karoon and Karkheh rivers) among 10-12 school students in Khuzestan in 2002. Journal of Dentistry, Shahid Beheshti University of Medical Sciences 2006;24:14-23. [In Persian]
  • Nasehinia HR, Naseri S. A survey of fluoride dosage in drinking water and DMF index in Damghan city. Water and Sewage 2005;49:70-2. [In Persian]
  • Ramazani G, Valaei N, Rojhani Shirazi M. Survey of flouride concentration in Zanjan Provence cities drink waters in summer 2010. Quarterly of Research in Dental Sciences 2010;6:69-73. [In Persian]
  • Ramazani G, Valaei N, Shahmirzadi S, Saadat S. Survey of flouride concentration in Sari city drink waters in spring 2010. Quarterly of Research in Dental Sciences 2010;6:72-6. [In Persian]
  • Ramazani G, Khajavi Khan A, Shahmirzadi S, Saadat S. Survey of flouride concentration in Shiraz city drink waters in spring 2010. Quarterly of Research in Dental Sciences 2010;6:79-83. [In Persian]
  • Rahmani K, Rahmani A, Rahmani H, Mahvi AH, Yousefi M, Goadini K. Effects of fluoride on child dental caries in Noorrabad Mamasani town in 2008. Scientific Journal of Ilam University of Medical Sciences 2012;19:12-9. [In Persian]
  • Davari A, Danesh Kazemi A, Mohammadi H, Abdollahi Alibeik F. The Prevalence of dental fluorosis and its relationship with the level of fluoride in 12-15 years old guidance school students in Southern Iran. Shiraz Univ Dent J 2004;5:36-43. [In Persian]
  • Amouei A, Mahvi A, Mohammadi A, Asgharnia H, Fallah S, Khafajeh A. Fluoride concentration in potable groundwater in rural areas of Khaf city, Razavi Khorasan province, Northeastern Iran. The International Journal of Occupational and Environmental Medicine 2012;3:201-3. [In Persian] [PubMed]
  • Moslemi M, Khalili Z, Karimi S, Shadkar MM. Fluoride concentration of bottled water and tap water in Tehran, Iran. J Dent Res Dent Clin Dent Prospects. 2011;5:132–5. [PMC free article] [PubMed]
  • Sapahri G, Bazrafshan MR, Tabasian A, Hosseinzadeh M. Measure of Kerman city drink water fluoride concentration. Dental Journal 1998;9:83-90. [In Persian]
  • Abbasi M. Survey and detemind of Zanjan city drink water fluoride concentration. Zanjan University of Medical Science Journal 1995;3:22-32. [In Persian]
  • Almasei H, Mostafaei G, Iranshahi L. Survey of Kashan city drink water fluor concentration in 2000. Feaiz 2003;21:37-43. [In Persian]
  • Samarghandi M, Sadri G. Determination of fluoride content in drinking water of Hamedan and Bahar cities since 1998-1999. Journal of Hamedan University of Medical Sciences 2001;8:42-7. [In Persian]
  • Araghizadeh A, Zareh S, Radafshar Z, Chanedeh S. Prevalence of dental fluorosis in Bandarabas city school childs. Hormozgan Medical Journal 2005;8:13-8. [In Persian]
  • Shidfar F, Aghilinejad M, Ameri A, Motavalian SA, Radfar A, Hoseini S. Determination of DMF index among workers of industrial city of Ilam-Iran and its relation with fluoride content of potable water. Iran Occupational Health 2008;4:64-8. [In Persian]
  • Mortazavi M, Bardestani G, Danesh M. The Prevalence of fluorosis and DMFT among 11-16 years old school children in Dayyer (Boshehr province). Scientific Quarterly of Shiraz University of Medical Sciences 2003;3:66-73. [In Persian]
  • Honarmand M, Molashahi Farad L, Shirazei M, Abbasi H. Epidemiology of dental fluorosis in 7-10 years old students refered to Zahedan Social Dental Center, 2007. Iran Epidemiology Journal 2012;7:66-72. [In Persian]
  • Mortazavi V, Karimian R. Prevalence of dental fluorosis and determined DMFT index in Jarghoveah guidence schools. Research in Medical Sciences 2001;5:260-4. [In Persian]
Articles from Journal of Dental Research, Dental Clinics, Dental Prospects are provided here courtesy of
Tabriz University of Medical Sciences