Indiana University-Purdue University Indianapolis (IUPUI) / In 1973 the state of Indiana initiated a program to fluoridate the water in rural school systems to a concentration of 4.0 ppm. Today, the optimal concentration is 3.5 ppm. When it was initiated, school water fluoridation was a popular method of providing fluoride supplementation to children who didn't have access to community-fluoridated water. Today, only Indiana runs a school water fluoridation program, and the CDC has stated that continuation of these efforts should be based on caries risk, alternate preventive measures, and periodic evaluation of program effectiveness. The purpose of this study was to assess the efficacy of the Indiana school water fluoridation program in order to determine if children participating in the program develop less caries with no increased risk of fluorosis. Four hundred sixty students were examined from Northwestern Consolidated School Corporation in Shelby County (fluoridated school) and North Knox School Corporation in Knox County (non-fluoridated school). Three hundred ninety-one students were statistically evaluated, 204 from the fluoridated school and 187 from the non-fluoridated school. A thorough visual examination was conducted by the same examiner collecting data on DMFS, defs, and fluorosis in grades 1-6. DMFS scores were 28 percent less for fluoridated students compared with non-fluoridated students (0.95 versus 1.32). Although the effect of fluoridation status on caries in permanent teeth is not statistically significant, the author believes this difference may be clinically significant. Analysis of defs scores showed fluoridated students with 6 percent less defs than non-fluoridated students, although the results were not statistically significant. Only 3.92 percent of the students at the fluoridated school showed fluorosis, while 10.16 percent showed signs of mild fluorosis at the non-fluoridated school. Conclusion: While not statistically significant, children attending the school fluoridated with 3.5 ppm of fluoride developed less caries and suffered no increase of fluorosis compared with children attending schools not participating in the school fluoridation program. Further analysis is necessary through statewide blind examinations at numerous school systems to further assess the efficacy of the Indiana School Water Fluoridation Program.

Text in Afrikaans / Die tydruimtelike variasie in die fluoriedinhoud vannatuurlike drinkwater en in die voorkoms van tandfluorose, die verband tussen hierdie veranderlikes asook hulle kovariasie is op 'n hoe resolusievlak in geselekteerde endemiese gebiede ondersoek. Die drie studiegebiede verskil grootliks van mekaar wat sommige fisies- en menslik-geografiese kenmerke betref, maar ondergrondse water was oral die belangrikste bron van drinkwater. Ioonspesifieke analise en laboratoriumtegnieke is gebruik om die fluoriedinhoud van die drinkwater uit 517 bronne te bepaal. Die tande van 3 068 kinders is klinies en fotografies ondersoek. Die erkende Tooth Fluorosis Index en die indeks van Dean is gebruik om die voorkoms van fluorose te beskryf. Grafiese tegnieke, beskrywende statistieke en nieparametriese analise van variansietoetse is gebruik om die voorkoms en tydruimtelike variasiepatrone van die sleutelveranderlikes in elke studiegebied, asook die verskillende ruimtelike eenhede binne die studiegebiede, te beskryf. Die verband tussen die sleutelveranderlikes asook hul intra- en interareale kovariasie is ontleed. Daar is gevind dat die fluoriedinhoud van die ondergrondse water in die Pilanesberg- en Hammanskraal-studiegebied relatief hoog tot hoog is en die in die Vrystaat-studiegebied relatief laag. Ruimtelike veranderlikheid met groot verskille oor klein afstande kenmerk die fluoriedinhoud van ondergrondse water ongeag die gesteentes waaruit dit onttrek word. Middelwaardes bied ontoereikende beskrywings van die fluoriedgehalte van die drinkwater. Die skep van nuwe drinkwaterbronne veroorsaak langtermynvariasie in die fluoriedinhoud van die beskikbare drinkwater. Fluoroseprevalensie in die studiegebiede bet van 62% tot 87% gewissel, met meer ernstige aantasting in die Pilanesberg- en Hammanskraal-gebied as in die Suid-Vrystaat. Beduidende intra-areale ruimtelike variasie is 'n wesenlike kenmerk van die voorkoms van fluorose in al drie studiegebiede. In alle gevalle het die variasiepatroon in die fluoriedinhoud van die drinkwater die in die voorkoms van fluorose slegs gedeeltelik verklaar. Sporadiese en/of periodieke kortstondige blootstelling aan hoe fluoriedkonsentrasies lei tot emstige aantasting ten spyte van die gereelde gebruik van water met 'n laefluoriedinhoud. Ligte fluorose ontwikkel geredelik in assosiasie met <0,5 mgF-/l en matige fluorose in assossiasie met 0,5-0,7 mgF-/l, die optimum konsentrasieinterval vir fluoridasie in Suid-Afrika. / The spatiotemporal variation in the fluoride content of natural drinking water and the occurrence of dental fluorosis, the relation between these variables as well as their covariation were investigated at a high resolution level in selected endemic areas. Groundwater was the most important source of drinking water in all three study areas, but they differed markedly in respect of some physical and human geographical characteristics. Ion specific analysis and laboratory techniques were used to determine the fluoride content of the water from 517 sources. The teeth of 3 068 children were examined clinically and photographically. The fluorosis was scored according to the Tooth Fluorosis Index and Dean's classification. Graphical techniques, descriptive statistics and nonparametric analysis of variance were used to describe the occurrence and variation patterns of the key variables in the different spatial units is each study area. The relation between the variables as well as their intra and interareal covariation were analysed. The fluoride content of the groundwater in the Pilanesberg and Hammanskraal areas was relatively high to high; in the southern Free State it was relatively low. Spatial variability and significant differences over small distances typify the fluoride content of the groundwater, irrespective of the aquifer. Central statistics inadequately describe the fluoride quality of the natural drinking water. The development of new water sources causes long term variation in the fluoride content of the available drinking water. Fluorosis prevalence varied form 62% to 87%, with more severe fluorosis in Pilanesberg and Hammanskraal than in the southern Free State. Significant intra-areal spatial variation is an attribute of fluorosis in all three study areas. In all cases the variation pattern in the fluoride content of the drinking water partly explained the spatial pattern in the occurrence of fluorosis. Sporadic and/or periodic brief exposure to high fluoride concentrations leads to severe fluorosis despite regul~ usage of water with a low fluoride content. Mild fluorosis readily develops in association with <0,5 mgF-1~ and medium fluorosis in association with 0,5-0,7 mgF-/l, the optimum concentration interval for fluoridation in South Africa. / Geography / D. Phil. (Geografie)

Text in Afrikaans / Die tydruimtelike variasie in die fluoriedinhoud vannatuurlike drinkwater en in die voorkoms van tandfluorose, die verband tussen hierdie veranderlikes asook hulle kovariasie is op 'n hoe resolusievlak in geselekteerde endemiese gebiede ondersoek. Die drie studiegebiede verskil grootliks van mekaar wat sommige fisies- en menslik-geografiese kenmerke betref, maar ondergrondse water was oral die belangrikste bron van drinkwater. Ioonspesifieke analise en laboratoriumtegnieke is gebruik om die fluoriedinhoud van die drinkwater uit 517 bronne te bepaal. Die tande van 3 068 kinders is klinies en fotografies ondersoek. Die erkende Tooth Fluorosis Index en die indeks van Dean is gebruik om die voorkoms van fluorose te beskryf. Grafiese tegnieke, beskrywende statistieke en nieparametriese analise van variansietoetse is gebruik om die voorkoms en tydruimtelike variasiepatrone van die sleutelveranderlikes in elke studiegebied, asook die verskillende ruimtelike eenhede binne die studiegebiede, te beskryf. Die verband tussen die sleutelveranderlikes asook hul intra- en interareale kovariasie is ontleed. Daar is gevind dat die fluoriedinhoud van die ondergrondse water in die Pilanesberg- en Hammanskraal-studiegebied relatief hoog tot hoog is en die in die Vrystaat-studiegebied relatief laag. Ruimtelike veranderlikheid met groot verskille oor klein afstande kenmerk die fluoriedinhoud van ondergrondse water ongeag die gesteentes waaruit dit onttrek word. Middelwaardes bied ontoereikende beskrywings van die fluoriedgehalte van die drinkwater. Die skep van nuwe drinkwaterbronne veroorsaak langtermynvariasie in die fluoriedinhoud van die beskikbare drinkwater. Fluoroseprevalensie in die studiegebiede bet van 62% tot 87% gewissel, met meer ernstige aantasting in die Pilanesberg- en Hammanskraal-gebied as in die Suid-Vrystaat. Beduidende intra-areale ruimtelike variasie is 'n wesenlike kenmerk van die voorkoms van fluorose in al drie studiegebiede. In alle gevalle het die variasiepatroon in die fluoriedinhoud van die drinkwater die in die voorkoms van fluorose slegs gedeeltelik verklaar. Sporadiese en/of periodieke kortstondige blootstelling aan hoe fluoriedkonsentrasies lei tot emstige aantasting ten spyte van die gereelde gebruik van water met 'n laefluoriedinhoud. Ligte fluorose ontwikkel geredelik in assosiasie met <0,5 mgF-/l en matige fluorose in assossiasie met 0,5-0,7 mgF-/l, die optimum konsentrasieinterval vir fluoridasie in Suid-Afrika. / The spatiotemporal variation in the fluoride content of natural drinking water and the occurrence of dental fluorosis, the relation between these variables as well as their covariation were investigated at a high resolution level in selected endemic areas. Groundwater was the most important source of drinking water in all three study areas, but they differed markedly in respect of some physical and human geographical characteristics. Ion specific analysis and laboratory techniques were used to determine the fluoride content of the water from 517 sources. The teeth of 3 068 children were examined clinically and photographically. The fluorosis was scored according to the Tooth Fluorosis Index and Dean's classification. Graphical techniques, descriptive statistics and nonparametric analysis of variance were used to describe the occurrence and variation patterns of the key variables in the different spatial units is each study area. The relation between the variables as well as their intra and interareal covariation were analysed. The fluoride content of the groundwater in the Pilanesberg and Hammanskraal areas was relatively high to high; in the southern Free State it was relatively low. Spatial variability and significant differences over small distances typify the fluoride content of the groundwater, irrespective of the aquifer. Central statistics inadequately describe the fluoride quality of the natural drinking water. The development of new water sources causes long term variation in the fluoride content of the available drinking water. Fluorosis prevalence varied form 62% to 87%, with more severe fluorosis in Pilanesberg and Hammanskraal than in the southern Free State. Significant intra-areal spatial variation is an attribute of fluorosis in all three study areas. In all cases the variation pattern in the fluoride content of the drinking water partly explained the spatial pattern in the occurrence of fluorosis. Sporadic and/or periodic brief exposure to high fluoride concentrations leads to severe fluorosis despite regul~ usage of water with a low fluoride content. Mild fluorosis readily develops in association with <0,5 mgF-1~ and medium fluorosis in association with 0,5-0,7 mgF-/l, the optimum concentration interval for fluoridation in South Africa. / Geography / D. Phil. (Geografie)

Introdução: A fluoretação da água dos sistemas de abastecimento é reconhecida como política pública eficaz no controle da doença cárie em nível populacional. Dentre os países que adotam a política, foram observadas desigualdades na distribuição dos serviços entre seus entes federativos, levando a necessidade de pesquisas mais aprofundadas com ointuito de identificar os determinantes da sua implantação. Objetivo: Foi investigadasituação da fluoretação da água dos sistemas de abastecimento dos municípios do Brasil, explorando o papel de variáveis contextuais na oferta deste serviço. Métodos: A partir de dados primárias do Censo Demográfico para o ano 2010 e a Pesquisa Nacional de Saneamento Básico de 2008, e, utilizando as divisões político-territoriais de região de saúde/município, verificou-se a possibilidade da oferta do serviço de fluoretação exibir relação de dependência com características das empresas prestadoras dos serviços de saneamento, e, com características contextuais das regiões de saúde em que os municípios estão inseridos. A análise para ambas foi ajustada por variáveis de características municipais. Resultados: 60% dos municípios contavam com serviço de fluoretação. Em análise das características das empresas de saneamento (natureza jurídica, esfera administrativa e forma de execução), estas mantiveram-se associadas positivamente independente das características municipais. Administrações municipais e empresas privadas associadas ou não a entidades públicas estiveram associadas a ausência de provisão do serviço.A oferta de fluoretação se alterou conforme as variáveis contextuais das regiões de saúde, eram maiores as chances de o serviço estar ausente em municípios pertencentes a regiões de saúde onde eram elevadas as mortalidades infantil e ocasionadas doença diarreica aguda, onde houvesse maior a proporção de pessoas com baixa renda e nas regiões saúde pertencentes às macrorregiões Nordeste/Norte. Conclusão: Verificou-se importante relação de dependência entre provisão da fluoretação da água com as características das empresas e características contextuais das regiões de saúde / Introduction: The fluoridation of water supply systems is recognized as an effective public policy in the control of caries disease at the population level. Among the countries that adopting the policy, inequalities were observed in the distribution of services among their federative entities, leading to the need for more detailed surveys in order to identify the determinants of their implementation. Objective: It was investigated the water fluoridation of water supply systems in Brazilian municipalities, exploring the role of contextual variables in the supply of this service. Methods: Based on primary data from the Demographic Census for the year 2010 and the 2008 National Survey on Basic Sanitation, and using the political-territorial divisions health region/municipality, it was verified the possibility of offering the fluoridation service show dependency relation with characteristics of the companies that providing the sanitation services, and, with contextual characteristics of the health regions in which the municipalities are inserted. The analysis for both was adjusted by variables of municipal characteristics. Results: 60% of municipalities had fluoridation service. In an analysis of the characteristics of the sanitation companies (legal nature, administrative sphere and form of water supply service provision), they were positively associated with municipal characteristics. Municipal administrations and private companies associated or not with public entities were associated with the absence of provision of the service. The fluoridation supply changed according to the contextual variables of the health regions, the chances of the service being absent were higher in municipalities belonging to health regions where child mortality was high and mortality caused by acute diarrheal disease, where there was a greater proportion of people with low income and in the health regions belonging to the North-East / North macro-regions. Conclusion: There was an important dependence relationship between the provision of water fluoridation with the characteristics of the companies and the contextual characteristics of the health regions.

Introdução - A política de fluoretação das águas de abastecimento público requer aplicação contínua desta medida em níveis adequados de flúor. O controle operacional é realizado pelas empresas de saneamento ao adicionar flúor às águas, cuja medida deve ser complementada pela ação dos sistemas de vigilância segundo o princípio do heterocontrole. Sistemas de vigilância lidam com informações de interesse público, nos marcos legais desenvolvidos pelos Estados. No mundo contemporâneo, tais marcos implicam contemplar o direito de acesso à informação. Objetivo - Descrever o sistema de vigilância da fluoretação da água no município de São Paulo, no período 1990-2011. Método - Pesquisa baseada em dados secundários disponibilizados pela Secretaria Municipal de Saúde de São Paulo, no período 1990-2011. Os teores de fluoreto nas amostras foram classificados segundo as dimensões de risco e benefício para fluorose e cárie dentária, avaliados concomitantemente. Adicionalmente, realizou-se revisão bibliográfica do marco legal brasileiro que trata da Lei de Acesso à Informação (LAI), tendo em vista que dados produzidos pelos sistemas de vigilância em saúde são de interesse público. Resultados - Foram analisadas 19.071 amostras. A média anual de registros identificados no período de pontos fixos atingiu 647 amostras, correspondendo a um valor acima do necessário para a cobertura total do sistema (n=180). A média anual de registros foi ainda maior para o período de pontos variáveis, com 1.340 amostras. A média geral dos teores de flúor foi de 0,66 mg/l. Com relação à prevenção da cárie, 44 por cento das amostras representam benefício moderado e 54 por cento benefício máximo. Quanto à fluorose dentária, 99 por cento das amostras representam risco mínimo. Com relação à LAI, o período histórico contemporâneo se apresenta, no Brasil, como um cenário de possibilidades e desafios aos avanços dos modelos de vigilância em saúde, incluindo a qualidade da água, com potencial para ampliar as possibilidades de controle sobre as políticas públicas. Conclusão: O benefício preventivo quanto à cárie não foi aproveitado em seu potencial pleno. O risco para fluorose dentária foi baixo. O número de amostras anuais coletadas apresentou tendência de aumento no período estudado, registrando-se variações que se situaram, contudo, sempre acima do limite inferior capaz de assegurar a cobertura total do sistema. Tendo em vista as disposições da LAI, dados e informações produzidos pelos sistemas de vigilância da qualidade da água são de interesse público e, portanto, devem estar disponíveis integralmente / Introduction - The policy of community water fluoridation requires continuous application of this measure by the adequate use of fluoride levels. Operational control is carried out by drinking-water suppliers to add fluoride to the water, which measure must be complemented by action of surveillance systems on the principle of external control. Surveillance systems deal with information of public interest, within the legal frameworks developed by the States. In the contemporary world, such landmarks contemplate the right of access to information. Objective - To describe the surveillance system of drinking-water fluoridation in the city of Sao Paulo, in the period 1990-2011. Method - Research based on secondary data provided by the Municipal Health Secretary of Sao Paulo, in the period 1990-2011. Fluoride levels in the samples were classified according to the dimensions of risk and benefit related to fluorosis and dental caries, concurrently assessed. Additionally, it was carried out a literature review of the Brazilian legal framework that deals with the Law on Access to Information (LAI), considering that data produced by health surveillance systems are of public interest. Results - It was analyzed 19,071 samples. The average annual records identified between fixed points period reached 647 samples, corresponding to a value higher than necessary to cover the entire system (n = 180). The average of the variable annual record points was even greater for the period, with 1,340 samples. The overall average fluoride concentration was 0.66 mg/l. With respect to the prevention of caries, 44 per cent of the samples represent moderate benefit and 54 per cent maximum benefit. As for dental fluorosis, 99 per cent of the samples represented minimal risk. With respect to LAI, the contemporary historical period presented in Brazil, as a scenario for possibilities and challenges to the improvement of health surveillance models, including water quality, with the potential to expand the possibilities of control over public policies. Conclusion: The preventive benefit concerning dental caries has not been tapped into its full potential. The risk for dental fluorosis was low. The annual number of collected samples showed a tendency to increase during the study period, registering variations which remained, however, always above the lower limit to ensure full coverage of the system. In view of the provisions of LAI, data and information produced by drinking-water surveillance systems are of public interest and therefore should be integrally available

Introdução - A política de fluoretação das águas de abastecimento público requer aplicação contínua desta medida em níveis adequados de flúor. O controle operacional é realizado pelas empresas de saneamento ao adicionar flúor às águas, cuja medida deve ser complementada pela ação dos sistemas de vigilância segundo o princípio do heterocontrole. Sistemas de vigilância lidam com informações de interesse público, nos marcos legais desenvolvidos pelos Estados. No mundo contemporâneo, tais marcos implicam contemplar o direito de acesso à informação. Objetivo - Descrever o sistema de vigilância da fluoretação da água no município de São Paulo, no período 1990-2011. Método - Pesquisa baseada em dados secundários disponibilizados pela Secretaria Municipal de Saúde de São Paulo, no período 1990-2011. Os teores de fluoreto nas amostras foram classificados segundo as dimensões de risco e benefício para fluorose e cárie dentária, avaliados concomitantemente. Adicionalmente, realizou-se revisão bibliográfica do marco legal brasileiro que trata da Lei de Acesso à Informação (LAI), tendo em vista que dados produzidos pelos sistemas de vigilância em saúde são de interesse público. Resultados - Foram analisadas 19.071 amostras. A média anual de registros identificados no período de pontos fixos atingiu 647 amostras, correspondendo a um valor acima do necessário para a cobertura total do sistema (n=180). A média anual de registros foi ainda maior para o período de pontos variáveis, com 1.340 amostras. A média geral dos teores de flúor foi de 0,66 mg/l. Com relação à prevenção da cárie, 44 por cento das amostras representam benefício moderado e 54 por cento benefício máximo. Quanto à fluorose dentária, 99 por cento das amostras representam risco mínimo. Com relação à LAI, o período histórico contemporâneo se apresenta, no Brasil, como um cenário de possibilidades e desafios aos avanços dos modelos de vigilância em saúde, incluindo a qualidade da água, com potencial para ampliar as possibilidades de controle sobre as políticas públicas. Conclusão: O benefício preventivo quanto à cárie não foi aproveitado em seu potencial pleno. O risco para fluorose dentária foi baixo. O número de amostras anuais coletadas apresentou tendência de aumento no período estudado, registrando-se variações que se situaram, contudo, sempre acima do limite inferior capaz de assegurar a cobertura total do sistema. Tendo em vista as disposições da LAI, dados e informações produzidos pelos sistemas de vigilância da qualidade da água são de interesse público e, portanto, devem estar disponíveis integralmente / Introduction - The policy of community water fluoridation requires continuous application of this measure by the adequate use of fluoride levels. Operational control is carried out by drinking-water suppliers to add fluoride to the water, which measure must be complemented by action of surveillance systems on the principle of external control. Surveillance systems deal with information of public interest, within the legal frameworks developed by the States. In the contemporary world, such landmarks contemplate the right of access to information. Objective - To describe the surveillance system of drinking-water fluoridation in the city of Sao Paulo, in the period 1990-2011. Method - Research based on secondary data provided by the Municipal Health Secretary of Sao Paulo, in the period 1990-2011. Fluoride levels in the samples were classified according to the dimensions of risk and benefit related to fluorosis and dental caries, concurrently assessed. Additionally, it was carried out a literature review of the Brazilian legal framework that deals with the Law on Access to Information (LAI), considering that data produced by health surveillance systems are of public interest. Results - It was analyzed 19,071 samples. The average annual records identified between fixed points period reached 647 samples, corresponding to a value higher than necessary to cover the entire system (n = 180). The average of the variable annual record points was even greater for the period, with 1,340 samples. The overall average fluoride concentration was 0.66 mg/l. With respect to the prevention of caries, 44 per cent of the samples represent moderate benefit and 54 per cent maximum benefit. As for dental fluorosis, 99 per cent of the samples represented minimal risk. With respect to LAI, the contemporary historical period presented in Brazil, as a scenario for possibilities and challenges to the improvement of health surveillance models, including water quality, with the potential to expand the possibilities of control over public policies. Conclusion: The preventive benefit concerning dental caries has not been tapped into its full potential. The risk for dental fluorosis was low. The annual number of collected samples showed a tendency to increase during the study period, registering variations which remained, however, always above the lower limit to ensure full coverage of the system. In view of the provisions of LAI, data and information produced by drinking-water surveillance systems are of public interest and therefore should be integrally available

This study investigated the effect of geographic location on Severe Early Childhood Caries (S-ECC) in Native American Children three years of age from a Norther Plains Tribal Community. Geographic location of study participants was ascertained by postal district and categorized into geographic regions as well as dental clinic accessibility, defined as dental services present or absent in that district. The association of location category and dental caries (dmfs) was evaluated cross-sectionally at 36 months of age. Descriptive statistics demonstrated differences in dental caries distribution by geographic region and accessibility category. Bivariate analysis of disease by location showed a significant difference in dmfs between 4 geographic regions (p=0.0159) but not between accessibility categories (p=0.0687). Multivariable regression modeling for geographic region demonstrated the unique effect of geographic region on dental caries experience as well as five other key risk factors. Incident Rate Ratios (IRR) were computed for each of the risk factors, including number of erupted teeth (IRR=1.89, p=0.0147), fluoride exposure from tap water (IRR=1.70, p=0.0173), annual family income (IRR=1.58, p=0.0392), maternal DMFS (IRR=1.02, p=0.0040), and Mean Adequacy Ratio (IRR=1.05, p=0.1042). This study demonstrated statistically significant variation in cumulative dental caries experience of Native American children aged 36 months among geographic regions and identified the specific unites of association through multivariate modeling. These findings can be used for local dental caries prevention programs and contribute to a broader understanding of S-ECC among very young Native American children.

In September 2000 water fluoridation became mandatory in South Africa. Since then water service providers like Umgeni Water (UW), a bulk water supply authority in the KwaZulu-Natal (KZN) province of South Africa began the process of implementing the legislation. This study was undertaken to establish the spatio-temporal variations of fluoride concentrations in surface and ground waters within the Umgeni Operational Area, to establish whether these waters would require fluoridation or defluoridation to meet a fluoride concentration of 0.70 mglf, and to assess the potential impacts of water fluoridation. Baseline fluoride concentrations of surface and ground water: It was concluded that the fluoride concentration of all sample types (rivers, dams, water works raw and final waters, wastewater influent and effluents, and boreholes), except pollution point sources, is less than O.S; mglR, 50 percent of the time. Some rivers (Mshazi, KwaNyuswa, KwaNgcolosi,·Mshwati and the MgoShongweni) exhibited high fluoride concentrations, while someboreholes also exhibited high fluoride concentrations. Temporal Variations and Seasonality: There are seasonal variations in the fluoride concentrations for surface waters, with higher fluoride concentrations in winter than in summer (64 out of 125 occasions). This low fluoride concentration in summer can be attributed to the dilution effects caused by rainfall runoff. Identification of "Hot Spots": "Hot Spots", sites where the fluoride concentration exceeds 1 mglR are present within the study area, for surface and borehole water. For surface water, the MgoShongweni exhibited fluoride concentrations in excess of 1mglRat least 75% of the time. The KwaNgcolosi and Mshwati exhibited fluoride concentrations In excess of 1mglR at least 25% of the time, while the Mshazi and the KwaNyuswa exhibited fluoride concentrations in excess of 1mglR only 5% of the time. The storm water discharge below AECI had high fluoride concentrations in excess of 1mg/R at least 20% of the time and the concentrations exceeded the fluoride concentration for seawater (1.4 mglf) at least 5% of the time. Of the 286 boreholes sampled, 17 boreholes (6% of all boreholes sampled) had fluoride levels in excess oft mglf . The impacts of long term consumption of water from these boreholes could range from slight mottling of the dental enamel in sensitive individuals (boretioles JD26, C29, H19, CB7, 112/1, 69/5, Thembeni 108 and EC (Thembeni 105, Keats Drift boreholes 1 and 2). Spatial patterns and possible sources of high fluoride concentrations: With respect to spatial patterns, relatively high concentrations of fluoride (300 IJglR to 1000 IJglR) can be found in surface water in the Msunduzi river, the Mgeni river downstream of the Msunduzi confluence and along the coastal belt. No spatial patterns are evident with respect to borehole water. For surface water, high fluoride concentrations in the Mshazi, KwaNyuswa and the KwaNgcolosi streams (inflows to the Inanda dam) appear to be associated with the catchment geology. The ~igh fluoride concentrations in Mshwati and the MgoShongweni are most likely as a result of industrial activities in the respective catchments. For borehole water, high fluoride concentrations may be attributed to catchment geology. Additional fluoride dosaqe ' at water treatment works: Since the fluoride concentrations at the water works were low (mean ranging between 0.5 mglf to 0.38 mglf) , fluoride would need to be added to meet the fluoride standard of 0.7 mgl£ . For most of the water works, the additional fluoride (sodium fluoride) requirement to meet the fluoride standard of 0.7 mgl£, ranged from 1.201 kglMRto 1.555 kg/MR. For the water works, Imfume and Umzinto, the additional fluoride , requirement is 0.768 kg/MR and 0.109 kg/MR respectively. In final water, the fluctuations in fluoride concentrations observed would translate to continuous testing being required to maintain optimal dosing of fluoride. Comparison of influent and effluent fluoride concentrations at wastewater works: There was no evidence of fluoride removal at the Mpophomeni Wastewater Works . There was evidence of 22.4% fluoride removal at the DarvHI Wastewater Works possibly due to the activated sludge treatment process at the wastewater works. Future fluoride levels in surface water that will receive return flows: Once water fluoridation is implemented, the Darvill Wastewater Works would receive fluoridated return flows, and discharge its fluoride rich effluent into the Msunduzi river. The average monthly fluoride road discharged from Darvill Wastewater Works would increase from 0.23 tons to 1.46 tons, an additional 1.23 tons per month on the aquatic environment of the Msunduzi river. The sludge fluoride load, disposed to land, could increase from 4 056 tons/month to 27 863 tons/month, which implies an increase in the fluoride runoff potential from the sludge-lands to the Msunduzi river. Number of people in sensitive groups that could be affected by water fluoridation: A significant number of people in KZN could be sensitive to water fluoridation. This has been estimated to be at least one third of KZN's population that are HIV infected. Recommendations were made and the most important ones are as follows: In the light of the large number of people, one-third the population of KZN, that is HIV positive and therefore could be sensitive to fluoridated water, it is recommended that the South African legislation mandating water fluoridation be withdrawn. Examination of the most recent literature indicated a significant lack of confidence in the best available studies that researched the safety and efficacy of water fluoridation. In the light of this it is recommended that the South African Department of Health re-examine and withdraw its legislation that mandates water fluoridation. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2002.

Made available in DSpace on 2014-08-20T14:30:07Z (GMT). No. of bitstreams: 1 Dissertacao_nihad_hasan.pdf: 553702 bytes, checksum: 7fd2cc70dbdb0933977f27c12e5636ab (MD5) Previous issue date: 2007-02-07 / Fluorine addition in public water supply has been associated to the enormous world decline in dental caries index, still is the most efficiency preventive method for dental health. However the implementation of the fluoridation of the water propitiated the increase of the prevalence of dental fluorosis. The aim of this study were evaluate the level of fluorine in the public water supply in the cities of Pelotas and Rio Grande-RS and compare two fluorine determination methods. The samples were collected, biweekly, in the same points of the companies of public water supply in the two cities evaluated, Rio Grande (8 points), Pelotas (44 points). To the mensuration of the fluoride present in the samples two methods were used, one was the spectrophotometric SPANDS, the other the electrometric. The samples were appraised in duplicate and the results obtained was that the methods electrometric and espectrofotométrico presented good correlation (p<0,01), however there was difference statistics (p < 0,05).The concentrations of fluoride in the public water supply were inside of the values recommended in the twelve months of evaluation in the two districts of Pelotas and Rio Grande/RS. It was ended that of the two tested methods are suitable for determination of fluoride concentration, however the most precise is the electrometric. During the twelve months of surveillance in the two districts, the concentrations of the fluoride stayed in the recommended and didn't represent a risk to the dental fluorosis / A adição de flúor à água de abastecimento público tem sido associada ao enorme declínio mundial dos índices de cárie, sendo considerado o método de maior eficiência em termos de saúde coletiva. Porém, a implementação da fluoretação da água propiciou aumento da prevalência de fluorose dental. O objetivo deste estudo foi avaliar a concentração de flúor existente na água de abastecimento público do município de Pelotas e Rio Grande RS e comparar os dois métodos mais utilizados na determinação da concentração do fluoreto (eletrométrico e espectrofotométrico). A coleta das amostras foi realizada, quinzenalmente, nos mesmos pontos que os das companhias de abastecimento público de água dos dois municípios avaliados, Rio Grande (8 pontos de coleta) e Pelotas (44 pontos de coleta). Para a mensuração do flúor presente nas amostras foram empregados os dois métodos mais utilizados, um foi espectrofotométrico, usando SPANDS, o outro o eletrométrico, com eletrodo seletivo para fluoreto. As amostras foram avaliadas em duplicata e, através dos resultados obtidos, observou-se que os métodos eletrométrico e espectrofotométrico apresentaram boa correlação (p<0,01), contudo houve diferença estatística (p< 0,05). As concentrações médias de fluoreto na água de abastecimento público estiveram dentro dos valores recomendados pela portaria 10/99 nos doze meses de avaliação nos municípios de Pelotas e Rio Grande/RS. Concluiu-se que os dois métodos testados são indicados para determinação da concentração de fluoreto, embora o eletrométrico seja mais preciso. Durante o heterocontrole nos dois municípios, as concentrações médias do fluoreto mantiveram-se dentro de valores que não representam risco à fluorose dentária

MENVSC / Department of Hydrology and Water Resources / See the attached abstract below