Seven years of external control of fluoride levels in the public water supply in Bauru, São Paulo, Brazil

Abstract

Fluoridation of the public water supplies is recognized as among the top ten public health achievements of the twentieth century. However, the positive aspects of this measure depend on the maintenance of fluoride concentrations within adequate levels.Objective:To report the results of seven years of external control of the fluoride (F) concentrations in the public water supply in Bauru, SP, Brazil in an attempt to verify, on the basis of risk/benefit balance, whether the levels are appropriate.Material and Methods:From March 2004 to February 2011, 60 samples were collected every month from the 19 supply sectors of the city, totaling 4,641 samples. F concentrations in water samples were determined in duplicate, using an ion-specific electrode (Orion 9609) coupled to a potentiometer after buffering with TISAB II. After the analysis, the samples were classified according to the best risk-benefit adjustment.Results:Means (±standard deviation) of F concentrations ranged between 0.73±0.06 and 0.81±0.10 mg/L for the different sectors during the seven years. The individual values ranged between 0.03 and 2.63 mg/L. The percentages of the samples considered "low risk" for dental fluorosis development and of "maximum benefit" for dental caries prevention (0.55-0.84 mg F/L) in the first, second, third, fourth, fifth, sixth, and seventh years of the study were 82.0, 58.5, 37.4, 61.0, 89.9, 77.3, and 72.4%, respectively, and 69.0% for the entire period.Conclusions:Fluctuations of F levels were found in the public water supply in Bauru during the seven years of evaluation. These results suggest that external monitoring of water fluoridation by an independent assessor should be implemented in cities where there is adjusted fluoridation. This measure should be continued in order to verify that fluoride levels are suitable and, if not, to provide support for the appropriate adjustments.

Fluoride concentrations in the water of Maringá, Brazil, considering the benefit/risk balance of caries and fluorosis

“…17 When this new classification of f luoride concentration in water is used instead of the current ordinance, a lower percentage of unacceptable samples would also be found in other cities, e.g., Jaguaribara, CE, 18 and Bauru, SP. 19 However, while only approximately 66% of the samples in these cities were within the range of greater benefit of Fluoride in preventing dental caries and a lower risk of fluorosis, this value was higher in Maringá, PR (84%).…”

Dental fluorosis and its influence on children’s life

“…3,4 Public water supply fluoridation became obligatory in Brazil in 1975 with the implementation of National Law number 6,050. Nevertheless, the increased prevalence of dental fluorosis worldwide has caused esthetic displeasure in children, which may lead to psychological and behavioral complications in affected individuals.…”

“…Nevertheless, the increased prevalence of dental fluorosis worldwide has caused esthetic displeasure in children, which may lead to psychological and behavioral complications in affected individuals. 4,5 The spots caused by "very mild" and "mild" fluorosis do not constitute a public health problem, although they do represent an abnormality. However, some studies have evaluated the levels at which dental fluorosis is self-perceived by children as a problem.…”

Building a "Smiling Brazil"? Implementation of the Brazilian National Oral Health Policy in a health region in the State of São Paulo

“…Por se tratar de um serviço de saúde pública que envolve riscos e benefícios à população, recomenda-se que o controle dos ní-veis de flúor seja realizado tanto pela companhia responsável pelo sistema de abastecimento de água como por terceiros (heterocontrole) 18,19 . Apesar disso, apenas 36,8% dos municípios do DRS III relataram realizar o heterocontrole dos teores de flúor, sendo este quadro mais preocupante que o encontrado por Colussi & Calvo 20 em Santa Catarina.…”