Most of the children are exposed to a daily fluoride intake above the suggested threshold for dental fluorosis. The dentifrice alone is responsible for an average of 81.5% of the daily fluoride intake, while among the constituents of the diet, water and milk are the most important contributors. In addition, small variations in daily fluoride intake cannot be detected in fingernails.

Background The inadequate management of solid waste impacts populations’ health and quality of life, and disproportionately affects developing countries. This study aims to describe a protocol for epidemiological diagnosis, the purpose being to estimate the prevalence of chronic and communicable and non communicable diseases in waste pickers, and the occupational and environmental risk factors to which these are exposed. Methods This is a cross-sectional study, based on survey design in an area of extreme social vulnerability – the largest garbage dump in Latin America. Using a multidimensional research protocol, divided in three stages : 1- The identification of the subjects, and the scheduling of tests; 2- Situational diagnosis through interviews, anthropometric evaluation, measuring blood pressure, collecting hair and nail samples to detect exposure to heavy metals and undertaking laboratory tests; 3- The return of the waste pickers to receive the test results, followed by referral to the health team and to report occupational accidents. Results One thousand twenty-five waste pickers undertook tests and interviews. The majority were women (67.0%), with 36–45 years old (45.7%), and 96.0% had children. In total, 27.3% of the participants did not attend to any school and 47.7% were educated only up to primary level. The majority of waste pickers (68.70%) reported accidents and most of them (89.69%) were related to sharp objects. The mean time working in this open dump was 15 years. According the anthropometric measure, 32.6% were overweight and 21.1% were obese. The most common reported diseases were: osteomuscular disorders (78.7%); arboviruses (28.6%); episodic diarrhea (24.9%); hypertension (24.2%); bronchitis (14.3%); intestinal worms (12.6%) and diabetes (10.1%). According to the blood tests, the values outside the reference limits were: Uric acid (23.89%); creatinine (54.06%); GGT range (16.04%); SGOT - Serum Glutamic Oxaloacetic Transaminase (5.29%); SGPT - serum Glutamic-Pyruvic Transaminase (35.52%). Conclusions This study is the first to evaluate multiple risks and diseases in the majority of waste pickers working in the largest garbage dump of a continent. These findings highlight the importance to address urgently the environmental, social and health impacts related to the management of solid waste in developmental countries to protect these workers and their families. Electronic supplementary material The online version of this article (10.1186/s12889-019-6879-x) contains supplementary material, which is available to authorized users.

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Chocolate bars and chocolate cookies are foodstuffs highly appreciated by children. The possibility of having fluorine (F) among their components, associated with an excessive consumption, may make them decisive contributors to the total daily F intake. Thus, they could participate in the establishment of dental fluorosis. The aim of this study was to analyze the fluorine concentration [F] of the chocolates bars (CB) Baton, Confeti, Garoto Ball, Kinder Ovo, M&M's, Milkybar, Nescau, Nescau Ball, Surpresa, Surpresa Bichos, Tortuguita; and of the chocolate cookies (CC) Danyt's, Hipopó, Nescau, Passatempo, Pokémon, Sítio do Pica-Pau Amarelo and Trakinas. Samples were purchased in Bauru, São Paulo, Brazil. Three grams of each product were previously ashed at 525°C (CB and cookies fillings) and at 550°C (cookies dough), during 4 hours. Fluorine was separated from the ash by hexamethyldisiloxane (HMDS)-facilitated diffusion. Fluorine analysis was carried out with the specific electrode. Mean [F]s ± SD and amplitude (unit mg/g) were: CB = 0.30 ± 0.45 (0.07 -1.60, n = 12) and CC = 1.08 ± 2.64 (0.04 -7.10, n = 7). It was concluded that some of the analyzed foods may be important contributors to the total daily F intake. As for the product that had the highest [F] (Danyt's), when only 3 units are consumed just once a day, they may supply up to 40% of the maximum recommended daily F intake (0.07 mg/kg body weight) for a 2-year-old child (12 kg). The [F] in these products should be informed on their labels. DESCRIPTORS: Chocolate; Fluorine; Fluorosis, dental; Child. RESUMO:Chocolates em barra e bolachas de chocolate são guloseimas altamente apreciadas pelas crianças. A possibilidade de conter flúor (F) em seus componentes, associada a seu excessivo consumo podem torná-los contribuintes decisivos para a ingestão diária total de F. Assim, eles poderiam participar no estabelecimento da fluorose dental. O objetivo deste estudo foi analisar a concentração de flúor [F] dos chocolates em barra (CB) Baton, Confeti, Garoto Ball, Kinder Ovo, M&M's, Milkybar, Nescau, Nescau Ball, Surpresa, Surpresa Bichos, Tortuguita; e das bolachas de chocolate (CC) Danyt's, Hipopó, Nescau, Passatempo, Pokémon, Sítio do Pica-Pau Amarelo e Trakinas. Os produtos foram adquiridos em Bauru, São Paulo, Brasil. Três gramas de cada produto foram previamente calcinadas a uma temperatura de 525°C (CB e recheio das bolachas), e de 550°C (massas das bolachas), durante 4 horas. O F foi separado das cinzas por difusão facilitada por hexametildisiloxano (HMDS). As análises de F foram feitas com o eletrodo específico. As [F]s médias ± DP e amplitude (mg/g) foram: CB = 0,30 ± 0,45 (0,07 -1,60, n = 12) e CC = 1,08 ± 2,64 (0,04 -7,10, n = 7). Concluiu-se que alguns dos alimentos analisados podem ser importantes contribuintes para a ingestão diária total de F. No caso do produto que apresentou a maior [F] (Danyt's), quando apenas 3 unidades são consumidas uma única vez ao dia, elas podem fornecer mais de 40% da ingestão diária máxima de F recomendada (0,07 m...

This double-blind study assessed the fluoride (F) concentration in whole saliva and F bioavailability after the use of low-F dentifrices with reduced pH. Whole saliva was collected from 10 volunteers after brushing with: experimental dentifrices (pH 5.5) 275, 550 and 1,100 ppm F; commercial 500 ppm F, pH 6.9 and a ‘gold standard’ 1,100 ppm F, pH 6.5. To analyze F bioavailability, 9 volunteers ingested weights of four dentifrices equivalent to 2 mg F: 1,500 ppm F/MFP/CaCO₃, pH 9.5; 1,100 ppm F/NaF/silica, pH 5.5; 1,100 ppm F/NaF/silica, pH 7.0 and 1,100 ppm F/NaF/silica, pH 6.5 (‘gold standard’). Ductal saliva and urine were collected. F was analyzed by electrode. Data were tested using ANOVA and Tukey’s post hoc test (p < 0.05). The 550 ppm F/pH 5.5 dentifrice was similar to the ‘gold standard’ in its effect on whole saliva F concentration. The area under the curve of ductal saliva F concentration × time and urinary F excretion rates did not differ among the dentifrices. The results show that acidic low-F dentifrices are effective in increasing salivary F concentration and pH reduction does not seem to affect their F bioavailability.

This study compares fluoride concentrations ([F]) in surface and whole bone for up to 27 days following an acute oral dose of F. Four groups of rats received single oral F dose (50 mg/kg body weight), and the control group received deionized water (n = 10/group). Groups were euthanized at 1, 3, 9, or 27 days after F administration. Plasma and femurs were collected. F on the femur surface was removed from a circular area (4.52 mm(2)) by immersion in 0.5M HCl for 15 s. The solution was buffered with total ionic strength adjustment buffer and analyzed with an electrode. The subjacent bone was sectioned and ashed at 600 degrees C. Ash and plasma were analyzed for F with the electrode following hexamethyldisiloxane-facilitated diffusion. Data were analyzed by Kruskall-Wallis and Dunn's test and by linear regression (p < 0.05). Peak plasma and bone surface [F] occurred on day 1 (0.26 +/- 0.14 microg/mL and 1801 +/- 888 microg/g, respectively). Bone surface [F] at 3, 9, and 27 were not statistically different from control. A significant increase in whole bone [F] was observed 3 days after F administration and the [F] remained relatively constant thereafter. The mean (+/- SD) surface/whole bone [F] ratios for the control and F groups were 2.45 +/- 0.98, 3.92 +/- 1.32, 1.61 +/- 0.82, 1.73 +/- 0.39, and 1.09 +/- 0.28, respectively. Plasma and bone surface [F]s were positively correlated (r = 0.74). Thus, bone surface was found to be a suitable biomarker for acute, sublethal F exposure 1 day after F administration. Whole bone [F] were significantly increased at 3, 9, and 27 days after F administration.

reakfast cereals and snacks are foodstuffs highly appreciated by children, and the possibility that they contain substantial amounts of fluoride, associated with their widespread consume, may make them important contributors to the total daily fluoride intake. The aim of this study was to analyze the fluoride content on several breakfast cereals (A) and snacks (B) purchased in Brazil. The analysis were made after HMDS-facilitated diffusion (Taves) using the ion-specific electrode (9609). Mean fluoride concentrations ± SD (range, unit µg F/g) were: A= 0.76 ± 0.60 (0.08-1.86, n=15) and B= 0.32 ± 0.09 (0.22-0.55, n=18). Our results suggest that the total amount of fluoride available in some products may contribute to the total daily fluoride intake. The product labels should provide information on their fluoride content to prevent fluorosis at the age of risk.

Objective:This study evaluated the bioavailability of fluoride after topical application of a dual-fluoride varnish commercially available in Brazil, when compared to Duraphat™.Material and methods:The urinary fluoride output was evaluated in seven 5-year-old children after application of the fluoride varnishes, in two different phases. In the first phase (I), children received topical application of the fluoride varnish Duofluorid XII (2.92% fluorine, calcium fluoride + 2.71% fluorine, sodium fluoride, FGM™). After 1-month interval (phase II), the same amount (0.2 mL) of the fluoride varnish Duraphat (2.26% fluorine, sodium fluoride, Colgate™) was applied. Before each application all the volunteers brushed their teeth with placebo dentifrice for 7 days. Urinary collections were carried out 24 h prior up to 48 h after the applications. Fluoride intake from the diet was also estimated. Fluoride concentration in diet samples and urine was analyzed with the fluoride ion-specific electrode and a miniature calomel reference electrode coupled to a potentiometer. Data were tested by ANOVA and Tukey's post hoc test (p<0.05).Results:There were significant differences in the urinary fluoride output between phases I and II. The use of Duofluorid XII did not significantly increase the urinary fluoride output, when compared to baseline levels. The application of Duraphat caused a transitory increase in the urinary fluoride output, returning to baseline levels 48 h after its use.Conclusions:The tested varnish formulation, which has been shown to be effective in in vitro studies, also can be considered safe.