Metabolism and Toxicity of Fluorine Compounds.

Fluorine has many beneficial features and applications but can cause toxicity at high doses. Herein, we describe its chemical properties and benefits to agrochemical design as well as potential metabolic liabilities and exposure assessment in vivo.

Effect of fluoride slow-release glass devices on salivary and gingival crevicular fluid levels of fluoride: A pilot study.

Objectives: To estimate the effect of fluoride slow-release glass devices on the levels of fluoride in a pooled sample of human gingival crevicular fluid and in human saliva. Materials and Methods: Ten healthy adult volunteers wore fluoride slow-release glass devices for 3 months in a longitudinal experimental clinical pilot study. Whole unstimulated human saliva and gingival crevicular fluid were collected using paper points at baseline, after 2 weeks and at 3 months and analysed for their fluoride levels using ion chromatography and fluoride electrode. Results: No adverse effects were reported, and the Löe Plaque and Gingival Index remained low (0.22). The saliva determination of fluoride using the fluoride electrode showed an increase after 3 months from 0.02 ± 0.04 ppm to 0.06 ± 0.12 ppm, whereas the ion chromatography showed an increase from 0.15 ± 0.10 ppm to 0.44 ± 0.36 ppm. The fluoride levels in a pooled sample of gingival crevicular fluid from four intraoral sites were determined using the ion chromatography, and the results showed that after 3 months, the fluoride levels were still low (0.71 ± 0.34 ppb) similar to those at baseline (0.74 ± 0.31 ppb). Conclusions: The fluoride concentration in a pooled sample of gingival crevicular fluid was reported to be low with a range from 0.46 to 0.75 ppb and was not changed by placement of fluoride slow-release glass devices. The fluoride concentration in unstimulated human saliva showed an increase after 3 months when the fluoride slow-release glass devices were attached when determined with both the fluoride electrode (from .02 ± 0.04 ppm to 0.06 ± 0.12 ppm) and ion chromatography (from 0.15 ± 0.10 ppm to 0.44 ± 0.36 ppm).

[Environmental pollution with fluoride compounds and their influence on children health].

Data of hygienic studies of air and soil during last 20 years have confirmed their correlating relationship with the general morbidity and a group of musculoskeletal diseases in children living in cities with the technogenic pollution of the environment. Their bones were established to grow unevenly and disproportionally, in 76% of children there have been violations in the development and growth of bones. The results of X-ray examination of hand bones in children and adolescents in the Irkutsk and Shelekhov cities are presented. Significant differences in morbidity patterns among children and adolescents including an increased incidence of musculoskeletal diseases by 5.6 in children and by 12 in adolescents have been revealed.

[Thyroid gland pathology in children population exposed to the combination of iodine deficiency and fluoride pollution of environment].

The article presents results of study of the impact of iodine deficiency and technogenic fluoride on the state of the thyroid gland in children. On the example of two districts of the city of Bratsk there were executed dynamic investigations (2002 and 2012), including the estimation of the pollution of ambient air and soil by fluorine compounds, levels of iodine intake by the body, the clinical examination of children aged from 5 to 7 years d and interviewing of their parents. In the course of the medical examination there were executed: physical examination by the pediatrician, endocrinologist, ultrasound examination of the thyroid gland, the determination both of serum hormone content by radioimmunoassay and urinary excretion offluorine and iodine. Concentrations of hydrogen fluoride and a solidfluorides in ambient air led to the accumulation offluoride ion in the soil. The iodine entering with drinking water and food, was established to provide only 37.5-50% of the daily requirement of iodine. Increased fluoride ion content in urine and milk teeth in children is associated with the concentrations of the fluorine-containing pollutants in the ambient air and soil. The fluoride pollution against the background of the natural iodine deficiency was established to increase the frequency of functional and morphological disorders of the thyroid gland in children.

Hypothyroidism in patients with colorectal carcinoma treated with fluoropyrimidines.

Targeted therapy with tyrosine kinase inhibitors, including vascular endothelial growth factor receptors, has been demonstrated to induce hypothyroidism and thyroid dysfunction. Cancer patients with thyroid dysfunction may be underdiagnosed and undertreated. Thyroid function in colorectal cancer patients receiving fluoropyrimidine-based chemotherapy with or without bevacizumab was evaluated at baseline and monthly. In the present study, 3 of 27 (11.1%) patients who received fluoropyrimidine-based chemotherapy developed a thyroid-stimulating hormone (TSH) level >10 µU/ml, and 13 (48.1%) developed an elevation above the upper limit of the normal range. No difference in TSH elevation was noted between the bevacizumab and chemotherapy-alone group (50 vs. 45%; P=1.00, respectively). Three (11.1%) patients developed a TSH level >10 µU/ml and 2 with hypothyroidism were treated with thyroid hormone replacement therapy. We demonstrated that bevacizumab does not affect thyroid function but fluoropyrimidines may induce thyroid dysfunction in patients with colorectal cancer. Further investigation is required to clarify the mechanism of fluoropyrimidine-induced thyroid dysfunction.

Factores familiares asociados con la prevalencia de Fluorosis dental en niños escolares en Cartagena-Colombia / Family Factors associated with Dental Fluorosis prevalence in school children Cartagena, Colombia

Objetivo. Evaluar la asociación entre prevalencia de Fluorosis dental y factores familiares responsables de la ingesta de fluoruros. Diseño. Estudio de corte transversal. Emplazamiento: Municipio de Cartagena de indias, Colombia. Participantes. 588 binomios madre-hijo que consultaron en clínicas odontológicas universitarias entre los años 2009 y 2010. Mediciones Principales. Se midió en niños la Fluorosis dental mediante el índice de Thylstrup y Fejerskov y los factores familiares responsables de la ingesta de fluoruros a través de una encuesta dirigida a las madres. Para el examen clínico se realizó estandarización intra-examinador e inter-examinador a partir de un observador clínico usado como referencia. La exploración de la asociación fue analizada con razones de disparidad e intervalos de confianza del 95%. El análisis multivariable por regresión logística nominal, incluyendo factores con probabilidades menores de 0. Resultados. La prevalencia de fluorosis dental fue del 64,8%, siendo la clasificación leve la más frecuente. Mediante análisis multivariable, el mejor modelo mostró significancia estadística (p<0,0001) para las variables frecuencia del cepillado dental tres veces al día (OR=1,68), uso de dentífrico con alto contenido de flúor en ppm (OR=2,21) e ingesta de crema dental en momentos diferentes al cepillado (OR=1,65). Conclusiones. Los factores familiares responsables del uso de crema dental con alto contenido de flúor fueron los de mayor peso para explicar la posible asociación con la alta prevalencia de Fluorosis en la población de estudio, lo que supone una interacción entre los efectos benéficos y secundarios del uso de fluoruros en la prevención de la caries (AU)

Objective. To assess the association between the prevalence of dental fluorosis and family factors responsible for fluoride intake Design. Cross-sectional study Location. Municipality of Cartagena de Indias, Colombia. Participants. 588 mother-child pairings attending university dental clinics between the years 2009-2010 Main measurements. Measurement of Dental fluorosis in children using the Thylstrup and Fejerskov index and family factors responsible for fluoride intake by way of a survey aimed at mothers. For the clinical examination, intra- and inter-examiner standardization was conducted using a clinical observer as a reference. The exploration of the association was analysed with odds ratios and 95% confidence intervals. Multivariable analysis by nominal logistic regression, including factors with probabilities below 0. Results. The prevalence of dental fluorosis was 64,8%, with the classification "slight" being the most frequent. By way of multivariable analysis, the best model showed statistical significance (p<0,0001) for the variables: frequency of teeth brushing three times per day (OR=1,68), use of toothpaste with high fluoride content in ppm (OR=2,21) and the intake of toothpaste at times different from brushing (OR=1,65). Conclusions. The family factors responsible for the use of toothpaste with a high fluoride content were those which gave the clearest explanation for a possible association with the high prevalence of fluorosis in the study population, which implies an interaction between the beneficial and secondary effects in the use of fluorides in the prevention of tooth decay (AU)

[Diffuse alveolar hemorrhage arising after use of a waterproofing spray].

A 33-year-old woman used waterproofing spray and subsequently developed cough, sputum and chest pain about 8 hours later accompanied by dyspnea, fever and general fatigue. She was admitted to our hospital 4 days after the symptoms appeared. A chest CT scan on the first visit revealed diffuse mild centrilobular nodular opacities and ground-glass opacities in both lung fields. Hemosiderin-laden macrophages accounted for 11% of the histiocytes found in her bronchoalveolar lavage fluid, which also contained blood. Based on these findings, the patient was given a diagnosis of diffuse alveolar hemorrhage. This is the first report in Japan of diffuse alveolar hemorrhage occurring after the use of a waterproofing spray.

[Exploration of demonstration and promotion experiment of fluorine fixation technology during coal burning].

OBJECTIVE: To demonstrate and promote the fluorine-fixing technology of the coal burning on a calcium-based compound as the additive for briquettes made in the coal-burning fluorosis area, in order to evaluate the effects of fluorine-fixing and indoor air pollutants condition. METHODS: The briquettes added calcium-based fluorine sorbent were used for heating and cooking. In the meantime, the figures on various components in briquettes and fluorine content in coal slag as well as concentrations of indoor air fluorides, sulfur dioxide and PM10 were calculated. RESULTS: On the basis of the coal burning fluorine-fixing pilot experiment, 100 households in Longli County, Guizhou Province were selected as the experimental group for coal burning fluorine-fixing demonstration and promotion. When the burning calcium-based fluorine-fixing bitumites were made into coalballs, the average fluorine-fixing ratios in demonstration and promotion were 77.26%. The average reduction ratios of indoor air pollutants, fluorides were 53.3% -73.8%, sulfur dioxide were 62.8% -91.1% and PM10 were 9.5% -41.4%. There were 10% increases in the cost of briquettes due to the addition of calcium-based fluorine sorbent in demonstration and promotion. CONCLUSION: The preparation process of calcium-based fluorine-fixing briquettes was simple and highly flammable and it was applicable to regions abundant in bitumite.

[Processes of adaptogenesis and heart remodelling in workers of electrolysis workshops in aluminum plants].

Workers in electrolysis workshops of aluminium plants demonstrate changes in intracardial hemodynamics and left ventricle diastolic function, heart remodelling to concentric and excentric hypertrophy, more in individuals with chronic occupational fluorine intoxication.

[Biologic markers of exposure to and effects of fluorine compounds in workers engaged into aluminum industry].

The study in 727 workers exposed to inorganic fluorine compounds revealed through ultrasound densitometry changes in fluorine excretion and bone tissue density in accordance with the length of service, through markers of bone destruction and synthesis features of bone remodelling were specified.

[Gastroduodenal system state and levels of gastro-intestinal peptides in workers exposed to fluor compounds].

Studies in 45 cryolite production workers (facing chronic gastritis and gastroduodenitis) demonstrated that the diseases in them have moderate inflammatory activity, atrophy of gastric lining contaminated with Helicobacter pylori, hypergastrine mia, hypopancreozymine mia and hyposecretine mia in half of the examinees.

Anesthetic properties of some fluorinated oxolanes and oxetanes.

BACKGROUND: The search for new potent inhaled anesthetics has slowed, in large part because of the excellence of the two most recent additions, desflurane and sevoflurane. Nonetheless, neither desflurane nor sevoflurane are ideal anesthetics, desflurane causing cardiorespiratory stimulation, and sevoflurane having a slower (albeit rapid) recovery from anesthesia. Sevoflurane also can produce convulsions and postoperative agitation. METHODS AND RESULTS: In the present report, we describe the physical and anesthetic properties of 31 cyclic ethers halogenated solely with fluorine. Although several produced anesthesia, none had solubilities that would make them better than sevoflurane. The remaining ethers were unstable or produced obvious central nervous system irritation, including convulsions. CONCLUSIONS: We find that none of these cyclic ethers appear to provide advantages over desflurane or sevoflurane.

Fluoride poisoning: a puzzle with hidden pieces.

Key industry data regarding harm from chronically inhaled fluoride have been unavailable publicly for decades. Recent unveiling of unpublished reports reveals three examples of data mishandling that disguised the need for more stringent occupational standards for particulate and gaseous fluorides and fluorine. Injury reports from workers handling chemicals show that unjustifiable reductions of injury and disability numbers in the process of publication shifted concern from respiratory to mineralized tissue damage. Selective editing and data omissions allowed bias that fluoride reduces caries without detrimental effects. Finally, industry's failure to publish an important industry-funded laboratory study buried knowledge of low thresholds for fluoride-induced lung disease. Data from that study are presented to clarify the dose- and duration-dependent changes caused by chronic inhalation of calcium fluoride.

Environmental risk assessment of hydrofluoroethers (HFEs).

Hydrofluoroethers (HFEs) are being used as third generation replacements to chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) and perfluorocarbons (PFCs) because of their nearly zero stratospheric ozone depletion and relatively low global warming potential. HFEs have been developed under commercial uses as cleaning solvents (incl., HFE-7500, C7F15OC2H5; HFE-7200, C4F9OC2H5; HFE-7100, C4F9CH3; HFE-7000, n-C3F7OCH3), blowing agents (incl., HFE-245mc, CF3CF2OCH3; HFC-356mec, CF3CHFCF2OCH3), refrigerants (incl., HFE-143a, CF3OCH3; HFE-134, CHF2OCHF2; HFE-245mc, CF3CF2OCH3), and dry etching agents in semiconductor manufacturing, (incl., HFE-227me, CF3OCHFCF3). From the environmental, ecological, and health points of view, it is important to understand their environmental risks for these HFEs from a diversity of commercial applications and industrial processes. This paper aims to introduce these HFEs with respect to physiochemical properties, commercial uses, and environmental hazards (i.e. global warming, photochemical potential, fire and explosion hazard, and environmental partition). Further, it addresses the updated data on the human toxicity, occupational exposure and potential health risk of commercial HFEs. It is concluded that there are few HFEs that still possess some environmental hazards, including global warming, flammability hazard and adverse effect of exposure. The partition coefficient for these HFEs has been estimated using the group contribution method; the values of logKow for commercial HFEs have been estimated to be below 3.5.

[The specific features of the development of iodine deficiencies in children living under environmental pollution with fluorine compounds].

Natural iodine deficiency and ambient air pollution with fluorine compounds were examined for their combined influence on the prevalence and severity of iodine-deficiency disorders. The excess intake of fluorine was shown to increase the incidence of thyroid diseases and to lower anthropometric indices in children. The preventive measures performed to eliminate iodine-deficiency disorders under intensive ambient air pollution with fluorine compounds were found to be insufficiently effective.

Predicted distribution and ecological risk assessment of a "segregated" hydrofluorrother in the Japanese environment.

An assessment of HFE-7500, a 'segregated' hydrofluoroether, was conducted to evaluate the potential for exposure to and subsequent effects on humans and wildlife in Japan. The segregated hydrofluoroethers belong to a class of fluorochemicals currently being proposed as replacements for traditional fluorochemicals (CFCs and PFCs) that are currently being used in several industries, in particular, the semiconductor industry. These traditional compounds have been implicated as ozone-depleting or potent "greenhouse gases". The segregated hydrofluoroethers have useful physical and chemical properties, but do not contribute to ozone depletion and have lower "global warming potential" (GWP) indices. Although the physical properties of these materials (low H2O solubility and high vapor pressure) suggest there would be a very low level of risk to aquatic systems, a thorough analysis had not been previously performed. Predicted environmental concentrations (PECs) of HFE-7500 in Japan were determined with the Higashino model, a Gausian puff and plume model that used an approximation of environmental releases to the atmosphere as input to the model. Allowable concentrations to protect aquatic life, wildlife, and humans from noncancer effects were determined as detailed in USEPA's final Water Quality Guidance for the Great Lakes Systems. Potential risk to ecological receptors and humans was determined by calculating hazard quotients and margins of safety. The results of the risk assessment indicate that HFE-7500 poses no significant risk to either aquatic or terrestrial wildlife species or humans living in the Japanese environment. The least margin of safety for any ecological receptor was 100,000, and a margin of safety greater than 100,000,000 for most receptors indicated that HFE-7500 poses no threat to human health. Because of a scarcity of toxicity and exposure data, the risk assessment was based on very conservative assumptions. Therefore, the actual margins of safety for both humans and wildlife could have been 100- to 1,000-fold greater if additional data were available such that less stringent uncertainty factors could be applied. These results suggest that the environmental impact of HFE-7500 should be inconsequential based on the marked improvement in its atmospheric properties relative to the traditional compounds currently in use. Given the short atmospheric lifetime and low global warming potential of this material, its replacement of CFCs and PFCs would result in a net improvement of environmental health and safety.

Análise crítica da concentraçäo de íons flúor em três águas minerais comercializadas no município de Säo Paulo, e sua importância nos esquemas terapêuticos com os compostos fluorados / Critical analysis of fluoride ions in three mineral waters sold in the city of Säo Paulo and its importance in fluoride therapeutic schedule

O objetivo deste estudo foi mostrar, na situaçäo descrita, o grande risco de fluorese dentária em alunos na idade pré-escolar. Avaliaçäo da concentraçäo de íons flúor em três águas minerais comercializadas no município de Säo Paulo. Imporancia nos esquemas terapêuticos de regiöes onde se faz o uso de água fluorada, e ocorre a ingestäo inadvertida de dentifrícios e suplementos dietéticos fluorados.(au)