The association between urinary metabolites of polycyclic aromatic hydrocarbons and diabetes: A systematic review and meta-analysis study.

To examine the association between urinary metabolites of polycyclic aromatic hydrocarbons (OH-PAHs) and diabetes, online databases, including PubMed, Scopus, and Web of Science, were searched on July 17, 2019. Of the 668 articles identified through searching, six cross-sectional studies involving 24,406 participants were included. The pooled odds ratio (OR) and 95% confidence interval (CI) were calculated using a random-effect model. Heterogeneity was measured by reporting the I-square index. Moreover, subgroup analysis according to types of metabolites was performed. We found a significantly higher odds of diabetes in the highest versus the lowest category of urinary naphthalene (NAP), fluorine (FLU), phenanthrene (PHEN), and total OH-PAH metabolites. The pooled OR (95% CI) was estimated at 1.47 (1.17, 1.78), 1.50 (1.29, 1.71), 1.41 (1.21, 1.60), and 1.61 (1.01, 2.21), respectively. We also found a significant association per 1-fold increase in FLU (OR = 1.09, 95% CI [1.00, 1.19]) and PHEN (OR = 1.19, 95% CI [1.08, 1.30]) metabolites. In subgroup analysis stratified by types of OH-PAH metabolites, A significant stronger odds of diabetes was observed in the highest versus the lowest category of 2-PHEN (OR = 1.66, 95% CI [1.32, 2.00]), 2-NAP (OR = 1.66, 95% CI [1.16, 2.17]), 2-FLU (OR = 1.62, 95% CI [1.28, 1.97]), and 9-FLU (OR = 1.62, 95% CI [1.21, 2.04]) metabolites. Furthermore, there was a meaningfully greater likelihood of diabetes per 1-fold increase in 2-FLU (OR = 1.34, 95% CI [1.10, 1.57]), 2-PHEN (OR = 1.33, 95% CI [1.14, 1.51]), and 3-PHEN (OR = 1.19, 95% CI [1.04, 1.34]) metabolites. In conclusion, our study suggests the significant odds of association between urinary OH-PAH metabolites and diabetes.

[Characteristic analysis of organic fluorosis caused by appliying of touch screen anti-fingerprint nanocoating material].

Objective: To analysis pathogenic conditions and pathogenic characteristics of organic fluorosis caused by applying of anti-fingerprint coating material on touch screen glass of the mobile phone. Methods: To collect clinical data and analyze the causes and pathogenic characteristics of poisoning through surveying occupational health, detecting occupational hazards in the workplace, collecting clinical data and diagnosing of occupational diseases. 6 employees in workshop 1 of packaging were as the organic fluorine exdposed group, and 16 employees in other workshops were as the non-exposed group. Results: Organic fluorine chemicals (perfluoro-1, 3-dimethylcyclohexane, hexadecafluoroheptane, perfluoro-hexane, perfluoromethy lopentane, perfluoro-2-methyl-2-pentene, etc.) can be volatilized by spraying and baking of anti-fingerprint nano-coating material on touch screen. The relative percentage of volatile components in air is 85.65%. Four cases of acute poisoning were caused by organic fluorosis deposited in a dustless air conditioning workshop with poor ventilation.The clinical manifestations of the patients were acute bronchitis, pulmonary edema and/or myocarditis. The average concentration of urine fluorine in the organic fluorine exposed group was 13.7± 4.4 mmol/mol creatinine, which was 4-5 times higher than that of other non-organic fluorine exposed groups. The difference of urine fluorine level between the organic fluorine exposed group and non exposed group was statistically significant (P<0.01) . The main indicators were abnormal for the blood oxygen saturation of finger pulse under suction air, leukocytes, neutrophils, monocytes, hypersensitivec-reactive protein, procalcitonin, l-lactate dehydrogenase, forebrain diuretic natriuretic peptide, hypersensitive troponin T in the four cases. One case was myocardial ischemia, four cases had bilateral lung symmetrically exudative lesions, one case was accompanied by a small amount of pleural pericardial effusion. Conclusion: Acute organofluorine poisoning can caused by the applying of the fingerprint nano-coating material on touch screen of the mobile phone. Attention should be paid to occupational poisoning caused by the applying of the small molecular perfluoroalkanes (olefins) in new industries, new processes and new materials.

[Optimization of ion selective electrode method in detection of urinary fluorine].

Objective: To optimize the ion selective electrode method of measuring urinary fluorine in WS/T 30-1996. Methods: The volume of 5 mol/L NaOH solution was fixed to confect the TISAB buffer solution. The samples were prepared by mixing 5 ml urine and equal volume of TISAB solution. Fluorine electrode and calomel electrode was used to test. When the potential value changed less than ±0.5 mV in one minute, it could be recorded. The standard curve method was selected as a quantitive method. Results: The linear range of this method was 0.07~50.0 mg/L, E=238.96-57.50lgC, r=0.999 8. The LOD and LOQ were 0.02 mg/L and 0.07 mg/L (with 5 ml urine) , respectively. The RSD of intra -and inter-batch precision were 0.80%~2.82% and 2.17%~2.86%, respectively. The recovery rate was 102%~107%. The urine sample could be preserved stably for 14 days at room temperature, and for 30 days at 4 ℃ and -20 ℃. Conclusion: In this method, the preparation process of TISAB buffer solution was simplified, and the linear range was expanded. It could meet the needs of occupational population detection.

[Determination of fluorine-ion in human urine by ion chromatography method].

Objective: To establish a method to determine fluorine ion in human urine by ion chromatography method. Methods: The samples were centrifuged, diluted and processed by C(18) solid-phase column, potassium hydroxide as mobile phase, gradient elution, separated by AS(15), and determined by anion conductivity detector. Results: The linear correlation coefficient of fluoride ion in the range of 0.02-10.00 mg/L was more than 0.999. The lowest detection limit of urinary fluoride was 0.06 mg/L (in 3 ml urine) . The recoveries of the method were 96.9%-99.5%, the inter batch precision range was 0.40%-2.89%. The intra batch precision was from 1.01 to 7.23%. Fluoride samples could be stored for 7 days at room temperature and 4 ℃, and be stored for 14 days at -20 ℃. Conclusion: Determination of fluoride in urine by ion chromatography, the method could meet the requirement in GBZ/T 210.5-2008.

Lebanese children are iodine deficient and urinary sodium and fluoride excretion are weak positive predictors of urinary iodine.

PURPOSE: To assess iodine and fluoride status among Lebanese children. METHODS: A nationally representative cross-sectional study of 6- to 10-year-old schoolchildren was conducted using multistage cluster sampling. Spot urine samples were collected from 1403 children, and urinary iodine, fluoride, creatinine and sodium levels were measured. Salt samples from markets (n = 30) were tested for iodine concentration by titration. RESULTS: Median urinary iodine concentration was 66.0 µg/l, indicating mild deficiency, and almost 75 % of Lebanese children had a urinary iodine concentration (UIC) <100 µg/l. UIC was higher among children from private schools and in areas of higher socioeconomic status. Most salt samples were fortified at levels far below the legislated requirement, and 56 % of samples contained less than 15 ppm iodine. Fluoride-to-creatinine ratio (F/Cr) was 0.250 (0.159-0.448) mg/g. There were weak positive correlations between UIC and urinary sodium (r 2 = 0.039, P value <0.001) and UIC and urinary fluoride (r 2 = 0.009, P value <0.001). CONCLUSIONS: Lebanese elementary school children are iodine deficient due to inadequately iodized salt. The weak correlation between UIC and urinary sodium suggests most dietary iodine does not come from iodized salt. The poor correlation between UIC and urinary fluoride suggests that fluoride intake is not affecting iodine metabolism. Efforts are needed in Lebanon to improve industry compliance with salt fortification through improved monitoring and enforcement of legislation.

Coal-burning endemic fluorosis is associated with reduced activity in antioxidative enzymes and Cu/Zn-SOD gene expression.

To study the effect of fluorine on the oxidative stress in coal-burning fluorosis, we investigated the environmental characteristics of coal-burning endemic fluorosis combined with fluorine content surveillance in air, water, food, briquette, and clay binder samples from Bijie region, Guizhou Province, southwest of China. The activities of antioxidant enzymes including copper/zinc superoxide dismutase (Cu/Zn-SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and level of lipid peroxidation such as malondialdehyde (MDA) were measured in serum samples obtained from subjects residing in the Bijie region. Expression of the Cu/Zn-SOD gene was assessed by quantitative reverse transcriptase PCR (qRT-PCR). Our results showed that people suffering from endemic fluorosis (the high and low exposure groups) had much higher MDA level. Their antioxidant enzyme activities and Cu/Zn-SOD gene expression levels were lower when compared to healthy people (the control group). Fluorosis can decrease the activities of antioxidant enzymes, which was associated with exposure level of fluorine. Down-regulation of Cu/Zn-SOD expression may play an important role in the aggravation of oxidative stress in endemic fluorosis.

[Study on the association between environmental chemical elements and fluorosis caused by coal-fire pollution].

OBJECTIVE: To understand the distribution of chemical elements in soil. To investigate the differences between patients under different state of fluorosis and normal population after preventive measurement was implemented to get rid of some chemical elements and to lower the urine fluoride levels so as to illustrate the pathogenesis of the disease. METHODS: Both ecological and comparative studies had been used to analyze the rates and levels of chemical elements. Teeth and skeletal from the patients with fluorosis and controls were taken and florin ion-selective-electrode method was used to determine urine the content of fluorine. Atomic Absorption Spectrometry was used to determine the copper, zinc, calcium, magnesium and iron contents in the whole blood. Differences of contents were analyzed. RESULTS: In Wushan county, the soil contents of nickel (r = 0.553, P = 0.050), iodine (r = 0.571, P = 0.041), fluorine (r = 0.303, P = 0.005), pH value (r = 0.304, P = 0.005) and the rates of fluorosis showed weaker positive relationship. In Fengjie county, the soil contents of mercury (r = 0.285, P = 0.001), nickel (r = 0.212, P = 0.00) and the rates of fluorosis also showed weaker positive relationship. In Wushan county, the urine fluoride level in the patients group [(0.64 ± 0.34) mg/L] was higher than that in the control group [(0.44 ± 0.59) mg/L], (P < 0.05). In Fengjie county, copper [(29.63 ± 3.32) µmol/L] and urine fluoride [(0.83 ± 0.37) mg/L] levels in the patients group showed higher than that in the control group [(26.76 ± 3.63) µmol/L, (0.53 ± 0.23) mg/L], (P < 0.05). zinc (Zn) [(76.13 ± 11.24) µmol/L], calcium (Ca) [(1.87 ± 0.25) mmol/L], magnesium (Mg) [(1.41 ± 0.18) mmol/L] and fluoride[(0.83 ± 0.37) mg/L]levels in urine of the patients in children were higher in Fengjie than that in Wushan [(71.95 ± 7.53) µmol/L, (1.43 ± 1.34) mmol/L, (1.34 ± 0.15) mmol/L, (0.64 ± 0.34) mg/L], (P < 0.05). Mg [(1.56 ± 1.96) mmol/L], ferrum [(8.15 ± 1.00) mmol/L] and fluoride [(2.17 ± 0.99) mg/L] levels among adult patients were significantly higher than in the control group [(1.46 ± 0.16) mmol/L, (7.64 ± 1.00) mmol/L, (1.44 ± 1.22) mg/L] (P < 0.05). CONCLUSION: Soil, rich in alkaline and fluorosis could increase the intake of fluorine while nickel, cadmium, iodine content in soil might relate to the occurrence of fluorosis. Residents living in endemic areas where anti-fluorine elements as Zn, Ca and Mg were in shortage, might be affected by these chemical elements that related with fluorosis.

Metabolismo e distribuição do flúor em ovinos jovens tratados cronicamente com fluoreto de sódio / Metabolism and distribution of fluor in lambs chronically treated with sodium fluoride

Este estudo teve por objetivo avaliar o metabolismo do flúor (F) em ovinos. Para tanto, utilizaram-se 12 animais, com cinco meses de idade, os quais receberam como dieta base 3 por cento do peso vivo de feno de alfafa e água ad libitum. Os animais foram divididos e constituíram um grupo Controle, que recebeu apenas sal iodado (5g de NaCl/animal + 0,2mg I/kg matéria seca) e, um grupo Tratado, que recebeu sal iodado adicionado de fluoreto de sódio (4,7mg F/kg de peso corporal). Esses sais foram administrados via sonda oro-esofágica, diariamente por um período de 150 dias. Para análise de F, coletaram-se amostras de sangue, urina e fezes e, ao fim do período experimental, após a eutanásia dos animais, coletou-se a glândula pineal e amostras de osso. Também nesta ocasião, coletou-se uma amostra de rim para exame histopatológico. Analisando-se os teores séricos, urinários e ósseos de F, verificou-se que foram significativamente superiores nos animais Tratados em relação aos Controles. Quanto ao F contido na glândula pineal, não houve diferença significativa entre os grupos. Na análise histológica do rim, não foram observadas alterações. Conclui-se que a administração crônica de flúor induz ao acúmulo desse elemento nos ossos, mesmo havendo um alto teor de cálcio na alimentação e esse acúmulo parece não ser nocivo aos animais. Em ovinos, a capacidade orgânica de acúmulo ósseo e excreção urinária do flúor é diferente de outras espécies animais.

The objective of the present study was to evaluate fluorine metabolism in growing lambs. Twelve 5-month-old male lambs maintained on alfalfa hay (3 percent BW) and non-fluorinated water ad libitum were used. Animals were allocated into Control, receiving 5g NaCl/animal/day + 0.2mg I/kg dry matter) and Treated group, receiving the same treatment plus sodium fluoride (4.7mg F/kg body weight). Mineral treatment was given by gavage, daily for 150 days. Blood, urine and fecal samples were collected during and the end of the experiment. At the end of treatment period animals were euthanized and kidney, pineal and bone samples were collected. Urine F was higher in treated animals throughout the experiment. Bone F levels were also increased in treated animals; pineal F content however, was not different between groups. Kidney histology revealed no differences. It is concluded that chronic F administration induces accumulation of the element in the skeleton. However such fact appears not to be detrimental to animals. Rates of F accumulation in bone and urine excretion obtained in other species can not be used in growing lambs.

Safe range of iodine intake levels: a comparative study of thyroid diseases in three women population cohorts with slightly different iodine intake levels.

Iodine excess may lead to thyroid diseases. Our previous 5-year prospective survey showed that the prevalence and incidence of hypothyroidism or autoimmune thyroiditis increased with iodine intake. The aim of the present study was to investigate the optimal range of iodine intake by comparing the prevalence of thyroid diseases in three areas with slightly different levels of iodine intake. In 2005, 778 unselected women subjects from three areas with different iodine intake levels were enrolled. Levels of serum thyroid hormones, thyroid autoantibodies, and urinary iodine were measured, and thyroid B ultrasounds were performed. Among the subjects with mildly deficient iodine intake, those with adequate intake, and those with more than adequate intake, the prevalence of clinical and subclinical hypothyroidism was 0, 1.13, and 2.84%, respectively (P = 0.014); that of thyroid goiter was 24.88, 5.65, and 11.37%, respectively (P < 0.001); that of serum thyrotropin values was1.01, 1.25, and 1.39 mIU/l, respectively; and that of serum thyrotropin/thyroglobulin ratio was 7.98, 6.84, and 5.11, respectively (P < 0.001). In conclusion, median urinary iodine 100~200 mug/l may reflect the safe range of iodine intake levels. Serum thyrotropin/thyroglobulin ratio might be a better index of evaluating iodine status.

[The relations between dental fluorosis and economic status in Shuicheng, a fluorosis-endemic County in Guizhou province].

OBJECTIVE: To discuss the relations of dental fluorosis and the social economic status in fluorosis-stricken villages where drying the corn by burning coal was prevail. METHODS: A total of 6 fluorosis-endemic villages and one non-endemic village were involved in the study. The general fluorine intake and the concentrations of fluorine in corn, in the pupils' were tested. Dental fluorosis among the pupils was also examen. A individual interview or household questionnaire survey was conducted to probe the economic condition and staple food structure in 600 adults. RESULTS: The fluorosis prevalence was lower in the villages of transportation convenience, higher income, less coal-dried corn intake. There was a declining trend of dental fluorosis in the corresponding age groups (r: 0.912, 0.916; P < 0.05); There was no significant changes in age-specified dental fluorosis in the low income villages. The correlation (r) of corn fluorine concentration and student's age-specified dental fluorosis prevalence and disparity was 0.755 - 0.980 (P < 0.05) and 0.302 - 0.811; The urine fluorine concentrations were 0.811 and 0.915 (P < 0.05). It was assumed that there was a negative correlation between family cash income and the dental fluorosis. CONCLUSIONS: The corn fluorine concentration is closely related to age-specified dental fluorosis. With the economic improvement, taking less coal-burned corn is the one of major factors in reducing the of dental fluorosis in these areas.

Concentração de flúor nas unhas e na urina: comparação entre crianças que receberam água natural ou artificialmente fluoretada, sal ou leite fluoretado / Fingernail and urine fluoride: comparison between children receiving naturally fluoridated water, artificially fluoridated water, fluoridated salt or fluoridated milk

Este estudo comparou a ingestão de flúor (F) através da dieta e do dentifrício bem como a excreção urinária de F de 24 horas de crianças recebendo diferentes fontes de F sistêmico: água artificialmente fluoretada (A-Bauru, SP-Brasil, 0,6-0,8 mgF/L, água naturalmente fluoretada (B-Brejo dos Santos, PB-Brasil, 0,6-0,9 mgF/L), sal fluoretado (C-Lima, Peru, 180-200 mgF/Kg) e leite fluoretado (D-Trujillo, Peru, 250 mL de leite contendo 1,0 mgF/L). Crianças de 4-6 anos (n=21-26) participaram em cada comunidade. Uma comunidade com água não fluoretada ( < 0,1 mgF/L) (E-Pirajuí, SP-Brasil) foi incluída como controle (n=24). A quantidade de F ingerida através da dieta foi determinada pela "dieta duplicada", considerando seus diferentes constituintes (água, outros líquidos e sólidos). A ingestão de F através do dentifrício foi determinada pela escovação simulada. A excreção urinária de F de 24 h e a concentração de F das unhas das mãos e dos pés também foram avaliadas. O F foi analisado por eletrodo, depois de difusão facilitada por hexametildiloxano ou após tamponameno com TISAB. A análise estatística foi feita pelos teste de Kruskall-Wallis, Dunn e regressão linear (p < 0,05). A média (±DP) da ingestão total de F (mg/Kg peso corporal/ dia) foi 0,065 0,030a,, 0,084 0,029a, 0,088 0044a,, 0,088 0,052a e 0,027 0,022b para A, B, C, D e E, respectivamente. Considerando somente a dieta, a média foi de 0,042 0,012b, 0,058 0,016a,b, 0,048 0,023a,b, 0,059 0,012a e 0,007 0,004c, respectivamente. A maior contribuição através da dieta para A/B e C/D/E foram a água e os sólidos, respectivamente. A média da quantidade F ingerida através do dentifrício variou entre 0,020 (E) e 0,040 (C) mg/Kg peso corporal/ dia e não foi significativamente diferente entre as comunidades. A média ( DP) da excreção urinária de F (mg) de 24 horas foi 0,693 0,198a, 0,625 0,297a,b, 0,808 0,305a, 0,666 0,194a e 0,478 0,321b para A, B, C, D e E, respectivamente. Houve uma correlação significativa entre a ex...

Health effects of occupational exposure to fluorine and its compounds in a small-scale enterprise.

A 7-yr study was conducted to evaluate the respiratory effects of fluorine compounds on exposed workers in a small-scale enamel enterprise. Air monitoring was done and 75 pairs, exposed and non-exposed workers were examined. The applied tests were: an epidemiological questionnaire, the bronchitis record, clinical examinations and urinary fluorine. Linear regression analysis was done. The values of fluorine in the air of workplaces ranged from 0.1 to 3.7 mg/m3 air during the study. Twenty five point and seven percent of exposed workers presented chronic rhinitis, laryngotracheitis and bronchitis. The smoking habit was similar in both groups. The incidence of chronic bronchitis was significantly higher in exposed workers compared to the non-exposed ones. The values of urinary fluorine were higher in the exposed versus the control group. Linear regression analysis has shown positive correlations between the fluorine exposure and incidence of chronic bronchitis (r=0.75), as well as the incidence of chronic respiratory diseases (r=0.71). Fluorine exposure may be responsible for the high incidence of chronic irritative respiratory diseases, especially for chronic bronchitis in exposed workers. For diseases prevention it is advisable to reduce the levels of fluorine in the air of workplaces and to decrease the concentration of fluorine compounds in the composition of enamel.

Dental caries in fluorine exposure areas in China.

In this study, fluorine concentrations in drinking water and in urine of residents from a fluorine exposure area in China were tested. DMFT (average number of decayed, missing and filled teeth) of local residents in four age groups were also determined. The results of the study indicate that in fluorine exposure areas, there is a strictly positive correlation between fluorine content in urine and the fluorine content in drinking water. Effect of dental caries by high fluorine content drinking water is different for the different age groups. High fluorine content drinking water is more dangerous for 15-and 18-year-old groups than 5- and 12-year-old groups.

Effect of volcanic gas exposure on urine, blood, and serum chemistry.

AIMS: This pilot study tested the hypothesis that aluminium (Al), rubidium (Rb), arsenic (As), lead (Pb), mercury (Hg), fluorine (F), and chlorine (Cl), which are all known to be present in volcanic emissions, may be useful biological markers for occupational gas exposure in volcanologists. METHODS: Ten human subjects were exposed to fumarole gases on White Island, New Zealand, for approximately 20 minutes. Sulphur dioxide (SO2) exposure was recorded by personal monitoring tubes. Pre- and post-exposure urine, blood and serum samples (collected using standard protocols) were analysed in the pathology laboratory for trace element and halogen content. RESULTS: Average personal exposure was measured at <75 ppm SO2 and calculated at approximately 25 ppm HCl, approximately 8 ppm hydrogen fluoride (HF), approximately 1 ppm Al, approximately 0.1 ppb Rb and approximately 4 ppb Pb. These concentrations almost certainly exceed those usually found in occupational exposure settings. Advanced levels of urinary Al and Rb were found following gas exposure and were statistically significant in the population at p<0.005 and p<0.001, respectively. The other chemical elements that were analysed (urinary Cl, F, and Hg; blood Pb, and serum Al) did not show such patterns. CONCLUSIONS: It is possible that urinary Al and Rb may be useful markers for exposure, a hypothesis which should be followed up in future work.

Bocio endémico por exceso de yodo en la población escolarde los campos de refugiadosde la RASD (República Árabe Saharaui Democrática) / Endemic goiter associated with high iodine intake in primary high school children in the saharawi arab democratic republic

Al objetivar una elevada prevalencia de bocio en los niños saharauis que acuden a Asturias en los veranos, nos planteamos realizar un estudio en profundidad de este problema. En una muestra de 570 escolares de la República Árabe Saharaui Democrática (RASD) se realizó palpación del cuello, peso, talla, medición de T4, TSH y anticuerpos antiTPO en la sangre capilar y en muestras de orina para determinar el contenido en yodo, flúor y tiocianatos. Se determinó también el contenido de estas sustancias en el agua de bebida. Hallamos un 58,1 por ciento de bocio (un 7 por ciento de grado 2), con mayor prevalencia en las niñas (el 65,4 frente al 51,4 por ciento). La yoduria fue de 965 ñ 348 µg/l, sin diferencias entre sexos ni por grado de bocio. La función tiroidea fue normal en todos los niños, y los anticuerpos y los tiocianatos fueron normales. La concentración de yodo en el agua de bebida osciló entre 180 y 400 µg/l, con un alto contenido en flúor (0,7-1,5 mg/l).En resumen, describimos un área geográfica con elevada prevalencia de bocio (58 por ciento) entre sus escolares y una yoduria elevada (965 ñ 348 µg/l). El principal aporte de esas cantidades tan altas de yodo es el agua de bebida (entre 180 y 400 µg/l). La función tiroidea es normal, la autoinmunidad puede descartarse como etiología de esta endemia y no se demuestra la existencia de compuestos antitiroideos en el agua ni en la orina de los niños. Creemos que el bocio hallado en esta población puede ser de origen multifactorial: exceso de yodo y flúor, gran dureza del agua de bebida y posible contaminación ocasional de la misma (AU)

Monitoring of fluorine in urine samples of patients involved in the tokyo sarin disaster, in connection with the detection of other decomposition products of sarin and the by-products generated during sarin synthesis.

We developed a new assay method for fluoride anion (F(-)) a specific metabolite of sarin. Trimethyifluorosilane (TMFS) was derivatized from F(-) with trimethylsilanol, and TMFS was detected with a GC-flame ionization detector (FID) and capillary column system. The linear range, detection limit and recovery rate were 0.02-10 ppm, 0. 01 ppm and 97.3-103.0%, respectively. The patients were reported to be exposed only once to the toxic substance (a bolus exposure). F(-) excretion in urine of the hospitalized patients demonstrated three or four peaks. Other common metabolites of sarin and by-products such as methylphosphonic acid (MPA) and isopropyl alcohol (IPA) also showed two or three peaks. These results suggested that the patients were exposed to not only sarin but also fluoride and isopropyl alcohol containing by-products. The sum of MPA excreted was 0.3-90 mM, far exceeding the human lethal dose of sarin. The residual acetyicholine esterase activity of erythrocytes on admission (4.7-57.2% of the individual reference value) of the patients showed statistically significant relationships only with the initial values of F(-) and the isopropyl methylphosphonate. This evidence also suggested the exposure to fluoride and isopropyl alcohol-containing by-products.

[Renal effects of prolonged sevoflurane anesthesia in Wistar rats]. / Efectos renales de la anestesia prolongada con sevoflurano en ratas Wistar.

OBJECTIVES: To assess renal safety of sevoflurane administered to Wistar rats at clinical concentrations during prolonged periods of inhalation. MATERIAL AND METHODS: The experimental animals were assigned to two groups of six rats each. Group I received anesthesia with 1.5% sevoflurane for 6 hours and group II received the same concentration of sevoflurane for 15 hours. The anesthesia was inhaled in an open circuit of fresh air at 1 l/min (medicinal air, 22.75% O2). The animals were kept in metabolic cages throughout the nine days the experiment lasted. Weight and urine output were recorded daily and the day before anesthesia was started, inorganic fluoride and blood was analyzed for renal function (urea, sodium, and blood urea nitrogen [BUN]). Between two and three hours after withdrawal of anesthesia, inorganic fluoride was again assessed, and on the last day of the experiment a new blood sample was taken to evaluate renal function. Kidney tissue was then studied. RESULTS: The two groups were similar as to weight, urea, sodium and BUN. Hourly diuresis was significantly greater after anesthesia in group II but not in group I. Inorganic fluoride was significantly higher in both groups, with postanesthetic levels of 22.42 +/- 1.76 microM/l in group I and 35.05 +/- 1.80 microM/l in group II. Renal tissue from both groups appeared normal under an optical microscope. CONCLUSIONS: Sevoflurane at the doses tested increases inorganic fluoride concentrations although for both periods the levels stayed under 50 microM/l, which has been considered the nephrotoxic threshold. No signs of changes in renal function were observed in blood texts or tissue studies.

Disponibilidad de flúor en pre-escolares de tres áreas geográficas, Región de La Araucanía, Chile / Flouride availability in preschool children of 3 geographical areas, Araucania, Chile

Fueron estudiados los niveles de ingesta y excreción de flúor en una muestra de 105 niños de 2 a 5 años en 6 centros abiertos de la fundación INTEGRA de la Región de La Araucanía escogiéndose dos centros por área geográfica: valle, cordillera y costa. Los niveles de ingesta de flúor fueron medidos en los alimentos y bebidas consumidos durante los almuerzos de 5 días consecutivos. La excreción fue medida en muestras de orina colectadas hasta 4 horas después de la ingesta. Con estos niveles, se obtuvo la disponibilidad de flúor de cada individuo de la muestra. Además, se relacionó la ingesta y el área geográfica de residencia de los pre-escolares. Los resultados indicaron que la disponibilidad de este ión es diferente en las áreas geográficas estudiadas, encontrándose el mayor valor en los pre-escolares de la cordillera, seguido por los residentes de la costa y del valle