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1.
Environ Monit Assess ; 192(11): 712, 2020 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-33070268

RESUMO

A major public health concern in Mexico is the natural contamination of groundwater with fluoride and arsenic. Therefore, this work aimed to evaluate the magnitude of human health risk after determining fluoride and arsenic concentrations in groundwater samples (n = 50) from the Metropolitan area of the city of San Luis Potosi, Mexico. Fluoride levels in water were determined via a potentiometric method using an ion-selective electrode. Arsenic concentrations in water samples were determined with an Atomic Absorption technique. Subsequently, a probabilistic health risk assessment was developed (Monte Carlo Analysis). Fluoride levels in water ranged from 0.20 to 3.50 mg/L. For arsenic, the mean level found in the assessed water samples was 15.5 ± 5.50 µg/L (range: 2.50-30.0 µg/L). In addition, when the probabilistic health risk assessment was completed, a mean HI (cumulative hazardous index) of higher than 1 was detected, indicating a high NCR (non-carcinogenic risk) for children and adults. According to the results found in this study, exposure protection campaigns are imperative in the Metropolitan area of the city of San Luis Potosí, Mexico, to successfully diminish exposure to arsenic and fluoride and, as a consequence, decrease the NCR in the population living in that region of Mexico.


Assuntos
Arsênico , Água Potável , Adulto , Arsênico/análise , Criança , Cidades , Água Potável/análise , Monitoramento Ambiental , Fluoretos/análise , Humanos , México , Medição de Risco
2.
Sci Total Environ ; 741: 140460, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32886997

RESUMO

Too little and too much fluorine are potentially hazardous for human health. In the Jiaokou Irrigation District, ionic concentrations, hydrogeochemistry, and fluoride contaminations were analyzed using correlation matrices, principal component analysis (PCA), and health risk assessment. The patterns for the average cation and anion concentrations were Na+ > Mg2+ > Ca2+ > K+ and SO42- > HCO3- > Cl- > NO3- > CO32-. The fluoride concentrations ranged between 0.29 and 8.92 mg/L (mean = 2.4 mg/L). 5% of the samples displayed lower than the recommended limit of 0.5 mg/L fluoride content, while 69% exceeded the allowable limits of 1.5 mg/L for drinking. The low F- content is distributed in a small part of the southeast, while elevated F- mainly in the central area of the study region. The PCA results indicated three principal components (PC), PC1 having the greatest variance (45.83%) and affected by positive loadings of TDS, Cl-, SO42-, Na+, and Mg2+, PC2 accounting for 17.03% and dominated by Ca2+, pH, HCO3-, and K+, and PC3 representing 12.17% and mainly comprising of CO32-. High fluoride groundwater is of the SO4-Cl-Na type, followed by HCO3-Na type. Evaporation and ion exchange play important roles in producing high fluoride groundwater. Furthermore, saturation index and anthropogenic activities also promote the high fluoride concentrations. The values of the total hazard quotient of 93% groundwater samples were greater than 1 for infants, followed by 85% for children, 68% for teenagers, and 57% for adults. Non-carcinogenic health risks to infants may occur over the entire study area, while for adults, health risks are mainly found in Weinan and Pucheng. High fluorine may have a potential negative influence on neurodevelopment, especially for infants and children. Adults in this region have serious dental fluorosis and skeletal fluorosis because of long-term drinking of high fluoride groundwater. Therefore, measures, including using organic fertilizers, strengthening defluoridation process, and optimizing water supply strategies, are necessary in this area.


Assuntos
Água Subterrânea , Poluentes Químicos da Água/análise , Adolescente , Adulto , Criança , China , Monitoramento Ambiental , Fluoretos/análise , Humanos , Medição de Risco
3.
Vet Clin North Am Food Anim Pract ; 36(3): 581-620, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32948413

RESUMO

Water is the most important nutrient for rangeland livestock. However, competition with municipalities, industry, and other water users often results in grazing livestock being forced to use water supplies that are less than perfect. Surface water in western rangleands are often contaminated by mineral extraction, irrigation runoff and other human activities. Mineral contaminants in drinking water are additive with similar contaminants in feedstuffs. The goal of this article is to provide producers and veterinarians with the basic background to make informed decisions about whether a given water supply is "safe" for livestock.


Assuntos
Doenças dos Bovinos/induzido quimicamente , Doenças dos Bovinos/prevenção & controle , Metais/análise , Metais/envenenamento , Qualidade da Água , Água/normas , Animais , Arsênico/análise , Intoxicação por Arsênico/prevenção & controle , Intoxicação por Arsênico/veterinária , Bovinos , Intoxicação por Flúor/prevenção & controle , Intoxicação por Flúor/veterinária , Fluoretos/análise , Humanos , Água/análise , Abastecimento de Água/normas
5.
Ecotoxicol Environ Saf ; 204: 111071, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32784015

RESUMO

The main objective of the study is to assess the groundwater quality based on water quality index and health threats associated with fluoride contamination in the Tiruppur region of southern India. Totally 40 groundwater samples were collected and analyzed for various physicochemical parameters such as pH, EC, TDS, Ca2+, Mg2+, Na+, K+, Cl-, HCO3-, SO42-, NO3- and F-. The dominance of major cations and anions conforms to the following order Ca2+> Na+> K+> Mg2+ and Cl- > HCO3- > SO42-> NO3- > F-, respectively. About 48% of the groundwater samples indicated Ca-Mg-Cl water type in the Piper trilinear diagram. The Gibbs plot indicated that all the water samples fell under rock dominance. Water quality index (WQI) results showed that 22.5, 75 and 2.5% of the samples represented good, poor and very poor quality water types, respectively. The fluoride ions in groundwater of this region ranged from 0.1 to 2.70 mg/L with a mean of 1.33 mg/L. About 50% of the groundwater samples experienced fluoride concentration exceeding the permissible limit of 1.5 mg/l. Hazard quotient (HQ) and total hazard index (THI) were computed based on the United States Environmental Protection Agency (USEPA) guidelines to evaluate the health threats for infants, children, teens, women and men. The THI ranged from 0.14 to 3.76, 0.11 to 3.01, 0.07 to 1.93, 0.06 to 1.64 and 0.06 to 1.50 for infants, children, teens, women and men, respectively. The percentages of risks in terms of THI were respectively 78, 75, 55, 33 and 23% for infants, children, teens, women and men respectively. The health risk assessment indicated that infants are most vulnerable to fluoride intake in this region. Therefore, proper treatment should be done by the government organizations to provide safe groundwater for the inhabitants.


Assuntos
Monitoramento Ambiental/métodos , Fluoretos/análise , Água Subterrânea/química , Indústria Têxtil , Poluentes Químicos da Água/análise , Qualidade da Água/normas , Adolescente , Criança , Humanos , Índia , Lactente , Medição de Risco
6.
J Chromatogr A ; 1627: 461394, 2020 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-32823099

RESUMO

The early identification of unstable glass objects in museum collections is essential for their conservation, but as yet cannot be accomplished straightforwardly. Accordingly, this paper describes the development and validation of a simple protocol for quantitative determination of ions characteristic of the chemical decay of historic glass, using surface swabbing combined with ion-exchange chromatography. The establishment of a robust protocol is an important step in the development of an early warning system for the chemical deterioration of unstable glass. Using a model system, the protocol was validated for specificity, linearity, accuracy, precision, limits of detection, and limits of quantification for 10 anionic species (fluoride, acetate, formate, chloride, nitrite, bromide, nitrate, carbonate, sulfate and phosphate) and 6 cationic species (lithium, sodium, ammonium, potassium, magnesium and calcium). Good validation parameters (R2 > 0.995; RSD < 5%; Recovery 90-100%) were obtained for acetate, formate, nitrite, nitrate, phosphate, lithium, sodium, potassium, magnesium and calcium. Chloride (R2 = 0.934; RSD = 13.6%; recovery 71.4%) and carbonate (R2 = 0.993; RSD = 10.3%; recovery 120%) had poor validation parameters. Sulfate had low recovery (78.2%), but high reproducibility (RSD = 4.32%) with R2 = 0.997. Limits of quantification were below 1 mg/L for all analytes, which is satisfactory for the study of unstable glass in museum collections. The validated sampling protocol was trialled using artificially aged unstable glass fragments, which resulted in a high relative standard deviation (between 1 and 30%). The ability to achieve improved care of historic glass by application of the validated protocol in museum collections is discussed in the context of a pilot study undertaken at the Rijksmuseum, Amsterdam.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Vidro/química , Íons/análise , Cloretos/análise , Cromatografia por Troca Iônica , Fluoretos/análise , Íons/química , Limite de Detecção , Metais/análise , Metais/química , Museus , Nitratos/análise , Reprodutibilidade dos Testes , Propriedades de Superfície
7.
Environ Sci Pollut Res Int ; 27(28): 34840-34861, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32638308

RESUMO

Understanding the formation of high fluoride (F-) groundwater in water-scarce northern China is critical for the sustainable development of the region. This study investigates the effects of F- enrichment in groundwater from seven typical regions of northern China, including Datong, Guide, Junggar, Yinchuan, Taiyuan, and Tarim basins and the North China Plain. A literature survey of 534 samples of selected regions showed that 45.13% of groundwater F- exceeded the 1.0 mg/L of Chinese drinking water guideline. Based on the geological background and hydrogeochemical analysis, in Datong and Yinchuan basins and part of the North China Plain, the main types of groundwater are soda water and controlling processes of F- enrichment are salinization, mineral dissolution, and desorption. In Taiyuan and Guide basins with Cl-Na water type, F- enrichment is mainly affected by salinization, cation exchange, and evaporation. The hydrogeochemical characteristics of high F- groundwater in Tarim and Junggar basins reflect the extent of salinization and weathering dissolution of minerals in groundwater. According to PCA, the contribution of salinization and mineral dissolution to F- enrichment is relatively high. Under the alkaline condition, groundwater with high Cl-, HCO3-, and Na+ concentration favors F- enrichment. Based on HCA, index clustering category I explains the influence of pH and buried depth on F- enrichment, and category II explains the effect of different ions. It is concluded that F- enrichment in groundwater is related to hydrogeochemical processes and hydrogeological conditions. The hydrogeochemical and alkaline conditions of groundwater are regulated by mineral dissolution, ion exchange, and evaporation, resulting in different degrees of F- enrichment.


Assuntos
Água Subterrânea , Poluentes Químicos da Água/análise , China , Monitoramento Ambiental , Fluoretos/análise , Minerais
8.
Sci Total Environ ; 744: 140749, 2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-32721666

RESUMO

The change of serum soluble Klotho (sKlotho) content is related to a variety of osteoarthropathy. However, its association with the severity of skeletal fluorosis (SF) is not clear. Here, the association of tea fluoride exposure with serum sKlotho levels and the severity of SF were investigated and further verified in a rat model of fluorosis. A cross sectional case control study was conducted in residents over 50 years old from brick-tea drinking areas in Qinghai and Xinjiang Provinces, China. Concentrations of fluoride in brick tea water and urine were determined by ion selective electrode method, and the levels of serum sKlotho were determined by ELISA method. Linear regression and ordered logistic regression models were constructed to examine the relationship among fluoride exposure, serum sKlotho levels and the severity of SF. The kidney and small intestine of Wistar rats were isolated for detection of Klotho by immunohistochemistry (IHC), and femoral artery blood was sampled to measure the serum levels of sKlotho. An increase of 1 mg/day in tea fluoride intake (TFI) was associated with a 12.070 pg/mL (95% CI: 0.452-23.689) increase in serum sKlotho levels and a 1.163-fold (95% CI: 1.007-1.342) increase in the severity of SF after adjusting for age, gender, and ethnicity. Serum sKlotho levels were also positively associated with the severity of SF (P < 0.05). The mediation analysis showed that serum sKlotho levels mediated 17.76% of the increase in the severity of SF caused by an increase of 1 mg/day of TFI. Moreover, a significant increase of serum sKlotho levels in fluoride-exposed groups was also seen in the rat model. The present study suggests that serum sKlotho may be a potential mediator of SF in brick tea-type fluorosis endemic areas.


Assuntos
Fluorose Dentária , Animais , Estudos de Casos e Controles , China , Estudos Transversais , Fluoretos/análise , Ratos , Ratos Wistar , Chá
9.
Environ Monit Assess ; 192(8): 514, 2020 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-32666298

RESUMO

Public health monitoring of Community Water Fluoridation (CWF) schemes requires estimates of exposure to fluoride in public water supplies (PWS). We aimed to use routine data to estimate population exposure to PWS-fluoride in England and to determine whether PWS-fluoride exposure from 2005 to 2015 could be used as a proxy for exposure for 1995-2004, when fluoride concentration data that could be linked to population health data were unavailable. We calculated annual mean water supply zone PWS-fluoride concentrations from monitoring data for 1995-2015, stratified by fluoridation scheme-flagging. We allocated annual 2005-2015 mean PWS-fluoride concentrations to small area boundaries to describe population exposure within five concentration categories (< 0.1 to ≥ 0.7 mg/L). We compared zone-level 1995-2004 and 2005-2015 mean PWS-fluoride concentrations using Spearman correlation. Most (72%) of the population received PWS with < 0.2 mg/L fluoride and 10% with ≥ 0.7 mg/L. Fluoride concentrations in 1995-2004 and 2005-2015 were similar (median 0.11 mg/L (lower quartile-upper quartile (LQ-UQ) 0.06-0.17) and 0.11 mg/L (LQ-UQ 0.07-0.17), respectively) and highly correlated (coefficient 0.93) if un-fluoridated but differed (1995-2004 median 0.78 mg/L (LQ-UQ 0.59-0.92); 2005-2015 0.84 mg/L (LQ-UQ 0.72-0.95)) and correlated weakly (coefficient 0.31) if fluoridated. Fluoride concentrations in 2005-2015 approximate those in 1995-2004 but with a greater risk of misclassification in fluoridation schemes.


Assuntos
Monitoramento Ambiental , Fluoretos/análise , Inglaterra , Fluoretação , Abastecimento de Água
10.
Artigo em Inglês | MEDLINE | ID: mdl-32525728

RESUMO

Groundwater is a major source of drinking water for millions of people around the world. Over 400 million people in Africa depend solely on it as their main source of water supply. Fluoride is a common contaminant in groundwater. In low concentration (0.5-1.0 mg/L), fluoride is needed by humans for healthy development of bones and teeth, however, a concentration >1.5 mg/L has been linked with several fluorosis and non-fluorosis diseases. Dental and skeletal fluorosis are the major fluorosis diseases commonly reported with the consumption of fluoride-rich water. Although fluoride intake through other pathways such as the drinking of tea and eating of vegetables have been reported, the drinking of fluoride-rich water remains the major pathway of fluoride into humans. Cases of high fluoride levels in groundwater have been reported in almost all the sub-Saharan Africa region but it is more prevalent in East African countries, Sudan and South Africa. Although fluoride is present in surface water mostly in the East African Rift Valley across different countries in East Africa, its significant or high levels are usually associated with groundwater. Geogenic sources such as fluorite, apatite, biotite, amphibole, micas, topaz, cryolite, muscovite and fluorspar have been identified as the major sources of fluoride in groundwater. High fluoride levels have been reported across sub Saharan Africa, with generally higher levels in East Africa resulting from the volcanic activities in the rift system. Dental fluorosis has been reported in many sub-Saharan African countries including South Africa, Tanzania, Uganda, Ethiopia, Kenya, Sudan, Niger, Nigeria, Benin, Ghana and Malawi. Geothermal temperature has been regarded as one of the driving forces for high fluoride levels recorded in groundwater from deep aquifers and geothermal springs. The most affected people with the consumption of fluoride-rich water are the poor with low socioeconomic status who live in rural areas. Some of the proposed alternative sources include rainwater and fog water harvesting and blending of water from various sources. Low-cost and sustainable deflouridation technique remains one of the best ways to treat fluoride contaminated water either at communal level or at the point-of-use.


Assuntos
Fluoretos/toxicidade , Sedimentos Geológicos/química , Água Subterrânea/química , Poluentes Químicos da Água/toxicidade , Abastecimento de Água/métodos , África ao Sul do Saara/epidemiologia , Fluoretos/análise , Fluorose Dentária/epidemiologia , Fluorose Dentária/etiologia , Água Subterrânea/normas , Humanos , Prevalência , Poluentes Químicos da Água/análise , Abastecimento de Água/normas
11.
Sci Total Environ ; 735: 139584, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32485458

RESUMO

Safe drinking water supply systems in naturally contaminated hydrogeological environments require precise geoinformation on contamination hotspots. Spatial statistical methods and GIS were used to study fluoride occurrence in groundwater and identify significant spatial patterns using fluoride concentrations. The global and local Morans I indices were used. While the significant positive global Morans I index indicated spatial structure in fluoride occurrence, the significant spatial clusters were identified using local Morans I index and mapped at p-value of 0.05. The spatial clusters demonstrated patterns of drinking water sources with fluoride concentrations below or above WHO guideline and Tanzania standard for drinking water and were considered as 'regional fluoride cool spots' and 'regional fluoride contamination hotspots', respectively. Two regional fluoride contamination hotspots were identified and mapped around the Stratovolcano Mountains in the north-east and south-west of the study area; and along the Neogene Quaternary volcanic formations and Palaeo-Neoproterozoic East African Orogen (Mozambique Belt). The two largest regional fluoride cool spots dominated the major and minor rift escarpments in the west and east of the study area respectively while the small ones emerged around the volcanic mountains in the north and south. Furthermore, significant spatial outliers emerged at the boundary of regional fluoride hotspots and cool spots as an indication of the spatial processes controlling the mobilization of fluoride in groundwater. While all water sources in the cool spots had fluoride concentrations below 1.5 mg/L, some had extremely low concentrations below 0.5 mg/L which is not safe for human consumption. For hotspots, 96% of water sources had fluoride concentrations above 1.5 mg/L. The probability of having safe source of drinking water varied from one geological unit to another with sources in the Neogene Quaternary volcanic formations having least probabilities.


Assuntos
Água Potável , Água Subterrânea , Poluentes Químicos da Água/análise , Monitoramento Ambiental , Fluoretos/análise , Sistemas de Informação Geográfica , Humanos , Tanzânia , Abastecimento de Água
12.
Chemosphere ; 257: 127186, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32516669

RESUMO

Fluoride is an element that is widely distributed in the environment. The involvement of fluoride in pathogenesis of Chronic Kidney Disease of uncertain aetiology (CKDu) in Sri Lanka is a much-debated topic. This study aimed to investigate the fluoride concentration in drinking water in CKDu affected areas in Sri Lanka and to evaluate the possible effect of renal impairment on serum fluoride levels in CKDu patients. Drinking water (n = 60) from the common water sources from two CKDu prevalent areas and serum samples of CKDu patients (n = 311) and healthy controls (n = 276) were collected. Both environmental and biological samples were analysed for the concentration of fluoride. The fluoride concentration in over 95% of drinking water samples was below the WHO guideline of 1.5 mg/L. Serum fluoride concentrations in majority of the unaffected and early-stage CKDu patients (stages 1 and 2, eGFR >60 ml/min/1.73m2) were below the normal upper concentration of 50 µg/l and significantly higher levels were observed in patients in late stages of CKDu compared to the healthy controls. The available guidelines for drinking water are solely based on healthy populations with normal renal function. But, it is evident that once the kidney function is impaired, patients enter a vicious cycle as fluoride gradually accumulates in the body, further damaging the kidney tissue. Thus, close monitoring of serum fluoride levels in CKDu patients and establishing health-based target guidelines for fluoride in drinking water for the CKDu patients are recommended to impede the progression to end stage renal disease.


Assuntos
Exposição Ambiental/estatística & dados numéricos , Fluoretos/metabolismo , Insuficiência Renal Crônica/epidemiologia , Poluentes Químicos da Água/metabolismo , Feminino , Fluoretos/análise , Taxa de Filtração Glomerular , Humanos , Masculino , Pessoa de Meia-Idade , Minerais/análise , Sri Lanka/epidemiologia , Incerteza , Água/análise , Poluentes Químicos da Água/análise
13.
Int Dent J ; 70(5): 340-346, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32358889

RESUMO

OBJECTIVE: This study investigates the impact of dental fluorosis on the oral health-related quality of life (OHRQoL) among 11- to 14-year-old school children in endemic fluoride areas of Haryana (India). MATERIALS AND METHODS: A cross-sectional survey was conducted among 2,200 school children in endemic fluoride areas of Haryana. Using cluster random sampling, three districts out of 14 endemic fluoride districts were selected, and children 11-14 years of age were examined. A child perception questionnaire (CPQ11-14 ) (Hindi version) evaluated the impact of dental fluorosis on OHRQoL. The Thylstrup-Fejerskov index (TFI) was used for assessing dental fluorosis. The data were analysed using SPSS version 18, and non-parametric tests were used to assess the significance. The regression analysis was used to determine the effect of change in CPQ scores with dental fluorosis at P < 0.05. RESULTS: The study participants included 45.3% males and 54.7% females among which mild to moderate level of dental fluorosis was identified with mean mean TFI Scores being 3.19 ± 1.55. Children without dental fluorosis had 1.17 times more odd of percieving their oral health as excellent/good when compared to children with dental fluorosis (P < 0.05). Study subjects with dental fluorosis did not have higher mean CPQ11-14 domain and total scores when compared with subjects without dental fluorosis. CONCLUSION: It can be concluded that mild dental fluorosis did not affect the OHRQoL of the children in the endemic fluoride areas of Haryana in India.


Assuntos
Cárie Dentária , Fluorose Dentária/epidemiologia , Adolescente , Criança , Estudos Transversais , Feminino , Fluoretos/análise , Humanos , Índia/epidemiologia , Masculino , Saúde Bucal , Prevalência , Qualidade de Vida
14.
Community Dent Health ; 37(3): 216-222, 2020 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-32338469

RESUMO

OBJECTIVE: Examine the association between marginalization and fluorosis with caries experience in Mexican rural children aged 8-12, in Oaxaca, Mexico. METHODS: Cross-sectional study of 283 rural schoolchildren selected from two locations with high and medium levels of marginalization where the water fluoride concentration ranged from 2.0 to 2.5 ppm/F. Caries was evaluated using the DMFT index and dental fluorosis with the Thylstrup-Fejerskov Index (TFI). Socioeconomic data were collected from participants' parents, with data on the children's characteristics collected from them via a questionnaire. RESULTS: The prevalence of caries was 72.4% (DMFT ≥1) in the permanent dentition. The prevalence of fluorosis was 98.0% (TFI ≥4=71.4%). 54.8% of the children brushed their teeth two or more times daily. In logistic regression children living in high levels of marginalization were more likely to present caries (OR=2.11, 95% CI 1.13 - 3.93) than children living in medium levels. Children with severe fluorosis (TFI ≥4) (OR=1.93, 95% CI 1.06 - 3.53) were more likely have caries than those with TFI ⟨3. CONCLUSION: Rural children with a high level of marginalization and fluorosis (TFI ≥4) were more likely to present caries. Poor oral hygiene and low dental service levels were found in both marginalized areas. Populations with medium/high marginalization are more susceptible to caries.


Assuntos
Cárie Dentária , Fluorose Dentária , Criança , Estudos Transversais , Índice CPO , Fluoretos/análise , Humanos , México , Prevalência
15.
Environ Sci Pollut Res Int ; 27(16): 20281-20291, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32239411

RESUMO

Endemic fluorosis is widespread in China, especially in the arid and semi-arid areas of northwest China, where endemic fluorosis caused by consumption of drinking water high in fluorine content is very common. We analyzed data on endemic fluorosis collected in Ningxia, a typical high-fluorine area in the north of China. Fluorosis cases were identified in 539 villages in 1981, in 4449 villages in 2010, and in 3269 villages in 2017. These were located in 19 administrative counties. In 2017, a total of 1.07 million individuals suffered from fluorosis in Ningxia, with more children suffering from dental fluorosis and skeletal fluorosis. Among Qingshuihe River basin disease areas, the high incidence of endemic fluorosis is in Yuanzhou District and Xiji County of Guyuan City. The paper holds that the genesis of the high incidence of endemic fluorosis in Qingshui River basin is mainly caused by chemical weathering, evaporation and concentration, and dissolution of fluorine-containing rocks around the basin, which is also closely related to the semi-arid geographical region background, basin structure, groundwater chemical characteristics, and climatic conditions of the basin. The process of mutual recharge and transformation between Qingshui River and shallow groundwater in the basin is intense. There is a close coupling relationship between the power of central and southern Ningxia disease areas and Qingshui River watershed of excess fluorine water. Because the traditional drinking water source of the residents in the basin is shallow groundwater, the underground water is the main cause of the high incidence of endemic fluorosis. The results show that Xiji County and Yuanzhou District were the areas of high incidence of endemic fluorosis which gradually decreased to the middle and lower reaches of Qingshui River. In space, distribution characteristics are Qingshui River source area > Qingshui River valley basin area, tributary area > trunk stream area, upstream area > middle reaches area> downstream area of Qingshui River. This is relatively consistent with the spatial distribution of fluoride ion content in Qingshui River groundwater.


Assuntos
Água Potável , Fluorose Dentária , Água Subterrânea , Criança , China , Fluoretos/análise , Flúor , Humanos
16.
Ecotoxicol Environ Saf ; 195: 110503, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32229352

RESUMO

Groundwater fluoride contamination is a major issue of water pollution in the world with health hazards such as dental and skeletal fluorosis. This research focused on exposure to the high concentration of fluoride in the springs water in the Bazman volcanic area, southeast Iran. The combination of chemical/isotopic analysis, geochemical modeling, health risk assessment and multivariate statistical methods were applied to investigate the contamination and sources of fluoride in the samples. Groundwater samples were collected from cold and thermal springs. Major ions, fluoride, trace elements and stable isotopes δ18O and δD were measured in the samples using standard methods, ICP-MS and OA-ICOS, respectively. Fluoride content in springs varied from 0.5 to 3.75 mg/L with an average value of 1.66 mg/L. The highest fluoride concentrations were observed in the eastern cold springs while thermal springs showed the minimum fluoride contents. The majority of samples showed F contents higher than the calculated optimal concentration of fluoride (0.75 mg/L). Reaction of fluorite mineral with HCO3 and replacement of F in clay minerals and metal oxy-hydroxides with OH- in water were likely cause fluoride enrichment in the eastern springs. Whereas, in the western springs and thermal springs, origin of fluoride was related to weathering of muscovite, cryolite, apatite and fluoroapatite minerals. The δ18O and δ2H of the water samples displayed the impact on evaporation on fluoride enrichment in all spring water samples. The average value of contamination index (Cd) in the water samples was 1.94 categorizing medium risk level while springs S7, S8, S9 and S4 were above the threshold value of Cd index. The fluoride hazard quotient (HQ) showed that 25%, 44%, 56% and 0% of springs' water resources had high risk level for age group of adults, teenager, children and infants, respectively. Therefore, health risk of fluoride in drinking water resources were in the following order: children > teenager > adults > infants.


Assuntos
Monitoramento Ambiental/métodos , Fluoretos/análise , Água Subterrânea/química , Nascentes Naturais/química , Poluentes Químicos da Água/análise , Adolescente , Adulto , Criança , Pré-Escolar , Água Potável/análise , Humanos , Lactente , Irã (Geográfico) , Isótopos , Minerais/análise , Medição de Risco , Erupções Vulcânicas/análise , Tempo (Meteorologia)
17.
Sci Total Environ ; 724: 138316, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32272415

RESUMO

Spatiotemporal distribution of fluoride in drinking water has been posing serious health concerns worldwide. However, in Bangladesh, to date, there is a very limited study reported the probabilistic health risks from fluoride content in drinking water. Therefore, we investigate the spatiotemporal distribution of fluoride concentration in drinking water and associated health risks in the coastal districts of Bangladesh based on randomly collected 840 groundwater samples (Dry-season = 302 and Wet-season = 538). Probabilistic health risk appraisal from fluoride was performed using the Monte-Carlo simulation and sensitivity analysis. Fluoride concentration in 11.89% (Wet-season) and 24.50% (Dry-season) of the samples exceeded the acceptable level of 1.0 mg/L, while 3.90% (Wet-season) and 7.28% (Dry-season) samples surpassed the maximum permissible limit (fluoride: 1.5 mg/L. The deficiency of fluoride content in groundwater (<0.50 mg/L) in Wet-season (60.41%) and in Dry-season (55.63%) was identified from the study area. The seasonality to the spatial change of fluoride concentration in drinking water has been explored. The mean non-carcinogenic risks e.g., hazard quotient (HQ) from the consumption of high fluoride-containing water for infants and children were mostly exceeded the threshold value 1 (HQ > 1) in both seasons. However, the risk of children and infants at the 95th percentile crossed the safe level (SL: 1) in the wet season and the risk of infants, children, teens and adults at the 95th percentile surpassed 1 in the dry season, indicating the potential adverse health effects. Apart from the high exposure, fluoride deficiency might be a severe problem in this region due to the very low concentration of fluoride (<0.50 mg/L) in drinking water. Sensitivity analyses indicate high fluoride-containing drinking water was the most contributing variables affecting the model outcome. Finally, the case-control study should be performed to examine further the health effects from the ingestion of high/low fluoride-bearing groundwater in the study area.


Assuntos
Água Potável/análise , Fluorose Dentária , Água Subterrânea , Poluentes Químicos da Água/análise , Adolescente , Adulto , Bangladesh , Estudos de Casos e Controles , Criança , Fluoretos/análise , Indicadores Básicos de Saúde , Humanos , Lactente , Medição de Risco
18.
Chemosphere ; 253: 126616, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32283421

RESUMO

Excessive exposure to fluoride has been reported to affect bone mineral density (BMD). CALCA expression plays a critical part in bone formation. However, the role of CALCA in the association between fluoride and BMD is not known. We conducted a cross-sectional study and recruited 722 women in rural areas of Henan Province, China, to assess the relationship between fluoride exposure, CALCA methylation, and BMD. Urinary levels of fluoride, CALCA methylation, and BMD were measured by a fluoride ion-selective electrode, standalone ultrasound bone densitometer, and quantitative methylation-specific polymerases chain reaction, respectively. The association among fluoride exposure, CALCA methylation, and BMD was age-specific. Specifically, BMD was negatively correlated with methylation (ß: -0.008; 95% CI: -0.016, 0.000) and fluoride exposure (ß: -0.063; 95% CI: -0.129, -0.002) in women over 45 years and 50-54 years of age, respectively, whereas methylation was positively correlated with fluoride exposure (ß: 4.953; 95% CI: 1.162, 8.743) in women aged 40-44 years. Besides, increased BMD in women aged 45-49 years induced by the interactive effect of the highest methylation of CALCA exon 1 (tertile 3) and fluoride exposure was observed (P for interaction < 0.05). Our findings suggest an age-specific association between exposure to excessive fluoride, CALCA methylation, and BMD in a rural population of women in China. Notably, the susceptibility of BMD to fluoride exposure may be modified by CALCA methylation.


Assuntos
Densidade Óssea/fisiologia , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Exposição Ambiental/estatística & dados numéricos , Fluoretos/toxicidade , Absorciometria de Fóton , Adulto , Idoso , Grupo com Ancestrais do Continente Asiático , Densidade Óssea/efeitos dos fármacos , China/epidemiologia , Estudos Transversais , Feminino , Fluoretos/análise , Humanos , Metilação , Pessoa de Meia-Idade , População Rural
19.
Chemosphere ; 249: 126126, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32142984

RESUMO

Arsenic (As) and fluoride (F-) are the two most conspicuous contaminants, in terms of distribution and menace, in aquifers around the world. While the majority of studies focus on the individual accounts of their hydro-geochemistry, the current work is an effort to bring together the past and contemporary works on As and F- co-occurrence. Co-occurrence in the context of As and F- is a broad umbrella term and necessarily does not imply a positive correlation between the two contaminants. In arid oxidized aquifers, healthy relationships between As and F- is reported owing desorption based release from the positively charged (hydr)oxides of metals like iron (Fe) under alkaline pH. In many instances, multiple pathways of release led to little or no correlation between the two, yet there were high concentrations of both at the same time. The key influencer of the strength of the co-occurrence is seasonality, environment, and climatic conditions. Besides, the existing primary ion and dissolved organic matter also affect the release and enrichment of As-F- in the aquifer system. Anthropogenic forcing in the form of mining, irrigation return flow, extraction, recharge, and agrochemicals remains the most significant contributing factor in the co-occurrence. The epidemiological indicate that the interface of these two interacting elements concerning public health is considerably complicated and can be affected by some uncertain factors. The existing explanations of interactions between As-F are indecisive, especially their antagonistic interactions that need further investigation. "Multi-contamination perspectives of groundwater" is an essential consideration for the overarching question of freshwater sustainability.


Assuntos
Arsênico/análise , Monitoramento Ambiental , Fluoretos/análise , Água Subterrânea/química , Poluentes Químicos da Água/análise , Água Doce , Metais , Minerais , Mineração , Óxidos
20.
Ecotoxicol Environ Saf ; 194: 110438, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32171120

RESUMO

The main objective of the present investigation is appraisal of human health hazard based on the intake and dermal contact of fluoride enriched potable groundwater used for rural water supply in a semi-arid region (Shanmuganadhi River basin) of south India. A variance decomposition based Sobol sensitivity method was used to assess the relative contribution as well as interaction of input variables for both oral and dermal models. Three different scores were evaluated: FOE (first order effect), SOE (second order effect) and TE (total effect) for different age groups of population including gender (kids, women and men). The spatio-temporal mapping indicates that about 26% of water supply wells exceeded the recommended limit (WHO) of fluoride (>1.5 mg l-1) for safe intake. These wells spread over 104.03 km2 area consisting 16 villages in the basin. To assess the human health risk related to fluoride enrichment in potable water, hazard index (HI) was calculated as per USEPA guidelines. The non-carcinogenic risk based on oral intake ranges from 0 to 1.81, from 0 to 1.59 and from 0 to 1.29 for kids, women and men respectively. Nearly 30%, 21% and 12% of well samples exceeded the upper permissible limit (HI > 1) for kids, women and men respectively. The Sobol sensitivity analysis reveals that, Cw (concentration of F- in water) and IR (intake rate) combination plays a vital role in the HQ oral model for the appraisal of health hazard in kids. However, these two parameters have negligible effect on health hazard for adult population (men and women). Therefore, lower age group people especially kids have significant ill effect due to the consumption of fluoride enriched potable water. The model output suggests that body weight (BW) has least effect on health hazard in the lower age group of population. Interestingly 'exposure frequency (EF)' and 'body weight (BW)' have not much effect on health hazards related to dermal contact, and 'skin surface area (SA)' has minimal effect for men (TE = 0.92) and women (TE = 1.26). However, 'SA' has vital effect for kids (TE = 17.39). Because of this, older age group people have more dermal risk than the younger people. Therefore, the HQ dermal results indicate that 49%, 64% and 67% of samples possess non-carcinogenic risk to the kids, women and men respectively.


Assuntos
Exposição Ambiental/estatística & dados numéricos , Fluoretos/análise , Indicadores Básicos de Saúde , Poluentes Químicos da Água/análise , Poluição da Água/estatística & dados numéricos , Adulto , Criança , Exposição Dietética/estatística & dados numéricos , Água Potável/análise , Monitoramento Ambiental/métodos , Feminino , Água Subterrânea/química , Humanos , Índia , Masculino , Minerais/análise , Medição de Risco , Rios , Abastecimento de Água/estatística & dados numéricos
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