1
|
Foat A, Stevens C, George G, Massawe J, Mhina A, Gray WK, Mmbaga BT, Rwakatema DS, Sallis P, Jarvis H, Haule I, Benedict D, Walker R. Prevalence of Skeletal Fluorosis in Northern Tanzania: A Follow-Up Study. GLOBAL HEALTH, SCIENCE AND PRACTICE 2023; 11:e2200342. [PMID: 38135514 PMCID: PMC10749641 DOI: 10.9745/ghsp-d-22-00342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Accepted: 11/19/2023] [Indexed: 12/24/2023]
Abstract
OBJECTIVES Skeletal fluorosis is a metabolic bone disease caused by excessive exposure to fluoride, predominantly through contamination of drinking water. This study aimed to identify all cases of skeletal fluorosis in Tindigani village situated in Northern Tanzania. This was done following changes in drinking water sources after a previous prevalence study in 2009 in this population. METHODS In a door-to-door cross-sectional study of Tindigani village, a sample of residents was assessed for skeletal fluorosis and dental fluorosis. Diagnosis of skeletal fluorosis was based on pre-defined angles of deformity of the lower limbs. Dental fluorosis was diagnosed and graded using the Thylstrup and Fejerskov Index. Samples from current drinking water sources underwent fluoride analysis. RESULTS Tindigani village had a population of 1,944 individuals. Of the 1,532 individuals who were screened, 45 had skeletal fluorosis, giving a prevalence of 3.3% (95% CI=2.4, 4.3). Dental fluorosis was present in 82.5% of those examined (95% CI=79.8, 85.3). Dental fluorosis was present in all individuals with skeletal fluorosis and at higher grades than in the rest of the population. Drinking water samples were collected from 28 sources. These included piped, surface, well, and borehole water sources. Fluoride concentrations ranged from 0.45-38.59 mg/L of fluoride. CONCLUSIONS Skeletal fluorosis is an ongoing but preventable health problem in the current population. The delivery of sustainable low fluoride piped water to this community would be of clear health benefit. This has been addressed at a local level.
Collapse
Affiliation(s)
- Anna Foat
- Faculty of Medical Sciences, Masters by Research, Newcastle University, Newcastle Upon Tyne, United Kingdom.
| | - Claire Stevens
- Faculty of Medical Sciences, Masters by Research, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | - Grace George
- Faculty of Medical Sciences, Masters by Research, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | - John Massawe
- Hai District Hospital, Boma Ng'ombe, United Republic of Tanzania
| | - Ally Mhina
- Hai District Hospital, Boma Ng'ombe, United Republic of Tanzania
| | - William K Gray
- Northumbria Healthcare NHS Foundation Trust, North Tyneside General Hospital, North Shields, United Kingdom
| | - Blandina T Mmbaga
- Kilimanjaro Clinical Research Institute, Moshi, United Republic of Tanzania
| | | | - Paul Sallis
- School of Engineering, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | - Helen Jarvis
- Population Health Science Institute, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | - Irene Haule
- Hai District Hospital, Boma Ng'ombe, United Republic of Tanzania
| | - Daniel Benedict
- Hai District Water Authority, Boma Ng'ombe, United Republic of Tanzania
| | - Richard Walker
- Northumbria Healthcare NHS Foundation Trust, North Tyneside General Hospital, North Shields, United Kingdom
- Population Health Science Institute, Newcastle University, Newcastle Upon Tyne, United Kingdom
| |
Collapse
|
2
|
Rojanaworarit C, Claudio L, Howteerakul N, Siramahamongkol A, Ngernthong P, Kongtip P, Woskie S. Hydrogeogenic fluoride in groundwater and dental fluorosis in Thai agrarian communities: a prevalence survey and case-control study. BMC Oral Health 2021; 21:545. [PMID: 34686164 PMCID: PMC8532340 DOI: 10.1186/s12903-021-01902-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 10/12/2021] [Indexed: 11/19/2022] Open
Abstract
Background Dental fluorosis can be a disease of social inequity in access to safe drinking water. This dental public health issue becomes prominent in socially disadvantaged agrarian communities in fluoride endemic areas where the standard irrigation system is unavailable and groundwater containing natural fluoride is the major drinking water source. This study aimed to determine the prevalence and severity of dental fluorosis in children and to evaluate its association with fluoride in groundwater in the aforementioned setting in Thailand. Methods A cross-sectional survey of 289 children in Nakhon Pathom Province was conducted in 2015. Children with very mild to severe fluorosis were regarded as ‘cases’ while their counterparts were ‘controls’ for a subsequent case–control study. Records of fluoride concentrations in groundwater used for household supply corresponding to resident and number of years by age of each child during 2008–2015 were retrieved. Other exposure variables were measured using a questionnaire. Prevalence ratio (PR), a measure indicating the relative effect of different levels of fluoride on dental fluorosis, was obtained from Poisson regression with robust standard error. Result There were 157 children with very mild to moderate dental fluorosis (54.3% prevalence). The univariable analysis revealed that the prevalence of dental fluorosis among children with fluoride concentrations in water sources of 0.7–1.49 (index category 1) and ≥ 1.5 ppm (index category 2) was 1.62 (95% CI; 0.78, 3.34) and 2.75 (95% CI; 1.42, 5.31) times the prevalence among those with fluoride < 0.7 ppm (referent category). After adjusting for all covariates, the adjusted prevalence ratios in both index categories were 1.64 (95% CI; 0.24, 11.24) and 2.85 (95% CI; 0.44, 18.52) which were close to their corresponding crude estimates. Since the magnitude of confounding, measured by (PRcrude–PRadjusted)/PRadjusted, were less than 10% for both index categories; this indicated the limited confounding effect of all covariates. Conclusions In fluoride endemic areas, groundwater containing natural fluoride utilized for household consumption resulted in high dental fluorosis prevalence, particularly in the groundwater with fluoride concentrations of ≥ 1.5 ppm. Supplementary Information The online version contains supplementary material available at 10.1186/s12903-021-01902-8.
Collapse
Affiliation(s)
- Chanapong Rojanaworarit
- Department of Health Professions, School of Health Professions and Human Services, Hofstra University, Hempstead, NY, USA.
| | - Luz Claudio
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Nopporn Howteerakul
- Department of Epidemiology, Faculty of Public Health, Mahidol University, Bangkok, Thailand
| | | | | | - Pornpimol Kongtip
- Department of Occupational Health and Safety, Faculty of Public Health, Mahidol University, Bangkok, Thailand
| | - Susan Woskie
- Department of Public Health, University of Massachusetts Lowell, Lowell, MA, USA
| |
Collapse
|
3
|
Mmbaga BT, Mwasamwaja A, Mushi G, Mremi A, Nyakunga G, Kiwelu I, Swai R, Kiwelu G, Mustapha S, Mghase E, Mchome A, Shao R, Mallya E, Rwakatema DS, Kilonzo K, Munishi OM, Abedi‐Ardekani B, Middleton D, Schüz J, McCormack V. Missing and decayed teeth, oral hygiene and dental staining in relation to esophageal cancer risk: ESCCAPE case-control study in Kilimanjaro, Tanzania. Int J Cancer 2021; 148:2416-2428. [PMID: 33320959 PMCID: PMC8048942 DOI: 10.1002/ijc.33433] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 11/02/2020] [Accepted: 11/19/2020] [Indexed: 12/24/2022]
Abstract
In the African esophageal squamous cell carcinoma (ESCC) corridor, recent work from Kenya found increased ESCC risk associated with poor oral health, including an ill-understood association with dental fluorosis. We examined these associations in a Tanzanian study, which included examination of potential biases influencing the latter association. This age and sex frequency-matched case-control study included 310 ESCC cases and 313 hospital visitor/patient controls. Exposures included self-reported oral hygiene and nondental observer assessed decayed+missing+filled tooth count (DMFT index) and the Thylstrup-Fejerskov dental fluorosis index (TFI). Blind to this nondental observer TFI, a dentist independently assessed fluorosis on photographs of 75 participants. Odds ratios (ORs) are adjusted for demographic factors, alcohol and tobacco. ESCC risk was associated with using a chewed stick to brush teeth (OR 2.3 [95% CI: 1.3-4.1]), using charcoal to whiten teeth (OR 2.13 [95% CI: 1.3, 4.1]) and linearly with the DMFT index (OR 3.3 95% CI: [1.8, 6.0] for ≥10 vs 0). Nondental observer-assessed fluorosis was strongly associated with ESCC risk (OR 13.5 [95% CI: 5.7-31.9] for TFI 5+ v 0). However, the professional dentist's assessment indicated that only 43% (10/23) of participants assessed as TFI 5+ actually had fluorosis. In summary, using oral charcoal, brushing with a chewed stick and missing/decayed teeth may be risk factors for ESCC in Tanzania, for which dose-response and mechanistic research is needed. Links of ESCC with "dental fluorosis" suffered from severe exposure misclassification, rendering it impossible to disentangle any effects of fluorosis, extrinsic staining or reverse causality.
Collapse
Affiliation(s)
- Blandina T. Mmbaga
- Kilimanjaro Clinical Research Institute—Kilimanjaro Christian Medical CentreMoshiTanzania
- Kilimanjaro Christian Medical University CollegeMoshiTanzania
| | - Amos Mwasamwaja
- Kilimanjaro Clinical Research Institute—Kilimanjaro Christian Medical CentreMoshiTanzania
| | - Godfrey Mushi
- Kilimanjaro Clinical Research Institute—Kilimanjaro Christian Medical CentreMoshiTanzania
| | - Alex Mremi
- Kilimanjaro Clinical Research Institute—Kilimanjaro Christian Medical CentreMoshiTanzania
- Kilimanjaro Christian Medical University CollegeMoshiTanzania
| | - Gissela Nyakunga
- Kilimanjaro Clinical Research Institute—Kilimanjaro Christian Medical CentreMoshiTanzania
- Kilimanjaro Christian Medical University CollegeMoshiTanzania
| | - Ireen Kiwelu
- Kilimanjaro Clinical Research Institute—Kilimanjaro Christian Medical CentreMoshiTanzania
- Kilimanjaro Christian Medical University CollegeMoshiTanzania
| | - Remigi Swai
- Kilimanjaro Clinical Research Institute—Kilimanjaro Christian Medical CentreMoshiTanzania
| | | | | | | | | | | | | | - Deogratias S. Rwakatema
- Kilimanjaro Clinical Research Institute—Kilimanjaro Christian Medical CentreMoshiTanzania
- Kilimanjaro Christian Medical University CollegeMoshiTanzania
| | - Kajiru Kilonzo
- Kilimanjaro Clinical Research Institute—Kilimanjaro Christian Medical CentreMoshiTanzania
- Kilimanjaro Christian Medical University CollegeMoshiTanzania
| | - Oresto Michael Munishi
- Kilimanjaro Clinical Research Institute—Kilimanjaro Christian Medical CentreMoshiTanzania
| | | | - Daniel Middleton
- Environmental and Lifestyle Epidemiology BranchInternational Agency for Research on CancerLyonFrance
| | - Joachim Schüz
- Environmental and Lifestyle Epidemiology BranchInternational Agency for Research on CancerLyonFrance
| | - Valerie McCormack
- Environmental and Lifestyle Epidemiology BranchInternational Agency for Research on CancerLyonFrance
| |
Collapse
|
4
|
Yadav PR, Hussain Basha S, Satyanarayana SDV, Pindi PK. Microsecond simulation analysis of carbonic anhydrase - II in complex with (+)-cathechin revealed molecular interactions responsible for its amelioration effect on fluoride toxicity. J Biomol Struct Dyn 2021; 40:7469-7482. [PMID: 33719850 DOI: 10.1080/07391102.2021.1898471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Fluorosis is a chronic condition caused by overexposure to fluoride, marked by impaired dental, skeletal, and non-skeletal health. In presence of excess fluoride ions, in severe cases calcification of the ligaments observed. Earlier studies have suggested that the disruption of carbonic anhydrase activity via ionic homeostasis change was associated with F toxicity. In a recent study, it was demonstrated that Tamarind fruit extract was effective in increasing the urinary F excretion in male Wistar rats via studying the mRNA expression of carbonic anhydrase II (CA II) in kidney homogenates using western blotting, immunohistochemistry and quantitative Realtime PCR based studies. We have carried out this study to understand the detailed molecular level interactions responsible for this tamarind extract based (+)-cathechin compound towards lowering the F toxicity via targeting CA-II. From our study, it was revealed that due to the ability of (+)-cathechin compound to bind tightly filling complete available space at the catalytically important site forming metal coordinated ionic bonds with His94, His96 and His119 residues helps in restricting F ions to interact with Zn ion located at the core of catalytic site responsible for its functionality. On the other hand, interaction of (+)-cathechin compound with Gln92 was observed to be critically important towards inducing conformational changes in CA-II, thus allowing (+)-cathechin compound to burry even deeply inside the catalytic site.Communicated by Ramaswamy H. Sarma.
Collapse
Affiliation(s)
- Pulala Raghuveer Yadav
- Department of Biotechnology, Indian Institute of Technology Hyderabad, Hyderabad, Telangana, India
| | | | | | - Pavan Kumar Pindi
- Department of Microbiology, Palamuru University, Mahabubnagar, Telangana, India
| |
Collapse
|
5
|
Onipe T, Edokpayi JN, Odiyo JO. A review on the potential sources and health implications of fluoride in groundwater of Sub-Saharan Africa. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2020; 55:1078-1093. [PMID: 32525728 DOI: 10.1080/10934529.2020.1770516] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 05/07/2020] [Accepted: 05/09/2020] [Indexed: 06/11/2023]
Abstract
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.
Collapse
Affiliation(s)
- Tobiloba Onipe
- Department of Hydrology and Water Resources, University of Venda, Thohoyandou, South Africa
| | - Joshua N Edokpayi
- Department of Hydrology and Water Resources, University of Venda, Thohoyandou, South Africa
| | - John O Odiyo
- Department of Hydrology and Water Resources, University of Venda, Thohoyandou, South Africa
| |
Collapse
|
6
|
Miranda-Rius J, Brunet-Llobet L, Lahor-Soler E, Mrina O, Mashala EI, Mahande MJ. Periodontal and dental conditions of a school population in a volcanic region of Tanzania with highly fluoridated community drinking water. Afr Health Sci 2020; 20:476-487. [PMID: 33402936 PMCID: PMC7750069 DOI: 10.4314/ahs.v20i1.54] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Introduction Dental fluorosis is endemic in the Rift Valley in Africa, especially around volcanic areas, due to the high fluoride content in daily drinking water. Objective This study evaluates the oral health status and types of occlusion in a school population, and to assess the possible association between dental fluorosis and other pathologies such as decay, gingivitis and periodontitis. Material and methods An observational study of 581 individuals recruited from a public secondary school in Arusha, Northern Tanzania was undertaken. The indices used were: the Silness & Löe Plaque Index, the Community Periodontal Index and the Decayed/Missing/Filled index. Descriptive statistical analyses were performed and a chi-square test was used to assess the associations between independent variables. Results Almost all the school children evaluated (96.73%) presented Angle class I dental occlusion, and 75.22% presented some degree of dental fluorosis. Most of the population (511, 87.95%) showed bleeding on probing. A moderate/high degree of some dental pathology (DMF score) was recorded in 14.46%. The association between dental fluorosis, gingival bleeding and tooth decay indicated a higher concentration of pathology in groups with more severe fluorosis (p<0.05). Conclusion In this large population sample, both tooth decay and gingivitis were significantly associated with moderate or severe dental fluorosis.
Collapse
Affiliation(s)
- Jaume Miranda-Rius
- Department of Odontostomatology. Faculty of Medicine and Health Sciences. University of Barcelona, Barcelona, Spain
- Hospital Dentistry, Clinical Orthodontics & Periodontal Medicine Research Group (HDECORPEMrg), Institut de Recerca Sant Joan de Déu (IRSJD), Barcelona, Spain
| | - Lluís Brunet-Llobet
- Hospital Dentistry, Clinical Orthodontics & Periodontal Medicine Research Group (HDECORPEMrg), Institut de Recerca Sant Joan de Déu (IRSJD), Barcelona, Spain
- Department of Pediatric Dentistry. Hospital Sant Joan de Déu. University of Barcelona, Barcelona, Spain
| | - Eduard Lahor-Soler
- Department of Odontostomatology. Faculty of Medicine and Health Sciences. University of Barcelona, Barcelona, Spain
- Hospital Dentistry, Clinical Orthodontics & Periodontal Medicine Research Group (HDECORPEMrg), Institut de Recerca Sant Joan de Déu (IRSJD), Barcelona, Spain
| | - Ombeni Mrina
- Dental & Oral Department, Soweto General Hospital, Arusha, United Republic of Tanzania
| | - Elias I Mashala
- Department of Orthopedic Surgery and Traumatology, Mount Meru Regional Hospital, Arusha, United Republic of Tanzania
| | - Michael J Mahande
- Department of Epidemiology and Biostatistics. Institute of Public Health. Kilimanjaro Christian Medical University College (KCMU College), Moshi, United Republic of Tanzania
| |
Collapse
|
7
|
Shen J, Jeihanipour A, Richards BS, Schäfer AI. Renewable energy powered membrane technology: Experimental investigation of system performance with variable module size and fluctuating energy. Sep Purif Technol 2019. [DOI: 10.1016/j.seppur.2019.03.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
8
|
Ibiyemi O, Zohoori FV, Valentine RA, Maguire A. Fluoride intake and urinary fluoride excretion in 4- and 8-year-old children living in urban and rural areas of Southwest Nigeria. Community Dent Oral Epidemiol 2018; 46:482-491. [PMID: 29971814 DOI: 10.1111/cdoe.12396] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 05/30/2018] [Indexed: 11/27/2022]
Abstract
OBJECTIVES To estimate and compare total daily fluoride intake (TDFI), daily urinary fluoride excretion (DUFE), daily fluoride retention (DFR), fractional urinary fluoride excretion (FUFE) and fractional fluoride retention (FFR) in 4- and 8 year-old Nigerians and explore associations between these outcomes to improve understanding of fluoride metabolism. METHODS Using a cross-sectional observational study, 72 four-year-olds and 72 eight-year-olds were recruited from nursery and primary schools (respectively) in lower and higher water F areas of urban and rural localities in Oyo State, southwest Nigeria. TDFI from diet and toothpaste ingestion was assessed using a validated Food Frequency Questionnaire and visual scale of toothpaste used during toothbrushing. DUFE was measured by collecting a 24-hour urine sample, FUFE estimated as the ratio between DUFE and TDFI, DFR estimated as TDFI-TDFE (where TDFE = DUFE + estimated faecal F excretion (ie TDFI × 10%), and FFR was estimated as [(TDFI-DFR)/TDFI] × 100. Data were analysed using ANOVA with post hoc tests and Student's t tests and strengths of associations between key variables measured. RESULTS Mean (SD) TDFI, DUFE, DFR, FUFE and FFR were 0.137 (0.169) mg/kg bw/d, 0.032 (0.027) mg/kg bw/d, 0.091 (0.147) mg/kg bw/d, 44% (44%) and 46% (44%), respectively, for 4-year-olds. Corresponding values for 8-year-olds (n = 63) were 0.106 (0.130) mg/kg bw/d, 0.022 (0.017) mg/kg bw/d, 0.073 (0.107) mg/kg bw/d, 36% (30%) and 54% (30%), respectively. Dietary contribution to TDFI was 79% and 75% (respectively), for 4- and 8-year-olds. Mean (SD) TDFI from toothpaste ingestion was 0.021 (0.013) mg/kg bw/d in 4-year-olds, 0.014 (0.010) mg/kg bw/d in 8-year-olds (P = .002) but with no differences between areas. Differences in dietary F intake determined the main differences in F exposure between areas. The positive correlation between TDFI and DUFE was weak for 4-year-olds (r = +.29) and strong for 8-year-olds (r = +.64). A strong positive correlation was observed between TDFI and DFR for both age groups: (r) = +.98 for 4-year-olds and (r) = +.99 for 8-year-olds. CONCLUSION Fluoride intake in these 4- and 8-year-old Nigerians was much higher than the "optimal range" of 0.05-0.07 mg/kg bw/d in rural, higher F water areas, with diet as the main contributor. F retention was similar in both age groups, with almost half of TDFI retained in the body. In terms of risk vs benefit for fluorosis and dental caries, this finding should be considered when mitigating against excessive fluoride exposure and planning F-based prevention.
Collapse
Affiliation(s)
- O Ibiyemi
- Centre for Oral Health Research, School of Dental Sciences, Newcastle University, Newcastle upon Tyne, UK.,Institute of Health and Society, Newcastle University, Newcastle upon Tyne, UK
| | - F V Zohoori
- School of Health and Social Care, Teesside University, Middlesbrough, UK
| | - R A Valentine
- Centre for Oral Health Research, School of Dental Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - A Maguire
- Centre for Oral Health Research, School of Dental Sciences, Newcastle University, Newcastle upon Tyne, UK
| |
Collapse
|
9
|
Owusu-Agyeman I, Shen J, Schäfer AI. Renewable energy powered membrane technology: Impact of pH and ionic strength on fluoride and natural organic matter removal. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 621:138-147. [PMID: 29179069 DOI: 10.1016/j.scitotenv.2017.11.111] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 11/03/2017] [Accepted: 11/09/2017] [Indexed: 06/07/2023]
Abstract
Real water pH and ionic strength vary greatly, which influences the performance of membrane processes such as nanofiltration (NF) and reverse osmosis (RO). Systematic variation of pH (3-12) and ionic strength (2-10g/L as total dissolved solids (TDS)) was undertaken with a real Tanzanian water to investigate how water quality affects retention mechanisms of fluoride (F) and natural organic matter (NOM). An autonomous solar powered NF/RO system driven by a solar array simulator was supplied with constant power from a generator. An open NF (NF270) and a brackish water RO (BW30) membrane were used. A surface water with a very high F (59.7mg/L) and NOM (110mgC/L) was used. Retention of F by NF270 was <20% at pH <6, increased to 40% at pH6, and 60-70% at pH7-12, indicating a dominance of charge repulsion while being ineffective in meeting the guideline of 1.5mg/L. Increase in ionic strength led to a significant decline in retention of F (from 70 to 50%) and electrical conductivity (from 60 to 10%) by NF270, presumably due to charge screening. In contrast, BW30 retained about 50% of F at pH3, >80% at pH4, and about 99% at pH >5, due to the smaller pore size and hence a more dominant size exclusion. In consequence, only little impact of ionic strength increase was observed for BW30. The concentration of NOM in permeates of both NF270 and BW30 were typically <2mg/L. This was not affected by pH or ionic strength due to the fact that the bulk of NOM was rejected by both membranes through size exclusion. The research is carried out in the context of providing safe drinking water for rural and remote communities where infrastructure is lacking, and water quality varies significantly. While other studies focus on energy fluctuations, this research emphasises on feed water quality that affects system performance and may alter due to a number of environmental factors.
Collapse
Affiliation(s)
- Isaac Owusu-Agyeman
- Membrane Technology Department, Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Junjie Shen
- Department of Water and Environmental Engineering, Nelson Mandela African Institute of Science and Technology, Arusha, Tanzania; School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
| | - Andrea Iris Schäfer
- Membrane Technology Department, Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany; Department of Water and Environmental Engineering, Nelson Mandela African Institute of Science and Technology, Arusha, Tanzania.
| |
Collapse
|
10
|
Shen J, Richards BS, Schäfer AI. Renewable energy powered membrane technology: Case study of St. Dorcas borehole in Tanzania demonstrating fluoride removal via nanofiltration/reverse osmosis. Sep Purif Technol 2016. [DOI: 10.1016/j.seppur.2016.06.042] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
11
|
Abstract
Chronic fluorosis is a widespread disease-related to the ingestion of high levels of fluoride through water and food. Prolonged ingestion of fluoride adversely affects the teeth, bones and other organs and alters their anatomy and physiology. Fluoride excess is a risk factor in cardiovascular disease and other major diseases, including hypothyroidism, diabetes and obesity. Although anaesthesiologists may be aware of its skeletal and dental manifestations, other systemic manifestations, some of which may impact anaesthetic management are relatively unknown. Keeping this in mind, the topic of chronic fluorosis was hand searched from textbooks, scientific journals and electronically through Google, PubMed and other scientific databases. This article concentrates on the effect of chronic fluorosis on various organ systems, its clinical features, diagnosis and the anaesthetic implications of the disease.
Collapse
Affiliation(s)
- Madhuri S Kurdi
- Department of Anesthesiology, Karnataka Institute of Medical Sciences, Hubli, Karnataka, India
| |
Collapse
|
12
|
Ghosh D, Rhodes S, Hawkins K, Winder D, Atkinson A, Ming W, Padgett C, Orvis J, Aiken K, Landge S. A simple and effective 1,2,3-triazole based “turn-on” fluorescence sensor for the detection of anions. NEW J CHEM 2015. [DOI: 10.1039/c4nj01411a] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
1,2,3-Triazole based chemosensor is synthesized using “Click chemistry” approach. Addition of fluoride ion “turn-on” the fluorescence response of probe.
Collapse
Affiliation(s)
- Debanjana Ghosh
- Department of Chemistry
- Georgia Southern University
- Statesboro
- USA
| | - Shannon Rhodes
- Department of Chemistry
- Georgia Southern University
- Statesboro
- USA
| | - Karena Hawkins
- Department of Chemistry
- Georgia Southern University
- Statesboro
- USA
| | | | - Austin Atkinson
- Department of Chemistry
- Georgia Southern University
- Statesboro
- USA
| | - Weihua Ming
- Department of Chemistry
- Georgia Southern University
- Statesboro
- USA
| | - Clifford Padgett
- Department of Chemistry and Physics
- Armstrong Atlantic State University
- Savannah
- USA
| | - Jeffrey Orvis
- Department of Chemistry
- Georgia Southern University
- Statesboro
- USA
| | - Karelle Aiken
- Department of Chemistry
- Georgia Southern University
- Statesboro
- USA
| | - Shainaz Landge
- Department of Chemistry
- Georgia Southern University
- Statesboro
- USA
| |
Collapse
|
13
|
Rango T, Vengosh A, Jeuland M, Tekle-Haimanot R, Weinthal E, Kravchenko J, Paul C, McCornick P. Fluoride exposure from groundwater as reflected by urinary fluoride and children's dental fluorosis in the Main Ethiopian Rift Valley. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 496:188-197. [PMID: 25084227 DOI: 10.1016/j.scitotenv.2014.07.048] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2014] [Revised: 07/12/2014] [Accepted: 07/12/2014] [Indexed: 06/03/2023]
Abstract
This cross-sectional study explores the relationships between children's F(-) exposure from drinking groundwater and urinary F(-) concentrations, combined with dental fluorosis (DF) in the Main Ethiopian Rift (MER) Valley. We examined the DF prevalence and severity among 491 children (10 to 15 years old) who are life-long residents of 33 rural communities in which groundwater concentrations of F(-) cover a wide range. A subset of 156 children was selected for urinary F(-) measurements. Our results showed that the mean F(-) concentrations in groundwater were 8.5 ± 4.1 mg/L (range: 1.1-18 mg/L), while those in urine were 12.1±7.3 mg/L (range: 1.1-39.8 mg/L). The prevalence of mild, moderate, and severe DF in children's teeth was 17%, 29%, and 45%, respectively, and the majority (90%; n=140) of the children had urinary F(-) concentrations above 3 mg/L. Below this level most of the teeth showed mild forms of DF. The exposure-response relationship between F(-) and DF was positive and non-linear, with DF severity tending to level off above a F(-) threshold of ~6 mg/L, most likely due to the fact that at ~6 mg/L the enamel is damaged as much as it can be clinically observed in most children. We also observed differential prevalence (and severity) of DF and urinary concentration, across children exposed to similar F(-) concentrations in water, which highlights the importance of individual-specific factors in addition to the F(-) levels in drinking water. Finally, we investigated urinary F(-) in children from communities where defluoridation remediation was taking place. The lower F(-) concentration measured in urine of this population demonstrates the capacity of the urinary F(-) method as an effective monitoring and evaluation tool for assessing the outcome of successful F(-) mitigation strategy in relatively short time (months) in areas affected with severe fluorosis.
Collapse
Affiliation(s)
- Tewodros Rango
- Division of Earth and Ocean Sciences, Nicholas School of the Environment, Duke University, Durham, NC, USA.
| | - Avner Vengosh
- Division of Earth and Ocean Sciences, Nicholas School of the Environment, Duke University, Durham, NC, USA
| | - Marc Jeuland
- Sanford School of Public Policy and Duke Global Health Institute, Duke University, Durham, NC, USA; Institute of Water Policy, National University of Singapore, Singapore
| | | | - Erika Weinthal
- Division of Environmental Sciences and Policy, Nicholas School of the Environment, Duke University, Durham, NC, USA
| | - Julia Kravchenko
- Duke University Medical Center, Department of Surgery, Division of Surgical Science, Duke University, Durham, NC, USA
| | - Christopher Paul
- Division of Environmental Sciences and Policy, Nicholas School of the Environment, Duke University, Durham, NC, USA
| | - Peter McCornick
- International Water Management Institute, Colombo, Sri Lanka
| |
Collapse
|