High Levels Of Fluoride Research Articles

Effect of Fluoride Contaminated Groundwater on Human Health in Fluorosis Endemic Areas

Background: Fluorosis is an endemic health problem in twenty-five nations around the globe. Objectives:To correlate fluoride content of groundwater and health status of affected population and suggest remedialmeasures. Methodology: A cross-sectional research design is followed because people from different agegroups were sampled, observations were made and skeletal examinations were conducted at a specified pointof time. The study is conducted in Yavatmal and Chandrapur districts of Vidarbha region of MaharashtraState. Health related surveys were carried out in 54 villages from study area selected on the basis of highfluoride level in groundwater. Result: Out of these, 32 villages are selected from Yavatmal district havinga population of 30320 and 22 villages from Chandrapur district with a population of 21581. Out of thetotal population of 51901 total 3268 subjects have been examined. Amongst these subjects 1760 were male(53.86%) and 1508 were female (46.14%). Out of the total 3268 subjects 2445 subjects included in the‘normal’ grade, which does not show indications of skeletal fluorosis. It has been observed that as theconcentration of fluoride increases the cases of ‘normal’ grade decreases. Out of the 360 subjects studied,about 102 (28.33%) subjects show radiological evidences of skeletal fluorosis. Mild radiological fluorosiswas seen in 55, moderate in 21, severe in 17 and very severe radiological fluorosis in 9 subjects. Conclusion:Based on the outcome of the research work carried out in the study area, it is recommended that awarenessamong the people residing in the area about the protection & prevention of groundwater contamination fromdifferent sources, groundwater quality, its impacts on health, soil and plants should be created on prioritybasis.

Determination of the Fluoride Content in Water of Aqueducts of Cauca (Colombia) by Ion Exchange Chromatography.

Water for human consumption is the main source of fluoride exposure. The concentration in water should not exceed 1mg/L of fluoride since, at higher levels; it increases the risk of dental fluorosis, among other adverse effects. The fluoride content of 149 water samples from different aqueducts in Cauca (Colombia) has been determined by ion exchange chromatography with the aim of fluoride risk assessment. The rural area of the Municipality of Santander de Quilichao registered fluoride concentrations between 0.012 and 0.150mg/L. The urban area of Santander de Quilichao recorded lower fluoride levels than the rural area (0.027-0.068mg/L). The urban area of the Municipality of Cajibío registered fluoride levels of 0.082-0.186mg/L. The highest levels of fluoride were found in Timbío (0.121-0.210mg/L). The fluoride levels recorded in this study are not considered sufficient to trigger dental fluorosis. Likewise, optimal levels are not considered to protect the child population against dental caries. However, a monitoring plan of fluoride concentrations in water should be implemented to assure the quality and safe of the water.

Mangiferin prevents the impairment of mitochondrial dynamics and an increase in oxidative stress caused by excessive fluoride in SH-SY5Y cells.

Previous studies both invivo and in vitro have revealed that high levels of fluoride cause neurotoxicity. Mangiferin has been reported to possess antioxidant, antiapoptotic, and anti-inflammatory properties. The present studywas designed to characterize the mechanisms by which mangiferin protects against NaF-induced neurotoxicity. Increased levels of proapoptotic Bax, Caspase-3, Caspase-9, and cleaved-caspase 3, as well as a decreased level of antiapoptotic Bcl-2 induced by fluoride in human neuroblastoma SH-SY5Y cells, these effects were prevented by pretreatment of mangiferin. In addition, mangiferin attenuated the enhancement of p-JNK, reductions of Nrf2 and HO-1, and increased level of the mitochondrial fission proteins Drp1 caused by fluoride. Moreover, oxidative stress, as reflected in the levels of reactive oxygen species, 8-hydroxy-2'-deoxyguanosine, and 4-hydroxynonenal, was elevated by fluoride and these effects were again ameliorated by mangiferin. In conclusion, protection by mangiferin against fluoride-induced neurotoxicity involves normalizing the impaired mitochondrial apoptotic pathway and dynamics and reducing oxidative stress via inactivation of the JNK and activation of the Nrf2/HO-1 pathways.

Fluorosis Mitigation Programmes and its Impact on Health - The Indian Scenario

In India, the availability of safe potable water remains a challenge in rural settings, where 72% of Indian population reside with high reliance on alternative water sources. In our country, the states having some circumscribed areas of high fluoride levels (endemic fluoride belts with F content in ground water above 4 ppm). Fluorosis mitigation is therefore necessary. Thus, the objective of this narrative review is to discuss various fluorosis mitigation programmes in India.Medline was the primary database used in the literature search. Other databases were also searched for relevant publications. Since the late 1980s, government and non-governmental agencies launched efforts to control fluorosis. However, most of attempts were mainly on defluoridation of water, so it cannot be proposed as the only or most effective solution to mitigate fluorosis.

Spatial distribution, occurrence, and health risk assessment of nitrate, fluoride, and arsenic in Bam groundwater resource, Iran

Evidence shows that exposure to high levels of arsenic, fluoride, and nitrate may be contributing to adverse hygienic effects. This work was carried out to detect the concentration of arsenic (As), fluoride (F−), and nitrate (NO3−) in the groundwater resource of Bam, southeastern Iran and approximate their health risk to citizenships. The GIS-mapping of As, F−, and NO3− concentrations was accomplished. As, F−, and NO3− concentrations in studied drinking water samples have been ranged from 9.26 to 14.65 μg/L, 0.91–1.12 mg/L, and 8.50–10.85 mg/L, respectively. Based on results, all measured concentrations of F− and NO3− were lower than the WHO standard value, while As levels were higher than the allowed value. The acquired findings revealed that the mean risk of As is 5.372 for oral hazard quotient (HQ) and 1.407 for dermal one. For F−, HQ values for children were computed above one for study areas, while all HQ values for adults were below one. The values of dermal and oral HQ for both groups obtained >1 for NO3−. Among studied contaminants, the carcinogenic risk (CR) values of As was more than one. The results showed that the carcinogenicity ratio of ‘children to adults’ is equal to 3.8 for As and 2.33 for NO3−. For all examined pollutants, the health risks of dermal exposure were less than that of oral. The levels of non-cancer and cancer risk for children were greater than those for adults. The highest non-carcinogenic risk in study areas was related to As. This research proposes that any attempt to mitigate the arsenic of the Bam citizenships must consider the health risk of As exposure from potable water.

Sustainability Assessment of the Groundwater Quality in the Khoyrasole Block, Birbhum District, West Bengal to Achieve Rural Water Security

In order to attain the water security goal, specifically in highly developing areas, delineation of pure and sustainable water resources is of utmost priority. In the present study, a preliminary investigation of the groundwater chemistry was carried out. This was followed by assessing the suitability of groundwater to be used as an alternative and reliable resource for public use in the Khoyrasole block, Birbhum district, India. Altogether 15(fifteen) samples of groundwater, were collected from bore wells spread well over the Khoyrasole block have been considered. After completing the chemical analysis of the groundwater samples, the study revealed the quality of groundwater. The spatial distribution of groundwater quality parameters such as pH, Total Dissolved solids (TDS), Hardness, Calcium, Magnesium, Sodium, Potassium, Iron, Chloride, Carbonate, Bicarbonate, Sulphate, Nitrate and Fluoride have also been studied. High to very high levels of iron and fluoride have been observed to be present in 67% and 53% of the samples respectively. Based upon the calculated parameters like SAR, MAR, PI and Chloro Alkaline Indices, groundwater of Khoyrasole block is majorly suitable for the purpose of agriculture and irrigation. Plotting of ionic scatter plots and geochemical facies also indicate the water samples to be of “fresh water” category, with no dominant cation or anion playing a selectively dominant role in influencing the groundwater chemistry in the study area.

Optimum Operating Conditions of Drinking Water Treatment System for Fluoride Removal using High Adsorption Bone Char

Objectives : Bone char is used in many eastern countries in Africa to remove high levels of fluoride from groundwater. However, due to the low adsorption efficiency of bone char, it is necessary to replace bone char frequently, which cause significant burden to the people in those areas. In this study, we developed a water treatment system to remove high level of fluoride in groundwater using a high efficiency bone char.Methods : In order to make a high efficiency bone char, cow bones were washed, dried and cut into small pieces. Then the bones were burned for 1, 3 and 5 hours at 350, 450 and 550℃ in electric furnaces. After that, the burned bones were sieved with 600~2,000 µm to match the size of bone char being used in Ethiopia. Surface analysis of bone char was performed using SEM and BET. The removal efficiency of bone char was conducted with various level of turbidity, TOC, and fluoride concentration for 90 minutes under the flow rate conditions of 100, 200, 300, and 400 L/day with an initial fluoride concentration of 4.8 mg/L.Result and Discussion : There was a significant difference between the bone char from Ethiopia and our study in terms of their surface roughness and specific surface area according to SEM and BET analysis. The adsorption capacity of the bone char produced in this study was 3.7 mg F/g, compared to 1 mg/L from the one from Ethiopia. In terms of turbidity and organic matter removal with column test, 200 L/d showed the shortest operating time to reach turbidity of less than 0.5 NTU, and was an effective operation for TOC removal. However, It took the longest to 1.5 mg/L of fluoride after breakthrough under 100 L/d operating conditions. In terms of operating time, bed volume, and energy efficiency, 100 L/d was found to be an effective operating condition.Conclusions : We developed a high efficiency bone char in this study with modification of its production process and tested it at various operating conditions. Our study showed that the bone char developed in this study is about 4 times more effective than traditional bone char and it is most effective at operation with low flow rates. Column operation is most effective at 100 L/d for fluoride removal under operating time and bed volume and energy efficiency. Therefore operating condition of drinking water treatment system for the fluorine removal using bone char in developing countries is effective in low flow rate operation.

Recycling of Spent Pot Lining First Cut from Aluminum Smelters by Utilizing the Two-Step Decomposition Characteristics of Dolomite.

Spent Pot Lining First Cut (shortened to SPL-1cut) is a solid waste discharged from a primary aluminum electrolytic production process. SPL-1cut is classified as hazardous waste in China because it contains large amounts of soluble sodium fluoride and a tiny amount of cyanide. Most of SPL-1cut is carbon—about 65%—and its calorific value is 22.587 MJ∙kg−1. There is a high level of sodium fluoride in SPL-1cut—about 15%—and sodium fluoride is randomly distributed in the carbon granule. The recycling of SPL-1cut using dolomite as a reactant, based on the characteristics of the two-step decomposition of dolomite at a high temperature, is discussed. The recycling of SPL-1cut was performed under the following heating conditions: the heating temperature was 850 °C, the holding time was 120 min, and 40% of the dolomite was added to the SPL-1cut. It was found that the cyanides are completely oxidized and decomposed, and dolomite is decomposed into MgO and active CaCO3. At the same time, NaF reacts with active CaCO3 and converts into CaF2. The results provide references for using SPL-1cut as an alternative fuel in the dolomite calcination process of the Pidgeon Process.

Aluminum coated natural zeolite for water defluoridation: A mechanistic insight

High fluoride concentration in drinking water is a public health concern worldwide. Therefore, this study is aimed to investigate the plausible adsorption mechanism and applicability of natural and aluminum-coated stilbite (Alc-STI) for fluoride removal. Batch adsorptive defluoridation experiments were performed as function of solution pH, adsorbent dose, contact time, and concentration variation at room temperature. Results of the study revealed that 10 mg/L fluoride reduced to ~0.339 mg/L using Alc-STI from aqueous solutions. The experimental data showed that maximum adsorption capacity of 11.52 mg/g was predicted through Freundlich isothermal model. The study suggested that adsorption mechanism was due to aluminol, silanol, and hydroxyl functional groups as well as water molecules within Alc-STI. Equally important in suitability of the adsorbent was that aluminum leached from Alc-STI surfaces during the experiment was <0.2 mg/L, making the adsorption media safe for water treatment. The co-incidence of large amount of natural zeolite and high level of fluoride in drinking waters in Ethiopian rift valley areas, pulls the very vital aspect of the work.

Frequency of Dental Fluorosis in Population Drinking Water with High Fluoride Level in Thar

OBJECTIVE: The objective of this study is to see the frequency of dental fluorosis in exposed area (Sammo Rind village of Thar District) and in unexposed area of Gadap town of Karachi and to find the association of fluoride level with dental fluorosis in both groups. METHODOLOGY: The water samples were taken from both the sites and fluoride estimation in water and geometrical, was determined using Fluoride Ion Selective Electrode (FISE) method. By random selection 121 subjects from Sammo Rind village and 121 controls from Gadap Town Karachi were included in study after informed consent. The participants were clinically examined by an expert university teacher dentist in proper dental setups in examination lights. RESULTS: A frequency of dental fluorosis of 100% was found among the study subjects with fluoride content as high as 6- 8 mg/dl as compared to prevalence of dental fluorosis 17.4% in unexposed group with water fluoride content as low as 0.30mg/dl. CONCLUSIONS: The high level of underground water fluoride level and cent per cent dental fluorosis in Thar area is an alarming situation that should be addressed immediately at national level. KEYWORDS: Exposed area, Dental Flurosis, Fluoride Level, Water Sample HOW TO CITE: Ahmed I, Ali A, Zaheer M, Fatima I, Khan N. Frequency of dental fluorosis in population drinking water with high fluoride level in Thar. J Pak Dent Assoc 2020;29(4):259-263. DOI: https://doi.org/10.25301/JPDA.294.259

Effect of Endemic Fluorosis on Cognitive Function of School Children in Alappuzha District, Kerala: A Cross Sectional Study.

Background:Exposure to high fluoride levels in drinking water can lead to a number of adverse effects in children, including cognitive dysfunction. Despite being endemic for fluorosis, studies on its effect on the cognitive function of children are lacking in Kerala.Aims:The aim of this study was to compare the cognitive function of school children with fluorosis with that of normal children and to correlate between the severity of dental fluorosis and cognitive function.Settings and Design:Cross-sectional study, conducted in collaboration with the National Fluorosis Control Programme, among school children in Alappuzha district, Kerala.Methods:Children aged 8–10 years, studying in 2 lower primary schools in Alappuzha district with confirmed fluorosis were selected, and compared with healthy age- and sex-matched children from the same school. Raven's Standard Progressive Matrices and MISIC digit span subtest were used to assess the cognitive function.Statistical Analysis:Continuous variables were assessed by independent samples t test and categorical variables by Chi-square test. The relationship between severity of dental fluorosis and grade of cognitive impairment was assessed using Spearman's correlation.Results:There were 60 children each in fluorosis and control groups. The mean age of the children was 8.95 ± 0.50. Only 15% of the children with fluorosis scored Grade I and II Raven's SPM grades (Intellectually superior/above the average) versus 30% in the control group. None of the children without fluorosis scored Grade V (intellectually impaired) category versus 20% in the fluorosis group. The mean digit span was significantly higher in the control group. A strong positive correlation between severity of dental fluorosis and Raven's SPM grades was found (Spearman's correlation coefficient = 0.740).Conclusions:Fluorosis is associated with impaired cognition in children. There is a positive correlation between severity of dental fluorosis and the grade of cognitive impairment.

GIS based evaluation of contamination of fluoride in groundwater quality and occurrence of dental fluorosis in Coimbatore district, TamilNadu, India

Groundwater is the major source of drinking water in urban and rural India. Groundwater is primarily used for various purposes like drinking, washing, irrigation, etc. Groundwater can become contaminated in many ways. The study has been carried out to assess the fluoride in groundwater of Coimbatore district. The secondary data of groundwater has been collected from PWD, Chennai, Tamil Nadu for the years of 2014 to 2018. Geographic information system (GIS) approach is used to develop spatial information and knowledge about fluoride in groundwater quality. Fluoride plays an important role in human metabolism within the permissible limit. But it is exceeded by many activities mainly by the human activities. High level of fluoride cause major impact on human health. It can replace calcium ion in bones and teeth, which can lead to fluorosis. Therefore this study was aimed to identify the high and low risk of fluoride contamination in groundwater. The study revealed that high level of fluoride 2014 (2.83mg/l), 2015 (1.86mg/l), 2016 (3.6mg/l), 2017 (1.56mg/l), and 2018 (1.68mg/l). It provides an understanding into the problem of fluorosis among people in the study area, where fluorosis is a public health problem of significant impact. Ambrampalayam, Puliampatti, Puravaipalayam, Ettimadai, Sirumugai and Therampalayam where the places shows the high level fluoride and people experiences the symptoms of dental fluorosis. There is compulsory need for defluoridation of the groundwater before consumption.

Prevalence of Dental Fluorosis among Southern Jordanian Population.

Introduction Jordan is one of the Middle Eastern countries that is classified as a poor water resource country. People in Jordan consume any available water. In the south of Jordan, water resources are limited. The drinking water contains high levels of fluoride, which in turn leads to augmented danger of both skeletal and dental fluorosis. Aims This study is focused on evaluating the pervasiveness of dental fluorosis among patients of Karak City and assessing the degree and distribution of fluorosis. Materials and Methods This research focuses on 2,512 patients ranging from 12 to 52 years old seeking dental treatment in the Dental Department at “Prince Ali ben Al Houssin Hospital” in Karak City. Dental fluorosis status was assessed by using Modified Dean's Fluorosis Index.” The data collected were subjected to statistical analysis. Results The dental fluorosis prevalence within our sample was 39.9% in Karak City. Females were more influenced than males, and fluorosis was detected more often in those who drank tap water and was more common in a very mild and localized form. Conclusion Fluorosis necessitates constant observation, and future study in terms of the intake in Jordan is recommended in terms of all sources. It would not be too soon to note that the supply of drinking water needs to be changed in South Jordan.

Health Impact Assessment of Contamination of River Ravi

The River Ravi is one of six transboundary rivers comprising the Indus River system. The Ravi drains a catchment area of about 25,000 km2 (14,500 km2 in India; 10,500 km2 in Pakistan). There are extreme low flows in the River Ravi for most of the year and flows that are considerably lower than historical in the summer monsoon season. Approximately 50 million people of Punjab province live in the basin, with more than 10 million concentrated in Lahore, its largest city. We conducted the health impact assessment of the population of the basin in Pakistan due to contamination of River.The parameters of assessments included communicable and non-communicable diseases associated with water contamination. We initially conducted a systematic review of existing literature about the contamination level and health status of the population in the basin. Secondly, we carried out a review and compilation of the information from nationally representative surveys and management information systems. In addition, we carried out block sampling of water quality regarding biological and chemical contaminants in the river basin. Furthermore, we carried out in-depth interviews of community, public and private sector health care providers and other stakeholders. The fecal coliform and E.coli were in acceptable range in only 71% and 75% of groundwater samples, respectively. However, 80% samples from the metropolitan areas of the basin were contaminated. High levels of TDS and fluoride (52-70%), and arsenic (23%) were also observed across the basin. The water quality across the Ravi River Basin, poses a significant, risk to public health both due to chemical contaminants as well as biological contamination. However, the risk may be mitigated if sufficient effort is made to sensitize the vulnerable communities regarding improved hygiene, and disease prevention measures; combined with efforts to enhance the health care facilities within the basin.

The water chemistry and microbiome of household wells in Medawachchiya, Sri Lanka, an area with high prevalence of chronic kidney disease of unknown origin (CKDu)

Chronic kidney disease (CKD) of unknown etiology (CKDu) mostly affects agricultural communities in Central America, South Asia, Africa, but likely also in North America and Australia. One such area with increased CKDu prevalence is the Medawachchiya District Secretariat Division of the Anuradhapura District in the North Central Province of Sri Lanka. Recent research has focused on the presence of various microbial pathogens in drinking water as potential causal or contributing factors to CKDu, yet no study to date has performed a more comprehensive microbial and water chemistry assessment of household wells used for domestic water supply in areas of high CKDu prevalence. In this study, we describe the chemical composition and total microbial content in 30 domestic household wells in the Medawachchiya District Secretariat Division. While the chemical composition in the tested wells mostly lies within standard drinking water limits, except for high levels of fluoride (F), magnesium (Mg), sodium (Na), chloride (Cl) and calcium (Ca) in some samples, we find a frequent presence of cyanotoxin-producing Microcystis, confirming earlier studies in Sri Lanka. Since the total microbial content of drinking water also directly influences the composition of the human gut microbiome, it can be considered an important determinant of health. Several bacterial phyla were previously reported in the gut microbiome of patients with CKD. Using these bacteria phyla to define operational taxonomic units, we found that these bacteria also occur in the microbiome of the sampled well water. Based on available environmental data, our study demonstrates associations between the abundances of these bacteria with geographical distribution, well water temperature and likely fertilizer use in the local surface water catchment area of the individual household wells. Our results reinforce the recommendation that household wells with stagnant or infrequently used water should be purged prior to use for drinking water, bathing and irrigation. The latter is suggested because of the reported potential accumulation of bacterial toxins by agricultural crops. The observation that bacteria previously found in chronic kidney disease patients are also present in household wells requires a more detailed systematic study of both the human gut and drinking water microbiomes in CKDu patients, in relation to disease prevalence and progression.

Molar-incisor hypomineralization (MIH), dental fluorosis, and caries in rural areas with different fluoride levels in the drinking water.

This study determined the prevalence of molar-incisor hypomineralization (MIH) and its association with dental fluorosis and caries in children living in rural areas in north-eastern Brazil who are exposed to residual fluoride (F) levels in the drinking water. A census was carried out with 610 schoolchildren aged 6 to 12years. The European Academy of Paediatric Dentistry criteria, Thysltrup and Fejerskov index, and World Health Organization index were used for diagnosis of MIH, dental fluorosis, and caries detection, respectively. The association between the outcome and exposure variables was determined by robust Poisson regression (P<.05). Water F-levels varied from 0.06 to 1.98ppm. MIH was not related to fluoride levels in the drinking water, but it showed an inverse and direct correlation with dental caries and fluorosis, respectively. Children with MIH had a higher DMFT, and severe MIH cases were most frequent in children with dental fluorosis. Drinking water F-levels were not directly related to the occurrence of MIH in schoolchildren. The severity of MIH, however, was likely to be associated with dental fluorosis in areas with moderate to high fluoride levels in the drinking water.

Smartphone-based Fluoride-specific Sensor for Rapid and Affordable Colorimetric Detection and Precise Quantification at Sub-ppm Levels for Field Applications

Higher levels of fluoride (F–) in groundwater constitute a severe problem that affects more than 200 million people spread over 25 countries. It is essential not only to detect but also to accurately quantify aqueous F– to ensure safety. The need of the hour is to develop smart water quality testing systems that would be effective in location-based real-time water quality data collection, devoid of professional expertise for handling. We report a cheap, handheld, portable mobile device for colorimetric detection and rapid estimation of F– in water by the application of the synthesized core–shell nanoparticles (near-cubic ceria@zirconia nanocages) and a chemoresponsive dye (xylenol orange). The nanomaterial has been characterized thoroughly, and the mechanism of sensing has been studied in detail. The sensor system is highly selective toward F– and shows unprecedented sensitivity in the range of 0.1–5 ppm of F–, in field water samples, which is the transition regime, where remedial measures may be needed. It addresses multiple issues expressed by indicator-based metal complexes used to determine F– previously. Consistency in the performance of the sensing material has been tested with synthetic F– standards, water samples from F– affected regions, and dental care products like toothpastes and mouthwash using a smartphone attachment and by the naked eye. The sensor performs better than what was reported by prior works on aqueous F– sensing.

Prevalence of dental caries (DMFT) in Iraqi children and adolescent living in areas with low and high level of natural fluoride

The purpose of the study was to determine the prevalence of dental caries in a group of school children lived in area with high and low natural fluoride contained drinking water in Ninevah governorate. The study is conducted among (1724) schools students aged 11-16 years from randomly selected schools (primary and intermediate) in two provinces in Ninevah governorate. Eight hundred and thirteen students who had lived since birth in high natural fluoride level area (Sinjar province)(2.05-222 ppm) and (911) students lived continuously from birth in low natural fluoride level area in their drinking water (Talkaif province)(0.11-0.19 ppm). WHO methodology (1997) has been used to assess the dental caries status and using DMFT index for permanent teeth. The results show that in Sinjar province the mean DMFT for total samples were (1.67) and (36.2%) are caries free with no sex difference. while there is a significant age differences. On the other hand, in Talkaif province the results reveal higher DMFT (3.7) and lower percent of caries free (19.1%), The mean DMFT reported twice in Talkaif province than Sinjar province with highly significant differences between them. The percentage of reduction of dental caries has been found to be (54.3%) in Sinjar province compare to Talkaif province.

Evidence of selected nephrotoxic elements in Sri Lankan human autopsy bone samples of patients with CKDu and controls

BackgroundThis article describes the analysis and interpretation of data relating to the presence of cadmium, lead, mercury and fluoride in human bone samples obtained from cadavers of patients dying of Chronic Kidney Disease of uncertain aetiology (CKDu) in a case-control study, which the authors believe to be the first in Sri Lanka.MethodsThis is a case-control study comparing selected nephrotoxins levels in autopsy samples of bones from persons confirmed to have died of CKDu, and who had lived in a CKDu hotspot and controls with no history of abnormal kidney functions who had lived in areas having a low prevalence of CKDu.ResultsThe average age at death of the cases was 59.6 ± 15.1 (±SD), while that for controls was 58.0 ± 19.3 (±SD) years with no significant statistical difference. Calcium adjusted bone lead and bone fluoride levels were significantly higher among CKDu cases (n = 14) than those of controls (n = 33). Further, younger and older clusters of CKDu cases can be differentiated when the calcium adjusted lead content was considered. Younger patients reported higher lead content compared to the older group. Cadmium and mercury content did not show a remarkable difference among cases and controls.ConclusionsOur results show a significant accumulation of lead in bone tissue in persons who have died of CKDu which indicates a higher chronic exposure of the CKDu victims, to lead. Fluoride content in the bones of cases is also significantly high. The results indicate that a gradual reduction of glomerular filtration rate (GFR) may have occurred with the chronic exposure to lead. At a certain point of the threshold of low GFR, excretion of fluoride may be impaired, since the main excretory pathway of fluoride is via the kidneys. Fluoride accumulation in blood in turn may exacerbate nephrotoxicity, triggering a synergistic cascade of events which may lead to a further deterioration in the GFR. The extremely high fluoride content detected suggests a cumulative effect in people exposed to comparatively higher fluoride levels, most probably from drinking water.

Undesirables in Mesopelagic Species and Implications for Food and Feed Safety-Insights from Norwegian Fjords.

The increase in the global population demands more biomass from the ocean as future food and feed, and the mesopelagic species might contribute significantly. In the present study, we evaluated the food and feed safety of six of the most abundant mesopelagic species in Norwegian fjords. Trace elements (i.e., arsenic, cadmium, mercury, and lead), organic pollutants (i.e., dioxins, furans, dioxin-like polychlorinated biphenyls, and polybrominated flame-retardants), and potentially problematic lipid compounds (i.e., wax esters and erucic acid) were analyzed and compared to existing food and feed maximum levels and intake recommendations. Furthermore, contaminant loads in processed mesopelagic biomass (protein, oil, and fish meal) was estimated using worst-case scenarios to identify possible food and feed safety issues. While most undesirables were low considering European food legislation, we identified a few potential food safety issues regarding high levels of fluoride in Northern krill, wax esters in glacier lanternfish, and long-chain monounsaturated fatty acids in silvery lightfish. Our estimates in processed biomass indicated high levels of undesirable trace elements in the protein fraction, frequently exceeding the maximum levels for feed ingredients. However, in fish meal, almost no exceedances were seen. In the oil fraction, dioxins and furans were above the maximum levels, given for food and feed ingredients. The present study is crucial to enable an evaluation of the value of these species; however, more data is needed before proceeding with large-scale harvesting of mesopelagic biomass.