Safety risk assessment of fluoride in brick-tea and consideration and suggestions on its limit in China at the present stage / 中华地方病学杂志

Drinking brick-tea type of endemic fluorosis is a kind of chronic fluorosis caused by excessive intake of fluoride into the body from long-term and high consumption of brick-tea, milk tea, butter tea, or other tea drinks with high fluoride content. It mainly distributes in seven western provinces of China, including Tibet Autonomous Region, Qinghai Province, Sichuan Province, Xinjiang Uygur Autonomous Region, Inner Mongolia Autonomous Region, Gansu Province, and Ningxia Hui Autonomous Region. In order to govern the production and sale of brick-tea and control the epidemic of drinking brick-tea type of endemic fluorosis, the former Ministry of Health of China issued the national standard "Fluoride Content of Brick-tea" (GB 19965-2005) in 2005, which stipulated that the total amount of water-soluble inorganic fluorine in brick-tea should not exceed 300 mg/kg. In the past 20 years, the prevalence of drinking brick-tea type of endemic fluorosis in China became clear gradually, and the habit of drinking brick-tea of residents in the epidemic fluorosis area also changed to some extent. In this paper, the dose-effect relationship between fluoride intake from brick-tea and skeletal fluorosis is reviewed, the brick-tea consumption of residents in the endemic fluorosis areas is analyzed, and the safety risk of brick-tea fluoride exposure is evaluated. It is suggested that the fluoride limit of brick-tea, ≤300 mg/kg, is still suitable for the prevention and control of drinking brick-tea type of endemic fluorosis in China at the present stage.

An investigation on current situation in control and prevention of coal-burning-borne endemic fluorosis in key counties of Yunnan Province / 中华地方病学杂志

Objective To understand the current situation on coal-burning-borne endemic fluorosis control and prevention in Yunnan Province,timely discover problems in prevention and control of the disease,and achieve the "13th Five-Year Plan" objectives as scheduled.Methods Simple random sampling method was adopted to conduct investigations in Weixin County,Daguan County of Zhaotong City,and Fuyuan County of Qujing City in the key diseased areas of Yunnan Province in 2017.Three townships from each endemic fluorosis area were randomly selected,and 2 villages of each township were randomly selected.The use of improved stoves (types of stoves,integrity rate and correct use),knowledge and behavior changes of endemic fluorosis prevention among local grade five pupils and housewives or household heads and the condition of endemic fluorosis (dental fluorosis and urinary fluoride situation in children) were investigated in above mentioned villages.Results A total of 532 households were investigated.The consumption rate of self-produced corn and pepper were 53.4％ (284/532) and 44.7％ (238/532),respectively.Totally 81.0％ (431/532) of households burned coal,the average annual coal burning time per household was 6.3 months.Totally 44.5％ (237/532) of the households used the improved iron stove,89.5％ (476/532) used the electric cooker to cook rice,84.2％ (448/532) used the induction cooker to cook,and 36.7％ (195/532)used the portable open stove.The integrity rate of improved stoves and the correct usage rate were 86.9％ (206/237) and 84.0％ (199/237),respectively,among the 237 households using improved stoves.The awareness rate of the prevention and control of coal-burning-borne fluorosis in grade five pupils and housewives or household heads were 85.8％ (921/1 074) and 17.7％ (283/1 596),respectively.The correct drying rates of edible corn and peppers were 66.5％ (189/284) and 52.9％ (126/238),respectively.A total of 3 333 children aged 8-12 years old were examined and the dental fluorosis positive rate was 11.28％ (376/3 333).Totally 377 samples of immediate urine samples were detected,the geometric mean of urinary fluoride content of children was 0.37 (0.06-2.14) mg/L.Conclusions The situation of coal-burning-borne endemic fluorosis in Yunnan Province is effectively controlled,but the correct use rate of improved stoves,the correct drying rate of edible com and peppers are low,and do not meet the requirements of the "13th Five-Year Plan".

Application prospects of a new model organism, Zebrafish, in the field of endemic diseases / 中华地方病学杂志

As a new model organism,Zebra.fish has been widely used in many aspects of life science research for its unique advantages in growth and development and the convenience of transgenic manipulation.Endemic disease is serious in China.Currently,on one hand,the pathogenesis of endemic fluorosis,endemic arsenism and iodine deficiency disorders is unclear,on the other hand,the cause of Keshan disease and KashinBeck disease is still unknown.This poses great difficulties in the prevention and control of endemic diseases.At present,there are some shortcomings and deficiencies in the animal models used to study the etiology and mechanism of endemic diseases.However,the advantages of Zebrafish as a new model organism just can make up for these deficiencies.Therefore,this paper reviews the application prospects of a new model organism,Zebrafish,in the field of endemic diseases.

Making energetic efforts for progress in targeted prevention and control of endemic fluorosis / 中华地方病学杂志

Endemic fluorosis is a generalized epidemic disease with complicated types of endemic areas and difficult to prevent and control in China.After several decades of efforts made,the situation in prevention and control of endemic tluorosis in China is in the best historical period.We should take the opportunities and make energetic efforts for targeted prevention and control of endemic fluorosis in order to completely implement intensive management of endemic areas with fluorosis and ensure sustainable prevention and control of the disease,and finally achieve the goal of complete control and elimination.This article analyzes and looks ahead in some aspects of targeted prevention and control of endemic fluorosis such as ideas,goals,conditions,supporting measures and so on.

The differences of X-ray findings of skeletal fluorosis between coal-burning type endemic fluorosis and industrial fluorosis / 实用放射学杂志

Objective To investigate the differences of X-ray findings of skeletal fluorosis between coal-burning type endemic fluo-rosis and industrial fluorosis.Methods The patients were randomly selected as research objects including 60 cases of coal-burning type endemic osteofluorosis and 60 cases of industrial osteofluorosis.The X-ray findings on the left forearm,crus and pelvic radio-graphs of these patients were analyzed retrospectively to find out the differences between skeletal fluorosis of coal-burning type endemic fluorosis and industrial fluorosis.Results X-ray features are no significant statistical differences between coal-burning type endemic fluorosis and industrial fluorosis,except these of interosseous membrane ossification of forearm and crus (forearmχ2=10.909,P<0.05;crusχ2=8.547,P<0.05),obturator membrane ossification of pelvis (χ2=36.554,P<0.05),periosteal proliferation outside bone of crus (χ2=4.937,P<0.05),and ossification of soleus (χ2=4.904,P<0.05).Conclusion The X-ray signs of endemic osteofluorosis and industrial skeletal fluorosis are almost similar,but there are some differences between them.

An epidemiological investigation of dental fluorosis of children aged 8-12 in coal-burning type endemic fluorosis areas in Guizhou Province / 中华地方病学杂志

Objective To investigate the prevalence of dental fluorosis in children aged 8-12 in coalburning-borne endemic fluorosis areas in 23 counties in Guizhou Province,and to evaluate the effects of prevention and control measures.Methods In 2014,five towns were selected according to their location of the east,the south,the west,the north and the center of the 23 counties,one primary school in each town was chosen.All the students aged 8-12 in each school were selected,according to the Diagnosis of Dental Fluorosis (WS/T 208-2011),dental fluorosis was examined.At the same time,the detection rate of dental fluorosis of children aged 8-12 was investigated in 23 counties in 2000 and 2007.Analysis and comparison of the data in 2000,2007 and 2014 were done.Results The total detectable rate of dental fluorosis of children aged 8-12 was 32.31％ (5 803/17 962).The detection rate of 3 counties was lower than 15％,12 counties ranged from 15％ to 30％ and 8 counties more than 30％.Very light,mild,moderate,and severe cases of dental fluorosis cases accounted for 48.39％ (2 808/5 803),30.43％ (1 766/5 803),15.16％ (880/5 803) and 6.01％ (349/5 803).Male and female children's overall detection rate was 33.05％ (3 083/9 329) and 31.51％ (2 720/8 633),the difference was statistically significant (x2=4.86,P ＜ 0.05).The detection rates of dental fluorosis of children aged 8,9,10,11 and 12 were 17.79％ (224/1 259),26.02％ (871/3 348),30.28％ (1 255/4 144),34.07％ (1 595/4 682) and 41.02％ (1 858/4 529),indicating that the detection rate increased with age (x2 =345.78,P ＜ 0.01).After longitudinal comparison of the detection rates of dental fluorosis of children aged 8-12 in 2000,2007 and 2014,we found that 17 counties were gradually decreased (all P ＜ 0.05) except Xiuwen,Weining,Qianxi,Qingzhen,Liuzhi and Xixiu (x2 =0.84,4.19,3.67,5.03,1.98,2.37,all P ＞ 0.05).The ratio of dental fluorosis detection rate ＜ 15％,15％-30％ and ＞ 30％ was accounted for 21.74％ (25/115),32.17％ (37/115) and 46.09％ (53/115),respectively,in the 115 villages.Conclusion The detection rate of dental fluorosis of children aged 8-12 in coal-burning-borne endemic fluorosis areas is significantly dropped,and the comprehensive prevention and control effect is gradually apparent.

Investigation and analysis of endemic fluorosis associated with drinking water in Jiaozuo City of Henan Province in 2016 / 中华地方病学杂志

Objective To fully grasp the epidemic situation of drinking water type of endemic fluorosis in Jiaozuo City of Henan Province,evaluate the efficacy of the prevention and control measures,and to provide a basis for prevention and control of the disease.Methods According to "The Measures for Control and Elimination of Key Endemic Diseases",all the diseased villages in Jiaozuo City were investigated.For all diseased villages in accordance with the improved water or no improved water,drinking water samples were collected,the fluorine content in water samples was determined based on the standard testing method for drinking water (GB/T 5750.5-2006);all children aged 8 to 12 years old of the surveyed villages were examined and determined dental fluorosis using "Diagnostic of Dental Fluorosis" (WS/T 208-2011);all evaluations were based on the criteria for drinking water-based fluorosis control (National Health Control [2014] No.79).Results Totally 7 counties (cities) 59 townships 589 diseased villages were surveyed in the city,586 diseased villages had improved the water quality,the rate was 99.49％,the number of villages that used the water facility normally was 571,the normal utilization rate was 97.44％,and there were 15 villages with excessive fluoride in water.A total of 35 057 children aged 8 to 12 years old in the diseased villages of the city were examined and 13 846 cases were detected dental fluorosis,the detection rate of dental fluorosis was 39.50％,the index of dental fluorosis was 0.65,which was a moderate epidemic;147 villages reached the control of standard among the 586 diseased villages with improved water,and the compliance rate was 25.09％,and the 7 drinking water type local fluoride poisoning epidemic counties (cities) in the area all did not reached the control standards.Conclusion Totally 439 diseased villages in the city have not meet the control standard,we should strengthen the monitoring,implement measures to improve water quality,strengthen the management and maintenance of water projects to ensure that the disease affected population to have qualified drinking water in a long-term,and gradually achieve the target to control and eliminate city's drinking water type of endemic fluorosis.

An analysis of surveillance outcomes of water-borne endemic fluorosis in Yushui district and Ningdu County of Jiangxi Province in 2014 / 中华地方病学杂志

Objectives To understand the control and prevention status of water-borne endemic fluorosis in Jiangxi Province, in order to provide a scientific basis for evaluate and perfect the strategies in control and prevention of the disease. Methods According to monitoring project of national water-borne endemic fluorosis, three villages were chosen to investigate the status and the fluoride content of fluorosis villages with water-improving and defluoridation projects in Yushui district and Ningdu county of Jiangxi Province. Investigation consisted of the status of dental fluorosis of children aged from 8 to 12 years and adult skeletal fluorosis, as well as fluoride content of drinking water and urinary fluorine. The standard detection methods of domestic drinking water was used for water fluoride content detection, fluoride selective electrode was chosen for urinary fluorine detection, Dean detection method was used to determine dental fluorosis, and diagnostic criteria of endemic skeletal fluorosis was chosen for diagnose of skeletal fluorosis. Results In fluorosis villages with water-improving and defluoridation projects which operated normally, the fluoride content of drinking water was lower than 1.00 mg/L. In fluorosis villages with water-improving and defluoridation projects which never operated normally, the average fluoride content of drinking water was 1.76 mg/L. The detection rate of dental fluorosis of children aged 8-12 years was 12.50%(22/176). A total of 294 adults were examined by X-ray, 3 adults were diagnosed as skeletal fluorosis, and the detection rate was 1.02%. A total of 294 adult urine samples were tested. The urinary fluoride content varied from 0.28 to 7.74 mg/L, and the geometric mean was 1.10 mg/L. Conclusions The illness condition of water-borne endemic fluorosis has been under control effectively. The maintenance of water-improving and defluoridation projects and surveillance were main tasks in control and prevention of the disease in the future.

An investigation of coal-burning type endemic fluorosis in Fuyuan County of Yunnan Province / 中华地方病学杂志

Objectives To study the prevailing status of coal-burning type endemic fluorosis in Fuyuan County of Yunnan Province, and to provide a scientific basis for fluorosis control and prevention. Methods In 2013, five towns were selected from the villages and towns which the defluoridation stove project was implemented and by the end of 2007 defluoridation stove rate was higher than 95%(including 95%), and two natural villages were selected in each township to carry out the investigation. Dental fluorosis was examined of all children aged 8 to 12 of survey points. At least 20 people were selected in each village. At the same time, 20 copies of instant urine samples were collected from these children of half male and half female, and urinary fluoride was determined. Then five natural villages were sampled from all survey points, and permanent residents were divided into25-,35-,45-,55-and≥65groups according to age. Six people were selected from each group with male and female in half who were conducted examination of adult skeletal fluorosis by X-ray. Dental fluorosis diagnosis was based on theDental Fluorosis Diagnosis(WS/T 208-2011). Urinary fluoride determination was done in accordance withUrine-Determination of Fluoride-Ion Specific Electrode Method(WS/T 30-1996). Skeletal fluorosis diagnosis was carried out according to Diagnostic Criteria for Endemic Skeletal Fluorosis (WS 192-2008). Results A total of 556 children aged 8 to 12 were monitored, the detection rate of dental fluorosis was 41.55%(231/556), the dental fluorosis index was 0.78. The very mild, mild, moderate and severe proportions of children's dental fluorosis were 20.50%(114/556), 17.09%(95/556), 3.60%(20/556) and 0.36%(2/556), respectively, given priority to very mild. The prevalence of dental fluorosis in children was increased with increasing age (χ2=74.27, P<0.05). One hundred and ninety-three copies of child urine samples were tested, the geometric mean of urinary fluoride was 0.62 mg/L, and the urinary fluoride contents were between 0.10-2.93 mg/L. A total of 116 adults were examined, and the detection rate of skeletal fluorosis was 9.48%(11/116). Detected cases of skeletal fluorosis was given priority to mild (9 cases, accounted for 81.81%), more men cases [16.36% (9/55)] than those of women [3.28% (2/61), χ2 = 5.77, P< 0.05]. Conclusion The hazard of coal-burning type fluorosis has been reduced in Fuyuan County , the affect of defluoridation stove project is obvious.

Surveillance on drinking-water-born endemic fluorosis in China, 2013 / 中华流行病学杂志

Objective To investigate the prevalence of fluorosis and related control measures on drinking water type of endemic fluorosis in China.Methods According to the national program"Surveillance Scheme of Drinking-Water-Borne Endemic Fluorosis",136 counties were selected in 29 provinces,autonomous regions and municipalities.Three epidemic villages were randomly selected as fixed monitoring sites in each county.Dental fluorosis of all the children aged 8-12 living in the villages under the monitoring program,was identified under the ariteria from "Diagnosis of dental fluorosis"(WS/T 208-2011).Operating conditions and contents of fluoride in all the'water-improved projects' were investigated.Contents of fluoride in drinking water were tested in villages without the 'water-improved projects'."Standard Test Method for Drinking Water" (GB/T 5750.5-2006) was used to detect the water fluoride.Results The overall prevalence of dental fluorosis among children aged 8-12 in all the villages under monitor program,was 28.58％ (7 950/27 817),with the dental fluorosis index (DFI) as 0.58.Among them,the prevalence was 22.28％ (3 917/17 583) and DFI was 0.44 in the' water-improved projects' villages that under normal operation and with qualified fluoride contents.The prevalence appeared as 38.74％ (1 926/4 971) with DFI as 0.84 in those villages with 'water-improved projects' but mal-operated or with excessive fluoride.The prevalence was 40.03％ (2 107/5 263),and DFI was 0.81 in those villages without'water-improved projects'.The prevalence rates of dental fluorosis in children from the three types of endemic areas were significantly different.For 'water-improved projects',the normal opration rate was 93.77％ (286/305) and the qualification rate of fluoride content was 76.77％ (228/297).Conclusions Dental fluorosis in children living in the drinking-water-born endemic fluorosis areas was on the edge of epidemics in China.Effective improvement on the quality of drinking water can significantly reduce the severity of dental fluorosis in children.The rate of proper operation on 'water-improved projects' was near to 95％ in the endemic area.However,rate that met the criteria on qualified fluoride contents of these projects was still below 80％.

Surveillance on drinking-water-born endemic fluorosis in China, 2013 / 中华流行病学杂志

Objective To investigate the prevalence of fluorosis and related control measures on drinking water type of endemic fluorosis in China.Methods According to the national program"Surveillance Scheme of Drinking-Water-Borne Endemic Fluorosis",136 counties were selected in 29 provinces,autonomous regions and municipalities.Three epidemic villages were randomly selected as fixed monitoring sites in each county.Dental fluorosis of all the children aged 8-12 living in the villages under the monitoring program,was identified under the ariteria from "Diagnosis of dental fluorosis"(WS/T 208-2011).Operating conditions and contents of fluoride in all the'water-improved projects' were investigated.Contents of fluoride in drinking water were tested in villages without the 'water-improved projects'."Standard Test Method for Drinking Water" (GB/T 5750.5-2006) was used to detect the water fluoride.Results The overall prevalence of dental fluorosis among children aged 8-12 in all the villages under monitor program,was 28.58％ (7 950/27 817),with the dental fluorosis index (DFI) as 0.58.Among them,the prevalence was 22.28％ (3 917/17 583) and DFI was 0.44 in the' water-improved projects' villages that under normal operation and with qualified fluoride contents.The prevalence appeared as 38.74％ (1 926/4 971) with DFI as 0.84 in those villages with 'water-improved projects' but mal-operated or with excessive fluoride.The prevalence was 40.03％ (2 107/5 263),and DFI was 0.81 in those villages without'water-improved projects'.The prevalence rates of dental fluorosis in children from the three types of endemic areas were significantly different.For 'water-improved projects',the normal opration rate was 93.77％ (286/305) and the qualification rate of fluoride content was 76.77％ (228/297).Conclusions Dental fluorosis in children living in the drinking-water-born endemic fluorosis areas was on the edge of epidemics in China.Effective improvement on the quality of drinking water can significantly reduce the severity of dental fluorosis in children.The rate of proper operation on 'water-improved projects' was near to 95％ in the endemic area.However,rate that met the criteria on qualified fluoride contents of these projects was still below 80％.

Changes of blood zinc content in patients with coal-burning endemic fluorosis and its implication / 第二军医大学学报

Objective To assess the association of zinc (Zn) with coal-burning endemic fluorosis (coal-burning fluorosis), so as to provide an evidence for the role of Zn in preventing coal-burning fluorosis. Methods Fifty children with dental fluorosis and 100 healthy controls were selected from Wushan County by stratified sampling, and the same number of children and controls were also selected from Fengjie County. Thirty adults were selected from skeletal fluorosis patients in Duping Township of Wushan County, and 60 healthy controls were selected in the same township. Fasting blood samples were collected from all the participants for Zn determination. Urine samples were collected to examine urine fluoride content. Wilcoxon rank sum test was used to analyze the differences in Zn and fluoride contents between cases and controls and between the two counties. The association between blood Zn and urine fluoride was examined by Pearson linear correlation/Spearman rank correlation. Results The average urine fluoride contents were significantly higher in the child fluorosis cases than in the controls from both counties (P<0.01); and the average blood Zn contents were significantly lower in the fluorosis cases than in the controls from both counties (P<0.01). Moreover, the child cases and controls from Wushan County had significantly lower average blood Zn contents compared with those from Fengjie County (P<0.05); the child fluorosis cases in Wushan County had a significantly lower urine fluoride content compared with those from Fengjie County (P<0.05). The average urine fluoride content of skeletal fluorosis adults from Wushan County was significantly higher than that of controls, and the average blood Zn content was significantly lower than that of controls (P<0.01). In addition, Pearson linear correlation/Spearman rank correlation showed a weak positive relationship between blood Zn and urine fluoride in both children and adults (P<0.05, P<0.01). Conclusion It is indicated that patients with fluorosis are generally Zn deficient, suggesting Zn deficiency might be a risk factor for fluorosis.

Analysis of surveillance results of drinking-water supply status in drinking-water-borne endemic fluorosis areas in Henan / 中国地方病学杂志

Objective To understand the status of drinking-water supply and the progress of waterimproving projects in drinking-water-borne endemic fluorosis areas in Henan,and to provide scientific data for related government departments to carry out prevention and surveillance plan for those areas.Methods Questionnaire survey was carried out in all the villages in drinking-water-borne endemic fluorosis areas in Henan in 2010.Each village was given one set of questionnaire.Results By the end of 2010,the total number of fluorosis villages in Henan was 25 434,among them 11 484 villages had been conducted water-improving projects,accounting for 45.15％.Currently,9267 water-improving projects worked properly,accounting for 36.4％(9267/25 434)of all villages surveyed,and 80.7％ (9267/11 484)villages had water-improving projects.The projects in 2217 villages do not work properly,accounting for 19.3％(2217/11 484) of all projects.There were 5832 water-imp.roving projects conducted amnog 2005-2010,accounting for 50.8％ (5832/11 484) of all water-improving projects.Among villages with no such projects,97.5％(15 769/16 167) of them used shallow groundwater,and in villages with water-improving projects,89.6％ (8303/9267) of them used deep groundwater as drinking-water supply.Conclusions After 2005,the water improving progress was significantly speed up in drinking-water-borne endemic fluorosis areas in Henan,but progress of the water improving projects is relatively slow due to changing and expanding of fluorosis areas.The government should increase investment and improve the proportion of waterimproving defluoridation.

Study on the association between environmental chemical elements and fluorosis caused by coal-fire pollution / 中华流行病学杂志

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

Role of placenta to combat fluorosis (in fetus) in endemic fluorosis area.

Fluoride (F) is known to cross the placenta from the maternal blood to the growing fetus. However, there are few studies on the role of placenta in conditions of high F intake in fluorosis endemic area. The present study is the first of its kind carried out in Nalgonda district, an endemic fluorosis area of Andhra Pradesh, India with an average ground and drinking water F of 10.94+2.09 ppm and 4.4+1.6 ppm respectively. The aim of the study is to determine the role of placenta in the transport of F from the maternal blood to the fetus in fluorosis endemic area. 200 healthy pregnant women aged 17-36 years were inducted in the study. All the women had normal and uneventful delivery. Samples collected were maternal blood, cord blood & placenta. The placenta was divided into three parts- peripheral, maternal and fetal surfaces. Placental extracts were obtained and stored at -20° C until processed. F concentrations of the newborn were well within the normal reference range despite high maternal F concentrations (1.62±0.78 ppm). Placental F concentration on the peripheral side (2.54±1.55 ppm) was two fold higher than the maternal serum F (1.62±0.78 ppm; p< 0.001) and six fold higher than the cord F (0.45±0.35 ppm; p< 0.001). Placental F on the maternal (1.62±0.78 ppm) and fetal surfaces (1.41±0.77 ppm) were three fold higher than that of cord blood (p<0.001). On the peripheral part of placenta F was found to be 1.5 times higher than maternal and fetal surfaces. Thus, it can be deduced that placenta does accumulate F especially in the peripheral part when women are exposed to relatively high F concentrations in water and food. The study also suggests that placenta can act as a backstop or guard for the passage of F to the fetus; thus protecting the developing fetus against neonatal fluoride complications.

Effects of Stoves Improving in Controlling Fluorosis in Coal-burning Endemic Fluorosis Areas in Shaanxi Province from 2001 to 2005 / 环境与健康杂志

Objective To observe the effect and the influential factors of stoves improving in controlling fluorosis in the coal-burning endemic fluorosis areas. Methods Among the households whose stoves had been improved by 2001 and the improved ones were in use during the whole monitor, the dental fluorosis in children aged 8-12 years (n=318) and the skeletal fluorosis in adults older than 16 years were examined and the fluoride concentration in the indoor air, the corn, chili and the urine of children (n=253) was determined respectively. Results The dental fluorosis rates were 64.79%-87.93%, the skeletal fluorosis rate were 17.95%-21.97%, the fluoride levels in the urine were 2.50-4.03 mg/L, in the indoor air per day were 0.033 7-0.175 3 mg/m3, in chili and corn were 48.13-251.40 mg/kg, 2.06-4.06 mg/kg respectively. The dental fluorosis rate and the index went down significantly year by year from 2001 to 2004. The fluoride content in the chili and the children’s urine decreased in varying degrees from 2001 to 2005. The fluoride levels in the indoor air in 2004 and 2005 were significantly lower than that in 2001 respectively. Conclusion Coal-burning endemic fluorosis is still prevailing in this village. Stoves improving is an effective measure to prevent endemic fluorosis caused by coal-burning.

Investigation of Fluoride Source in Coal-burning Endemic Fluorosis Areas in Hunan Province / 环境与健康杂志

Objective To explore the origin of fluoride in the coal-combustion endemic fluorosis areas in the middle part of Hunan Province and to provide basic data for making preventive measure in the regions. Methods In November, 2006, the prevalence rate of dental fluorosis of children aged 10-12 years were examined, the villages were divided into three groups based on the prevalence rate of dental fluorosis. The fluoride content in the drinking water, coal, briquettes, briquette ash, clay and indoor air was determined by fluoride ion selective electrode. The quantity of fluoride release was calculated. Results There was no significant difference in the concentration of fluoride in water among the three groups, and it was below 1.0 mg/L in fluorosis and non-fluorosis areas. The fluoride levels in the coal, briquette ash and indoor air showed no statistical difference among groups. The fluoride levels of briquettes, clay and the quantity of fluorine release showed significant difference (P

Effects of Coal Burning Related Endemic Fluorosis on Body Development and Intelligence Levels of Children / 实用儿科临床杂志

Objective To study the effects of coal burning related endemic fluorosis on body development and intelligence levels of fluorosic children in Zhijin county.Methods One hundred and seventy-six fluorosic children and 50 healthy(without fluorostic teeth) children aging 7-12 years who were sampled in cluster sampling were examined for urine fluorosis,physical examination and intelligence tests in Zhijin county,with coal burning pollution related fluorosis.Results Physical development of sick children and the children in control group were in low levels. The intelligence levels and the leves of urine fluorosis in study group were lower than those in control group and there was a significant difference(P

Effect Assessment of Water Supply Improvement in the Fluorosis Prevalent Regions in Meizhou, China / 环境与健康杂志

Objective To understand thoroughly the effect of water improvement by investigating fluoride contents of drinking water in Meizhou fluorosis prevalent regions, the prevalence of fluorosis and the problems in water supply improvement projects. Methods In 2004, fluoride contents in drinking water were determined, 5 082 native pupils were examined for dental fluorosis according to Dean's method and the running status of water supply improvement projects was investigated also. Results After water supply improvement, the prevalence rate of the dental fluorosis in the fluorosis region(28.43 %) decreased significantly compared with that(56.99%) before the water supply improvement, the rate of fluoride content in drinking water that was up to standard reached 83.33%, the good running rate of water supply improvement projects was 68.42%. Conclusion The effect of water supply improvement is remarkable and satisfactory. In some regions little attention was paid to the management and daily maintenance of water supply but water source, which may cause water supply improvement projects damaged, in addition, water insufficiency and the alternate consumption of high fluoride water and normal water may be the main factors for fluorosis prevalence in some areas where although the water supply improvement has been finished.

Cistanche Salsa Tablets for Endemic Fluorosis:Observation of Clinical Efficacy / 中国药房

OBJECTIVE:To observe the clinical efficacy of Cistanche salsa tablets in treating endemic fluorosis. METHODS: A total of 137 cases were enrolled from endemic fluorosis disease-stricken area: 37 were assigned to receive Cistanche salsa tablets(1.2 g) po bid (trial group), and another 100 to receive Fenbid (300 mg) po bid as control for a treatment course of 4 weeks. The outcome measures included the total efficacy, time to take effect, adverse drug reaction and patients’ drug tolerance. RESULTS: In the trial group, the total effective rate was 86.49%, the time to take effect ranged from 7 to 15 days, and the ADR incidence rate was 35.14%, which was of significant difference as compared with control group.The patients in both groups had good drug tolerance. CONCLUSION: Cistanche salsa tablets are effective for endemic fluorosis and superior to Fenbid in efficacy.