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Objective To investigate the progress and effectiveness of water-improving defluoridation projects comprehensively in control of fluorosis in drinking-water-borne endemic fluorosis areas in Hubei Province,and to provide a scientific basis for making strategies in prevention and control of endemic fluorosis.Methods All villages affected by fluorosis in drinking-water-borne endemic fluorosis areas were selected in Hubei Province,in which the progress and effectiveness of water-improving and defluoridation projects were investigated in 2015.Those villages were chosen to determine fluoride content of drinking water,and to check the prevalence of dental fluorosis of children 8 to 12 years old.Water fluoride content was tested with fluoride ion-selective electrode,and dental fluorosis was diagnosed by the Dean method.Results The water improvement projects were completed in 197 villages in the 30 disease affected counties (cities) with accomplishment rate 100.00％ (197/197),geometric mean of water fluorine 0.36 mg/L,qualified rate of water fluorine 100.00％ (197/197) and normal operation rate of the water-improvement projects 95.94％ (189/197).Totally 14 856 children aged 8-12 were examined their dental fluorosis.The prevalence rate was 1.78％ (265/14 856) and the dental fluorosis index was 0.04,which meant epidemic strength was negative.Totally 29 out of the 30 disease affected counties (cities) had met the disease control standards.Conclusion The prevalence of drinking-water-borne endemic fluorosis in Hubei Province has been under control,but management and monitoring of the water improvement projects still should be strengthened.
ABSTRACT
Objective Through the dynamical monitoring of the water improvement projects operation,we intend to understand the prevalent trends of endemic fluorosis of children aged 8 to 12 in Hubei,to evaluate the effect of control measures and to provide the basis for making preventive measures.Methods In Hubei,ten surveillance counties were selected,and three epidemic villages were selected as fixed monitoring villages in each county from 2010 to 2014.In those villages,the operation situation of water improvement projects and the fluoride content in drinking water were detected,and the dental fluorosis of children aged 8 to 12 was diagnosed.Results From 2010 to 2014,the normal operation rate of water improvement projects was 75.61％-100.00％,the average of water fluorine content did not change,the differences were not statistically significant (F =2.00,P ＞ 0.05).The numbers of water improvement projects with water fluorine content in excessive amount was increased in the past five years which was only one project in 2010-2012 and was increased to two projects in 2013 and 2014.In 2010-2014,the dental fluorosis prevalence rate of whole children was 9.45％ (525/5 557),the dental fluorosis prevalence rate of exceeding-standard villages of water fluoride content was 42.40％ (92/217),the dental fluorosis prevalence rate of qualified villages was 8.11％ (433/5 340).The children's dental fluorosis prevalence rate of exceeding-standard villages of water fluoride content was higher than that in qualified villages;the differences were statistically significant (x2 =282.60,P ＜ 0.05).Conclusions The operation rate of water-improving projects is mostly higher than 90％,and so is the qualification rate of fluoride content in drinking water.The operation condition and water quality of the water-improving projects in Hubei need to be improved.The prevalence of children dental fluorosis of affected villages has dropped significantly after low fluoride water is provided continuously.
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Objective To understand the variation of arsenic concentration in underground water at the endemic arsenic poison disease area of Jianghan Plain so as to better understand the spatial distribution of high arsenic groundwater,hydro-chemical evolution and source of arsenic in this region.Methods Thirty underground water samples were collected respectively around 3 km radius of the two houses where arsenic poisoning patients lived,in Xiantao and Honghu.Sediment cores of three drillings were collected as well.Both paired t-test or paired Wilcoxon Signed Ranking Test were used to compare the arsenic concentration of water.Results The arsenic concentration in 2011-2012 appeared lower than that in 2006-2007 at the Nanhong village of Xiantao (t=4.645 3,P＜0.000 1),but was higher(S=-150,P＜0.000 1) in the Yaohe village of Honghu.The pH value showed weak acidity with Eh as weak oxidated.Positive correlations were observed between arsenic concentration and C1,HCO3-,Fe,Mn.However,negative correlations were found between As and SO42-,NO3-.The range of arsenic content in the sediment was 1.500 mg/kg to 17.289 mg/kg.The maximum arsenic content existed in the soil layer,while the minimum arsenic content existed in the sand layer.Conclusion The concentration of arsenic varied widely with time and space at endemic arsenic poison disease area of Jianghan Plain.Characteristics of these water chemicals showed significant differences,when compared to the groundwater from Datong Basin,Shanxi Shanyin and Hetao Plain of Inner Mongolia,which presented a typical environment with high arsenic contents in the groundwater.The arsenic content in the sediment samples seemed related to the lithologic structure.
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Objective To investigate and analyze the examination and acceptance results for coalburning-borne endemic fluorosis control and elimination in Hubei Province.Methods A county-level selfinspection and a provincial-level spot-check were conducted to investigate the status of improved-stove usage,the situation of correctly drying corn and chili,and the dental fluorosis prevalence among children aged 8 to 12 in 501 historic coal-burning-borne endemic fluorosis villages of 6 counties (cities) in Hubei Province from 2012 to 2014.The endemic areas were selected according to the Control Standards of Endemic Fluorosis in Endemic Areas (GB 17017-2010) and Eliminating Standards of Coal-burning Type Endemic Fluorosis.Results The results of county-level inspection showed that the qualified rates of improved stoves,the correct-usage rates of qualified stoves,and the correctly drying rates of corn and chili were all higher than 98％ in targeted villages,and the prevalence rate of dental fluorosis of children was 7.73％ (2 319/30 003).The results of provincial-level recheck were more than 99％ and 8.25％ (353/4 277),respectively.The results of county-level inspection were of good consistency with those of provincial-level recheck (88.89％,48/54).Five counties (cities) but one had met the standard of fluorosis control or elimination.Conclusion Coal-burning-borne endemic fluorosis scope in Hubei Province is narrowed greatly and the prevalence rates are decreased significantly.
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Objective To know the changing characteristics of residents' iodine nutritional status after eating salt with different iodine concentrations in Hubei Province,according to the assessment standard of iodine nutrition recommended by WHO/UNICEF/ICCIDD provide a scientific standard for appropriate iodine concentration in edible salt.Methods According to inhabitants' salt and urine surveillance of Hubei in 2010,Xinzhou District,Tianmen City and Changyang County were selected for trial.Salt with two kinds of iodine content was used in 3 trial areas in 4 months for the study of community intervention.Before the intervention,3 months and 4 months after the intervention,urine samples of observed participants(40 from 8-10 old children,40 from pregnant women or lactating women and 40 from adults aged older than 18) were collected and tested.The urinary medians of different groups of people and at different times were calculated and compared.Results Three months and 4 months after the intervention,in those towns using iodized salt of (15 ± 3) mg/kg,the urinary medians of children,declined from 294.2 μg/L to 185.6,195.7 μg/L,respectively.The urinary medians of pregnant women or lactating women dropped from 269.0 μg/L to 141.7,176.1 μg/L.For adults aged 18 and older,the urinary medians changed from 304.9 μg/L to 199.7,202.2 μg/L.In those trial towns of using (25 ± 3)mg/kg iodized salt,the urinary medians of children,pregnant women or lactating women and adults older than 18 all went down from 301.1 μg/L to 229.7,253.8 μg/L,from 261.4.0 μg/L to 196.6 and 206.5 μg/L and from 379.7 μg/L to 244.3,237.4 μg/L,respectively.Conclusions According to the assessment standard of iodine nutrition recommended by WHO/UNICEF/ICCIDD and the decreasing of urinary iodine median and per capita daily salt intake,salt with 25 mg/kg iodine is suitable as the average level of salt iodine concentration after the adjustment in Hubei Province.