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Objective To investigate the fluoride content in drinking water as well as the current status of endemic fluorosis in 5 counties of Shandong Province,in order to provide a scientific basis for making prevention and control strategies.Methods According to the survey data of fluoride content in drinking water in Shandong Province between 2005 to 2007,an epidemiological investigation was carried out in Mudan,Jiaxiang,Wucheng,Pingdu and Boxing Counties from September to November 2013.The fluoride content in drinking water and urine and dental fluorosis of children aged 8 to 12 were investigated in 3-4 major survey villages selected in the five counties.The fluoride content in drinking water was detected by fluoride ion selective electrode method,and dental fluorosis was diagnosed by Deans method.Results Fifty-eight drinking water samples were investigated in 16 villages of the five counties.Water fluorine content in Wucheng,Mudan,Pingdu,Boxing and Jiaxiang counties was 4.14,3.84,1.83,1.33 and 0.43 mg/L,respectively.There were 4 counties' fluorine content exceeding the national standard (1.20 mg/L) except Jiaxiang County.The exceeding rate was 100％ in Wucheng and Mudan counties.Urine fluorine content of 320 children aged 8 to 12 in Wucheng,Mudan,Boxing,Pingdu and Jiaxiang counties was 4.51,4.62,1.82,1.30,1.01 mg/L respectively;the total detection rate of dental fluorosis of 574 children was 61.85％ (355/574),the rate of dental damage was 12.89％ (74/574),and dental fluorosis index was 1.27;the detection rate of dental fluorosis in Wucheng,Mudan,Boxing,Pingdu and Jiaxiang Counties was 90.18％ (101/112),97.73％ (86/88),62.22％ (84/135),54.90％ (28/51) and 29.79％ (56/188),respectively.Conclusions The exceeding rate of water fluorine content is very high in 5 counties of severe endenic fluorosis areas in Shandong Province.The urinary fluorine level of the population is still high and the prevalence of dental fluorosis of children is high.Endemic fluorosis in Shandong Province has not yet been effectively controlled,control situation is still grim.
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Objective To study the spinal neurocyte apoptosis and the changes of p53 in chronic fluorosis rats,and the improvement after drinking no fluoride water.Methods One hundred twenty Wistar rats were divided into 4 groups by random number table method according to body mass,30 rats in one group fed with high concentration NaF water (200 mg/L) to make fluorosis model and classified as high fluoride group;other 30 rats were fed with distilled water as control group;another 30 rats were fed with high concentration NaF water (200 mg/L) for 12 weeks,then fed with distilled water for 12 weeks and classified as defluorination group;the rest 30 rats were classified as defluorination control group.The content of fluoride in urine was tested after the 4th,8th,and 12th weeks.Then the content of fluoride in urine of defluorination group and defluorination control group was tested.The high fluoride group rats and control group rats were killed after 12th week.Defluorination group rats and defluorination control group rats were killed after 24th week.Their spinal cord was collected.The expression of p53 protein in spinal cord was detected by immunohistochemistry and Westem blotting.Apoptosis of the neurocyte was quantitatively analyzed by flow cytometry (FCM).Results By FCM,apoptosis of neurocyte was increased in both high fluorosis group rats and defluorination group rats compared with those in control group rats [(3.36 ± 0.71)％ vs.(0.78 ± 0.65)％;(3.47 ± 0.56)％ vs.(0.83 ± 0.64)％,t =14.680,17.003,all P ＜ 0.01)],but no difference was found between these two groups [(3.47 ± 0.56)％ vs.(3.36 ± 0.71)％,P ＞ 0.05)].Immunohistochemistry and Western blotting revealed that p53 expression in spinal cord of high fluorosis group rats was increased compared with those in control group rats (422.69 ± 12.35 vs.177.82 ± 14.16;253.37 ± 10.42 vs.87.14 ± 7.39,t =77.212,72.988,all P ＜ 0.01).And p53 expression in spinal cord of defluorination group rats was increased compared with those in control group rats (418.75 ± 11.84 vs.163.47 ± 8.57;248.29 ± 10.23 vs.98.74 ± 11.52,t =95.663,53.167,all P＜ 0.01).But the differences were not statistically significant (418.75 ± 11.84 vs.422.69 ± 12.35;248.29 ± 10.23 vs.253.37 ± 10.42,t =1.261,1.906,all P ＞ 0.05).Conclusions There is apoptosis of neurocytes in the spinal cord of chronic fluorosis rats;overexpression of p53 probably plays an important role in the mechanism of damage induced by excessive fluorine.Apoptosis can not be recovered after defluorination for a short time,and persistent overexpression of p53 may be one of the reasons that apoptosis of neurocytes in the spinal cord can not decrease.
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Objective To understand the situation of indoor air fluoride and arsenic pollution caused by coal-burning and the impact of the pollution on children health in the rural area,southern Shaanxi Province.Method 77 fluoride samples and 186 arsenic samples were collected in 65 investigated villages of 5 counties in southern Shaanxi Province.13 120 children aged 8-12 years were selected for dental fluorosis examination,13 386 children aged 6-18 years for arsenism examination.Results Both of the average content of fluoride and arsenic in the indoor air exceeded the national standard limit.Fluorine content was 0.001-0.541 mg/m3 with an average of 0.038 4 mg/m3,arsenic content was 0.00-63.83 ?g/m3 with an average of 4.76 ?g/m3.The prevalence rates of dental fluorosis and arsenism were 45.50% and 1.86% respectively.Conclusion The indoor air fluoride and arsenic pollution caused by coal-burning in the investigated rural area is serious and the pollution has caused the prevalence of endemic fluorosis and endemic arsenism among the local children.