ABSTRACT
Objective To understand distribution of the endemic fluorosis areas and running status of water-improving defuoridation projects in Gausu province. Methods In 2006, Gansu province endemic fluorosis areas, the content of fluoride in drinking water was measured in villages where water was not improved, running status of delluoridation projects was investigated and the content of fluoride in drinking water were determined in villages where water was improved. Dental fluorosis and skeletal fluorosis prevalence were examined in children in identified high-fluorlde villages. The fluorine content in drinking water was determined by F-ion selective electrode, dental fluorosis of children was diagnosed using Dean method, and adults skeletal fluorosis was diagnosed according to "National Standard for Clinical Diagnosis of Endemic Skeletal Fhiorosis" (GB 16396-1996). Results Water samples were examined in 1997 villages of 26 countries, among which water fluoride content was higher than 1.0 mg/L in 598 villages, accounting for 29.94%(598/1997). All 1215 water-improving and defluoridation projects had been investigated, among which 94.90%(1153/1215) of the projects were functioning well, and intermittent and abandoned projects accounted for 2.96%(36/1215) and 2.14%(26/1215). Mean fluoride of treated water of 1084 water-improving and defluoridation projects had water fluoride content ≤ 1.0 mg/L, accounted for 90.79%(1084/1194) ; mean fluoride of water from 1068 water-improving and defluoridation projects had water fuoride content ≤ 1.0 mg/L, accounting for 91.75%(1068/1164). Total 86 390 children of 8 to 12 year-old were examined, the detectable rate of dental fluorosis was 22.47%(19 414/86 390) and 142 211 adults above 16 year-old were examined, the detectable rate of skeletal fluorosis was 4.20%(5967/142 211). Conclusions Some villages yet have water fluoride content exceeding the standard. Some projects are abandoned and running badly, leading to fluoride content exceeding the standard. In a few areas, the prevalence of children dental fluorosis and adult skeletal fluorosis still exists in Gansu province, the task of prevention and control for endemic fluorosis is still arduous. We must raise the effect of prevention and treatment of this disease.
ABSTRACT
Objective To investigate the prevalence of endemic fluorosis and the progress acchieved through control measures in Taian County of Gansu Province so as to provide basis and technique support for endemic fluorosis control. Methods The survey was carried out according to the National Surveillance Scheme of Endemic Fluorosis. Fulfillment of control measures and the quality of water improving projects were surveyed. Samples of household water and urine in children aged 8-12 years were collected and fluoride content was detected by iron selective electrode method. Children's dental fluorosis were examined with Dean method. Results In Qinan County, water was improved in a rate of 100%. In water-improving and defluoridation projects investigated, 81.15% (99/122) projects worked well, 18.85% (23/122) projects were closed or abandoned. The number of water improvement projects monitored were 24,81,9,8,respectively in the year through 2004 to 2007, revealing 13 projects having water fluorine content(>1.0-2.0 mg/L) in 2004, 15 and 5 projects having water fluorine content higher that 1.0-2.0 and 2.0-4.0 mg/L respectively in 2005, 2 projects having water fluorine content(>1.0-2.0 mg/L) in 2006, and no projects above 4.0 mg/L. In Anfu Village, the fluorine content of source and drinking water were all below 1.0 mg/L in 2006 and 2007. The urinary fluoride content of 8-12 years old children was equal and higher than 1.5 mg/L, dental fluorosis rate was 34.47% (354/1027), and dental fluorosis index was 0.65 in 2004-2007. Conclusions Projects running out of status and excessive levels of water fluorine are frequently seen, dental fluorosis is not controlled in Taian County of Gansu Province
ABSTRACT
Objective To evaluate the intervention effects of low-fluoride brick tea in the population, and to provide data for the prevention and control of the brick-tea type fluorosis. Methods Eighty-six Kazakh families with 5-12 years old children were selected and divided into two groups in the severe brick-tea type fluorosis areas of Akesai County of Gansu Province. Forty-six households were intervened by drinking low-fluoride brick tea as intervention group and another 40 households drank general brick tea as control group. The fluoride content in water, tea and urine was monitored and the total daily fluoride intake of adults and children was calculated by the fluoride content of the tea before and during intervention. The baseline prevalence of dental fluorosis was surveyed in all Kazakh school students aged 5 - 12 years before intervention, dental fluorosis prevalence were surveyed in two groups after the intervention. The fluoride content in water, urine,tea, and brick-tea samples was detected by iron electrode method, and dental fluorosis was diagnosed by Dean's method. Results The fluoride content of water were 0.36,0.50 mg/L respectively before and 42 months after intervention. The total daily fluoride intake of adults and children in the intervention group (being 4.39,5.12,5.38,4.49 mg in adults and 1.90,2.33 in children, 2.33, 1.94 mg for four calculations) were lower than those in control group (8.42,9.07,8.35,7.92 and 3.65,3.93, 3.62,3.43 mg). Except the second batch (530.4 mg/kg), the average fluoride content of the other 3 batches of low-fluoride brick tea(239.3,222.88,154.7 mg/kg) was lower than that of 4 batches of market brick tea(366.9,412.2, 286.0,379.6 mg/kg). The fluoride content of low-fluoride brick tea samples was in accordance with the national standard(< 300 mg/kg) in 16 of 21 samples in 4 the batches, and the qualifying rate was 76.19%(16/21). Only 5 of 21 market brick tea samples in 4 batches was qualified, accounting for 23.80%(5/21), both were significantly different(χ2= 11.52, P < 0.01). In 12, 36, 42 months after intervention, urine fluoride content in the intervention group of adult(1.84,1.23,1.77 mg/L) and children(1.55,0.65,1.10 mg/L) was less than that of the control group (adults: 3.37,3.68,3.02 mg/L, children: 2.64,1.64,2.62 mg/L), both being statistically significant (t value were 2.94,2.43,3.91,3.29,2.31,4.42, P < 0.01 or 0.05). The detective rate of dental fluorosis was 69.02%(127/184)at baseline among children. After the intervention, it lowered to [44.83% (13/29) in the intervention group, significantly lower than that in the control group[71.88%(23/32), χ2 = 4.60, P < 0.05]. Conclusion Low-fluoride brick tea can reduce the fluoride intake of the residents who drink brick tea, and alleviate excessive fluoride and the damage of high-fluoride.
ABSTRACT
Objective To investigate the distribution of water fluoride and the present status of water- improving delluoridation projects in the endemic fluorosis areas in Gansu Province. Methods According to "The National Technical Scheme for Endemic Disease Control in 2004" for the water improving projects, water fluoride content was determined from fluorosis villages in 34 counties of 11 cities in Gansu Province. The fluoride content in drinking water was assessed by F-ion selective electrode. Results Water fluoride content was determined in 1576 fluorosis villages of 34 counties. Water fluoride content of 7829 water samples was determined, and the fluoride content of 1891 samples was over standard. Water fluoride content was ≤ 1.00 mg/L(accounting for 75.19%) in 1185 villages and 1.00 mg/L(accounting for 24.81%) in 391 villages; the highest water fluoride content was 6.78 mg/L Nine hundred and ninety three water-improving and defluoridation projects were determined. Water fluoride content of 867 water-improving and defluoridation projects was determined; 768 projects had water fluoride content ≤1.00 mg/L(accounting for 87.67%) and water fluoride content of 108 projects was 1.00 mg/L(accounting for 12.33%),with the highest water fluoride content being 5.27 mg/L. Water-improving and delluoridation projects mostly relied on drilling a well to obtain under-grand water. Abandoned projects accounted for 30%. Conclusions In 34 counties of 11 cites(prefecture), nearly 30% of the villages had water fluoride content exceeding the standard. The situation of endemic fluorosis control is still serious in Gausu Province, countermeasures for endemic fluorosis must be carried out as soon as possible and surveillance of water-improving and defluoridation projects must be strengthened.