Surveillance on the prevention and control status of drinking-water-borne endemic fluorosis areas and dental fluorosis of children in Xi'an City, 2018 / 中华地方病学杂志

ABSTRACT

Objective:To assess the implementation of control measures and dental fluorosis of children in drinking-water-borne endemic fluorosis areas in Xi'an City, and to evaluate the implementation effects of the prevention and control measures.Methods:All drinking-water-borne endemic fluorosis villages in Xi'an were selected as the investigation sites. The progress and running condition of all water-improved projects were investigated, fluoride concentration in all the water-improved projects and tap water were tested. "Standard Test Method for Drinking Water" (GB/T 5750.5-2006) was used to test the water fluoride. A cross-sectional analytical study was conducted on school children aged 8 - 12 years old, the dental fluorosis was determined according to "Diagnosis of Dental Fluorosis" (WS/T 208-2011).Results:There were 273 drinking-water-borne endemic fluorosis villages, the rate of water improved villages was 91.58% (250/273), and all of the water-improved projects were operating normally (100.00%, 196/196). The rate of water-improved projects with qualified water fluoride was 88.27% (173/196), 237 villages had fluoride safe drinking water and the qualified rate was 86.81% (237/273). The median of water fluoride in the 250 villages with water-improved projects was 0.78 mg/L, the median was 0.83 mg/L in the 23 villages without water-improved projects, and the difference was not significant ( Z = 1.475, P > 0.05) . The overall prevalence of dental fluorosis among children aged 8 - 12 years old was 19.86% (1 960/9 871), and the dental fluorosis index was 0.39. The prevalence of dental fluorosis in the villages with qualified water fluoride was 16.13% (1 377/8 539), and the rate was 43.77% (583/1 332) in the villages with unqualified water fluoride, and the difference was significant (χ 2 = 553.283, P < 0.01). The prevalence of dental fluorosis in children with water fluoride content of 0.00 - 1.20, 1.21 - 1.50, and ≥1.51 mg/L was 16.13% (1 377/8 539), 41.20% (281/682), 46.46% (302/650), and the difference was significant (χ 2 = 559.011, P < 0.01), the severity of the disease was positively correlated with water fluorine concentration ( r = 0.273, P < 0.01). The epidemic situation in 202 villages was effectively controlled and 71 villages did not reach the control standard. Conclusions:The progress of water-improved projects and the rate of qualified water fluoride are not optimistic in Xi'an, the dental fluorosis of children is still higher than the government standard in the high fluoride drinking-water areas. The measures for water improving defluorination and disease surveillance should be strengthened.