Investigation on Drinking-water-borne Fluorosis in Some Areas in Shaanxi / 环境与健康杂志

ABSTRACT

Objective To master the running conditions of water project and the defluoridation results in monitoring sites of drink-water type fluorosis in Shaanxi Province,to provide a scientific basis of preventing and controlling endemic fluoroisis. Methods Every April and September 1998—2005 children aged 8～12 at school from the two monitoring sites of Wupo and Bayi village received the dental fluorosis examination by using the Deans method.The urine samples of 50 children from 5 age groups who were selected randomly and were grouped in 5 with 10 children each were collected,measured in accordance with WS/T 89—1996 Determination of Fluoride in Urinlon Selective Electrode Method,evaluated by Manual of Endemic Fluorosis Control(1991). At least 5 water samples were collected randomly from five directions(east,west,north,south,center).The fluoride contents in urine and drinking water were determined with FSIE,in accordance with GB/T 5750--2006 Standard Examination Methods for Drinking Water,evaluated by GB 5749—2006 Standards for Drinking Water Quality.Results After changing water,morbidity rate of children dental fluorosis fell from 66.67%in 1998 to 31.79%in 2005 and the dental fluorosis index also fell form 1.49 to 0.65 of Wupo village,morbidity rate of children dental fluorosis fell from 33.15%in 1998 to 13.10%in 2005 and the dental fluorosis index also fell from 0.50 to 0.24 of Bayi village.The fluoride contents in urine of children and the fluoride contents in drinking water were maintained stability.Conclusion After water improvement,the fluorosis has been effectively controlled in a certain degree in the investigated area.