ABSTRACT
Objective To find out the status of drinking-water-borne endemic fluorosis and the effect of preventive measures in Hebei Province,so as to provide a basis to prevent and cure fluorosis.Methods One affected county (city,district) with drinking-water-borne endemic fluorosis was sampled in every city and 10 water improvement projects were investigated in that county.Three villages were taken out in every county.The operating state of the projects,the water fluoride content,and the dental fluorosis of children aged 8-12 and skeletal fluorosis of adults were investigated in these villages.Results A total of 93 projects were investigated,among which 94.6％(88/93) were operating properly and the qualified rate(fluoride content ≤ 1.2 mg/L) of the projects was 54.84％(51/93).Among the 9 large projects,the water fluoride content of 7 projects exceeded 1.2 mg/L.A total of 23 villages with water improvement projects were investigated and only 43.4％ (10/23) of them water fluoride content were lower than 1.2 mg/L.The dental fluorosis rate,the dental fluorosis index and the rate of skeletal fluorosis were 33.2％ (532/1601),0.74 and 5.7％ (66/1155),respectively.In the 7 villages without water improvement projects,2 of them exceeded 2.0 mg/L,but lower than and equal to 4.0 mg/L of water fluorosis and 5 of them were normal(＜ 1.2 mg/L).The dental fluorosis rate,the dental fluorosis index and the rate of skeletal fluorosis were 33.4％ (111/332),0.72 and 2.9％ (10/350),respectively.Conclutions The qualified rate of water improvement projects of fluoride content ≤ 1.2 mg/L is low and the endemic fluorosis is still comparatively serious in Hebei Province.The progress of water improvement projects in the areas with endemic fluorosis should be accelerated and the quality of water improvement projects should be increased.
ABSTRACT
Objective To understand the status of drinking-water-borne endemic fluorosis and the effect of preventive measure in Hebei province, so as to provide a basis to prevent and cure the disease. Methods Thirtyeight affected counties(cities, districts) with drinking-water-borne endemic fluorosis were sampled by random sampling in Hebei in 2009. All affected villages in every county were divided into mild, moderate and severe endemic fluorosis areas and a village was randomly selected from each category of the area to carry out the monitoring of endemic fluorosis. Dental fluorosis of children aged 8 - 12 were examined and 6 copies of urine samples were randomly collected in each age group in the above-mentioned villages. Clinical skeletal fluorosis was diagnosed among adults aged 16 and over and 20 copies of urine samples were tested for fluorosis in every village.Results A total of 112 affected villages were investigated, among which the drinking water quality of 66 villages were improved and 46 villages were not improved. A total of 236 copies of water samples from the 66 villages were measured and the fluoride content ranged from 0.1 to 4.3 mg/L, among which 20 copies of water samples exceeded the fluorine standard of 1.2 mg/L, accounting for 33.3%. A total of 230 copies of water samples were collected in the 46 villages and the fluoride content ranged from 0.2 to 4.6 mg/L, among which 76.1% (35/46) of the water samples exceeded the fluorine standard of 1.2 mg/L. A total of 5169 children aged 8 - 12 were examined of dental fluorosis, the dental fluorosis rate was 36.43%(1883/5169) and the dental fluorosis index was 0.81. A sum of 71 497 adults aged over 16 years were examined, and the rate of skeletal fluorosis was 4.81%(3438/71 497), moderate or severe clinical detection rate of skeletal fluorosis was 1.56%( 1114/71 497). A total of 2876 copies of children urine samples and 2021 copies of adult urine samples were tested and the geometric mean of fluoride content was 2.30,3.32 mg/L, respectively. Conclusions The prevalence of dental fluorosis of children in the areas with improved water is less than 30% and the rate of dental fluorosis and skeletal fluorosis decline gradually with time.The rate of dental fluorosis and skeletal fluorosis increases with the increase of water fluoride in the water quality not improved areas. The endemic fluorosis is still comparatively serious in Hebei. The progress of improving water quality in the areas with endemic fluorosis should be accelerated and the acceptability of improved water should be enhanced.