Laboratory Study On Systemic Fluoride Intake And Urine Fluoride Content Of Children In Kunming

Objective 1)To measure fluoride intake from drinking water, diet and urinary fluoride of children living in Kunming city covered with tap water.2)To study their living habits,assess fluoride concentration in the air,and estimate the total fluoride intakes. 3)To provide feasible basis for determining optimal and safe fluoride adding dosage in the drinking water fluoridation program in Kunming.Method 45 children born and grew up in Kunming were selected from east,west,south,north and middle bordered area using stratifided randomized sampling method.22 children were selected in 12-year-old group and 23 children were selected in 5-year-old group.24 hour urine samples were collected directly.Fluoride concentration in the urine was detected by the fluoride ion-selective electrode method. The" duplicate plate "method was used for the assessment of fluoride intake from solid and liquid foods and drinking water on three successive days.Drinking water volume was counted and food was weighed. Sensitive electrode method and ion chromatography method were used to determine the fluoride content in the food and water respectively.Living habits were investigated with using questionnaires. Standard atmospheric conditions were inquired and analysed.The total fluoride intakes were calculated.Result Urine fluoride concentration of the 12-year-old group was 0.395±0.185mg/L, fluoride intakes from food and water was 0.255±0.597mg/d and 0.065±0.075mg/d respectively,while that of the 5-year-old group was 0.179±0.047mg/L,0.383±0.452mg/d and 0.054±0.044mg/d,respectively.According to the questionnaires 64.4% children didn't use toothpaste with fluoride or use fluoridated toothpaste casually.Children didn't have special drinking habits and didn't have the history of using fluorides for caries prevention.The fluoride concentration in air was lower than the lower limit of detection. Total fluoride intakes of 12-year-old group and the 5-year-old group was 0.320±0.605 mg/person/day and 0.437±0.446 mg/person/day respectively.Conclusion Fluoride intakes from all resources including drinking water,diet and air among the children living in Kunming city covered by tap water were lower than that of the optimal level recommended by WHO,as well as urine fluoride content.According to the data obtained in the study and the previous epidemiological study,Kunming is an optimal area for implementing drinking water fluoridation program.