Urinary fluoride excretion in children aged 3 to 5 years exposed to fluoridated salt at 60 to 90 mgF/Kg in two Venezuelan cities. A pilot study.

The aim of the present work was to obtain information on the total urinary fluoride concentration and excretion of Venezuelan children at the age of 3 to 5 years, as part of a program to monitor fluoride ingestion. A 24 hour urine sample was collected from each of 63 children, between 3 and 5 years of age and analyzed for (i) total urinary volume (ml), (ii) urinary flow rate (ml/h), (iii) fluoride concentration (ppm) and (iv)fluoride excretion rate (microg/h). The group comprised 32 boys and 31 girls who resided in two different communities, 32 in Caracas, DC and 31 in San Juan de los Morros, Guarico state. Fluoride analyses were done with an ion-specific electrode. Age and gender did not affect total urine volume, urinary flow rate, or urinary fluoride concentration and excretion rate. The children from San Juan de los Morros had a significantly higher total urinary volume (426.45 +/- 36.31 ml) and flow rate (17.09 +/- 1.57ml/h) than children from Caracas (297.06 +/- 23.59 ml and 12.40 +/- 0.98, respectively) (p=0.0039). Significant differences were also observed when the urinary fluoride excretion rate of the two communities was compared. Mean urinary fluoride concentrations did not differ significantly (p < 0.05) between the two communities. These values were 0.67 +/- 0.40, 0.57 +/- 0.34, 0.76 +/- 0.27 ppmF in the 3, 4 and 5 year-old children of Caracas and 0.69 +/- 0.33, 0.65 +/- 0.20, 0.63 +/- 0.36 mgF in San Juan de los Morros children. The results showed low urinary fluoride concentration and excretion, indicating that children residing in the evaluated communities are receiving fluoride below the recommended optimal range.