Fluoride concentrations in salt marketed in Managua, Nicaragua

Abstract Nicaraguan legislation has established that fluoride concentrations in salt should be 200-225 mg/kg, but no report describes fluoride concentrations in salt marketed in this country. We evaluated the fluoride concentrations in 33 packages of salt of 11 brands (n = 3 each) purchased in Managua, Nicaragua. According to the package information, 9 of the 11 brands were fluoridated. Six aliquots of each package were weighed (mean 2.5 ± 0.3 g; n = 198) and dissolved in 0.025 g/ml water. Duplicates of 1.0 ml of solutions prepared were buffered (1:1; v/v) with TISAB II. Fluoride concentrations were determined with ion-specific electrode, calibrated with standard solutions (0.25-16.0 μg F/ml) mixed (1:1; v/v) with TISAB II added to 0.025 g (p.a.) NaCl/ml. The mean (± standard deviation, n = 3) fluoride concentrations of two fluoridated brands were in accord with Nicaraguan law (209.8 ± 48.0 and 211.4 ± 26.0 mg F/kg), and those of five brands were below the mandated range (131.0 ± 34.3, 180.6 ± 12.3, 184.6 ± 34.8, 190 ± 47.2, and 199.0 ± 18.9 mg F/kg); two brands contained only traces of fluoride. The two non-fluoridated brands had traces of fluoride. The findings show that the surveillance system for the salt fluoridation program in Nicaragua should be improved, as most salt analyzed violated the requirements of the national legislation.

Fluoride concentration in Peruvian salts determined with specific electrode by the direct method

According to the Peruvian legislation, salt for human consumption should contain 200-250 mg F/kg, but there is limited data showing whether this requirement is being accomplished. Aim: In this pilot study, we evaluated the fluoride concentration in samples of salt marketed in Lima, Peru, using a standardized protocol with ion-specific electrode by direct method (ISE). Methods: Seven 1 kg salt packages of four brands were purchased in two supermarkets of Lima. Six aliquots of each package were weighed and dissolved in the proportion of 0.025 g/mL of water. Duplicates of 1.0 mL of these solutions were mixed with 1.0 mL of TISAB II and fluoride concentration was determined with ISE calibrated with standards fluoride solutions ranging from 0.25 to 16.0 µg F/mL. The ionic strength of the standards was adjusted with p.a NaCL (25 mg/mL). In addition, triplicates of 15 g of each salt package were fractionated in a set of sieves (0.590 to 0.177 mm) to determine the homogeneity of fluoride concentration in salt. Results: In four packages the mean fluoride (mean±SD,n=6) concentration (mg F/kg) was in agreement to the Peruvian regulation (214.5±10.4; 221.8±14.3; 226.9±19.1 and 237.2±52.0 mg F/kg), but in 3 packages it was lower (145.2±7.9; 145.7±23.3 and 158.4±20.6 mg F/kg). Variability in fluoride concentration was observed within the same brand and among brands. Also, the fluoride concentration was not homogeneous in none of the salt samples, ranging from 72.0 to 1449.7 mg F/kg. Conclusion: The findings suggest that the manufacturing and sanitary surveillance of fluoridated salt in Peru should be improved