Monitoring the fluoride ions concentration in water for human consumption from a municipality with different public water supply systems

This study aimed at evaluating the concentrations of fluoride ions in water samples for human consumption in a city with different public supply systems. A total of 139 samples collected at the entry point of the buildings in the period from 2003 to 2007 were analyzed for determining fluoride ions concentrations using selective combined electrode for fluoride. Concentrations in compliance with the State standard criteria (0.6 to 0.8 mg/L) were detected in 87 (62.6%) samples, and the proportions of compliant results increased from 46.9% to 71.9% during this study period. Considerable variations in these proportions, as well as in the minimum and maximum concentrations were found in both samples from the same system and from different systems of water supply. These findings indicate the need for developing the sampling plans for each system or even another strategy for monitoring the water fluoridation in cities with different public systems of water supply for human consumption.