Tap Water Filtration and Purification Usage and Their Impact on Fluoride Concentration - A Community-Based Study

Abstract

Water filtration and purification systems (WFPS) are a rapidly growing market aimed at improving water quality by removing harmful chemicals and bacteria. However, there is limited research on how WFPS affect fluoride concentrations, which are critical for preventing dental caries, as well as other essential minerals like calcium, magnesium, potassium, and sodium, which are vital for overall health. Our first aim was to assess the prevalence of WFPS use among residents of Indianapolis, Indiana, through a distributed questionnaire. Water samples were collected from participants to analyze fluoride, calcium, magnesium, potassium, and sodium. For the second aim, we replicated this study in Jeddah, Saudi Arabia, to compare findings across different geographic and cultural contexts. In the third aim, we conducted a laboratory study to test nine popular water pitcher filter brands for their effects on fluoride and other essential minerals. The results of the first aim of the study revealed that 71% of participants used some type of WFPS, with water pitcher filters being the most commonly used (31%). Additionally, reverse osmosis systems significantly reduced all studied minerals, while water softeners increased sodium concentrations. For the second aim, 60% of participants reported using WFPS, with reverse osmosis systems being the most commonly selected (62%). The findings also indicated that unfiltered tap water samples had very low fluoride levels, and reverse osmosis systems effectively reduced all tested minerals. The third aim demonstrated that water pitcher filters did not completely remove fluoride but had varying effects on the other studied minerals. In conclusion, in both locations, WFPS were widely used, but the types of systems preferred, and the mineral content of public water supplies varied. Our study also highlighted the importance of understanding the effects of different WFPS on essential minerals, especially fluoride, which plays a key role in preventing dental caries. These findings emphasize the need for further research to understand how WFPS impact both water quality and health outcomes, particularly in regions with differing water supplies and public health practices.