Effects of household water filters on fluoride concentrations

从公共卫生的角度来看，自来水加氟是预防龋齿的一种极好的方法。日本现在也可以进行氟化处理（卫生、劳动和福利省，2000年），只要该地区的公民同意。日本民众对安全饮用水供应的兴趣日益浓厚，因此，在水龙头上安装滤水器的家庭数量有所增加。因此，在进行氟化处理时，有必要研究水通过过滤器后的氟(F)浓度。在本研究中，我们使用家用滤水器中常用的两种过滤材料制作了一种滤水器，并研究了过滤材料对F浓度的影响。采用活性炭过滤器和中空纤维过滤器构建了一种简单的水过滤装置，这两种过滤器在家庭水过滤系统中都被广泛使用。将NaF加入纯净水或自来水中，制备F浓度为0.1 ~ 10mg/mL的各种测试溶液。每个测试溶液在通常使用的压力下通过过滤系统，然后用F离子电极（直读法）测定过滤后的F浓度。用流动注射仪测定过滤后滤芯中的F浓度。过滤后的F浓度约为过滤前的1/10，直到过滤器体积为10L。随后，F浓度随着过滤体积的增加而增加。中空纤维过滤器过滤前后F浓度没有变化。实验结束后，活性炭过滤器中含有高浓度的F。结果清楚地表明，氟化处理后的自来水中的氟浓度受到使用活性炭过滤器的家用滤水器的影响。因此，为了保证水氟化的防龋齿效果，必须考虑使用的滤水器的类型。除氟离子（Cl、Mg、Ca）外，其他负离子和正离子均吸附在活性炭和中空纤维过滤器上。对于其他离子，没有得到明确的结果。少

The fluoridation of tap water is an excellent method from a public hygiene point of view for preventing dental caries. Fluoridation is now possible in Japan as well (Ministry of Health, Labour, and Welfare, 2000), provided the citizens in the area are in agreement. Interest in the supply of safe drinking water among Japanese citizens has increased, and as a result, there has been an increase in the number of households installing water filters on their taps. Therefore, when fluoridation is carried out, there is a need to study the concentrations of fluoride (F) after the water passes through the filter. In the present study, we have produced a water filter using 2 types of filter materials that are commonly used in household water filters and examined the effects of the filter materials on F concentrations.A simple water filtration device was constructed using activated charcoal filters and hollow fiber filters, both of which are widely employed as filters in household water filtration … More systems. NaF was added to purified water or tap water to prepare a variety of test solutions with F concentrations ranging from 0.1 to 10mg/mL. Each test solution was passed through the filtration system at a pressure normally used and then the F concentration after filtration was determined with an F ion electrode (direct reading method). The F concentration in the filter after filtration was measured using a flow-injection apparatus.The F concentration after filtration through the activated charcoal filter was approximately 1/10 that of before filtration for all test solutions up to a filter volume of 10L. Subsequent to this, the F concentration increased as the volume filtered increased. No change in the F concentration before and after filtration was observed for the hollow fiber filter. The activated charcoal filters contained high concentrations of F after completion of the experiments.The results clearly indicate that the F concentration in tap water after fluoridation is affected by household water filters that use activated charcoal filters. Therefore, the type of water filter used must be taken into consideration in order to ensure the anti-dental caries effect of water fluoridation. Negative and positive ions other than F (Cl, Mg, and Ca) were adsorbed to the activated charcoal and hollow fiber filters. Definitive results were not obtained for any other ions. Less