Fluoride Levels in Urine and Tap Water in Canada: Data from the Canadian Health Measures Survey 2012-2015 and Interpretation in a Risk-Based Context

摘要

Fluoride is recognized as beneficial to dental health because of its ability to prevent tooth decay. However, excessive fluoride intake may cause dental fluorosis, and at much higher levels skeletal fluorosis and other adverse health effects. For many years, water fluoridation has been introduced in various Canadian communities and around the world as a public health measure to prevent dental decay. Besides tap water, Canadians are exposed to fluoride through food, beverages, and fluoridated dental products. In order to track fluoride exposure in Canada, fluoride levels in urine and tap water of Canadians have been monitored in the Canadian Health Measures Survey (CHMS) in 2012-2015. Using CHMS data and municipal fluoridation information, this study examined fluoride levels in urine and tap water of the Canadian population and potential associations between urinary fluoride levels and various exposure factors. It also aimed at interpreting the urinary fluoride levels in a risk-based context using biomonitoring equivalent (BE) values. Analysis showed that urinary fluoride levels varied by age and sex. Children aged 3-5 years had the highest urinary fluoride levels while the 11-19-year-old had the lowest concentrations. Females had higher urinary fluoride levels than males. The vast majority of Canadians had tap water fluoride levels lower than Health Canada's maximum acceptable concentration. The results also showed that the majority of the population had urinary fluoride levels below the BE values, suggesting that exposure levels in Canadians are generally below the recommended adequate intake levels for fluoride for the prevention of dental caries. This study presents the first nationally representative dataset on fluoride, which will be helpful to inform future risk assessment and management of this chemical in Canada.