What is the ideal concentration of fluoride that is artificially added to water supplies as a public health measure, in parts per million (ppm)?

The ideal concentration of fluoride that is commonly added to water supplies as a public health measure is 1 part per million (ppm). This concentration has been established based on extensive research indicating that it effectively reduces the incidence of dental caries (cavities) while minimizing the risk of dental fluorosis, a condition caused by excessive fluoride exposure during tooth development.

At 1 ppm, fluoride helps strengthen tooth enamel, making it more resistant to acid attacks from bacteria and dietary sugars. This optimal level strikes a balance between providing dental health benefits and avoiding adverse effects associated with higher concentrations.

In contrast, lower concentrations, such as 0.1 ppm, would not provide sufficient benefits in preventing tooth decay, while much higher concentrations, like 10 ppm or 100 ppm, significantly increase the risk of negative health effects, including dental and skeletal fluorosis. Therefore, the choice of 1 ppm represents a well-researched, effective public health practice aimed at improving community dental health.