An Overview of Drinking Water Fluoridation

Despite a long history of dental health benefits, the fluoridation of community drinking water remains a topic of concern for many customers. Given this apprehension, water operators must be able to explain the societal impacts and history of water fluoridation to alleviate concerns. 

Fluoridating drinking water first began in 1945 in Grand Rapids, Michigan. The new practice resulted in a clear reduction in cavities and tooth decay, one of the most prevalent chronic diseases experienced during childhood to this day. As of 2014 about 74% of consumers under a community public water system received fluoridated water. According to the Center for Disease Control (CDC), school children in communities without fluoridation have 25% more tooth decay compared to children in treated communities. These cavities can cause a variety of issues related to pain, diet, sleep, physical health, and mental health.

With cost efficiency community fluoridation overcomes disparities in oral health regardless of community size, age, education, or income level. A dental health study found that the savings from fluoridation in communities of 1,000 people or more exceeded program costs by $20 per every dollar invested. When Juneau, Alaska voted to end fluoridation in 2007, a study found that children six years and under had an increase of one dental cavity per year, roughly equivalent to $300 in dental costs per child annually. Juneau’s increase in cavities was also reflected in adults.

All water contains some levels of naturally-occurring fluoride though these levels are often too low for health benefits. In untreated water, fluoride levels vary considerably with geology and land practices. Fluoride is introduced to water when dissolved from the Earth’s crust into groundwater or discharged from fertilizer and aluminum factories. Systems with fluoridation should set final levels near 0.7 mg/L as suggested by the Department of Public Health. This concentration factors for other sources of consumer fluoride exposure such as toothpaste. Fluorosilicic acid (FSA) is most commonly used in water treatment. Though fluoridation decisions are left to a state or local municipality, the EPA has established federal standards for the upper limits allowed in drinking water.

At high levels fluoride can cause the development of bone disease and tooth mottling. As a result, the EPA has set both the Maximum Contaminant Level Goal (MCLG) and the MCL for fluoride at 4 mg/L. Levels higher than 4 mg/L can lead to increased rates of bone fracture, Enamel Fluorosis, and Skeletal Fluorosis. If systems find fluoride concentrations higher than the MCL, they are required to notify customers within 30 days and potentially install treatment methods such as distillation or reverse osmosis to remove the excess fluoride. 

The EPA has also set a secondary standard for fluoride at 2.0 mg/L. The secondary standard is intended to be used as a guideline for an upper bound level in areas with high levels of naturally occurring fluoride. Below this level, the chance for tooth mottling and more severe health impacts are close to zero. Even if the secondary standard is reached, systems must notify customers. In the U.S. very few systems have exceeded the fluoride MCL at all. Where violations have occurred, the concentrations are generally a result of natural, geological conditions. 

Even with this track record, some concerned customers are still weary of fluoridation. When customers broach fluoridation concerns, operators can offer educational materials and refer customers to consumer confidence reports. The CDC and the EPA offers a variety of consumer-friendly educational material that operators can reference in addition to the resources linked in this blog post. Remember that good customer service starts by establishing a trusted relationship with your community.