For the past few years I’ve heard a lot about “nasty chemicals,” especially when people discuss their city water. Municipality water in the US is treated in a multitude of ways, one of them being with chemical treatment. It’s common to add chlorine to kill dangerous microbes, or calcium to soften water. I wanted to briefly discuss the commonly stated pros and cons of the major chemical treatments, so that we all know what these things do and how we can be in control of the water we drink. In this blog post, I’ll focus on fluoride, one of the most common chemical treatments of public drinking water. Back in the 1940s, municipalities began adding fluoride to the water to prevent dental disease in their citizens.1 Fluoride is known to prevent bacteria from growing and producing acid that destroys tooth enamel and creates entrances to the tooth pulp to the cavity-causing bacteria.2 Bacterial acid causes minerals on teeth to be lost, allowing bacteria an entrance into soft tissues. By increasing mineralization on teeth, fluoride prevents bacteria from entering these soft tissues and causing infections in the tooth and throughout the body. However, since public water fluoridation began, critics have fought against this treatment.1
Health benefits: The ADA lists the tooth decay prevention as a major reason to fluoridate public drinking water.3 Untreated dental disease can worse, causing infections that affect the jaw and digestive system. It is predicted that for every $1 spent on fluoridation, $38 is saved on dental treatment.2
Dental disease can affect the entire body.4 Inflammation and infection can spread past teeth and affect our gastrointestinal and immune systems. Preventing this at the dental stage is important. Because some either cannot afford dental care or choose not to take advantage of it, fluoridating public water gives some fluoride treatment to everyone using that water.
Consent Violation: One criticism against fluoridation is that it is with or without the consent of the person consuming the water.5 This is criticized both as a violation of the rights of a citizen to choose what they will consume and as a potential hazard to those with kidney disease. For those suffering from kidney disease, being careful with what they consume is essential. Excess minerals and ions need to be filtered by the kidneys. If a person’s kidneys are damaged or susceptible to damage, fluoride in drinking water could be a problem. Acceptable fluoride levels for a healthy individual could overwork failing or unhealthy kidneys.
Health risks: Recent studies are more critical than early studies of fluoride’s negative affects to health. In 2006 the National Research Council (NRC) published a two-year review of the EPA standards for water fluoridation.6 While the EPA has a set limit of 4 milligrams/liter fluoride in drinking water, the NRC recommended lowering this to offset observed health risks in children and adults. The review cites the prevalence of enamel fluorosis (discoloration and disfigurement of teeth that can become permanent) in children exposed to 4 mg/L concentrations of fluoride. Below 2 mg/ L concentrations, dental fluorosis becomes rare. In adults exposed to 4 mg/ L fluoride concentrations, bone fracture risk increased, and there was a possible increased risk of skeletal fluorosis. Because fluoride can mineralize onto bone, the bone density can increase, resulting in bone growths (oseteophytes) on bones and joints, causing pain and joint stiffness. Also evaluating studies that looked at fluoride’s effect on bone strength, the review found that fluoride causes bones to weaken and be more fracture prone.
Because fluoride is now prevalent in toothpaste, food, and drinks, the fluoride levels we consume may be higher than what the EPA allows in drinking water. When water fluoridation began, these fluoride sources may not have been available, but in time their increased availability combined with water fluoridation may contribute to “too much” fluoride.
- Fagin, D. Second Thoughts about Fluoride. Scientific American. 2008. 298 (1). http://www.waterloowatch.com/Index_files/Second%20Thoughts%20About%20Fluoride,%20Scientific%20American%20Jan-08.pdf
- White, J.; Guenter, P.; Jensen, G.; Malone, A.; Schofield, M.; Academy of Nutrition and Dietetics Malnutrition Work Group; A.S.P.E.N. Malnutrition Task Force, A.S.P.E.N. Board of Directors. Consensus statement of the Academy of Nutrition and Dietetics/ American Society for Parenteral and Enteral Nutrition: characteristics recommended for the identification and documentation of adult malnutrition (undernutrition). J Acad Nutr Diet. 2012. 112 (5). https://www.ncbi.nlm.nih.gov/pubmed/22709779
- Fluoridation Facts. http://www.ada.org/~/media/ADA/Member%20Center/FIles/fluoridation_facts.ashx (accessed 19 April 2017).
- Mayo Clinic Staff. Oral health: A window to your overall health. http://www.mayoclinic.org/healthy-lifestyle/adult-health/in-depth/dental/art-20047475. (accessed 19 April 2017).
- Main, D.; Facts About Fluoridation. LiveScience. 30 April 2015. http://www.livescience.com/37123-fluoridation.html (accessed 19 April 2017).
- National Academy of Sciences. Fluoride in drinking water: A scientific review of EPA’s standards. 2006, http://www.actionpa.org/fluoride/nrc/NRC-2006.pdf.