Dr. Water

Dear D. Stockin,

You have raised one of the most controversial subjects concerning drinking water safety and health today. What has made this subject so controversial is the myriad interpretations offered through internet exchanges, blogs, tweets, etc.

The internet is replete with uniformed biased viewpoints on many environmental health topics, which arises from misinterpretation by a vast array of NGOs of the scientific literature.  The most egregious example of this is the citing of epidemiological studies that claim associations between fluoridation and certain supposedly harmful effects.  It must be kept in mind that even epidemiologists recognize that results from such studies are only correlations and not always supported by good exposure analysis.

Let’s start with the actual risks of water fluoridation.  The National Research Council (NRC) of the National Science Foundation concluded that only three adverse health effects should be considered in setting regulatory standards for high levels of fluoride in drinking water. These include: 1) severe enamel fluorosis from exposure to high levels of fluoride between birth to 8 years of age; 2) the potential risk for bone fractures in elderly people and; more severe forms of skeletal fluorosis after lifetime exposure. Severe skeletal fluorosis is a rare condition in the United States.  Water is fluoridated because it has been established as an effective barrier to dental caries or tooth decay in children. Dental cavities are a major public health concern in many industrialized countries. It affects between 60–90% of schoolchildren and a majority of adults.  Water fluoridation prevents cavities in both children and adults. The EPA regulates fluoride in drinking water at 4 mg/L (ppm) to prevent the harmful effects.  Enamel fluorosis is regarded as a cosmetic effect. Typically this occurs in children where fluoridation exceeds this 4 ppm guideline. In my opinion – if water contains fluoride at or above 2 ppm, the water does not require any fluoride supplementation.

With the array of products on the market today that contain fluoride, tooth paste, mouth washes, gels, etc., adults may not derive any benefit from water fluoridation. However, since 1950 the American Dental Association’s (ADA) position has remained that fluoridation of community water supplies is safe. According to the ADA this conclusion is based on an overwhelming weight of credible scientific evidence. This body of knowledge is that of internationally recognized scientists, whose findings are published in widely held peer-reviewed professional journals e.g., The Journal of the American Medical Association and the American Journal of Public Health.

The Centers for Disease Control (CDC) reviews the latest scientific literature on an ongoing basis and maintains an active national community water fluoridation quality assurance program. CDC promotes research on the topic of fluoride and its effect on the public’s health. CDC’s recommendation remains the same—that community water fluoridation is safe and effective for preventing tooth decay. Water fluoridation should be continued in communities currently fluoridating and extended to those without fluoridation. The CDC and the World Health Organization (WHO) have called fluoridation of community water one of the 10 great public health achievements of the 20th Century.
Some internet sites by activist groups argue that fluoridation causes cancer.  The overwhelming body of evidence refutes this. In closing – I have no qualms about fluoride supplementation of water where the fluoride is below 0,5 to 1.7 ppm up to a maximum concentration not to exceed 2 ppm.

You will be inundated with myriad opinions on the topic – my opinion is one based on numerous committee meetings with focus on this very issue. My advice is to read and rely only on reputable scientific literature in peer reviewed journals. Continue to monitor position  statements by the CDC, NRC, EPA, ADA, and the World Health Organization. Avoid the inflammatory jargon of activist groups who often use scare tactics.  

Best wishes,
"Dr. Water"

Dr. Water is Dr. Gary Winston, Director, National Center for Water Quality Research, Heidelberg University, Tiffin, OH. gwinston@heidelberg.edu

Do you have a question about drinking water? Where it comes from? How it is cleaned? Why does it smell like chlorine? How much do you need to drink every day? Or, where to find information about your drinking water? "Dear Dr. Water" can help you. Send your question to dr.water@ipwr.org. Selected inquiries will be answered in the next issue of Dr. Water .

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