Fluoride is TOXIC for your child - if they drink 90 litres of water/day

The fluoridation of municipal water supplies is a controversial topic that has been debated for many years. On one side are the opponents who argue that exposure to excess fluoride can lead to weakened bone structure, kidney toxicity and a condition called dental fluorosis, where the enamel of the teeth appears mottled and brown in colour. The proponents (of which I am one) argue that water fluoridation is the most cost effective and simple way to reduce the rate of cavities.

Please keep in mind that we are not talking about infants in this discussion. Infants represent a special portion of the population whose health needs differ due to their size and specialized physiology.

It is true that large amounts of ingested fluoride can have negative health effects and we've all seen the warning label on toothpaste that instructs us to call Poison Control if you ingest a large amount of toothpaste; however, toothpaste on average contains 1500 ppm (parts per million) of fluoride while drinking water at the maximum fluoridated level has 1 ppm of fluoride.

If the average 5 year-old child weighs 40 lbs and the maximum fluoride dose is 5mg/kg of body weight, this means your child would have to drink 90 litres of water in a short period of time (less than a day) to reach a toxic level (you would suffer the effects of water toxicity before fluoride toxicity in this situation). The fact that humans can suffer from water toxicity shows that a substance at low dose can be good for us but can be harmful at a higher dose.

Childhood Dental Decay

I practice dentistry in 2 areas that do not have water fluoridation and I can personally attest to the fact that the decay rates are surprisingly high. I have observed that there is often a negative correlation between decay rates in children and socioeconomic status (those with lower household incomes often have more cavities). As healthcare practitioners, we cannot completely control the diet and hygiene habits of our patients but the fluoridation of the municipal water supplies is a significant public health achievement that can help those who are most severely affected by cavities.