Fluoridation Of Water: Finding The Right Balance For Dental Health
After removing fluoride from drinking water, Canada has seen a rise in cavities in children, and it is now deciding whether or not to re-introduce fluoride to its water system. Fluoride is added to water in around 24 countries worldwide for the purposes of protecting teeth against cavities, but the practice is often a subject of debate due to concern over its safety, and because it is added without common consent. In other areas of the world, water is contaminated by too much fluoride, either naturally occurring or as a result of anthropogenic pollution. In these places, it can cause devastating dental and other health problems.
The Effects Of Fluoride On Human Health
Adding fluoride to drinking water, combined with accessible dental and orthodontic treatments, has resulted in improved oral health in the USA and other developed countries. Low levels of fluoride can reduce cavities in the general population, especially in children, and the US Department of Health and Human Services now recommends adding 0.7 milligrams of fluoride to each litre of water. This is to prevent tooth decay and the further damage, such as gum disease and infection of the jaw, to which it can lead. At the same time, in areas of the world where fluoride infiltrates water systems in large quantities, it can cause serious dental and skeletal problems, damage to the kidneys and even cancer. Consumption of water with fluoride concentration above 1.5 milligrams per litre can lead to dental fluorosis. In mild cases, the teeth become discoloured or stained but, in more extreme cases, teeth can be physically damaged.
How Is Water Contaminated With Fluoride?
Fluoride is a compound derived from the element fluorine, which is found commonly in rocks. Weathering of these rocks raises concentrations of fluoride in water. Fluoride is also released into the atmosphere from volcanic eruptions from where it goes on to contaminate land and water. High concentrations can also be released through anthropogenic pollution, usually from the use of fertilisers or combustion of coal. This is a particular problem in China, where coals rich in fluoride are burnt in large amounts, mainly by industry, but also in homes in rural areas. Here, the prevalence of dental fluorosis is severe.
How Can Excess Levels Be Treated?
Fluoride contamination is also high in India, where using natural ‘green technology’ in the form of aquatic plants has been shown to be relatively effective in removing fluoride from water. In Estonia, where the amount of naturally occurring fluoride can reach as high as 7 milligrams per litre of water, some success in lowering levels was achieved through the efforts of public water suppliers. They used the method of reverse osmosis to take fluoride out of the water supply, as well as simply discovering new, less contaminated water sources to use for public consumption.
In small amounts, fluoride can undoubtedly be beneficial to dental health but, at very high levels, it becomes toxic. As fluoride is a natural element, it is impossible to completely remove the risk it poses in high levels. However, the development and implementation of technologies for reducing the impact of excessive fluoride levels is now showing positive results across the globe.