Friday, 1 March 2013

Fluoride in Your Water?

The issue of water fluoridation comes up from time to time, and I’ve been figuring for a while that I should know more about this issue, so I did a little digging. Here’s what I’ve found:

In New Zealand, a little over 60% of our country’s drinking water has fluoride added to it[i]. Here in the Wellington Region where I live, only Petone and the suburb of Korokoro have fluoride-free water.  According to the Greater Wellington Regional Council, fluoride is added to the rest of the region’s drinking water to bring it up to a level between 0.7 and 1.0 parts per million (ppm), at a cost of $195,000 annually[ii]. The 0.7-1.0 ppm figure is based on the Ministry of Health’s recommendation,[iii] a level they consider optimum for dental health. In the U.S., the recommended level is 0.7 ppm[iv].

Fluoride is an industrial chemical. The most common form to be added to drinking water is Fluorosilicic acid[v], a liquid by-product of the fertilizer industry. In Wellington they use sodium fluorosilicate[vi] which, being a powder, is easier to ship. Fluoride occurs naturally in some water supplies, especially in volcanic and hydrothermal areas[vii].  

Fluoride was first added to a municipal water supply in 1945 when Grand Rapids, Michigan (USA) became the first city in the world to have artificially fluoridated water. This followed an earlier dental discovery that teeth discoloured by unusually high natural levels of fluoride in some local water sources were also unusually resistant to decay. Further research suggested that if fluoride was added to pure water, and levels were maximized at around 1.0 ppm, the tooth staining (flurosis) caused by the fluoride would be minimal and white (rather than brown), and teeth might be more decay-resistant[viii]. By 1960, many cities in the U.S. had introduced fluoridated water.

Other than its [assumed] advantage for dental health—more on that shortly—fluoride is not advocated for any other health benefit. In fact, concern has been raised in recent years about the health RISKS of excess fluoride consumption. The US EPA (Environmental Protection Agency) sets a maximum safety level of 4 ppm[ix], which is twice what their senior scientist recommended (see the documentary Fluoridegate). The World Health Organisation (WHO) recommends a maximum of 1.5 ppm[x]

Excessive consumption—and it is cumulative in the body over time—can lead to an increased likelihood of bone fractures and bone pain, and in children can caused pitted teeth and cosmetic tooth damage[xi]. Although there have been attempts to establish whether or not drinking fluoridated water increases the risk of cancer, examination of population records has proven inconclusive. Rats, however, showed increased risk of bone and liver cancers when given only fluoridated water to drink (see Fluoridegate). Fluoride, when combined with aluminium, may be a risk factor in the development of Alzheimer's (see here); aluminium is sometimes added to drinking water at the same time as fluoride, or can leech out of cookware. And in a recent meta analysis of several studies, fluoride exposure was linked to lowered intelligence levels in children[xii].

One concern is that we get fluoride from other sources besides our tap water, and we cannot  as individuals easily monitor the amount of fluoride we are consuming. Most of us brush with fluoride toothpaste, and if you read the back of the toothpaste tube it will say in bold print something like: Do not swallow. Rinse well after brushing. Fluoride is, after all, poisonous. But how much lingers and gets swallowed with your saliva? Many mouthwashes also have fluoride. So do many soft drinks, sports drinks, wines, and juices. Tea leaves concentrate any fluoride that was in the soil, and if you make tea with fluoridated water you’re getting a double dose. Some pesticides that may have been used while your food was growing contain fluoride. Some drugs are fluorinated. If your water is fluoridated, and you drink more of it in the summer when it’s hot, you’re getting more fluoride than you might do if the weather is cooler and you drink less. So it’s hard to measure. One caution: if you are using infant formula, be sure to NOT use fluoridated tap water to mix baby’s formula as the amount of fluoride your baby is likely to consume will exceed safe levels[xiii].

Lastly, I’d like to come back to the central issue: does fluoridated water actually decrease tooth decay? If it does, then countries with a high percentage of water fluoridation should have lower levels of tooth decay than countries that don't put fluoride in their water. Yet of the top seven countries[xiv] with the lowest tooth decay rates, only England fluoridates some of its water (around 11%) according to the WHO. Meanwhile, New Zealand is one of just 11 countries worldwide where over half the population drinks fluoridated water. The other “50%+ fluoridated” countries are the U.S., Australia, Chile, Brunei, Guyana, Hong Kong, Malaysia, Singapore, Israel, and Ireland[xv]. In Europe, where tooth decay rates are low, only 3% of the population drink fluoridated water[xvii].  Surprisingly, the WHO has recorded a general drop in decay levels over time in all countries completely irrespective of water fluoridation.

Which begs the question...if fluoride is a toxic chemical, and fluoridation doesn’t make any difference to rates of tooth decay, but it does cause dental fluorosis; it may increase the risk of developing bone damage, cancer, and Alzheimer's; it appears to impair children’s intelligence; AND it costs the taxpayers money to add it to our water...why in the world are we letting this stuff be put in our water supply?

[iii] Ibid.
[xiv] These countries are Denmark, Germany, England, Netherlands, Switzerland, Belgium, and Sweden.
[xvi] Ibid.
[xvii] Ibid.

1 comment:

  1. Thanks to Ray Foxley who emailed me this link to a just published (February 2013) report comparing people's health in Ireland (more than 50% of drinking water fluoridated) with Northern Ireland and the rest of Europe (no fluoridation). It makes for sobering reading.


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