Ever wondered where the expression 'Mad as a Hatter' came from? I did, and out of such a casual query opened the door to a discovery that I cannot ignore. Mad as a hatter was a reference to the mental disorders that occurred in hat makers caused by the mercury once used to process felt for hats. To be more specific, it is the exposure to mercury vapour that proves to be so hazardous. When inhaled, it is easily absorbed into the bloodstream causing toxic buildup in various organs.
Mercury, thankfully, is no longer used in hat making. But it is still widely used as a major component in silver amalgam fillings. Over 50% of the compound is mercury (which equals approximately one half gram per filing = as much mercury used in a thermometer, which is loads), the other metals being silver, tin and zinc. The thing is, every time you chew or brush your teeth, that amalgam filling starts smoking and releasing it's toxic vapour. It's the mercury that causes the problems, with a substantial body of evidence demonstrating the hazards of mercury poisoning affecting the endocrine, the central nervous system, the kidneys and the brain. High levels in pregnant women are attributed to a three-fold increase in sterility, still-births and miscarriages. When mercury enters the blood after leaking out of an amalgam filling, it remains there only for a few minutes. Henceforth it is locked into the cells of our body as we excrete far less than we absorb. This is called 'Retention Toxicity'. Once in our organs it can stay there for decades. As Dr Lars Freiberg, chief advisor to the World Health Organisation on mercury safety put it, "there is no safe level of mercury" (1)
Still not convinced? You can watch this gory but nevertheless informative Youtube video on smoking mercury fillings from the IAOMT.
Given this state of affairs, how is it that mercury is so prevalent? It transpires it was that old chestnut, market economics, that had won the day. Amalgam was a cheaper compound than gold for a dental fillings, and despite health reservations, in 1819 it was introduced into the UK, and later worldwide, dental repertoire - it was touted as the filling everybody could afford. But as we now know, this has come at great cost to humans and the environment. In business terms, the external costs have not been factored in.
Thus, it looked like mercury fillings are pretty much here to stay. But times they are a- changing. So concerned about the high levels of poisoning, amalgam fillings are now banned in Sweden and Denmark. Austria is phasing out mercury fillings, and in Switzerland and Japan the dental schools no longer teach amalgam use as the primary form of dental care. In 1991, Germany's Ministry of Health recommended that no further amalgam fillings be used for children, pregnant women or those with kidney disease. In 1993 this was extended to include all women, and the Health Ministry is now considering whether to ban it's use entirely. Now recognised as such a dangerous substance, that the EU is currently onto it's second reading of a Directive proposing a Mercury Exports Ban by 2010.
Here in the UK, you can have your mercury fillings removed - not a cheap option, but one that I intend doing. It's a delicate job that requires a qualified dentist. Your dentist can measure your levels of mercuy toxicity, as can a good kinesiologist (although remember, your reading will be higher if you have just been munching beforehand) Society for Mercury Free Dentistry adheres to a strict code of practise to ensure extraction is undertaken as safely as possible (see their list for qualified dentists). In London extraction and replacement of an amalgam filling with a porcelain one costs around £700-£800 per filling (enough to make you choke on your methylmercury tainted tuna filled sarnie). In Scotland, it's roughly half the price. If you have like me a few that need replacing, a short trip over the border may just be what the dentist ordered.
If you want to read more, have a look at the following books:
Stop the 21st Century Killing You, 2005 Dr Paula Baillie-Hamilton, Vermilion and Toxics A to Z, a Guide to Everyday Pollution Hazards, University of California Press.
Mercury Free Dentistry
See also: Summary of the United Nations Environment Programme on Mercury Assesment
EU policy tracker: EU proposed Directive on the Banning of Exports and the Safe Storage of Metallic Mercury
(1) Panorama, Poison in the Mouth, 1994
Posts
No comments:
Post a Comment