[feiying]

I was just curious if they use Aluminium to clear tap water in Britain as I have read they do that in Canada and Australia. I have also read numreous atricles about it being linked to alzheimer's and dementia. Is this true?
Also I dought it but would it be as harmful if you drank the tap water in coffee as it's boiled.
Fay

[shelanachium]

Sometimes aluminium salts plus alkali are used to precipitate aluminium hydroxide from water, as this bulky precipitate carries down with it many impurities and potentially toxic substances.

Aluminium compounds are only water soluble, and therefore likely to be absorbed by the body, if the pH  of the ingested water is very low (as [Al(H2O)6]3+) or very high (as [Al(OH)4(H2O)2]-). Water supplied to the water-mains, for drinking or washing, is at near-neutral pH so soluble and therefore absorbable aluminium is absent from it.

Aluminium is one of the commonest elements on Earth (7% or so of Earth's crust). Life has had 4 billion years to learn to handle it. Therefore life is likely to have evolved resistance to Al toxicity in all that time. That which did not would not have survived.

Those elements which are most toxic to life are mostly very rare ones like Thallium, Arsenic, Lead and Mercury which living matter has, before human intervention, not had to deal with in any quantity.

[feiying]

Ah I see that makes sense
but what about all the research linking aluminum with Alzheimer's and dementia, do you thing they are just jumping to conclusions?
Fay

[lutesium]

It might be true because excess Cu in the urine is the result of a condition called Wilson's Disease which manifests itself with liver function disorders and lesions in the brain. Yes its true we also have Cu in our bodies.


Lutesium...

[shelanachium]

There was a poisoning incident involving Al salts in a water-supply in England a few years back. It was not caused directly by the Al salts, however. What happened is that far too much was added, perhaps because someone misplaced a decimal point.

Al salts are acidic in solution, and if you add far too much, as happened in this case, the resulting water is highly acidic and can dissolve more toxic elements such as copper and lead from the pipes in the supply system. These are what caused the problems. (I'll leave you to look up the incident on the Net - try aluminium water-supply toxic incident England).

Many foods contain acids such as citric acid which can dissolve Al as chelate complexes when these foods are cooked in aluminium pans. However, chelate complexes by their very nature tend to be very stable, so the aluminium in them is likely to remain in the complexes, and be excreted from the body rather than absorbed.

The concern about Al being involved in dementia arises because the plaques that form in dementias have been shown to contain Al. This does not mean Al is the cause - it may simply be that these plaques tend to sequester what little Al is already present in the body.

I think there are risks far more worth worrying about (like those you take every time you drive or cross the road) than the very small ones posed by dietary aluminium.