Naked Science Forum
Life Sciences => Physiology & Medicine => Topic started by: deepthinker on 12/01/2007 22:28:13
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Hi
We have been investigating water filters but the subject seems a potential minefield. Can anyone help clarify the situation for me?
Many people (mainly the ones selling the units!) suggest reverse osmosis units are best.
However, there seems to be some scientific evidence suggesting that drinking demineralised water from reverse osmosis filters could be bad:
http://www.who.int/water_sanitation_health/dwq/nutrientschap12.pdf
http://www.lenntech.com/demi-water-FAQ.htm
Some of my confusion is over terms, some people say deminerilized, purified, distilled is all the same, others seem to say they are different and for example have different ph levels.
Can anyone shed any light on the subject?
Many thanks
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I don't know about water filters, but I can tell you the following. I grew up in Cumbria, where the water is clean; it has not passed through porous rock and been mineralised, and it does not taste of anything. I remember my school science teacher telling me that hard water can cause kidney stones, so our water was much healthier. Now, I live in Huntingdon (16 miles from the Naked Scientists in Cambridge!) and the water here is really hard- I think of it as liquid chalk, and it tastes awful. There are things I like about living here, but not the water!
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Purified water doesn't taste of anything. If you have lead pipes it will take up lead and carry it to the body. If there are not adequate sources of minerals in the rest of your diet then hard water might (just) be a useful source of them.
Otherwise I don't see how it could make any difference.
Any of the techniques and be used to remove most of the minerals from water. The details vary but the overall effect is the same.
I have drunk high purity wster in the past and I would definitley choose to do the same again if the alternative were water of which I had any doubts about the safety or purity.
When it comes down to it, people are "designed" to drink rain water and that's pretty near pure water.
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It depends upon the process because it's detect when the water is dirty.
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When rainwater is filtered it leaves a nice feeling inside and no after taste in the mouth. Coffee and tea taste much better using filtered rainwater, probably makes it more effective in taking up the minerals from the tea and coffee to some degree, but whatever the reason is 10 out of ten dogs and cats prefer it to tap water :)
Purified water doesn't taste of anything. If you have lead pipes it will take up lead and carry it to the body. If there are not adequate sources of minerals in the rest of your diet then hard water might (just) be a useful source of them.
Otherwise I don't see how it could make any difference.
Any of the techniques and be used to remove most of the minerals from water. The details vary but the overall effect is the same.
I have drunk high purity wster in the past and I would definitley choose to do the same again if the alternative were water of which I had any doubts about the safety or purity.
When it comes down to it, people are "designed" to drink rain water and that's pretty near pure water.
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Andrew is quite right, dogs, cats and other animals do prefer to drink rainwater to tap water.
Rainwater preferred by animals probably contains a fairly low level of minerals, but a high level of dissolved air, but then those animals do still seem to prefer 'dirty' water which, after lying in puddles for while, may contain a fairly high level of minerals dissolved from the ground.
I put this down, mainly, to the chlorine in tap water. Fish should not be put into water straight from the tap. The reason being, the chlorine can strip the protective mucus from the gills, causing irritation and can kill the fish. It's the same for my tortoises, their water must be boiled to evaporate off the chlorine, or the mucus in their mouth will be stripped away.
Tap water probably has a similar effect on other animals, even humans. I find drinking tap water can leave my mouth feeling dry because it does seem to strip away the saliva. While any drink will wash away saliva, chlorinated water does seem to do a better job of it, leaving the mouth feeling dry for longer than with any chlorine free water.
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Aha! So thats why I often feel thirstier after having a drink than before! Sometimes the chlorine is so strong in our tap water that we can smell it. If we leave water in the kettle for any length of time it becomes concentrated, and tastes disgusting even after boiling. The same goes for the pipes - we have to run the water for a while if we've been away for a few days to get rid of the water that has been standing.
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Is there not a risk to young children of reduced levels of fluoride, and hence poorer teeth if they don't drink tap water?
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I don't think all the UK's water supplies are fluoridated yet anyway. See this BBC article from Feb. 09 http://news.bbc.co.uk/1/hi/england/hampshire/7911820.stm (http://news.bbc.co.uk/1/hi/england/hampshire/7911820.stm).
There are still some who question the value of fluoridation.
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There are still some who question the value of fluoridation.
Certainly - there are also those that question the validity of vaccinations - that doesn't mean to say that their arguments are valid, and are more likely to be based on bad science. I had a look at one of the partner websites who were against fluoridation (Hampshire based) and it was just knee-jerk reactionary rhetoric unsupported by evidence. It merely stated that fluoride was a poison, which is hardly an argument.
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Quite so, nobody actually gives any good reason for their objections.
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flourosis?
http://www.fluoridealert.org/dental-fluorosis.htm
Quite so, nobody actually gives any good reason for their objections.
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There's no question that too much fluoride is bad for you. So is too much water.
If you use this as the basis to ban fluoridation then logically you need to ban water too.
It's not a valid argument, so, even with the correct spelling, fluorosis isn't a good reason for objection.
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As rat poison it's quite useful, pouring it into the water supply and getting paid for it instead of trying to find a safe disposal site for this toxic waste makes economical sense I suppose,
But ask yourself, if a little too much fluoride can do this to teeth, then just maybe "the correct dose" might be very capable of damaging the soft tissue and bones. Add to this the effects from chlorine which are known to putrefy milk, and milk being the very first food we encounter, one begins to engage the thoughts that there might be something bad in our water supply.
Reverse osmosis, and ultraviolet radiation are much safer and oddly enough resemble what goes on in the atmosphere in nature.
I always spell flouride wrong :)
And maybe I am unwilling to accept the security of trusting and drinking from a company who tipped aluminium sulphate into the drinking water of Cornwall and poisoned a whole community. Maybe my choice of drinking habits, but I will choose to drink rainwater over the stinking tap water any day.
Chemtrails, Aluminum Powder
And A Mass Aluminum
Poisoning In The UK
http://www.rense.com/general12/alum.htm
http://www.dailymail.co.uk/news/article-502442/A-lethal-cover-Britains-worst-water-poisoning-scandal.html
There's no question that too much fluoride is bad for you. So is too much water.
If you use this as the basis to ban fluoridation then logically you need to ban water too.
It's not a valid argument, so, even with the correct spelling, fluorosis isn't a good reason for objection.
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"But ask yourself, if a little too much fluoride can do this to teeth, then just maybe "the correct dose" might be very capable of damaging the soft tissue and bones."
OK, I will ask.
First, it's not a little excess fluoride that does that to teeth, its quite a large excess.
Secondly plenty of people (my aunt is one of them) have fluorosis, but no other health problems related to (in that case considerable) excess fluoride.
So we know that as an experimentally observed fact, a small or moderate amount of excess fuoride just leads to mottled teeth.
Also we know why- it's because the fluoride is concentrated in the teeth.
Since it isn't concentrated in the soft tissues it isn't generally going to cause a problem there.
Since the amount aded to the water by the water companies is closely controled, it won't even give rise to fluorosis.
Also you really ought to know better than to raise the Camelford incident in this thread.
A lorry driver made a mistake so, rather than blaming the trucking company or the individual who made the mistake, you blame the people to whom the delivery was made.
That's odd- they were, after all, the first victims of the error.
Presumably you are now going to tell me that it could happen again with the tanker truck full of fluoride.
Nice try; they don't actually use fluoride any more in most cases.
They use sodium fluorophosphate which is much less toxic. (LD 50 in rats about 0.1% compared to fluoride LD 50 aboput 50ppm)
While I'm at it; "to this the effects from chlorine which are known to putrefy milk,".
Known by whom? Do you actually have a valid set of evidence for that? If you do is it relevant; last time I tried nobody was chlorinating milk but, on the other hand, Milton (based on hypochlorite) has been used for sterilising bay's bottles for ages.
Feel freee to drink rain water if you like (though you ought to consider what bird droppings will add to the stuff), but don't pretend that the supply of cheap clean water which is widely recognised as one of the cornerstones of our society, is a bad thing.
While you ae at it, perhaps you should have a look at what this bloke
http://en.wikipedia.org/wiki/Paracelsus
said many years ago.
"Paracelsus, sometimes called the father of toxicology, wrote:
German: Alle Ding sind Gift, und nichts ohn Gift; allein die Dosis macht, daß ein Ding kein Gift ist.
"All things are poison and nothing is without poison, only the dose permits something not to be poisonous."
That is to say, substances often considered toxic can be benign or beneficial in small doses, and conversely an ordinarily benign substance can be deadly if over-consumed. Even water can be deadly if overconsumed.
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There is a problem with fluoride!
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Which part of "they don't use fluoride" don't you understand?