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Re: [at-l] water bottles

Hi Peter,

At 08:22 PM 11/24/97 PST, you wrote:
>It's been 5 days since my hike and I don't have giardia, so the iodine
>must have worked.

Or the water wasn't contaminated, or you're one of the many people who are
resistant to the bugs or who don't show symptoms.

Here is some information from


that you might be interested in:

 --Methods of Purification
	The oldest (and cheapest) method of purifying water is to boil it. 
Boiling for five minutes will kill any biological hazards you could expect
to find.  Most pathogens are actually long dead by the time the water
boils, but the five minute boil will g et them all (remember to add 1
minute to this time for each 1,000 feet above 10,000 feet).  Boiling will
NOT neutralize chemical pollutants. 
	Chemical purification involves the use of iodine or chlorine to
kill the nasties in the water.  This method is lightweight and relatively
inexpensive, but will not neutralize chemical toxins.  In addition, you
must make sure that water at 25 deg. C (7 5deg. F) sits for 20-30 minutes
with iodine in it for purification to take place.  If the water is colder
(as it usually is), you will need to let it sit longer - possibly
overnight for cold stream water.  Warm the water against your body or even
on y our stove if you want it to be purified faster.  Once the appropriate
time has elapsed, the "band-aid" taste of iodine can be neutralized with a
small amount of ascorbic acid (vitamin C).  Used properly, iodine will
kill most protozoa and all bacteria and viruses in water.  After prolonged
use, some people develop thyroid problems, so be aware of this potential
side effect. 

Happy hiking.

-- Jim
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