[pct-l] Giardia, Chlorine and Iodine

[Brick Robbins <brick@fastpack.com>]

At 04:07 PM 8/22/99 -0700, Carolyn M Eddy wrote:
>Glad to hear you made it back. Because of a bad liver I am very careful of
>what I drink. I always got sick even with a good filter. I just started to
>use the chlorine crystals and hydrogen peroxide neutralizer kit and haven't
>gotten sick this year.

If you have been using chlorine and using a 10 minute wait time, then you
have probably avoided illness because the water was not contaminated, not
because of the treatment.

Chlorine is not considered "safe yet effective" against Giardia by the CDC
or the EPA.

Here is what the Centers for Disease Control memo "GIARDIASIS Transmission
and Control " had to say
(see http://www.gorp.com/gorp/health/WTRFLFAQ.HTM for the full text)
======
"neither the U.S. Environmental Protection Agency nor the CDC has
been able to identify a chlorine concentration that would be safe yet
effective against Giardia cysts under all water conditions."
======

Even using Idodine, it takes longer than 10 minutes to kill Giardia.
here is what "Water filters & Giardia Distilled Wisdom (9/28)" has to say
=======
"In addition, you must make sure that water at 25 deg. C (75 deg. 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."
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