Iodine, Water, and Bacteria
Name: Lara G.
Date: May 2004
I work in a wilderness program; my shifts are eight days
on, six off. We drop all our water with iodine- eight drops per gallon.
I drink at least a gallon a day, so I figure give or take I drink 64
drops of iodine every shift. Does this mess up the bacteria in my body?
In large enough doses, everything is toxic. Here you have to balance the
risk of iodine toxicity vs. the consequences of being infected by a
water-borne pathogen or parasite (in the wild). I would vote for iodine every
time!! An approximate calculation (below) suggests you are quite safe: 1ml ~
20 drops. You take 8 drops.
Let us make that 10 drops to be conservative. So you ingest about 0.5 ml. of
iodine solution. I do not know what the concentration is, but lets say that
it is 1% active I2. So your 0.5 ml (assuming a density of 1 gm/ml, close
enough) contains about 0.005 gm I2 or 5 mg/day. The toxicity rating for
iodine for humans in the literature is 28 mg/kg. Estimate a body weight of
132 lb = 60 kg, which places the toxicity level of I2 at 1680 mg = 1.7 gm.
So you are well below any toxicity concerns. Iodine is rapidly metabolized,
so unless someone had a thyroid disease, its use should be quite safe in my
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