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Name: Lara G.
Status: Student
Age: 20s
Location: N/A
Country: N/A
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 estimation.

Vince Calder

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