Giardia Hysteria
Those of us who grew up camping and hiking in the 1980s and 1990s were constantly warned of the dangers of giardia lamblia and giardiasis. We were cautioned that if we ever drank water from a stream without first purifying it we risked our health and perhaps our very lives. Giardiasis was reputed to cause six months of uncontrollable diarrhœa; it was supposedly found in almost any stream, river or lake; it was bad juju.
Upon reflection, this didn’t really make a whole lot of sense.
Old books are full of ways to find good water—they aren’t
full of ways to purify water (although they might recommend boiling
when in doubt). It always seemed a bit strange to me that the
purported symptoms lasted for six months,
a curiously round
figure. Wild animals drink wild water, and they rarely seem to be
suffering from intestinal trouble. Our ancestors—and many in
the uncivilised world—drink wild water all the time. And then
there are many of our fellows who do the same. I’m proud to say
that I’ve been drinking water from streams for years, and
I’ve never had a problem yet.
Well, it turns out that the giardia threat is massively overblown. Back in the 1980s some testing of wild water in the Sierra Nevadas was done: it turns out that the most contaminated water was purer than that found in San Francisco and that all but the two worst sites purer than that in Los Angeles. Even in other parts of the country, at the very worst sites one would need to drink almost 3 gallons of water in order to have a 50% chance of getting consuming enough giardia to have an effect.
Worse, it seems that 1 in 14 people have giardia in them already, and that the most likely path of contamination when camping is by food. Whoops.
All that said, there are plenty of other nasty microörganisms which can be found in water, and one needs to exercise some care. Areas which are commonly used by people are less safe than isolated areas; water that is stagnant is less safe than running water; it’s always safest to purify water one way or another. But really, it’s just not that big a deal.
I don’t really plan on carrying a purification kit. If I need to, I can boil it. And there’s something wonderfully tasty about ice-cold, crystal clear water from a mountain stream which runs through a stream bed lined with leaves. Iodine-tainted, bleached, boiled or filtered water are not the same thing.
