Picking Apart the Cherry-Pickers

Wednesday, February 07, 2018

The anti-treatment "raw water" crowd* are at it again, this time improperly citing a study as "scientific" evidence that campers and hikers need not filter naturally-occurring water. Fortunately, the merits of treating naturally-occurring water are quite well established, and Wes Siler of Outside Online is paying attention. Siler notes something that opponents of this easy, prudent practice are all too eager to sweep under the rug: context. The study itself, the state of the scientific literature on the subject matter, and widely-known facts easily applicable with an ounce of common sense all contradict that foolhardy conclusion. Here is just a small sample of Siler's well-reasoned and clearly-written rebuttal:

Image of Giardia via Wikipedia.
The irresponsibility of the don't-filter argument is exacerbated by two things:
  1. While most Giardia, E. coli, Cyrptosporidium, and [other] waterborne pathogens induce fairly minor illnesses in adults, the effects can be much more severe if the infected person suffers from immunosuppression, is very young or old, or, as with my friend, is simply unlucky. In children, for instance, the CDC says giardiasis can may lead to symptoms as severe as delayed physical and mental growth, slow development, and malnutrition.
  2. Effective treatment options are affordable and easy to use. Use an expensive filter because you're short on time or like cleaner tasting water -- cheaper methods will keep you just as healthy.
Both [physician Thomas R.] Welch and [Slate author Ethan] Linck argue that the failure to wash hands after taking a poo is responsible for more infections than drinking unpurified water. But while that is an argument for taking some hand sanitizer along, it is not an argument against water treatment. [link in original, bold added, minor edits]
Even the study cited by Slate doesn't advise against treating water: "If our objective is to protect the backcountry user from enteric infection, then we should emphasize the overwhelming evidence showing that assiduous hand-washing or using alcohol-based hand cleansers is by far the most important strategy." I disagree with Welch that also urging water purification "dilutes" such a message.

There is one point on which I do agree with Linck: Not purifying for oneself should be a personal decision since it is not risk-free, while purifying it is nearly so.

As I have noted before, even this will probably not deter some people from flirting with the following scenario (or worse), anyway:
Last year, a good friend of mine caught chronic giardiasis. The diarrhea that resulted was unpredictable, frequently sending him scrambling for a bathroom. For most of the year, that meant his dating life was totally on hold and he couldn’t travel. Already a thin guy, the resulting weight loss caused him to look visibly ill. To him, the worst part was the embarrassment all this caused, all from a parasite he caught on a camping trip here in California. [minor edits]
It is with amusement that I consider those cases, so long as they are self-inflicted. To everyone else: You have been warned. And, if you are sending your kids to a camp, I recommend making sure those in charge will be treating any water they find.

-- CAV

* The author of the Slate piece claims not to be in this crowd, but his anti-capitalist sentiments, which permeate the entire piece, place him in the same "return of the primitive" camp, if you will. One can imagine him yelling "check your privilege" as he rushes to the water closet some time after a hike.


Anonymous said...

Hi Gus,

My oldest brother returned from a volunteer stint in Brazil almost 50 years ago. Despite his best efforts, he also repatriated a bad case of liver flukes and giardia. Whether because of some synergy with the liver flukes or for other reasons, his giardia infection took up residence in his liver. And while he got rid of the flukes, the only treatment, until recently, attacked giardia in the alimentary canal, not the liver. So it would clear out the bugs only to have them re-infect from the primary liver site.

A few years back, a new drug came on the market that was designed to deal with his particular giardia problem. Irony of ironies, they found out that he is deathly allergic to it.

So California dude should be grateful it was only 1 year's worth of the Trotskies. I wonder when natural selection will set in. As Glenn Reynolds is wont to say, "Faster, Please". (evil grin)

c andrew

Gus Van Horn said...


That sounds rough. I feel bad for your brother.

On the natural selection front, I noticed a headline yesterday to the effect that global warming alarmists are apparently considering not reproducing out of guilt for the kind of world they'll leave their children. Amen to that on many levels, none of which they intend, and none in the way they intend.