[pct-l] Some Sierra Water Shown to be Unsafe

Bruce 'Buck' Nelson buck at bucktrack.com
Wed Sep 5 10:22:06 CDT 2012


>From a 2010 article: "As director of the emergency room at University
of California Medical Center, Robert Derlet always wondered what made
people sick.

Each summer, on hiking trips into the high Sierra, he brought that
curiosity along, asking himself: Where do you get infections in the
wilderness? The most obvious possibility, he believed, was the water.
Now, after 10 years of fieldwork and 4,500 miles of backpacking,
Derlet knows for sure. What he has learned, after analyzing hundreds
of samples dipped from backcountry lakes and streams, is that parts of
the high Sierra are not nearly as pristine as they look.

Nowhere is the water dirtier, he discovered, than on U.S. Forest
Service land, including wilderness areas, where beef cattle and
commercial pack stock — horses and mules — graze during the summer.

There, bacterial contamination was easily high enough to sicken hikers
with Giardia, E. coli and other diseases." (Derlet has been considered
a "skeptic" in this debate, but I have a lot of respect for him.)

The salient points: High Sierra, pristine looking wilderness, some of
it unsafe to drink because of Giardia and other disease causing
organisms.

http://www.modbee.com/2010/05/08/1158938/fouled-waters-sierra-lakes-streams.html#

And from Rockwell's paper: "One conclusion of this paper is that you
can indeed contract giardiasis on visits to the high mountains of the
Sierra Nevada, but it almost certainly won’t be from the water. So
drink freely and confidently."

Having gotten Giardiasis after reading and believing the Rockwell
paper, I wish I had read the former much more recent quote first. I
WAS selective with my water sources. It was too late when I saw one of
my safe looking sources had been fouled by cattle.

I have cited a major study and a survey, both of which show the
giardiasis infection rate for those not treating backcountry water is
triple. http://bucktrack.blogspot.com/2011/03/waterborne-giardia-for-backpackers-no.html
There are clickable links to those and many other sources on that blog
post which I've linked to in each of my prior posts.

The EPA, Rockwell and all the other sources that say it takes a
minimum of 10 cysts to become infected are wrong as I show in my blog
post. Look at the graph showing where the "10-25 cysts" quote comes
from. Many inaccuracies are repeated over and over in science without
people digging down to see the original work.

On the under-reporting of Giardiasis to health departments: "Several
backpackers appear weekly at Centinela Mammoth Hospital in Mammoth
Lakes sick enough with giardiasis to need urgent care, said Dr. Jack
Bertman, an emergency physician, who noted, 'We publicize it a great
deal more in Mammoth.' "

http://articles.latimes.com/1988-07-26/news/vw-6536_1_day-care-program

My Doc, also in Mammoth, said he treats many cases of backpacker
Giardiasis but doesn't report them. You know how many cases of
Giardiasis were reported in that county (Modoc) in 2010? Zero.
Including my case.

http://www.cdph.ca.gov/data/statistics/Documents/GIARDIASIS.pdf

"Neither health department surveillance nor the medical literature
supports the widely held perception that giardiasis is a significant
risk to backpackers in the United States. In some respects, this
situation resembles (the threat to beachgoers of) a shark attack."
Robert Rockwell

That conclusion is solidly refuted by all the backpackers actually
getting Giardiasis requiring urgent care in the Sierras and the more
recent study cited at the top.



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