Is Backcountry Water Safe to Drink?

Keep an eye out for nature's water-borne nightmares.
Water Drop

Photo by Janet Ramsden

I’ve heard that the dangers of drinking backcountry water are way overblown. Is that true? – Tim Ready, via email

Everyone hates to think they’ve been had by jumpy scientists or slick marketers, but don’t let paranoia carry you away.

The truth about wild water is trickier than a simple yes or no. It’s often safe to drink, but you can’t determine that by sight or taste.

Take high-altitude water. You’d think it’d be OK since there are no people or cows uphill or upstream, but scientists have been finding giardia in the scat of high-altitude critters since the ’70s. Alpine soil is thin, and whenever snowmelt or rainwater washes across it, those leavings sweep right into your water supply.

It’s true: The chances of catching a bug are lower than you might think. Practically speaking, it takes about 10 giardia cysts for a normal, healthy adult to contract the runs, and alpine water typically has less than a cyst per liter, according to a variety of surveys conducted in the High Sierra.

But if you fill up next to a vole’s favorite commode, that could mean thousands of cysts in your Nalgene. Is that a chance you want to take, or would you rather pack the filter just to be safe?

Getting poison ivy anywhere is a drag, but is it ever an emergency? – Steve Barczak, via email

Generally speaking, the more sensitive the area on your body, the worse it is to get poison ivy there, but even if you’re walking funny, that’s probably not a medical emergency. No, for that you need to get the poison in you, not just on you.

But before I get to your answer, let me dispel a myth: Urushiol oil (the poison in poison ivy) doesn’t spread through your bloodstream if you get it in an open wound. Varying doses of toxin on different body parts react at different times, which can make it look like the rash is spreading, but once you’ve got the urushiol washed off, the reaction won’t migrate.

Now, your answer: The most common way to get poison ivy in your body is through smoke. Making a campfire? Gather wood wisely. Old, even dead poison ivy vines still contain urushiol. Charred particles can carry tiny drops of the poison oil into your lungs, which can belabor your breathing and even launch you into anaphylactic shock—a pretty good knock on the reaper’s door.

The other method, equally as gruesome, is getting urushiol or urushiol smoke in your eyes. You won’t go permanently blind, but your eyelids may swell shut. And if that happens, your next task (finding your way to the hospital) just got a lot harder.

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