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Risks of Drinking Stream Water

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Risks of Drinking Stream Water

May 21, 2014

You’re hiking and you see a clear stream with what seems to be drinkable water. The question is, do you drink it? Emergency room physician Dr. Troy Madsen tells you his views on drinking water directly from any babbling brook. He also tells you the one thing to bring in case you’re that unlucky person who got poisoning from bad water.

Episode Transcript

Interviewer: You're out camping, hiking, or something like that, and that water in that stream looks so refreshing, but you hear that you shouldn't be drinking it. Well, should you? We're going to explore that next on The Scope.

Man: Medical news and research from the University of Utah physicians and specialists you can use for a happier and healthier life. You're listening to The Scope.

Interviewer: Is it okay to drink stream water if you're out camping or something like that? We're with Dr. Troy Madsen, Emergency Medicine at the University of Utah Hospital. We hear that it's bad. You should always take your own water. But is it? Do you see a lot of people visit in the ER for something like that?

Dr. Troy Madsen: I've rarely seen it. It's one of those things I've heard the same thing, and I certainly take the precaution where I don't stream water. Maybe that's why we don't see people because they're not drinking stream water. We don't see a lot of people. I've rarely seen anyone in the ER. I have heard of a few cases of people who drank some stream water or lake water and then came to the emergency department with profuse diarrhea, which is often what you get a week or two later.

Interviewer: That's the big thing?

Dr. Troy Madsen: Yep. That's the big thing you get. But, again, I don't see it a lot, and it's probably because I think the risk is not really high, but the risk is there. It certainly is there, and the big thing we're worrying about is Giardia.

Interviewer: okay.

Dr. Troy Madsen: That's something you can pick up from stream water or lake water. That's often the issue, and that's why we hear that, "Don't drink stream water or lake water."

Interviewer: All right. So we're not encouraging that you do it, but at this point, in your opinion, if worse came to worse and you needed to have water, is it probably okay?

Dr. Troy Madsen: Yeah. If I were out somewhere and I needed water and I just felt like the thirst was going to affect my ability to get out of an area or hike out, I would drink the water. We're talking either about the immediate danger of severe dehydration versus the risk of an infection that's not going to hit you for one to two weeks, and that can typically be treated with antibiotics. So if I had to weigh the risks, I would err on the side of that infection.

Interviewer: That's interesting. Is there anything else to consider? I feel like this conversation is almost done.

Dr. Troy Madsen: Well, it's a great conversation to have, you know. If you ever are out hiking or backpacking, the best to have is just carry some iodine tablets. I like to do some trail running, and just in the little handheld water bottle I carry, I've got a little packet with a couple of iodine tablets because I figure if I'm out somewhere in the mountains and there's a water source there, but I'm too far away to really refill my bottle and I need some water, that's some option.
It's easy to do. That's going to take care of most things. So it's very simple. You can also carry water filters, which are very simple. They're very small to fit in your backpack. Those are nice because you just drop something in the water, you pump it, and it brings out water right into your bottle. And that stuff is great. You can drink that stuff, and that's going to filter pretty much everything out that you would be concerned about.

Interviewer: So as I'm weighing the risks versus maybe the need to drink water, are there other risks that are out there than Giardia?

Dr. Troy Madsen: There's one called Cryptosporidium as well. That's a risk there. We think of that probably a little bit more with people who may have some immune system issues, certainly someone who might have HIV or are on chemotherapy. Anything that's going to affect your immune system there, you have to take extra precautions.
But Giardia is typically the big one. That's often what we think about with really kind of the classic case of someone who drank some stream water, comes to the ER, sees their doctor a week later just saying that they're just having profuse, watery diarrhea. That's usually the big risk.

Interviewer: Is that caused by dead animals in the water?

Dr. Troy Madsen: Usually. That's often what we think about. Maybe animal feces or a dead animal, some sort of source. And obviously, when you're in the mountains, you might see this crystal, clear spring and think, "This is just fine." But who knows what's upstream from that.

Interviewer: Just ten feet away.

Dr. Troy Madsen: Who knows, right? Who knows what's right around the corner or in, you know, the small mountain lake that's then the source of that? You know, you never know what could be in there that could be a source of infection. So you can't trust it just based on how it looks.

Interviewer: And iodine is enough to take care of it?

Dr. Troy Madsen: Yes.

Interviewer: Take care of most problems that we would run into here in the United States?

Dr. Troy Madsen: It is. Yeah. If you've got iodine tablets with you, you should be safe. Again, if you've got immune problems, reconsider. But for most of us, iodine tablets are going to make things just fine.

Man: We're your daily dose of science, conversation, medicine. This is The Scope, the University of Utah Health Sciences Radio.