Liquid consumption (TIGHAR Tracks 40.3)

Jennifer Hubbard · July 21, 2024, 03:07:56 PM

This is just a small and somewhat tangential factor, but I'm curious about the reference for the statement in the latest TIGHAR Tracks (p.3) that people need 3.7 liters of fluid per day. US drinking water regulations have traditionally been based on a daily intake of 2 liters per day for adults, and risk assessments for potable water in the Superfund program now typically use a rate of 2.5 liters per day, which is the 90th percentile consumption rate from EPA's 2011 Exposure Factors Handbook.

So I was curious about the source for 3.7 L/day, and whether that is based on increased needs of liquid for people during flight. Thanks!

Don Yee · August 04, 2024, 05:29:41 PM

I had a different question related to this that maybe experienced pilots can answer. They took a lot of food and as was pointed out not a lot of liquids. Given their flight suits and the open cockpit how did they get rid of that waste? Not like there was a bathroom aboard and holding it that long would likely not be possible. Sorry but I had to ask.
Don...

Friend Weller · August 14, 2024, 08:38:45 AM

It's called the "Human Endurance Range Extender". An empty bottle labeled "Go H.E.R.E."......

Of course, that only deals with "Number 1".

Ric Gillespie · August 20, 2024, 09:54:04 AM

"The U.S. National Academies of Sciences, Engineering, and Medicine determined that an adequate daily fluid intake is:

About 15.5 cups (3.7 liters) of fluids a day for men
About 11.5 cups (2.7 liters) of fluids a day for women"

That's from The Mayo Clinic (https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/water/art-20044256)

As for eliminating waste, nothing is mentioned in the literature. The traditional method was a "relief tube", just a rubber hose with a funnel on the end. The drawback was, because the other end of the hose was open to the outside, it often got cold enough for pee to freeze and back up. When we used the relief tube in a pressurized Beech King Air, we always opened the valve and let warm cabin air flow through before we put it to use.

Martin X. Moleski, SJ · August 20, 2024, 06:15:49 PM

Quote from: Ric Gillespie on August 20, 2024, 09:54:04 AMAbout 15.5 cups (3.7 liters) of fluids a day for men

Oh. My. Heavens.

Call it a gallon of water a day.

I think I'm behind on my intake!

Don White · August 21, 2024, 02:06:50 PM

Quote from: Martin X. Moleski, SJ on August 20, 2024, 06:15:49 PM
Quote from: Ric Gillespie on August 20, 2024, 09:54:04 AMAbout 15.5 cups (3.7 liters) of fluids a day for men
Oh. My. Heavens.

Call it a gallon of water a day.

I think I'm behind on my intake!

Most people are.
Having been diagnosed with kidney disease in June, I am now acutely aware of this.

LTM,
Don W

Bill Mangus · August 21, 2024, 02:46:53 PM

Agree Don and it doesn't include beer, wine or spirits.

I had to have laser surgery for a 6mm kidney stone a couple of years ago and that's what surgeon and internal medicine doc. told me

Dale O. Beethe · August 24, 2024, 07:19:06 AM

I was going to ask if the latitude (read heat) they were at would make a difference, but then realized it would probably be nice and cool at altitude. Of course, once they were on the ground at Gardner, that would go up significantly if my experience in various deserts is any indicator. I would think solid waste would be a bigger problem.

Jennifer Hubbard · August 25, 2024, 02:51:32 PM

Thanks for the clarification: as that includes liquid from all sources, including food, their pure water needs would be a bit less depending on what foods they had. (The 8 glasses of water a day that Mayo mentions equals about 2 liters a day.) But as the TIGHAR article points, the food and drinks they had would not seem to stave off dehydration: dried and canned foods; alcohol; coffee plus more caffeine. I agree that "A possible, and previously unconsidered, factor in the outcome of the flight is deterioration of cognitive ability due to severe dehydration."