Hair... and another totally unrelated question

How much total hair does the average human produce in a lifetime?
This includes:
[li]head hair (male and female)[/li][li]body hair (male and female)[/li][li]cumulative lifetime weight of hair in each category (preferably stated in pounds/ounces)[/li][li]cumulative lifetime length of hair in each category (preferably stated in feet/inches)[/li]
Second totally unrelated question:

How many hours and minutes total during an average person’s lifetime are spent going to the toilet?

Assuming a total toilet time per day of 20 minutes, we have:

20 minutes/day x 365.25 days/year x 75 years/lifetime = 547,875 minutes = 9,131.25 hours = 380.46875 days

About 1 year, 15.5 days.

With an average of 30 minutes/day, it comes to 570.703125 days, or almost a year and seven months.

Protesilaus,

Damn! I always knew was a big ol’ waste of time, but I didn’t know it was that significant.

Why can’t I become a fuel cell powered cyborg who just emits harmless h2o vapor exhaust…arrrgh!

Cumulative length of hair over a lifetime (Sorry, I can only do this in metrics)

Assuming 2.5 million follicles per head with average rate of 3.5millimeters per week over lifetime of 75 years (3900 weeks)
plus
1 million follicles per body (hairy) with average rate of 3.5 mm per week over lifetime
you get
47775 million mm of hair. Or about 477.75 kilometers. That’s about 287 miles.

Same assumption per head
plus
.5 million follicles per body (not-so-hairy) with average rate of 2.5 mm per week over lifetime
you get
34125 million mm head plus 4875 million mm body to yeild 39,000 million mm of hair, or about 390 km. That’s about 234 miles.

Of course these are very rough estimates, failing to take into account either the follicularly challenged or the pelt people among us. And the figures for growth rate are listed for Europeans, not other groups.

But still, you have to wonder - where does all that hair go? Hair fibers decompose much more slowly than most other human tissue (due to all the keratin, I think), so I always figured there would be a terminal hair buildup at some point that will clog all the world’s drains and set civilization back quite a few years. Multiply and average of 260 miles times 6 billion people and what do you get? I predict Hairball Earth.

These are interesting speculations, but I just have to say that if you are spending 20 minutes a day on the toilet, you need to decrease your fluid intake or increase your fiber intake.

Where in the Sam Hill did you get these figures. In Med School the quoted number for head hair was about 10,000-20,000 or about 100X less than the figure you use. I’ve never seen a figure for body hair.

I can’t find a cite right now but consider this: assume that the hair-covered area of the scalp is 15X15 cm (probably too large, but I’m feeling generous). That area therefore is 225cm[sup]2[/sup]. Using the hair follicle count you provide, there need to be 2,500,000 follicles over the 225cm[sup]2[/sup] area or 11,000 hair follicles per square centimeter. Using 20,000 follicles per head, the number is 90/ cm[sup]2[/sup].

Which sound closer to reality?

Alright, I found a cite for hair density here

So I was a little off on the hair density thing, sue me. I checked their 20 km/year figure and it works out. Assuming a 75 year lifespan, that’s 1500 km or 900 miles.

However from the above passage, we learn that at any moment, approximately 20% of the follicles are resting. So it may be more appropriate to take only 80% of the above figures.

And since you asked for weight, dear OP, when I get to work today, I’ll pluck out one of my few remaining, treasured follicles, measure it’s length and then it’s weight on an analytical balance.

Hey, kids! What time is it? It’s time to “Stump Beekman!”

"The lemon shark grows a new set of teeth every two weeks.
"Your brain is 80% water.
"The average person has over 100,000 hairs on their head.
"A housefly lives only for an average of two weeks.
"Fish do get seasick, when kept on a boat.
“When you’re Beekman, you know these things, ha ha!”

Every freakin’ ten minutes in the afternoons.

Ok, I weighed a hair (not to self-get life). A precious 9cm long strand came in at 0.59mg. Assuming I am the model human, that’s 6.6mg/m hair.

Since a lifetime of hair growth produces 1500km, the weight of said hair is 9.8kg or 21.6 pounds.

Guess this means weight gain cannot be attributed to hair loss.