
Pee, Not Chlorine, Causes Red Eyes from Swimming Pools: CDC (2015) - colinprince
https://www.cbc.ca/news/trending/pee-chlorine-red-eyes-swimming-pools-cdc-1.3127865
======
keypusher
Chlorine reacts with pretty much any organic compound (hair, sweat, skin,
urine) to produce chloramine. And yes, while this is the thing that irritates
your eyes, it's not to say that chlorine is harmless either. There is evidence
for respiratory and organ damage from extended exposure to chlorinated pools.

[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4351252/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4351252/)

~~~
xiii1408
> "Unfortunately, one of the rats accidentally drowned during swimming
> training; therefore, the final animal number of the [experimental group] was
> 17."

Damn, poor guy.

> "When training, a screw nut approximately 3% of their mean body weight was
> tied to the top end of the tail of each rat, and all rats were kept in the
> special pools with water of 60 cm depth (water temperature 25–30°C, pH
> 6.5–7.0) until fatigued (submerged below the surface for five seconds
> twice). The fatigued rats ceased training immediately, were removed from the
> water for a short break, showered with running water and then dried with
> hair dryers."

So, systematically drowning rats until they aspirate water, every day for
twelve weeks. And they showed negative respiratory effects. Huh.

~~~
Pristina
This gives me an idea of an online gambling site where people bet crypto on
which rat will drown first. I will call it thunderpool. 2 rats enter, 1 rat
leaves.

~~~
bryanrasmussen
Place your bets if this cat in this box will be dead or alive when the box is
opened at Schroedinger's online casino!

------
mchannon
This article's full of problems.

The first reason chloramine gets to be a problem is users don't shower before
entering the pool. The amount of urine a swimmer can introduce into the water
is small compared to the amount of urea coming off their unwashed body.
Icelandic people religiously shower before entering their shared baths, and
look on non-showering the way we might look at people not bothering to wiping
their backside.

And the other two big misconceptions are that time will take care of the
problem (chlorine evaporates, amines don't) and that you can just dump in
chlorine or other chemicals to get rid of the problem. It uses far less energy
and wastes less water to simply dump and replace the pool water (chlorine
tablets require ridiculous amounts of water and energy in their manufacture).

~~~
PeterisP
"The amount of urine a swimmer can introduce into the water is small compared
to the amount of urea coming off their unwashed body" \- really? how much urea
does a normal human have on their body, assumed they wash at all e.g. if they
showered this morning, and go to pool after work ? Assuming they don't spend
the day pissing on themselves, do we just secrete urea?

~~~
paulddraper
Also remember the number of people getting in the pool is likely much larger
then the number of people peeing in it.

~~~
Pristina
That's weird, because the only reason to go to a public pool is so you could
pee in it.

------
sizzzzlerz
I've always wanted a product that you could add to the swimming pool water
that reacts to human urine by coloring the water immediately surrounding the
pee-er. Say a neon orange or red. Over time, the colored water gets diluted
and disappears. Maybe pee-shaming is what's required to stop people from doing
it.

~~~
deepGem
Gosh this is not gonna go well with the public. I know several kids who just
can't hold pee in the pool. They'll just let it out. Also its not like the
toilets are right there. You often have to get out of the pool, walk like 100
yards or down a flight of stairs. It's a PITA. Even Michael Phelps once said
in an interview that very rarely competitive swimmers get out of the pool to
pee.

~~~
gambiting
I'm constantly shocked and disgusted that people actually pee in pools and
that it's not some joke someone made up somewhere.

~~~
nck4222
I mean, what about all the other body fluids/debris that are in pools? Saliva,
sweat, earwax, belly button lint, bird shit, insects, band-aids, small animal
carcasses that get trapped in the filters but are removed before the pool
opens?

There's no avoiding other peoples/animals grossness, frankly whether your in a
pool or just out and about.

Urine may be gross, but it's sterile, and at least for me, there are grosser
things in pools.

~~~
tptacek
What was it W.C. Fields used to say about drinking water?

~~~
gok
Fish chlorinate it?

------
tj-teej
I see a lot of comments in these threads regarding the old idea of a red cloud
to indicate someone has peed in the pool. This idea never dies and I think I
know where it started...

When I was a lifeguard, we had to test the pH levels of the pool water every
few hours. This entailed taking a sample of water, adding a few drops from a
dropper and noting the shade of red the sample turned.

We would tell the kids that we were checking that the "pee detector" was
working. I really think this is what has fueled the notion that it's possible
to turn pool water red to catch pool pee-ers.

PS - I cannot recommend a summer job lifeguarding to anyone teenager, it was
honestly one of the best jobs I ever had.

~~~
agrippanux
I think you mean "I can recommend a summer job lifeguarding" :)

I also was a lifeguard all during high school, and if it was financially
viable at this stage in my life I would do it again.

~~~
tj-teej
You are very correct! Unfortunately it's too late to edit now..

------
teekert
"Approximately 58 per cent of Canadians admitted to peeing in the pool at
least once in a recent survey of 9,500 people conducted by Travelocity." Never
looking a Canadians the same ever again.

~~~
braythwayt
To paraphrase a HaHaOnlySerious joke about diving:

"There are two kinds of people in the world. Those who have peed in a pool.
And those who lie about it."

~~~
mc32
Everyone as a kid who has gone into a pool is probably right, but I doubt all
adults who’ve been in a pool have done so.

~~~
braythwayt
A HaHaOnlySerious joke is not meant to represent absolute truth, but to be
truthful enough to provoke reflection on the subject.

In this case, I am suggesting that if you survey some large group of
Canadians, and 58% admit to peeing in a pool, there is also some non-trivial
number of Canadians surveyed who have peed in a pool, but will not admit it to
you.

Maybe not 42%, but also maybe not 2%.

------
xiii1408
This has been well-known by swimmers for a long time: chlorine itself is
pretty much fine for you. It's the chemical reaction of chlorine with waste
products, including human waste, that produces toxic byproducts and the
concomitant "pool smell."

If you swim in a well-maintained pool (e.g. one of my university's competition
swimming pools), there's no "pool smell."

~~~
jedberg
Are you sure your University isn't using bromine instead of chlorine? Bromine
is more expensive but then you don't get the "pool smell". It's what they use
at Disney parks.

~~~
selectodude
I think you're thinking of bromine, not boron.

~~~
jedberg
Yes. Thanks.

------
1e1f
"People who swim while they have diarrhea and unleash even very tiny amounts
of germs like Cryptosporidium (or 'crypto' for short)"

~~~
howard941
"are evil"

~~~
quickthrower2
“are shitbags”

------
g051051
I've been in pools that I'm 100% certain no one had peed in, and still got red
eyes.

I'm certain because I was the only one who swam in it (a backyard pool) and I
know I never did.

~~~
Stevvo
Probably peed in by wildlife

~~~
ghostbrainalpha
Ambient pee if you will. Or background pee from the hose used to fill the
pool.

------
ivanhoe
They talk about dichloramine and trichloramine which are the products of
chlorine reaction with ammonia, but also any amino acid - which means it can
come as well from reactions with any part of our body it gets in contact with,
like almost 2 sq. meters of our skin. How did they rule out all those other
sources?

------
dleslie
And this is why I prefer pools that are athletic-focused, rather than pools
that are entertainment-focused. They really ought to be considered as separate
facilities.

~~~
_i____ii_______
[https://youtu.be/0iKAyfaPqKM](https://youtu.be/0iKAyfaPqKM)

~~~
misterman0
And now YT thinks I'm into pee clips. Thx!

------
wuschel
If my memory serves me well, it is not chlorine, but the product from
hypochloric acid[1] and urea/urea-derivatives that that make eyes hurt.
Although, I don't know if they use Cl2 as reagent here.

[1] Hypochloric acid is generated in a disproportionation reaction: Cl2 + H2o
--> HCl + HOCl

------
crusso
I'm not sold. We had a pool when I was growing up and since I was the youngest
child, there was a several year stretch in high school where I was taking care
of the chemicals in the pool and really the only person ever swimming in it.

If the pool was looking a little green, I dumped some chlorine in and guess
what, the increased chlorine created increased irritation to my eyes. And no,
I wasn't the kind to pee in my own pool - not that the amount of pee I could
generate would cause the requisite chlorine-pee interaction that makes the
pool such an irritant.

------
clarkevans
There exist more articulate writings on this subject. Chloramines are formed
when urea (pee and sweat) meets chlorine [1,2]. It contributes to athlete
asthma [3,4,5,6,7]. It is an identified occupational health issue [8].
Chloramines are a concern with aquatic facility operation [9,10]. One way to
help is to use UV filtering [11,12]. I believe the solution is just better
aquatic center ventilation [13] especially moving air across the water surface
[14].

[1] [https://nextgws.com/chloramine-simplified-chemistry-
lesson/](https://nextgws.com/chloramine-simplified-chemistry-lesson/) [2]
[https://chlorine.americanchemistry.com/Science-
Center/Chlori...](https://chlorine.americanchemistry.com/Science-
Center/Chlorine-Compound-of-the-Month-Library/Chloramines-Understanding-Pool-
Smell/) [3] [https://www.webmd.com/asthma/news/20040611/chlorine-pools-
br...](https://www.webmd.com/asthma/news/20040611/chlorine-pools-breathing-
trouble#1) [4] [https://lungdiseasenews.com/2015/04/07/competitive-
swimming-...](https://lungdiseasenews.com/2015/04/07/competitive-swimming-
linked-to-asthma-in-new-study/) [5]
[http://www.jiaci.org/issues/vol21issue3/12.pdf](http://www.jiaci.org/issues/vol21issue3/12.pdf)
[6] [https://www.reuters.com/article/us-health-asthma-swimmers-
id...](https://www.reuters.com/article/us-health-asthma-swimmers-
idUSKBN0MT2I620150402) [7]
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4351252/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4351252/)
[8]
[https://erj.ersjournals.com/content/29/4/690](https://erj.ersjournals.com/content/29/4/690)
[9] [https://www.cdc.gov/healthywater/swimming/aquatics-
professio...](https://www.cdc.gov/healthywater/swimming/aquatics-
professionals/chloramines.html) [10]
[https://www.chicagotribune.com/suburbs/park-
ridge/sports/ct-...](https://www.chicagotribune.com/suburbs/park-
ridge/sports/ct-prh-maine-south-high-school-pool-health-concerns-
tl-0208-20160208-story.html) [11]
[https://www.poolspanews.com/facilities/maintenance/technical...](https://www.poolspanews.com/facilities/maintenance/technical-
guide-to-using-uv-sanitation-on-swimming-pools_o) [12]
[http://halmapr.com/news/hanovia/2008/07/26/uv-chloramine-
red...](http://halmapr.com/news/hanovia/2008/07/26/uv-chloramine-reduction-
disinfection-and-water-savings-in-one-neat-package/) [13]
[http://aquaticnews.com/2018/04/17/indoor-pool-air-quality-
th...](http://aquaticnews.com/2018/04/17/indoor-pool-air-quality-the-ultimate-
solution-to-bad-air/) [14]
[http://paddockevacuator.com/](http://paddockevacuator.com/)

Disclaimer: I've got no relation or interest in Paddock (the 1st and last 2
links), I just happen to be a swim coach.

------
tyingq
So how much water do you need before it's socially acceptable? I pee in the
lake. What about a large pond or a really huge pool in a water park?

~~~
jschwartzi
I've always been told not to urinate or defecate within 100 feet of water
sources in the backcountry because if everyone does it it builds up and then
the water is unsafe to drink even when filtered.

The 6 micron filters used to filter giardia from the water will not filter
viruses, which are present in your feces.

Please stop doing this.

~~~
ams6110
Do you think all the animals that use these water sources follow the same
rules?

~~~
jschwartzi
Deer viruses also don't typically infect humans. But human viruses will
readily infect other humans.

------
viburnum
If you've ever been lucky enough to swim in a pool that's just been filled up,
you know this is true.

------
danielpal
another shocker. The smell of "Chlorine" in the pools is not caused by
"chlorine" but by the urine. Chlorine has no smell when mixed with water. Add
urine, and you get the "Chlorine" smell thats typical of pools.

See:
[https://www.youtube.com/watch?v=S32y9aYEzzo&t=607s&frags=pl%...](https://www.youtube.com/watch?v=S32y9aYEzzo&t=607s&frags=pl%2Cwn)

[https://chlorine.americanchemistry.com/Science-
Center/Chlori...](https://chlorine.americanchemistry.com/Science-
Center/Chlorine-Compound-of-the-Month-Library/Chloramines-Understanding-Pool-
Smell/)

~~~
marcoperaza
Kind of a deceptive video, which might make you think that if no one peed in
the pool, there would be no pool smell. Urea is what reacts to create
trichloramine, which gives off the smell. But urea, as the video acknowledges,
also comes from sweat. Yet they go on to talk about chlorine reacting with
_urine_ as being the sole cause of the smell.

They should have gone into what percent of the urea comes from sweat vs.
urine.

------
jillesvangurp
I just came back from a swim. Accidentally swallowed a bit as well (it
happens, never pleasant). I do use goggles to protect my eyes. Overall it's a
good work out but the chlorine is definitely unpleasant.

I've encountered a few pools in Denmark that use salt water rather than
chlorine. Much more pleasant to swim in and seems to have the same effect of
killing off bacteria. Seems like a nice alternative. Refreshing the water more
often is probably costly but could work as well. The pool I go to is always
very busy and I suspect they are cutting corners on refreshing the water
regularly.

~~~
angry_octet
'Salt water' pools are still using chlorine, just via a continuous process
that maintains the right level of chlorine (splitting the salt: NaCl). Much
easier to maintain. If the system has a super chlorination function
(periodically gives a burst of increased chlorine, e.g. overnight) you don't
have to shock the pool very often.

Big municipal pools have continous chemistry monitoring so they can achieve
the same effect with less electricity. They can also increase the flow rate
when there are more people etc.

------
bArray
Wasn't the pool closed due to aids?

Memes aside, it certainly shows how it's easy to draw an incorrect conclusion.
It really makes me second guess how healthy swimming in a pool really is. Lots
of people jumping in and out of the same water is an problem waiting to
happen.

As children we used to swim and kayak in the sea (to the point where we could
no longer see the coast, which in hindsight was very dangerous). I wonder how
being in the sea compares to a pool?

------
ravenstine
Why do pools still use chlorine? Is it just because it's really cheap? I've
seen non-chlorine pool treatments advertised in the past but haven't been to a
single pool in 20+ years that wasn't chlorinated.

[http://www.baquacil.com/](http://www.baquacil.com/)

EDIT: Also, ewww.

~~~
jhawk28
Some are saline (salt) based instead of chlorine.

~~~
ISL
Salt = NaCl.

~~~
astazangasta
Chlorine = Cl2.
[https://en.m.wikipedia.org/wiki/Chemical_bond#Covalent_bond](https://en.m.wikipedia.org/wiki/Chemical_bond#Covalent_bond)

~~~
24gttghh
_Chlorine Gas_ = Cl2, which is generated by electrolysis of NaCl in a
saltwater pool setup.

------
reilly3000
Our species has weathered all kinds of terrible waterborne communicable
diseases since time began. It’s fair to say we wouldn’t cover the earth as we
do without our sophisticated biome being adapted to all manner of disease from
shared bathing.

------
kowdermeister
Mark Rober (glitter bomb) did a video on this. He also did a test on the "pool
smell" if it really caused by pee reacting with chlorine:

[https://www.youtube.com/watch?v=S32y9aYEzzo](https://www.youtube.com/watch?v=S32y9aYEzzo)

~~~
justtopost
Not sure I can trust anything from that dude. He realy did a number on his
credibility by not making the glitter bombs, faking the 'prank', and lying
about it afterward after being presented with clear evidince of his deception,
and his pre-existing knowledge of it. No thanks, people who sell their
credibility for views deserve no respect.

------
tapanjk
> The only solution is to pee in the pool, then at least you think it's your
> own.........

This caught my eye in the comments at the bottom of the article. It answers
the question that we all asked (sometimes of ourselves): Why would anyone pee
in the pool?

------
saluki
My Great Aunt is in hospice care at home, I was talking with her yesterday
about a sign she had by her pool when I was growing up.

Welcome to my OOL notice there is no P in it and I'd like to keep it that way.

------
wfbarks
Already knew this thanks to Mark Rober!

[https://www.youtube.com/watch?v=S32y9aYEzzo](https://www.youtube.com/watch?v=S32y9aYEzzo)

------
alexhultman
I've been a swimmer for 15 years and I had to get used to floating boogers and
used band aids and I can just imagine how much dingleberry I have swallowed
over time!

------
mcny
Anecdotal but I was at a hotel on a weekday. Nobody else had been in the pool
all day as far as I know when I jumped in the pool. Still got slightly red
eyes.

------
elyobo
Off topic, so feel free to downvote, but I have a possibly related question
that may find some answers here.

I generally have a dry scalp, and dry skin around eye brows and beard. I
started swimming about five months back and these drastically improved. I
cracked a couple of ribs in a cycling accident and had to stop... the problems
returned. Back swimming again now and they're gone again.

The only info I can find online is of people complaining that pool swimming
_causes_ dry scalp problems but I seem to be experiencing the opposite.

Any reasons why this might be the case?

~~~
vorpalhex
ph?

------
ham_sandwich
As a longtime swimmer and water polo player, my eyes have been absolutely
wrecked by harsh pools many, many times.

However, I don’t think it’s pee. First off, every swimmer pees in the pool.

I have been a part of tens of thousands of man-hours in the pool and seen
people get out to pee maybe three times.

I have been in the first games of the day at water polo tournaments and have
seen them chlorine shock the water followed by everyone’s eyes getting
decimated. To me, the devil is unbalanced chlorine coupled with the thick,
thick film of sunscreen that develops in the water after a scorching day with
hundreds of people jumping in and out.

You get desperate when your eyes get that destroyed. The classic trick is to
fill a pair of goggles with milk and just put ‘em on for a few minutes.

~~~
crescentfresh
> First off, every swimmer pees in the pool

A friend expressed this to me once when I caught her peeing in the pool and I
was honestly skeptical that "everyone does it" as I would have never felt
comfortable doing that. Still don't.

~~~
ham_sandwich
When you’re in the water that much, I think you just end up getting
desensitized to it.

I’ve seen things you people wouldn’t believe. Teammates going to a corner and
openly declaring “don’t come over here I’m peeing.” Coaches literally
encouraging it, saying it’s not worth it to get out and miss a set when you
can stay in the water: “your urine is just a tiny, minuscule fraction of the
total volume anyways”

When you spend that much time in the water with your teammates, it’s no longer
an “open secret” that eveyone is doing it. It’s simply open.

~~~
saalweachter
"Everyone does it" does not mean "it's harmless".

If you want to see other examples of ubiquitous practices that were treated as
harmless and necessary to be competitive and ultimately shown to be incredibly
harmful, I would just refer you to {the entire history of competitive and
professional sports}.

------
yalogin
So if the eyes turn red in the pool does it mean there isn't enough Chlorine
in it?

------
YeahSureWhyNot
i get red eyes even from my shower, unless there is pee in the water pouring
from the shower head, I dont know what to say.

~~~
deckar01
The lack of salt in tap water is likely the cause of eye irritation and
redness. The concentration of salt in tap water about 2% of human tears. The
concentration in chlorinated pool water is closer to 30% of human tears.
Perfectly clean and balanced pool water should be less of an irritant than tap
water.

[https://www.aao.org/eye-health/ask-ophthalmologist-q/is-
it-o...](https://www.aao.org/eye-health/ask-ophthalmologist-q/is-it-ok-to-
wash-your-eyes-out-with-tap-water)

[https://blog.hayward-pool.com/maintenance/how-much-salt-
do-y...](https://blog.hayward-pool.com/maintenance/how-much-salt-do-you-add/)

~~~
quickthrower2
If a salt chlorinator is in use then yes salt will tend to be added.

------
raverbashing
I wonder if there is a technically feasible (and cheap) way of eliminating
those substances from the water (apart from the obvious "cycling it" way)

------
Kenji
This is bullshit. I get red eyes and inflammation from swimming in the
chlorinated pool in our backyard if I keep my eyes open under water, and I
know for a fact that nobody pees in there, unless evil goblins sneak into our
backyard to relieve themselves.

------
kfwhp
This is the reason I never go to pools. You're basically swimming in a
solution of pee, sweat, vaginal fluids, and God knows what else.

------
bcaulfield
Oh no. Oh no no no.

------
Simulacra
Oh. Well, sorry guys...

------
peter_retief
Damn

------
black-tea
Why "pee"? The word is urine.

------
sriku
A colleague and friend of mine once commented that having open designated
smoking areas is like having a designated peeing area in a swimming pool.

------
ryanmarsh
Umm, pool owner here. This is horseshit.

Come over and I will drain my pool, fill it up with fresh water, stabilize the
chemistry and give it just a bit too much chlorine and lets see if your eyes
don’t get red.

~~~
Domenic_S
Former pool owner here, for reasonable values of "just a bit too much" they
won't get red. Eye irritation is a function of pH and unfiltered particulates.

Check out the Trouble Free Pool forum, you might save some money and learn
some stuff!

~~~
Zimahl
That was his point. Public swimming pools crank up the chlorine to counteract
the number of people using them.

------
jsilence
Your pools are still being sanitized with chlorine?

The fact that the 'chlorine' smell stems from urine in the pool is news to
you?

This has been common knowledge for decades now and most of the public pools
here in Germany have been retrofitted to O2 base sanitization to eliminate the
chlorine.

So all the authorities actually do about it is print a warning on paper?

This is odd.

------
anonytrary
I've always avoided swimming because of this. Other people, who may not wipe
their bottoms properly, are getting into the same pool as you. Sometimes they
pee (and they always excrete saliva) into the pool. It kind of grosses me out,
and I've never really understood why it's not more taboo.

In elementary school, I was never a fan of the game "bobbing for apples",
because all of the other kids stick their mouths into the same bucket, and I
had a basic conceptual understanding of germs and how they spread.

~~~
hire_charts
On the other hand, what better way to give your immune system a head start?

~~~
anonytrary
Not washing your hands 20 times a day or profusely applying hand sanitizer is
something to avoid. Doesn't mean you should be seeking out bacteria, though.

