Most people have claimed to do it at some point in their
life. Some people even think it’s acceptable to do, but did you know that
peeing in pools causes a set of unidentified reactions that releases toxic
chemicals into the air and water?
Cyanogen chloride (CNCl) and trichloramine (NCl3)
are nitrogen containing disinfection byproducts (N-DBPs) in found in most chlorinated
swimming pools. Both of these compounds are toxic to the human body. NCl3
is associated with acute lung injuries and CNCl has been shown to affect the
lungs, heart, and central nervous system when it is inhaled. The N-DBPs found
in chlorinated pools are mainly attributed to chlorination of human body fluids
of sweat and urine.
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| Source: jezebel.com |
A recent study done at Purdue University studied the impacts
of uric acid on CNCl an NCl3 concentrations. They stated that close
to 90% of uric acid found in pools comes from urination, if the only source of
uric acid is urine and sweat. The study didn’t use actual body fluids, but
instead made a body fluid analog to react with free chlorine of varying
concentrations. They also collected pool water to see how uric acid reacts in
these solutions. One of the key findings of their study is that uric acid is an
“efficient precursor” of these toxic compounds and that it is also a strong
function of chlorine/precursor ratio, pH, and temperature. Overall, the
research article concluded that decreasing the urination in pools, which is
mostly a voluntary action, would improve air and water quality without having
to change any other factors.
The article from the Latin Post did a pretty good job in
summarizing the study. It reported on most of the aspects that were in the study.
It mentions that how most uric acid comes from urination and what the two toxic
compounds that come from uric acid are. They author also gives a good amount of
background to the implications of the article, discussing the related health
impacts of CNCl and NCl3. Most of the information in this article
though is almost word for word from the news release about the study published by Purdue University. The parts that aren’t word for word have only a couple of words changed. Also, the only link in the news article is to the news release by Purdue, not the actual research study. Overall, the article did a good
job summarizing the findings of the study but did so by essentially copying
another news release.
Study (from MLibrary): http://pubs.acs.org.proxy.lib.umich.edu/doi/pdf/10.1021/es405402r
News article from Latin Post: http://www.latinpost.com/articles/9931/20140401/study-urinating-in-pools-produces-harmful-toxins.htm
News release by Purdue University: http://www.purdue.edu/newsroom/releases/2014/Q2/swimming-pool-urine-combines-with-chlorine-to-pose-health-risks.html
This is a very interesting article, I had no idea that urine generates potentially hazardous "volatile hazardous byproducts" by interacting with chlorine. Researchers are advising swimmers to observe "improved hygiene habits." When I went swimming in Iceland, at every pool and at the Blue Lagoon, you could not get into the pool without showering beforehand and they monitored this by having a guard stand at the door that led to the pool. I think the United States should adopt this practice, because honestly it is disgusting for people to jump in the pool who haven't showered in days or are profusely sweating. Another countermeasure swimming pools should put into effect is when individuals decide to urinate in the pool, the water will turn discolored. I have seen this before, as a way to discourage younger children and sadly adults from urinating in pools.
ReplyDeleteI thought the title was pretty entertaining. I also had no idea that urea could react in pools to create toxic chemicals. Unfortunately, I don't think any amount of science can change people's hygiene habits when it comes to swimming.
ReplyDeleteI wonder if this reaction only occurs in chlorinated pools or if these reactions can occur in pools that use other sanitation methods.
I wonder what the cost and safety considerations were for the decision between real urine and the "body fluid analog" used in the study. Probably came down to replicability.
ReplyDeleteI thought this study was very interesting. (I kind of want to read the grant proposal outlining the reasons for studying urinating in pools) I had never really considered "pool air quality" issues, but it makes sense that the air in those areas would be very different chemically than the normal atmosphere. I would have liked to see a little more background in the article about previous work on the harmful volatile species to get a better understanding of much this chemistry effects an average person.
ReplyDeleteI find the topic of the study very eye-catching, and like Eric said, it would be interesting to see what reasons drove them to do this unique study in the first place. Looking at the other actor in this play, chlorination is probably by far the most common way of disinfection, yet it does have potential health risks by generating toxic by-products, which to some degree reminds me of the story of DDT.
ReplyDeleteI would like to see studies evaluating possible health impacts of these other disinfection methods, including ozone, salt water pools, and bromine (often used in hot tubs).
ReplyDeleteAlso, the Risk Science Center from SPH here at UofM has a video about this very topic! (although mostly just focusing on the urination part) https://www.youtube.com/watch?v=GIU8Qwf6Snk&feature=youtu.be
I'm curious if other studies have already examined the extent of uric acid that is in a common pool. Even if urinating in the pool is not considered (as common as it is) we do know that sweat can contain uric acid as well. If there are truly harmful impacts, I'm surprised that I am only just hearing about this seeing as though people are exposed via inhalation, dermal uptake and orally.
ReplyDeleteOne interesting thing I saw on the study was that the reactive N-DBP's react pretty fast (within 5-10 minutes) with uric acid, which is definitely an important consideration when explaining that the toxic products can affect the people within the pool.
ReplyDeleteReally interesting topic, Jennifer!
ReplyDeleteI am curious how they found out that 90% uric acid comes from urination.
Super interesting read! I would be interested to find the mechanism of action behind how urine causes the creation of these potentially toxic compounds; does it act as a catalyst? I agree with Michael, however, in saying that asking people to stop peeing in pools may be somewhat of an uphill battle.
ReplyDelete