Being in the health industry and knowing what adverse health issues are associated with Chlorine, I prefer to take my chances with mineral products to treat my water. I have been a pool/spa owner for over 20 years and never had an issue with bacterial infections while using mineral products. I have filtration systems to remove the chlorine from the water I drink and have a system that removes it from my shower. I do this for a very good reason, and it's for my health.
The so called experts on here can tout Chlorine use all they want but when it comes to your health you should investigate what soaking in Chlorine and breathing in it's fumes can do to your health. Here's an exert from an article regarding Chlorine, this is one of many ...
In 1964, the World Health Organization estimated that 80% of all cancers are due to synthetic carcinogens. One group of dangerous chemicals, organochlorines, is a class of industrial agents made of chlorine and carbon. The combination is basically indestructible making it an ideal medium for industry.
Organochlorines do not occur in nature. They are used to manufacture plastic and pesticides. The end products, the by-products, and the production process all expose humans to organochlorines. Paper, for example. Pulp and paper industries use chlorine bleaches to whiten paper. The process of bleaching (chlorine) paper (carbon) releases dioxin, one of the most deadly substances on earth. According to Greenpeace, there is no such thing as a safe level of dioxin.
Mounting evidence suggests that organochlorines are persistent in the environment and in the human body. They are bio-accumulative, increasing in toxicity and magnitude as they move up the food chain. WHAT DO YOU THINK SOAKING IN YOUR SPA BREATHING AND SOAKING IN CHLORINE DOES TO YOU BODY?
Greenpeace released a comprehensive report in 1993 entitled Chlorine, Human Health and the Environment: the Breast Cancer Warning. Cited are 177 organochlorines found in tissues of human and animals: 177 that simply did not exist 50 years ago.
Women's bodies are particularly vulnerable to organochlorines because these chemicals accumulate in fatty cells in the breast and because they mimic estrogen causing abnormal cell reproduction.
Profit Motive
Could it be a cover up? Read the label on a bottle of bleach and tell me what you think?
"To fully understand the big picture," says WHAN's Maia Syfers, "you have to come from the point of view that we live in a free enterprise, profit-oriented society."
First manufactured around the turn of the century, organochlorine production escalated during World War II. When the war ended, chemical companies turned to the domestic market. During the 50s, 60s, and 70s, Dow Chemical, Imperial Chemical Industries (ICI, to Europe what Dow is the US), Occidental Chemical and the like made millions.
When scientists started making connections between cancer and chemicalization in the early 60s, the industry rebuffed environmental regulations placing profitability above all else. As our health industry is moving closer to a for-profit model, so has the cancer establishment. For the full article click the link below or copy and paste it in your URL. www.fwhc.org/health/nocure.htm
The information below is from the State of California
bepreparedcalifornia.ca.gov/NR/rdonlyres/.../ENG_Chlorine.pd
What is chlorine gas?
Chlorine gas comes from chlorine, a common
chemical used in factories, labs, and in some
household products. When liquid chlorine
mixes with air, it turns into chlorine gas.
What does chlorine gas look like?
• It is yellow-green and has a strong smell,
like bleach, and
• It stays close to the ground and spreads fast.
How would I come into contact with
chlorine gas?
You could have contact with chlorine gas if:
• You mix household bleach with other
cleaning products,
• There is an industrial accident, or
• Terrorists release chlorine gas into the air.
Is chlorine gas dangerous?
Yes. Chlorine gas is a poison. If you breathe it,
you could die.
What are the symptoms?
Large amounts of chlorine gas can quickly cause:
• Burning in your nose, throat, and eyes
• Pain, redness, and blisters on your skin
• Watery eyes, blurry vision
• Coughing and trouble breathing
• Nausea and vomiting
With smaller amounts of chlorine gas, the
symptoms may show up later.
I can't believe people arguing over the safety of Chlorine and the advantages using it has over alternative products, just because it's EPA approved and has faster kill rates ... Can any of the water experts tell me, does using Chlorine and its faster kill rates include us humans?
I've been using a mineral product that has worked exceedingly well for me and I would never, ever use toxic Chlorine.
Toxic Chlorine
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Medical Man
-
duraleigh
- Swimming Pool Wizard
- Posts: 81
- Joined: Sat 07 Aug, 2010 23:26
- My Pool: 24X52 DIY Concrete and liner
- Location: Raleigh NC
Toxic Chlorine
Medical Man,
Wouldn't you serve your mission better if you posted your information over on the City Drinking Water forum?
Wouldn't you serve your mission better if you posted your information over on the City Drinking Water forum?
-
chem geek
- Pool Industry Leader
- Posts: 2381
- Joined: Thu 21 Jun, 2007 21:27
- Location: San Rafael, California
Toxic Chlorine
Medical Man,
You lump all kinds of chemicals together as if they are all the same. Dioxin (specifically, 2,3,7,8-tetrachlorodibenzo-p-dioxin) is very toxic, but is produced at high temperatures during incineration or under extremely high chlorine, low pH and high organics conditions of bleaching fiber for paper. In the most recent study with a comprehensive identification of disinfection by-products in high bather load chlorinated and brominated indoor pools, out of 108 compounds, dioxin is not among them (which is, of course, no surprise). In spite of being high bather load pools, the water was found to be as mutagenic at levels similar to treated drinking water.
This related study found that swimming was not associated with DNA damage detectable by the comet assay. Exposure to brominated trihalomethanes was associated with higher genotoxicity. There was increased urine mutagenicity associated with exhaled bromoform and in general the brominated organics are more genotoxic than chlorinated organics. After swimming, the four trihalomethanes in exhaled breath were found to be seven times higher than before swimming.
It is important to understand the difference between the high bather-load indoor pools in these studies vs. outdoor low bather-load residential pools. Virtually all studies of disinfection by-products (DBPs) in pools and spas show that their amount is proportional to bather load. Residential pools have at least 5-10 times lower bather load than most public and many commercial pools including the pools in the aforementioned studies that apparently had very high bather loads given the 1.2-1.3 ppm Free Chlorine (FC) with no CYA yet with 0.29 ppm monochloramine and 0.38 dichloramine (probably a chlorourea) so Combined Chlorine (CC) of 0.67 ppm.
The pools in the studies were in Barcelona, Spain where the authors acknowledged the fill water is high in bromide which explains why even the chlorinated pool was high in brominated organics (that as noted above are more mutagenic), unlike other studies of chlorinated pools. These were also indoor pools that don't have the air circulation nor exposure to UV in sunlight of outdoor pools. These factors significantly lower DBPs in outdoor pools, probably by a factor of 2-5 or more.
Also, the indoor pools in these studies most likely did not have Cyanuric Acid (CYA) in the water so had active chlorine (hypochlorous acid) levels over 10 times higher than found in residential pools that use CYA and that have roughly the equivalent of 0.1 ppm FC with no CYA (when the FC is around 10% of the CYA level). The rate of any elementary chemical reaction involving chlorine will be at least 10 times slower as a result in pools using CYA.
So while it would be better if high bather load pools (such as public pools) and especially indoor public pools used supplemental oxidation (UV, ozone, non-chlorine shock, enzymes) to reduce DBPs, chlorinated outdoor residential pools are much, much safer in that regard. So please stop sensationalizing by referring to very toxic chemicals not even found in pools (e.g. dioxin) and quoting information on chlorine gas that is also not applicable. Since you referred to the World Health Organization (WHO), why don't you read Guidelines for Safe Recreational Waters: Volume 2 -- Swimming pools and similar recreational-water environments, in particular Chapter 3 on Microbial hazards and Chapter 4 on Chemical hazards (especially Section 4.5.2 Risks associated with disinfection by-products) which give a very different take than your older more generalized WHO report that you quoted.
Many drinking water districts now use monochloramine instead of chlorine as a residual to reduce the amount of DBPs formed in the pipes and to have the residual last longer. So filtering chlorine (and monochloramine) in your drinking and showering water is of course fine to do and it's your pool that you can sanitize any way you want (or not at all since regulations only enforce sanitation in public/commercial pools and spas). [EDIT] Actually, you also want to filter THMs themselves as well. [END-EDIT] You still need some sort of oxidizer in your pool since copper and silver ions will not remove the ammonia and urea that comes from your sweat and urine.
As for chlorine kill rates, it does oxidize some of your outer "Stratum corneum" layer of skin cells, which are mostly dead already mostly due to exposure to the environment.
As for copper/silver ionization, I wrote about that in the thread you posted to here and there is more info from the Australian Pesticides and Veternary Medicines Authority. In addition, copper and silver ions are heavy metals that persist in the environment whereas chlorine in pools mostly breaks down to chloride salt.
Richard
You lump all kinds of chemicals together as if they are all the same. Dioxin (specifically, 2,3,7,8-tetrachlorodibenzo-p-dioxin) is very toxic, but is produced at high temperatures during incineration or under extremely high chlorine, low pH and high organics conditions of bleaching fiber for paper. In the most recent study with a comprehensive identification of disinfection by-products in high bather load chlorinated and brominated indoor pools, out of 108 compounds, dioxin is not among them (which is, of course, no surprise). In spite of being high bather load pools, the water was found to be as mutagenic at levels similar to treated drinking water.
This related study found that swimming was not associated with DNA damage detectable by the comet assay. Exposure to brominated trihalomethanes was associated with higher genotoxicity. There was increased urine mutagenicity associated with exhaled bromoform and in general the brominated organics are more genotoxic than chlorinated organics. After swimming, the four trihalomethanes in exhaled breath were found to be seven times higher than before swimming.
It is important to understand the difference between the high bather-load indoor pools in these studies vs. outdoor low bather-load residential pools. Virtually all studies of disinfection by-products (DBPs) in pools and spas show that their amount is proportional to bather load. Residential pools have at least 5-10 times lower bather load than most public and many commercial pools including the pools in the aforementioned studies that apparently had very high bather loads given the 1.2-1.3 ppm Free Chlorine (FC) with no CYA yet with 0.29 ppm monochloramine and 0.38 dichloramine (probably a chlorourea) so Combined Chlorine (CC) of 0.67 ppm.
The pools in the studies were in Barcelona, Spain where the authors acknowledged the fill water is high in bromide which explains why even the chlorinated pool was high in brominated organics (that as noted above are more mutagenic), unlike other studies of chlorinated pools. These were also indoor pools that don't have the air circulation nor exposure to UV in sunlight of outdoor pools. These factors significantly lower DBPs in outdoor pools, probably by a factor of 2-5 or more.
Also, the indoor pools in these studies most likely did not have Cyanuric Acid (CYA) in the water so had active chlorine (hypochlorous acid) levels over 10 times higher than found in residential pools that use CYA and that have roughly the equivalent of 0.1 ppm FC with no CYA (when the FC is around 10% of the CYA level). The rate of any elementary chemical reaction involving chlorine will be at least 10 times slower as a result in pools using CYA.
So while it would be better if high bather load pools (such as public pools) and especially indoor public pools used supplemental oxidation (UV, ozone, non-chlorine shock, enzymes) to reduce DBPs, chlorinated outdoor residential pools are much, much safer in that regard. So please stop sensationalizing by referring to very toxic chemicals not even found in pools (e.g. dioxin) and quoting information on chlorine gas that is also not applicable. Since you referred to the World Health Organization (WHO), why don't you read Guidelines for Safe Recreational Waters: Volume 2 -- Swimming pools and similar recreational-water environments, in particular Chapter 3 on Microbial hazards and Chapter 4 on Chemical hazards (especially Section 4.5.2 Risks associated with disinfection by-products) which give a very different take than your older more generalized WHO report that you quoted.
Many drinking water districts now use monochloramine instead of chlorine as a residual to reduce the amount of DBPs formed in the pipes and to have the residual last longer. So filtering chlorine (and monochloramine) in your drinking and showering water is of course fine to do and it's your pool that you can sanitize any way you want (or not at all since regulations only enforce sanitation in public/commercial pools and spas). [EDIT] Actually, you also want to filter THMs themselves as well. [END-EDIT] You still need some sort of oxidizer in your pool since copper and silver ions will not remove the ammonia and urea that comes from your sweat and urine.
As for chlorine kill rates, it does oxidize some of your outer "Stratum corneum" layer of skin cells, which are mostly dead already mostly due to exposure to the environment.
As for copper/silver ionization, I wrote about that in the thread you posted to here and there is more info from the Australian Pesticides and Veternary Medicines Authority. In addition, copper and silver ions are heavy metals that persist in the environment whereas chlorine in pools mostly breaks down to chloride salt.
Richard
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Medical guy
Toxic Chlorine
In response to my first post, the article at the bottom is an example of one study that offsets that of Richard's long drawn out reply. After having surfed a little through these forums I see Richard is quite opinionated, is that based on your expertise in the field of water quality and some of your own studies or involvement in research? To be quite frank, I do not care to waste my time educating people who think they know everything, especially when they consistently base their words on other people's findings and opinions.
In response to the public drinking water forum comment, perhaps you are correct, I should have posted there. I came across this forum quite by accident, I only read a few of the posts on here and thought I would add my 2 cents worth.
I (posted others published works) to show a few of the obvious harmful effects of chlorine, and what was the response to that?
A response from a person I do think is knowledgeable to a certain degree, (reading others findings online). I do know using others expertise as one's own can often be misleading. People who do this often times, do not have correct information, only someone else's opinions or studies to base their own on and that can be misleading.
If you take the time to do a little research you can always find another article, another study to offset those you have found or read about. I would liken that to those medical experts you find in court of law. The expert witnesses for the prosecution will have an exact opposite opinion to that of the defenses expert witnesses. I have often asked myself, how can experts in specific fields have exact opposite opinions and what are they based on? Most often its due to being paid, is it not?
Good old common sense tells us that Chlorine is not good for our health ... so I elect not to use it despite it's attributes. Look what bleach does to you laundry so why soak and breathe it in when there's no need to do so.
Even though I've used online articles to prove a point, my expertise is based on my education and my own studies as well studies done by others. I am a retired Epidemiologist and I personally elect not to have my children or grandchildren soak in chlorinated pools or hot tubs. There is no need to use toxic, harmful chemicals, there are alternative solutions that can and do work.
BARCELONA, Spain, Sept. 14 (UPI) -- Swimming in chlorinated indoor pools can cause DNA damage, but researchers in Spain, Germany and the Netherlands say they don't suggest not swimming.
http://www.upi.com/Health_News/2010/09/14/Chlorinated-pools-linked-to-DNA-damage/UPI-74881284438222/tab-listen/
Manolis Kogevinas, co-director of the Center for Research in Environmental Epidemiology, and colleagues at the Research Institute Hospital del Mar, the Higher Council for Scientific Research, Hospital Clinic de Barcelona, Universidad Autonoma de Barcelona and scientists from the United States, Germany and the Netherlands, say the study is an exhaustive investigation of disinfection by-products and mutagenicity ability -- to cause permanent DNA mutations -- in water samples collected from two indoor pools.
The disinfection by-products from pools are the result of the reactions between the water disinfectants found in chlorine pools and organic matter introduced by swimmers through sweat, skin cells and urine.
Despite the results, which require more research, Kogevinas says the positive health impacts of swimming can be increased by reducing the levels of chemicals used in pools.
"In no case do we want to stop (people) swimming, but to encourage the reduction of chemicals in swimming pools," Kogevinas says.
http://www.upi.com/.../14/Chlorinated-p ... 1284438222 /
In response to the public drinking water forum comment, perhaps you are correct, I should have posted there. I came across this forum quite by accident, I only read a few of the posts on here and thought I would add my 2 cents worth.
I (posted others published works) to show a few of the obvious harmful effects of chlorine, and what was the response to that?
A response from a person I do think is knowledgeable to a certain degree, (reading others findings online). I do know using others expertise as one's own can often be misleading. People who do this often times, do not have correct information, only someone else's opinions or studies to base their own on and that can be misleading.
If you take the time to do a little research you can always find another article, another study to offset those you have found or read about. I would liken that to those medical experts you find in court of law. The expert witnesses for the prosecution will have an exact opposite opinion to that of the defenses expert witnesses. I have often asked myself, how can experts in specific fields have exact opposite opinions and what are they based on? Most often its due to being paid, is it not?
Good old common sense tells us that Chlorine is not good for our health ... so I elect not to use it despite it's attributes. Look what bleach does to you laundry so why soak and breathe it in when there's no need to do so.
Even though I've used online articles to prove a point, my expertise is based on my education and my own studies as well studies done by others. I am a retired Epidemiologist and I personally elect not to have my children or grandchildren soak in chlorinated pools or hot tubs. There is no need to use toxic, harmful chemicals, there are alternative solutions that can and do work.
BARCELONA, Spain, Sept. 14 (UPI) -- Swimming in chlorinated indoor pools can cause DNA damage, but researchers in Spain, Germany and the Netherlands say they don't suggest not swimming.
http://www.upi.com/Health_News/2010/09/14/Chlorinated-pools-linked-to-DNA-damage/UPI-74881284438222/tab-listen/
Manolis Kogevinas, co-director of the Center for Research in Environmental Epidemiology, and colleagues at the Research Institute Hospital del Mar, the Higher Council for Scientific Research, Hospital Clinic de Barcelona, Universidad Autonoma de Barcelona and scientists from the United States, Germany and the Netherlands, say the study is an exhaustive investigation of disinfection by-products and mutagenicity ability -- to cause permanent DNA mutations -- in water samples collected from two indoor pools.
The disinfection by-products from pools are the result of the reactions between the water disinfectants found in chlorine pools and organic matter introduced by swimmers through sweat, skin cells and urine.
Despite the results, which require more research, Kogevinas says the positive health impacts of swimming can be increased by reducing the levels of chemicals used in pools.
"In no case do we want to stop (people) swimming, but to encourage the reduction of chemicals in swimming pools," Kogevinas says.
http://www.upi.com/.../14/Chlorinated-p ... 1284438222 /
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lbridges
- Swimming Pool Pro
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Toxic Chlorine
Medical guy - have you put as much energy into an analysis of contact and ingestion of the minerals that build up in the pool as well as the slower kill rate of such mechanisms against the effect from chlorine? Can you list the counterpoints?
I respect your desire to keep you and yours safe, but every aspect of life has a trade-off. Reading a study of an indoor public pool in Spain with unknown bather conditions and interpolating that to a back-yard outdoor residential pool seems like extremely poor science.
Disclaimer: I am not a medical practitioner, a biochemist, or even a plain-jane inorganic chemist - but with a PhD in physics I do understand the use, and misuse, of science and statistics.
I respect your desire to keep you and yours safe, but every aspect of life has a trade-off. Reading a study of an indoor public pool in Spain with unknown bather conditions and interpolating that to a back-yard outdoor residential pool seems like extremely poor science.
Disclaimer: I am not a medical practitioner, a biochemist, or even a plain-jane inorganic chemist - but with a PhD in physics I do understand the use, and misuse, of science and statistics.
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chem geek
- Pool Industry Leader
- Posts: 2381
- Joined: Thu 21 Jun, 2007 21:27
- Location: San Rafael, California
Toxic Chlorine
As a (retired) Epidemiologist, you should know better than to link to "popular" websites or even news report summaries when making a point about health concerns. I am a pool homeowner and do not work in the pool/spa or chemical industries. I intentionally link to scientific peer-reviewed studies in major scientific journals, preferably multiple studies so that they are not "cherry-picked". In that way, this isn't about me or my credibility at all, but about the actual science to the degree that it is currently known. You did not post others' published scientific works -- you did not link to the WHO document so that we could all see that the organochlorines they refer to have a wide-range of degree of harm and were not specifically talking about those found in pools nor about the concentrations of such chemicals found in pools. The more recent and more specific WHO document I linked to did so with very different conclusions.
The Women's Health Information page you linked to (written by Alle C. Hall, a "feminist activist and freelance writer living in Seattle") isn't about the specific chemicals nor concentrations found in swimming pools and makes no mention of that. There are absolutely organochlorines in the environment that in some cases are at concentrations that are harmful, but we're talking specifically about the disinfection by-products and their concentrations found in swimming pools. As I wrote before, you mix up different chemicals and ignore actual concentrations and results from real studies in real pools and then assume that low bather load outdoor residential pools are the same.
This scientific peer-reviewed paper is a study of studies of organochlorines and breast cancer (full text here). I download (and pay for, when required) many such papers to get an assessment of scientific facts based on evidence, not just people's opinions. I could easily search the web for non-scientific articles such as The Women's Environmental Network where they talk about the problems of chlorine including dioxin, but they correctly state that the level of chlorine in pools is low, that dioxin is not present, that organochlorines are produced, etc. However, I give little weight to such sites regardless of whether their position supports (as in this case) or refutes what is in the scientific literature.
In my earlier post I purposefully linked to the most recent studies that DO show mutagenic and genotoxic effects including the paper referred to in your linked UPI news article (how can such an article referring to a paper I linked to and discussed in my earlier post possibly offset my "long drawn out reply"?). I'm not trying to pull any punches here, but even in those studies they did not show the kinds of scary information you were giving regarding unrelated chemicals. Instead of linking to news report summaries about the papers I linked to, read the actual scientific papers themselves (which I did link to). As I wrote (in summary form) earlier, the paper on genotoxicity explicitly stated on PDF pages 6-7:
You can see where the UPI article that says "Swimming in chlorinated indoor pools can cause DNA damage" and "cause permanent DNA mutations" is misleading based on the very study they are writing about. As noted in the study conclusions, "swimming was not associated with DNA damage detectable by the comet assay" while the study did indicate mutagenecity in their tests of urine (from 0.6 +/- 2.3 to 1.2 +/- 2.2 Rev/ml-eq where the fraction of variance explained by exposure to THMs was only statistically significant with bromoform and even then that fraction was only 16% -- that is, most of the increase might be due to exercise itself). The study basically showed that the high levels of THMs in breath (7 times higher after 40 minutes of swimming) were handled by the body and at least partially flushed out in urine. The related mutagenicity paper explicitly stated on page PDF pages 6-7:
So here we find out that the level of mutagenicity in this high bather load indoor public pool water is in fact no higher than that found in typical drinking waters. That doesn't mean it's good, of course, but is actually surprising given the nature of this high bather-load indoor public pool.
There is no question that chlorine produces disinfection by-products in pools. That is a fact. The questions, however, are whether the concentration of those products raises a risk that outweighs the benefits and whether the situation with high bather load public indoor pools can be improved and whether the situation with low bather load outdoor residential pools is at all similar (with regard to the proportionality of DBP formation with bather load, see Fig. 1 in this scientific paper as just one of many examples).
At least I have proposed a relatively simple solution which is to 1) use low levels of Cyanuric Acid (CYA) even in indoor pools to significantly lower the active chlorine (hypochlorous acid) concentration and 2) use supplemental oxidation (UV, ozone, non-chlorine shock, enzymes) to reduce the amount of organic precursors (as well as chloramines) to reduce the amount of disinfection by-products.
I also explained why low bather load outdoor residential pools are a far cry from the situation described in most DBP studies and in my post about copper/silver ions I explained the downside to those systems at least as far as disinfection times are concerned (I didn't talk about potential staining issues). [EDIT] See this post for detailed kill times for copper and silver ions in pools and note that metal ions kill slowly or not at all as in the case of copper ions against nearly all fecal and blood-borne bacteria (since many live in lower quantities in the G.I. tract so have mechanisms to completely handle the metal copper ion level in pools that are no higher than the 0.7 to 1.5 mg/L found in blood serum). [END-EDIT] Even in my earlier post in this thread, I stated the following in conclusion:
Chlorine is used in public/commercial pools because it provides a fast-acting killer of bacteria and viruses in the bulk pool water that can prevent person-to-person transmission of disease where one person could otherwise infect dozens if not hundreds of people (or more, with some Cryptosporidium outbreaks, but then chlorine doesn't handle that either). This isn't as much of a concern in a private pool where you usually just swim with your family, but you still need an oxidizer in your pool so would need to use non-chlorine shock or have an ozone system since metal ions do not oxidize bather waste. You have made your own rational choice, but please don't use scare tactics and refer to popular websites rather than scientific peer-reviewed papers to try and convince others that they should make the same choice.
Richard
The Women's Health Information page you linked to (written by Alle C. Hall, a "feminist activist and freelance writer living in Seattle") isn't about the specific chemicals nor concentrations found in swimming pools and makes no mention of that. There are absolutely organochlorines in the environment that in some cases are at concentrations that are harmful, but we're talking specifically about the disinfection by-products and their concentrations found in swimming pools. As I wrote before, you mix up different chemicals and ignore actual concentrations and results from real studies in real pools and then assume that low bather load outdoor residential pools are the same.
This scientific peer-reviewed paper is a study of studies of organochlorines and breast cancer (full text here). I download (and pay for, when required) many such papers to get an assessment of scientific facts based on evidence, not just people's opinions. I could easily search the web for non-scientific articles such as The Women's Environmental Network where they talk about the problems of chlorine including dioxin, but they correctly state that the level of chlorine in pools is low, that dioxin is not present, that organochlorines are produced, etc. However, I give little weight to such sites regardless of whether their position supports (as in this case) or refutes what is in the scientific literature.
In my earlier post I purposefully linked to the most recent studies that DO show mutagenic and genotoxic effects including the paper referred to in your linked UPI news article (how can such an article referring to a paper I linked to and discussed in my earlier post possibly offset my "long drawn out reply"?). I'm not trying to pull any punches here, but even in those studies they did not show the kinds of scary information you were giving regarding unrelated chemicals. Instead of linking to news report summaries about the papers I linked to, read the actual scientific papers themselves (which I did link to). As I wrote (in summary form) earlier, the paper on genotoxicity explicitly stated on PDF pages 6-7:
RESULTS: After swimming, the total concentration of the four trihalomethanes in exhaled breath was seven times higher than before swimming. The change in the frequency of micronucleated lymphocytes after swimming increased in association with exhaled concentrations of the brominated trihalomethanes (p=0.03 for CHCl2Br, p=0.05 for CHClBr2, p=0.01 for CHBr3) but not for chloroform. Swimming was not associated with DNA damage detectable by the comet assay. Urine mutagenecity increased significantly after swimming in association with the concentration of exhaled CHBr3 (p = 0.004). No significant associations with changes in micronucleated urothelial cells were observed.
CONCLUSIONS: Our findings support potential genotoxic effects of exposure to DBPs from swimming pools. The positive health effects gained by swimming could be increased by reducing the potential health risks of pool water.
You can see where the UPI article that says "Swimming in chlorinated indoor pools can cause DNA damage" and "cause permanent DNA mutations" is misleading based on the very study they are writing about. As noted in the study conclusions, "swimming was not associated with DNA damage detectable by the comet assay" while the study did indicate mutagenecity in their tests of urine (from 0.6 +/- 2.3 to 1.2 +/- 2.2 Rev/ml-eq where the fraction of variance explained by exposure to THMs was only statistically significant with bromoform and even then that fraction was only 16% -- that is, most of the increase might be due to exercise itself). The study basically showed that the high levels of THMs in breath (7 times higher after 40 minutes of swimming) were handled by the body and at least partially flushed out in urine. The related mutagenicity paper explicitly stated on page PDF pages 6-7:
RESULTS: We identified more than 100 DBPs, including many nitrogen-containing DBPs that were likely formed from nitrogen-containing precursors from human inputs, such as urine, sweat, and skin cells. Many DBPs were new and have not been reported previously in either swimming pool or drinking waters. Bromoform levels were greater in the brominated vs. chlorinated pool waters, but many brominated DBPs were also identified in the chlorinated waters. The pool waters were mutagenic at levels similar to that of drinking water (~1200 revertants/L-eq in strain TA100-S9 mix).
CONCLUSIONS: This study identified many new DBPs not identified previously in swimming pool or drinking water and found that swimming pool waters are as mutagenic as typical drinking waters.
So here we find out that the level of mutagenicity in this high bather load indoor public pool water is in fact no higher than that found in typical drinking waters. That doesn't mean it's good, of course, but is actually surprising given the nature of this high bather-load indoor public pool.
There is no question that chlorine produces disinfection by-products in pools. That is a fact. The questions, however, are whether the concentration of those products raises a risk that outweighs the benefits and whether the situation with high bather load public indoor pools can be improved and whether the situation with low bather load outdoor residential pools is at all similar (with regard to the proportionality of DBP formation with bather load, see Fig. 1 in this scientific paper as just one of many examples).
At least I have proposed a relatively simple solution which is to 1) use low levels of Cyanuric Acid (CYA) even in indoor pools to significantly lower the active chlorine (hypochlorous acid) concentration and 2) use supplemental oxidation (UV, ozone, non-chlorine shock, enzymes) to reduce the amount of organic precursors (as well as chloramines) to reduce the amount of disinfection by-products.
I also explained why low bather load outdoor residential pools are a far cry from the situation described in most DBP studies and in my post about copper/silver ions I explained the downside to those systems at least as far as disinfection times are concerned (I didn't talk about potential staining issues). [EDIT] See this post for detailed kill times for copper and silver ions in pools and note that metal ions kill slowly or not at all as in the case of copper ions against nearly all fecal and blood-borne bacteria (since many live in lower quantities in the G.I. tract so have mechanisms to completely handle the metal copper ion level in pools that are no higher than the 0.7 to 1.5 mg/L found in blood serum). [END-EDIT] Even in my earlier post in this thread, I stated the following in conclusion:
There is simply a spectrum of risk with regard to the type of disinfectant that you use. Not having an EPA-approved sanitizer (chlorine, bromine, Biguanide/Baqua/PHMB) simply means the risk is higher, but it does not mean that your water is teaming with bacteria. If you were to have someone who was sick be in your pool, they could transmit their disease to you (including the fecal-to-oral route). Also, some bacteria can form biofilms and be more resistant to disinfection so that a more powerful disinfectant is required (or an enzyme or oxidizer specifically able to break down biofilms).
Chlorine is used in public/commercial pools because it provides a fast-acting killer of bacteria and viruses in the bulk pool water that can prevent person-to-person transmission of disease where one person could otherwise infect dozens if not hundreds of people (or more, with some Cryptosporidium outbreaks, but then chlorine doesn't handle that either). This isn't as much of a concern in a private pool where you usually just swim with your family, but you still need an oxidizer in your pool so would need to use non-chlorine shock or have an ozone system since metal ions do not oxidize bather waste. You have made your own rational choice, but please don't use scare tactics and refer to popular websites rather than scientific peer-reviewed papers to try and convince others that they should make the same choice.
Richard
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chem geek
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Toxic Chlorine
chem geek wrote:Also, the indoor pools in these studies most likely did not have Cyanuric Acid (CYA) in the water so had active chlorine (hypochlorous acid) levels over 10 times higher than found in residential pools that use CYA and that have roughly the equivalent of 0.1 ppm FC with no CYA (when the FC is around 10% of the CYA level). The rate of any elementary chemical reaction involving chlorine will be at least 10 times slower as a result in pools using CYA.
I just realized that if you hadn't read some of my other posts, you may not be familiar with why the above statements are true since I did not reference scientific peer-reviewed papers for the above in this thread (though I have documented such references in other threads). The relationship between chlorine, specifically hypochlorous acid, and chlorine combined with cyanuric acid, in compounds called chlorinated isocyanurates, was definitively determined in 1974 by O'Brien, et.al. in this scientific peer-reviewed paper.
I used the equilibrium constants from the O'Brien paper to create this spreadsheet to calculate the hypochlorous acid concentration given standard measured water parameters, especially Free Chlorine (FC), Cyanuric Acid (CYA) and pH. A simplified discussion of the chemistry involved including a derivation of why the FC/CYA ratio is a reasonable proxy for the equivalent FC level with no CYA is in this post.
So not everything I wrote about is a direct reference to scientific peer-reviewed research. Some, as noted above, is derived from such research though doesn't require more than 1st year college chemistry (though the PoolEquations spreadsheet is quite tedious due to the number of simultaneous equations involved and the handling of ionic strength through iterative calculations).
I look forward to seeing the scientific peer-reviewed research and/or your own studies and education you mentioned since so far you've only referred to popular websites not directly related to the subject of DBPs in pools except for the news article about one of the papers I had already linked to and discussed in my original response post. You will probably notice that virtually all of the disinfection by-product studies that you find are with high bather-load indoor pools and the few that included outdoor pools showed lower DBPs though they were still fairly high as the pools were still public pools with high bather loads. The only study I am aware of that included residential outdoor pools is the 2008 Bernard paper on asthma and I wrote about this and an earlier Bernard paper in this thread. As I note in that thread, Bernard's asthma hypotheses are inconsistent with a meta-analysis of numerous other studies on asthma and swimming pool use.
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chem geek
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Toxic Chlorine
There's another epidemiological study here from 2006 showing a doubled risk of bladder cancer from exposure to THMs in drinking water, showering/bathing, and swimming pool exposure combined. (Note that this study was also in Spain including Barcelona which is known to have water high in bromide and that brominated THMs are more mutagenic and potentially carcinogenic than the chlorinated THM chloroform.) It looks like most of the risk (odds ratios in Tables 2 and 3) is associated with showering/bathing. Interestingly, the micronucleated urothelial cells were associated with THM levels, but in the more recent swimming pool genotoxicity studies they showed no such association. This could mean that the non-swimming THM exposure was more related to micronuclei and that the odds ratio for bladder cancer and swimming could be associated with other factors correlated to swimming rather than to swimming itself (which could explain why there was virtually no odds ratio difference relative to exposure amounts between lifetime hours of swimming, 1.00 for no swimming but virtually no change from 1.50 to 1.52 for increasing amounts of swimming, as opposed to increasing odds ratios for both ingestion, 1.00 to 0.88 to 1.17 to 1.35, and showering/bathing, 1.00 to 1.30 to 1.38 to 1.83).
So if one wanted to reduce risks, the shower would be the first place to start, possibly followed by drinking water. Not all shower filters remove THMs. You would need an activated carbon type of filter for such removal, but should also have KDF which has more capacity for removing chlorine (if your water district uses monochloramine instead of chlorine, then the KDF isn't as needed as the activated carbon filter can break monochloramine down without filling up in capacity though the KDF may reduce the liklihood of bacterial growth in the activated carbon media). For drinking water, activated carbon media is used (you don't want to ingest the copper and zinc from KDF). As noted earlier, outdoor residential pools should have lower THMs due to the vastly lower bather loads while for commercial/public pools it would be best if they used supplemental oxidation systems to reduce DBPs in general.
So if one wanted to reduce risks, the shower would be the first place to start, possibly followed by drinking water. Not all shower filters remove THMs. You would need an activated carbon type of filter for such removal, but should also have KDF which has more capacity for removing chlorine (if your water district uses monochloramine instead of chlorine, then the KDF isn't as needed as the activated carbon filter can break monochloramine down without filling up in capacity though the KDF may reduce the liklihood of bacterial growth in the activated carbon media). For drinking water, activated carbon media is used (you don't want to ingest the copper and zinc from KDF). As noted earlier, outdoor residential pools should have lower THMs due to the vastly lower bather loads while for commercial/public pools it would be best if they used supplemental oxidation systems to reduce DBPs in general.
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