Levels of Risk

Umbra on chlorine 13

Dear Umbra,

So I've been buying unbleached diapers for my baby, using chlorine-free laundry and dish soaps and non-chlorine bleached paper, and generally thinking that's better for me and the environment. Then I go swimming in a chlorinated pool twice a week, sometimes with my kids! Is there a difference in the type of chlorine exposure? Is swimming a health risk? It certainly bothers my nose (I think I'll start using some nose plugs). Can you explain some more of the science behind the effects of chlorine?

Joan Haysom
Ottawa, Ontario, Canada

Dearest Joan,

Quite a dilemma, you're right. But take strength in numbers, because you are far, far from alone in this conundrum -- I'm with you. At least we're together. And your instincts are correct: The major issues with bleached paper products and chlorinated dish soap are different from the major issues with chlorinated pools.

Just another day at the bleach?

Photo: iStockphoto

The biggie with bleached paper products and chlorinated cleaning products is dioxins. They are also a problem with backyard burning, incineration of household waste, and the manufacture of vinyl, among other hot topics seen in Ask Umbra.

Dioxins are a category of chemical, a sort of evil family that is a byproduct of the manufacturing and disposal of chlorine. They are highly persistent in the environment and harmful to our health as well as the health of other living beings. Pretty much everyone agrees that dioxins are carcinogens and disruptive to our hormonal and reproductive systems. The point of purchasing unbleached paper and avoiding vinyl (that's final!), etc., isn't to protect us from immediate dioxin exposure in our homes, but to protect the larger environment from further dioxin buildup.

We primarily take up dioxins not from our paper products but through our food, because they accumulate in the food chain, in fatty tissues. Vegans have got it right on that count and many others: to eat less dioxin, eat no meat or dairy products. Sadly, this applies to human breast milk as well. (Breast milk is still the best food for babies, but feel free to stop drinking cow and yak milk.)

Your shopping (or lack thereof -- not shopping at all is often ecologically fabulous) is helping the larger environment and eventually filtering down to help you a little, or maybe your great-grandchildren. Swimming, on the other hand, is all about your immediate environment and how it will affect your health.

I wrote about pools a few years back, and other articles in Grist have covered the slow reveal on health problems resulting from pool chlorine. The chlorine is used to keep us safe from very unpleasant bacteria such as cryptosporidium and E. coli, but it reacts with air and human bodies to make a wide variety of new chemical compounds. Swimmers, who are breathing rapidly either because they are exercising or because they are children, or both, then inhale and absorb and swallow these compounds. Basically, the news is sobering, and after I wrote the pool piece we got a nice letter from an academic adding that the trihalomethanes I had highlighted as bad news were only a few of the phalanx of dangerous chemicals created when chlorine reacts with organic substances (dioxin is one of these items). Then last year Belgians linked chlorinated pool exposure to asthmatic wheezing.

Back to your original question. I hope I have clarified the difference in chlorine exposure: one is big picture and the other is immediate; but both have to do with chemicals created when chlorine interacts with organic compounds. Swimming pools are a health "risk," yes, but a "risk" in the sense that it may be a problem or it may not -- we don't quite know. I don't think pool water is yet called a health hazard. I'm not giving you too much detailed chlorine science; if you want organic chemistry, you'll have to ask elsewhere. Should you swim with your kids at the pool? I can't make that choice for you. Maybe you could have a discussion with pool staff about the levels of chlorine (they are regulated by health codes so won't vary much), the adequacy of ventilation, and their own awareness of chlorine overexposure, and that discussion could help you decide.

Resignedly,
Umbra

 

Yours is to wonder why, hers is to answer (or try). Send your green-living questions to Umbra.

Umbra Fisk is Grist Research Associate II, Hardcover and Periodicals Unit, floors 2B-4B.

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  1. AskPablo Posted 2:41 am
    12 Mar 2007

    Danger of ChlorineHello Umbra!
    Did you know that the US chlorine industry is a major source of mercury emissions? You can find out all about this in a report by  Oceana.
    I used to work as an engineer in the ozone generator industry and have performed a material intensity analysis (using an LCA tool called MIPS)on ozone generation vs. chlorine in pool sanitation. The ozone comes out far ahead in the numbers but does even better in the qualitative results. You don't even know it's there, and when it's done oxidizing the "bather load" it simply turns back into O2.
    Cheers!
    Pablo

    AskPablo.org

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  2. cnplum Posted 3:04 am
    12 Mar 2007

    Chlorine: It's not just in the poolI am in the process of adding a whole house activated carbon filter to because of the chlorine that is added by the local water provider.  I moved into my house in Silver Spring, MD last summer after living over 20 years on well water, and I found that I could smell the chlorine in the air every time I took a shower or did laundry.  The chlorine level out of the tap is 2.5 ppm: both 'safe' (according to water standards) and also higher than I ever maintained in my swimming pool when I had one (no more than 1 ppm).

     

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  3. misvickie2 Posted 3:22 am
    12 Mar 2007

    Chlorine in PoolsLast summer I visited my aunt & uncle who have just retired to Palm Springs. They have a new house with a built in swimming pool only they don't use chlorine in their pool they use a salt instead. From what I am told it keeps it just as santized. There might be a little more upkeep to it compared to chlorine but it seems a lot more user friendly for the atmosphere. And you can still open your eyes under water without any burning.

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  4. greyowl Posted 3:28 am
    12 Mar 2007

    ChlorineChlorine is powerful bactericide, the alternatives are even nastier.  Thus you will find all sorts of household products that contain bleach.  Suprisingly this is one of the major sources of chlorine in municiple waste streams.  There are a few things one can do to eliminate household chlorine.   Use sodium percarbonate as a bleach/cleaner, when it breaks down it produces water and sodium carbonate.  Good old soap does a decent job of killing bacteria.
    We are stuck with chlorine for drinking water, or chlorine dioxide.  Besides the usual bacteria, one can now find viri such as Hep A in the water.  Not cool.  I would much rather consume a little chlorine than catch Hep A.
    Bob

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  5. rglater Posted 5:48 am
    12 Mar 2007

    ChlorineDid you notice the Google Ads that came up when viewing the article?
    I wonder if any of them work and are any better for us or the environment?

    RD

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  6. linden Posted 8:37 pm
    12 Mar 2007

    Chlorine v. iodineSee discussion of iodine displacement in the human body by chlorine (and other halogens) at jcrows.com
    Linden

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  7. CyberBrook's avatar

    CyberBrook Posted 11:38 pm
    12 Mar 2007

    dioxinsHere's my takeaway message:
    To avoid dioxins and other persistent organic pollutants (POPs), Umbra says the risk of pool water is unclear, but the risk of meat and milk, where dioxins bioaccumulate, are clear.
    Of course, there are MANY other risks associated with meat and milk. You know, things from heart disease, cancer, stroke, diabetes, and gout to global warming, deforestation, loss of topsoil, and water pollution. Little stuff like that.
    But if those things don't bother you, then have a cow and don't worry about it.
    If you're even slightly concerned about your health and the health of life on Earth, please take a look at Eco-Eating: Eating as if the Earth Matters

    http://www.brook.com/veg

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  8. GaGa Posted 11:47 pm
    12 Mar 2007

    swimming and chlorineHave you thought about swimming in a lake?  I have to believe there are some around Ottawa.

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  9. andrewjoslyn Posted 12:36 am
    13 Mar 2007

    CryptosporidiumI'm pretty sure that cryptosporidium is not a bacterium, it is a protozoan, and it is a big problem because it can be much more difficult to kill in disinfection systems than many bacteria are because it can create cysts that are resistant to chlorine.  So try not to swallow that pool water if you can avoid it!

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  10. SnoDragon Posted 7:30 am
    13 Mar 2007

    Salt waterI, too, have heard about and read articles about saline pools. They're supposed to be better for your skin (soft water) and the salt content makes it difficult if not impossible for dangerous bacteria to survive.
    Saline pools can be cheaper than chlorine pools, too, because you don't have to buy expensive chemicals and check the pH constantly.
    If I ever have a pool, I want it to be a saline one.
    If you're going to do lakes or rivers, make sure they're not polluted (or, as unpolluted as possible)! Swimming in a river just downstream from a paper mill would be far worse than swimming in a chlorine pool. Think of all the bleach and dioxins!
    Maybe the mom could take her kids to a spa instead? :)

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  11. AskPablo Posted 10:32 am
    13 Mar 2007

    Saline PoolsMost "saline pools" use an electrolysis device that converts the NaCl in the water into Chlorine (and Na2). I believe, like ozone, it reverts back to NaCl when it is done oxidizing the bad stuff. When used in combination with ozone (like in Del Ozone's TrioPure) it is an extremely effective sanitation system and vastly better than a chlorinated pool. Usually the salt levels are below the taste threshold.

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  12. Earth Shaman Posted 4:10 am
    20 Mar 2007

    Chlorine InhalationYou also get quite a hit of the chlorine gas from showering in city water.They have screw on chlorine filters for the shower.I use nothing except ozone in my hot tub as chlorine ingestion into hot open pores is really deadly.

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  13. Liara Covert Posted 8:25 pm
    05 Apr 2007

    Consider the alternativesIt's true most household cleaning products contain chlorine. As chlorine is in some way connected with many products we consume, its almost impossible to avoid.  Why not read labels and minimize usage?  Desirable actions would stick to simple cleansers like natural soap, bicarb soda and vinegar, and avoid using products made from PVC and PVDC. They aren't easily disposed of when their usefulness has ended. Polyethelene is a safer substitute.
    As for chlorine  as a disinfectant in swimming pools, its useful to reflect on how much is going too far? The whole safety thing can be overdone. Cleaning and sterilising things for children can lead to serious allergies and other issues later in life. We swim at the beach. If kids build no immunity, they become more susceptible to other diseases or reactions. What is it with the trend of treating minor sniffles with strong medicines and anti-biotics? Why not minimize chlorine in pools and consider alternatives? Think of eco-friendly fish tanks. Chlorine would kill the fish.

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