View Full Version : Chlorine - Health effects
I have done *some* research on the negative health effects of chlorine in the swimming pool, the shower and drinking water. I also did a search on SDMB and found not one useful thread devoted to the health effects of this mineral, and not one useful, working site cited in the few somewhat related threads.
Most sites I have seen, biased and unbiased, say:
1) that showering is the most dangerous because of open pores and steam inhalation.
2) drinking water's content is not high enough to cause serious risk.
3) Swimming pools: I could not find any direct statements concerning swimming pools, but I assume the risk is high because of the high concentration and the obvious drying of the skin after a swim and some people are known to have bowel problems after swimming too.
Here are two sites, one biased, the other I think not, respectively, to give you a taste of what is being said about chlorine:
There is much talk about breast cancer and the numerous chlorine compounds found in the breast area. Although I am not personally concerned with breast cancer, it stands to show the effects on humans in general.
My question is, is there a real ST or LT danger from exposure to any form of chlorine, in the shower, faucet or pool? I am most concerned with pool and shower exposure (pool=high concentration, shower=open pores and steam), but info on drinking water is welcome too. I am sure some of you out there have done research on this, and I would be much obliged if you could share your findings here as it is extremely hard to find unbiased info on the net concerning this issue.
05-12-2003, 03:16 PM
I did some research on pool chlrorine and found that the amounts were far below any danger levels, and a lack of information that would demonstrate the dangers.
Pool chlorine (bleach essentially) is the most effective way to provide consistently safe sanhitized water. As for the chlorine itself, the levels are far below what is considered dangerous.
I had a ton of info which amounted to a alot of references to a LACK of info indicating anything dangerous.
After doing alot of research for use of chemicals around the home, my conclusions in the biggest areas were:
1. chlorine based cleaners for pools are best/safest for choosing a pool chem and choosing one that sanitizes easily and consistenyly
2. organic fertilizers are best and safest for overall environment
3. weed killers and pesticides are the biggest around-home-threat.
05-12-2003, 03:37 PM
[minor nitpick] Chlorine is, by itself a gas, not a mineral and is poisonous in its elemental form. [/minor nitpick] However, chlorine is also highly reactive with a wide variety of other substances. Chlorinated substances in either solid or liquid form are the result of chemically combining chlorine with other stuff. Frequently the "other stuff" is just as hazardous to humans, if not moreso than chlorine and, in fact, makes the chlorine component much more stable and long-lasting thus increasing its effects as well. So to blame it all on the chlorine is probably something of an exaggeration.
I wouldn't get too bent out of shape about chlorine in your shower/pool water. In the tap water, chlorine is in such a diluted concentration that you shouldn't suffer any ill effects. It is dissolved into the water and cannot be easily released. The small amount of shower water that turns to mist will not release sufficient chlorine to do any damage.
The situation is much the same in a pool. Although concentrations are higher (still measured in tens or hundreds of parts per million), there is no steam or vapor in a pool to allow the release of chlorine in its gaseous form. You may consume small quantities of chlorine by swallowing the water and some may be absorbed through your skin, but again in such small quantities as to be negligible. The vast majority will be processed by your liver and kidneys and will be on its way out again in no time, though hopefully not directly back into the pool. :D
That suprising about the low levels in pools. I mean, I can smell it, feel it in my eyes, taste it and it makes people's skin and hair dry out. That certainly suggests a high concentration. Now, how absorbable the stuff is through the skin while doing laps is the real question. Anyone have some technical info on that?
I'll continue to search around with what little free time I have.
05-12-2003, 05:24 PM
What concentration is used in pools? I know that when I fill my hot tub up with fresh tap water, the chlorine concentration is just exactly right for that, at 1 ppm. Wouldn't a pool have the same amount?
And El Marko, can't the chlorine be easily released from water? It evaporates out of swimming pools, that's why you have to keep adding it. I've heard that you can get the chlorine out of a glass of water by letting it sit for about a half-hour.
05-12-2003, 06:00 PM
The chlorine smell you get from pools and some tap water isn't gaseus chlorine, it's the chloramines formed by the dissolved chlorine reacting with organic "stuff" in the water and then volatilizing off (remember the bit about chlorine being highly reactive? Just enough is added to react with whatever's in the water and leave a little residual behind... so it's not like they just dump in a big overdose every time). That'll be what you taste as well, and the eye irritant from pools isn't caused so much by the chlorine as by the organics in the water (yep, the yellow water and crap that washes off us that the chlorine reacts with - blame the 5 year-olds for that one).
If you want to see actual chlorine gas (a greenish substance), you can do that by mixing some bleach with acid. BUT DON'T DO IT!!! You'll find out how toxic the real gas form is (and how relatively benign the other forms are) if you take a whiff of that stuff - you'll likely be coughing up chunks of lung tissue. Chlorine gas is very nasty stuff, and that's the form that was used in wars. Until some serious research is presented to show that your tap water chlorination is any more dangerous than natural daylight (part of which remember is already a proven danger), I wouldn't worry about it.
05-12-2003, 06:03 PM
I've heard that you can get the chlorine out of a glass of water by letting it sit for about a half-hour.
That at least isn't true. Water in most places is stored for many hours in reservoirs and towers, If simply allowing to stand removed the chlorine then there wouldn't be any need to leave it any longer when it left the pipes.
'Chlorine' will vaporate from swimming polls, but this is a minor loss. The biggest problem is that it becomes neutralised by reacting with dirt, oil etc. The more people swimming and the more dirt they drag in the faster the chlorine is deactivated.
05-12-2003, 11:30 PM
It's mostly true - though it takes more than 30 minutes. Try a day or two, depending on the volume. Water stored in a reservoir (you're talking like a little lake?) isn't chlorinated, that's done at the treatment plant right before it's piped out. Water stored in towers doesn't have nearly as much access to the air as a glass of water - surface to volume ratio, and sometimes may not be chlorinated anyways.
I use hundreds of liters of tap water per week for my fish tanks sans dechlorinating chemicals, and nobody dies from the chlorine (more specifically lack there of). Will absolutey all traces of any chlorine containing compound completely disappear? no. But enough volatilizes off so as not to be toxic to my aquatic life.
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