Yes, chlorine kills bacteria - But at what cost? Yes, chlorine kills organic matter - But we are organic matter too.
Now, a newly released medical study, in the January 2007 issue of the American Journal Of Epidemiology, directly links chlorinated water to increased risks of cancer. Its time to free ourselves from our addiction to chlorine.
According to the study conducted by Dr. Cristina M. Villanueva of the Municipal Institute of Medical Research in Barcelona, Spain, drinking, bathing or swimming in chlorinated water may increase the risk of bladder cancer by as much as 57%.
Actually the findings are the first to suggest that these chemicals can be harmful when they are inhaled or absorbed through the skin, as well as when they are ingested.
When THM is absorbed through the skin or lungs, Villanueva and her team note, it may have a more powerful carcinogenic effect because it does not undergo detoxification via the liver.
But it means we have some work to do. We need to start finding and discovering alternatives to chlorine, which has been the staple for H2O disinfection and general disinfection for quite some time. We must find ways of getting chlorine out of our lives and the lives of our children.
But it was used in so many ways - from a chemical war weapon to use in making medicines. Click here for a complete Wikipedia rundown of the uses of chlorine in our everyday lives.
But now, with this information out, its use and sale of chlorine can be considered negligent, given the health effects.
No worries, there are alternatives, especially in water disinfection - such as ozone and solar.
Richard F. says:
Concentration means everything. The amount of THMs and other disinfection byproducts is going to be a function of the bather load so in residential pools it is far, far lower than in a high-bather-load commercial/public pool. Also, the rate of production of some disinfection by-products (DBPs), such as irritating nitrogen trichloride, may be a function of the active chlorine (hypochlorous acid) level and this is strongly influenced by the stabilier/conditioner (Cyanuric Acid, CYA) level. Since CYA is not typically used in indoor pools, this may mean that more nitrogen trichloride is produced in such pools.
There are other ways of minimizing DBPs such as the German DIN 19643 standard that uses lower active chlorine levels (0.3 to 0.6 ppm FC with no CYA) and filters out all chloramines and chlorine on each filtration pass using activated carbon. Chlorine is then reinjected. Though this is a reasonable solution for commercial/public pools, it would be far too expensive for residential pools.
Ozone does not leave a residual disinfectant in pool water. Copper/silver metal ion systems do not kill pathogens as quickly as chlorine. Moderation is key.
James E. says:
Richard, my understanding is that Chloramines, are not effectively filtered using activated carbon filters. In fact, many municipalities in the US now use Chloramines instead of Chlorine because it is more stable...meaning it doesn't break down as easily. If you have a fish tank, and replace your water with tap water, your fish will likely die if the water has been treated with Chloramine, and a local pet store will sell you an agent that treats the water so fish can survive. I live in the SF Bay Area where we now use Chloramines in our drinking water. I discovered this recently because I noticed that the toilets in our home all started running at the same time. I took out the rubber stoppers inside the bowl and it almost melted in my hands! When I showed it to the guy at the local plumbing store, he said that he's been seeing tons of people coming in with this same problem...ever since the town switched to Chloramines. Makes me wonder what the stuff does to me in my drinking water. I've tried to purchase water filters that remove Chloramines, but I have learned that it is extremely difficult to remove, and even expensive, high-end filters don't take it all out. I'm sure we've not heard the last word on this stuff. I think the challenge from the municipal water treatment side is that Chlorine is too reactive in transit, so they needed something more stable. It doesn't seem to me that effective, long-term analysis was done for safety before switching to Chloramines.
Richard F. says:
James,
I'm also in the SF Bay Area and experienced the switch from chlorine to monochloramine, though fortunately did not have any side effects on rubber used in our toilet seals. I'm sorry that you had such problems with the conversion. I can't speak for your specific water filter, but I have a Multi-Pure water filter at home for the kitchen sink and I can assure you that it is removing monochloramine. Not only is this listed in what the filter removes as shown here:
http://www.multipureco.com/Health%20Effects%20of%20Water%20Pollutants.pdf
but I have tested the water with a FAS-DPD chlorine test that can test separately for Free Chlorine (FC) and Combined Chlorine (CC) down to below 0.2 ppm. Before the switch from chlorine to monochloramine, I readily measured FC (i.e. chlorine) at around 0.4-0.6 ppm or so with virtually no CC. After the water district switched, I now measure no FC and around 0.8-1.0 CC. I also confirmed the CC test using an ammonia test kit since that technically measures the sum of both ammonia and monochloramine (specifically, so is not interfered by other CC) and it was consistent with the CC test (with the units scaled appropriately).
As noted in the following link:
http://www.multipureco.com/scb.htm
the filter is activated carbon, though it is a solid carbon block rather than granular.
It is true that the traditional methods for removing chlorine from water for aquariums by using a reducing agent such as thiosulfate cannot be used anymore for chloramines since they would simply convert the chloramines to ammonia which is also a problem for fish. So other methods must be used including activated carbon filtration or oxidizing the chloramine to nitrogen gas (such as by adding excess chlorine, waiting, and then dechlorinating via traditional reducing agents).
Richard F. says:
P.S.
I should have written that I measured the CC, so monochloramine, testing unfiltered water. Water through the filter shows no FC nor CC so no chlorine nor monochloramine.
James E. says:
Thanks Richard. I checked out your spec sheet at multipure co....and, it is very important to note that the spec sheet says it "reduces" the amount of chloramines...with no facts about the quantity reduced. Also, it's important for readers to know that studies on chloramines are inadequate, namely,
* The EPA states that there are NO dermal (skin) and NO inhalant (respiratory) studies on chloramine as used as a disinfectant for drinking water.
* The EPA states that there are INADEQUATE cancer studies on humans or animals.
Here's a great site on chloramines for those who want to dig deeper:
http://www.chloramine.org/chloraminefacts.htm#top
And from the site:
Filtration
* Filtration for chloramine is very expensive compared to filtration for chlorine.
* To remove chloramine, an extensive carbon filter (to remove the chlorine part of the chloramine molecule) followed by a reverse osmosis or cation filter (to remove the ammonia) is necessary.
* There is NO certified showerhead filter to remove chloramine. The high flow rate and large volume of water passing through a showerhead renders the showerhead filter useless.
* Sink water filters for chloramine handle low flow, cold water conditions only.
* For high flow uses like showering and bathing, a whole house filtration system would be needed to effectively remove chloramine and ammonia.
* Even with a comprehensive filtration system, no filtration system engineer will guarantee complete removal of chloramine. Chlorine is by far easier to remove with inexpensive carbon filtration.
The fact that this new chemical is being used across the country in our bathing and drinking water supply is troublesome, to say the least. There are many municipalities that are investigating this at the request of their residents, but shouldn't something be done on a more coordinated basis, given the importance and widespread use?
Richard F. says:
The following is a link to the spec. sheet for the specific water filter I have in my home (I think):
http://www.multipureco.com/br170.pdf
(I keep getting the message "Your comment contains characters we don't understand. Keep it simple." and haven't figure out which part of my comment is the offending piece so I'm sending my response in parts).
Richard F. says:
(I think it didn't like the greater than and less than symbols so I'll use words instead)
It specifically states that the percentage reduction of chlorine is 99% and for chloramine it is greater than 97% and that these reduction amounts are when the unit is tested at 200% of capacity. A test at around 3 mg/L with greater than 97% reduction means a resulting level of less than 0.09 mg/L and I can tell you from my testing that it's probably less than 0.05 mg/L (i.e. less than 0.05 ppm) as there was not even a hint of pink in the FAS-DPD test even using larger water samples with more DPD powder.
When I mentioned filtration for aquariums, I should have noted that if activated carbon is used to remove monochloramine, then a subsequent zeolite or cationic exchange filter is typically used to remove the resulting ammonia. I should have seen ammonia in the water from the filter, so I'll redo that test since I didn't seem to see any (but the ammonia test is inexpensive and not as sensitive as the FAS-DPD). If it's there, it's low enough to not taste or smell.
I was aware of the chloramine.org site, but thanks for sharing it so others can take a look.
Notwithstanding the degradation of some types of rubber seals, monochloramine is generally far less reactive than chlorine so produces far less of the known problem disinfection by-products (DBPs) which is why many municipalities are switching to it. It also lasts longer in the distribution system. It is true that there are some unregulated DBPs that form more readily under monochloramine and those are currently being studied by the EPA so it's possible that the switch from chlorine to monochloramine is reducing the devil we know and increasing the devil we don't know (so to speak). By the way, the activated carbon water filter significantly reduces many of the worst regulated DBPs.
Richard F. says:
The following EPA web page has links to detailed data basically saying that information from studies with monochloramine is extremely limited though what is known from limited studies and field research has the EPA allow monochloramine in water supplies.
http://www.epa.gov/ogwdw000/disinfection/chloramine/index.html
http://www.epa.gov/ncea/pdfs/water/chloramine/dwchloramine.pdf
As for showering, monochloramine is far less volatile than chlorine. So yes, it is true that with chlorine you could just use a simple activated carbon filter to mostly remove it while with monochloramine that would just mostly convert it to ammonia. The 1 ppm monochloramine (measured as ppm Cl2) in our local tap water would get converted to 0.2 ppm ammonia (measured as ppm N) from an activated carbon water filter and from what I have read, that's a very low amount for humans (much more of a problem for fish).
Personally, since most people don't have whole-house water filters, I think using monochloramine is less risky for most than using chlorine as a secondary disinfectant in water systems. I'd much rather reduce the known problem volatile disinfection by-products as well as chlorine itself (as in showers). As for rubber in seals, you can read more about this in the following link:
http://www.ashtabularubber.com/ARC%20Images/Chloramine%20Resistance.pdf
Chemical reactions are very specific so you can't jump to the conclusion that attack of monochloramine on certain rubber seals means it's a problem for skin -- the rubber-like seals are polymers vastly unlike natural organics and the problem depends a lot on the specific formulation. If water districts had initially used monochloramine instead of chlorine years ago, then plumbing washer/seal manufacturers would have formulated chemically resistant seals that held up better against monochloramine years ago. Unfortunately, what resists chemical degradation from chlorine doesn't always resist such degradation from monochloramine.
Richard F. says:
So I remeasured my tap water and found that unfiltered it had 1.2 ppm Combined Chlorine (CC) which I presume is monochloramine and had 0 ppm Free Chlorine (FC) so no regular chlorine (hypochlorous acid). The ammonia test kit shows approximately 0.25 ppm "ammonia" though the test cannot distinguish between ammonia and monochloramine and therefore is reporting monochloramine (but in ammonia "units"). The test is a rough visual test going from 0 ppm, 0.25 ppm, 0.5 ppm, etc., but it is very clear when there is no ammonia/monochloramine as the test is "yellow" vs. when there is as the test is various shades of "green". So this is all consistent since 1.2 ppm monochloramine is the same as around 0.25 ppm in ammonia units.
I redid the test for the filtered water and found no FC nor CC, so no chlorine or monochloramine, and that makes sense. However, the ammonia test kit also shows no ammonia/monochloramine or nearly zero (it's pretty yellow and clearly not green as with the unfiltered water). So it appears that the water filter is not just converting monochloramine to ammonia but either filtering the ammonia or completely breaking down the monochloramine (to nitrogen gas). Either that or there is some sort of test error. I'm writing to Multi-Pure to see if I can find out more.
James E. says:
Thanks for the info Richard. I'd be very curious what Multi-Pure says about that...while you're writing to them about this, I'm also curious to what extent it removes fluoride, and what the mechanism is for that? My understanding is that this is another very difficult to filter or break down chemical. This would be for sodium fluoride and not calcium fluoride. I think most water districts are using the sodium kind, and my understanding of that chemical is that originally that was a waste product from the aluminum industry...
Richard F. says:
The solid activated carbon block filters do not remove fluoride, but Multi-Pure does make a filter, MP750plusRO, that also has reverse osmosis that does reduce fluoride by 93.9%.
The San Francisco 2008 Water Quality Report here:
http://sfwater.org/Files/FactSheets/Final_WQ_ccsf_singles_v20.pdf
lists fluoride from the erosion of natural deposits. Sodium vs. calcium fluoride wouldn't be relevant since the sodium or calcium ions would be separate from the fluoride in water. The levels are fairly low in most reports I've seen in the Bay Area. Remember that some water districts used to add fluoride to the water (to strengthen enamel to prevent cavities), though they aren't doing that as much anymore.
So I found out more about why I wasn't seeing the expected amount of ammonia. First off, the way that activated carbon removes chlorine is through the following process:
HOCl + C* ----- H+ + Cl- + CO*
so the chlorine (hypochlorous acid) reacts with activated carbon to produce hydrochloric acid so basically acid and chloride salt and leaves an activated carbon oxide. So over time, the filter will build up with carbon oxide and need to be replaced (most home activated carbon filters aren't recharged since that requires a process with very high temperatures).
For monochloramine, the process can go one of two ways as follows. I also show the net reaction after a steady-state is achieved.
NH2Cl + H2O + C* ----- NH3 + H+ + Cl- + CO*
2NH2Cl + CO* ----- N2 + 2H+ + 2Cl- + H2O + C*
----------------------------------------------------------------
3NH2Cl ----- NH3 + N2 + 3H+ + 3Cl-
So for a new activated carbon filter, the first reaction occurs and produces more ammonia, but once one get closer to a steady-state, the second reaction occurs enough so that the activated carbon is essentially regenerated. The net result is that the amount of ammonia that is produced is 1/3rd the amount it was when the filter was new. It also means the filter will last a lot longer.
Richard F. says:
In my case, I was measuring 1.2 ppm CC which was monochloramine and was expecting to see around 1.2/5 = 0.24 ppm ammonia, but my filter is not new so if it is near steady-state then the expected amount of ammonia (measured as ppm-N) would be 1.2/5/3 = 0.08 ppm. That is certainly possible in what I was seeing since the test only shows comparative patches at 0 and 0.25 ppm. That is, the amount of ammonia was below the limit of what the test would normally be able to detect.
The bottom line is that activated carbon water filters (of high quality) will reduce monochloramine and produce relatively little ammonia.
You can see a list of certified water filters at NSF International here that reduce chloramine:
http://www.nsf.org/certified/dwtu/Listings.asp?ProductFunction=042|Chloramine+Reduction&ProductType=&submit2=SEARCH
Note that most are plumbed-in point-of-use products (i.e. where the filter is at the sink where it is used) since they only handle flow rates of .5 to 1.0 gallons-per-minute (GPM). There are some systems with 5 GPM or higher flow rates that might be suitable as a whole-house system (the low-flow shower head standard is 2.5 GPM at 80 PSI).
NSF does not certify showerhead systems. These usually work by adding ascorbic acid (Vitamin C) to the water as this is a reducing agent that will convert both chlorine and monochloramine into hydrochloric acid and chloride salt. Since tap water always has some buffering and the ascorbic acid systems often use sodium ascorbate as well, the pH doesn't change very much at all. The good news is that one can easily see if such systems actually work by using a relatively inexpensive DPD (or FAS-DPD) total chlorine test to see if there is any visible "pink" indicating either chlorine or monochloramine.