Is This Additive Contaminating the Water and Air in Your Home? – Body Ecology – 2012 July 3
Disinfection by-products = DBPs
http://en.wikipedia.org/wiki/Disinfection_by-product
Municipal water supplies are treated with oxidizing agents to kill pathogenic microbes. Unfortunately the reaction of these agents with other particulates can result in the formation of hazardous DBPs. We absorb DBPs through drinking or swimming in water containing DBPs, or from breathing contaminated water vapor. (The absorption vectors are gut, skin, and lungs.)
Chlorine-based disinfectants combine with a range of organic and inorganic matter (including iodide and bromide ions) to form various known or suspected carcinogenic DBPs. For example, in indoor swimming pools they combine with urea from urine and sweat to form trihalomethanes (THMs) which are suspected in the elevated rate of asthma in elite swimmers and children. THMs are also linked to higher rates of bladder cancer, miscarriage, and birth defects (from exposure through drinking and bathing in tap water).
http://swimming.about.com/od/allergyandasthma/a/cl_pool_problem.htm
The THM bromoform (CHBr3) is a known carcinogen. Per the Wikipedia article on Bromoform: “It is the main trihalomethane produced in salt swimming pools with some public swimming pools found to contain up to 1.3PPM bromoform.[3] Occupational skin exposure limits are set at 0.1PPM.”
DBPs resulting from ozonation disinfection include bromate (a suspected carcinogen) and formaldehyde. (Per the ‘Safety’ section of the Wikipedia article on formaldehyde, “Formaldehyde can be toxic, allergenic, and carcinogenic”.) (Ozone disinfection is much more prevalent in Europe than in the US, though its use as an alternative to chlorine-based disinfectants in the US is increasing.)
In the US tap water (for drinking) is held to a much higher standard than water used for other purposes such as swimming pools. (Phoenix uses reclaimed water to mist outdoor spaces such as bus stops. I wonder what the health impact is on regular bus patrons due to absorption of DBPs through the lungs and skin.)
While the DBP load at the treatment plant may be within acceptable limits, factors such as pipe corrosion and temperature may raise the load to an unacceptable level in the water coming out of the tap.
Brita filters do not filter out THM (or fluoride). Since THM is fat-soluble, showering or bathing in tap water containing THM should be just as much of a concern as drinking said tap water – in other words a fancy filtration system on your kitchen sink or drinking bottled water (which is presumably not also subject to the same disinfectant system as your tap water) is only going to take care of one source of DBP exposure.
Brita filters are useful for making water taste better, but be sure to change the filters regularly to avoid ‘dumping’: the filter becomes saturated and releases a concentration of contaminants into the pitcher. When the water starts to taste off, I change the filter. (Look on the Brita site for places to recycle your used filters.) When the bottom of the pitcher (easier to see if you use a clear model) gets a green tinge, I empty the pitcher, spritz the pitcher (including the filter holder) with a little white vinegar, and then scrub it clean. Because I keep my Brita pitcher on the kitchen counter (i.e. at room temperature), I can more easily taste when the water is getting ‘off’… but the pitcher does go green more quickly.
Interesting that per the Wikipedia article on Brita, in 2000 Brita, a German company, sold Clorox the sole rights to the Brita brand in North America. In 2008 the Brita company reentered the North American market under the brand name ‘Maeva’.