Every few months, along with the water bill, I receive a little brochure from the water company that assures me that the level of coliform and fecal bacteria in the water that flows through the taps has been tested at well below required levels. Ditto for the amounts of lead and other heavy metals and nitrates. One important missing category, however, is the residues of pharmaceuticals which have been dumped or excreted into the water sources.
This article gives an indication of the effects of these pharmaceuticals making it into the water supply:
Pharmaceuticals have since been found in treated sewage effluents,
surface waters, soil, and tap water, though at very low levels (parts
per trillion, ppt). These levels are unable to induce acute effects in
humans, i.e., they’re far below the recommended prescription dose, but
have been found to affect aquatic ecosystems. To date, most attention
has been focused on hormone disruption in fish due to pharmaceutical
estrogens present in the environment, and the rise of bacterial
pathogens resistant to conventional antibiotic treatment due, in part,
to their exposure to sub-lethal levels of antibiotics in their
environment. Antibiotics and estrogens are only two of many
pharmaceuticals suspected of persisting in the environment either due
to their inability to naturally biodegrade or continued prevalence as a
result of continuous release. Other studies have shown antidepressants
to trigger premature spawning in shellfish while drugs designed to
treat heart ailments block the ability of fish to repair damaged fins.Recent monitoring studies fail to address one question: Are the
levels of pharmaceuticals in the environment significant? At first
glance, one would say ‘no’ since levels found in the environment are
six to seven orders of magnitude lower than therapeutic doses in spite
of the fact up to 90 percent of an oral drug can be excreted in human
waste. Low and consistent exposures wouldn’t likely produce acute,
notable effects but rather subtle impacts such as behavioral or
reproductive effects that could very well go unnoticed. The good news
is any threat to human health is probably not imminent but rather
long-term.
So it’s not merely the direct route from adulteration of food products such as melamine in pet food and now, Chinese infant formula and milk, or the long-term effect of Bisphenol A used in polycarbonate plastics that is associated with an increase in heart disease and diabetes, apart from phytoestrogenic effects.
Wonder chemicals and drugs are the double-edged sword of modern life. There is probably little we can do to reduce our exposure to these, no matter how hard we might try to avoid it by going ‘green’, switching to bottled water (bisphenol exposure, anyone?) or switching to organic/hormone free food only.
Accidental Blogger 
4 responses to “What’s in your water?(Sujatha)”
Bottled water in most cases is tap water too, or PWS (Public Water Source) as they like to call it :)
Some time back, I wrote a post about lead and Legionnaire’s disease bacteria in tap water – how we are getting our dose of minerals and immunity boosters ;) Now you tell me we are getting our medications as well? How nice :P
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oops..I am sorry, can you fix that link? I seem to have messed up on the html code :(
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I feel bad for the fish – premature spawning and wounded fins are bad news. On the other hand, I feel bad for people dealing with depression and heart attacks.
I guess, in theory, we would improve water treatment to filter out these residual pharmaceuticals. However, I have no idea what the engineering challenges are in doing that. Do you Sujatha?
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Lekhni,
The link seems to be working just fine now. So now you don’t need to go running in search of your Tylenol, just a couple of glasses of water from your tap will do ;)
Andrew,
I don’t know what the water treatment plants will do to address the issue. European countries (Germany & France for instance) seem to be ahead of the curve in recognizing and studying the problem as well as coming up with possible solutions like membrane filtration techniques. (The 2002 article I linked to shows very promising results for a reverse osmosis process using a special semi-permeable membrane that was very effective in removing the pharmaceutical residues for common drugs from a highly polluted sample of water from a canal). Another option suggested by a U.S. researcher is that of decentralized wastewater systems which can help dilute the effect by using soil as a filter of sorts for these residues:
“Wastewater is collected from small areas, often from a single dwelling, treated on-site or in close proximity, and typically dispersed into the soil. Decentralized systems release small amounts of pharmaceutical laden wastewater to the environment at numerous and widespread locations. Multiple studies have shown that pharmaceutical residues dispersed into the soil are attenuated by natural geologic processes, and do not migrate long distances underground. In contrast, pharmaceuticals released to surface water typically migrate longer distances prior to being attenuated by natural processes. Not surprisingly, pharmaceutical detections attributable to decentralized systems are significantly less numerous than those for centralized systems.”
Now, if we could just get around to finding and implementing solutions instead of just ordering study after study to ‘study the problem’, we might get somewhere!
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