Is it Safe to Drink Your Tap Water?

A recent news report, which can be found all over the web, indicated that there may be small amounts of prescription drugs in the drinking water of most towns. The Associated Press tested tap water in 24 major metropolitan areas, and all were found to include some prescription drugs, ranging from hormones (from birth control and hormone replacement therapy (HRT)) to anti-depressants and mood stabilizers. A major cause is found in city waste processing plants; most drugs only partially remain in the human system, while the rest is excreted through urine and/or feces, and not removed by the current waste processing technologies, and so end up back in the drinking water supply.

In an interview with Sarah Janssen, MD, PhD, MPH, who is a member of the Natural Resources Defense Council, WebMD author Kathleen Doheny learned that this is not a new problem, but has been known to scientists for over a decade (see below for website link). It raised concerns for many scientists when they learned that fish in the Potomac River and elsewhere who had been exposed to estrogen-like substances were developing both male and female characteristics. Analyses are now expanding to look at fish, a great indicator species because they live in potentially contaminated water, for exposure to other types of drugs.

Suzanne Rudzinski of the Office of Water at the US Environmental Protection Agency (EPA) is quoted in that same article as saying that right now "we don't have evidence of a health effect" for people drinking water contaminated by prescription drugs, but that as analytical methods improve, so will their knowledge of potential adverse effects.

Both these experts state that people shouldn't be alarmed or stop drinking tap water. Dr. Janssen suggests that those who are concerned can try a home filtering system such as reverse osmosis or charcoal filtering, but warns that this will reduce most but not all medications in drugs. They also point out that bottled water is not an especially good alternative; EPA standards for drinking water (from municipal systems) are much higher than those used by the FDA, who regulate bottled water.

In an interview, Alan Walter, the Public Works Director for the city of Minot, ND, where water was tested the Associated Press study, said that he believes drug testing of drinking water "may be on the horizon." He says that in addition to drugs that enter the water system by human excretion, people are flushing unused drugs down their toilets, or simply throwing them away into a landfill.

Dr. Rudzinski, in the WebMD article, is quoted as saying that people shouldn't flush unneeded or expired medications. Rather, they should be mixed with something like kitty litter to make them unpalatable to pets, then placed in a sealed container, and placed in the trash. Mr. Walter took issue with this, when I asked him about it. He stated that sooner or later, everything in the landfill, if not treated as hazardous waste, will eventually leach into the water table, and then into city water systems, whether the water source is a river or wells. His advice is that cities provide a hazardous waste disposal for unused or expired medications, just as they do for other home waste that is considered hazardous, like paint or paint thinner, or used motor oil.

It does seem clear that although the significance of relatively small amounts of prescription drugs isn't yet known, this is not a problem that will disappear any time soon.

(References include WebMD, specifically http://www.webmd.com/a-to-z-guides/features/drugs-in-our-drinking-water?ecd=wnl_wmh_031708 ; http://www.kxnet.com; personal communication with Alan Walter)