First, let’s build awareness of the issue: pharmaceutical drugs (among other chemicals) are routinely detected in public drinking water supplies here in the United States. One of the primary sources of these drugs is people--specifically, those who use pharmaceutical drugs. When you use a drug (prescription or over-the-counter) some of that drug passes un-metabolized through your body and is excreted into the septic system. Those drugs then enter the ground water or sewer systems (depending on where you live) and ultimately end up in the bodies of wild animals or in the bodies of people (especially if you live in an area with waste water treatment facilities that recycle water for drinking). So, to summarize this paragraph, many people in metropolitan areas (and some people in rural areas) are being exposed to low, constant doses of antibiotic, antifertility, pain-relieving, and mood-altering medications. Even aquifers have been found to be contaminated by synthetic medicines.
The amount of these drugs in the public water system is low (it would be described as trace). That has led many water suppliers to claim there is no harm caused by the presence of these compounds. However, no test has shown that exposure is safe (especially in the long run) and some recent research finds that harm is being caused. Remember that most medicine is to be taken for a short time and then discontinued. But when you get low doses in your drinking water, you are constantly exposed to a myriad of chemicals—in one review, 63 drugs were found during testing in watersheds around cities and 56 of those were in the public water supply. These low dose medicines in the water have been shown to slow growth of human embryonic kidney cells, speed cancer cell proliferation, and alter blood cell activity. Further, there is evidence that adding chlorine, a common component of urban drinking water, makes the pharmaceutical drugs more toxic. There is no doubt that some wildlife species are being affected. For example, male fish in some areas are being feminized.
So, what do you do about this? Well, you may decide to drink only spring water. That would protect you and your family (note: your home filtration system was likely not designed to remove trace amounts of pharmaceutical drugs). But what about those people who can’t afford bottled water? And what about the other-than-human-persons we share this world with? This is a case where we need to be unselfish. Drugs in the water supply are going to come back to harm us. What if your child lives or one day moves to a metropolitan area and becomes exposed to these compounds? The solution for this dilemma is that we need to be healthier. We need to ingest fewer drugs, wash and adorn ourselves with more eco-friendly products (because those end up in the water as well), and even consider what our toilet paper is doing to the world (recycled paper contains Bisphenol-A, an endocrine disruptor, which also ends up in the water supply).
Regardless of your diet and lifestyle, most people will become ill and be in need of medicine at some point in their life. This is where I encourage people to turn to natural products, even better, those medicines that they gather from the landscapes around their homes. These plants and fungi are ever present in the ecosystem. They are eaten by animals (who excrete them into the environment). They decay in the fall, releasing minerals and various natural compounds. They are all around us, in the leaf litter and in the ground water, and anyone who spends time in the outdoors is constantly exposed to them. Based on what we know, constant exposure to wild plant phytochemicals has a role in generating health (so long as toxins are avoided). Hypothetically, if I were to ingest staghorn sumac for an infection, I would ultimately be excreting chemicals that are already found in the watershed (where I gathered them in the first place). There is no introduction of new or synthetic compounds. No need to gain resistance to novel drugs. No need to worry about the secondary impacts.
Being healthy is the primary way we protect our water supplies from pharmaceutical drugs. Using natural medicine is the second line of defense. Of course, the over-arching principle here is that we need to be aware of what our actions do to the world (and the many ways that poor health hurts everyone, not just the person afflicted with the ailment). Remember: humans did not weave the web of life, they are merely a strand in it. Whatever humans do to the web, they do to themselves (adapted from Chief Seattle).