Modern plumbing is too good. If you lived with an outhouse 100 years ago, you might not throw a bunch of chemicals into that pit. We live in a different world now, where a flush solves all sorts of problems. Some modern flushable materials like antibacterial soap may complicate the wastewater process. Other issues, like pharmaceutical waste, are not easy to remove. Overall, the wastewater treatment facilities are being bombarded with new issues related to modern medicine. 

How do we treat wastewater? The goal is to get the stuff you don’t want going back into the river or lake to settle to the bottom or float to the top of the treatment tanks where it can be filtered or separated. 

According to a PBS interview with John Trotter, Bloomington, Indiana water treatment plant superintendent: “Like blood forming a scab, the alum (aluminum sulfate) helps to chunk up the organic material in the water, so it can fall to the bottom of the tank. It works because alum has a positive charge, whereas the organic gunk floating in the water tends to be negatively charged. They stick together and form a solid, which falls out of the water in a process called sedimentation. Then the now clear water goes through the filtration step, where it wends its way through several layers of sand, gravel and charcoal. This removes many of the smaller particles. In the last step, it’s treated with chloramines to kill bacteria and other microorganisms, giving the water its faintly stinky swimming pool smell.”

What happens when materials don’t bond to the additives and sink? The process becomes more complicated. Scientific American cites a report that found that, “Only about half of the prescription drugs and other newly emerging contaminants in sewage are removed by treatment plants.” These findings come from the International Joint Commission; their group studies the Great Lakes from the U.S. and Canada.    

Emerging drugs, like nanomedicines used for cancer treatment, are not so easy to catch. Conventional medicine is ingested and broken down by your stomach or synthesized somewhere else in your body. Nanomedicines are more complex.  They are like little packages that don’t react with your body right away and allow doctors to better specify when, where and how your body metabolizes the substance. These drugs may avoid reacting with non-targeted parts of your body.  Something like a gel cap pill would be the opposite side of the spectrum, because it quickly releases all the medicine into your stomach. The downside of nanomedicines is that they may not coagulate in a wastewater stream and could end up reacting in the liver of fish months later, for example. Eventually, a small dose of that nanomedicine could end up on your dinner plate.   

According to the NCBI, there are way more new nanomedicines and nanoparticles than we know what to do with. “It has been estimated that in 2010, 63–91 percent of over 260,000–309,000 metric tons of global nanoparticles production released into the land that could find its way to fresh and wastewater sources.” Don’t panic. The wastewater treatment facilities are getting better at removing higher percentages of the pharmaceuticals every day. In addition, the occasional part per trillion dose of a nanomedicine may not be a problem for your health.  

The NCBI group blames disposal by toilet as the source for most of the pharmaceuticals. In the past, flushing was the easiest and fastest way for consumers to get rid of old medicine. The federal guidelines don’t allow for flushing everything, but federal agents don’t directly oversee every medicine cabinet in the U.S. We haven’t changed our habits as consumers, and the wastewater equation is getting trickier to balance with more emerging pharmaceuticals.  

What should you do instead of flushing old drugs? Don’t just toss them in the garbage either; they may seep down into the water table from the landfill. If you have prescription drugs that you no longer need, it is best to get them out of your house so someone else doesn’t consume them, but a flush isn’t the best way to do that.

When in doubt for how to properly get rid of your old medicine, check with your local pharmacy. You can also go to DisposeMyMeds.org and the FDA.gov for specific locations for drug collection points. The disposal will vary by the type of medicine. Sometimes, the goal is to keep narcotics from getting into the wrong hands; sometimes it is to keep hard-to-filter substances out of the toilet.  Concerning the general nanomedicine issue, I assume they will do more good than harm to the world. In a decade or so, we will find out. 

 As an interesting side note: if you want to know how many people do cocaine in your neighborhood, wastewater piping is a way to find a ballpark number. They can measure the amount of drugs that flush into untreated wastewater.  According to Popular Science, this may even be a more accurate way to determine the amount of drugs in an area than other measurement options, like voluntary surveys. Some are calling it sewage epidemiology. These tests can even find spikes in amphetamine levels during finals weeks near college campuses.  

Not all modern medical wastewater issues involve ingested drugs. Antibacterial detergents can also affect your drinking water. We live in a world where antibacterial gels are everywhere. Antibacterial soaps are more popular than regular soap in many public places. Do you need to kill 99.9 percent of the bacteria you run into every day?

  The FDA has a page titled, “Antibacterial Soap? You Can Skip It — Use Plain Soap and Water.” Antibacterial soap is not a silver bullet for disease; it could even help bacteria that resists antibiotics to develop. Good hand-washing is a mechanical process, not a chemical one. Scrubbing your nail beds and the webs of your fingers with plain soap and water is the underrated way to keep clean. 

I took a community health issues class in college where they passed around a bottle of lotion for everyone to use on their hands. Next, they told us to go wash our hands. They then had us look under a black light to see what was left of the lotion, which showed up bright green with the light. The group results were terrifying, because a lot of hands in the room were still glowing bright green after a normal hand wash.  

I usually take a small hand-sanitizer gel with me when I travel. I’m going to reconsider as long-term, non-hospital uses of antibacterial soaps may be complicating the clean water world. Not all bacteria are bad. In the same way your intestines use bacteria to keep you alive and digest your food, the wastewater process needs bacteria to break down the bad stuff.