Did you know you have been taking trace amounts of hydrocodone for pain, ranitidine for acid reflux, and hydrochlorothiazide for congestive heart failure simply from drinking tap water? A new national study, conducted by the EPA, has found trace amounts of pharmaceuticals in water supplies nationwide.

The pharmaceuticals enter the water supply two ways: from our bodies releasing them when we urinate or from when we flush old pharmaceuticals down the toilet. Studies have proven that the low-doses of pharmaceuticals are affecting fish, frogs, and lobsters, with one study showing that some male fish are developing eggs.

In the new study, set to be released in this month’s Environmental Pollution, researchers examined water samples from 50 large-size wastewater treatment plants from all over the U.S. and tested for 56 drugs, including oxycodone, high-blood pressure medications, and over-the-counter drugs like Tylenol and ibuprofen. More than half of the samples tested positive for at least 25 of the drugs monitored, with high blood pressure medications appearing in the highest concentrations and most frequently. While health officials say these compounds in water pose a low risk to humans, there are currently no models to predict the effect the cocktail of medications have on human or aquatic life.  Also there are no federal or state regulations requiring drinking water or wastewater plants to monitor for pharmaceuticals.

When pharmaceutical companies apply for a new drug approval, they have to submit an estimate of how much of the drug will end up in the environment, based on how many people they estimate will take the drug, how it will pass through the body, and how it degrades in water. If this estimate is over 1 part per billion (ppb) the FDA may ask for a more thorough evaluation of how the drug will affect aquatic life.

Shane Snyder, the co-director of the Arizona Laboratory for Emerging Contaminants at the University of Arizona, has been studying pharmaceuticals in water supplies for more than a decade. Snyder contends it would not be difficult to determine how to remove the compounds from the water, however it might be costly and the byproducts might be worse than the original contaminants.

“If you put in ozone or advance oxidation to take out a compound, when you oxidize chemicals it becomes something different,” he said. “So while it’s no longer a statin it’s not some byproduct. It’s now very common to make water more toxic after treatment than it was before treatment.”

The FDA says it is working to study the how low-levels of pharmaceuticals affect human health, but other researchers would like to see studies on the low-level mixture of pharmaceuticals in the water supply. Nick Schroeck, the executive director of the Great Lakes Environmental Law Center in Detroit, says “The scary thing for me is not one particular drug, although do I want to be drinking Viagra in my water? No. It’s potentially hundreds or thousands of compounds interacting with each other and how that affects aquatic life and human health.”