There is an unintended and largely unexplored consequence of Americans’ increased use of pain relievers, antibiotics, hormones, anti-depressants and even drugs taken illegally like fentanyl and heroin: Some of it lands in our streams and rivers and eventually back into our drinking water taps.
Researchers and health officials say the probability is extremely low that human health is being impacted by the compounds, but there is also little research available on the risks.
“As far as I can tell, the present levels are not a cause for alarm,” said Dr. Michael Dohn, Public Health-Dayton & Montgomery County medical director. “But the fact that the water is subject to more and more contaminants is of concern.”
That concern is heightened because of the skyrocketing use of drugs in this country. Prescriptions for both adults and children nearly doubled between 1997 and 2016 — from 2.4 billion to 4.5 billion a year — and by 2013 almost 70 percent of Americans were taking at least one prescription drug regularly.
All those drugs — 1,800 that were legally approved and scores more used illegally — don’t all disappear after entering our bodies.
“Whatever we’re taking as medication, whatever we use in the shower or excrete as waste … low levels of those compounds often make it through the treatment process and into the natural environment,” said Mike Ekberg, a Miami Conservancy District scientist. “They get into water when we flush them down the toilet or when we rinse them down the sink.”
Ekberg and a fellow researcher discovered low concentrations of 17 emerging organic wastewater contaminants — mostly pharmaceuticals and personal care products — in water sampled from the Great Miami River basin in 2010 and 2011. The assorted drugs were found in rivers and streams, in water taken from municipal wells and in effluent discharged from wastewater treatment plants.
Another 2011 study, done by the Environmental Protection Agency’s Cincinnati-based National Exposure Research Laboratory, found high blood pressure medication appeared most frequently in samples taken downstream of 50 large wastewater treatment plants in the country.
“Now that we can find them, we are trying to figure out what the consequences are,” said Daniel Snow, director of the Water Sciences Laboratory and professor of natural resources at the University of Nebraska.
Specific studies haven’t examined whether the nation’s skyrocketing opioid epidemic has introduced more illicit drugs into wastewater, but Snow said he wouldn’t be surprised if those too were slipping through the treatment process.
“Would increasing use lead to increasing occurrence? I think that’s a safe assumption,” Snow said. “But we may not have enough data to confirm that’s the case.”
Studies show large fractions of pharmaceuticals — anywhere from 30 to 90 percent of a dose depending on the drug — leave the body in urine.
Few municipal water systems routinely test for pharmaceuticals, though officials say other contaminants — bacteria, heavy metals and too much nitrogen or phosphorus, for example — pose more of a risk.
“You are looking at parts per trillion,” Keisha Kinney, Dayton’s acting division manager for water supply and treatment, said of the drug traces in the water supply. “For us right now, that is not one of the things we are concerned about based off our current data.”
Dayton’s system supplies water to about 400,000 area residents in multiple municipalities. Its wells pull water from the Great Miami Buried Valley Aquifer, a 3-trillion-gallon reservoir created through tens of thousands of years of glacial activity that left enormous sand and gravel beds that stretch from Logan and Shelby counties in the north, all the way to the Ohio River.
The underground sand and gravel serve as a natural filter, Ekberg said.
“The aquifer itself can be a barrier and naturally remove some of these compounds,” he said. “We found those compounds in groundwater, although we didn’t see as many and they were at lower concentrations.”
Butalbital, a barbiturate commonly used to treat tension headaches, was one drug detected in the Miami Conservancy District study. At the maximum groundwater concentration of butalbital recorded, one would need to drink more than 224 million eight ounce glasses of water to exceed published drinking water guidelines, according to Ekberg and the study’s co-author Bruce Pletsch.
But even as the probability remains low that traces of pharmaceuticals in water are affecting human health, the same may not hold true with smaller aquatic species.
Researchers in at least one study reported changes in the reproductive organs of fish and mollusks downstream from where endocrine-disrupting compounds — including hormones such as synthetic estrogen and androgens — were detected in wastewater effluent.
Ekberg said it’s not clear what if any damage is being done to fish and water species by drugs that may appear in the waterways.
“I don’t think our findings suggest there’s anything to be worried about from a human health perspective, but some of these compounds have the potential to impact the endocrine systems of aquatic wildlife,” he said. “The jury is still out as to exactly what degree. It might potentially impact the reproduction cycles of fish and macroinvertebrates.”
Scientists also say more study is needed to determine whether the accumulation of drug contaminants in water may affect the environment and disrupt the food chain.
“It probably varies from compound to compound. Some compounds may accumulate in sediments,” Ekberg said. “They may accumulate in tissue of fish and other living things and build up over time. All that has to be sorted out.”
‘It’s really important’
Currently no applicable regulatory standards exist for many of the compounds that turn up in the environment. Roughly a third of all prescribed medications are never taken by patients, who then often contribute to the problem by not disposing of unused drugs properly, officials say.
“We talk about it all the time, and it’s really important,” said Brianna Wooten, Montgomery County’s environmental services communications coordinator. “But I think a large number of people probably still flush pharmaceuticals down the toilet.”
Contaminants aren’t always easy to detect, but some long-buried compounds are being brought to light with improved scientific processes.
“These compounds have been around as long as probably humans have been creating them,” said Ekberg, referring to the pharmaceuticals and personal care products that get washed into the environment. “It’s just in recent years the ability to detect these compounds in the natural environment has improved and we can get down to parts-per-trillion-kind-of levels.”
Much of the research didn’t exist before 2000 when scientists at the United States Geological Survey developed equipment to test water for the compounds found in such small quantities.
The advanced testing has detected everything from insect repellent to fire retardants.
Livestock antibiotics and hormone medications have also been found in small concentrations.
Keeping drug compounds in the water from becoming a large, looming risk to the environment and human health will likely require a multi-pronged approach, officials say.
Reducing overprescribing, distributing drug disposal bags, sponsoring “take-back” drug programs, developing “greener” pharmaceuticals and making available alternative forms of pain management are all methods receiving attention.
Dohn said the easiest solution is stopping the drugs from seeping into the water in the first place.
“Prevention is always better than trying to deal with the aftereffects, whether it has to do with heart disease, or diabetes or obesity,” he said. “The same thing is true here. If we can prevent something from getting into the environment, it’s much more effective than trying to clean up the situation later.”
Thank you for reading the Dayton Daily News and for supporting local journalism. Subscribers: log in for access to your daily ePaper and premium newsletters.
Thank you for supporting in-depth local journalism with your subscription to the Dayton Daily News. Get more news when you want it with email newsletters just for subscribers. Sign up here.