Increased drug use triggers worry: risks to water supply
Research is scarce on how environment, human health affected.
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 lev
els 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 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 intro- duced 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 assump- tion,” Snow said. “But we may not have enough data to confirm that’s the case.”
Studies show large frac- tions of pharmaceuticals — anywhere from 30 to 90 percent of a dose depending on the drug — leave the body in urine.
Natural filter
Few municipal water systems routinely test for phar- maceuticals, though officials say other contaminants — bacteria, phosphorus and heavy metals, for example — pose more of a risk.
“You are looking at parts per trillion,” Keisha Kinney, Dayton’s acting division man- ager 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 munic- ipalities. 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 natu- ral 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 butalbi- tal 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 down- stream from where endo- crine-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 find- ings suggest there’s anything to be worried about from a human health perspective, but some of these compounds have the poten
tial 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 inwater may affect the environment and disrupt the food chain.
“It probably varies from compound to compound. Some compounds may accu- mulate 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 environ- ment. 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.
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-trillionkind-of levels.”
Much of the research didn’t exist before 2000 when sci
entists 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.
Prevention urged
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 obe
sity,” he said.