Myth Flushed? Study Finds Flushing Drugs May Not be Primary Source of CECs in Wastewater

News about contaminants of emerging concerns (CECs) have been hitting the headlines fast these last couple of weeks. On September 2nd the Food and Drug Administration (FDA) announced it is ruling out the use of triclosan in anti-bacterial soaps. Several years of research led the FDA to conclude the chemicals added to soap were ineffective and of no benefit to the consumer.

For the wastewater world that’s one CEC down, more to go.

On September 12th the websites New Scientist and Mashabe picked up a recent US Geological Service study from Vermont that found college students do not flush their old medication down the drain when they’re packing up to leave at the end of the term.  Researchers did find concentrations of CECs increase in the sewage as the students left town, indicating the higher concentrations are coming from the older population who lives there year-round.

New Scientist declared “Myth busted: dumped pills aren’t main source of drugs in sewage.”

Mashable came to the same conclusion  – CEC problems are not created by flushing drugs, rather the drugs are passing right through people and enter sewers via their urine. The Mashable writer concluded, “The growing body of research shows an immediate need for better wastewater treatment.”

The bloggers may not realize building advanced water treatment systems for all Americans would cost tens of billions of dollars on top of the current $200 billion backlog in deferred maintenance of aging water systems. Many CWEA members believe pretreatment and pollution prevention are an important first step in combating CECs. Outreach plays a critical role in preventing CECs from reaching the environment, a topic frequently discussed at CWEA’s P3S committee meetings.

We had a chance to talk with the study authors and talk about what steps the wastewater community should take next –technology? Regulations? Pretreatment? Patrick Phillips is with the US Geological Survey (USGS) in Troy, New York and Dr. Christine Vatovec is a professor with the University of Vermont. Their study appeared in Science of the Total Environment.

1. Should we take from your study flushed medications are not a priority wastewater professionals should focus on to prevent CEC pollution?

Patrick:  No.  Our study showed that based on student behavior and measured concentrations, the evidence for our study suggests that flushed medications are not an important factor.  One plausible reason for this is that education efforts have led people to not flush medications.

Christine: I’ll reiterate that down-the-drain disposal among college students does not appear to be an important source of pharmaceuticals in wastewater. Other populations may be more likely to flush unused drugs, and we are working on this question.

2. In the New Scientist article it mentions the myth about flushed medicines is now busted by your study, what does that mean?

Patrick: The importance of flushing medications is an urban myth because its importance has never been tested.  As we state in our paper ‘scholars have noted that there is little to no data to show the importance of flushing of medications in impacting observed concentrations of pharmaceuticals in wastewater samples.’

We tried a novel approach of combining a survey of behavior with measuring pharmaceuticals, which provides a more complete assessment of the importance of flushing than had ever been attempted before.  Our paper notes that there are instances where researchers have measured elevated concentrations of select pharmaceuticals that can be tied back to illicit activities or suspected disposal by a pharmacy.

3. Right now municipal waste management professionals in California are in a tough fight to encourage the development of drug take back programs inside pharmacies. Do you think we should push forward or are drug take back programs not needed?

Patrick:  Regardless of the effect on concentrations in water, takeback programs can ensure that pharmaceuticals are managed in a responsible manner from both a human health and water resources point of view.

Christine: Our study showed that flushing of unused medications was not a major source of pharmaceutical contaminants among a population of college students – the population is important because our results might mean that these young adults have been better educated about proper disposal than older generations, or it could mean that the students just haven’t accumulated enough drug waste to think about flushing it down the drain.

One question we are working on now is how different populations, and different age groups in particular, are disposing of their unused meds. From my earlier work, there seems to be good potential that older populations may have large accumulations of drugs that get flushed because of a variety of barriers for proper disposal, including a lack of takeback programs and regulations.

So while this current study showed that flushing was not a major source among one population, there are many questions remaining about disposal routes.

4. To combat CEC pollution wastewater professionals are focused on public outreach campaigns, such as the No Drugs Down the Drain Campaign. Has your research found public outreach is not worth our time?

Patrick: No.  Our research shows that flushing medications is not a major factor in our study, which was conducted after several years of education on this matter.  This may very well indicate that education has resulted in this not being a common practice.

Christine: I’ll add again the importance of the population factor – perhaps this population of university students has been better educated about proper disposal, though there are other reasons that might explain their disposal behaviors as well, such as a lack of accumulated drugs.

Other populations may exhibit different disposal behaviors. If this is the case, and this is a question we are working on, we may be able to better target certain groups for education while at the same time supporting the development of take-back programs that are easily accessible to people.

5. If you were running a wastewater agency what’s something you would do to get CECs under control?

Patrick: Encourage Federal agencies such as the FDA to assess the effectiveness of claims of some CECs in consumer products, which is what is being done now with several antimicrobials.  Encourage consumers to understand the presence of these compounds in consumer products.

Christine: I would urge regulating agencies to work together to identify effective models for prescribing and dispensing less medication in a way that would support both human and ecological health. We have a “buy in bulk and save” model that appears to result in large volumes of pharmaceuticals that go unused for a variety of reasons ranging from not offering the desired effect and the patients stops using them, to expiring before the patient can use them all.

Evidence for these large volumes of drugs is easily available at the DEA site. The title of the most recent press release from the National Take-Back Day program says that a “record-setting amount” of drugs was collected this past spring. The DEA collected 893,498 pounds of unused prescription drugs alone over one weekend.

If we can find ways to minimize the source of these CECs we will be able to minimize their potential negative environmental and public health effects.

6. How often do you meet with water and wastewater professionals to plan what your research project?

Patrick: Every study we perform that includes wastewater treatment plant sampling includes wastewater professionals.  We have worked at over 20 wastewater plants and at numerous water supply plants over the last decade, and always involve them in planning.  In many studies, we also work with environmental engineers.  As a scientist studying the presence of CECs in the environment for nearly 15 years, I would also consider myself a water professional.

7. When will your next study about CECs and wastewater come out?

Patrick: We have several studies in the works that will come out in the next year or so.

8. Any other recommendations for wastewater professionals when it comes to medicines entering waterways?

Patrick: Be aware of the potential for unusual sources, such as pharmaceutical manufacturing facilities, or unusual hydrologic conditions, such as combined sewer overflows.


Thank you Patrick and Christine for sharing your insights on CECs!

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Alec Mackie

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