Pharmaceuticals

Prescription for Trouble? Studying Pharmaceuticals in Wastewater.

By Marguerite Huber

EPA researchers are studying pharmaceuticals in wastewater to help protect the nation’s waterways. Image courtesy of U.S. Food and Drug Administration.

EPA researchers are studying pharmaceuticals in wastewater to help protect the nation’s waterways. Image courtesy of U.S. FDA.

Approximately 1,800 drugs are approved for prescription use in the United States. Have you ever thought of what happens to all those drugs once they have left you (or your medicine cabinet)? Due to human excretion and people flushing unused pills, these pharmaceuticals can end up in the wastewater stream, presenting a challenge to the nation’s wastewater treatment plants.

To estimate potential pharmaceutical concentrations in wastewater, EPA scientists conducted a survey of wastewater effluent from 50 large U.S. municipal wastewater treatment plants between January and April 2011. They then used the data to evaluate an EPA model designed to estimate potential concentrations of active pharmaceuticals in treated wastewater.

The model generates preliminary estimates of associated risks, and provides a basis for prioritizing the pharmaceuticals that generate the greatest concern for future research efforts.

EPA scientists used pharmaceutical marketing data to choose the 56 pharmaceuticals with the highest number of minimum daily dose equivalents dispensed in the U.S. each year. You may recognize acetaminophen, ibuprofen, and hydrocortisone from the list.

The 50 wastewater treatment plants were chosen based on a number of factors, but together they produce about six billion gallons of treated wastewater a day that is released into rivers and streams. In all, these facilities serve more than 46 million people.

The researchers then analyzed treated wastewater samples from the selected plants to determine the concentrations of the 50 high-priority active pharmaceutical ingredients they identified from the marketing data.

Overall, the survey found low concentrations of pharmaceuticals present in every water sample the researchers analyzed.

Based on the screening data, the researchers estimated that risks were low for both healthy adults and aquatic life from pharmaceutical exposure in wastewater effluent for most drugs. They also found that even under the extreme scenario of someone consuming half a gallon of treated wastewater per day over the course of a year, they would get the equivalent of less than a daily dose of any pharmaceutical currently in use. For most pharmaceuticals, it would be less than one daily dose over the course of a lifetime.

Additionally, based on what the survey revealed about pharmaceuticals in wastewater effluent, the researchers determined that risk of antibiotic-resistant bacteria developing in aquatic environments is low.

Mitchell Kostich, an EPA Scientist who worked on the study, said Agency researchers plan to now focus on the handful of pharmaceuticals that are most frequently used, and appear at levels for which risks to aquatic life cannot be ruled out. With the help of the model and additional data, they expect to be able to predict the maximum wastewater concentrations of any pharmaceutical in current use.

Interested in more about this topic? Join our Water Research Webinar: Pharmaceutical Residues in Municipal Wastewater on Wednesday, September 24th from 12:00 PM – 1:00 PM (EDT), and check out our previous post, A Prescription for a Healthier Environment!

About the Author: Marguerite Huber is a Student Contractor with EPA’s Science Communications Team.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

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A Prescription for a Healthier Environment

By Dustin Renwick

Many different colored pillsNext time you’re waiting at the doctor’s office, consider how what is prescribed there could also contribute to the health of the environment.

Christian Daughton, an EPA research scientist, does just that by looking at the connection between the examination room and the expansive beauty of the outdoors in his research paper, Lower-dose prescribing: Minimizing “side effects” of pharmaceuticals on society and the environment.

The paper is a result of his Pathfinder Innovation Project that explores the idea of considering the environment and the patient as one entity.

When someone ingests a drug, not all of it is absorbed. The human body excretes parts of that medication, including active pharmaceutical ingredients (APIs) that often end up in the sewers and eventually disperse into the environment.

The most common methods for reducing APIs in nature is by treating wastewater (remediation) and organizing take-back programs, where people in a community drop off unused medications for proper disposal. For example, National Prescription Drug Take-Back Day occurred in late October.

“My interest has long been on solving the upstream problem – minimizing the generation of waste rather than its more costly remediation,” Daughton says. “That aspect has long been discounted.”

Daughton is now directing his attention to identifying and reducing inefficiencies of pharmaceuticals in health care: how they are prescribed, dispensed, and ultimately used by the patients.

His research points to two major changes that could positively affect the types and quantities of APIs that infiltrate aquatic ecosystems.

First, doctors can focus on doses. Based on patient needs, physicians can prescribe lower doses of pharmaceuticals to prevent leftover drugs as well as decrease the excreted amounts. The strategy could keep the environment cleaner, reduce costs for patients and improve therapeutic outcomes.

“The idea isn’t to benefit environment at the expense of possibly jeopardizing the patient,” Daughton says. ”It’s a win-win for environment and health care.”

A second aspect of Daughton’s research involves tracking reliable data about which APIs are extensively metabolized by the body and which are excreted unchanged.

Imagine two similar drugs. The one that the human body thoroughly processes has what’s called an “environmentally favorable excretion profile,” and that drug is likely to do less damage to the local creek.

Unfortunately, that information isn’t easy to find.

“Excretion data submitted for regulatory approval purposes isn’t sufficiently comprehensive for examining the potential for environmental impact,” Daughton says. In other words, drug companies don’t need to scrutinize an API beyond what is relevant for human safety.

“That becomes a major stumbling block” to discovering which APIs could have negative environmental impacts.

As the topic of health care moves to the forefront of national discussions, Daughton’s work points to the environment as one missing component in those conversations.

“That’s where I get this expression – treating the environment and the patient as an interconnected whole.”

About the author: Dustin Renwick works as part of the innovation team in the EPA Office of Research and Development.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

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Spring Cleaning | Your Medicine Cabinet

By Kristin Giacalone

Spring has arrived, and with it, the ever dreaded spring cleaning.  While you are washing your windows and cleaning your curtains, take a look inside your medicine cabinet.  If you are anything like me, it is overflowing with unfinished, expired prescriptions and cold remedies.  Now is a great time to clean out that medicine cabinet, but don’t throw those medicines away and definitely do not flush them!

Did you know that 80% of America’s waters that were tested during a recent US Geological Survey study were found to be contaminated with low levels of pharmaceuticals like cholesterol medication, hormones and antidepressants?    These medications enter our water supply through several different pathways, including human and animal excretion of unmetabolized drugs, waste water treatment plants that are not designed to remove these chemicals at such low concentrations, and through septic systems and poorly designed landfills.   So when we flush our expired medications, as we have always been told to, we are introducing our medications straight into our drinking water supply and waters that serve as habitat to countless aquatic species.  While research has clearly shown that constant low level exposure to these medications is having unwanted health effects on aquatic species, it is not yet known what the effects might be on humans.

So how exactly do you get rid of those half empty bottles of antibiotics you stopped taking when you were feeling better or that prescription you didn’t finish because your doctor prescribed you something else instead?  Bring them to your local drop-off location during the Drug Enforcement Agency’s (DEA) Prescription Drug Take Back Day on Saturday, April 28.  The DEA has set up drop-off locations around the country to collect unused and unwanted prescriptions as well as over the counter medications.  The items collected will be properly disposed of through incineration.

Here in Region 2, we are sponsoring collection days on Wednesday, April 25 for our New York City and Edison, NJ employees and on Thursday, April 26 for our Puerto Rico employees.   DEA agents will collect the medications dropped off by EPA and other federal employees for proper disposal.  I look forward to emptying my medicine cabinet!  What about you?

Check out the DEA website to find a collection site near you.

About the Author: Kristin is a Project Manager in the Superfund Program and oversees the clean up of three Superfund sites in New Jersey.  She is also a participant in EPA Region 2’s Leadership Development Program, and as a member of Team Symbiotics, is working with DEA to increase awareness of the water quality issues posed by the improper disposal of pharmaceuticals and personal care products.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

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