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PPCPs' Double Life

Experts are concerned about the potential health and environmental impacts of contaminants from pharmaceuticals and personal care products that survive municipal wastewater treatment

By Sherleen H. Mahoney September 1, 2006

Each and every one of us contribute to water pollution. "Not I," you say? Well, if you use personal care products, such as shampoos, lotions, or antiperspirants, you do. If you take any kind of medication, over-the-counter or prescription, you do. Each year, thousands of tons of chemicals from pharmaceuticals and personal care products (PPCPs) infiltrate our environment with little or no resistance. PPCPs include all drugs, over-the-counter and prescription, and any products used for personal care, such as fragrances, cosmetics, sunscreens, antiseptics, and soaps. In the United States, the top prescribed drug in 2005 was hydrocodone with more than 100 million prescriptions, and according to the American Academy of Dermatology, and the average adult uses at least seven different skin-care products each day. And many households dispose of expired or unwanted medication by simply flushing them down the toilet.

A Big Dose of Reality
PPCPs live a double life. We need many of them to stay hygienic and healthy, but they are believed to adversely affect the environment. Whenever we pop a pill, its effects continue long after the ailment is alleviated. In fact, up to 90 percent of oral medications pass through our bodies unchanged, and those compounds end up at water treatment facilities that are not equipped to remove them. The same is true for chemicals from personal care products. Aside from the aesthetic results, chemicals from products that are applied topically are easily washed off and end up in the environment. Researchers at the Johns Hopkins Bloomberg School of Public Health found 75 percent of triclocarban, an ingredient found in antibacterial hand soap, which is toxic when ingested, remained intact after treatment in a wastewater facility. It accumulates in wastewater sludge, which is then used to fertilize citrus fruit, soy bean and carrot crops.

"Typical wastewater treatment facilities, secondary, and tertiary treatment plants are not designed to remove PPCPs from wastewater," said Karin North, associate engineer with the City of Palo Alto's Environmental Compliance Group. PPCPs are currently unregulated, and with no means of specific removal, municipal wastewater, health, and environmental professionals are concerned. PPCPs are constantly flowing into the environment with unknown cumulative and synergistic effects. They are designed to produce biological effects, even at therapeutic doses, which means that even at low concentrations, they remain active and may deviate from their original intent and cause different reactions in the environment.

Mounting Evidence
Recent monitoring studies have found low trace levels of PPCPs in the parts-per-trillion and -billion, comparable to one drop in an Olympic-sized swimming pool, in soils, sewage treated effluent, surface water, groundwater, and even drinking water around the world. In Canada, researchers at Edmonton's Enviro-Test Labs, found carbamazepine, an epileptic drug, and emfibrozil, a cholesterol reducing drug in the drinking water of four cities. Germany has been studying PPCPs for the past decade. Thirty-one different PPCPs were found in 40 German rivers and streams. The antidepressant, fluoxetine, better known as Prozac, was found in trace amounts in groundwater in England. The most notable state-side study was conducted by the U.S. Geological Survey (USGS) in 1999-2000, where 139 rivers in 30 states were tested and found that 80 percent of streams contained 31 different drugs. U.S. studies have also confirmed the presence of PPCPs, such as naproxen, estrone, and clofibric acid in drinking water. Thanks to new technology capable of detecting low concentrations, it is no longer a question of if these compounds are in our waters -- they are. A flood of new questions has emerged with no answers; most importantly, what are their effects?

Side Effects
We are ingesting low traces of medication we don't need or want. Sensitive populations, particularly pregnant women and children, are believed to be most susceptible to any negative effects, but studies have not shown any impacts on human health as of yet. The Biogeochemistry Research Group at Harvard School of Public Health is currently studying PPCPs to develop a ranking system to identify which compounds pose the most significant threat to humans and the environment.

To date, most of the research has been focused on aquatic environments. There's a lot we don't know yet, but what we do know is that PPCPs are blamed for various negative effects on marine life. Populations of male fish are being feminized when exposed to wastewater containing low concentrations of estrogen from oral contraceptives. They are growing ovaries, suffering from low sperm count, producing egg proteins usually found only in females, and in some cases, trying to lay eggs.

Antidepressants, including Prozac, Zoloft, and Paxil have been linked to significantly delayed metamorphosis in amphibians, which may seriously impact their survival rate. Fish and amphibians are sensitive to subtle environmental changes and serve as biological indicators that may predict future effects on other species.

Increased use of antibiotics has created antibiotic-resistant pathogens, and trace compounds from antibiotics may exacerbate the problem. USGS found ampicillin-resistant bacteria in every U.S. river tested in 1999. Combating drug-resistant bacterial strains will require more expensive and more toxic alternatives, which, without PPCP removal, will only cause a cyclical, snowballing effect.

What Works and What Doesn't
Municipal wastewater treatment facilities are not always successful in removing PPCPs from wastewater. "There are thousands of PPCPs, each chemical with different characteristics, some are water soluble, some tend to sorb into solids, and some are a little of both. Therefore, some PPCPs are removed or degraded during the normal treatment process and some are not," North said. "Many PPCPs sorb into solids which are often land applied. The sheer volume and constant input of PPCPs to the wastewater treatment plant results in a constant discharge of PPCPs to the environment, which results in a pseudo-persistence."

The EU project, POSEIDON, was formed to assess technologies for PPCP removal. Participants in this project included researchers from various European countries, such as Germany's Federal Institute of Hydrology and ECT Ecotoxicology Gmbh; Eawag; the Swiss Federal Institute of Aquatic Science and Technology; France's Suez Environment and universities from Finland, Austria, Spain, and Poland. The final results were published in June 2005. They indicate:

• Biological degradation and sorption are the main mechanisms for PPCP removal during municipal wastewater treatment.
  
• Ozonation of treated effluent substantially reduces PPCP content.
  
• Some PPCPs are degraded significantly during anaerobic sludge digestion.
  
• Removal by sorption onto suspended solids is an important mechanism for hydrophobic and positively charged compounds.
  
• Stripping is not relevant for PPCP removal in state-of-the-art municipal wastewater treatment.
  
• A rough estimate of PPCP concentration in raw wastewater is directly proportional to the amount of PPCPs sold.
  
• During irrigation and soil passage, most of the PPCPs (more than 80 percent) are sorbed or degraded. However, the irrigation can lead to a pollution of groundwater with iodinated contrast media (ICM).
  
• Ozonation or advanced oxidation processes (AOPs) are able to substantially reduce the contamination of groundwater prior to irrigation of treated wastewater.
  
• Acidic drugs, such as diclofenac, bezafibrate, and ibuprofen that are removed easily during wastewater treatment are subject to additional removal during post- treatment steps like polishing lagoons, gravel filters, or infiltration ponds. Conversely, neutral substances, such as diazepam and carbamazepine, that show poor removal rates during wastewater treatment, remain stable during post-treatment steps as well as in the groundwater. The polycyclic musks tonalide and galaxolide were significantly removed during wastewater treatment and post-treatment steps, but showed no significant further reduction during groundwater flow.
  
• With few exceptions, coagulation and flocculation are inappropriate to remove PPCPs.
  
• Ozonation is a very effective treatment process to oxidize PPCPs. Currently, there is no indication that the formed oxidation products are toxic.
  
• Disinfection with chlorine and chlorine dioxide does not lead to a general oxidation/removal of PPCPs. Only a few PPCPs were transformed.
  
• Activated carbon is a powerful process to remove PPCPs. Only a limited number of PPCPs, such as iodinated contrast media and the antibiotic, sulfamethoxazole show insufficient affinity to activated carbon.
  
• Nanofiltration and ultrafiltration/powdered activated carbon (PAC) are powerful processes to remove PPCPs.

What Can We Do Today?
Most wastewater professionals agree that the first step is source control. One way to accomplish this is by educating the public about how to properly disposal of medication. "We must first look at the low-hanging fruit, which is the unwanted or expired medication that people have historically and traditionally been told to flush down the toilet as poison control measures, North said. "Now, we would rather people bring them to their health hazard waste site or to a collection event."

Currently, pharmacies in the United States are not allowed to accept unwanted or expired medication, but in May 2006 the Bay Area Pollution Prevention Group (BAPPG) held Safe Medicine Collection Events at 32 locations throughout the San Francisco Bay area. More than 3,500 pounds of unused or expired medications were collected at senior centers, city hall, and pharmacies, mostly Walgreen's. "The goal is to provide residents with an easy disposal option and to increase public awareness," North said.

As the United States is still in the pilot-program stage, Europe, Australia, and Canada are leading the way in instituting permanent medication-return programs at pharmacies. The National Return and Disposal of Unwanted Medicines, known as the RUM program in Australia, allows the return of unwanted or expired medication to any pharmacy, at any time. The medicines are then incinerated. The government pays for disposal and advertising. The RUM program started in 1998 and collected 696,241 pounds of unwanted or expired medication in 2005. Canada has a similar program that collected 52,800 pounds in 2004.

Unknown Fate
The U.S. Environmental Protection Agency (EPA) began formally tracking pharmaceuticals and PPCPs in 2002 and is conducting research to determine potential negative effects.

"The EPA formed the Federal Inter-Agency Task Group on Pharmaceuticals in the Environment in January 2006, with a goal is develop research strategies by 2007," said EPA spokesperson Enesta Jones. "PPCP research has also been identified as one of the top 14 short-term, cross-regional priorities." PPCPs are on the map, but it will be years until we learn the results of all these studies. As we wait, the use of PPCPs will certainly continue, if not increase, only adding to a larger problem to clean up years from now.

Is My Water Safe to Drink? With the public becoming more aware of PPCPs, municipal utilities will be receiving calls from concerned residents. Though there are not a lot of answers yet, utilities have a responsibility to calm their concerned customers. Here are some suggestions, courtesy of Southern Nevada Water Authority, for representatives of municipal drinking water and wastewater treatment plants when communicating with the public: Keep in mind, to the average person "parts per billion/trillion" means contaminants are present, and that causes concern. They feel as though water should be contaminant-free. This is impossible, so if a contaminant doesn't warrant removal, the reason must be explained. Due to the lack of answers, the public needs to feel that utilities are taking a serious, proactive approach. Use lay terms and everyday language instead of technical jargon to describe current measures. For example, "We're working hard to find out whether or not these compounds are harmful at low levels, and if they are, we will try to figure out the best way to remove them." Give them real-world examples of other sources of exposure. For example, soy products such as tofu, soy milk, and soy sauce contain millions of times more estrogen than drinking water containing trace concentrations, or stress how someone would need to drink hundreds of thousands of gallons of water every day to match one Advil tablet. Never use cost as a reason to avoid implementing new or additional treatment options. Assign a primary contact who is knowledgeable and friendly to discuss the issue with the public. Develop and maintain a Web site on the topic and include articles from agency publications. Customers will feel their utility is staying current and wishes to serve as a source of information.

U.S. Universities Involved in PPCP Studies Harvard University Columbia University Duke University Johns Hopkins University Tulane University Villanova University Carnegie Mellon University State University of New York at Stony Brook Washington State University Baylor University University of Cincinnati University of Washington University of Delaware University of North Carolina University of Alaska Anchorage University of Kansas University of Arizona University of Hawaii University of Georgia University of Tennessee University of New Mexico University of Minnesota University of Oklahoma

About the author

Sherleen H. Mahoney

Sherleen H. Mahoney is an associate editor of Water & Wastewater Products.