July 2005

by Karin D. North

Karin D. North is associate engineer for the City of Palo Alto. She can be reached at karin.north@cityofpaloalto.org.

During the past decade, there has been growing concern about potentially adverse effects of pharmaceuticals released in the environment through treated wastewater. These include prescription drugs such as hormones, antidepressants and antibiotics; over-the-counter medicines such as pain relievers, cold/flu remedies and antiseptics; and veterinary medicines. Small concentrations of these substances are found in various waterways nationwide.¹

Pharmaceuticals do not typically remain in the environment for long periods of time, but it appears that continual input into a water body can cause the concentration to be relatively constant.² While they may not kill aquatic organisms, medications may interfere with growth and reproduction in water organisms by disrupting their endocrine system (a collection of glands that secrete hormones), particularly when exposure occurs during developmentally sensitive times such as before birth. There are several well-documented cases of such endocrine-disrupting
effects on fish and wildlife.³

Because of the large number of pharmaceuticals and the high cost of testing, relatively little data is available on the presence of pharmaceutical products in natural water bodies. The most recent extensive study of pharmaceuticals in surface waters was performed by the U.S. Geological Survey (USGS) in 1999 and 2000.⁴ This nationwide study surveyed 139 streams throughout the United States in locations that were thought to be susceptible to contamination from agriculture or urban activities. The USGS analyzed samples from these waterways for 95 organic chemicals usually found in wastewater; in 80 percent of the samples analyzed, one or more pharmaceuticals were detected, albeit at very low concentrations. Examples of medications found included acetaminophen, steroids, hormones, codeine, antibiotics, antimicrobials and ibuprofen.

Point of Entry

Pharmaceuticals enter surface waterways from various sources, which include industrial dischargers, commercial animal feeding operations, surface applications of manure and biosolids, and wastewater treatment plants that treat residential, commercial and industrial wastewater.⁵ Pharmaceuticals primarily enter wastewater treatment plants from two sources: 1) excretion by the human body; and 2) disposal of unused or expired medications down the toilet or drain. Hospitals and residences account for the majority of pharmaceuticals entering municipal wastewater treatment plants.

Wastewater treatment plants are designed to remove biodegradable organic material, but they are not designed to remove low concentrations of synthetic pollutants. Therefore, one way to reduce the level of pharmaceuticals in surface water is to educate hospitals and community residents that unused or expired pharmaceuticals should not be disposed of down the toilet or drain.

Wastewater and stormwater agencies have recognized that trace pharmaceuticals in surface water bodies are a concern. In the San Francisco Bay Area, multiple agencies have been coordinating on a regional basis to become more efficient and effective in addressing this issue. Two key points are shared by most agencies: 1) unwanted medications should not be disposed down sinks, drains or toilets; and 2) unwanted or expired medications should be disposed of as hazardous waste.

A primary challenge thus far is that waste-water and stormwater agencies want to advertise household hazardous waste (HHW) programs as the preferred disposal alternative. However, most HHW programs are funded through solid waste fees and lack the financial resources to handle additional waste generated from stormwater- and wastewater-related outreach. These agencies have not traditionally been funding partners for HHW programs, which is a point that has been the highlight of considerable discussion. In addition, jurisdictional boundaries often differ between stormwater agencies, wastewater agencies and HHW facilities, making cost sharing difficult.

Other Ways to Mitigate Contamination

While it is recognized that municipal agencies have multiple priorities competing for fewer and fewer resources, there may be cases in which individual agencies have the resources to pursue actions within their own community.

Regarding hospital outreach, agencies are encouraged to conduct or participate in regional trainings and provide follow-up with local hospitals and clinics regarding appropriate disposal. Local agencies that do not currently have frequent contact with their hospitals may wish to consider doing so, and they may also want to consider adopting "zero pharmaceutical waste" policies.

Agencies are encouraged to consider promoting and supporting proper residential disposal practices for pharmeceuticals. Some outreach events that have been pi- loted in the San Francisco Bay Area include household hazardous waste drop-off events and take-back events at local senior centers and pharmacies. When planning such programs, agencies should coordinate efforts with other interested agencies to ensure that implementation is as efficient as possible. The bottom line for success is that agencies need to work together to provide one easy message for community residents and hospitals.

[1] Kolpin, Dana et al. (2002) Pharmaceuticals, Hormones and Other Organic Wastewater Contaminants in U.S. Streams, 1999-2000: A National Reconnaissance, Environmental Science and Technology v. 36: 1202-1211.

[2] Daughton, C.G. and Ternes, T.A. (1999) Pharmaceuticals and Personal Care Products in the Environment: Agents of Subtle Change. Environmental Health Perspectives, Vol 107, Supplement 6: 907‑938 [available at http://epa.gov/nerlesd1/chemistry/ppcp/images/errata.pdf]

[3] http://www.ourstolenfuture.org

[4] Reference info: http://pubs.acs.org/hotartcl/est/es011055j_rev.html

[5] Origins and Fate of PPCPs in the Environment, by the U.S. Environmental Protection Agency, Office of Research and Development, http://www.epa.gov/nerlesd1/chemistry/pharma/images/drawing.pdf.