207219 Pharmaceutical residues in the drinking water supply: Modeling residue concentrations in surface waters of drugs prescribed in the United States

Wednesday, November 11, 2009

Rafael Guerrero-Preston, Dr PH, MPH , Otolaryngology Department, Johns Hopkins University, Baltimore, MD
Paul Brandt-Rauf, MD, PhD, Dr PH , Mailman School of Public Health, Columbia University, New York, NY
Pharmaceutical residues and other organic wastewater contaminants (OWC) have been shown to survive conventional water-treatment processes and persist in drinking water supplies.

To estimate the geographical distribution of the Predicted Environmental Concentration (PEC) of selected drugs prescribed by office based physicians in the United States (US), after non-metabolized residues have been excreted and processed in wastewater treatment plants.

The geographical distribution of the PEC of pharmaceutical residues in surface waters was calculated, in four regions of the US. Prescription drug data was obtained from the National Ambulatory Medical Care Survey, a representative sample of office based physicians in the US. The PEC of Metformin, Cimetidine and Ranitidine prescribed by office based physicians in the US between 1998 and 2000 was compared to the concentrations of these pharmaceuticals estimated in a surface water characterization project conducted by the United States Geological Survey between 1999 and 2000.

There were 803,185,420 medications prescribed by office-based physicians in the US between 1998 and 2000. Relief of pain, hormonal, cardiovascular and antimicrobial medications were the top four drug classes prescribed, most of which prescribed in the Southern states where the largest concentrations of African Americans reside. The concentration of Metformin estimated by USGS in surface waters was correlated to the PEC of Metformin prescribed by office-based physicians, albeit not significantly.

The PEC may be a useful tool to predict the concentration of pharmaceutical residues in surface waters for those pharmaceuticals not characterized in surface waters. The geographic disparity in pharmaceutical prescriptions also merits further attention.

Learning Objectives:
1) To discuss the geographical distribution of pharmaceuticals prescribed in the US by office based physicians. 2) To assess the Predicted Environmental Concentration of pharmaceuticals in surface waters. 3) To describe the threat posed by pharmaceuticals and personal care products in the drinking water supply.

Keywords: Emerging Health Issues, Drinking Water Quality

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: My DrPH degree is in environmental health sciences, my thesis was in drinking water quality and my post-doctoral fellowship was in the Departments of Epidemiology and Environmental Health Sciences of Mailman School of Public Health. I have two peer-reviewed publications on water quality.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.