Looking For Traces of Pharmaceuticals in Drinking Water
By Daniel D. Snow, Ph.D.
Director of Laboratory Services, UNL Water Sciences Laboratory
A recent study by the Associated Press reported detecting traces of drugs in the public drinking water supplies of 24 major U.S. metropolitan areas. This has spurred further inquiries into the level and extent of pharmaceutical-based contamination in public water supplies and what should be done about them.
The presence of low concentrations of organic chemicals in drinking water supplies is not new, but the classes of contaminants being tested for are. Pharmaceuticals are of interest because they are biologically active and though their concentrations are usually very, very low –well below the part per billion levels we typically monitor other contaminants – their presence in water supplies is still of considerable interest.
Traces of many of chemicals we use daily end up in the environment and can ultimately wind up in water supplies. Municipal wastewater contains measurable levels of many over the counter and prescription drugs, steroid hormones, and other chemicals.
Agricultural wastewater may contain steroid hormones as well as antimicrobial compounds used in the livestock industry. The relative importance of these contaminants to water supplies depends on their proximity to water sources, concentrations of the chemicals and their potential to persist in the environment. Many questions remain regarding the occurrence and impacts of pharmaceuticals and other biologically active chemicals in the environment.
Several University of Nebraska research projects currently focus on improving our understanding of the occurrence and effects of steroids and pharmaceuticals in water.
For example, University of Nebraska, Omaha aquatic toxicologist Alan Kolok has been using a new sampling device along with genetic tools to study the occurrence and biological effects of natural and synthetic steroids from municipal and livestock waste. Natural estrogens are found in both types of wastewater and are known to affect the reproductive health of fish.
Because concentrations are quite low and vary over time, new devices for sampling are being developed and tested to get a better understanding of these sources.
University of Nebraska-Lincoln civil engineer Shannon Bartelt-Hunt is developing and using new samplers to study occurrence of pharmaceuticals and steroid hormones in municipal and livestock waste to better understand their fate and transport in the environment. Bruce Dvorak, also in the UNL Civil Engineering Department, is also working on a new device for sampling drinking water systems for wastewater-derived contaminants such as caffeine.
These and other efforts in Nebraska will help better understand the sources of these “new” contaminants and ways to minimize their potential impacts on our public water supplies.
