Damming the Flow of Drugs into Drinking Water

Abstract

Roughly 100 pharmaceuticals have now been identified in rivers, lakes, and coastal waters through out Europe and the United States in concentrations of parts per billion to parts per trillion. The first major European studies on this topic—in journals such as volume 67, issue 1–4 (1997) of the International Journal of Environmental Analytical Chemistry and the November 1998 issue of Water Research—examined German ground and surfaces waters, and found occurrences of drugs including cholesterol regulators, analgesics, and antiseizure medications. Since that time, numerous other studies have documented the presence of pharmaceuticals, including potential endocrine disruptors, in other locales as well. So far there is no evidence of adverse human health effects due to traces of pharmaceuticals in water. But scientists have linked certain pharmaceuticals with disturbing ecosystem changes. For example, in volume 8 (1994) of Chemistry and Ecology, researchers demonstrated that the feminization of fish—male carp and trout producing vitellogenin, an egg protein usually found only in females—was associated with exposure to sewage effluent now known to contain ethinyl estradiol, the active ingredient in birth control pills. There is much concern about what is not known: ecotoxicity data are available for less that 1% of human pharmaceuticals, according to estimates published in the April 2004 issue of Regulatory Toxicology and Pharmacology. Today, intensive research is under way to investigate the effect of human medications on the environment. In 1999, in response to these concerns, the European Medicines Agency (EMEA) began drafting guidance that outlined an environmental risk assessment procedure to accompany pharmaceutical companies’ applications to market new drugs in Europe. The latest draft was published in January 2005, after several revisions, and the public comment period closed in April 2005. Scientists and pharmaceutical companies alike hope the guidance will be finalized later this year. The proposed European guidance is the first to recommend long-term ecotoxicity testing for environmental risk assessment of pharmaceuticals from the outset of the proposed testing program (in contrast, U.S. Food and Drug Administration [FDA] requirements for chronic ecotoxicity testing come later in that agency’s assessment). The European guidance is also the first to take into account the possibility of environmental effects from extremely low concentrations of bioactive substances, such as endocrine disruptors. If finalized, the guidance could call for substantially more testing of new drugs than has been demanded thus far. Its implementation would also generate much-needed chronic ecotoxicity data. “The main advance in this draft guideline is that we really address this issue and get more information on the toxicity of these compounds,” says Thomas Heberer, an environmental chemist at the Technical University of Berlin and coauthor of many papers on the topic, including the 1997 International Journal of Environmental Analytical Chemistry report.