Hot spot pollutants: pharmaceuticals in the environment.

Pharmaceuticals are an important and indispensible element of modern life. They are employed in human and veterinary medicine, agriculture and aquaculture. Until the 1990s however, relatively little consideration was given to the likely fate, occurrence or effects of pharmaceuticals in the environment (PIE) following normal use. This apparent lack of scientific interest in pharmaceuticals as contaminants of the aquatic environment is somewhat puzzling. Common OTC drugs such as paracetamol or aspirin are sold in quantities comparable to high production volume (HPV) materials—close to or exceeding 1000 tons/annum in EU countries such as the UK or Germany (Webb, 2001; Ternes, 2001a). Total use of human prescription drugs in such countries will exceed this (Webb, 2001). Drugs are also inherently biologically active and often exquisitely potent. They are often resistant to biodegradation as metabolic stability is necessary to pharmacological action. Certain pharmaceuticals (or their metabolites) are also highly water soluble. When combined with a lack of biodegradation, removal during wastewater treatment will consequently be limited for such compounds. These compounds will consequently enter the aquatic environment to result in exposure of aquatic biota. Contributions to our knowledge of PIE that predate this period include the observations by Aherne et al. (1985) and others on compounds such as ethinyl oestradiol, diazepam, theophylline, erythromycin, tetracycline and methotrexate in various environmental matrices as a consequence of normal patient use. Richardson and Bowron (1985) likewise report on analytical studies. They also detail the development of simple modeling techniques aimed at predicting likely concentrations in surface waters following normal use by the patient. This pioneering work included a consideration of national usage patterns, human metabolism, fate during wastewater treatment and surface water dilution of effluents. The last decade has seen a marked growth in the literature relating to observations of PIE at concentrations that result from normal use by the patient. At least 60 compounds have now been reported from aquatic matrices (Stumpf et al., 1996a,b; Heberer and Stan, 1997; Ternes, 1998; Hirsch et al., 1999; Ternes 2001a,b). Such observations necessitate a consideration of any potential risk. This in turn requires knowledge of the effects of pharmaceuticals upon relevant aquatic biota. This requirement is now being addressed for many classes of compounds such as SSRIs (Fong et al., 1998), steroids (Länge et al., 2001) and antihyperlipoproteinemics (Köpf, 1995). Concurrently, there have been various regulatory developments in the USA and the EU relating to * Corresponding author. E-mail address: [email protected] (D.R. Dietrich).