Occurrence of pharmaceuticals and their by-products in drinking water and the environment

As analytical instrumentation used to monitor water for contaminants improves, our ability to detect very small amounts of chemicals in water samples, including medications and their by-products, increases. Numerous regional and nationwide investigations on water and drinking water quality conducted by state and federal scientists have shown the presence of low levels of unregulated contaminants in water samples. Examples of these unregulated contaminants include pharmaceuticals and their by-products, antibiotics, hormones, personal care products, and various industrial and commercial products. In fact, unregulated contaminants have been detected in virtually all water systems where such analysis has been conducted. While the contaminants include chemicals like flame retardants and pesticides, studies also show an alarming number of medications in the water. In several studies conducted in New Jersey, carbamazepine, gitoxiginen and cotinine were detected in water samples. The levels are not high enough to be of health significance by themselves (1 ug/L or lower), but in combination with other contaminants, may pose ecological and human health issues. Further, although toxicity testing that is required for new pharmaceuticals and pesticides provides some information about their potential health effects, no such testing is required for their environmental transformation products or for other domestic and industrial chemicals. Given the large number of chemicals released into the environment either through discharges or through domestic/industrial/ commercial use, it is not surprising that various combinations of mixtures of chemicals have been found in water samples. Several issues are raised that are of concern to public health professionals: 1) what is the potential impact on human health and the environment; 2) how might these unregulated contaminants interact with other naturally-occurring or regulated contaminants in the water; and 3) what measure may be effective to treat or to prevent the occurrence of these substances in drinking water. Medical health professionals and patients can be instrumental in preventing and reducing the release of these products to the environment by taking some simple steps regarding their over-the-counter (OTC) and prescription medications. These steps include using the drugs according to the label instructions and returning unused OTC and prescription medicines to state take-back programs rather than disposing in the trash or flushing down the toilet.