Pharmaceuticals, pharmaceutical residues

A new type of pollution in groundwater and surface water – the source for our drinking water production – has been first detected in the early 1990s, namely trace amounts of pharmaceutical residues. Detection of these chemical ingredients was possible by gradual improvement of laboratory analytical methods, leading to detection of constituents undetectable before. The concept of “emerging contaminants or micropollutants“ was invented. In later years trace concentrations of residues of commonly used pharmaceuticals started to be detected in drinking water. A good reason to worry as the quality of drinking water is a powerful determinant of human health.

 The following pharmaceutical residues – and their metabolites and transformation products – are frequently encountered in drinking water, mostly at the ng/L level: painkillers, lipid (cholesterol) regulators, NSAIDS, carbamazepine, iodinated contrast media, β-blockers, antidepressants (mostly SSRIs like Prozac), benzodiazepines (like oxazepam), narcotic substances (cocaine, amphetamines, etc.), anticonvulsants (used to treat addiction to alcohol, nicotine, food, cocaine and other drugs), antibiotics, chemotherapy medication, antiseptics, and hormones. To understand the occurrence pharmaceutical residues in groundwater and surface water, and therefore also in drinking water one should realize that only a part of medication taken in by humans is actually absorbed by the human body, the rest of it (approximately 30-60%, see ref. 2002) passes through the body and is via urine flushed down the toilet into the sewage.
Another source of  pharmaceuticals – though of minor importance – is agriculture, largely by overuse of antibiotics in farming, manure used as fertiliser, and agricultural land overflow to surface water and seepage to groundwater.