Pharmaceutical products although usually beneficial to human health often end up in the environment with just the opposite effect on wildlife. But we are at risk as well since increasing amounts of drugs end up in our drinking water. To predict where current and future drugs may end up, researchers from the Autonomous University of Barcelona have come up with a new tool, which has been published in Water Air and Soil Pollution.

Partially metabolised

We use an increasing amount of drugs, not just in quantity but also in diversity. Many of these products are only partially metabolised by the human body and may end up in waste water. A lot of the drugs are then removed in sewage plants, but some drugs are not since the plants are not designed to eliminate them.

In the worst cases the substances used in sewage plants where the water is treated even revert the partially metabolised drugs back to the original. Those drugs either end up in the environment through the effluent of the plants or in our drinking water.

Much remains unknown

The concentration of the cocktail of drugs that end up in our drinking water is quite low (nanograms per litre) and the effects are as of yet unknown. The amount of drugs that end up in the environment is much higher, with possibly much larger effects, which are however also still unknown. But considering that something as simple as aspirin can already be lethal in small doses to the common housecat the harmful effects may be significant.

The researchers found at least one drug that winds up in the environment in significant amounts. The drug is called carbamazepine and is a psychotropic anti-epilepsy drug which can lead to damage to unborn babies when ingested by pregnant women.

Determining the likelihood of new drugs proposed for marketing ending up in the environment and in what concentrations is therefore not just necessary because it is required by the European Medicines Agency (EMEA), but also to safeguard our own health.

© Jorn van Dooren | www.bitsofscience.org