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Geneesmiddelen en waterkwaliteit


Pharmaceuticals are valuable for public health. In recent years, more information about the effects of the use of pharmaceuticals on water quality, has become available. In the Netherlands, risks for aquatic life may be expected. Drinking water quality is not at stake, but in the future the quality of drinking water sources may be under pressure due to an aging population (increase in emissions) and climate change (lower water levels in rivers). RIVM collected facts and figures about pharmaceuticals in the environment and provided these along with an interpretation.

After their use, pharmaceuticals end up in the sewage system via the toilet. Sewage treatment plants purify the water, but do not remove all pharmaceutical residues. Thus, effluent with pharmaceuticals residues is discharged into surface waters. About 2000 different active substances are in use. Water managers identified about 80 pharmaceutical active substances and researched their presence in surface waters. Of those 80 substances, five were found in higher concentrations than the safe concentration for water organisms. These five are diclofenac (pain killer), azithromycin, clarithromycin and sulfamethoxazole (antibiotics), and carbamazepine (an anti-epileptic). Human and veterinary pharmaceutical residues are also found in groundwater.

Roughly estimated, at least 140 tonnes of pharmaceuticals are discharged by sewage treatment plants into surface waters every year in the Netherlands. This is considerably higher than the level of plant protection products that end up in surface water (17 tonnes). Environmental quality standards for plant protection products are often exceeded. Like plant protection products, pharmaceuticals are biologically active substances. Despite a lack of data for many pharmaceuticals, for some it is already known that safe concentrations are exceeded. This indicates a cause for concern for the environment.

The possible effects of pharmaceuticals include behavioral changes, tissue damage and effects on reproduction of water organisms, as a result of which the ecosystem as a whole may be disrupted. The extent of the risk to the environment cannot be determined accurately, since data on environmental loads and effects are only available for a fraction of pharmaceutical active substances. Whether pharmaceuticals are actually currently responsible for damaged ecosystems in the Netherlands is not clear. This is not actively monitored. Many other factors, such as water level, currents and the presence of other micro pollutants and nutrients, may determine whether animals and plants flourish. Currently, the environmental assessment of water quality does not take potential mixture effects into account.

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