Cytostatics, immunotherapy and hormone therapy are important to treat cancer patients. Via urine, residues of these medicines end up in waste water. This waste water is treated in waste water treatment plants and subsequently discharged into surface waters.

The number of patients that are treated with cancer medicines is increasing. The use of tumor specific therapies is on the rise, due to their advantages compared to classical cytostatics. RIVM assessed the environmental risks of cytostatics following requests of the health care sector.

Sufficient removal

Residues of commonly used cytostatics and two active substances used as hormone therapy do not pose a risk to the surface water environment. These substances are metabolized sufficiently in the human body and removed in waste water treatment plants. Because of this, surface water concentrations are lower than concentrations at which effects on water organisms may be expected.

The active substances in immunotherapy are fully metabolised by the human body and consequently, do not pose a risk to the environment.

Four hospitals

For this research project, user data on cytostatics from four Dutch hospitals were used, since these date are not recorded on a national scale. With these data, the amount of cytostatic residues entering surface waters was estimated. Environmental risks were assessed by comparing these data with information on toxicity to aquatic organisms. Data on ecotoxicity and behaviour in the environment was collected from literature.