Pharmaceutical residues: concentration evaluation and risk assessment based on the sales of human drugs in Estonia in 2010

Although the growth in sales of pharmaceuticals could be taken as a sign of the availability of medical services and medicine, it also indicates an increasing input of drug residues to the environment via treated sewage water. In this paper the medicine consumption in mass units was calculated on the basis of the sale of pharmaceuticals in 2010. Eleven active substances (ASs) were selected for risk assessment according to the Swedish model. The predicted environmental concentration (PEC) for each AS was calculated and divided by the predicted no-effect concentration. Additionally, hazardous properties were taken into consideration. The calculated values of amoxicillin (PEC = 0.24–1.43 μg/l), diclofenac (PEC = 0.2–0.59 μg/l), ciprofloxacin (PEC = 0.052–0.13 μg/l), and ethinyl estradiol (PEC = 0.3 × 10-3 μg/l) reflect a high level of risk to the aquatic environment in the area.