This summary information comes from Fass. The risk is also confirmed by the investigation from Goodpoint.
Persistence. Metoprolol is potentially persistent.
Bioaccumulation. Metoprolol has low potential for bioaccumulation.
Toxicity. Metoprolol has moderate acute toxicity.
Risk. The use of metoprolol (sales data Sweden 2017) has been considered to result in low environmental risk.
Fass environmental information for Bloxazoc (metolprolol) from Krka (hämtad 2021-06-28). The environmental information for metoprolol is provided by the company AstraZeneca for Mozoc, Mozoc® and Seloken®.
Persistence: "The aerobic biodegradation was determined in accordance with ISO 7827-1984 (E), using the OECD guidelines’ criteria for ready biodegradation. According to the results, metoprolol is not readily biodegradable (loss of Dissolved Organic Carbon (DOC) <70% after 28 days). Based on the data above (considering that no ther data is available), the statement “Metoprolol is potentially persistent” is justified."
Bioaccumulation: "Log P = < 4 at pH 7. Metoprolol has no significant bioaccumulation potential, as indicated by the Log P. Therefore the statement: “Metoprolol has low potential for bioaccumulation” is used."
Toxicity: There are data for 3 trophic levels, most sensitive green alga (Desmodemus subspicatus) 7 300 microg/L.
PEC/PNEC is based on sales data in Sweden in year 2017. PEC/PNEC = 0.29 which gives the risk low.
The knowledge of exposure in Sweden is very good. Reports showing effects at low levels are doubtful. Based on evidence-based efficacy data, the risk is assessed as low.
Metoprolol has been detected in treated wastewater, surface water and drinking water in Region Stockholm.
Metoprolol was one of the top 5 most frequently detected pharmaceuticals in spiders (article Richmond et al. 2018).
Author: Health and Medical Care Administration, Region Stockholm