The T-value in the score for hazard refers to acute toxicity. Underlying data for P, B and T are from Fass.
Fass environmental information for SelokenZoc (downloaded 2019-02-15).
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”."
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”."
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 2014. PEC/PNEC = 0.27 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.
Pharmaceuticals in the aquatic environment in Stockholm Region
Metoprolol has been detected in treated wastewater and surface water in Stockholm County in the last five years (2012-2016). In 2017 metoprolol was found in treated wastewater, surface water and drinking water.
Metoprolol was one of the top 5 most frequently detected pharmaceuticals in spiders (article Richmond et al. 2018).
Author: Department of Strategic Careers, Stockholm County Council.