This summary information about persistence, bioccumulation and toxicity comes from the assessment report. The risk is supported by all three references.
Persistence. Esomeprazole is not persistent.
Bioaccumulation. Esomeprazole has low potential for bioaccumulation.
Toxicity. Esomeprazole has moderate chronic toxicity.
Risk. The use of esomeprazole has been considered to result in insignificant environmental risk.
Assessment report for Nexium Control (esomeprazole), 27 June 2013, EMA/498929/2013.
Persistence: Kd(ads) = 48, "DT50, water = 2.2 to 3.7, DT50, sediment = 3.1 to 6.8 (OECD 308)." According to expert, esomeprazole does not seem to be persistent (Researcher at the Department of Environmental Science and Analytical Chemistry (ACES), Stockholm University 2018-09-05).
Bioaccumulation: log Kow < 4.5.
Chronic toxicity: There is NOEC for 3 trophic levels, lowest NOEC for fish (Pimephales promelas) 1000 microg/L.
The risk, PEC/PNEC, calculated from data in the assessment report from a European perspective:
PEC = 0.1 microg/L.
PNEC = Lowest NOEC, 1 000 microg/L/10 (Assessment Factor (AF) for 3 chronic studies) = 100 microg/L.
PEC/PNEC = 0.001 which gives the risk insignificant.
Fass environmental information for Nexium (esomeprazole) from Grunenthal Sweden produced by AstraZeneca (downloaded 2021-06-24).
Persistence: OECD 308: Radiolabelled test substance was dosed into the overlying water and the subsequent dissipation from the water phase and partitioning and/or degradation in the sediment was observed over a 100 day test period, leaving less than 7 % of the parent substance in the sediment-water system. In both the high organic matter (HOM) and low organic matter (LOM) test vessels,esomeprazol was observed to be rapidly dissipated from the water phase and total system, with a half-life <14 days. [...] The Kd(ads) was 48, indicating that esomeprazole is likely to partition into the aqueous phase during wastewater treatment. The substance has hence been assigned the phrase: “Esomeprazole is slowly degraded in the environment”.
Bioaccumulation: Log Dow = 1.58 @ pH 7.
Chronic toxicity: There is NOEC for 3 trophic levels, lowest NOEC for fish (Fathead Minnow)) 1000 microg/L.
PEC/PNEC is based on sales data in Sweden in year 2017. PEC/PNEC = 0.0094 which gives the risk insignificant.
Comparative assessment of environmental risk when using the gastric acid secretion inhibitors esomeprazole, lansoprazole, omeprazole, pantoprazole and ranitidine from a Swedish perspective (Report Goodpoint 2019).
Even if one assumes a "worst-case" exposure (PEC) or based on measured levels in environmental/wastewater (below detection limits except for ranitidine), the margins are against either CEC (risk of interaction with target species in aquatic organisms, especially fish) or against established toxicity levels in aquatic organisms very large (lower than 0.001 for all substances). Thus, the environmental risk is insignificant for all the investigated substances in Swedish water. No exchanges are therefore recommended from an environmental point of view.
Author: Health and Medical Care Administration, Region Stockholm