This summary information comes from Fass. The risk is supported by the report from Goodpoint.
Persistence. Omeprazole is potentially persistent.
Bioaccumulation. Omeprazole has low potential for bioaccumulation.
Toxicity. Esomeprazole* has moderate chronic toxicity.
Risk. The use of omeprazole in Sweden has been considered to result in insignificant environmental risk (year 2019).
*Esomeprazole is the S-enantiomer of the racemate omeprazole. See also esomeprazole.
Fass environmental information for Losec (omeprazole) from AstraZeneca (downloaded 2021-06-24).
Persistence: Omeprazole was found not to be readily biodegradable in biodegradability studies. The substance has hence been assigned the phrase: “Omeprazol is potentially persistent”.
Bioaccumulation: Log D = 2.24.
Chronic toxicity: Long-term tests of esomeprazole have been undertaken for species from three trophic levels, based on internationally accepted guidelines. There are data for 3 trophic levels, lowest 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.
Omeprazole has previously been found in purified wastewater in Stockholm County (2005–2012). Omeprazole has not been analyzed in recent years.
Report Pharmaceutial residues in the Stockholm aquatic environment. Omeprazole has been detected in purified wastewater and in drinking water.
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