Measurements in the environment or wastewater are lacking, even internationally. Also environmental degradation data is missing. When selecting the algal test for antibiotics the European Medicines Agency, EMA, recommends test on blue-green algae (cyanobacteria). No information on toxicity on blue-green algae has been found, which means that a calculation of the toxicity becomes uncertain.
Studies have shown that even low concentrations of antibiotics in the environment may contribute to antibiotic resistance and therefore measures should be taken to ensure that as little as possible ends up in our environment.
Both ciprofloxacin and trimethoprim are included in the Stockholm County Council's table of pharmaceuticals with risk for negative environmental impact according to the environmental program 2017–2021. Ciprofloxacin and trimethoprim are found in Swedish wastewater treatment plants in concentrations that are likely to select for antibiotic resistance. Risks associated with large emissions of ciprofloxacin to the environment in manufacturing abroad have been detected.
Nitrofurantoin is expected to have low environmental risk for aquatic organisms and low risk of resistance selection in wastewater, although the use would increase significantly.
Author: Department of Strategic Careers, Stockholm County Council.