Hazard assessment of the veterinary pharmaceuticals monensin and nicarbazin using a soil test battery

Veterinary pharmaceuticals are widely used as food additives in the poultry industry, and the unknown consequences of releasing these compounds into the environment are of concern. The purpose of the present study was to determine the direct impact of 2 veterinary pharmaceuticals (nicarbazin and monensin), commonly used in the poultry industry, on nontarget invertebrates and plant species. Ecotoxicological tests were used to evaluate the acute and chronic toxicity in earthworms (Eisenia andrei), collembolans (Folsomia candida), and 2 plant species (Brassica rapa and Triticum aestivum). Chemical analytical measurements were in good agreement with the nominal concentrations used, although some variability was seen. The results obtained showed no effects of nicarbazin at the highest nominal tested concentration of 1000 mg a.i./kg soil dry weight on any of the organisms, whereas exposure to monensin caused a concentration-specific response pattern. Species sensitivity to monensin decreased in the following rank order: B. rapa > T. aestivum > E. andrei > F. candida, with measured median effect concentrations (based on soil exposure) ranging between approximately 10 and 120 mg/kg. Our results emphasize the importance of using a test battery when assessing ecotoxicological effects by using different ecophysiological endpoints and species from different trophic levels. Environ Toxicol Chem 2018;37:3145-3153. © 2018 SETAC.