From agricultural fields to surface water systems: the overland transport of veterinary antibiotics

The aim of this study was to assess if veterinary antibiotics, which are introduced to agricultural fields via fertilizer, are present in water systems (in both water and sediment) following overland transport via runoff and soil erosion. Three water and sediment sampling schemes were conducted in Germany between June 2013 and June 2014 to examine the effects of (1) season, (2) heavy rainfall and (3) high veterinary antibiotic usage. The samples were analysed for 15 veterinary antibiotics using liquid chromatography tandem mass spectrometry. Antibiotics were detected in all three schemes in trace quantities. This is the first time that veterinary antibiotics have been detected in German sediment. In particular, the presence of tetracycline in sediment taken from irrigation ditches in an agricultural area of high veterinary antibiotic usage offers proof that the overland transport of veterinary antibiotics is occurring. Due to the strong sorption of veterinary antibiotics (particularly tetracyclines) to soils, further research into their transport via soil erosion and assessment of their presence in sediment is advised.