PARENT SESSION

1H a/b/c - Pesticides, pharmaceuticals, perfluoroalkylated substances, antibiotics
Poster Hall
8:30 AM - Wednesday, 30 April 2003
Chair: de Voogt, P.¹, ¹
Co-chair: Purdy, R.², Pluecken, U.³, Koerdel, W.⁴, Tolls, J.⁵, Kümmerer, K.⁶, ^{2 3 4 5 6}

(WEP/45) Mobility of tetracycline and sulfamethazine in sandy soils fertilized with liquid manure.

Pawelzick, Heike¹, Höper, Heinrich², Nau, Heinz¹, Hamscher, Gerd¹, ¹ Department of Food Toxicology, School of Veterinary Medicine, Hannover, Lower Saxony, Germany² Geological Survey of Lower Saxony, Bremen, Bremen, Germany

ABSTRACT- Since a couple of years the occurence and fate of veterinary pharmaceuticals in the terrestrial and aquatic environment is a research subject of increasing importance. In a field study we recently detected tetracyclines (TC) in soil using HPLC-ESI-MS-MS and demonstrated that these antibiotics are only slowly degraded and can accumulate after repeated fertilization with liquid manure. Furthermore, we found significantly lower concentrations of sulfamethazine (SMZ) in soil, whereas in ground water (sampled 1.40 m below soil surface) only SMZ was detected. With regard to the mobility of these antibiotics in sandy soils, laboratory studies were performed to characterise their sorption behaviour. The mobility was determined by employing a modified batch equilibrium method. For TC, of which its complex forming capacity with divalent cations (esp. calcium) is well known, the current batch equilibrium adsorption method (OECD Guideline 106) appeared to be unsuitable. Therefore we took rain water (pH 6.5) instead of 0.01 M CaCl₂ to simulate leaching conditions in the field and used the test parameters described in OECD Guideline 106. Soil samples with residues of TC (mean value 316 g/kg) and SMZ (mean value 2g/kg) were taken from our field study. For each substance 8 samples were investigated and the desorbed residues were determined in the aqueous phase as recently described. TC was strongly adsorbed in all samples analysed, and the mean desorption was less than 0.4%. SMZ showed a higher mobility than TC and approximately 10% of the total amount in soil was extractable. These findings clearly illustrate the different mobility of tetracyclines and sulfonamides. They indicate a risk of sulfonamide leaching into ground water, even though this veterinary compound is only present in soil at low concentrations.

Key words: antibiotic, soil, leaching