Sorption and degradation of veterinary drugs in soil

Abstract

Veterinary drugs, in particular antimicrobials, have been widely employed in livestock to ensure animal health, as well as allowing an increase in food production of animal origin. Despite of their benefits, the use of veterinary drugs can result in serious risk to water, soil, plants , terrestrial and aquatic organism and also to humans, since a large quantity of these substances enters in the environment in their non metabolized form, through feces and urine of the treated animals. Once present in the field, veterinary drugs with high sorption capacity tend to accumulate in soils and sediments. In contrary, compounds with low sorption capacity will be leached and may contaminate surface water, groundwater, and also potable water. There is a great concern for the development of resistant bacteria, which may be caused, among others, by the dispersion of antimicrobials in the environment. There is a lack in studies on the behavior of veterinary drugs in soils, as well as, analytical methods for the determination of residues of veterinary drugs in this matrix. Mostly, researches have been conducted in European Countries with climatic conditions and soils types very different from those found in Brazil. In view of this fact, this project aims to develop methods for the determination of residues of veterinary drugs, metabolites or degradation products in Brazilian soils, as well as the evaluation of sorption and desorption of antimicrobials of the classes of tetracyclines, sulfonamides and fluoroquinolonas in characteristic soils of the Sate of São Paulo. Moreover, anaerobic and aerobic degradation of antimicrobials in soils will be evaluated. (AU)