Probenecid markedly reduces urinary excretion of ethinylestradiol and trimethoprim slightly reduces urinary excretion of clenbuterol

Food safety/food security aspects related to the environmental release of pharmaceuticals

The environmental presence of pharmaceuticals in top soil and in water where extensive animal farming occurs may represent an involuntary source of residues in food that might affect both food safety and food security. We modelled the presence of residues in animal matrices from the inventoried environmental concentration of selected drugs in surface waters (range: 0.1-10μgL(-1)) and agriculture soils (range: 1-100μgkg(-1) dry weight), accounting for animal production parameters (i.e., forages, water intake and milk and egg production) and drug pharmacokinetics. The results indicate that the contamination of tetracyclines in top soil may represent a major issue both for the compliance with maximum residue levels in food (100-300ngg(-1)) and for the claim of organic products. via surface water, animals may be vulnerable to the intake of anabolics and growth-promoting agents, such as 17-beta estradiol and clenbuterol, only under a worst-case scenario. Their identification, which is currently achievable at a pgg(-1) level in animal specimens, is considered proof of illegal treatment and can lead to the prosecution of farmers. The Environmental Quality Standards that have been proposed for priority substances in surface waters may also be considered protective in terms of food security/food safety; however, a broad-spectrum characterisation of drugs within the agriculture context could be envisaged to refine the uncertainties in the risk assessment and for combined intakes.