Substances with pharmacological effects including hormonally active substances in the environment: Identification of tetracyclines in soil fertilizedwith animal slurry.

Many drugs used in human medicine are detectable in surface waters from the low to the very low mu g/L concentration range. In drinking waters only so me of these substances were detected, the concentrations are usually an ord er of magnitude below the concentrations found in surface waters. A risk as sessment of long time effects caused by a permanent intake of these low con centrations of drug residues cannot be done at this time. Hormonally active substances in surface waters may present an ecotoxicological risk, there a re many investigations currently under way to assess this problem. Our inve stigations show for the first time that residues of the commonly used veter inary drugs tetracycline and chlortetracycline can be detected in the surfa ce of soil (0-40 cm) fertilized with animal slurry. The maximum concentrati ons found were 32,3 mu g/kg and 26,4 mu g/kg respectively. Leaching of thes e compounds into seeping water sampled at a depth of 80-140 cm could not be detected with the methods employed. The significance of the detected antib iotic residues in soil samples for the quality of food of animal origin or any ecotoxicological consequences needs further investigations. The knowled ge about the concentrations of veterinary drug residues resulting from anim al husbandry in the environment is the first step for such a risk assessmen t.