Workshop: Pharmaceuticals in Soil, Sludge and Slurry
German Federal Environment Agency Dessau-Roßlau
Pharmaceutical residues in sludge and slurry applied on soil may persist for a long period in soil, accumulate, pose a problem for soil micro- and macrofauna and can be taken up by plants.
Pharmaceuticals are biologically active substances applied to restore human or animal health but are also found throughout the environment, and concerns about their presence and potential effects on environmental health have been raised. Tons of human pharmaceuticals are consumed that partially enter wastewater and sewage sludge. Also veterinary pharmaceuticals like antibiotics (1.734 tons, DIMDI 2011, Germany) and antiparasitics are released on fields with the slurry nutrient load where they can accumulate in the soil; enter the groundwater via leakage water or run-off directly into waterways. Because of the wide consequences of the occurrence of those residues in the environment, data concerning the fate, effects and risks on the environment are necessary.
Results and Conclusion of the workshop
The Federal Environment Agency invited experts from academia and from state and federal authorities, including a selection of international scientists to present new results concerning characteristics, occurrence and risks of pharmaceuticals in soil, sludge and slurry and to determine substances for monitoring processes.
The participants agreed that pharmaceutical residues can persist and accumulate in soil over a long time. Several presentations demonstrated that there is evidence of an uptake of certain pharmaceuticals in plants and soil organisms like earthworms. There is also an indication that pharmaceutical residues like antibiotics may lead to changes in the structure of soil-microorganisms going along with a decrease of certain microbiologic performances. Furthermore there is evidence that antibiotics in soil can further select resistance. Livestock excrements that contain residues of antiparasitics may pose a danger for dung organisms provoking lower degradation rates.
At present there is no regulation with regard to pharmaceuticals in sludge, slurry or soil and no monitoring after marketing authorization of pharmaceutical products.
Therefore, nationwide and European monitoring programs for more reliable data of pharmaceutical concentrations in soil, sludge and slurry are necessary. For the revision of German Sewage Sludge Ordinance indicator substances for monitoring connected to quality assurance processes were proposed, like Ciprofloxacin, Sulfamethoxazol and Carbamazepin.
As a result of the workshop further fields of research were identified, e.g the placing of antibiotic resistance in risk assessment framework, the assessment of mixture toxicity and the identification and assessment of active metabolites in soil was identified.