Study of the uptake of non-steroid anti-inflammatory drugs in wheat and soybean after application of sewage sludge as a fertilizer.

Non-steroid anti-inflammatory drugs (NSAIDs) are frequently occurring in sludge and waters from sewage treatment plants (STPs). Sludge obtained from sewage treatment is often applied as a fertilizer in agriculture and not many studies about the uptake of pharmaceuticals into crops can be found. In this paper, we present a greenhouse experiment to study the presence of four NSAIDs (naproxen, ketoprofen, diclofenac and ibuprofen) in two different crops (soybean and wheat) after application of sludge as a fertilizer. Two different amounts of sludge were added to the soil; the recommended amount (with respect to phosphorus content) and the double recommended amount. One treatment without sludge was also included as a blank. The crops were harvested after 60 as well as 110 days. Only diclofenac and ibuprofen were detected in the sludge in concentrations of 22 and 217 ng g(-1) dry weight, respectively. None of the NSAIDs were detected in the crops from any of the treatments. Compared to the amounts applied to the soil, detection limits correspond to an uptake of less than 2% for diclofenac and 0.8% for ibuprofen.