Contaminants of Emerging Concern in Tomatoes Grown in Sludge-Amended Peat: Uptake, Translocation and Risk Assessment

Although sewage sludge in agriculture can promote circular economy goals, concerns remain about the transfer of contaminants of emerging concern (CECs) into crops and soils. This study evaluated the uptake and risk of 27 CECs in tomatoes cultivated in peat substrate amended with stabilised anaerobically digested (dried) sludge from a local municipal wastewater treatment plant at two rates corresponding to nitrogen and nitrogen/potassium requirements. Peat substrate served as the control. Additional treatments included CEC-spiked media and peat amended with non-dried sludge. Analysis was performed with LC-MS/MS. In tomato fruits, ibuprofen (15.8 ng/g) and triclosan (17.9 ng/g) were quantified at the low amendment rate, while caffeine (381 ng/g), carbamazepine (18.1 ng/g), ciprofloxacin (306 ng/g) and ibuprofen (5.3 ng/g) were quantified at the high amendment rate. Dietary exposure estimates were below the health-based reference values for most compounds; however, a potential risk was identified for bisphenol S when non-dried anaerobically digested sludge was applied. Soil risk quotients (RQ > 1) for several CECs at the end of the experiment indicate possible ecological concern. These findings emphasise that monitoring CECs in sludge-amended soil remains essential to ensure the safety of sludge reuse in agriculture.