With an increase in the generation of sewage sludge, there comes a demand for disposal methods for it, and agricultural use is a sustainable alternative. However, there are gaps regarding emerging pollutants, especially in the pharmaceutical class. Nimesulide - an anti-inflammatory pharmaceutical recently associated with liver damage and banned in some European countries - is among the most consumed pharmaceuticals in Brazil hence can be found in wastewater and, therefore, in sewage sludge used for agriculture at ng L-1 concentrations. The objective of this research was to evaluate the toxicity of the anti-inflammatory pharmaceutical nimesulide through toxicity tests using the organism Enchytraeus crypticus in both natural and artificial soils, adopting concentrations about studies carried out with other anti-inflammatory drugs on seeds in the soil. In this work, the toxicity of nimesulide was evaluated in natural tropical soil sampled in Sao Paulo - Brazil, and in tropical artificial soil. The invertebrate E. crypticus was exposed to nimesulide nominal concentrations of 200; 340; 578; 982 and 1670 mg nimesulide kg-1 of dry soil and the reproduction test was performed according to ISO 16.387 (2014) standard, with 5 replicates per concentration. The results obtained through reproduction testing with E. crypticus in each concentration presented were EC50 values of 699 and 759 mg nimesulide Kg-1 dry soil, respectively for both natural and artificial soil. The Tukey test showed no significant difference between the soils, however. Finally, this study suggests that the anti-inflammatory drug nimesulide displays a toxicological effect on the reproduction of soil fauna organisms in high concentrations. Therefore, stresses the importance of identifying and monitoring unknown concentrations of this emerging pollutant in the environment.

The detrimental impacts of plastic nanoparticles (PNPs) are a worldwide concern, although knowledge is still limited, in particular for soil mesofauna. This study investigates the biochemical impact of 44 nm polystyrene PNPs on three soil models-Enchytraeus crypticus (Oligochaeta), Folsomia candida (Collembola) and Porcellionides pruinosus (Isopoda). Exposure durations of 3, 7 and 14 days (d) were implemented at two concentrations (1.5 and 300 mg kg(-1) PNPs). Results revealed PNPs impact on the activities of the glutathione-dependent antioxidative enzyme, glutathione S-transferase (GST) and on the neurotransmitter acetylcholinesterase (AChE) for all three species. Catalase (CAT) played a minor role, primarily evident in F. candida at 300 mg kg(-1) PNPs (CAT and GST response after 14 d), with no lipid peroxidation (LPO) increase. Even with the antioxidant defence, P. pruinosus was the most sensitive species for lipid oxidative damage (LPO levels increased after 7 d exposure to 300 mg kg(-1) PNPs). Significant AChE inhibitions were measured already after 3 d to both PNP concentrations in F. candida and E. crypticus, respectively. Significant AChE inhibitions were also found in P. pruinosus but later (7 d). Overall, the toxicity mechanisms of PNPs involved antioxidant imbalance, being (mostly) the glutathione-associated metabolism part of that defence system. Neurotoxicity, linked to AChE activities, was evident across all species. Sensitivity to PNPs varied: P. pruinosus > F. candida congruent to E. crypticus. This pioneering study on PNPs toxicity in soil invertebrates underscores its environmental relevance, shedding light on altered biochemical responses, that may compromise ecological roles and soil ecosystem fitness.