The antidepressant, sertraline, impacts growth and reproduction in the benthic deposit feeder, Tubifex tubifex.

Among emerging contaminants, pharmaceuticals are considered one of the most pertinent substances that may threaten aquatic ecosystems. Pharmaceuticals are designed to be directed at specific metabolic- and molecular pathways. Thus, they are assumed to be still biologically active when entering the ecosystem and may result in unpremeditated impacts on non-target organisms. One of the most widely used selective serotonin reuptake inhibitors, sertraline (an antidepressant), is regularly found in aquatic environments. However, knowledge about the effects, and in particular, of sediment-associated sertraline in benthic invertebrates is limited. We examined the impacts of chronic exposure (28 d) to sediment-associated sertraline (3.3, 33, 330 µg/g dw sed.) on survival, growth and reproduction in the deposit-feeding oligochaete, Tubifex tubifex. Sertraline significantly decreased T. tubifex survival and growth. Worms exposed to high sertraline concentrations (330 µg/g) had a lower growth rate and reproduction, as indicated by a significantly lower number of cumulated cocoons. Worms exposed to an environmentally relevant concentration (3.3 µg/g) decreased growth but maintained a reproduction rate similar to that of the control. The implications are that adult worms exposed to high sertraline concentrations presumably required more energy for maintenance and detoxification, thereby reducing available energy for reproduction and growth. This represents a trade-off between survival, reproduction and growth. In contrast, T. tubifex exposed to environmentally relevant concentrations allocated more energy to reproduction by slightly increasing the number of cocoons produced and reducing growth. However, the quantity and quality of offspring may be impacted as we observed fewer juveniles in the environmentally relevant treatment than in the control. Overall, the results indicate that sediment-associated sertraline is bioavailable and negatively impacts T. tubifex survival, growth, and reproduction even at environmentally relevant concentrations.

Dietary diisononylphthalate contamination induces hepatic stress: a multidisciplinary investigation in gilthead seabream (Sparus aurata) liver.

In this study, adult gilthead seabream (Sparus aurata) were exposed for 21 days to Di-iso-nonylphthalte (DiNP at 15 and 1500 µg kg-1 bw day-1) via the diet. This plastic additive has been recently introduced to replace the di-(2-ethylhexyl)phthalate, the toxicity of which has been demonstrated conclusively both in vivo and in vitro trials. An analysis of a set of biomarkers involved in stress and immune response provides evidence of hepatic toxicity by DiNP in the present study. Both hsp70 and gr mRNA levels were upregulated significantly by DiNP, while plasma cortisol increased only in fish fed with the lowest DiNP dose. The oxidative stress markers g6pdh, glut red, gpx1 and CAT were upregulated by DiNP; gst mRNA was induced by the high dose and gck mRNA was downregulated significantly by the low dose. The mRNA levels of genes involved in the immune response, such as pla2, 5-lox, tnfa and cox2, were upregulated significantly only by the high dose of DiNP, while il1 mRNA increases in both doses. These molecular evidences were complemented with features obtained by Fourier Transform Infrared Imaging (FTIRI) analysis regarding the hepatic distribution of the main biological macromolecules. The FTIRI analysis showed an alteration of biochemical composition in DiNP samples. In particular, the low dose of DiNP induced an increase of saturated and unsaturated lipids and phosphorylated proteins, and a decrease of glycogen levels. The levels of caspase did not change significantly in the study, suggesting that DiNP does not activate apoptosis. Finally, the results also suggested the onset of hepatic oxidative stress and the activation of immune response, adding new knowledge to the already described hepatic DiNP toxicity.

When and How to Conduct Ecotoxicological Tests Using Natural Field-Collected Sediment.

In recent years, the sediment compartment has gained more attention when performing toxicity tests, with a growing emphasis on gaining more ecological relevance in testing. Though many standard guidelines recommend using artificially formulated sediment, most sediment studies are using natural sediment collected in the field. Although the use of natural field-collected sediment contributes to more environmentally realistic exposure scenarios and higher well-being for sediment-dwelling organisms, it lowers comparability and reproducibility among studies as a result of, for example, differences in the base sediment depending on sampling site, background contamination, particle size distribution, or organic matter content. The aim of this methodology contribution is to present and discuss best practices related to collecting, handling, describing, and applying natural field-collected sediment in ecotoxicological testing. We propose six recommendations: (1) natural sediment should be collected at a well-studied site, historically and by laboratory analysis; (2) larger quantities of sediment should be collected and stored prior to initiation of an experiment to ensure a uniform sediment base; (3) any sediment used in ecotoxicological testing should be characterized, at the very least, for its water content, organic matter content, pH, and particle size distribution; (4) select spiking method, equilibration time, and experimental setup based on the properties of the contaminant and the research question; (5) include control-, treated similarly to the spiked sediment, and solvent control sediment when appropriate; and (6) quantify experimental exposure concentrations in the overlying water, porewater (if applicable), and bulk sediment at least at the beginning and the end of each experiment. Environ Toxicol Chem 2023;00:1-10. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.