Pharmaceuticals and endocrine disrupting compounds modulate adverse effects of climate change on resource quality in freshwater food webs

Bioenergetic responses mediate interactive effects of pharmaceuticals and warming on freshwater arthropod populations and ecosystem functioning

Freshwater ecosystems are increasingly impacted by pharmaceutical contaminants (PhACs) and climate change-induced warming. Yet, their joint effects on freshwater taxa remain unclear. This is partly due to poorly understood mechanisms linking the effects on (sub)individual scales to higher levels of ecological organisation. We investigated the responses of two aquatic arthropods, Asellus aquaticus and Cloeon dipterum, to environmentally realistic levels of a 15-PhAC mixture (total concentration: 2.9 µg/L) and warming (+4 °C above ambient) in outdoor pond mesocosms (1000 L) across winter and summer. We measured physiological traits (bioenergetic responses based on quantification of energy consumption and energy stored in proteins, sugars and lipids, and oxidative damage based on malondialdehyde [MDA] levels), population density and ecosystem functions (leaf litter decomposition and insect emergence). In winter, PhACs reduced energy availability and increased MDA levels. In contrast, PhACs increased energy availability and decreased MDA levels in summer. The stressors reduced Asellus abundance, leading to reduced leaf litter decomposition, while Cloeon emergence in summer declined due to a PhAC-induced decline in larval abundance. Warming alone consistently decreased arthropod abundances and emergence, except for Asellus abundance in winter. The stressor effects through changes in bioenergetics were stronger than their direct effects on population abundances and ecosystem functions. Our findings highlight the vulnerability of aquatic arthropods to PhAC pollution and warming, emphasising the need for effective management strategies to mitigate the effects of emerging contaminants and climate change on freshwater biota.

Bioaccumulation of Pharmaceutically Active Compounds from Treated Urban Wastewaters in Aquatic Insect Larvae and Aerial Adults

The bioaccumulation of 80 pharmaceutically active compounds (PhACs) was examined in larvae, pupae, and (sub)adults of three groups of aquatic insects (caddisflies Oligotricha striata and Limnephilus spp. and mayfly Siphlonurus aestivalis) reared in laboratory conditions, with their larvae exposed to a treated urban wastewater for up to 3 months and fed with uncontaminated food. The probability of PhAC detection (above limits of quantification) in larvae was relatively constant throughout the exposure time, while in adults, it was lower at the beginning with a subsequent increase. The total concentration of detected PhACs was highest in larvae of Limnephilus spp. and lowest in larvae of S. aestivalis, decreasing similarly in the adults of all three species. Significant differences in the composition of PhACs with different levels of changes after emergence were detected between species. Only telmisartan was detected in all species and life stages. Sertraline and its active metabolite norsertraline exhibited significantly higher relative concentrations in caddisfly adults compared to larvae. Apart from the bioconcentration factor, increasing biodegradation half-life was the second-best predictor of increased PhAC concentration in adults compared to larvae. At the same time, log Kow, commonly associated with bioaccumulation, was not found to be a good predictor of this relationship. The present study provides valuable insights into the bioaccumulation patterns and potential transfer of PhACs from aquatic to terrestrial ecosystems.

Endocrine disruptor identification and multitoxicity level assessment of organic chemicals: An example of multiple machine learning models

Endocrine-disrupting chemicals (EDCs) pollution is a major global environmental issue. Assessing the multiple toxic effects of EDCs is key to managing their risks. This study successfully developed an EDCs classification and recognition model based on recursive feature elimination and random forest coupling, which passed external validation. Furthermore, the study classified the hormonal effects of EDCs and elucidated their hormonal roles. Molecular dynamics simulations were employed to investigate the toxicity of EDCs, and a regression model for such toxicity was developed using neural networks. A multi-toxicity regression model for EDCs was also developed using the XGBoost algorithm. This model can evaluate carcinogenicity, teratogenicity, and potential developmental toxicity of EDCs. The Spearman and Kendall correlation coefficient methods were used to assess the relations between toxicities. This study combines data filtering with model optimisation to ensure the use of efficient and concise methods. This allows for a comprehensive assessment of EDCs toxicity. It also helps analyse the link between EDCs molecular structure and their toxic effects, providing ideas for designing new chemicals. However, the model exhibits high complexity, and some processes are difficult to fully explain.

Wastewater and warming effects on aquatic invertebrates: Experimental insights into multi-level biodiversity consequences

Wastewater effluents and global warming affect freshwater ecosystems and impact their crucial biodiversity. Our study aimed at characterizing individual and combined impacts of wastewater effluent and increased water temperature (as one aspect of climate change) on model freshwater communities. We tested the effect of experimental treatments on genetic diversity, survival, body weight, total lipid content, lipidome and metabolome of individual species as well as community composition and phylogenetic diversity. In a 21-day mesocosm experiment we assessed the responses of a simplified freshwater food web comprising of moss and seven species of benthic macroinvertebrate shredders and grazers (mayflies, stoneflies, caddisflies and amphipods) to four treatments in a full factorial design: control, increased water temperature, wastewater and a multiple stressor treatment combining increased temperature and wastewater. Physiological responses varied among taxa, with species-specific sensitivities observed in survival and lipid content. The lowest total lipid content was observed in caddisflies and a mayfly subjected to multiple stressor treatment. The effects of stressors were reflected in the altered metabolic pathways and lipid metabolism of the individual taxa, with differential treatment effects also observed between taxa. A notable decrease in phylogenetic diversity was observed across all experimental communities. Gammarus fossarum demonstrated a high susceptibility to environmental stressors at the genetic level. Hence, while commonly used indicators of ecosystem health (e.g. community composition) remained stable, molecular indicators (e.g. phylogenetic diversity, metabolome and lipidome) responded readily to experimental treatments. These findings underscore the vulnerability of macroinvertebrates to environmental stressors, even over relatively short exposure periods. They highlight the importance of molecular indicators in detecting immediate ecological impacts, offering valuable information for conservation strategies and understanding the ecological consequences in freshwater ecosystems.

Pharmaceutical Removal with Photocatalytically Active Nanocomposite Membranes

The advancement of pharmaceutical science has resulted in the development of numerous tailor-made compounds, i.e., pharmaceuticals, tuned for specific drug targets. These compounds are often characterized by their low biodegradability and are commonly excreted to a certain extent unchanged from the human body. Due to their low biodegradability, these compounds represent a significant challenge to wastewater treatment plants. Often, these compounds end up in effluents in the environment. With the advancement of membrane technologies and advanced oxidation processes, photocatalysis in particular, a synergistic approach between the two was recognized and embraced. These hybrid advanced water treatment processes are the focus of this review, specifically the removal of pharmaceuticals from water using a combination of a photocatalyst and pressure membrane process, such as reverse osmosis or nanofiltration employing photocatalytic nanocomposite membranes.

The effect of warming and seasonality on bioaccumulation of selected pharmaceuticals in freshwater invertebrates

Multiple human-induced environmental stressors significantly threaten global biodiversity and ecosystem functioning. Climate warming and chemical pollution are two widespread stressors whose impact on freshwaters is likely to increase. However, little is known about the combined effects of warming on the bioaccumulation of environmentally relevant mixtures of emerging contaminants, such as pharmaceutically active compounds (PhACs) in freshwater biota. This study investigated the bioaccumulation of a mixture of 15 selected PhACs at environmentally relevant concentrations in common freshwater macroinvertebrate taxa, exposed to ambient temperatures and warming (+4 °C) during the warm and cold seasons in two outdoor mesocosm experiments. Nine PhACs (carbamazepine, cetirizine, clarithromycin, clindamycin, fexofenadine, telmisartan, trimethoprim, valsartan and venlafaxine) were dissipated faster in the warm season experiment than in the cold season experiment, while lamotrigine showed the opposite trend. The most bioaccumulated PhACs in macroinvertebrates were tramadol, carbamazepine, telmisartan, venlafaxine, citalopram and cetirizine. The bioaccumulation was taxon, season and temperature dependent, but differences could not be fully explained by the different water stability of the PhACs and their partitioning between water and leaf litter. The highest water-based bioaccumulation factors were found in Asellus and Planorbarius. Moreover, the bioaccumulation of some PhACs increased with warming in Planorbarius, suggesting that it could be used as a sentinel taxon in environmental studies of the effects of climate warming on PhAC bioaccumulation.