Assessment of ecological risks posed by veterinary antibiotics in European aquatic environments: A comprehensive review and analysis

Pharmaceuticals and Microplastics in Aquatic Environments: A Comprehensive Review of Pathways and Distribution, Toxicological and Ecological Effects

Pharmaceuticals and microplastics are persistent emerging contaminants that pose significant risks to aquatic ecosystems and ecological health. Although extensively reviewed individually, a comprehensive, integrated assessment of their environmental pathways, bioaccumulation dynamics, and toxicological impacts remains limited. This review synthesizes current research on the environmental fate and impact of pharmaceuticals and microplastics, emphasizing their combined influence on aquatic organisms and ecosystems. This review provides a thorough and comprehensive examination of their predominant pathways, sources, and distribution, highlighting wastewater disposal, agricultural runoff, and atmospheric deposition. Studies indicate that pharmaceuticals, such as antibiotics and painkillers, are detected in concentrations ranging from ng/L to μg/L in surface waters, while MPs are found in densities up to 106 particles/m3 in some marine and freshwater systems. The toxicological effects of these pollutants on aquatic organisms, particularly fish, are discussed, with emphasis on bioaccumulation and biomagnification in the food chain, physiological effects including effects on growth, reproduction, immune system performance, and behavioral changes. The ecological consequences, including disruptions to trophic dynamics and ecosystem stability, are also addressed. Although valuable efforts, mitigation and remediation strategies remain inadequate, and further research is needed because they do not capture the scale and complexity of these hazards. This review highlights the urgent need to advance treatment technologies, establish comprehensive regulatory frameworks, and organize intensive research on long-term ecological impacts to address the environmental threats posed by pharmaceuticals and microplastics.

Influence of the source and molecular weights on sulfathiazole/sulfadiazine binding in sedimentary dissolved organic matter

Sedimental dissolved organic matter (DOM) plays a crucial role in the migration of antibiotics in a lake environment, which is strongly associated with its physicochemical properties influenced by temporal and spatial variations. This study systematically investigated the binding behavior of sulfathiazole (ST) and sulfadiazine (SD) to DOM across different molecular weights (MWs) in sediments from Poyang Lake using multiple spectroscopic techniques. Results showed that the MW fractions of DOM from the onset of the dry season were higher than those before flooding. Additionally, key carbon parameters, including dissolved organic carbon and fluorescent components, were present in greater proportion in the truly dissolved phase and the low MW fraction of DOM. These properties of the low MW fraction of DOM enhanced its binding capacity for the two sulfonamides, with the partitioning coefficient (logKcoc) values of 5.20 and 5.06 for ST and SD, respectively. Dialysis experiments investigating the interaction between different concentrations of DOM and sulfonamides indicated that humic-like and protein-like components significantly influenced the migration of ST and SD, respectively. Moreover, protein-like components exerted a more substantial impact on the migration of sulfonamides in heavily polluted sampling sites, while the humic-like substances played a more significant role for the samples from the wetland protection area. The results enhanced the understanding of the significance of DOM sources and MW in influencing the environmental fate of antibiotics in lake ecosystems.

Neomycin affects cardiovascular and hematopoietic system via the PI3K/Akt pathway in zebrafish larvae

Neomycin, a widely used aminoglycoside antibiotic, poses potential risks to organism and the environment that remain incompletely evaluated. This study systematically evaluates its toxic effects on zebrafish embryos across physiological, cellular, molecular, and behavioral dimensions. At the physiological level, neomycin exposure induces severe developmental abnormalities, including yolk sac edema, reduced body length, and craniofacial malformations. Developmental disorders of the cardiovascular and hematopoietic systems are confirmed in exposed larvae. In addition, zebrafish larvae exposed to neomycin exhibit significant locomotor deficits, including reduced swimming speed, distance traveled, and impaired responsiveness to light-dark stimulation, indicating reduced activity. Mechanically, neomycin triggers oxidative stress through a dose-dependent elevation of reactive oxygen species (ROS) levels and induces cellular apoptosis through the PI3K/Akt signaling pathway. Collectively, our findings demonstrate that neomycin exerts toxic effects on zebrafish embryonic development, highlighting concerns regarding neomycin exposure risks during early pregnancy and providing critical insights into its potential environmental hazards.

Photocatalytic degradation of veterinary antibiotics in wastewaters: A review

The extensive use of veterinary antibiotics worldwide has led to their increasing accumulation in aquatic environments, adversely affecting both ecosystems and human health and leading to the emergence of antibiotic-resistant bacteria. Antibiotic residues enter water bodies primarily through wastewater effluent discharge, agricultural runoff, and improper disposal of pharmaceuticals. Several emerging technologies have been developed in response to the challenge of antibiotic contamination in wastewater. Among these, advanced oxidation processes (AOPs), including photocatalysis, have demonstrated significant potential for antibiotic degradation. Photocatalysis relies on the production of powerful oxidants to degrade pollutants under simulated or solar-light irradiation. Apart from the well-known TiO2, various photocatalytic materials have been used with metal oxides on the frontline. In this context, metal doping has been used to reduce the bandgap energy and enhance the absorption of visible light and charge-carrier separation. Doping with non-metals and carbon-based materials is another attractive alternative that promotes better degradation efficiency and suppresses recombination. Moreover, advanced designs, such as heterojunction constructions, have been developed for effective charge separation and wider utilization of the light spectrum. This comprehensive review summarizes recent advances in the design, characterization, efficiency, and mechanisms of various photocatalysts for degrading veterinary antibiotics in wastewater, along with toxicity assessments of the resulting transformation products. By examining these parameters, the current body of knowledge is consolidated, providing valuable insights into wastewater purification processes for effective antibiotic removal. Finally, by emphasizing the critical environmental importance of streamlined photocatalysis and the challenges associated with scaling up the process, this review highlights its feasibility in mitigating veterinary antibiotic pollution, thereby safeguarding aquatic ecosystems and reducing the risks of antibiotic resistance.

Exposure of Enchytraeus crypticus to ciprofloxacin - A multi- and transgenerational study

The increased consumption of antibiotics and their partial metabolism by the human and animal body have led to the frequent identification of such compounds in various environmental matrices. Ciprofloxacin (CIP) is one of the most widely used antibiotics worldwide and it has low mobility and high sorption to soil, leading to the potential to accumulate and persist on organic fertilizers (manure and sewage sludge) and agricultural soils. Therefore, the presence of CIP in the agricultural environment has become an emerging concern as it may negatively affect soil organisms and soil quality, and contribute to the spread of antibiotic-resistant bacteria, thus threatening food security and public health. In this study, we aimed to evaluate the multigenerational and transgenerational effects of CIP on the reproduction of Enchytraeus crypticus to properly assess the long-term impacts of such exposure. Our results for the multigenerational test showed that the reproduction of the organisms was affected from the third to the last (sixth) generation, highlighting the importance of long-term evaluation. There was also evidence of tolerance to reproduction of E. crypticus, as there was no statistical difference between concentrations for all generations, including for among the last three generations themselves. For the transgenerational tests, almost all results showed no statistical difference from the controls, indicating that the effects of CIP may be reversible when the organisms are transferred to clean media. However, since the last generations in the transgenerational tests showed significant differences from the first of the multigenerational tests, the adverse effects may still persist to some extent in the subsequent generations. Thus, when evaluating the effects of CIP on soil media, its persistence and behavior in this matrix must be considered. We strongly recommend that further long-term exposure studies be conducted and considered in regulatory decision-making, especially for persistent compounds.