Among microplastics (MPs), fibers are one of the most abundant shapes encountered in the aquatic environment. Growing attention is being focused on this typology of particles since they are considered an important form of marine contamination. Information about microfibers distribution in the Mediterranean Sea is still limited and the increasing evidence of the high amount of fibers in the aquatic environment should lead to a different classification from MPs which, by definition, are composed only of synthetic materials and not natural. In the past, cellulosic fibers (natural and regenerated) have been likely included in the synthetic realm by hundreds of studies, inflating “micro-plastic” counts in both environmental matrices and organisms. Comparisons are often hampered because many of the available studies have explicitly excluded the micro-fibers (MFs) content due, for example, to methodological problems. Considering the abundance of micro-fibers in the environment, a chemical composition analysis is fundamental for toxicological assessments. Overall, the results of this review work provide the basis to monitor and mitigate the impacts of microfiber pollution on the sea ecosystems in the Mediterranean Sea, which can be used to investigate other basins of the world for future risk assessment.

Combined sewer overflows (CSOs) release a significant amount of pollutants, including microplastics (MPs), due to the discharge of untreated water into receiving water bodies. Constructed Wetlands (CWs) offer a promising strategy for CSO treatment and have recently attracted attention as a potential solution for MP mitigation. Nevertheless, limited research on MP dynamics within CSO events and MP removal performance in full-scale CW systems poses a barrier to this frontier of application. This research aims to address both these knowledge gaps, representing the first investigation of a multi-stage CSO-CW for MP removal. The study presents one year of seasonal data from the CSO-CW upstream of the WWTP in Carimate (Italy), evaluating the correlation of MP abundance with different water quality/quantity parameters and associated ecological risks. The results show a clear trend in MP abundance, which increases with rainfall intensity. The strong correlation between MP concentration, flow rate, and total suspended solids (TSS) validates the first flush phenomenon hypothesis and its impact on MP release during CSOs. Chemical characterization identifies acrylonitrile-butadiene-styrene (ABS), polyethylene (PE), and polypropylene (PP) as predominant polymers. The first vertical subsurface flow (VF) stage showed removal rates ranging from 40 % to 77 %. However, the unexpected increase in MP concentrations after the second free water surface (FWS) stage suggests the stochasticity of CSO events and the different hydraulic characteristics of the CW units have diverse effects on MP retention. These data confirm filtration as the main retention mechanism for MP within CW systems. The MP ecological risk assessment indicates a high-risk category for most of the water samples, mainly related to the frequent presence of ABS fragments. The results contribute to the current understanding of MPs released by CSOs and provide insights into the performance of different treatment units within a large-scale CSO-CW system, suggesting the requirement for further attention.

The persistence of brominated flame retardants (BFRs) in the environment and the associated toxicological risks have made the development of efficient and rapid detection methods increasingly urgent. Despite regulatory mitigation action in many countries, BFRs such as polybrominated diphenyl ethers (PBDEs) and tetrabromobisphenol A (TBBPA) continue to threaten ecosystems due to their resistance to degradation. BFRs persist in air, water, soil, and sediments, and bioaccumulate in the food chain, leading to prolonged exposure risks for both humans and wildlife. Additionally, in regions with less stringent regulations, products containing BFRs are still being manufactured, posing a challenge for customs agencies responsible for regulating imports. This scenario underscores the urgent need for rapid, sensitive, and cost-effective methods to monitor BFRs in commercial products and environmental matrices. Biosensors present a promising solution, offering rapid detection and screening of BFR contamination at trace levels. Their ability to provide accurate, real-time data makes them invaluable for environmental monitoring, product safety, and regulatory compliance. This review explores the recent advancements in biosensor technology for BFR detection, highlighting their potential for improving environmental and human health protection but also underlining the specific areas that require further research.

The presence of organic UV filters (OUVAs) has been detected worldwide in aquatic ecosystems. These pollutants, originating from various anthropogenic sources, can persist and transform within wastewater treatment plants (WWTPs), posing a potential environmental hazard. In this framework, this research presents electrochemical sensors based on molecularly imprinted polymers (MIPs) for the selective detection of Benzophenone-3 (BP-3) and Octocrylene (OC), two of the OUVA most spread in the aquatic environment, to overcome the analytical challenges related to the quantification of this class of contaminants in wastewater samples. Key parameters, including the selection of the electropolymerization conditions, the template washing, polymer surface blocking, and analyte re-binding conditions, were optimized to maximize the selectivity and sensitivity. Electrochemical detection was performed using electrochemical impedance spectroscopy (EIS) supported by an electrochemical probe. In addition, cross-reactivity tests were carried out in the presence of possible interferents, selected based on their size, chemical structure, and occurrence in wastewater samples. The sensors demonstrated significant selectivity and sensitivity for the target analytes, with detection limits of 30 nM for BP-3 and 1 nM for OC, while tests on complex wastewater samples showed recovery rates of 77 % and 101 % for BP-3 and OC, respectively. The study yielded interesting results that could lead to a specific, cost-effective approach to enable widespread monitoring and support early detection of these increasingly relevant contaminants in wastewater samples.