Risk assessment of natural and synthetic fibers in aquatic environment: A critical review.

Marine microplastics, categorized as primary and secondary, including synthetic microfibers like polyethylene terephthalate (PET), polypropylene (PP) and acrylic (PC), represent a potential environmental concern. The complex classification of these fibers, originating from diverse sources such as textiles and many others commercial goods, prompts a need for understanding their impact on aquatic organisms. This study assesses the ecological risks associated with both natural and synthetic fibers in aquatic ecosystems, focusing on toxicity data and their effects on taxonomic groups like Mollusca, Arthropoda, Echinodermata, Cnidaria, and Chordata. To carry out species sensitivity distribution (SSD) curves, a comprehensive analysis of scientific literature was conducted, collecting toxicity data related to various fibers. The resulting SSDs provide insights into the relative sensitivity of different taxonomic groups. The potential ecological risks were evaluated by comparing measured concentrations in diverse aquatic environments with Predicted No-Effect Concentration (PNEC) values. The calculation of Risk Quotient (RQ) allowed to indicate areas where fibers abundance poses a potential threat to aquatic organisms. The study reveals that nylon fibers can pose the highest toxicity risk, especially in Atlantic and Pacific Ocean, Arabian Gulf and VietNam river. Mollusca emerged as particularly sensitive to different fiber types, likely due to their body structure facilitating the accumulation of microfibers. The research emphasizes the urgent need for further studies to get data to human health risk analysis and to address comprehensive environmental management strategies to address the global issue of microfiber pollution.

An 1H NMR study of the cytarabine degradation in clinical conditions to avoid drug waste, decrease therapy costs and improve patient compliance in acute leukemia.

Cytarabine, the 4-amino-1-(ß-D-arabinofuranosyl)-2(1H)-pyrimidinone, (ARA-C) is an antimetabolite cytidine analogue used worldwide as key drug in the management of leukaemia. As specified in the manufacturers' instructions, once the components-sterile water and cytarabine powder-are unpackaged and mixed, the solution begins to degrade after 6 hours at room temperature and 12 hours at 4°C. To evaluate how to avoid wasting the drug in short-term, low-dose treatment regimens, the reconstituted samples, stored at 25°C and 4°C, were analyzed every day of the test week by reversed-phase HPLC and high-field NMR spectroscopy. All the samples remained unchanged for the entire week, which corresponds to the time required to administer the entire commercial drug package during low-dose therapeutic regimens. The drug solution was stored in a glass container at 4°C in an ordinary freezer and drawn with sterile plastic syringes; during this period, no bacterial or fungal contamination was observed. Our findings show that an cytarabine solution prepared and stored in the original vials retains its efficacy and safety and can, therefore, be divided into small doses to be administered over more days, thus avoiding unnecessary expensive and harmful waste of the drug preparation. Moreover, patients who require daily administration of the drug could undergo the infusion at home without need to go to hospital. The stability of the aliquots would help decrease hospitalization costs.