After the scientific development of Biotic Ligand Models (BLMs) in recent decades these models are now considered suitable for implementation in regulatory risk assessment of metals in freshwater bodies. The approach has been developed over several years and has been described in many peer-reviewed publications. The original complex BLMs have been applied in prospective risk assessment reports for metals and metal compounds and are also recommended as suitable concepts for the evaluation of monitoring data in the context of the European Water Framework Directive. Currently, several userfriendly BLM-based bioavailability software tools are available for assessing the aquatic toxicity of a limited number of metals (mainly copper, nickel, and zinc). These tools need only a basic set of water parameters as input (e.g., pH, hardness, dissolved organic matter and dissolved metal concentration). Such tools seem appropriate to foster the implementation in routine water quality assessments. This work aims to review the existing bioavailability-based regulatory approaches and the application of available BLM-based bioavailability tools for this purpose. Advantages and possible drawbacks of these tools (e.g., feasibility, boundaries of validity) are discussed, and recommendations for further implementation are given.

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Arsenic trioxide (ATO) has been used successfully to treat acute promyelocytic leukaemia, and since this discovery, it has also been researched as a possible treatment for other haematological and solid cancers. Even though many positive results have been found in the laboratory, wider clinical use of ATO has been compromised by its toxicity at higher concentrations. The aim of this study was to explore an improved method for delivering ATO using liposomal nanotechnology to evaluate whether this could reduce drug toxicity and improve the efficacy of ATO in treating human papillomavirus (HPV)-associated cancers. HeLa, C33a, and human keratinocytes were exposed to 5 μm of ATO in both free and liposomal forms for 48 h. The stability of the prepared samples was tested using inductively coupled plasma optical emission spectrometer (ICP-OES) to measure the intracellular arsenic concentrations after treatment. Fluorescent double-immunocytochemical staining was carried out to evaluate the protein expression levels of HPV-E6 oncogene and caspase-3. Cell apoptosis was analysed by flow cytometry. Results showed that liposomal ATO was more effective than free ATO in reducing protein levels of HPV-E6 and inducing cell apoptosis in HeLa cells. Moreover, lower toxicity was observed when liposomal-delivered ATO was used. This could be explained by lower intracellular concentrations of arsenic. The slowly accumulated intracellular ATO through liposomal delivery might act as a reservoir which releases ATO gradually to maintain its anti-HPV effects. To conclude, liposome-delivered ATO could protect cells from the direct toxic effects induced by higher concentrations of intracellular ATO. Different pathways may be involved in this process, depending on local architecture of the tissues and HPV status.

The introduction to the market of wet wipes, advertised and labelled as "flushable", has been the subject of controversy due to their perceived potential to block sewer systems as observed with other non-woven cloths such as traditional non-flushable wipes. Non-woven cloths that enter wastewater systems can find their way into the aquatic environment via wastewater effluents and it has been suggested that the breakdown of these fabrics can release materials such as microplastics into the environment. Worldwide research has revealed the alarming number of aquatic organisms affected by the presence of plastic debris in the aquatic environment harbouring a potential risk to humans through the introduction of microplastics into the food chains. However, the actual material composition of flushable wipes, their fate and impacts in the aquatic environment have not yet been scientifically studied. This paper investigates the fibre composition of flushable and non-flushable wipes, specifically with regard to synthetic polymer material, using Fourier transform infrared (FTIR) and microRaman spectroscopy along with fluorescence microscopy. The study demonstrated the presence of polyester (polyethylene terephthalate, (PET)), high-density polyethylene (HDPE) and polyethylene/vinyl acetate (PEVA/EVA) in some flushable wipes and PET in all non-flushable. Other polymers such us polypropylene (PP), low-density polyethylene (LDPE), expanded polystyrene (EPS) and polyurethane (PU) were also identified as potential components in the flushable material. Hence, commercially available wet wipes labelled as flushable could also be considered as a possible source of microplastic fibres in the wastewater streams and, if not retained, in the environment.

Focused sonication was used to extract As-GS/PC complexes from Chlorella vulgaris and the integrity of such complexes was determined by HPLC online with simultaneous HR-ICP-MS and ES-MS/MS detection. C. vulgaris was found to produce intact arsenic phytochelatins and homo-phytochelatins (with Ala and desGly instead of Gly) complexes.