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- Integrating Fungi in the Drinking Water Regulation and in Guidelines for Materials in Contact With Drinking Water. Is there Room for Change?Publication . Novak Babič, Monika; Brandão, João; Gunde-Cimerman, NinaDrinking water is essential for life. To ensure its safe use, up to date regulation is promoted by the World Health Organization, but ultimately established by individual countries and states federations. The European Union uses directives transposed to Member-states legislation. This regulation targets specific bacterial pathogens, but changes, like climate alterations, increasing human population and antimicrobial resistance bring along the necessity to adjust regulation to emerging threats. The authors herewith discuss the integration of fungi in drinking water regulation and in guidelines for materials in contact with drinking water. Core species should be established with possible indicators and specificities of water distribution to more susceptible users.
- Occurrence of Estradiol in Environmental Waters. Estradiol: Synthesis, Health Effects and Drug InteractionsPublication . Domingues, Valentina F.; Fernandes, Virgínia C.; Correia-Sá, Luísa; Catarina, MansilhaNatural estrogens are a group of steroid hormones that include the main active hormones, 17ß-estradiol (E2), estrone and estriol. Among these compounds, E2 is recognized to be the most active estrogen synthesized in female ovaries. Environmental problems due to estrogenic compounds are mainly related to aquatic environments. Indeed, numerous studies confirmed the occurrence of these substances at concentrations of toxicological concern (e.g., the feminization of fish in large rivers and toxicological effects on wildlife). Generally, the main sources of estrogens are recognized as treated and untreated municipal and industrial effluents, as well as livestock wastes from agricultural practices, as sewage and manure often used as fertilizers. Moreover the steroid hormones found in the urine of mammals are largely present as inactive conjugates, however the behavior of these forms will deconjugate to rapidly release the free hormones in the environment. As a consequence, large quantities of estrogens are spread in environmental waters, where they may sorb to sediments and persist for relatively long periods. Recently, the development of new analytical equipment, namely tandem mass spectrometers coupled to LC and GC systems, allowed improvements in the sensitivity, selectivity, and speed of analysis. Such improvements in sensitivity and selectivity could also be accomplished by innovative sample preparation techniques, most of them with the added benefit to be easy to execute, cost effective, and environmental friendly. Concerning the evaluation of the biological effects of estradiol, several methods have recently been developed: on whole organisms (vitellogenine assay), cells (cell proliferation), yeast estrogen screen, ER CALUX and molecular assays. In this chapter, various aspects of the estradiol presence in environmental waters are discussed. An overview of the current legislation related to water quality is given. The work then focuses on the health and environmental impacts and evaluation methods. Then, finally, the example case studies illustrate the health effects of estradiol and its environmental impact.
- Risk Assessment of Cyanobacteria and Cyanotoxins, the Particularities and Challenges of Planktothrix spp. MonitoringPublication . Churro, Catarina; Dias, Elsa; Valério, Elisabete
- The Kidney Vero-E6 Cell Line: a Suitable Model to Study the Toxicity of MicrocystinsPublication . Menezes, Carina; Valério, Elisabete; Dias, ElsaMicrocystins (MCs) are toxins produced by cyanobacteria from water environments that can induce acute and chronic effects on humans and animals, after ingestion/contact with contaminated water. This group of cyclic heptapeptides comprises approximately 80 variants, being microcystin-LR (MCLR) the most frequent and toxic variant. The studies of MCs effects on cell lines often lead to contradictory results, given the fact that distinct MC toxicity endpoints (mainly cytotoxicity and genotoxicity) have been studied in diverse cell lines (and cell clones) under distinct exposure conditions (different doses-ranges, time of exposure, MCs variants, etc). In our work with Vero-E6 cells we tested MCLR (both pure toxin and from cyanobacterial extracts of M. aeruginosa) within a wide range of concentrations (1 nM- 200 μM), using several endpoints and methodologies (cytotoxicity, morphology, genotoxicity, protein expression). In this chapter we will summarize our results and discuss the utility of Vero-E6 cell line to evaluate the toxicological properties of MCLR.