[en] Emerging contaminants, such as plastic additives, represent an environmental problem in aquatic ecosystems. Of particular concern is the evidence that their inhabitants, such as microalgae, are exposed, not to a single compound, but to heterogeneous mixtures of pollutants, and repeated discharges are common in coastal waters near urban and/or industrial centers. Based on this, in the present work the potential cytotoxicity on the marine microalga Dunaliella tertiolecta of a mixture of 5 organic phosphorus flame retardant (TiBP, TnBP, TCPP (Σisomers), TDCPP and TPPO), designed as alternative additives of lower toxicity to those used in recent years, was studied. For this purpose, cultures of the microalgae were exposed to concentrations of 8 (EC25) and 16 (EC50) μg/mL analyzing by flow cytometry different biomarkers of toxicity (viability, vitality, intracellular ROS levels, intracellular pH, mitochondrial membrane potential and cytoplasmic membrane potential). The assays were performed with a first exposure to 8 μg/mL of the OPRFs mixture, analyzing the results at 3 and 48 hours. In addition, the removal of the 5 contaminants from the medium by D. tertiolecta was studied, quantifying them by vortex-assisted liquidliquid microextraction performing separation and detection with programmable temperature vaporize-gas chromatography-mass spectrometry of triple quadrupole (VALLME-PTV-GC-MS-MS). Finally, to simulate a new contaminant discharge, the cultures previously treated at 8 μg/mL of the mixture were subjected to a second 48h exposure at 16 μg/mL, repeating the referred analyses. The results obtained show that exposure to the mixture of 5 OPRFs causes cytotoxicity on the microalga D. tertiolecta, significantly affecting all biomarkers tested and being the analysis of intracellular ROS levels the most affected. In addition, the removal of compounds from the microalgal culture medium is observed as early as 3 hours after exposure to the contaminant mixture, with chlorinated compounds (TCPP and TDCPP) showing the least removal. Finally, a second exposure to the contaminant mixture produces a more severe toxicity in the re-exposed microalgal cells compared to the alterations recorded in the microalgae exposed for the first time.

[gl] Os contaminantes emerxentes, como os aditivos de plásticos, representan un problema medioambiental nos ecosistemas acuáticos. Particularmente preocupante é a evidencia de que os seus habitantes, como as microalgas, encóntranse expostos, non a un único composto, se non a mesturas heteroxéneas de contaminantes, sendo ademais habitual que se produzan descargas repetidas en augas costeiras próximas a núcleos urbanos e/ou industriais. En base a isto, no presente traballo estudouse a potencial citotoxicidade sobre a microalga mariña Dunaliella tertiolecta de unha mestura de 5 retardantes de chama organofosforados (TiBP, TnBP, TCPP (Σisómeros), TDCPP e TPPO), deseñados como aditivos alternativos de menor toxicidade aos utilizados nos últimos anos. Para elo, expuxéronse cultivos de la microalga a concentracións de 8 (EC25) y 16 (EC50) μg/mL analizando mediante citometría de fluxo diferentes biomarcadores de toxicidade (viabilidade, vitalidade, niveis intracelulares de ROS, pH intracelular, potencial de membrana mitocondrial e potencial de membrana citoplasmática). Os ensaios se realizaron cunha primeira exposición a 8 μg/mL da mestura de OPRFs, analizando os resultados ás 3 e 48 horas. Ademais, estudouse a retirada dos 5 contaminantes do medio por parte de D. tertiolecta, cuantificándoos mediante microextracción líquido-líquido asistida por vórtice realizando a separación e detección con cromatografía de gases acoplada a espectrometría de masas de triplo cuadrupolo con inxección con temperatura programada (VALLME-PTV-GC-MS-MS). Finalmente, para simular una nova descarga de contaminantes, os cultivos previamente tratados a 8 μg/mL da mestura sometéronse a unha segunda exposición de 48h a 16 μg/mL, repetíndose los análises referidos. Os resultados obtidos mostran que la exposición á mestura de 5 OPRFs provoca citotoxicidade sobre a microalga D. tertiolecta, afectando significativamente a todos os biomarcadores ensaiados e o análise dos niveis intracelulares de ROS foi o máis afectado. Ademais, a retirada dos compostos do medio de cultivo microalgal observase xa ás 3 horas de la exposición á mestura de contaminantes, sendo os clorados (TCPP e TDCPP) os que presentan unha menor retirada. Por último, unha segunda exposición á mestura de contaminantes produce unha toxicidade más severa nas células microalgais reexpostas en comparación coas alteracións rexistradas nas microalgas expostas por primeira vez.