Temporal and spatial variations in metals and arsenic contamination in water, sediment and biota of freshwater, marine and coastal environments after the Fundão dam failure.

Temporal and spatial variabilities in concentrations of metals (Cd, Cr, Cu, Fe, Hg, Mn, Pb and Zn) and metalloid (As) associated with the Fundão dam tailings were evaluated in water, sediment and biota from freshwater (tributary, river, lakes and lagoons), marine and coastal (mangroves and beaches) ecosystems affected by the Mariana dam disaster (southeastern Brazil). In freshwater shrimps and fishes, temporal increases in the concentrations of most elements analyzed were observed. This finding was clearly associated with temporal increases in the concentrations of As and metals observed in both water and sediment. In turn, freshwater plankton showed only a temporal increase in Hg concentration, which was also associated with an increased concentration of this metal in the abiotic matrices. In marine fishes, temporal increases were only observed for Cu, Fe and Pb concentrations. Also, temporal increase was observed for Fe concentration in marine plankton (phytoplankton and zooplankton) and shrimps. Marine phytoplankton also showed a temporal increase in Hg concentration. All these findings were clearly associated with temporal increases in the concentrations of these metals in marine sediments. Mangrove crabs showed temporal increases in Hg and Cd, which were associated with temporal increases in water Hg and sediment Cd concentrations, respectively. In turn, beach crabs displayed temporal increases in Mn and Zn, which were associated with temporal increases in the concentrations of these metals in sediments, especially for Mn. In summary, all environmental matrices evaluated in the present study were shown to be contaminated with metals and metalloid associated with the Fundão dam tailings. Additionally, findings reported in the present study relative to the spatial variabilities observed in the whole aquatic area affected by the Fundão dam failure clearly reinforce the need of incorporating biological diversity in monitoring programs aiming to assess environmental health of aquatic systems, considering that patterns of metals and metalloid contamination levels may vary among taxa.

Impacts of tailings of Fundão dam (Brazil) rupture on marine fish: Metals bioaccumulation and physiological responses.

This study evaluated the impacts of the mining tailings after the rupture of the Fundão dam on fish communities on the Atlantic Ocean southeast coast. Four sample collections were carried out over two years (2018-2020), in seasonal periods. Omnivorous/herbivorous and carnivorous fish were collected for analysis of metal bioaccumulation, multibiomarkers of environmental contamination and histopathology. Metal bioaccumulation was stronger correlated in carnivorous fish in the dry-2018 collection, besides higher activity of antioxidant enzymes, energy metabolism and higher morphological damage; however, there was less oxidative damage and less metallothioneins induction, and these variables were strongly associated with the wet-2020 collection. In a temporal view, it was possible to observe a reduction in metal levels in fish, except in the mouth of the Doce River. These events can be explained by seasonal natural events, which tend the resuspension and boost metal levels, mainly in the mouth region during the rainy season.

Fast and simple method of simultaneous preservative determination in different processed foods by QuEChERS and HPLC-UV: Method development, survey and estimate of daily intake.

A fast and simple method, which employs QuEChERS and HPLC-UV, was developed to determine preservatives in processed foods from different classes. The method showed correlation coefficients above 0.99, LOQs between 0.13 and 0.33 mg kg-1 and recoveries between 91 and 107%, with RSD ≤ 5.3%. Levels of preservatives were up to 2040 mg kg-1 for benzoates, up to 3185 mg kg-1 for sorbates and up to 452 mg kg-1 for methylparaben. Only four out of 82 samples under analysis were above the maximum level allowed by the legislation. Additionally, daily intakes of preservatives were estimated. Regarding benzoates, relatively high intakes were estimated (25% of the acceptable daily intake - ADI) in comparison with sorbates (5% of ADI) and parabens (<1% of ADI), when mean consumption is considered. This method is a good alternative to determining preservatives in different food samples.

Multi-residue method for determination of 58 pesticides, pharmaceuticals and personal care products in water using solvent demulsification dispersive liquid-liquid microextraction combined with liquid chromatography-tandem mass spectrometry.

A rapid and efficient sample pretreatment using solvent-based de-emulsification dispersive liquid-liquid microextraction (SD-DLLME) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was studied for the extraction of 58 pharmaceuticals and personal care products (PPCPs) and pesticides from water samples. Type and volume of extraction and disperser solvents, pH, salt addition, amount of salt and type of demulsification solvent were evaluated. Limits of quantification (LOQ) in the range from 0.0125 to 1.25 µg L(-1) were reached, and linearity was in the range from the LOQ of each compound to 25 µg L(-1). Recoveries ranged from 60% to 120% for 84% of the compounds, with relative standard deviations lower than 29%. The proposed method demonstrated, for the first time, that sample preparation by SD-DLLME with determination by LC-MS/MS can be successfully used for the simultaneous extraction of 32 pesticides and 26 PPCPs from water samples. The entire procedure, including the extraction of 58 organic compounds from the aqueous sample solution and the breaking up of the emulsion after extraction with water, rather than with an organic solvent, was environmentally friendly. In addition, this technique was less expensive and faster than traditional techniques. Finally, the analytical method under study was successfully applied to the analysis of all 58 pesticides and PPCPs in surface water samples.