Potentially toxic elements (PTEs) in seabirds foraging across a heterogeneous landscape: Cross-species bioaccumulation patterns.

Seabirds are particularly susceptible to potentially toxic elements (PTEs) due to the tendency of biomagnification of some elements, thus serving as potential bioindicators for assessing environmental health. In this study, we analyzed As, Cd, Cu and Zn concentrations in liver samples from nine seabird species (51 specimens) collected along the Southwestern Atlantic Ocean. Results revealed substantial variations in PTE concentrations among species, with taxonomic orders influencing accumulation patterns.

Fractionation and speciation of metals in lakes formed by abandoned clay pits from industrial effluents (Santa Gertrudes, São Paulo, Brazil) using the diffusive gradient in thin films (DGT) technique.

Environmental impacts caused by mining activities (mainly tailings and effluents) are presenting serious challenges for humanity worldwide. In Brazil, clay extraction activities in the Ceramic District of Santa Gertrudes (CDSG) have led to the formation of abandoned drainage wells causing environmental and human health concerns. In the 90's, it was discovered that in one of the production areas, known as the region of the lakes of Santa Gertrudes, several ceramic industries had contaminated lakes created by abandoned clay pits with industrial effluents containing toxic metals.

Use of carminic acid immobilized in agarose gel as a binding phase for DGT: A new approach for determinations of rare earth elements.

Recently, rare-earth elements (REEs) have attracted great interest due to their importance in several fields, such as the high-technology and medicine industries. Due to the recent intensification of the use of REEs in the world and the resulting potential impact on the environment, new analytical approaches for their determination, fractionation and speciation are needed. Diffusive gradients in thin films are a passive technique already used for sampling labile REEs, providing in situ analyte concentration, fractionation and, consequently, remarkable information on REE geochemistry.

Combining ultrafiltration and diffusive gradients in thin films techniques for speciation/fractionation of Cu and Zn in cytosol of liver of Nile tilapia (Oreochromis niloticus).

This work aims to evaluate the size and lability of Cu and Zn bound to proteins in the cytosol of fish liver of Oreochromis niloticus by employing solid-phase extraction (SPE), diffusive gradients in thin films (DGT), and ultrafiltration (UF). SPE was carried out using Chelex-100. DGT containing Chelex-100 as binding agent was employed.

A new approach to improve the accuracy of DGT (Diffusive Gradients in Thin-films) measurements in monitoring wells.

The Diffusive Gradients in Thin-films (DGT) technique represents an ideal tool for monitoring water quality of inorganic species in systems with a high flow such as rivers, streams, lakes and seas. However, in low-flow systems (non-turbulent waters), the influence of a diffusive boundary layer (DBL) formed on the surface of the DGT device has been observed, which can lead to erroneous measurements by DGT. Therefore, the use of DGT in wells for groundwater monitoring is still very limited until now.

Lability and bioavailability of Co, Fe, Pb, U and Zn in a uranium mining restoration site using DGT and phytoscreening.

Mine restoration is a long and ongoing process, requiring careful management, which must be informed by site-specific, geochemical risk assessment. Paired topsoil and tree core samples from 4 sites within the uranium mining complex of INB Caldas in Minas Gerais (Brazil) were collected. Soil samples were analysed for their total content of Co, Fe, Pb, U and Zn by XRF, and subsequently, the potential environmental bioavailability of these metals were investigated by DGT and pore water analysis.

Intraspecific variation of trace elements in the kelp gull (): influence of age, sex and location.

Hepatic tissue of sampled on the coastline of the state of Santa Catarina in Brazil between October 2016 and May 2018 was used to evaluate intraspecific trends and spatial distribution of essential trace elements (Mn, Co, Cu, Zn, Mo and Cr) and non-essential trace elements (As, Pb, Cd, Hg, Ba and V). Principal Component Analysis (PCA) indicated differences in the bioaccumulation of trace elements between female adults and male adults, differences to sex and age were indicated by Kruskal-Wallis test. Heat maps suggest hot spots in locals with high concentration of trace elements in liver of .

Metal speciation of the Paraopeba river after the Brumadinho dam failure.

On January 25, 2019, a tailings dam at the Córrego do Feijão iron ore mine (Brumadinho, Minas Gerais, southern Brazil) ruptured and released ~12 million m of mine tailings into the Paraopeba River, which is an important source of drinking water to a populous region. While water potability due to a strong increase in turbidity has been well documented, possible effects of metal contamination are yet to be addressed. We investigated the speciation of metals in the river water and desorption of metals from sediments as a means of supporting risk assessment, using the diffusive gradient in thin films (DGT) technique, desorption experiments and chemical speciation calculations.

Heterobimetallic Ru(ii)/Fe(ii) complexes as potent anticancer agents against breast cancer cells, inducing apoptosis through multiple targets.

Antimetastatic activity, high selectivity and cytotoxicity for human tumor cell lines make ruthenium(ii) complexes attractive for the development of new chemotherapeutic agents for cancer treatment. In this study, cytotoxic activities and the possible mechanism of cell death induced by three ruthenium complexes were evaluated, [Ru(MIm)(bipy)(dppf)]PF (1), [RuCl(Im)(bipy)(dppf)]PF (2) and [Ru(tzdt)(bipy)(dppf)]PF (3). The results showed high cytotoxicity and selectivity indexes for the human triple-negative breast tumor cell line (MDA-MB-231) with IC value and selectivity index for complex 1 (IC = 0.

Residual biomass of coffee as a binding agent in diffusive gradients in thin-films technique for Cd, Cu, Ni, Pb and Zn measurement in waters.

Spent coffee grounds (SCG) immobilized in agarose gel are proposed as a novel binding agent for application in the Diffusive Gradients in Thin films (DGT) technique for the determination of Cd, Cu, Ni, Pb and Zn in waters. The SCG-agarose gel was characterized by Scanning Electron Microscopy, Energy Dispersive X-ray Spectrometry and Porosimetry by nitrogen adsorption. Elution of analytes from the binding agent was effectively performed with 2 mol L HCl.

Elemental and isotopic determination of lead (Pb) in particulate matter in the Brazilian city of Goiânia (GO) using ICP-MS technique.

The toxic metal lead (Pb) can be harmful to human health in various manners, but is also considered as a distinguished tracer of environmental pollution since the relative abundance of its four stable isotopes with the atomic masses of 204, 206, 207, and 208 varies with the emission source. This study is focused on the Pb concentrations and isotope ratios in the particulate matter of the Brazilian city of Goiânia in order to determine the main Pb emission sources. Particulate matter samples were collected on clean Teflon filters during rainy and dry season in 2014 in the center of Goiânia city near main roads with a high traffic volume.