Biomonitoring Metal Pollution in a Reservoir and River in Brazil Using Bullfrog Tadpoles' Tissues and Biomarkers.

Bullfrog tadpoles were exposed (96 h) to water from two sites (the Ibiúna and the Itupararanga reservoir) on the Sorocaba River (São Paulo, Brazil). Metal concentrations (Ba, Cu, Mn, Sr and Zn) and metallothioneins (MTs) levels were determined in the gills (n = 27) and caudal muscle (n = 18). Metals increased in the gills of the animals exposed to the waters of the Sorocaba River in relation to the control and in relation to the animals exposed to the waters of the Ibiúna point.

Use of biomarkers in bullfrog tadpoles Aquarana catesbeiana (Shaw 1802) for ecotoxicological evaluation of Pirajibú River (São Paulo, Brazil).

This study focused on investigating the water quality in the Pirajibú River, a relevant water body that flows through the industrial zone of Sorocaba (São Paulo/Brazil). Due to the limitations of assessing water quality based solely on standard physicochemical tests, an ecotoxicological approach was used to assess biomarker changes in the liver of bullfrog tadpoles (Aquarana catesbeiana). The animals were divided into groups and exposed to water samples collected upstream and downstream of the industrial zone.

Comparative analysis of sediment quality indices using different reference values in an environmental protection area in Southeastern Brazil.

Contamination of aquatic ecosystems by potentially toxic elements (PTEs) is a concerning environmental issue, given their persistence, toxicity potential, and ability to accumulate in living organisms. Several studies have been conducted to assess the contamination of aquatic ecosystems by PTEs, using pollution and ecological risk indices that rely on the concentration of these elements in aquatic sediments. However, many of these studies use global reference values for calculating the indices, which can lead to misleading interpretations due to substantial variations in PTEs concentrations influenced by the geological characteristics of each region.

Urban river recovery: a systematic review on the effectiveness of water clean-up programs.

Urban rivers are affected at different levels by the intensification of human activities, representing a serious threat to the maintenance of terrestrial life and sustainable urban development. Consequently, great efforts have been dedicated to the ecological restoration of urban rivers around the world, as a solution to recovering the environmental functionality of these environments. In this sense, the present work aimed to investigate the effectiveness of interventions carried out aimed at the recovery of urban rivers, through a systematic review of the literature between 2010 and 2022, using the search term "rivers recovery.

Leafy vegetables marketed as organic and conventional: assessment of essential and non-essential elements' content.

Trace and potentially toxic elements represent one class of food contaminants that has stimulated research. In markets, two main methods of growing vegetables are generally available: conventional and organic. Conventional farming has been the target of some concerns about the use of agrochemicals, especially the excessive use of pesticides, whereas organic agriculture minimizes the use of agrochemicals.

Natural and anthropogenic sources of potentially toxic elements to aquatic environment: a systematic literature review.

Potentially toxic elements (PTEs) constitute a class of metals, semimetals, and non-metals that are of concern due to their persistence, toxicity, bioaccumulation, and biomagnification in high concentrations, posing risks to the ecosystem and to human health. A systematic literature review (SLR) was used in this study to identify natural and anthropogenic sources of PTEs for the aquatic environment. The databases consulted were ScienceDirect, Scopus, and Web of Science, in the period 2000-2020, using specific terms and filters.

The environmental importance of iron speciation in soils: evaluation of classic methodologies.

Iron is an essential mineral and one of the most abundant in soils, presenting itself in the environment as ferrous and ferric ions. As each oxidation state of iron has a different role in the environment, its speciation in environmental studies is important. The determination of ferrous iron received great attention from soil chemists because of its important role in agriculture, in redox processes, and as an electron acceptor in the catalysis of organic matter.

Spatial modeling applied to environmental monitoring: identifying sources of potentially toxic metals in aquatic system.

Aquatic contamination by potentially toxic metals is a problem that has been aggravated, especially due to the quantity and the diversity of sources. Locating these sources is not always an easy task, especially because of the wide variety of possibilities. In this context, the application of geostatistical methods may represent an excellent tool to find out sources of metal contaminants in aquatic systems.

Natural organic matter residue as a low cost adsorbent for aluminum.

The contamination of aquatic and terrestrial environments by potentially toxic metals is highlighted by the possible impacts that their high availability can have on the environment. Thus, the development of alternative absorbents that can be used in the remediation of contaminated areas is of great environmental interest. Humin, one of the fractions of natural organic matter, is a promising alternative in studies on the retention of different metals that are environmentally toxic.

Effect of the competition of Cu(II) and Ni(II) on the kinetic and thermodynamic stabilities of Cr(III)-organic ligand complexes using competitive ligand exchange (EDTA).

The effect of competition of Cu(II) and Ni(II) on the kinetic stability of Cr(III) complexed with natural organic matter (NOM) was characterized using EDTA exchange with single-stage tangential-flow ultrafiltration. For a water sample from Serra de Itabaiana, 3% of spiked Cr(III) was exchanged, while for a sample from the Itapanhaú River, 7, 10, 10, and 21% was exchanged in experiments using Cr(III) alone and in combination with Cu(II), Ni(II), or Cu(II) + Ni(II), respectively. Times required to reach exchange equilibrium with EDTA were less than 360 min.

Paraquat-loaded alginate/chitosan nanoparticles: preparation, characterization and soil sorption studies.

Agrochemicals are amongst the contaminants most widely encountered in surface and subterranean hydrological systems. They comprise a variety of molecules, with properties that confer differing degrees of persistence and mobility in the environment, as well as different toxic, carcinogenic, mutagenic and teratogenic potentials, which can affect non-target organisms including man. In this work, alginate/chitosan nanoparticles were prepared as a carrier system for the herbicide paraquat.

Peat humic substances enriched with nutrients for agricultural applications: competition between nutrients and non-essential metals present in tropical soils.

Improved agricultural productivity, and reduction of environmental impacts, require studies of the interactions between different soil components. Fertilizers marketed as "organic" or "natural", such as peats or humic substances (HS) extracted from peats, are enriched with macro and micronutrients that, according to the manufacturers, are released to the plant in accordance with its needs. This work investigates the complexation capacity of HS for macro and micronutrient metal species, considering the competition, for HS complexation sites, between non-essential metals (aluminium and lead), present in the soil, and the nutrients.