Tracing sewage contamination in a South Atlantic UNESCO Natural Heritage estuary using sedimentary linear alkylbenzenes and their diagnostic ratios.

The Paranaguá Estuarine System (PES) is an extensive subtropical estuarine system on the Southern Brazilian coast. It encompasses one of the last preserved areas of the Atlantic Forest and is recognized by UNESCO as a Natural Heritage site. This study evaluates the human impact of rapid and unplanned urbanization, an inefficient sewage system, and two port complexes by using linear alkylbenzenes (LABs) as a molecular marker for sewage input.

Electrochemical impedance biosensor for detection of saxitoxin in aqueous solution.

Saxitoxin is a cyanotoxin which is very harmful to human health; the concentration limit in drinking water is only 3 μg/L. Therefore, a simple, fast, sensitive, low-cost, and specific method for its detection, quantification, and monitoring in water bodies is needed to avoid adverse effects on animal and human health. In this work, we developed an electrochemical impedimetric biosensor using a specific aptamer as recognition element for saxitoxin detection.

Toxicological Evaluation and Quantification of Ingested Metal-Core Nanoplastic by Daphnia magna Through Fluorescence and Inductively Coupled Plasma-Mass Spectrometric Methods.

There are few studies on nanoplastic that propose quantification of the amount ingested combined with evaluation of the toxic effects on aquatic organisms. We propose 2 methods to quantify the amount of polystyrene nanoplastic (PSNP) ingested by Daphnia magna: fluorescence intensity, where a fluorescent monomer (F) is added to the PSNP and quantified through fluorescence light microscopy, and total aluminum quantification, where PSNP is synthesized with Al O metal-core nanoparticles and used for quantification of the nanoplastic ingested by the organism Daphnia magna using inductively coupled plasma-mass spectrometry. In addition, the PSNP was functionalized with palmitic acid to simulate the environmental conditions leading to biological and chemical transformations.

Can the surface modification and/or morphology affect the ecotoxicity of zinc oxide nanomaterials?

Among nanomaterials, zinc oxide (ZnO) is notable for its excellent biocidal properties. In particular, it can be incorporated in mortars to prevent biofouling. However, the morphology of these nanomaterials (NMs) and their impact on the action against biofouling are still unknown.

Comparative assessment of acute and chronic ecotoxicity of water soluble fractions of diesel and biodiesel on Daphnia magna and Aliivibrio fischeri.

The widespread use of diesel as a transportation fuel and the introduction of biodiesel into the world energy matrix increase the likelihood of aquatic contamination with these fuels. In this case, it is important to know the environmental impacts caused by water-soluble fraction (WSF) of these fuels, since it is the portion that can result in long-term impacts and affect regions far away from the location of a spill. Therefore, we evaluated and compared the aquatic ecotoxicity of the WSF of biodiesel and diesel through acute ecotoxicity tests with the aquatic microcrustacean Daphnia magna and the marine bacteria Aliivibrio fischeri, as well as chronic ecotoxicity tests with D.

Effect of chromium oxide (III) nanoparticles on the production of reactive oxygen species and photosystem II activity in the green alga Chlamydomonas reinhardtii.

With the growth of nanotechnology and widespread use of nanomaterials, there is an increasing risk of environmental contamination by nanomaterials. However, the potential implications of such environmental contamination are hard to evaluate since the toxicity of nanomaterials if often not well characterized. The objective of this study was to evaluate the toxicity of a chromium-based nanoparticle, Cr2O3-NP, used in a wide diversity of industrial processes and commercial products, on the unicellular green alga Chlamydomonas reinhardtii.

Oxidative stress and hypermethylation induced by exposure of Oreochromis niloticus to complex environmental mixtures of river water from Cubatão do Sul, Brazil.

In this study, we investigated the effects of oxidative stress and hypermethylation through lipid peroxidation and DNA methylation, respectively, in erythrocytes of Oreochromis niloticus exposed to environmental complex mixture of water from Cubatão do Sul River throughout the year. This river is the source of drinking water for the region of Florianópolis, the capital of Santa Catarina State, Brazil. Lipid peroxidation was quantified by the rate of malondialdehyde (MDA) formation, and DNA methylation was quantified by the rate of 5-methyldeoxycytosine (m(5)dC) formation.

Comparative evaluation of acute and chronic toxicities of CuO nanoparticles and bulk using Daphnia magna and Vibrio fischeri.

Copper oxide (CuO) has various applications, as highlighted by the incorporation of this compound as a biocide of antifouling paints for coating ships and offshore oil platforms. The objective of this study was to evaluate and compare the aquatic toxicity of CuO nanoparticles (NPs) and microparticles (MPs) through acute and chronic toxicity tests with the freshwater microcrustacean Daphnia magna and an acute toxicity test with the bioluminescent marine bacteria Vibrio fischeri. Acute toxicity results for D.

Evaluation of toxicity and oxidative stress induced by copper oxide nanoparticles in the green alga Chlamydomonas reinhardtii.

Copper oxide nanoparticles (CuO NP) are frequently employed for their antimicrobial properties in antifouling paints. Their extensive use can contaminate aquatic ecosystems. However, the toxicological effects of this NP in the environment are poorly known.

Genotoxic effects of copper oxide nanoparticles in Neuro 2A cell cultures.

Copper oxide nanoparticles (CuO NPs) are used for their biocide potential however they were also shown to be highly toxic to mammalian cells. Therefore, the effects of CuO NPs should be carefully investigated to determine the most sensitive processes for CuO NP toxicity. In this study, the genotoxicity of CuO NPs was investigated in vitro, using the mouse neuroblastoma cell line Neuro-2A.

Polymer coating of copper oxide nanoparticles increases nanoparticles uptake and toxicity in the green alga Chlamydomonas reinhardtii.

Copper oxide nanoparticles (CuO NPs) are frequently used in a polymer-coated form, to be included in paints or fabrics for antimicrobial properties. Their application in antifouling paints may lead to the contamination of aquatic ecosystems. However, the toxicological risk of NPs in the environment is hard to evaluate due to a lack of knowledge on the mechanisms of NP interaction with biological systems.

Toxicity of PAMAM-coated gold nanoparticles in different unicellular models.

Polyamidoamine (PAMAM) dendrimers are used for many pharmaceutical and biomedical applications. However, the toxicological risks of several PAMAM-based compounds are still not fully evaluated, despite evidences of PAMAM deleterious effects on biological membranes, leading to toxicity. In this report, we investigated the toxicity of generation 0 PAMAM-coated gold nanoparticles (AuG0 NPs) in four different models to determine how different cellular systems are affected by PAMAM-coated NPs.

Effects of exposure to soluble fraction of industrial solid waste on lipid peroxidation and DNA methylation in erythrocytes of Oreochromis niloticus, as assessed by quantification of MDA and m⁵dC rates.

In this study, lipid peroxidation and DNA methylation were observed in erythrocytes of Oreochromis niloticus exposed to soluble fractions of textile, metal-mechanic and pulp and paper industrial waste, after a period of 48 h. Lipid peroxidation was quantified by the rate of malondialdehyde (MDA) and DNA methylation was quantified by the rate of 5-methyldeoxycytosine (m⁵dC). Soluble fractions of textile industrial waste caused metabolic changes for all studied samples.

Investigation of animal and algal bioassays for reliable saxitoxin ecotoxicity and cytotoxicity risk evaluation.

Contamination of water bodies by saxitoxin can result in various toxic effects in aquatic organisms. Saxitoxin contamination has also been shown to be a threat to human health in several reported cases, even resulting in death. In this study, we evaluated the sensitivity of animal (Neuro-2A) and algal (Chlamydomonas reinhardtii) bioassays to saxitoxin effect.