Nanotechnology-based strategies have played a pivotal role in innovative products in different technological fields, including medicine, agriculture, and engineering. The redesign of the nanometric scale has improved drug targeting and delivery, diagnosis, water treatment, and analytical methods. Although efficiency brings benefits, toxicity in organisms and the environment is a concern, particularly in light of global climate change and plastic disposal in the environment. Therefore, to measure such effects, alternative models enable the assessment of impacts on both functional properties and toxicity. Caenorhabditis elegans is a nematode model that poses valuable advantages such as transparency, sensibility in responding to exogenous compounds, fast response to perturbations besides the possibility to replicate human disease through transgenics. Herein, we discuss the applications of C. elegans to nanomaterial safety and efficacy evaluations from one health perspective. We also highlight the directions for developing appropriate techniques to safely adopt magnetic and organic nanoparticles, and carbon nanosystems. A description was given of the specifics of targeting and treatment, especially for health purposes. Finally, we discuss C. elegans potential for studying the impacts caused by nanopesticides and nanoplastics as emerging contaminants, pointing out gaps in environmental studies related to toxicity, analytical methods, and future directions.

Chromium nitride nanoparticles with mean diameter distribution between 0.8 nm and 30 nm were produced by laser irradiation of a chromium target immersed in liquid nitrogen. Cr was directly converted to chromium nitride nanoparticles according to selected-area electron diffraction analyses using the transmission electron microscopy technique. Crystalline nanoparticles mostly consist of ${\mathrm{Cr}}_2\mathrm{N},$ which is commonly reported together with the conversion of ${\mathrm{Cr}}_2\mathrm{N}$ to CrN and the mixture of chromium oxides. In addition, there is no evidence of oxidation by storage or photodegradation of the nanoparticles in isopropyl alcohol suspensions. The intensity profile of small-angle X-ray scattering indicates that the geometrical shape of the nanoparticles is not spherical but cylindrical with aspect ratio (height-to-radius) of $0.35$ –$0.05$ . UV-Vis absorption spectroscopy reveals the presence of surface plasmon absorption at the ultraviolet region at wavelengths of 350, 372, and 397 nm. First-principles calculations of density of states, dielectric function, and optical conductivity performed within the theoretical framework of density functional theory for ${\mathrm{Cr}}_2\mathrm{N}$ with a hexagonal structure corroborate the formation of surface plasmons.

This study investigates the dispersion of floating plastic from Recife-PE harbor using a particle tracking model and examines contaminants in fishing nets collected from Brazilian beaches. Simulations were conducted for both dry and rainy seasons. Fishing nets were collected from eight beaches for analysis. The plastic movement simulation showed particles dispersed 0.41 km southward during the dry season and 177.50 km northward during the rainy season. Most particles (90 %) beached within the first week, indicating localized litter distribution. The study identified 14 pesticide residues in the collected nets, along with heavy metals such as arsenic, cadmium, chromium, copper, nickel, zinc, and iron, detected via Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The pesticide and metal data were used to calculate the toxicological priority index (ToxPi), showing the sample from Joaquina-SC had the highest toxicity, while the sample from Sancho-PE had the lowest. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) revealed pollution patterns, with potential associations between pesticides and metals. These findings raise concerns about the contaminants' impact on marine organisms and human health, highlighting the importance of understanding plastic pollution dynamics and associated risks. Also, the outcomes emphasize the need to reevaluate environmental regulations to better protect ecosystems and species from harmful pollutants, including plastics.

Magnetic nanoparticles (NPs) are suitable candidates for various medical and biological applications, despite some concerns that they may have negative impacts on human health. In this study, the toxicity effects of magnetic NPs consisting of α”-Fe₁₆N₂ captured and bioaccumulated by the nematode Caenorhabditis elegans (C. elegans) in the early larval stage are evaluated. The choice of α”-Fe₁₆N₂ NPs is based on their good structural stability when stored in saline solution and high magnetic performance. The uptake and bioaccumulation of α”-Fe₁₆N₂ NPs in intestinal cells of C. elegans was evidenced by transmission electron microscopy. After exposure to NPs up to 40 mg mL⁻¹, C. elegans larval development, survival, feeding behavior, defecation cycles, movement and reproduction were monitored. C. elegans survival and other monitored behavioral evolutions do not show significant changes, except for a slight statistical reduction in the reproductive profile. Therefore, the present results are promising and very encouraging for investigations of applications of α”-Fe₁₆N₂ NPs in the biomedical area.

Anais do Encontro Nacional da EJA EPT (PROEJA) da Rede Federal (978-65-5941-630-1) - Curso De Formação Continuada Para Professores Da Educação De Jovens E Adultos Ofertado Em Ead Pelo Instituto Federal Catarinense - Ifc