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The widespread use of plastics has revolutionized modern life, but also led to environmental pollution. Although microplastics (MPs) have been detected in various environments, their presence in the atmosphere, particularly in Brazil, is poorly studied. This research investigated atmospheric MP concentrations at Alvaro Guião School in São Carlos, Brazil, from 2021 to 2022. Outdoor MP concentrations ranged from the limit of detection (LOD) to 168.03 items m -2 day -1 , and indoor concentrations ranged from LOD to 60.16 items m -2 day -1 . Predominantly, these MPs were fragments, even in the indoor environment, suggesting abundant sources, such as resuspension. Seasonal variations were not observed for outdoor fragments and fibers, nor for indoor fragments. However, indoor fiber concentrations were higher during the dry season (p > 0.05), likely due to winter clothing and reduced ventilation. Fragment sizes were mainly <60 μm, while fibers ranged from <60 μm to 3000-5000 μm. Polyester was the primary MP component (83-100% outdoors and 29-100% indoors), followed by ethylene vinyl acetate (EVA, 0-17% outdoors and 0-57% indoors), common in synthetic clothing and school supplies, respectively. Other plastics, found in packaging and bottles, like polyethylene (0-14%) and polyethylene terephthalate (0-6%), were also identified indoors. This study not only enhances the current understanding, but also pioneers analyses within a school environment. Despite being a work in progress, this study has already shown the presence of plastic particles in environments where children, one of the most susceptible groups to air pollution, spend a significant portion of their time. Furthermore, it can assist in developing an assessment of acceptable levels and guidelines., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Brazil maintains its position at the top of the global ranking of plastic producers, yet recycling efforts have been incipient. Recent data reveals an annual production of approximately 14 million tons of plastic waste, not accounting for the surge in the usage of plastic masks and related materials due to the COVID-19 pandemic. However, what remains largely unreported is that over half of post-consumer plastic packaging in Brazil is managed without any monitoring, and it remains unclear how this will contribute to the occurrence of plastic waste and microplastics in Brazilian freshwaters. This scenario requires the consideration of several other crucial factors. Studies have been carried out mainly in marine and estuarine waters, while data on freshwaters are lacking. Brazil has continental dimensions and the highest water availability on the planet, yet the demand for water is greatest in regions with medium to low supply. Many densely populated Brazilian urban areas face chronic flood problems, possess inadequate levels of wastewater treatment, and display inadequate solid waste management practices. Consequently, urban freshwater with tropical characteristics in Brazil presents an intriguing scenario and is complementary to the most commonly studied marine environments. In this study, we explore the nuances of pollution in Brazilian urban freshwater and discuss how various parameters, such as organic matter, suspended solids, temperature, and pH, among others, influence the behavior of microplastics and their interactions with organic and inorganic contaminants. Furthermore, we address how microplastic conditions, such as biofouling, the type of plastic, or degradation level, may impact their behavior. By analyzing how these conditions change, we propose priority themes for investigating the occurrence of microplastics in Brazilian urban freshwater systems under different degrees of human impact. Ultimately, this study aims to establish a network dedicated to standardized monitoring of microplastic pollution in Brazilian urban freshwaters., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The dosimeter characteristics of jade samples were studied for application in high-dose dosimetry. Jade is the common denomination of two silicates: jadeite and actinolite. The EPR spectra of different jade samples were obtained after irradiation with absorbed doses of 100 Gy up to 20 kGy. The jade samples present signals that increase with the absorbed dose (g-factors around 2.00); they can be attributed to electron centers. The EPR spectra obtained for the USA jade samples and their main dosimetric properties as reproducibility, calibration curves and energy dependence were investigated., (Copyright 2009 Elsevier Ltd. All rights reserved.)

Ancient potteries usually are made of the local clay material, which contains relatively high concentration of iron. The powdered samples are usually quite black, due to magnetite, and, although they can be used for thermoluminescene (TL) dating, it is easiest to obtain better TL reading when clearest natural or pre-treated sample is used. For electron paramagnetic resonance (EPR) measurements, the huge signal due to iron spin-spin interaction, promotes an intense interference overlapping any other signal in this range. Sample dating is obtained by dividing the radiation dose, determined by the concentration of paramagnetic species generated by irradiation, by the natural dose so as a consequence, EPR dating cannot be used, since iron signal do not depend on radiation dose. In some cases, the density separation method using hydrated solution of sodium polytungstate [Na6(H2W12O40).H2O] becomes useful. However, the sodium polytungstate is very expensive in Brazil; hence an alternative method for eliminating this interference is proposed. A chemical process to eliminate about 90% of magnetite was developed. A sample of powdered ancient pottery was treated in a mixture (3:1:1) of HCl, HNO(3) and H(2)O(2) for 4h. After that, it was washed several times in distilled water to remove all acid matrixes. The original black sample becomes somewhat clearer. The resulting material was analyzed by plasma mass spectrometry (ICP-MS), with the result that the iron content is reduced by a factor of about 9. In EPR measurements a non-treated natural ceramic sample shows a broad spin-spin interaction signal, the chemically treated sample presents a narrow signal in g=2.00 region, possibly due to a radical of (SiO(3))(3-), mixed with signal of remaining iron [M. Ikeya, New Applications of Electron Spin Resonance, World Scientific, Singapore, 1993, p. 285]. This signal increases in intensity under gamma-irradiation. However, still due to iron influence, the additive method yielded too old age-value. Since annealing at 300 degrees C, Toyoda and Ikeya [S. Toyoda, M. Ikeya, Geochem. J. 25 (1991) 427-445] states that E1'-signal with maximum intensity is obtained, while annealing at 400 degrees C E1'-signal is completely eliminated, the subtraction of the second one from 300 degrees C heat-treated sample isolate E1'-like signal. Since this is radiation dose-dependent, we show that now EPR dating becomes possible.

The dosimetric properties of sand from Brazilian beaches have shown to be useful for high-dose dosimetry. The thermoluminescent (TL) and electron paramagnetic resonance (EPR) techniques were utilised, and the sand samples were recently studied in relation to their main dosimetric properties. The EPR signal at g = 1.999 grows significantly in function of the absorbed dose, and the TL peaks appear at 110 and 170 degrees C. However, these sand samples present a post-irradiation thermal decay at room temperature, which is a problem for dosimetric procedures. In this study, sand samples have been studied in relation to different thermal treatments. Post-irradiation treatments were performed at 50 degrees C up to 230 degrees C.

The electronic paramagnetic resonance (EPR) technique was utilized to study sand samples from different Brazilian beaches for high-dose dosimetry. Sand also contains concentrations of heavy minerals. Sand samples were studied in relation to their main dosimetric properties: response reproducibility, reutilization, batch uniformity, detection range and dose response. The EPR signal grows significantly as a function of absorbed dose for g=1.999. All studied sand samples can be used as EPR dosimeters for different applications in medical, agricultural and industrial areas.

Commercial transparent and colored (bronze, brown, and green) glasses were studied as possible dosimeters for high gamma doses using electronic paramagnetic resonance (EPR). All EPR spectra showed the characteristic Fe3+ signals, g=4.27 and 2.01. The signal at g=2.01 presented a more useable behavior for the calibration curve. All samples showed their usefulness as high dose dosimeters.

The TL, optical absorption (OA) and EPR properties of natural Brazilian alexandrite and chrysoberyl have been investigated. The TL measurements for natural alexandrite show five peaks between 100 and 450 degrees C, with their emission spectrum having 370 and/or 570 nm components. The intensity of the 320 degrees C TL peak was found to be enhanced with pre-annealing treatment, more prominently above 600 degrees C. The OA and EPR measurements showed that this kind of heat treatment induces the Fe2+ --> Fe3+ conversion in the natural sample. Chrysoberyl samples exhibited the TL peaks at the same temperatures as alexandrite samples, but the glow curves were more than 200 times less intense than alexandrite ones.

We present the neuropsychological assessment with computer aid of six cerebral palsy children. Three children had right hemiparesis and three, left hemiparesis. The tomographic examination showed parietal cavities (porencephalic cyst in 4 children, ischemic injury in 1 case and subarachnoid cyst in 1 case). We have proposed to assess the visuo-spatial function since we suspected the children could have disturbance of this function. We did not detect this disturbance. On the other hand, the children had astereognosia and the right hemiparetic children preferred to execute signs on the right part of the computer visor. We discuss and propose explanations for both findings.