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This study investigated the genotoxic risk of chronic exposure of hemolymph’s cells of Drosophila melanogaster (Insecta, Diptera) to water samples from Boqueirão de Parelhas Dam and from Lucrécia Dam in the semiarid region of Brazil. The dams are located over the Pegmatite Province of Borborema, with rocks rich in uranium and thorium. Water samples hydrated a culture medium composed of mashed potatoes, where larvae of D. melanogaster fed for 24 h, before be underwent to the Comet assay. The same water was evaluated for the presence of dissolved Radon gas (222Rn) and concentrations of 11 toxic metals (Ag, Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn). The results indicated a genotoxic effect resulting from exposure to the waters of the Parelhas dam, in the samples of August 2018; and in Lucrécia dam, in January 2019. D. melanogaster stood out for its high sensitivity to monitor the genotoxic effects of compounds dissolved in public dams. And unlike to other essentially aquatic sentinel organisms, this species stood out as a model to concomitant studies of air and water possible contaminated, in a scenario of natural environmental radioactivity present in semiarid of Brazil. [ABSTRACT FROM AUTHOR]

In view of the relevance of urban parks and public squares to the well-being of the population, coupled with the presence of uraniferous phosphorite in the Metropolitan Region of Recife, State of Pernambuco, Brazil, this study aimed to evaluate the contribution of natural radionuclides and the toxic chemical elements As, Cd, Ni, Pb, and Sb found in the soils of urban green spaces to the population's carcinogenic risks. Samples consisting of soils collected from a depth of 0–15 cm were analyzed by High Resolution Gamma Spectrometry, Graphite Furnace Atomic Absorption Spectrometry and Inductively Coupled Plasma Mass Spectrometry, after chemical treatment. The annual effective dose rates were estimated to be lower than the threshold for individual exposure to ionizing radiation of 1 mSv year−1, even in green spaces close to uraniferous outcrops. There were As, Cd, Ni, and Pb hotspots in these soils, resulting in high values of Pollution Load Index (PLI) for practically all the studied green spaces. Although considerable non-carcinogenic risks were not found, two green spaces presented significant carcinogenic risks for adults. Furthermore, significant carcinogenic risks would be expected for children at all study sites. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effects of the Rn-222 progeny on the lichen Cladonia verticillaris under controlled conditions. The results showed resistance of the species, and few changes in the level of photosynthetic pigments. Blockage in the biosynthetic route of the major phenolic compound fumarprotocetraric acid was also identified, and accumulation of protocetraric acid, as defense mechanism against external pollutants, to maintain thallus vitality. The accumulation of the 210Pb and 226Ra, radioisotopes estimated from the daughter of 214Bi and 214Pb, was incipient. C. verticillaris showed resistance to 222Rn, with accumulation of intermediary phenolic only at the begining of experiments. Highlights: Cladonia verticillaris was resistant to high doses of radiation, showing stability in the production of chlorophyll. Blockage in the biosynthesis of fumarprotocetraric acid was identified, causing accumulation of protocetraric acid, as a form of protection against the activity of Rn-222. Daughters of Rn-222 were determined, but the species reported low accumulation, and ability of self-protection. [ABSTRACT FROM AUTHOR]

Radioactive minerals in the process of being smuggled were seized in the North Region of Brazil. As it is a practically unknown material, the quali-quantitative characterization of a subsample of the mineral was conducted, using High-Resolution Gamma-Ray Spectrometry (HRGRS). Self-attenuation correction by means of quali-quantitative analysis through Energy Dispersion X-Ray Fluorescence (EDXRF) was deemed necessary due to the incongruence among the results of the gamma energies. The respective average values of activity concentrations (ACs) were estimated at 3.08 MBq kg−1 (± 0.10 MBq kg−1) and 1.37 MBq kg−1 (± 0.12 MBq kg−1) for 232Th and 238U. With the concentrations converted from 86 and 13% for ThO2 and U3O8, respectively, it was confirmed that the mineral was predominantly thorianite (U/Th ratio below 20%) and of a high risk of the population's exposure to ionizing radiation. [ABSTRACT FROM AUTHOR]

The Itapessoca Estuarine Complex is characterized by a history of intense economic activities developed on the banks of its tributary rivers, often exercised without any control or planning. In order to relate natural and/or anthropic events to the sediment age, radiometric dating method was performed by determining excess 210Pb in the sediment using the proportional gas flow technique. To investigate possible disturbances in recent sedimentation processes in studied area, 20 surfaces sediment samples and 2 sediment cores were collected for determination of concentrations of the chemical elements. Al, Ca, Fe, K, Mg, Mn, Ni, Pb, Si, Sr, Ti and Zn concentrations were determined by the energy-dispersive X-ray fluorescence (EDXRF) technique. Through the enrichment factors and ratios among some elements associated with geochronological data, it was possible identify geochemical changes in sedimentation of sampled points, with increase of minerals associated with fine fractions and decrease of the proportions of elements associated with coarse fractions. The radiometric dating reveals that Pb enrichment and the exacerbated increase of Ca and Sr enrichment factors are strongly related to the anthropic activity in the region. [ABSTRACT FROM AUTHOR]

Waste produced in homes is one of the main sources of pollutants in freshwater ecosystems. Therefore, it is imperative to implement methodologies that aid in environmental monitoring procedures. The use of organisms as biomonitors has grown increasingly prevalent as they are models that provide data that can be adequately evaluated. In this work, we investigated the genotoxic and cytotoxic effects caused by domestic sewage sludge through an analysis of biomarkers in the mollusk Biomphalaria glabrata. For the tests, increasing concentrations of 50, 100, 150, and 500 mg L−1 of domestic sewage sludge were standardized, in addition to control groups. Assays were performed after the mollusks were exposed to the domestic sewage sludge in acute (48 h) and chronic (15 d) manner. Toxicity tests were performed with embryonic and adult snails. The cytoplasmic and nuclear changes were analyzed in the hemocyte cells. Lastly, genotoxic damage was analyzed using the comet assay. Adult snails and embryos of B. glabrata showed no significant morphological changes. Domestic sludge caused deleterious effects on mollusks as confirmed after cell genotoxicity tests. Therefore, based on the results obtained from the analysis of B. glabrata hemocytes, we can affirm that domestic sewage sludge causes genotoxic and cytotoxic effects on mollusk cells. Therefore, it is possible to conclude that the mollusk Biomphalaria glabrata can be used as a good low-cost alternative to assist in the biomonitoring of freshwater environments. [ABSTRACT FROM AUTHOR]

Layered double hydroxides (LDH) have been extensively studied for a broad range of applications because their ease synthesis and chemical/crystal structure provides opportunities of combination with polymers forming nanocomposites. In this way, we have attempted to develop polymethylmethacrylate/LDH (PMMA/LDH) nanocomposites by using nonmodified Mg–Al LDH and Zn-Al LDH following in situ polymerization reaction. The effect of the varying loadings of LDH in the PMMA structure, morphology, and thermal properties of the synthesized PMMA/LDH nanocomposites has been investigated. The data showed nanocomposites formation with exfoliation /intercalation of LDH in PMMA matrix. Besides, not all the loadings of LDH in nanocomposites have improved thermal stability. This result does mean that loading of LDH plays an important role in the properties of PMMA/LDH nanocomposite. [ABSTRACT FROM AUTHOR]

This work aims at the application of chitosan-based materials in the treatment of oil incrustations containing Ra-226 and Ra-228 after an initial extraction process. Acid digestion in ultrasound and microwave of oil resulted in radium extraction. In this way, adsorption assay with chitosan powder (without modification) and chitosan bead (chemical modification) were performed using high-resolution gamma-ray spectrometry. The adsorption test revealed that chitosan beads were more efficient in the capture of Ra-226 and Ra-228 than chitosan control. Thus, the chitosan beads as a biomaterial may be utilized as a green alternative in the management of oil incrustation. [ABSTRACT FROM AUTHOR]

The application of geochronology for tracking mercury contamination was remarkably demonstrated in the Itamaracá Estuarine Ecosystem, Pernambuco State, Brazil. Here, two sediment cores were sampled, layered and analyzed by the Gas Flow Proportional Counter technique for determining 210Pb, radionuclide applied to geochronology. Mercury was quantified in sediment samples by Cold Vapor Atomic Absorption Spectrometry, varying from 0.17 to 1.29 mg kg−1 in deep sediments. From 210Pb results, the sedimentation rates of 0.84 (0.07) cm year−1 and 1.03 (0.22) cm year−1 confirmed Hg contamination in Itamaracá since mid-1965. Events of extreme precipitation and drought have been also related to the distribution pattern for Hg concentrations in deep sediments. [ABSTRACT FROM AUTHOR]

Several substances of synthetic and natural origin have been studied to determine their ability to protect the body from damage caused by ionizing radiation. Among these substances, quercetin has been shown to be a naturally occurring molecule with high radioprotective and radiomitigator potential due to its antioxidant properties. The objective of this work was to ascertain the potential radiomitigator effect of quercetin on chromosome aberration yield in lymphocytes of in vitro-irradiated human peripheral blood. At first, the DPPH (2,2-diphenyl-1-picryl-hydrazyl) radical capture test was performed to determine the antioxidant activity of quercetin and to select the concentrations to be tested. The blood was irradiated at doses of 2.5, 3.5, and 4.5 Gy and lymphocytes were cultured with quercetin at preselected concentrations of 37.5 and 75 μM. Then, the slides were prepared for scoring unstable chromosome aberrations (dicentrics, rings, and fragments). The results showed that the lymphocytes irradiated and later exposed to quercetin presented a lower frequency of chromosomal alterations compared to the control sample which was irradiated and not exposed to quercetin. The results suggest a potential radiomitigator effect of the flavonoid quercetin on human lymphocytes exposed, in vitro, to ionizing radiation. This effect may be related to decrease in the release of cytokines (INF-γ, PGE2, IL-1β, IL6, IL-8) involved in the proinflammatory processes as well as downregulation of NF-kB and reduction of expression TGF-β. [ABSTRACT FROM AUTHOR]

Chemicals released from anthropogenic activities such as industry and agriculture often end up in aquatic ecosystems. These substances can cause serious damage to these ecosystems, thus threatening the conservation of biodiversity. Among these substances are pesticides, such as oxyfluorfen, a herbicide used for the control of grasses and weeds. Considering its widespread use, it is important to investigate the possible toxicity of this compound to aquatic organisms, especially invertebrates. Hence, the use of biological systems able to detect such effects is of great importance. The mollusk Biomphalaria glabrata has been shown to be useful as an environmental indicator to assess the potential ecological effects of physical and chemical stressors in freshwater environments. The present study sought to detect mutagenic changes in hemocytes of B. glabrata exposed to oxyfluorfen. To perform these tests, this study used ten animals per group, exposed acutely (48 h) and chronically (15 days) to oxyfluorfen. The herbicide concentrations were 0.125, 0.25, and 0.5 mg/L. The results showed that oxyfluorfen induced significant frequencies of micronuclei, binucleated cells, and apoptosis in hemocytes of mollusks when compared to the control group. Unlike chronic exposure, acute exposure was dose-dependent. The present study's results demonstrate the cytotoxic and genotoxic effects of oxyfluorfen on hemocytes of B. glabrata. [ABSTRACT FROM AUTHOR]

This study evaluated the genotoxic potential of atmospheric pollution associated with urbanization using the model organism Drosophila melanogaster and the Comet assay with hemolymph cells. Larvae were exposed to atmospheric compounds in an urban and a rural area in the municipality of Vitória de Santo Antão, Pernambuco, Brazil, for 6 days (from the embryo stage to the third larval stage) in April 2015 and April 2017. The results were compared to a negative environmental control group exposed to a preserved area (Catimbau National Park) and to a negative control exposed to the laboratory room conditions. The Comet assay demonstrated significant genetic damage in the organisms exposed to the urban area compared with those exposed to the rural area and negative control groups. The evidences were supported by particulate matter analysis showing higher photopeaks of chemical elements such as aluminum, silicon, sulfur, potassium, calcium, titanium, and iron, associated to road dust fraction in urban environment. Once again, the results confirm D. melanogaster an ideal bioindicator organism to monitor genotoxic hazard associated with atmospheric pollution. [ABSTRACT FROM AUTHOR]

There is no information on arsenic distribution in terrestrial invertebrates from riparian forests of urban and rural areas in Brazil. The objective of this study was to evaluate the As levels in invertebrates from riverine forests of the Piracicaba River Basin, São Paulo, Brazil, using the instrumental neutron activation analysis, k -comparator method. After correction of mass fractions, values higher than 0.10 mg kg were quantified in invertebrates from both urban and agricultural areas. An unexpected As mass fraction of 13 mg kg obtained in the Coleopteran pest Macrodactylus pumilio indicated resistance to As-containing-pesticides. [ABSTRACT FROM AUTHOR]

The quality assessment of tropical soils and sediments is still under discussion, with efforts being made on the part of governmental agencies to establish reference values. Energy dispersive X-ray fluorescence (EDXRF) is a potential analytical technique for quantifying diverse chemical elements in geological material without chemical treatment, primarily when it is performed at an appropriate metrological level. In this work, analytical curves were obtained by means of the analysis of geological reference materials (RMs), which allowed for the researchers to draw a comparison among the sources of analytical uncertainty. After having determined the quality assurance of the analytical procedure, the EDXRF method was applied to determine chemical elements in soils from the state of Pernambuco, Brazil. The regression coefficients of the analytical curves used to determine Al, Ca, Fe, K, Mg, Mn, Ni, Pb, Si, Sr, Ti, and Zn were higher than 0.99. The quality of the analytical procedure was demonstrated at a 95% confidence level, in which the estimated analytical uncertainties agreed with those from the RM's certificates of analysis. The analysis of diverse geological samples from Pernambuco indicated higher concentrations of Ni and Zn in sugarcane, with maximum values of 41 mg kg and 118 mg kg, respectively, and agricultural areas (41 mg kg and 127 mg kg, respectively). The trace element Sr was mainly enriched in urban soils with values of 400 mg kg. According to the results, the EDXRF method was successfully implemented, providing some chemical tracers for the quality assessment of tropical soils and sediments. [ABSTRACT FROM AUTHOR]

Even considered not essential for plants, cesium may cycle within forest ecosystems. Taking into account the lack of knowledge on the distribution of this chemical element in Brazilian ecosystems, this work encompasses the unexpected cesium accumulation in native plant leaves from Cerradao, a Brazilian hotspot of world biodiversity. Some trees were Cs accumulators, achieving mass fractions in leaves 700 times higher (up to 12.7 mg kg) when compared to other Brazilian native tree leaves from the Atlantic Forest. In fact, such trace element accumulation in leaves was not previously noticed for Brazilian ecosystems despite the intra- and inter-species variability observed in Cerrado tree leaves. [ABSTRACT FROM AUTHOR]

Mangroves are essential for protecting coastal environments and biodiversity; however few studies encompass the distribution of radionuclides in soils from these ecosystems. By applying high resolution gamma-ray spectrometry, natural radionuclides were quantified in soils from the Chico Science Mangrove and Rio Formoso Mangrove (RFM), areas subjected to different human impacts. The activity concentrations of Ra and Ra were quite similar for the mangroves despite the differences found for K. Moreover, no correlation with the environmental impacts on the mangroves was observed, although RFM soil was K-enriched compared to deep sediments from other estuaries in the world. [ABSTRACT FROM AUTHOR]

In natural forest soils, the radon transport processes can be significantly intensified due to the contribution of living organism activities to soil porosity. In this paper, the first results of the radon concentrations were obtained for soil gas from the Atlantic Forest, particularly in the Refúgio Ecológico Charles Darwin, Brazil. The estimation of permeability and radon exhalation rate were carried out in this conservation unit. For forested soils, radon concentrations as high as 40 kBq m were found. Based on the radon concentrations and on the permeability parameter, the results indicated considerable radon hazard for human occupation in the neighborhood. [ABSTRACT FROM AUTHOR]

Considerable amounts of biological material contaminated with artificial radionuclides were generated to obtain the efficiency curves for low-activity radionuclide analyses of large environmental samples. Likewise, improving detection geometry is also an important task, mainly for studies involving conservation units with a high level of biodiversity preservation. This study aimed to evaluate the Monte Carlo efficiency curves without generating contaminated material with artificial radionuclides for water and vegetation measurements. An in-house adapted Marinelli geometry was applied to reduce the sampled amount of biological material in the ecosystem, which was combined with the Monte Carlo assisted efficiency curve for a more sustainable radiometric analysis. [ABSTRACT FROM AUTHOR]

The purpose of this work was to determine concentrations of Ra, Ra and K in scales generated inside industrial boilers. Radionuclide activities were determined by high resolution gamma-ray spectrometry. Activity concentrations of Ra were in the range of 3.0 (22) to 1300 (6) Bq kg and Ra activity concentrations varied from <2.0 Bq kg (Minimum detectable activity concentration) to 266 (3) Bq kg. Activity concentrations of K were in the range of <15 Bq kg (Minimum detectable activity concentration) to 290 (5) Bq kg. Activity concentrations were lower than the limits established by the Brazilian Commission of Nuclear Energy. [ABSTRACT FROM AUTHOR]

The availability of chemical elements for plants is mainly dependent on the nature of the soil and characteristics of each species. The transfer factors of lanthanides from the soil to the tree leaves of the Atlantic Forest, Brazil, were calculated for one fern species ( Alsophila sternbergii-Pteridophyta division) and four magnoliophytes species ( Bathysa australis, Euterpe edulis, Garcinia gardneriana and Guapira opposita-Magnoliophyta division) obtained in two areas of Serra do Mar State Park and collected in two different seasons. Samples were analyzed by instrumental neutron activation analysis (INAA). The soil-to-plant transfer factor (TF = C:C) in magnoliophytes species was correlated to the mass fraction of lanthanides in the soil, described by a exponential model (TF = a.C). Despite the tree fern Alsophila sternbergii presented a hyperaccumulation of lanthanides, this species did not have a significant relationship between TF and mass fraction in soil. Results indicated that plants of Magnoliophyta division selected the input of lanthanides from the soil, while the same was not observed in Alsophila sternbergii. [ABSTRACT FROM AUTHOR]

For environmental quality assessment, INAA has been applied for determining chemical elements in small (200 mg) and large (200 g) samples of leaves from 200 trees. By applying the Ingamells’ constant, the expected percent standard deviation was estimated in 0.9–2.2% for 200 mg samples. Otherwise, for composite samples (200 g), expected standard deviation varied from 0.5 to 10% in spite of analytical uncertainties ranging from 2 to 30%. Results thereby suggested the expression of the degree of representativeness as a source of uncertainty, contributing for increasing of the reliability of environmental studies mainly in the case of composite samples. [ABSTRACT FROM AUTHOR]

The quality of environmental studies depends on the utilization of adequate sampling protocol and analytical method for obtaining reliable results and minimizing analytical uncertainties. In order to demonstrate the applicability of INAA for determining chemical element composition of invertebrates, this work evaluated sample representativeness in terms of subsampling and sample size. Br, Co, Fe, K, Na, Sc and Zn could be determined in very small samples despite increasing of analytical uncertainties. Special attention should be directed to invertebrate species with small structures because of the high chemical variation observed among different sample sizes tested. [ABSTRACT FROM AUTHOR]

The Atlantic Forest, a hotspot in the world with a great diversity of plants and animals, is located in the most industrialized area of Brazil, a potential source of chemical elements for the atmosphere. From its original area about 10% has been preserved mainly through the implementation of conservation units, among which the Parque Estadual Carlos Botelho (PECB) is one of the most representative. Here, leaves of the predominant species in the PECB were analyzed by instrumental neutron activation analysis (INAA) for the establishment of natural backgrounds of As, Ba, Br, Ca, Cd, Ce, Co, Cs, Fe, Hg, K, Na, Rb, Sc, Se, Sr and Zn. Biomonitoring of the Atlantic Forest was realized through the tree community study taking in account the interspecies and the intraspecies variability of chemical concentrations. Results pointed out the low status of pollution based on the concentrations of chemical elements of environmental concerning. However, Br concentrations were higher in the understory species, which could be related to the possible effects of atmospheric pollution or sea influence. In addition, someHyeronima alchorneoidestrees showed to be hyperaccumulators of Co. [ABSTRACT FROM AUTHOR]