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Prenatal exposure to potentially toxic metals (PTM) may impair fetal growth (FG). We investigated the relationship between maternal exposure to lead (Pb), cadmium (Cd) and manganese (Mn) and birth weight (BW) of 74 newborns. Blood was collected during the second trimester of pregnancy to determine Pb (PbB) and Cd (CdB), while hair (MnH) and toenails (MnTn) were used for Mn. Samples were analyzed by graphite furnace atomic absorption spectrophotometry (GFAAS). Sociodemographic and BW data were collected from questionnaires and maternity records, respectively. The medians (P25th-P75th) of PbB, CdB, MnH, and MnTn were, respectively, 0.9 (0.5-1.8) µg/dL; 0.54 (0.1-0.8) µg/L; 0.18 (0.1-0.4) µg/g; and 0.65 (0.37-1.22) µg/g. The means (standard deviation) of birth weight according to sex were 3067 (426.3) and 3442 (431) grams, respectively, for girls and boys. MnTn presented an inverse correlation with the BW/gestational age ratio for girls (rho = -0.478; p = 0.018), suggesting the effect of sex modification. Although BW correlation with CdB was not statistically significant, hierarchical linear regression (beta = -2.08; 95% CI-4.58 to 0.41) suggested a fetotoxic effect. These results confirmed the threat PTMs may represent and the need for more extensive research to elucidate their role in inadequate FG in developing countries.

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This study evaluated metal contamination in surface sediments and macroalgae of mangroves and port complexes on the Brazilian equatorial margin. Samples were collected between August 2020 and February 2021 at seven points in a mangrove swamp under the influence of port activity and at two points without port activity. Metal concentrations in the macroalgae and sediments were determined using inductively coupled plasma‒optical emission spectrometry. All macroalgal species bioaccumulated metals, as demonstrated by their bioaccumulation factors. The geochemical contamination indices indicated that the estuarine complex was influenced by port activity as moderately contaminated by Pb, Cr, Mn, and Fe and considerably contaminated by Zn and Cu. The enrichment factor confirmed significant mineral enrichment of Zn and Cu in this environment. The concentrations of the metals in the sediment followed the order Fe > Mn > Cr > Zn > Cu > Pb at most sampling points. Cladophoropsis membranacea recorded the highest bioaccumulation values for Pb (0.44), Rhizoclonium africanum for Zn (1.08), Cr (0.55), and Fe (0.30), and Bostrychia radicans for Mn (2.22). The bioaccumulation pattern of metals in the most abundant macroalgal species followed the order Bostrychia radicans (Mn > Zn > Cu > Cr > Pb > Fe) and Rhizoclonium africanum (Zn > Mn > Cr > Cu > Pb > Fe).

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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. As the main route for potentially toxic elements' absorption by humans is by food intake, it is important to evaluate if the method of cultivation influences their concentrations. This study evaluated the levels of potentially toxic elements and nutrients on four leafy vegetables: curly lettuce, collard greens, escarole, and rocket, cultivated by conventional and organic farming. We found that Al, Ba, Fe, and Sr levels were higher in conventional samples, whereas K, Pb, and Zn were higher in organic. Amongst the elements analysed, values of Fe, Al, and K were around 0.2, 0.3, and 70 g kg-1, respectively, except in collard greens, in which the values were lower. On the other hand, Ba, Sr, and Mn presented higher concentration in collard greens compared to the other vegetables in conventional cultivation (~ 35, 80, and 120 mg kg-1, respectively). The principal component analysis result shows that the samples were grouped according to the type of vegetable, regardless of the type of cultivation. Despite this, the evaluation of the cultivation by different types of farming is important in order to choose the healthiest option.

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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. After analyzing the titles, abstracts, and full texts, 79 articles were selected for the SLR, in which 15 sources and 16 PTEs were identified. The main anthropogenic sources identified were mining, agriculture, industries, and domestic effluents, and the main natural sources identified were weathering of rocks and geogenic origin. Some places where environmental remediation studies can be carried out were highlighted such as Guangdong province, in China, presenting values of Cd, Cr, and Cu exceeding the national legislation from drinking water and soil quality, and Ardabil Province, in Iran, presenting values of As, Cr, Cu, Ni, Zn, and Pb exceeding the standard for freshwater sediments of USEPA, among others places. With the results exposed in this work, the government and the competent bodies of each locality will be able to develop strategies and public policies aimed at the main sources and places of contamination, in order to prevent and remedy the pollution of aquatic environments by potentially toxic elements.

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Lead (Pb) is a highly neurotoxic chemical element known for reducing intelligence quotient (IQ) and promoting antisocial behavior in children and adolescents, while cadmium (Cd) is a carcinogenic bioaccumulative element. Both these metals are included in the priority pollutant list of the United States Environmental Protection Agency and in the WHO List of Chemicals of Major Public Health Concern, where contaminated foods and beverages are the most common pathways of exposure. The objective of this study was to determine total Cd and Pb levels in colored plastic utensils (cups, mugs, bowls, feeding bottles, and plates) for use by children and to measure the specific migration of these elements into beverages and foods. Total contaminant levels were determined using a handheld X-ray fluorescence analyzer. Specific migration tests were conducted using the simulant solutions acetic acid 3% (m/v) and water. Migration levels were determined by ICP-MS. Specific migration tests for Pb were also performed on commercially available samples (cola soft drink, orange juice, vinegar, and milk), with levels determined by graphite-furnace atomic absorption spectrometry (GF-AAS). A total of 674 utensils were analyzed in loco at major commercial centers in Greater São Paulo, of which 87 were purchased for containing Cd and Pb concentrations above permitted limits. Mean concentrations of the metals detected in the purchased utensils were 1110 ppm for Pb and 338 ppm for Cd. For specific migration assays, Pb levels were 187, 13, and 380 times above the permitted limit (0.01 mg.kg -1) for acetic acid, water, and orange juice, respectively. Cd levels were 50 and 2.4 times above the maximum permitted limit (0.005 mg.kg -1) for acetic acid and water, respectively. The districts where the utensils were purchased were grouped according to their social vulnerability index and compared using ANOVA. Pb levels were different between low and medium/high social vulnerability groups (p = 0.006). The findings corroborate the initial hypothesis that these utensils constitute a major source of exposure to PTEs such as Cd and Pb, pointing to the need for stricter regulation and inspection by the Brazilian regulatory agencies.

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Baru (Dipteryx alata Vogel) is a native tree plant, widely distributed in Brazil, and has a growth and development in acidic soils like Cerrado, indicating a probable tolerance to adverse soil conditions, such as the high concentration of metals and the acidic pH. Due to the lack of information about the tolerance of this species to metals and the possibility of being used in the recovery of degraded areas and/or in phytoremediation, this work was developed with the objective of evaluating the in vitro germination and growth capacity of baru in medium supplemented with different concentrations of aluminum, iron, and manganese, as well as through chemical analysis, to determine the concentration of metals accumulated in cultivated plants in these conditions. The treatments consisted in different concentrations of metals: aluminum, Al3+ (0, 3.5, 7.0, 10.5, 21.0, or 42.0 mg L-1); iron, Fe3+ (0, 2.5, 4.9, 7.4, 14.7, or 29.4 mg L-1); and manganese, Mn2+ (0, 0.4, 0.8, 1.2, 2.4, or 4.8 mg L-1) added to the medium WPM. The tested values were based on using the lower concentration as the limit value, calculated based on risk to human health in accordance with CONAMA resolution 420/2009 for groundwater. At 60 days of cultivation, the percentage of germination, the average number of leaves, the length of the main root and the aerial part, the fresh and dry mass of the aerial part and the root system and the cations concentration Al3+, Fe3+ and Mn2+ in the plant biomass, were evaluated. The results showed that under the conditions in which the experiment was conducted, germination and in vitro growth of baru were not affected by the presence in high concentrations of any of the evaluated metals, with no differences in the percentage of germination and plant growth, as well as typical toxicity characteristics were not observed, such as changes in root morphology, chlorosis, or tissue oxidation. The absence of toxicity symptoms in baru plants, in the presence of Al3+, Fe3+, and Mn2+, indicate that the species is tolerant to these metals. The accumulation of Al3+ and Fe3+ in the plant biomass at the beginning of growth, simultaneously with the increase in the concentrations of these elements in the culture medium, indicates that this species can be used for phytoremediation, because it is a probable accumulator of these elements throughout its development, given the presence in significant concentrations of these elements also in the seeds.

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Soil management using fertilizers can modify soil chemical, biochemical and biological properties, including the concentration of trace-elements as cadmium (Cd), chromium (Cd) and nickel (Ni). Bacterial isolates from Cd, Cr, and Ni-contaminated soil were evaluated for some characteristics for their use in bioremediation. Isolates (592) were obtained from soil samples (19) of three areas used in three maize cultivation systems: no-tillage and conventional tillage with the application of mineral fertilizers; minimum tillage with the application of sewage sludge. Four isolates were resistant to Cr3+ (3.06 mmol dm-3) and Cd2+ (2.92 mmol dm-3). One isolate was resistant to the three metals at 0.95 mmol dm-3. All isolates developed in a medium of Cd2+, Cr3+ and Ni2+ at 0.5 mmol dm-3, and removed Cd2+ (17-33%) and Cr6+ (60-70%). They were identified by sequencing of the gene 16S rRNA, as bacteria of the genera Paenibacillus, Burkholderia, Ensifer, and two Cupriavidus. One of the Cupriavidus isolate was able to remove 60% of Cr6+ from the culture medium and showed high indole acetic acid production capacity. We evaluated it in a microbe-plant system that could potentially be deployed in bioremediation by removing toxic metals from contaminated soil.

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The inadequate transportation of foundry slags during the construction of a mining waste landfill accounted for the presence of slags in the dirt road that connects the working district of Vila Mota to the city of Adrianópolis. The objectives of this work were to assess the lead (Pb) and zinc (Zn) contamination of the dirt. Three samples separated by 2 km were collected along a dirt road (samples: Adrianópolis, Deposit, and Plant). The conducted assays were physico-chemical parameters, pseudototal concentration, three sequential extraction procedures, and bioaccessibility assay. The laboratory data was used as input in the calculation of contamination indices risk assessment code (RAC) and potential ecological risk (Eri). The dirt road presented high concentrations of Pb (mean 1426.5 mg kg-1) and Zn (mean 4964.8 mg kg-1). The BCR SEP (Bureau Community of Reference Sequential Extraction Procedure) method was more adequate in extracting the soluble-exchangeable fraction, and this fraction was correlated with the gastric phase. The bioaccessible fraction is mainly present in the stomach fraction and is transported to the intestinal phase. Using BCR SEP method to calculate the contamination indices, sample Deposit yielded very high risk when calculating RAC and Eri for Pb (72.9% and 639.5, respectively). For Zn, high risk was obtained with RAC and very high risk for Eri (42.5% and 344.2, respectively). The high content of Pb and Zn on the dirt road presents a risk to the population that uses this road, since the soil particles are easily transported, deposited on the dermis, and inhaled.

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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. Thus, the objective of this work was to elaborate an approach to identify sources of potentially toxic metals (Zn, Ba, Pb, Cr, Mn and Fe), by relating their spatial-temporal variations with the local land use patterns, along a longitudinal profile of the Pirapora River, located in the State of Sao Paulo, Brazil. For this purpose, water samples were collected at different points, taking into consideration each specific land use pattern and quantifying the metals contents by microwave plasma atomic emission spectrometry. In this work, thirteen land use patterns have been identified: mining, forestry, abandoned pasture, water, urban area, human occupation, floodplain, bare soil, temporary crop, roads, forest, streets and pasture. The results revealed temporal variations for the metals Ba, Cr, Fe, and Pb and spatial for Zn and Mn, making possible to correlate the presence of these two latter metals with mining and forestry, the most proeminent activities in the region. Overall, this work proposes a model which brings together geoprocessing and analytical methods, in order to correlate spatial-temporal variations of potentially toxic metals with specific land use patterns of a determined region, aiming the environmental monitoring.

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A monolithic column affording complexing groups was synthesized for automated solid-phase extraction of potentially toxic metal ions in a low-pressure sequential injection analyzer. Poly(glycidyl methacrylate-co-ethylene dimethacrylate) monoliths were synthesized by free-radical polymerization in the coffins of fused silica-lined stainless-steel tubes (2.10 mm i.d. × 5-6 cm length). High permeability (4.33 × 10-13 m2) was achieved for monoliths polymerized for 24 h at 60 °C from a mixture of 30 wt% glycidyl methacrylate, 10 wt% ethylene glycol dimethacrylate, 35 wt% n-propanol, 20 wt% 1,4 butanediol and 5 wt% water. Azobisisobutyronitrile (1 wt% with respect to the monomers) initiated the free-radical polymerization. These generic columns were modified with iminodiacetate to create complexing functionalities on the polymer surface, being further used for online solid-phase extraction of Cu2+, Pb2+ and Cd2+ from natural, tap and drinking waters prior to their determination by stripping chronopotentiometry. The high permeability of the column allowed the loading, washing, eluting and reconditioning steps to be made at flow rate of 10 µL s-1. The limits of detection and quantification achieved by processing 1500 µL of sample were 0.51 and 1.7 µg L-1 for Cu2+, 1.4 and 4.7 µg L-1 for Pb2+, and 1.2 and 3.8 µg L-1 for Cd2+, respectively. Recoveries were between 75.5% and 117%, obtained by quantification via external calibration curves, thus eliminating the need for the laborious standard addition strategies.