Multiple potentially toxic elements in urban gardens from a Brazilian industrialized city.

Urban agriculture should be promoted as long as the food produced is safe for consumption. Located in the metropolitan region of São Paulo-Brazil, Santo André has intense industrial activities and more recently an increasing stimulus to urban gardening. One of the potential risks associated to this activity is the presence of potentially toxic elements (PTEs). In this study, the concentration of PTEs (As, Ba, Cd, Co, Cu, Cr, Ni, Mo, Pb, Sb, Se, V and Zn) was evaluated by soil (n = 85) and soil amendments (n = 19) in urban gardens from this municipality. Only barium was above regulatory limits in agricultural soil ranging from 20 to 112 mg kg-1. Geochemical indexes (Igeo, Cf and Er) revealed moderate to severe pollution for As, Ba, Cr, Cu, Pb Se and Zn, especialy in Capuava petrochemical complex gardens. A multivariate statistical approach discriminated Capuava gardens from the others and correlated As, Cr and V as main factors of pollution. However, carcinogenic and non-carcinogenic risks were below the acceptable range for regulatory purposes of 10-6-10-4 for adults. Soil amendments were identified as a possible source of contamination for Ba, Zn and Pb which ranged from 37 to 4137 mg kg-1, 20 to 701 mg kg-1 and 0.7 to 73 mg kg-1, respectively. The results also indicated the presence of six pathogenic bacteria in these amendments. Besides that, the occurrence of antimicrobial resistance for Shigella, Enterobacter and Citrobacter isolates suggests that soil management practices improvement is necessary.

Implications of ZnO Nanoparticles and S-Nitrosoglutathione on Nitric Oxide, Reactive Oxidative Species, Photosynthetic Pigments, and Ionomic Profile in Rice.

Zinc is an important nutrient for several plants and humans. Nitric oxide (NO) is a free radical that is important to biological processes that mediate the growth and mitigation of biotic and abiotic stresses in plants. The present study investigated the enzymatic and photosynthetic profile and the accumulation of macro- and microelements in rice plants (Oryza sativa L.) that received foliar treatments of zinc oxide nanoparticles (ZnO NPs), nitric oxide donor (GSNO), and the association of both (GSNO-ZnO NPs). Zinc concentration in rice husks increased by 66% and 68% in plants treated with ZnO NPs and GSNO-ZnO NPs, respectively. The GSNO treatment caused an increase of 25% in the Fe concentration in the rice grains. Only a small disturbance of the antioxidant system was observed, with increases in H2O2, S-NO, and NO2-, mainly in the group treated with GSNO-ZnO NPs; however, the disturbance did not affect the yield, the growth, or vital processes, such as as photosynthetic pigments production. There was an increase in chlorophyll B of 290% and an increase in chlorophyll A of 187% when ZnO NPs was applied. GSNO-ZnO NPs increased chlorophyll B by 345% and chlorophyll A by 345%, indicating that the treatments GSNO, ZnO NPs, and GSNO-ZnO NPs reduced possible oxidative stress and helped as protective treatments.

Chronic exposure to nitric oxide sensitizes prostate cancer cells and improved ZnO/CisPt NPs cytotoxicity and selectivity.

The co-therapy of common chemotherapeutics with nitric oxide (NO), an endogenous signaling molecule, is proposed as an alternative to sensitize cancer cells and enhance treatments' efficacy. Herein, we have synthesized cisplatin-releasing zinc oxide nanoparticles (ZnO/CisPt NPs), which promoted a sustained and pH targeted release, able to release a higher amount of CisPt at tumor microenvironment conditions. This material was combined with a chronic NO treatment, at low concentration, in prostate cancer cells (PC3). NO treatment enhanced the S-NO concentration in PC3 cells, suggesting the nitrosylation or transnitrosylation processes enhancement, which are directly related to S-NO binding to proteins, function alterations and cancer cells death. Indeed, these mechanisms directly impacted the cytotoxic effect of ZnO/CisPt NPs, inducing a 30 % higher viability reduction of PC3 cells after NO treatment, along with a higher selectivity index when compared to normal human fibroblasts (FN1).

Impact of DNA repair polymorphisms on DNA instability biomarkers induced by lead (Pb) in workers exposed to the metal.

Although the mechanisms of Pb-induced genotoxicity are well established, a wide individual's variation response is seen in biomarkers related to Pb toxicity, despite similar levels of metal exposure. This may be related to intrinsic variations, such as genetic polymorphisms; moreover, very little is known about the impact of genetic variations related to DNA repair system on DNA instability induced by Pb. In this context, the present study aimed to assess the impact of SNPs in enzymes related to DNA repair system on biomarkers related to acute toxicity and DNA damage induced by Pb exposure, in individuals occupationally exposed to the metal. A cross-sectional study was run with 154 adults (males, >18 years) from an automotive batteries' factory, in Brazil. Blood lead levels (BLL) were determined by ICP-MS; biomarkers related to acute toxicity and DNA instability were monitored by the buccal micronucleus cytome (BMNCyt) assay and genotyping of polymorphisms of MLH1 (rs1799977), OGG1 (rs1052133), PARP1 (rs1136410), XPA (rs1800975), XPC (rs2228000) and XRCC1 (rs25487) were performed by TaqMan assays. BLL ranged from 2.0 to 51 µg dL-1 (mean 20 ± 12 µg dL-1) and significant associations between BLL and BMNCyt biomarkers related to cellular proliferation and cytokinetic, cell death and DNA damage were observed. Furthermore, SNPs from the OGG1,XPA and XPC genes were able to modulate interactions in nuclear bud formation (NBUDs) and micronucleus (MNi) events. Taken together, our data provide further evidence that polymorphisms related to DNA repair pathways may modulate Pb-induced DNA damage; studies that investigate the association between injuries to genetic material and susceptibilities in the workplace can provide additional information on the etiology of diseases and the determination of environmentally responsive genes.

Selenium Biofortification Enhanced Grain Yield and Alleviated the Risk of Arsenic and Cadmium Toxicity in Rice for Human Consumption.

Arsenic (As) and Cadmium (Cd) are toxic to rice plants. However, selenium (Se) has the potential to regulate As and Cd toxicity. The present study aimed to evaluate the co-exposure to As5+ and Se6+ species in two rice cultivars, BRS Pampa and EPAGRI 108. The plants were divided into six groups and cultivated until complete maturation of the grains, under greenhouse conditions. Regarding total As and inorganic As (i-As) accumulation in grains, the highest concentrations were found for BRS Pampa. For Se, EPAGRI 108 presented the highest concentration of inorganic and organic Se (i-Se and o-Se). The exposure assessments showed that Se biofortification can mitigate the As accumulation in rice and, consequently, the risk of As and Cd toxicity in grains for human consumption. The combined effect of As and Se in rice plants could represent an alternative to biofortify this food in a safe way and with a higher percentage of bioavailable Se. Although Se is able to mitigate As toxicity in rice plants, in the present study we showed that co-exposure in different cultivars under the same growing conditions may present different responses to As and Se exposure.

Chromium Speciation by HPLC-DAD/ICP-MS: Simultaneous Hyphenation of Analytical Techniques for Studies of Biomolecules.

The first element legislated adopting chemical speciation was chromium (Cr) for differentiation between the highly toxic Cr(VI) from the micronutrient Cr(III). Therefore, this work aimed to develop a new analytical method through the coupling of High-Performance Liquid Chromatography with Diode-Array Detection (HPLC-DAD) with inductively coupled plasma mass spectrometry (ICP-MS) to obtain molecular and elemental information simultaneously from a single sample injection. In the first step, a low-cost flow split made of acrylic was developed aiming at optimally directing the sample to the detectors, enabling the HPLC-DAD/ICP-MS coupling. After the extraction of Certified Reference Materials (CRM of natural water NIST1640a and sugar cane leaf agro FC_012017), the recoveries determined by ICP-MS were 99.7% and 85.4%, respectively. Then, the method of HPLC-DAD/ICP-MS was applied for real samples of the CRMs. The presence of possible biomolecules associated with Cr(III) and Cr(VI) species was evaluated, with the simultaneous response detection of molecular (DAD) and elementary (ICP-MS) detectors. Potential biomolecules were observed during the monitoring of Cr(VI) and Cr(III) in sugar cane leaves, water samples and a supplement of Cr picolinate. Finally, the article also discusses the potential of the technique applied to biomolecules containing other associated elements and the need of more bioanalytical methods to understand the presence of trace elements in biomolecules.

Artisanal Gem Mining in Brazil: A Source of Genotoxicity and Exposure to Toxic Elements.

Environmental and occupational exposure to toxic metals has led many people around the world to have serious health problems. Mining activities contribute to an increased risk of exposure to these elements. In this work, a study of environmental biomonitoring and routes of exposure to toxic metals in a region of artisanal mining was performed. This study was carried out in the district of Taquaral de Minas, located in the Jequitinhonha Valley in the state of Minas Gerais. The valley is one of the wealthiest and highest gem-producing areas in Brazil. Five artisanal mines were sampled (Bode, Pirineu, Pinheira, Lajedo, and Marmita). Several potentially toxic metals (Be, Zn, Mn, Ba Cd, Hg, and U) were investigated in the soils and dust over the rocks and the soils. Samples from 22 individuals occupationally exposed and 17 unexposed persons, who formed the reference group, were analyzed for trace elements by an inductively coupled plasma mass spectrometer. The genotoxicity was evaluated by the micronucleus test in buccal mucosa epithelial cells, where the following changes were scored: micronuclei (MN) binucleate (BN) cells and kariolytic (KL) cells. The MN test showed significantly increased frequencies in all alterations of exposed individuals compared to the controls (p < 0.05, Student's t-test). The urine analysis showed levels of Cr, Ni Ba, Pb, and As in the blood, which were higher than the ATSDR recommended levels. The association between the MN test and the trace element concentrations found in the blood and urine was significant (p < 0.05). The higher the number of years of working, the higher the concentrations in the blood were, due to chronic exposure. The results of the present study indicate environmental contamination and a potential risk to the health of miners, suggesting an intervention.

Influence of Agaricus bisporus Mushroom on Pb Toxicokinetic in Pregnant Rats.

(Pb) is a toxic metal, responsible for several damages to human health. Agaricus bisporus (Ab) is a mushroom with promising antioxidant properties to be used as an alternative chelator in Pb intoxication. The aim was to understand the Pb toxicokinetic and the potential of Ab as a protective agent. A total of 20 female Wistar rats were distributed into 4 groups (n = 5/group): Control (receiving water); Group Ab 100 mg/kg (gavage); Group Pb 100 mg/L in water; and Group Ab + Pb-100 mg/kg + 100 mg/L (gavage and water). Pb administration occurred daily until the 19th day of pregnancy. On day 19 of gestation, the rats were euthanized, and the blood and tissues were collected for Pb measurement, using an inductively coupled plasma mass spectrometer. The results showed that the levels of Pb in the blood, placenta, and liver of the mothers, and in the brain of the fetuses increased significantly in the Pb group. On the other hand, the combined exposure to Pb + Ab showed a significant decrease in the metal concentration in relation to the Pb group, returning to normal levels. Kidney and bone lead levels also increased significantly in the Pb group. However, in the combined exposure group, levels did not return to the control amounts; there was protection, but the Pb concentration was still significantly higher than in the control. In the brain, no significant differences were observed. In conclusion, we suggest A. bisporus is a natural chelator, because the co-administration of the mushroom was able to interact with Pb ions, minimizing the Pb absorption and distribution. These effects are suggested since A. bisporus have antioxidants and beta glucan that interact with Pb, chelating it and, thus, reducing its toxic effects.

Risk evaluation of occupational exposure of southern Brazilian flower farmers to pesticides potentially leading to cholinesterase inhibition and metals exposure.

This work presents a frequency matched observational study comparing flower farmers exposed to pesticides and unexposed individuals as controls. All subjects were interviewed before plasma and urine collection. Manganese and Zinc were measured in theses samples by using dynamic reaction cell inductively coupled mass spectrometry. Cholinesterase activity was analyzed through spectrophotometry by using a modified version of the Ellman method. Seventy-eight percent of subjects reported occupational contact with pesticides, from which 37% reported exposure for over 9 years. Flower farms farmers had increased odds of having headache and irritability, respectively, by factors of 6.2 and 2.4 than the control subjects. While the odds of exposed subjects to have insomnia was smaller than control subjects by a factor of 0.34. Exposure to pesticides had a significant effect regarding the plasmatic plasma and urinary manganese levels and whole blood cholinesterase activity (p < 0.05). High levels of plasma and urinary manganese, as well as cholinesterase inhibition in whole blood, were evident in the flower farmers who participated in the study.

Evaluation of collision/reaction gases in single-particle ICP-MS for sizing selenium nanoparticles and assessment of their antibacterial activity.

Selenium nanoparticles (SeNPs) have recently attracted attention because they combine the benefits of Se and lower toxicity compared to other chemical forms of this element. In this study, SeNPs were synthesized by a green method using ascorbic acid as the reducing agent and polyvinyl alcohol as stabilizer. The nanoparticles were widely characterized. To determine the total concentration of Se by ICP-MS, several isotopes and the use of He as collision gas were evaluated, which was effective in minimizing interferences. A method for sizing SeNPs by single particle ICP-MS (SP-ICP-MS) was developed. For this purpose, He and H2were evaluated as collision/reaction gases, and the second one showed promising results, providing an average diameter of 48 nm for the SeNPs. These results agree with those obtained by TEM (50.1 nm). Therefore, the SP-ICP-MS can be implemented for characterizing SeNPs in terms of size and size distribution, being an important analytical tool for Se and other widely studied nanoparticles (e.g. Ag, Au, Ce, Cu, Fe, Zn). Finally, the antibacterial activity of SeNPs was assessed. The SeNPs showed bacteriostatic activity against three strains of Gram-positive bacteria and were particularly efficient in inhibiting the growthE. faecaliseven at very low concentrations (MIC < 1.4 mg l-1). In addition, a bactericidal activity of SeNPs againstS. aureuswas observed. These nanoparticles may have potential application in pharmaceutical industry, biomedicine and agriculture.

Determination of 14 trace elements in blood, serum and urine after environmental disaster in the Doce River basin: Relationship between mining waste and metal concentration in the population.

BACKGROUND: Exposure to chemical substances after an environmental disaster can cause both toxic effects and changes in the health status of people who live in or have proximity to environments of this nature, so that the concern with populations is growing. METHODS: In this cross-sectional study, blood, serum and urine samples were collected from 100 volunteers from Santo Antônio do Rio Doce, eight from Ilha das Pimentas and 50 from the control group; and analyzed by inductively coupled plasma mass spectrometry for biomonitoring of Al, As, Ba, Cd, Co, Cu, Cr, Fe, Hg, Mn, Ni, Se, Pb, Zn. In addition, a comprehensive questionnaire was applied to collect demographic and socioeconomic information, as well as lifestyle. RESULTS: The concentrations of As, Al, Cd, Ni and Mn were above the reference value in some biological matrices, with more pronounced exposure in Ilha das Pimentas. The concentrations of As, Cd, Cu, Co, Pb and Zn showed statistical differences regarding gender in the different biological matrices. The trace elements in the blood, serum and urine showed significant correlations when considering age and habits such as the consumption of cigarettes, alcoholic beverages and fish. The main correlations were observed between Co, Cr, Mn, Ni and Pb in the blood and cigarette consumption. CONCLUSION: This is the first study in these regions after the environmental disaster and confirmation of the diagnosis and health care of the participants should be promoted for clinical investigation and the eventual need for treatment. Human biomonitoring demonstrated high concentrations of some toxic elements, with more accentuated exposure in Ilha das Pimentas.

Occupational exposure to potentially toxic elements in the foundry industry: an integrated environmental and biological monitoring.

Industrial foundry processes release metal dust and fumes into the environment. Our study evaluated the exposure to potentially toxic elements in foundry workers. The assessed samples consisted of air particulate matter (n = 42), urine (n = 194), and blood (n = 167). Six workers had high concentrations of arsenic (As) in urine and one of them had a high cadmium (Cd) content in blood, according to Biological Exposure Index from the American Conference of Governmental Industrial Hygienists. The work task significantly influenced the concentrations of cobalt (Co), copper (Cu), iron (Fe), and manganese (Mn) in air, barium (Ba) in urine, and lead (Pb) and cesium (Cs) in blood, while the employment years affected concentrations of Mn, tin (Sn), and uranium (U) in urine and iodine (I) in blood. Arsenic, Pb, Co, and Cd in particulate matter and biological matrices presented significant covariation by working activity, supporting the occupational exposure. In this study, subjects were occupationally exposed to multiple potentially toxic elements. Carcinogenic and noncarcinogenic risks were associated with As, Co, Ni, and Mn exposure.

Comparison of foliar spray and soil irrigation of biogenic CuO nanoparticles (NPs) on elemental uptake and accumulation in lettuce.

Nanoparticles (NPs) can be used in several ways in agriculture, including increasing production rates and improving nutritional values in plants. The present study aims to clarify how biogenic copper oxide nanoparticles (CuO NPs) applied by two routes of exposure (foliar spray and soil irrigation) affect the elemental uptake by lettuce. In vivo experiments using lettuce (n = 4) were performed with CuO NPs in comparison with copper salt (CuSO4), considering a final mass added of 20 mg of CuO per plant. The elemental composition of roots was mostly affected by the soil irrigation exposure for both Cu forms (NPs and salt). Neither Cu form added by soil irrigation was translocated to leaves. Copper concentration in leaves was mainly affected by foliar spray exposure for both Cu forms (NPs and salt). All Cu forms through foliar spray were sequestered in the leaves and no translocation to roots was observed. Foliar spray of CuO NPs caused no visual damage in leaves, resulted in less disturbance of elemental composition, and improved dry weight, number of leaves, CO2 assimilation, and the levels of K, Na, S, Ag, Cd, Cr, Cu, and Zn in leaves without causing significant changes in daily intake of most elements, except for Cu. Although Cu concentration increased in leaves by foliar spray of CuO NPs, it remained safe for consumption.

Occupational exposure of foundry workers assessed by the urinary concentrations of 18 elements and arsenic species.

BACKGROUND: Some raw materials applied in Fe foundry industries may contain potentially toxic elements. Thus, foundry worker's occupational exposure is a constant health concern. METHOD: In this study, 194 urine samples from foundry workers were analyzed by inductively coupled plasma mass spectrometry for biomonitoring of Al, As, Ba, Cd, Co, Cr, Cs, Cu, Fe, I, Mn, Ni, Pb, Sb, Sn, Se, U and Zn. Moreover, arsenic speciation was performed in representative samples of production sector workers (group A) and administration sector workers (group B). RESULTS: Concentrations of As, Pb, Cd, Cu, Cs, I, Sb in urines from group A were higher than those found for group B. Samples of group A presented Cs, Ni, Mn, Pb, U and Zn concentrations higher than values reported for exposed workers assessed by other studies. Forty-four samples from group A exceed As-reference limits. Group A had approximately seven times more inorganic As (as arsenite) and 14 times more organic As (as dimethyl As) than group B. A statistically significant difference was observed in the elemental concentration in the workers' urine by the time in the function. Moreover, alcohol consumption is probably influencing the urine concentration of As, Ba, Cd, Co, Cu, Fe, I, Se and Zn. CONCLUSION: The monitored foundry workers are exposed to potentially toxic elements and more attention must be given to their health. Therefore, workplace safety conditions must be improved, and constant biomonitoring is necessary to ensure workers' health.

Availability of arsenic in rice grains by in vitro and in vivo (humans) assays.

BACKGROUND: Rice grains are consumed by approximately half of the world's population. This cereal has higher arsenic (As) concentrations in grains than wheat or barley. Arsenic determination in food and/or in vitro studies are important for risk assessment; however, it is not enough to assess the real human exposure. METHOD: In vitro bioaccessibility was carried out in husked-rice using gastric and intestinal solutions similar to humans. Also, As naturally found in husked-rice was evaluated by in vivo bioavailability in humans. For this purpose, diets from the 1st and 2nd days were free of foods known to be high in As; 3rd and 4th days the diets were composed by rice and water and; 5th and 6th the diet was similar the 1st and 2nd days. During all experimentation, a representative aliquot of each meal, blood and urine were collected for total As (t-As) determination. Arsenic species were determined in the urine. RESULTS: t-As in husked rice varied from 157.3 ±â€¯30.6 to 240.2 ±â€¯85.2 µg kg-1. The in vitrobioaccessible fractions ranged from 91 to 94%. Inorganic As (i-As) ranged from 99.7 ±â€¯11.2 to 159.5 ±â€¯29.4 µg kg-1. For the in vivo assay, t-As concentrations in the woman and man blood were about 3 µg mL-1 from the 1st to 6th day. Arsenic from the rice ingested was excreted by urine about 72 h after ingestion. The t-As and dimethyl As (DMA) in urine ranged from 3.59 to 47.17 and 1.02 to 2.55 µg g-1 creatinine for the volunteers, indicating a two-fold DMA-increase in urine after ingestion of husked-rice. CONCLUSION: After rice ingestion, As was quickly metabolized. The higher As concentrations were found in urine 72 h after rice ingestion. The main As-specie found in urine was DMA, indicating that methylation of As from rice followed by urine excretion is the main biological pathway for As excretion.

Mineral profile exploratory analysis for rice grains traceability.

Rice geographical traceability requires analytical procedures and data evaluation capable of linking its composition to the producing area. In this work, major and trace elements in soil and rice grains and husk from 9 cities and 17 producers were evaluated. Arsenic species were measured solely in rice grains. The rice mineral profile evaluated by principal component analysis allowed the identification of controlling variables and origin fingerprints. Vectors controlling data variability were linked to the geographical area, to crop management, producers and in a lower extent to soil composition. Elemental discrimination through 3D models was proposed. Arsenic species in the grains and elemental husk composition were decisive to achieve the required discrimination. Rice discrimination was obtained by cities, producers and varieties. The present work model was compared with others from similar studies.