Evaluation of the effect of nanoparticles on the cultivation of edible plants by ICP-MS: a review.

Nanoparticle (NP) applications aiming to boost plant biomass production and enhance the nutritional quality of crops hae proven to be a valuable ally in enhancing agricultural output. They contribute to greater food accessibility for a growing and vulnerable population. These nanoscale particles are commonly used in agriculture as fertilizers, pesticides, plant growth promoters, seed treatments, opportune plant disease detection, monitoring soil and water quality, identification and detection of toxic agrochemicals, and soil and water remediation. In addition to the countless NP applications in food and agriculture, it is possible to highlight many others, such as medicine and electronics. However, it is crucial to emphasize the imperative need for thorough NP characterization beyond these applications. Therefore, analytical methods are proposed to determine NPs' physicochemical properties, such as composition, crystal structure, size, shape, surface charge, morphology, and specific surface area, detaching the inductively coupled plasma mass spectrometry (ICP-MS) that allows the reliable elemental composition quantification mainly in metallic NPs. As a result, this review highlights studies involving NPs in agriculture and their consequential effects on plants, with a specific focus on analyses conducted through ICP-MS. Given the numerous applications of NPs in this field, it is essential to address their presence and increase in the environment and humans since biomagnification and biotransformation effects are studies that should be further developed. In light of this, the demand for rapid, innovative, and sensitive analytical methods for the characterization of NPs remains paramount.

Feasibility study for mercury remediation by selenium competition in Pleurotus mushrooms.

Mushrooms may incorporate significant levels of Hg making its consumption harmful to human health. Mercury remediation induced by Se competition in edible mushrooms represents a valuable alternative since Se plays effective roles against Hg uptake, accumulation, and toxicity. In this way, Pleurotus ostreatus and Pleurotus djamor were cultivated on Hg-contaminated substrate simultaneously supplemented with Se(IV) or Se(VI) under different dosages in this study. The protective role of Se was assessed taking into account morphological characteristics and Hg and Se total concentrations determined by ICP-MS, as well as proteins and protein-bound Hg and Se distribution by SEC-UV-ICP-MS, and Hg speciation studies (Hg(II) and MeHg) by HPLC-ICP-MS. Both Se(IV) and Se(VI) supplementation were able to recover the morphology mainly of Hg-contaminated Pleurotus ostreatus. The mitigation effects induced by Se(IV) stood out more than Se(VI) in terms of Hg incorporation, decreasing the total Hg concentration up to 96 %. Also, it was found that supplementation mainly with Se(IV) reduced the fraction of Hg bound to medium molecular weight compounds (17-44 kDa) up to 80 %. Finally, it was shown a Se-induced inhibitory effect on Hg methylation, decreasing MeHg species content in mushrooms exposed to Se(IV) (51.2 µg g-1) up to 100 %.

Effects of Se(IV) or Se(VI) enrichment on proteins and protein-bound Se distribution and Se bioaccessibility in oyster mushrooms.

A successful mushroom enrichment process must produce foods that have compounds potentially absorbed by the human body. In this study, Pleurotus ostreatus and Pleurotus djamor mushrooms were grown on organic substrate supplemented with different Se(IV) and Se(VI) concentrations, and evaluated in the following features: Fruiting bodies morphology; Se uptake and accumulation; Distribution of proteins and protein-bound Se; Se species identification on enzymatic extracts; Se bioaccessibility; and Distribution of bioaccessible protein-bound Se. Pleurotus djamor grown on Se(IV)-supplemented substrate showed the greatest potential to uptake and accumulate Se. For Se species screening, selenomethionine was identified in white oyster mushroom, while selenomethionine, selenocystine, and Se-methylselenocysteine in pink oyster mushrooms. In soluble fractions from in vitro gastrointestinal digestion assays, Se showed high bioaccessibility (>94%). Lastly, bioaccessible Se species were found to be mainly associated to LMW (<17 kDa) in Pleurotus ostreatus (74%) and Pleurotus djamor (68%) grown on Se(IV)-supplemented substrates.

The protective role of selenium against uptake and accumulation of cadmium and lead in white oyster (Pleurotus ostreatus) and pink oyster (Pleurotus djamor) mushrooms.

Mushrooms are bioaccumulators and have been used to produce Se-enriched foods. However, these fungi can also bioaccumulate potentially toxic metals, producing food dangerous to human health. It is known that co-exposure to Se plays a protective role against metal accumulation and toxicity in some organisms due to its antioxidant properties. Thus, this study aimed to evaluate the protective effect of Se(IV) and Se(VI) on elemental uptake and accumulation as well as proteins and protein-bound Se, Cd, and Pb distribution in Pleurotus mushrooms. Pink oyster and white oyster mushrooms showed high ability to bioaccumulate Se (19-205 µg g-1), Cd (4.5 to 18.8 µg g-1), and Pb (1.6 to 7.0 µg g-1). Growth substrate supplementation with Se(IV) or Se(VI) decreased the Cd total concentration in mushrooms by 4 to 89%, while Se(VI) increased the Pb total concentration by 9% to 187%, compared to growth in absence of Se. It was found that despite molecular weights distributions of mushrooms grown on Se(IV) and Se(VI)-supplemented substrates being similar, Se(VI) supplementation favoured Se interaction with proteins of medium molecular weight (17-44 kDa), when compared to supplementation with Se(IV). Therefore, we propose the supplementation of growth substrates with Se(VI) to reduce eventual Cd accumulation and produce Se-enriched oyster mushrooms.

Elemental imaging by Laser-Induced Breakdown Spectroscopy to evaluate selenium enrichment effects in edible mushrooms.

Mushrooms are bioaccumulating organisms commonly used in selenium (Se) enrichment studies. However, the addition of Se in the culture medium may alter the distribution of other essential elements in the mushroom fruiting body. To evaluate the effects of the Se enrichment, Ca, Mg, and K distributions in pink oyster (Pleurotus djamor) and K and Mg distributions in white oyster (Pleurotus ostreatus) mushrooms were mapped by laser-induced breakdown spectroscopy (LIBS), which can be used at room temperature and requires minimal or no sample preparation. It was verified that Se enrichment favoured the accumulation of Ca in the lower part of the pink oyster mushroom and prevented the transport of this element to the edges and tops. The Se enrichment also altered the distribution of K and Mg, decreasing the numerical correlation between the K and Mg distributions (R² = 0.5871). In the white oyster mushroom, however, despite the changes in the morphological characteristics of the fruiting bodies after enrichment, there were generally nonsignificant differences in the K and Mg distributions between the control and the Se-enriched mushrooms.

Protein and Metalloprotein Distribution in Different Varieties of Beans (Phaseolus vulgaris L.): Effects of Cooking.

Beans (Phaseolus vulgaris L.) are among the main sources of protein and minerals. The cooking of the grains is imperative, due to reduction of the effect of some toxic and antinutritional substances, as well as increase of protein digestibility. In this study, the effects of cooking on albumins, globulins, prolamins, and glutelins concentration and determination of Fe associated with proteins for different beans varieties and on phaseolin concentration in common and black beans were evaluated. Different extractant solutions (water, NaCl, ethanol, and NaOH) were used for extracting albumins, globulins, prolamins, and glutelins, respectively. For the phaseolin separation NaOH, HCl, and NaCl were used. The total concentration of proteins was determined by Bradford method; Cu and Fe associated with phaseolin and other proteins were obtained by graphite furnace atomic absorption spectrometry and by flame atomic absorption spectrometry, respectively. Cooking promoted a negative effect on (1) the proteins concentrations (17 (glutelin) to 95 (albumin) %) of common beans and (2) phaseolin concentration (90%) for common and black beans. Fe associated with albumin, prolamin, and glutelin was not altered. In Fe and Cu associated with phaseolin there was an increase of 20 and 37% for the common and black varieties, respectively.

In vivo bioavailability of selenium in enriched Pleurotus ostreatus mushrooms.

The in vivo bioavailability of Se was investigated in enriched Pleurotus ostreatus mushrooms. A bioavailability study was performed using 64 Wistar male rats separated in 8 groups and fed with different diets: without Se, with mushrooms without Se, with enriched mushrooms containing 0.15, 0.30 or 0.45 mg kg(-1) Se and a normal diet containing 0.15 mg kg(-1) of Se using sodium selenate. The experiment was performed in two periods: depletion (14 days) and repletion (21 days), according to the Association of Official Analytical Chemists. After five weeks, the rats were sacrificed under carbon dioxide, and blood was drawn by heart puncture. Blood plasma was separated by centrifugation. The total Se concentration in the plasma of rats fed with enriched mushrooms was higher than in rats fed with a normal diet containing sodium selenate. The plasma protein profiles were obtained using size exclusion chromatography (SEC) and UV detectors. Aliquots of effluents (0.5 mL per minute) were collected throughout in the end of the chromatographic column. However, Se was determined by graphite furnace atomic absorption spectrometry (GF AAS) only in the aliquots where proteins were detected by SEC-UV. The plasma protein profile of rats fed with different diets was similar. The highest Se concentration was observed in a peptide presenting 8 kDa. Furthermore, the higher Se concentration in this peptide was obtained for rats fed with a diet using enriched mushrooms (7 µg L(-1) Se) compared to other diets (2-5 µg L(-1) Se). These results showed that Se-enriched mushrooms can be considered as an alternative Se food source for humans, due to their high bioavailability.

Association of dental enamel lead levels with risk factors for environmental exposure / Associação de níveis de chumbo no esmalte dentário com fatores de risco para exposição ambiental / Asociación de niveles de plomo en el esmalte dental con factores de riesgo a la exposición ambiental

OBJECTIVE: To analyze household risk factors associated with high lead levels in surface dental enamel. METHODS: A cross-sectional study was conducted with 160 Brazilian adolescents aged 1418 years living in poor neighborhoods in the city of Bauru, southeastern Brazil, from August to December 2008. Body lead concentrations were assessed in surface dental enamel acid-etch microbiopsies. Dental enamel lead levels were measured by graphite furnace atomic absorption spectrometry and phosphorus levels were measured by inductively coupled plasma optical emission spectrometry. The parents answered a questionnaire about their children's potential early (05 years old) exposure to well-known lead sources. Logistic regression was used to identify associations between dental enamel lead levels and each environmental risk factor studied. Social and familial covariables were included in the models. RESULTS: The results suggest that the adolescents studied were exposed to lead sources during their first years of life. Risk factors associated with high dental enamel lead levels were living in or close to a contaminated area (OR = 4.49; 95 percent CI: 1.69;11.97); and member of the household worked in the manufacturing of paints, paint pigments, ceramics or batteries (OR = 3.43; 95 percent CI: 1.31;9.00). Home-based use of lead-glazed ceramics, low-quality pirated toys, anticorrosive paint on gates and/or sale of used car batteries (OR = 1.31; 95 percent CI: 0.56;3.03) and smoking (OR = 1.66; 95 percent CI: 0.52;5.28) were not found to be associated with high dental enamel lead levels. CONCLUSIONS: Surface dental enamel can be used as a marker of past environmental exposure to lead and lead concentrations detected are associated to well-known sources of lead contamination.

OBJETIVO: Analisar fatores de risco no ambiente domiciliar associados com altos níveis de chumbo no esmalte dentário superficial. MÉTODOS: Estudo transversal conduzido com 160 adolescentes brasileiros (14 a 18 anos), residentes em bairros pobres do município de Bauru, SP, de agosto a dezembro de 2008. A concentração de chumbo no esmalte dentário foi avaliada por microbiópsias ácidas do esmalte dentário superficial, quantificada por espectrometria de absorção atômica com forno de grafite e a concentração de fósforo foi medida por espectrometria de absorção óptica com plasma indutivamente acoplado. Os pais dos adolescentes responderam a questionário sobre possível exposição prévia (cinco primeiros anos de vida do adolescente) a chumbo decorrente de fontes de contaminação bem conhecidas. Usou-se regressão logística para identificar associações entre concentração de chumbo no esmalte e fatores de risco ambientais. Covariáveis familiares e sociais foram incluídas nos modelos. RESULTADOS: Os resultados sugerem que os jovens avaliados foram expostos a fontes de chumbo durante seus primeiros anos de vida. Os fatores de risco associados com o desfecho foram residir em área contaminada por chumbo ou nas suas proximidades (OR = 4,49; IC 95 por cento: 1,69;11,97) e ter convivido, no mesmo domicílio, com pessoa que trabalhava em fábrica de tintas, pigmentos, cerâmicas ou baterias (OR = 3,43; IC 95 por cento: 1,31;9,00). Ter usado, em casa, cerâmica vitrificada, brinquedos de baixa qualidade ou piratas, ter aplicado zarcão em portões de ferro sem cobertura esmaltada ou armazenar baterias de carro usadas na residência (OR = 1,31; IC 95 por cento: 0,56;3,03) e hábito de fumar não foram associados com altas concentrações de chumbo no esmalte dentário (OR = 1,66; IC 95 por cento: 0,52;5,28). CONCLUSÕES: O esmalte dentário superficial pode ser utilizado como marcador de exposição ambiental passada ao chumbo e as concentrações encontradas desse metal estão ligadas a fontes bem conhecidas de contaminação por chumbo.

OBJETIVO: Analizar factores de riesgo en el ambiente domiciliar asociados con altos niveles de plomo en el esmalte dental superficial. MÉTODOS: Se realizó estudio transversal con 160 adolescentes brasileros (14 a 18 años), residentes en urbanizaciones pobres del municipio de Bauru, SP, de agosto a diciembre de 2008. La concentración de plomo en el esmalte dental fue evaluada por micro biopsias ácidas del esmalte dental superficial, cuantificada por espectrometría de absorción atómica con horno de grafito y la concentración de fósforo fue medida por espectrometría de absorción óptica con plasma inductivamente acoplado. Los padres de los adolescentes respondieron a cuestionario sobre posible exposición previa (5 primeros años de vida del adolescente) al plomo producto de fuentes de contaminación bien conocidas. Se usó regresión logística para identificar asociaciones entre concentración de plomo en el esmalte y factores de riesgo ambientales. Covariables familiares y sociales fueron incluidas en los modelos. RESULTADOS: Los resultados sugieren que los jóvenes evaluados fueron expuestos a fuentes de plomo durante sus primeros años de vida. Los factores de riesgo asociados con el resultado fueron residir en área contaminada por plomo o en sus proximidades (OR=4,49; IC 95 por ciento: 1,69;11,97) y haber convivido, en el mismo domicilio, con persona que trabajaba en fábrica de tintas, pigmentos, cerámicas o baterías (OR= 3,43; IC 95 por ciento: 1,31;9,00). Haber usado, en casa, cerámica vitrificada, juegos de baja calidad o piratas, haber aplicado zircón en portones de hierro sin cobertura esmaltada o almacenar baterías de carro usadas en la residencia (OR= 1,31; IC 95 por ciento: 0,56-3,03) y hábito de fumar no fueron asociados con altas concentraciones de plomo en el esmalte dental (OR=1,66; IC 95 por ciento: 0,52;5,28). CONCLUSIONES: El esmalte dental superficial puede ser utilizado como marcador de exposición ambiental pasada al plomo y las concentraciones encontradas de dicho metal están relacionadas con fuentes bien conocidas de contaminación por plomo.

Association of dental enamel lead levels with risk factors for environmental exposure.

OBJECTIVE: To analyze household risk factors associated with high lead levels in surface dental enamel. METHODS: A cross-sectional study was conducted with 160 Brazilian adolescents aged 1418 years living in poor neighborhoods in the city of Bauru, southeastern Brazil, from August to December 2008. Body lead concentrations were assessed in surface dental enamel acid-etch microbiopsies. Dental enamel lead levels were measured by graphite furnace atomic absorption spectrometry and phosphorus levels were measured by inductively coupled plasma optical emission spectrometry. The parents answered a questionnaire about their children's potential early (05 years old) exposure to well-known lead sources. Logistic regression was used to identify associations between dental enamel lead levels and each environmental risk factor studied. Social and familial covariables were included in the models. RESULTS: The results suggest that the adolescents studied were exposed to lead sources during their first years of life. Risk factors associated with high dental enamel lead levels were living in or close to a contaminated area (OR = 4.49; 95% CI: 1.69;11.97); and member of the household worked in the manufacturing of paints, paint pigments, ceramics or batteries (OR = 3.43; 95% CI: 1.31;9.00). Home-based use of lead-glazed ceramics, low-quality pirated toys, anticorrosive paint on gates and/or sale of used car batteries (OR = 1.31; 95% CI: 0.56;3.03) and smoking (OR = 1.66; 95% CI: 0.52;5.28) were not found to be associated with high dental enamel lead levels. CONCLUSIONS: Surface dental enamel can be used as a marker of past environmental exposure to lead and lead concentrations detected are associated to well-known sources of lead contamination.

Microbiopsies of surface dental enamel as a tool to measure body lead burden.

Lead (Pb) poisoning is preventable but continues to be a public health problem in several countries. Measuring Pb in the surface dental enamel (SDE) using microbiopsies is a rapid, safe, and painless procedure. There are different protocols to perform these microbiopsies, but the reliability of dental enamel lead levels (DELL) determination is dependent upon biopsy depth (BD). It is established that DELL decrease from the outermost superficial layer to the inner layer of dental enamel. The aim of this study was to determine DELL obtained by two different microbiopsy techniques on SDE termed protocol I and protocol II. Two consecutive enamel layers were removed from the same subject group (n=138) for both protocols. Protocol I consisted of a biopsied site with a diameter of 4 mm after the application of 10 microl HCl for 35 s. Protocol II involved a biopsied site of 1.6 mm diameter after application of 5 microl HCl for 20 s. The results demonstrated that there were no significant differences for BD and DELL between homologous teeth using protocol I. However, there was a significant difference between DELL in the first and second layers using both protocols. Further, the BD in protocol II overestimated DELL values. In conclusion, SDE analyzed by microbiopsy is a reliable biomarker in protocol I, but the chemical method to calculate BD in protocol II appeared to be inadequate for measurement of DELL. Thus, DELL could not be compared among studies that used different methodologies for SDE microbiopsies.

Surface dental enamel lead levels and antisocial behavior in Brazilian adolescents.

Lead poisoning has been reportedly linked to a high risk of learning disabilities, aggression and criminal offenses. To study the association between lead exposure and antisocial/delinquent behavior, a cross-sectional study was conducted with 173 Brazilian youths aged 14-18 and their parents (n=93), living in impoverished neighborhoods of Bauru-SP, with high criminality indices. Self-Reported Delinquency (SRD) and Child Behavior Checklist (CBCL) questionnaires were used to evaluate delinquent/antisocial behavior. Body lead burdens were evaluated in surface dental enamel acid microbiopsies. The dental enamel lead levels (DELL) were quantified by graphite furnace atomic absorption spectrometry (GFAAS) and phosphorus content was measured using inductively coupled plasma optical emission spectrometry (ICP-OES). Logistic regression was used to identify associations between DELL and each scale defined by CBCL and SRD scores. Odd ratios adjusted for familial and social covariates, considering a group of youths exposed to high lead levels (>or=75 percentile), indicated that high DELL is associated with increased risk of exceeding the clinical score for somatic complaints, social problems, rule-breaking behavior and externalizing problems (CI 95%). High DELL was not found to be associated with elevated SRD scores. In conclusion, our data support the hypothesis that high-level lead exposure can trigger antisocial behavior, which calls for public policies to prevent lead poisoning.