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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.

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BACKGROUND: Shrimp is a worldwide food commodity, it is a source of several nutrients and vitamins; however, this food is one of the major sources of arsenic for humans. Legislation around the world set limits for the concentration of this element in crustaceans but is mainly concerned with total analysis. Although, arsenic species have different toxicities and total analysis could be ineffective for making decisions about food security. METHODS: Samples of wild (Farfantepenaeus brasiliensis) and farmed shrimps (Litopenaeus vannamei) from NE Brazil were fractionated in subsamples of carapace, muscle tissue and viscera. The whole shrimp as well as the animal tissue fractions were decomposed using microwave digestion and total arsenic was analyzed by mass spectrometry inductively coupled plasm (ICP-MS). The water-soluble arsenic species were extracted, and the extract was carried for speciation analysis using HPLC-ICP-MS with an anionic and cationic column. RESULTS: Total As in wild shrimp samples exceeded Brazilian and USA food legislation by one order of magnitude, with concentrations of 11.5 ± 0.5 mg kg-1, while farmed shrimp had significantly lower total arsenic levels (0.53 ± 0.09 mg kg-1). More than 60% of the As was in the edible fraction in the wild shrimp, while in farmed shrimp this was less than 50%. The speciation analysis showed that arsenobetaine (AsB) was the predominant As form and iAs was below the Chinese legislation levels (iAs <0.50 mg kg-1) for shrimp in both species. CONCLUSION: The arsenic uptake in wild and farmed shrimp was discussed and some differences were found related to feed and salinity. About legislation, it has been concluded that most food legislations that consider only tAs are not appropriate to assess the toxicity of As in seafood. It is necessary to update the legislation of food control agencies to insert As speciation analysis in their protocols.

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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.

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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.

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Arsenic (As) is a non-threshold human carcinogenic. This element can be volatilized either by nature or anthropogenic sources. In the present study, the analytical performance of an As volatile species trapping system was evaluated to assess the As volatilization promoted by Penicillium sp. and Aspergillus sp., both isolated from rice rhizosphere, and Aspergillus niger sp. considered as a reference. The study was conducted for 60 days (sampling of volatile As species from 1st to 30th day and from 31st to 60th day). The efficiency of As-volatilization was associated with the fungal growth. The highest As volatilization occurred from 31st to 60th day. Penicillium sp., Aspergillus sp. and A. niger were capable of producing 57.8, 46.4, and 5.2% of volatile arsenic species, respectively. The speciation analysis has shown trimethylarsine (TMAs) as the main volatilized As-form, followed by mono- and dimethylarsine (MMAs and DMAs). The results are following the "Challenger pathway". Therefore, the tested fungi isolated from rice rhizosphere have shown promising properties concerning bio-volatilization with potential use for As-mitigation in paddy soils.

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Inorganic arsenic contamination in rice is a global public concern due to the risks associated. In spite of being an important issue, few studies concerning differences between inorganic arsenic in rice grains under organic and conventional methods of cultivation are available in Brazil, which is an important producer and consumer. In the present work, samples of polished and husked rice (organic and conventional) and gastronomic rice (Arborio, Carnaroli and red/black rice) were analyzed and the results compared to FAO/Codex maximum limits. The total determination and speciation analysis of arsenic were carried out by ICP-MS and HPLC-ICP-MS, respectively. The results showed no significant statistical differences in total As concentration in organic rice (157.7±56.1ngg-1) vs. conventional rice (137.4±46.6ngg-1) and also in organic husked rice (227.7±95.5ngg-1) vs. conventional husked (217.7±60.9ngg-1). However, inorganic As was 45% higher in organic polished rice than in conventional polished rice and 41% higher in organic husked rice than in conventional husked rice. Gastronomic rice presented total arsenic ranging from 65.4 to 348ngg-1 for black and Arborio rice, respectively. Regarding the maximum levels adopted by Codex for i-As (200ngg-1), no violation was found.

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Rice has the predilection to take up arsenic in the form of methylated arsenic (o-As) and inorganic arsenic species (i-As). Plants defend themselves using i-As efflux systems and the production of phytochelatins (PCs) to complex i-As. Our study focused on the identification and quantification of phytochelatins by HPLC-ICP-MS/ESI-MS, relating them to the several variables linked to As exposure. GSH, 11 PCs, and As-PC complexes from the roots of six rice cultivars (Italica Carolina, Dom Sofid, 9524, Kitrana 508, YRL-1, and Lemont) exposed to low and high levels of i-As were compared with total, i-As, and o-As in roots, shoots, and grains. Only Dom Sofid, Kitrana 508, and 9524 were found to produce higher levels of PCs even when exposed to low levels of As. PCs were only correlated to i-As in the roots (r=0.884, P <0.001). However, significant negative correlations to As transfer factors (TF) roots-grains (r= -0.739, P <0.05) and shoots-grains (r= -0.541, P <0.05), suggested that these peptides help in trapping i-As but not o-As in the roots, reducing grains' i-As. Italica Carolina reduced i-As in grains after high exposure, where some specific PCs had a special role in this reduction. In Lemont, exposure to elevated levels of i-As did not result in higher i-As levels in the grains and there were no significant increases in PCs or thiols. Finally, the high production of PCs in Kitrana 508 and Dom Sofid in response to high As treatment did not relate to a reduction of i-As in grains, suggesting that other mechanisms such as As-PC release and transport seems to be important in determining grain As in these cultivars.

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