Arsenic in cooked rice foods: Assessing health risks and mitigation options

A comprehensive review on arsenic contamination in groundwater: Sources, detection, mitigation strategies and cost analysis

While groundwater is commonly perceived as safe, the excessive presence of trace metals, particularly arsenic (As), can pose significant health hazards. This review examines the current scenario of pollutants and their mitigations focusing on As contamination in groundwater across multiple nations, with a specific emphasis on the Indian Peninsula. Arsenic pollution surpasses the WHO limit of 10 ppb in 107 countries, impacting around 230 million people worldwide, with a substantial portion in Asia, including 20 states and four union territories in India. Analysis of the correlation between the aquifer and arsenic poisoning highlights severe contamination in groundwater originating from loose sedimentary aquifer strata, particularly in recently formed mountain ranges with geological sources presumed to contribute over 90% of arsenic pollution, i.e. a big environmental challenge. A myriad of techniques, including chromatographic, electrochemical, biological, spectroscopic, and colorimetric methods among others, are available for the detection and removal of arsenic from groundwater. Removal strategies encompass a wide array of approaches such as bioremediation, adsorption, coagulation/flocculation, ion exchange, biological processes, membrane treatment, and oxidation techniques specifically tailored for affected areas. Constructed wetlands help to eliminate heavy metal impurities such as As, Zn, Cd, Cu, Ni, Fe, and Cr. Their efficiency is influenced by design and environmental factors. Nanotechnology and nanoparticles have recently been studied to remove arsenic and toxic metal ions from water. Cost-effective solutions including community-based mitigation initiatives, alongside policy and regulatory frameworks addressing arsenic contamination, are essential considerations.

Sulfur-modified tea-waste biochar improves rice growth in arsenic contaminated soil and reduces arsenic accumulation

Arsenic (As) is a non-essential carcinogenic metalloid and an issue of concern for rice crops. This study investigated the effects of sulfur-loaded tea waste biochar (TWB) due to modification with sodium sulfide (SSTWB) or thiourea (TUTWB) on As stress and accumulation in rice plants. The results showed that sulfur-modified TWB improved plant morphology compared to plants grown in As-contaminated soil alone. Biochar amendments elevated the activity of antioxidant enzymes in rice plants harvested at 15 and 30 days after transplant (DAT). Additionally, SSTWB and TUTWB significantly reduced As content in shoots by 26% and 19% at 15 DAT, respectively, as compared to TWB. This trend continued at 30 DAT with SSTWB achieving the maximum decrease of 30%. Similar reductions were observed in plant roots. The study suggests that sulfur-modified biochar amendments offer a promising strategy to mitigate the negative effects of As on, and reduce its accumulation in, rice.

Rice sample preparation method for ICP-MS and CV-AFS analysis: Elemental levels and estimated intakes

Eight sample digestion procedures were compared to determine 41 elements in rice samples by ICP-MS and CV-AFS. Analytical methods were evaluated using certified rice flour reference material (NIST 1568b) and recovery experiments. The microwave-assisted digestion of 0.5 g rice sample and reagent mixture of 2 mL HNO3, 0.5 mL H2O2, and 0.5 mL deionized water yielded the best recovery for all elements ranging from 90 to 120% at three different levels, bias% within 10%, and precision (coefficient of variation percent, CV% intra- and inter-day) below 15%. The best analytical method was applied to the elemental determination in nine types of rice available on the Italian market. Daily or weekly rice consumption meets the nutritional and safety requirements of EFSA and WHO. The present study allows extensive and detailed knowledge of the content of essential and non-essential/toxic elements in different types of rice produced or packaged in Italy.

Review on the impact of heavy metals from industrial wastewater effluent and removal technologies

The incidence of water pollution in developing countries is high due to the lack of regulatory policies and laws that protect water bodies from anthropogenic activities and industrial wastewater. Industrial wastewater contains significant amounts of heavy metals that are detrimental to human health, aquatic organisms, and the ecosystem. The focus of this review was to evaluate the sources and treatment methods of wastewater, with an emphasis on technologies, advantages, disadvantages, and innovation. It was observed that conventional methods of wastewater treatment (such as flotation, coagulation/flocculation, and adsorption) had shown promising results but posed certain limitations, such as the generation of high volumes of sludge, relatively low removal rates, inefficiency in treating low metal concentrations, and sensitivity to varying pH. Recent technologies like nanotechnology, photocatalysis, and electrochemical coagulation have significant advantages over conventional methods for removing heavy metals, including higher removal rates, improved energy efficiency, and greater selectivity for specific contaminants. However, the high costs associated with these advanced methods remain a major drawback. Therefore, we recommend that future developments in wastewater treatment technology focus on reducing both costs and waste generation.

Interactions between nanobiochar and arsenic: Effects of biochar aging methods on arsenic binding capacity and mechanisms

Nano-biochar (nanoBC), produced from biochar aging, exhibits significant molecular heterogeneity that may affect the fate and toxicity of co-occurring pollutants. However, the interaction between nanoBC and arsenic (As) remains unclear. Herein, we simulated biochar aging through water erosion, photoaging, and thermal chemical decomposition to generate three types of nanoBC (nUBC, nPBC, and nHBC). We then investigated their distinct binding affinities and interaction mechanisms with arsenite (AsIII) and arsenate (AsV). Complementary analysis using optical spectrophotometer and high-resolution mass spectrometry revealed significant differences in properties and chemical compositions among the three nanoBCs at a size of 100 nm. Specifically, nHBC had higher yield, nPBC had higher aromaticity, and nUBC had more intricate molecular compositions and larger molecular weights. Binding experiments showed that nHBC and nUBC exhibited the highest conditional distribution coefficient (KD) for AsIII and AsV, respectively. In nHBC, a higher proportion of humic-like fluorescent component C3 enhanced its affinity for AsIII, attributed to lignin-like molecules with CHONS formulas where thiol acted as active binding sites. In contrast, the robust AsV binding capacity of nUBC stemmed from its richness in humic-like fluorescent component C1 and tryptophan-like fluorescent component C2. This is facilitated by lipid-like molecules and CHO formulas in C1 and aliphatic/peptide-like molecules and CHON formulas in C2, which provided oxygenic and nitrogen-containing groups for binding. All nanoBC had a significantly higher binding affinity for As than bulk BC. These findings provide a deeper understanding of As-nanoBC binding mechanisms at the molecular level, facilitating more accurate prediction of As fate in biochar-amended soil and associated ecosystem risks.

An assessment of the impact of traditional rice cooking practice and eating habits on arsenic and iron transfer into the food chain of smallholders of Indo-Gangetic plain of South-Asia: Using AMMI and Monte-Carlo simulation model

The current study was designed to investigate the consequences of rice cooking and soaking of cooked rice (CR) with or without arsenic (As) contaminated water on As and Fe (iron) transfer to the human body along with associated health risk assessment using additive main-effects and multiplicative interaction (AMMI) and Monte Carlo Simulation model. In comparison to raw rice, As content in cooked rice (CR) and soaked cooked rice (SCR) enhanced significantly (at p < 0.05 level), regardless of rice cultivars and locations (at p < 0.05 level) due to the use of As-rich water for cooking and soaking purposes. Whereas As content in CR and SCR was reduced significantly due to the use of As-free water for cooking and soaking purposes. The use of As-free water (AFW) also enhanced the Fe content in CR. The overnight soaking of rice invariably enhanced the Fe content despite the use of As-contaminated water in SCR however, comparatively in lesser amount than As-free rice. In the studied area, due to consumption of As-rich CR and SCR children are more vulnerable to health hazards than adults. Consumption of SCR (prepared with AFW) could be an effective method to minimize As transmission and Fe enrichment among consumers.

The association between toxic metals (As, Pb and Cd) exposure and rice cooking methods: A systematic review and meta-analysis

Heavy metal exposure through rice consumption (Oryza sativa L.) is a human health concern. This systematic review and meta-analysis investigated the association between toxic metals exposure and rice cooking methods. Based on the inclusion and exclusion criteria, fifteen studies were selected as eligible for the meta-analysis. Our results showed a significant decrease in the content of arsenic, lead, and cadmium following the cooking rice (WMD= -0.04 mg/kg, 95% CI: -0.05, -0.03, P = 0.000), (WMD = -0.01 mg/kg, 95% CI: -0.01, -0.01, P = 0.000), and (WMD = -0.01 mg/kg, 95% CI: -0.01, -0.00, P = 0.000), respectively. Furthermore, based on the subgroup analysis the overall rank order of cooking methods in the rice was rinsed > parboiling > Kateh > high-pressure, microwave, and steaming. The findings of this meta-analysis indicate the beneficial effects of cooking on reducing arsenic, lead, and cadmium exposure via rice consumption.

Silica sources for arsenic mitigation in rice: machine learning-based predictive modeling and risk assessment

Arsenic (As) is a well-known human carcinogen, and the consumption of rice is the main pathway for the South Asian people. The study evaluated the impact of the amendments involving CaSiO3, SiO2 nanoparticles, silica solubilizing bacteria (SSB), and rice straw compost (RSC) on mitigation of As toxicity in rice. The translocation of As from soil to cooked rice was tracked, and the results showed that RSC and its combination with SSB were the most effective in reducing As loading in rice grain by 53.2%. To determine the risk of dietary exposure to As, the average daily intake (ADI), hazard quotient (HQ), and incremental lifetime cancer risk (ILCR) were computed. The study observed that the ADI was reduced to one-third (0.24 μg kg-1bw) under RSC+SSB treatments compared to the control. An effective prediction model was established using random forest model and described the accumulation of As by rice grains depend on bioavailable As, P, and Fe which explained 48.5, 5.07%, and 2.6% of the variation in the grain As, respectively. The model anticipates that to produce As benign rice grain, soil should have P and Fe concentration more than 30 mg kg-1 and 12 mg kg-1, respectively if soil As surpasses 2.5 mg kg-1.

Stabilization and solidification of arsenic contaminated silty sand using alkaline activated slag

Contamination of soils by arsenic represents a significant environmental and public health risk, making effective remediation strategies a pressing concern. One commonly employed technique is stabilization and solidification, which involves the addition of stabilizing binders such as cement to immobilize arsenic. This study investigates the potential of alkaline activated slag for stabilization and solidification of arsenic-contaminated soil, employing the toxic characteristic leaching procedure (TCLP) and unconfined compressive strength (UCS) tests. To assess the strength and leachability behavior, the research examines the effect of several factors, including binder content, curing time, curing conditions, alkaline activator solution to slag ratio, sodium silicate to sodium hydroxide ratio, and sodium hydroxide concentration. Additionally, field emission scanning electron microscopes (FE-SEM) in combination with energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) tests are employed to analyze the stabilization and solidification mechanism. The study shows that increasing the slag content to 20% by weight after 28 days of curing at ambient temperature leads to a decrease of almost 92% in the concentration of leached arsenic and an increase in UCS from 80 kPa to approximately 19 MPa. The formation of albite and anorthite crystals, along with gels such as (N, C)-A-S-H and C-S-H, contributes to enhanced strength and reduced leachability. As a result, the use of alkaline activated slag is identified as an effective and environmentally friendly approach for the stabilization/solidification of arsenic-contaminated soils. This study highlights the use of alkaline activated slag as an effective solution for remediating arsenic-contaminated soils while simultaneously reducing waste, greenhouse gas emissions, and energy consumption. Slag, a byproduct of metal production, is often wasted due to a lack of value and landfill space. However, alkaline activated slag demonstrates the potential to stabilize soil, immobilize heavy metals, and provide efficient and sustainable soil remediation.

Occurrence and dietary exposure assessment of heavy metals in baby foods in the Kingdom of Saudi Arabia

Early childhood exposure to heavy metals like arsenic (As), cadmium (Cd), and lead (Pb) through baby foods unfolds many concerns about their toxic effects on growth and health. In this study, occurrence and dietary intake of As, Cd, and Pb in stage 1 infant formula (0-6 months), stage 2 infant formula (7-12 months), cereal-based meals, and biscuits were estimated. First, the levels of As, Cd, and Pb were determined with ICP-MS, followed by the calculation of estimated daily intake (EDI), target hazard quotient (THQ), and hazard index (HI) for As and Cd, and margin of exposure (MoE) for Pb. Mean levels of As, Cd, and Pb were the highest in cereal-based meals and biscuits as 15.5-11.1, 5.18-8.76, and 35.2-53.8 μg/kg, respectively. Newborns to 6 months old infants were estimated to be the highest exposed population to Cd and Pb (0.08 and 0.36 μg/kg bw/day), while infants aged 7-12 months old were exposed the highest to As. Based on the THQ, HI, and MoE findings, the current exposure levels from the selected baby foods to As, Cd, and Pb pose low potential chronic risks to both infant age groups. This research provides a roadmap for future investigations in chemical contaminants often detected in baby foods consumed regularly by Saudi infants.

A mini-review on arsenic remediation techniques from water and future trends

Arsenic contamination is a severe issue because of its toxicity and related health risks. This review article presents an overview of the sources, health hazards, and treatment options for arsenic pollution. Conventional approaches to achieving the permitted level of 10 ppb set by the WHO, such as chemical oxidation, biological oxidation, and coagulation-flocculation, are ineffective and time-consuming. The paper analyses the advantages and disadvantages of various advanced treatment technologies, including membrane filtration, ion exchange, advanced oxidation, phytoremediation, and adsorption. This paper summarized the effectiveness of hybrid arsenic remediation techniques in removing arsenic and its operating conditions. This study is a helpful tool for putting remediation strategies into practice. This article describes arsenic pollution's damaging effects on human health, underscoring the necessity for careful treatment. The article addresses numerous treatment technologies, each with advantages and disadvantages preventing widespread use. Due to these limitations, deciding the best technique for arsenic remediation is difficult. As a result, hybrid treatment systems are urgently needed, with photocatalysis-adsorption being the most popular approach. The relevance of adaptable, user-friendly, low-maintenance hybrid technologies that are versatile, easy to use, and provide affordable arsenic removal options, especially for poor populations, is highlighted by prospects.

Changing on the Concentrations of Neonicotinoids in Rice and Drinking Water through Heat Treatment Process

Neonicotinoids (NEOs) have become the most widely used insecticides in the world since the mid-1990s. According to Chinese dietary habits, rice and water are usually heated before being consumed, but the information about the alteration through the heat treatment process is very limited. In this study, NEOs in rice samples were extracted by acetonitrile (ACN) and in tap water, samples were extracted through an HLB cartridge, then, a high-performance liquid chromatography system and a triple quadrupole mass spectrometry (HPLC-MS/MS) were applied for target chemical analysis. The parents of NEOs (p-NEOs) accounted for >99% of the total NEOs mass (∑NEOs) in both uncooked (median: 66.8 ng/g) and cooked (median: 41.4 ng/g) rice samples from Guangdong Province, China, while the metabolites of NEOs (m-NEOs) involved in this study accounted for less than 1%. We aimed to reveal the concentration changes of NEOs through heat treatment process, thus, several groups of rice and water samples from Guangdong were cooked and boiled, respectively. Significant (p < 0.05) reductions in acetamiprid, imidacloprid (IMI), thiacloprid, and thiamethoxam (THM) have been observed after the heat treatment of the rice samples. In water samples, the concentrations of THM and dinotefuran decreased significantly (p < 0.05) after the heat treatment. These results indicate the degradation of p-NEOs and m-NEOs during the heat treatment process. However, the concentrations of IMI increased significantly in tap water samples (p < 0.05) after heat treatment process, which might be caused by the potential IMI precursors in those industrial pesticide products. The concentrations of NEOs in rice and water can be shifted by the heat treatment process, so this process should be considered in relevant human exposure studies.

Different levels of arsenic exposure through cooked rice and its associated benefit-risk assessment from rural and urban populations of West Bengal, India: a probabilistic approach with sensitivity analysis

Rice arsenic (As) contamination and its consumption poses a significant health threat to humans. The present study focuses on the contribution of arsenic, micronutrients, and associated benefit-risk assessment through cooked rice from rural (exposed and control) and urban (apparently control) populations. The mean decreased percentages of As from uncooked to cooked rice for exposed (Gaighata), apparently control (Kolkata), and control (Pingla) areas are 73.8, 78.5, and 61.3%, respectively. The margin of exposure through cooked rice (MoE_{cooked rice}) < 1 signifies the existence of health risk for all the studied exposed and control age groups. The respective contributions of iAs (inorganic arsenic) in uncooked and cooked rice are nearly 96.6, 94.7, and 100% and 92.2, 90.2, and 94.2% from exposed, apparently control, and control areas. LCR analysis for the exposed, apparently control, and control populations (adult male: 2.1 × 10^-3, 2.8 × 10^-4, 4.7 × 10^-4; adult female: 1.9 × 10^-3, 2.1 × 10^-4, 4.4 × 10^-4; and children: 5.8 × 10^-4, 4.9 × 10^-5, 1.1 × 10^-4) through cooked rice is higher than the recommended value, i.e., 1 × 10^-6, respectively, whereas HQ > 1 has been observed for all age groups from the exposed area and adult male group from the control area. Adults and children from rural area showed that ingestion rate (IR) and concentration are the respective influencing factors towards cooked rice As, whereas IR is solely responsible for all age groups from urban area. A vital suggestion is to reduce the IR of cooked rice for control population to avoid the As-induced health risks. The average intake (μg/day) of micronutrients is in the order of Zn > Se for all the studied populations and Se intake is lower for the exposed population (53.9) compared to the apparently control (140) and control (208) populations. Benefit-risk assessment supported that the Se-rich values in cooked rice are effective in avoiding the toxic effect and potential risk from the associated metal (As).

Meta-analyses of arsenic accumulation in Indica and Japonica rice grains

Arsenic (As) is a worldwide concern because of its toxic effects on crop yield and prevalence in the food chain. Rice is consumed by half of the world's population and is known to accumulate As. The present study reviews the available literatures on As accumulation in different subspecies of rice grains (indica, japonica and aromatic) and performs meta-analyses for grain size and texture; these data include 120 studies conducted over the last 15 years across different parts of the world. Aromatic rice varieties accumulate less As with its 95% confidence interval (CI) being 73.90 - 80.94 μg kg^-1 which is significantly lower than the As accumulation by either indica or japonica rice varieties with their overall 95% CI being 135.48 - 147.78 μg kg^-1 and 204.71 - 212.25 μg kg^-1, respectively. Japonica rice varieties accumulate higher As than indica rice grains and within each subspecies polished and/or shorter rice grains accumulated significantly lower As compared to larger and/or unpolished grains; 95% CIs for the polished indica and japonica rice varieties are seen to be 96.33 - 111.11 μg kg^-1 and 203.34 - 211.09 μg kg^-1, respectively, whereas the same for unpolished varieties are seen to be 215.99 - 238.18 μg kg^-1 and 215.27 - 248.63 μg kg^-1, respectively. This shows that rice-based As bioaccumulation in humans could be lowered by increased use of aromatic or polished indica rice varieties, followed by the cultivation of shorter polished grains of japonica rice. These findings will be important to inform policy on rice cultivation and dietary uptake of As for a large portion of the global population.

Assessment of health risk, genotoxicity, and thiol compounds in Trigonella foenum-graecum (Fenugreek) under arsenic stress

Arsenic (As) traces have been reported worldwide in vegetables and crops cultivated in As-polluted soils. Being carcinogenic, the presence of As in edibles is of great concern as it ultimately reaches humans and animals through the food chain. Besides, As toxicity adversely affects the growth, physiology, metabolism, and productivity of crops. In the present study, Trigonella foenum-graecum (Fenugreek) was exposed to the As stress (0, 50, 100, and 150 μM sodium arsenate) for a week. Further, evaluation of As accumulation in roots and shoots, magnitude and visualization of oxyradicals, and thiol-based defence offered by Fenugreek was assessed. The root and leaf accumulated 258-453 μg g^-1 dry wt (DW) and 81.4-102.1 μg g^-1 DW of As, respectively. An arsenic-mediated decline in the growth index and increase in oxidative stress was noted. Arsenic stress modulated the content of thiol compounds; especially cysteine content increased from 0.36 to 0.43 µmole g^-1 FW protein was noted. Random Amplified Polymorphic DNA (RAPD)-based analysis showed DNA damage in As-treated plants. Health risk assessment parameters showed that As concentration in the consumable plant shoot was below the critical hazard level (hazard quotient < 1). Moreover, T. foenum-graecum showed varied responses to As-induced oxidative stress with applied concentrations (150 μM being more toxic than lower concentrations). In addition, the RAPD profile and level of thiol compounds were proved significant biomarkers to assess the As toxicity in plants. The conclusion of this study will help users of fenugreek to have a clue and create awareness regarding the consumption.

Heavy metals in daily meals and food ingredients in the Yangtze River Delta and their probabilistic health risk assessment

Heavy metal exposure via food consumption is inadequately investigated and deserves considerable attention. We collected hundreds of food ingredients and daily meals and assessed their probabilistic health risk using a Monte Carlo simulation based on an ingestion rate investigation. The detected concentrations of four heavy metals (Cr, Cd, Pb, and Hg) in all daily meal samples were within the limits stipulated in the National Food Safety Standard (GB 2762-2017), while that for As level was excessive in 0.3 % of daily meal samples. The same results were also observed in most food ingredient samples, and a standard-exceeding ratio of 23 % of As was observed in aquatic food or products, especially seafood, which was with the highest concentration reaching 1.24 mg/kg. Combining the detected heavy metal amounts with the ingestion rate investigation, the hazard quotients (HQs) of As, Cr, Cd, Pb, and Hg in daily meals and food ingredients were all calculated as lower than 1 (no obvious harm), while the incremental lifetime cancer risk (ILCR) of As and Cr (>1 × 10-4), indicating that the residual As posed potential health effects to human health. It was noteworthy that the proportion of aquatic foods only accounted for 6.3 % of daily meals, but they occupied 41.1 % of the heavy metal exposure, which could be attributed to the high amounts of heavy metals in aquatic foods. This study not only provided basic data of heavy metal exposure and potential health risks through daily oral dietary intake, but also illuminated the contribution of different kinds of food ingredients. Specifically, the study highlighted the contamination of aquatic foods with As, especially seafood such as shellfish and bivalves.

Speciation and bioaccessibility of arsenic in rice under different cooking methods and its implication in risk assessment

Numerous studies have studied the health risk assessment of human exposure to As or bioaccessible As via rice intake; however, the bioaccessibility of different As species in rice is seldom reported. In the present study, 31 rice samples were collected from markets or individual growers to investigate the speciation and bioaccessibility of As. Five different species (As^III, As^V, DMA, MMA, and AsB) were detected in rice samples from different regions, among which As^III accounted for the largest proportion (62.95% in average), followed by DMA and As^V. In addition, the cooking method could facilitate the release of As from rice into gastric and intestinal juice, and subsequently increase the bioaccessibility of As. The bioaccessibility of inorganic As in cooked rice ranged from 71.83 to 100%, and that of organic As ranged from 31.69 to 61.04%. Non-carcinogenic and carcinogenic risk assessment of children and adults exposure to As via rice intake considering the bioaccessibility of cooked rice was carried out. The target hazard quotient (THQ) of iAs and total As for children ranged from 0.21 to 1.61 and 0.48 to 2.26, respectively, while those for adults ranged from 0.12 to 0.88 and 0.26 to 1.23, respectively. Incremental lifetime cancer risk (ILCR) for children and adults ranged from 9.57 [Formula: see text] 10^-5 to 7.25 [Formula: see text] 10^-4 and 5.21 [Formula: see text] 10^-5 to 3.95 [Formula: see text] 10^-4, respectively. The results of risk assessment indicated that children would face a higher health risk than adults when they took the same type of rice as their staple food.

Contemporary Comprehensive Review on Arsenic-Induced Male Reproductive Toxicity and Mechanisms of Phytonutrient Intervention

Arsenic (As) is a poisonous metalloid that is toxic to both humans and animals. Drinking water contamination has been linked to the development of cancer (skin, lung, urinary bladder, and liver), as well as other disorders such as diabetes and cardiovascular, gastrointestinal, neurological, and developmental damage. According to epidemiological studies, As contributes to male infertility, sexual dysfunction, poor sperm quality, and developmental consequences such as low birth weight, spontaneous abortion, and small for gestational age (SGA). Arsenic exposure negatively affected male reproductive systems by lowering testicular and accessory organ weights, and sperm counts, increasing sperm abnormalities and causing apoptotic cell death in Leydig and Sertoli cells, which resulted in decreased testosterone synthesis. Furthermore, during male reproductive toxicity, several molecular signalling pathways, such as apoptosis, inflammation, and autophagy are involved. Phytonutrient intervention in arsenic-induced male reproductive toxicity in various species has received a lot of attention over the years. The current review provides an in-depth summary of the available literature on arsenic-induced male toxicity, as well as therapeutic approaches and future directions.

Arsenolipids in raw and cooked seafood products in southwest China: A non-targeted analysis

Arsenolipids are the primary form of arsenic in the fat of marine organisms. Because seafood is a common source of arsenic exposure and some arsenolipids are toxic, studying the abundance and species of arsenolipids in seafood is crucial for health risk assessment. Current arsenolipid research is confined by analytical techniques and limited to raw seafood analysis, despite the fact that most seafood is ingested cooked. Therefore, the aim of this study is to evaluate which seafood contributes to arsenolipid dietary intake and investigate the changes in arsenolipids before and after cooking. In Chongqing, China, popular seafood such as clam, shrimp, oyster, abalone, hairtail, and yellow croaker were collected. The raw and cooked samples prepared from these seafood products were examined using a non-targeted screening approach established for arsenolipids, which coupled high-performance liquid chromatography with data-independent high-resolution quadrupole-time-of-flight electrospray ionization tandem mass spectrometry. Arsenic-containing hydrocarbons (AsHC330, AsHC332, and AsHC360), arsenic-containing fatty acids (AsFA362, AsFA390, AsFA404, AsFA418, and AsFA422), trimethylarsine oxide, and thiolated trimethylarsinic acid were detected. The species of arsenolipids in each type of seafood remained intact after heating in the microwave oven. In cooked samples, the concentrations of AsFA362 and AsFA390 were significantly lower than in raw samples, whereas the concentrations of other arsenolipids were unchanged. Microwave cooking did not result in the thiolation of the detected arsenolipids. The most detected species in raw and cooked samples were AsFA362, AsFA390, and AsFA418. Most arsenolipid species were found in the highest levels in hairtails and yellow croakers. It is the first time that arsenolipids have been found in the oyster, abalone, abalone liver, and yellow croaker. The present study contributes to a better understanding of arsenolipids exposure from seafood, which is useful for assessing the health risks of arsenic.

Gaseous emissions and grain-heavy metal contents in rice paddies: A three-year partial organic substitution experiment

To reduce the utilization of chemical fertilisers, which cause substantial nitrogen loss and widespread nonpoint source pollution, the application of organic manure has become an increasingly popular alternative in rice agriculture. It plays key roles in improving soil quality and maintaining rice yields, but its integrated impacts on trace gas emissions and heavy metal contents in rice grains remain poorly documented. We conducted a three-year field experiment with two application ratios (25% and 50%) of sewage sludge compost (S) and pig manure compost (P) during the rice season in eastern China. The emissions of methane (CH₄), nitrous oxide (N₂O), ammonia (NH₃), and the grain contents of nickel (Ni), copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb) were measured. Compared with urea, partial organic application, particularly 50%S and 50%P, led to a considerable increase in CH₄ emission (52%-71%), global warming potential (GWP, 50%-69%), and greenhouse gas intensity (46%-68%). However, it substantially decreased N₂O emission and NH₃ volatilisation, thus lowering the cumulative nitrogen loss by 32%-62%. Moreover, the average concentrations of Ni, Cu, Zn, Cd, and Pb in rice grains were 100-151 μg kg^-1, 2.31-2.78 mg kg^-1, 20.3-24.3 mg kg^-1, 44.3-123 μg kg^-1, and 8.69-15.2 μg kg^-1, respectively, which were significantly lower than food standard limits for rice in China. Both 25%S and 50%S achieved the highest grain yields while significantly decreasing grain Ni and Cd contents. Health risk assessment showed that the target hazard quotient of all the metals was <1 (0.006-0.73), and the hazard index that represents additive effects of pollutants was higher than the threshold, except for 25%S and 50%S. The results suggested 25%S as a potential fertilisation practice in rice fields that not only maintains low GWP and high yields but also seldom poses grain pollution or health risks.

Uncertainty and sensitivity analyses of human health risk from bioaccessible arsenic exposure via rice ingestion in Bangkok, Thailand

BACKGROUND

Rice can be a source of arsenic (As) exposure, causing health impacts after ingestion.

OBJECTIVE

This study analyzed health risks due to As exposure through rice consumption, focusing on both bioaccessible (bAs) and total (tAs) As levels.

METHODS

Monte Carlo simulations were applied to determine health risk uncertainties and to analyze factors influencing health risks.

RESULTS

Cooked white and brown rice contained lower tAs and bAs than FAO/WHO standards of 0.20 and 0.35 mg/kg, respectively. As became less bioaccessible after cooking (14.0% in white rice and 18.5% in brown rice). Non-carcinogenic effects (MOS < 1) were found in 5% of children. Carcinogenic effects (MOE<100), especially lung cancer, were found in 75% of adults, with a probable incidence of 7 in 1,000,000. The lowest and highest annual cancer cases were 18 in 10,000,000 adolescents and 15 in 1,000,000 adults, respectively. The risks were mainly affected by body weight and bAs concentration.

SIGNIFICANCE

The results identified a certain risk level of non-carcinogenic effects in children and adolescents as well as carcinogenic effects in adults. The per capita consumption of rice in Thai adults should be reduced to prevent incidences of lung cancer.

Arsenic alters nitric oxide signaling similar to autism spectrum disorder and Alzheimer's disease-associated mutations

Epidemiological studies have proven that exposure to Arsenic (AS) leads to the development of many neurological disorders. However, few studies have investigated its molecular mechanisms in the brain. Our previous work has revealed nitric oxide (NO)-mediated apoptosis and SNO reprogramming in the cortex following arsenic treatment, yet the role of NO and S-nitrosylation (SNO) in AS-mediated neurotoxicity has not been investigated. Therefore, we have conducted a multidisciplinary in-vivo study in mice with two different doses of Sodium Arsenite (SA) (0.1 ppm and 1 ppm) in drinking water. We used the novel SNOTRAP-based mass spectrometry method followed by the bioinformatics analysis, Western blot validation, and five different behavioral tests. Bioinformatics analysis of SA-treated mice showed significant SNO-enrichment of processes involved in mitochondrial respiratory function, endogenous antioxidant systems, transcriptional regulation, cytoskeleton maintenance, and regulation of apoptosis. Western blotting showed increased levels of cleaved PARP-1 and cleaved caspase-3 in SA-treated mice consistent with SA-induced apoptosis. Behavioral studies showed significant cognitive dysfunctions similar to those of Autism spectrum disorder (ASD) and Alzheimer's disease (AD). A comparative analysis of the SNO-proteome of SA-treated mice with two transgenic mouse strains, models of ASD and AD, showed molecular convergence of SA environmental neurotoxicity and the genetic mutations causing ASD and AD. This is the first study to show the effects of AS on SNO-signaling in the striatum and hippocampus and its effects on behavioral characteristics. Finally, further investigation of the NO-dependent mechanisms of AS-mediated neurotoxicity may reveal new drug targets for its prevention.

Removal of Toxic and Essential Nutrient Elements from Commercial Rice Brands Using Different Washing and Cooking Practices: Human Health Risk Assessment

This study determined the influence of different cooking procedures on the removal of toxic elements (TEs) including arsenic (As), cadmium (Cd), and lead (Pb) along with other nutrient elements from different commercially available rice brands sold in Bangladeshi markets. We observed 33%, 35%, and 27% average removal of As, Cd, and Pb accordingly from rice when cooked with a rice to water ratio of 1:6 after washing 5 times. We also found a significant reduction in essential elements: Zn (17%), Cu (10%), Mn (22%), Se (49%), and Mo (22%), when rice cooking was performed as in traditional practice. Daily dietary intakes were found to be between 0.36 and 1.67 µg/kgbw for As, 0.06 and 1.15 µg/kgbw for Cd, and 0.04 and 0.17 µg/kgbw for Pb when rice was cooked by the rice cooker method (rice:water 1:2), while in the traditional method (rice:water 1:6) daily intake rates ranged from 0.23 to 1.3 µg/kgbw for As, 0.04 to 0.88 µg/kgbw for Cd, and 0.03 to 0.15 µg/kgbw for Pb for adults. The HQ and ILCR for As, Cd, and Pb revealed that there is a possibility of noncarcinogenic and carcinogenic risk for As but no appreciable risk for Cd and Pb from consumption of rice.

Biological Properties of Vitamins of the B-Complex, Part 1: Vitamins B1, B2, B3, and B5

This review summarizes the current knowledge on essential vitamins B1, B2, B3, and B5. These B-complex vitamins must be taken from diet, with the exception of vitamin B3, that can also be synthetized from amino acid tryptophan. All of these vitamins are water soluble, which determines their main properties, namely: they are partly lost when food is washed or boiled since they migrate to the water; the requirement of membrane transporters for their permeation into the cells; and their safety since any excess is rapidly eliminated via the kidney. The therapeutic use of B-complex vitamins is mostly limited to hypovitaminoses or similar conditions, but, as they are generally very safe, they have also been examined in other pathological conditions. Nicotinic acid, a form of vitamin B3, is the only exception because it is a known hypolipidemic agent in gram doses. The article also sums up: (i) the current methods for detection of the vitamins of the B-complex in biological fluids; (ii) the food and other sources of these vitamins including the effect of common processing and storage methods on their content; and (iii) their physiological function.

Arsenic in Portuguese Rice: Is There Any Risk?

Arsenic is a metalloid with natural and anthropogenic sources and its inorganic form is toxic to humans. Rice is highly consumed worldwide and is prone to arsenic contamination; therefore, this study evaluated the inorganic arsenic content of 70 Portuguese rice samples. These were analysed through inductively coupled plasma mass spectrometry (ICP-MS) with a detection limit of 3.3 µg kg−1. The average contamination was of 29.3 µg kg−1, with brown and short rice presenting higher values than white and long rice. The highest concentration, 100 µg kg−1, equalled the maximum residue limit (MRL) for rice destined for infants’ consumption. The estimated daily intake (EDI) surpassed the benchmark dose (lower confidence limit 10%) (BMDL10) of 0.3 µg kg−1 of bw/day considering children in the 95th percentile of rice consumption and the worst-case scenario concentration. However, other sources also contribute to the EDI and some population groups can exceed the BMDL10.

Effect of P/As molar ratio in soil porewater on competitive uptake of As and P in As sensitive and tolerant rice genotypes

Phosphorus (P) can affect the bioavailability and mobility of arsenic (As) in paddy soil-plant system, but it is not clear how different forms of phosphorus fertilizers affect P/As molar ratio in soil and how the ratio in turn affects the competitive uptake of P and As in two genotypes. Different P fertilizers, i.e., calcium-magnesium phosphate (CMP), superphosphate (SP) and potassium phosphate monobasic (PPM), were used to investigate the difference in competitive uptake between As sensitive (IIY3301) and As tolerant (SY9519) rice genotypes. Our results indicated that the contents of total As in brown rice of PPM and SP treatments (II-PPM and II-SP) were 15.4% and 26.9% lower than that of CMP treatment (II-CMP) for IIY3301 genotype, but their P contents were 27.0% and 17.8% higher than that of II-CMP treatment. However, the As content in brown rice showed no significant difference between PPM and CMP treatments for SY9519 genotype (S-PPM and S-CMP). The net As accumulation in shoots of II-PPM during the tillering stage was significantly lower than that of II-CMP, but the difference of net As accumulation between S-PPM and S-CMP was not significant. The As translocation factor in II-PPM and II-SP were 16.7% and 22.2% lower than that in II-CMP, but the difference of As translocation factor between S-PPM and S-CMP was not significant. In addition, the contents of total As in porewater showed no significant difference between PPM and CMP. Conversely, the P/As molar ratio in porewater of PPM during tillering stage was 10.9% higher than that of CMP. In summary, PPM led to a higher P/As molar ratio in porewater, which promoted the competitive uptake of As and P by IIY3301 genotype; and the competitive uptake of As and P was more likely to occur in As sensitive rice genotype than in As tolerant rice genotype.

Health effect and risk assessment of the populations exposed to different arsenic levels in drinking water and foodstuffs from four villages in arsenic endemic Gaighata block, West Bengal, India

Health exposure and perception of risk assessment have been evaluated on the populations exposed to different arsenic levels in drinking water (615, 301, 48, 20 µg/l), rice grain (792, 487, 588, 569 µg/kg) and vegetables (283, 187, 238, 300 µg/kg) from four villages in arsenic endemic Gaighata block, West Bengal. Dietary arsenic intake rates for the studied populations from extremely highly, highly, moderately, and mild arsenic-exposed areas were 56.03, 28.73, 11.30, and 9.13 μg/kg bw/day, respectively. Acute and chronic effects of arsenic toxicity were observed in ascending order from mild to extremely highly exposed populations. Statistical interpretation using 'ANOVA' proves a significant relationship between drinking water and biomarkers, whereas "two-tailed paired t test" justifies that the consumption of arsenic-contaminated dietary intakes is the considerable pathway of health risk exposure. According to the risk thermometer (SAMOE), drinking water belongs to risk class 5 (extremely highly and highly exposed area) and 4 (moderately and mild exposed area) category, whereas rice grain and vegetables belong to risk class 5 and 4, respectively, for all the differently exposed populations. The carcinogenic (ILCR) and non-carcinogenic risks (HQ) through dietary intakes for adults were much higher than the recommended threshold level, compared to the children. Supplementation of arsenic-safe drinking water and nutritional food is strictly recommended to overcome the severe arsenic crisis.

Arsenic bioaccessibility in rice grains via modified physiologically-based extraction test (MPBET): Correlation with mineral elements and comparison with As relative bioavailability

Rice consumption is a major dietary source of human exposure to arsenic (As), with As bioavailability being an important factor influencing its health risk. In this study, the As bioaccessibility was measured in 11 rice grains (140-335 μg As kg^-1), which were compared to As relative bioavailability previously measured based on a mouse bioassay (Li et al., 2017). Using modified physiologically-based extraction test for rice (MPBET), As bioaccessibility in raw rice samples (44-88% in the gastric phase and 47-102% in the intestinal phase) was similar to those in cooked rice (42-73% and 43-99%). Arsenic bioaccessibility in rice was generally higher in the intestinal phase than in the gastric phase, with Fe and Ca concentrations in rice being negatively correlated with As bioaccessibility in the gastric phase (R² = 0.47-0.49). In addition, for cooked rice, strong positive correlation was observed between bioaccessible As and inorganic As (R² = 0.63-0.72), suggesting inorganic As in rice was easier to dissolve than organic As in gastrointestinal digestive fluids. Due to limited variation in As bioaccessibility and As bioavailability among the 11 samples, a weak correlation was observed between them (R² = 0.01-0.03); however, As bioaccessibility values measured by the gastric phase (GP) of the MPBET agreed with As bioavailability values based on a mouse bioassay, suggesting the potential of the MPBET_GP to predict As bioavailability in rice. Future work is needed to ascertain the robustness of the MPBET_GP in predicting As bioavailability in rice using additional samples.

New insight into the mechanism of graphene oxide-enhanced phytotoxicity of arsenic species

Graphene oxide (GO) has exhibited significant potential to improve crop cultivation and yield. The application of GO in agriculture will inevitably result in interactions with conventional contaminants, causing potential changes to environmental behavior and toxicity of conventional contaminants. This study explored the joint phytotoxicity of GO and arsenic species (arsenite [As (III)], arsenate [As (V)]) to monocot (Triticum aestivum L.) and dicot (Solamun lycopersicum) plant species. Under the environmentally relevant concentrations, GO (1 mg/L) significantly increased the phytotoxicity of As (III) and As (V) (1 mg/L), with effects being both As- and plant species-specific. One mechanism of enhanced arsenic phytotoxicity could be GO-induced up-regulation of the aquaporin and phosphate transporter related genes expression, which would lead to the increased accumulation of As (III) and As (V) in plants. In addition, co-exposure with GO resulted in more severe oxidative stress than single As exposure, which could subsequently induce damage in root plasma membranes and compromise key arsenic detoxification pathways such as complexation with glutathione and efflux. Co-exposure to GO and As also led to more significant reduction in macro- and micronutrient content. The provided data highlight the high-impact of nanomaterials on the environmental risk of As in agricultural systems.

Rice genotype's responses to arsenic stress and cancer risk: The effects of integrated birnessite-modified rice hull biochar-water management applications

The health risks associated with ingestion of arsenic (As) via consumption of rice are a global concern. This study investigated the effects of integrated biochar (BC)-water management approaches to As stress and to associated health risks in rice. Rice cultivars, Jayanthi and Ishikari, were grown, irrigated with As-containing water (1 mg L^-1), under the following treatments: (1) birnessite-modified rice hull biochar (Mn-RBC)-flooded water management, (2) Mn-RBC-intermittent water management, (3) conventional flooded water management, and (4) intermittent water management. Rice yield in both rice varieties increased by 10%-34% under Mn-RBC-flooded and Mn-RBC-intermittent treatments compared to the conventional flooded treatment. In most cases, inorganic As concentration in rice roots, shoots, husks, and unpolished grains in both rice varieties was significantly (p ≤ 0.05) lowered by 20%-81%, 6%-81%, 30%-75%, and 18%-44%, respectively, under Mn-RBC-flooded, Mn-RBC-intermittent, and intermittent treatments over flooded treatment. Incremental lifetime cancer risks associated with consumption of both rice varieties were also lowered from 18% to 44% under Mn-RBC-flooded, Mn-RBC-intermittent, and intermittent treatments compared to flooded treatment. Overall, the integrated Mn-RBC-intermittent approach can be applied to As-endemic areas to produce safer rice grains and reduce the incremental lifetime cancer risk through rice consumption.

The effect of Ulva lactuca and Sargassum hemiphyllum var. chinense on arsenic metabolites and enzymes in broilers

This study investigated the effect of seaweed supplementation (Ulva lactuca (UL) or Sargassum hemiphyllum var. chinense (SHC)) on the distribution and metabolites of As in broiler breasts. Broilers fed 5% UL or 5% SHC ingested 1.4- or 78- fold greater total As than birds fed the control diet. The majority of As species were arsenate in the SHC feed and dimethylarsinic acid in breasts from chicks fed the SHC-containing diet. Arsenate and arsenobetaine were the dominant metabolites in the UL-containing feed, and arsenobetaine was the major metabolite in breasts from chicks fed the UL-containing diet. Feeding SHC enhanced hepatic S-adenosyl-methionine and arsenic methyltransferase, whereas feeding UL elevated renal arsenic methyltransferase. Taken together, considerable variation in the profiles of As species and As metabolites existed in broilers fed seaweed. The use of SHC-containing feeds in poultry production should be approached cautiously because of the potential accumulation of inorganic As species in chicken breasts.

Thiourea supplementation mediated reduction of grain arsenic in rice (Oryza sativa L.) cultivars: A two year field study

The present study delineates the interactions of arsenic (As), a carcinogenic metalloid, and thiourea (TU), a non-physiological reactive oxygen species (ROS) scavenger, in rice plants grown in As contaminated fields in West Bengal, India. The study was performed for four consecutive seasons (two boro and two aman) in 2016 and 2017 with two local rice cultivars; Gosai and Satabdi (IET-4786) in a control and two As contaminated experimental fields. Thiourea (0.05% wt/vol) treatment was given in the form of seed priming and foliar spray. Thiourea significantly improved growth and yield of rice plants and reduced As concentration in root, shoot, husk and grains in both cultivars and fields. The reduction in As concentration ranged from 10.3% to 27.5% in four seasons in different fields. The average (four seasons) increase in yield was recorded about ~8.1% and ~11.5% in control, ~20.2% and ~18.6% in experimental field 1, and ~16.2% and ~24.1% in experimental field 2, for gosai and satabdi, respectively. Mean hazard quotient (HQ) and incremental lifetime cancer risk (ILCR) values of As reduced upon TU supplementation for both cultivars as compared to that of non-TU plants. Hence, TU can be effectively used to cultivate rice safely in As contaminated fields.

Variety-specific arsenic accumulation in 44 different rice cultivars (O. sativa L.) and human health risks due to co-exposure of arsenic-contaminated rice and drinking water

Arsenic (carcinogenic) is a global health concern due to its presence in groundwater and subsequent accumulation in cultivated-rice via irrigation. The present work focused on the evaluation of arsenic concentration in groundwater, different cultivated-rice varieties (studied together for the first-time) and related health-risks. Arsenic in groundwater (0.26-0.73 mg/L) exceeded the World Health Organization limit for drinking water (0.01 mg/L). Arsenic concentration in rice-grains was found in the range: < 0.0003-2.6 mg/kg dry-weights, where 42 rice varieties (out of total 44) exceeded the Codex Alimentarius Commission limit of polished-rice (0.2 mg/kg). The variety-specific differential-response of arsenic-accumulation was observed (first-time report), where high yielding rice varieties (HYV) were more prone to accumulate arsenic in comparison to local varieties (LV), however, 'Radhunipagol' (an aromatic LV) exhibited as a moderate arsenic-accumulator (BCF = 2.8). The cumulative estimated-daily-intakes (EDI_Cumulative) of arsenic in central-tendency-exposure were observed to be 0.029, 0.031 and 0.04 mg/kg-day among children, teenagers and adults, respectively. The EDI_Cumulative for possible reasonable-maximum-exposure among the above mentioned subpopulation was 0.038, 0.04 and 0.05 mg/kg-day, respectively. The evaluated Cumulative Hazard Index and Individual Excess Lifetime Cancer Risk values suggested that the studied population is under extremely severe cancerous and noncancerous risks to arsenic co-exposures via drinking water and rice.

Advanced application of nano-technological and biological processes as well as mitigation options for arsenic removal

Arsenic (As) removal is a huge challenge, since several million people are potentially exposed (>10 μg/L World Health Organization guideline limit) through As contaminated drinking water worldwide. Review attempts to address the present situation of As removal, considering key topics on nano-technological and biological process and current progress and future perspectives of possible mitigation options have been evaluated. Different physical, chemical and biological methods are available to remove As from contaminated water/soil/wastes, where removal efficiency mainly depends on absorbent type, initial adsorbate concentration, speciation and interfering species. Oxidation is an important pretreatment step in As removal, which is generally achieved by several media such as O₂/O₃, HClO, KMnO₄ and H₂O₂. The Fe-based-nanomaterials (α/β/γ-FeOOH, Fe₂O₃/Fe₃O₄-γ-Fe₂O₃), Fe-based-composite-compounds, activated-Al₂O₃, HFO, Fe-Al₂O₃, Fe₂O₃-impregnated-graphene-aerogel, iron-doped-TiO₂, aerogel-based- CeTiO₂, and iron-oxide-coated-manganese are effective to remove As from contaminated water. Biological processes (phytoremediation/microbiological) are effective and ecofriendly for As removal from water and/or soil environment. Microorganisms remove As from water, sediments and soil by metabolism, detoxification, oxidation-reduction, bio-adsorption, bio-precipitation, and volatilization processes. Ecofriendly As mitigation options can be achieved by utilizing an alternative As-safe-aquifer, surface-water or rainwater-harvesting. Application of hybrid (biological with chemical and physical process) and Best-Available-Technologies (BAT) can be the most effective As removal strategy to remediate As contaminated environments.

The effects of low-dose biochar amendments on arsenic accumulation in rice (Oryza sativa L.)

The accumulation of arsenic (As) in rice is one of the food security-related concerns in As-contaminated areas all over the world. Biochar, a potential green and cost-efficient amendment material, affects As mobility/phytoavailability in soil and As accumulation in rice plants to some extent, which remains unclear. Thus, three different biochars derived from rice straw, corn stalks, and bamboo were used to investigate the impacts of biochar amendments on As mobility/phytoavailability in As-contaminated soil using pot and microcosm experiments. The results showed a limited reduction (by 12-16%) in As accumulation in rice grains under a low-dose (0.5%, w/w) biochar amendment, although the three biochars displayed different physicochemical properties. In addition, the biochar amendments did not significantly decrease the As levels in the straw and roots, potentially because of the small changes in As mobility/phytoavailability in amended soil relative to the control. However, As levels in soil solution in the biochar treatment groups increased substantially, by 2.8-6.6 times, with increasing biochar doses (0.5-5%, w/w) in microcosm-based anaerobic incubation experiments, particularly at higher doses (3-5%, w/w). These results could be attributed to the biochar-enhancing activity of As(V)-/Fe(III)-reducing bacteria at a high biochar application rate. Our results suggested that applying high biochar doses may increase the release of As into the soil, resulting in As accumulation in rice plants. Therefore, to mitigate the health risk of As in As-contaminated paddy soils, the remediation technologies from biochar methods should be subjected to more evaluation.

Mineral and Fatty Acid Content Variation in White Oat Genotypes Grown in Brazil

A healthy diet is directly associated with a nutrient-rich and toxic contaminant poor intake. A diet poor in diversity can lead to micronutrient deficiency. The intake of functional foods can provide benefits in the prevention and treatment of diseases. Oats are a functional food; are a source of soluble fiber, lipids, proteins, vitamins, minerals, and polyphenols; and are low in carbohydrate content. Thus, in this study, we characterize mineral accumulation, fatty acid composition, and the absence of contaminants in oat genotypes to evaluate the potential of this cereal as food to minimize the effects of micronutrient deficiency. Most of the oat genotypes showed higher mineral levels than other cereals such as wheat, rice, and maize. FAEM 5 Chiarasul, Barbarasul, UPFA Ouro, URS Altiva, URS Brava, and URS Taura showed higher iron concentration while URS Brava showed the highest zinc concentration. The oat genotypes did not show significant arsenic, strontium, and cadmium accumulation. Considering the accumulation of trace elements in the grain, little genetic diversity among the analyzed oat accessions was detected, dividing into two groups. Regarding fatty acid composition, IPR Afrodite, FAEM 4 Carlasul, FAEM 5 Chiarasul, URS Taura, Barbarasul, and URS 21 showed higher essential fatty acid concentrations. These genotypes can be used in crosses with URS Brava, which displayed a higher Fe and Zn accumulation and is genetically distant from the other cultivars. Oat is a functional food showing ability for the accumulation of minerals and also essential fatty acids.

ROS-mediated genotoxic stress is involved in NaAsO2-induced cell cycle arrest, stemness enhancement and chemoresistance of prostate cancer cells in a p53-independent manner

Several epidemiological studies reported that chronic arsenic exposure increased risk of prostate cancer. This study aimed to investigate whether chronic NaAsO₂ exposure elevates stemness and chemoresistance in prostate cancer cells. DU145 (wild-type p53) and PC-3 (p53-null) cells were exposed to NaAsO₂ (2 μmol/L) for 30 generations. IC50s to docetaxel and cisplatin were increased in NaAsO₂-exposed DU145 and PC-3 cells. The number of tumor spheres was elevated in NaAsO₂-exposed DU145 and PC-3 cells. Nanog, SOX-2 and ALDH1A1, three markers of cancer stemness, were upregulated in NaAsO₂-exposed PC-3 spheres. Moreover, NaAsO₂-exposed DU145 and PC-3 cells were arrested in G2/M phase. Histone H2AX phosphorylation on Ser139, an indicator for DNA double-strand break, was upregulated in NaAsO₂-exposed DU145 and PC-3 cells. ATM phosphorylation on Ser1981, a key sensor of genotoxic stress, was rapidly elevated in NaAsO₂-exposed DU145 cells. Phosphor-p53, a downstream molecule of ATM signaling, and p21, a direct target of p53, were upregulated in NaAsO₂-exposed DU145 cells. Unexpectedly, p21 was also elevated in NaAsO₂-exposed p53-null PC-3 cells. Antioxidant NAC alleviated NaAsO₂-induced ATM phosphorylation, cell cycle arrest, and subsequent stemness enhancement and chemoresistance in both DU145 and PC-3 cells. These results suggest that ROS-mediated genotoxic stress is involved in NaAsO₂-induced cell cycle arrest, stemness enhancement and chemoresistance of prostate cancer cells in a p53-independent manner.

Characterization of Coprecipitates of As(III) and Fe(II) in the Presence of Phyllosilicate Nanoparticles

Phyllosilicate nanoparticles play an important role in regulating the biogeochemical processes of Fe(II) and As(III) in paddy soils due to their high mobility and activity. In the present work, two prepared muscovite nanoparticles with different sizes (LNPs and SNPs) were used to investigate the effect of the size of phyllosilicate nanoparticles on the coprecipitation of Fe(II) and As(III) during oxidation process. The results showed that muscovite nanoparticles could significantly promote the removal of Fe(II) and As(III) during coprecipitation process. The formation of crystalline iron oxide and oxidation of As(III) tended to be suppressed by the two muscovite nanoparticles, and the suppression increased as muscovite nanoparticle size decrease. The findings of this study provide a contribution to understanding the roles of the natural phyllosilicate nanoparticles in regulating the biogeochemical processes of Fe and As elements in polluted paddy soils.

Selective removal of arsenic in water: A critical review

Selective removal of arsenic (As) is the key challenge for any of As removal mechanisms as this not only increases the efficiency of removal of the main As species (neutral As(III) and As(V) hydroxyl-anions) but also allows for a significant reduction of waste as it does not co-remove other solutes. Selective removal has a number of benefits: it increases the capacity and lifetime of units while lowering the cost of the process. Therefore, a sustainable selective mitigation method should be considered concerning the economic resources available, the ability of infrastructure to sustain water treatment, and the options for reuse and/or safe disposal of treatment residuals. Several methods of selective As removal have been developed, such as precipitation, adsorption and modified iron and ligand exchange. The biggest challenge in selective removal of As is the presence of phosphate in water which is chemically comparable with As(V). There are two types of mechanisms involved with As removal: Coulombic or ion exchange; and Lewis acid-base interaction. Solution pH is one of the major controlling factors limiting removal efficiency since most of the above-mentioned methods depend on complexation through electrostatic effects. The different features of two different As species make the selective removal process more difficult, especially under natural conditions. Most of the selective As removal methods involve hydrated Fe(III) oxides through Lewis acid-base interaction. Microbiological methods have been studied recently for selective removal of As, and although there have been only a small number of studies, the method shows remarkable results and indicates positive prospects for the future.

Content of Toxic Elements in 12 Groups of Rice Products Available on Polish Market: Human Health Risk Assessment

Background: Rice is one of the most commonly consumed grains. It could be a good source of nutrients in a diet, but its consumption could also contribute to exposure to toxic elements. All rice products available on the Polish market are imported, which may pose a particular concern as to the safety of their consumption. The aim of our study was to estimate the content of As, Cd, Pb, and Hg in rice products and to assess the health risk indicators related to exposure to toxic elements consumed with rice products among the adult population in Poland. Methods: A total of 99 samples from 12 groups of rice products (basmati, black, brown, parboiled, red, wild, white rice and expanded rice, rice flakes, flour, pasta, and waffles) available in the Polish market were obtained. The content of Hg was determined using the atomic absorption spectrometry method (AAS). To measure As, Cd, and Pb, inductively coupled plasma-mass spectrometry (ICP-MS) was used. The health risk was assessed by calculating several indicators. Results: The average As, Cd, Pb, and Hg contents in all studied products were 123.5 ± 77.1 μg/kg, 25.7 ± 26.5 μg/kg, 37.5 ± 29.3 μg/kg, and 2.8 ± 2.6 μg/kg, respectively. Exceedance of the limit established by the Polish National Food Safety Standard was observed in one sample as regards the As content and exceedance of the European Commission standard in two samples for Hg. The samples of foods imported from European markets (n = 27) had statistically higher As content (p < 0.05) than those imported from Asian countries (n = 53). The values of health risk indicators did not show an increased risk for the Polish adult population. However, the daily intake of 55 g of rice corresponds to the benchmark dose lower confidence limit (BMDL) for Pb. Conclusion: The studied rice products could be regarded as safe for consumption by the Polish population as far as the content of As, Cd, Pb, and Hg is concerned.

Association between rice consumption and risk of cancer incidence in the California Teachers Study

PURPOSE

We evaluated the contribution of rice intake, a source of dietary arsenic, to cancer risk in a population of women with likely low arsenic exposure from drinking water and variable rice intake who participated in the California Teachers Study.

METHODS

Rice consumption was categorized into quartiles (< 9.6, 9.7-15.6, 15.7-42.7, and ≥ 42.8 g/day). Multivariable-adjusted hazard ratios and 95% confidence intervals (95% CI) for incident cancer were estimated comparing rice consumption categories with bladder, breast, kidney, lung, and pancreatic cancer, with progressive adjustment for age, total calories, BMI, race, smoking status, physical activity, and cancer-specific covariates.

RESULTS

The number of breast, lung, pancreatic, bladder, and kidney cancer cases was 7,351; 1,100; 411; 344; and 238, respectively. The adjusted hazard ratios (95% CI) comparing the highest versus lowest rice intake quartiles were 1.07 (1.00-1.15); 0.87 (0.72-1.04); 0.95 (0.66-1.37); 1.11 (0.81-1.52) and 1.07 (0.72-1.59) for breast, lung, pancreatic, bladder, and kidney cancers, respectively. Results were consistent when rice was modeled as a continuous variable and in analyses stratified by smoking status.

CONCLUSION

Rice consumption was not associated with risk of kidney, lung or pancreatic cancer, except maybe a small excess risk for breast cancer and a small non-significant excess risk for bladder cancer, comparing the highest versus lowest quartile of rice intake. Due to lower consumption patterns in this cohort, future studies should involve populations for which rice is a staple food and use of an arsenic biomarker.

Grain and dietary fiber intake and bladder cancer risk: a pooled analysis of prospective cohort studies

BACKGROUND

Higher intakes of whole grains and dietary fiber have been associated with lower risk of insulin resistance, hyperinsulinemia, and inflammation, which are known predisposing factors for cancer.

OBJECTIVES

Because the evidence of association with bladder cancer (BC) is limited, we aimed to assess associations with BC risk for intakes of whole grains, refined grains, and dietary fiber.

METHODS

We pooled individual data from 574,726 participants in 13 cohort studies, 3214 of whom developed incident BC. HRs, with corresponding 95% CIs, were estimated using Cox regression models stratified on cohort. Dose-response relations were examined using fractional polynomial regression models.

RESULTS

We found that higher intake of total whole grain was associated with lower risk of BC (comparing highest with lowest intake tertile: HR: 0.87; 95% CI: 0.77, 0.98; HR per 1-SD increment: 0.95; 95% CI: 0.91, 0.99; P for trend: 0.023). No association was observed for intake of total refined grain. Intake of total dietary fiber was also inversely associated with BC risk (comparing highest with lowest intake tertile: HR: 0.86; 95% CI: 0.76, 0.98; HR per 1-SD increment: 0.91; 95% CI: 0.82, 0.98; P for trend: 0.021). In addition, dose-response analyses gave estimated HRs of 0.97 (95% CI: 0.95, 0.99) for intake of total whole grain and 0.96 (95% CI: 0.94, 0.98) for intake of total dietary fiber per 5-g daily increment. When considered jointly, highest intake of whole grains with the highest intake of dietary fiber showed 28% reduced risk (95% CI: 0.54, 0.93; P for trend: 0.031) of BC compared with the lowest intakes, suggesting potential synergism.

CONCLUSIONS

Higher intakes of total whole grain and total dietary fiber are associated with reduced risk of BC individually and jointly. Further studies are needed to clarify the underlying mechanisms for these findings.

Comparison of bioaccessibility and relative bioavailability of arsenic in rice bran: The in vitro with PBET/SHIME and in vivo with mice model

Rice bran, a super food or health food supplement, contains high arsenic (As) levels. However, the evaluation of relative bioavailability (RBA) or bioaccessibility (BA) is limited in the rice bran. In this study, the As-RBA in rice bran was determined based on mice model and compared to As-BA using in vitro methods. The As-BA from rice bran-amended feed in the gastric, small intestinal, and colon phases were 33.1-56.4%, 50.5-75.6%, and 35.5-71.4%, respectively. The As-BA was adversely associated with bioaccessible Ca and Fe concentrations in the gastrointestinal phases. Similarly, the As-RBA was significant negative relative with Ca, Fe, and Zn concentrations. The As-RBA values were 37.9-65.5%, 41.5-75.6% and 38.7-71.5% based on liver, kidneys, and combined endpoint (liver plus kidneys), respectively. The in vitro-in vivo correlations (IVIVCs) in the gastric (R² = 0.392) and colon (R² = 0.362) phases were weak. While the IVIVC (R² = 0.544) in the small intestinal phase was stronger than those of the gastric and colon phases. In addition, there was no significant difference in As speciation between colonic residual solids and faeces (p > 0.05). This work provides a better view of human health risk evaluation on rice bran As consumption in humans.

Phosphorus regulates As uptake by rice via releasing As into soil porewater and sequestrating it on Fe plaque

Phosphorus (P) application rate can affect the As uptake by rice, but its mechanism lacks systematic studies. In this study, P fertilizers with different dosages (0, 75, 150, and 300 mg P₂O₅ kg^-1 soil) were used to investigate the effects of P on As release in soil porewater, As sequestration on Fe plaque and the change of abundance and communities of aioA and arsC genes in rhizosphere, and then explore its effect on As uptake by rice. Our results indicated that As content in brown rice under P0 and P75 treatments was 14.3-28.6% lower than that under P150 treatment. The total accumulation of As in brown rice under P0 treatment (1.51 μg plant^-1) was significantly lower than that under P150 treatment (2.17 μg plant^-1). Compared to P150 treatment, P0 treatment decreased the total As content in porewater but increased the proportion of As(V) to total As in porewater. The activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in rice roots and the Fe and As contents in Fe plaque were significantly higher under P0 treatment than under P150 treatment. Most of As (80.3-82.9%) sequestered by Fe plaque was in the form of arsenate (As(V)), and the associated As(V) on Fe plaque was 11.0% higher under P0 treatment than under P150 treatment. In addition, the abundance of aioA gene was 73.5% higher under P0 treatment than under P150 treatment, and the dominant aioA at genus level was Rhizobium and Rhodoferax. In general, P0 treatment led to higher root oxidation activity, which improved the formation of Fe plaque; and P0 treatment also improved the abundance of aioA gene in rhizosphere, thus increased the oxidation of As; so, P0 treatment indirectly enhanced As sequestration on Fe plaque, and that in turn reduced As accumulation in brown rice.

Flow of arsenic between rice grain and water: Its interaction, accumulation and distribution in different fractions of cooked rice

Arsenic (As) contaminated water is a major threat to human health when used for drinking, cooking and irrigational purposes. Rice being consumed by 50% of the world's population, supplies considerable amount of As to the human body. Our study provides a detailed understanding of As distribution in each fraction of rice while cooking (viz. uncooked rice, cooking water, cooked rice and gruel/total discarded water), ultimately leading to a better explanation of As movement between rice grain and water. A significant decrease of As was observed in cooked rice (34-89% and 23-84% for sunned and parboiled rice respectively) when cooked with low-As containing water, <3 μg/l and moderate As-contaminated water, 36-58 μg/l (3-50% and 12-61% for sunned and parboiled rice respectively) with increasing selenium (Se) concentration. Movement of As from water to rice grain has been inferred with increasing water As (84-105 μg/l), which results in a significant increase of As in cooked rice (24-337% and 114% for sunned and parboiled rice, respectively) with decreasing Se concentration. Arsenic speciation study emphasizes the fact of similar reduction percentage of As (III), As (V) and total As in wet cooked rice when cooked with low-As containing water. The SAMOE value in 'risk thermometer' supports the higher risk of suffering from wet cooked rice (class 4) with increasing cooking water As concentration (class 3 to class 5).