Determination of toxic heavy metals and speciation of arsenic in seaweeds from South Korea

Europium anomaly as a robust geogenic fingerprint for the geographical origin of aquatic products: A case study of nori (Neopyropia yezoensis) from the Japanese market

Rare earth element (REE) concentration patterns, while essential in geochemistry for tracing sample histories, have yet to be utilised entirely in food origin authentication. This research analysed 13 heavy metal(oid)s and REEs in Japanese edible seaweed Nori sheet samples (Neopyropia yezoensis), showing that the concentrations mirror the laver cultivation area's geological features (island arc-trench systems vs. continental crust). Thresholds for cadmium (0.5 ppm) and thorium (3.3 ppb) differentiate Japanese products from Korean imports. The slope of REE pattern, gadolinium anomalies, and yttrium/holmium ratios were also examined. However, nori samples significantly conveyed europium (Eu) anomalies, aligning with the mariculture hinterland's geochemistry. Both Japan's major seaweed mariculture areas, the Ariake Sea and the Seto Inland Sea, and Korean imports revealed distinct Eu anomalies (Eu/Eu* = 0.81-0.90, 0.58-0.66, 0.71-0.77), underscoring the potential of Eu anomalies as reliable seafood origin verifiers. This was also confirmed by literature values of Chinese samples.

A comprehensive review on arsenic exposure and risk assessment in infants and young children diets: Health implications and mitigation interventions in a global perspective

The early stages of human development are critical for growth, and exposure to arsenic, particularly through the placenta and dietary sources, poses significant health risks. Despite extensive research, significant gaps remain in our comprehension of regional disparities in arsenic exposure and its cumulative impacts during these developmental stages. We hypothesize that infants in certain regions are at greater risk of arsenic exposure and its associated health complications. This review aims to fill these gaps by providing a comprehensive synthesis of epidemiological evidence related to arsenic exposure during early life, with an emphasis on the underlying mechanisms of arsenic toxicity that contribute to adverse health outcomes, including neurodevelopmental impairments, immune dysfunction, cardiovascular diseases, and cancer. Further, by systematically comparing dietary arsenic exposure in infants across Asia, the Americas, and Europe, our findings reveal that infants in Bangladesh, Pakistan, and India, exposed to levels significantly exceeding the health reference value range of 0.3-8 µg/kg/day, are particularly vulnerable to dietary inorganic arsenic. This comparative analysis not only highlights geographic disparities in exposure but also underscores the variability in regulatory frameworks. Finally, the review identifies early life as a critical window for dietary arsenic exposure and offers evidence-based recommendations for mitigating arsenic contamination in infant foods. These strategies include improved agricultural practices, dietary modifications, stricter regulatory limits on arsenic in infant products, and encouragement of low-arsenic dietary alternatives. Our work establishes the framework for future research and policy development aimed at reducing the burden of arsenic exposure from source to table and effectively addressing this significant public health challenge.

Bio-accessibility and bio-availability evaluation of each arsenic species existing in various edible seaweeds in vitro and in vivo for arsenic risk assessment

Seaweeds consumption is one of main internal exposure sources of arsenic for human. However, the absence of representative bio-availabilities of arsenic species makes the accurate assessment of arsenic health risk originating from seaweeds consumption impossible. Herein, the arsenic species in various seaweeds collected from Fujian of China were investigated, and the bio-accessibilities/bio-availabilities of arsenic species existing in seaweeds were evaluated in vitro and in vivo. Results revealed that in vitro bio-availabilities of arsenic species presenting in seaweeds, which obtained with Caco-2 cells, were lower than those of pure arsenic standards, and varied with order of inorganic arsenic (iAs) > dimethylarsinic acid (DMA) ≈ arsenobetaine (AsB) > arsenosugars. During gastrointestinal digestion of mice, As5+ was partly methylated into monomethylarsonic acid (MMA) and DMA, which makes the in vivo bioavailability of iAs (⁓31.8 %) obtained with mouse metabolic experiment is much higher than its in vitro bio-availability (⁓10.3 %). The in vivo bio-availabilities of DMA and total arsenic (tAs) are similar to their in vitro bio-availabilities. As the dominant arsenic species in most seaweeds, arsenosugars have an ⁓0.0 % of in vivo bioavailability and only a ⁓3.7 % of in vitro bioavailability. The simulated calculation of target hazard quotient (THQ) and target cancer risk (TR) revealed that the arsenic risk originating from seaweeds was greatly degraded by taking into consideration of arsenic species and bio-availabilities, and all seaweeds collected from Fujian are safety for consumption. The simulated calculation also revealed that arsenic risk of seaweeds can be also more accurately assessed based on tAs together with bioavailability, which provides a simple but accurate and protective method for the risk assessment of arsenic originating from seaweeds. Our work provides the possible representative bio-availabilities of arsenic species presenting in seaweeds for accurately assessing arsenic risk of seaweeds, and novel insights into the bio-availabilities of arsenic in animal.

Evaluation of carcinogenic risk of heavy metals due to consumption of rice in Southwestern Iran

Pollution by heavy metals is a serious global problem due to its toxicity, abiotic characteristics, abundant sources, and cumulative behavior. On the other hand, considering the importance of rice consumption as an important part of nutrition in Lordegan and Ahvaz cities, this study was conducted to evaluate the carcinogenic risk of heavy metals lead, cadmium, zinc, nickel and in local Champa rice cultivated in these two cities. 16 Champa rice samples were collected from the fields of Lordegan and Ahvaz cities. The elements were read in three replicates by Varian 710-ES atomic emission device. The results showed that the concentration of cadmium and nickel in the cultivated rice in the two studied cities was within the range of the national standard of Iran and the Codex standard. Carcinogenic risk values for lead, cadmium and nickel in Champa Lordegan and Ahvaz rice were within the safe range. Also, the non-carcinogenic risk for these heavy metals in the two studied areas was less than 1 and was in the safe range. Rice pollution in Champa in Ahvaz can be due to the industrial nature of this city, and in Lordegan, it is due to pollution through pesticides, chemical fertilizers, and transportation. Long-term consumption of contaminated rice may endanger the health of residents of these areas. It is recommended to carry out regular and up-to-date monitoring strategies in these two cities to prevent the entry of these toxic heavy metals into the human food chain. Also, more studies are needed to evaluate the complete scenario and make definitive decisions.

Exploiting the role of plant growth promoting rhizobacteria in reducing heavy metal toxicity of pepper (Capsicum annuum L.)

Microorganisms are cost-effective and eco-friendly alternative methods for removing heavy metals (HM) from contaminated agricultural soils. Therefore, this study aims to identify and characterize HM-tolerant (HMT) plant growth-promoting rhizobacteria (PGPR) isolated from industry-contaminated soils to determine their impact as bioremediators on HM-stressed pepper plants. Four isolates [Pseudomonas azotoformans (Pa), Serratia rubidaea (Sr), Paenibacillus pabuli (Pp) and Bacillus velezensis (Bv)] were identified based on their remarkable levels of HM tolerance in vitro. Field studies were conducted to evaluate the growth promotion and tolerance to HM toxicity of pepper plants grown in HM-polluted soils. Plants exposed to HM stress showed improved growth, physio-biochemistry, and antioxidant defense system components when treated with any of the individual isolates, in contrast to the control group that did not receive PGPR. The combined treatment of the tested HMT PGPR was, however, relatively superior to other treatments. Compared to no or single PGPR treatment, the consortia (Pa+Sr+Pp+Bv) increased the photosynthetic pigment contents, relative water content, and membrane stability index but lowered the electrolyte leakage and contents of malondialdehyde and hydrogen peroxide by suppressing the (non) enzymatic antioxidants in plant tissues. In pepper, Cd, Cu, Pb, and Ni contents decreased by 88.0-88.5, 63.8-66.5, 66.2-67.0, and 90.2-90.9% in leaves, and 87.2-88.1, 69.4-70.0%, 80.0-81.3, and 92.3%% in fruits, respectively. Thus, these PGPR are highly effective at immobilizing HM and reducing translocation in planta. These findings indicate that the application of HMT PGPR could be a promising "bioremediation" strategy to enhance growth and productivity of crops cultivated in soils contaminated with HM for sustainable agricultural practices.

Association between blood arsenic concentration and dyslipidemia: Mediating effect of lipid peroxidation in the elderly

BACKGROUND

The earlier investigations have revealed heavy metals exposure is implicated in the pathogenesis of dyslipidemia. The goal was to evaluated the relationship of blood arsenic (As) concentration with dyslipidemia in the elderly through a cross-sectional study.

METHODS

The entire 360 elderly population were selected. Fasting blood specimens, demographic information, and clinical characteristics were obtained. The concentration of blood As was detected using ICP-MS. Serum 8-iso-PGF2α, a biomarker of lipid peroxidation, was measured by ELISA.

RESULTS

Pearson correlative analysis hinted there were strong relationships of blood As with liver function indices in the elderly. Besides, blood As was positively associated with total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL-C), and apolipoprotein A-I (ApoA I). Further multivariate linear and logistic regression suggested that the incidences of TC and LDL-C elevation were upregulated with the rising tertiles of blood As. Blood As was positively related with the prevalence of dyslipidemia (OR=3.609; 95%CI: 1.353, 6.961). Additionally, serum 8-iso-PGF2α was dramatically and positively linked to the levels of blood As and lipid profiles. Mediation analyses verified that 8-iso-PGF2α partially mediated the correlations between blood As with TC (36.63%) and LDL-C (34.03%).

CONCLUSION

Blood As concentration is positively related to lipid profiles in the elderly. Higher blood As concentration elevates the prevalence of dyslipidemia. Lipid peroxidation partially mediates the correlation of As exposure with dyslipidemia.

Monitoring arsenic species concentration in rice-based processed products distributed in South Korean markets and related risk assessment

Rice is an important grain as a major source of carbohydrates in Asia but contains more arsenic (As) than other grains. A total of 239 rice-based processed foods (rice, n = 30; rice cake, n = 30; porridge, n = 39; noodles, n = 33; bread, n = 20; snack, n = 59; powder, n = 28) were purchased in 2019 from domestic markets to measure total As (tAs) and As species. The average tAs and inorganic As (iAs) in each sample group ranged from 20 to 180 μg/kg (porridge for baby to noodle) and 4.4-85 μg/kg (porridge for baby to powder), respectively. The correlation between the iAs and tAs was affected by the variety of ingredients, such as the presence of seaweed (tAs) and the milling type of rice (iAs). Although rice cakes and baby rice-based powders are a source of concern for both adults and children, respectively, risk assessments indicate that most rice-based foods are generally safe to consume in South Korea.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01270-9.

Variation in Anti-inflammatory, Anti-arthritic, and Antimicrobial Activities of Different Extracts of Common Egyptian Seaweeds with an Emphasis on Their Phytochemical and Heavy Metal Contents

The anti-inflammatory, anti-arthritic, and antimicrobial activities of some common Egyptian seaweeds in addition to their phytochemical and heavy metal contents were investigated. Phytochemical screening of the seaweed extracts showed the presence of different primary and secondary metabolites with different concentrations according to their species and the used solvent. The ethanolic extract of Colpmenia sinuosa (CSBE2) exhibited the maximum anti-inflammatory and anti-arthritic activity at 1000 μg/ml concentration compared to other seaweed extracts. The dichloromethane extract of Corallina officinalis (CORM) exerted the highest antimicrobial activity with an average inhibition zone diameter (AV) = 15.29 mm and activity index (AI) = 1.53 and with the highest antagonistic activity against Escherichia coli (28 mm). It is followed by Ulva linza ethanolic extract (ULGE2) which recorded (AV) of 14.71 mm and (AI) of 1.30 with the highest antifungal activity against Candida albicans (30 mm). The collected seaweeds would therefore be a very promising source for treating inflammatory, arthritic, and microbial diseases. Moreover, the investigated seaweeds showed variable concentrations of heavy metals among various species. The mean concentrations of the heavy metals took the following order: Fe > Zn > Mn > Ba > Cu > As > Cr > Ni > Pb > V > Cd > Se > Co > Mo. Based on the permissible limits set by the WHO and CEVA, Pb and Ni in the studied seaweeds were found to be within the permissible limits, whereas Cd and Zn contents were at the borderline. Significant correlations were observed between studied parameters. The estimated daily intakes for most heavy metals were lower than the recommended daily intakes.

Concentrations of blood and urinary arsenic species and their characteristics in general Korean population

Arsenic (As) exposure has been extensively studied by investigating As species (e.g., inorganic arsenic (iAs), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA)) in urine, yet recent research suggests that blood could be a possible biomarker of As exposure. These investigations, however, were conducted on iAs-contaminated areas, and evidence on populations exposed to low levels of iAs is limited. This study aimed to describe the levels and distributions of As species in urine and blood, as well as to estimate methylation efficiency and related factors in the Korean population. Biological samples were obtained by the Korean Ministry of Food and Drug Safety. A total of 2025 urine samples and 598 blood samples were utilized in this study. Six As species were measured using ultra-high-performance liquid chromatography with inductively coupled plasma mass spectrometry (UPLC-ICP-MS): As(V), As(III), MMA, DMA, arsenobetaine (AsB), and arsenocholine (AsC). Multiple linear regression models were used to examine the relationship between As species (concentrations and proportions) and covariates. AsB was the most prevalent species in urine and blood. The relative composition of iAs, MMA, DMA, and AsC in urine and blood differed significantly. Consumption of blue-backed fish was linked to higher levels of AsB in urine and blood. Type of drinking water and multigrain rice consumption were associated with increased iAs concentration in urine. Except for iAs, every species had correlations in urine and blood in both univariate and multivariate analyses. Adolescents and smokers presented a lower methylation efficiency (higher %MMA and lower %DMA in urine) and females presented a higher methylation efficiency (lower %iAs, %MMA, and higher %DMA in urine). In conclusion, blood iAs concentration cannot represent urinary iAs; nonetheless, different compositions of urine and blood might reflect distinct information about iAs exposure. Further investigations on exposure factors and health are needed using low-exposure groups.

Trace element bioaccumulation in edible red seaweeds (Rhodophyta): A risk assessment for consumers

As a precursor to risk assessment and risk management through consuming contaminated seafood, food safety needs to be quantified and assured. Seaweed is an increasing dietary component, especially in developing countries, but there are few studies assessing uptake rates of contaminants from this route. As such, the present study determined likely human uptake due to the trace elemental (Fe, Mn, Ni, Cu, Zn, Se, Hg, and As) concentrations in the edible red seaweeds (Rhodophyta) Gelidium pusillum and Hypnea musciformis, growing in the industrialised Cox's Bazar coastal area of Bangladesh. Metal and metalloid concentrations in G. pusillum were in the order (mg/kg): Fe (797 ± 67) > Mn (69 ± 4) > Ni (12 ± 5) > Zn (9 ± 4) > Cu (9 ± 4) >Se (0.1 ± 0.1) > Hg (0.1 ± 0.01), and in H. musciformis: Fe (668 ± 58) > Mn (28 ± 5) > Ni (14 ± 2) > Zn (11 ± 5) > Cu (6 ± 4) >Se (0.2 ± 0.03) > Hg (0.04 ± 0.01). Despite the industrial activities in the area, and based on 10 g. day-1 seaweed consumption, it is concluded that these concentrations pose no risk to human health as part of a normal diet according to the targeted hazard quotient and hazard index (THQ and HI) (values < 1). In addition, and as a novel aspect for seaweeds, Selenium Health Benefit Values (Se-HBV) were determined and found to have positive values. Seaweed can be used as an absorber of inorganic metals for removing contamination in coastal waters. The results are a precursor to further research regarding the efficiency and rate at which seaweeds can sequester metal contamination in water. In addition, management techniques need to be developed thereby to control the contaminant inputs.

Research progress on speciation analysis of arsenic in traditional Chinese medicine

Traditional Chinese medicine contains arsenic (As), which in the natural environment accumulates in plants during the growth of Chinese medicinal materials; there are mineral medicines containing As in Chinese patent medicine such as As4S4, As2S3, etc. Due to the toxicity of As-containing compounds and its role in inflammation and treatment of cancers such as leukemia, it is necessary to analyze the chemical form of As. A comprehensive investigation of the compound forms of heavy metals rather than the simple total amount of elements will lay the foundation for the scientific and objective evaluation of the safety of heavy metals. This article summarizes the speciation of As in bulk Chinese medicinal materials and Chinese patent medicines in recent years, and reviews the main research methods of As speciation analysis. The separation and detection combined analysis method focuses on the high-performance liquid chromatography-plasma mass spectrometry and high-performance liquid chromatography-hydride generation-atomic fluorescence spectroscopy, etc. Taking the advanced synchrotron radiation source as the research platform, the use of X-ray near edge absorption fine structure spectrum and micro-area X-ray fluorescence analysis as a microscopic analysis technique supports direct analysis of the As speciation in situ. It is the most promising morphological analysis method.

Distribution, accumulation and health risk assessment of trace elements in Sargassum fusiforme

This study compared the ability of Sargassum fusiforme to accumulate As, Cd, Cr, Cu, Ni, Pb and Zn in its five tissues (main branch, lateral branch, leaf, receptacles and pneumathode). The concentrations of these trace elements in seawater, surface sediments and different tissues of S. fusiforme were analyzed in different areas in Dongtong County (Wenzhou City, China). The presence of receptacle at all sites indicated that S. fusiforme had entered the mature stage. However, the proportion of each tissue in S. fusiforme in different sites was varied, indicating subtle differences in growth. S. fusiforme has a great capacity to accumulate trace elements, showing relatively high levels of As (28.2-64.2 mg kg-1) and Zn (19.9-80.8 mg kg-1). The elements are mainly stored in leaf, receptacles and pneumathode. Compared to element concentrations in the surrounding environment, the seaweed exhibited stronger bioconcentration capacity for As and Cd than for other elements. According to our health risk assessment results, the hazard index and carcinogenic risk were below the limit, suggesting that the S. fusiforme ingestion would not pose any health risk and the potential risk of intake branches was even lower than that of other tissues.

Preparation of chitosan-coated polystyrene microspheres for the analysis of trace Pb(ii) ions in salt by GF-AAS assisted with solid-phase extraction

Chitosan-coated polystyrene solid-phase extraction fillers.

Metabolic and residual characteristic of different arsenic species contained in laver during mouse digestion

Laver is one of the major arsenic contributors to human diets. The study on metabolic and residual characteristic of each arsenic species contained in laver is important to scientifically assess the intake risk of arsenic in the laver. The metabolic and residual characteristic of main arsenic species in laver, namely arsenate [As(V)], dimethylarsinic acid [DMA(V)] and two arsenosugars, was investigated by mouse experiments in this study. The results showed that the intake of higher-dose laver did not lead to a notable increase of As(V) concentration in mouse muscle/organs and feces. In contrast, DMA(V) excretion in feces and DMA(V) residue in muscle/organs showed a close correlation with laver-dose intake. Most DMAsSugarMethoxy was translated into other arsenic species and then was together excreted out via mouse feces; two dominant arsenic species, arsenosugar DMAsSugarMethoxy and DMAsSugarPhosphate, were not detected in mouse muscle/organs after 20-Day or 30-Day feeding whether in lower-dose laver groups containing 1/36 (mass ratio) of the laver in mouse feed or higher-dose laver groups containing 1/6 (mass ratio) of the laver in mouse feed. About 65-77% of total arsenic digested by mouse was excreted out via feces; only 0.12-0.78% of it was accumulated in mouse organs/muscle. The results of this study provided valuable knowledge for comprehending the stability and metabolic characteristics of different arsenic species from Fujian laver in vivo, also for more scientifically assessing the intake risk of arsenic in laver.

Provision of folic acid for reducing arsenic toxicity in arsenic-exposed children and adults

BACKGROUND

Arsenic is a common environmental toxin. Exposure to arsenic (particularly its inorganic form) through contaminated food and drinking water is an important public health burden worldwide, and is associated with increased risk of neurotoxicity, congenital anomalies, cancer, and adverse neurodevelopment in children. Arsenic is excreted following methylation reactions, which are mediated by folate. Provision of folate through folic acid supplements could facilitate arsenic methylation and excretion, thereby reducing arsenic toxicity.

OBJECTIVES

To assess the effects of provision of folic acid (through fortified foods or supplements), alone or in combination with other nutrients, in lessening the burden of arsenic-related health outcomes and reducing arsenic toxicity in arsenic-exposed populations.

SEARCH METHODS

In September 2020, we searched CENTRAL, MEDLINE, Embase, 10 other international databases, nine regional databases, and two trials registers.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs comparing the provision of folic acid (at any dose or duration), alone or in combination with other nutrients or nutrient supplements, with no intervention, placebo, unfortified food, or the same nutrient or supplements without folic acid, in arsenic-exposed populations of all ages and genders.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included two RCTs with 822 adults exposed to arsenic-contaminated drinking water in Bangladesh. The RCTs compared 400 µg/d (FA400) or 800 µg/d (FA800) folic acid supplements, given for 12 or 24 weeks, with placebo. One RCT, a multi-armed trial, compared FA400 plus creatine (3 g/d) to creatine alone. We judged both RCTs at low risk of bias in all domains. Due to differences in co-intervention, arsenic exposure, and participants' nutritional status, we could not conduct meta-analyses, and therefore, provide a narrative description of the data. Neither RCT reported on cancer, all-cause mortality, neurocognitive function, or congenital anomalies. Folic acid supplements alone versus placebo Blood arsenic. In arsenic-exposed individuals, FA likely reduces blood arsenic concentrations compared to placebo (2 studies, 536 participants; moderate-certainty evidence). For folate-deficient and folate-replete participants who received arsenic-removal water filters as a co-intervention, FA800 reduced blood arsenic levels more than placebo (percentage change (%change) in geometric mean (GM) FA800 -17.8%, 95% confidence intervals (CI) -25.0 to -9.8; placebo GM -9.5%, 95% CI -16.5 to -1.8; 1 study, 406 participants). In one study with 130 participants with low baseline plasma folate, FA400 reduced total blood arsenic (%change FA400 mean (M) -13.62%, standard error (SE) ± 2.87; placebo M -2.49%, SE ± 3.25), and monomethylarsonic acid (MMA) concentrations (%change FA400 M -22.24%, SE ± 2.86; placebo M -1.24%, SE ± 3.59) more than placebo. Inorganic arsenic (InAs) concentrations reduced in both groups (%change FA400 M -18.54%, SE ± 3.60; placebo M -10.61%, SE ± 3.38). There was little to no change in dimethylarsinic acid (DMA) in either group. Urinary arsenic. In arsenic-exposed individuals, FA likely reduces the proportion of total urinary arsenic excreted as InAs (%InAs) and MMA (%MMA) and increases the proportion excreted as DMA (%DMA) to a greater extent than placebo (2 studies, 546 participants; moderate-certainty evidence), suggesting that FA enhances arsenic methylation. In a mixed folate-deficient and folate-replete population (1 study, 352 participants) receiving arsenic-removal water filters as a co-intervention, groups receiving FA had a greater decrease in %InAs (within-person change FA400 M -0.09%, 95% CI -0.17 to -0.01; FA800 M -0.14%, 95% CI -0.21 to -0.06; placebo M 0.05%, 95% CI 0.00 to 0.10), a greater decrease in %MMA (within-person change FA400 M -1.80%, 95% CI -2.53 to -1.07; FA800 M -2.60%, 95% CI -3.35 to -1.85; placebo M 0.15%, 95% CI -0.37 to 0.68), and a greater increase in %DMA (within-person change FA400 M 3.25%, 95% CI 1.81 to 4.68; FA800 M 4.57%, 95% CI 3.20 to 5.95; placebo M -1.17%, 95% CI -2.18 to -0.17), compared to placebo. In 194 participants with low baseline plasma folate, FA reduced %InAs (%change FA400 M -0.31%, SE ± 0.04; placebo M -0.13%, SE ± 0.04) and %MMA (%change FA400 M -2.6%, SE ± 0.37; placebo M -0.71%, SE ± 0.43), and increased %DMA (%change FA400 M 5.9%, SE ± 0.82; placebo M 2.14%, SE ± 0.71), more than placebo. Plasma homocysteine: In arsenic-exposed individuals, FA400 likely reduces homocysteine concentrations to a greater extent than placebo (2 studies, 448 participants; moderate-certainty evidence), in the mixed folate-deficient and folate-replete population receiving arsenic-removal water filters as a co-intervention (%change in GM FA400 -23.4%, 95% CI -27.1 to -19.5; placebo -1.3%, 95% CI -5.3 to 3.1; 1 study, 254 participants), and participants with low baseline plasma folate (within-person change FA400 M -3.06 µmol/L, SE ± 3.51; placebo M -0.05 µmol/L, SE ± 4.31; 1 study, 194 participants). FA supplements plus other nutrient supplements versus nutrient supplements alone In arsenic-exposed individuals who received arsenic-removal water filters as a co-intervention, FA400 plus creatine may reduce blood arsenic concentrations more than creatine alone (%change in GM FA400 + creatine -14%, 95% CI -22.2 to -5.0; creatine -7.0%, 95% CI -14.8 to 1.5; 1 study, 204 participants; low-certainty evidence); may not change urinary arsenic methylation indices (FA400 + creatine: %InAs M 13.2%, SE ± 7.0; %MMA M 10.8, SE ± 4.1; %DMA M 76, SE ± 7.8; creatine: %InAs M 14.8, SE ± 5.5; %MMA M 12.8, SE ± 4.0; %DMA M 72.4, SE ±7.6; 1 study, 190 participants; low-certainty evidence); and may reduce homocysteine concentrations to a greater extent (%change in GM FA400 + creatinine -21%, 95% CI -25.2 to -16.4; creatine -4.3%, 95% CI -9.0 to 0.7; 1 study, 204 participants; low-certainty evidence) than creatine alone.

AUTHORS' CONCLUSIONS

There is moderate-certainty evidence that FA supplements may benefit blood arsenic concentration, urinary arsenic methylation profiles, and plasma homocysteine concentration versus placebo. There is low-certainty evidence that FA supplements plus other nutrients may benefit blood arsenic and plasma homocysteine concentrations versus nutrients alone. No studies reported on cancer, all-cause mortality, neurocognitive function, or congenital anomalies. Given the limited number of RCTs, more studies conducted in diverse settings are needed to assess the effects of FA on arsenic-related health outcomes and arsenic toxicity in arsenic-exposed adults and children.

An Investigation of Toxic Metal Levels (Pb, Cd, Cr, As, Hg) in Dried Porphyra and Laminaria Collected from Coastal Cities, China

This investigation was aimed at determining the concentration levels of five toxic heavy metals (lead, cadmium, chromium, arsenic, and mercury) in dried Porphyra and Laminaria samples from coastal city of China. Inductively coupled plasma-mass spectrometry (ICP-MS) was used for determination of lead, cadmium and total arsenic. Atomic fluorescence spectrometry was used for mercury, and liquid chromatography coupled with ICP-MS was used for arsenic speciation. The mean concentrations of lead, cadmium, chromium, total arsenic, and mercury were 0.96 ± 0.03 mg/kg, 2.62 ± 0.07 mg/kg, 1.64 ± 0.08 mg/kg, 36.67 ± 0.53 mg/kg, and 7.56 ± 0.42 μg/kg for Porphyra samples and 0.61 ± 0.03 mg/kg, 0.48 ± 0.02 mg/kg, 3.78 ± 0.56 mg/kg, 43.85 ± 1.42 mg/kg, and 46.61 ± 2.02 μg/kg for Laminaria samples. The results were comparable with previous similar research. The potential health risk assessment was conducted by comparing the calculated weekly intakes of toxic metals from Porphyra and Laminaria with provisional tolerable weekly intake. Consumption of these seaweeds does not seem to pose a risk for the consumers' health regarding their content of heavy metals. However, the potential health risk of cadmium should not be overlooked for consumers with high intake of Porphyra.

Elemental Composition of Algae-Based Supplements by Energy Dispersive X-ray Fluorescence

The aim of this study is to evaluate the elemental composition of fifteen algae-based supplements commonly sold in the Portuguese market, by energy dispersive X-ray fluorescence. Despite the fact that the majority of Kelp samples were a good source of iodine, the levels observed might well contribute to an excess in the human body, which can cause dysfunction of the thyroid gland. Furthermore, the presence of lead in Sea spaghetti, Arame, Hijiki and Wakame caused a considerable risk to public health vis a vis possible ingestion of a high daily dose. Regarding arsenic, great variability was observed in all the samples with concentrations equal to or above 60 μg/g in the case of Arame, KelpJ and Hijiki. Although algae mainly accumulate organic arsenic, some also contain high levels of its inorganic form, as is commonly pointed out for Hijiki. Thus, regular ingestion of these supplements must also take into account the mentioned facts. There is no doubt that these supplements are also good sources of other nutrients, but the lack of accurate regulations and control should alert consumers to avoid indiscriminate use of these types of products.

Determination of Toxic Elements and Arsenic Species in Salted Foods and Sea Salt by ICP-MS and HPLC-ICP-MS

Toxic elements (Cd, Pb, and As) accumulate into the environment by industrialization and natural phenomena and then pass to organisms. Analysis of toxic elements in food must be accurately carried out on a regular basis so as to avoid any adverse impact. Salted foods are difficult samples and accurate analysis of As is not easy due to salt interference. In this study, analysis of As was carried without influence of salts in three types of salted foods via an analytical method, which was validated using spiking recovery experiments and by analyzing certified reference materials. As a result, toxic elements were detected in all samples but none of these exceeded the World Health Organization recommended limits. Among the As species, arsenobetaine (AsB) was the most abundant, while inorganic As was below the detection limit in all samples. All the analyzed salted food samples appeared to be safe for consumption. In addition, the analysis of sea shrimp, freshwater shrimp, and seawater verified As bioaccumulation in these organisms from the environment.

Dietary exposure to trace elements (B, Ba, Li, Ni, Sr, and V) and toxic metals (Al, Cd, and Pb) from the consumption of commercial preparations of Spirulina platensis

Spirulina is a multicellular cyanobacterium that is consumed as a dietary supplement. The content of trace elements (B, Ba, Li, Ni, Sr, V) and toxic metals (Al, Cd, Pb) was determined in 24 spirulina samples marketed in two different formulations (tablets and powder) by ICP-OES (inductively coupled plasma optical emission spectrometry). The highest element concentration was found in the powder presentation, except for Li. The powder presentation element levels (mg/kg dry weight) were Al (28.1), Sr (10.3), B (1.73), Li (1.47), Ba (1.25), Ni (0.63), Pb (88.1 μg/kg dw), Cd (37.2 μg/kg dw), and V (22.9 μg/kg dw). Considering an adult with a body weight of 68.48 kg and the posology guidelines (14 tablespoons per week), the consumption of powdered spirulina contributes greatly to the Al intake by 2.04% of its TWI (tolerable weekly intake) set at 1 mg/kg body weight/week, followed by Cd with 1.05% of its TWI set at 2.5 μg/kg bw/week. Pb intake represents 1.05% of the BMDL (benchmark dose) level associated with nephrotoxicity and 0.44% of the BMDL associated with cardiovascular effects. This assessment suggests that spirulina consumption does not pose risks to the consumer as far as exposure to toxic metals (Al, Cd, Pb) is concerned. However, the presence of trace elements and toxic metals in spirulina preparations should be monitored to ensure its quality and safety.

Absorption and speciation of arsenic by microalgae under arsenic-copper Co-exposure

Combined pollutions of arsenic (As) and copper (Cu) are common in water bodies near mines, non-ferrous metal smelting and power plants. This study investigated the effect of Cu(II) on the absorption and speciation of As(V) by microalgae. We compared the absorption and speciation of arsenic by microalgae (mainly Cyanophyta and Chlorophyta) when exposed to single As(V) with that exposed to As-Cu co-exposure in laboratory. The results showed that in the case of single As(V) exposure, the inhibitory effect of As(V) on microalgae was primarily affected by the exposure time, instead of the concentration of As(V) in the water solution. Compared with single As(V) exposure, the presence of Cu(II) under As-Cu co-exposure promoted the absorption and accumulation of As(V) by algae. The combination effect of As and Cu on algae was antagonistic instead of synergistic within the tolerance range of algae to them. In the presence of Cu(II), more monomethylarsonous acid (MMA) and dimethylarsinous acid (DMA), which are volatile organic arsenic compounds, were produced in algae compared with the control. The finding that Cu(II) can mediate the absorption and speciation processes of arsenic in algae has significance in possible bioremediation of arsenic pollution in aquatic environment.

Human exposure assessment to potentially toxic elements (PTEs) from tofu consumption

Potentially toxic elements (PTEs) (V, B, Ba, Li, Sr, Cr, Ni, Al, Pb, Cd) were determined in 130 samples of different tofu types (natural, flavored, smoked, and fresh made) by ICP-OES (inductively coupled plasma optical emission spectrometry). Al was the most notable element found with the highest concentration (6.71 mg/kg ww) found in flavored tofu. Ni level (0.38 mg/kg) stands out in smoked tofu. European tofu has higher PTE levels than Chinese tofu. Organic-produced tofu has higher PTE concentrations than conventional produced tofu. A total of 200 g/day of smoked tofu confers a contribution percentage of 39.6% of its TDI (tolerable daily intake). In addition, 200 g/day of flavored tofu would mean a high Pb contribution with a 23.2% of the BMDL (benchmark dose level) set in 0.63 μg/kg bw/day to the development of nephrotoxicity. Mean consumption would not pose a risk to adults' health. Considering the obtained results, it would be advisable to establish limits for certain metals such as Pb, Al, and Ni in this type of product. Furthermore, it is recommendable to set consumer guidelines to some tofu types in order to avoid excessive intake of PTEs.

Sensing of mercury ions in Porphyra by Copper @ Gold nanoclusters based ratiometric fluorescent aptasensor

A novel aptamer-modified Copper @ Gold nanoclusters (apt-Cu@Au NCs) based ratiometric fluorescent probe was developed for mercury ions (Hg²⁺) determination in Porphyra. The apt-Cu@Au NCs were well dispersed in solution without Hg²⁺ but combined together for the formation of thymidine-Hg-thymidine structure with the addition of Hg²⁺, which further caused the changes in their fluorescence intensities owing to fluorescence resonance energy transfer. Along with that, the changes in fluorescent colors are visible to the naked eye. Accordingly, Hg²⁺ were determined ranging from 0.1 to 9.0 μM by fluorescence analysis with the detection limit of 4.92 nM. Moreover, a homemade device utilizing smartphone and microfluidic chip was designed for colorimetric determination of Hg²⁺ ranging from 0.5 to 7.0 μM with good portability and usefulness. The proposed methods were used for Hg²⁺ detection in Porphyra with the recoveries of 101.83-114.00%, suggesting the considerable potential for evaluating Hg²⁺ levels in aquatic products.

Total and inorganic arsenic biosorption by Sarcodia suiae (Rhodophyta), as affected by controlled environmental conditions

Temperature, light intensity (LI), adsorbent source and concentrations are key external factors affecting algal metabolism and thus metal-accumulation mechanisms. In this study, the alga Sarcodia suiae was exposed individually to a range of temperature (15, 20, and 25 °C), and LI (30, 55, and 80 μmol photons m^-2 s^-1) at initial arsenate [As(V)] concentration (_iconc: 0, 62.5, 125, 250, and 500 μg L^-1) conditions, to investigate the variations of total arsenic (TAs) and inorganic arsenic (iAs) accumulation mechanisms in the algal body. Temperature significantly affected TAs and arsenite [As(III)] production and maximum absorption were obtained at 15 °C, which was significantly stimulated by increasing _iconc. However, the temperature did not affect As(V) production. LI had no significant effect on TAs or iAs production, although maximum absorption was estimated in 80 μmol photons m^-2 s^-1. The iAs component of TAs was much greater in the temperature experiment particularly under 250-500 μg L^-1_iconc than in the LI experiment, is witnessed. Overall, temperature and _iconc strongly affected As accumulation. The predominant iAs produced was As(III), regardless of temperature or LI, suggesting that the alga favored As(III) biosorption. Also, visible effects on the morphology of this alga were adverse with increased concentration and environmental factors did affect the difference somewhat. Our results contribute to improving our understanding of the effects of the tested factors on As cycling, which is necessary for maximizing biosorption of algae if utilized for bioremediation studies as well as in the wastewater treatment implementation approach in the environment.

Health Functionality and Quality Control of Laver (Porphyra, Pyropia): Current Issues and Future Perspectives as an Edible Seaweed

The growing interest in laver as a food product and as a source of substances beneficial to health has led to global consumer demand for laver produced in a limited area of northeastern Asia. Here we review research into the benefits of laver consumption and discuss future perspectives on the improvement of laver product quality. Variation in nutritional/functional values among product types (raw and processed (dried, roasted, or seasoned) laver) makes product-specific nutritional analysis a prerequisite for accurate prediction of health benefits. The effects of drying, roasting, and seasoning on the contents of both beneficial and harmful substances highlight the importance of managing laver processing conditions. Most research into health benefits has focused on substances present at high concentrations in laver (porphyran, Vitamin B12, taurine), with assessment of the expected effects of laver consumption. Mitigation of chemical/microbiological risks and the adoption of novel technologies to exploit under-reported biochemical characteristics of lavers are suggested as key strategies for the further improvement of laver product quality. Comprehensive analysis of the literature regarding laver as a food product and as a source of biomedical compounds highlights the possibilities and challenges for application of laver products.

Dietary intake assessment of macro, trace, and toxic elements via consumption of kimchi in South Korea

BACKGROUND

Kimchi, a Korean food, is now produced and consumed in many other countries. In this study, the macro, trace, and toxic element content in varieties of kimchi from Korea and China was evaluated. A health-risk assessment, involving the calculation of estimated dietary intake values, was undertaken. To discriminate among samples with different origins, linear discriminant analysis (LDA) and principal component analysis (PCA) were applied.

RESULTS

The analytical methods used for analyses were successfully validated. In the quantification of elements, no significant differences were detected in the concentrations of the elements that were analyzed. Based on the fresh weight of kimchi, among the macro elements, the concentrations of Na and K were relatively high, with values of 4181.9-9919.8 mg kg^-1 and 1661.8-6623.5 mg kg^-1 , respectively. Among the trace elements that were analyzed, zinc in Korean samples, and strontium in Chinese samples showed the highest concentrations, at 2.67 and 2.98 mg kg^-1 , respectively. Concentration levels of the toxic trace elements were within permissible limits. The amount of daily intake and provisional daily intake of each element calculated based on kimchi intake confirmed its safety for consumption. Linear discriminant analysis and PCA successfully discriminated among the samples of Chinese and Korean origin.

CONCLUSION

The provisional daily intake of the toxic elements was within provisional tolerable daily intake values. The normal intake of kimchi could not pose a threat upon consumption. © 2019 Society of Chemical Industry.

Tracing the natural and anthropogenic influence on the trace elemental chemistry of estuarine macroalgae and the implications for human consumption

Macroalgae (seaweed) has been shown to be an effective environmental indicator. We investigate the trace element chemistry of macroalgae samples from locations along the Firth of Forth and Forth Estuary in Scotland. The overall trend in elemental abundance (Os ≪ Re < Ag < U < Cd < Co < Ni < Pb < Cu < As < Zn ≪ I), and changes along the estuary (seawards: increase As, I, Cd, U, Re, Os; decrease Pb, Cu; mid-estuary peak Zn; based on certain species), are controlled by a number of factors, including: salinity, mixing and macroalgal species differences. Within the same macroalgal species, some elemental abundances (As, I, Pb, Cu, Cd and U) are affected by mixing between freshwater riverine and North Sea marine saltwater. Additional mixing of natural and anthropogenic inputs from the surrounding geology and industry are also observed, affecting Zn, Ni, Co, Re and Os. Macroalgae is also an increasingly popular food, with some species harvested in the Firth of Forth. Iodine (67-5061 ppm), lead (0.047-4.1 ppm) and cadmium (0.006-0.93 ppm) macroalgal abundances are at safe levels for human consumption (WHO limits). However, many samples exceed the American (3 ppm) and Australian (1 ppm) limits for inorganic arsenic in macroalgae, with values ranging 0-67 ppm. In most of the samples, soaking and cooking the macroalgae reduced the inorganic arsenic content to within the American and Australian limits. However, this has further implications if the macroalgae is used to cook soups (e.g., Dashi), as the leached elements become a significant component of the soup.

Arsenic speciation and biotransformation by the marine macroalga Undaria pinnatifida in seawater: A culture medium study

Freshwater and marine organisms are capable of metabolizing arsenic (As) efficiently and regulating the As biogeochemical cycles. In this study, Undaria pinnatifida was exposed to As(V) (0, 0.1, and 1 μM) and phosphate (P; 1 and 10 μM) in seawater under laboratory-controlled conditions for up to seven days to analyze As biotransformation. The growth rates and chlorophyll fluorescence of the alga were unaffected by As stress, and statistically insignificant differences were observed among the cultures (p > 0.05). As(V) was readily accumulated by this macroalga through phosphate transporters, transformed intracellularly, and excreted into the medium, depending on the As(V) to P molar ratios. The concentration of As(V) and biotransformed species As(III) and DMAA(V) varied significantly in the algal cultures on the basis of the exposure period (p < 0.05). The concentration of As(III) was initially higher but decreased with the incubation period, whereas the concentration of DMAA(V) increased gradually. At the end of the incubation, 0.04 and 0.32 μM DMAA(V) were recorded in the media containing 0.1 and 1 μM As(V) with a constant 1.0 μM P, respectively. The results also indicated that the cellular uptake of As(V) and subsequent release of DMAA(V) were inhibited by P in the medium. The biotransformation was consistent with the As(V) detoxification mechanism based on reduction and methylation, which was enhanced by the lower As(V) to P molar ratios. These findings can be helpful in understanding the contribution of macroalgae to As biogeochemistry in marine environments and the potential risks of As dietary intake.

Concentrations of various elements in seaweed and seawater from Shen'ao Bay, Nan'ao Island, Guangdong coast, China: Environmental monitoring and the bioremediation potential of the seaweed

Seaweeds take up elements directly from seawater and have been widely employed in coastal field studies of trace element contamination. In our study, the contents of the elements, K, P, Ca, Mg, Na, Fe, Mn, Zn, Cu, B, Cd, Cr, Ni, Pb and Se, were determined from eight dominant seaweeds and the seawater from Shen'ao bay, Nan'ao Island. The levels of Cr, Ni, Mn, Zn, Cd and Pb in the seaweeds showed similar contents. Moreover, B and Se levels were in a similar pattern as those reported from other coastal areas. Rhodophyta showed higher contents and bioconcentration factors (BCF) of B than Chlorophyta or Phaeophyta. Chlorophyta had greater contents of Fe, Ni and Pb than either Rhodophyta or Phaeophyta. U. fasciata is a good biomonitor and strong accumulator of Ni and Pb, G. lemaneiformis of Zn, Cr and Se, and S. fusiforme of Cu and Cd. Our data, along with those from other investigators, can help interpret the biomonitoring data and the design of biomonitoring programs for the protection and management of coastal environments.

Metals accumulation in edible marine algae collected from Thondi coast of Palk Bay, Southeastern India

This study aimed to monitor the concentrations of metals including Cd, Pb, Cu and Zn in commercially important and commonly edible brown, red and green algal species collected from Thondi coast, southeast India. Green seaweed Chaetomorpha linum contained higher (Cd 8.51 mg kg^-1, Pb 5.24  mg kg^-1, Cu 15.38 mg kg^-1, and Zn 22.34  mg kg^-1) concentrations of metals than other tested seaweed samples. The concentrations of metals significantly varied within and between the investigated species of seaweed samples (P < 0.05). It was revealed that Cd, Pb, Cu and Zn metals were present in the species of seaweeds at different concentration. The residual levels of metals were less than the maximum allowable levels specified for human consumption compared to PTWIs, JECFA, FAO/WHO, FSSAI and EC. This study suggested that exposure to the analysed metals (Cd, Pb, Cu and Zn) through seaweeds consumption does not raise serious health effects to consumers and it is safe for human consumption.

Determination of macro, micro and trace elements in citrus fruits by inductively coupled plasma-optical emission spectrometry (ICP-OES), ICP-mass spectrometry and direct mercury analyzer

BACKGROUND

Citrus fruits are widely consumed around the world. Several elements are known to have important physiological functions in living things, whereas others are reported to have toxic effects. This study was aimed to analyze the concentration of macro, micro and trace elements in citrus fruit varieties. Samples were acid digested using a microwave system and analyzed for macro elements by inductively coupled plasma-optical emission spectrometry (ICP-OES) and for micro and trace elements by inductively coupled plasma-mass spectrometry (ICP-MS). The application of analytical techniques was analyzed by determining method validation parameters including limits of detection and quantification, linearity, precision, spiking experiments and analyzing certified reference material (NIST CRM-1570a), Spinach leaves.

RESULTS

The elemental levels of citrus fruits were found largely to be dependent upon the type of analyzed samples. Among nutritionally important elements, citrus fruits were good sources of potassium (95.13-270.4 mg kg^-1 ), calcium (10.57-75.29 mg kg^-1 ), zinc (466.5-1611 µg kg^-1 ) and manganese (35.35-1902 µg kg^-1 ). The concentrations of toxic elements (Pb, Cd, As, Al, Hg) were very low.

CONCLUSION

In general, the concentrations of analyzed elements were within the critical levels specified by the Food and Agriculture Organization/World Health Organization and Food and Nutrition Board USA. Linear discriminant analysis successfully separated the samples into clear groups with 93.9% correct classification. © 2018 Society of Chemical Industry.

Toxic metals (Al, Cd, Pb and Hg) in the most consumed edible seaweeds in Europe

Algae are becoming increasingly common because of their importance in vegan and vegetarian diets. Although they are a source of essential minerals, vitamins and antioxidants, these marine organisms have a high absorption capacity that can lead to the accumulation of toxic metals which are dangerous in humans. The objective of this study is to determine the content of toxic metals (Al, Cd, Pb and Hg) in edible seaweed samples marketed in Spain (Europe) to assess the toxicological risk from the intake of these metals. A total of 73 European and Asian algae samples marketed in Tenerife (Canary Islands, Spain) were analyzed by ICP - OES (Inductively Coupled Plasma - Optical Emission Spectrometry) and by CV-AAS (Cold Vapor - Atomic Absorption Spectrophotometry). The major toxic metal was Al, whose highest level was recorded in seaweed salad (57.5 mg Al/kg dry weight). Regarding the origin, the highest concentrations of Al (38.9 mg/kg dw), Cd (0.59 mg/kg dw) and Pb (0.40 mg/kg dw) were found in Asian algae, which may be due to the high levels of industry in the Asian countries. However, the highest concentration of Hg (0.017 mg/kg dw) was found in European algae. The consumption of 5 g of dehydrated seaweed per day represents a percentage of contribution to the tolerable weekly intake of Cd of 22.7%, this percentage may entail a risk when considering total Cd intake. However, the consumption of 5 g a day of dehydrated seaweed would not, pose a risk to the health of adults.

Occurrence, toxicity, and speciation analysis of arsenic in edible mushrooms

Owing to the strong concentration and biotransformation of arsenic, the influence of some edible mushrooms on human health has attracted widespread attention. The toxicity of arsenic greatly depends on its species, so the speciation analysis of arsenic is of critical importance. The aim of the present review is to highlight recent advances in arsenic speciation analysis in edible mushrooms. We summarized the contents and distribution of arsenic species in some edible mushrooms, the methods of sample preparation, and the techniques for their identification and quantification. Stability of the arsenic species during sample pretreatment and storage is also briefly discussed.