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Arsenic is a ubiquitous metalloid whose high levels of toxicity pose major health concerns to millions of people worldwide by increasing susceptibility to various cancers and non-cancer illnesses. Since arsenic is not a mutagen, the mechanism by which it causes changes in gene expression and disease pathogenesis is not clear. One possible mechanism is through generation of reactive oxygen species. Another equally important mechanism still very much in its infancy is epigenetic dysregulation. In this review, we discuss recent discoveries underlying arsenic-induced epigenetic changes in cancer development. Importantly, we highlight the proposed mechanisms targeted by arsenic to drive oncogenic gene expression.

We have developed a quantitative determination method of the concentration of inorganic arsenic in pet foods using a liquid chromatograph-inductively coupled plasma-mass spectrometer (LC-ICP-MS). After adding 2 w/v% TMAH solution to a sample, inorganic arsenic was extracted by heating and the extract was collected by water. The pH of the solution was adjusted, and injected into a LC-ICP-MS to determine the concentration of inorganic arsenic. LC separation was carried out on an ODS column with 10 mmol/L sodium 1-butanesulfonate, 4 mmol/L malonic acid, 4 mmol/L TMAH and 0.05% methanol solution as a mobile phase. A collaborative study was conducted by nine laboratories using dry and wet-type pet foods, formed jerky, dried jerky and biscuit. Dry-type pet food and dried jerky was added with 2 mg/kg of As (III). Wet-type pet food was added with 0.5 mg/kg of As (III). Formed jerky was added with 1 mg/kg of As (III). Biscuit was added with 0.2 mg/kg of As (III). The mean recoveries, repeatabilities and reproducibilities in the form of relative standard deviation (RSDr and RSDR), and HorRat, were 95.4% to 98.3%, less than 2.9%, less than 9.1%, and 0.22 to 0.51, respectively.

Arsenite (As(III)) is far more toxic than arsenate (As(V)) to human health. To investigate the potential effects of petroleum exploitation activities on the relative abundance of inorganic As(III) ...

PurposeThe consumption of rice that contains high levels of inorganic arsenic may cause human health risk. This study aims to determine As species concentrations, particularly iAs, in raw rice in Ho Chi Minh (HCM) City and its health risks.Design/methodology/approachA total of 60 polished raw composite samples of rice were purchased from traditional markets and supermarkets in HCM City. All samples were analyzed by HPLC-ICPMS for As species determination.FindingsMean concentrations of inorganic arsenic in all samples, which were purchased from supermarket and traditional market, were 88.8 µg/kg and 80.6 µg/kg, respectively. Overall, inorganic arsenic level was 84.7 µg/kg and contributed the highest proportion of arsenic species in rice with 67.7%. The proportion profiles for arsenic species were: As (III) (60 %); dimethylarsinic acid (32.2 %); As (V) (7.7 %) and methylarsonic acid (0.1 %). Inorganic arsenic level in raw rice was below the recommendation of World Health Organization. Using the benchmark dose recommended by the Joint FAO/WHO Expert Committee on Food Additives (JECFA), all exposure doses were lower than BMDL05. However, as the doses ranged from 3.0 to 8.6 of Margin of Exposure (MOE), the health risk of iAs from rice consumption remains public health concern.Originality/valueThe study results report on the surveillance data of the presence of inorganic arsenic in raw rice products, which are available in the supermarkets and traditional markets, and its health risk to consumers in a metropolitan city in Vietnam.

Arsenic (As) and cadmium (Cd) concentrations have been analysed in locally grown rice grains from North Central Province, Sri Lanka. Totally, 186 samples including newly improved and traditional varieties were collected during September-December 2016, and As and Cd concentrations were determined by electrothermal atomic absorption spectroscopy. The potential health risks were estimated by three indices namely Estimated Daily Intake, Target Hazard Quotient, and Cancer Risk. The values of As and Cd varied from 1 in children was higher than the threshold value. The cancer risk of inorganic arsenic was also higher than the acceptable range for both children and adults, but children are more exposed to both elements than adults.

Rice (Oryza sativa L.) grown in flooded paddy fields is a large contributor of inorganic arsenic (As) to human diets. The absorption pathway of arsenite via rice roots is known to be similar to tha...

Yellowknife, Northwest Territories, Canada, is located near two closed gold mines. Elevated arsenic concentrations reported in fish are a public health concern. We collected 180 samples of three sp...

To investigate the role of glutathione transferases (GSTs) in the metabolism of inorganic arsenic (iAs), we compared the disposition of iAs and its metabolites in wild-type mice and mice lacking genes encoding GST-P, -M and -T after exposure to 100 ppb iAs in drinking water. We found no differences between the two genotypes in the concentrations of total arsenic or arsenic species in urine, liver, and kidneys. No genotype-dependent differences were found in proportions of arsenicals in the tissues, and only small differences were observed in the urine. Thus, under these conditions, GST-P, -M and -T did not play a significant role in iAs metabolism in mice.

Background: The presence of toxic metals in human populations is strongly associated with chronic diseases. Aim: To determine levels of lead, chromium, cadmium, mercury and inorganic arsenic (AsIn) in the general population aged over 5 years in Antofagasta, Chile. Material and Methods: People living in Urban Antofagasta for at least five years were considered eligible. Biological samples were obtained to measure heavy metals. Results: One thousand two hundred three participants with a median age of 43 years (656 women) were studied. Their mean time of residence in the city was 30 years, and 52% smoked. Eight percent of the adult population and 12% of children had AsIn values above 35 µg/L, while 75% of the population had levels below 21.9 µg/L. The other metals were below the risk levels defined by the health authority (10 µg/L for chromium, 10 µg/L for mercury, 2 µg/L for cadmium, 5 and 10 μg/dL for blood lead for children and adults, respectively). The factors associated with high levels of AsIn in adults were male sex, living more than 200 meters from monitoring points, and low schooling. In children, the associated variables were high intake of seafood products and having a caregiver with less than 8 years of schooling. Contrary to expectations, the greatest risk of presenting altered levels of the metals occurred in the population living more than 500 meters from the identified risk sources (90% of the population). Conclusions: The findings of this study suggest that all potential sources of exposure to AsIn should be evaluated, and surveillance actions should be established to reduce involuntary exposure to this metalloid.

To describe interindividual metabolism variations and sociodemographic characteristics associated to urinary arsenic, and to estimate the arsenic contamination in water from urinary total arsenic (TAs).Women (n=1 028) from northern Mexico were interviewed about their sociodemographic characteristics and their urinary concentrations of arsenic species were measured by liquid chromatography. Inorganic arsenic (iAs) in water was estimated from urinary TAs.Women were 20-88 years old. TAs in urine ranged from p10=3.41 to p90=56.93 μg/L; 74% of women had levels6.4 μg/L. iAs in water varied from p10=3.04 to p90=202.12 μg/L; 65% of women had concentrations10 μg/L, and 41%, concentrations25 μg/L. Large variations in iAs metabolism were observed. TAs was significantly negatively associated with age and schooling, and positively with the state of residence.Exposure to iAs is an environmental problem in Mexico. Individual variations in metabolism are a challenge to design prevention and control programs.Describir las variaciones interindividuales del metabolismo y las características sociodemográficas asociadas con el arsénico urinario, así como estimar su contaminación en el agua.Se entrevistó a 1 028 mujeres del norte de México; por cromatografía de líquidos se midieron los metabolitos urinarios de arsénico y, a partir de ellos, se estimó la concentración en agua.Las mujeres tuvieron 20-88 años. El arsénico urinario varió de p10=3.41 a p90=56.93 μg/L; 74% de las mujeres tuvieron niveles6.4 μg/L. El arsénico en agua varió de p10=3.04 a p90=202.12 μg/L; 65% de las mujeres tenían concentraciones10 μg/L, y 41%,25 μg/L. Se observaron amplias variaciones en el metabolismo del arsénico. El arsénico urinario se asoció negativamente con la edad y escolaridad, y positivamente con el estado de residencia.La exposición a arsénico es un problema ambiental en México. Las variaciones individuales en su metabolismo son un desafío para diseñar programas de prevención y control.

BACKGROUND: Detoxification of inorganic arsenic (iAs) occurs when it methylates to form monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA). Lower proportions of urinary iAs and MMA, and higher proportions of DMA indicate efficient methylation. The role of B-vitamins in iAs methylation in children with low-level arsenic exposure is understudied. OBJECTIVES: Our study objective was to assess the association between B-vitamin intake and iAs methylation in children with low-level arsenic exposure (

The contents of total arsenic (tAs), inorganic arsenic (iAs), Cd, Cr, Cu, Mn, Ni, Pb, Sb, and Zn in 135 rice grain samples from Zijiang River basin were determined, and the probabilistic distribution of noncarcinogenic and carcinogenic risks associated with ingesting locally produced rice was determined by Monte Carlo simulation. Further, multivariate statistical analysis was used to analyze the potential sources of the heavy metals in rice grains. The average concentrations of the heavy metals in rice grains were ranked as follows: Mn (17.314 mg/kg) > Zn (16.043 mg/kg) > Cu (2.013 mg/kg) > Ni (1.332 mg/kg) > Cr (0.571 mg/kg) > Cd (0.283 mg/kg) > tAs (0.241 mg/kg) > Pb (0.145 mg/kg) > Sb (0.027 mg/kg). These heavy metals were significantly enriched in some rice grain samples. The analysis of potential sources indicated that As, Pb, Sb, and Zn were mainly derived from mining and smelting and agricultural activities; Cd, Cu, Mn, and Ni were mainly derived from the agricultural activities; Cr were mainly derived from the natural source. The results of Monte Carlo simulation indicated that ingestion of rice grown in the area may pose health risks for children, adult males, and adult females. The noncarcinogenic risks were mainly from As, Cd, Mn, Ni, and Sb, and the carcinogenic risk was mainly from As, Cd, and Ni. This study could provide basic information for land management and rice intake in the study area.

The arsenic (As) methylation capacity is an important determinant of the susceptibility to arsenic-related diseases. Total As (TAs) or inorganic As (iAs) was reported to associate with As methylation capacity individually, however, influencing trend and extent of their combined exposure levels on methylation capacity remains poorly understood. We measured urinary concentrations of iAs, monomethylarsonic (MMA), and dimethylarsinic (DMA) acids using HPLC-HG-AFS, and calculated the primary (PMI: (MMA+DMA)/TAs) and secondary (SMI: DMA/(MMA+DMA)) methylation capacity indexes in 209 university students in Hefei, China, a non-As endemic area. Subjects were given with a standardized questionnaire to inquire their sociodemographic characteristics. Bayesian kernal machine regression (BKMR) analysis was used to estimate the association of lnTAs and lniAs levels with methylation indices (ln%MMA, ln%DMA, lnPMI, lnSMI). The median concentration of iAs, MMA and DMA was 1.22, 0.92 and 12.17 μg/L, respectively; the proportions of iAs, MMA and DMA were 8.76%, 6.13% and 84.84%, respectively. Females had higher %DMA and lower %MMA, while males had lower %DMA and higher %MMA. The combined levels of lnTAs and lniAs showed monotonic decrease in change of ln%DMA and lnSMI other than ln%MMA, additionally, change in ln%PMI was decreased only when levels of lnTAs and lniAs were larger than their 60th percentiles compared to they were at 50th percentile. With regard to single exposure level, the lnTAs showed positive correlation with ln%DMA, lnPMI, lnSMI when lniAs was set at a specific level; while lniAs showed negative correlation with ln%DMA, lnPMI, lnSMI when lnTAs was set at a specific level; and all the dose-response relationships were nonlinear. Our results suggested that combined levels of TAs and iAs played an important role in reducing As methylation capacity, expecially iAs; and the reduction only occured when TAs and iAs were up to a certain combined level.

An inter-laboratory study was carried out to characterize a candidate hijiki seaweed for its concentrations of total arsenic and water-soluble arsenic compounds, particularly arsenosugar compounds. The candidate material, a dried hijiki seaweed powder, was analyzed by individual techniques in two laboratories. The water-soluble arsenic compounds were separated by anion exchange, and reversed-phase columns, and As(V), DMA and four kinds of arsenosugars, namely glycerol (-OH), phosphate (-PO4), sulfonate (-SO3), and sulfate (-SO4) types were detected by HPLC-ICP-MS. The methods applied were validated by analyzing a second sample, the NMIJ CRM 7405-a hijiki seaweed, which is certified for both total arsenic and As(V). Techniques for the inter-laboratory study, extraction efficiencies under different extraction conditions, some chromatographic techniques and sequential extraction were investigated. The results from the two laboratories for the candidate hijiki material showed good agreement within the measurement uncertainties for total and water-soluble arsenic compounds.

Phenylarsonic acid compounds could be oxidized by manganese oxides in surface soils, resulting in quick release of inorganic arsenic. This study investigated the structure–reactivity relationships ...

The effects of nutrient distribution and structure on the behavior and speciation of dissolved inorganic arsenic (DIAs) in coastal waters were analyzed based on the data of 48 surface water samples collected in the southwestern coast of Laizhou Bay and its adjacent rivers (SWLZB). The concentration of DIAs in the SWLZB ranged from 0.016 to 0.099 μmol l −1 and generally decreased from west to south. The inshore waters exhibited higher DIAs level than the open ocean. The As 5+ /As 3+ ratio was significantly positively correlated with the concentration of TDN, NO 3 -N, PO 4 -P, DSi, Chl- a and DO. The concentration of DIAs was strongly correlated with the concentration of PO 4 -P and DSi, suggesting that adsorption/desorption was an important process for regulating the total DIAs concentration. The results indicated that the distribution of nutrients might well be an important environmental factor affecting the speciation and behavior of DIAs in surface water of the SWLZB.

The measurement of arsenic has received considerable attention due to its contaminant to environment and harm on human safety. This paper provides an overview of optical methods on the measurement of inorganic arsenic (arsenite and arsenate). We present and discuss the colorimetric, scattering, and fluorimetric strategies for inorganic arsenic detection based on the organic/biological molecules and their coupling with inorganic nanomaterials. The detection mechanism for arsenite and arsenate is summarized and the advantages/limitations are highlighted in the present review. In addition, prospects and future developments of optical sensors for arsenic analysis are also proposed.

It is estimated that approximately 200 million people are exposed to arsenic levels above the World Health Organization provisional guideline value, and various agencies have indicated the need to reduce this exposure. In view of the difficulty of removing arsenic from water and food, one alternative is to reduce its bioavailability (the amount that reaches the systemic circulation after ingestion). In this study, dietary components [glutathione, tannic acid, and Fe(III)] were used to achieve this goal. As(III) or As(V) (1 mg/kg body weight) was administered daily to BALB/c mice, along with the dietary components, for 15 days. The results confirm the efficacy of Fe(III) and glutathione as reducers of arsenic bioavailability and tissue accumulation. Also, these treatments did not result in reductions of Ca, K, P, and Fe contents in the liver. These data suggest that use of these two compounds could be part of valid strategies for reducing inorganic arsenic exposure in chronically exposed populations., This work was supported by the Spanish Ministry of Economy and Competitiveness (AGL2015-68920-R) for which the authors are deeply indebted. Gabriela de Matuoka e Chiocchetti received a fellowship from the Brazilian Government (CAPES- BEX1086/14-6) to carry out this study.

The speciation of arsenic in wet and dry deposition are ambiguously described in current literature. Presented here is a 2 year study quantifying arsenic species in atmospheric deposition collected daily from an E. Atlantic coastal, semirural site, with comparative urban locations. Inorganic arsenic (As

The multi-walled carbon nanotubes-branched polyethyleneimine (MWCNTs-BPEI) adsorbent composite material was employed to separate and pre-concentrate As(V) in water samples. The characterization of MWCNTs-BPEI by X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopy showed successful modification of the composite. The MWCNTs-BPEI composite exhibited selective retention of As(V) in the presence of As(III) in water samples of pH 7 using 40 mg of composite as adsorbent. The pre-concentrated As(V) was quantified using inductively coupled plasma-mass spectrometry (ICP-MS). A limit of detection (LOD) of 0.0537 µg L

A diffusive gradients in thin films (DGT) method using a new high-capacity cerium oxide (CeO2) binding gel, for the first time, was developed for measuring dissolved inorganic arsenic in freshwater and seawater. The capacities of the new CeO2 binding gel were 682 μg and 375 μg for AsIII and AsV, respectively. The masses of AsIII and AsV accumulated by CeO2-DGT device increased linearly with time and agreed well with the theoretical value calculated by DGT equation. The arsenic accumulation by CeO2-DGT was independent of pH (4.05–9.04) and ionic strength (0.1–750 mM), and common anions including CO32−, SO42−, Cl− and PO43− had no obvious interference. CeO2-DGT showed excellent long-term deployment performance in freshwater and synthetic seawater. Field trials with CeO2-DGT achieved successfully the time-weighted-average concentrations of total inorganic arsenic in reservoir water (1.38 ± 0.09 μg/L) and coastal seawater (0.45 ± 0.06 μg/L). The results were comparable to those measured by grab sampling. The proposed method was reliable and robust for in-situ measurements of dissolved inorganic arsenic in environmental waters.

BACKGROUND AND AIM: Arsenic methylation—the conversion of inorganic arsenic (iAs) to less toxic monomethyl (MMA) and dimethyl (DMA) species—could modify the developmental and reproductive toxicity ...

Toxicity of arsenic compounds depends on the chemical structure as well as the concentration. Thus, separation of the toxic arsenic species should precede the quantification for the accurate toxicity assessment. Ion chromatography inductively coupled plasma mass spectrometry (IC-ICP-MS) has been the most popular method for separation and quantification of toxic arsenic species. However, the method requires complex instrument, elaborate sample preparation, and long analysis time. In this work, toxic inorganic arsenic species in water was separated by the simple solid phase extraction (SPE) using a strong anion-exchange membrane filter, and then the membrane filter was analyzed by femtosecond laser ablation inductively coupled plasma mass spectrometry (fs-LA-ICP-MS). The pH value of the sample was adjusted to 4 using ammonium hydroxide and phosphoric acid for the complete separation of the toxic inorganic arsenic from the other organic arsenics. The linear dynamic range was from 0.5 to 1000 μg/kg, and the correlation coefficient was 0.99989. The recovery efficiency was 96‑106%. The detection limit of the inorganic arsenic was 0.028 μg/kg. Our results indicate that SPE-fs-LA-ICP-MS provides enough analytical performance to analyze the toxic inorganic arsenic in water at the level of parts per trillion using the simple separation method and the rapid laser ablation sampling.

During sediment remediation, adsorbent addition is an effective technology for the removal of contaminants but the cost is often high. In this study, a low-cost adsorbent, ceramsite, made from contaminated riverbed sediment was synthesized. The Fe-modified ceramsite (FMC) was used as adsorbent to remove arsenate from aqueous solutions and reduce the inorganic arsenic release from contaminated sediments. Kinetic studies showed that chemisorption mainly governed the adsorption process while batch studies yielded the theoretical adsorption capacity for arsenate of 10.63 mg/g at pH = 7 condition. Co-existing anions and pH have no significant impact on the adsorption process. In the regeneration studies, 91, 86, and 80% of the adsorption capacity were recovered in 3 cycles. In-situ remediation trials revealed that the addition of the adsorbent to sediment surface significantly reduced the release of inorganic arsenic into aqueous system, with a reduction efficiency of 86%. Furthermore, the species of the arsenic in the surface layer was significantly inactivated from an active state to a stable state. These findings highlight the application of the FMC as a facile and cost-effective adsorbent for containment of arsenic in solutions and sediments, demonstrating that they are highly applicable for practical cases. HIGHLIGHTS Contaminated sediment was used as the support for the iron oxides.; FMC was used as an adsorbent and remediator.

The toxic metalloid inorganic arsenic (iAs) is widely distributed in the environment. Chronic exposure to iAs from environmental sources has been linked to a variety of human diseases. Methylation of iAs is the primary pathway for metabolism of iAs. In humans, methylation of iAs is catalyzed by arsenic (+ 3 oxidation state) methyltransferase (AS3MT). Conversion of iAs to mono- and di-methylated species (MAs and DMAs) detoxifies iAs by increasing the rate of whole body clearance of arsenic. Interindividual differences in iAs metabolism play key roles in pathogenesis of and susceptibility to a range of disease outcomes associated with iAs exposure. These adverse health effects are in part associated with the production of methylated trivalent arsenic species, methylarsonous acid (MAs(III)) and dimethylarsinous acid (DMAs(III)), during AS3MT-catalyzed methylation of iAs. The formation of these metabolites activates iAs to unique forms that cause disease initiation and progression. Taken together, the current evidence suggests that methylation of iAs is a pathway for detoxification and for activation of the metalloid. Beyond this general understanding of the consequences of iAs methylation, many questions remain unanswered. Our knowledge of metabolic targets for MAs(III) and DMAs(III) in human cells and mechanisms for interactions between these arsenicals and targets is incomplete. Development of novel analytical methods for quantitation of MAs(III) and DMAs(III) in biological samples promises to address some of these gaps. Here, we summarize current knowledge of the enzymatic basis of MAs(III) and DMAs(III) formation, the toxic actions of these metabolites, and methods available for their detection and quantification in biomatrices. Major knowledge gaps and future research directions are also discussed.

Chitosan is a kind of biodegradable natural polysaccharide, and it is a very promising adsorber material for removing metal ions from aqueous solutions. In this study, chitosan-based magnetic adsorbent CMC@Fe3O4 was synthesized by a one-step method using carboxymethyl chitosan (CMC) and ferric salts under relatively mild conditions. The Fe3O4 microspheres were formed and the core–shell structure of CMC@Fe3O4 was synthesized in the meantime, which was well characterized via SEM/TEM, XRD, VSM, FT-IR, thermo gravimetric analysis (TGA), XPS, size distribution, and zeta potential. The effects of initial arsenic concentration, pH, temperature, contact time, and ionic strength on adsorption quantity of inorganic arsenic was studied through batch adsorption experiments. The magnetic adsorbent CMC@Fe3O4 displayed satisfactory adsorption performance for arsenic in water samples, up to 20.1 mg/g. The optimal conditions of the adsorption process were pH 3.0, 30−50 °C, and a reaction time of 15 min. The adsorption process can be well described by pseudo-second-order kinetic model, suggesting that chemisorption was main rate-controlling step. The Langmuir adsorption model provided much higher correlation coefficient than that of Freundlich adsorption model, indicating that the adsorption behavior is monolayer adsorption on the surface of the magnetic adsorbents. The above results have demonstrated that chitosan-based magnetic adsorbent CMC@Fe3O4 is suitable for the removal of inorganic arsenic in water.

The extraction behaviors for inorganic arsenic removal under batch system using food additives at actual pH with other conditions, concentration, extraction volume, and extraction time were studied. In batch extraction, 100 rpm orbital shaker speed at room temperature was held constant. The results showed that EDTA was the most effective extractant for inorganic arsenic removal. Afterward, with the increase of EDTA concentration, at 0.10 M, inorganic arsenic removal increased to reach 100% extraction efficiency. Batch extraction using 0.10 M EDTA at the volume of 75 mL for 120 min shaking was optimal giving the highest extraction efficiency, up to 98%. Under optimized conditions, the amounts of arsenic in real seaweed samples were reduced from 4.60 ± 0.15 to 0.09 ± 0.01 mg kg−1-dry weight, lower than that of standard levels of community seaweed product. Therefore, these results provided strong evidence of the promising procedure for arsenic removal from Gracilaria fisheri seaweed by batch extraction.

Abundant epidemiological evidence has shown that there is a strong causal relationship between long-term exposure to inorganic arsenic (iAs) through drinking water and a few types of cancer (e.g., lung and bladder cancer). Traditionally, a linear low-dose extrapolation assumption was applied in risk assessment for iAs which resulted in a relatively conservative cancer risk estimate. Growing biological evidence suggests that the mode of action of iAs-induced cancer follows a threshold process (e.g., sufficient concentration of trivalent arsenic is required to disrupt normal cellular function). In this study, we applied the benchmark dose (BMD) methodology to model the relationship between the relative risk of bladder and lung cancer and the iAs concentration in drinking water using the high-quality epidemiological data reported in recently published papers, with a special focus on the low exposure range (i.e.,150 μg/L). Because of its biological plausibility and statistical flexibility, the Hill model has been chosen to model the data under a Bayesian framework. A Bayesian hierarchal model together with a bootstrap method for exposure estimation were applied to quantify uncertainty from various sources, including the within-study, between-study, and exposure uncertainties. Dose-response assessment results obtained from a number of alternative model structures and methods consistently demonstrate a threshold type dose-response curve with a threshold in the range between 40-60 μg/L of iAs concentration in drinking water. The BMD for iAs in drinking water associated with 0.1 % increase in relative risk of bladder cancer is 42.2 μg/L (BMDL 39.2 μg/L); for 0.05 % increase, the BMD is 41.6 μg/L (BMDL 38.6 μg/L). For lung cancer, the two counterpart BMD estimates are 57.0 μg/L (BMDL 43.6 μg/L) and 55.7 μg/L (BMDL 42.5 μg/L) for 0.1 % and 0.05 % increase, respectively. These analyses provide additional statistical support for a non-linear dose response for cancer risk from inorganic arsenic which may have important policy implications.

Background: Evidence evaluating the association between low- to moderate- inorganic arsenic (iAs) exposure and heart disease (HD) mortality in the general US population is limited. We evaluated the...

Autism spectrum disorder (ASD) is a complex neurobehavioral disorder that is believed to be multifactorial in origin. As the incidence of ASD is rising along with industrialization, and because certain metals have been linked to neurological problems, it is important to consider whether such metals may play a role in the development of ASD. Previously, we performed a meta-analysis of existing literature to examine the potential link between inorganic arsenic and lead exposure and ASD. This is a continuation of that study investigating the association of the exposure to aluminum (Al), cadmium (Cd), and mercury (Hg) and ASD. These metals were chosen because they are abundant in our environment, are known to cause neurological problems in humans, and have multiple published studies examining their potential links with ASD. Following the same approach as our previous paper, we conducted a systematic review of the existing literature and performed a meta-analysis to evaluate the current evidence regarding these metals and their potential relationship with autism. We reviewed 18 studies on Al, 18 on Cd, and 23 on Hg, and the individual studies showed inconsistent results. When the measurements were integrated into the meta-analysis, we found significant associations between all the metals and ASD, but the associations were not always in the same direction. Levels of Hg in hair, urine, and blood were all positively associated with ASD. Levels of Al in hair and urine were positively associated with ASD, while levels of Al in blood were negatively associated. In comparison, levels of Cd in hair and urine were negatively associated with ASD. These results imply that, while these metals are all neurotoxic, their impact on the development of ASD and their modes of action could be different. Further research is warranted to examine the longitudinal effects of these toxic metals on the risk of ASD, to assess the critical period when exposure may affect development, and to investigate potential factors that may enhance or ameliorate the effect of metals. Overall, these findings support policies that advocate limiting exposure to neurotoxic metals, particularly for pregnant women and young children, in order to help reduce the rising incidence of ASD.

OBJECTIVES: Exposure to inorganic arsenic through drinking water is a threat for public health. Using the arsenic-containing water in the long-term causes a variety of skin diseases, high blood pressure, and skin cancer. Arsenic also damages the nervous system. A wide range of studies have studied the effect of arsenic in drinking water on the level of intelligence in children. METHODS: For the purpose of our research, we searched three electronic databases including Scopus, Web of Science, and Medline (PubMed) in English from 2000 to January 2018. We used the dose-response meta-analysis through applying random effect models in order to estimate the pooled association (with a 95% uncertainty) between water arsenic concentration and intelligence level. RESULTS: Using a two-stage random effect model to investigate the dose-response association between arsenic concentration and Intelligence Quotient scale, we estimated a significant linear association as −0.08 (95% CI: −0.14, −0.01). Actually, for each unit increase in arsenic concentration (one microgram per liter), intelligence quotient scale decreases by 0.08%. CONCLUSIONS: Considering the significance of the relationship between arsenic concentration in drinking water and the level of intelligence quotient as an important factor in training, the level of arsenic and its associated risks should be decreased in water resources.

Cadmium in the diet is of concern as it is a renal toxicant and a carcinogen, with a half-life in the body measured in decades. Inorganic arsenic is a chronic carcinogen. For many subpopulations, rice and rice products may be the dominate source of cadmium and inorganic arsenic. In particular, rice porridge, cereal and cake are widely used to feed infants (children

Direct or indirect exposure to inorganic arsenic (iAs) in the forms of AsIII (arsenite) and AsV (arsenate) through consumption of As-contaminated food materials and drinking water leads to arsenic poisoning. Rice (Oryza sativa L.) plant potentially accumulates a high amount of iAs from paddy fields than any other cereal crops. This makes it to be a major source of iAs especially among the population that uses it as their dominant source of diet. The accumulation of As in human bodies poses a serious global health risk to the human population. Various conventional methods have been applied to reduce the arsenic accumulation in rice plant. However, the success rate of these techniques is low. Therefore, the development of efficient and effective methods aimed at lowering iAs toxicity is a very crucial public concern. With the current advancement in technology, new strategies aimed at addressing this concern are being developed and utilized in various parts of the world. In this review, we discuss the recent advances in the management of iAs in rice plants emphasizing the use of nanotechnology and biotechnology approaches. Also, the prospects and challenges facing these approaches are described.

Background: Chronic exposure to inorganic arsenic (iAs) is a significant public health problem. Methylation of iAs by arsenic methyltransferase (AS3MT) controls iAs detoxification and modifies risk...

We investigated the effect of temperature during the ripening period on the rice yield and arsenic (As) concentration in brown rice, using temperature gradient chambers (TGCs). Rice grown in Wagner pots (1/5000a) was placed in three TGCs (each TGC was set at four temperature levels: ambient, mildly-high temperature, moderately-high temperature, and super-high temperature) from one week after heading until harvest. In the TGCs, a range of mean air temperatures was observed in the range of 2 &deg, C above the ambient temperature. There was a significant negative correlation between the brown rice yield and the air and soil temperatures, and the increase in air and soil temperatures resulted in a decrease in the yield. The reduction in yield was significantly mitigated by the application of calcium silicate. The concentration of As in the brown rice was significantly positively correlated with the air and soil temperature, and the concentration of As increased with increasing air and soil temperatures. When calcium silicate was applied, the concentration of As in brown rice was significantly lower at all temperature ranges, and its application was effective in reducing the arsenic concentration even at high temperatures. These results suggest that the application of silicate material may help mitigate the decrease in yield and the increasing As concentration in brown rice even under high-temperature conditions.

Arsenic (As) removal is of major significance because inorganic arsenic is highly toxic to all life forms, is a confirmed carcinogen, and is of significant environmental concern. As contamination in drinking water alone threatens more than 150 million people all over the world. Therefore, several conventional methods such as oxidation, coagulation, adsorption, etc., have been implemented for As removal, but due to their cost-maintenance limitations; there is a drive for advanced, low cost nanofiltration membrane-based technology. Thus, in order to address the increasing demand of fresh and drinking water, this review focuses on advanced nanofiltration (NF) strategy for As removal to safeguard water security. The review concentrates on different types of NF membranes, membrane fabrication processes, and their mechanism and efficiency of performance for removing As from contaminated water. The article provides an overview of the current status of polymer-, polymer composite-, and polymer nanocomposite-based NF membranes, to assess the status of nanomaterial-facilitated NF membranes and to incite progress in this area. Finally, future perspectives and future trends are highlighted.

Cadmium, inorganic arsenic and, potentially, dimethyl arsenic acid are carcinogens widely elevated in rice. Here it was identified that the food-safe and common cadmium chelator citric acid efficiently removed cadmium from intact grain via pre-soaking procedure, while also reducing arsenic species. A twostep pre-soaking stage was developed whereby rice was first incubated, at ambient temperature, in 1 M citric acid for 12 h, and then in 1 M calcium carbonate for another 12 h, the latter step to neutralize pH, followed by cooking. When 10 different individual types of rice were processed in such a way this resulted in removal rates of 79% for cadmium, 81% for inorganic arsenic and a 66% for DMA. The technology is particularly suitable for bulk food processing and could be deployed in the most cadmium and arsenic impacted regions where rice is a staple.

A survey of highly toxic arsenic compounds, together with some other elements was carried out on 40 polished rice samples (white, basmati and parboiled) and 10 brown rice samples from the Slovenian market. The average total As concentration was 157 ± 60 μg kg−1; highest levels were found in parboiled and brown rice and lowest in basmati. The average inorganic As concentration was 90 ± 35 μg kg−1. Dimethylarsinic acid and monomethylarsonic acid, which also exhibit high toxicity levels in some cases constitute >50% of total arsenic and might deserve more attention. Contrary to other foods, the total arsenic concentration in rice may even be a better health hazard indicator than the inorganic arsenic concentration. Elemental analysis of rice revealed large differences between polished and brown rice, especially for Mg, Mn, P, Fe and K, which were 2–4 times higher in brown rice than in polished rice.

Background: There have been concerns related to inorganic arsenic (iAs) in rice and the risk of chronic toxicity in human beings, especially children. Rice is a common constituent of pet food, and dogs often eat the same food on a continual daily basis for long periods of time. Therefore, the purpose of this study was to assess the risk of chronic iAs exposure in rice-based diet-fed dogs. Methods: Hair iAs level was measured in seven rice-based diet-fed dogs (mean age 3.8 years) and in nine dogs that did not consume any rice (mean age 4.4 years), using inductively coupled plasma mass spectrometry. Results: The hair iAs level was significantly higher (P=0.005) in dogs fed a rice-based diet (mean 0.143 µg/g) than in dogs that did not consume any rice (mean 0.086 µg/g), while age and sex did not show associations with hair iAs level. Conclusion: The results suggest that eating a rice-based diet for long periods of time represents a risk for chronic iAs exposure in dogs.

The exposure of Finnish 1-year-olds to cadmium, lead and inorganic arsenic via food and drinking water was determined. The food consumption data consisted of 3-day records from 1010 children aged 12 months, collected during 2002 to 2005 in Southwest Finland. One fifth of these children were still breastfed when the consumption data were collected and their exposure was assessed separately from the non-breastfed children. The heavy metal concentration data in foodstuffs were mainly analysis results from national authorities and they were mostly from the years 2005 to 2012. Dietary exposure assessment was performed probabilistically using the online program MCRA. With middle bound estimates, 89% of the non-breastfed and 56% of the breastfed children exceeded the tolerable weekly intake of cadmium. The benchmark dose (BMDL01) for neurological damage caused by lead was exceeded by 60% of the non-breastfed and by 50% of the breastfed children, while the lowest BMDL01 for cancer risk increase caused by inorganic arsenic was exceeded by 77% of the non-breastfed and by 61% of the breastfed children. The assessment did not include the unknown heavy metal exposure from breast milk. Heavy metal exposure differences between the boys and the girls were also assessed. Breastfed girls had significantly higher heavy metal exposure relative to their bodyweight than the breastfed boys, while in the non-breastfed group there were no differences by sex.

Quantitative relationship between intake of inorganic arsenic (iAs) and urinary excretion of iAs and its metabolite, methylarsonic acid (MMA), was investigated for 150 adult Japanese subjects. Duplicate diet was used for the determination of intake and first void of urine on the next day of duplicate diet sampling was used for urinary iAs + MMA determination. Speciation analysis of arsenic in diet and urine was carried out with liquid chromatography-inductively coupled plasma mass spectrometry. Geometric mean iAs intake of the subjects was 0.349 μg/kg/day and that of urinary iAs + MMA concentration was 5.20 ng As/mL (specific gravity (SG) corrected) or 4.05 ng As/mg creatinine (Cre). There was a significant positive correlation between iAs intake and urinary iAs + MMA concentration: the correlation coefficient between intake and Cre-corrected urinary concentration (r = 0.544) was greater than that between intake and SG-corrected concentration (r = 0.458). The regression equation of intake-excretion was: log 10 [ d a i l y i n t a k e ] = 0.451 × log 10 [ c r e a t i n i n e c o r r e c t e d u r i n a r y i A s + M M A ] + 0.814 . This equation has a practical value for converting urinary As levels, measured as a biomarker of exposure in epidemiologic study, to dietary intake levels in the future risk assessment.

The export of e-waste from industrialized to developing countries has led to the formation of a large-scale informal e-waste recycling sector in Accra, Ghana. During recycling processes, workers are exposed to several hazardous substances, such as heavy metals. As a common component of e-waste, inorganic arsenic can be released during e-waste recycling processes. The aim of this study was to assess the exposure to inorganic arsenic species in e-waste workers compared to a control group. N = 84 e-waste workers and n = 94 control subjects were included in this analysis. Inorganic arsenic species were determined in urine samples using HPLC-ICP-MS. E-waste workers showed higher median concentrations of As(III), As(V), MMA, DMA and the sum of inorganic arsenic in comparison to the control group. More than 80% of the e-waste workers exceeded the acceptable concentration (14 μg/L), which was significantly higher in comparison to the control group (70%). The tolerable concentration (40 μg/L) was exceeded in 17.2% of the participants, meaning a statistically relevant risk of developing cancer due to arsenic exposure throughout their (working) life. In conclusion, the exposure to inorganic arsenic is not only a problem of informal e-waste recycling, but a major public health concern that needs further investigation.

Diet is the major route of exposure to arsenic (As), with rice and rice products as food groups with relatively high As levels. This study was aimed at determining the concentrations of total arsenic (total As) and inorganic arsenic (InAs) in rice and rice products. The dietary exposure and health risks for infant and adult population were also estimated. Brown varieties of rice showed higher As levels than white rice (189 vs 132 μg/kg). Toddlers and infants presented the highest dietary exposure to total As (4.08 and 3.99 μg/day, respectively), but unlike the rest of population groups, the main contributor was organic arsenic. Focusing on the contribution of each food item, rice represents the major contributor to InAs exposure by the adult population, while baby cereals and breakfast cereals are the most important contributors for infant exposure. Anyhow, none of the population groups exceeded the lower limit of the BMDL01 range (from 0.3 to 8.0 μg/kg body weight/day) set by EFSA in any of the three exposure scenarios (high, mean, and low) hereby considered. Finally, consumption of white rice varieties or pre-cooked rice, as well as washing rice before cooking, are recommended in order to minimize the exposure to arsenic.

Inorganic arsenic (As) is one of the most ubiquitous and toxic substances with widespread health effects on human populations and biodiversity. Although arsenic is a frequent surface water pollutant, there is scant evidence about neurotoxicity in aquatic species in different stages of development. In the present study, we investigated the neurobehavioral effects of chronic exposure to environmentally relevant doses of arsenic. We exposed zebrafish to 50 and 500 ppb during the larval, juvenile, and adult stage (from 4 h to 150 days postfertilization). We then used broad behavioral screening to evaluate motor function, social behavior, learning and memory, and anxiety-like behaviors. Our results show that arsenic exposure to 500 ppb alters motor function from the embryo to the adult stage. Furthermore, during the adult phase, associative learning and the sensorimotor response are affected with both high and low doses of As, respectively. Notably, exposure to 500 ppb of As induces behaviors associated with anxiety, during the juvenile and adult phase but not the larval stage, without changes in whole-body cortisol levels. These results indicate that chronic exposure to arsenic during their lifespan is capable of producing alterations in different behavioral markers in aquatic vertebrates.

Arsenic metabolism in macroalgae has gained considerable interest because it controls the risk of arsenic contamination in algal products. This article reviews the total and inorganic arsenic contents in seaweeds, including 92 (red), 154 (brown) and 36 (green) species belonging to Rhodophyta, Phaeophyta and Chlorophyta, respectively. All the data collected from the published seaweeds support the conclusion that the total and inorganic arsenic contents in seaweeds are category-dependent, with species from Phaeophyta having the highest and those from Chlorophyta having the lowest. Total arsenic contents in the top 10 species of Phaeophyta are all over 100 mg kg−1 DW, but those in the top 7 species of Rhodophyta and the top 3 species of Chlorophyta vary from 20 to 50 mg kg−1 DW and 10 to 15 mg kg−1 DW, respectively. The average total and inorganic arsenic contents in species of Phaeophyta are significantly (P

This study aimed to evaluate the reduction of total, organic, and inorganic arsenic content in Hizikia fusiforme (hijiki). Initially, the six most common arsenic compounds in hijiki and its organs were evaluated, among which only arsenate and arsenobetaine were detected. Thereafter, the entire plant, including the stalk and leaves, was treated with heat and NaCl solution, individually and in combination. Heating at 90 °C for 5 min significantly reduced arsenic content in hijiki by approximately 33–80%. Treatment with NaCl solution significantly reduced arsenic content in hijiki, except for arsenobetaine content in the stalk. Combinatorial treatment further decreased arsenic content by more than 5–20%. In conclusion, consumption of hijiki after boiling at 90 °C and soaking in 2% NaCl solution reduces the intake of inorganic arsenic by consumers.

Beef and poultry as well as cattle and chicken livers are staple food items for Brazilian population, and previous studies had detected arsenic levels in these foods. This study aims to evaluate the risk of exposure to total and inorganic arsenic by meat intake in three age groups from Brazil (11–16, 16–21, and > 21 years). Our hypotheses are (i) that there is differences in the risk of exposure between age groups and (ii) the older individuals (> 21 years) are under higher risk. To test these hypotheses, we calculated the probabilistic estimated daily intake of total As (TAsEDI) from poultry, beef, cattle liver, and chicken liver, and the probabilistic estimated incremental lifetime skin, bladder, and lung cancer risk (ILCR) associated with inorganic As ingestion from poultry only. TAsEDI and ILCR from poultry differed among groups which confirm the first hypothesis. However, TAsEDI and ILCR results cannot support the second hypothesis. Even though the age groups are under a low risk of exposure to As by meat intake, the results indicate that bladder/lung cancer risk (from poultry intake) slightly exceeds the safe limits in the older population.

A commercial arsenic field kit designed to measure inorganic arsenic (iAs) in water was modified into a field deployable method (FDM) to measure iAs in rice. While the method has been validated to give precise and accurate results in the laboratory, its on-site field performance has not been evaluated. This study was designed to test the method on-site in Malawi in order to evaluate its accuracy and precision in determination of iAs on-site by comparing with a validated reference method and giving original data on inorganic arsenic in Malawian rice and rice-based products. The method was validated by using the established laboratory-based HPLC-ICPMS. Statistical tests indicated there were no significant differences between on-site and laboratory iAs measurements determined using the FDM (p = 0.263, ά = 0.05) and between on-site measurements and measurements determined using HPLC-ICP-MS (p = 0.299, ά = 0.05). This method allows quick (within 1 h) and efficient screening of rice containing iAs concentrations on-site.