Lagoons are ecosystems for biodiversity and the livelihoods of coastal communities. The main objective of the study was to analyze the variability of arsenic concentrations in gastropods and bivalves in the Aby and Te...Lagoons are ecosystems for biodiversity and the livelihoods of coastal communities. The main objective of the study was to analyze the variability of arsenic concentrations in gastropods and bivalves in the Aby and Tendo lagoons, taking into account spatial, seasonal and hydrological variations. The study was carried out in four stages spread over two successive hydroclimatic cycles, including two seasons during the rainy season and two more during the dry season. The samples were taken in two areas of the Aby and Tendo lagoons. Arsenic levels were measured by ICP-MS. The results showed that mean arsenic concentrations in the muscles of organisms in Aby Lagoon ranged from 0.01 to 1.26 μg As/g, with a mean and median of 0.17 and 0.06 μg As/g, respectively. Fish had the highest levels of arsenic, followed by crustaceans, while molluscs and plants had lower and comparable concentrations of As. Arsenic concentrations in tilapia and jawbones varied significantly between sites and seasons, with higher concentrations at Tendo and during the rainy season. Arsenic concentrations in gastropods and bivalves were significantly higher than those of other species, with averages of 0.74 and 1.03 mg As/kg, respectively.展开更多
Arsenic toxicity,imposed mainly by arsenic-contaminated groundwater,is considered a critical threat to global communal health,as there is no specific and proven conventional therapy for chronic arsenic toxicity,i.e.,a...Arsenic toxicity,imposed mainly by arsenic-contaminated groundwater,is considered a critical threat to global communal health,as there is no specific and proven conventional therapy for chronic arsenic toxicity,i.e.,arsenicosis,which is an insidious global public health menace affecting 50 countries.Alternative options should,therefore,be explored for the mitigation of arsenicosis.Literature survey reveals several natural compounds from plants possess significant protective efficacy against arsenic toxicity in chiefly preclinical and few clinical investigations.The studies on the ameliorative effects of plant-derived natural compounds against arsenic toxicity published in the last 25 years are collated.Forty-eight plant-based natural compounds possess alleviative effects on experimental arsenic-induced toxicity in animals,six of which have been reported to be clinically effective in humans.A potential nutraceutical or therapeutic candidate against arsenicosis for humans may thus be developed with the help of recent advancements in research in this area,along with the currently available treatments.展开更多
Objective Arsenic(As) and fluoride(F) are two of the most common elements contaminating groundwater resources. A growing number of studies have found that As and F can cause neurotoxicity in infants and children, lead...Objective Arsenic(As) and fluoride(F) are two of the most common elements contaminating groundwater resources. A growing number of studies have found that As and F can cause neurotoxicity in infants and children, leading to cognitive, learning, and memory impairments. However, early biomarkers of learning and memory impairment induced by As and/or F remain unclear. In the present study, the mechanisms by which As and/or F cause learning memory impairment are explored at the multi-omics level(microbiome and metabolome).Methods We stablished an SD rats model exposed to arsenic and/or fluoride from intrauterine to adult period.Results Arsenic and/fluoride exposed groups showed reduced neurobehavioral performance and lesions in the hippocampal CA1 region. 16S rRNA gene sequencing revealed that As and/or F exposure significantly altered the composition and diversity of the gut microbiome, featuring the Lachnospiraceae_NK4A136_group, Ruminococcus_1, Prevotellaceae_NK3B31_group, [Eubacterium]_xylanophilum_group. Metabolome analysis showed that As and/or F-induced learning and memory impairment may be related to tryptophan, lipoic acid, glutamate, gamma-aminobutyric acidergic(GABAergic) synapse, and arachidonic acid(AA) metabolism. The gut microbiota, metabolites, and learning memory indicators were significantly correlated.Conclusion Learning memory impairment triggered by As and/or F exposure may be mediated by different gut microbes and their associated metabolites.展开更多
Objective:To explore the cardioprotective effect of hesperidin against arsenic trioxide-induced cardiac toxicity in rats.Methods:Cardiac toxicity was induced by oral administration of 4 mg/kg arsenic trioxide for 30 d...Objective:To explore the cardioprotective effect of hesperidin against arsenic trioxide-induced cardiac toxicity in rats.Methods:Cardiac toxicity was induced by oral administration of 4 mg/kg arsenic trioxide for 30 days.Hematological,biochemical,electrocardiography,echocardiography,and histopathological examinations were performed.Results:Hesperidin decreased the neutrophil-to-lymphocyte ratio,calcium,creatine kinase-myoglobin binding,lactate dehydrogenase,IL-6,and lipid peroxidation,as well as increased sodium and potassium concentration and superoxide dismutase and catalase activity in arsenic trioxide-intoxicated rats.Moreover,it reduced peak systolic velocity and end-diastolic velocity while increasing heart rate.Arsenic trioxide-induced histopathological damage to cardiac tissue was prominently alleviated by hesperidin treatment.Conclusions:Hesperidin attenuates arsenic trioxide-induced cardiac toxicity in rats.Therefore,it can be further explored as a cardioprotective agent.展开更多
Arsenic is one of the main harmful elements in industrial wastewater.How to remove arsenic has always been one of the research hotspots in academic circles.In the process of arsenic removal by traditional sulfuration,...Arsenic is one of the main harmful elements in industrial wastewater.How to remove arsenic has always been one of the research hotspots in academic circles.In the process of arsenic removal by traditional sulfuration,the use of traditional sulfurizing agent will introduce new metal cations,which will affect the recycling of acid.In this study,phosphorus pentasulfide (P_(2)S_(5)) was used as sulfurizing agent,which hydrolyzed to produce H_(3)PO_(4) and H_(2)S without introducing new metal cations.The effect of ultrasound on arsenic removal by P_(2)S_(5) was studied.Under the action of ultrasound,the utilization of P_(2)S_(5) was improved and the reaction time was shortened.The effects of S/As molar ratio and reaction time on arsenic removal rate were investigated under ultrasonic conditions.Ultrasonic enhanced heat and mass transfer so that the arsenic removal rate of 94.5%could be achieved under the conditions of S/As molar ratio of 2.1:1 and reaction time of 20 min.In the first 60 min,under the same S/As molar ratio and reaction time,the ultrasonic hydrolysis efficiency of P_(2)S_(5) was higher.This is because P_(2)S_(5) forms ([(P_(2)S_(4))])^(2+)under the ultrasonic action,and the structure is damaged,which is easier to be hydrolyzed.In addition,the precipitation after arsenic removal was characterized and analyzed by X-ray diffraction,scanning electron microscope-energy dispersive spectrometer,X-ray fluorescence spectrometer and X-ray photoelectron spectroscopy.Our research avoids the introduction of metal cations in the arsenic removal process,and shortens the reaction time.展开更多
Clinically,arsenic trioxide(ATO)was applied to the treatment of acute promyelocytic leukemia(APL)as a reliable and effective frontline drug.However,the administration regimen of AsⅢwas limited due to its fast clearan...Clinically,arsenic trioxide(ATO)was applied to the treatment of acute promyelocytic leukemia(APL)as a reliable and effective frontline drug.However,the administration regimen of AsⅢwas limited due to its fast clearance,short therapeutic window and toxicity as well.Based on CD71 overexpressed on APL cells,in present study,a transferrin(Tf)-modified liposome(LP)was established firstly to encapsulate AsⅢin arsenic-nickel complex by nickel acetate gradient method.The AsⅢ-loaded liposomes(AsLP)exhibited the feature of acid-sensitive release in vitro.Tf-modified AsLP(Tf-AsLP)were specifically taken up by APL cells and the acidic intracellular environment triggered liposome to release AsⅢwhich stimulated reactive oxygen species level and caspase-3 activity.Tf-AsLP prolonged half-life of AsⅢin blood circulation,lowered systemic toxicity,and promoted apoptosis and induced cell differentiation at lesion site in vivo.Considering that ATO combined with RA is usually applied as the first choice in clinic for APL treatment to improve the therapeutic effect,accordingly,a Tf-modified RA liposome(Tf-RALP)was designed to reduce the severe side effects of free RA and assist Tf-AsLP for better efficacy.As expected,the tumor inhibition rate of Tf-AsLP was improved significantly with the combination of Tf-RALP on subcutaneous tumor model.Furthermore,APL orthotopic NOD/SCID mice model was established by 60CO irradiation and HL-60 cells intravenously injection.The effect of co-administration(Tf-AsLP+Tf-RALP)was also confirmed to conspicuous decrease the number of leukemia cells in the circulatory system and prolong the survival time of APL mice by promoting the APL cells’apoptosis and differentiation in peripheral blood and bone marrow.Collectively,Tf-modified acid-sensitive AsLP could greatly reduce the systemic toxicity of free drug.Moreover,Tf-AsLP combined with Tf-RALP could achieve better efficacy.Thus,transferrinmodified AsⅢliposome would be a novel clinical strategy to improve patient compliance,with promising translation prospects.展开更多
Groundwater with high arsenic(As) content seriously threatens human life and health. Drinking high-As groundwater for a long time will lead to various pathological changes such as skin cancer, liver cancer,and kidney ...Groundwater with high arsenic(As) content seriously threatens human life and health. Drinking high-As groundwater for a long time will lead to various pathological changes such as skin cancer, liver cancer,and kidney cancer. High-As groundwater has become one of the most serious environmental geological problems in China and even internationally. This paper aims to systematically summarize the sources,migration, distribution, toxicological effects, and treatment techniques of As in natural groundwater in China based on a large number of literature surveys. High-As groundwater in China is mainly distributed in the inland basins in arid and semi-arid environments and the alluvial and lacustrine aquifers in river deltas in humid environments, which are in neutral to weakly alkaline and strongly reducing environments.The content of As in groundwater varies widely, and As(Ⅲ) is the main form. The main mechanism of the formation of high-As groundwater in China is the reduced dissolution of Fe and Mn oxides under the action of organic matter and primary microorganisms, alkaline environment, intense evaporation and concentration, long-term water-rock interaction, and slow groundwater velocity, which promote the continuous migration and enrichment of As in groundwater. There are obvious differences in the toxicity of different forms of As. The toxic of As(Ⅲ) is far more than As(V), which is considered to be more toxic than methyl arsenate(MMA) and dimethyl arsenate(DMA). Inorganic As entering the body is metabolized through a combination of methylation(detoxification) and reduction(activation) and catalyzed by a series of methyltransferases and reductases. At present, remediation methods for high-As groundwater mainly include ion exchange technology, membrane filtration technology, biological treatment technology, nanocomposite adsorption technology, electrochemical technology, and so on. All the above remediation methods still have certain limitations, and it is urgent to develop treatment materials and technical means with stronger As removal performance and sustainability. With the joint efforts of scientists and governments of various countries in the future, this worldwide problem of drinking-water As poisoning will be solved as soon as possible. This paper systematically summarizes and discusses the hot research results of natural high-As groundwater, which could provide a reference for the related research of high-As groundwater in China and even the world.展开更多
[Objectives]To prepare biomanganese oxide/biochar composite(BMO-BC)and examine its remediation performance on arsenic contamination.[Methods]The BMO-BC was prepared by cultivating Pseudomonas putida MnB1 in the presen...[Objectives]To prepare biomanganese oxide/biochar composite(BMO-BC)and examine its remediation performance on arsenic contamination.[Methods]The BMO-BC was prepared by cultivating Pseudomonas putida MnB1 in the presence of Mn 2+and biochar.[Results]The initial concentration of Mn 2+in the culture system had no significant effect on the growth rate and domestication cycle of Pseudomonas putida MnB1.The results of SEM-EDS and XRD analysis confirm that the adsorbent prepared in this experiment was a composite of biomanganese oxide and biochar particles.The results of arsenic pollution removal test in simulated environment showed that the in-situ formed BMO-BC composite had certain removal effect on As(III)and the presence of biochar particles and manganese dioxide in the reaction system and the manganese oxidation ability of microbial strain MnB1 affect its remediation performance to As(III).[Conclusions]When the initial concentration is in the range of 0-10.0 mg/L,the isothermal adsorption data of BMO-BC on As(III)conforms to the Langmuir model.展开更多
The Tongon mine generates millions of tons of waste rock and tailings, which are stored in landfills in the vicinity of the mine. These tailings contain arsenic. The risk of soil contamination in this area is evident....The Tongon mine generates millions of tons of waste rock and tailings, which are stored in landfills in the vicinity of the mine. These tailings contain arsenic. The risk of soil contamination in this area is evident. This study assesses the arsenic contamination of soils around the mine and the health risks to the local population. Soil samples were taken from plastic bags and other materials used as working tools. Arsenic concentrations were determined by inductively coupled plasma mass spectroscopy, after the soil samples had been concentrated and digested. Metal contamination indices were used to assess the degree of soil contamination. The results obtained indicate that soils in the industrial zone of the Tongon gold mine have very high average concentrations, well above the world average for uncontaminated soils of 6 mg/kg arsenic. Geoaccumulation index values range from 1.28 to 3.40. These values highlight severe arsenic soil contamination. The human health risk assessment revealed that exposure risks are well above the critical limit of 1 and are, in descending order, children > adult women > adult men. These results indicate an ecological risk, requiring environmental monitoring, underpinned by the development of an effective remediation strategy to reduce local pollution and contamination.展开更多
The opening of the Panama Canal in 1913 increased the availability of internationally traded goods and transformed ocean-shipping by shortening travel time between the Atlantic Ocean and Pacific Ocean. The canal spark...The opening of the Panama Canal in 1913 increased the availability of internationally traded goods and transformed ocean-shipping by shortening travel time between the Atlantic Ocean and Pacific Ocean. The canal sparked the growth of port authorities and increased ship tonnage on both coasts of Panama. Since the construction of the Panama Canal, in the 1910s, pesticides, herbicides and chemicals, including arsenic, have been essential for controlling wetland vegetation, including hyacinth, which blocked rivers, lakes, and the canal as well as managing mosquitoes. Pesticides and chemicals flowed into Lake Gatun (reservoir) either attached to sediment or in solution during the monsoon season. Lake Gatun was the drinking water source for most of the people living in the Panama Canal Zone. The United States military base commanders had the ability to order and use cacodylic acid (arsenic based) from the Naval Depot Supply Federal and Stock Catalog and the later Federal Supply Catalog on the military base grounds in the Panama Canal Zone. Cacodylic acid was shipped to Panama Canal Zone ports, including Balboa and Cristobal, and distributed to the military bases by rail or truck. The objective of this study is to determine the fate of arsenic: 1) applied between 1914 and 1935 to Panama Canal shipping lane hyacinth and other wetland vegetation and 2) cacodylic acid (arsenic) sprayed from 1948 to 1999 on the US military base grounds in the Panama Canal Zone.展开更多
Objective The effects of arsenic exposure from drinking water, arsenic metabolism, and arsenic methylation on blood pressure(BP) were observed in this study. Methods The BP and arsenic species of 560 participants were...Objective The effects of arsenic exposure from drinking water, arsenic metabolism, and arsenic methylation on blood pressure(BP) were observed in this study. Methods The BP and arsenic species of 560 participants were determined. Logistic regression analysis was applied to estimate the odds ratios of BP associated with arsenic metabolites and arsenic methylation capability. Results BP was positively associated with cumulative arsenic exposure(CAE). Subjects with abnormal diastolic blood pressure(DBP), systolic blood pressure(SBP), and pulse pressure(PP) usually had higher urinary i As(inorganic arsenic), MMA(monomethylated arsenic), DMA(dimethylated arsenic), and TAs(total arsenic) than subjects with normal DBP, SBP, and PP. The i As%, MMA%, and DMA% differed slightly between subjects with abnormal BP and those with normal BP. The PMI and SMI were slightly higher in subjects with abnormal PP than in those with normal PP. Conclusion Our findings suggest that higher CAE may elevate BP. Males may have a higher risk of abnormal DBP, whereas females have a higher risk of abnormal SBP and PP. Higher urinary i As may increase the risk of abnormal BP. Lower PMI may elevate the BP. However, higher SMI may increase the DBP and SBP, and lower SMI may elevate the PP.展开更多
A method was developed for the determination of total arsenic concentration in less than ng/ml level by decomposition of organoarsenicals using photo -oxidation combined with in situ trapping of arsenic hydride on a p...A method was developed for the determination of total arsenic concentration in less than ng/ml level by decomposition of organoarsenicals using photo -oxidation combined with in situ trapping of arsenic hydride on a palladium coated graphite tube with subsequent atomization and detection by AAS. The organoarsenicals include monomethylarsenic, dimethylarsenic, arsenobetaine, arsenocholine, o -aminobenzenarsenate and p -aminobenzenarsenate. The method is simple and sensitive. Detection limit was obtained from different arsenic compounds over the range from 0. 058 to 0.063 ng/ml as As (based on three times of the standard deviation of 10 blank measurements) and the relative standard deviations for ten replicate measurements were from 2.0 to 3.8%. The calibration curves of arsenic compounds including inorganic and organic arsenicals were linear over the range from 0.1 to 3.0 ng/ml as As. The recommended method has been applied to the determination of total arsenic in tap and lake water samples at ng/ml展开更多
One of the main food crops in the world,rice can accumulate high levels of arsenic from flooded paddy soils,which seriously threatens human health.Soaking,a common processing method for brown rice products,especially ...One of the main food crops in the world,rice can accumulate high levels of arsenic from flooded paddy soils,which seriously threatens human health.Soaking,a common processing method for brown rice products,especially for brown rice noodles,was investigated in this study.Japonica rice(Dao Hua Xiang No.2)and Indica rice(Ye Xiang You No.3)were selected for studying the effects of soaking on arsenic concentrations,species,and distributions.Results revealed that soaking can efficiently remove arsenic in these two rice varieties,and the main part of removal is endosperm with the maximal rate of about 40%.Inorganic arsenic(I-As)(about 85%)is the main species of arsenic reduction.Meanwhile,the variations of four other elements(i.e.,Mg,Ca,Zn,and Fe)were analyzed.Collectively,the findings of this study indicate that soaking can efficiently remove arsenic in brown rice under controlled soaking conditions,which thereby reduces the arsenic intake for brown rice customers.展开更多
The mechanism of arsenic removal during a sintering process was investigated through experiments with a sintering pot and arsenic-bearing iron ore containing arsenopyrite; the corresponding chemical properties of the ...The mechanism of arsenic removal during a sintering process was investigated through experiments with a sintering pot and arsenic-bearing iron ore containing arsenopyrite; the corresponding chemical properties of the sinter were determined by inductively coupled plasma atomic emission spectrometry(ICP-AES),X-ray diffraction(XRD),and scanning electron microscopy(SEM) coupled with energy-dispersive X-ray spectroscopy(EDS). The experimental results revealed that the reaction of arsenic removal is mainly related to the oxygen atmosphere and temperature. During the sintering process,arsenic could be removed in the ignition layer,the sinter layer,and the combustion zone. A portion of Fe As S reacted with excess oxygen to generate Fe AsO_4,and the rest of the Fe As S reacted with oxygen to generate As_2O_3(g) and SO_2(g). A portion of As_2O_3(g) mixed with Al_2O_3 or CaO,which resulted in the formation of arsenates such as AlAsO_4 and Ca_3(AsO_4)_2,leading to arsenic residues in sintering products. The Fe As S component in the blending ore was difficult to decompose in the preliminary heating zone,the dry zone,or the bottom layer because of the relatively low temperatures; however,As_2O3(g) that originated from the high-temperature zone could react with metal oxides,resulting in the formation of arsenate residues.展开更多
A 45 d pot experiment was conducted to examine the effects of silicon fertilizer or iron fertilizer on the growth of two typical Ipomoea aquatica cultivars(Daye and Liuye) and arsenic(As) accumuation of Daye and Liuye...A 45 d pot experiment was conducted to examine the effects of silicon fertilizer or iron fertilizer on the growth of two typical Ipomoea aquatica cultivars(Daye and Liuye) and arsenic(As) accumuation of Daye and Liuye grown in As-contaminated soils at different As dosage levels. The results showed that the application of these two fertilizers generally enhanced the growth of the plants, which may be partly attributable to the reduction in As toxicity. The addition of these two fertilizers also significantly reduced the uptake of As by the plants though the iron fertilizer was more effective, as compared to the silicon fertilizer. The accumulation of As in shoot portion was weaker for Daye than for Liuye. The research findings obtained from this study have implications for developing cost-effective management strategies to minimize human health impacts from consumption of As-containing I. aquatica.展开更多
In Zimapan Valley, Mexico, up to 1.1 mg·L-1 of arsenic concentrations have been detected in deep wells that are used as drinking water supply for almost 39,000 people, which could have been exposed to level...In Zimapan Valley, Mexico, up to 1.1 mg·L-1 of arsenic concentrations have been detected in deep wells that are used as drinking water supply for almost 39,000 people, which could have been exposed to levels higher than 10 μg·L-1 of arsenic, the maximum level recommended by the World Health Organization. Chronic consumption of water contaminated with arsenic can cause several diseases, including cancer. For it, the implementation of practical and economical methods to remove arsenic from drinking water is crucial to protect the population health. In this work, an electrochemical method to remove arsenic from drinking water is described. The process, monitored by Tyndall effect, utilizes Cu2+ and Zn2+ ions from a brass electrode in an electrochemical cell with water as electrolyte. Results show that the EC process reduces the concentration of the arsenic diluted in Zimapan water to a level below the limit of detection of the atomic absorption spectrophotometer employed. Arsenic was removed through the formation of Cu and Zn arsenic compounds. Cu2+ and Zn2+ ions form a hydroxide and eventually polycrystalline precipitation of kottigite and cornubite complexes (identified by energy-dispersive X-ray spectroscopy and X-ray diffraction), which are then filtered to eliminate the precipitated arsenic compounds.展开更多
Arsenic is a known toxic chemical, has immuno-modulatory properties, and can change the susceptibility of infection in humans. Acute hepatitis E is an infectious disease;it can be self-limiting, but in severe cases, c...Arsenic is a known toxic chemical, has immuno-modulatory properties, and can change the susceptibility of infection in humans. Acute hepatitis E is an infectious disease;it can be self-limiting, but in severe cases, can cause acute-on-chronic liver failure. The presence of IgG anti-HEV (hepatitis E IgG antibody) in blood represents a past hepatitis E infection in an individual. Very few studies have investigated the association between arsenic levels and hepatitis E seroconversion in humans. The primary objective of this study was to assess the relationship between total urinary arsenic and speciated urinary arsenic (urinary arsenous acid, urinary arsenic acid, urinary arsenobetaine, urinary arsenocholine, urinary dimethylarsinic acid, urinary monomethylarsonic acid) and the presence of IgG anti-HEV. The 2011-2012, 2013-2014, and 2015-2016 National Health and Nutrition Examination Survey (NHANES) III data sets were analyzed, with participants aged 20 years and older (n = 7061). We used weighted logistic regression to determine the association between total and speciated urinary arsenic concentrations and IgG anti-HEV. For each analyte considered, a separate weighted logistic regression model was fitted. Each of these models regressed log-transformed analyte levels on the log-odds of the presence of IgG Anti-HEV. To evaluate the relationships between the urinary arsenic measurements, pairwise Pearson correlation coefficients were determined for each of the urinary arsenic measurements. Of the human subjects included, 6628 (93.9%) were negative for IgG Anti-HEV while 433 (6.1%) were positive for IgG anti-HEV. Total urinary arsenic was associated with 1.161 times greater odds of IgG anti-HEV (95% CI: [1.035, 1.303]) for each unit increase in concentration on a log-scale. For speciated urinary arsenic measurements, the odds ratios and 95% CI’s were: arsenobetanine 1.168 [1.075, 1.270], arsenocholine 1.201 [0.944, 1.529], dimethylarsinic acid 1.183 [1.009, 1.386], monomethylacrsonic acid 1.095 [0.915, 1.310], aresnous acid 0.907 [0.762, 1.079], and arsenic acid 1.951 [0.905, 4.209]. Our analysis indicates that total urinary arsenic, arsenobetanine, and dimethylarsinic acid are significantly associated with the odds of the presence of IgG anti-HEV. Future prospective studies are required to evaluate the association between hepatitis E infection and arsenic exposures.展开更多
Arsenic is commonly found in seafood,and the toxicity of different speciation varies widely.Therefore,there is an urgent need to reduce the content and analyze the speciation of arsenic to improve the safety of seafoo...Arsenic is commonly found in seafood,and the toxicity of different speciation varies widely.Therefore,there is an urgent need to reduce the content and analyze the speciation of arsenic to improve the safety of seafood.In this study,arsenic was removed from Chlamys farreri by adding ferric ions and sodium citrate or reducing the salinity of seawater.Then,the speciation of arsenic was analyzed.The results showed that the removal rates of arsenic were 20%,23%,24%and 18%when C.farreri individuals were treated with 0.1 g L^(−1)Fe^(3+),0.4 g L^(−1),0.6 g L^(−1)sodium citrate or decreasing seawater salinity to 17 within 48 h,respectively.Furthermore,it was detected that the arsenic speciation in the C.farreri was mainly polar arsenic,and among the polar arsenic was mainly arsenic betaine.These results indicated that the removal of arsenic can be achieved by adding the removal agent or changing the seawater salinity under the experimental conditions.The speciation of arsenic did not change during the removal process and it was mainly excreted in the speciation of arsenic betaine.展开更多
Human exposure to arsenic (As) is primarily through drinking water and food ingestion. Arsenic is naturally present in the environment and has been known as “the king of poisons” since the Middle Ages. It is mutagen...Human exposure to arsenic (As) is primarily through drinking water and food ingestion. Arsenic is naturally present in the environment and has been known as “the king of poisons” since the Middle Ages. It is mutagenic, teratogenic, and carcinogenic and approximately 70% comes from ingested food and 29% from water. Once ingested, arsenic can bio-accumulate in the human body or be excreted. Arsenic in groundwater is a main source of As in humans and the two arsenicals most abundant in water are arsenite (+3 oxidation state) and arsenate (+5 oxidation state). In order of toxicity from the most toxic to least toxic are arsines, arsenites, arsenoxides, arsenates, pentavalent arsenicals, Arsenic compounds, and metallic arsenic. Arsenic accumulates in the body when ingested in small doses. It often takes decades before physical symptoms of As poisoning show. While As is element normally found in the human body, it is highly toxic in excess amounts. The lethal dose for rates is 48 μg/L which translates to 125 mg for a middle-aged male. The maximum safe limit for As ingestion for an average Vietnamese middle-aged male is 220 μg per day. This lethal dosage puts As in a highly toxic category in food and toxicology. Most of the As in the Mekong Delta groundwater is from natural alluvial sediment sources. Other anthropic sources include the burial of millions of Vietnamese with elevated As levels since 1962, industrial sources, smelting by-products, water treatment plants, sewage and wastewater treatment discharges into waterways have added to the Mekong Delta As levels in the soil and groundwater. However, Agent Blue, the As-based herbicide, used during the Vietnam War, did contribute a significant amount (over 1,132,400 kg of manufactured (anthropic) As) to Southern Vietnam landscape. The As spikes and levels in the Mekong Delta soils and groundwater need restoration. The uptake of trace amounts of As in rice is indeed a critical food security and human health issue and requires mitigation.展开更多
AIM To study the effects of arsenic trioxide andHCPT on different degrees of differentiated gastriccancer cells（SGC-7901,MKN-45,MKN-28）withrespect to both cytotoxicity and induction ofapoptosis in vitro.METHODS The ...AIM To study the effects of arsenic trioxide andHCPT on different degrees of differentiated gastriccancer cells（SGC-7901,MKN-45,MKN-28）withrespect to both cytotoxicity and induction ofapoptosis in vitro.METHODS The cytotoxicity of As<sub>2</sub>O<sub>3</sub> and HCPTon gastric cancer cells was determined by MTTassay.Morphologic changes of apoptosis ofgastric cancer cells were observed by lightmicroscopy and transmission electron microscopy.Apoptosis and cell cycle changes of gastric cancercells induced by HCPT and As<sub>2</sub>O<sub>3</sub> were investigatedby TUNEL method and flow cytometry.RESULTS As<sub>2</sub>O<sub>3</sub> and HCPT had remarkablecytotoxic effects on different degrees ofdifferentiated gastric cancer cells.The IC<sub>50</sub>ofAs<sub>2</sub>O<sub>3</sub> on well differentiated gastric cancer cellMKN-28,moderately differentiated gastric cancercell SGC-7901,and poorly differentiated gastriccancer cell MKN-28 were 8.91 μmol/L,10.57μmol/L,and 11.65 μmol/L,respectively.The IC<sub>50</sub>of HCPT on MKN-28,SGC-7901,and MKN-45 were9.35 mg/L,10.21 mg/L,and 12.63 mg/Lrespectively after 48 h treatment.After 12 h ofexposure to both drugs,gastric cancer cellsexhibited morphologic features of apoptosis,including cell shrinkage,nuclear condensation, and formation of apoptotic bodies.A typicalsubdiploid peak before G<sub>0</sub>/G<sub>1</sub> phase was observedby flow cytometry.The apoptotic rates of SGC-7901,MKN-45,and MKN-28 were 13.84%,22.52%,and 9.68%,respectively after 48 hexposure to 10 μmol/L As<sub>2</sub>O<sub>3</sub>.The apoptotic ratesof SGC-7901,MKN-45,and MKN-28 were 21.88%,12.35%,and 30.26%,respectively after 48 hexposure to 10 mg/L HCPT.The apoptotic indicewere 7%-15% as assessed by TUNEL method.The effect of As<sub>2</sub>O<sub>3</sub> on SGC-7901 showedremarkable cell cycle specificity,which inducedcell death in G<sub>1</sub> phase,and blocked G<sub>2</sub>/M phase.HCPT also showed a remarkable cell cyclespecificity,by inducing cell death and apoptosis inG<sub>1</sub> phase and arrest of proliferation at S phase.CONCLUSION As<sub>2</sub>O<sub>3</sub> and HCPT exhibitsignificant cytotoxicity on gastric cancer cells byinduction of apoptosis.As<sub>2</sub>O<sub>3</sub> and HCPT mighthave a promising prospect in the treatment ofgastric cancer,which needs to be further studied.展开更多
文摘Lagoons are ecosystems for biodiversity and the livelihoods of coastal communities. The main objective of the study was to analyze the variability of arsenic concentrations in gastropods and bivalves in the Aby and Tendo lagoons, taking into account spatial, seasonal and hydrological variations. The study was carried out in four stages spread over two successive hydroclimatic cycles, including two seasons during the rainy season and two more during the dry season. The samples were taken in two areas of the Aby and Tendo lagoons. Arsenic levels were measured by ICP-MS. The results showed that mean arsenic concentrations in the muscles of organisms in Aby Lagoon ranged from 0.01 to 1.26 μg As/g, with a mean and median of 0.17 and 0.06 μg As/g, respectively. Fish had the highest levels of arsenic, followed by crustaceans, while molluscs and plants had lower and comparable concentrations of As. Arsenic concentrations in tilapia and jawbones varied significantly between sites and seasons, with higher concentrations at Tendo and during the rainy season. Arsenic concentrations in gastropods and bivalves were significantly higher than those of other species, with averages of 0.74 and 1.03 mg As/kg, respectively.
文摘Arsenic toxicity,imposed mainly by arsenic-contaminated groundwater,is considered a critical threat to global communal health,as there is no specific and proven conventional therapy for chronic arsenic toxicity,i.e.,arsenicosis,which is an insidious global public health menace affecting 50 countries.Alternative options should,therefore,be explored for the mitigation of arsenicosis.Literature survey reveals several natural compounds from plants possess significant protective efficacy against arsenic toxicity in chiefly preclinical and few clinical investigations.The studies on the ameliorative effects of plant-derived natural compounds against arsenic toxicity published in the last 25 years are collated.Forty-eight plant-based natural compounds possess alleviative effects on experimental arsenic-induced toxicity in animals,six of which have been reported to be clinically effective in humans.A potential nutraceutical or therapeutic candidate against arsenicosis for humans may thus be developed with the help of recent advancements in research in this area,along with the currently available treatments.
基金supported by National Natural Science Foundation of China [No. 81773405 to Y.Q. and No. 82173644to X.Y.]Shanxi Natural Science Foundation of China [No.202203021211246 and No. 202103021224242]。
文摘Objective Arsenic(As) and fluoride(F) are two of the most common elements contaminating groundwater resources. A growing number of studies have found that As and F can cause neurotoxicity in infants and children, leading to cognitive, learning, and memory impairments. However, early biomarkers of learning and memory impairment induced by As and/or F remain unclear. In the present study, the mechanisms by which As and/or F cause learning memory impairment are explored at the multi-omics level(microbiome and metabolome).Methods We stablished an SD rats model exposed to arsenic and/or fluoride from intrauterine to adult period.Results Arsenic and/fluoride exposed groups showed reduced neurobehavioral performance and lesions in the hippocampal CA1 region. 16S rRNA gene sequencing revealed that As and/or F exposure significantly altered the composition and diversity of the gut microbiome, featuring the Lachnospiraceae_NK4A136_group, Ruminococcus_1, Prevotellaceae_NK3B31_group, [Eubacterium]_xylanophilum_group. Metabolome analysis showed that As and/or F-induced learning and memory impairment may be related to tryptophan, lipoic acid, glutamate, gamma-aminobutyric acidergic(GABAergic) synapse, and arachidonic acid(AA) metabolism. The gut microbiota, metabolites, and learning memory indicators were significantly correlated.Conclusion Learning memory impairment triggered by As and/or F exposure may be mediated by different gut microbes and their associated metabolites.
文摘Objective:To explore the cardioprotective effect of hesperidin against arsenic trioxide-induced cardiac toxicity in rats.Methods:Cardiac toxicity was induced by oral administration of 4 mg/kg arsenic trioxide for 30 days.Hematological,biochemical,electrocardiography,echocardiography,and histopathological examinations were performed.Results:Hesperidin decreased the neutrophil-to-lymphocyte ratio,calcium,creatine kinase-myoglobin binding,lactate dehydrogenase,IL-6,and lipid peroxidation,as well as increased sodium and potassium concentration and superoxide dismutase and catalase activity in arsenic trioxide-intoxicated rats.Moreover,it reduced peak systolic velocity and end-diastolic velocity while increasing heart rate.Arsenic trioxide-induced histopathological damage to cardiac tissue was prominently alleviated by hesperidin treatment.Conclusions:Hesperidin attenuates arsenic trioxide-induced cardiac toxicity in rats.Therefore,it can be further explored as a cardioprotective agent.
基金support of the Basic Research Project of Science and Technology Planning Project of Yunnan Provincial Department of Science and Technology (202201AS070031)Yunnan Pronince Top young talents of The Ten Thousand Project+4 种基金the central government guides local science and technology development projects (CB22005R006A)the National Key Research and Development Program of China (2019YFC1904204)Kunming Key Laboratory of Special MetallurgyKunming Academician Workstation of Advanced Preparation for Super hard Materials FieldKunming Academician Workstation of Metallurgical Process Intensification。
文摘Arsenic is one of the main harmful elements in industrial wastewater.How to remove arsenic has always been one of the research hotspots in academic circles.In the process of arsenic removal by traditional sulfuration,the use of traditional sulfurizing agent will introduce new metal cations,which will affect the recycling of acid.In this study,phosphorus pentasulfide (P_(2)S_(5)) was used as sulfurizing agent,which hydrolyzed to produce H_(3)PO_(4) and H_(2)S without introducing new metal cations.The effect of ultrasound on arsenic removal by P_(2)S_(5) was studied.Under the action of ultrasound,the utilization of P_(2)S_(5) was improved and the reaction time was shortened.The effects of S/As molar ratio and reaction time on arsenic removal rate were investigated under ultrasonic conditions.Ultrasonic enhanced heat and mass transfer so that the arsenic removal rate of 94.5%could be achieved under the conditions of S/As molar ratio of 2.1:1 and reaction time of 20 min.In the first 60 min,under the same S/As molar ratio and reaction time,the ultrasonic hydrolysis efficiency of P_(2)S_(5) was higher.This is because P_(2)S_(5) forms ([(P_(2)S_(4))])^(2+)under the ultrasonic action,and the structure is damaged,which is easier to be hydrolyzed.In addition,the precipitation after arsenic removal was characterized and analyzed by X-ray diffraction,scanning electron microscope-energy dispersive spectrometer,X-ray fluorescence spectrometer and X-ray photoelectron spectroscopy.Our research avoids the introduction of metal cations in the arsenic removal process,and shortens the reaction time.
基金supported by the Science and Technology Commission of Shanghai Municipality (20S11902600)the National Natural Science Foundation of China (82172615)the PDH-SPFDU Joint Research Fund (RHJJ2018-05)
文摘Clinically,arsenic trioxide(ATO)was applied to the treatment of acute promyelocytic leukemia(APL)as a reliable and effective frontline drug.However,the administration regimen of AsⅢwas limited due to its fast clearance,short therapeutic window and toxicity as well.Based on CD71 overexpressed on APL cells,in present study,a transferrin(Tf)-modified liposome(LP)was established firstly to encapsulate AsⅢin arsenic-nickel complex by nickel acetate gradient method.The AsⅢ-loaded liposomes(AsLP)exhibited the feature of acid-sensitive release in vitro.Tf-modified AsLP(Tf-AsLP)were specifically taken up by APL cells and the acidic intracellular environment triggered liposome to release AsⅢwhich stimulated reactive oxygen species level and caspase-3 activity.Tf-AsLP prolonged half-life of AsⅢin blood circulation,lowered systemic toxicity,and promoted apoptosis and induced cell differentiation at lesion site in vivo.Considering that ATO combined with RA is usually applied as the first choice in clinic for APL treatment to improve the therapeutic effect,accordingly,a Tf-modified RA liposome(Tf-RALP)was designed to reduce the severe side effects of free RA and assist Tf-AsLP for better efficacy.As expected,the tumor inhibition rate of Tf-AsLP was improved significantly with the combination of Tf-RALP on subcutaneous tumor model.Furthermore,APL orthotopic NOD/SCID mice model was established by 60CO irradiation and HL-60 cells intravenously injection.The effect of co-administration(Tf-AsLP+Tf-RALP)was also confirmed to conspicuous decrease the number of leukemia cells in the circulatory system and prolong the survival time of APL mice by promoting the APL cells’apoptosis and differentiation in peripheral blood and bone marrow.Collectively,Tf-modified acid-sensitive AsLP could greatly reduce the systemic toxicity of free drug.Moreover,Tf-AsLP combined with Tf-RALP could achieve better efficacy.Thus,transferrinmodified AsⅢliposome would be a novel clinical strategy to improve patient compliance,with promising translation prospects.
基金The study was funded by the National Natural Science Foundation of China(41672225 and 41902243)the Natural Science Foundation of Jiangxi Province(20202BABL211018)the East China University of Technology Research Foundation for Advanced Talents(DHBK2019098).
文摘Groundwater with high arsenic(As) content seriously threatens human life and health. Drinking high-As groundwater for a long time will lead to various pathological changes such as skin cancer, liver cancer,and kidney cancer. High-As groundwater has become one of the most serious environmental geological problems in China and even internationally. This paper aims to systematically summarize the sources,migration, distribution, toxicological effects, and treatment techniques of As in natural groundwater in China based on a large number of literature surveys. High-As groundwater in China is mainly distributed in the inland basins in arid and semi-arid environments and the alluvial and lacustrine aquifers in river deltas in humid environments, which are in neutral to weakly alkaline and strongly reducing environments.The content of As in groundwater varies widely, and As(Ⅲ) is the main form. The main mechanism of the formation of high-As groundwater in China is the reduced dissolution of Fe and Mn oxides under the action of organic matter and primary microorganisms, alkaline environment, intense evaporation and concentration, long-term water-rock interaction, and slow groundwater velocity, which promote the continuous migration and enrichment of As in groundwater. There are obvious differences in the toxicity of different forms of As. The toxic of As(Ⅲ) is far more than As(V), which is considered to be more toxic than methyl arsenate(MMA) and dimethyl arsenate(DMA). Inorganic As entering the body is metabolized through a combination of methylation(detoxification) and reduction(activation) and catalyzed by a series of methyltransferases and reductases. At present, remediation methods for high-As groundwater mainly include ion exchange technology, membrane filtration technology, biological treatment technology, nanocomposite adsorption technology, electrochemical technology, and so on. All the above remediation methods still have certain limitations, and it is urgent to develop treatment materials and technical means with stronger As removal performance and sustainability. With the joint efforts of scientists and governments of various countries in the future, this worldwide problem of drinking-water As poisoning will be solved as soon as possible. This paper systematically summarizes and discusses the hot research results of natural high-As groundwater, which could provide a reference for the related research of high-As groundwater in China and even the world.
文摘[Objectives]To prepare biomanganese oxide/biochar composite(BMO-BC)and examine its remediation performance on arsenic contamination.[Methods]The BMO-BC was prepared by cultivating Pseudomonas putida MnB1 in the presence of Mn 2+and biochar.[Results]The initial concentration of Mn 2+in the culture system had no significant effect on the growth rate and domestication cycle of Pseudomonas putida MnB1.The results of SEM-EDS and XRD analysis confirm that the adsorbent prepared in this experiment was a composite of biomanganese oxide and biochar particles.The results of arsenic pollution removal test in simulated environment showed that the in-situ formed BMO-BC composite had certain removal effect on As(III)and the presence of biochar particles and manganese dioxide in the reaction system and the manganese oxidation ability of microbial strain MnB1 affect its remediation performance to As(III).[Conclusions]When the initial concentration is in the range of 0-10.0 mg/L,the isothermal adsorption data of BMO-BC on As(III)conforms to the Langmuir model.
文摘The Tongon mine generates millions of tons of waste rock and tailings, which are stored in landfills in the vicinity of the mine. These tailings contain arsenic. The risk of soil contamination in this area is evident. This study assesses the arsenic contamination of soils around the mine and the health risks to the local population. Soil samples were taken from plastic bags and other materials used as working tools. Arsenic concentrations were determined by inductively coupled plasma mass spectroscopy, after the soil samples had been concentrated and digested. Metal contamination indices were used to assess the degree of soil contamination. The results obtained indicate that soils in the industrial zone of the Tongon gold mine have very high average concentrations, well above the world average for uncontaminated soils of 6 mg/kg arsenic. Geoaccumulation index values range from 1.28 to 3.40. These values highlight severe arsenic soil contamination. The human health risk assessment revealed that exposure risks are well above the critical limit of 1 and are, in descending order, children > adult women > adult men. These results indicate an ecological risk, requiring environmental monitoring, underpinned by the development of an effective remediation strategy to reduce local pollution and contamination.
文摘The opening of the Panama Canal in 1913 increased the availability of internationally traded goods and transformed ocean-shipping by shortening travel time between the Atlantic Ocean and Pacific Ocean. The canal sparked the growth of port authorities and increased ship tonnage on both coasts of Panama. Since the construction of the Panama Canal, in the 1910s, pesticides, herbicides and chemicals, including arsenic, have been essential for controlling wetland vegetation, including hyacinth, which blocked rivers, lakes, and the canal as well as managing mosquitoes. Pesticides and chemicals flowed into Lake Gatun (reservoir) either attached to sediment or in solution during the monsoon season. Lake Gatun was the drinking water source for most of the people living in the Panama Canal Zone. The United States military base commanders had the ability to order and use cacodylic acid (arsenic based) from the Naval Depot Supply Federal and Stock Catalog and the later Federal Supply Catalog on the military base grounds in the Panama Canal Zone. Cacodylic acid was shipped to Panama Canal Zone ports, including Balboa and Cristobal, and distributed to the military bases by rail or truck. The objective of this study is to determine the fate of arsenic: 1) applied between 1914 and 1935 to Panama Canal shipping lane hyacinth and other wetland vegetation and 2) cacodylic acid (arsenic) sprayed from 1948 to 1999 on the US military base grounds in the Panama Canal Zone.
基金supported by the State Key Program of National Natural Science foundation of China(Grant No.41230749)the National Natural Science foundation of China(Grant No.41601559)
文摘Objective The effects of arsenic exposure from drinking water, arsenic metabolism, and arsenic methylation on blood pressure(BP) were observed in this study. Methods The BP and arsenic species of 560 participants were determined. Logistic regression analysis was applied to estimate the odds ratios of BP associated with arsenic metabolites and arsenic methylation capability. Results BP was positively associated with cumulative arsenic exposure(CAE). Subjects with abnormal diastolic blood pressure(DBP), systolic blood pressure(SBP), and pulse pressure(PP) usually had higher urinary i As(inorganic arsenic), MMA(monomethylated arsenic), DMA(dimethylated arsenic), and TAs(total arsenic) than subjects with normal DBP, SBP, and PP. The i As%, MMA%, and DMA% differed slightly between subjects with abnormal BP and those with normal BP. The PMI and SMI were slightly higher in subjects with abnormal PP than in those with normal PP. Conclusion Our findings suggest that higher CAE may elevate BP. Males may have a higher risk of abnormal DBP, whereas females have a higher risk of abnormal SBP and PP. Higher urinary i As may increase the risk of abnormal BP. Lower PMI may elevate the BP. However, higher SMI may increase the DBP and SBP, and lower SMI may elevate the PP.
文摘A method was developed for the determination of total arsenic concentration in less than ng/ml level by decomposition of organoarsenicals using photo -oxidation combined with in situ trapping of arsenic hydride on a palladium coated graphite tube with subsequent atomization and detection by AAS. The organoarsenicals include monomethylarsenic, dimethylarsenic, arsenobetaine, arsenocholine, o -aminobenzenarsenate and p -aminobenzenarsenate. The method is simple and sensitive. Detection limit was obtained from different arsenic compounds over the range from 0. 058 to 0.063 ng/ml as As (based on three times of the standard deviation of 10 blank measurements) and the relative standard deviations for ten replicate measurements were from 2.0 to 3.8%. The calibration curves of arsenic compounds including inorganic and organic arsenicals were linear over the range from 0.1 to 3.0 ng/ml as As. The recommended method has been applied to the determination of total arsenic in tap and lake water samples at ng/ml
基金the Special National Key Research and Development Plan[grant number 2016YFD0400204]the Ministry of Science and Technology of the People’s Republic of China[grant number2015FY111300]the Technology Innovation Program of the Chinese Academy of Agricultural Sciences[grant number CAAS-ASTIP-201X-IAPPST].
文摘One of the main food crops in the world,rice can accumulate high levels of arsenic from flooded paddy soils,which seriously threatens human health.Soaking,a common processing method for brown rice products,especially for brown rice noodles,was investigated in this study.Japonica rice(Dao Hua Xiang No.2)and Indica rice(Ye Xiang You No.3)were selected for studying the effects of soaking on arsenic concentrations,species,and distributions.Results revealed that soaking can efficiently remove arsenic in these two rice varieties,and the main part of removal is endosperm with the maximal rate of about 40%.Inorganic arsenic(I-As)(about 85%)is the main species of arsenic reduction.Meanwhile,the variations of four other elements(i.e.,Mg,Ca,Zn,and Fe)were analyzed.Collectively,the findings of this study indicate that soaking can efficiently remove arsenic in brown rice under controlled soaking conditions,which thereby reduces the arsenic intake for brown rice customers.
基金financially supported by the Open Research Fund of Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education,Wuhan University of Science and Technology(No.FMRU201405)the National Natural Science Foundation of China(Nos.51471122 and 51604202)the China Postdoctoral Science Foundation(No.2016M592397)
文摘The mechanism of arsenic removal during a sintering process was investigated through experiments with a sintering pot and arsenic-bearing iron ore containing arsenopyrite; the corresponding chemical properties of the sinter were determined by inductively coupled plasma atomic emission spectrometry(ICP-AES),X-ray diffraction(XRD),and scanning electron microscopy(SEM) coupled with energy-dispersive X-ray spectroscopy(EDS). The experimental results revealed that the reaction of arsenic removal is mainly related to the oxygen atmosphere and temperature. During the sintering process,arsenic could be removed in the ignition layer,the sinter layer,and the combustion zone. A portion of Fe As S reacted with excess oxygen to generate Fe AsO_4,and the rest of the Fe As S reacted with oxygen to generate As_2O_3(g) and SO_2(g). A portion of As_2O_3(g) mixed with Al_2O_3 or CaO,which resulted in the formation of arsenates such as AlAsO_4 and Ca_3(AsO_4)_2,leading to arsenic residues in sintering products. The Fe As S component in the blending ore was difficult to decompose in the preliminary heating zone,the dry zone,or the bottom layer because of the relatively low temperatures; however,As_2O3(g) that originated from the high-temperature zone could react with metal oxides,resulting in the formation of arsenate residues.
基金financially supported by the National High-Tech R&D Program of China(863 Program,2013AA102402)the National Natural Science Foundation of China(41271469)the Science&Technology Planning Project of Guangdong Province,China(2013B020303001,2015A020208012)
文摘A 45 d pot experiment was conducted to examine the effects of silicon fertilizer or iron fertilizer on the growth of two typical Ipomoea aquatica cultivars(Daye and Liuye) and arsenic(As) accumuation of Daye and Liuye grown in As-contaminated soils at different As dosage levels. The results showed that the application of these two fertilizers generally enhanced the growth of the plants, which may be partly attributable to the reduction in As toxicity. The addition of these two fertilizers also significantly reduced the uptake of As by the plants though the iron fertilizer was more effective, as compared to the silicon fertilizer. The accumulation of As in shoot portion was weaker for Daye than for Liuye. The research findings obtained from this study have implications for developing cost-effective management strategies to minimize human health impacts from consumption of As-containing I. aquatica.
文摘In Zimapan Valley, Mexico, up to 1.1 mg·L-1 of arsenic concentrations have been detected in deep wells that are used as drinking water supply for almost 39,000 people, which could have been exposed to levels higher than 10 μg·L-1 of arsenic, the maximum level recommended by the World Health Organization. Chronic consumption of water contaminated with arsenic can cause several diseases, including cancer. For it, the implementation of practical and economical methods to remove arsenic from drinking water is crucial to protect the population health. In this work, an electrochemical method to remove arsenic from drinking water is described. The process, monitored by Tyndall effect, utilizes Cu2+ and Zn2+ ions from a brass electrode in an electrochemical cell with water as electrolyte. Results show that the EC process reduces the concentration of the arsenic diluted in Zimapan water to a level below the limit of detection of the atomic absorption spectrophotometer employed. Arsenic was removed through the formation of Cu and Zn arsenic compounds. Cu2+ and Zn2+ ions form a hydroxide and eventually polycrystalline precipitation of kottigite and cornubite complexes (identified by energy-dispersive X-ray spectroscopy and X-ray diffraction), which are then filtered to eliminate the precipitated arsenic compounds.
文摘Arsenic is a known toxic chemical, has immuno-modulatory properties, and can change the susceptibility of infection in humans. Acute hepatitis E is an infectious disease;it can be self-limiting, but in severe cases, can cause acute-on-chronic liver failure. The presence of IgG anti-HEV (hepatitis E IgG antibody) in blood represents a past hepatitis E infection in an individual. Very few studies have investigated the association between arsenic levels and hepatitis E seroconversion in humans. The primary objective of this study was to assess the relationship between total urinary arsenic and speciated urinary arsenic (urinary arsenous acid, urinary arsenic acid, urinary arsenobetaine, urinary arsenocholine, urinary dimethylarsinic acid, urinary monomethylarsonic acid) and the presence of IgG anti-HEV. The 2011-2012, 2013-2014, and 2015-2016 National Health and Nutrition Examination Survey (NHANES) III data sets were analyzed, with participants aged 20 years and older (n = 7061). We used weighted logistic regression to determine the association between total and speciated urinary arsenic concentrations and IgG anti-HEV. For each analyte considered, a separate weighted logistic regression model was fitted. Each of these models regressed log-transformed analyte levels on the log-odds of the presence of IgG Anti-HEV. To evaluate the relationships between the urinary arsenic measurements, pairwise Pearson correlation coefficients were determined for each of the urinary arsenic measurements. Of the human subjects included, 6628 (93.9%) were negative for IgG Anti-HEV while 433 (6.1%) were positive for IgG anti-HEV. Total urinary arsenic was associated with 1.161 times greater odds of IgG anti-HEV (95% CI: [1.035, 1.303]) for each unit increase in concentration on a log-scale. For speciated urinary arsenic measurements, the odds ratios and 95% CI’s were: arsenobetanine 1.168 [1.075, 1.270], arsenocholine 1.201 [0.944, 1.529], dimethylarsinic acid 1.183 [1.009, 1.386], monomethylacrsonic acid 1.095 [0.915, 1.310], aresnous acid 0.907 [0.762, 1.079], and arsenic acid 1.951 [0.905, 4.209]. Our analysis indicates that total urinary arsenic, arsenobetanine, and dimethylarsinic acid are significantly associated with the odds of the presence of IgG anti-HEV. Future prospective studies are required to evaluate the association between hepatitis E infection and arsenic exposures.
基金supported by the National Key R&D Program of China (No.2017YFC1600702).
文摘Arsenic is commonly found in seafood,and the toxicity of different speciation varies widely.Therefore,there is an urgent need to reduce the content and analyze the speciation of arsenic to improve the safety of seafood.In this study,arsenic was removed from Chlamys farreri by adding ferric ions and sodium citrate or reducing the salinity of seawater.Then,the speciation of arsenic was analyzed.The results showed that the removal rates of arsenic were 20%,23%,24%and 18%when C.farreri individuals were treated with 0.1 g L^(−1)Fe^(3+),0.4 g L^(−1),0.6 g L^(−1)sodium citrate or decreasing seawater salinity to 17 within 48 h,respectively.Furthermore,it was detected that the arsenic speciation in the C.farreri was mainly polar arsenic,and among the polar arsenic was mainly arsenic betaine.These results indicated that the removal of arsenic can be achieved by adding the removal agent or changing the seawater salinity under the experimental conditions.The speciation of arsenic did not change during the removal process and it was mainly excreted in the speciation of arsenic betaine.
文摘Human exposure to arsenic (As) is primarily through drinking water and food ingestion. Arsenic is naturally present in the environment and has been known as “the king of poisons” since the Middle Ages. It is mutagenic, teratogenic, and carcinogenic and approximately 70% comes from ingested food and 29% from water. Once ingested, arsenic can bio-accumulate in the human body or be excreted. Arsenic in groundwater is a main source of As in humans and the two arsenicals most abundant in water are arsenite (+3 oxidation state) and arsenate (+5 oxidation state). In order of toxicity from the most toxic to least toxic are arsines, arsenites, arsenoxides, arsenates, pentavalent arsenicals, Arsenic compounds, and metallic arsenic. Arsenic accumulates in the body when ingested in small doses. It often takes decades before physical symptoms of As poisoning show. While As is element normally found in the human body, it is highly toxic in excess amounts. The lethal dose for rates is 48 μg/L which translates to 125 mg for a middle-aged male. The maximum safe limit for As ingestion for an average Vietnamese middle-aged male is 220 μg per day. This lethal dosage puts As in a highly toxic category in food and toxicology. Most of the As in the Mekong Delta groundwater is from natural alluvial sediment sources. Other anthropic sources include the burial of millions of Vietnamese with elevated As levels since 1962, industrial sources, smelting by-products, water treatment plants, sewage and wastewater treatment discharges into waterways have added to the Mekong Delta As levels in the soil and groundwater. However, Agent Blue, the As-based herbicide, used during the Vietnam War, did contribute a significant amount (over 1,132,400 kg of manufactured (anthropic) As) to Southern Vietnam landscape. The As spikes and levels in the Mekong Delta soils and groundwater need restoration. The uptake of trace amounts of As in rice is indeed a critical food security and human health issue and requires mitigation.
基金the Natural Science Foundation of Committee of Science and Technology of Shanghai Municipality(№964119035)
文摘AIM To study the effects of arsenic trioxide andHCPT on different degrees of differentiated gastriccancer cells（SGC-7901,MKN-45,MKN-28）withrespect to both cytotoxicity and induction ofapoptosis in vitro.METHODS The cytotoxicity of As<sub>2</sub>O<sub>3</sub> and HCPTon gastric cancer cells was determined by MTTassay.Morphologic changes of apoptosis ofgastric cancer cells were observed by lightmicroscopy and transmission electron microscopy.Apoptosis and cell cycle changes of gastric cancercells induced by HCPT and As<sub>2</sub>O<sub>3</sub> were investigatedby TUNEL method and flow cytometry.RESULTS As<sub>2</sub>O<sub>3</sub> and HCPT had remarkablecytotoxic effects on different degrees ofdifferentiated gastric cancer cells.The IC<sub>50</sub>ofAs<sub>2</sub>O<sub>3</sub> on well differentiated gastric cancer cellMKN-28,moderately differentiated gastric cancercell SGC-7901,and poorly differentiated gastriccancer cell MKN-28 were 8.91 μmol/L,10.57μmol/L,and 11.65 μmol/L,respectively.The IC<sub>50</sub>of HCPT on MKN-28,SGC-7901,and MKN-45 were9.35 mg/L,10.21 mg/L,and 12.63 mg/Lrespectively after 48 h treatment.After 12 h ofexposure to both drugs,gastric cancer cellsexhibited morphologic features of apoptosis,including cell shrinkage,nuclear condensation, and formation of apoptotic bodies.A typicalsubdiploid peak before G<sub>0</sub>/G<sub>1</sub> phase was observedby flow cytometry.The apoptotic rates of SGC-7901,MKN-45,and MKN-28 were 13.84%,22.52%,and 9.68%,respectively after 48 hexposure to 10 μmol/L As<sub>2</sub>O<sub>3</sub>.The apoptotic ratesof SGC-7901,MKN-45,and MKN-28 were 21.88%,12.35%,and 30.26%,respectively after 48 hexposure to 10 mg/L HCPT.The apoptotic indicewere 7%-15% as assessed by TUNEL method.The effect of As<sub>2</sub>O<sub>3</sub> on SGC-7901 showedremarkable cell cycle specificity,which inducedcell death in G<sub>1</sub> phase,and blocked G<sub>2</sub>/M phase.HCPT also showed a remarkable cell cyclespecificity,by inducing cell death and apoptosis inG<sub>1</sub> phase and arrest of proliferation at S phase.CONCLUSION As<sub>2</sub>O<sub>3</sub> and HCPT exhibitsignificant cytotoxicity on gastric cancer cells byinduction of apoptosis.As<sub>2</sub>O<sub>3</sub> and HCPT mighthave a promising prospect in the treatment ofgastric cancer,which needs to be further studied.
