[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
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
This study was carried out to assess arsenic in deep groundwater resources in the Kathmandu Valley, Nepal and to predict arsenic mobilization process in relation to iron, manganese, pH and ORP. Forty-one deep groundwa...This study was carried out to assess arsenic in deep groundwater resources in the Kathmandu Valley, Nepal and to predict arsenic mobilization process in relation to iron, manganese, pH and ORP. Forty-one deep groundwater samples were collected during pre monsoon and post monsoon in 2013. The depths of the wells were ranged from 84 to 304 m. In pre monsoon and post monsoon, arsenic concentration in 17% and 26% of examined groundwater wells, respectively exceeded permissible World Health Organization (WHO) guideline value of 0.010 mg/L for drinking water. The concentrations of arsenic were in the range between < 0.003 to 0.137 mg/L. The study demonstrated elevated concentrations of iron and manganese in the groundwater. Arsenic is highly correlated with iron and manganese. The strong negative correlation between arsenic and ORP indicates that arsenic mobilization occurs under reducing condition. These distinct relationships indicate that arsenic release is considered to be affected by the reductive dissolution of Fe/Mn oxides in the groundwater. Arsenic has very weak negative correlation with pH suggesting less effect of pH on arsenic mobilization. Arsenic is not significantly correlated with the season which infers similar distribution of arsenic in both seasons. Arsenic varies spatially in groundwater of the valley showing high concentrations in central groundwater district.展开更多
This study aims to reveal the occurrence and origin of typical groundwater with high arsenic and fluoride concentrations in the loess area of the Guanzhong Basin—a Neogene faulted basin.Key findings are as follows:(1...This study aims to reveal the occurrence and origin of typical groundwater with high arsenic and fluoride concentrations in the loess area of the Guanzhong Basin—a Neogene faulted basin.Key findings are as follows:(1)Groundwater samples with high arsenic and fluoride concentrations collected from the loess area and the terraces of the Weihe River accounted for 26%and 30%,respectively,of the total samples,with primary hydrochemical type identified as HCO_(3)-Na.The karst and sand areas exhibit relatively high groundwater quality,serving as preferred sources for water supply.It is recommended that local governments fully harness groundwater in these areas;(2)groundwater with high arsenic and fluoride concentrations in the loess area and the alluvial plain of rivers in Dali County is primarily distributed within the Guanzhong Basin,which represents the drainage zone of groundwater;(3)arsenic and fluoride in groundwater originate principally from natural and anthropogenic sources;(4)the human health risk assessments reveal that long-term intake of groundwater with high arsenic and fluoride concentrations pose cancer or non-cancer risks,which are more serious to kids compared to adults.This study provides a theoretical basis for the prevention and treatment of groundwater with high arsenic and fluoride concentrations in loess areas.展开更多
Firstly, the general situation of arsenic pollution caused by livestock and poultry industry at home and abroad was introduced, and then the transformation and adsorption of roxarsone in the environment were analyzed,...Firstly, the general situation of arsenic pollution caused by livestock and poultry industry at home and abroad was introduced, and then the transformation and adsorption of roxarsone in the environment were analyzed, finally the control measures of roxarsone pollution was discussed,展开更多
INTRODUCTIONThe main component of a traditional Chinese drug 'Pishuang'. arsenic trioxide (As2O3), has obviously selective anti-tumor effect on human hepatocellular carcinoma (HCC)in both in vitro and in vivo ...INTRODUCTIONThe main component of a traditional Chinese drug 'Pishuang'. arsenic trioxide (As2O3), has obviously selective anti-tumor effect on human hepatocellular carcinoma (HCC)in both in vitro and in vivo studies[1-5]. Due to limited effectiveness when any anti-carcinogen is used alone and obviously increased toxicity when the dose is raised, there is no exception for As2O3. Furthermore, combined chemotherapy contributes to improve therapeutic effectiveness, disperse toxicity and surmount drug-resistance,in which the combination of traditional Chinese and modern medicine has more advantages and characteristics. As a result,we made an experimental study on anti-tumor effect of As2O3in combination with cisplantin (PDD) or doxorubicin (ADM)on HCC. to investigate the possibility of AS2O3 in combination with PDD or ADM and nature of interaction between them,and to provide experimental basis for clinical application.展开更多
Abstract A system of quasilinear coupled equations which arise from simulation of contamination of geologic nulear waste in porous media is studied. We’ll discuss Galerkin method for the model of compressible flow wi...Abstract A system of quasilinear coupled equations which arise from simulation of contamination of geologic nulear waste in porous media is studied. We’ll discuss Galerkin method for the model of compressible flow with molecular diffusion and dispersion. Some new techniques are introcued to error analysis. Only one dimensional case is considered. The optimal error estimate in both L^2 and H^1 is proved. A contribution of this paper is how the dispersion term can be handled,展开更多
The regular hydrochemical monitoring of groundwater in the Mila basin over an extended period has provided valuable insights into the origin of dissolved salts and the hydrogeochemical processes controlling water sali...The regular hydrochemical monitoring of groundwater in the Mila basin over an extended period has provided valuable insights into the origin of dissolved salts and the hydrogeochemical processes controlling water salinization.The data reveals that the shallow Karst aquifer shows an increase in TDS of 162 mg L^(-1) while the ther-mal carbonate aquifer that is also used for drinking water supply exhibits an increase of 178 mg L^(-1).Additionally,significant temperature variations are recorded at the sur-face in the shallow aquifers and the waters are carbo-gaseous.Analysis of dissolved major and minor elements has identified several processes influencing the chemical composition namely:dissolution of evaporitic minerals,reduction of sulphates,congruent and incongruent car-bonates’dissolution,dedolomitization and silicates’weathering.The hydrogeochemical and geothermometric results show a mixing of saline thermal water with recharge water of meteoric origin.Two main geothermalfields have been identified,a partially evolved water reservoir and a water reservoir whosefluid interacts with sulphuric acid(H_(2)S)of magmatic origin.These hot waters that are char-acterized by a strong hydrothermal alteration do ascend through faults and fractures and contribute to the contamination of shallower aquifers.Understanding the geothermometry and the hydrogeochemistry of waters is crucial for managing and protecting the quality of groundwater resources in the Mila basin,in order to ensure sustainable water supply for the region.A conceptual model for groundwater circulation and mineralization acquisition has been established to further enhance under-standing in this regard.展开更多
We recently read the study by Kayano et al on intracorporeal anastomosis(IA)for colon cancer,which assessed bacterial contamination and medium-term onco-logical outcomes and affirmed that IA is analogous to extracorpo...We recently read the study by Kayano et al on intracorporeal anastomosis(IA)for colon cancer,which assessed bacterial contamination and medium-term onco-logical outcomes and affirmed that IA is analogous to extracorporeal anastomosis in reducing intraperitoneal bacterial risk and achieving similar oncological results.Our commentary addresses gaps,particularly concerning bowel preparation and surgical site infections(SSIs),and highlights the need for comprehensive details on the bowel preparation methods that are currently employed,including mecha-nical bowel preparation,oral antibiotics(OA),their combination,and specific OA types.We emphasize the necessity for further analyses that investigate these me-thods and their correlation with SSI rates,to enhance clinical protocol guidance and optimize surgical outcomes.Such meticulous analyses are essential for refi-ning strategies to effectively mitigate SSI risk in colorectal surgeries.展开更多
BACKGROUND:It has been pointed out that only low-dose arsenic trioxide(ATO)presents therapeutic benefits outweighing the toxic side effects.Low-dose ATO can effectively alleviate acute promyelocytic leukemia(APL). How...BACKGROUND:It has been pointed out that only low-dose arsenic trioxide(ATO)presents therapeutic benefits outweighing the toxic side effects.Low-dose ATO can effectively alleviate acute promyelocytic leukemia(APL). However,it is quite challenging in treating solid tumors. The purpose of this study was to investigate the effect of ATO at low concentrations on the metastatic potential of mouse hepatoma H22 cells and the anti-metastatic mechanism of ATO. METHODS:The metastatic potential of H22 cells was evaluated by adhesion,migration and invasion assays after exposure to a low dose of ATO in vitro.The mouse lung metastatic model induced by injection of H22 cells via the tail vein was adopted for the evaluation of metastatic potential. Different proteins in the lysate of H22 cells exposed to ATO at different concentrations were investigated by surface- enhanced laser desorption and ionization time-of-flight mass spectrometry(SELDI-TOF-MS).Finally,Western blotting analyses were made to detect the expression pattern of MMP-2 and nm23-M1 proteins. RESULTS:Significant cell death started at ATO concentrations above 2μmol/L.The growth and adhesion potential of H22 cells was inhibited in a time-and dose- dependent manner,and the migration and invasion potential of H22 cells was inhibited in a dose-dependent manner while ATO concentration was below 2μmol/L. Mice injected with ATO at a dose of 0.5 mg/kg had fewer lung metastases.However,mice injected with ATO at a dose of 2 mg/kg or 4 mg/kg had a high mortality rate and more liver injuries.A total of 15 different protein peaks were identified between the lysate of H22 cells treated with ATO and controls.Two proteins that peaked atm/z 5302 and 17207 coincided with MMP-2(fragment) and nm23-M1,respectively.Western blotting analyses demonstrated that MMP-2 and MMP-2 fragments were down-regulated and nm23-M1 was up-regulated in H22 cells treated with 2μmol/L ATO for 48 hours. CONCLUSIONS:ATO at a low dose inhibits the metastatic potential of mouse hepatoma H22 cells in vitro and in vivo, and involves down-regulation of MMP-2 and up-regulation of nm23-M1.展开更多
Arsenic （As） is one of the most important elemental pollutants in groundwater and drinking water because it causes health problem of arsenicosis after consumption of drinking arsenic-rich water more than 5-10 years....Arsenic （As） is one of the most important elemental pollutants in groundwater and drinking water because it causes health problem of arsenicosis after consumption of drinking arsenic-rich water more than 5-10 years. Arsenic contamination of groundwater is an emerging issue in Mekong Basin including Cambodia, Vietnam, and Thailand. In Thailand, information about arsenic contamination in drinking water resources are quite rare due to that arsenic is not the main element in water qualification assay. The objective of this study is to determine groundwater quality and arsenic contamination in rural Mekong Basin, Ubon Ratchathani. Groundwater samples were collected from 20 different sampling points, between August 2009 and February 2010 in Amphoe Khemmarat, Ubon Ratchathani, Thailand. Physical and chemical characteristics of groundwater were determined. It was observed that the groundwater was 27.9-30.3 ~C, pH 5.7-6.9. The conductivity was 707-767 p.S.cm＂. Dissolved oxygen was 2.04-5.12 mg.L-1 and TDS was 352-384 mg.L~. The samples showed soft- to very hardness-water properties. In some area, few parameters like CI, Fe, Mn, and As exceeded the WHO guideline limits. This result represents basic information for quality of groundwater and the arsenic contamination in rural Mekong Basin, Ubon Ratchathani. Thus, it is probably useful for arsenic standard level assignment and public health authorities. Moreover, it also leads to establish research activity in treatment of arsenic-contaminated groundwater for different purposes展开更多
The destruction of the South Vietnamese rice (<em>Oryza sativa L</em>) crop using an arsenic-based herbicide known as Agent Blue during the American Vietnam War (1965-1972) was not a secret;however, it rec...The destruction of the South Vietnamese rice (<em>Oryza sativa L</em>) crop using an arsenic-based herbicide known as Agent Blue during the American Vietnam War (1965-1972) was not a secret;however, it received little media attention in the United States. Republic of Vietnam and United States (U.S.) militaries began destroying food crops (rice) in November of 1962 primarily via aerial applications in the Mekong Delta and Central Highlands of South Vietnam. Spraying of Agent Blue on 100,000 ha of mangrove forests and about 300,000 ha of rice paddies just before rice harvest time resulted in the destruction of the standing crop and rendered the land contaminated with arsenic (As). Six Rainbow herbicides, commonly called Agent Orange, Agent Green, Agent Pink, Agent Purple, Agent White, and Agent Blue, were sprayed on wetlands, rice paddies, forests, mangroves, bamboo and military base perimeter fences to defoliate jungle vegetation, reveal guerilla hiding places and destroy the food supply of enemy troops. South Vietnamese farmers, U.S. and Republic of Vietnam military personnel, and communist insurgents were exposed to these herbicides with immediate and longer term impacts on personal health, civilian household food security and population-wide famine. Agent Blue (cacodylic acid, C<sub>2</sub>H<sub>2</sub>AsO<sub>2</sub>,) was the most effective of all the Rainbow herbicides in killing rice and grasses. Manufacturing of cacodylic acid began in the late 1950s in the U.S. at the Ansul Company chemical plant in Marinette, Wisconsin and Menominee, Michigan. During the Vietnam War, ocean going ships were loaded with 208-liter Agent Blue barrels and shipped via the St. Lawrence Seaway to the coast of South Vietnam. Arsenic (As) is a naturally occurring element that is found throughout SE Asia deltas including the Mekong Delta. Today arsenic contaminated rice and groundwater are growing concerns as neither naturally occurring arsenic nor anthropic arsenic have a half-life and cannot be destroyed. Anthropic arsenic has remained in the Mekong Delta environment for the last 60 years and added to persistent As contamination in water supplies, sediments and soils. Water soluble arsenic primarily leaches into the soil root zone and the groundwater or is carried by floodwater into adjacent waterways or volatilized under anaerobic rice paddy conditions as gaseous arsine. The health of 15 million Vietnamese people living in the Mekong Delta is at risk from the combination of manufactured and natural As in drinking water and food supply. The As in the contaminated rice paddy soil, sediment and water is up taken by fish, shrimp or by crop vegetation and trace amounts can end up in the food supply (rice grain) or be bioaccumulated by the fish, shrimp and birds which when eaten were bioaccumulated in the Vietnamese people. It is urgent that elevated As concentrations in water supplies and agricultural products be identified and mitigated through better run-off control and groundwater management;improved rice genetics and alternate crop selections;shifts in crop management associated with tillage, fertilization and phosphorus use;and systematic monitoring of food and drinking water.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
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
Assessing the concentration of trace elements in aquifers is increasingly subjected to study in Iran due to the lack of groundwater resources. This study was undertaken with the objective of determining trace elements...Assessing the concentration of trace elements in aquifers is increasingly subjected to study in Iran due to the lack of groundwater resources. This study was undertaken with the objective of determining trace elements in the alluvial aquifer located in the southern part of the Rafsanjan plain, Kerman province, Iran. The total of 73 groundwater samples from individual water wells were analyzed by atomic absorption spectroscopy (AAS). Results showed that the levels of As, Hg, Pb, Al, Fe, Cr, Ni, and Cd elements were above the World Health Organization standards for drinking-water in some parts of the plain. Thus, statistical data analyses and spatial distribution interpretation were performed to identify the main sources of the pollution. A health risk assessment model derived from US environmental protection agency was applied to calculate the cumulative exposure to As as well as toxic and carcinogenic risks caused by drinking contaminated raw groundwater. Results show that residents of some part of region may suffer from significant adverse toxic health impacts and are exposed to drinking water with As concentrations.展开更多
The World Health Organization states that foodborne diseases are a worldwide public health issue. Although street foods can provide nutritious and affordable ready-to-eat meals for city dwellers, their health risks ca...The World Health Organization states that foodborne diseases are a worldwide public health issue. Although street foods can provide nutritious and affordable ready-to-eat meals for city dwellers, their health risks can outweigh the benefits. A cross-sectional study was conducted in the Bamako district, focusing on street food vendors near schools, universities, extensive markets, administrative centers, and major roads. We aimed to sample fifty (50) sellers per municipality, making 300 sellers for the Bamako district. We developed a survey sheet to collect data, and six teams rotated between the municipalities each month. Before starting the collection, the teams were provided administrative papers approved by the municipal authority. The survey revealed three types of sales sites: fixed (65%), semi-fixed (30%), and mobile (4.40%). The proportion of sellers was 26.8%, 23.2%, 19.7%, and 4.2% in municipalities III, IV, and I. In municipalities I, II, III, IV, and VI, respectively, 92%, 95.70%, 93%, 87.2%, and 100% of the sellers were female. The age distribution of sellers was 65.63%, 46.81%, 40.82%, 38.30%, 36.17%, 36%, and 32% in the 25-34 and 35 - 44 age groups. Illiteracy rates were 59.20%, 61.70%, 55.30%, 75%, and 56% in municipalities I, II, III, IV, and VI, respectively. The study identified two categories of sellers: 48.3% in type 1 and 51.7% in type 2. The first category comprised 154 sellers, and the second 165 sellers. The survey found that 66.00%, 56.00%, 48.90%, 44.90%, 38.30%, and 34.40% of municipal V, VI, III, I, II, and IV sales sites were open-air. In municipality I, 63.30% of the sites were under hangars, while in municipalities II and IV, the corresponding percentages were 51.10% and 59.40%, respectively. Moreover, 46.00%, 31.90%, 31.30%, 30.60%, and 27.70% of the sites in municipalities VI, II, IV, I, and III were located next to gutters. In conclusion, this study identified several factors that could compromise the quality of street foods sold in the six municipalities of Bamako.展开更多
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This study was carried out to assess arsenic in deep groundwater resources in the Kathmandu Valley, Nepal and to predict arsenic mobilization process in relation to iron, manganese, pH and ORP. Forty-one deep groundwater samples were collected during pre monsoon and post monsoon in 2013. The depths of the wells were ranged from 84 to 304 m. In pre monsoon and post monsoon, arsenic concentration in 17% and 26% of examined groundwater wells, respectively exceeded permissible World Health Organization (WHO) guideline value of 0.010 mg/L for drinking water. The concentrations of arsenic were in the range between < 0.003 to 0.137 mg/L. The study demonstrated elevated concentrations of iron and manganese in the groundwater. Arsenic is highly correlated with iron and manganese. The strong negative correlation between arsenic and ORP indicates that arsenic mobilization occurs under reducing condition. These distinct relationships indicate that arsenic release is considered to be affected by the reductive dissolution of Fe/Mn oxides in the groundwater. Arsenic has very weak negative correlation with pH suggesting less effect of pH on arsenic mobilization. Arsenic is not significantly correlated with the season which infers similar distribution of arsenic in both seasons. Arsenic varies spatially in groundwater of the valley showing high concentrations in central groundwater district.
基金funded by the ministry-province cooperation-based pilot project entitled A Technological System for Ecological Remediation Evaluation of Open-Pit Mines initiated by the Ministry of Natural Resources in 2023(2023-03)survey projects of the Land and Resources Investigation Program([2023]06-03-04,1212010634713)a key R&D projects of Shaanxi Province in 2023(2023ZDLSF-63)。
文摘This study aims to reveal the occurrence and origin of typical groundwater with high arsenic and fluoride concentrations in the loess area of the Guanzhong Basin—a Neogene faulted basin.Key findings are as follows:(1)Groundwater samples with high arsenic and fluoride concentrations collected from the loess area and the terraces of the Weihe River accounted for 26%and 30%,respectively,of the total samples,with primary hydrochemical type identified as HCO_(3)-Na.The karst and sand areas exhibit relatively high groundwater quality,serving as preferred sources for water supply.It is recommended that local governments fully harness groundwater in these areas;(2)groundwater with high arsenic and fluoride concentrations in the loess area and the alluvial plain of rivers in Dali County is primarily distributed within the Guanzhong Basin,which represents the drainage zone of groundwater;(3)arsenic and fluoride in groundwater originate principally from natural and anthropogenic sources;(4)the human health risk assessments reveal that long-term intake of groundwater with high arsenic and fluoride concentrations pose cancer or non-cancer risks,which are more serious to kids compared to adults.This study provides a theoretical basis for the prevention and treatment of groundwater with high arsenic and fluoride concentrations in loess areas.
基金the Major State Basic Research Development Program(2010CB428804-1)Survey Project of Land and Resources(1212010634600)
文摘Firstly, the general situation of arsenic pollution caused by livestock and poultry industry at home and abroad was introduced, and then the transformation and adsorption of roxarsone in the environment were analyzed, finally the control measures of roxarsone pollution was discussed,
基金Supported by the Youth Science Grant of Jiangshu Province,No.BQ98048.
文摘INTRODUCTIONThe main component of a traditional Chinese drug 'Pishuang'. arsenic trioxide (As2O3), has obviously selective anti-tumor effect on human hepatocellular carcinoma (HCC)in both in vitro and in vivo studies[1-5]. Due to limited effectiveness when any anti-carcinogen is used alone and obviously increased toxicity when the dose is raised, there is no exception for As2O3. Furthermore, combined chemotherapy contributes to improve therapeutic effectiveness, disperse toxicity and surmount drug-resistance,in which the combination of traditional Chinese and modern medicine has more advantages and characteristics. As a result,we made an experimental study on anti-tumor effect of As2O3in combination with cisplantin (PDD) or doxorubicin (ADM)on HCC. to investigate the possibility of AS2O3 in combination with PDD or ADM and nature of interaction between them,and to provide experimental basis for clinical application.
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)
基金This work is suported by National Science Foundation
文摘Abstract A system of quasilinear coupled equations which arise from simulation of contamination of geologic nulear waste in porous media is studied. We’ll discuss Galerkin method for the model of compressible flow with molecular diffusion and dispersion. Some new techniques are introcued to error analysis. Only one dimensional case is considered. The optimal error estimate in both L^2 and H^1 is proved. A contribution of this paper is how the dispersion term can be handled,
文摘The regular hydrochemical monitoring of groundwater in the Mila basin over an extended period has provided valuable insights into the origin of dissolved salts and the hydrogeochemical processes controlling water salinization.The data reveals that the shallow Karst aquifer shows an increase in TDS of 162 mg L^(-1) while the ther-mal carbonate aquifer that is also used for drinking water supply exhibits an increase of 178 mg L^(-1).Additionally,significant temperature variations are recorded at the sur-face in the shallow aquifers and the waters are carbo-gaseous.Analysis of dissolved major and minor elements has identified several processes influencing the chemical composition namely:dissolution of evaporitic minerals,reduction of sulphates,congruent and incongruent car-bonates’dissolution,dedolomitization and silicates’weathering.The hydrogeochemical and geothermometric results show a mixing of saline thermal water with recharge water of meteoric origin.Two main geothermalfields have been identified,a partially evolved water reservoir and a water reservoir whosefluid interacts with sulphuric acid(H_(2)S)of magmatic origin.These hot waters that are char-acterized by a strong hydrothermal alteration do ascend through faults and fractures and contribute to the contamination of shallower aquifers.Understanding the geothermometry and the hydrogeochemistry of waters is crucial for managing and protecting the quality of groundwater resources in the Mila basin,in order to ensure sustainable water supply for the region.A conceptual model for groundwater circulation and mineralization acquisition has been established to further enhance under-standing in this regard.
文摘We recently read the study by Kayano et al on intracorporeal anastomosis(IA)for colon cancer,which assessed bacterial contamination and medium-term onco-logical outcomes and affirmed that IA is analogous to extracorporeal anastomosis in reducing intraperitoneal bacterial risk and achieving similar oncological results.Our commentary addresses gaps,particularly concerning bowel preparation and surgical site infections(SSIs),and highlights the need for comprehensive details on the bowel preparation methods that are currently employed,including mecha-nical bowel preparation,oral antibiotics(OA),their combination,and specific OA types.We emphasize the necessity for further analyses that investigate these me-thods and their correlation with SSI rates,to enhance clinical protocol guidance and optimize surgical outcomes.Such meticulous analyses are essential for refi-ning strategies to effectively mitigate SSI risk in colorectal surgeries.
文摘BACKGROUND:It has been pointed out that only low-dose arsenic trioxide(ATO)presents therapeutic benefits outweighing the toxic side effects.Low-dose ATO can effectively alleviate acute promyelocytic leukemia(APL). However,it is quite challenging in treating solid tumors. The purpose of this study was to investigate the effect of ATO at low concentrations on the metastatic potential of mouse hepatoma H22 cells and the anti-metastatic mechanism of ATO. METHODS:The metastatic potential of H22 cells was evaluated by adhesion,migration and invasion assays after exposure to a low dose of ATO in vitro.The mouse lung metastatic model induced by injection of H22 cells via the tail vein was adopted for the evaluation of metastatic potential. Different proteins in the lysate of H22 cells exposed to ATO at different concentrations were investigated by surface- enhanced laser desorption and ionization time-of-flight mass spectrometry(SELDI-TOF-MS).Finally,Western blotting analyses were made to detect the expression pattern of MMP-2 and nm23-M1 proteins. RESULTS:Significant cell death started at ATO concentrations above 2μmol/L.The growth and adhesion potential of H22 cells was inhibited in a time-and dose- dependent manner,and the migration and invasion potential of H22 cells was inhibited in a dose-dependent manner while ATO concentration was below 2μmol/L. Mice injected with ATO at a dose of 0.5 mg/kg had fewer lung metastases.However,mice injected with ATO at a dose of 2 mg/kg or 4 mg/kg had a high mortality rate and more liver injuries.A total of 15 different protein peaks were identified between the lysate of H22 cells treated with ATO and controls.Two proteins that peaked atm/z 5302 and 17207 coincided with MMP-2(fragment) and nm23-M1,respectively.Western blotting analyses demonstrated that MMP-2 and MMP-2 fragments were down-regulated and nm23-M1 was up-regulated in H22 cells treated with 2μmol/L ATO for 48 hours. CONCLUSIONS:ATO at a low dose inhibits the metastatic potential of mouse hepatoma H22 cells in vitro and in vivo, and involves down-regulation of MMP-2 and up-regulation of nm23-M1.
文摘Arsenic （As） is one of the most important elemental pollutants in groundwater and drinking water because it causes health problem of arsenicosis after consumption of drinking arsenic-rich water more than 5-10 years. Arsenic contamination of groundwater is an emerging issue in Mekong Basin including Cambodia, Vietnam, and Thailand. In Thailand, information about arsenic contamination in drinking water resources are quite rare due to that arsenic is not the main element in water qualification assay. The objective of this study is to determine groundwater quality and arsenic contamination in rural Mekong Basin, Ubon Ratchathani. Groundwater samples were collected from 20 different sampling points, between August 2009 and February 2010 in Amphoe Khemmarat, Ubon Ratchathani, Thailand. Physical and chemical characteristics of groundwater were determined. It was observed that the groundwater was 27.9-30.3 ~C, pH 5.7-6.9. The conductivity was 707-767 p.S.cm＂. Dissolved oxygen was 2.04-5.12 mg.L-1 and TDS was 352-384 mg.L~. The samples showed soft- to very hardness-water properties. In some area, few parameters like CI, Fe, Mn, and As exceeded the WHO guideline limits. This result represents basic information for quality of groundwater and the arsenic contamination in rural Mekong Basin, Ubon Ratchathani. Thus, it is probably useful for arsenic standard level assignment and public health authorities. Moreover, it also leads to establish research activity in treatment of arsenic-contaminated groundwater for different purposes
文摘The destruction of the South Vietnamese rice (<em>Oryza sativa L</em>) crop using an arsenic-based herbicide known as Agent Blue during the American Vietnam War (1965-1972) was not a secret;however, it received little media attention in the United States. Republic of Vietnam and United States (U.S.) militaries began destroying food crops (rice) in November of 1962 primarily via aerial applications in the Mekong Delta and Central Highlands of South Vietnam. Spraying of Agent Blue on 100,000 ha of mangrove forests and about 300,000 ha of rice paddies just before rice harvest time resulted in the destruction of the standing crop and rendered the land contaminated with arsenic (As). Six Rainbow herbicides, commonly called Agent Orange, Agent Green, Agent Pink, Agent Purple, Agent White, and Agent Blue, were sprayed on wetlands, rice paddies, forests, mangroves, bamboo and military base perimeter fences to defoliate jungle vegetation, reveal guerilla hiding places and destroy the food supply of enemy troops. South Vietnamese farmers, U.S. and Republic of Vietnam military personnel, and communist insurgents were exposed to these herbicides with immediate and longer term impacts on personal health, civilian household food security and population-wide famine. Agent Blue (cacodylic acid, C<sub>2</sub>H<sub>2</sub>AsO<sub>2</sub>,) was the most effective of all the Rainbow herbicides in killing rice and grasses. Manufacturing of cacodylic acid began in the late 1950s in the U.S. at the Ansul Company chemical plant in Marinette, Wisconsin and Menominee, Michigan. During the Vietnam War, ocean going ships were loaded with 208-liter Agent Blue barrels and shipped via the St. Lawrence Seaway to the coast of South Vietnam. Arsenic (As) is a naturally occurring element that is found throughout SE Asia deltas including the Mekong Delta. Today arsenic contaminated rice and groundwater are growing concerns as neither naturally occurring arsenic nor anthropic arsenic have a half-life and cannot be destroyed. Anthropic arsenic has remained in the Mekong Delta environment for the last 60 years and added to persistent As contamination in water supplies, sediments and soils. Water soluble arsenic primarily leaches into the soil root zone and the groundwater or is carried by floodwater into adjacent waterways or volatilized under anaerobic rice paddy conditions as gaseous arsine. The health of 15 million Vietnamese people living in the Mekong Delta is at risk from the combination of manufactured and natural As in drinking water and food supply. The As in the contaminated rice paddy soil, sediment and water is up taken by fish, shrimp or by crop vegetation and trace amounts can end up in the food supply (rice grain) or be bioaccumulated by the fish, shrimp and birds which when eaten were bioaccumulated in the Vietnamese people. It is urgent that elevated As concentrations in water supplies and agricultural products be identified and mitigated through better run-off control and groundwater management;improved rice genetics and alternate crop selections;shifts in crop management associated with tillage, fertilization and phosphorus use;and systematic monitoring of food and drinking water.
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.
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Assessing the concentration of trace elements in aquifers is increasingly subjected to study in Iran due to the lack of groundwater resources. This study was undertaken with the objective of determining trace elements in the alluvial aquifer located in the southern part of the Rafsanjan plain, Kerman province, Iran. The total of 73 groundwater samples from individual water wells were analyzed by atomic absorption spectroscopy (AAS). Results showed that the levels of As, Hg, Pb, Al, Fe, Cr, Ni, and Cd elements were above the World Health Organization standards for drinking-water in some parts of the plain. Thus, statistical data analyses and spatial distribution interpretation were performed to identify the main sources of the pollution. A health risk assessment model derived from US environmental protection agency was applied to calculate the cumulative exposure to As as well as toxic and carcinogenic risks caused by drinking contaminated raw groundwater. Results show that residents of some part of region may suffer from significant adverse toxic health impacts and are exposed to drinking water with As concentrations.
文摘The World Health Organization states that foodborne diseases are a worldwide public health issue. Although street foods can provide nutritious and affordable ready-to-eat meals for city dwellers, their health risks can outweigh the benefits. A cross-sectional study was conducted in the Bamako district, focusing on street food vendors near schools, universities, extensive markets, administrative centers, and major roads. We aimed to sample fifty (50) sellers per municipality, making 300 sellers for the Bamako district. We developed a survey sheet to collect data, and six teams rotated between the municipalities each month. Before starting the collection, the teams were provided administrative papers approved by the municipal authority. The survey revealed three types of sales sites: fixed (65%), semi-fixed (30%), and mobile (4.40%). The proportion of sellers was 26.8%, 23.2%, 19.7%, and 4.2% in municipalities III, IV, and I. In municipalities I, II, III, IV, and VI, respectively, 92%, 95.70%, 93%, 87.2%, and 100% of the sellers were female. The age distribution of sellers was 65.63%, 46.81%, 40.82%, 38.30%, 36.17%, 36%, and 32% in the 25-34 and 35 - 44 age groups. Illiteracy rates were 59.20%, 61.70%, 55.30%, 75%, and 56% in municipalities I, II, III, IV, and VI, respectively. The study identified two categories of sellers: 48.3% in type 1 and 51.7% in type 2. The first category comprised 154 sellers, and the second 165 sellers. The survey found that 66.00%, 56.00%, 48.90%, 44.90%, 38.30%, and 34.40% of municipal V, VI, III, I, II, and IV sales sites were open-air. In municipality I, 63.30% of the sites were under hangars, while in municipalities II and IV, the corresponding percentages were 51.10% and 59.40%, respectively. Moreover, 46.00%, 31.90%, 31.30%, 30.60%, and 27.70% of the sites in municipalities VI, II, IV, I, and III were located next to gutters. In conclusion, this study identified several factors that could compromise the quality of street foods sold in the six municipalities of Bamako.
