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1.
Food Chem ; 303: 125392, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31446362

RESUMO

In this article, an easy and quick method based on microwave assisted acid digestion technique prior to quantification using inductively coupled plasma mass spectrometry for the analysis of heavy metals in cocoa beans, cocoa powder and chocolate was established and validated for arsenic (As), cadmium (Cd), lead (Pb), and antimony (Sb). Limit of quantification for all elements were product dependent and varies from 7.84 to 194.52 µg/kg. The recoveries of the heavy metals at 250 and 1000 µg/kg spiking levels were ranged between 96.27-108.75%, 90.43-101.97% and 89.72-106.26% for cocoa beans, cocoa powder, and chocolate, respectively. Relative standard deviation values obtained were all below 20% and the expanded uncertainty measurements for the elements were less than 25%. The analysis of real samples found that the concentration level is far from the national alarming level except for cadmium in cocoa beans.


Assuntos
Cacau/química , Fracionamento Químico/métodos , Espectrometria de Massas/métodos , Metais Pesados/análise , Micro-Ondas , Sementes/química , Antimônio/análise , Arsênico/análise , Cádmio/análise , Chocolate/análise , Chumbo/análise
2.
Zhongguo Zhong Yao Za Zhi ; 44(14): 3078-3086, 2019 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-31602856

RESUMO

The element speciation analysis for heavy metals in herbal medicines is still in the beginning stage. In this study,the total amount of arsenic( As) in 103 batches of 17 commonly used Chinese medicines( including 16 plant medicines and 1 medicinal fungus) was detected by inductively coupled plasma mass spectrometry( ICP-MS). Furthermore,based on HPLC-ICP-MS,the simultaneous detection methods of six As speciation kinds in traditional Chinese medicines were established. An AS7 anion exchange column was selected and the As forms in 17 traditional Chinese medicines was systematically analyzed. The results showed that the method of pretreatment of medicinal materials by microwave digestion and the detection of total amount of As by ICP-MS was stable and reliable. As for the speciation analysis of As,the high-speed ultrasonic extraction method was adopted,and it showed that the linear relationship of the six As speciation was satisfied with the correlation coefficient R2>0. 999 9. The LOQ of six kinds of As speciation were 0. 20,0. 10,0. 15,0. 10,0. 25,0. 10 µg·L~(-1) for arsenic betaine( As B),arsenious acid [As( Ⅲ) ],dimethyl arsenic( DMA),arsenic choline( As C),monomethyl arsenic( MMA),arsenic acid[As( Ⅴ) ],respectively. The recoveries were between 84. 24% and 121. 5%,and the relative standard deviations were 2. 7% to 11%. Among the 103 batches of medicinal materials,only one batch of sample As exceeded the Chinese Pharmacopoeia limit standard; As( Ⅲ) and As( Ⅴ) had high detection rate in 103 batches of Chinese herbal medicines,within which As( Ⅴ) was the main detected form,and inorganic As accounted for the ratio reached 80. 90%-98. 73%; some samples detected DMA,MMA and As B,As C was not detected in any batch. This study established an analytical method suitable for the speciation of As in Chinese herbal medicines,and provided basic data for As residual residue in Chinese herbal medicines,which can provide important reference for the risk assessment and quality standards.


Assuntos
Arsênico/análise , Medicamentos de Ervas Chinesas/análise , Cromatografia Líquida de Alta Pressão , Medicamentos de Ervas Chinesas/normas , Espectrometria de Massas
3.
Anal Bioanal Chem ; 411(27): 7251-7260, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31612256

RESUMO

Chloride widely exists in the environment and will cause serious interference for arsenic speciation analysis. The determination of four arsenic species including arsenite (As(III)), arsenate (As(V)), monomethylarsenate (MMA), and dimethylarsonate (DMA) in samples containing high concentrations of Cl- was carried out in this work by coupling of liquid chromatography (LC) with hydride generation atomic fluorescence spectrometry (HG-AFS). The interference of Cl- was successfully eliminated by coupling two anion-exchange chromatographic columns in series and eluting with 35.0 mmol L-1 (NH4)2HPO4 (pH = 6.00). A novel pre-treatment system was subsequently developed to realize on-line column switch and pre-reduction of As(V). The analysis time was shortened by an isocratic elution but programmed flow rate method, and the sensitivity of As(V) was also enhanced by the introduction of pre-reduction using the developed system. The proposed method can resist at least 10 g L-1 Cl- without any pre-treatment operations. Since LC-HG-AFS is low-cost and can be afforded or self-assembled by most labs, the developed method can be adopted as a routine analysis method for arsenic species in chloride-bearing samples, such as urine and seawater. Graphical abstract.


Assuntos
Arseniatos/análise , Arsenicais/análise , Arsenitos/análise , Poluentes Químicos da Água/análise , Arseniatos/urina , Arsênico/análise , Arsênico/urina , Arsenicais/urina , Arsenitos/urina , Cloretos/análise , Cloretos/urina , Cromatografia Líquida de Alta Pressão/instrumentação , Desenho de Equipamento , Humanos , Limite de Detecção , Metilação , Água do Mar/análise , Espectrometria de Fluorescência/instrumentação , Espectrofotometria Atômica/instrumentação , Poluentes Químicos da Água/urina
4.
Wei Sheng Yan Jiu ; 48(5): 739-744, 2019 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-31601314

RESUMO

OBJECTIVE: To understand the toxicological indexes of rural drinking water quality in 2016-2018 in Shaanxi Province. METHODS: From 2016 to2018, rural drinking water monitoring points were set up in all( 102) agriculture-related counties( districts) in Shaanxi Province. Each township selected 1-2 rural water supply systems for terminal water supply and terminal water and waste water for distributed water supply as monitoring points. A total of 18 284 monitoring points were set. Water samples were collected during the dry season from April to June and from July to September, according to the Standard Test Method for Drinking Water( GB/T 5750. 5-2006, GB/T5750. 6-2006, GB/T 5750. 8-2006). Carried out experimental analysis and collected water quality monitoring information through the "National Drinking Water Quality Monitoring Information System ". Experimental analysis according to the Standard Test Method for Drinking Water( GB/T 5750. 5-2006, GB/T 5750. 6-2006, GB/T5750. 8-2006); 11 toxicological indicators of the routine indicators were analyzed and evaluated according to the Standard of Drinking Water Hygiene( GB 5749-2006). RESULTS: From 2016 to 2018, the overall compliance rate of drinking water toxicology indicators in rural areas of Shaanxi Province was 81. 02%. The top four indicators exceeding the standard were fluoride( 9. 74%), nitrate nitrogen( 6. 09%) and hexavalent chromium. ( 4. 50%) and arsenic( 1. 44%), the other indicators exceeding the standard exceeds the range of 0. 01%-0. 32%. The difference of water quality compliance rates of cadmium, selenium, cyanide, fluoride and nitrate nitrogen in different years was statistically significant( P<0. 05), and the compliance rate of selenium, cyanide, fluoride and nitrate nitrogen increased with the year. Increasing trend( P<0. 05). The compliance rate of cadmium and selenium in the wet season was higher than that in the dry season, and the compliance rate of nitrate nitrogen in the dry season was higher than that in the wet season, the difference was statistically significant( P<0. 05). The compliance rate of arsenic, cadmium, hexavalent chromium, lead, selenium, fluoride and nitrate nitrogen in surface water were higher than that of groundwater( P < 0. 05). There was a statistically significant difference in the overall compliance rate of water toxicology between different water supply method in centralized water supply projects( P < 0. 001). The highest standard rate of water quality was observed in conventional water treatment, followed by sedimentation and filtration. There were 10, 10 and 4 types of over-standard indicators in Guanzhong, northern Shaanxi and southern Shaanxi, and the regional differences of 7 indicators including arsenic, cadmium, hexavalent chromium, lead, selenium, fluoride and nitrate nitrogen had statistics significance( P<0. 05). CONCLUSION: The overall compliance rate of toxicological indicators of drinking water in rural areas of Shaanxi Province is low, fluoride, nitrate nitrogen, hexavalent chromium and arsenic are serious and have obvious regional characteristics. In the future, we should focus on the excessive toxicological indicators, and ensure the safety and hygiene of drinking water from the aspects of water supply and treatment technology.


Assuntos
Água Potável/química , Monitoramento Ambiental , Poluentes Químicos da Água/análise , Arsênico/análise , Água Subterrânea/química , Humanos , Qualidade da Água , Abastecimento de Água
5.
J Water Health ; 17(5): 801-812, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31638030

RESUMO

Well water around the world can be contaminated with arsenic, a naturally occurring geological element that has been associated with myriad adverse health effects. Persons obtaining their drinking water from private wells are often responsible for well testing and water treatment. High levels of arsenic have been reported in well water-supplied areas of the United States. We quantified - in cases and dollars - the potential burden of disease associated with the ingestion of arsenic through private well drinking water supplies in the United States. To estimate cancer and cardiovascular disease burden, we developed a Monte Carlo model integrating three input streams: (1) regional concentrations of arsenic in drinking water wells across the United States; (2) dose-response relationships in the form of cancer slope factors and hazard ratios; and (3) economic cost estimates developed for morbidity endpoints using 'cost-of-illness' methods and for mortality using 'value per statistical life' estimates. Exposure to arsenic in drinking water from U.S. domestic wells is modeled to contribute 500 annual premature deaths from ischemic heart disease and 1,000 annual cancer cases (half of them fatal), monetized at $10.9 billion (2017 USD) annually. These considerable public health burden estimates can be compared with the burdens of other priority public health issues to assist in decision-making.


Assuntos
Arsênico/análise , Efeitos Psicossociais da Doença , Água Potável/química , Poluentes Químicos da Água/análise , Purificação da Água , Poços de Água , Estados Unidos , Abastecimento de Água
6.
Environ Monit Assess ; 191(10): 602, 2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31478102

RESUMO

Globally, millions of tons of coal fly ash (CFA) are generated per year, and the majority of this material is usually stored in stock piles or landfills, and in a long-term, it can be an environmental hazard if rainwater infiltrates the ashes. Long-term leaching studies of Brazilian ashes are scarce. The purpose of this study was to evaluate arsenic, cadmium, molybdenum, lead, and zinc leaching behavior from a Brazilian CFA by a column experiment designed to simulate field conditions: slightly acid rain considering seasonality of precipitation and temperature for a long-term leaching period (336 days). All elements were leached from CFA, except lead. Elements leaching behavior was influenced by leaching time, leaching volume, and temperature. Higher leachability of As and Cd from CFA during warm and wet season was observed. Results indicate a potential risk to soil and groundwater, since ashes are usually stored in uncovered fields on power plants vicinity.


Assuntos
Cinza de Carvão/química , Monitoramento Ambiental , Metais Pesados/análise , Arsênico/análise , Arsênico/química , Brasil , Cádmio/análise , Cádmio/química , Água Subterrânea , Chumbo/análise , Chumbo/química , Molibdênio/análise , Molibdênio/química , Centrais Elétricas , Solo/química , Instalações de Eliminação de Resíduos , Zinco/análise , Zinco/química
7.
Environ Res ; 177: 108616, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31442790

RESUMO

BACKGROUND: Chronic exposure to inorganic arsenic (iAs) in the US occurs mainly through drinking water and diet. Although American Indian (AI) populations have elevated urinary arsenic concentrations compared to the general US population, dietary sources of arsenic exposure in AI populations are not well characterized. METHODS: We evaluated food frequency questionnaires to determine the major dietary sources of urinary arsenic concentrations (measured as the sum of arsenite, arsenate, monomethylarsonate, and dimethylarsinate, ΣAs) for 1727 AI participants in the Strong Heart Family Study (SHFS). We compared geometric mean ratios (GMRs) of urinary ΣAs for an interquartile range (IQR) increase in reported food group consumption. Exploratory analyses were stratified by gender and study center. RESULTS: In fully adjusted generalized estimating equation models, the percent increase (95% confidence interval) of urinary ΣAs per increase in reported food consumption corresponding to the IQR was 13% (5%, 21%) for organ meat, 8% (4%, 13%) for rice, 7% (2%, 13%) for processed meat, and 4% (1%, 7%) for non-alcoholic drinks. In analyses stratified by study center, the association with organ meat was only observed in North/South Dakota. Consumption of red meat [percent increase -7% (-11%, -3%)] and fries and chips [-6% (-10%, -2%)] was inversely associated with urinary ΣAs. CONCLUSIONS: Organ meat, processed meat, rice, and non-alcoholic drinks contribute to ΣAs exposure in the SHFS population. Organ meat is a unique source of ΣAs exposure for North and South Dakota participants and may reflect local food consumption. Further studies should comprehensively evaluate drinking water arsenic in SHFS communities and determine the relative contribution of diet and drinking water to total arsenic exposure.


Assuntos
Arsênico/análise , Arsenicais/análise , Dieta , Exposição Dietética/análise , Adulto , Ácido Cacodílico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Adulto Jovem
8.
Sci Total Environ ; 691: 1242-1250, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31466204

RESUMO

In Argentina, drinking water for c.a. 10% of the population has arsenic (As) concentrations higher than those recommended by WHO (10 µg L-1). Reverse osmosis (RO) appears as an immediate and effective solution for As remediation. However, this process has a residual flow known as "rejection" or "concentrate" where dissolved species are more concentrated than in the feed flow. In this study, phytoremediation with subsurface horizontal-flow constructed wetlands (CW) was proposed to reduce As concentration in the RO residues. Experiments were carried out during 419 days at room temperature and using a continuous regime (flow of 36 L d-1, As concentration around 85 µg L-1) of RO rejection from a water treatment plant located in Buenos Aires province, Argentina. The study was performed using prototypes planted with Cyperus haspan (PA), Juncus effusus (PB) and a mix of inert gravel and laterite (substrate) that was used as a control (PC). Results showed that after a stabilization time, As removal (%) was between 30% and 80% in the CW planted with J. effusus and between 10 and 40% with C. haspan. As concentration along CW showed similarities between the prototypes PC and PA. The cumulative mass of As was 62%, 34% and 27% for PA, PB and PC, respectively. The contribution of C. haspan and J. effusus during the experimental time was between 12 and 67% and 22 to 87%, respectively. The bioaccumulation and translocation factors indicated that for J. effusus the accumulation is more important than the translocation process (1.6 and 0.2, respectively), while for C. haspan both factors were similar (1.1 and 1.0, respectively). Results suggested that this technology has the potential for an efficient and environmentally sustainable alternative to RO rejection treatment and disposal regarding As concentration.


Assuntos
Arsênico/análise , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Áreas Alagadas , Biodegradação Ambiental , Purificação da Água/métodos
9.
Ecotoxicol Environ Saf ; 183: 109550, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31419698

RESUMO

Recent discoveries on arsenic (As) biogeochemistry in aquifer-sediment system have strongly improved our understanding of As enrichment mechanisms in groundwater. We summarize here the research results since 2015 focusing on the As interfacial geochemistry including As speciation, transformation, and mobilization. We discuss the chemical extraction and speciation of As in environmental matrices, followed by As redox change and (im)mobilization in typical minerals and aquifer system. Then, the microbial-assisted reductive dissolution of Fe (hydr)oxides and As transformation and liberation are summarized from the aspects of bacterial isolates, microbial community and gene analysis by comparing As rich groundwater cases worldwide. Finally, the potential effect of organic matter on As interfacial geochemistry are addressed in the aspects of chemical interactions and microbial respiring activities for Fe and As reductive release.


Assuntos
Arsênico/análise , Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Água Subterrânea/química , Substâncias Húmicas/análise , Poluentes Químicos da Água/análise , Sedimentos Geológicos/microbiologia , Água Subterrânea/microbiologia , Minerais/análise , Oxirredução
10.
Environ Pollut ; 254(Pt B): 113049, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31454582

RESUMO

This study aimed to determine if there is a co-elevation of human blood arsenic and mercury levels in the Midwestern population of the United States (U.S.) and to determine any geographical patterns and variation of arsenic and mercury that may exist in Michigan. 58,800 blood specimens along with associated demographic/geographic data from the contiguous United States were reviewed. Univariate and multivariable logistic regression were used to analyze demographic/geographic variables associated with elevated arsenic concentrations. Furthermore, blood data from patients in Michigan were aggregated to the ZIP code tabulation area (ZCTA) in order to assess geographic variation using spatial regression models. SaTScan software was also used to analyze potential clustering of arsenic and mercury across Michigan ZCTAs. Within the contiguous United States, elevated mercury blood concentrations, older age, female sex, and coastal status were all associated with elevated arsenic blood concentrations (elevated mercury odds ratio (OR) 3.18 (3.04-3.33); female sex OR 1.06 (1.02-1.11); +10 yr age OR 1.12 (1.11-1.14); coastal state OR 1.33 (1.27-1.40). Within the state of Michigan, as with the continuous U.S., elevated mercury blood concentrations and older age were associated with elevated arsenic blood concentrations (elevated mercury OR 2.75 (2.38-3.18); female sex OR 1.06 (0.95-1.19); +10 yr age OR 1.10 (1.06-1.13). Using spatial regression, it was determined that within Michigan, economic inequality (measured via the Gini coefficient) was also associated with elevated concentrations of mercury in the blood. Clinical reference laboratory data, in conjunction with spatial analysis methods, may enhance our understanding of how elemental exposure affects human health and should be considered for studying how environmental contaminants, socioeconomics and geography affect the health of populations.


Assuntos
Arsênico/análise , Exposição Ambiental/análise , Mercúrio/análise , Adulto , Idoso , Exposição Ambiental/estatística & dados numéricos , Feminino , Geografia , Humanos , Masculino , Michigan , Pessoa de Meia-Idade , Estados Unidos
11.
Sci Total Environ ; 689: 1037-1043, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31466144

RESUMO

Dissolved organic matter (DOM) elucidated from biochars enhances the dissolution of iron oxides and reduction of iron. However, given that reduction mechanism of iron (Fe(III)) in the practical biochar applications for soil amendment and environmental remediation have not been fully elucidated, this study laid great emphasis on the photo-induced Fe(II) liberated from DOM-Fe(III) complexes. Thus, pyrolysis of biomass was carried out at 300 °C to maximize DOM release from biochars. Moreover, three different biomass samples (rice straw (R), granular sludge (G) from an anaerobic digester, and spent coffee grounds (C)) were chosen as carbon substrates for biochars preparation. To demonstrate the transformation of Fe(III), 1 and 5 wt% biochar was applied to the clean (S1) and arsenic-contaminated (S2) soil with/without the light. The results indicate that the light condition produces more Fe(II). The amount of Fe(II) accounts for 25.3, 28.6, and 30.7% of total iron under the light with 5 wt% GB, RB, and CB in S1, and 10.6, 13.1, and 13.8% in S2. This study demonstrates that Fe(II) is generated more under ultraviolet irradiation than visible light and dark condition. In addition, a control experiment without biochar showed that DOM plays an important role in the reduction of Fe(III). The mobility of arsenic increased under the light condition since the intermediates of DOM photo-degradation accelerates the dissolution of iron oxides and arsenic competes with DOM for the adsorption. Therefore, there was no significant correlation between the elution of arsenic and the formation of Fe(II) during the reductive dissolution of iron oxide under the light condition.


Assuntos
Arsênico/análise , Recuperação e Remediação Ambiental/métodos , Poluentes do Solo/análise , Adsorção , Arsênico/química , Biomassa , Carbono , Carvão Vegetal/química , Compostos Férricos , Ferro/química , Oryza , Oxirredução , Solo/química , Poluentes do Solo/química
12.
Sci Total Environ ; 689: 1244-1254, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31466163

RESUMO

Bioaccessibility (BAC) of fine surface dust (FSD, particle size ≤10 µm) and surface dust samples (particle size ≤250 µm) collected from a gold mining district was used as a tool to determine the portion of arsenic that would be available via simulated lung and gastrointestinal (G.I) fluids. BAC was considered low for both tests (lung 2.7 ±â€¯1%, n = 5 and G.I 3.4 ±â€¯2%, n = 14 for residential surface dust samples). An analytical procedure was developed to further identify arsenic-bearing phases found in FSD samples and analyze the main components that regulate arsenic solubility. Up to five different arsenic-bearing phases were identified among a total of 35 minerals surveyed by scanning electron microscopy-based automated image analysis (Mineral Liberation Analyzer - MLA). Arsenic-bearing Fe oxy-hydroxides and mixed phases comprised the main arsenic phases encountered in FSD samples, thus likely being responsible for regulating arsenic bioaccessibility. Transmission electron microscopy showed that the mixed phases comprised a mix of oriented nanostructure aggregates formed by hematite and goethite entangled with phyllosilicates. The main As-bearing phases identified in FSD samples are similar to those reported in soil samples in the same region. The predominant arsenic-bearing phase encountered in the ore was arsenopyrite, mostly in large particles (>10 µm in size), and therefore unlikely to be found in residential dust. Arsenic intake from both inhalation and ingestion were minimal when compared to total arsenic intake (considering food and water ingestion), which itself was <7% of the value established by the Food and Agriculture Organization of the United Nations Benchmark Dose Lower Confidence Limit (BMDL0.5) of 3.0 µg per kg-1 body weight per day. These results indicated that the relative risks associated with arsenic exposure by inhalation and oral ingestion in this region are low.


Assuntos
Arsênico/análise , Exposição Ambiental/análise , Poluentes do Solo/análise , Poeira/análise , Exposição Ambiental/estatística & dados numéricos , Mineração
13.
Environ Monit Assess ; 191(8): 528, 2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31367959

RESUMO

The distribution and bioavailability of arsenic (As) in indoor/outdoor total suspended particulates (TSP), inhalable particulate matters (PM10), and fine particulate matters (PM2.5) in Baoding, China were investigated. The average I/O ratios for TSP, PM10, and PM2.5 were 0.52, 0.66, and 0.96, respectively. There was no significant correlation between indoor/outdoor TSP, PM10, and PM2.5. The indoor/outdoor concentrations of As surpassed the limited value of As. I/O ratios of arsenic in TSP, PM10, and PM2.5 were 0.52, 0.58, and 0.55, respectively. The contents of arsenic in different fractions were mainly affected by the total concentrations of arsenic in particulate matters (PM) rather than the particle sizes for TSP and PM10. Arsenic was mainly in non-specifically sorbed fraction (F1) in both indoor and outdoor PM2.5. The evaluated carcinogenic risk (CR) was within the safe level. The bioavailability of As increased with particle size decreasing for both indoor and outdoor PM. The potential bioavailability of As in outdoor particles was higher than that of indoor particles with the same size, especially PM2.5.


Assuntos
Poluentes Atmosféricos/análise , Arsênico/análise , Material Particulado/química , Poluentes Atmosféricos/química , Poluição do Ar em Ambientes Fechados/análise , Arsênico/química , China , Monitoramento Ambiental , Humanos , Tamanho da Partícula , Material Particulado/análise
14.
Sci Total Environ ; 686: 1185-1193, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31412514

RESUMO

A novel Fe-Mn-La-impregnated biochar composite (FMLBC) was synthesized using an impregnation method for efficient As (III) adsorption. The pseudo-second-order model (R2 values are 0.996, 0.996, and 0.994 for different FMLBC rate used) better fitted the kinetic adsorption of arsenic (As) on the FMLBC than the pseudo-first order model (R2 values are 0.978, 0.971, and 0.991 respectively). The SEM-EDS, FTIR and XPS results confirmed the addition of Fe, Mn and La into the BC structure. Compared with pristine biochar (3.73 mg g-1) and Fe-Mn-impregnated biochar (9.48 mg g-1), the As (III) adsorption capacity of Fe-Mn-La impregnated biochar (14.9 mg g-1) was significantly improved. The presence of NO3- and SO42- did not influence As adsorption, whereas PO43- influenced As removal. The mechanism of As adsorption on the FMLBC involved oxidization, electrostatic attraction, ligand exchange, and formation of an inner-sphere R-O-As complex. Among them, the electrostatic attraction and inner-sphere complexation contributed the most. The simple preparation process and high adsorption performance suggest that the FMLBC could be served as a promising adsorbent for As (III) removal from aqueous solution.


Assuntos
Arsênico/análise , Carvão Vegetal/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Adsorção , Ferro/química , Lantânio/química , Manganês/química
15.
Environ Pollut ; 253: 966-973, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31351305

RESUMO

In present study, the analyses of essential [copper (Cu), cobalt (Co), selenium (Se) and zinc (Zn)] and non-essential elements [mercury (Hg), lead (Pb), cadmium (Cd) and arsenic (As)] in 7 fish species consumed by the indigenous people of the European Russia Arctic were conducted. The Nenets Autonomous Region, which is located in the north-eastern part of European Russia, was chosen as a Region of interest. Within it, the Nenets indigenous group (n = 6000) constitutes approximately 10% of the total population. Nearly all of the Nenets live a traditional life with fish caught in the local waters as a subsistence resource. We found that northern pike contained twice the amount of Hg compared with roach, and 3-4 times more than other fish species commonly consumed in the Russian Arctic (namely, Arctic char, pink salmon, navaga, humpback whitefish and inconnu). Fish Hg concentrations were relatively low, but comparable to those reported in other investigations that illustrate a decreasing south-to-north trend in fish Hg concentrations. In the current study, northern pike is the only species for which Hg bioaccumulated significantly. In all fish species, both Cd and Pb were present in considerably lower concentrations than Hg. The total As concentrations observed are similar to those previously published, and it is assumed to be present primarily in non-toxic organic forms. All fish tissues were rich in the essential elements Se, Cu and Zn and, dependent on the amount fish consumed, may contribute significantly to the nutritional intake by indigenous Arctic peoples. We observed large significant differences in the molar Se/Hg ratios, which ranged from 2.3 for northern pike to 71.1 for pink salmon. Values of the latter <1 may increase the toxic potential of Hg, while those >1 appear to enhance the protection against Hg toxicity.


Assuntos
Exposição Dietética/estatística & dados numéricos , Peixes/metabolismo , Alimentos Marinhos/estatística & dados numéricos , Oligoelementos/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Regiões Árticas , Arsênico/análise , Cádmio/análise , Cobalto/análise , Cobre/análise , Cyprinidae , Humanos , Mercúrio/análise , Federação Russa , Alimentos Marinhos/análise , Selênio/análise , Oligoelementos/análise , Poluentes Químicos da Água/análise , Zinco/análise
16.
Food Chem ; 299: 125126, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31284243

RESUMO

The health risk assessment of exposure to toxic metals through the consumption food crops is very important. The present study was aimed to investigate the bioaccessibility of toxic metals (including arsenic, lead and cadmium) in rice through an in vitro gastrointestinal digestion model, and assess health risks associated with these metals in raw, cooked and digested rice. Total and bioaccessible concentration of metals were measured by introducing the prepared samples into the inductively coupled plasma-optical emission spectroscopy. Based on the results, the bioaccessible toxic metals in gastric phase were significantly higher than that in both oral and small intestinal phases. The estimated concentrations of these metals in the raw and cooked rice are very far from the actual exposure state. Therefore, to assess the extent of health risks associated with the subjected toxic metals through the rice consumption, the actual exposure value of the metals (bioaccessible value) should be considered.


Assuntos
Arsênico/farmacocinética , Cádmio/farmacocinética , Contaminação de Alimentos/análise , Chumbo/farmacologia , Metais/farmacocinética , Oryza/química , Arsênico/análise , Disponibilidade Biológica , Cádmio/análise , Culinária , Digestão , Humanos , Irã (Geográfico) , Chumbo/toxicidade , Metais/toxicidade , Medição de Risco
17.
Environ Pollut ; 252(Pt B): 1439-1447, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31265954

RESUMO

Arsenic (As) and antimony (Sb) are considered as priority environmental pollutants and their accumulation in crop plants particularly in rice has posed a great health risk. This study endeavored to investigate As and Sb contents in paired soil-rice samples obtained from Xikuangshan, the world largest active Sb mining region, situated in China, and to investigate As speciation and location in rice grains. The soil and rice samples were analyzed by coupling the wet chemistry, laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS), synchrotron-based micro X-ray fluorescence mapping (µ-XRF) and micro X-ray absorption near-edge structure (µ-XANES) spectroscopy. The results of field survey indicated that the paddy soil in the region was co-polluted by Sb (5.91-322.35 mg kg-1) and As (0.01-57.21 mg kg-1). Despite the higher Sb concentration in the soil, rice accumulated more As than Sb indicating the higher phytoavailability of As. Dimethylarsinic acid (DMA) was the predominant species (>60% on average) in the rice grains while the percentage of inorganic As species was 19%-63%. The µ-XRF mapping of the grain section revealed that the most of As was distributed and concentrated in rice husk, bran and embryo. Sb was distributed similarly to As but was not in the endosperm of rice grain based on LA-ICP-MS. The present results deepened our understanding of the As/Sb co-pollution and their association with the agricultural-product safety in the vicinity of Sb mining area.


Assuntos
Antimônio/análise , Arsênico/análise , Poluição Ambiental/análise , Oryza/química , Poluentes do Solo/análise , China , Mineração , Solo/química , Espectroscopia por Absorção de Raios X
18.
Environ Pollut ; 252(Pt B): 1448-1454, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31265955

RESUMO

The Keban Reservoir, which is the second man-made waterbody in Turkey, has the biggest rainbow trout production in the country. In this study, the impacts of rainbow trout farms on water and sediment chemistry were investigated. Water and sediment samples were taken at distances of 0, 10, 25, 50 and 100 m from the edge of the cages at the three fish farms, and at the respective reference stations. Samples were also taken at 0 m stations and reference stations in the late August when there were no fish in the cages. Physico-chemical variables and trace metals were analysed in all samples. Due to likely high dilution rates and recycling processes in the water column of the reservoir, little changes in the water quality parameters associated with wastes of the fish farms were noticed. When compared with those in the sediment samples at the stations near the edge of cages, the lower concentrations of total phosphorus (TP), total nitrogen (TN), organic matter (OM), total carbon (TC), sulfide (S2-), arsenic (As), cobalt (Co), copper (Cu), manganese (Mn) and zinc (Zn), and higher values of redox potential (Eh) were found at the reference stations. According to organic enrichment classification based on S2- and Eh values, sediments of the three fish farms in the period when there were fish in the cages fell into the oxic category, whereas sediments in the August (no fish farming activity) fell into the normal category. Also, it was found in the August that most of sediment quality parameters at the 0 m stations had close values to those at the reference stations. These results revealed that a three-month period when there were no fish in the cages allows for sediments to return to reference station conditions.


Assuntos
Monitoramento Ambiental/métodos , Pesqueiros , Sedimentos Geológicos/química , Poluentes Químicos da Água/análise , Água/química , Animais , Arsênico/análise , Carbono/análise , Cobre/análise , Fazendas , Peixes , Nitrogênio/análise , Oncorhynchus mykiss , Fósforo/análise , Alimentos Marinhos/análise , Oligoelementos/análise , Turquia , Qualidade da Água , Zinco/análise
19.
Ecotoxicol Environ Saf ; 182: 109460, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31349103

RESUMO

Phytomanagement of polycontaminated soils is challenging, especially in areas simultaneously affected by salinity. The wetland halophyte plant species Kosteletzkya pentacarpos was cultivated in a column device allowing leachate harvest, on a polycontaminated spiked soil containing Cd (6.5 mg kg-1 DW), As (75 mg kg-1 DW), Zn (200 mg kg-1 DW) and Pb (300 mg kg-1 DW) and irrigated with salt water (final soil electrical conductivity 5.0 ms cm-1). Salinity increased Cd bioavailability in the soil and Cd accumulation in the shoots while it had an opposite effect on As. Salinity did not modify Pb and Zn bioavailability and accumulation. Cultivating plants on the polluted soil drastically reduced the volume of leachate. In all cases, salinity reduced the total amounts of heavy metals removed by the leachate and significantly increased the proportion of Cd and Zn removed by the plants. Heavy metal contamination induced a decrease in shoot dry weight and an increase in malondialdehyde (an indicator of oxidative stress); both symptoms were alleviated by the additional presence of NaCl but this positive impact was not related to increase in protecting phytochelatins synthesis. It is concluded i) that bioavailability estimated by the 0.01M CaCl2 extraction procedure is not fully relevant from the heavy metal mobility, ii) that salinity decreased heavy metal percolation, especially in soils cultivated with K. pentacarpos and iii) that salinity improves plant tolerance to heavy metals in K. pentacarpos and that this species is a promising plant material for phytoremediation of polycontaminated soils.


Assuntos
Arsênico/análise , Malvaceae/química , Metais Pesados/análise , Plantas Tolerantes a Sal/química , Poluentes do Solo/análise , Poluentes Químicos da Água/análise , Áreas Alagadas , Absorção Fisico-Química , Biodegradação Ambiental , Malvaceae/efeitos dos fármacos , Salinidade , Plantas Tolerantes a Sal/efeitos dos fármacos , Cloreto de Sódio/farmacologia , Solo/química
20.
Environ Monit Assess ; 191(7): 472, 2019 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-31256242

RESUMO

To improve accuracy and efficiency of monitoring remediated sites, the current study proposed the use of bivariate linear mixed modelling and subsequent hypothesis testing to determine significant change in contaminant concentrations over time. The modelling method integrated soil heavy metal (arsenic-As, lead-Pb and zinc-Zn) concentrations obtained from Bicentennial Park, Sydney, Australia, in the years 1990 (n = 144) and 2015 (n = 60), alongside potential influencing factors as predictor variables. Following variable selection, significant predictors included As (1990)-plan curvature, land cover change; As (2015)-multi-resolution ridge top flatness (MRRTF); Pb (1990)-elevation, MRRTF, type of nearest road; Pb (2015)-land cover change; Zn (1990)-distance to the nearest road and road type; and for Zn (2015)-aspect and land cover change. Model quality statistics (standardised squared prediction error; SSPE) indicated relatively good estimates of the prediction variance (mean ~ 1.0 for all metals, median = 0.512 for As (1990), 0.420 for As (2015), 0.417 for Pb (1990), 0.388 for Pb (2015), 0.342 for Zn (1990) and 0.263 for Zn (2015)), however Lin's concordance correlation coefficient indicated poor prediction of point estimates (LCCC = 0.263 for As (1990), 0.414 for As (2015), 0.250 for Pb (1990), 0.166 for Pb (2015), 0.233 for Zn (1990) and 0.408 for Zn (2015)). Pb in 1990 exceeded the Australian guide value of 600 mg kg-1 in small, isolated areas of the park, and by 2015, these 'hotspots' had significantly diminished (P < 0.05). Concentrations of As were low in both 1990 and 2015, not exceeding the 300 mg kg-1 guide; yet, in 2015, As had significantly increased in the south of the study area (P < 0.2). Zn concentrations in 1990 were elevated but did not exceed the guide value of 30,000 mg kg-1. Overall, the models exhibited good estimation of prediction variance and therefore are suitable for hypothesis testing; however, they exhibited poor prediction quality at times. Despite this, bivariate linear mixed modelling is worth exploring as it provides an advantage over modelling single time points and can assist with tracking potential contaminant sources before they cause harm.


Assuntos
Monitoramento Ambiental/métodos , Modelos Lineares , Metais Pesados/análise , Poluentes do Solo/análise , Arsênico/análise , Austrália , Chumbo , Análise Espacial , Instalações de Eliminação de Resíduos , Zinco/análise
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