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1.
Cien Saude Colet ; 26(6): 2253-2270, 2021 Jun.
Artigo em Português | MEDLINE | ID: mdl-34231736

RESUMO

This study aimed to review studies of human biomonitoring (HBM) that evaluated exposure to lead (Pb), cadmium (Cd), mercury (Hg), nickel (Ni), arsenic (As) and manganese (Mn) in adults living close to industrial areas. A systematic review of studies was selected, without initial date limit through to December 2017, from the MEDLINE and BVS databases. Original studies in English, Portuguese or Spanish conducted among the adult population using blood and/or urine as biomarkers were included. The articles were evaluated according to methodological criteria, including studies with comparison groups and/or probabilistic sampling. Of the 28 studies selected, 54% were conducted in Europe, 36% in Asia, 7% in North America and 4% in Africa. Foundries, metal works and steel mills were the most frequently studied. Urine and blood were used in 82% and 50% of studies, respectively. The elements most investigated were Cd, Pb and As. Despite using heterogeneous methodologies, the results revealed higher metal concentrations, especially from As and Hg in general, than in the comparison group. This review highlights the need for more rigorous methodological studies of HBM, stressing the importance of public health vigilance among populations exposed to toxic metals, especially in developing countries.


Assuntos
Arsênio , Mercúrio , Adulto , Arsênio/análise , Cádmio/análise , Monitoramento Ambiental , Europa (Continente) , Humanos , Chumbo/análise , Mercúrio/análise
2.
Huan Jing Ke Xue ; 42(7): 3494-3506, 2021 Jul 08.
Artigo em Chinês | MEDLINE | ID: mdl-34212676

RESUMO

The accumulation of heavy metals in crops is largely dependent on the availability of heavy metals in soils. Due to the differences of soil types and pollution characteristics, there is no widely recognized method for the determination of the bio-available heavy metals in soils such as Pb and Cd. In order to screen and establish suitable methods, the extractable abilities of five extractants (CaCl2, NH4OAc, HCl, EDTA, and DTPA) and Gradient Diffusion Film Technology (DGT) on four typical farmland soils with very different properties in Chongqing (acid purple soil, neutral purple soil, calcareous yellow soil and calcareous purple soil) were systematically compared. Simultaneously, pot experiments were carried out with Lolium perenne L. as an indicator plant to explore the relationship between the extractable soil Pb and Cd and their accumulation in plants. The feasibility of the tested methods were evaluated based on the extractability and co-relationships. The results showed that the extractability of the tested extractants for soil Pb and Cd varied a lot. HCl showed highest extractability on Pb in acid purple soil and calcareous yellow soil, while EDTA did the best in neutral purple soil and calcareous purple soil; HCl showed best extractability in all soils except calcareous purple soil, where EDTA was the best. Considering the correlation between the extraction amount and uptake by plant, all the extraction methods could be applied for the evaluation of the bioavailability of soils Pb and Cd except CaCl2 for Pb due to its weak extractability for Pb for a specific soil type. For the comparison of heavy bioavailability in different soil types, EDTA-extractable Pb and DGT-extractable Cd were recommended due to their well co-relationships between extractable amount in soil and uptake by plant (Lolium perenne L.) as indicated by the correlation coefficients of 0.941 and 0.919, respectively. HCl was relatively suitable as Cd extractant compared to others if DGT method could not be used.


Assuntos
Metais Pesados , Poluentes do Solo , Cádmio/análise , Fazendas , Chumbo , Solo , Poluentes do Solo/análise
3.
Huan Jing Ke Xue ; 42(7): 3527-3534, 2021 Jul 08.
Artigo em Chinês | MEDLINE | ID: mdl-34212679

RESUMO

Simultaneously reducing the availability of Cd and As is difficult owing to converse chemical behaviors of Cd and As in soil. In this study, amendments that can simultaneously immobilize Cd and As in soil were determined by an pure soil culture experiment in which flooding and wetting were performed for 30 d each. The effects of sepiolite (Sep), modified sepiolite (IMS and Sep-FM), steel slag (SS), and iron modified biochar (Fe-Bio) on soil pH, Eh, Cd, and As concentrations in pore water, and Cd and As fractions in soil were investigated. It showed that Sep (1%, 2.5%), IMS (1%, 2.5%), Sep-FM (1%, 2.5%), and SS (1%, 5%) treatments increased soil pH value and decreased Eh value and Cd concentrations in soil solution. In addition, As concentrations in soil solution treated with high doses of IMS (2.5%) and SS (5%) were lower than that of CK treatment during the whole incubation period. However, Fe-bio treatment decreased soil pH and increased Eh value and only decreased Cd and As concentrations in soil solution under wet conditions. Compared with the control, the application of the above amendments promoted the transformation of Cd fraction from exchangeable to reducible, oxidizable, and residual. High application rates of IMS (2.5%), Sep-FM (2.5%), and SS (5%) also reduced available As fraction (non-specifically sorbed and specifically-sorbed As fraction), and increased amorphous and poorly-crystalline hydrated Fe and Al oxide-bound As. On the contrary, Fe-bio treatment increased the fractions of non-specifically sorbed, specifically sorbed and residual As in soil. In short, IMS, Sep-FM, and SS are potential materials for remediation of Cd and As contaminated soil. They can effectively immobilize soil Cd and As and promote their transformation to the fractions that plants are difficult to uptake.


Assuntos
Oryza , Poluentes do Solo , Cádmio/análise , Carvão Vegetal , Poluição Ambiental/análise , Solo , Poluentes do Solo/análise
4.
Huan Jing Ke Xue ; 42(7): 3535-3548, 2021 Jul 08.
Artigo em Chinês | MEDLINE | ID: mdl-34212680

RESUMO

Two iron-based materials, Fe-Ca composite (FeCa) and Fe-Mn binary oxide (FMBO), were applied to immobilize As, Pb, and Cd in heavy metal contaminated paddy soils. Seven kinds of paddy soil (tidal soil) contaminated by arsenic, lead and cadmium were collected from Shangyu, Shaoxing (SY), Foshan, Guangdong (FS), Shaoguan, Guangdong (SG), LiuYang, Hunan (LY), Ganzhou, Jiangxi (GZ), Dushan, Guizhou (DS), and Ma'anshan, Anhui (MAS). The effects of iron-based materials on the dynamic changes of As, Pb, and Cd concentration in soil solution, the stabilization efficacy of available As, Pb, and Cd in soil, and the effects of soil types and properties on stabilization efficacy were studied through soil incubation experiment. The results showed that the content of soil dissolved As, Pb, and Cd were lower in iron-based material treatments than in control throughout the incubation. The addition of two iron-based materials significantly reduced the availability of Cd, Pb, and As. Moreover, the stabilization efficiency of FeCa for As was higher than FMBO, but no significant difference was found in the stabilization efficiency of Pb and Cd between two materials. The stabilization efficiency of As, Pb, and Cd in FeCa treatments could be ordered as GZ > SG > DS and MAS; FS>SY, LY, and SG>MAS; SY, GZ, and DS>MAS, respectively. While the stabilization efficiency for As, Pb, and Cd in FMBO could be ordered as SY, LY, and GZ > DS > FS; FS > GZ > SY; DS > LY > MAS, respectively. In addition, the statistical results showed that the stabilization efficiencies of various soils under the treatment of iron-based materials were significantly correlated with sand content (negatively correlated for As), soil pH (positively correlated for Pb), and clay content (negatively correlated for Cd). In conclusion, the two iron-based materials evaluated in this study may be effective stabilization agents for remediating different types of arsenic-, lead-, and cadmium-contaminated soils.


Assuntos
Arsênio , Oryza , Poluentes do Solo , Cádmio/análise , Ferro , Chumbo , Solo , Poluentes do Solo/análise
5.
Environ Monit Assess ; 193(8): 467, 2021 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-34224011

RESUMO

The equilibrium and kinetic studies of removal of Pb2+, Cd2+, Ni2+, and Cu2+ metal ions were carried out using activated carbon prepared from palm kernel shell and doped with CeO2 (Ce/AC). The obtained material carbon was characterized by XRD which showed some crystalline traces of CeO2, SEM displaying the porous texture with spherical pores and the determination of pH of point of zero charge (pHPZC) which was found to be equal to 6. The contact time and adsorbate were thoroughly investigated. The maximum adsorption depends inversely on the hydrated metal radius. This observation was confirmed by calculating the formation energies (ΔH(M(OH)2)) of M(OH)2. The metal ionic radii were acting on calculated sorption capacity and that sorption efficiency related to ionic radii of metal was as follows: R(Ni2+) ≤ R(Cd2+) < R(Cu2+) < R(Pb2+). The texture and morphology of the material after sorption were affected by the metallic ion nature as observed by SEM. The kinetic studies showed that the rate constant (k2) of pseudo-second-order model decreased with the increase of the hydrated cations radii, while the rate constant of intraparticle diffusion increased with the increase of the ionic radii. The Freundlich isotherm model best fit the experimental sorption data for all the metallic ions.


Assuntos
Oligoelementos , Poluentes Químicos da Água , Adsorção , Cádmio/análise , Cério , Carvão Vegetal , Monitoramento Ambiental , Concentração de Íons de Hidrogênio , Cinética , Chumbo , Poluentes Químicos da Água/análise
6.
Chemosphere ; 281: 130969, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34289623

RESUMO

Lignin is a low-cost and environmental-friendly material and could increase the solubility of phosphorus (P) in soils. Meanwhile, application of P compounds to soils decreases the bioavailability of heavy metals. However, there are few reports on whether lignin-induced P release immobilizes heavy metals in soil. This study investigated this possibility by adding alkaline lignin to forest, paddy and upland soils differing in pH and available P. The amendment of alkaline lignin increased soil P availability and enhanced the adsorption and decreased the desorption percentages of Cd in acid forest and paddy soils. The P released from the soil could immobilize Pb and Cd but the presence of Pb decreased the adsorption capacity of Cd on the acid soils. In comparison, the alkaline lignin decreased Cd adsorption and raised Cd desorption in the alkaline upland soil, due to the formation of soluble complex of hydrophilic organic matter with Cd. In addition, precipitation, complexion, and competition effect among Cd, P and lignin in different soils led to various P concentrations in the experiment. The study suggests that alkaline lignin was effective in Cd/Pb immobilization partly via enhanced P availability in acid soils, but was ineffective in Cd immobilization in alkaline soils.


Assuntos
Poluentes do Solo , Solo , Cádmio/análise , Chumbo , Lignina , Poluentes do Solo/análise
7.
Chemosphere ; 281: 130990, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34289633

RESUMO

Three types of hierarchically porous magnetic biochars (HMBs) were prepared by pyrolyzing low-cost wheat straw and potassium ferrate (K2FeO4) under a nitrogen atmosphere at 600, 700 and 800 °C, respectively, which could be used as amendments for cadmium (Cd) in water and soil. HMB fabricated at 700 °C (HMB700) had the best remediation performance for Cd in water and soil, which was mainly due to its largest specific surface area and micropore volume. Batch sorption experiments showed that Cd(II) sorption onto HMBs were well-described by a pseudo-second-order model and Sips (Freundlich-Langmuir) model, indicating that HMBs removed Cd(II) mainly through chemical adsorption. MINTEQ modeling evidenced that HMBs adsorbed Cd(II) mainly through precipitation rather than surface complexation. The adsorption behavior of HMB700 to Cd(II) could be explained by surface complexation (-OCd, -COOCd), precipitation (Cd(OH)2 and CdCO3), physical adsorption (rich pore structure) and ion exchange (K+, Ca2+, Mg2+). Furthermore, adding HMBs (1 wt%) (incubation 60 days) could also significantly increase soil pH and electrical conductivity (EC), and significantly reduce the available Cd content in soil (47.97%-61.38%). Adding HMBs could promote the conversion of bioavailable to less bioavailable Cd forms. These results provided a new idea for fabricating agricultural waste-based HMBs to remediate Cd in water and soil.


Assuntos
Cádmio , Poluentes do Solo , Adsorção , Cádmio/análise , Carvão Vegetal , Fenômenos Magnéticos , Porosidade , Solo , Poluentes do Solo/análise , Água
8.
Artigo em Inglês | MEDLINE | ID: mdl-34205439

RESUMO

(1) Background: Trace metal (TM) contamination of farmland soil in Taiwan occurs because factories dump wastewater into irrigation ditches. Since vermicompost affects the bioavailability of TMs, the objective of this study was to evaluate its effects on the accumulation of growth of TMs in leafy vegetables. (2) Methods: Two TM-contaminated soils and different types of pak choi and lettuce were used and amended with vermicompost. Besides soil properties, the study assessed vermicompost's influence on the growth, accumulation, and chemical forms of TMs and on the health risks posed by oral intake. (3) Results: Vermicompost could increase the content of soil organic matter, available phosphorus, exchangeable magnesium, and exchangeable potassium, thus promoting the growth of leafy vegetables. The accumulation of four TMs in crops under vermicompost was reduced compared to the control, especially for the concentration of cadmium, which decreased by 60-75%. The vermicompost's influence on changing the chemical form of TMs depended on the TM concentrations, type of TM, and crop species; moreover, blanching effectively reduced the concentrations of TMs in high-mobility chemical forms. Although vermicompost mostly reduced the amount of cadmium consumed via oral intake, cadmium still posed the highest health risk compared to the other three TMs.


Assuntos
Metais Pesados , Poluentes do Solo , Cádmio/análise , Metais Pesados/análise , Solo , Poluentes do Solo/análise , Taiwan , Verduras
9.
Anal Chem ; 93(23): 8257-8264, 2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-34077178

RESUMO

Despite increased interest in microplasma-induced vapor generation (µPIVG) over the past several years, applications in real sample analyses remain limited due to their relatively low vapor generation efficiency and ambiguous mechanism. In this work, a novel method using methanol for significantly enhancing the liquid electrode discharge µPIVG efficiency was developed for the simultaneous and sensitive determination of Hg, Cd, and Zn by atomic fluorescence spectrometry (AFS). It is worth noting that the possible enhancement mechanism was investigated via the characterizations of volatile products by AFS, microplasma optical emission spectrometry, online gas chromatography, and gas chromatography-mass spectrometry, which involved the reductive species such as electrons, hydrogen radicals (·H), methyl radicals (·CH3), and other intermediates in the argon plasma adding methanol. Under the optimized conditions, the limits of detection of 0.007, 0.05, and 0.5 µg L-1 were obtained for Hg, Cd, and Zn, respectively, with relative standard deviations of 3.1, 3.7, and 5.2% for these elements, respectively. Vapor generation efficiencies of 90, 83, and 55% were achieved for Hg, Cd, and Zn, respectively, and improved 2.7-, 4.8-, and 7.9-fold, respectively, compared to those obtained in the absence of methanol. The accuracy and practicability of the proposed method were validated by the determination of Hg, Cd, and Zn in a certified reference material (CRM, Lobster hepatopancreas, TORT-3) and crayfish samples collected from three different provinces of China.


Assuntos
Cádmio , Mercúrio , Cádmio/análise , China , Eletrodos , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Mercúrio/análise , Metanol , Alta do Paciente , Zinco
10.
Ecotoxicol Environ Saf ; 220: 112404, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34111660

RESUMO

Cadmium (Cd), chromium (Cr), lead (Pb), mercury (Hg) and arsenic (As) are potent toxicants to human health via dietary intake. It is imperative to establish accurate soil thresholds based on soil-plant transfer models and food safety standards for safe agricultural production. This study takes rice genotypes and soil properties into account to derive soil thresholds for five heavy metal(loid)s using the bioconcentration factors (BCF) and species sensitivity distribution (SSD) based on the food safety standard. The BCF generated from two paddy soils was calculated to investigate the sensitivity of heavy metal accumulation in nine rice cultivars in a greenhouse pot experiment. Then, empirical soil-plant transfer models were developed from a middle-sensitivity rice cultivar (Denong 2000, one selected from nine rice) grown in nineteen paddy soils with various soil properties under a proper exogenously metal(loid)s concentration gradient. After normalization, hazardous concentrations from the fifth percentile (HC5) were calculated from the SSD curves, and the derived soil thresholds were obtained from HC5 prediction models that based on the combination of pH and organic carbon (OC) or cation exchange capacity (CEC). The soil Cd threshold derived based on pH and organic carbon (pH < 7.5, OC ≥ 20 g kg-1) was 1.3-fold of those only considering pH, whereas the Pb threshold (pH > 6, CEC ≥ 20 cmolc kg-1) was 3.1 times lower than the current threshold. The derived thresholds for five elements were validated to be reliable through literature data and field experiments. The results suggested that deriving soil heavy metal(loid)s threshold using SSD method and local food safety standards is feasible and also applicable to other crops as well as other regions with potential health risks of toxic elements contamination in agricultural production.


Assuntos
Metais Pesados/normas , Oryza/crescimento & desenvolvimento , Poluentes do Solo/normas , Solo/normas , Arsênio/análise , Arsênio/normas , Cádmio/análise , Cádmio/normas , Cromo/análise , Cromo/normas , Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/normas , Inocuidade dos Alimentos , Humanos , Chumbo/análise , Chumbo/normas , Mercúrio/análise , Mercúrio/normas , Metais Pesados/análise , Oryza/química , Oryza/genética , Solo/química , Poluentes do Solo/análise
11.
Ecotoxicol Environ Saf ; 220: 112382, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34090106

RESUMO

The mining-metallurgical industry in the central Andes of Peru is a source of lead (Pb) and cadmium (Cd) contamination in milk, and there are no studies on the impact of their ingestion. Using flame atomic absorption spectrometry, we quantified the concentration of these metals in raw milk produced in agroecological zones near these industries, and estimated the exposure and dietary risk in people aged 2-85 yr with minimum, average and maximum daily milk intake. In 2018, 40 raw milk samples were collected from 20 cows at two times of the year. The mean Pb and Cd concentrations were 577 ± 18.2 and 18.35 ± 5.4 µg/kg, all samples exceeded the maximum limits (ML). Children aged 2-5 and 6-15 yr, with average milk consumption, had Pb weekly intakes (WI) of 2019 and 2423 µg, exceeding the risk value; values for Cd 64 and 77 µg were below the risk values. In those older than 20 years the WI for both metals are below the risk values. The Dietary Risk Coefficient (DRC) to Pb in children younger than 8 years was >3 due to higher milk consumption in relation to body weight; for children aged 9-19 years it was 1.7 and 2.9, being <1 for those older than 20 yr. Cd RDCs were <1 at all ages, with the exception of 2-year-olds in the high milk consumption scenario (RDC > 1). There was notable evidence of Pb and Cd exposure risk from consumption of milk produced near mining-metallurgical activities, predominantly for children under 19-year-olds. In Peru there are no regulations for Pb and Cd in fresh milk and milk products, we recommended that ML for heavy metals in food be established.


Assuntos
Monitoramento Ambiental , Contaminação de Alimentos/análise , Chumbo/química , Leite/química , Adolescente , Animais , Cádmio/análise , Bovinos , Criança , Pré-Escolar , Dieta , Poluentes Ambientais , Feminino , Humanos , Metais Pesados/análise , Mineração , Peru , Medição de Risco , Espectrofotometria Atômica , Adulto Jovem
12.
Artigo em Inglês | MEDLINE | ID: mdl-34070880

RESUMO

In this study, the role of exogenous root exudates and microorganisms was investigated in the application of modified nanoscale zero-valent iron (nZVI) for the remediation of cadmium (Cd)-contaminated soil. In this experiment, citric acid (CA) was used to simulate root exudates, which were then added to water and soil to simulate the pore water and rhizosphere environment. In detail, the experiment in water demonstrated that low concentration of CA facilitated Cd removal by nZVI, while the high concentration achieved the opposite. Among them, CA can promote the adsorption of Cd not only by direct complexation with heavy metal ions, but also by indirect effect to promote the production of iron hydroxyl oxides which has excellent heavy metal adsorption properties. Additionally, the H+ dissociated from CA posed a great influence on Cd removal. The situation in soil was similar to that in water, where low concentrations of CA contributed to the immobilization of Cd by nZVI, while high concentrations promoted the desorption of Cd and the generation of CA-Cd complexes which facilitated the uptake of Cd by plants. As the reaction progressed, the soil pH and cation exchange capacity (CEC) increased, while organic matter (OM) decreased. Meanwhile, the soil microbial community structure and diversity were investigated by high-throughput sequencing after incubation with CA and nZVI. It was found that a high concentration of CA was not conducive to the growth of microorganisms, while CMC had the effect of alleviating the biological toxicity of nZVI.


Assuntos
Recuperação e Remediação Ambiental , Poluentes do Solo , Cádmio/análise , Exsudatos e Transudatos/química , Ferro , Raízes de Plantas/química , Solo , Poluentes do Solo/análise
13.
Artigo em Inglês | MEDLINE | ID: mdl-34073355

RESUMO

Cadmium, Cu, Ni, Pb, and Zn removal via soil flushing with tannic acid (TA) as a plant biosurfactant was studied. The soil was treated for 30 h in a column reactor at a constant TA concentration and pH (3%, pH 4) and at variable TA flow rates (0.5 mL/min or 1 mL/min). In the soil leachates, pH, electrical conductivity (EC), total dissolved organic carbon, and metal concentrations were monitored. Before and after flushing, soil pH, EC, organic matter content, and cation exchange capacity (CEC) were determined. To analyze the organic matter composition, pyrolysis as well as thermally assisted hydrolysis and methylation coupled with gas chromatography-mass spectrometry were used. Metal fractionation in unflushed and flushed soil was analyzed using a modified sequential extraction method. The data on cumulative metal removal were analyzed using OriginPro 8.0 software (OriginLab Corporation, Northampton, MA, USA) and were fitted to 4-parameter logistic sigmoidal model. It was found that flushing time had a stronger influence on metal removal than flow rate. The overall efficiency of metal removal (expressed as the ratio between flushed metal concentration and total metal concentration in soil) at the higher flow rate decreased in this order: Cd (86%) > Ni (44%) > Cu (29%) ≈ Zn (26%) > Pb (15%). Metals were removed from the exchangeable fraction and redistributed into the reducible fraction. After flushing, the soil had a lower pH, EC, and CEC; a higher organic matter content; the composition of the organic matter had changed (incorporation of TA structures). Our results prove that soil flushing with TA is a promising approach to decrease metal concentration in soil and to facilitate carbon sequestration in soil.


Assuntos
Metais Pesados , Poluentes do Solo , Cádmio/análise , Metais Pesados/análise , Solo , Poluentes do Solo/análise , Taninos
14.
Ecotoxicology ; 30(6): 1071-1083, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34101047

RESUMO

Salinity may increase metal mobilization with a potentially significant consequence for soil enzymatic activity and nutrient cycling. The goal of this study was to investigate changes in soil enzyme activity in response to salinization of a clay loam soil artificially polluted with cadmium (Cd) and lead (Pb) during a 120-day incubation experiment. Soil samples were polluted with Cd (10 mg Cd kg-1), Pb (150 mg Pb kg-1), and a combination of Cd and Pb, then preincubated for aging and eventually salinized with three levels of NaCl solution (control, low and high). NaCl salinity consistently increased the mobilization of Cd (12-22%) and Pb (5-16%) with greater increases at high (17-22% for Cd, 9-16% for Pb) than low (12% for Cd, 5-7% for Pb) salinity levels. While the increased Cd mobilization was greater in co-polluted (22%) than Cd-polluted (17%) soils, the increase of Pb mobilization was lower in co-polluted (9%) than Pb-polluted (16%) soils at high salinity level. The salinity-induced increases in metal mobilization significantly depressed soil microbial respiration (up to 43%), microbial biomass content (up to 63%), and enzymatic activities (up to 87%). The multivariate analysis further supported that the increased soil electrical conductivity, Cd mobilization, and pH after salinization were the most important factors governing microbial activity and biomass in metal-polluted soils. Results showed that changes in microbial biomass and mobile metal pool with increasing salinity had a major effect on enzyme activities, particularly under the combined metals. This study indicated that the secondary salinization of metal-polluted soils would impose an additional stress on enzymatic activities as biochemical indicators of soil quality, and therefore should be avoided for the maintenance of soil microbial and biochemical functions, especially in arid regions. In metal-polluted soils, the observed responses of extracellular and intracellular enzymes to salinity can be used to advance our knowledge of microbial processes when modeling the carbon and nutrient cycling.


Assuntos
Poluentes do Solo , Solo , Biomassa , Cádmio/análise , Poluição Ambiental , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
15.
Ann Agric Environ Med ; 28(2): 283-290, 2021 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-34184512

RESUMO

INTRODUCTION: Interactions occur between concentrations of metals in the human body and the environment in various geographic locations, which can be of importance for both the proper development and the course of pregnancy. OBJECTIVE: The aim of the study was to assess the concentrations of Zn, Cu and Cd and Zn:Cu and Zn:Cd molar ratios in the placenta, umbilical cord and in the foetal membrane, and to examine the relationship between concentrations of these elements and the place of residence. MATERIAL AND METHODS: The research material was obtained from 99 healthy women from north-western and central Poland. Data for the study were collected from the medical history and documents of admission to the ward and documents confirming the birth of the newborn. Concentrations of zinc (Zn), copper (Cu) and cadmium (Cd) were determined using the ICP-AES method (spectrophotometry of atomic absorption) in inductively coupled argon plasma. RESULTS: The average concentration of Zn, Cu and Cd in afterbirths was ~ 0.01 mg/kg of dry weight (dw). In central Poland, the results revealed a significant increase in zinc in the membrane (OR=1.098, p=0.002), cadmium in the placenta (OR=1.324, p=0.006), Zn:Cu in the membrane (OR=1.012, p<0.001). In north-western Poland, an increase in copper in the membrane (OR=1.239, p=0.025) was revealed. CONCLUSIONS: The use biological materials, such as the placenta, foetal membrane and umbilical cord to assess exposure to heavy metals and necessary elements is justified.


Assuntos
Cádmio/análise , Cobre/análise , Placenta/química , Gravidez/metabolismo , Zinco/análise , Adulto , Exposição Ambiental/análise , Feminino , Humanos , Placenta/metabolismo , Polônia , Espectrofotometria Atômica , Adulto Jovem
16.
Environ Monit Assess ; 193(7): 412, 2021 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-34114120

RESUMO

Arsenic (As), cadmium (Cd), lead (Pb), mercury (Hg), beryllium (Be), nickel (Ni), selenium (Se), and thallium (Tl) are reportedly notorious toxic contents of make-ups, with potential to cause cancer and chronic kidney disease, warranting investigation on their toxic effects. One hundred female university students were randomly selected as consistent users of make-ups for upward of 3 years. The serum/urine levels of the 8 elements were regressed against the kidney functions (estimated glomerular rate, eGFR) of the subjects. At coefficient of - 0.009, As had insignificant (0.518) level. The coefficient for Cd was - .155 and insignificant (0.423). At coefficient of - 039, Pb level was insignificant (0.595). The coefficient, 0.061, for Hg was insignificant (0.462). At - 1.585, the coefficient of Be was insignificant (0.292). The coefficient for Ni, 1.384, was insignificant (0.354). At - .002, the coefficient of Se was insignificant (0.635). The coefficient, 0.039, for Tl was significant at 5% (0.015). This finding internally validated the mean serum Tl level, 201.4900 ± 20.63316 µg/L, which was much higher than the normal level of < 2 µg/L and within the toxic range of > 200 µg/L. A policy is needed to address the use of make-ups containing Tl.


Assuntos
Arsênio , Mercúrio , Selênio , Oligoelementos , Arsênio/análise , Cádmio/análise , Cádmio/toxicidade , Monitoramento Ambiental , Feminino , Humanos , Mercúrio/análise , Mercúrio/toxicidade , Nigéria , Estudantes , Oligoelementos/análise , Oligoelementos/toxicidade , Universidades
17.
J Environ Manage ; 294: 112920, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34130132

RESUMO

Rice is a crucial part of the world's food supply but is also susceptible to uptake of contaminants including arsenic (As) and cadmium (Cd) depending on the soil redox potential. Careful control of soil redox state by implementing alternate wetting and drying (AWD) water management can decrease mobility of soil As and Cd, but can be difficult to manage. Indicators of reduction in soil (IRIS) tubes and films have been studied by pedologists for wetland delineation; here, we explore the use of the IRIS film technology as passive samplers of soil redox potential in rice paddies. The goal of this study was to test the response time of IRIS films under different water management (i.e., variable soil redox potentials). After paddy soils were exposed to severe or safe AWD, where rice paddies were allowed to dry to >30 cm below the soil surface and 15 cm below the soil surface, respectively, IRIS films, coated with Fe oxide or Mn oxide paint, were installed. Immediately following IRIS film installation, soils were reflooded, and percent removal of Fe or Mn oxides were monitored on films that were removed every 12 h for Fe films, and every 6 h for Mn films. Porewater was collected at installation and every 12 h during the studies to observe correlations between IRIS film paint removal and porewater chemistry. We observed quicker paint removal for Mn films than Fe films, and paint removal varied due to growing season and water management. Moreover, correlations between porewater chemistry and Mn paint removal were observed. While further work is still needed to understand kinetics of IRIS paint removal as it relates to porewater parameters, this work illustrates that IRIS films are a low-cost tool that rice farmers can use to better manage water and we highlight considerations for possible implementation strategies for the future.


Assuntos
Arsênio , Oryza , Poluentes do Solo , Arsênio/análise , Cádmio/análise , Fazendeiros , Humanos , Oxirredução , Solo , Poluentes do Solo/análise , Água , Abastecimento de Água
18.
Artigo em Inglês | MEDLINE | ID: mdl-34066097

RESUMO

The excessive cadmium (Cd) concentration in agricultural products has become a major public concern in China in recent years. In this study, two amendments, 4A molecular sieve (MS) and wollastonite (WS), were evaluated for their potential passivation in reducing Cd uptake by amaranth (Amaranthus tricolor L.) in six soils with different properties. Results showed that the responses of amaranth biomass to these amendments were soil-property-dependent. The effects of MS and WS on soil available Cd were in turn dependent on soil and amendment properties. The application of WS and MS at a dose of 660 mg·kg-1 Si produced the optimum effect on inhibiting Cd accumulation in amaranth shoots (36% and 34%, respectively) and did not affect crop yield. This was predominantly attributed to the marked increase in pH and exogenous Ca or Na, which facilitated the adsorption, precipitation, and complexation of Cd in soils. The immobilization effects of WS and MS were dependent on soil properties, where soil organic matter may have played an important role. In conclusion, MS and WS possess great potential for the remediation of Cd-contaminated acidic soils.


Assuntos
Cádmio , Poluentes do Solo , Cádmio/análise , Compostos de Cálcio , China , Concentração de Íons de Hidrogênio , Silicatos , Solo , Poluentes do Solo/análise
19.
Chemosphere ; 280: 130724, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34162085

RESUMO

The mechanisms of the stimulatory effect of external magnetic fields on plant growth have been revealed; however, the role of magnetic fields in the efficiency of phytoremediation with Celosia argentea grown under drought stress which results in detrimental influences on food security has not been reported. Therefore, this study evaluated the physiological responses of C. argentea to the interactions between exposure to a magnetic field and drought stress. Compared with a control, a drought treatment negatively affected the dry weight, transpiration rate, and Cd extraction efficiency of the species and caused oxidative damage in plant cells, as manifested by the increase in malondialdehyde levels and antioxidant enzyme activities. The biomass production, pigment levels, Cd content, and phytoremediation efficiency of the plant were positively affected by all magnetic field treatments compared to the control. All magnetic treatments, except those at 30 mT, alleviated the detrimental effects induced by a 10-day irrigation regime by enhancing the dry weight, chlorophyll content, and activities of antioxidant enzymes in the leaves of the plant. In terms of the interaction between pre-sowing magnetic field seed treatment and drought stress, a 100 mT treatment increased most of the measured parameters, particularly under a 3-day irrigation regime; this corresponded to the optimal phytoremediation efficiency. The results suggest that magnetic field treatment is a novel, economical, and practicable strategy by which to increase the efficiency of phytoremediation using C. argentea under drought stress.


Assuntos
Celosia , Poluentes do Solo , Biodegradação Ambiental , Cádmio/análise , Secas , Campos Magnéticos , Sementes/química , Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
20.
Chemosphere ; 280: 130830, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34162097

RESUMO

Biochar has the potential to control the bioavailability and transformation of heavy metals in soil, thereby ensuring the safe crop production. A three seasons field experiment was conducted to investigate the effect of crop straw-derived biochar on the bioavailability and crop accumulation of Cd and Cu in contaminated soil. Wheat straw biochar (WSB), corn stalk biochar (CSB), and rice husk biochar (RHB) were applied at the rate of 0, 1.125, and 2.25 × 104 kg ha-1, respectively. The results showed that all types of biochar significantly increased soil pH, organic carbon and cation exchangeable capacity (CEC), compared to the control. The reduction in DTPA extractable Cd and Cu contents was much greater under high dosage biochar application, with a prominence at RHB treatment throughout the three cropping seasons, compared to the control. Moreover, the biological accumulation of Cd and Cu in the grains of rapeseed and corn significantly decreased after biochar application. Linear regression also confirmed the effective role of biochar in controlling the translocation and accumulation of Cd and Cu due to their inactive bioavailability. In addition, the sequential extraction indicated that exchangeable fraction (EXF) of Cu and Cd had decreased, while residual fraction (RSF) had increased under all biochar amendments. Contrarily, the oxidizable fraction (OXF) of Cd decreased while OXF of Cu increased under biochar treatments. Biochar application, especially RHB, could be an effective measure to enhance Cd and Cu adsorption and immobilization in polluted soils and thereby reducing its uptake and translocation to crops.


Assuntos
Oryza , Poluentes do Solo , Disponibilidade Biológica , Cádmio/análise , Carvão Vegetal , Cobre/toxicidade , Rotação , Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidade , Zea mays
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