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1.
Food Chem ; 399: 134017, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36055068

RESUMO

Rice ratooning system is becoming increasingly important for food security in China, however, information on grain cadmium (Cd) and arsenic (As) levels is lacking. We collected grain samples of main crop (MC) and ratoon crop (RC) from five sites, where the same eleven varieties were planted, and determined the Cd and As concentration in brown rice. Results showed that differences in grain Cd level between MC and RC were inconsistent across experimental sites, although the average value was comparable. In contrast, the grain As level was significantly higher in MC than in RC by 99.8% on average, which was consistent across all sites. Moreover, there was a significant positive correlation in grain Cd concentration between RC and MC. Overall, RC-produced rice is safer than MC with dramatically lower As concentration, and planting rice varieties with low Cd accumulation capacity is important for production of safe rice in rice ratooning system.


Assuntos
Arsênio , Oryza , Poluentes do Solo , Arsênio/análise , Cádmio/análise , China , Grão Comestível/química , Solo , Poluentes do Solo/análise
2.
Braz. j. biol ; 83: e247562, 2023. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1339410

RESUMO

Abstract To investigate the role of cow dung in soil reclamation and bio assimilation along with bio accumulation of heavy metals in earthworm (P. posthuma) (N=900) earthworms were used and treatment groups of CD-soil mixture of different proportion of cow dung were designed. Nonlethal doses of lead acetate and cadmium chloride were added in treatment groups. Mature P. posthuma were released in each experimental pot maintaining the favorable conditions. The pH, carbon, nitrogen, phosphorus, exchangeable cations, and heavy metal level of each mixture was evaluated. The results indicated that bio-assimilation of Pb and Cd by P. posthuma were significantly (P ˂ 0.01) higher in different soil-CD treatments compared to control. Highest bio-assimilation of both metals was observed in T1 of both groups (Pb = 563.8 mg/kg and Cd = 42.95 mg/kg). The contents of both metals were significantly (P ˂ 0.05) lowered in casting. The nutrient concentration in the final castings of all soil-CD treatments were also equally transformed from less or insoluble to more soluble and available for plants, except for carbon level which increased with CD proportion. It is concluded that cow dung as organic matter has a positive effect on soil reclamation and bio-assimilation of metals by P. posthuma.


RESUMO Para investigar o papel do esterco de vaca na recuperação do solo e bioassimilação, juntamente com a bioacumulação de metais pesados ​​em minhocas (P. posthuma) (N = 900), minhocas foram usadas e grupos de tratamento de mistura CD-solo de diferentes proporções de esterco de vaca foram projetados. Doses não letais de acetato de chumbo e cloreto de cádmio foram adicionadas aos grupos de tratamento. P. posthuma maduros foram liberados em cada vaso experimental, mantendo as condições favoráveis. Foram avaliados o pH, carbono, nitrogênio, fósforo, cátions trocáveis ​​e nível de metais pesados ​​de cada mistura. Os resultados indicaram que a bioassimilação de Pb e Cd por P. posthuma foi significativamente (P ˂ 0,01) maior em diferentes tratamentos de solo-CD em relação ao controle. A maior bioassimilação de ambos os metais foi observada em T1 de ambos os grupos (Pb = 563,8 mg / kg e Cd = 42,95 mg / kg). O conteúdo de ambos os metais foi significativamente (P ˂ 0,05) reduzido na fundição. A concentração de nutrientes nas fundições finais de todos os tratamentos de solo-CD também foi igualmente transformada de menos ou insolúvel para mais solúvel e disponível para as plantas, exceto o nível de carbono que aumenta com a proporção de CD. Conclui-se que o esterco de vaca como matéria orgânica tem um efeito positivo na recuperação do solo e na bioassimilação de metais por P. posthuma.


Assuntos
Animais , Feminino , Oligoquetos , Poluentes do Solo , Metais Pesados/análise , Solo , Cádmio , Bovinos , Bioacumulação
3.
Braz. j. biol ; 83: e240015, 2023. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1285624

RESUMO

Abstract Zinc is an essential micronutrient that is required for optimum plant growth. It is present in soil in insoluble forms. Bacterial solubilization of soil unavailable form of Zn into available form, is an emerging approach to alleviate the Zn deficiency for plants and human beings. Zinc solubilizing bacteria (ZSB) could be a substitute for chemical Zn fertilizer. The present study aimed to isolate and characterize bacterial species from the contaminated soil and evaluate their Zn solubilizing potential. Zn resistant bacteria were isolated and evaluated for their MIC against Zn. Among the 13 isolated bacterial strains ZSB13 showed maximum MIC value upto 30mM/L. The bacterial strain with the highest resistance against Zn was selected for further analysis. Molecular characterization of ZSB13 was performed by 16S rRNA gene amplification which confirmed it as Pseudomonas oleovorans. Zn solubilization was determined through plate assay and broth medium. Four insoluble salts (zinc oxide (ZnO), zinc carbonate (ZnCO3), zinc sulphite (ZnS) and zinc phosphate (Zn3(PO4)2) were used for solubilization assay. Our results shows 11 mm clear halo zone on agar plates amended with ZnO. Likewise, ZSB13 showed significant release of Zn in broth amended with ZnCO3 (17 and 16.8 ppm) and ZnO (18.2 ppm). Furthermore, Zn resistance genes czcD was also enriched in ZSB13. In our study, bacterial strain comprising Zn solubilization potential has been isolated that could be further used for the growth enhancement of crops.


Resumo O zinco é um micronutriente essencial necessário para o crescimento ideal das plantas. Ele está presente no solo em formas insolúveis. A solubilização bacteriana da forma indisponível de Zn no solo para a forma disponível é uma abordagem emergente para aliviar a deficiência de Zn em plantas e seres humanos. Bactérias solubilizadoras de zinco (ZSB) podem ser um substituto para fertilizantes químicos de Zn. O presente estudo teve como objetivo isolar e caracterizar espécies bacterianas de solo contaminado e avaliar seu potencial de solubilização de Zn. Bactérias resistentes ao Zn foram isoladas e avaliadas quanto ao seu MIC contra o Zn. Entre as 13 cepas bacterianas isoladas, ZSB13 apresentou valor máximo de MIC de até 30 mM/L. A cepa bacteriana com maior resistência ao Zn foi selecionada para análise posterior. A caracterização molecular de ZSB13 foi realizada por amplificação do gene 16S rRNA que o confirmou como Pseudomonas oleovorans. A solubilização do Zn foi determinada através de ensaio em placa e meio caldo. Quatro sais insolúveis (óxido de zinco (ZnO), carbonato de zinco (ZnCO3), sulfito de zinco (ZnS) e fosfato de zinco (Zn3 (PO4) 2) foram usados ​​para o ensaio de solubilização. Nossos resultados mostram uma zona de halo clara de 11 mm em placas de ágar corrigidas com ZnO. Da mesma forma, ZSB13 mostrou liberação significativa de Zn em caldo alterado com ZnCO3 (17 e 16,8 ppm) e ZnO (18,2 ppm). Além disso, os genes de resistência ao Zn czcD também foram enriquecidos em ZSB13. Em nosso estudo, a cepa bacteriana compreendendo potencial de solubilização de Zn foi isolada e poderia ser usada posteriormente para o aumento do crescimento de safras.


Assuntos
Humanos , Poluentes do Solo , Pseudomonas oleovorans , Solo , Microbiologia do Solo , Zinco , RNA Ribossômico 16S/genética
4.
Braz. j. biol ; 83: e242676, 2023. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1278552

RESUMO

Abstract Trees occurring on the margins of agricultural areas can mitigate damage from residual herbicides. Rhizospheric microbial activity associated with trees is one of the main remedial capacity indicators. The objective of this study was to evaluate the rhizospheric microbiological activity in tree species subjected to the herbicides atrazine and sulfentrazone via the rhizosphere. The experiment was designed in four blocks and a 6 × 3 factorial scheme. The first factor consisted of six tree species from Brazil and the second of atrazine, sulfentrazone, and water solutions. Four herbicide applications were performed via irrigation. The total dry mass of the plants, mycorrhizal colonization, number of spores, basal respiration of the rhizospheric soil, and survival rate of bioindicator plants after phytoremediation were determined. Trichilia hirta had higher biomass when treated with atrazine and sulfentrazone. Herbicides decreased the microbial activity in Triplaris americana and did not affect the microbiological indicators of Myrsine gardneriana, Schizolobium parahyba, and Toona ciliata. Fewer bioindicator plants survived in soil with Triplaris americana and sulfentrazone. Microbiological indicators were influenced in different ways between species by the presence of herbicides in the rhizosphere.


Resumo As árvores que ocorrem nas margens das áreas agrícolas podem mitigar os danos dos herbicidas residuais. A atividade microbiana rizosférica associada às árvores é um dos principais indicadores de capacidade corretiva. O objetivo deste trabalho foi avaliar a atividade microbiológica rizosférica em espécies arbóreas submetidas aos herbicidas atrazina e sulfentrazone via rizosfera. O experimento foi estruturado em quatro blocos e esquema fatorial 6 × 3. O primeiro fator consistiu em seis espécies de árvores do Brasil e o segundo em soluções de atrazine, sulfentrazone e água. Quatro aplicações de herbicidas foram realizadas via irrigação. Foram determinados a massa seca total das plantas, colonização micorrízica, número de esporos, respiração basal do solo rizosférico e taxa de sobrevivência de plantas bioindicadoras após fitorremediação. Trichilia hirta apresentou maior biomassa quando tratada com atrazina e sulfentrazone. Os herbicidas diminuíram a atividade microbiana em Triplaris americana e não afetaram os indicadores microbiológicos de Myrsine gardneriana, Schizolobium parahyba e Toona ciliata. Menos plantas bioindicadoras sobreviveram no solo com Triplaris americana e sulfentrazone. Os indicadores microbiológicos foram influenciados de formas distintas entre as espécies pela presença dos herbicidas na rizosfera.


Assuntos
Poluentes do Solo , Micorrizas/química , Herbicidas , Solo , Microbiologia do Solo , Árvores , Brasil , Raízes de Plantas/química , Plântula , Rizosfera
5.
J Environ Sci (China) ; 124: 61-75, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36182167

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) and their oxygenated derivates (O-PAHs) are identified in soils and groundwater of industrialized sites and contribute to the risk for Humans and the Environment. Nevertheless, data are scarce in literature concerning their retention and transfer in soils and no soil - water partition coefficients are available for these compounds. Sorption of two PAHs, fluorene and acenaphthene and two O-PAHs, 9H-fluorenone and dibenzofuran onto two soils with different organic carbon contents was evaluated and compared by determining their sorption isotherms. Effect of ionic strength and liquid to solid ratio, on fluorene and fluorenone sorption was also evaluated. Sorption equilibrium is achieved within less than 24 hr of mixing and linear sorption models best fit the isotherm data. Acenaphthene and dibenzofuran are similarly sorbed onto the soil. KD of fluorene is higher than the one of fluorenone, showing a smaller affinity of fluorenone towards the solid phase. This means that O-PAH could form larger contamination plumes in groundwater than PAHs. Decreasing the L/S ratio from 100 to 50 and 30, increases the sorption of fluorenone onto the soil by 56% and 67% respectively, while the sorption of fluorene is slightly increased. Increasing the ionic strength of the aqueous phase also modifies the sorption of fluorenone, contrary to the sorption of fluorene which is slightly affected.


Assuntos
Água Subterrânea , Hidrocarbonetos Policíclicos Aromáticos , Poluentes do Solo , Acenaftenos , Adsorção , Carbono , Dibenzofuranos , Fluorenos , Humanos , Hidrocarbonetos Policíclicos Aromáticos/análise , Solo , Poluentes do Solo/análise , Água
6.
J Hazard Mater ; 441: 129840, 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36088879

RESUMO

Hyperaccumulators are plant species that tolerate and accumulate very high concentrations of toxic metals, including Cd. Hyperaccumulation of heavy metals is reported to benefit plant biotic resistance; however, no prior study has examined the possible role of toxic metals on abiotic stress resistance in hyperaccumulators. A preliminary experiment found that Cd significantly improved plant growth of a hyperaccumulator, Sedum alfredii Hance, under heat stress. This study investigated the possible role of Cd in S. alfredii's heat resistance, using infrared thermography, transmission electron microscopy (TEM), real-time quantitative polymerase chain reaction (RTqPCR), and high-throughput sequencing. The results showed that high temperatures irreversibly damaged stomatal function, chloroplast structure, photosynthesis in S. alfredii, and lowered survival rates to 25%. However, Cd application significantly decreased the leaf temperature of S. alfredii and increased the survival rate to 75%. Cd penetrated the guard cells, restored stomatal function, and mitigated excessive water loss from S. alfredii under heat stress. Moreover, it activated antioxidant enzymes, promoted phytohormone biosynthesis, and upregulated a series of unigenes, thereby augmenting heat resistance in S. alfredii. These results indicate that Cd effectively improved thermotolerance in S. alfredii by regulating stomatal movement and antioxidant systems via upregulation of phytohormones and heat shock proteins.


Assuntos
Sedum , Poluentes do Solo , Termotolerância , Antioxidantes/metabolismo , Biodegradação Ambiental , Cádmio/metabolismo , Cádmio/toxicidade , Proteínas de Choque Térmico/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Raízes de Plantas/metabolismo , Sedum/metabolismo , Poluentes do Solo/metabolismo , Água
7.
J Hazard Mater ; 441: 129863, 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36088880

RESUMO

Heavy metals (HMs) from smelters pose severe challenges to the environmental soil quality of surrounding farmlands, and threaten human health through the food chain. This study explored the environmental effects of smelting activities on farmland soil, and additionally assessed the enrichment, transfer and health risk of HMs in soil-wheat systems. Multiple characterization results were combined to demonstrate that HMs from smelter waste were transferred to the surrounding soil. It was determined that the enrichment of HMs in soil-wheat systems is mainly controlled by the total HM concentration and pH in soil. Furthermore, the priority pollutant in soil-wheat systems was found to be Cd, and Cd affected the transfer of Cu, Mn and Pb from soil to wheat roots. Interestingly, the -OH stretching, C-H stretching, N-H amide and C-O bending were involved in detoxifying HMs in wheat. The mean values of non-carcinogenic and carcinogenic risks by consuming wheat grain were 9.1, 1.4E-02 (adults) and 11.3, 3.3E-03 (children), respectively, indicating a noteworthy health risk. This study highlighted the critical issues arising from Pb/Zn smelting activities on agricultural soils. Notwithstanding, to ensure food security, the affected regions could opt to follow up on the type of crops grown.


Assuntos
Metais Pesados , Poluentes do Solo , Adulto , Amidas , Cádmio/análise , Criança , China , Monitoramento Ambiental/métodos , Humanos , Chumbo , Metais Pesados/análise , Medição de Risco , Solo/química , Poluentes do Solo/análise , Triticum/química , Zinco
8.
J Hazard Mater ; 441: 129906, 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36088882

RESUMO

For decades, reclamation of pesticide contaminated sites has been a challenging avenue. Due to increasing agricultural demand, the application of synthetic pesticides could not be controlled in its usage, and it has now adversely impacted the soil, water, and associated ecosystems posing adverse effects on human health. Agricultural soil and pesticide manufacturing sites, in particular, are one of the most contaminated due to direct exposure. Among various strategies for soil reclamation, ecofriendly microbial bioremediation suffers inherent challenges for large scale field application as interaction of microbes with the polluted soil varies greatly under climatic conditions. Methodically, starting from functional or genomic screening, enrichment isolation; functional pathway mapping, production of tensioactive metabolites for increasing the bioavailability and bio-accessibility, employing genetic engineering strategies for modifications in existing catabolic genes to enhance the degradation activity; each step-in degradation study has challenges and prospects which can be addressed for successful application. The present review critically examines the methodical challenges addressing the feasibility for restoring and reclaiming pesticide contaminated sites along with the ecotoxicological risk assessments. Overall, it highlights the need to fine-tune the available processes and employ interdisciplinary approaches to make microbe assisted bioremediation as the method of choice for reclamation of pesticide contaminated sites.


Assuntos
Praguicidas , Poluentes do Solo , Bactérias/genética , Bactérias/metabolismo , Biodegradação Ambiental , Ecossistema , Estudos de Viabilidade , Humanos , Praguicidas/metabolismo , Solo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Água
9.
J Hazard Mater ; 441: 129904, 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36096061

RESUMO

As an important subtopic within phytoremediation, hyperaccumulators have garnered significant attention due to their ability of super-enriching heavy metals. Identifying the factors that affecting phytoextraction efficiency has important application value in guiding the efficient remediation of heavy metal contaminated soil. However, it is challenging to identify the critical factors that affect the phytoextraction of heavy metals in soil-hyperaccumulator ecosystems because the current projections on phytoremediation extrapolations are rudimentary at best using simple linear models. Here, machine learning (ML) approaches were used to predict the important factors that affecting phytoextraction efficiency of hyperaccumulators. ML analysis was based on 173 data points with consideration of soil properties, experimental conditions, plant families, low-molecular-weight organic acids from plants, plant genes, and heavy metal properties. Heavy metal properties, especially the metal ion radius, were the most important factors that affect heavy metal accumulation in shoots, and the plant family was the most important factor that affect the bioconcentration factor, metal extraction ratio, and remediation time. Furthermore, the Crassulaceae family had the highest potential as hyperaccumulators for phytoremediation, which was related to the expression of genes encoding heavy metal transporting ATPase (HMA), Metallothioneins (MTL), and natural resistance associated macrophage protein (NRAMP), and also the secretion of malate and threonine. New insights into the effects of plant characteristics, experimental conditions, soil characteristics, and heavy metal properties on phytoextraction efficiency from ML model interpretation could guide the efficient phytoremediation by identifying the best hyperaccumulators and resolving its efficient remediation mechanisms.


Assuntos
Metais Pesados , Poluentes do Solo , Adenosina Trifosfatases/metabolismo , Biodegradação Ambiental , Ecossistema , Aprendizado de Máquina , Malatos/metabolismo , Metais Pesados/análise , Plantas/metabolismo , Solo , Poluentes do Solo/metabolismo , Treonina/metabolismo
10.
J Hazard Mater ; 441: 129909, 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36099736

RESUMO

Soil pollution caused by cadmium (Cd) is a serious concern. Phytoremediation is a popular technology in the remediation of Cd-contaminated soil. Salix matsudana var. matsudana f. umbraculifera Rehd. has been characterized as a high Cd-accumulating and tolerant willow (HCW). Here, transcriptome and proteome profiling, along with morphology analyses were performed to explore molecular cross-talk involved in Cd tolerance. Our results showed that 73%- 83% of the Cd in roots accumulated in the cell walls and root xylem cell walls were significantly thickened. From transcriptome and proteome analysis, a total of 153 up-regulated differentially-expressed genes and 655 up-regulated differentially-expressed proteins were found in common between two comparison groups (1 d and 4 d vs. respective control). Furthermore, phenylpropanoid biosynthesis was identified as a key pathway in response to Cd stress. In this pathway, lignin biosynthesis genes or proteins were significantly up-regulated, and lignin content increased significantly in roots under Cd stress. Two Cd-induced genes cinnamoyl-CoA reductase 1 (SmCCR1) and cinnamyl alcohol dehydrogenase 7 (SmCAD7) from HCW increased the lignin content and enhanced Cd tolerance in transgenic poplar calli. These results lay the foundation for further clarifying the molecular mechanisms of Cd tolerance in woody plants.


Assuntos
Salix , Poluentes do Solo , Cádmio/análise , Cádmio/toxicidade , Lignina , Raízes de Plantas/química , Raízes de Plantas/genética , Proteoma , Salix/genética , Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidade , Transcriptoma
11.
J Hazard Mater ; 441: 129891, 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36103763

RESUMO

Ecological risks can vary dramatically depending on abiotic factors, such as soil properties and the background values of elements. This study developed a framework for an integrated risk assessment system to derive soil quality criteria (SQC) for heavy metals (HMs) applicable to different soil types and to assess ecological risks at a multi-regional scale. Through the construction of normalization and species sensitivity distribution models, 248 SQC values for Cd, Pb, Zn, As, Cu, Cr, Sb, and Ni in 31 Chinese provinces were derived. These SQC considered the soil types and background values of the elements and effectively reduced the uncertainty caused by spatial heterogeneity. Using the derived SQC values, the qualitative and quantitative ecological risks of HMs in the terrestrial environment of China were comprehensively assessed using a three-level ecological risk assessment (ERA) approach. Compared to traditional ERA methods, the new methodology reached a more quantitative conclusion. The mean overall probabilities of ecological risk in China were 2.42 % (Cd), 2.82 % (Pb), 12.17 % (Zn), 14.89 % (As), 10.42 % (Cu), 32.20 %(Cr), and 8.88 % (Ni). The new framework could be useful for the ERA of various soil types.


Assuntos
Metais Pesados , Poluentes do Solo , Cádmio , China , Monitoramento Ambiental/métodos , Chumbo , Metais Pesados/análise , Medição de Risco , Solo , Poluentes do Solo/análise
12.
J Hazard Mater ; 441: 129883, 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36108495

RESUMO

Cadmium (Cd) and lead (Pb) are two of the most common elements found in contaminated sites. The behavior of specific metals in the soil may be affected by other metals because of the competition for adsorption sites. In this study, adsorption experiments after chemical extraction, multi-surface models, and advanced spectroscopy technology were jointly used to explain the adsorption mechanism of Cd and Pb and to determine the contribution of each component in the competitive system. The results show that pH is the key factor in determining the contribution of soil components to metal adsorption. Soil organic matter (SOM) is the dominant adsorbent for both Cd and Pb. Clay minerals play an adsorption role at low pH, whereas Fe/Al oxides adsorb metals primarily in the high pH range. Further, the competitive effect of Pb on Cd occurred primarily on SOM rather than on clay minerals. When the Pb concentration increased from 0 to 500 mg/L, the adsorption of Cd on SOM decreased by 132.0 mg/kg, whereas it decreased only by 1.9 mg/kg on clay minerals. Therefore, the competitive effect of Pb on Cd cannot be ignored in soils with high organic matter content.


Assuntos
Metais Pesados , Poluentes do Solo , Adsorção , Cádmio/química , Argila , Chumbo/análise , Metais Pesados/análise , Minerais , Óxidos/análise , Solo/química , Poluentes do Solo/análise
13.
J Hazard Mater ; 441: 129887, 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36115092

RESUMO

Aromatic amines (AA) are one of the most commonly used classes of compounds in industry and the most common pollutants found in both soil and water. 3,4-Dichloaniline (3,4-DCA) is a persistent residue of the phenylurea herbicide in the environment. In this study, we used a colorimetric method as a new approach to screen 12 filamentous fungal strains of the genera Aspergillus, Chaetomium, Cladosporium, and Mucor to assess their capacity to perform AA N-acetylation since it is considered a potential tool in environmental bioremediation. Subsequently, the selected strains were biotransformed with different AA substrates to evaluate the product yield. The strains Aspergillus niveus 43, Aspergillus terreus 31, and Cladosporium cladosporioides showed higher efficiencies in the biotransformation of 3,4-DCA at 500 µM into its N-acetylated product. These fungal strains also showed great potential to reduce the phytotoxicity of 3,4-DCA in experiments using Lactuca sativa seeds. Furthermore, N-acetylation was shown to be effective in reducing the cytotoxic and genotoxic effects of 3,4-DCA and other AA in the immortalized human keratinocyte (HaCaT) cell line. The isolated products after biotransformation showed that fungi of the genera Aspergillus and Cladosporium appeared to have N-acetylation as the first and main AA detoxification mechanism. Finally, A. terreus 31 showed the highest 3,4-DCA bioremediation potential, and future research can be carried out on the application of this strain to form microbial consortia with great potential for the elimination of toxic AA from the environment.


Assuntos
Herbicidas , Poluentes do Solo , Acetilação , Aminas/química , Compostos de Anilina , Biodegradação Ambiental , Dano ao DNA , Fungos/metabolismo , Herbicidas/metabolismo , Humanos , Solo/química , Poluentes do Solo/metabolismo , Poluentes do Solo/toxicidade , Água
14.
Mar Pollut Bull ; 177: 113489, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35325795

RESUMO

Heavy metal-contaminated wastes can threaten mangrove forests, one of the most biodiverse ecosystems in the world. The study evaluated the geospatial distribution of heavy metals concentrations in soils, the ecological and human health risks, and metal contents in soil fractions and mangrove organisms in the Botafogo estuary, Brazil, one of the most environmentally impacted estuaries in the country. The metal concentrations exceeded by up to 2.6-fold the geochemical background; 91%, 59%, 64%, 31%, and 82% of the soils were contaminated with Cr, Zn, Pb, Cu, and Ni, respectively. Adverse effects to the biota may occur due to Cr, Cu, Ni and Pb exposures. Contents of clay and organic matter were the main factors governing the distribution of metals in soil, contributing to up to 63% of the total variability. However, the geospatial modeling showed that the predictive ability of these variables varied spatially with the metal and location. The ecological and human health risks assessments indicated that the metal concentrations in soils are safe for the environment and human beings. There was a low transfer of metals from the soil to the biota, with values of sediment-biota accumulation factor (SBAF) and biological accumulation coefficients (BAC) lower than 1.0, except for Zn (SBAF = 13.1). The high Zn bioaccumulation by Crassostrea rhizophorae may be associated with the concentrations of Zn in the bioavailable fractions.


Assuntos
Metais Pesados , Poluentes do Solo , Ecossistema , Monitoramento Ambiental , Humanos , Metais Pesados/análise , Medição de Risco , Solo/química , Poluentes do Solo/análise
15.
Environ Monit Assess ; 194(10): 788, 2022 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-36104572

RESUMO

In order to investigate the situation of heavy metal pollution in the heavy metal industry in Gansu Province, a large copper mining province, two large and typical copper mining and beneficiation enterprises with differences in topographic features, climatic conditions, and soil types were selected as the target of this study based on similar ore types and beneficiation processes. Around these two enterprises, geochemical baselines of the six heavy metals were established, while the degree of local soil heavy metal pollution and potential hazards to humans were assessed based on statistical analysis, single-factor and multi-factor index analysis, and health risk evaluation models. In addition, Spearman's correlation analysis and hierarchical cluster analysis were used to explore the intrinsic association between each heavy metal in the two mining industries to reveal the pattern of soil heavy metal pollution in the copper mining and beneficiation industry and to propose targeted measures to improve and prevent soil heavy metal pollution. The results showed that the heavy metal pollution in the soil around Shengxi Mining Co., Ltd. of Subei County (SX enterprise) was higher than that around Yangba Copper Co., Ltd. of Gansu Province (YB enterprise), but the two enterprises had similar patterns of pollution, with an overall medium level of pollution. The carcinogenic and non-carcinogenic risks for children and adults were within acceptable limits for both enterprises. Besides, the correlation between the different heavy metals to similarity in their sources of contamination and the different degrees of association between the soil heavy metals of the two enterprises due to their environmental characteristics.


Assuntos
Metais Pesados , Poluentes do Solo , Adulto , Criança , China , Cobre/análise , Monitoramento Ambiental/métodos , Humanos , Metais Pesados/análise , Mineração , Solo , Poluentes do Solo/análise
16.
J Environ Manage ; 321: 115770, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36104873

RESUMO

Soil microbial community is the main indicator having a crucial role in the remediation of polluted soils. These microbes can alter soil pH, organic matter in soils (SOM), soil physic-chemical properties, and potential soil respiration rate via their enzymatic activities. Similarly, heavy metals also have a crucial role in soil enzymatic activities. For this purpose, a number of methods are studied to evaluate the impact of soil pH (a key factor in the formation of biogeographic microbial patterns in bacteria) on bacterial diversity. The effects of pH on microbial activity are glamorous but still unclear. Whereas, some studies also indicate that soil pH alone is not the single key player in the diversity of soil bacteria. Ecological stability is achieved in a pollution-free environment and pH value. The pH factor has a significant impact on the dynamics of microbes' communities. Here, we try to discuss factors that directly or indirectly affect soil pH and the impact of pH on microbial activity. It is also discussed the environmental factors that contribute to establishing a specific bacterial community structure that must be determined. From this, it can be concluded that the environmental impact on soil pH, reducing soil pH and interaction with this factor, and reducing the effect of soil pH on soil microbial community.


Assuntos
Metais Pesados , Microbiota , Poluentes do Solo , Bactérias , Concentração de Íons de Hidrogênio , Solo/química , Microbiologia do Solo , Poluentes do Solo/farmacologia
17.
Arch Microbiol ; 204(10): 614, 2022 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-36088522

RESUMO

An integrated approach involving vermicompost, chromate reducing bacteria and AMF was tested to manage the toxic impacts of Cr(VI) on Ocimum basilicum as a model plant. Pot experiments were conducted on O. basilicum plants in an artificially Cr(VI)-contaminated soil in two phases of experiment as bioinoculants experiment and vermicompost experiment. In the first phase of the bioinoculants experiment the series of gradient concentrations of Cr(VI) (0, 25, 50 and 100 mg kg-1 in soil) were evaluated with previously isolated four efficient Cr(VI)-reducing rhizo-bacterial strains (Bacillus Cereus strain SUCR 44, BC; Microbacterium sp. strain SUCR 140, MB; Bacillus thuringiensis strain SUCR186, BT; and Bacillus subtilis strain SUCR188; BS) along with Arbuscular Mycorrhizal Fungus-Glomus fasciculatum (GF) in alone and in co-inoculation form. In the second experiment (vermicompost) the best performing strain (MB) was tested alone or in combination with GF along with different doses of vermicompost. It was observed that vermicompost by itself could be useful in decreasing the bioavailable Cr(VI), uptake of Cr besides improving the nutritional status of plants. The vermicompost also played an important and indirect role and improved herb yield by supporting the multiplication of MB (Microbacterium sp.), an efficient chromate reducing rhizobacteria, that further decreased the bioavailable and toxic form of Cr and improved population and colonization of GF too. The translocation of Cr(VI) was averted through improved colonization of GF, also prevented higher accumulation of Cr in aerial parts (leafy herb) of O. basilicum.


Assuntos
Alphaproteobacteria , Micorrizas , Ocimum basilicum , Poluentes do Solo , Bacillus cereus , Cromatos , Cromo , Plantas , Solo , Microbiologia do Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
18.
Huan Jing Ke Xue ; 43(9): 4756-4766, 2022 Sep 08.
Artigo em Chinês | MEDLINE | ID: mdl-36096616

RESUMO

In order to explore the characteristics of soil heavy metal pollution and ecological risk status in southern hilly areas, a hilly area of a southern province was selected as the research area, using soil samples collected at 60 points in 2017. The single factor pollution index (Pi), Nemero comprehensive pollution index, and potential ecological risk index (RI) were used to evaluate the content characteristics and potential ecological risks of eight heavy metal elements (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn), and positive definite matrix factor analysis models (PMF) were used to analyze their sources of pollution. The results were as follows:① the content of eight heavy metal elements in the study area exceeded the standard, and the Nemeiro comprehensive pollution index showed that the proportions of light, moderate, and heavy pollution in the study area were 63%, 8%, and 2%, respectively. Unpolluted and lightly polluted samples accounted for 27% and were thus basically lightly polluted. ②The comprehensive potential ecological risk index showed that the RI of soil heavy metals was 39.58-224.15, the proportions of samples with low and medium ecological risks were 73.33% and 25%, respectively, and the proportion of sites with severe ecological risks was 1.67%. Although this site had the highest ecological risk, the content of heavy metals was lower than the background value of soil elements in the province. ③Six pollution sources were obtained through the PMF model:natural sources, agricultural activity sources, mixed sources composed of copper mining and transportation, industrial activity sources, transportation sources, and domestic waste emission sources. The contribution rates of each source were 24.8%, 17.7%, 17.7%, 17.6%, 12.0%, and 10.2%, respectively.


Assuntos
Metais Pesados , Poluentes do Solo , Monitoramento Ambiental/métodos , Metais Pesados/análise , Medição de Risco , Solo , Poluentes do Solo/análise
19.
Huan Jing Ke Xue ; 43(9): 4767-4778, 2022 Sep 08.
Artigo em Chinês | MEDLINE | ID: mdl-36096617

RESUMO

Heavy metals in cultivated soil may migrate and transform through the food chain to harm the ecological environment and human health. At present, the ecological environment and human health risks of heavy metals in cultivated soil in Lanzhou city remain unclear, which impacts the effective management and control of heavy metals. The potential ecological risk hazard index was used to evaluate the ecological environmental risks of As, Cd, Cr, Hg, and Pb in the surface soil of cultivated land in Lanzhou, and the health risk model proposed by USEPA and the recommended standard were used to evaluate their human health risk. The main factors influencing the spatial differentiation of human health risk were explored by using geographic detectors. The risk of heavy metals to the ecological environment of the cultivated land surface soil in the study area was mainly medium (65.25%), and small portions were low (13.80%) and high (20.95%). The low-risk areas were mainly located in the southeast of Yongdeng County, the middle and north of Yuzhong County, and the southwest of Gaolan County. Moderate risk areas were distributed in three counties and five districts. The high-risk areas were located in the north and southeast of Yongdeng County, the south of Chengguan District, the northeast of Qilihe, the east of Xigu District, and the middle of Yuzhong County. The non-carcinogenic and carcinogenic risks of five types of heavy metal exposure pathways were as follows:oral ingestion>skin contact>respiratory ingestion; generally speaking, children were at higher risk than adults. The non-carcinogenic risk in children was higher than that in adults; however, there was no such risk for local residents, as they were all less than 1. At the same time, the carcinogenic risk of As was greater than 1×10-5 (children 2.04×10-5) and less than 1×10-4 (adults 1.91×10-5), respectively. This indicated an acceptable medium risk to the local residents, and the risk to children was again greater than that to adults. Geographical detector analysis showed that average precipitation during the sampling season had the greatest impact on the spatial differentiation of human health risks of As and Cd, GDP had the greatest impact on the spatial differentiation of human health risks of Cr, and distance from the railway had the greatest impact on the spatial differentiation of human health risks of Hg and Pb. Interaction detection showed that all factors were enhanced by double factors. In addition to leading factors, other factors such as pH, slope, and altitude also enhanced the influence of leading factors on the spatial differentiation of heavy metal risk in cultivated soil.


Assuntos
Mercúrio , Metais Pesados , Poluentes do Solo , Adulto , Cádmio/análise , Carcinógenos/análise , Criança , Monitoramento Ambiental , Humanos , Chumbo/análise , Mercúrio/análise , Metais Pesados/análise , Metais Pesados/toxicidade , Medição de Risco , Solo , Poluentes do Solo/análise
20.
Huan Jing Ke Xue ; 43(9): 4779-4790, 2022 Sep 08.
Artigo em Chinês | MEDLINE | ID: mdl-36096618

RESUMO

In order to explore the distribution characteristics of heavy metal contamination of farmland soil surrounding Luancheng town, Shijiazhuang City, Henan province, the concentrations of As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn in the surface soil and crops were determined and assessed. The principal components were also analyzed for source apportionment. The heavy metal concentrations in crops were further detected, and the non-carcinogenic health risks in the study area were evaluated using the probabilistic risk assessment method, as to provide a theoretical basis for the treatment, prevention, and control of heavy metal pollution in farmland soil in Luancheng. According to the results, ω(Cd), ω(Cr), ω(Cu), ω(Pb), and ω(Zn) in the soils were 0.06-1.08, 22.14-473.47, 12.83-150.74, 10.75-577.72, and 62.23-652.78 mg·kg-1, which exceeded the standard with over-standard rates reaching 1.83%, 1.22%, 0.61%, 0.61%, and 1.22%, respectively. Further, Cd and Pb were transported into crops, in which Cd concentrations exceeded the standard in some corn samples, and Cd and Pb concentrations exceeded the standard in some wheat samples. The total non-carcinogenic health risks (TTHQ) to the human body caused by the consumption of heavy metals in corn grown in the study area were all less than 1, with no obvious negative effects, and TTHQ was higher than 1 in wheat, increasing the likelihood of negative impacts on the human body. With the influence of the distribution of pollution-related enterprises in the industrial zone, heavy metal concentrations were higher in the south, west, and middle directions of the study area. Among them, the study area soil was slightly contaminated by Cd (Level 1). Cd and Hg had a slight potential ecological risk (Level 2), whereas other heavy metals had low potential ecological risk (Level 1). In general, most of the surface cultivated soil was not obviously polluted by heavy metals in the study area. According to the PMF results and survey, we speculated that soil heavy metals mainly came from soil parent material (52.05%), artificial pollution sources (historical sewage irrigation and industrial manufacture) (32.98%), and atmospheric deposition (14.97%). To summarize, the study area should be divided into a priority protection category and safe utilization category. The input of pollution sources should be strictly controlled for the priority protection category, and alternative planting, rotating, and fallow should be implemented for the safe utilization category to reduce the risk of standard-exceeding agricultural products.


Assuntos
Mercúrio , Metais Pesados , Poluentes do Solo , Cádmio , Produtos Agrícolas , Monitoramento Ambiental , Fazendas , Humanos , Chumbo , Metais Pesados/análise , Medição de Risco , Solo , Poluentes do Solo/análise
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