Inorganic Environmental Pollutants Research Articles

Emerging Trends in Zinc Ferrite Nanoparticles for Biomedical and Environmental Applications.

Over the last fewdecades, the application of nanoparticles (NPs) gained immenseattention towardsenvironmental and biomedical applications. NPs are ultra-small particles having size ranges from 1 to 100nm. NPs loaded with therapeutic or imaging compounds have proved a versatile approach towards healthcare improvements. Among various inorganic NPs, zinc ferrite (ZnFe2O4) NPs are considered asnon-toxic and having animproved drug delivery characteristics. Several studies have reported broader applications of ZnFe2O4 NPs for treating carcinoma and various infectious diseases. Additionally, these NPs are beneficial for reducing organic and inorganic environmental pollutants. This review discussesaboutvarious methods to fabricate ZnFe2O4 NPs and their physicochemical properties. Further, their biomedical and environmental applications have also been exploredcomprehensively.

Characterization of Soil Toxicity in Kinkazi, Kitombe and Thiende Villages Affected by Oil Activities in Muanda and Potential Risk of Chemical Poisoning

Aims: Discharges from oil exploitation contain very toxic and persistent organic and inorganic environmental pollutants. The present study aims to characterize the ecotoxicity of the soils of these three villages subjected to oil exploitation activities.
 Study Design: This research consists of four parts, an introduction with literature review, a description of the study environment, the methods used and finally the results obtained.
 Place and Duration of Study: In order to assess the impacts due to oil exploitation activities on the soil, a study was carried out on six soil samples taken from the villages Kinkazi, Kitombe and Thiende during the month of November 2022 in the territory of Muanda, Kongo Central, D.R. Congo.
 Methodology: The soil samples were prepared in the laboratory according to standard procedures and a series of ecotoxicological tests were carried out with the analysis of some physico-chemical parameters using a Multiparameter. The data collected was processed and analysed with Excel 2010 software.
 Results: The soils of the Kinkazi, Kitombe and Thiende villages, like dumping grounds for pollutants from oil activities, are and represent a risk of chemical poisoning for the population. The inhibitory dose (ID50) varies from 26.25 to 36 g/g indicating the toxicity of these soils to Hibiscus asper seeds and the germination index obtained gives an average of around 58.7%.
 Conclusion: The ecotoxicological impact of oil activities on the soil represents a risk of chemical poisoning for the local population of Muanda given that these polluted soils are primarily used for agriculture and the species Hibiscus asper is one of the most popular species for crops market gardeners in the region.

Binary organic-inorganic nanocomposite of polyaniline-MnO2 for non-enzymatic electrochemical detection of environmental pollutant nitrite

Due to wide usage as nitrogen fertilizer in agriculture and food additive in industry, nitrite, as one of inorganic environmental pollutants, could cause detrimental effects to the ecological environment. Therefore, accurate, sensitive and rapid detection of nitrite is necessary. In this work, binary hybrid polyaniline-MnO2 organic-inorganic nanocomposite is prepared chemically and characterized via X-ray diffraction spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy and energy-dispersive X-ray spectroscopy. Polyaniline-MnO2 organic-inorganic nanocomposite serves as excellent electrode modifier for electrochemical sensing of nitrite by two modes of cyclic voltammetry and chronoamperometry, achieving broad linear ranges and low limits of detection for both methods. Moreover, the organic-inorganic nanocomposite displays satisfactory sensing performance in real water sample analysis. Amine and imino groups of polyaniline contribute to the better adsorption behavior of nitrite onto the nanocomposite, which improves the nanocomposite's sensing performance. In summary, the synergistic effects between polyaniline and MnO2 is taken advantaged in the nanocomposite for effective electrochemical sensor development.

Observed and predicted embryotoxic and teratogenic effects of organic and inorganic environmental pollutants and their mixtures in zebrafish (Danio rerio)

Risk assessment of chemicals is still primarily focusing on single compound evaluation, even if environmental contamination consists of a mixture of pollutants. The concentration addition (CA) and independent action (IA) models have been developed to predict mixture toxicity. Both models assume no interaction between the components, resulting in an additive mixture effect. In the present study, the embryo toxicity test (OECD TG no. 236) with zebrafish embryos (Danio rerio) was performed to investigate whether the toxicity caused by binary, ternary, and quaternary mixtures of organic (Benzo[a]pyrene, perfluorooctanesulfonate, and 3,3´,4,4´,5-pentachlorobiphenyl 126) and inorganic (arsenate) pollutants can be predicted by CA and IA. The acute toxicity and sub-lethal alterations such as lack of blood circulation were investigated. The models estimated the mixture toxicity well and most of the mixtures were additive. However, the binary mixture of PFOS and PCB126 caused a synergistic effect, with almost a ten-fold difference between the observed and predicted LC50-value. For most of the mixtures, the CA model was better in predicting the mixture toxicity than the IA model, which was not expected due to the chemicals' different modes of action. In addition, some of the mixtures caused sub-lethal effects not observed in the single compound toxicity tests. The mixture of PFOS and BaP caused a division of the yolk and imbalance was caused by the combination of PFOS and As and the ternary mixture of PFOS, As, and BaP. Interestingly, PFOS was part of all three mixtures causing the mixture specific sub-lethal effects. In conclusion, the present study shows that CA and IA are mostly resulting in good estimations of the risks that mixtures with few components are posing. However, for a more reliable assessment and a better understanding of mixture toxicity, further investigations are required to study the underlying mechanisms.

Clay–gemini surfactant hybrid materials for elimination of inorganic pollutants: A comprehensive review

Though organoclays modified with gemini surfactants are one of the ubiquitous adsorbents due to their enlarged interlayer spacing, modified surface characteristic and hydrophobic property, its usage for elimination of inorganic pollutants is still at a budding stage in comparison to their applicability for removal of various organic pollutants. This article addresses the intercalation of both conventional and gemini surfactants into clay minerals to transform them to hybrid materials, their characterization, adsorption performance and factors influencing the adsorption capacity of the hybrid materials. The kinetic model, adsorption isotherms, mechanism of adsorption, thermodynamic parameters and reusability of the material have also been discussed. Furthermore, the applicability of clay–gemini hybrid materials has been demonstrated to serve as an economic benign, natural adsorbent towards inorganic pollutants in aquatic environment.

Toxic Metal Species and 'Endogenous' Metalloproteins at the Blood-Organ Interface: Analytical and Bioinorganic Aspects.

Globally, human exposure to environmental pollutants causes an estimated 9 million deaths per year and it could also be implicated in the etiology of diseases that do not appear to have a genetic origin. Accordingly, there is a need to gain information about the biomolecular mechanisms that causally link exposure to inorganic environmental pollutants with distinct adverse health effects. Although the analysis of blood plasma and red blood cell (RBC) cytosol can provide important biochemical information about these mechanisms, the inherent complexity of these biological matrices can make this a difficult task. In this perspective, we will examine the use of metalloentities that are present in plasma and RBC cytosol as potential exposure biomarkers to assess human exposure to inorganic pollutants. Our primary objective is to explore the principal bioinorganic processes that contribute to increased or decreased metalloprotein concentrations in plasma and/or RBC cytosol. Furthermore, we will also identify metabolites which can form in the bloodstream and contain essential as well as toxic metals for use as exposure biomarkers. While the latter metal species represent useful biomarkers for short-term exposure, endogenous plasma metalloproteins represent indicators to assess the long-term exposure of an individual to inorganic pollutants. Based on these considerations, the quantification of metalloentities in blood plasma and/or RBC cytosol is identified as a feasible research avenue to better understand the adverse health effects that are associated with chronic exposure of various human populations to inorganic pollutants. Exposure to these pollutants will likely increase as a consequence of technological advances, including the fast-growing applications of metal-based engineering nanomaterials.

Applied biaxial strain induced tunable sensing performance of green phosphorene monolayer towards small molecules: A DFT study

The development of sensors for inorganic environmental pollutants is crucial for global public health and environmental ecology. Herein, we highlight the tunable sensing performance of harmful carbon oxides and nitrogen oxides on green phosphorene nanosheet induced by applied external biaxial using van der Waals corrected spin-polarized density functional calculations. The results reveal that the charge transfer and electronic structures are effectively changed only after nitrogen oxides exposure, suggesting the high selectivity of green phosphorene towards nitrogen oxides rather than carbon oxides, exhibiting promising targeting selectivity. Moreover, we find that the interactions between target adsorbates and green phosphorene would be further enhanced upon compressive biaxial mechanical strain. The electronic structures of the nitrogen oxides adsorbed systems would be effectively modulated under applying biaxial strain. Additionally, the calculated recovery time indicates that applied tensile strain remarkably facilities the desorption of the considered gas. Our main findings would provide a new avenue to tune the sensing performance of green phosphorene nanosheet and demonstrate the potential application prospect for green phosphorene nanosheet as a reversible sensor for nitrogen oxides detection.

Biochemical synthesis of palladium nanoparticles: The influence of chemical fixatives used in electron microscopy on nanoparticle formation and catalytic performance

Palladium nanoparticles (PdNPs) can catalyse a range of reductive chemical reactions transforming both organic and inorganic environmental pollutants. PdNPs that ranged from <2 to 2–40 nm were synthesized using chemical methods, and bacterial biomass with/without chemical fixatives. PdNP formation was enhanced by adsorption of Pd(II) to bacterial biomass, followed by fixation with formate or glutaraldehyde. TEM-SAED analyses confirmed that the cell associated PdNPs were polycrystalline with a face-centered cubic structure. Chemically formed PdNPs possessed a higher Pd(0):Pd(II) ratio and produced structurally similar nanoparticles as the biotic systems. These PdNPs were employed to catalyze two, reductive chemical reactions, transforming 4-nitrophenol (4-NP) and hexavalent chromium [Cr(VI)], into 4-aminophenol and Cr(IV), respectively. In the reduction of 4-NP, the catalytic performance was directly proportional to PdNP surface area, i.e., the smallest PdNPs in formate-PdCH34 cells had the fastest rate of reaction. The mass of Pd(0) as PdNPs was the main contributor to Cr(VI) reduction; the chemically synthesized PdNPs showed the highest removal efficiency with 96% at 20 min. The use of glutaraldehyde enhanced the reduction of Pd(II) and promoted PdNPs formation, i.e., creating an artefact of fixation; however, this treatment also enhanced the catalytic performance of these PdNPs.

Metal W connected Z-scheme C fibers@WO3-x core-shell composites with highly efficient solar-driven photocatalystic activity

A series of novel metal W connected Z-scheme C fibers@WO3-x (0 ≤ x < 3) core-shell composites were developed by simply pyrolyzing preoxidized polyacrylonitrile fibers impregnated with slurries of WO3 nanopowder in absolute ethanol in a vacuum furnace. Such structured composites are a kind of more excellent solar-driven photocatalyst for degrading various aqueous organic and inorganic environmental pollutants, compared with pure tungsten oxides catalysts under the same condition. The optimally selected composite catalyst (x = 2.01) was also applied in photocatalytically purifying waste water from paper mills under sunlight, presenting high efficiency in reducing chemical oxygen demand, biology oxygen demand and heavy metal Cr content, displaying great prospect in environmental remediation through removing various toxic industrial chemicals. The greatly enhanced photocatalytic performance could be mainly ascribed to the C fiber core and metal W connection layer between the tungsten oxides and C core in the composites, which can promptly conduct electrons and promote the separation of photogenerated electrons and holes. Moreover, this work provides a simple, eco-friendly and very efficient synthesis approach, which will be of much help to design diversified semiconductors composite structures, and suitable for large-scale production and thus practical industrial application.

Metagenomic Insights and Genomic Analysis of Phosphogypsum and Its Associated Plant Endophytic Microbiomes Reveals Valuable Actors for Waste Bioremediation.

The phosphogypsum (PG) endogenous bacterial community and endophytic bacterial communities of four plants growing in phosphogypsum-contaminated sites, Suaeda fruticosa (SF), Suaeda mollis (SM), Mesembryanthmum nodiflorum (MN) and Arthrocnemum indicum (AI) were investigated by amplicon sequencing. Results highlight a more diverse community of phosphogypsum than plants associated endophytic communities. Additionally, the bacterial culturable communities of phosphogypsum and associated plant endophytes were isolated and their plant-growth promotion capabilities, bioremediation potential and stress tolerance studied. Most of plant endophytes were endowed with plant growth-promoting (PGP) activities and phosphogypsum communities and associated plants endophytes proved highly resistant to salt, metal and antibiotic stress. They also proved very active in bioremediation of phosphogypsum and other organic and inorganic environmental pollutants. Genome sequencing of five members of the phosphogypsum endogenous community showed that they belong to the recently described species Bacillus albus (BA). Genome mining of BA allowed the description of pollutant degradation and stress tolerance mechanisms. Prevalence of this tool box in the core, accessory and unique genome allowed to conclude that accessory and unique genomes are critical for the dynamics of strain acquisition of bioremediation abilities. Additionally, secondary metabolites (SM) active in bioremediation such as petrobactin have been characterized. Taken together, our results reveal hidden untapped valuable bacterial actors for waste remediation.

Quantum Dots as Components of Electrochemical Sensing Platforms for the Detection of Environmental and Food Pollutants: a Review.

The determination of organic and inorganic environmental and food pollutants is a key matter of concern in analytical chemistry due to their effects as a serious threat to human health. Focusing on this issue, several methodologies involving the use of nanostructured electrochemical platforms have been recently reported in the literature. Among these methods, those employing the use of quantum dots (QDs) stand out because of features such as signal amplification, good reproducibility and selectivity, and the possibility for multiplexed detection, and because they preserve the outstanding characteristics of electrochemical methodologies with respect to simplicity, ease-of-use, and cost-effective instrumentation. This review describes recent electrochemical strategies, in which design QDs play a key role, for the determination of pollutants in food and environmental samples. The particular role of QDs in the reported methodologies, their preparation, and the electrochemical platform design, as well as the advantages that QDs provide in the analysis of target analytes, are critically discussed.

The identification of genes associated with Pb and Cd response mechanism in Brassica juncea L. by using Arabidopsis expression array

Heavy metals are significant inorganic environmental pollutants. Brassica juncea, frequently used as model for phytoremediation studies, can (hyper)accumulate some heavy metals with well-developed root system. Even though the elucidation of the differentially expressed genes in response to heavy metals is important for the improvement of phytoremediation capacity of plants, there has been limited number of reports about detailed functional characterization of these genes. In this study, 50μM Pb(NO3)2 and 25μM CdSO4 were applied separately to 31days-old Brassica juncea (var. P78) plants for 24h to identify the putative genes associated with lead (Pb) and cadmium (Cd) stress. The metal content analyses indicated that B. juncea (var. P78) is lead and cadmium hyperaccumulator. To reveal molecular mechanisms responsible for metal metabolism, the differentially expressed genes in the roots of Pb-treated plants were investigated by using the microarray chips of Arabidopsis thaliana probes (Affymetrix-The GeneChip® Arabidopsis ATH1 Genome Array). Out of 183 differentially expressed genes in response to Pb stress, only 20 of the up-regulated and 18 of the down-regulated genes were statistically significant at p<0.05. Since most of 38 genes differentially expressed under Pb stress were interspecifically very well conserved, we concluded that the use of interspecific hybridization approaches for global gene expression profiling would be limited. The interspecific usability of the probes was further tested by determining the level of conservation between Arabidopsis microarray oligo and Brassica spp. sequences. The microarray results were validated by quantifying the level of expression of six important genes, which are likely to play a role in Pb metabolism, through quantitative RT-PCR. To further pinpoint the possible role of Pb stress-response genes, the expression of these genes at different tissues of the plants after Pb and Cd treatments were measured. In conclusion, the described genes are likely to be associated with Pb and Cd stress metabolism and provide potential targets for the improvement of phytoremediation capacity in plants.

Tuber borchii Vitt. mycorrhiza protects Cistus creticus L. from heavy metal toxicity

Heavy metals (HMs), such as copper, zinc, lead, mercury and cadmium, are the most abundant and dangerous inorganic environmental pollutants. Growing pieces of evidence suggest that mycorrhizal fungi can alleviate metal toxicity in plants. In this study, we focused attention on the ectomycorrhizal (ECM) fungus Tuber borchii Vitt., which is widespread in Italy and is of great ecological interest because of the mutualistic associations and the advantages it provides to host plants. Seedlings of the Mediterranean shrub Cistus creticus L., mycorrhized and non mycorrhized with the ECM fungus T. borchii, were treated with HMs (zinc, lead and chromium). HMs induced leaves’ chlorosis in non mycorrhized seedlings; while no significant difference was observed in pigmentation of mycorrhized seedlings’ leaves. This observation was confirmed by Euclidean Distance of color measurements in L*a*b* units from RGB digital images of leaves. The decrease in leaves pigmentation observed in HM treated non mycorrhized seedlings strongly correlated with a reduced expression of key genes associated with chlorophyll biosynthesis; instead, no significant variation of gene expression was detected in mycorrhized seedlings treated with HMs.Finally, a comet test on nuclei isolated from leaves of mycorrhized and non mycorrhized C. creticus seedlings, treated or not with HMs, confirmed that the DNA damage induced by HMs stress was lower in mycorrhized than in non mycorrhized seedlings. Taken together, the data suggest the involvement of the mycorrhizal fungus T. borchii in the improvement of HM stress tolerance in C. creticus host.

Toxic and genotoxic effects of hexavalent chromium in environment and its bioremediation strategies

Chromium is one of the major inorganic environmental pollutants, which is added in the environment through various natural and anthropogenic activities and exists mainly in two forms: Cr(III) and Cr(VI). Cr(VI) is considered to be more toxic than Cr(III) due to its high solubility and mobility. It is a well-reported occupational carcinogen associated with lung, nasal, and sinus cancers. Thus, this review article provides the detailed information on the occurrence, sources of chromium contamination in the environment and their toxicological effects in human, animal, plants as well as in microorganisms, and bioremediation strategies to minimize the toxic effects.

Bioremediation

Bioremediation

Hydroxyl Radical: a Key Species in Atmospheric Reaction

Rapid industrialization and urbanization result in accumulation of verities of pollutants in the atmosphere which have significant detrimental effects on both biotic and abiotic components of the environment. One of the natural defence mechanisms for the removal of pollutants is the involvement of hydroxyl radical (.OH), a potent reactive oxygen species in the atmosphere. It is generated either through photo-dissociation reactions or through some photocatalytic reactions. It acts as a strong oxidant causing destruction or transformation of both organic and inorganic pollutants in the environment. However its presence in excess can cause degradation of lipid-protein complex of biomembranes and other biomolecules possibly through membrane lipid peroxidation

Probing bioinorganic chemistry processes in the bloodstream to gain new insights into the origin of human diseases

In the context of elucidating the origin of human diseases, past poisoning epidemics have revealed that exceedingly small doses of inorganic environmental pollutants can result in dramatic effects on human health. Today, numerous organic and inorganic pollutants have been quantified in human blood, but the interpretation of these concentrations remains--from a public health point of view--problematic. Conversely, the biomolecular origin for several grievous human diseases is essentially unknown. Taken together and viewed in the context of recent bioinorganic research findings, the established human blood concentrations of toxic metals and metalloids may be functionally connected with the etiology of specific human diseases. To unravel the underlying biomolecular mechanisms, and taking into account the basic flow of dietary matter through mammalian organisms, a better understanding of the bioinorganic chemistry of toxic metals and metalloid compounds in the bloodstream is emerging as a promising avenue for future research. To this end, the concerted application of modern proteomic methodologies, synchrotron-based X-ray absorption spectroscopy and established spectroscopic techniques will contribute to better define the role that blood-based bioinorganic chemistry-related processes play in the origin of human diseases. The application of this and other modern proteomic methodologies could contribute to a better understanding of the role that blood-based bioinorganic chemistry-related processes play in the origin and etiology of human diseases.

Greening of the coasts: a review of the Perna viridis success story

The green mussel Perna viridis has been receiving a lot of attention from workers working in the research areas of intertidal ecology, aquaculture, pollution monitoring, biofouling, zoogeography and invasion biology. P. viridis is a remarkable species in terms of its ability to reach very high biomass levels, to withstand environmental fluctuations, to concentrate a variety of organic and inorganic environmental pollutants, to colonise artificial marine habitats and to invade new geographic territories. This review collates data available on salient aspects of the distribution, biology and ecology of P. viridis. It is argued that the remarkable success of P. viridis as an invasive species basically stems from its long larval duration, fast growth rate, high fecundity, early maturity, high productivity and ability to withstand fluctuating environmental conditions (temperature, salinity, water turbidity and pollutants). Relevant aspects of the data are compared with the data available for a similar species Perna perna, which too is an invasive species, but to a more limited extent.

Potential of laser ablation and laser desorption mass spectrometry to characterize organic and inorganic environmental pollutants on dust particles

Stainless steel factories are known to release particles into the atmosphere. Such particulate matter contains significant amounts of heavy metals or toxic inorganic compounds and organic pollutants such as, for example, Cr(VI) and polycyclic aromatic hydrocarbons (PAHs). The investigation of Cr(VI) and PAHs is often complicated by the associated matrix. Organic and inorganic pollutants present in stainless steel dust particles have been investigated with the same laser microprobe mass spectrometer according to two original methodologies. These analytical methods do not require time-consuming pretreatment (extraction, solubilization) or preconcentration steps. More specifically, experiments are conducted with a Fourier transform ion cyclotron resonance mass spectrometer coupled to an ArF (193 nm) or a tripled frequency Nd-YAG (355 nm) laser. Experiments at 355 nm allow the nature of the most frequently occurring Cr(III)/Cr(VI) compounds in dust particles to be identified. Examination of PAHs at 193 nm is assisted by the formation of pi-complexes with 7,7',8,8'-tetracyanoquinodimethane to prevent their evaporation in the mass spectrometer during analysis and to ensure an increase in sensitivity.

Toxicity Assessment of 16 Inorganic Environmental Pollutants by Six Bioassays

The relative toxicity of 16 environmental pollutants, such as inorganic elements (Ba, Cd, Co, Cr, Cu, Fe, Ge, Hg, Mn, Nb, Pb, Sb,Sn, Ti, V, and Zn), is evaluated on the L-929 established cell line of murine fibroblasts, with five bioassays [RNA synthesis rate assay (RNA), MTT reduction assay (MTT), neutral red incorporation assay (NRI), Coomassie blue assay, and cellular growth rate assay], and on the ciliated protozoaTetrahymena pyriformisGL [doubling time ofT. pyriformis GLpopulation assay (DTP)]. For each inorganic substance, the six bioassays allowed the toxicological index IC50(“inhibitory concentration 50%”) to be calculated. The IC50values are useful to rank the tested elements and to compare the features of the six bioassays. The most sensitive assays were the RNA, MTT, NRI, and DTP assays. Moreover, thein vitroIC50values correlated with thein vivoLD50values; these results were close to those obtained with established lines of human, murine, or fish cells. The sensitivity and the complementarity of these bioassays would be in favor of their incorporation in a “battery” of tests used for toxicological screening studies of xenobiotics.