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1.
Dalton Trans ; 53(18): 7801-7811, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38623752

RESUMO

Transition and rare earth metals serve as indispensable raw materials across a broad spectrum of technological applications. However, their utilization is frequently linked to substantial waste production. Consequently, the recycling and recovery of these metals from end-of-life products or metal-contaminated aqueous environments hold significant importance within the framework of a circular economy. In our investigation, we employed synthetic mesoporous silica monoliths, synthesized via the sol-gel method and functionalized with chelating groups, for the efficient recovery of metal ions from aqueous matrices. The monoliths were characterized using a multi-technique approach and were tested in the recovery of paramagnetic Gd3+, Cu2+ and Co2+ ions from aqueous solutions, using 1H-NMR relaxometry to evaluate their uptake performance in real time and under simple conditions. Detailed information on the kinetics of the capture process was also highlighted. Finally, the possibility to regenerate the solid sorbents was evaluated.

3.
Materials (Basel) ; 15(22)2022 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-36431482

RESUMO

The synthesis and characterization of novel luminescent amorphous POSS-based polysilsesquioxanes (PSQs) with Tb3+ and Eu3+ ions directly integrated in the polysilsesquioxane matrix is presented. Two different Tb3+/Eu3+ molar ratios were applied, with the aim of disclosing the relationships between the nature and loading of the ions and the luminescence properties. Particular attention was given to the investigation of site geometry and hydration state of the metal centers in the inorganic framework, and of the effect of the Tb3+ → Eu3+ energy transfer on the overall optical properties of the co-doped materials. The obtained materials were characterized by high photostability and colors of the emitted light ranging from orange to deep red, as a function of both the Tb3+/Eu3+ molar ratio and the chosen excitation wavelength. A good energy transfer was observed, with higher efficiency displayed when donor/sensitizer concentration was lower than the acceptor/activator concentration. The easiness of preparation and the possibility to finely tune the photoluminescence properties make these materials valid candidates for several applications, including bioimaging, sensors, ratiometric luminescence-based thermometers, and optical components in inorganic or hybrid light-emitting devices.

4.
Children (Basel) ; 9(10)2022 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-36291415

RESUMO

BACKGROUND: Environmental factors seem to influence clinical manifestations of sickle cell disease (SCD), but few studies have shown consistent findings. We conducted a retrospective multicentric observational study to investigate the influence of environmental parameters on hospitalization for vaso-occlusive crises (VOC) or acute chest syndrome (ACS) in children with SCD. METHODS: Hospital admissions were correlated with daily meteorological and air-quality data obtained from Environmental Regional Agencies in the period 2011-2015. The effect of different parameters was assessed on the day preceding the crisis up to ten days before. Statistical analysis was performed using a quasi-likelihood Poisson regression in a generalized linear model. RESULTS: The risk of hospitalization was increased for low maximum temperature, low minimum relative humidity, and low atmospheric pressure and weakly for mean wind speed. The diurnal temperature range and temperature difference between two consecutive days were determined to be important causes of hospitalization. For air quality parameters, we found a correlation only for high levels of ozone and for low values at the tail corresponding to the lowest concentration of this pollutant. CONCLUSIONS: Temperature, atmospheric pressure, humidity and ozone levels influence acute complications of SCD. Patients' education and the knowledge of the modes of actions of these factors could reduce hospitalizations.

5.
Artigo em Inglês | MEDLINE | ID: mdl-36078735

RESUMO

Reducing children's exposure to air pollutants should be considered a primary goal, especially for the most vulnerable subjects. The goal of this study was to test the effectiveness of applying a protocol in the event of alert days, i.e., days with forecasted PM10 levels above the EU limit value (50 µg/m3). The test was conducted, before the onset of SARS-CoV-2 restrictions, in a classroom of a primary school in Parma (Italy)-a highly polluted area in Northern Italy. The protocol included indications for the frequency of opening windows and doors, as well as the activation of an air purifier. Teachers and students were asked to apply the protocol only in the event of alert days, while no indications were provided for non-alert days. A monitoring system measuring PM1, PM2.5, PM10, CO2, and NO2 was deployed in the classroom. Measurements of the same parameters were also performed outdoors near the school. The application of the protocol reduced the indoor/outdoor (I/O) ratio for all toxic pollutants. The reduction was also remarkable for PM10-the most critical air quality parameter in the study area (1.5 and 1.1 for non-alert and alert days, respectively). Indoor concentrations of PM10-especially during non-alert days-were often higher than outdoors, showing a major contribution from resuspension due to the movement of people and personal cloud. The protocol did not cause any increase in indoor CO2 levels. Our findings showed that the application of a ventilation protocol together with the contribution of an air purifier may represent an effective way to reduce children's exposure to air pollution during severe air pollution episodes. Considering the onset of COVID-19 and the airborne transmission of pathogens, this protocol now has more meaningful implications for children's welfare, and can be integrated with protocols designed as measures against the spread of SARS-CoV-2.


Assuntos
Poluentes Atmosféricos , Poluição do Ar em Ambientes Fechados , COVID-19 , Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/análise , Poluição do Ar em Ambientes Fechados/prevenção & controle , COVID-19/epidemiologia , COVID-19/prevenção & controle , Dióxido de Carbono , Criança , Monitoramento Ambiental , Humanos , Dióxido de Nitrogênio , Material Particulado/análise , SARS-CoV-2 , Instituições Acadêmicas
6.
Small ; 18(17): e2106097, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35344274

RESUMO

Circulating tumor cell (CTC) clusters are associated with increased metastatic potential and worse patient prognosis, but are rare, difficult to count, and poorly characterized biophysically. The PillarX device described here is a bimodular microfluidic device (Pillar-device and an X-magnetic device) to profile single CTCs and clusters from whole blood based on their size, deformability, and epithelial marker expression. Larger, less deformable clusters and large single cells are captured in the Pillar-device and sorted according to pillar gap sizes. Smaller, deformable clusters and single cells are subsequently captured in the X-device and separated based on epithelial marker expression using functionalized magnetic nanoparticles. Clusters of established and primary breast cancer cells with variable degrees of cohesion driven by different cell-cell adhesion protein expression are profiled in the device. Cohesive clusters exhibit a lower deformability as they travel through the pillar array, relative to less cohesive clusters, and have greater collective invasive behavior. The ability of the PillarX device to capture clusters is validated in mouse models and patients of metastatic breast cancer. Thus, this device effectively enumerates and profiles CTC clusters based on their unique geometrical, physical, and biochemical properties, and could form the basis of a novel prognostic clinical tool.


Assuntos
Neoplasias da Mama , Células Neoplásicas Circulantes , Animais , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Separação Celular , Feminino , Humanos , Dispositivos Lab-On-A-Chip , Camundongos , Células Neoplásicas Circulantes/patologia , Prognóstico
7.
Dalton Trans ; 51(11): 4502-4509, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-35233589

RESUMO

The removal of paramagnetic metal ions with different charges and ionic radii (i.e. Gd3+, Cu2+, and Co2+) from aqueous solutions was carried out by using a Na+-exchanged synthetic saponite clay. Saponite, composed of sub-micrometer particles and characterized by high cation-exchange capacity, was prepared through a classical low-cost hydrothermal approach. The metal ion uptake tests were performed in water at pH = 5.5 and 3.0, and the capture process was monitored in real time by 1H-NMR relaxometry. The experimental data were confirmed by the conventional ICP-OES technique. Details of the uptake process kinetics were extrapolated from the NMR analyses as well. Saponite showed good sorption capacity for all selected metal ions. The regeneration of the solid sorbent after metal uptake was also analysed, obtaining encouraging results.

8.
Inorg Chem ; 60(14): 10749-10756, 2021 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-34237936

RESUMO

A novel bifunctional saponite clay incorporating gadolinium (Gd3+) and europium (Eu3+) in the inorganic framework was prepared by one-pot hydrothermal synthesis. The material exhibited interesting luminescent and paramagnetic features derived from the co-presence of the lanthanide ions in equivalent structural positions. Relaxometry and photoluminescence spectroscopy shed light on the chemical environment surrounding the metal sites, the emission properties of Eu3+, and the dynamics of interactions between Gd3+ and the inner-sphere water placed in the saponite gallery. The optical and paramagnetic properties of this solid make it an attractive nanoplatform for bimodal diagnostic applications.

9.
Chemistry ; 27(14): 4723-4730, 2021 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-33368657

RESUMO

For the first time, the co-presence in the saponite structure of luminescent EuIII and catalytic NbV metal sites was exploited for the simultaneous detection and catalytic abatement of sulfur-containing blister chemical warfare agents. Metal centers were introduced in structural positions of the saponite (in the interlayer space or inside the inorganic framework) following two different synthetic methodologies. The functionalized saponites were able to reveal the presence of a sulfur mustard simulant (2-chloroethyl)ethyl sulfide (CEES) after few seconds of contact time and more than 80 % of the substrate was catalytically decomposed after 24 h in the presence of aqueous hydrogen peroxide.

10.
Front Genet ; 11: 579964, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33240326

RESUMO

As the novel coronavirus disease sweeps across the world, there is growing speculation on the role that atmospheric factors may have played on the different distribution of SARS-CoV-2, and on the epidemiological characteristics of COVID-19. Knowing the role that environmental factors play in influenza virus outbreaks, environmental pollution and, in particular, atmospheric airborne (particulate matter, PM) has been considered as a potential key factor in the spread and mortality of COVID-19. A possible role of the PM as the virus carrier has also been debated. The role of PM in exacerbating respiratory and cardiovascular disease has been well recognized. Accumulating evidence support the hypothesis that PM can trigger inflammatory response at molecular, cellular and organ levels. On this basis, we developed the hypothesis that PM may play a role as a booster of COVID-19 rather than as a carrier of SARS-CoV-2. To support our hypothesis, we analyzed the molecular signatures detected in cells exposed to PM samples collected in one of the most affected areas by the COVID-19 outbreak, in Italy. T47D human breast adenocarcinoma cells were chosen to explore the global gene expression changes induced by the treatment with organic extracts of PM 2.5. The analysis of the KEGG's pathways showed modulation of several gene networks related to the leucocyte transendothelial migration, cytoskeleton and adhesion system. Three major biological process were identified, including coagulation, growth control and immune response. The analysis of the modulated genes gave evidence for the involvement of PM in the endothelial disease, coagulation disorders, diabetes and reproductive toxicity, supporting the hypothesis that PM, directly or through molecular interplay, affects the same molecular targets as so far known for SARS-COV-2, contributing to the cytokines storm and to the aggravation of the symptoms triggered by COVID-19. We provide evidence for a plausible cooperation of receptors and transmembrane proteins, targeted by PM and involved in COVID-19, together with new insights into the molecular interplay of chemicals and pathogens that could be of importance for sustaining public health policies and developing new therapeutic approaches.

11.
Nat Commun ; 11(1): 3516, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32665580

RESUMO

It is unclear whether the establishment of apical-basal cell polarity during the generation of epithelial lumens requires molecules acting at the plasma membrane/actin interface. Here, we show that the I-BAR-containing IRSp53 protein controls lumen formation and the positioning of the polarity determinants aPKC and podocalyxin. Molecularly, IRSp53 acts by regulating the localization and activity of the small GTPase RAB35, and by interacting with the actin capping protein EPS8. Using correlative light and electron microscopy, we further show that IRSp53 ensures the shape and continuity of the opposing plasma membrane of two daughter cells, leading to the formation of a single apical lumen. Genetic removal of IRSp53 results in abnormal renal tubulogenesis, with altered tubular polarity and architectural organization. Thus, IRSp53 acts as a membrane curvature-sensing platform for the assembly of multi-protein complexes that control the trafficking of apical determinants and the integrity of the luminal plasma membrane.


Assuntos
Membrana Celular/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Proteínas rab de Ligação ao GTP/metabolismo , Actinas/metabolismo , Polaridade Celular/genética , Polaridade Celular/fisiologia , Células Epiteliais/metabolismo , Feminino , Humanos , Morfogênese/genética , Morfogênese/fisiologia , Proteínas do Tecido Nervoso/genética , Transporte Proteico/genética , Transporte Proteico/fisiologia , Sialoglicoproteínas/genética , Sialoglicoproteínas/metabolismo , Proteínas rab de Ligação ao GTP/genética
12.
Nat Commun ; 11(1): 2122, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32358486

RESUMO

Cell polarity refers to the intrinsic asymmetry of cells, including the orientation of the cytoskeleton. It affects cell shape and structure as well as the distribution of proteins and organelles. In migratory cells, front-rear polarity is essential and dictates movement direction. While the link between the cytoskeleton and nucleus is well-studied, we aim to investigate if front-rear polarity can be transmitted to the nucleus. We show that the knock-down of emerin, an integral protein of the nuclear envelope, abolishes preferential localization of several nuclear proteins. We propose that the frontally biased localization of the endoplasmic reticulum, through which emerin reaches the nuclear envelope, is sufficient to generate its observed bias. In primary emerin-deficient myoblasts, its expression partially rescues the polarity of the nucleus. Our results demonstrate that front-rear cell polarity is transmitted to the nucleus and that emerin is an important determinant of nuclear polarity.


Assuntos
Núcleo Celular/metabolismo , Proteínas de Membrana/metabolismo , Proteínas Nucleares/metabolismo , Western Blotting , Linhagem Celular , Núcleo Celular/ultraestrutura , Imunofluorescência , Humanos , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Mioblastos/metabolismo , Mioblastos/ultraestrutura , Membrana Nuclear/metabolismo , Membrana Nuclear/ultraestrutura , Interferência de RNA
13.
Dalton Trans ; 49(20): 6566-6571, 2020 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-32347275

RESUMO

Positively charged Gd(iii) and Y(iii) complexes were intercalated in the gallery of a synthetic saponite. A combination of solid-state NMR and 1H NMR relaxometric investigations has been employed to characterize these hybrid systems. This enabled us to gain atomic level insights into the local environment of the chelates and to evaluate the interactions of the metal species with the co-intercalated water molecules.

14.
Epidemiol Prev ; 44(5-6 Suppl 2): 169-182, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33412808

RESUMO

As the Coronavirus situation (COVID-19) continues to evolve, many questions concerning the factors relating to the diffusion and severity of the disease remain unanswered.Whilst opinions regarding the weight of evidence for these risk factors, and the studies published so far are often inconclusive or offer contrasting results, the role of comorbidities in the risk of serious adverse outcomes in patients affected with COVID-19 appears to be evident since the outset. Hypertension, diabetes, and obesity are under discussion as important factors affecting the severity of disease. Air pollution has been considered to play a role in the diffusion of the virus, in the propagation of the contagion, in the severity of symptoms, and in the poor prognosis. Accumulating evidence supports the hypothesis that environmental particulate matter (PM) can trigger inflammatory responses at molecular, cellular, and organ levels, sustaining respiratory, cardiovascular, and dysmetabolic diseases.To better understand the intricate relationships among pre-existing conditions, PM, and viral infection, we examined the response at the molecular level of T47D human breast adenocarcinoma cells exposed to different fractions of PM. T47D cells express several receptors, including the aryl hydrocarbon receptor (AhR), and ACE2, the main - but not the only - receptor for SARS-CoV-2 entry.PM samples were collected in an urban background site located in the Northern area of the City of Bologna (Emilia-Romagna Region, Northern Italy) during winter 2013. T47D cells were exposed to organic or aqueous (inorganic) extracts at the final concentration of 8 m3 for a 4-hour duration. Both the concentration and the exposure time were chosen to resemble an average outdoor exposure. RNA was extracted from cells, purified and hybridised on 66k microarray slides from Agilent.The lists of differentially expressed genes in PM organic extracts were evaluated by using Metacore, and an enrichment analysis was performed to identify pathways maps, process networks, and disease by biomarkers altered after T47D treatment.The analysis of the modulated genes gave evidence for the involvement of PM in dysmetabolic diseases, including diabetes and obesity, and hypertension through the activation of the aryl hydrocarbon receptor (AhR) canonical pathway.On the basis of current knowledge, existing data, and exploratory experimental evidence, we tease out the likely molecular interplay that can ultimately tip the disease outcome into severity. Looking beyond ACE2, several additional key markers are identified. Disruption of these targets worsens pre-existing conditions and/or exacerbates the adverse effects induced by SARS-CoV-2 infection. Whilst appropriately designed, epidemiological studies are very much needed to investigate these associations based on our hypothesis of investigation, by reviewing recent experimental and epidemiological evidence, here we speculate and provide new insights on the possible role of environmental pollution in the exacerbation of effects by SARS-CoV-2 and other respiratory viruses. This work is intended to assist in the development of appropriate investigative approaches to protect public health.


Assuntos
Poluição do Ar/efeitos adversos , COVID-19/epidemiologia , Material Particulado/efeitos adversos , SARS-CoV-2/fisiologia , Enzima de Conversão de Angiotensina 2/fisiologia , COVID-19/etiologia , Linhagem Celular Tumoral , Comorbidade , Coronaviridae/fisiologia , Citocromo P-450 CYP1A1/fisiologia , Diabetes Mellitus/epidemiologia , Diabetes Mellitus/genética , Diabetes Mellitus/metabolismo , Suscetibilidade a Doenças , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Hipertensão/epidemiologia , Hipertensão/genética , Hipertensão/metabolismo , Inflamação/epidemiologia , Inflamação/genética , Inflamação/metabolismo , Itália , Obesidade/epidemiologia , Obesidade/genética , Obesidade/metabolismo , Material Particulado/farmacologia , Receptores de Hidrocarboneto Arílico/fisiologia , Receptores Virais/fisiologia , Risco , SARS-CoV-2/ultraestrutura , Transdução de Sinais
15.
RSC Adv ; 10(50): 29765-29771, 2020 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-35518223

RESUMO

Tb3+ and Eu3+ ions were encapsulated for the first time in the inorganic layers of a synthetic saponite clay following a one-pot synthetic approach. The co-presence of the two metal ions led to tuneable light-emitting properties, promoted by an efficient Tb3+ → Eu3+ energy transfer and enhanced Stokes shift character. To our knowledge, the so-prepared luminescent material was tested for the first time as an optical sensor for the detection of chromate anions in water.

16.
Philos Trans R Soc Lond B Biol Sci ; 374(1779): 20180224, 2019 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-31431177

RESUMO

Selective evolutionary pressure shapes the processes and genes that enable cancer survival and expansion in a tumour-suppressive environment. A distinguishing lethal feature of malignant cancer is its dissemination and seeding of metastatic foci. A key requirement for this process is the acquisition of a migratory/invasive ability. However, how the migratory phenotype is selected for during the natural evolution of cancer and what advantage, if any, it might provide to the growing malignant cells remain open issues. In this opinion piece, we discuss three possible answers to these issues. We will examine lines of evidence from mathematical modelling of cancer evolution that indicate that migration is an intrinsic selectable property of malignant cells that directly impacts on growth dynamics and cancer geometry. Second, we will argue that migratory phenotypes can emerge as an adaptive response to unfavourable growth conditions and endow cells not only with the ability to move/invade, but also with specific metastatic traits, including drug resistance, self-renewal and survival. Finally, we will discuss the possibility that migratory phenotypes are coincidental events that emerge by happenstance in the natural evolution of cancer. This article is part of a discussion meeting issue 'Forces in cancer: interdisciplinary approaches in tumour mechanobiology'.


Assuntos
Evolução Biológica , Carcinogênese/metabolismo , Movimento Celular/genética , Neoplasias/metabolismo , Seleção Genética , Humanos , Fenótipo
17.
Math Biosci Eng ; 16(4): 2795-2810, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-31137238

RESUMO

This work investigates the mechano-biological features of cells cultured in monolayers in response to different osmotic conditions. In-vitro experiments have been performed to quantify the long-term effects of prolonged osmotic stresses on the morphology and proliferation capacity of glioblastoma cells. The experimental results highlight that both hypotonic and hypertonic conditions affect the proliferative rate of glioblastoma cells on different cell cycle phases. Moreover, glioblastoma cells in hypertonic conditions display a flattened and elongated shape. The latter effect is explained using a nonlinear elastic model for the single cell. Due to a crossover between the free energy contributions related to the cytosol and the cytoskeletal fibers, a critical osmotic stress determines a morphological transition from a uniformly compressed to an elongated shape.


Assuntos
Neoplasias Encefálicas/fisiopatologia , Glioblastoma/fisiopatologia , Pressão Osmótica , Astrócitos/metabolismo , Divisão Celular , Linhagem Celular Tumoral , Proliferação de Células , Simulação por Computador , Citoesqueleto/metabolismo , Dextranos/química , Elasticidade , Humanos , Microscopia , Modelos Biológicos , Osmose , Pressão , Esferoides Celulares/citologia , Estresse Fisiológico , Resultado do Tratamento
18.
Dalton Trans ; 47(24): 7896-7904, 2018 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-29761810

RESUMO

Novel paramagnetic lanthanide-exchanged saponite clays, bearing in the interlamellar region positively charged Gd3+-complexes, were synthesized using a hydrothermal approach followed by a classical ion exchange reaction. A detailed characterization was performed to assess the physico-chemical properties of the samples, which showed a hydrodynamic diameter between 50 and 90 nm and good thermal stability. 1H-NMR relaxometric studies in aqueous solution as a function of magnetic field and temperature were carried out to evaluate the local chemical environment of the intercalated paramagnetic centres and their interaction with water molecules. The data indicate a strong interaction of the confined complexes with the lamellae, resulting in a restriction of the local rotational dynamics and of the exchange process of water molecules between the inner coordination sphere of Gd3+ and the bulk. The stability over time in aqueous solutions of varying complexity was also studied by relaxometric techniques.

19.
Sci Total Environ ; 627: 67-77, 2018 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-29426191

RESUMO

A large number of studies have shown much higher health effects of particulate matter (PM) during the warm compared to the cold season. In this paper we present the results of an experimental study carried out in an unoccupied test apartment with the aim of understanding the reasons behind the seasonal variations of the health effects due to ambient PM2.5 exposure. Measurements included indoor and outdoor PM2.5 mass and chemical composition as well as particle size distribution of ultrafine particles. Monitoring campaigns were carried out during summer and winter following a ventilation protocol developed to replicate typical occupant behaviour according to a questionnaire-based survey. Our findings showed that seasonal variation of the relationship between ambient and indoor mass concentrations cannot entirely explain the apparent difference in PM toxicity between seasons and size distribution and chemical composition of particles were identified as other possible causes of changes in the apparent PM toxicity. A marked decrease of ultrafine particles (<100 nm) passing from outdoors to indoors was observed during winter; this resulted in higher indoor exposure to nanoparticles (<50 nm) during summer. With regards to the chemical composition, a pooled analysis showed infiltration factors of chemical species similar to that obtained for PM2.5 mass with values increasing from 0.73 during winter to 0.90 during summer and few deviations from the pooled estimates. In particular, significantly lower infiltration factors and sink effect were found for nitrates and ammonium during winter. In addition, a marked increase in the contribution of indoor and outdoor sulfates to the total mass was observed during summer.


Assuntos
Exposição Ambiental/estatística & dados numéricos , Material Particulado , Poluentes Atmosféricos , Poluição do Ar em Ambientes Fechados , Monitoramento Ambiental , Humanos , Tamanho da Partícula , Estações do Ano
20.
Environ Pollut ; 235: 339-349, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29304467

RESUMO

Substantial efforts have been made in recent years to investigate the horizontal variability of air pollutants at regional and urban scales and epidemiological studies have taken advantage of resulting improvements in exposure assessment. On the contrary, only a few studies have investigated the vertical variability and their results are not consistent. In this study, a field experiment has been conducted to evaluate the variation of concentrations of different particle metrics and gaseous pollutants on the basis of floor height at a high rise building. Two 15-day monitoring campaigns were conducted in the urban area of Bologna, Northern Italy, one of the most polluted areas in Europe. Measurements sites were operated simultaneously at 2, 15, 26, 44 and 65 m a.g.l. Several particulate matter metrics including PM2.5 mass and chemical composition, particle number concentration and size distribution were measured. Time integrated measurement of NO2 and BTEX were also included in the monitoring campaigns. Measurements showed relevant vertical gradients for most traffic related pollutants. A monotonic gradient of PM2.5 was found with ground-to-top differences of 4% during the warm period and 11% during the cold period. Larger gradients were found for UFP (∼30% during both seasons) with a substantial loss of particles from ground to top in the sub-50 nm size range. The largest drops in concentrations for chemical components were found for Elemental Carbon (-27%), iron (-11%) and tin (-36%) during winter. The ground-to-top decline of concentrations for NO2 and benzene during winter was equal to 74% and 35%, respectively. In conclusion, our findings emphasize the need to include vertical variations of urban air pollutants when evaluating population exposure and associated health effects, especially in relation to some traffic related pollutants and particle metrics.


Assuntos
Poluição do Ar/análise , Derivados de Benzeno/análise , Habitação , Dióxido de Nitrogênio/análise , Benzeno/análise , Monitoramento Ambiental/métodos , Humanos , Itália , Tamanho da Partícula , Estações do Ano , Tolueno/análise , Xilenos/análise
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