RESUMO
The toxicological impact of airborne polluting ultrafine particles (UFPs, also classified as nanoparticles with average sizes of less than 100 nm) is an emerging area of research pursuing a better understanding of the health hazards they pose to humans and other organisms. Hemolytic activity is a toxicity parameter that can be assessed quickly and easily to establish part of a nanoparticle's behavior once it reaches our circulatory system. However, it is exceedingly difficult to determine to what extent each of the nanoparticles present in the air is responsible for the detrimental effects exhibited. At the same time, current hemolytic assessment methodologies pose a series of limitations for the interpretation of results. An alternative is to synthesize nanoparticles that model selected typical types of UFPs in air pollution and evaluate their individual contributions to adverse health effects under a clinical assay of osmotic fragility. Here, we discuss evidence pointing out that the absence of hemolysis is not always a synonym for safety; exposure to model nanopollutants, even at low concentrations, is enough to increase erythrocyte susceptibility and dysfunction. A modified osmotic fragility assay in combination with a morphological inspection of the nanopollutant-erythrocyte interaction allows a richer interpretation of the exposure outcomes. Membrane-nanoparticle interplay has a leading role in the vulnerability observed. Therefore, future research in this line of work should pay special attention to the evaluation of the mechanisms that cause membrane damage.
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Due to the recent coronavirus-2019 pandemic, several studies have emerged looking for new materials, especially with biocidal characteristics. Thus, the present research investigates the antibacterial properties of biodegradable cellulose acetate (CA) / cetylpyridinium bromide (CPB) electrospun nanofibers, their aerosol filtration, and the possible use as a filter media of surgical face masks. Then, samples of these nanofibers were produced over a nonwoven substrate, using different volumes of polymeric solution during the electrospinning process. The evaluation of the antibacterial properties of the nanofibers was performed for Escherichia coli and Staphylococcus aureus using quantitative methods. The aerosol filtration performance was evaluated in these samples for NaCl nanoparticles (from 7-300â nm) and with 8â mL min-1 of air flow rate. The results show that the single use of the surfactant has antibacterial properties from a concentration of 39â µg mL-1 of solution. The nanofibers presented a reduction of 100% for both bacteria. Air filtration tests showed 126.03 and 207.73 Pa cm-² of pressure drops and 63 and 77% of aerosol filtration efficiency (FE) for samples with 0.13 and 0.15 mL, respectively. Regarding the nanofiber produced with 0.35 mL, the value obtained was 115.13 ± 33.64 Pa cm-2 and 3.15% of particle penetration. These breathability values are higher than those required for the surgical face mask standard, indicating that improvements in the porosity and thickness are necessary to meet the Brazilian requirements. However, the nanofibers could be applied as filter media for indoor air conditioning systems due to their FE and biocidal properties.
Assuntos
Filtros de Ar , Nanofibras , Nanofibras/química , Máscaras , Filtração/métodos , Antibacterianos , Aerossóis , Escherichia coliRESUMO
Road-deposited dust (RD) is a pervasive form of particulate pollution identified (typically via epidemiological or mathematical modelling) as hazardous to human health. Finer RD particle sizes, the most abundant (by number, not mass), may pose greater risk as they can access all major organs. Here, the first in vitro exposure of human lung epithelial (Calu-3) cells to 0−300 µg/mL of the ultrafine (<220 nm) fraction of road dust (UF-RDPs) from three contrasting cities (Lancaster and Birmingham, UK, and Mexico City, Mexico) resulted in differential oxidative, cytotoxic, and inflammatory responses. Except for Cd, Na, and Pb, analysed metals were most abundant in Mexico City UF-RDPs, which were most cytotoxic. Birmingham UF-RDPs provoked greatest ROS release (only at 300 µg/mL) and greatest increase in pro-inflammatory cytokine release. Lancaster UF-RDPs increased cell viability. All three UF-RDP samples stimulated ROS production and pro-inflammatory cytokine release. Mass-based PM limits seem inappropriate given the location-specific PM compositions and health impacts evidenced here. A combination of new, biologically relevant metrics and localised regulations appears critical to mitigating the global pandemic of health impacts of particulate air pollution and road-deposited dust.
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Outdoor ultrafine particles (UFP, <0.1 µm) and black carbon (BC) vary greatly within cities and may have adverse impacts on human health. In this study, we used a hybrid approach to develop new models to estimate within-city spatial variations in outdoor UFP and BC concentrations across Bucaramanga, Colombia. We conducted a mobile monitoring campaign over 20 days in 2019. Regression models were trained on land use data and combined with predictions from convolutional neural networks (CNN) trained to predict UFP and BC concentrations using satellite and street-level images. The combined UFP model (R2 = 0.54) outperformed the CNN (R2 = 0.47) and land use regression (LUR) models (R2 = 0.47) on their own. Similarly, the combined BC model also outperformed the CNN and LUR BC models (R2 = 0.51 vs 0.43 and 0.45, respectively). Spatial variations in model performance were more stable for the CNN and combined models compared to the LUR models, suggesting that the combined approach may be less likely to contribute to differential exposure measurement error in epidemiological studies. In general, our findings demonstrated that satellite and street-level images can be combined with a traditional LUR modeling approach to improve predictions of within-city spatial variations in outdoor UFP and BC concentrations.
Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Carbono , Cidades , Colômbia , Monitoramento Ambiental , Humanos , Material Particulado/análiseRESUMO
In the present study, the daily dose in terms of particle surface area received by citizens living in different low- and middle-income countries, characterized by different lifestyles, habits, and climates, was evaluated. The level of exposure to submicron particles and the dose received by the populations of Accra (Ghana), Cairo (Egypt), Florianopolis (Brazil), and Nur-Sultan (Kazakhstan) were analyzed. A direct exposure assessment approach was adopted to measure the submicron particle concentration levels of volunteers at a personal scale during their daily activities. Non-smoking adult volunteers performing non-industrial jobs were considered. Exposure data were combined with time-activity pattern data (characteristic of each population) and the inhalation rates to estimate the daily dose in terms of particle surface area. The received dose of the populations under investigation varied from 450 mm2 (Florianopolis, Brazil) to 1300 mm2 (Cairo, Egypt). This work highlights the different contributions of the microenvironments to the daily dose with respect to high-income western populations. It was evident that the contribution of the Cooking & Eating microenvironment to the total exposure (which was previously proven to be one of the main exposure routes for western populations) was only 8%-14% for low- and middle-income populations. In contrast, significant contributions were estimated for Outdoor day and Transport microenvironments (up to 20% for Cairo, Egypt) and the Sleeping & Resting microenvironment (up to 28% for Accra, Ghana), highlighting the effects of different site-specific lifestyles (e.g. time-activity patterns), habits, socioeconomic conditions, climates, and outdoor air quality.
Assuntos
Poluentes Atmosféricos , Poluição do Ar em Ambientes Fechados , Adulto , Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/análise , Brasil , Países em Desenvolvimento , Egito , Monitoramento Ambiental , Gana , Humanos , Cazaquistão , Tamanho da Partícula , Material Particulado/análiseRESUMO
The exposure to environmental pollutants, such as fine and ultrafine particles (FP and UFP), has been associated with increased risk for Parkinson's disease, depression and schizophrenia, disorders related to altered dopaminergic transmission. The striatum, a neuronal nucleus with extensive dopaminergic afferents, is a target site for particle toxicity, which results in oxidative stress, inflammation, astrocyte activation and modifications in dopamine content and D2 receptor (D2R) density. In this study we assessed the in vitro effect of the exposure to FP and UFP on dopaminergic transmission, by evaluating [3H]-dopamine uptake and release by rat striatal isolated nerve terminals (synaptosomes), as well as modifications in the affinity and signaling of native and cloned D2Rs. FP and UFP collected from the air of Mexico City inhibited [3H]-dopamine uptake and increased depolarization-evoked [3H]-dopamine release in striatal synaptosomes. FP and UFP also enhanced D2R affinity for dopamine in membranes from either rat striatum or CHO-K1 cells transfected with the long isoform of the human D2R (hD2LR)2LR). In CHO-K1-hD2L In CHO-K1-hD2LR cells or striatal slices, FP and UFP increased the potency of dopamine or the D2R agonist quinpirole, respectively, to inhibit forskolin-induced cAMP formation. The effects were concentration-dependent, with UFP being more potent than FP. These results indicate that FP and UFP directly affect dopaminergic transmission.
Assuntos
Poluentes Atmosféricos/toxicidade , Corpo Estriado/efeitos dos fármacos , Dopamina/metabolismo , Material Particulado/toxicidade , Animais , Células CHO , Corpo Estriado/metabolismo , Cricetulus , Técnicas In Vitro , Masculino , México , Ratos Wistar , Receptores de Dopamina D2/metabolismo , Transdução de Sinais/efeitos dos fármacos , Sinaptossomos/efeitos dos fármacos , Sinaptossomos/metabolismoRESUMO
The present work investigates hazardous elements and nanomineralogical assemblages of phosphogypsum waste from an abandoned phosphate fertilizer industry located in Santa Catarina state (Brazil). Correlations between the chemical composition, nanominerals, and ultrafine particles are discussed. Multifaceted physical-geochemical study provided a careful understanding of the nanomineralogical assemblage of the phosphogypsum waste. The electron beam investigation revealed the presence of many hazardous elements in the ultrafine particles. Cr, Pb, Mn, Se, Sr, and Zr, among others, were found in individual ultrafine particles and nanominerals in all studied samples. Besides that, rare earth elements were found in different concentration ranges, being Ce, La, and Nd, the rare earth elements, found in the higher concentrations, above 900 mg kg-1. The data supplied by this article are important to characterize the phosphogypsum waste, assessing the potential hazard to the environment and human health, and also, provides information to enable the designing of alternatives to manage this waste.
Assuntos
Sulfato de Cálcio/química , Monitoramento Ambiental , Fertilizantes/análise , Metais Pesados/análise , Metais Terras Raras/análise , Fósforo/química , Brasil , Humanos , Material Particulado/análise , Fosfatos/análiseRESUMO
Cooking and heating with solid fuels results in high levels of household air pollutants, including particulate matter (PM); however, limited data exist for size fractions smaller than PM2.5 (diameter less than 2.5 µm). We collected 24-h time-resolved measurements of PM2.5 (n = 27) and particle number concentrations (PNC, average diameter 10-700 nm) (n = 44; 24 with paired PM2.5 and PNC) in homes with wood-burning traditional and Justa (i.e., with an engineered combustion chamber and chimney) cookstoves in rural Honduras. The median 24-h PM2.5 concentration (n = 27) was 79 µg/m3 (interquartile range [IQR]: 44-174 µg/m3); traditional (n = 15): 130 µg/m3 (IQR: 48-250 µg/m3); Justa (n = 12): 66 µg/m3 (IQR: 44-97 µg/m3). The median 24-h PNC (n = 44) was 8.5 × 104 particles (pt)/cm3 (IQR: 3.8 × 104-1.8 × 105 pt/cm3); traditional (n = 27): 1.3 × 105 pt/cm3 (IQR: 3.3 × 104-2.0 × 105 pt/cm3); Justa (n = 17): 6.3 × 104 pt/cm3 (IQR: 4.0 × 104-1.2 × 105 pt/cm3). The 24-h average PM2.5 and particle number concentrations were correlated for the full sample of cookstoves (n = 24, Spearman ρ: 0.83); correlations between PM2.5 and PNC were higher in traditional stove kitchens (n = 12, ρ: 0.93) than in Justa stove kitchens (n = 12, ρ: 0.67). The 24-h average concentrations of PM2.5 and PNC were also correlated with the maximum average concentrations during shorter-term averaging windows of one-, five-, 15-, and 60-min, respectively (Spearman ρ: PM2.5 [0.65, 0.85, 0.82, 0.71], PNC [0.74, 0.86, 0.88, 0.86]). Given the moderate correlations observed between 24-h PM2.5 and PNC and between 24-h and the shorter-term averaging windows within size fractions, investigators may need to consider cost-effectiveness and information gained by measuring both size fractions for the study objective. Further evaluations of other stove and fuel combinations are needed.
Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/análise , Culinária/instrumentação , Material Particulado/análise , Biomassa , Monitoramento Ambiental , Honduras , HumanosRESUMO
We report on commuters' exposure to black carbon (BC), PM2.5 and particle number (PN, with aerodynamic diameter, da, in the range 0.01 Assuntos
Poluentes Atmosféricos
, Emissões de Veículos
, Poluentes Atmosféricos/análise
, Biocombustíveis
, Brasil
, Cidades
, Monitoramento Ambiental
, Veículos Automotores
, Material Particulado/análise
, Emissões de Veículos/análise
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Diesel exhaust particles (DEPs) from diesel engines produce adverse alterations in cells of the airways by activating intracellular signaling pathways and apoptotic gene overexpression, and also by influencing metabolism and cytoskeleton changes. This study used human bronchial epithelium cells (BEAS-2B) in culture and evaluates their exposure to DEPs (15ug/mL for 1 and 2 h) in order to determine changes to cell rheology (viscoelasticity) and gene expression of the enzymes involved in oxidative stress, apoptosis, and cytotoxicity. BEAS-2B cells exposed to DEPs were found to have a significant loss in stiffness, membrane stability, and mitochondrial activity. The genes involved in apoptosis [B cell lymphoma 2 (BCL-2 and caspase-3)] presented inversely proportional expressions (p = 0.05, p = 0.01, respectively), low expression of the genes involved in antioxidant responses [SOD1 (superoxide dismutase 1); SOD2 (superoxide dismutase 2), and GPx (glutathione peroxidase) (p = 0.01)], along with an increase in cytochrome P450, family 1, subfamily A, polypeptide 1 (CYP1A1) (p = 0.01). These results suggest that alterations in cell rheology and cytotoxicity could be associated with oxidative stress and imbalance between pro- and anti-apoptotic genes.
Assuntos
Antioxidantes/metabolismo , Apoptose/efeitos dos fármacos , Brônquios/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Expressão Gênica/efeitos dos fármacos , Material Particulado/toxicidade , Emissões de Veículos/toxicidade , Apoptose/genética , Brônquios/metabolismo , Brônquios/patologia , Caspase 3/genética , Caspase 3/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Citocromo P-450 CYP1A1/genética , Citocromo P-450 CYP1A1/metabolismo , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Glutationa Peroxidase/genética , Glutationa Peroxidase/metabolismo , Humanos , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Tamanho da Partícula , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , ReologiaRESUMO
Temuco is one of the most highly wood smoke polluted cities in Chile; however, there is scarce evidence of respiratory morbidity due to fine particulate matter. We aimed to estimate the relationship between daily concentration of ultrafine particles (UFP), with an aerodynamic diameter ≤ 0.1 µm, and outpatient visits for respiratory illness at medical care centers of Temuco, Chile, from August the 20th, 2009 to June the 30th, 2011. The Air Pollution Health Effects European Approach (APHEA2) protocol was followed, and a multivariate semi-parametric Poisson regression model was fitted with GAM techniques using R-Project statistical package; controlling for trend, seasonality, and confounders. The daily UFP were measured by a MOUDI NR-110 sampler. We found that results of the statistical analyses show significant associations between UFP and respiratory outpatient visits, with the elderly (population ≥ 65 years), being the group that presented the greatest risk. An interquartile increase of 4.73 µg/m(3) in UFP (lag 5 days) was associated with respiratory outpatient visits with a relative risk (RR) of 1.1458 [95% CI (1.0497-1.2507)] for the elderly. These results show novel findings regarding the relevance of daily UFP concentrations and health risk, especially for susceptible population in a wood smoke polluted city.
Assuntos
Exposição Ambiental , Tamanho da Partícula , Material Particulado/toxicidade , Sistema Respiratório/efeitos dos fármacos , Doenças Respiratórias/epidemiologia , Fumaça/efeitos adversos , Madeira/química , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Chile/epidemiologia , Demografia , Humanos , Pessoa de Meia-Idade , Análise de Regressão , Risco , Tempo , Adulto JovemRESUMO
Se realizó un estudio exploratorio con los objetivos de identificar empresas que produzcan o manipulen nanopartículas en Chile, evaluar los riesgos para la salud de estas actividades y entregar recomendaciones para su control. Se encontró que la nanotecnología está en una etapa incipiente, con un reducido número de aplicaciones en procesos industriales, concentrándose el desarrollo y aplicación principalmente en centros de investigación de las universidades, donde los investigadores y estudiantes son el principal grupo de potenciales expuestos. Para evaluar la exposición en las empresas e instituciones identificadas, se utilizó un método cualitativo simplificado y un método cuantitativo que se basa en las técnicas tradicionales de higiene ocupacional complementadas con la caracterización de las nanopartículas mediante microscopía electrónica. Se evalúa la exposición a nanopartículas de cobre, carbonato de calcio y partículas ultrafinas de humos de soldadura. La metodología de evaluación cualitativa, si bien requiere algún grado de acondicionamiento, demostró ser una herramienta particularmente útil para definir sistemas de protección en el caso de las nanopartículas, cuya toxicidad es incierta y de las cuales no se tienen establecidas técnicas de medición ni límites permisibles. Los métodos de medición tradicionales de la higiene industrial no entregan la información suficiente para evaluar la exposición, debiendo ser complementados con microscopía electrónica para caracterizar el tamaño y composición química, parámetros claves en la toxicidad de las nanopartículas. El trabajo realizado entrega una base de información y conocimiento a nivel exploratorio, que se estima útil para evaluar el riesgo de exposición en aplicaciones que pudieran surgir en el contexto actual del desarrollo de la nanotecnología en nuestro país.
An exploratory research was developed in order to identify companies which produce or handle nanoparticles in Chile, evaluate the risks for health from these activities and give suggestions for controlling them. It was found that nanotechnology is in an incipient stage, with a reduced numbers of applications in industrial processes, focusing the development and application mainly on research centers in Universities, where researchers and students are the main exposed potential groups. To evaluate the exposure in identified companies and institutions, it was used a qualitative simplified method and a quantitative method which is based in traditional technique of occupational hygiene complemented by the characterization of nanoparticles with electronic microscopy. It was evaluated the exposure to nanoparticles of copper, calcium carbonate and welding smoke ultrafine particles. The methodology of qualitative evaluation, although requires some degree of conditioning, showed being a especially useful tool to define protection systems in nanoparticles case, whose toxicity is uncertain and we do not have established techniques of measuring them or permissible limits. Traditional measuring methods of industrial hygiene do not bring enough information to evaluate the exposure, and they must be complemented with electronic microscopy to characterize the size and chemical composition, key parameters in nanoparticles toxicity. This work provides a base of information and knowledge in a exploratory level, which is estimated as a useful tool to evaluate the exposure risk in applications that may appear in the current nanotechnology development in our country.