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1.
Cent Eur J Public Health ; 27(3): 239-244, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31580561

RESUMO

OBJECTIVES: This study was aimed to assess the concentration of microbial aerosol and species composition of airborne staphylococci in 10 healthcare facilities in southern Poland including primary healthcare units and hospital wards; and to assess whether the selected components of microbial aerosol pose a threat of severe infections to either patients or the personnel. METHODS: The study was conducted at monthly intervals over a period of one year. Air samples were collected by MAS-100 sampler. The number of mesophilic bacteria, mould fungi, actinomycetes and staphylococci was determined on general and selective media. The species identification of staphylococci was conducted using API tests for strains that were pre-selected based on macroscopic and microscopic observations. RESULTS: A total number of 1,584 samples were collected during the sampling period. The numbers of airborne microorganisms varied between the examined premises and between the seasons of the year. The observed differences were statistically significant with one exception for actinomycetes and their differences between the examined premises. The concentrations of mesophilic bacteria varied from 5 to 297 CFU/m3 of air, for Staphylococcus the values ranged from 1 to 96 CFU/m3, for fungi - from 1 to 100 CFU/m3, and the number of actinomycetes ranged from 7 to 321 CFU/m3. Ten species of coagulase-negative staphylococci (CoNS) were identified among 55 isolates with S. saprophyticus and S. warneri being the most frequently detected (n = 14 and 13, respectively). S. haemolyticus, which is one of the most common causal agents of nosocomial infections was observed in four facilities (n = 5). CONCLUSIONS: The microbial concentrations varied both between the seasons of the year and between the examined facilities. The highest bioaerosol concentrations were observed in most crowded premises. The identified species of staphylococci, although not typically associated with human infections, are common causal agents of nosocomial infections and infections in immunocompromised people.


Assuntos
Microbiologia do Ar , Exposição Ocupacional , Aerossóis , Poluentes Ocupacionais do Ar/análise , Fungos , Humanos , Exposição Ocupacional/análise , Polônia
2.
J Environ Radioact ; 208-209: 106037, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31476609

RESUMO

Pacific Northwest National Laboratory (PNNL) staff developed the Radionuclide Aerosol Sampler Analyzer (RASA) for worldwide aerosol monitoring in the 1990s. Recently, researchers at PNNL and Creare, LLC, have investigated possibilities for how RASA could be improved, based on lessons learned from more than 15 years of continuous operation, including during the Fukushima Daiichi Nuclear Power Plant disaster. Key themes addressed in upgrade possibilities include having a modular approach to additional radionuclide measurements, optimizing the sampling/analyzing times to improve detection location capabilities, and reducing power consumption by using electrostatic collection versus classic filtration collection. These individual efforts have been made in a modular context that might constitute retrofits to the existing RASA, modular components that could improve a manual monitoring approach, or a completely new RASA. Substantial optimization of the detection and location capabilities of an aerosol network is possible and new missions could be addressed by including additional measurements.


Assuntos
Aerossóis/análise , Poluentes Radioativos do Ar/análise , Monitoramento de Radiação , Acidente Nuclear de Fukushima
3.
Toxicol Lett ; 316: 127-135, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31539569

RESUMO

Carfentanil (CRF) is an extremely potent opioid capable of inducing fatal respiratory depression. Naloxone (NX) and naltrexone (NTX) are opioid antagonists for which the efficacy against CRF remains largely unexplored. In this study, the effects of aerosolized CRF on respiratory function were investigated using adult male CD-1 mice. Mice were exposed to 0.4 mg/m3 of CRF for 15 min using custom whole-body plethysmograph units. Minute volume (MV), respiratory frequency (f), duty cycle (DC), and tidal volume (TV) were monitored and compared to control animals exposed to aerosolized H2O. CRF exposure induced respiratory depression, characterized by a marked decrease in MV, which was sustained throughout 24 h post-exposure. Prophylactic and therapeutic treatment with intramuscular (i.m.) NX marginally improved MV, with slight dose-dependent effects. Analogous treatment with i.m. NTX returned MV to baseline levels, with all doses and intervention times performing similarly. Despite improvements in MV, treatment administration did not reverse changes in DC, a measure of respiratory timing. Overall, NX and NTX administration alleviated volumetric aspects of opioid-induced respiratory toxicity, while changes in respiratory timing remained unresolved throughout post-exposure observation. These sustained changes and differences in recovery between two aspects of respiratory dynamics may provide insights for further exploration into the underlying mechanism of action of opioids and opioid antagonists.


Assuntos
Analgésicos Opioides/administração & dosagem , Analgésicos Opioides/toxicidade , Fentanila/análogos & derivados , Pulmão/efeitos dos fármacos , Naloxona/administração & dosagem , Naltrexona/administração & dosagem , Antagonistas de Entorpecentes/administração & dosagem , Respiração/efeitos dos fármacos , Insuficiência Respiratória/prevenção & controle , Administração por Inalação , Aerossóis , Analgésicos Opioides/farmacocinética , Animais , Simulação por Computador , Relação Dose-Resposta a Droga , Fentanila/administração & dosagem , Fentanila/farmacocinética , Fentanila/toxicidade , Humanos , Pulmão/fisiopatologia , Masculino , Camundongos , Modelos Biológicos , Pletismografia Total , Insuficiência Respiratória/induzido quimicamente , Insuficiência Respiratória/fisiopatologia , Medição de Risco
4.
Toxicol Lett ; 315: 14-22, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31400404

RESUMO

In vitro testing can facilitate the rapid assessment of next generation nicotine delivery products (NGPs) with comparisons to combustible tobacco products. In vitro assays for cytotoxicity and oxidative stress were employed at BAT (UK) and JT (Japan) to test total particulate matter (TPM) of a scientific reference cigarette and aerosol collected mass (ACM) of a commercially available E-cigarette and two tobacco heating products (THP). 3R4F TPMs were generated using the Health Canada intense (HCI) regimen, a modified regime (mHCI) for the THP ACMs and the CORESTA recommended method no. 81 for the E-cigarette ACM. Human lung cells were exposed to the test product TPM/ACMs at concentrations between 0-200 µg/ml followed by the employment of commercially available assays for endpoint analysis that included reactive oxygen species (ROS) generation, the glutathione ratio (GSH:GSSG), activation of the antioxidant response elements (ARE) and cellular viability. TPM/ACM nicotine concentrations were quantified using a UPLC-PDA technique. At both laboratories the 3R4F TPM induced significant and dose-dependent responses in all in vitro assays, whereas no significant responses could be measured for the NGP ACMs. In conclusion, both laboratories obtained comparable results across all endpoints therefore demonstrating the utility of the in vitro techniques combined with standardised test products to support the assessment of NGPs.


Assuntos
Aerossóis/análise , Sobrevivência Celular/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Nicotina/análise , Material Particulado/análise , Produtos do Tabaco/análise , Sistemas Eletrônicos de Liberação de Nicotina , Humanos , Japão , Reino Unido
5.
J Environ Radioact ; 208-209: 106034, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31454588

RESUMO

A radiological dispersal device (RDD) is built using an explosive device laced with radioactive materials. The RDD appears as a speculative radiological weapon with the aim of spreading radioactive material across an inhabited area. This study seeks to evaluate how the official decision-making process is influenced by the radiation vertical profile dose, using the hypothetical scenario of a simulated RDD detonation in a densely populated urban area. A simulated plume of strong radiation was generated from the explosion site, contaminating the surrounding area. Several atmospheric conditions impact on the contamination. However, this study focusses on the following main variables considered by HotSpot for a conservative simulation: (a) the atmospheric stability conditions (Pasquill-Gifford - PG classes); (b) the explosive power, and (c) the source-term. Gaussian modeling was used for its speed, and for its capacity to estimate the time-integrated atmospheric concentration of an aerosol at any point in 3D space. The simulation provided information about four main outcomes: (a) contamination plume area; (b) radiological risk dependency on PG classes; (c) total effective dose equivalent (TEDE) with a possible dependence on receptor height; and (d) potentially affected population's size. The findings suggest that a protocolled response from authorities should be implemented in order to effectively follow possible changes in the PG class. Which, in turn, may negatively impact the decision-making process.


Assuntos
Doses de Radiação , Liberação Nociva de Radioativos , Aerossóis , Tomada de Decisões , Explosões , Armas Nucleares , Monitoramento de Radiação , Medição de Risco
6.
Environ Monit Assess ; 191(9): 576, 2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31428877

RESUMO

Evolution of submicron particles in terms of particle number concentration and mobility-equivalent diameter was measured during Diwali festival-specific intensive pyrotechnic displays in Varanasi over central Indo-Gangetic Plain (IGP). A scanning mobility particle sizer coupled with an optical particle sizer was used to fit in an overlapping size range, and particle number concentration was analyzed to have an insight into the new particle formation and subsequent evolution of particles from nucleation to accumulation mode. Further, variation in black carbon (BC) concentration and aerosol ionic composition was measured simultaneously. Frequent fluctuation in particle number concentration in and around Diwali festival was evidenced, primarily influenced by local emission sources and meteorology, with three distinct peaks in number concentrations (dN/dlogDp, 3.1-4.5 × 104 cm3) coinciding well with peak firework emission period (18:00-23:00 h). Submicron particle size distribution revealed a single peak covering a size range of 80-130 nm, and for all instances, number concentration maximum coincided with geometric mean minimum, indicating the emission primarily in the ultrafine range (< 0.1 µm). Interestingly, during peak firework emissions, besides rise in accumulation mode, an event of new particle formation was identified with increase in nucleation and small Aitken mode, before being dispersed to background aerosols. On an integral scale, a clear distinction was noted between a normal and an episodic event, with a definite shift in the formation of ultrafine particles compared with the accumulation mode. The BC diurnal profile was typical, with a prominent nocturnal peak (12.0 ± 3.9 µg m-3) corresponding to a decrease in the boundary layer height. A slight variation in maximum BC concentration (16.8 µg m-3) was noted in the night of the event coinciding well with firework emissions. An increase in some specific ionic species was also noted in combination with an increase in the overall cation to anion ratio, which was explained in terms of heterogeneous transformation of NOx and catalytic conversion of SO2. Graphical abstract Time-resolved evolution of particle size distribution during normal and episodic events.


Assuntos
Aerossóis/análise , Poluentes Atmosféricos/análise , Monitoramento Ambiental , Substâncias Explosivas , Material Particulado/análise , Férias e Feriados , Índia , Tamanho da Partícula , Fuligem/análise , Fatores de Tempo
7.
Environ Pollut ; 253: 1089-1099, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31434186

RESUMO

Elemental concentrations of ambient aerosols are commonly sampled over 12-24 h, and the low time resolution puts a great limit on current understanding about the temporal variations and source apportionment based on receptor models. In this work, hourly-resolved concentrations of eighteen elements in PM2.5 at an urban site in Nanjing, a megacity in Yangtze River Delta of east China, were obtained by using a Xact 625 ambient metals monitor from 12/12/2016 to 12/31/2017. The influence of traffic activities was clearly reflected by the spikes of crustal elements (e.g., Fe, Ca, and Si) in the morning rush hour, and the firework burning and sandstorm events during the sampling periods were tracked by sharp enrichment of Ba, K and Fe, Ca, Si, Ti in PM2.5, respectively. To evaluate the advantage of hourly-resolved elements data in identifying impacts from specific emission sources, positive matrix factorization (PMF) analysis was performed with the 1-h data set (PMF1-h) and 23-h averaged data (PMF23-h), respectively. The 4- and 6-factor PMF23-h solutions had similar factor profiles and consistent factor contributions as the corresponding PMF1-h solutions. However, due to the limit in inter-sample variability, PMF analysis with 23-h average data misclassified some major (e.g., K, Fe, Zn, Ca, and Si) and trace (e.g., Pb) elements in factor profiles, resulting in different absolute factor contributions between PMF23-h and PMF1-h solutions. These results suggested the use of high time-resolved data to obtain valid and robust source apportionment results.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Material Particulado/análise , Aerossóis/análise , China , Análise Fatorial , Metais/análise , Rios
8.
AAPS PharmSciTech ; 20(7): 271, 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-31363868

RESUMO

Dry powder inhalers have attracted more interest over the years in every aspect related to them. Interestingly, when focusing on the effects of particle morphology of the active or carrier (excipient), it is generally regarded particle size and shape to influence drug availability of aerosolized particles. However, to date, few studies have examined the effect of texture, i.e., roughness, on this relationship. The main objective of the present work is to gain a closer understanding of the influence of carrier morphology on the aerosolization performance of dry powder inhaler formulations. Image analysis and microscopy were used to visualize the aerosolization process. It is considered that the scale of morphological features on the surface of the carrier particles is responsible for the dispersion of the powder formulation, separation of the drug/carrier, and entrainment from a dry powder inhaler. Thus, for this study, the carrier particles of different surface roughness were mixed with micronized salbutamol sulphate. Aerosolization in vitro testing was used to evaluate the performance. The results indicate a connection between the qualitative surface roughness of coarse carriers and aerosolization performance during powder dispersibility. This investigation demonstrated that indeed, powder dispersion, a dynamic process, is influenced by the scale of the carrier morphology.


Assuntos
Albuterol/química , Albuterol/farmacocinética , Broncodilatadores/química , Broncodilatadores/farmacocinética , Química Farmacêutica/métodos , Inaladores de Pó Seco/métodos , Administração por Inalação , Aerossóis/química , Aerossóis/farmacocinética , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Liberação Controlada de Fármacos , Inaladores de Pó Seco/instrumentação , Excipientes/química , Excipientes/farmacocinética , Tamanho da Partícula , Pós , Propriedades de Superfície
9.
Pharm Res ; 36(9): 136, 2019 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-31321552

RESUMO

PURPOSE: Human tuberculosis (TB) is a global health problem that causes nearly 2 million deaths per year. Anti-TB therapy exists, but it needs to be administered as a cocktail of antibiotics for six months. This lengthy therapy results in low patient compliance and is the main reason attributable to the emergence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains of Mycobacterium tuberculosis. METHODS: One alternative approach is to combine anti-TB multidrug therapy with inhalational TB therapy. The aim of this work was to develop and characterize dry powder formulations of spectinamide 1599 and ensure in vitro and in vivo delivered dose reproducibility using custom dosators. RESULTS: Amorphous dry powders of spectinamide 1599 were successfully spray dried with mass median aerodynamic diameter (MMAD) = 2.32 ± 0.05 µm. The addition of L-leucine resulted in minor changes to the MMAD (1.69 ± 0.35 µm) but significantly improved the inhalable portion of spectinamide 1599 while maintaining amorphous qualities. Additionally, we were able to demonstrate reproducibility of dry powder administration in vitro and in vivo in mice. CONCLUSIONS: The corresponding systemic drug exposure data indicates dose-dependent exposure in vivo in mice after dry powder intrapulmonary aerosol delivery in the dose range 15.4 - 32.8 mg/kg.


Assuntos
Antituberculosos/farmacocinética , Inaladores de Pó Seco/métodos , Espectinomicina/análogos & derivados , Administração por Inalação , Aerossóis , Animais , Antituberculosos/administração & dosagem , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Farmacorresistência Bacteriana Múltipla , Feminino , Camundongos Endogâmicos BALB C , Mycobacterium tuberculosis/efeitos dos fármacos , Tamanho da Partícula , Pós , Reprodutibilidade dos Testes , Espectinomicina/administração & dosagem , Espectinomicina/farmacocinética
10.
J Environ Sci (China) ; 84: 197-204, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31284911

RESUMO

Intermediate volatility organic compounds (IVOCs) are crucial precursors of secondary organic aerosol (SOA). In this study, gaseous IVOCs emitted from a ship main engine burning heavy fuel oil (HFO) were investigated on a test bench, which could simulate the real-world operations and emissions of ocean-going ships. The chemical compositions, emission factors (EFs) and volatility distributions of IVOC emissions were investigated. The results showed that the main engine burning HFO emitted a large amount of IVOCs, with average IVOC EFs of 20.2-201 mg/kg-fuel. The IVOCs were mainly comprised of unspeciated compounds. The chemical compositions of exhaust IVOCs were different from that of HFO fuel, especially for polycyclic aromatic compounds and alkylcyclohexanes. The volatility distributions of IVOCs were also different between HFO exhausts and HFO fuel. The distinctions in IVOC emission characteristics between HFO exhausts and HFO fuel should be considered when assessing the IVOC emission and related SOA formation potentials from ocean-going ships burning HFO, especially when using fuel-surrogate models.


Assuntos
Emissões de Veículos/análise , Compostos Orgânicos Voláteis/análise , Aerossóis/análise , Óleos Combustíveis , Navios
11.
BMC Infect Dis ; 19(1): 568, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31262260

RESUMO

BACKGROUND: With the aim of preparing a more effective, safe and economical vaccine for tuberculosis, inhalable live mycobacterium formulations were evaluated. METHODS: Alginate particles in the size range of 2-4 µm were prepared by encapsulating live Bacille Calmette-Guérin (BCG) and "Mycobacterium indicus pranii" (MIP). These particles were characterized for their size, stability and release profile. Mice were immunized with liquid aerosol or dry powder aerosol (DPA) alginate encapsulated mycobacterium particles and their in-vitro recall response and infection with mycobacterium H37Rv were investigated. RESULTS: It was found that the DPA of alginate encapsulated mycobacterium particles invoked superior immune response and provided higher protection in mice than the liquid aerosol. The BCG encapsulated in alginate particles (BEAP) and MIP encapsulated in alginate particles (MEAP) were engulfed by bone marrow dendritic cells (BMDCs) and co-localized with lysosome. The MEAP/BEAP activated BMDCs exhibited higher chemotaxis movement and had enhanced ability of antigen presentation to T cells. The in-vitro recall response of BEAP/MEAP immunized mice when compared in terms of proliferation index and Interferon gamma (IFN-gamma) released by splenocytes and mediastinal lymph node cells was found to be higher than mice immunized by liquid aerosol of BCG/MIP. Finally, different groups of immunized mice were infected with M. tb H37Rv and after 16 weeks the Colony forming units (CFUs) in lung and spleen estimated. The bacilli burden in the BEAP/MEAP immunized mice was significantly less than the respective liquid aerosol immunized mice and the histopathology of BEAP/MEAP immunized mice lungs showed very little damage. CONCLUSIONS: These inhale-able vaccines formulation of alginate coated live mycobacterium are more immunogenic as compared to the aerosol of bacilli and they provide better protection in mice when infected with H37Rv.


Assuntos
Aerossóis/administração & dosagem , Pulmão/imunologia , Vacinas contra a Tuberculose/farmacologia , Tuberculose/prevenção & controle , Alginatos/química , Animais , Vacina BCG/imunologia , Sistemas de Liberação de Medicamentos/métodos , Interferon gama/imunologia , Pulmão/efeitos dos fármacos , Pulmão/microbiologia , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Complexo Mycobacterium avium/química , Complexo Mycobacterium avium/imunologia , Mycobacterium bovis/química , Mycobacterium bovis/imunologia , Mycobacterium tuberculosis/imunologia , Mycobacterium tuberculosis/patogenicidade , Baço/microbiologia , Linfócitos T/imunologia , Linfócitos T/microbiologia , Tuberculose/imunologia , Vacinas contra a Tuberculose/administração & dosagem , Vacinas contra a Tuberculose/imunologia , Vacinação/métodos
12.
J Chromatogr A ; 1603: 327-337, 2019 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-31266643

RESUMO

An analytical methodology based on thermal desorption and comprehensive two-dimensional gas chromatography with dual time-of-flight mass spectrometry and flame ionization detection (TD-GC × GC-TOFMS/FID) has been developed for non-target analysis of volatile organic compounds (VOCs). The technique was optimised for the measurement of the VOC content of the particulate phase (PP) fraction of aerosols produced by a tobacco heating product (THP1.0) and 3R4F mainstream tobacco smoke (MTS). The method involves sampling the PP fraction on quartz wool packed in a sorbent tube directly connected to machine-puffing, followed by a dilution through a TD recollection procedure over Tenax/Sulficarb sorbent before TD-GC × GC-TOFMS/FID analysis. The comparison of the VOC content of the PP fraction of aerosols produced by THP1.0 and MTS highlighted the compositional difference between tobacco combustion (592 peaks) and tobacco heating process (160 peaks). Mass spectrometric signals were used for qualitative analyses based on linear retention indices, mass spectral matches, and GC × GC structured chromatograms, which collectively identified up to 90% of analytes detected in PP samples. FID signals were used for semi-quantitative analyses based on a chemical class external calibration method. The global chemical composition of PP samples showed that hydrocarbons, oxygenated, and nitrogen-containing compounds were fewer in number and much less abundant in THP1.0 PP. Overall, 93 compounds were common to the two sample types. Excepted for a few highly volatile compounds (mainly furan family) as well as glycerine and its acetate, analyte concentrations were higher in MTS PP.


Assuntos
Aerossóis/análise , Ionização de Chama/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Material Particulado/análise , Temperatura Ambiente , Produtos do Tabaco/análise , Razão Sinal-Ruído , Compostos Orgânicos Voláteis/análise
13.
Environ Pollut ; 253: 190-198, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31310869

RESUMO

Increased public awareness of the health impacts of atmospheric fine particulate matter (PM2.5) has led to increased demand and deployment of indoor air cleaners. Yet, questions still remain about the effectiveness of indoor air cleaners on indoor PM2.5 concentrations and personal exposure to potentially hazardous components of PM2.5. Metals in PM2.5 have been associated with adverse health outcomes, so knowledge of their sources in urban indoor and outdoor areas and how exposures are influenced by indoor air cleaners would be beneficial for public health interventions. We collected 48-h indoor, outdoor, and personal PM2.5 exposure samples for 43 homes with asthmatic children in suburban Shanghai, China during the spring months. Two sets of samples were collected for each household, one set with a functioning air filter placed in the bedroom ("true filtration") and the other with a non-functioning ("sham") air cleaner. PM2.5 samples were analyzed for elements, elemental carbon, and organic carbon. The major sources of metals in PM2.5 were determined by Positive Matrix Factorization (PMF) to be regional aerosol, resuspended dust, residual oil combustion, roadway emissions, alloy steel abrasion, and a lanthanum (La) and cerium (Ce) source. Under true filtration, the median indoor to outdoor percent removal across all elements increased from 31% to 78% and from 46% to 88% across all sources. Our findings suggest that indoor air cleaners are an effective strategy for reducing indoor concentrations of PM2.5 metals from most sources, which could translate into improved health outcomes for some populations.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/estatística & dados numéricos , Exposição Ambiental/análise , Metais/análise , Aerossóis , Filtros de Ar , Poluição do Ar em Ambientes Fechados/análise , Criança , China , Poeira , Monitoramento Ambiental , Filtração , Humanos , Material Particulado/análise , Estações do Ano
14.
Environ Pollut ; 253: 19-28, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31302399

RESUMO

We studied the size distribution of ions (Cl-, NO3-, SO4=, Na+, NH4+, K+, Mg++, Ca++) and elements (As, Ba, Cd, Co, Cs, Cu, Fe, Li, Mn, Ni, Pb, Rb, Sb, Se, Sn, Sr, Ti, Tl, V, Zn) during the winter and summer seasons of seven consecutive years (2008-2014) in an area of the Po Valley (Northern Italy) characterised by industrial, agricultural and urban settings. The study included the collection and analysis of 41 series of size-segregated samples (MOUDI sampler, 10 stages, cut sizes from 0.18 to 18 µm). Ions were analysed by ion chromatography; elemental analysis was carried out by ICP-MS, by applying a chemical fractionation method able to increase the selectivity of PM source tracers. Our results indicate that important winter/summer variations occurred in both the concentration and size distribution of most PM components. These variations were explained in terms of variations in the strength of the prevailing sources of each component. The contribution of biomass burning for domestic heating was highlighted by the well-known tracer K+ but also by the soluble fraction of Rb, Cs and Li. Biomass burning contribution to atmospheric PM was mostly contained in the fine fraction, with a broad size-distribution from 0.18 to 1.8 µm. This source also appreciably increased the concentration of other elements in fine PM (As, Cd, Co, Mn, Pb, Sb, Sn). A few PM components (tracers of sea-spray, brake lining and some industries) did not show marked seasonal variations in concentration and size distribution. However, during winter, for brake lining and industry tracers we observed an upward shift in the dimension of fine particles and a downward shift in the dimension of coarse particles, due to the ageing of the air masses.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Material Particulado/análise , Aerossóis/análise , Envelhecimento , Fracionamento Químico , Calefação , Indústrias , Íons/análise , Itália , Peso Molecular , Tamanho da Partícula , Estações do Ano
15.
Environ Pollut ; 253: 49-60, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31302402

RESUMO

Carbonaceous aerosols (CAs) scatter and absorb incident solar radiation in the atmosphere, thereby influencing the regional climate and hydrological cycle, particularly in the Third Pole (TP). Here, we present the characteristics of CAs at 19 observation stations from the Atmospheric Pollution and Cryospheric Change network to obtain a deep understanding of pollutant status in the TP. The organic carbon (OC) and elemental carbon (EC) concentrations decreased noticeably inwards from outside to inland of the TP, consistent with their emission load and also affected by transport process and meteorological condition. Urban areas, such as Kathmandu, Karachi, and Mardan, exhibited extremely high OC and EC concentrations, with low and high values occurring in the monsoon and non-monsoon seasons, respectively. However, remote regions inland the TP (e.g., Nam Co and Ngari) demonstrated much lower OC and EC concentrations. Different seasonal variations were observed between the southern and northern parts of the TP, suggesting differences in the patterns of pollutant sources and in distance from the sources between the two regions. In addition to the influence of long-range transported pollutants from the Indo-Gangetic Plain (IGP), the TP was affected by local emissions (e.g., biomass burning). The OC/EC ratio also suggested that biomass burning was prevalent in the center TP, whereas the marginal sites (e.g., Jomsom, Dhunche, and Laohugou) were affected by fossil fuel combustion from the up-wind regions. The mass absorption cross-section of EC (MACEC) at 632 nm ranged from 6.56 to 14.7 m2 g-1, with an increasing trend from outside to inland of the TP. Urban areas had low MACEC values because such regions were mainly affected by local fresh emissions. In addition, large amount of brown carbon can decrease the MACEC values in cities of South Asia. Remote sites had high MACEC values because of the coating enhancement of aerosols. Influenced by emission, transport process, and weather condition, the CA concentrations and MACEC presented decreasing and increasing trends, respectively, from outside to inland of the TP.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Material Particulado/análise , Aerossóis/análise , Ásia , Atmosfera/química , Biomassa , Carbono/análise , Cidades , Clima , Poluição Ambiental , Combustíveis Fósseis , Estações do Ano , Tempo (Meteorologia) , Vento
16.
Environ Pollut ; 253: 439-448, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31325889

RESUMO

Ambient submicron particles (PM1) exert significant impacts on visibility degradation during severe pollution episodes of urban China. The U.S. IMPROVE algorithms are widely used for assessing the extinction effect of atmospheric aerosols, but only suitable for fine particulate matter. A proper algorithm for PM1 extinction estimation is lacking and becomes urgent, especially after the online measurement of PM1 species is routine by aerosol mass spectrometers. Here we conducted three-month in-situ measurements to explore mass scattering efficiencies (MSE) of PM1 major species at a supersite of eastern China. Results indicated that MSEs of ammonium sulfate and nitrate increase quickly and then keep stable with the mass accumulation, while those of organic matter keep at ∼5.5 m2/g but with a large vibration in the whole mass range. The algorithm for reconstructing PM1 dry scattering coefficient was derived from the integral of the variation patterns for the three PM1 species. The algorithm was then validated and compared with other empirical algorithms through separate field measurements. Good correlations between the reconstructed and measured dry scattering coefficient were observed with R square higher than 0.9 and slope of 1.01-1.05, indicating that the reconstructed algorithm can predict the dry scattering coefficient well based on PM1 chemical composition measurements in urban China. Our study is expected to provide observed insights on the variation of MSE in the wide mass range especially in the high region, as well as accurate formulas for ambient PM1 dry scattering apportionment.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/estatística & dados numéricos , Monitoramento Ambiental/métodos , Aerossóis/análise , Algoritmos , China , Espectrometria de Massas/métodos , Nitratos/análise , Óxidos de Nitrogênio , Tamanho da Partícula , Material Particulado/análise
17.
Sci Total Environ ; 690: 76-84, 2019 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-31284198

RESUMO

Interactions of particulate matter (PM) and respiratory tract play a crucial role in PM-related respiratory diseases. The majority of the work focuses on the oxidative stress induced by reactions between PM-borne redox-active components and lung lining fluid (LLF). The effects of PM-borne biological components are largely unknown. Of all PM-borne biologicals, bacteria, as living microorganisms, are closely related with inflammatory immune responses. However, its inhalation risk is usually determined without considering the respiratory physiological conditions. In this study, a surrogate lung fluid (SLF) with four typical antioxidants was applied to characterize the ambient bacteria, including concentrations of total bacteria/viable bacteria/culturable bacteria, metabolic activity, bacteria-derived endotoxin, as well as the community structure. Comparing to those determined by SLF, we find that use of PBS leads to an underestimation of the bacterial culturability and metabolic activity. No effect was seen regarding the number of total bacteria and viable bacteria (with intact membrane). Population structure change was seen for bacteria cultured from SLF-collected samples, when compared to that from PBS. Spore-forming bacteria, e.g., genus Bacillus, were found to be easily recovered with SLF. This implies that use of PBS could underestimate the bacteria inhalation risk, especially those bacterial endospores. Our work highlights the necessity to consider the respiratory airway environment when evaluating microbial inhalation risk.


Assuntos
Aerossóis/análise , Poluentes Atmosféricos/análise , Monitoramento Ambiental , Material Particulado/análise , Poluição do Ar , Antioxidantes , Bactérias , Endotoxinas , Exposição por Inalação , Pulmão , Oxirredução , Estresse Oxidativo , Tamanho da Partícula , Doenças Respiratórias
18.
Environ Sci Process Impacts ; 21(8): 1280-1300, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31328749

RESUMO

The House Observations of Microbial and Environmental Chemistry (HOMEChem) study is a collaborative field investigation designed to probe how everyday activities influence the emissions, chemical transformations and removal of trace gases and particles in indoor air. Sequential and layered experiments in a research house included cooking, cleaning, variable occupancy, and window-opening. This paper describes the overall design of HOMEChem and presents preliminary case studies investigating the concentrations of reactive trace gases, aerosol particles, and surface films. Cooking was a large source of VOCs, CO2, NOx, and particles. By number, cooking particles were predominantly in the ultrafine mode. Organic aerosol dominated the submicron mass, and, while variable between meals and throughout the cooking process, was dominated by components of hydrocarbon character and low oxygen content, similar to cooking oil. Air exchange in the house ensured that cooking particles were present for only short periods. During unoccupied background intervals, particle concentrations were lower indoors than outdoors. The cooling coils of the house ventilation system induced cyclic changes in water soluble gases. Even during unoccupied periods, concentrations of many organic trace gases were higher indoors than outdoors, consistent with housing materials being potential sources of these compounds to the outdoor environment. Organic material accumulated on indoor surfaces, and exhibited chemical signatures similar to indoor organic aerosol.


Assuntos
Microbiologia do Ar/normas , Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/análise , Monitoramento Ambiental/métodos , Habitação/normas , Material Particulado/análise , Aerossóis , Ar Condicionado , Filtros de Ar , Culinária , Gases , Humanos , Tamanho da Partícula
19.
Environ Pollut ; 253: 207-220, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31310871

RESUMO

Characterizing the vertical distribution of aerosol optical properties is crucial to reduce the uncertainty in quantifying the radiative forcing and climate effects of aerosols. The analysis of four-year (2007-2010) Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) lidar measurements revealed the existence of tropospheric aerosol layers associated with the Asian summer monsoon. The measurements of five typical aerosol optical and microphysical parameters were used to explore the properties, spatial/vertical distributions, annual evolution of tropopause aerosols over the South Asia region. Results extracted from various latitude-height and longitude-height cross sections of aerosol extinction coefficient at 532 and 1064 nm, backscatter coefficient at 532 nm, and depolarization ratio at 532 nm demonstrated that a large amount of aerosols vertically extended up to the tropopause (12 km) during the monsoon season over the north Arabian Sea, India, north Bay of Bengal, and equatorial Indian Ocean, finally reaching the southeast of the Tibetan Plateau. Convective transport associated with Asian summer monsoon is an important factor controlling the vertical distribution of tropopause aerosols. The evolution of aerosol scattering ratio at 532 nm indicated that from equatorial Indian Ocean to South Asia, there exists an upward tilting and ascending structure of the aerosols layer during the monsoon season, which typically indicates enhanced aerosols over the Asian monsoon region. Information on aerosol size distribution and detailed composition are needed for better understanding the nature and origin of this aerosol layer. Enhancement of the tropopause aerosols should be considered in the future studies in evaluating the regional or global climate systems. Further satellite observations of aerosols and in-situ observations are also urgently needed to diagnose this aerosol layer, which likely originate from anthropogenic emissions.


Assuntos
Aerossóis/análise , Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Ásia , Atmosfera/química , Clima , Índia , Oceano Índico , Estações do Ano
20.
Environ Pollut ; 253: 377-383, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31325882

RESUMO

Changzhou, an industrial city in the Yangtze River Delta, has been experiencing serious haze pollution, particularly in winter. However, studies pertaining to the haze in Changzhou are very limited, which makes it difficult to understand the characteristics and formation of winter haze in this area, and develop effective control measures. In this study, we carried out continuous online observation of particulate matter, chemical components, and meteorology in Changzhou in February 2017. Our results showed that haze pollution occurred frequently in Changzhou winter and exhibited two patterns: dry haze with low relative humidity (RH) and wet haze with high RH. Water-soluble inorganic ions (SO42-, NO3-, and NH4+) accounted for ∼52.2% of the PM2.5 mass, of which sulfate was dominant in wet haze periods while nitrate was dominant in other periods. With the deterioration of haze pollution, the proportion of nitrate in PM2.5 increased, while sulfate proportion increased under wet haze and decreased under dry haze. Dry haze and wet haze appeared under slow north wind and south wind, respectively, and strong north wind or sea breeze scavenged pollution. We found that formation of nitrate occurred rapidly in daytime with high concentrations of odd oxygen (Ox = O3 + NO2), whereas formation of sulfate occurred rapidly during nighttime with high RH, indicating that photochemistry and heterogeneous reaction were the major formation mechanisms for nitrate and sulfate, respectively. Through the cluster analysis of 36-h backward trajectories, five sources of air masses from three directions were identified. High PM2.5 concentrations (84.1 µg m-3 on average) usually occurred under the influence of two clusters (46%) from the northwest, indicating that regional transport from northern China aggravated the winter haze pollution in Changzhou. Emission reduction, particularly the mobile sources, and regional joint prevention and control can help to mitigate the winter haze in Changzhou.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Material Particulado/análise , Aerossóis/análise , China , Cidades , Umidade , Meteorologia , Nitratos/análise , Óxidos de Nitrogênio/análise , Rios , Estações do Ano , Sulfatos/análise , Vento
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