Pierre Madl

Aerosol size distribution and mass concentration measurements in various cities of Pakistan

During March and April 2010 aerosol inventories from four large cities in Pakistan were assessed in terms of particle size distributions (N), mass (M) concentrations, and particulate matter (PM) concentrations. These M and PM concentrations were obtained for Karachi, Lahore, Rawalpindi, and Peshawar from N concentrations using a native algorithm based on the Grimm model 1.109 dust monitor. The results have confirmed high N, M and PM concentrations in all four cities. They also revealed major contributions to the aerosol concentrations from the re-suspension of road dust, from sea salt aerosols, and from vehicular and industrial emissions. During the study period the 24 hour average PM(10) concentrations for three sites in Karachi were found to be 461 μg m(-3), 270 μg m(-3), and 88 μg m(-3), while the average values for Lahore, Rawalpindi and Peshawar were 198 μg m(-3), 448 μg m(-3), and 540 μg m(-3), respectively. The corresponding 24 hour average PM(2.5) concentrations were 185 μg m(-3), 151 μg m(-3), and 60 μg m(-3) for the three sites in Karachi, and 91 μg m(-3), 140 μg m(-3), and 160 μg m(-3) for Lahore, Rawalpindi and Peshawar, respectively. The low PM(2.5)/PM(10) ratios revealed a high proportion of coarser particles, which are likely to have originated from (a) traffic, (b) other combustion sources, and (c) the re-suspension of road dust. Our calculated 24 hour averaged PM(10) and PM(2.5) concentrations at all sampling points were between 2 and 10 times higher than the maximum PM concentrations recommended by the WHO guidelines. The aerosol samples collected were analyzed for crustal elements (Al, Fe, Si, Mg, Ca) and trace elements (B, Ba, Cr, Cu, K, Na, Mn, Ni, P, Pb, S, Sr, Cd, Ti, Zn and Zr). The averaged concentrations for crustal elements ranged from 1.02 ± 0.76 μg m(-3) for Si at the Sea View location in Karachi to 74.96 ± 7.39 μg m(-3) for Ca in Rawalpindi, and averaged concentrations for trace elements varied from 7.0 ± 0.75 ng m(-3) for B from the SUPARCO location in Karachi to 17.84 ± 0.30 μg m(-3) for Na at the M. A. Jinnah Road location, also in Karachi.

Implementation of Charged Particles Deposition in Stochastic Lung Model and Calculation of Enhanced Deposition

The experimental studies using hollow lung cast of human tracheobronchial (TB) tree and in-vivo experiments have demonstrated enhanced charged deposition in the lung. The present study was carried out to implement charge particle deposition into the stochastic human lung model and to estimate enhanced deposition for various charged particles at the airway generation level. Enhanced deposition calculations of charged particles are performed by implementing two different efficiency equations derived for the TB and alveolar (Al) region. Deposition fractions of inhaled charged particles are computed by the stochastic airway generation model IDEAL (Inhalation, Deposition and Exhalation of Aerosols in the Lung) for various breathing conditions and particle sizes. Enhanced deposition of charged particles in the Al region is found to be up to five times higher than in the TB region. Enhanced deposition in the TB region is higher under sitting breathing condition than under light exercise breathing condition. The introduction of pause time, during inhalation, increases the probability of increased enhanced deposition up to a certain breath-hold time limit. The calculated enhancement factors (EF) reveals that more than two times higher deposition can be achieved in the lung by the introduction of charged particles during inhalation. By introducing the charged particles during inhalation and by optimizing the flow rate, tidal volume, and particle size, the targeted deposition in the lung is improved for the best therapeutic aerosols utilization. In addition, the unnecessarily high deposition of toxic particles in the sensitive lung regions can be avoided. Copyright 2012 American Association for Aerosol Research

Stochastic Morphometric Model of the Balb/c Mouse Lung

The laboratory mouse is often used as a human surrogate in aerosol inhalation studies. Morphometric data on the tracheobronchial geometry of three in situ lung casts of the Balb/c mouse lung produced by the Air Pollution Health Effects Laboratory were analyzed in terms of probability density functions and correlations among the different airway parameters. The results of this statistical analysis reveal significant differences in diameters and branching angles between major and minor progeny branching off from the same parent airway at a given airway bifurcation. Number of bronchial airways generations along a given path, expressed by the termination probability, branching angles, and daughter‐to‐parent diameter ratios indicate that the location of an airway with defined linear airway dimensions within the lung is more appropriately identified by its diameter (or its parent diameter) than by an assigned generation number. We, therefore, recommend classifying the mouse lung airways by their diameters and not by generation numbers, consistent with our previous analysis of the rather monopodial structure of the rat lung (Koblinger et al., J Aerosol Med 1995;8:7–19; Koblinger and Hofmann, J Aerosol Med 1995;8:21–32). Because of lack of corresponding information on respiratory airways, a partly stochastic symmetric acinar airway model was attached to the tracheobronchial model, in which the number of acinar airways along a given path was randomly selected from a measured acinar volume distribution. The computed distributions of the geometric airway parameters and their correlations will be used for random pathway selection of inhaled particles in subsequent Monte Carlo deposition calculations. Anat Rec 293:1766–1786, 2010.

A Novel Exposure System Termed NAVETTA for In Vitro Laminar Flow Electrodeposition of Nanoaerosol and Evaluation of Immune Effects in Human Lung Reporter Cells

A new prototype air-liquid interface (ALI) exposure system, a flatbed aerosol exposure chamber termed NAVETTA, was developed to investigate deposition of engineered nanoparticles (NPs) on cultured human lung A549 cells directly from the gas phase. This device mimics human lung cell exposure to NPs due to a low horizontal gas flow combined with cells exposed at the ALI. Electrostatic field assistance is applied to improve NP deposition efficiency. As proof-of-principle, cell viability and immune responses after short-term exposure to nanocopper oxide (CuO)-aerosol were determined. We found that, due to the laminar aerosol flow and a specific orientation of inverted transwells, much higher deposition rates were obtained compared to the normal ALI setup. Cellular responses were monitored with postexposure incubation in submerged conditions, revealing CuO dissolution in a concentration-dependent manner. Cytotoxicity was the result of ionic and nonionic Cu fractions. Using the optimized inverted ALI/postincubation procedure, pro-inflammatory immune responses, in terms of interleukin (IL)-8 promoter and nuclear factor kappa B (NFκB) activity, were observed within short time, i.e. One hour exposure to ALI-deposited CuO-NPs and 2.5 h postincubation. NAVETTA is a novel option for mimicking human lung cell exposure to NPs, complementing existing ALI systems.

Oscillations of ultra-weak photon emission from cancer and non-cancer cells stressed by culture medium change and TNF- α

Cells spontaneously emit photons in the UV to visible/near-infrared range (ultra-weak photon emission, UPE). Perturbations of the cells’ state cause changes in UPE (evoked UPE). The aim of the present study was to analyze the evoked UPE dynamics of cells caused by two types of cell perturbations (stressors): (i) a cell culture medium change, and (ii) application of the pro-inflammatory cytokine tumor necrosis factor alpha (TNF-α). Four types of human cell lines were used (squamous cell carcinoma cells, A431; adenocarcinomic alveolar basal epithelial cells, A549; p53-deficient keratinocytes, HaCaT, and cervical cancer cells, HeLa). In addition to the medium change, TNF-α was applied at different concentrations (5, 10, 20, and 40 ng/mL) and UPE measurements were performed after incubation times of 0, 30, 60, 90 min, 2, 5, 12, 24, 48 h. It was observed that (i) the change of cell culture medium (without added TNF-α) induces a cell type-specific transient increase in UPE with the largest UPE increase observed in A549 cells, (ii) the addition of TNF-α induces a cell type-specific and dose-dependent change in UPE, and (iii) stressed cell cultures in general exhibit oscillatory UPE changes.

Enhanced Deposition by Electrostatic Field-Assistance Aggravating Diesel Exhaust Aerosol Toxicity for Human Lung Cells.

Air pollution is associated with increased risk of cardiovascular and pulmonary diseases, but conventional air quality monitoring gives no information about biological consequences. Exposing human lung cells at the air-liquid interface (ALI) to ambient aerosol could help identify acute biological responses. This study investigated electrode-assisted deposition of diesel exhaust aerosol (DEA) on human lung epithelial cells (A549) in a prototype exposure chamber. A549 cells were exposed to DEA at the ALI and under submerged conditions in different electrostatic fields (EFs) and were assessed for cell viability, membrane integrity, and IL-8 secretion. Qualitative differences of the DEA and its deposition under different EFs were characterized using scanning mobility particle sizer (SMPS) measurements, transmission electron microscopy (TEM), and electron energy loss spectroscopy (EELS). Upon exposure to DEA only, cell viability decreased and membrane impairment increased for cells at the ALI; submerged cells were unaffected. These responses were enhanced upon application of an EF, as was DEA deposition. No adverse effects were observed for filtered DEA or air only, confirming particle-induced responses. The prototype exposure chamber proved suitable for testing DEA-induced biological responses of cells at the ALI using electrode-assisted deposition and may be useful for analysis of other air pollutants.

How Corals Coordinate and Organize: An Ecosystemic Analysis Based on Biocommunication and Fractal Properties

Tropical coral reefs harbour some of the most diverse biological communities on our planet and as such rival tropical forests communities in species diversity and number of individuals from all domains. The cooperative interplay of prokaryotes, eukaryotes – particularly – the interactions among plantae and animalia shape this delicate balance, which ultimately culminate in the beauty of the coral reef biome. Some algal species but especially scleractinian corals with their interconnected organizational structure precipitate a calcium-carbonate skeleton that, upon generation after generation, form and shape structures that can even be seen from space. Yet this process is limited by light penetrability – either by depth or by visibility – that provides endosymbiotic algae with the energetic flux to convert light quanta into biochemically available energy. As a result, the sheer dominance of coral species somewhat camouflages the delicate balance between reef builders and bioerosive processes. This intrinsically interwoven biocommunicative dynamics is a key issue in order to comprehend how such structures can evolve and stretch out over 1,000s of km. Neglecting the importance of these processes compromises a full understanding of reef-dynamics and in turn promotes accelerated reef degradation due to improper use of reef resources to those who rely on them. Doing so simply increments reef instability and as such its long-term survival. This article attempts to shed light on the crucial role of biocommunicative processes and how these are manifested across taxa. In fact biocommunication is so essential in assigning each organism a specific role in this network of interdependences that the elegance even within organisms themselves – seen from a biomic perspective –attain self-similar properties. In turn and regardless of the taxa involved, self-similarity in coral reef ecosystems is an underlying feature that relies on intact and efficient biocommunicative pathways.

Urban background aerosols: Negative correlations of particle modes and fragmentation mechanism

We demonstrate new powerful methods of statistical analysis of atmospheric aerosols on the example of urban background aerosol in the Brisbane area, Australia. It is shown that even in the absence of notable features on the size distribution, it is still possible to identify distinct particles modes and analyze their mutual interactions and transformations. The obtained unique anti-symmetric correlation patterns between particle modes may serve as fingerprints of particular evolutionary processes in the background aerosols. The obtained results suggest that thermal fragmentation of nano-particles may be one of the major physical mechanisms shaping urban background aerosols. In particular, based on the fragmentation theorem, we demonstrate possible existence of substantially different time scales for fragmentation of atmospheric aerosols. The proposed approaches and obtained results may also be important for the analysis of different types of atmospheric aerosols on local, regional and global scales.