air-sampled-filter-analysis-for-endotoxins-and-dna-content

Air-sampled Filter Analysis for Endotoxins and DNA Content

Outdoor aerosol research commonly uses particulate matter sampled on filters. This procedure enables various characterizations of the collected particles ...

Weizmann Institute of Science

Understanding the chemical interactions of common allergens in urban environments may help to decipher the general increase in susceptibility to allergies observed in recent decades. In this study, asexual conidia of the allergenic mold Aspergillus fumigatus were exposed to air pollution under natural (ambient) and controlled (laboratory) conditions. The allergenic activity was measured using two immunoassays and supported by a protein mass spectrometry analysis. The allergenicity of the conidia was found to increase by 2-5 fold compared to the control for short exposure times of up to 12h (accumulated exposure of about 50 ppb NO2 and 750 ppb O3), possibly due to nitration. At higher exposure times, the allergenicity increase lessened due to protein deamidation. These results indicate that during the first 12h of exposure, the allergenic potency of the fungal allergen A. fumigatus in polluted urban environments is expected to increase. Additional work is needed in order to determine if this behavior occurs for other allergens.

Impact of urban air pollution on the allergenicity of Aspergillus fumigatus conidia: Outdoor exposure study supported by laboratory experiments.

Primary biological organic aerosols (PBOA) represent a major component of the coarse organic matter (OMCOARSE). Although this fraction affects human health and climate, its quantification and chemical characterization currently remain elusive. We present the quantification of the entire PM10 PBOA mass and its main sources by analyzing size-segregated filter samples collected during summer and winter at the rural site of Payerne (Switzerland), representing a continental Europe background environment. The size-segregated water soluble OM was analyzed by a newly developed offline aerosol mass spectrometric technique (AMS). The spectra were then analyzed by 3-dimensional positive matrix factorization (3D-PMF), showing that PBOA represented the main OMCOARSE source during summer and its contribution to PM10 was as high as that of secondary organic aerosol. We found substantial cellulose contributions to OMCOARSE, which in combination with gas chromatography mass spectrometry molecular markers quantification, underlines the predominance of plant debris. Quantitative polymerase chain reaction (qPCR) analysis instead revealed that the sum of bacterial and fungal spores mass represented only a minor OMCOARSE fraction (<0.1%). X-ray photoelectron spectroscopic (XPS) analysis of C and N binding energies throughout the different size fractions revealed an organic N increase in the PMCOARSE compared to PM1 consistent with AMS observations.

Article	Year
Impact of urban air pollution on the allergenicity of Aspergillus fumigatus conidia: Outdoor exposure study supported by laboratory experiments. The Science of the total environment\| PubMed ID: 26410711	2016
Size-resolved identification, characterization and quantification of primary biological organic aerosol at a European rural site. Environmental science & technology\| PubMed ID: 26900965	2016

Yinon Mazar

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