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Birch pollen rupture and the release of aerosols of respirable allergens

Taylor, P. E. and Flagan, R. C. and Miguel, A. G. and Valenta, R. and Glovsky, M. M. (2004) Birch pollen rupture and the release of aerosols of respirable allergens. Clinical and Experimental Allergy, 34 (10). pp. 1591-1596. ISSN 0954-7894. doi:10.1111/j.1365-2222.2004.02078.x.

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Backgound: Birch pollen allergens have been implicated as asthma triggers; however, pollen grains are too large to reach the lower airways where asthmatic reactions occur. Respirable-sized particles containing birch pollen allergens have been detected in air filters, especially after rainfall but the source of these particles has remained speculative. Objective: To determine the processes by which birch pollen allergens become airborne particles of respirable size with the potential to contribute to airways inflammation. Methods: Branches with attached male catkins were harvested and placed in a controlled emission chamber. Filtered dry air was passed through the chamber until the anthers opened, then they were humidified for 5 h and air-dried again. Flowers were disturbed by wind generated from a small electric fan. Released particles were counted, measured and collected for immuno-labelling and high-resolution microscopy. Results: Birch pollen remains on the dehisced anther and can rupture in high humidity and moisture. Fresh pollen takes as long as 3 h to rupture in water. Drying winds released an aerosol of particles from catkins. These were fragments of pollen cytoplasm that ranged in size from 30 nm to 4 μm and contained Bet v 1 allergens. Conclusion: When highly allergenic birch trees are flowering and exposed to moisture followed by drying winds they can produce particulate aerosols containing pollen allergens. These particles are small enough to deposit in the peripheral airways and have the potential to induce an inflammatory response.

Item Type:Article
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Flagan, R. C.0000-0001-5690-770X
Additional Information:© 2004 Blackwell. Submitted 28 July 2003; revised 23 April 2004; accepted 24 May 2004. We thank Sarah Flores, Pasadena City College for permission to sample birch trees and Pat Koen for assistance with microscopy. This work was funded by the Sunair Children's Foundation of Altadena, California, the Ayrshire Foundation, Pasadena, Philip Morris USA, Inc., Philip Morris International and grant Y068GEN of the Austrian Science Fund.
Funding AgencyGrant Number
Sunair Children's FoundationUNSPECIFIED
Ayrshire FoundationUNSPECIFIED
Philip Morris InternationalUNSPECIFIED
Austrian Science FundY068GEN
Subject Keywords:birch; particulate aerosol; pollen allergens; pollen rupture; respirable particles
Issue or Number:10
Record Number:CaltechAUTHORS:20150818-102537482
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Official Citation:Taylor, P. E., Flagan, R. C., Miguel, A. G., Valenta, R. and Glovsky, M. M. (2004), Birch pollen rupture and the release of aerosols of respirable allergens. Clinical & Experimental Allergy, 34: 1591–1596. doi:10.1111/j.1365-2222.2004.02078.x
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:59707
Deposited By: Irina Meininger
Deposited On:20 Aug 2015 00:03
Last Modified:10 Nov 2021 22:24

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