Approaches to Assessing Exposure to Airborne Allergens

James House(1), Gregory Griffin(1), Jason Gamba(1), Pietro Perona(1), RICHARD FLAGAN(1)

(1) California Institute of Technology, Pasadena, CA

     Abstract Number: 261
     Last modified: November 9, 2009

Abstract
In addition to their direct actions, atmospheric pollutants can act as adjuvants that enhance susceptibility to allergens, so a full understanding of their health consequences requires knowledge of exposures to allergenic aerosols as well. Climate change may further confound the challenge by altering the distribution of allergenic aerosols. Our research focuses on pollen allergens that are present in whole pollen grains that larger than the usual coarse particle fraction. Pollen antigen is also found in respirable particles that form when pollen undergoes osmotic rupture within the flowers of anemophilous plants or other special environments that enable their entrainment into the air. Methods for measuring and reporting airborne allergens have changed little over the past several decades. Whole pollen are now identified by manual microscopy. We have applied computer-controlled microscopy and computer vision to make it possible to replace such measurements with image processing. Matlab software based upon scale invariant feature transforms and nearest neighbor algorithms has have enable accuracy that approaches that of an expert pollen reader, in a small fraction of the time and much lower cost. Our efforts to measure respirable antigen focus on the development of new whispering gallery mode resonator sensors that enable immunological assays to be performed on unlabeled antigen, at solution concentrations in the attomolar regime.