AERODYNAMIC PROPERTIES OF THE MAJOR DOG ALLERGEN CAN-F-1 - DISTRIBUTION IN HOMES, CONCENTRATION, AND PARTICLE-SIZE OF ALLERGEN IN THE AIR

Exposure and sensitization to dog allergen is a significant cause of a sthma. In this study we investigated the distribution, aerodynamic cha racteristics, and particle-size distribution of the major dog allergen Can f 1. Dust samples were collected in 50 homes with a dog and 50 ho mes without dogs. Airborne Can f 1 concentration was measured in 28 ho mes with dogs and 36 homes without a dog. Particle-size distribution w as determined by using 10 separate Andersen sampler measurements in a dog-handling facility, and in 10 homes with dogs, and by repeated meas urements in a home with one dog. High levers of Can f 1 (> 10 mu g/g) were found in dust in all but one home with a dog and in eight of 50 h omes without dogs. Airborne Can f 1 levels varied greatly between the homes with dogs (range: 0.3 to 99 ng/m(3)). Low levels of airborne Can f 1 (range: 0.4 to 1.1 ng/m(3)) were detected in 11 of 36 homes witho ut a dog. Can f 1 was predominantly associated with large particles co llected on the first stage of the Andersen sampler (> 9 mu m), which a veraged 42 to 49% of the total allergen recovered in the dog-handling facility and in homes with dogs. Small particles (< 5 mu m diameter) a lso carried Can f 1, and these particles comprised similar to 20% of t he total airborne allergen load. There was an excellent concordance be tween the results obtained in different sampling areas, and between th e total Can f 1 recovered on the Andersen sampler and on the parallel filter. In conclusion, airborne Can f 1 was detectable in undisturbed conditions in all homes with dogs and in almost one third of the homes without dogs. In houses with dogs, a significant proportion (similar to 20%) of airborne Can f 1 was associated with small particles (< 5 m u m diameter). Owing to their aerodynamic characteristics, these parti cles would be expected to remain airborne fare long period and, when i nhaled, could penetrate into the lower airways and initiate asthma att acks.