A new method for collecting airborne allergens.
BACKGROUND
Measurement of airborne allergens has hitherto been done with the use of fixed-location pumps or personal air samplers. Our objective was to find out whether ionizers could be good tools for collecting airborne allergens. As a model we have used cat allergen (Fel d l). We have compared Fel d l levels collected by the ionizer at different time periods, as well as comparing Fel d l levels obtained with the ionizer with those of low- and high-volume pumps.


METHODS
Dust samples from floors and air samples collected with ionizers and pumps, obtained in 31 homes with cat, 23 homes without cats, and 28 day-care centres, were analysed for cat allergen content (Fel d I) by ELISA.


RESULTS
Fel d l was present in the reservoir in all homes with cats, ranging from 660 to 375,000 ng/g (GM 75,000) and in the air collected by the ionizer from 2.0 to 204 ng/24 h (GM 19.3). The allergen in homes without cat varied from < 55 to 1,800 ng/g (GM 166). Corresponding levels in air were found in two of these homes (2.3 and 7.3 ng/24 h). There was a correlation between the number of cats and the amount of airborne cat allergen (r: 0.47; P < 0.05). The levels in day-care centres were < 55 to 3,070 ng/g in dust (GM 360) and < 1.1 to 7.9 ng/24 h in the air (GM 1.6). We obtained a moderately strong correlation between air and dust samples in homes with cats (rs: 0.64; P< 0.001) and in day-care centres (rs: 0.49; P<0.05). We found that a collection period of 24 h is preferable for the ionizer. The intrahome reliability coefficient was nearly two times higher for the ionizer (r: 0.69) than the pump (r: 0.39).


CONCLUSIONS
The ionizer seems to be a good tool for monitoring the environment. It is easy to use and silent and does not disturb the airflow in the room.
Parvaneh
S
S
Department of Medicine, Karolinska Institutet and Hospital, Stockholm, Sweden.
Elfman
L
L
Ahlf
E
E
Nybom
R
R
Elfman
L H
LH
van Hage-Hamsten
M
M
D000390:Air Ionization; D016902:Air Pollution, Indoor / Q000032:analysis*; D000485:Allergens / Q000032:analysis*; D004391:Dust / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay; D006023:Glycoproteins / Q000032:analysis*; D013997:Time Factors
D000485:Allergens; D004391:Dust; D006023:Glycoproteins; C059296:Fel d 1 protein, Felis domesticus