D2.386 - Quantification of airborne allergens – Comparison between inhalable dust sampling and a new ambient air sampler

Air sampling of inhalable dust on filters using pumps is a common approach for assessing airborne allergen exposure, particularly in occupational health and safety. However, this method is noisy and requires expensive equipment and trained staff. Recently, a novel ambient air sampling device (Apollo, InBio, Charlottesville) had been developed, offering a quieter and more user-friendly alternative. The aim is to compare the allergen concentrations in airborne dust collected using both methods.

Measurement technicians collected samples during housework in 68 households (13 with cats, 5 with dogs) in the living room and bedroom over 2 hours. The total dust sampling system (GSP, IFA Germany) was positioned parallel to the Apollo in each room. The GSP flow rate was 10 L/min, the Apollo flow rate was specified by the manufacturer as >500 L/min. Each sample (n = 272) was analysed for domestic mite, cat (Fel d 1), dog (Can f 1) and Cladosporium allergens.

Consistent with a higher flow rate, the results after Apollo collection were more often above the detection limit than after GSP sampling. Nearly all Apollo samples contained measurable Domestic mite (134 of 136) and Cladosporium (136) allergens. In contrast, only 105 of 136 GSP samples (77%) contained measurable concentrations of these allergens. Fel d 1 was detected in 103 Apollo (76%) and 43 GSP samples (32%), whereas Can f 1 was detected in 71 Apollo (54%) and 16 GSP samples (12%). The correlations (Spearman r) between the double-positive results of the two collection methods were highly significant (p<0.0001): Domestic mite (r = 0.803), Cladosporium (r = 0.767), Fel d 1 (r = 0.945), Can f 1 (r = 0.901). However, assuming a flow rate of 500 L/min for the Apollo, the calculated allergen concentrations per cubic meter of air are a factor 6.5 to 14 lower than with GSP collection. This indicates that the effective flow rate of the Apollo is <100 L/min.

The allergen concentrations sampled with GSP and Apollo devices correlate very well with each other. For comparison between these collection methods, the effective flow rate of the Apollo should be determined.