D2.514 - Breathing zone pollen and fungal spore monitoring with an IOM Personal Sampler: A pilot study

Inhalable allergenic bioaerosol exposure varies with daily activity and the microenvironments encountered. Personal biomonitoring can capture breathing‑zone pollen and fungal spore loads for detailed exposure evaluation. We tested a IOM personal sampler for quantifying mobile breathing-zone exposure loads.

A 5-day sampling campaign (March 2025) was done on the 13‑ha Faculty of Sciences campus. An IOM sampler with 25‑mm MCE filter, connected to a Leland Legacy pump (4.0 L/min), ran in parallel with a portable volumetric airborne sampler (PVAS). Both devices were carried for 3 h each morning along a walking route with 20‑min stops at seven sites (entrances/gardens). Filters were mounted on slides with fuchsine-stained glycerol jelly, fully scanned by microscopy to identify/count pollen and fungal spores. Concentrations (particles/m³ air) correspond to total counts/sampled volume. Comparison used IOM/PVAS ratios (R), summarised as: i) pooled total pollen/spores (Rt); ii) for common representative taxa (>1% counts) were calculated median daily ratios (mRd) per taxa and directional signal consistency (days Rd>1 or <1). Per‑taxon detection agreement between samplers was evaluated via positive agreement (PA) on presence/absence (count>0).

IOM and PVAS each detected 14 pollen types (12 common) and 27 vs 30 fungal spore types (25 common). Six pollen and 13 spore taxa exceeded 1% representativeness (~50% and 52% of common taxa). Polled concentrations were higher with IOM: pollen 2515 vs 1261/m³ (Rt=2.0) and spores 5297 vs 1304/m³ (Rt=4.4). Spore Rt was driven by Aspergillaceae (IOM 21.1x PVAS), and fell to 1.1 when this taxon was excluded.

For representative pollen taxa, IOM had higher median daily concentrations (mRd 1.5–8.9), with Rd indicating that exceeds PVAS on ≥4/5 sampling days for all taxa. For representative spores, higher medians occurred in 7 taxa (mRd 1.1–15.6), with Rd >1 on more than 4/5 days for 5 taxa.

Detection agreement across all taxa was moderate (median PA of 0.5 for pollen; 0.7 for spores) but was near-perfect for representative taxa (PA=1 for all pollen types and in 10/13 spores; PA=0.9 for the remaining three spore taxa), indicating that detection discordance between samplers mainly occurred in very low‑abundance taxa.

Both samplers showed similar taxonomic richness. IOM yielded slightly higher loads for dominant pollen; fungal spores showed a taxon-dependent trend towards each method. A Detection was synchronised for representative taxa between IOM and PVAS. These results are interpreted as a pilot validation for further prolonged studies.