Passive Sampling to Track Pollen Concentration Across Urban and Rural Areas

CHAMARI MAMPAGE, Lillian Jones, Emma Schopen, Rachel Larson, Heather Sander, Thomas Peters, Elizabeth Stone, University of Iowa

     Abstract Number: 483
     Working Group: Bioaerosols

Abstract
Pollen grains can trigger allergy reactions that exacerbate respiratory diseases. To assess the exposure risks, it is important to understand the spatial distribution of allergenic pollen in the environment. Traditional pollen counting methods typically use one location to reflect the pollen concentration in larger areas. The current study uses a novel, scalable, low-cost passive sampling technique to evaluate the distribution of pollen across urban and rural landscapes during weed pollen season in Iowa. Two microscopic slides mounted on custom-made slide holders placed inside a passive shelter were deployed at 34 sites around Johnson County, Iowa. These sites were located nearby wooded areas, a reservoir, non-paved roads, prairies, recreational, institutional, or residential areas. Two-week integrated samples were collected in August-September 2021. Pollen concentrations in each location were assessed using the flux of pollen grains on to the deposition surface and estimated deposition velocity of pollen grains. Clumped pollen grains were observed in all samples and were explicitly treated in estimating the atmospheric pollen grain concentrations. Preliminary analysis of the samples showed that the fraction of pollen in clumps ranged from 0.04 - 0.34. Pollen grain concentrations were in the range of 32 - 2100 grains m^-3 with an average concentration of 280 grains m^-3, with the highest recorded concentration occurring near a prairie. Further analysis is underway to understand the spatial distribution of pollen concentrations across different landscapes and exposure variability with land use, vegetation, and population socioeconomic attributes.