A modeling system for assessing population exposures to bioaerosols and other air pollutants
Sastry Isukapalli1, Christos Efstathiou1, Leonard Bielory2, and Panos Georgopoulos1
1UMDNJ - RW Johnson Medical School; 2UMDNJ - NJ Medical School
Rationale: Understanding major factors contributing to allergic airway diseases requires characterization of human exposures to bioaerosols such as pollen and other air pollutants. Human exposures depend critically on both the ambient levels of these allergens and activity patterns/demographics.
Methods: A framework for estimating human exposures to bioaerosols and other air pollutants is developed. This includes modules for predicting pollen emissions (Efstathiou et al., abstract in AAAAI 2008), and for estimating ambient pollen levels by simulating transport of pollen at local and regional scales. A range of air quality models are used to simulate pollen transport, including the HYbrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model that computes air parcel trajectories, and a modified version of the USEPA’s Community Multiscale Air Quality (CMAQ) model that simulates complex dispersion and deposition. Modules for simulating population activity patterns and inhalation of bioaerosols and other air pollutants are developed based on modules of the MENTOR framework (Modeling ENvironment for TOtal Risk studies). Ongoing work focuses on integrative applications for population exposures in metropolitan areas of North East US.
Results: Emissions and transport of different types of pollen were simulated for Eastern US. Alternative formulations for the modeling pollen transport (HYSPLIT and CMAQ) showed close agreement. Significant levels of pollen were transported over tens of kilometers of distance, depending on the height of release, pollen type, and meteorological conditions.
Conclusion: The work presented here is the first effort to mechanistically model human exposures to pollen starting from emissions, outdoor transport, indoor penetration, and finally personal exposure to pollen.