TY - JOUR TI - Climate change and airborne allergens DO - https://doi.org/doi:10.7282/T3FT8NSM PY - 2015 AB - Climate change is expected to alter the spatiotemporal dynamics of airborne allergens and potentially increase occurrence of allergic airway disease. Climate change impact on allergenic pollen was investigated through statistical analysis and modeling of observed airborne pollen counts and climatic factors, and through simulation using a deterministic modeling system. A probabilistic exposure model was developed to study exposures to allergenic pollen during the 1990s (1994-2000) and the 2000s (2001-2010) in nine climate regions in the contiguous United States (CONUS). The allergenic pollen seasons of representative trees, weeds and grass during the 2000s across the CONUS have been observed to start 3.0 days earlier on average than in the 1990s. The average peak value and annual total of daily counted airborne pollen have increased by 42.4% and 46.0%, respectively. The deterministic modeling system consists of modules of emission, meteorology and air quality. It correctly predicted the observed pollen season start date and duration, and airborne level at the majority of monitor stations for oak and ragweed pollen, and performed reasonably well for birch, mugwort and grass pollen. Dry deposition, emission and vertical eddy diffusion were the dominant processes determining the ambient pollen concentrations. The response of the allergenic pollen season to climate change varies in different climate regions for different taxa in the CONUS. Under scenarios of regionally and economically oriented future development, the weed and grass pollen concentrations were predicted to decrease from period of 2001-2004 to 2047-2050 in the majority of regions. The number of hours in which birch and oak pollen concentrations exceed the threshold values for triggering allergy has been predicted to increase in the majority of regions. Inhalation and dermal deposition were the dominant exposure routes for allergenic pollen. The aggregated exposure to allergenic pollen in outdoor environments was more than twice as that in indoor environments during the 2000s in the CONUS. Meantime, inhalation exposure for children of 1-4 years old was two to five times higher than for other age groups. Changes in exposures to allergenic pollen between the 2000s and the 1990s varied in different climate regions for different taxa. KW - Chemical and Biochemical Engineering KW - Climate change KW - Air--Pollution KW - Allergens LA - eng ER -