Projecting Pollen Allergens and Their Health Implications in a Changing World

EPA Grant Number: R834358
Title: Projecting Pollen Allergens and Their Health Implications in a Changing World
Investigators: Flagan, Richard , Chung, Sandra , Gilliland, Frank D. , Guenther, Alex , Lamb, Brian , VanReken, Timothy M.
Institution: California Institute of Technology , National Center for Atmospheric Research , University of California - Los Angeles , Washington State University
EPA Project Officer: Ilacqua, Vito
Project Period: October 1, 2009 through September 30, 2012 (Extended to September 30, 2013)
Project Amount: $900,000
RFA: Climate Change and Allergic Airway Disease (2008) RFA Text |  Recipients Lists
Research Category: Global Climate Change , Health , Climate Change


The objective of the proposed research is to improve our understanding of the linkages among global change, pollen occurrence, and respiratory health impacts. We will take advantage of ongoing global change and air quality simulations for the U.S. modified to incorporate methods for projecting pollen production, emission, and conversion to respirable allergenic material. We will use the modeling system to project pollen levels and their health impacts in a changing world. We will address the following key scientific questions: (i) How do biological sources respond to a changing climate, in terms of pollen production and the conversion of pollen to respirable allergenic material? (ii) How will these species-specific responses combine with land use, population, and climatic changes to change the levels of atmospheric allergens in the future? (iii) What links exist between airborne pollen levels, concentrations of respirable allergenic material, and human allergenic response? (iv) What will be the response of the U.S. population to these future projected allergen levels, including the synergistic response due to projected allergen and pollutant levels?


To address the science questions we have posed, we will: (i) Develop a parameterization for linking pollen occurrence to vegetative state and environmental conditions. In this step, data on the present and past geographical distribution of different plant species, and on the production of aeroallergens will be used to parameterize the influence of climatic conditions on the atmospheric burden of a major class of allergenic primary biological particles, pollen. The parameterization will elucidate the potential yield, and enable examination of local effects such as winds, temperature extremes, and rain on airborne pollen concentrations. This will provide first order measure of the allergenic potential of the atmosphere. (ii) We will further parameterize the link between allergenic pollen and respirable allergen that has been implicated in pollen-induced asthma. The direct link between pollen antigen, both as whole pollen and as pollen fragments, will be established through a retrospective examination of data obtained in the Children’s Health Study (CHS) that has followed a cohort of 11,000 school children at thirteen communities in Southern California. Laboratory and field measurements will be used to quantify the relationship between the widely dispersed measurements of pollen and exposures in the studied communities, and to quantify the relationship between pollen, meteorological conditions, and respirable allergen exposures. (iii) We will use the parameterizations developed in the first two steps to incorporate pollen and pollen-derived allergens into our ongoing U.S. global change/air quality simulations. This will involve modifications to the MEGAN biogenic emission model, developed by Guenther and colleagues, and then use of the new version of MEGAN as input to the WRF/CMAQ modeling system currently used for our global change runs. (iv) The results from the data analysis, measurements studies and modeling results will be used to develop an overall picture of how global change, including climate changes as well as land management changes, can affect the occurrence of pollen and respirable allergens and how these can affect asthma in our future world.

Expected Results:

This project will increase our basic understanding of the links between climatic conditions and atmospheric concentrations of pollen and pollen-derived respirable allergenic material, and impacts of airborne pollen on human health. The work will result in new parameterizations to yield estimates of pollen and respirable allergen levels for both present and future environmental conditions, and to examine the synergistic effects of air pollution and pollen on respiratory outcomes. This will include new methods for estimating the pollen potential, the timing and duration of pollen season, and the production of respirable allergenic material from the rupture of pollen grains. The parameterizations developed in this research will be used to project the effects of climate change on the incidence of allergic airway disease.

Publications and Presentations:

Publications have been submitted on this project: View all 13 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 2 journal articles for this project

Supplemental Keywords:

pollen; respirable allergen; pollen fragmentation; respiratory health; asthma; climate change; vegetation distribution,, RFA, Health, Air, climate change, Air Pollution Effects, Risk Assessments, Atmosphere, environmental monitoring, pollen, allergic airway disease, respiratory illness

Progress and Final Reports:

  • 2010 Progress Report
  • 2011 Progress Report
  • 2012 Progress Report
  • Final Report