Grantee Research Project Results
2011 Progress Report: Projecting Pollen Allergens and Their Health Implications in a Changing World
EPA Grant Number: R834358Title: Projecting Pollen Allergens and Their Health Implications in a Changing World
Investigators: Flagan, Richard , Gilliland, Frank D. , VanReken, Timothy M. , Guenther, Alex , Lamb, Brian , Chung, Sandra
Institution: California Institute of Technology , University of California - Los Angeles , Washington State University , National Center for Atmospheric Research
Current Institution: California Institute of Technology , National Center for Atmospheric Research , University of California - Los Angeles , Washington State University
EPA Project Officer: Chung, Serena
Project Period: October 1, 2009 through September 30, 2012 (Extended to September 30, 2013)
Project Period Covered by this Report: July 1, 2010 through June 30,2011
Project Amount: $900,000
RFA: Climate Change and Allergic Airway Disease (2008) RFA Text | Recipients Lists
Research Category: Climate Change , Human Health
Objective:
The overall goal of this project is to improve our understanding of linkages among global change, pollen occurrence, and respiratory health impacts through a combination of focused experimental studies, modeling, and statistical analysis that will ultimately lead to the integration of pollen allergen and population health outcome models into an existing air quality modeling framework. The primary products from this work will be models for the U.S. and southern California that will describe pollen and respirable pollen antigen concentrations, and air quality for recent and future decades for a range of emission and climate change scenarios, and estimates of the impacts that these exposures may have on allergic airway disease.
Progress Summary:
Dose-Response Function Development
We previously reported that we operated Burkard samplers at the sites of the CHS to measure pollen levels in communities where exhaled nitric oxide was measured on the participants of the southern California Children's Health Study. This was done to allow evaluation of the relationship between the pollen counts during the previous seven days and FeNO. During March to June 2010, we operated six Burkard samplers to collect pollen samples from all eight CHS communities where FeNO was measured. During this time, 950 children had FeNO measurements. FeNO testing was conducted following the American Thoracic Society
guidelines.1 These children also completed a questionnaire, an in-person interview with field staff to provide data on recent asthma-related outcomes (e.g., asthma symptoms and medication use), and performed spirometry. Two samplers were placed in three of the communities, with distance between samplers ranging from 3-5 miles. The data show that there are some correlations between pollen measurements within study communities with spatial variability in exposure levels. We have developed methods and performed extended NO testing within a large longitudinal study of a school-based population and related results to respiratory
health status determined from questionnaires. Currently, we are in the process of combining the pollen, questionnaire and FeNO data together.
Atmospheric Modeling
Based on the availability of southern California pollen and health outcome data, the March-June 2010 period was selected for evaluation of the WRF-MEGAN-CMAQ modeling system, which was applied in nested domains. The WRF meteorology simulations were driven by initial and boundary conditions from the North American Regional Reanalysis Results; observational nudging was applied to the southern California domain simulations using wind and temperature data that were obtained from the California Air Resources Board (CARB) from meteorological stations throughout the region. For California, anthropogenic emissions of NOx,
VOC, and PM were based on the ARCTAS-2008 inventory developed by CARB. For regions outside of California, anthropogenic emissions were based on the National Emissions Inventory 2002 (NEI 2002; https://www.epa.gov/ttn/chief/2002inventory.html). Biogenic VOC emissions were modeled using MEGAN with 8-day leaf area index data from MODIS. Model evaluation is ongoing.2
MEGAN Modeling
The model framework and algorithms are now in place for six tree and two grass species, and we have nearly completed initial domain simulations for the selected time period (March 1, 2010-June 30, 2010). The vegetation cover and species composition data has been processed for each grid cell, as these are needed as inputs into the model (along with meteorological data, which has also been processed). We have also incorporated a simulation of the natural variability observed within a given population with respect to start dates for flowering. We have developed a database of average pollen production potentials for the allergenic species selected to be included in the initial simulations, derived from the literature. Finally, we have obtained observational data taken within the study domain for the purpose of tuning the model algorithms to the species and climatic regimes typical of the simulation region. Pollen measurements have been made both in southern California and in eastern Washington using Burkard Sporewatch samplers using protocols developed by the Caltech group. Sample drums from southern California sites were transported to Caltech for subsequent processing. Those collected by the WSU team were mounted on slides according to standard protocols before being shipped to Caltech for analysis. To improve analytical efficiency and accuracy, an automated pollen counting system (developed with other sources of funding) has been validated against the manual pollen analysis. A virtual impaction system has been developed and integrated into a proven PM2.5 sampling system (Andersen RAAS sampler) for collection of respirable pollen antigen, and is being used to collect atmospheric samples at the Pasadena, CA SCAQMD air quality monitoring station for analysis using fluorescent
immunological assays or other analytical methods. Additional laboratory and field observations are being conducted to probe mechanisms and source strengths for respirable pollen antigens.
Future Activities:
During the coming year, pollen modeling will be extended to predict airborne pollen concentrations. The predictions will be validated using extensive pollen count data that will be generated using the automated pollen counting system (with validation using conventional manual analysis). Results from these studies will be integrated into the WRF/MEGAN/CMAQ modeling framework, along with results from the laboratory and field
studies of respirable pollen antigen to predict present and future exposure levels that will then be used to model health outcomes.
References:
- ATS/ERS recommendations for standardized procedures for the online and offline measurement of exhaled lower respiratory nitric oxide and nasal nitric oxide, 2005. Am J Respir Crit Care Med 2005;171:912-30.
- Mesinger, F. et al. (2006), North American Regional Reanalysis, Bull. Amer. Meteor. Soc., 87(3), 343-360, doi:10.1175/BAMS-87-3-343. See also http://www.emc.ncep.noaa.gov/mmb/rreanl.
- https://www.epa.gov/ttn/chief/2002inventory.html.
- https://www.epa.gov/mrlc/nlcd-2001.html.
Journal Articles:
No journal articles submitted with this report: View all 13 publications for this projectSupplemental 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 illnessRelevant Websites:
Caltech Pollen Group: http://pollen.che.caltech.edu/
NCAR Biosphere-Atmosphere Interactions Group: http://bai.acd.ucar.edu/
Southern California Environmental Health Sciences Center: http://hydra.usc.edu/scehsc/
Washington State University Laboratory for Atmospheric Research: http://lar.wsu.edu/
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.