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This progress report provides an overview of the MESA Air Study timeline, including subject recruitment, baseline exams, and exposure monitoring for Years 1-5 and Years 6-10. It also discusses the integration of information for exposure assessment and the ongoing data analysis and manuscript preparation. The report highlights the completion of MESA Air monitoring and the ongoing exposure modeling efforts.
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MESA Air Progress Report MESA Steering Committee Meeting March 18, 2009
Study Timeline: Years 1-5 Year 1 08/04 - 7/05 Year 2 8/05 – 7/06 Year 3 8/06 – 7/07 Year 4 8/07 – 7/08 Year 5 8/08 – 7/09 Subject Recruitment; Baseline Exam MESA Exam 3 MESA Exam 4 Exposure Monitoring for Air and Ancillary Studies F/U Calls including Air (starting F/U8) Surveillance for Clinical Events
Exposure Monitoring: Years 1-5 Year 1 08/04 - 7/05 Year 2 8/05 – 7/06 Year 3 8/06 – 7/07 Year 4 8/07 – 7/08 Year 5 8/08 – 7/09 07/05 07/31/09 Fixed Site Monitoring: On-going through this summer 02/06 07/31/08 Residential Monitoring: Complete 10/06 07/31/08 Personal Monitoring: Complete 05/06 07/31/07 NOx Snapshots: Complete
Study Timeline: Years 6-10 Year 6 08/09 - 7/10 Year 7 8/10 – 7/11 Year 8 8/11 – 7/12 Year 9 8/12 – 7/13 Year 10 8/13 – 7/14 Data Analysis and Manuscript Preparation MESA Exam 5 Follow Up Calls Surveillance for Clinical Events
MESA Air “Baseline Exam” Complete, Follow Up Underway • Full recruitment into our Subclinical Cohort • Follow-Up 8 complete; F/U 9 in progress • Planning for MESA Air Exam 2 (MESA Exam 5) is underway
Health Data Available for Analysis • February 2009: • MESA Exam 4 CT • Baseline Air questionnaire • New Recruit dataset (excluding IMT) • Q2 or Q3 2009: • IMT
Exposure Assessment: Big Picture Over-arching goal: Most accurate estimate possible of each individual study participant’s exposure to air pollutants of interest over the period of study Focus is on ambient air pollutants Concentration vs. Exposure
Individual Exposure Estimates EA = CA= [fo +(1- fo)Finf] CA EAAmbient exposure Attenuation factor fo Time outdoors (1-fo) Time indoors Finf Infiltration factor CA Outdoor concentration
Exposure Assessment Overview Integrating Information from: Spatio-temporal outdoor concentration model (for CA) residential characteristics including pollutants’ infiltration efficiencies (for Finf ) personal time-activity records (for fo )
Measurements Questionnaires Predictions Indoor Pollutant Measurements Outdoor Pollutant Measurements Geographic Data Reported Housing Characteristics Observed Housing Characteristics Deterministic Models Spatio-temporal Hierarchical Modeling Infiltration Modeling Predicted Outdoor Concentrations at Homes Predicted Indoor Concentrations at Homes Reported Time/Location Information Weighted Average Personal Exposure Predictions for Each Subject
MESA Air Monitoring Campaigns Fixed Sites Home-based monitoring Outdoor Infiltration Traffic gradient and community-based NOx snapshots Personal monitoring
Exposure Monitoring: Sample Counts Paired indoor-outdoor residential locations (collected twice) NOx snapshot monitoring campaign locations (collected 3x) Number of biweekly fixed site samples collected (2-7 fixed sites per city) * * *LA and NY include New Recruit areas of Coastal LA, Riverside, CA, and Rockland NY
MESA Air Exposure Monitoring Concludes July 31, 2009 • Includes ancillary studies (HEI, Coarse*) • Exposure technicians in some sites being transferred to interview duties or other projects *with the possible exception of an additional month of Coarse monitoring in Chicago
Exposure Modeling In Progress • First iteration (“pragmatic”) of spatio-temporal modeling estimates complete, incorporating AQS data, early MESA Air monitoring data, land use and certain GIS covariates • Infiltration modeling underway: first set of results available based on early data • Incorporation of time-location data underway: first set of personal-level estimates
Measurements Questionnaires Predictions Indoor Pollutant Measurements Outdoor Pollutant Measurements Geographic Data Reported Housing Characteristics Observed Housing Characteristics Deterministic Models Spatio-temporal Hierarchical Modeling Infiltration Modeling Predicted Outdoor Concentrations at Homes Predicted Indoor Concentrations at Homes Reported Time/Location Information Weighted Average Personal Exposure Predictions for Each Subject
Individual Exposure Estimates EA = CA= [fo +(1- fo)Finf] CA EAAmbient exposure Attenuation factor fo Time outdoors (1-fo) Time indoors Finf Infiltration factor CA Outdoor concentration
25 20 15 10 LA Riverside LA LA Coastal NYC Chi. Balt. W-S NY Rockland St.Paul Interim Long-Term Avg PM2.5 (mg/m3) Estimates at Participant Homes
MESA and Air Pollution: Between-City Exposure Heterogeneity L=Low, M=Medium, H=High, VH=Very High e.g., for PM2.5: L= (~12 g/m3), M= (~16 g/m3), H = (~20g/m3), VH= (~24 g/m3) annual averages Blue = Areas of New Recruitment for MESA Air
25 20 15 10 LA Riverside LA LA Coastal NYC Chi. Balt. W-S NY Rockland St.Paul Interim Long-Term Avg PM2.5 (mg/m3) Estimates at Participant Homes
Outdoor Contributions to Indoor AirHomes Undergoing Indoor-Outdoor Monitoring SUMMER WINTER Mean Indoor PM2.5 = 10.8 ug/m3 Mean Indoor PM2.5 = 8.9 ug/m3 79% 83% CHI Mean Indoor PM2.5 = 15.0 ug/m3 Mean Indoor PM2.5 = 13.6 ug/m3 87% 81% LA Mean Indoor PM2.5 = 17.2 ug/m3 Mean Indoor PM2.5 = 15.3 ug/m3 82% NY 74% Mean Indoor PM2.5 = 7.6 ug/m3 Mean Indoor PM2.5 = 6.0 ug/m3 67% SP 75% *Indoor/outdoor monitoring only in non-smoking homes.
FinfModels LOO = “Leave one out”
Reported Average Hrs/Day Spent Outdoors (fo) Summer Winter
Ambient Outdoor PM2.5 Concentration Ambient Infiltrated PM2.5 Concentration Personal Exposure to Ambient PM2.5
PM2.5 Exposure Modeling Estimates: Dataset Timepoints Teleatlas Road Network Emissions Sources Traffic Counts Deterministic Model Outputs Measurement Error Considerations AQS 2000-09 MESA Air Fixed & Homes 2005-09 Air Quality Model Integration AQS 1982-2011 MESA Air Fixed & Home 2005-09 Flexible Long-term Residential Histories Census Road Network “Land Use” Variables AQS 2000-06 MESA Air Fixed & Homes 2005-06 MESA AIR 2008 2009 2011 “Pragmatic” Interim Estimates Spatio-Temporal Interim Estimates Spatio-Temporal Final Estimates Infiltration & Time-Location Information Infiltration & Time-Location Information Nearest Monitor/ Distance to Nearest Road Interim Exposure Predictions for Each Subject Final Exposure Predictions for Each Subject Long-Term PM10 Long-Term PM2.5 2006 AQS 1982 – 2002 Road Network Data “Land Use” Variables Meteorology UNIVERSITY OF MICHIGAN
Interim analyses of exposure and health • Microvascular abnormalities (Adar et al.) • Left ventricular mass (Van Hee et al.) • Serum and plasma biomarkers of endothelial activation (Van Hee et al.) • Systemic vascular response (Krishnan et al.) • Quantitative markers of emphysema (Barr et al.)
Health Model Building • Current focus on Agatston CAC • Model selection underway • Identification of confounders • Treatment of cross-sectional and longitudinal components • Coordinating with main MESA investigators
Exam 5 • Air components included in proposed schedule • Working with Participant Relations Committee to ensure minimum participant burden • Electronic Data Capture
Minimizing Participant (& Interviewer) Burden • Faster administration of Air Questionnaire with Electronic Data Capture • Include shortcuts, like allowing participant to state that their activity patterns don’t change by season • Reanalysis of actual time required for administration • Reiterate to interviewers primary importance of retaining participants • Review with interviewers the purpose of MESA Air, and provide a list of FAQs
Exam 5 Ultrasound and CT/CAC Responsibilities Fall to MESA Air • Sub-contracts with Reading Centers • Imaging Protocols • Training • Data Transfer Protocols • Reading Procedures • QA/QC Processes
MESA Environmental Health Working Group • Meeting this evening 6:30 pm • Scientific opportunities • Writing opportunities • Funding opportunities • 7:15 pm Scientific Presentation • RG Barr et al, PM2.5 and Emphysema in MESA
Summary • On target with regards to schedule: • Baseline exam complete • Exposure monitoring nearly complete • “Pragmatic” estimates of outdoor concentrations at participants’ residences available • First iterations of infiltration estimation and time-location data integration underway • Initial cross-sectional health analyses and health modeling underway • Positive response from On-Site Peer Review • Planning for smooth integration with MESA Exam 5
MESA Air • EPA Grant RD831697 • Project Period 8/1/04 – 7/31/13 • Although the research described in this presentation has been funded wholly or in part by the United States Environmental Protection Agency through RD831697 to the University of Washington, it has not been subjected to the Agency's required peer and policy review and therefore does not necessarily reflect the views of the Agency and no official endorsement should be inferred.