How Can TEMPO Contribute to Air Pollution Health Effects Research Yang Liu, Ph.D. Emory University, Rollins School of Public Health 1st Tropospheric Emissions: Monitoring of Pollution (TEMPO) Applications Workshop July 12-13, 2016 Huntsville, AL

The health effects of air pollutants Outline The health effects of air pollutants PM2.5, O3, NO2, and SO2 Based on EPA’s Integrated Science Assessments Satellite data used in air quality health research Based on personal experience and peer-reviewed literature TEMPO’s potentials In terms of air pollution exposure modeling Personal opinion based on my limited knowledge of TEMPO

The EPA ISA The Integrated Science Assessments (ISA) provide a synthesis and evaluation of the most policy-relevant science that builds the scientific foundation for the periodic review of the NAAQS. Determination Interpretation Research Needs Causal Sufficient and conclusive evidence Not much research is needed in the US Likely causal Sufficient evidence but with uncertainties More research is needed Suggestive Limited evidence

Health Effects of PM2.5 Acute effects (e.g., daily asthma ED visits linked with daily PM2.5 level) Chronic effects (e.g., heart attacks linked with long-term PM2.5 level) Health effects caused by short-term exposure to PM2.5, which is based on a daily standard, include: 1. Premature death, especially death related to heart and lung diseases 2. Increased hospital admissions and emergency department visits for cardiovascular effects, such as non-fatal heart attacks and strokes. 3. Increased hospital admissions and emergency department visits for respiratory effects, such as asthma attacks, coughing, wheezing and shortness of breath. 4. Reduced lung function, especially in children and people with lung diseases, such as asthma. Health effects caused by long-term exposure to PM2.5, which is based on an annual standard, include: Premature death, especially related to heart disease Cardiovascular effects, such as heart attacks and strokes Reduced lung development as well as the development of chronic respiratory diseases, such as asthma, in children Some studies also suggest that long-term PM2.5 exposures may be linked to cancer and to harmful developmental and reproductive effects, such as infant mortality and low birth weight. Source: EPA EPA/600/R-08/139F, 2009

Health Effects of O3 Acute exposure (i.e., hours, days, weeks): Source: EPA 600/R-10/076F, 2013

Health Effects of O3 Chronic exposure (i.e., months to years):

Health Effects of NO2 Acute exposure (minutes up to 1 month) Source: EPA/600/R-14/006, 2015

Health Effects of NO2 Chronic exposure (i.e., > 1 month to years):

Health Effects of SO2 Source: EPA/600/R-15/066, 2015

Summary of Research Needs Acute Exposure (i.e, hrs – months) Chronic Exposure (i.e., seasons - yrs) PM2.5 Causal / Likely Causal / Likely/ Suggestive O3 Likely / Suggestive NO2 Causal / Suggestive SO2 Suggestive

Question: how Can tempo help address these research needs? Good news: all of these air pollutants need more research on their health effects! Question: how Can tempo help address these research needs?

People will figure out ways to use tempo data no matter what Bottom line: People will figure out ways to use tempo data no matter what

Key Factors in Exposure Modeling Study duration Means sample size in acute studies Makes more accurate exposure estimates in chronic studies Temporal resolution Acute study NEEDS accurate short-term fluctuation of exposure Chronic study cares less about temporal resolution Spatial resolution Acute study can get more accurate effect estimates with high resolution exposure data Chronic study NEEDS accurate spatial gradient of exposure Accuracy and spatial coverage Important to both study types

Health Applications of Current Sensors Well established for PM2.5 (not sure if in the upcoming ISA) A lot of methods proposed to convert AOD to PM2.5 and fill data gaps Have been used to drive both acute and chronic effects studies in the US and worldwide Spatial resolution: as high as 1 km Applications of other species are lacking due to Poor spatial resolution (e.g., SO2 and NO2) Poor sensitivity in boundary layer (e.g., O3) Low correlation with ground observations

TEMPO’s Capabilities Duration: >= 2 years Temporal resolution: Hourly NO2 and aerosol 0–2 km O3 every 2 hours (possibly at 1 hour at target locations) SO2 sampled every 3 hours Spatial resolution: required at 8.4 x 4.7 km2 (possibly at 2.1 x 4.7 km2 at target locations) Coverage: greater North America Accuracy: TBD

TEMPO’s Potential Contributions Aerosols (PM2.5) - focus on acute effect studies Temporal resolution is great Accuracy: should be comparable with MODIS? Duration is OK for national scale studies Spatial resolution is not great but OK Not competitive for chronic studies Long-term possibility Retrieve aerosol composition info (AAI, AAOD, and more?) Oversampling to get higher spatial res (1 km) with AAOD?

TEMPO’s Potential Contributions O3 – focus on acute effect studies Temporal resolution is great Spatial coverage is great Spatial resolution of 2.1 x 4.7 km2 is desired Duration is OK for national scale studies Challenge Need to derive MDA8 and MDA1 values to be compatible with existing health study results Long-term possibility Sampling duration is not good for chronic studies but people will probably try it anyway

TEMPO’s Potential Contributions NO2 – focus on acute effect studies Temporal resolution is great Spatial coverage is great Sampling duration is OK for national scale studies Spatial resolution is not good Challenge Need to derive MDA1 values Need to develop models to improve spatial resolution Long-term possibility Sampling duration is not good for chronic studies but people will probably try it anyway Further, airway responsiveness was increased following <1 to 6-hour 15 exposures to NO2 at concentrations in the range of 100 to 300 ppb, which are not much 16 higher than peak ambient concentrations. The majority of the recent 1 evidence is from epidemiologic studies, which expand on findings for associations 2 between ambient NO2 and a broad array of respiratory effects from subclinical increases 3 in pulmonary inflammation to respiratory mortality, but particularly for effects related to 4 asthma exacerbation. Given that motor vehicles are a major source, air concentrations of NO2 can be highly variable across neighborhoods (urban scale), depending on distance to roads. NO2 concentrations tend to decrease over a distance of 200−500 meters from the road and can be 30 to 100% higher within 10−20 meters of a road than at locations 20 farther away

TEMPO’s Potential Contributions SO2 – focus on acute effect studies Spatial coverage is great Duration is OK for national scale studies Temporal resolution is maybe OK Spatial resolution is OK (away from sources) Challenge Need to derive daily and MDA1 values Long-term possibility Sampling duration is not good for chronic studies but people will probably try it anyway Consistent associations between SO2 concentrations and asthma hospital admissions and emergency department visits that are generally unchanged in copollutant models have been demonstrated in epidemiologic studies using daily exposure metrics (24-hour average and 1-hour daily max), although the observed effects could be related to very short duration (5−10 minutes) peak exposures experienced during the day.

Personal Research Priority Ranking Exposure models first! convert TEMPO retrievals to ground concentrations! Acute O3 > Chronic O3 Acute NO2 > Acute SO2 Acute PM2.5 Multi-pollutant acute studies Chronic PM2.5, NO2, and SO2