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Environmental Health Risks: The Health Effects of Ozone. Healthy Carolinians Conference September 29, 2010 Susan Lyon Stone US EPA Office of Air Quality Planning and Standards stone.susan@epa.gov. Review Process for Standards. EPA Risk/Exposure Assessment (REA) + Policy Assessment (PA).
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Environmental Health Risks: The Health Effects of Ozone Healthy Carolinians Conference September 29, 2010 Susan Lyon Stone US EPA Office of Air Quality Planning and Standards stone.susan@epa.gov
Review Process for Standards EPA Risk/Exposure Assessment (REA) + Policy Assessment (PA) Scientific studies on health and environmental effects EPA Integrated Science Assessment (ISA) Scientific peer review of published studies Reviews by CASAC and the public Reviews by CASAC and the public Final Decision Public hearings and comments on proposals Proposed Decision Ozone final decision around the end October 2010
Human Lung • Air conducting • Trachea • Bronchi • Bronchioles • Gas exchange • Respiratory bronchioles • Alveoli
Ozone Irritates Airways • Symptoms • Cough • Sore or scratchy throat • Pain with deep breath • Fatigue • Rapid onset • Asthma symptoms - greater in people with asthma, also occur in people without asthma
Ozone Reduces Lung Function 0 -20 FEV1, % CHANGE -40 -60 BASELINE 2HR 4HR M-10
Ozone Causes Inflammation • Ozone reacts completely in surface layer - forms reactive oxygen molecules • Increases permeability of cells that line airways • Influx of white blood cells and proteins • Damages cells that line the airways • Effect is greater 24 hours after exposure • Increases airway reactivity • Concern about repeated exposures
Respiratory Hospital Admissions by Daily Maximum Ozone Level, Lagged One Day (Burnett et al, 1994) 114 112 110 108 106 104 102 Respiratory Admissions .01 .02 .03 .04 .05 .06 .07 .08 .09 .1 Ozone concentration (ppm) D-8a
CHS: Ozone and School Absences • 20 ppb increase in O3 associated with an 83% increase in school absences for acute respiratory disease (Gilliland et al., 2001) • Large economic impact of pollution-related school absences (Hall and Lurmann, 2003)
CHS: Ozone and New-onset Asthma McConnell et al., 2002
Evidence from 2008 Review of Ozone Standard • Evidence of lung function decrements and symptoms at 0.060 ppm in healthy people • New information about physiological bases of increased sensitivity of people with asthma • Larger decreases lung function • Increased magnitude and duration airway responsiveness • Increased inflammatory responses • Different cellular responses • Epidemiological studies show: • Increased symptoms and medication use in asthmatic children • School absences • Emergency room visits and hospital admissions • Premature mortality
Sensitive Groups for Ozone • People with lung disease • Children • Older adults • People who are active outdoors
Air Quality Index • Pollutant-specific health effects and cautionary statements address question “who will be affected” Dose = Concentration x Ventilation rate x Time C - be active outdoors when air quality is better V - take it easier when active outdoors T - spend less time being active outdoors • Reduce these factors (C,V,T) to reduce dose • Pay attention to symptoms • People with asthma – follow asthma action plan • Coaches – rotate players frequently • People with heart disease – check with your doctor
Physical Activity and Health Osteoporosis Prevention of Weight Gain Diabetes Mellitus Risk of “Disease” CHD Stroke Musculoskeletal Injury Functional Health Status Activity Source: HW Kohl, University of Texas School of Public Health
Effectiveness of the AQI • Effectiveness has been measured many ways • Surveys: What people say • Behavior • Behavior and demographics (EPA, BRFSS) • Activity diaries: What people do (RTI) • Health studies: Changes in health outcomes • Surveys • Large proportion report awareness (50 -75%) • Of those about 50% report taking action • People of older age, fair or poor health status, and females more likely to reduce exposure (EPA Health and Aging Survey) • Recommendation by healthcare provider much more likely to reduce exposure (Wen et al., 2009 - 2005 BRFSS Survey) • Odds ratio of changing behavior based on media reports = 2.16 (95% CI: 1.61, 2.90) • Percent change in behavior based on alerts with professional advice = 50.7%; without professional advice = 14.2%
Determinants of Parents’ Ozone Forecast Monitoring • Parents of asthmatics more likely to report checking AQI forecast frequently • More serious asthma = more frequent checking • More children = less frequent checking • White parent = less frequent checking Source: Carol Mansfield, RTI
Summary of results on time outdoors • Evidence that • Air pollution sensitive asthmatics reduce time outdoors on code red days (based on daily diaries) • 30+ minute reduction in time outdoors on Code Red day relative to non-Code Red day Source: Carol Mansfield, RTI
Air Pollution Sensitive vs. Not Air Pollution Sensitive Asthmatics Source: Carol Mansfield, RTI
Increase asthma hospitalizations per 10 ppb O3 - Neidell and Kinney (2010) Health Studies • Los Angeles study: Neidell and Kinney (2010) • Asthma hospital admissions 1989-1997 • Control for air quality forecasts to account for avoidance behavior • Accounting for behavior leads to significantly larger effects estimates; however there is a cost to behavior • DFW: Carls U of MI dissertation • Forecasts protective of health and alter relationships between asthma exacerbations and air quality • Previous day O3 alerts were protective for high morbidity outcomes (hospital/ER); but not for the low morbidity outcomes (outpatient visits, medication use) **P<0.01; *P<0.10 Change in asthma hospitalizations per 20 ppb O3 - Carls (2010) *P<0.05
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AQI Curriculum for Children and Students Colorful lessons and games for children and students
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