1. Why Georgia Needs Gooder: Health Effects of O3 and PM2.5
Stefanie E. Sarnat, Sc.D.
Emory University
Georgia Air Quality and Climate Summit
Atlanta, GA, May 7th, 2008

2. Background U.S. EPA recently revised NAAQS standards O3 standard:
Including “primary” standards – designed to protect human health
O3 standard:
Revised March 12, 2008
0.08 ppm 8-hour standard lowered to ppm
PM2.5 standard:
Revised September 21, 2006
65 µg/m3 24-hour standard lowered to 35 µg/m3
15 µg/m3 annual standard retained
Revisions were made to short-term standards
Should protect against acute O3- and PM2.5-related health effects

3. Respiratory System Morphology
Naso-oro
Alveolar
Tracheal
Bronchial, Bronchiolar

4. Mechanisms of Ozone Toxicity
Common denominator of all ozone-related health effects:
Inflammatory response mechanism
Ozone inhaled…
Not likely to penetrate deeper than epithelial lining fluid
May react with cellular components
E.g., polyunsaturated fatty acids, amino acids, and low-molecular-weight compounds (glutathione, urate, vitamins C and E)
Linked to release of pro-inflammatory mediators
Thickening of air-blood barrier
Impeded oxygen diffusion to blood
U.S. EPA, O3 Air Quality Criteria Document, 2006

5. Example of Lung Tissue Damage
Upper slide = exposure to filtered air
Cilia clear lungs of mucus
Cilia appear in neat and regular rows
Lower slide = exposure to 200 ppb of O3 for four hours while exercising
Missing, misshapen cilia
Neutrophil release (arrows) indicates inflammation
Figure 1. Microscopic views of human lung tissue (epithelium, or lining) show damage resulting from exposure to relatively low levels of ozone. In the control image (upper) from the lung of a person exposed only to air, the tiny cilia that clear the lungs of mucus appear along the top of the image in a neat and regular row. In the lung exposed to 0.20 ppm of ozone added to the air for four hours during moderate exercise, many cilia appear missing and others appear misshapen. Arrows point to tiny bodies called neutrophils in the ozone-exposed subject. The presence of neutrophils indicates inflammation. Magnification: x400. (American Review of Respiratory Diseases, Vol. 148, 1993, Robert Aris et al., pp )
Aris et al. American Review of Respiratory Diseases, 1993

6. Mechanisms of PM Toxicity
Pope and Dockery. Journal of the Air and Waste Management Association, 2006

7. Health Impacts of O3 and PM2.5
Premature death in people with heart and lung disease
Increased hospital visits for respiratory diseases (and for CVD for PM2.5)
Reduced lung function
Increased symptoms (coughing, wheezing)
Aggravation of chronic lung diseases
Increased susceptibility to respiratory infection (O3)
Heart rate variability, arrhythmias (PM2.5)
Severity
Proportion of Population Affected
U.S. EPA,

8. Study of Particles & Health in Atlanta
SOPHIA
Study of Particles and Health in Atlanta

9. SOPHIA - Ambient O3 & ED Visits
Exposure:
Daily 8-hr max O3
8-hr standard
Outcome:
Daily respiratory ED visits

10. SOPHIA - Ambient O3 & ED Visits
IQR=29.75 ppb
Unpublished SOPHIA results using data

11. SOPHIA - Multi-Pollutant Modeling
Modified figure from Tolbert et al. Journal of Exposure Science and Environmental Epidemiology, 2007

12. Health Benefits of Reduced Standards*
Reduced cases of…
O3^
PM2.5
Premature death
~260 to 2,300
1,200 to 13,000 in people with heart or lung disease
Chronic bronchitis
380
2,600
Nonfatal heart attacks
890
5,000
Hospital admissions & emergency department visits
1,900
1,630 CV and resp HAs
1,200 asthma ED visits
Acute bronchitis
1,000
7,300
Upper and lower respiratory symptoms
11,600
97,000
Aggravated asthma
6,100
51,000
Missed work or school days
243,000
350,000
Restricted activity days
750,000
2 million
*By year 2020, according to EPA Regulatory Impact Analyses; summaries found at
^Reflect both O3 and PM pollution reductions resulting from revised O3 standard