Ozone NAAQS – Issues with the Science Presented by: Lucy Fraiser Zephyr Environmental Corporation February 5, 2015 Air & Waste Management Association Hot Air Topics, Houston TX

Epidemiological studies – Determine factors associated with diseases (risk factors) at population level by linking temporal trends in air monitor data to health effects (e.g., Emergency Room visits or death) No information on actual exposures Confounding - health impacts attributed to O 3 erroneously Controlled human exposure studies – Human volunteers exposed to known concentrations in lab setting Types of Health Studies Supporting NAAQS

Focus on inconsistent/infrequent physiological changes observed in controlled exposure studies, often too mild to be considered clinically relevant Abandonment of requirement for results used as evidence for adverse effects be statistically significant and come from studies that adequately control confounders Focus on responses in sensitive individuals within study populations rather than group mean responses Recent Trends that Stack the Deck

Revised standard of 60 – 70 ppb expected to limit: – O 3 exposure concentrations that result in respiratory symptoms Respiratory symptoms have not been demonstrated in controlled human studies below 72 ppb (mild/transient effect) – Test subjects were engaging in vigorous exercise for 6.6 hours – Much higher exposures than if a lightly exercising (shorter duration or lower activity) or person at rest was exposed to 72 ppb in ambient air – O 3 -induced lung function decrements large enough to be adverse Lung function decrements not considered adverse unless accompanied by respiratory symptoms and clinically meaningful lung function decrement has not been demonstrated below 88 ppb in controlled human studies Where EPA’s Conclusions Fall Apart

Controlled Human Studies - Lung Function Decrement below 75 ppb O 3 *+ * Clinically Significant Adverse + Clinically Relevant Adverse Healthy volunteers exposed to O 3 during 6.6 hrs quasi-continuous exercise simulates “heavy physical labor” for full workday Forced Expiratory Volume in one second FEV 1

Group mean lung function changes are small but significant fraction of individuals experience clinically meaningful decrements at ppb O 3 – Dependent on assumption that 10%  in FEV 1 is clinically meaningful, even though 15% has been historically used studies in healthy adults and assumption that 10%  in FEV 1 may be more adverse in asthmatics or those with compromised lung function (mild reversible effects) Evidence that these populations are more sensitive is limited Evidence for O 3 -Induced Lung Function Decrement below 75 ppb

Rationale for lower 10% FEV 1 cutoff for O 3 exposures not well supported – Based on CASAC advice and 1996 NAAQS review Occasional medication use in asthmatics A few asthmatics may limit activity Scientific basis not apparent Asthma medication usage/symptoms not correlated w/FEV 1 Source: Can Resp J, v. 14(6) Sep, 2007; Chest, v 113(2), 1998; Eur Respir J, v 17, 2001; Resp Care, v 52(12), 2007 Activity restriction not correlated w/FEV 1 Source: Can Resp J, v. 14(6) Sep, 2007 Lung Function, Symptoms, and Medication

High degree of variation in FEV 1 throughout the day in people with and without respiratory diseases 10%  in FEV 1 is within range of most variable individuals in each group High Degree of Normal Variation in Lung Function Range in individual w/highest variability 11%  10%  14%  15%  7%  10%  Thorax (1975), 30, 548

Use air monitoring/modeling to estimate number people exposed above 75 – 60 ppb – Use results from lung function studies to estimate no. people with FEV 1 decrements > 10%, 15%, and 20% – REA indicates FEV 1 decrements ≥ 10% are appropriate for evaluating people with asthma or lung disease, but a 15% threshold is more appropriate for healthy people – Apply 10% threshold across all populations Health Risk and Exposure Analysis (REA)

HDDM (Higher Order Direct Decoupled Method) – Adjusts monitored air quality to simulate meeting current and alternative standards – Estimates  and  in O 3 in response to  precursors (NOx and VOC) APEX (Air Pollution Exposure model) – Simulates activity patterns to estimate personal exposure based on age-dependent physiological parameters – Likely overstates exposure MSS (McDonnell-Stewart-Smith model) – Estimates lung function response to O 3 using clinical study results – Extrapolates to populations and exposures beyond those included in studies -  uncertainty – Estimates consistently higher than previous models REA is Heavily Dependent on Models and Assumptions Used

REA Results - % Children w/One or More Lung Function Decrements/Season Averaged over % threshold applied across all populations

Multiple Exposures > 70 ppb in Exercising Children at Alternatives small % of most highly exposed population encounter > 70 ppb twice if current NAAQS retained

Implications  Texas Counties in Non-Attainment 75 ppb70 ppb65 ppb60 ppb Ozone NAAQS level County with at least 1 regulatory monitor in non-attainment County with no regulatory monitor in non-attainment County without regulatory monitor

 NAAQS will result in substantial  in counties in non-attainment Additional requirements and regulatory hurdles would be justifiable if health studies suggested a reduction in NAAQS was necessary to protect public health Scientific evidence does not support that a reduction in the O 3 NAAQS is necessary to protect public health EPA’s REA fails to demonstrate significant  risk associated with  NAAQS Conclusions

Thank you! Lucy Fraiser, PhD, DABT Zephyr Environmental Corporation Phone: Visit us at and