Ozone NAAQS Reconsideration: 

Supplement to the 2008 

Regulatory Impact Analysis (RIA)

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Briefing for OMB and Interagency 

Group

November 5, 2009
Need for Supplement to the 2008 RIA

• Because this is a reconsideration of the 

2008 ozone NAAQS, the 2008 RIA is still 

applicable.

• However, the 2008 RIA did not include 

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certain elements new to this proposal.

• This briefing will walk through the new 

analyses contained in the supplement.

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Basis for Ozone RIA Supplement

• Like the reconsideration of the standard itself, this RIA 

supplement is based primarily on the analysis done for 

the 2008 final rule.

• Consistent with OMB guidance, we present results of 

analysis for options within the proposal range (0.060, 

0.065, and 0.070 ppm), as well as one lower option 

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(0.055 ppm) and one higher option (0.075 ppm).

• These levels are analyzed relative to the old 0.084 ppm 

standard

– This is the appropriate baseline for comparison because this is 

a reconsideration of the 2008 standard decision

• The underlying air quality modeling and emissions 

inventory are the same as for the 2008 RIA.
Updates to the 2008 Ozone RIA 

Contained in this Supplement

This supplemental analysis includes:

• An analysis of the costs and benefits of attaining 0.055 and 0.060 

ppm, as these levels were not analyzed in the 2008 RIA (in addition 

to presenting results for levels of 0.065, 0.070, and 0.075 ppm). 

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• Several key updates to the benefits methodology, which have 

occurred since the 2008 Ozone RIA. All these assumptions have 

already been incorporated into the RIAs for cement, NO2 NAAQS 

and the C3 rules, and are thus included in this RIA as well.*

• An analysis of the proposed secondary ozone standard.

*Note that issues concerning the mortality benefits calculations will be the subject of a 

separate, more focused, upcoming meeting, and thus are not included in today’s 

overview.
Control Strategies and Cost Analyses 

Contained in this Supplement

• No control strategy approach or cost estimation 

methodological changes have occurred since the 2008 

RIA.

• For the analysis of the 0.055 and 0.060 ppm levels, we 

used the same cost methodology as in the 2008 RIA, 

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including the hybrid approach for estimating extrapolated 

costs. 

• The analysis of the 0.055 and 0.060 ppm levels are not 

extended to the year 2030 because of the inherent 

uncertainty involved at these lower levels. (The 2008 RIA 

extended to 2030 for severe and serious nonattainment 

areas in California). 
Benefits Methodology Updates Contained in 

this Supplement

Ozone:

• Removed assumption of no causality with ozone mortality per NAS 

advice 

• Included two more NMMAPS studies per NAS advice (Huang and 

Schwartz).

• Revised value of a statistical life (VSL), as done in C3 and NO2

NAAQS RIAs.

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• Removed one morbidity study because age ranges overlapped

PM2.5:

• Removed thresholds from the concentration-response functions as 

done in Cement, C3 and NO2 NAAQS RIAs.

• Revised value of a statistical life (VSL), as done in C3 and NO2

NAAQS RIAs.

• Updated benefit-per-ton estimates.

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Secondary Ozone Standard Analysis

Contained in this Supplement

• No secondary standard analysis was included in 

the 2008 RIA, as a separate secondary was not 

finalized.

 This supplement includes:

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 Counts of additional counties which may not attain a 

given secondary standard for various levels of a 

primary standard 

 Qualitative description of the standard, and 

 Qualitative description of the benefits of reduced 

ozone exposure on vegetation.
Secondary Ozone Standard Analysis

Contained in this Supplement (cont.)

 For the reasons outlined below, this supplemental 

analysis of the secondary proposal options will not 

include estimates of the benefits and costs of attaining 

the separate secondary standard.

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– There is no specific attainment year to measure costs and 

benefits towards; the secondary standard is “as soon as 

practicable.”

– A new and/or revised monitoring network is being considered to 

understand the extent of the nonattainment with a separate 

secondary standard.

– There is limited experience with air quality modeling of the W126 

form of the standard.

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Secondary Ozone Standard Analysis

Contained in this Supplement (cont.)

Number of Counties Projected to Exceed Various W126 Levels While Meeting 

Various Levels of the Primary Standard in the Control Strategy in 2020 a

Levels of 12-hr W126 (ppm-hrs)

8-Hour Level Met > 21 > 15 > 7

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0.075 ppm 1 12 130

0.070 ppm 1 8 98

0.065 ppm 0 3 46

0.060 ppm 0 1 12

0.055 ppm 0 0 2

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Summary of Cost and Benefit Results for this 

Supplement: Baseline Projected Ozone Air 

Quality in 2020

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Legend

28 counties exceed 0.075 ppm

61 additional counties exceed 0.070 ppm

142 additional counties exceed 0.065 ppm

205 additional counties exceed 0.060 ppm

141 additional counties exceed 0.055 ppm

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Summary of Cost and Benefit Results for 

this Supplement: Health Benefits

Summary of Total Number of Annual Ozone and PM2.5-Related Premature Mortalities and 

Premature Morbidity Avoided: 2020 National Benefits*

Combined Estimate of 

Mortality 0.075 ppm 0.070 ppm 0.065 ppm 0.060 ppm 0.055 ppm

Bell et al. (2004) 760 to 1,900 1,500 to 3,500 2,500 to 5,600 4,000 to 8,700 5,900 to 13,000

NMMAPS Schwartz 800 to 1,900 1,600 to 3,600 2,700 to 5,800 4,500 to 9,200 6,700 to 13,000

Huang 820 to 1,900 1,600 to 3,600 2,800 to 5,900 4,600 to 9,300 6,900 to 14,000

Bell et al. (2005) 930 to 2,000 2,000 to 4,000 3,500 to 6,600 6,000 to 11,000 9,400 to 16,000

Ito et al. 1,000 to 2,100 2,300 to 4,300 4,000 to 7,100 7,100 to 12,000 11,000 to 18,000 Metaanalysis

Levy et al. 1,000 to 2,100 2,300 to 4,300 4,100 to 7,200 7,100 to 12,000 12,000 to 18,000

Combined Estimate of 

Morbidity

0.075 ppm 0.070 ppm 0.065 ppm 0.060 ppm 0.055 ppm

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Morbidity

0.075 ppm 0.070 ppm 0.065 ppm 0.060 ppm 0.055 ppm

Acute Myocardial 

Infarction 1,300 2,200 3,500 5,300 7,500 

Upper Respiratory

Symptoms

9,900 19,000 31,000 48,000 69,000 

Lower Respiratory

Symptoms

13,000 25,000 41,000 63,000 91,000 

Chronic Bronchitis 470 880 1,400 2,200 3,200 

Acute Bronchitis 1,100 2,100 3,400 5,300 7,600 

Asthma Exacerbation 12,000 23,000 38,000 58,000 83,000 

Work Loss Days 88,000 170,000 270,000 420,000 600,000 

School Loss Days 190,000 600,000 1,100,000 2,100,000 3,700,000 

Hospital and ER Visits 2,600 6,700 11,000 21,000 35,000 

Minor Restricted Activity 

Days 1,000,000 2,600,000 4,500,000 8,100,000 13,000,000 

*Only includes areas required to meet the current standard by 2020, does not include San Joaquin Valley and 

South Coast air basins in California. 

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Summary of Cost and Benefit Results for 

this Supplement: Costs

Total Monetized Costs with Ozone Benefits and PM2.5 Co-Benefits in 2020 

(in Billions of 2006$)*

Total Benefits ** Total Costs *** Net Benefits

3% 7% 7% 3% 7%

$6.9 to $18 $6.4 to $15 $7.6 to $8.8 $-1.9 to $10 $-2.4 to $7.4

0.075 

ppm

$13 to $37 $11 to $31 $19 to $25 $-12 to $18 $-14 to $12

0.070 

ppm

12

0.0

65 

ppm

$22 to $61 $19 to $53 $32 to $44 $-22 to $29 $-25 to $20

$35 to $100 $30 to $87 $52 to $90 $-55 to $48 $-60 to $35

0.060 

ppm

$53 to $160 $45 to $140 $78 to $130 $-77 to $82 $-85 to $62

0.055 

ppm

***Range reflects lower and upper bound cost estimates. Data for calculating costs at a 3%

discount rate was not available for all sectors, and therefore total annualized costs at 3% are not

presented here

Note also that California counties attaining by 2030 are not included in the cost estimates.
Summary of Cost and Benefit Results for 

this Supplement: Costs and Benefits

$80

$100

$120

$140

$160

Billions of 2006$

Comparison of Total Monetized Benefits to Costsfor Alternative 

Standard Levels in 2020 (Updated results, 7% discount rate)

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$0

$20

$40

$60

$80

0.075 

ppm 

0.070 

ppm 

0.065 

ppm 

0.060 

ppm 

0.055 

ppm 

Billions of 2006$

Alternative Standard Level

*The low benefits estimate is based on Pope/Bell 2004 and the high benefits 

estimate is based on Laden/Levy. The two cost estimates (unchanged) are based 

on two different extrapolated cost methodologies. The dotted lines are a visual 

cue only, and these lines do not imply a uniform range between these endpoints.