Supporting Information for: “The Geographic Distribution and Economic Value of Climate-Related
Ozone Health Impacts in the United States in 2030”
Authors:
Part 1: Health Impact Assessment
Estimating air quality concentrations across the population
To quantify the level of ozone among populations in each 36km grid cell, we started with 2010 U.S.
Census block-level population data and aggregated population counts to the 36km CMAQ model
cells in BenMAP-CE across the continental U.S. This software contains the appropriate age, sex and
race stratification that corresponds to the demographic characteristics of the concentrationresponse relationship specified in the impact function. Using an economic forecasting model, we
next projected this national population data to the year 2030, which corresponds to the projected
years for the air quality modeling scenarios (Woods and Poole 2012). We estimated the climateattributable summer-season ozone levels among populations in each grid cell by calculating the
difference between each baseline and model projected ozone levels.
Selection of concentration-response relationships and baseline incidence rates
For each sector we assessed the number of ozone-related premature deaths and non-fatal illnesses
using concentration-response functions that are drawn from the peer reviewed literature (See
Supplemental Material, Table 1) that are generally consistent with recent EPA analyses and other
health impact assessments using BenMAP (EPA 2011; Fann et al. 2011).
Finally, we applied baseline incidence rates matched to each health endpoint; these rates are
generally consistent with recent EPA analyses (EPA 2011) (See Supplemental Material, Table 2).
When quantifying the number of deaths, we apply all-cause baseline mortality rates that have been
projected to 2030 using an approach described in US EPA (2012).
Calculating health impacts
To quantify the number of ozone-related deaths and illnesses, for each health endpoint we applied
the health impact function summarized in Table 1 below. This procedure generates counts of
premature deaths and illnesses for each climate scenario. We also employ a Monte Carlo approach
to calculate a distribution around each point estimate, using the standard error reported in each
epidemiological study; we report the 95th percentile confidence interval from this distribution. All
ozone-related premature deaths are estimated to occur in the year 2030.
Page 1 of 6
Part 2: Supplemental Figures and Tables
Supplemental Material, Table 1. Ozone-Related Health Endpoints and Studies Included
Endpoint
Study
Study
Population
Risk Estimate
(95th Percentile Confidence
Interval)A
Premature death
Daily time
series
Bell et al. (2004) (non-accidental)
Huang et al. (2004)
(cardiopulmonary)
Schwartz (2005)(non-accidental)
Bell et al. (2005)(all-cause)
Ito et al. (2005) (non-accidental)
Levy et al. (2005) (all-cause)
β=0.000390 (0.000133)
β=0.000813 (0.000259)
All ages
β=0.000426 (0.000150)
β=0.000794 (0.000212)
β=0.001173 (0.000239)
β=0.001119 (0.000179)
Hospital Admissions
Pooled using random/fixed effects:
Schwartz (1995)—ICD 460–519
(all resp)
Respiratory
Schwartz ( 1994a, 1994b)—ICD
480–486 (pneumonia)
Moolgavkar et al. (1997)—ICD
480–487 (pneumonia)
Schwartz (1994b)—ICD 491–492,
494–496 (COPD)
Moolgavkar et al. (1997)—ICD
490–496 (COPD)
Burnett (2001)
>64 years
RR = 1.20 (1.06 – 1.37) per 50
µg/m3
RR = 1.07 (1.00 – 1.15) per 50
µg/m3
RR = 1.22 (1.02 – 1.47) per 50
µg/m3
Increase = 5.7% (2.5% – 8.9%) per
15 ppb
RR=1.57 (2.06—1.020) per 1 ppb
Increase = 4.2% (-1.0% – 9.4%)
per 15 ppb
<2 years
Increase =
33.0 (t-statistic 3.44) per 45.2 ppb
Pooled using random/fixed effects:
Asthma-related ER
visits
Peel et al. (2005)
All ages
Wilson et al. (2005)
Other Health Endpoints
Pooled estimate:
School absence
days
Gilliland et al. (2001)
5–17 years
Chen et al. (2000)
Minor
Restricted
Activity Days
(MRADs)
Ostro and Rothschild (1989)
18–65 years
RR = 1.022 (0.996 – 1.049) per 25
ppb
β=0.010 (0.0090)
β=0.0060 (0.0110)
Increase = 16.3% (-2.6% - 38.9%)
per 20 ppb
β= 0.015763454 (0.0049851)
β=0.00741 (0.00070)
Values in this column reflect the information reported by each study. When calculating health impacts, relative risk
estimates were subsequently converted to beta coefficients.
A
Page 2 of 6
Supplemental Material, Table 2. Baseline and Prevalence Rates for Included Morbidity and
Mortality Endpoints
Rates
Endpoint
Parameter
Mortality
Daily or annual
mortality rate
Hospitalizations
Daily hospitalization
rate
Asthma ER
Visits
Daily asthma ER visit
rate
School Loss
Days
Rate per person per
year, assuming 180
school days per year
Minor
RestrictedActivity Days
Daily MRAD incidence
rate per person
a
b
c
d
Value
Sourcea
Age-, cause-, and countyspecific rate
Centers for Disease
Control (2008)
(rates for 2004–2006)
Age-, region-, and causespecific rate
Agency for Healthcare
Research and Quality
(2007)
Age- and region- specific
visit rate
Agency for Healthcare
Research and Quality
(2007)
9.9
0.02137
NCHS (1996)
Adams et al. (1999)
Table 41
Ostro and Rothschild
(1989)
Healthcare Cost and Utilization Program (HCUP) database contains individual level, state and
regional-level hospital and emergency department discharges for a variety of ICD codes.
See ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Datasets/NHDS/.
See ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Datasets/NHAMCS/.
Lower respiratory symptoms are defined as two or more of the following: cough, chest pain,
phlegm, and wheeze.
Supplemental Material, Table 3. Economic unit values
Supplemental Figure 1. Additional Ozone-Related Deaths in GISS/RCP 6.0 by Projected Population
Page 3 of 6
Central Estimate of
Value Per Statistical
Incidence for 2024A
ICLUS B2 2050 ICLUS A1 2050
Woods & Poole
ICLUS B2 2030 ICLUS A1 2030
2030
Least, Moderately and Most Conducive Years
Forming Ozone
Health Endpoint
Derivation offor
Distributions
of Estimates
NCA
Average of
Least
Moderately
Most
Premature death
Region
Three Years The EPA currently
(2035) recommends
(2027)
(2025)
a central VSL of $4.8
million (1990$,
Northwest
-22
-21 1990 income) based
-17 on a Weibull -26
distribution fitted to 26 published VSL estimates (5
Great Plains
21
-26
-44
132
Value of a
contingent valuation and 21 labor market studies). The
$9,900,000
35
63 parameters, and other
95
StatisticalSouthwest
Life
underlying -53
studies, the distribution
useful
information
are
available
in
Appendix
B
of
the
EPA’s
Midwest
41
11
-21
134
Guidelines
for
Preparing
Economic
Analyses
(U.S.
EPA,
Southeast
-23
-97
7
21
2010).
Northeast
-16
-39
7
-15
Hospital visits
Northwest
-19
-19 information available.
-16
-23
No distributional
The COI estimates
(lost
earnings
plus
direct
medical
costs)
are
based
on
ICD-9
Great Plains
18
-19
-37
109
Chronic Lung
code-level
information
(e.g.,
average
hospital
care
costs,
Southwest
-49
60
83
$22,000 31
Disease (18–64)
average length of hospital stay, and weighted share of total
Midwest
43
140
chronic lung11illnesses) reported-21
in Agency for Healthcare
Southeast
-20
-86Quality (2007) (www.ahrq.gov).
2
23
Research and
No
distributions
available.
The
COI
point
estimates
(lost
Northeast
-14
-35
4
-10
earnings plus direct medical costs) are based on ICD-9
Northwest
-18
-18
-16
-21
All respiratory
code level information (e.g., average hospital care costs,
$36,000 13
-17 of hospital stay, and
-33 weighted share of90
(ages 65+)Great Plains
average length
total
Southwest
28
55
respiratory-49
category illnesses) reported
in Agency for79
Healthcare Research
and Quality,
2007 (www.ahrq.gov).
Midwest
37
9
-20
122
No distributional information available. Simple average of
Southeast
Emergency
-21
-82
0
17
two unit COI values (2000$):
Department
Visits
$430
Northeast
-10
-28 Smith et al. (1997)3 and
-5
(1) $310, from
for Asthma
(2) $260, from
Northwest
-25
-24 Stanford et al. (1999).
-20
-32
Respiratory Great
Ailments
Not Requiring Hospitalization
Plains
27
-38
-60
178
No distribution
on (1) the probability
that,
Southwest
51
-69 available. Based 87
135
if a school child stays home from school, a parent will have
School Loss
Days
$98 46
Midwest
12from work to care -25
to stay home
for the child, and (2)151
the
Southeast
-27
-120
14
26
value of the
parent’s lost productivity.
Median
WTP
estimate
to
avoid
one
MRAD
from
Tolley
et al.
Northeast
-19
-47
10
-20
(1986).
Distribution
is
assumed
to
be
triangular
with
a
Northwest
-23
-22
-19
-28
minimum of $22 and a maximum of $83, with a most likely
Great Plains
23
-47 on assumption 142
value of $52-27
(2000$). Range is based
that
Southwest
44
-64
82 mild symptom 114
Minor Restricted
value should
exceed WTP for a single
(the
Activity Days
$69 50
highest estimate
for
a
single
symptom—for
eye
irritation—
Midwest
13
-26
162
(MRADs)
is $16) and be less than that for a Work Loss Day. The
Southeast
-23
-100
5
26
triangular distribution acknowledges that the actual value
Northeast
-17
-42closer to the point estimate
5
is likely to be
than either-14
extreme.
A
We are unable to project changes in income beyond the year 2024 and so this year is a surrogate for 2030.
Page 4 of 6
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