Climate Change and Children's Health and Well-Being in the United States
Appendix D: Supplemental Information for
Analyses in the Changing Seasons Chapter
This appendix describes methods, data sources, and assumptions for the changing seasons analyses
presented in Chapter 5 of the main report. First is the information for the detailed analysis of pollen
exposure and children's health. Second is information required for the discussion of emerging
literature related to the impacts of changing seasonality on several forms of outdoor recreation.
Detailed Analysis of Pollen and Children's
Health
This section includes analytic details of the pollen and children's health analysis: a
summary of studies used in the analysis, analysis steps, detailed results, and limitations of the
approach.
SUMMARY OF STUDIES USED IN THIS ANALYSIS
NEUMANN ETAL. (2019)1
Neumann et al. studied the association between emergency department (ED) visits associated with
asthma, pollen exposure, and climate change in the United States (U.S.). The authors examined
season-length pollen counts from 1994 to 2010, and then forecasted changes in pollen season length
using established relationships between temperature, precipitation, growing degree days, and pollen
for several sources from Zhang et al.2, including oak, birch, and grass. Using the change in pollen
season length and epidemiological functions from Iko et al.3, the authors project future ED visits from
asthma that are attributable to increased pollen exposure.
Under a high emissions scenario (RCP8.5) and across all three pollen types, changes in pollen season
duration associated with climate change result in an additional 3,700 ED visits peryear in 2030 (6%
increase, 95% CI 1,200 to 6,800) to over 10,000 additional ED visits per year in 2090 (95% CI 4,000 to
20,000). Under a lower emission scenario (RCP4.5), the case numbers are roughly comparable in
2030, but approach only 6,100 ED visits per year by 2090 (95% CI 2,200 to 11,000). Children make up
a majority of the cases, both now and in the future, for oak and birch pollen exposure specifically.
SAHA ETAL. (2021)4
Saha et al. investigated less severe and more commonly occurring outcomes associated with a
broader set of pollen exposure sources; specifically, physician visits and prescriptions filled to treat
allergy symptoms. Using a daily pollen data from 28 metropolitan statistical areas (MSAs) in the
United States (U.S.) and health insurance claims data covering approximately 40 million Americans,
the authors calculated location-specific relative risk (RR) between three pollen concentrations (tree,
grass, and weeds) from within a given day, and two allergy outcomes (allergic rhinitis physician visits
and prescriptions filled for allergies). The authors found varied relationships across MSAs. Overall,
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Climate Change and Children's Health and Well-Being in the United States
the RR of allergic rhinitis visits increased as concentrations increased for all pollen types, while the RR
of prescriptions filled for allergies increased for tree and weed pollen only. The authors of Saha et al.
do not report results specifically for children but include children in their overall assessment.
ANALYSIS STEPS
Chapter 5 of this report examines the effects of pollen exposures linked to climate change on
children's health. It relies on estimates of ED visits related to asthma from Neumann et al. specific to
children and presents the results in an impacts-by-degree format. Then, given findings from Saha et
al., projections are provided for how increases in pollen season length may affect asthma-related
physicians visits and prescriptions filled for allergies for children.
While this analysis does not forecast changes in the number of days at each level of pollen
concentration—the environmental variable used in Saha et al.—it is assumed that pollen season
length and pollen concentrations are well-correlated, as suggested by Zhang and Steiner.5 More
importantly, this analysis assumes that less severe physician visits and prescriptions filled for allergies
are well-correlated with more severe health outcomes, as reflected by the ED visits for asthma.
Relating the findings from Saha et al. and Neumann et al. also assumes that the pollen types explored
in each analysis are relatively comparable. Table 1 details the analytic steps, data sources, and
assumptions used to project these health effects on children resulting from increasing pollen
exposure due to climate change.
This analysis considers all of the contiguous U.S. and is performed at the county level, but results are
also interpreted at the census tract level (with identical incidence rates for all tracts within a county)
for the social vulnerability analysis.
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Climate Change and Children's Health and Well-Being in the United States
Table 1: Analytic Steps in Climate Change Impacts on Pollen Exposure and Children's Health Analysis
Step
Data
Methods, Assumptions, and Notes
Baseline Risks
1. Identify baseline
incidence of health and
well-being impacts
under baseline pollen
exposure and
population
Asthma-related ED visits: Countv-level
incidence obtained from BenMAP and
derived from the Health Care Utilization
Project's (HCUP) Nationwide Emergency
Department Sample Database and State
Emergency Department Database
Phvsicians visits and prescriptions filled:
based on information presented in Saha et
al.
Asthma-related ED visits: As described in Neumann et al. Table S-4,
the baseline annual number of ED visits is 34,110 across CONUS.
Phvsicians visits and prescriptions filled: Because Saha et al. does
not provide a baseline estimate for all children in CONUS, the
analysis estimates this number using the following method:
1. Calculate the total annual prescription fills and first- time
physician visits due to allergic rhinitis incidence among
children across the 28 MSAs in Table ST3 of Saha et al.
2. The MarketScan data used in the study covers 40 million
Americans of all ages, which is about 13.1% of the total
population of the contiguous U.S. in 2010. The totals from
Step 1 are divided by 13.1% to "inflate" to CONUS
numbers.
Table 2 presents the process and findings.
Future Climate
Stressor
2. Calculate future
season length by pollen
source (oak, birch,
grass) as a function of
temperature,
precipitation, and
growing degree days
Future climate: LOCA future climate data at
the census tract-level
Environmental function: Neumann et al.
(2019) use the relationships between climate
variables and pollen season lengths from
Zhang et al. (2015)
This analysis relies on the analysis completed in Neumann et al.
Changes in pollen season length are adjusted for future climate
using reduced form relationships found in Zhang et al. (2015). See
both papers for details.
Future Effects on
Children
3. Estimate the
incidence of health
impacts among children
associated with each
degree-C increase in
global mean
temperatures
Health impact functions are derived from
Neumann et al. (2019), who use multiple
pollen-specific model relationships between
asthma ED visits and pollen exposure. See
paper for details.
See Chapter 2 of the main report and
Appendix A for details on population
methods and data sources used throughout
the analysis.
Asthma-related ED visits: This assessment relies on the analysis
completed in Neumann et al. (2019). See that paper for details.
Phvsicians visits and prescriptions filled: Using findings related to
ED visits from, the analysis estimates the percent increases
between each degree of global warming and baseline. Then, those
percent increases are applied to the baseline number of
prescriptions filled and physician's visits estimated in Step 1 above
to calculate the future effects on children.
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Climate Change and Children's Health and Well-Being in the United States
BASELINE HEALTH EFFECTS
Table 2 below provides details on the implementation of Step 1 in our analytic steps described in
Table 1. Specifically, it demonstrates how the baseline annual number of prescriptions filled for
allergies and allergic-rhinitis first doctor visits were calculated using information from Saha et al. and
other data sources.
Table 2: Construction of Baseline Health Impacts for Children (Aged 0-17) in the Contiguous U.S.
Location (MSA)
Prescriptions Filled
for Allergies1
Allergic Rhinitis -
First Doctor Visit1
2010 Population2
Atlanta, GA
136,002
38,607
1,393,056
Austin, TX
48,698
14,621
440,327
Baltimore, MD
25,008
12,415
624,701
Chicago, IL
105,013
31,977
2,365,597
College Station, TX
5,952
1,432
56,017
Colorado Springs, CO
4,392
2,646
167,915
Dayton, OH
8,222
5,381
185,051
Erie, PA
3,167
1,634
65,219
Eugene, OR
1,476
656
72,608
Houston, TX
79,114
23,353
1,646,476
Kansas City, MO
29,828
5,014
509,943
Louisville, KY
25,822
12,541
293,076
Madison, Wl
2,059
301
136,316
Minneapolis, MN
14,532
2,682
831,800
Oklahoma City, OK
29,150
10,834
194,128
Omaha, NE
7,288
1,691
315,893
Rochester, NY
4,564
1,384
226,647
Saint Louis, MO
51,267
16,404
247,418
Salt Lake City, UT
4,381
2,825
662,309
San Antonio, TX
30,504
12,821
319,968
San Jose, CA
21,145
5,494
27,479
Seattle, WA 23,706 5,008 444,536
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Climate Change and Children's Health and Well-Being in the United States
Location (MSA)
Prescriptions Filled
for Allergies1
Allergic Rhinitis -
First Doctor Visit1
2010 Population2
Springfield, MO
2,502
494
785,623
Tulsa, OK
18,572
7,384
103,282
Waco, TX
8,306
6,471
238,805
Washington, DC
45,451
25,122
65,637
Waterbury, CT
7,250
3,525
1,340,278
York, PA
4,037
3,488
101,385
Total in sample (2008-2015)
747,408
256,205
13,861,491
Annual in sample3
93,426
32,026
Annual CONUS4
714,709
244,996
Sources and notes:
1. From Table ST3 ofSaha et al. supplemental materials.
2. 2010 U.S. Census data.
3. Saha et al. MarketScan data covers 8 years (2008-2015).
4. Saha et al. MarketScan data covers 40 million individuals of all ages per year, which is 13.1% of
individuals in the contiguous U.S. based on 2010 population. In the analysis, the sample is scaled to a
CONUS number using this percentage. Saha et al. does not document the portion of individuals in their
dataset that are children, so the analysis inflates based on a multiplier that considers all ages.
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Climate Change arid Children's Health and Well-Being in the United States
FUTURE LENGTH OF POLLEN SEASON
Figure 1 presents how birch and grass pollen season lengths are expected to increase throughout the 21st century. As shown,, the pollen
season length scalar, indexed to baseline season length, increases between 2030 and 2090 (see color legend) at all included pollen monitor
sites across a broad range of latitudes (with higher, more northern latitudes to the left). Similarly, the lengths are greater under a higher
emission scenario (RCP8.5, filled boxes) than the lower emission scenario (RCP4.5, open circles).
Figure i: Estimates of Change in Pollen Season Length by Monitor Location for Birch (Left) and Grass (Right)
Year 1-7 B Year
¦ 2030 ¦ ¦ ¦ ¦ 2030
¦ 2050 " ¦ 2050
¦ 2070 1 6 " ¦ ¦ 2070
¦ 2090 ... . ¦ 2090
¦ ¦ ¦ ¦
RCP a ¦ ¦ " ¦ a ' RCP
OAS * ¦ ¦¦ " O 4.5
¦ 8.5 £ 1 5 . ¦ . ¦ ¦ " . ¦ ¦ ¦ 8.S
£ ¦ " * ¦
-¦ "
0 ¦ ¦¦ J*m " I -2 14 ¦ n" ¦¦ "°
fl ¦ ¦ — ¦ ¦ c O . o" mrp . m
¦ „cf ¦•«¦¦¦ ¦ ¦ ¦ H 8 Oq _ o ¦ 2. ° "
_ ^ o 08 so . ¦ 8* . __ " I ¦ S 8° o" o «
"¦2 8_8® 88arpo s " ¦ ¦ m ¦¦ ¦¦ « sj ®o °° «° ° ° "
sfer:"• «•%l.: „v~;
. V$B "
¦o- ^ S.e
¦ ooo ooa% 0®
% . ^8. ifl -¦*\ . <,«¦* sf'.WvXfk
. 90 o ° g
o •
°'o-
o o
O o \
1.0 •
Decreasing Latitude -> Decreasing Latitude -->
Source: Neumann et al. (2019), reprinted with permission of the author. Notes: Pollen monitors along x-axis are arranged by decreasing latitude, indicating that
effects on season length are more pronounced in the north (left side of graphic). Estimates are averaged across five climate models, for each era and RCP
assessed. The y-axis represents pollen season length scalar, with baseline (current climate) season length equal to 1.
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Climate Change and Children's Health and Well-Being in the United States
EFFECTS ON CHILDREN RESULTS
Table 3 describes the results of the analyses assuming population growth (see Chapter 2 and
Appendix A). The analysis estimates additional health impacts attributable to climate change relative
to the baseline period and sums the impacts across the three pollen sources (oak, birch, grass). Table
4 provides the same estimates but assumes population remains constant at 2010 levels, isolating the
influence of climate change specifically. With population growth (Table 3), the increase in annual ED
visits relative to baseline levels applied to the other two health impacts were 7%, 17%, 24%, and 30%
at 1°C, 2°C, 3°C, and 4°C of global warming, respectively. For the analysis that holds population
constant at 2010 levels (Table 4), the analogous increases were 6%, 14%, 19%, and 23% at 1°C, 2°C,
3°C, and 4°C of global warming, respectively.
Table 3: Projected Annual Risks to Children's Health Associated with Future Exposure to Oak,
Birch, and Grass Pollens (with Population Growth)
Degree of Global
Warming (°C)
(1)
ED Visits for Asthma
(2)
Allergic Rhinitis First
(3)
Prescriptions Filled for
Doctor Visit
Allergies
rc
2,380
17,100
49,800
(1,920 to 2,730)
(13,800 to 19,600)
(40,200 to 57,200)
2°C
5,760
41,400
121,000
(4,800 to 7,990)
(34,500 to 57,400)
(101,000 to 167,000)
3°C
8,130
58,400
170,000
(6,950 to 10,600)
(49,900 to 76,100)
(146,000 to 222,000)
4°C
10,100
72,300
211,000
(9,460 to 10,700)
(68,000 to 76,700)
(198,000 to 224,000)
Notes: All estimates presented in the table are incremental relative to baseline risk: (1) 34,100 ED visits,
(2) 256,000 physicians visits, and (3) 747,000 prescriptions filled for allergies. Tables 1 and 2 of this
appendix provide further details on baseline calculations. Data from Neumann et al. do not support
extrapolation to 5°C. The table displays the average and range across climate models.
Table 4: Projected Annual Risks to Children's Health Associated with Future Exposure to Oak,
Birch, and Grass Pollens (2010 Population)
Degree of Global
Warming (°C)
(1)
ED Visits for Asthma
(2)
Allergic Rhinitis First
(3)
Prescriptions Filled for
Doctor Visit
Allergies
rc
2,170
15,600
45,500
(1,750 to 2,490)
(12,600 to 17,900)
(36,600 to 52,200)
2°C
4,830
34,700
101,000
(4,160 to 6,600)
(29,900 to 47,400)
(87,200 to 138,000)
3°C
6,540
47,000
137,000
(5,520 to 8,390)
(39,700 to 60,300)
(116,000 to 176,000)
4°C
7,900
56,800
166,000
(7,430 to 8,380)
(53,300 to 60,200)
(156,000 to 176,000)
Notes: See Table 3.
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Climate Change and Children's Health and Well-Being in the United States
Figures 2 and 3 shows the change in ED visits for asthma per 100,000 children aged 0-17 at 2°C and
4°C of global warming at the county level. For each figure, one panel shows the combined impacts
across pollen sources, which are subsequently split out by source. The five states with largest
impacts per 100,000 children are outlined in black for each pollen source and listed below each map.
Table s5 and 6 then follow with the average number of ED visits for asthma per 100,000 children for
each state at 2°C and 4°C of global warming specifically to provide perspective on the range of
impacts across states, although there can be considerable heterogeneity within states (see Figure 2
and Figure 3).
Figure 4 shows the change in total ED visits for asthma among children aged 0-17 at 2°C and 4°C of
global warming at the county level. Impacts are generally highest in areas with large children's
populations. The five states with largest total impacts are outlined in black and listed below each
map. The relevant quantities or rates presented in each figure are provided in parentheses after the
state name in the lists of top 5 states.
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Climate Change arid Children's Health and Well-Being in the United States
Figure 2: Estimated Changes in Annual ED Visits for Asthma Per 100,000 Children {Aged 0-17) at
2°C Global Warming (with Population Growth)
ir
Combined Pollen Sources
tv lmt\
Oak Pollen
if
m
~
s ?A
o i_Lj
Top five states: WV (20.4), OH (19.8), KY (14.1), IN (14.1), VT Top five states: VT (5.0), NH(4.9), ME (4.8), Rl (4.8), MA (4.7)
(11.3)
Birch Pollen
Grass Pollen
rf
£
) i
V V
m
r
Top five states: WV (15.2), OH (14.7), IN (10.7), KY (10.6), Ml Top five states: OR (3.6), OH (3.5), KS (3.5), MT (2.9), OK (2.9)
(6.9)
1 - 5
6-9
10 - 15
16-25 26 - 51
Note: These maps describe the projected change in new ED visits for asthma linked with climate-induced pollen
exposure per 100,000 children at 2°C of global warming relative to the baseline (1986-2005). Darker shading conveys
larger increases while lighter shading conveys small increases. The five states with the largest increases on average
are outlined in black. The map at the top left provides impacts across all three included pollen sources; subsequent
maps show the contributions of individual pollen sources.
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Climate Change and Children's Health and Well-Being in the United States
Table 5: Estimated Annual ED Visits for Asthma Per 100,000 Children by State with 2°C Global
Warming (with Population Growth)
State
Incidence Per 100,000
Children
State
Incidence Per 100,000
Children
West Virginia
20.4
North Dakota
6.1
Ohio
19.8
Washington, DC
6.0
Kentucky
14.1
Utah
5.9
Indiana
14.1
Montana
5.9
Vermont
11.3
Wyoming
5.6
New Hampshire
11.0
Illinois
5.5
Maine
11.0
Wisconsin
5.4
Rhode Island
10.9
Tennessee
5.3
Connecticut
10.7
Idaho
5.3
Massachusetts
10.6
North Carolina
5.1
New York
10.0
Oregon
4.2
Pennsylvania
9.9
Arkansas
4.1
Michigan
9.8
Colorado
3.8
New Jersey
9.2
South Carolina
3.6
Delaware
8.8
Florida
3.4
Oklahoma
8.1
Louisiana
3.3
Kansas
7.9
New Mexico
3.3
Iowa
7.4
Washington
3.1
Maryland
7.2
Georgia
2.9
Texas
7.2
Mississippi
2.8
Virginia
6.8
Alabama
2.6
Missouri
6.7
Arizona
2.2
Minnesota
6.6
Nevada
1.7
South Dakota
6.3
California
0.9
Nebraska
6.2
Notes: This table describes the projected new ED visits for asthma linked with climate-induced pollen
exposure per 100,000 children at 2°C of global warming using the methods described in Table 1
averaged to the state level. States are listed from largest to smallest impacts.
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Climate Change arid Children's Health and Well-Being in the United States
Figure 3: Estimated Changes in Annual ED Visits for Asthma Per 100,000 Children (Aged 0-17) at
4°C Global Warming (with Population Growth)
Combined Pollen Sources
Oak Pollen
Top five states: WV (25.4), OH (23.7), CT (18.3), Rl (18.2), VT Top five states: CT (8.2), Rl (8.0), NY (7.9), VT (7.6), NH (7.5)
(18.1)
Grass Pollen
W \)
Top five states: OR (8.7), MT (5.7), ID (5.6), UT (5.3), KS (5.2)
Birch Pollen
Top five states: WV (17.2), OH (16.4), IN (12.2), KY (11.
(8.8)
8), CT
1-5 6-9 10-15 16-25 M26-51
Note: These maps describe the projected change in new ED visits for asthma linked with climate-induced pollen
exposure per 100,000 children at 4°C of global warming relative to the baseline (1986-2005). Darker shading conveys
larger increases while lighter shading conveys small increases. The five states with the largest increases on average
are outlined in black. The map at the top left provides impacts across all three included pollen sources; subsequent
maps show the contributions of individual pollen sources.
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Climate Change and Children's Health and Well-Being in the United States
Table 6: Estimated Annual ED Visits for Asthma Per 100,000 Children by State with 40C Global
Warming (with Population Growth)
State
Incidence Per 100,000
Children
State
Incidence Per 100,000
Children
West Virginia
25.4
Minnesota
10.3
Ohio
23.7
North Dakota
10.3
Connecticut
18.3
South Dakota
10.3
Rhode Island
18.2
Wyoming
9.9
Vermont
18.1
Utah
9.8
New York
17.8
Idaho
9.7
Maine
17.6
Nebraska
9.4
New Hampshire
17.6
North Carolina
9.3
Indiana
17.4
Tennessee
9.1
Kentucky
17.3
Illinois
8.9
Massachusetts
17.2
Wisconsin
8.5
New Jersey
16.9
South Carolina
8.3
Pennsylvania
16.0
Florida
7.7
Delaware
15.6
Washington
7.7
Michigan
13.1
Georgia
7.6
Oklahoma
12.4
Arkansas
7.0
Maryland
12.2
Colorado
7.0
Kansas
11.9
Louisiana
6.7
Texas
11.9
Alabama
6.5
Iowa
11.2
Mississippi
6.4
Oregon
11.0
New Mexico
5.7
Montana
10.9
Arizona
3.6
Virginia
10.9
Nevada
3.1
Missouri
10.4
California
2.1
Washington, DC
10.3
Notes: This table describes the projected new ED visits for asthma linked with climate-induced pollen
exposure per 100,000 children at 4°C of global warming using the methods described in Table 1
averaged to the state level. States are listed from largest to smallest impacts.
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Climate Change arid Children's Health and Well-Being in the United States
Figure 4: Estimated Changes in Total Annual ED Visits for Asthma Among Children (Aged 0-17)
(with Population Growth)
2°C of Global Warming
Top five states: TX (694), NY (578), OH (535), PA (286), IN (278)
40C of Global Warming
Top five states: TX (1,270), NY (1,110), OH (631), NJ (550), FL (477)
0-2 3- 5 6- 10 ¦111-50 HI 51 - 155
Note: These maps describe projected total change in ED visits for asthma linked with climate-induced pollen
exposure at 2°C and 4°C of global warming relative to baseline (1986-2005). The five states with the highest
impacts are outlined in black. See Table 1 for analytic details.
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Climate Change and Children's Health and Well-Being in the United States
Figures 5 and 6 describe the results of the social vulnerability analysis at 2°C and 4°C of global
warming, respectively (see Chapter 2 and Appendix A for methods, data sources, and assumptions).
Within each figure, the results are presented separately for each pollen source and then combined.
Figure 7 includes results by racial and ethnic group for oak pollen and combined pollen specifically.
The estimated risks for each socially vulnerable group are presented relative to each group's
reference population, defined as all individuals other than those in the group analyzed. Positive
numbers indicate the group is disproportionately affected by the referenced impact. Negative
numbers indicate the group is less likely to live in the areas with the highest projected impacts.
Figure 5: Social Vulnerability Analysis Results for Pollen and ED Visits for Asthma Among
Children at 2°C Global Warming
Birch
Oak
Limited English Speaking
No Health Insurance
Low Income
BIPOC
28%
Grass
Combined
Limited English Speaking
No Health Insurance
Low Income
BIPOC
-27%
-11%
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Climate Change arid Children's Health and Well-Being in the United States
Figure 6: Social Vulnerability Analysis Results for Pollen and ED Visits for Asthma Among
Children at 4°C Global Warming
Limited English Speaking
Low Income
BIPOC
No Health Insurance
Birch
-17%
-10%
-39%
-31%
Oak
46%
Grass
Combined
Limited English Speaking
-33%
-6%
Low Income
-6%
-6%
BIPOC
-33%
-27%
No Health Insurance
1 8%
-10%
Figure 7: Social Vulnerability Analysis Results by Racial and Ethnic Minority Group Results for
Pollen and ED Visits for Asthma Among Children
American Indian or Alaska Native
Asian
Black or African American
Pacific Islander
Hispanic or Latino
White, non-Hispanic
American Indian or Alaska Native
Asian
Black or African American
Pacific Islander
Hispanic or Latino
White, non-Hispanic
Oak
-19%
I 6%
-2%
-52%
-8%
17%
-52%
E5%
5%
-63%
-18%
2°C
4°C
33%
Combined
-60%
-5%
-3%
-63%
-31%
38%
-60%
-6%
-3%
-62%
-30%
37%
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Climate Change and Children's Health and Well-Being in the United States
LIMITATIONS
Below are some of the limitations of this analysis:
1. Using the Neumann eta/. ED visit projections as a basis for predicting the number of future
doctor visits for allergic rhinitis and prescriptions filled for allergies. This analysis describes
several major assumptions in the "Analysis Steps" section of this appendix that are made in
order to apply the results of the Saha et al. paper results. Ragweed exposure is considered
within the scope of the Saha et al. paper, along with tree and grass pollen more broadly, but
is excluded from the scope of the Neumann et al. paper. The functions for change in season
length associated with climate factors in Zhang et al. for ragweed appear similar in structure
to those estimated for birch, which provides some support for the scaling approach used in
this analysis (i.e., applying the Neumann et al. ED-visit metric to the Saha et al. physician visit
and prescriptions filled metrics). The Zhang et al. functions show greater sensitivity to
temperature, suggesting that the impacts of climate change on ragweed season length and
pollen concentration might be more extreme for ragweed-driven health impacts than
estimated for trees and grasses. Therefore, the impact of ragweed pollen changes on the
Saha et al. health outcome metrics could grow faster than is estimated by the approach used
in this analysis.
2. Limited health effect scope. Inclusion of the results of the Saha et al. paper, while limited by
available data, is responsive to the limitation noted in Neumann et al. that the focus on
asthma-related ED visits as the sole measure of health endpoints in that study. Existing
epidemiologic literature in Canada, the Netherlands, and elsewhere suggests that
aeroallergen exposure may also be linked to cardiovascular disease, allergen sensitization,
and allergic rhinitis6,7,8 as well as lost school or workdays and lower overall productivity.
Therefore, this report likely underestimates the full impact of climate change on pollen and
on increased exposure to aeroallergens on human health.
3. Estimation of baseline number of future doctor visits allergic rhinitis and prescriptions filled
for allergies. This analysis starts with a sample of future doctor visits for allergic rhinitis and
prescriptions filled for allergies presented in a table in Saha et al. then applies multipliers to
estimate potential baseline numbers. The approach assumes doctor visits and prescriptions
filled in the non-represented MSAs occur at the same rate as represented MSAs. It is
unknown how this assumption affects the analysis.
4. Results of this analysis are available at the county level as the finest spatial scale. The
BenMAP analysis was run using county-level baseline incidence and population data, which
limits the geographic level to which health impacts associated with pollutant changes can be
specified. Therefore, results may underrepresent the spatial precision of the 36-km grid air
quality surfaces.
5. This analysis does not capture fine-scale health effects ofpopuI a tions tha t may beat grea ter
risk of exposure or disproportionate impacts, including racial and ethnic minorities, low
income individuals, the unhoused, and children with other types of comorbidities. This analysis
estimates health effects at the county-level using 50-km square pollen concentrations and
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Climate Change and Children's Health and Well-Being in the United States
may not capture localized health effects experienced by fenceline and near-road children,
who are likely disproportionately vulnerable.
6. Reliance on pollen season length as metric for aeroallergen exposure is a limitation of the
underlying study. A key assumption in Neumann et al. is the reliance on pollen season length
as the best metric of the effect of climate change on pollen exposure. Implicitly, there is an
assumption that the average daily pollen concentration remains the same, which is
reasonable based on current information. Nonetheless, further research is needed to better
understand the effect of climate change on the full temporal distribution of daily pollen
concentrations during the lengthened season.
7. The underlying study does not consider the extent to which pollen-producing species will
respond to global warming. Another important assumption in Neumann etal. is that the
future season-length models assume that in each location the set of species that contributed
to the baseline pollen data are going to be the same in the future. At the time that study was
published, tree and grass species prevalence modeling was not available, and would have to
be coupled with species-specific pollen production data as well. There is some evidence that
climate change could alterthe geographic range of tree species in the future,9,10,11 and Zhang
and Steiner also consider effects on pollen emissions rates. The extent to which this factor
affects the results presented here is currently unknown, but the Zhang and Steiner results
suggest this report may underestimate the full effect of climate change on pollen season
exposure.
DATA SOURCES
Table 7: Summary of Data Sources Used in the Pollen and Children's Health Analysis
Data Type
Description
Data Documentation and Availability
Baseline
health impact
incidence
rates
Analysis followed methods described
in Neumann et al. Asthma-related
emergency department morbidity
incidence rates were obtained from
BenMAP-CE and the Health Care
Utilization Project's (HCUP)
Nationwide Emergency Department
Sample Database and State
Emergency Department Database.
Neumann, J.E., Anenberg, S.C., Weinberger, K.R.,
Amend, M., Gulati, S., Crimmins, A., Roman, H.,
Fann, N. and Kinney, P.L, 2019. Estimates of
present and future asthma emergency department
visits associated with exposure to oak, birch, and
grass pollen in the United States. GeoHealth, 3(1),
pp.11-27.
• U.S. EPA. (2018). Environmental Benefits
Mapping and Analysis Program:
Community Edition (BenMAP-CE) User
Manual and Appendices. Washington, DC.
Accessible at:
httos://www.eDa.gov/benmaD.
• HCUP data are available at: https://hcup-
us.ahra.eov/nedsoverview.iso
MarketScan data used in Saha et al.
covers 8 years (2008-2015) and 40
million individuals of all ages per year,
which is 13.1% of individuals in the
contiguous U.S. based on 2010
Saha, S., Vaidyanathan, A., Lo, F., Brown, C. and
Hess, J.J., 2021. Short term physician visits and
medication prescriptions for allergic disease
associated with seasonal tree, grass, and weed
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Climate Change and Children's Health and Well-Being in the United States
Data Type
Description
Data Documentation and Availability
population. We scale the sample to a
CONUS number using this percentage.
Saha et al. does not document the
portion of individuals in their dataset
that are children, so the analysis
inflates based on a multiplier that
considers all ages.
pollen exposure across the United States.
Environmental Health, 20(1), pp. 1-12.
• MarketScan data available at:
https://www.ibm.com/watson-
health/merative-divestiture
Pollen counts
modeling
National Allergy Bureau (NAB) data
were used via aggregated average
pollen counts and season lengths for
birch, oak, and grass pollen
NAB daily pollen data are available at:
https://p0llen.aaaai.0rg/#/
Modeling
lengths of
pollen season
Based on Zhang et al.
Zhang, Y., Bielory, L, Mi, Z., Cai, T., Robock, A., and
Georgopoulos, P. 2015. Allergenic pollen season
variations in the past two decades under changing
climate in the United States. Global Change
Biology, 21,1581-1589.
Future
climate
modeling
See Appendix A for data sources
Future
population
growth for
children
See Appendix A for data sources
Demographics
for social
vulnerability
analysis
See Appendix A for data sources
Outdoor Recreation
Chapter 5 highlights various studies that forecast how changing seasonality will
impact the number of outdoor recreation trips. The summary considers impacts
across all outdoor recreation types observed in the American Time Use Survey, as well as
winter recreation, freshwater fishing, and recreation activities at reservoirs. The chapter summarizes
the main findings from the underlying studies, which forecast trips across people of all ages, then
cites other data sources that provide perspective on the portion of total trips that may include
children. No new analysis is included in the chapter.
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Climate Change and Children's Health and Well-Being in the United States
References
1 Neumann, J.E., Anenberg, S.C., Weinberger, K.R., Amend, M., Gulati, S., Crimmins, A., Roman, H., Fann, N. and
Kinney, P.L., 2019. Estimates of present and future asthma emergency department visits associated with
exposure to oak, birch, and grass pollen in the United States. GeoHealth, 3(1), pp. 11-27.
2 Zhang, Y., Bielory, L, Mi, Z., Cai, T., Robock, A. and Georgopoulos, P., 2015. Allergenic pollen season variations in
the past two decades under changing climate in the United States. Global Change Biology, 21(4), pp.1581-1589.
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2015. The associations between daily spring pollen counts, over-the-counter allergy medication sales, and
asthma syndrome emergency department visits in New York City, 2002-2012. Environmental Health, 14(1), pp.l-
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prescriptions for allergic disease associated with seasonal tree, grass, and weed pollen exposure across the
United States. Environmental Health, 20(1), pp.1-12.
5 Zhang, Y. and Steiner, A.L, 2022. Projected climate-driven changes in pollen emission season length and
magnitude over the continental United States. Nature Communications, 13(1), pp.1-10.
6 Brunekreef, B., Hoek, G., Fischer, P. and Spieksma, F.T.M., 2000. Relation between airborne pollen concentrations
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8 Weichenthal, S., Lavigne, E., Villeneuve, P.J. and Reeves, F., 2016. Airborne pollen concentrations and emergency
room visits for myocardial infarction: a multicity case-crossover study in Ontario, Canada. American Journal of
Epidemiology, 183(7), pp.613-621.
9 Varaldo, L, Davide, D., Guerrina, M., Minuto, L, Conti, F., Bartolucci, F. and Gabriele, C., 2011. Can Species
Distributions Models Help to Design Conservation Strategies for Narrow-Ranged Species under Climate Change?
A Case Study from Santolina Genus. Proceedings 2021, 68.
10 Tang, G., Beckage, B. and Smith, B., 2012. The potential transient dynamics of forests in New England under
historical and projected future climate change. Climatic Change, 114(2), pp.357-377.
11 Woodall, C.W., Oswalt, C.M., Westfall, J.A., Perry, C.H., Nelson, M.D. and Finley, A.O., 2009. An indicator of tree
migration in forests of the eastern United States. Forest Ecology and Management, 257(5), pp.1434-1444.
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