Document ID: EPA-HQ-OAR-2002-0030-0196
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2005-04-05T04:00Z

APPENDIX
B
Figures
B.
1
through
B.
8
are
graphs
from
Johnson
et
al.
(
1996b)
showing
8­
hour
daily
maximum
dose
exposures
for
outdoor
children
under
various
air
quality
scenarios.
Two
graphs
are
provided
for
each
of
four
study
areas
(
Houston,
New
York,
Philadelphia,
and
Washington,
D.
C.).
The
graphs
use
two
indicators
to
characterize
O
3
exposure:

­
Number
of
children
experiencing
8­
hour
daily
maximum
dose
exposures
on
one
or
more
days
under
moderate
exertion
conditions,

­
Number
of
total
occurrences
in
which
a
child
experiences
a
daily
maximum
dose
exposure
under
moderate
exertion
conditions.

Moderate
exertion
conditions
are
defined
as
an
EVR
level
between
13
and
27
l
min­
1
m­
2.

Figure
B.
1
presents
results
for
the
first
indicator
(
number
of
outdoor
children)
based
on
applications
of
pNEM/
O
3
to
Houston.
Nine
distributions
are
plotted
on
the
graph:
one
for
baseline
("
As
Is")
conditions;
two
for
1­
hour,
1­
exceedance
standards
(
1H1EX­
0.12
and
1H1EX­
0.10);
four
for
8­
hour,
1
exceedance
standards
(
8H1EX­
0.10,
8H1EX­
0.09,
8H1EX­
0.08,
8H1EX­
0.07);
and
two
for
8­
hour,
5­
exceedance
standards
(
8H5EX­
0.08,
8H5EX­
0.09).
For
example,
8H5EX­
0.08
indicates
an
8­
hour,
5­
exceedances
standard
with
O
3
concentration
set
at
8
pphm
or
0.08
ppm.

The
ordinate
(
y
coordinate)
of
each
point
on
the
graph
shows
the
number
of
children
with
one
or
more
daily
maximum
dose
exposures
equal
to
or
above
the
O
3
concentration
indicated
by
the
point's
abscissa
(
x
coordinate).
In
Figure
B.
1,
the
"
As
Is"
curve
is
associated
with
the
highest
number
of
children
exposed
when
the
specified
O
3
concentrations
fall
between
0.05
and
0.16
ppm.
The
nine
curves
tend
to
converge
at
lower
and
higher
O
3
concentrations.
In
a
similar
manner,
the
8H1EX­
0.07
standard
is
associated
with
the
lowest
number
of
children
exposed
when
the
specified
O
3
concentration
falls
between
0.03
and
0.08
ppm.

Appendix
E
of
Johnson
et
al.
(
1996b)
provides
similar
graphs
for
two
other
EVR
ranges
of
interest:
16­
30
l
min­
1
m­
2
and

30
l
min­
1
m­
2
for
1­
hour
exposures.