NASA-TM-1OS061
W,
sW
7 X/ - .?'.6--
A
Study
of
Interior
Landscape
Plants
for
Indoor
Air
An
Pollution
Abatement
Interim
Report
J
B. C. Wolverton,
Ph.D.
Principal
Investigator
National
Aeronautics
and
John
C. Stennis
Stennis
Space
Space
Space
Center,
Administration
Center
MS
39529-6000
u%
p.p,.
O
pI
0
(,_
C
D
Willard
L.
Research
Douglas,
Chemist
Ph.D.
,
0
O"
Keith
Bounds,
M.S.
Research
Chemist
Sverdrup
Technology,
Inc.
John
C.
Dt_nnis
Space
Center
Stennis
Space
Center,
MS
39529
0CZ
LL. 0 _LJ
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1989
BACKGROUND:
In the privious
ability
of
report,
a group
of
chemicals
from
indoor
chosen for
this
study
National
Aeronautics
Associated
PLANTS
Landscape
CHOSEN
FOR
Common
Name:
Bamboo
palm
1989, preliminary
common indoor
air
plants
was presented.
was determined
and
Space
by joint
Ivy
Gerbera
daisy
agreement
Administration
Contractors
of America
plants
between the
and
Name:
seifritzii
modestum
Hedera
Gerbera
Dracaena
deremensis
cane
Dracaena
Sansevieria
tongue
mum
Chrysanthemum
lily
Dracaena
PRECEDING
PAGE
BLANK
NOT
FILMED
massanqeana
laurentii
Loa"
"Warneckei"
Ficus
2
marqinata
"Mauna
deremensis
Ficus
Craiq"
morifolium
Spathyphvllum
Warneckei
helix
jamesonii
"J_net
Dracaena
Marginata
Mother-in-Law's
of
(ALCA).
'
cane/Corn
organic
(NASA)
_alaonema
Craig
Peace
group
Chamaedorea
English
Pot
The
remove
Scientific
evergreen
Mass
to
data on the
SCREENING:
Chinese
Janet
dated October
benjamina
The
In
addition
during
to
the
family
this
study.
such
as
the
plant
included
which
some
were
and
and
chemicals
indoor
The
SUMMARY
OF
tests
equipment.
specific
through
were
for
original
"work
serve
as
were
of
benzene,
other
green
are
being
of
plants
group
done
in
comparison
this
between
are
sources
previous
trichloroethylene
chemicals
have
and
shows
performed
equipment
different
tubes.
plants
the
point
the
are
been
some
of
commonly
indi'cated
of
these
the
more
and
found
as
possible
commonly
chemicals
in
in
found.
indoor
air
report.
RESULTS:
report
This
the
the
PREVIOUS
that
and
of
many
and
in
previous
aureus)
the
study
teratogens
described
philodendron
(Philodendron
These
a
used
(Philodendron
represent
these
characteristics
were
The
for
atmospheres,
or
the
they
some
Although
carcinogens
in
been
work.
chosen
formaldehyde.
have
philodentron
elatum).
therefore
previous
plants
(Scindapsus
because
in
others
philodendron
ear
pothos
tests
used
laboratory
The
leaf
elephant
golden
several
several
heart
(ChloroDhvtum
in
current
plants,
include
the
the
domesticum),
of
These
oxycardium),
spider
group
the
using
of
air
preliminary
Sensidyne-Gastec
consists
chemicals
When
results
and
of
a
containing
detector
hand
held
the
screening
air
tubes
pump
chemical
to
sampling
that
are
draw
air
is
drawn
through
the tube,
which
is
a reaction
takes
place
and a color
proportional
to the concentration
sample.
Table
the plants
October,
1988 report.
plants
TESTING
in
gave
a good
the
above
the
15
after
removal
of
the
enough
benzene
part
per
million
of
which
plants
might
or
more
of
chosen
low
commonly
air.
As
for
testing
(GC)
included
air
in the
screening
in
previous
these
method
be
this
maintained
indoor
of all
is
currently
chemical.
in
thah
a
1
As
to
PPM)
is
for
in
a
GC
of
the
method
evaluated
with
all
not
sensitive
a
of
same
and
for
previous
condition
far
chemical
analysis
being
healthy
is
investigate
concentrations,
(TCE)
by
it
Therefore,
began
developed
determined
suited
chemicals,
equipment
been
this
particularly
we
(less
chemical
Although
atmospheres.
lower
has
of
range.
be
report,
Sensidyne-Gastec
method
of
concentrations
(PPM)
the
trichloroethylene
levels
studies
the
concentrations
the
cannot
were
found
the
lower
chemical
Miracle-Grow
one
issuing
and
sensitive
20
of
much
Formaldehyde
All
not
initial
to
chromatographic
plants
the
reported,
levels
shortly
of
completes
previously
indication
removal
the
from
and chemicals
in the
METHODS:
experiments
were
to
This
of chemical
on the ALCA list.
CURRENT
For
1 lists
change occurs
gas
both
sample.
an
ultra
analysis
studies,
using
Stern's
fertilizer.
are
being
performed
using
the
plexiglass
chambers
from
previous
experiments.
underway,
two
volumes
For
chambers
of 0.868 cubic
of
by
containing
Tenax adsorbent
interfaced
past
plants
to
potting
studies,
test
soil
for
from
soil
major
exact
soil
the
sealed
could
be
made
air
2
having
Sampling
a glass
hand pump.
5890
gas
is
tube
The samples
desorption
capillary
pea
unit
chromatography,
column
and
be
24
hour
period
in
with
from
the
incorporating
Mature
study
using
to
plants
to
this
a
the
an
flame
that
soil
containinq
test
for
full
5
this
foliage
testing
of
pots
the
of
with
removal
for
leaves.
to
determine
removal
and
plant
free
corrections
effort
chemical
benzene
by
that
plant
in
full
and
making
experiments
with
followed
assumed
after
attributed
chambers
leakage,
then
chambers
gravel
were
from
was
the
appeared
began
It
during
found
used
chemicals
for
we
we
controls
involved
plants
with
experiments.
more
of
surprise,
removal
or
Model
used,
through
Supelco
Ultra
plants.
change
of
potting
Thus,
a
only
loss
mechanism
defoliation
our
using
the
without
potting
Another
To
being
currently
meters.
air
a Sensidyne
a Hewlett-Packard
chemicals
the
with
of
study
detector.
During
the
are
and 0.694 cubic
a Hewlett-Packard
with
ionization
size
200 mil
promptly
to
equipped
of
withdrawing
analyzed
benzene/TCE
similar
meters
performed
are
the
the
was
the
coverage
of
foliage.
significant
the
chemical
plant
hypothesis
were
the
roots.
into
tested
same
plants
for
all
one
from
which
all
stalks
the
foliage
1 "to 2 inches
potting
the
of
soil.
chemical
soil
the
major
that
the
plant
organics
leaves
from
the
hypothesis
vapor
were
only
short
level
of
was important,
saturated
were tested
methods
previously
from which
all
1 to
The general
Thus,
all
with
the
some of
water
to be a major
for
before
actor
in
in
Plants
solely
responsible
for
removal
we began incorporating
followed
Mature
a test
plants
period
by testing
of
were
protruding
also
full
(identical
the
of
for
with
to
same plants
had been cut away, leaving
length
of plants
work_ we began to suspect
one or more 24 hour
used),
2 inches
was the analysis
experiments.
of the foliage
soil.
with
were not
into
study
Due to recent
air.
foliage
covered
water
Change made for this
have been defoliated.
potting
if
leaving
above the
Water did not appear
that
stalks
protruding
containers
tests.
away,
removal.
Another
this
length
To determine
potting
conducting
in
had been cut
only
above the
level
tested
with
the
potting
these
tests
is
short
of the
soil
pea gravel.
protocol
followed
for
summarized
as
follows:
l.
For
each
species
placed
test,
to
into
be
each
two
healthy
tested
of
were
two
individuals
used.
chambers.
6
One
of
the
individual
plant
was
-2.
The chambers
injected
After
•
were
into
a
short
equilibration
on
the
more
did
some
final
At
the
were
was
.
The
during
a
sample,
drawn
end
cut
of
were
the
and
the
chambers
which
inside
withdrawn
analyzed
without
from
from
delay
a
single
10%,
two
in
the
drawn
sealed
4
in
to
6
most
As
withdraw_
from
hours
after
cases,
21
collected.
chambers.
to
only
22
a
hours
with
the
initial
each
chamber
and
above.
24
the
from
hour
testing
plants
the
period,
All
removed.
plant
potting
1
to
2
the
of
chambers
the
inches
foliage
above
the
soil.
remained
time
chemicals
approximatel_
was
complete
analyzed.
However,
described
away
of
was
for
approximately
overnight
injection,
as
and
allow
drawn
within
sample
chemical•
opened
surface
left
replicates
analyzed
benzene/TCE
were
samples
drawn
of
following
sample,
were
cases
were
two
replicate
were
injection
.
not
plants
of
the
samples
samples
the
replicates
The
In
If
to
of
replicate
These
GC.
period
circulation
two
chamber.
chamber
•
and
chamber,
each
and a mixture
each.
volatilization
the
sealed
open
a
good
7
for
approximately
circulation
one
of
air
hour,
was
maintained
in them to remove any remaining
organics
prior
to resealing.
•
The
defoliated
and
the
plants
chambers
were
were
placed
back
into
the
chambers
resealed.
ii
.
Initial
and
final
sampling
was
performed
as
des%ribed
above.
Although
the
variations
above
occurred
two
individuals
was
completely
several
with
potting
chambers
did
were
not
leak
at
plants
with
of
gravel.
after
course
Table
1
a
leak
of
to
the
and
two
however,
the
two
similar
foliage
plants.
or
three
period
were
of
followed,
tests,
these
for
removal
conducted
the
of
Tests
experiments,
periodically
during
one
for
all
tested
tested
testing
soil
these
least
protocol
In
were
were
pea
general
trials.
species
following
potting
course
same
two
the
actual
from
covered
uncovered
the
the
the
foliage,
indicate_
most
removed
soil
During
in
of
trials,
full
with
outline
then
with
In
days
the
conducted
foliage.
tests
affirm
on
that
sealed,
the
empty
chambers
experiments.
RESULTS:
It
all
can
be
plants
seen
from
tested,
the
and
earlier
reductions
in
8
reports
benzene
that
and
for
virtually
formaldehyde
are
significant.
Table
The most interesting
2 is
marginata
This
that
the
is greater
suggests
in this
try
than
This
the
plant
determine
implemented
in an effort
to better
understand
1 and 2 also
demonstrates
carbon
filters
removing
contaminated
used is
air
a major
be cleaned
inside
sealed
controlling
of smoke and toxic
used in Figure
removal,
at least
explained
at this
aspects
this
have
been
of plant/activated
from
of the
in the speed in which
fan rating
Th6 small
of
to
phenomenon.
The cfm rate
chemicals.
1 had a motor
associated
and trichloroethylene
chambers.
factor
foliage.
studies
the efficiency
benzene
full
from various
Microbial
shown in
defoliated
their
be fully
occurs.
Figures
for
and
this
the
with
chemical
phenomenon cannot
why it
by
by plants
roots
to study
from data
benzene
pathway for
We are continuing
to
of
the removal
are the major
study.
writing.
mean removal
that
microorganisms
observation
a room can
8" pot
15 cfm free
fan
system
air
flow.
DISCUSSION:
As
in
previously
plants
can
indoor
air.
and
not
of
these
the
a
The
major
work
potting
of
and
chemicals
studies,
role
in
reported
soil
chemicals.
microorganisms
removal
play
reported
itself,
removal
than
roots
was
of
herein
are
However,
plant
these
it
play
indicate
that
organic
chemicals
from
confirms
that
responsible
now
may
previously
9
results
for
appears
be
plant
more
believed.
systems,
removing
that
important
This
most
the
part
in
opens
the
a
broad
new avenue that
in the
It
fihal
is
also
be
interesting
its
in
of
or
buildings
and discussed
potting
plants
our studies,
soil.
air
is desirable
indoor
air
Therefore,
pollution
through
concentrations
it
in
removing
indoor
indirectly
high
inside
in
this
in removing
leaves
removal
to note
effective
growing
important
be investigated
in depth
report.
to be highly
must
will
the
of
either
that
the
systems.
i0
soil
plants
plant
is
directly
very
through
pathway.
and/or
to have an integrated
and one or more activated
the
pollutants,
root/soil
chemical_
for
carbon/plant
For
smoke from
system using
filtration
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FIGURE
1. REMOVAL
OF LOW CONCENTRATIONS
OF BENZENE
AND TRICHLOROETHYLENE
FROM
THE AIR INSIDE
SEALED
EXPERIMENTAL
CHAMBERS
USING
GOLDEN
POTHOS
IN AN
8-IN. ACTIVATED
CARBON
FILTER
SYSTEM.
0.250
0.225
0.200
0.175
EE
*..,.,.,.
Z
0.150
i
I--
Z
0.125
Z
0.075 -
0.050 -
0.025 -
0.000
T
I"
0.5
T
I
1.0
T
[
1.5
T
2.0
TIME (hr)
WOLVB.9-O031
FIGURE
2.
REMOVAL
OF
HIGH
CONCENTRATIONS
OF BENZENE
AND TRICHLOROETHYLENE
FROM
THE AIR INSIDE
SEALED
EXPERIMENTAL
CHAMBERS
USING
GOLDEN
POTHOS
IN AN
8-IN. ACTIVATED
CARBON
FILTER
SYSTEM.
4O
36
32
E
z
c_
z
LU
Z
C_
16-
\
12-
m
0
I
0.5
I
I
1.0
TIME (hr)
I
1.5
2.0