ArticlePDF Available

The use of plants to improve indoor air quality in small office space

Authors:

Abstract and Figures

Exposure to volatile organic compounds (VOC) can cause a series of effects towards human health. VOC is also associated with Sick Building Syndrome and other building related illnesses. Common materials found in every home and place of business may cause elevated exposure to toxic chemicals. The aim of this study was to examine the best indoor plants that could be used to improve indoor air quality in a small office space. In this study, the concentration of VOC inside a room was monitored before and after the test, using Aeroquol Model S500 VOC Gas Detector and by using oil-based paint painted on a panel measuring 0.05 x 0.05 m in order to create a minimum of 3ppm of VOC. Three types of tropical indoor plants were used in this study; Nephrolepis exaltata, Rhapis excelsa and Dracaena fragrans. Data were monitored for eight hours at 10 minutes interval. The results showed no significant differences between the number of pots and the type of plants used in reducing VOC content in the real room environment. This was probably due to several factors, such as the interference of outside air and the condition of the experimental room. This experiment suggests that further experiments should be carried out in a controlled environment to improve our knowledge of how indoor plants can improve indoor air quality, and thus improve human health and well-being.
Content may be subject to copyright.
Pertanika J. Soc. Sci. & Hum. 20 (2): 493 - 503 (2012)
ISSN: 0128-7702 © Universiti Putra Malaysia Press
SOCIAL SCIENCES & HUMANITIES
Journal homepage: http://www.pertanika.upm.edu.my/
Article history:
Received: 14 October 2010
Accepted: 19 January 2011
E-mail addresses:
jasmin.ghazalli@gmail.com (Aini Jasmin, G.),
noorizan16@hotmail.com (Noorizan, M.), inakrisatia@yahoo.com
(Suhardi, M.), muradupm@yahoo.co.uk (Murad, A. G.),
shdi@yahoo.com (Ina, K.)
* Corresponding author
The Use of Plants to Improve Indoor Air Quality in
Small Ofce Space
Aini Jasmin, G.*, Noorizan, M., Suhardi, M., Murad, A. G. and Ina, K.
Department of Landscape Architecture, Faculty of Design and Architecture, Universiti Putra Malaysia, 43300
Serdang, Selangor, Malaysia
ABSTRACT
Exposure to volatile organic compounds (VOC) can cause a series of effects towards human health.
VOC is also associated with Sick Building Syndrome and other building related illnesses. Common
materials found in every home and place of business may cause elevated exposure to toxic chemicals.
The aim of this study was to examine the best indoor plants that could be used to improve indoor air
quality in a small ofce space. In this study, the concentration of VOC inside a room was monitored
before and after the test, using Aeroquol Model S500 VOC Gas Detector and by using oil-based
paint painted on a panel measuring 0.05 x 0.05 m in order to create a minimum of 3ppm of VOC.
Three types of tropical indoor plants were used in this study; Nephrolepis exaltata, Rhapis excelsa
and Dracaena fragrans. Data were monitored for eight hours at 10 minutes interval. The results
showed no signicant differences between the number of pots and the type of plants used in reducing
VOC content in the real room environment. This was probably due to several factors, such as the
interference of outside air and the condition of the experimental room. This experiment suggests that
further experiments should be carried out in a controlled environment to improve our knowledge of
how indoor plants can improve indoor air quality, and thus improve human health and well-being.
Keywords: Human health, indoor air quality, tropical indoor plants, volatile organic compounds
(VOC)
INTRODUCTION
Media reports regarding air pollution have
long been realized by the public. Awareness
towards the quality of air that we breathe is
important as people spend more than 80%
of their daily life indoors (e.g. home, ofce,
shopping malls and vehicles). Everyday,
people are exposed to a certain level of toxic
gases, both indoor and outdoor. However,
outdoor air pollution has always been seen
as the main problem regarding air quality;
but due to changes of lifestyle, the indoor
Aini Jasmin, G., Noorizan, M., Suhardi, M., Murad, A. G., and Ina, K.
494 Pertanika J. Soc. Sci. & Hum. 20 (2): 494 - 504 (2012)
air quality (IAQ) is also seen as a problem
as well.
Acceptable temperature and relative
humidity, controlled airborne contaminants
and adequate distribution of ventilated air
are some elements that promote good IAQ.
Some examples of common indoor air
pollutants include radon, carbon monoxide
and ozone. One of the pollutions that is
widely found indoors is VOCs. VOCs
are organic chemical compounds that
have high enough vapour pressures under
normal conditions to signicantly vaporize
and enter the atmosphere. Many VOCs
are human-made chemicals and used
as industrial solvents. Some of VOC
sources are formaldehyde and methane.
Formaldehyde is found in many building
materials, such as paints, adhesives and
wall boards. Many VOCs are neurotoxic,
nephrotoxic or hepatotoxic, or carcinogenic
and many can damage the blood components
and the cardiovascular system and cause
gastrointestinal disturbances (Leslie, 2000).
Indoor air pollution can even increase the
chance of long-term and short-term health
problems for indoor occupants, reduce in
productivity and degrade students’ learning
environment and comfort (Lee & Chang,
2000).
VOCs are emitted by various types of
products that can be found indoors, such as
paints and lacquers, cleaning agents, building
materials and furnishings, ofce equipment
like copiers and printers, correction uids
and carbonless copy paper, permanent
markers, and photographic solutions. Table
1 shows some common emissions and their
sources (Wolverton, 1997). However,
VOCs did not only originate from internal
sources but are influenced by outdoor
sources as well (Ekberg, 1994).
People now build well-sealed homes
and install insulation and other materials to
conserve energy. This reduces movement
of air through a building and increases the
concentration of many indoor pollutants.
Dependencies on air-conditioning and bad
ventilation system worsen the condition and
quality of the indoor air. There are several
TABLE 1
Some common emissions and their sources (Wolverton, 1997)
Sources of Chemical Emissions
Formaldehyde Xylene Benzene Alcohols Acetone
Adhesives √ √ √
Carpeting
Computer VDU screens
Draperies √
Fabrics
Ofce correction uid
Paints √ √ √
Plywood
Upholstery √
The Use of Plants to Improve Indoor Air Quality in Small Ofce Space
495Pertanika J. Soc. Sci. & Hum. 20 (2): 495 - 504 (2012)
effects caused by poor indoor air quality
and a common symptom associated with
poor indoor air quality is the Sick Building
Syndrome (SBS).
SBS is dened as a set of sub-clinical
symptoms with no specically identied
cause. It is a collection of symptoms
experienced when a person is exposed
to high concentrations of certain gasses,
specically those living or working inside
a building. The SBS symptoms include
irritation in the eyes, blocked nose and throat,
complaints in upper airways, headache,
dizziness, sensory discomfort from odours,
dry skin, fatigue, lethargy, wheezing, sinus,
congestion, skin rash, irritation, nausea,
difculty in concentrating, fatigue and can
even cause the occupants to be sensitive to
odours (Gupta et al., 2007).
The toxicity level of certain VOCs
can be carcinogenic. Among other,
formaldehyde has been long considered as
a probable human carcinogen (Group 2A
chemical) based on experimental animal
studies and limited evidence of human
carcinogenicity. However, the International
Agency for Research on Cancer (IARC)
reclassified formaldehyde as a human
carcinogen (Group 1) in June 2004 based
on the ‘‘sufcient epidemiological evidence
that formaldehyde causes nasopharyngeal
cancer in humans’ (Zhang et al., 2008). The
chemical characteristic of VOCs indicates
that these chemicals decline with time.
Newer materials emit higher concentration
of VOC. It was concluded that common
materials found in every home and place of
business may cause elevated exposures to
toxic chemicals (Wallace et al., 1987).
There are three common ways to
improve indoor air quality; these include
source control, good ventilation systems to
exhaust contaminated air, and air cleaning.
Other methods include phytoremediation,
photocatalytic oxidation, adsorption and
by using plants. Recently, using plants
as a bioltering system is widely advised.
Plants not only serve as an ornament but
they can also promote a better indoor air
condition. This does not apply only to
indoor environment but also the outdoor
(Jim & Chen, 2008). Most plants transpire
through their stomata. During the process,
plants absorb indoor air pollution (Song
et al., 2007). Gaseous pollutants could
be absorbed into plant tissues through
the stomata, together with CO2 in the
process of photosynthesis, and with O2 in
respiration. After entering the plant, transfer
and assimilation could x the pollutants in
the tissues (Jim & Chen, 2008).
Plants also have psychological effects
on humans. A review suggests that indoor
plants can and provide psychological
benefits such as stress-reduction and
increased pain tolerance (Bringslimark
et al., 2009). Despite the fact that many
research has been carried out in this area
(Oyabu, 2003; Raza, 1991; Song et al.,
2007), little emphasizes on the effectiveness
of indoor plants in reducing indoor pollution
in the tropical, as well as work done in real
room or office environment. Therefore,
this study was conducted to investigate
the effectiveness of three different species
and treatments of indoor plants in reducing
indoor pollutants in real working or ofce
environment.
Aini Jasmin, G., Noorizan, M., Suhardi, M., Murad, A. G., and Ina, K.
496 Pertanika J. Soc. Sci. & Hum. 20 (2): 496 - 504 (2012)
MATERIALS AND METHODS
Characteristics of the Plants
The plants chosen for this study were divided
into three categories of characteristics;
palms, herbaceous and ferns. The selected
plants were Rhapis excelsa, Dracaena
fragrans and Nephrolepis exaltata. These
plants were chosen to represent leaf
characteristic groups. Rhapis excelsa
represents the palm group, Dracaena
fragrans represents the herbaceous group
and Nephrolepis exaltata represents the fern
group. The characteristics of the plants are
shown in Fig.1 to Fig.3. All the three plants
are known to have the ability to purify the air
in a previous study (Wolverton, 1997) and
are therefore suitable to be used as indoor
plants. All plants were planted in a standard
clay pot and the soil mixture used was the
John Innes 3:2:1 compost. The soil mixture
consisted of three parts of loam, 2 parts of
peat and 1 part of sand. This soil mixture
is widely used and it is known as a standard
soil mixture for plants in Malaysia. Plants
were randomly selected from a total of 10
plants from each group and divided into
three different treatments (one, three and six
pots). No plants were used for the control.
The Experimental Room
The experiment was conducted at the
Landscape Research Laboratory, Faculty of
Design and Architecture, Universiti Putra
Malaysia. The room measures 0.3m width
x 0.5m length x 0.3m height, with four
window panes, a door and a personal air-
conditioning unit. In order to imitate a real
small ofce condition, the air-conditioning
was set at 21oC, with a medium speed
fan and lights were turned on during the
experiment.
Measurement of VOC
The source of VOC came from a panel
painted with oil paint. Oil-based paint
was chosen because the emission rate
Fig.1: Dracaena fragrans (herbaceous plant group)
The Use of Plants to Improve Indoor Air Quality in Small Ofce Space
497Pertanika J. Soc. Sci. & Hum. 20 (2): 497 - 504 (2012)
is slower as compared to water based
spray paint. A few guidelines suggested a
minimum of four hours to collect air sample
(Environmental Protection Agency, 2007).
For this experiment, however, the data were
measured for a duration of eight hours,
from 9.30 a.m. to 5.30 p.m., which are the
standard working hours (Ministry of Human
Resources, 2005).
Measurement of VOC was carried
out using a hand-held data logging device
Aeroqual 500 Series, with a maximum
measurement limit of 25ppm. The relative
humidity and temperature was recorded
using the MC-83 Relative Humidity-
Temperature meter. The recorded data
will show if the temperature and humidity
levels are within human comfort level. The
Fig.2: Rhapis excelsa (palm group)
Fig.3: Nephrolepis exaltata (fern group)
Aini Jasmin, G., Noorizan, M., Suhardi, M., Murad, A. G., and Ina, K.
498 Pertanika J. Soc. Sci. & Hum. 20 (2): 498 - 504 (2012)
devices were placed in the middle of the
room. Some previous experiments (see
Wallace et al., 1987; Chan et al., 2009; Sohn
et al., 2007) indicated that the experimental
device should be put between 1 meter to
1.5 meter above the oor level. However,
according to the manufacturer of the device
used in this experiment, the Aeroqual 500
Series, can be placed anywhere in the
experimental room. Fig.5 shows the layout
of the experiment.
Statistical Analysis
The one-way analysis of variance (ANOVA)
and Fisher least significant difference
(LSD) tests were used to determine the
differences between the group of plants
and the treatment used in reducing VOC
concentration.
RESULTS AND DISCUSSION
From the analysis, no signicant difference
was found between the plants species and
even the number of pots. Nonetheless, there
were still decrements in the concentration of
VOC. The results derived from the analysis
are as follows:
TABLE 2
ANOVA test results for Nephrolepis exaltata
Sum of
Squares Df Mean
Square FSig.
Between
Groups
.016 3.005 .322 .809
Within
Groups
.333 20 .017
Total .349 23
TABLE 3
ANOVA test results for Rhapis excelsa
Sum of
Squares df Mean
Square FSig.
Between
Groups
.009 3.003 .087 .966
Within
Groups
.719 20 .036
Total .729 23
TABLE 4
ANOVA test results for Dracaena fragrans
Sum of
Squares df Mean
Square FSig.
Between
Groups
.024 3.008 .440 .727
Within
Groups
.362 20 .018
Total .386 23
In general, however, a decrease in VOC
was found in the number of plants, ranging
from 70% to 77% in Nephrolepis exaltata,
63% to 72% in Dracaena fragrans and 75%
to 81% in Rhapis excelsa, with the highest
value recorded in 6 plants. From Table 5,
and by disregarding the control treatment,
Rhapis excelsa (3 pots) has the highest value
(0.8078), while the lowest is Dracaena
fragrans (1 pot), with a value of 0.6320.
The decrement in the percentage of Rhapis
excelsa (3 pots) is the highest (81%) as
compared to other species and the numbers
of pots. The lowest percentage is Dracaena
fragrans (1 pot) with 63%.
When the results of the experiments
with the plants and no plants (control)
in the room were compared, the VOC
concentration still seemed to decrease.
This could be due to the interference of air
The Use of Plants to Improve Indoor Air Quality in Small Ofce Space
499Pertanika J. Soc. Sci. & Hum. 20 (2): 499 - 504 (2012)
Fig.4: The experimental room
Fig.5: The layout of the experiment
Fig.6: The experimental devices
Aini Jasmin, G., Noorizan, M., Suhardi, M., Murad, A. G., and Ina, K.
500 Pertanika J. Soc. Sci. & Hum. 20 (2): 500 - 504 (2012)
which entered the room from outside (i.e.
from beneath the door, windows and air-
conditioning). VOC is not mainly reduced
by plants but by dilution of air. According
to Wallace et al. (1987), the concentrations
of several VOCs (ethylbenzene, l,l,l-
trichloroethane, xylenes) declined sharply
over time, indicating that building materials
or nishings (paints, carpets, adhesives, etc.)
were likely the sources. Assuming a decline
in emissions with age, the newer materials
used in the chamber should lead to higher
concentrations than in the building.
Based on the findings presented in
the tables above, there is no significant
difference between the numbers of pots in
all the three species of plants used in the
experiment. Each species was tested with
several numbers of pots. 1 pot, 3 pots, 6
pots and control treatment were used to
compare the plants ability in improving
indoor air quality. From the results, the
plant with the best ability to purify the air
was Rhapis excelsa, with 3 pots in one room.
This nding indicates that different types of
foliage can inuence the reduction of VOC.
According to Lohr (1992), plants
can increase indoor relative humidity by
releasing moisture into the air. During
photosynthesis, the nal products are glucose
(C6H12O6), oxygen (O2) and water (H2O).
Plants with large leaf surface area emit more
water vapour during photosynthesis, and
thus increase the humidity level in a space.
Relative humidity can affect temperature.
It gets warmer if the relative humidity
increases (Swanson, 2006). According
to Zhang et al. (2007), temperature is
one of the environmental parameters that
inuences VOC emissions from building
materials, together with air velocity and
humidity (Wolkoff, 1998). Bremer et al.
(1993), Cox et al. (2005) and Yang (1999)
reported that the emitted substances were
temperature dependant.
Meanwhile, the emission of
formaldehyde from particle-board was
also observed to be strongly dependent on
relative humidity which has to be taken into
account when examining these materials in
climate chamber studies (Sollinger et al.,
1994). Therefore, the use of plants is not
only to lter the air but can help maintain a
good relative humidity and temperature in
order to control airborne pollutants.
Previous research indicates that the
plants, Crassula portulacea, Cymbidium
Golden Elf, and Hydrangea macrophylla,
have very high removal rates (60-80%) of
the pollutant benzene (Liu et al., 2007).
On the contrary, no signicant difference
was found between all the three plant
TABLE 5
Decrement value of VOC by plant species and treatment (data are means ± standard error)
Species Treatment
1 pot 3 pots 6 pots Control
Nephrolepis exaltata 0.70 ± 0.05 0.74 ± 0.07 0.77 ± 0.05 0.75 ± 0.04
Dracaena fragrans 0.63 ± 0.06 0.69 ± 0.07 0.72 ± 0.04 0.67 ± 0.05
Rhapis excelsa 0.75 ± 0.07 0.81 ± 0.07 0.77 ± 0.08 0.72 ± 0.09
The Use of Plants to Improve Indoor Air Quality in Small Ofce Space
501Pertanika J. Soc. Sci. & Hum. 20 (2): 501 - 504 (2012)
species used in the experiment in this study.
This might e due to the use of a real room
condition. The previous experiments were
mainly done in sealed gas chambers to test
the plants’ capability to purify the air. The
chamber’s size ranges from 1m³ (Raza et
al., 1995) to a set of four interconnected,
cylindrical Plexiglas chamber measuring
40cm in diameter x 60cm tall (Liu et al.,
2007) to 3.5 m x 3.5 m x 2.4m (Song, Kim,
& Sohn, 2007). These chambers are air-
tight, i.e. there is no outside air interference
that can dilute the contaminated air.
This experiment was done in a real room
environment. Even though the laboratory
size used by Liu et al. (2007) is about the
same as the experimental room used in
this study, the reading of VOC may vary
because the room used for the experiment is
more airtight and has no ventilation system,
whereas this study imitated the real personal
office environment. Salthammer (1997,
as cited in Guieysse et al., 2008), indoor
VOC concentrations depend on the total
space volume, the pollutant production and
removal rates, the air exchange rate with
the outside atmosphere, and the outdoor
VOC concentrations. This also shows that
different sizes of experimental room may
give different VOC readings.
CONCLUSIONS
There have been a lot of changes in the
world we live in today. The effects of
global warming have caused people to
spend more time indoors. Even outdoor
activities have been brought indoors because
of heat and polluted air. Technological
advancements have caused people to be
dependant to alternatives sources. Even
though it positively improves the way of
living, it can also negatively affect human
health at the same time.
The issue regarding indoor air quality
is of every field’s concern. Architects,
landscape architects and even interior
designers must always put human health
and comfort as priorities in their designs.
Architects have been known to be the
main persons in a building design process.
Therefore, an architect must produce a good
design, not only to beautify the building, but
also to make it environmentally friendly for
humans.
Similarly, ventilation system plays a
big role as big ofces depend on it to bring
in fresh air. Natural aeration is always the
best but issues, such as outdoor air pollution
and safety in high buildings, often make it
not possible. According to Wargocki et al.
(2002), periodical air refreshing is often not
efcient because many indoor air pollutants
are constantly released. Hence, forced
ventilation is still one the most common
methods used for air treatment (Guieysse
et al., 2008). A central air conditioning re-
circulates air in order to save energy, but it
also circulates airborne biological materials.
There are numerous effects on health due
to airborne biological materials. These
include a range of infections and allergic
diseases, such as extrinsic allergic alveoli,
allergic rhinitis and asthma and perhaps
even lung cancer (Leslie, 2000). A central
air conditioning must be installed with
some sort of device that can lter the air.
Aini Jasmin, G., Noorizan, M., Suhardi, M., Murad, A. G., and Ina, K.
502 Pertanika J. Soc. Sci. & Hum. 20 (2): 502 - 504 (2012)
However, the lter system must be properly
maintained because the lter is seen as the
main pollution source (Bitter & Fitzner,
2002). At the same time, indoor air must
be brought outside and fresh air from the
outside be brought inside, provided that the
outdoor environment allows a better outdoor
air quality. In this study, the ventilation
system is the main suspect for the null
hypothesis.
Plants have always been seen as a
good biological lter for both indoor and
outdoor. They do not only serve as the
green lung of the earth, but also bring
physiological benefits to humans. The
focus of this study was to identify which
tropical indoor plant in Malaysia has better
efciency in improving indoor air quality.
Nevertheless, only three plant species were
experimented in this study. To provide
further insights into how plants can reduce
indoor pollution and improve our health
and working environment, more plants
need to be tested, and a more controlled
environment is needed as well.
REFERENCES
Bitter, F., & Fitzner, K. (2002). Odour emissions
from an HVAC-system. Energy and
Buildings, 34(8), 809-816.
Bringslimark, T., Hartig, T., & Patil, G. G.
(2009). The psychological benets of indoor
plants: A critical review of the experimental
literature. Journal of Environmental
Psychology, In Press, Corrected Proof.
Chan, W., Lee, S.-C., Chen, Y., Mak, B., Wong,
K., Chan, C.-S., Zhen, C., & Guo, X.
(2009). Indoor air quality in new hotels’
guest rooms of the major world factory
region. International Journal of Hospitality
Management, 28(1), 26-32.
Ministry of Human Resources, Malaysia. (2005).
Code of Practice on Indoor Air Quality.
Ekberg, L. E. (1994). Volatile organic
compounds in ofce buildings. Atmospheric
Environment, 28(22), 3571-3575.
Testing for Indoor Air Quality § 01 81 09 (2007),
Environmental Protection Agency.
Guieysse, B., Hort, C., Platel, V., Munoz, R.,
Ondarts, M., & Revah, S. (2008). Biological
treatment of indoor air for VOC removal:
Potential and challenges. Biotechnology
Advances, 26(5), 398-410.
Gupta, S., Khare, M., & Goyal, R. (2007).
Sick building syndrome--A case study
in a multistory centrally air-conditioned
building in the Delhi City. Building and
Environment, 42(8), 2797-2809.
Jim, C. Y., & Chen, W. Y. (2008). Assessing the
ecosystem service of air pollutant removal
by urban trees in Guangzhou (China).
Journal of Environmental Management,
88(4), 665-676.
Lee, S. C., & Chang, M. (2000). Indoor and
outdoor air quality investigation at schools
in Hong Kong. Chemosphere, 41(1-2),
109-113.
Leslie, G. B. (2000). Review: Health Risks
from Indoor Air Pollutants: Public Alarm
and Toxicological Reality. Indoor and Built
Environment, 9(1), 5-16.
Liu, Y.-J., Mu, Y.-J., Zhu, Y.-G., Ding, H., &
Crystal A. N. (2007). Which ornamental
plant species effectively remove benzene
The Use of Plants to Improve Indoor Air Quality in Small Ofce Space
503Pertanika J. Soc. Sci. & Hum. 20 (2): 503 - 504 (2012)
from indoor air? Atmospheric Environment,
41(3), 650-654.
Lohr, V. I., & Pearson-mims, C. H. (1996).
Particulate matter accumulation on
horizontal surfaces in interiors: Inuence
of foliage plants. Atmospheric Environment,
30(14), 2565-2568.
Oyabu, T., Sawada, A., Onodera, T., Takenaka,
K., & Wolverton, B. (2003). Characteristics
of potted plants for removing offensive
odors. Sensors and Actuators B: Chemical,
89(1-2), 131-136.
Raza, S. H., Shylaja, G., & Gopal, B. V. (1995).
Different abilities of certain succulent
plants in removing CO2 from the indoor
environment of a hospital. Environment
International, 21(4), 465-469.
Raza, S. H., Shylaja, G., Murthy, M. S. R., &
Bhagyalakshmi, O. (1991). The contribution
of plants for CO2 removal from indoor air.
Environment International, 17(4), 343-347.
Sohn, J., Yang, W., Kim, J., Son, B., & Park,
J. (2007). Indoor air quality investigation
according to age of the school buildings
in Korea. Journal of Environmental
Management, 90(1), 348-354.
Sollinger, S., Levsen, K., & Wünsch, G. (1994).
Indoor pollution by organic emissions from
textile oor coverings: Climate test chamber
studies under static conditions. Atmospheric
Environment, 28(14), 2369-2378.
Song, J.-E., Kim, Y.-S., & Sohn, J.-Y. (2007).
The Impact of Plants on the Reduction
of Volatile Organic Compounds in a
Small Space. Journal of Physiological
Anthropology, 26(6), 599-603.
Swanson, B. (2006). Understanding Humidity.
Retrieved from http://www.usatoday.com/
weather/whumdef.htm.
Wallace, L. A., Pellizzari, E., Leaderer, B.,
Zelon, H., & Sheldon, L. (1987). Emissions
of volatile organic compounds from
building materials and consumer products.
Atmospheric Environment (1967), 21(2),
385-393.
Wolverton, B. C. (1997). How to Grow Fresh
Air: 50 House Plants that Purify Your Home
or Office. Penguin (Non-Classics); First
Edition (April 1, 1997).
Zhang, L., Steinmaus, C., Eastmond, D. A., Xin,
X. K., & Smith, M. T. (2008). Formaldehyde
exposure and leukaemia: A new meta-
analysis and potential mechanisms.
Mutation Research/Reviews in Mutation
Research, 681(2-3), 150-168.
... Among the tested plants, Chlorophytum comosum displayed superior removal efficiency for HCHO and SO x as 1830 μg day -1 and 2120 μg day -1 and Spathiphyllum wallisii for NO x as 3200 μg day -1 . Also, it was found that stomatal density can be used as an indicator for the efficiency of indoor plants in the absorption of air pollutants; especially for HCHO, SO x or NO x 39 . ...
... The best indoor plants that could be used to improve indoor air quality in a small office space was studied 39 . They found that, the concentration of Volatile Oil Compound (VOC) inside a room was monitored before and after the test, using Aeroquol Model S500 VOC Gas Detector and by using oil-based paint painted on a panel measuring 0.05 x 0.05 m in order to create a minimum of 3ppm of (VOC) 39 . ...
... The best indoor plants that could be used to improve indoor air quality in a small office space was studied 39 . They found that, the concentration of Volatile Oil Compound (VOC) inside a room was monitored before and after the test, using Aeroquol Model S500 VOC Gas Detector and by using oil-based paint painted on a panel measuring 0.05 x 0.05 m in order to create a minimum of 3ppm of (VOC) 39 . Three types of tropical indoor plants were used in this study; Nephrolepis exaltata, Rhapis excels and Dracaena fragrans. ...
Article
Full-text available
Public attitudes towards plants usage for air filtration from the environmental pollutants and the evidence of phytoremediation efficacy exhibited by some plants have prompted new investigations into the use of ornamental plants and woody trees as a green technology in phytoremediation for air contamination. Air pollutant can define as any substance emitted into the air from an anthropogenic, biogenic, or gynogenic source, that is either not part of the natural atmosphere or is present in higher concentrations than the natural atmosphere, and may cause a short-term or long-term adverse effect. Air pollution caused a problematic health include breathing problems, respiratory illness, changes in the lung's defenses, and worsening respiratory, and cardiovascular disease. Using the ornamental plants, weedy trees and green space as natural filters of air pollution reduces respiratory illness mortality rates and reducing visits to the hospital. Non radioactive As, Cd, Cu, Hg, Pb and Zn and radioactive Sr, Cs and U are the most environmentally important metallic pollutants. Metabolism of foreign compounds in plant system is generally considered to be a’ detoxification’ process that is similar to the metabolism of xenobiotic compounds in humans, which considerd a ‘green liver’. Trees and plants have been labeled as the “lungs of cities” because they have the ability to remove contaminants from the air that is breathed. The amount of air-borne pollutants removed increases with leaf surface area. Therefore, trees tend to be better filters than shrubs and grasses. Due to their large surface area and year round coverage, conifers (evergreens) are very good pollution filters. Many species of ornamental shrubs and herbaceous landscape plants have been identified as phytoremedator to improve indoor and outdoor air quality. Stomata density can be used as an indicator for the efficiency of plants in the absorption of air pollutants. Biowalls were developed due to the evidence of plants as efficient filters of air. One potted plant per 100 square feet of indoor space in an average home or office was sufficient to cleanse the air of pollutants. Based on available literature it could be concluded that ornamental plants and trees have the ability to filtrate the air from the contaminants.
... Land, water, plants, and buildings are parts of the physical environment. The outdoor physical environment has a direct effect on people, as well as on the indoor environment (Ghazalli et al., 2012). There are many variables that alter the physical environment, and urbanization is one of the major causes of increases in urban heat, noise, and air pollution. ...
... Where air pollution cannot be prevented, vegetation in cities has been demonstrated as a natural method for mitigation (Fujii et al., 2005;Krüger et al., 2011;Yang et al., 2008). Research on the effectiveness of vegetation in pollutant removal has been performed both indoors (Ghazalli et al., 2012;Yarn et al., 2013) and outdoors (Ottelé et al., 2010;Sternberg et al., 2010;Strohbach et al., 2012). Various studies have examined the capabilities of vegetation in mitigating air pollutants in cities (e.g., Tallis et al., 2011). ...
Article
Urban green infrastructure improves the urban environment and enriches the lives of urban dwellers by positively affecting ambient temperatures, noise levels, and air quality, and creating an environment that promotes human health. Green technologies are increasingly used to increase green patches in urban areas. In this review of 108 vertical greenery publications, the potential physical and non-physical contributions of a subset of green infrastructure—vertical greenery systems—are presented. Most studies focus on how greenery improves the thermal performance of individual buildings and the potential energy savings, but non-physical benefits, such as health and well-being, have received little attention.
... ppm per 1 h from a 100 cm 2 leaf area, but these are mainly laboratory results [28,29]. The air quality improvement effect of indoor plants is constantly changing because pollutants in actual space do not maintain a constant concentration [30,31]. On the other hand, because there is a difference between the minimum detected concentration of the human body and the exposure reference concentration of indoor air pollutants, occupants are not properly aware of this, even though they are exposed to dangerous levels of indoor air quality [32][33][34]. ...
Article
Full-text available
The objective of this paper is to investigate the effect of improving indoor air quality with indoor plants. As a methodology, two target classrooms with the same size (120.64 m2) and 32 students per room were selected. Then, 48 areca palm pots (average leaf area of 300 cm2/pot) were placed, and the plant density was 14.68% of the floor area. Subjective assessment for general questions, learning motivation, perceived air quality, and SBS symptoms was conducted at 5 min after the class started and 5 min before the class ended. The results showed that the CO2 concentration by respiration of the students (average of 1873 ppm) exceeded the regulatory standard (1000 ppm), but the students did not recognize the indoor CO2 concentration. The increase in CO2 concentration in the classroom was lower in the case with plant placement (624 ppm) compared with the case without plant placement (about 1205 ppm). It was statistically proven that the CO2 concentration by respiration could be reduced by 50% if the indoor plant leaf area density were maintained at about 14.68% of the floor area. In the case with plant placement, the students perceived the indoor air quality to be 40% fresher and showed a 140% higher acceptability. Moreover, the complaining of SBS symptoms was improved by 108%, and the students’ perception that it was better to focus on learning increased by about 120%. As the awareness of sustainability increases, indoor plants will be more actively placed in the United Arab Emirates. Indoor plants not only provide a visual green effect to improve human comfort but also purify indoor air pollutants.
... In the indicators of factors that influence the quality of indoor air, most people also already know this, but for the knowledge of the components that affect the quality of indoor air is still lacking. For example, many people consider putting plants indoors as a negative effect on indoor air, even though placing plants indoors can help neutralize indoor air pollution (Aini Jasmin, Noorizan, Suhardi, Murad, & Ina, 2012;Brilli et al., 2018). Another example is that many people assume that opening a window in the morning increases the risk of bacteria entering, even though opening a window in the morning can help kill airborne contaminants in the house, as well as exchanging air from inside and out of the house (Siswanti & Wijayanti, 2018;Yao & Zhao, 2017) (Permana, Wijaya, et al., 2020). ...
Article
Full-text available
- This research is motivated by the poor air quality in the room at home that can cause Sick Building Syndrome (SBS). The purpose of this research is to increase public awareness of the environment through indoor air quality workshops, with a Pre-Experimental method and One Group Pre-Test Post-Test research design. The sample in this study was Pasteur RW6, Sukajadi District at Bandung City, which was selected based on criteria including non slum areas, as well as high community participation. The results showed that the level of public awareness, knowledge, attitudes, and actions on air quality in the room before the Workshop was in the medium category. Then it increased after the Workshop, which was on a relatively moderate increase in knowledge. This can be seen from the majority of people who already know the importance of indoor air quality, but the knowledge of specific components that affect indoor air quality is still not understood. Whereas attitudes and actions experienced a relatively small increase due to the knowledge gained in the Workshop not being implemented in the form of real attitudes and actions in daily life because people's habits are difficult to change. Keywords – Environmental Awareness, Indoor Air Quality, Workshop, Community Awareness
... In addition, it can tolerate dryness, grow better in cool, and slightly moist places, even when indirectly exposed to light. In few studies, Nephrolepsis exaltata is included in plants that have high efficiency to absorb air pollutants including formaldehyde [8][9][10][11]. ...
Article
Full-text available
Background: Chronic occupational exposure in textile workers lowers the pulmonary function and levels of sinonasal IgA. A Nephrolepis exaltata herbal mask can protect the respiratory tract. This study aims to understand the effect of this herbal mask on the IgA levels and pulmonary function in textile workers. Thirty employees were selected for this study. Methods: The pre- and post-test randomized experimental control trials were conducted in a garment industry of Bawen, Semarang, Indonesia. The subjects that qualified to participate (n = 30) fulfilled the inclusion criteria i.e., 20-35 years old, healthy, and willing to be a research subject; and exclusion criteria i.e., having history of alcohol consumption, smoking, history of liver disease, autoimmune disease, cancer, pulmonary and heart disease and/or being pregnant. The subjects were then divided randomly into control group (n = 15), who used regular mask that was rewashed and changed every month for eight weeks, and treatment group (n = 15), who used Nephrolepis exaltata mask that was changed every two days for eight weeks. Pulmonary function tests were carried out using MIR Spirolab III before and after the experiment. IgA levels were measured by nasal wash method using ELISA. Results: IgA levels of the treatment group before and after usage of mask were significantly different (p<0.001) compared to the control group. There were significant difference in FVC of the control group, but no significant difference was observed for FEV1 (p = 0.507) and PEF (p = 0.001). In the treatment group, all three parameters showed significant differences [FVC (p = 0.038), FEV1 (p = 0.004), and PEF (p = 0.001)]. The means of ΔFVC, ΔFEV1, and ΔPEF were significantly (p<0.05) higher in the treatment group with OR = 5.1 for higher IgA levels. Conclusions: The herbal mask is better in increasing IgA and improving the pulmonary function compared to the regular mask.
... Urban areas are often associated with poor air quality (Gulia et al. 2015;Han et al. 2014), as the activities in these areas promote the generation of airborne pollutants, primarily particulate matter (PM) (Guo et al. 2010;Morawska and Clark 2000), which can penetrate and contaminate the urban indoor environment (Perez et al. 2016). Additionally, a range of common household and office materials and products, such as building materials, furnishings, plastics and solvents, can emit volatile organic compounds (VOCs) (Aini Jasmin et al. 2012;Cruz et al. 2014a), thus allowing the potential for these pollutants to accumulate within the indoor environment (Weschler 2009). For many VOCs, such as benzene and poly-aromatic hydrocarbons, the World Health Organization recommends no safe level of exposure (World Health Organization 2010). ...
Article
Full-text available
Atmospheric pollutant phytoremediation technologies, such as potted plants and green walls, have been thoroughly tested in lab-scale experiments for their potential to remove air pollutants. The functional value of these technologies, however, is yet to be adequately assessed in situ, in ‘high value’ environments, where pollutant removal will provide the greatest occupant health benefits. Air pollution in countries such as China is a significant public health issue, and efficient air pollution control technologies are needed. This work used pilot-scale trials to test the capacity of potted plants, a passive green wall and an active green wall (AGW) to remove particulate matter (PM) and total volatile organic compounds (TVOCs) from a room in a suburban residential house in Sydney, Australia, followed by an assessment of the AGW’s potential to remove these pollutants from a classroom in Beijing. In the residential room, compared to potted plants and the passive green wall, the AGW maintained TVOCs at significantly lower concentrations throughout the experimental period (average TVOC concentration 72.5% lower than the control), with a similar trend observed for PM. In the classroom, the AGW reduced the average TVOC concentration by ~ 28% over a 20-min testing period compared to levels with no green wall and a filtered HVAC system in operation. The average ambient PM concentration in the classroom with the HVAC system operating was 101.18 μg/m³, which was reduced by 42.6% by the AGW. With further empirical validation, AGWs may be implemented to efficiently clean indoor air through functional reductions in PM and TVOC concentrations.
... The vast majority of the knowledge regarding the efficacy of potted-plants to remove VOCs comes from static chamber trials, in which a high concentration of a pollutant is spiked into a small sealed chamber containing potted-plants, with VOC concentrations within the chamber headspace monitored over time (Llewellyn and Dixon, 2011). Given the nature of these trials, generalizing their results to realistic indoor air concentrations in larger rooms has been subject to controversy (Llewellyn and Dixon, 2011;Aini Jasmin et al., 2012). Furthermore, there has been uncertainty regarding how the substrate's active microbial populations will be sustained if exposed to fluctuating concentrations of the VOCs that they catabolize, a situation that is likely in real-world situations (Guieysse et al., 2008). ...
Article
Indoor air quality has become a growing concern due to the increasing proportion of time people spend indoors, combined with reduced building ventilation rates resulting from an increasing awareness of building energy use. It has been well established that potted-plants can help to phytoremediate a diverse range of indoor air pollutants. In particular, a substantial body of literature has demonstrated the ability of the potted-plant system to remove volatile organic compounds (VOCs) from indoor air. These findings have largely originated from laboratory scale chamber experiments, with several studies drawing different conclusions regarding the primary VOC removal mechanism, and removal efficiencies. Advancements in indoor air phytoremediation technology, notably active botanical biofilters, can more effectively reduce the concentrations of multiple indoor air pollutants through the action of active airflow through a plant growing medium, along with vertically aligned plants which achieve a high leaf area density per unit of floor space. Despite variable system designs, systems available have clear potential to assist or replace existing mechanical ventilation systems for indoor air pollutant removal. Further research is needed to develop, test and confirm their effectiveness and safety before they can be functionally integrated in the broader built environment. The current article reviews the current state of active air phytoremediation technology, discusses the available botanical biofiltration systems, and identifies areas in need of development.
... One of the examples of indoor air pollutants that is usually found is VOC. According to Aini Jasmin et al, (2012), VOC is one of the chemical compounds that able to affect the health of the building occupants. Previous researchers have suggested that plants can be used as an alternative to minimize the air pollution for better indoor air condition. ...
Article
Full-text available
Nowadays, the importance of the indoor environmental quality (IEQ) has become more serious as it is highly related to the satisfaction of the occupants. However, most building occupants are not normally aware of the importance of the Indoor Environmental Quality (IEQ). Good IEQ specifically for educational oriented environment should be focused on as it affects students’ learning performance. Therefore, two methods have been specifically selected for this research. One is classroom environment intervention and the other is by classroom measurement set up. In both conditions, the sampling devices were placed for 2 weeks in certain selected locations to see any clianges on environment in the classroom. Measurement of thermal comfort and indoor air quality were recorded and at the same time questionnaires were distributed among the students in order to identify their satisfaction. Results for the measurement in normal condition show that the level of VOC was high (11.7ppm). However, by placing the selected potted plants during the intervention, the action has decreased the level of relative humidity, level of CO2 and TVOC.
... When the system was illuminated again, the gas concentrations in the exhaust were re-stabilized to the previous levels. It is well known that CO 2 is absorbed through the stomata of plants during the process of photosynthesis (that is, in the presence of illumination), and O 2 is absorbed during respiration (in the absence of illumination) (Aini Jasmin et al., 2012). Therefore, these results indicate that the experimental plants in the biofilter system are the active factor for the operation of the air filter system. ...
Article
We investigated a novel plant-based air filter system for bacterial growth control. The volatile components released from the experimental plant ( Cupressus macrocarpa ) were used as the basis of the bacterial growth control and inhibition. We monitored the effect of light on the gas exhausted from the system, and we found that the presence of light induced an increase in the O 2 concentration and a decrease in the CO 2 concentration in the exhaust gas. A variety of Gram-positive and -negative bacteria was used to elucidate the effect of the exhaust gas on bacterial growth. In the Bacillus subtilis cultivation aerated with the exhaust gas (batch mode), we observed a decrease in the specific growth rate (μ = 0.227 h -1 ) compared with the control experiments (0.257 h -1 ). The same result was observed for the Staphylococcus aureus cultivation aerated with the exhaust gas. In the case of Gram-negative bacterial cultivation aerated with the gas, no significant inhibitory effect of the exhaust gas on the bacterial growth was observed. When the number of bacteria ( B. subtilis ) in a continuous culture was varied at different aeration rates (between 50 to 200 mL/min) using the exhaust gas, a prominent inhibitory effect was observed. Preliminary gas analysis showed that the major inhibitory factors in the exhaust gas are α- and β-pinene and linalool. The results show that the air filter system used in this study could be applied not only as a methodological aspect for estimating antibacterial activity but also for bacteria control in a given system. Keywords : Plant-based biofilter, Cupressus macrocarpa, Bacillus subtilis , Staphylococcus aureus , α-pinene, β-pinene African Journal of Biotechnology Vol. 12(16), pp. 2027-2033
... When the system was illuminated again, the gas concentrations in the exhaust were re-stabilized to the previous levels. It is well known that CO 2 is absorbed through the stomata of plants during the process of photosynthesis (that is, in the presence of illumination), and O 2 is absorbed during respiration (in the absence of illumination) (Aini Jasmin et al., 2012). Therefore, these results indicate that the experimental plants in the biofilter system are the active factor for the operation of the air filter system. ...
Article
Herein, we present a novel photoelectrochemical sensor system for the rapid enumeration of algal biomass. The photosynthesis-based reducing action of algal cells on the electrochemical mediator 2-hydroxyl-1,4-naphthoquinone (HNQ) was used as the basis of an amperometric sensor system. By using a simple LED (Light-Emitting Diode) installed three-electrode cell, the mediator that was reduced by algal metabolic activity was reoxidized at a platinum-working electrode and held at a positive potential. In the presence of CO2 as an electron donor, and LED illumination as an energy source for the algal cells, the reoxidation current and its rate of increase were found to depend on the concentration of algal biomass. Regression analyses plotting the initial rate of current (μA min−1) against algal biomass concentrations (g L−1) produced a reasonable correlation coefficient (r2 = 0.9938). The sensor system exhibited a high sensitivity to algal biomass at a concentration as low as 0.065 g L−1and a rapid response time, which is promising for further applications of the sensor system in algal-related industries.
Article
This paper deals with the different ability of certain succulent plants in absorbing CO2 from the hospital environments. Plants are known to remove CO2 during day by photosynthetic metabolism. CO2 increases during night in a small unit of space and time in the absence of a good air circulatory system and ventilation. Apicra deltoidea, Sedum pachyphyllum, Bryophyllum pinnata, and B. calycinum were employed as the succulent plants to remove the CO2 that accumulated in the experimental chamber and the rooms. Apicra deltoidea seems to be a very useful succulent plant in removing almost 80% of the accumulated CO2. Mixed succulent plants like Apicra deltoidea, Sedum pachyphyllum and Bryophyllum pinnata in a hospital room were observed to remove considerable amounts of CO2. Mixed succulent plants in the hospital rooms not only can be used to decorate the interior of the hospital environment and increae its aesthetic value but also be used to freshen the air quality and increase the comfort by removing CO2 and other unknown gases from the indoor environments.
Article
This paper concerns field measurements of volatile organic compounds (VOCs) in five office buildings. The buildings were selected to represent buildings without obvious problems with regard to the indoor air quality. The total concentrations of VOCs (TVOC) were measured using two different detection principles. Both short-term measurements and continuous monitoring were carried out. The results show that the use of continuous TVOC monitoring can provide valuable information in addition to the results obtained by sampling. The indoor TVOC concentrations obtained by gas chromatography ranged from 0.16 to 0.35 mgm−3. The indoor-outdoor TVOC concentration difference obtained by photoacoustic spectroscopy was about twice as high during working hours as during the night time. Furthermore, it is indicated that VOCs in indoor environments do not only originate from construction materials and other internal sources. Outdoor sources can also have a substantial influence on the indoor VOC concentrations.
Article
In the present study, the odour emission of a new HVAC-system in an office building of the Technical University of Berlin has been investigated. The system was built as part of a research project to develop an HVAC-system, which emits low pollution to the supply air. The odour intensity of the air before and after each component of the system was assessed by a human panel. The sources of odour emission inside the system should be localized.The system is equipped with a frequency-controlled fan to vary the airflow rate. Variances in the airflow rate can influence the odour intensity of the supply air due to changes in the odour emissions from the materials (velocity at the surfaces, friction) and the ratio of emitting substances from surfaces to the supply airflow (dilution of the emitted substances with outdoor air). In this study the influence of the airflow on the air quality of the supply air is investigated.Besides the odour emission inside the ventilation system the impact of the quality of the supply air on the indoor air quality in the ventilated rooms is of major interest. Therefore, the perceived air quality (PAQ) of the rooms was assessed by a trained panel in this study. The tests have been carried out with and without mechanical ventilation. Since the other pollution sources in the rooms emitted from building materials and furnishings did not change significantly during the measurement period, the differences in the assessments are mainly caused by the HVAC-system.
Article
The air, particularly the indoor air, contains a consider able burden of unwanted pollution. Overall there may be thousands of pollutants. They are brought in with the outside air or are generated from or within buildings. Most will be present in minute amounts but several will be present in measurable quantities. The reaction of peo ple to the components of this pollution has little to do with toxicological assessment but is more concerned with political responses and media scares. The health effects from exposure to the very low levels commonly found in the indoor environment of materials such as combustion products, whether from coal, petrol or to bacco or to lead or asbestos fibres, are probably negligi ble but we worry about them. On the other hand, gases such as carbon monoxide or nitrogen dioxide which are not infrequently present in dangerous concentrations, many solvents and dust-generating DIY projects cause little concern. The distinction between concern and indif ference is made without reference to any toxicological knowledge. Although it is certainly prudent, through source control, design and ventilation of buildings, to reduce all pollutants to the lowest level, concentrating on media favourites rather than more important dangers, including disease transmission, may well be a poor use of our resources.
Article
Recently, airtight envelope system has become popular in the design of office buildings to reduce heating and cooling loads. Maintaining allowable indoor air quality (IAQ) for such airtight buildings totally depends on mechanical ventilation systems. Subsequently, poor operation of the ventilation system in such office buildings causes ineffective removal of polluted indoor air, and displays a sign of ''sick building syndrome'' (SBS). User's perception is an important parameter for evaluating IAQ. A questionnaire study was carried out to investigate the prevalence of the SBS at a multistory centrally air-conditioned Airport Authority of India (AAI) building in the New Delhi city. Quantification of the perceptions of the users regarding IAQ was done by converting their responses to a SBS score. The quantified answers were then subjected to statistical analysis. Qualitative analysis of the questionnaire was carried out to evaluate relationships between SBS score and carbon dioxide (CO 2) and other parameters related to building and work environment. Quantitative analysis of IAQ was also conducted by monitoring indoor concentrations of four pollutants, namely, nitrogen dioxide (NO 2), sulphur dioxide (SO 2), suspended particulate matter (SPM) and carbon monoxide (CO). Concentrations of pollutants were complying with IAQ standards as given by ASHRAE and WHO. The SBS was higher on the third floor as compared to other floors and the control tower. The main symptoms prevailing were headache (51%), lethargy (50%), and dryness in body mucous (33%). The third floor and the control tower were affected by infiltration, mainly from entrance doors. A direct relation between the average SBS score and CO 2 concentration was found, i.e., the average SBS score increased with CO 2 concentration and vice versa, clearly signifying the usefulness of SBS score in IAQ.
Article
The Pearl River Delta (PRD) region of Guangdong province has been developed rapidly in recent years, and many new hotels have been built. Nevertheless, the indoor air quality (IAQ) of hotels is seldom investigated and reported. Therefore this study aimed at examining the air quality in newly opened hotels in the region. A 2-day field test was carried out in each of the eight sampled hotels, investigating both indoor and outdoor air qualities. Major air pollutants including individual volatile organic compounds (VOC) and total volatile organic compounds (TVOC), as well as physical background parameters such as air temperature (Ta), relative humidity (RH), and ventilation rate were investigated. The results showed that most of the sampled hotels were unable to provide a completely healthy indoor environment. Compare with findings of similar studies, this study found that in terms of air quality, new hotels were more polluted than older hotels and residential buildings. The dominant pollution sources came from indoor, rather than ambient environment. At the end of this paper, some recommendations for improving hotel IAQ are presented.
Article
Plants have the capability to remove indoor air pollutants and furthermore to decompose odor molecules in an indoor environment. Hydrogen sul®de (H 2 S), ammonia (NH 3) and methyl mercaptan (CH 3 SH) are the three main offensive odors in a nursing home. It is strongly desired to develop an effective method for reducing those substances. In this study, the pollutant-removing characteristics of a potted plant for three substances, ammonia, formaldehyde and acetone, are examined using a tin oxide gas sensor. As for the results, it became obvious that the removing characteristics for ammonia gas could be indicated using an approximate function of y ˆ a exp…Àbx† ‡ c. In this function, the coef®cient b stands for the removing effect and c means the offset level of sensor output. The coef®cient a stands for the intercept from that level. It can indicate the number of pots and the kind of plants to maintain the clean air quality in an indoor environment. The pothos plant is very available for putting this to practical use. # 2002 Published by Elsevier Science B.V.
Article
Phytoremediation—using plants to remove toxins—is an attractive and cost effective way to improve indoor air quality. This study screened ornamental plants for their ability to remove volatile organic compounds from air by fumigating 73 plant species with 150 ppb benzene, an important indoor air pollutant that poses a risk to human health. The 10 species found to be most effective at removing benzene from air were fumigated for two more days (8 h per day) to quantify their benzene removal capacity. Crassula portulacea, Hydrangea macrophylla, Cymbidium Golden Elf., Ficus microcarpa var. fuyuensis, Dendranthema morifolium, Citrus medica var. sarcodactylis, Dieffenbachia amoena cv. Tropic Snow; Spathiphyllum Supreme; Nephrolepis exaltata cv. Bostoniensis; Dracaena deremensis cv. Variegata emerged as the species with the greatest capacity to remove benzene from indoor air.
Article
The emission of organic compounds from textile floor coverings was studied in a climate test chamber under static conditions (zero air exchange) in order to test the parameters which influence such chamber experiments, i.e. the temperature, the humidity and the adsorption on the walls. While depending on the volatility and the polarity of the compound, the equilibrium concentrations increase in part substantially with increasing temperature, the humidity has little impact on the observed concentrations. The chamber walls represent an important sink for polar and less volatile compounds, although this sink does not influence the equilibrium concentrations. Ten textile floor coverings have been tested (7 of which had a polyamide pile and a styrene-butadiene rubber backing). Ninety-nine compounds have been identified. The equilibrium concentrations of 20 compounds have been determined. These equilibrium concentrations do not depend on the sample size, the sample loading nor on wall effects, in contrast to the dynamic method, where these parameters play an important role.
Article
This paper deals with the ability of certain succulent plants in absorbing CO2 in different types of rooms inhabited by household members. Plants, generally, are known to remove CO2 in daytime in the presence of sunlight but certain succulent plants, which have a crassulacean acid metabolism (CAM), have a specialized mechanism of stomatal opening and closing which help in the reduction of CO2 during night. A study, using Bryophyllum and Agave, has been carried out in rooms used mostly for resting and sleeping. The number of persons, along with many other parameters, plays a prominent role in the maintenance of CO2 levels in indoor conditions. These plants, grown in pots, were placed in the bedrooms. They lowered CO2 levels to a considerable extent, thus establishing the ability of succulents and CAM plants in lowering CO2 in indoor environments.