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Indoor Air Quality and Human Activities in Buildings

Conference Paper · January 2012

DOI: 10.13140/RG.2.1.2124.2961

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 Civil Engineering Research Exchange Symposium 2012

Session I

STRUCTURES AND MATERIALS

Faculty of Engineering 1 University of Ruhuna

 Civil Engineering Research Exchange Symposium 2012

Indoor Air quality and human activities in buildings

Perera T.M. 1,*, Jayasinghe C. 2, Perera S.A.S 3, Rajapaksa S.W. 4

Abstract
People spend most of their time indoors either at home or at work. If the indoor
environment is polluted, the occupants may experience number of possible health
conditions such as sneezing, fatigue, headache, dizziness, nausea, irritability, and
respiratory diseases as asthma. Also, long term exposure into the pollutants can
cause more serious health effects. Therefore it is very important to maintain a high
degree of hygienic level in all our buildings by achieving a proper design and
maintaining an adequate ventilation system in the indoor environment. There are
different types of ventilation that can be used in the indoor environment such as
free running systems by opening windows and doors, fans and air conditioners.
But due to the poor operational practices in the modern buildings such as
restricting free ventilation by closing doors and windows in most of the time and no
proper maintenance in the air conditioning system may pollute the indoor
environment. Therefore numerous forms of indoor air pollution are possible in the
modern buildings. In this paper, recent research is revised on effect of air
freshener and tobacco smoke on indoor environment with modern operational
practices.

Keywords: Indoor air pollution, Air fresheners, Tobacco smoke

seriously polluted than the outdoor air

1. Introduction1 in most of the industrialized cities.
Most of us spend around 90% of our Thus, there can be several risks
time in the indoor environment. involved for the occupants of various
Therefore, it is essential to maintain types of buildings.
higher level of health and safety inside
all types of buildings. In the last several When we consider the modern
years, the scientific evidence has buildings with prevailing operational
indicated that the air within domestic practices and maintenance, there is a
and other buildings can be more great possibility for the contamination of
the indoor environment.
1
Most of the indoors get polluted due to
Postgraduate Research Student, poor operational practices of both free
Department of Civil Engineering University running and air conditional buildings.
of Moratuwa
2 Although the windows are provided in
Professor, Department of Civil Engineering
University of Moratuwa
buildings according to the building
3
Professor, Department of Chemical and regulations, the occupants do not open
Process Engineering University of them daily due to various reasons such
Moratuwa as poor micro climate around the
4
Medical Professor, National Cancer building with dusty outdoor
Institute of Sri Lanka environments and vehicle fumes

Faculty of Engineering 2 University of Ruhuna

 Civil Engineering Research Exchange Symposium 2012

etc...Also the air conditional spaces are Air Fresheners are consumer
not well maintained by providing products that typically emit fragrance
adequate amount of fresh air. and used in houses, offices, stores,
Therefore air conditioners should also restrooms and commonly in public
be serviced on proper maintenance bathrooms with the promise of creating
schedule. NIOSH[1] looked at 500 of a clean, healthy, and sweet-smelling
the first IAQ investigations that they indoor atmosphere. Furthermore there
had done and found that inadequate are broad range of air fresheners such
ventilation, contamination from inside as traditional sprays, continuous
the building, and contamination from release (Outlet and battery operated),
outside the building were the top three solid gel dispensers, hanging car air
sources of IAQ problems. [2] fresheners and potpourri.
In this investigation it was found that Air
In order to understand the indoor air Freshener that we commonly use is a
pollution it is very essential to identify simply mask odor with chemicals and it
causative agents and the sources of is failed to remove contaminants in the
them. Sulfur Dioxide (SO2),Nitrogen indoor environment. They sometimes
Dioxide (NO2),Carbon Monoxide (CO) add toxic chemicals to the atmosphere
,Volatile Organic Compounds that may lead to cause severe health
(VOC),Carbon Dioxide problems to the occupants. Mainly the
(CO2),Particulate Matter (PM) and levels of volatile organic compounds
undesirable temperature can be (VOC) will increase due to some types
identified as common types of of air freshener. Furthermore many of
causative agents. These pollutants are these air fresheners contain Phthalates,
caused due to combustion products, hazardous chemicals known to cause
building materials, equipment used in hormonal abnormalities, birth defects,
buildings, vehicle emissions, chemicals and reproductive problems and it will
used in maintenance, environmental help to enhance and maintain the smell
tobacco smoke and polluted outdoor of the air freshener. NRDC’s[3]
air. A comprehensive study is going on independent testing of 14 common air
considering above factors on indoor air fresheners, none of which listed
quality and their effect on sick building Phthalates as an ingredient, uncovered
syndrome. This paper highlights two these chemicals in 86 percent (12 of
such factors such as effect of air 14) of the product tested, including
freshener and tobacco smoke on indoor those advertised as “all natural” or
air quality. “unscented”. According to the state of
California notes that five types of
1.1 Pollutant sources studied Phthalates found in air freshener
product are Di-ethyl Phthalate (DEP),
A study has been carried out to Di-n-butyl Phthalate (DBP), Di-isobutyl
investigate the effect of building Phthalate (DIBP),Di-methyl Phthalate
operational practices and two causes (DMP), Di- isohexyl Phthalate (DIHP).
for polluted indoors such as air [4]
freshener and tobacco smoke.
In addition, many cleaning agents and
1.1.1 Air freshener air fresheners contain chemicals that
can react with the other air
contaminants to yield potentially

Faculty of Engineering 3 University of Ruhuna

 Civil Engineering Research Exchange Symposium 2012

harmful secondary products .For NO2.VOC, temperature and relative

example, terpenes can react rapidly humidity of the atmosphere.IQM meter
with ozone in indoor air generating had been placed in the enclosed
many secondary pollutants, including working space with a height of 2.2m
toxic air contaminants such as from the ground level in order to
Formaldehyde. Furthermore, ozone- simulate the height of the, at rest
terpene reactions produce the hydroxyl person on the chair. The occupant
radical, which reacts rapidly with density was kept at zero in order to
organics, leading to the formation of isolate the effect of pollutants. This
other potentially toxic air pollutants. enclosed area is having one window-
[5][6] But this bad effect of toxicants type air condition system with
can be diluted with the opened completely restricted natural air flow
windows in a free running building and into the room. In order to enhance the
properly serviced air conditioner. accuracy of the test, instrument has
been kept at particular place (usually at
2.2 Tobacco smoke the center of the room) 1 hour before
obtain the readings.
Smoking in enclosed spaces exposes
occupants to indoor air pollution from 3. Results and Discussion
the by-products of tobacco combustion
in confined spaces where airborne
contaminant removal is slow and 3.1 Air freshener
uneven. The physical design of the
cigar, leaf type and composition, and In order to contrast the indoor air
wrapper type may all affect the cigar quality with and without air freshener,
emissions. For a given composition, the instrument had been kept 30 min to
mass of a cigar consumed during measure the indoor air quality before
smoking is a primary determinant of the sprayed the air freshener. In addition to
quantity of its emissions. Tobacco that, air freshener sprayed several
active smoking and passive smoking times after some time lag in order to
have been implicated as risk factors for see the variation of the air quality due
most of malignant disease such as lip to the air freshener. From this study, we
and oral malignancies, lung cancer, have identified that mainly the levels of
oesophageal cancers and also infection volatile organic compounds (VOC) will
diseases like tuberculosis (TB), and increase due to the tested types of air
pneumonia. In this experiment it has fresheners. Here are some graphs
revealed that CO, CO2 and VOC have which explain the effect of air freshener
exceeded the permissible indoor air on indoor air quality.
quality limit due to the tobacco smoke. Therefore we decided to fix the
boundaries by testing the constant
2. Methodology volume of the air fresher content (60ml)
in the particular space. Besides that we
In this study, we have used Indoor Air have studied the time requirement for
Quality Monitor (IQM60 Environmental the dispersion of the above quantity up
Monitor V5.0) to identify the air to the permissible limit. Figure 2 gives
pollutants from the air fresheners and the more details;
tobacco smokes. From this equipment, According to the figure 02, max VOC
it is possible to identify CO, CO2, content is 3.65ppm which is 5 times

Faculty of Engineering 4 University of Ruhuna

 Civil Engineering Research Exchange Symposium 2012

higher than the indoor permissible openings in free running ventilation, a

value and also time requirement for the better micro climate should be created
dispersion is approximately 1hr 30 min. with a desirable tree cover.

3.2 Tobacco smoke 5. Acknowledgement

As mentioned above same The authors gratefully acknowledge the
methodology has been adopted for the fund allocated by UOM for the research
tobacco smoke test. Descriptively, equipments and the contribution of the
compare the indoor air quality with and non academic staff members of the
without tobacco smoke by burning 3 Civil Engineering Department,
cigars, one cigar at a time with the University of Moratuwa.
above working conditions. In this
experiment it has revealed that CO,
CO2 and VOC have exceeded the References
permissible indoor air quality limit due
to the tobacco smoke. Below graphs [1] National Institute for Occupational
will demonstrate the effect of tobacco Safety and Health
smoke on indoor air quality.
As figures 03, 04, 05 illustrated, CO [2] www.osha.gov
content is 139.43ppm-15 times higher
than the indoor CO level (9ppm- [3] National Resource Defense Council
ASHRAE), CO2content is 1257ppm-that
is higher than the permissible indoor [4] www.nrdc.org/policy
CO2 level (1000ppm-ASHRAE), VOC
content is 19.29ppm-25 times higher [5]William W. Nazaroof, Charles J.
than the indoor VOC level (0.75ppm- Weschler,” Cleaning products and air
OSHA). freshener: exposure to primary and
secondary air pollutants”, Atmospheric
Furthermore we have contrast the Environment 38 (2004) 2841-2865.
above pollutants emission by burning
and smoking one person a one cigar at [6] Raiph Scott, “Air Freshener, Indoor
the time. From those results we have Air Quality & Federal Policy”, 2008
observed that CO, CO2 and VOC levels National Healthy Homes Conference:
are above the indoor permissible September 15-17, 2008 in Baltimore,
values in both cases. But when MD .
someone smoking, CO and VOC levels
are much far below than the results
obtained from the burning cigar.

4. Conclusion

This study reveals that enclose space

can restrict the dispersion of indoor
pollutants such as air fresheners,
tobacco smoke etc. Opening windows
in free running space would dilute the
most of the indoor pollutants. Also to
promote opening of windows and

Faculty of Engineering 5 University of Ruhuna

 Civil Engineering Research Exchange Symposium 2012

Figure 01 Variation of VOC with time for air freshener

Figure 02 Variation of VOC with time for air freshener

Faculty of Engineering 6 University of Ruhuna

 Civil Engineering Research Exchange Symposium 2012

Figure 03 Variation of CO with time for tobacco smoke

Figure 04 Variation of CO2 with time for tobacco smoke

Figure 05 Variation of VOC with time for tobacco smoke

Faculty of Engineering University of Ruhuna
7

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