Evaluation of the indoor air quality of beato angelico building of the university of santo tomas

Evaluation of the Indoor Air Quality of Beato Angelico
Building of the University of Santo Tomas
Crisencio M. Paner *
* College of Fine Arts and Design, University of Santo Tomas
Abstract
Out of 11 locations in Beato Angelico building sampled on by
agar exposure method, 409 molds isolates were obtained from
which Aspergillus was the most prevalent with 58% occurrence,
Cladosporium, 32%, Curvularia, 9%, and the least was
Neurospora, with only 1% occurrence. Interestingly, surface-
swabbing of airconditioners and water stained ceilings had also
produced similar fungal genera as that of the agar-exposures,
except for Neurospora which was absent in the surface swab
results. After calibrating the mold counts in accordance with the
standards for settling-plate and surface swab methods, results
showed that 75% of the sampling stations for settling plate
method and 100% of the sampling areas for surface swab
method had mold count far beyond the threshold limit value of
100 cfu/90mm/4hr [17, 18, 34, 61].
Meanwhile, Chemical analysis had revealed the following
results: a) the TVOC values of 4.2 ppm and 5.4 ppm
respectively based on two stations were far beyond the TLV
required by WHO, OSHA, and NIOSH [32], b)Total respiratory
dust(TRD) values of 0.9 & 0.3 mg/m3 respectively based
on two stations showed that these values were within the OSHS-
DOLE TLV of 5 mg/m3, & c) the results of CO2

measurements(< 1mg/m3 based on two stations) showed that
these levels were within threshold limit value of 9,000 mg/m3
required by OSHS-DOLE(2005).
Key words: agar exposure method, threshold limit value, Indoor
air quality, TVOC, TRD, CO2
Background of the Study
According to Jackson et al. [35] on average most people spend
80% or more of their daily lives indoors whether at home, work,
or in commercial buildings. The US Environmental Protection
Agency [66] notes that indoor air is often two to five times more
polluted than outdoor air. Over the last two decades, there has
been increasing awareness regarding the potential impact of
indoor air pollution on health.
Indoor air quality (IAQ) is a term referring to the air quality
within and around buildings and structures, especially as it
relates to the health and comfort of building occupants [33].
Indoor air quality (IAQ) is one of many issues that building
owners should address because better IAQ leads to more
productive and happier occupants.
In schools and institutional buildings IAQ are tied to learning
outcomes and organizational missions. While it is hard to put
firm numbers on these benefits, there is increasing evidence of
measurable productivity increases and reduced absentee rates in
spaces with better IAQ. Second, IAQ problems that get out of

hand can be quite costly in terms of lost work time, lost use of
buildings, expensive building or mechanical system repairs,
legal costs, and bad publicity. While extreme IAQ problems are
rare, they do occur, and the consequences can be dramatic. Less
severe problems are more common and can erode occupant
productivity and lead to costs for smaller legal disputes or
repairs. [9]
Experts generally agree that healthy indoor school environments
are a necessity if a high standard of education is to be expected.
Recent studies have shown that schools have significant indoor
environmental problems. High indoor air pollutant concentration
may have a significant adverse impact on the health and
academic performance of students. [38]
Epidemiological investigations have shown that the `sick-
building syndrome(SBS)’ and hypersensitivity diseases (for
example, asthma) are often associated with exposure to large
concentrations of airborne microbes. [2, 22, 31]
A study of teachers working in a moisture- and mold-damaged
school building showed, that levels of these inflammatory
markers in nasal lavage fluid were higher compared to control
group.[29]
In related studies, 80 fungal genera have been associated with
symptoms of respiratory tract allergies, these include
Cladosporium, Alternaria, Aspergillus and Fusarium,
Penicillium, Ulocladium, Sistotrema, Alternaria, Eurotium,
Wallemiu. [25, 30]

Hourly variations of four orders of magnitude of mold aerosols
have been found in a classroom. [47]
Total Volatile Organic Compounds(TVOCs) are one of the most
commonly measured pollutants in schools. VOCs are suspected
as one of the causes of SBS [44, 70]. Measured values of TVOC
can vary significantly depending upon the sampling and analysis
methods used. Particularly high TVOC concentrations, above 1
to 2 mg/m3, indicate the presence of strong VOC sources and/or
low ventilation. Results of studies by the US Environmental
Protection Agency (EPA) and other researchers have found that
VOCs are common in the indoor environment and that their
levels may be ten to thousands times higher indoors than
outdoors. In addition, there may be anywhere from 50 up to
hundreds of individual VOCs in any one indoor air sample. At
very low levels, some VOCs may produce odors that some
people may consider to be objectionable, while others are
irritants that can cause people to have headaches and eye, nose
and throat irritation, and dizziness. At high concentrations, some
VOCs are toxic or may be carcinogenic. Whether or not
someone will become sick or notice an odor is highly variable.
Complaints should be taken seriously, however, and
investigated. Primary VOCs found are associated with solvents,
paints and coating, adhesives, cleaners, furnishings, and
personal care products. In schools, VOCs are associated with
cleaning supplies, pesticides, building materials and furnishings,
office equipment such as copiers and printers, correction fluids
and carbonless copy paper, graphics and craft materials
including glues, adhesives and turpentine for painting students,

permanent markers, whiteboard markers, and photographic
solutions.
Most standards and guidelines consider 200 µg/m3 to 500
µg/m3 TVOC as an acceptable level in buildings. Levels higher
than this may result in irritation to some occupants. However,
lower levels can also be an issue if a particularly toxic substance
or odorant is present. The World Health Organization
recommends that indoor exposures not exceed 0.1 ppm, and that
actions be taken to reduce levels once they read 0.05 ppm.
Although the legal limit covered by OSHA is 0.75 ppm, NIOSH
recommends workers not be exposed to more than 0.016 ppm
averaged over a 10-hour day. [32]
Some chemical constituents of floor cleaning materials have
been recognized as a possible cause of asthma in indoor
environments i.e. colophony based products such as pine oil and
tall oil, and benzalkonium chloride [39]. Building materials are
important emission sources of VOCs, especially in new
buildings [69].
Dust means solid particles being blown about or suspended in
the air generated by handling, crushing, cutting, drilling, rapid
impact, spraying, detonations, or disintegrations of inorganic or
organic materials and are of a composition similar to the
substance or substances from which they are derived. Total
Respirable Dust (TRD) is measured gravimetrically. Dust can
contain particles of a wide range of sizes. The effect of these
particles when ingested into the body depends on the size, shape
and chemical nature of the particles. Several studies have

demonstrated that particles in ambient air have adverse effects
on respiratory health. [14, 19, 52 53, 56, 57, 64]
Carbon dioxide is a normal constituent of exhaled breath and is
commonly measured as a screening tool to evaluate whether
adequate volumes of fresh outdoor are being introduced into
indoor air. The carbon dioxide level is usually greater inside a
building than outside, even in buildings with few complaints
about indoor air quality. ASHRAE recommends that the indoor
CO2 concentration be no greater than 700 ppm above the
outdoor concentration for comfort (odor) reasons [6].
Air Velocity or Ventilation rates have rarely been measured in
schools, although inadequate ventilation is often suspected to be
an important condition leading to reported health symptoms.
ASHRAE Standard 62-1999 [8] recommends a minimum
ventilation rate of 8 L/s-person (15 cfm/person) for classrooms.
Given typical occupant density of 33 per 90m2 (1000 ft2) and a
ceiling height of 3m (10 ft), the current ASHRAE standard
would require an air exchange rate of about 3 air changes per
hour (ACH) for a classroom.
Humans have difficulties perceiving changes of the relative
humidity (RH), due to lack of sensory receptors for humidity
[49]. In contrast, specific sensors exist for the perception of the
temperature. However, reporting of “dry air” has been
associated with poor indoor air quality (IAQ) or a sub-standard
indoor environment since the 1980's [16]. Temperature and RH
measurements are often collected as part of an IEQ investigation
because these parameters affect the perception of comfort in an
indoor environment. The perception of thermal comfort is

related to one's metabolic heat production, the transfer of heat to
the environment, physiological adjustments, and body
temperature [50]. Heat transfer from the body to the
environment is influenced by factors such as temperature,
humidity, air movement, personal activities, and clothing.
Moisture is one of the most common causes of IAQ problems in
buildings and has been responsible for some of the most costly
IAQ litigation and remediation. Moisture enables growth of
microorganisms, production of microbial VOCs and allergens,
deterioration of materials, and other processes detrimental to
IAQ. In addition, dampness has been shown to be strongly
associated with adverse health outcomes. Control of moisture is
thus critical to good IAQ. High indoor humidity can lead to
dampness and low indoor humidity (less than 30% RH) can
cause mucus membrane irritation, dry eyes, and sinus
discomfort. Maintaining indoor humidity between 30-50% will
control mold growth and alleviate the symptoms associated with
low humidity. Negative building pressure can draw moist
outdoor air into the building envelope, potentially leading to
condensation. It can also draw moist air into the conditioned
space itself, potentially increasing the latent load beyond the
cooling system design capacity and leading to elevated indoor
humidity. Positive building pressure can push moist indoor air
into the building enclosure, potentially leading to condensation
under heating conditions [15].
ASHRAE recommends that relative humidity in indoor
environments be maintained between 30% and 50% relative
humidity [6] and that the indoor temperature range provide for
occupant comfort (69.0oF to 76.5oF in the winter and 75.5oF to
81.0oF in the summer at 40% relative humidity [7]. Studies

indicate that RH about 40% is better for the eyes and upper
airways than levels below 30%. The optimal RH may differ for
the eyes and the airways regarding desiccation of the mucous
membranes [71].
There has been a long-standing historical use of settle plates,
and that European regulatory agencies have supported their use.
However, current active air sampling technology can be more
advantageous and effective in assessing airborne viable
contamination in clean rooms than settle plate monitoring. The
use of settle plate monitoring may still be an optional test
method for those applications where other more efficient
sampling methods may not be possible or may have limited
applicability [5]. Agar exposure method also known as the
“Settle plate method” relies on the principle that the molds
carrying particles are allowed to settle onto the medium for a
given period of time and incubated at the required temperature.
Malt extract agar is the appropriate medium used to culture
molds. The normal sampling time is between 10 to 60 minutes.
Though the method has the advantage of simplicity, it has
certain limits. In this method only the rate of deposition of large
particles from the air, not the total number of molds carrying
particles per volume, is measured [62]. Settle plate methods are
insensitive unless a long exposure period is adopted in order to
detect the low number of airborne microorganisms. If this is not
carried out the results are biased to give favorable data. If this is
not practicable then plates should be monitored for successive
work sessions and the incidence of contamination analyzed. The
average size of microbial particle will deposit, by gravity, onto
surfaces at a rate of approximately 1 cm/s. Petri dishes which are
90 mm in diameter (approximate internal area 64 cm2) are most

commonly used. For settle-plate method, the standard values are
50 cfu/90mm/4hours for ordinary indoor air at rest, and 100
cfu/90mm/4hours for indoor air operational. Clean room at rest
is 5 cfu/90 mm/4 hours, while clean room operational is 50
cfu/90mm/4 hours. For swab and contact plate methods, the
standards are 25 cfu/25cm2(for air at rest) and 50 cfu/25cm2(for
air at operational). Clean support standard values on the other
hand are 5 cfu/25cm2(at rest) and 25 cfu/25cm2(operational)
[17, 18, 34, 61].
The Beato Angelico Building (Fig. 5), built in 1991, is an eight-
storey structure that houses the College of Architecture, the
College of Fine Arts and Design, and an art gallery for the
exhibits of students, faculty members, and alumni artists. Since
2001, a portion of the ground floor has also served as the offices
and technical facilities of the UST Publishing House. The
building was designed by Architect Yolanda D. Reyes, a former
dean of the College of Architecture. Beato Angelico building is
located at the corner of España and P.Noval Streets, Manila
[12]. The building accommodates around six thousand students
and faculties from both the College of Fine Arts and Design and
the College of Architecture.
There is a scarcity of studies in the Philippines regarding Indoor
air quality of schools encompassing both the chemical and
microbiological aspects. In particular there are no figures
available on the prevalence in the Philippines of fungal
contamination in indoor environments. It was the first time that
this study was conducted on the indoor air of a building within
the campus of the University of Santo Tomas (UST). The study
had the following objectives:

1. To find the typical concentration levels of fungal bioaerosol
in selected indoor environment of Beato Angelico Building.
2. To determine the level of concentrations of selected key
indicators of air pollution such as Total volatile organic
compounds (TVOCs), Total respirable dust(TRD), and Carbon
dioxide (CO2) .
Materials and Methods
I. Walk-through Inspection
The building were surveyed and observed for signs of building
damage and microbial contaminations such as water stains.
II. Determination of Fungal Contaminations
A. Agar Exposure Method
Five agar plates were exposed for one hour in each floor (near
the stairs) of the building as well as in the three rooms
identified: Faculty room, Rooms 101 and 102 of the 8th Floor.
The plates were placed on a table with a height of at least 1.5
meter above the ground. Malt-extract agar (half-strength) plates
with pH maintained at 3.5 to specifically select for the molds
were prepared.

At the end of each exposure period, the plates were placed in an
incubator with temperature maintained at room temperature for
3-5 days. For identification of molds, each fungal isolate were
cultured on MEA agar blocks on glass slides based on Henrici’s
culture technique. Subsequent sporulating growth were
examined with both stereoscopic and bright field microscopes.
Fungal genera were identified using literatures on Fungal
Taxonomy and Mycology. During the agar exposure, other
parameters of the indoor air were also measured such as
temperature and relative humidity. The number of occupants at
the time of exposure were also counted.
B. Surface Sampling by Swab Method
Sterilized cotton buds moistened with normal saline solution
were swabbed gently on different surfaces (with an area 25 of
cm2 each) suspected with microbial contaminants like water
stain marks on the ceilings and walls, and including louvers of
the airconditioners. The swabs were then streaked directly onto
plates of half-strength Malt Extract Agar (with pH 3.5 to inhibit
bacteria). Prepared culture plates were incubated at room
temperature for 3-5 days. Molds genera were identified using the
same procedures as in IIA.
III. Determining the Levels of Indoor Air Chemical
Pollutants
In the absence of specific instruments to be used on this part of
the study, the researcher commissioned the company First
Analytical Services and Technical Cooperative (F.A.S.T.

LABORATORIES) to conduct the sampling and analysis. Due
to budgetary constraints only few indicators of indoor air
pollution were measured such as Carbon dioxide(CO2), Total
volatile organic compounds (TVOCs), and Total respirable dusts
(TRD).
Aside from these other physical parameters of the indoor air
were also measured such as air velocity, temperature, and
humidity. For TRD and CO2, the Main Entrance/Exit and the
area near the stairs in the 2nd floor were the areas sampled on.
While for TVOC, Room 1(first floor) and room 1(eight floor)
were the areas selected for sampling.
Results and Discussions
I. Walk-through Inspection of the Building
During the inspection of the building last March 2, 2010, which
began at 2 O’clock in the afternoon and ended at around 5
O’clock in the afternoon, the following things had been
observed: a) several water stains on the ceiling of the faculty
room; b) intense smell of volatile organic chemicals at room
101(ground floor), and room 1 and 2 (eight floor). It was later
found that this volatile chemical at room 101(ground floor) was
due to the adhesives that the students of the Industrial Design
had bee using, while at room 1 and 2 (eight floor), the volatile
chemical was due to ‘turpentine’ that the Painting students had
been using as thinning agent for their painting pigments, c)
Louvers of the aircon in all the rooms selected for sampling

were found to be full of dust, an indication that they have not
been cleaned for a long time.
Furthermore, from ground floor up to the eight floor near the
stairways, it was also observed that air was very hot and humid.
Many students were also observed coming in and out the
building at that time.
II. Determination of Fungal Contaminations
A. Agar Exposure Method or Settle Plate Method
As indicated in Table 1, there was a generally slight decreasing
trend in the number of molds isolated from ground floor to the
8th floor of the building. This could be attributed to the number
of people [55] who were present at the time of the sampling. It
has been observed that majority of people were present at the
ground floor more than in the other floors because of its function
as entrance and exit. Next to ground floor, second floor were
found to have also a greater number of students. It was because
this floor housed the offices and faculty rooms of both the
College of Fine Arts and Design and the College of
Architecture.
The decreased number of molds isolated from third floor to eight
floor may also be attributed to the lesser number of students
observed to be present during the time of sampling. For room
1(ground floor) and rooms 1 & 2 (eight floor), the number
of molds isolated showed almost similarly small. Reason for this
was because these rooms were airconditioned and even though

there were occupants (mean 35) inside, they performed lesser
activity compared with those people in the ground floor.
According to Flannigan [25] any activity in the building might
disturb settled spores causing them to spread in the air.
As for the temperature and relative humidity, Table 1 showed a
generally high values from ground floor to the eight floor with
an exception for room 1(ground floor) and rooms 1 and 2 of the
eight floor which were airconditioned.
Increased temperatures and humidities in the environment are
conducive to the growth of molds, causing them to multiply
faster and produce spores in great amounts.
Half-strength of Malt-Extract Agar was used in the experiment
in order to delay the growth of some fast growing molds.
As shown in Table 1 & Figure 1, of the 409 molds that
were isolated from 11 different locations, Aspergillus (Fig. 6b)
was found to be the most prevalent with 58% occurrence,
Cladosporium (Fig. 6c) with 32%, Curvularia (Fig.6a) with 9%,
and the least was Neurospora (Fig. 6d), with only 1%
occurrence. The results were not surprising because for example,
Aspergillus niger, has been found growing on damp walls and
ceilings [10]. Miller [42] stated that among the facultative
pathogens of Interest, Aspergillus fumigatus, A terreus and
sometimes A flavus cause aspergillosis, an invasive lung
disease. On the other hand Cladosporium is a dematiaceous
(pigmented) mold widely distributed in air and rotten organic
material and frequently isolated as a contaminant on foods [23,

24]. The genus Cladosporium includes over 30 species and the
most common ones include Cladosporium elatum,
Cladosporium herbarum, Cladosporium sphaerospermum, and
Cladosporium cladosporioides. Cladosporium spp. are causative
agents of skin lesions, keratitis, onychomycosis, sinusitis and
pulmonary infections [20, 59]. Furthermore, Miller [42] had also
affirmed that most people diagnosed as allergic to mold are
tested for allergy to Cladosporium cladosporiodes,
Cladosporium herbarum and Alternara alternate. In another
related study, it was found that hay fever has a significant
correlation with indoor fungi, such as Cladosporium,
Epicoccum, and Yeast [63]. Curvularia has three ubiquitous
species which have been recovered from human infections,
principally from cases of mycotic keratitis; C. lunata, C.
pallescens and C. geniculata. Clinical manifestations of
phaeohyphomycosis include sinusitis, endocarditis, peritonitis
and disseminated infection [60]. Neurospora is a common bread
mold and has not been normally implicated in any human
disease. But its presence in the air can also possibly cause
allergic rhinitis specially to a compromised individuals if
inhaled.
Figure 3 is the experiment set-up for agar exposure method. It
shows a petri-dish placed on top of a stool with half-strength
Malt-Extract Agar(pH 3.5) being exposed for one hour to air at
the ground floor of the Beato Angelico building. Relative
humidity and temperature of the indoor air were also taken in
this site as well as in other 10 more sites. The area with the
highest number of molds isolated were the water stains on the
ceiling (Table 2 & Fig. 2) of the faculty room. While the
rest of the sampling areas had similarly small numbers of

isolated molds. But the mere fact that molds were isolated from
all the sampling areas was an indication that majority of
airconditioners were not being cleaned or not being cleaned as
regularly as it should.
A higher number of molds isolated in the water-stained ceiling
can be attributed more on the water that may have infiltrated the
gypsum board ceiling and which made it a good breeding
ground for a variety of molds.
This is a rather dangerous situation on the part of the occupants
of this room particularly those who stay there for quite sometime
because if the contaminated tile ceiling is not replaced
immediately, prolong periods would generate thousands of
spores which when inhaled by a compromised person may cause
him or her an allergic rhinitis or much worse a respiratory
disease such as aspergillosis.
Differences in the size and sedimentation rate of spores also
affect what is detected in air samples. For instance, it has been
found out that large Ulocladium spores released from mold
patches on walls in damp houses sediment rapidly [25] so that,
even where growth is profuse, the mold is likely to be detected
in the air in quantity only shortly after disturbance of the growth
or re-entrainment of settled spores as a result of activity.
Out of 117 molds that were isolated through agar swab method
from four sampling locations (consisting of 13 aircon louvers
and three water stained gypsum ceiling boards), Aspergillus
revealed the highest percent occurrence at 60.7%, Cladosporium
was next with 31.6% occurrence, and the least was Curvularia,

with 7.7% occurrence(figure 5 & table 2). This result is
almost similar as that of Agar exposure results in terms of the
kind of fungal genera that were isolated. It was not impossible
because this population of molds after being suspended in the air
for a while would eventually fall on different surfaces due to
earth’s gravitational pull.
In order to calibrate the average number of molds in Table 1
with that of the standards, the values in the table had to be
multiplied by 4. This was because in the standard, the exposure
time was 4 hours while in the experiment conducted the
exposure period was only 1 hour.
It can be seen in Table 3 that in general the number of molds
isolated from ground floor to eight floor were all beyond the
threshold limit value of 100 cfu/90mm/4hr except for room
1(ground floor) and rooms 1 & 2 at the eight floor which
were below the threshold limit values. Again these values above
the threshold limit can be accounted for the presence of people
at the sampling areas during the sampling time. The observed
high temperature and high humidity were also possible reason
for the high mold count since these could provide a conducive
environment for the growth of molds [11]. The mold count may
be reduced if only there were exhaust fans in the areas sampled
on.
Dampness can occur from existing leaks or new leaks from the
windows, building façade, leaking pipes above the ceiling, or
leaking unit ventilators from the floor above.

It is generally recognized that the growth of mold on interior
surfaces in buildings is unacceptable and that the amount of
growth (surface area) in a room is important in determining the
procedures used in mold remediation [ 3, 45, 46, 51, 67 ].
According to Miller [42], fungal contamination of building air is
almost always caused by poor design and/or maintenance.
Molds are transported into the indoor environment through air
circulation or are carried indoors by organisms, including human
beings, or in the moving of inanimate objects that have molds
attached to their surfaces. When the food source, moisture,
temperature, and so forth in the indoor environment are
favorable, molds can grow.
Ghosh and Hines [27] said that fungi are introduced into an
indoor environment, they can settle in amplification sites where
they thrive and grow. Amplification sites include any site with
the proper pH, temperature, and moisture content.
In some moisture damaged buildings, mold growth is hidden on
construction materials within wall cavities or building
assemblies and thus not readily evident during inspection.
Microbial volatile organic compounds reportedly can diffuse
through building construction and may be useful in locating
concealed mould growth [68].
P. chrysogenum was the dominant culturable mold
(concentrations about 200 cfu/m3) found in air samples
collected in leaky rooms. P. crustosum, P. commune, P.
spinulosum, and P. aurantiogriseum were also present in leaky

rooms at concentrations at least an order of magnitude higher
than those detected in the outdoor air [46] .
According to a recent study of Bornehag et al. [13] early
detection of water leakage was indicative of the extent of visible
mold growth subsequently found on biodegradable construction
materials hidden within exterior walls. The study also showed
that spores from hidden mould growth in exterior walls can enter
the indoor air in sufficient amounts to significantly degrade
indoor air quality, e.g., by changing the rank order of taxa in
room air.
Molds may grow on the stagnant water left in the humidifier and
then be aerosolized when the unit is reactivated [54].
Currently, it is suggested by the American Conference of
Governmental Industrial Hygiene [1] that bioaerosol
concentrations higher than 500 CFU/ m3 be considered as a sign
of the presence of a building-related air pollution source.
The fungal concentrations found at most of the indoor
environments should fall within the specified guidelines of the
American Conference of Government Industrial Hygienists,
between 100 and 1000 CFU/m3 for the total fungi [2].
As presented in Table 4, the calibrated average number of molds
based on surface swab method for all locations were above the
standard TLV of 50 cfu/25 cm2. These results were proof that in
a natural way, the molds in the air may later on find its way on
different surfaces by gravity. However, high number of molds

found on the surfaces are also indicative of poor cleaning
practices.
The standards set by ACGIH [2] which is between 100-1000
CFU/m3 for the total fungi could not be applied in this study
because the methods of sampling of indoor air were both
different. In ACGIH standards, the method of sampling was
based on an Andersen air sampler (impinger or impactor
apparatus) while in this study, the indoor air was sampled
through settling-plate method. Of course, the first one was much
more accurate than the second one, however in the absence of
the air sampling apparatus which is more expensive, Agar
exposure method may still be used as an alternative. It’s
accuracy however may be just increased by using higher number
of agar-exposure plates per sampling location, by increasing the
time of exposure (at least up to 4 hours), by being careful not to
contaminate the plates, and by using appropriate media for
culturing the molds like malt-extract-agar, saboraud’s dextrose
agar, etc…
III. Determining the Levels of Indoor Air Chemical
Pollutants
In the chemical analysis of the indoor air of Beato Angelico
building, a private company (FAST Laboratories) was
commissioned to the job, the methods of sampling and analysis
were based on Occupational Safety and Health Standards-
Department of Labor and Employment (OSHS-DOLE), 2005
and the National Institute for Occupational Safety and Health
(NIOSH).

Table 5 shows the summary of different parameters that were
measured as well the different sampling methods and analytical
methods applied in this study.
Total Volatile Organic Compounds(TVOCs)
In this study the Total Volatile Organic Compounds (TVOCs)
were collected using VX 500 Gas analyzer and measured using a
PID RAE monitor.
Presented in Table 6 were the levels of Total Volatile Organic
Compounds in the two identified locations namely Room F101
and room F802. These two rooms were particularly selected
because of the observed presence of VOC smell in these rooms.
In room F101, it was observed that there was a smell of
adhesives which the Industrial Design students were using.
While in room F802, there was a recurring smell of turpentine in
the room which the Painting students were using when they
conduct oil painting sessions.
Unfortunately, OSHS-DOLE had no existing Threshold Limit
Value(TLV) for TVOCs, so the researcher conducted intensive
research on the reference standards from the library and the
World Wide Web.
Lucky enough, the researcher had found what he was looking
for. He had found actually not only one but 3 different reference
standards, namely: WHO, OSHA, and NIOSH [32] . So,
referring again to Table 6, the TVOC values of 4.2 ppm (for
room F101) and 5.4 ppm (for room F802) were very far higher
compared with the 0.1 ppm TLV set by World Health

Organization [32]. In this case TVOC value in F101 was 42
times higher than WHO TLV, while in room F802 the TVOC
value was 54 times higher compared with WHO Threshold limit
values for VOCs. Comparing still the measured TVOC values
with OSHA [32] standard of 0.75 ppm, it was obvious that the
measured values for the two rooms were very much higher
compared with the OSHA TLV.
NIOSH [32] has even stricter standard when it recommends
workers not be exposed to more than 0.016 ppm averaged over a
10-hour day. If this would be applied to the two rooms
mentioned then the students in these rooms, assuming they stay
in that rooms for 10 hours, then they are exposed to 300 times
more than the threshold limit value. This reminded me when one
time, Prof. Noel Escultura (Pers. Comm., March 7, 2010)
admitted that he knew his Painting class were getting high
already on turpentine(VOC) when suddenly they began making
noises and there was also a sudden change in his students’
behavior.
But actually, this problem may be easily remedied by putting
exhaust fans in the room. These fans can siphon out these
volatile organic compounds that are present in the room.
Requiring students to wear gas mask is also one solution
although, some may complain of uneasy feeling in using the
mask.
Total Respirable Dust(TRD)
The Threshold Limit Value(TLV) for Total respirable
Dust(TRD) set by OSHS-DOLE(2005) was 5 mg/m3. In this

study TRD was collected through filtration method and analysis
was done gravimetrically.
Presented in Table 7 is the dust concentrations (TRD) measured
at Main Entrance/Exit and 2nd floor of Beato Angelico building.
Comparing the two values with the OSHS-DOLE TLV of 5
mg/m3 would show that they are within the threshold limit
value. However, if we would apply the standard of Molhave [43]
and Helmis et al. [28], the two values are much higher compared
with threshold limit value of 50 microgram/m3 even if these two
values are adjusted with that of the standard.
Differences in standards are expected because one could decide
to increase his standard in order to achieve higher quality indoor
air while the other one could not increase yet the standard
because of some considerations like inability of majority of
companies to follow yet a higher standard in terms of indoor air
quality. Financial factor is also one reason because it also
requires big amount of money to achieve or maintain a higher
quality of indoor air.
Particulate air pollution is a complex mixture of solid particles
and liquid droplets of different size, composition and origin.
Particles with a diameter less than 10 micron are of special
interest since they are inhalable. These particles are often
referred to us PM10 [52].
According to Molhave [43] and Helmis et al. [28], the minimum
acceptable concentration PM10 in the indoor environment
should be 50 microgram (µg)/m3 at 24 continuous hour
exposure.

RH has an effect on the formation and size of secondary
aerosols and therefore on the deposition. Low RH appears to
enhance particle deposition of fine particles [36] and high RH
likewise [26, 41].
Carbon Dioxide (CO2)
The threshold limit value for CO2 level based on the OSHS-
DOLE(2005) is 9,000 mg/m3. In this study CO2 was collected
using gas sampling bag then analyzed through direct
measurement. As shown in Table 8, the results of CO2
measurements were within Threshold Limit Value of 9,000
mg/m3 required by OSHS-DOLE(2005). These findings show
an adequacy of ventilations for the areas measured.
Elevated CO2 concentrations suggest that other indoor
contaminants may also be increased. Carbon dioxide is a simple
asphyxiant, and can also act as a respiratory irritant [37]. But
exposure to an extremely high CO2 concentration (above
30,000ppm) is required before significant health problems are
likely.
Exposures above 30,000 ppm can lead to headaches, dizziness,
and nausea [65]. Yang et al. [72] found that these concentrations
also affect perception of motion. This may be because CO2 has
been shown to moderate the activity of cells within the visual
cortex.
Few studies are available about the ventilation levels and the
CO2 concentration in schools. Most studies conclude that

schools do not meet the ventilation levels foreseen by the
ASHRAE standard 62-1999, while the indoor CO2
concentration usually exceeds the threshold of 1000 ppm [21,
40].
Myhrvold, et al. [48] studied 22 classrooms in 5 Norwegian
schools renovated with the objective of improving indoor air
quality. Pre- and post-renovation measurements were made,
including health symptom questionnaires and performance tests
administered to 550 students, and measurements of CO2
concentrations. These investigators found a statistically
significant partial correlation (one way ANOVA, p< 0.001)
between symptoms of headaches, dizziness, heavy headed,
tiredness, difficulties concentrating, unpleasant odor, and high
CO2 concentrations (1500-4000 ppm compared to
concentrations below 1500 ppm). Health symptoms
characterized as "irritations of the upper airways" were also
higher at higher CO2 concentrations (p=0.024). Reduced
performance on the Swedish Performance Evaluation System
test was also observed at higher concentrations of CO2.
On the other hand, an epidemiological study in 3 complaint and
4 non-complaint Dutch schools (14 classrooms total) assessed
relationships between SBS symptom complaints of children and
CO2 levels and indoor climate [58]. The complaint of “bad odor
of the air” was associated with high CO2 levels.
Air Velocity or Ventilation Rates
Ventilation rate was measured using thermo-anemometer. Air
movements were taken near the supply of air and students’

position. While monitoring was being conducted, the general
weather condition was taken into consideration and applicable
standards were used. In the sampling conducted, the general
weather condition was sunny.
Results presented in Table 9 demonstrate air velocity (of fan)
values for room F101 and room F802 were generally higher than
the 150 ft./min (summer) standards of OSHS-DOLE(2005) .
These higher values are interestingly indicative of a higher
ventilation rates in the two rooms sampled on. But it was also
ironic because it was in these two rooms where TVOCs were
very high. Well, even if the electric fans are put on but if there
are no exit points or no exhaust fans that would remove the
VOCs, then these VOCs will still remain inside the room. It
would just circulate inside the room and not come out because
there is no exit point .
Conclusion and Recommendations
Microbiological analysis of the indoor air of Beato Angelico
building revealed the existence of high level of molds in the air
which were beyond the standards. This implies therefore, the
need to conduct a more thorough clean-up process of the
affected areas. As for the chemical analysis of the selected areas,
it was found out that a greater concern was on the Total volatile
organic compounds(TVOCs) values of the three rooms F101,
F801 and F802 which were far beyond the threshold limit values
set by the three respected institutions namely, World Health
Organization(WHO), National Institute for Occupational Safety
and Health (NIOSH) and Occupational Safety and Health Act
(OSHA) [32]. But this problem can be remedied by simply

putting up powerful exhaust fans in the concerned rooms. In this
way, for example, the turpentine released in the air will be
siphoned out and is not going to stay inside the room.
But to make sure that all the remedial measures are being
applied effectively, it would be better if there will be a regular
monitoring of the indoor air.
Acknowledgments
The researcher would like to thank the University of Santo
Tomas for extending financial support in order to make this
research a success. Special mentioned is given also to the
following persons for their guidance and unwavering support:
Dr. Clarita M. de Leon Carillo, Director of UST Academic
Affairs & Research, Dr. Christina A. Binag, Director
Research Center for the Natural Sciences, and Dr. Cynthia B.
Loza, Dean UST-College of Fine Arts and Design.
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List of Tables:

Acknowledgement: The author would like to thank the University of Santo
Tomas administrations for providing the funds needed for the above research.
About the Author: Prof. Crisencio Paner has been teaching at the College of Fine
Arts and Design,University of Santo Tomas Manila for more than 18 years now.
He has also been restoring paintings and other artworks since 2000. His
portfolio can be found in his blog, http://cmpaner.blogspot.com (The Painting
Doctor-Restorer/Conservator). He can be contacted at mobile nos. 0999-
9401794 or at Tel. 02 416-2489)

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