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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

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This research work on the Evaluation of the Indoor Air Quality of Beato Angelico Building of the University of Santo Tomas, Manila was made possible through a grant provided by the university.

This research work on the Evaluation of the Indoor Air Quality of Beato Angelico Building of the University of Santo Tomas, Manila was made possible through a grant provided by the university.

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    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 Document Transcript

    • Evaluation of the Indoor Air Quality of Beato AngelicoBuilding of the University of Santo TomasCrisencio M. Paner ** College of Fine Arts and Design, University of Santo TomasAbstractOut of 11 locations in Beato Angelico building sampled on byagar exposure method, 409 molds isolates were obtained fromwhich Aspergillus was the most prevalent with 58% occurrence,Cladosporium, 32%, Curvularia, 9%, and the least wasNeurospora, with only 1% occurrence. Interestingly, surface-swabbing of airconditioners and water stained ceilings had alsoproduced similar fungal genera as that of the agar-exposures,except for Neurospora which was absent in the surface swabresults. After calibrating the mold counts in accordance with thestandards for settling-plate and surface swab methods, resultsshowed that 75% of the sampling stations for settling platemethod and 100% of the sampling areas for surface swabmethod had mold count far beyond the threshold limit value of100 cfu/90mm/4hr [17, 18, 34, 61].Meanwhile, Chemical analysis had revealed the followingresults: a) the TVOC values of 4.2 ppm and 5.4 ppmrespectively based on two stations were far beyond the TLVrequired by WHO, OSHA, and NIOSH [32], b)Total respiratorydust(TRD) values of 0.9 & 0.3 mg/m3 respectively basedon 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 thatthese levels were within threshold limit value of 9,000 mg/m3required by OSHS-DOLE(2005).Key words: agar exposure method, threshold limit value, Indoorair quality, TVOC, TRD, CO2Background of the StudyAccording to Jackson et al. [35] on average most people spend80% or more of their daily lives indoors whether at home, work,or in commercial buildings. The US Environmental ProtectionAgency [66] notes that indoor air is often two to five times morepolluted than outdoor air. Over the last two decades, there hasbeen increasing awareness regarding the potential impact ofindoor air pollution on health.Indoor air quality (IAQ) is a term referring to the air qualitywithin and around buildings and structures, especially as itrelates to the health and comfort of building occupants [33].Indoor air quality (IAQ) is one of many issues that buildingowners should address because better IAQ leads to moreproductive and happier occupants.In schools and institutional buildings IAQ are tied to learningoutcomes and organizational missions. While it is hard to putfirm numbers on these benefits, there is increasing evidence ofmeasurable productivity increases and reduced absentee rates inspaces with better IAQ. Second, IAQ problems that get out of
    • hand can be quite costly in terms of lost work time, lost use ofbuildings, expensive building or mechanical system repairs,legal costs, and bad publicity. While extreme IAQ problems arerare, they do occur, and the consequences can be dramatic. Lesssevere problems are more common and can erode occupantproductivity and lead to costs for smaller legal disputes orrepairs. [9]Experts generally agree that healthy indoor school environmentsare a necessity if a high standard of education is to be expected.Recent studies have shown that schools have significant indoorenvironmental problems. High indoor air pollutant concentrationmay have a significant adverse impact on the health andacademic performance of students. [38]Epidemiological investigations have shown that the `sick-building syndrome(SBS)’ and hypersensitivity diseases (forexample, asthma) are often associated with exposure to largeconcentrations of airborne microbes. [2, 22, 31]A study of teachers working in a moisture- and mold-damagedschool building showed, that levels of these inflammatorymarkers in nasal lavage fluid were higher compared to controlgroup.[29]In related studies, 80 fungal genera have been associated withsymptoms of respiratory tract allergies, these includeCladosporium, Alternaria, Aspergillus and Fusarium,Penicillium, Ulocladium, Sistotrema, Alternaria, Eurotium,Wallemiu. [25, 30]
    • Hourly variations of four orders of magnitude of mold aerosolshave been found in a classroom. [47]Total Volatile Organic Compounds(TVOCs) are one of the mostcommonly measured pollutants in schools. VOCs are suspectedas one of the causes of SBS [44, 70]. Measured values of TVOCcan vary significantly depending upon the sampling and analysismethods used. Particularly high TVOC concentrations, above 1to 2 mg/m3, indicate the presence of strong VOC sources and/orlow ventilation. Results of studies by the US EnvironmentalProtection Agency (EPA) and other researchers have found thatVOCs are common in the indoor environment and that theirlevels may be ten to thousands times higher indoors thanoutdoors. In addition, there may be anywhere from 50 up tohundreds of individual VOCs in any one indoor air sample. Atvery low levels, some VOCs may produce odors that somepeople may consider to be objectionable, while others areirritants that can cause people to have headaches and eye, noseand throat irritation, and dizziness. At high concentrations, someVOCs are toxic or may be carcinogenic. Whether or notsomeone will become sick or notice an odor is highly variable.Complaints should be taken seriously, however, andinvestigated. Primary VOCs found are associated with solvents,paints and coating, adhesives, cleaners, furnishings, andpersonal care products. In schools, VOCs are associated withcleaning supplies, pesticides, building materials and furnishings,office equipment such as copiers and printers, correction fluidsand carbonless copy paper, graphics and craft materialsincluding glues, adhesives and turpentine for painting students,
    • permanent markers, whiteboard markers, and photographicsolutions.Most standards and guidelines consider 200 µg/m3 to 500µg/m3 TVOC as an acceptable level in buildings. Levels higherthan this may result in irritation to some occupants. However,lower levels can also be an issue if a particularly toxic substanceor odorant is present. The World Health Organizationrecommends that indoor exposures not exceed 0.1 ppm, and thatactions be taken to reduce levels once they read 0.05 ppm.Although the legal limit covered by OSHA is 0.75 ppm, NIOSHrecommends workers not be exposed to more than 0.016 ppmaveraged over a 10-hour day. [32]Some chemical constituents of floor cleaning materials havebeen recognized as a possible cause of asthma in indoorenvironments i.e. colophony based products such as pine oil andtall oil, and benzalkonium chloride [39]. Building materials areimportant emission sources of VOCs, especially in newbuildings [69].Dust means solid particles being blown about or suspended inthe air generated by handling, crushing, cutting, drilling, rapidimpact, spraying, detonations, or disintegrations of inorganic ororganic materials and are of a composition similar to thesubstance or substances from which they are derived. TotalRespirable Dust (TRD) is measured gravimetrically. Dust cancontain particles of a wide range of sizes. The effect of theseparticles when ingested into the body depends on the size, shapeand chemical nature of the particles. Several studies have
    • demonstrated that particles in ambient air have adverse effectson respiratory health. [14, 19, 52 53, 56, 57, 64]Carbon dioxide is a normal constituent of exhaled breath and iscommonly measured as a screening tool to evaluate whetheradequate volumes of fresh outdoor are being introduced intoindoor air. The carbon dioxide level is usually greater inside abuilding than outside, even in buildings with few complaintsabout indoor air quality. ASHRAE recommends that the indoorCO2 concentration be no greater than 700 ppm above theoutdoor concentration for comfort (odor) reasons [6].Air Velocity or Ventilation rates have rarely been measured inschools, although inadequate ventilation is often suspected to bean important condition leading to reported health symptoms.ASHRAE Standard 62-1999 [8] recommends a minimumventilation rate of 8 L/s-person (15 cfm/person) for classrooms.Given typical occupant density of 33 per 90m2 (1000 ft2) and aceiling height of 3m (10 ft), the current ASHRAE standardwould require an air exchange rate of about 3 air changes perhour (ACH) for a classroom.Humans have difficulties perceiving changes of the relativehumidity (RH), due to lack of sensory receptors for humidity[49]. In contrast, specific sensors exist for the perception of thetemperature. However, reporting of “dry air” has beenassociated with poor indoor air quality (IAQ) or a sub-standardindoor environment since the 1980s [16]. Temperature and RHmeasurements are often collected as part of an IEQ investigationbecause these parameters affect the perception of comfort in anindoor environment. The perception of thermal comfort is
    • related to ones metabolic heat production, the transfer of heat tothe environment, physiological adjustments, and bodytemperature [50]. Heat transfer from the body to theenvironment 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 inbuildings and has been responsible for some of the most costlyIAQ litigation and remediation. Moisture enables growth ofmicroorganisms, production of microbial VOCs and allergens,deterioration of materials, and other processes detrimental toIAQ. In addition, dampness has been shown to be stronglyassociated with adverse health outcomes. Control of moisture isthus critical to good IAQ. High indoor humidity can lead todampness and low indoor humidity (less than 30% RH) cancause mucus membrane irritation, dry eyes, and sinusdiscomfort. Maintaining indoor humidity between 30-50% willcontrol mold growth and alleviate the symptoms associated withlow humidity. Negative building pressure can draw moistoutdoor air into the building envelope, potentially leading tocondensation. It can also draw moist air into the conditionedspace itself, potentially increasing the latent load beyond thecooling system design capacity and leading to elevated indoorhumidity. Positive building pressure can push moist indoor airinto the building enclosure, potentially leading to condensationunder heating conditions [15].ASHRAE recommends that relative humidity in indoorenvironments be maintained between 30% and 50% relativehumidity [6] and that the indoor temperature range provide foroccupant comfort (69.0oF to 76.5oF in the winter and 75.5oF to81.0oF in the summer at 40% relative humidity [7]. Studies
    • indicate that RH about 40% is better for the eyes and upperairways than levels below 30%. The optimal RH may differ forthe eyes and the airways regarding desiccation of the mucousmembranes [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 moreadvantageous and effective in assessing airborne viablecontamination in clean rooms than settle plate monitoring. Theuse of settle plate monitoring may still be an optional testmethod for those applications where other more efficientsampling methods may not be possible or may have limitedapplicability [5]. Agar exposure method also known as the“Settle plate method” relies on the principle that the moldscarrying particles are allowed to settle onto the medium for agiven period of time and incubated at the required temperature.Malt extract agar is the appropriate medium used to culturemolds. The normal sampling time is between 10 to 60 minutes.Though the method has the advantage of simplicity, it hascertain limits. In this method only the rate of deposition of largeparticles from the air, not the total number of molds carryingparticles per volume, is measured [62]. Settle plate methods areinsensitive unless a long exposure period is adopted in order todetect the low number of airborne microorganisms. If this is notcarried out the results are biased to give favorable data. If this isnot practicable then plates should be monitored for successivework sessions and the incidence of contamination analyzed. Theaverage size of microbial particle will deposit, by gravity, ontosurfaces at a rate of approximately 1 cm/s. Petri dishes which are90 mm in diameter (approximate internal area 64 cm2) are most
    • commonly used. For settle-plate method, the standard values are50 cfu/90mm/4hours for ordinary indoor air at rest, and 100cfu/90mm/4hours for indoor air operational. Clean room at restis 5 cfu/90 mm/4 hours, while clean room operational is 50cfu/90mm/4 hours. For swab and contact plate methods, thestandards are 25 cfu/25cm2(for air at rest) and 50 cfu/25cm2(forair at operational). Clean support standard values on the otherhand 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, theCollege of Fine Arts and Design, and an art gallery for theexhibits of students, faculty members, and alumni artists. Since2001, a portion of the ground floor has also served as the officesand technical facilities of the UST Publishing House. Thebuilding was designed by Architect Yolanda D. Reyes, a formerdean of the College of Architecture. Beato Angelico building islocated at the corner of España and P.Noval Streets, Manila[12]. The building accommodates around six thousand studentsand faculties from both the College of Fine Arts and Design andthe College of Architecture.There is a scarcity of studies in the Philippines regarding Indoorair quality of schools encompassing both the chemical andmicrobiological aspects. In particular there are no figuresavailable on the prevalence in the Philippines of fungalcontamination in indoor environments. It was the first time thatthis study was conducted on the indoor air of a building withinthe campus of the University of Santo Tomas (UST). The studyhad the following objectives:
    • 1. To find the typical concentration levels of fungal bioaerosolin selected indoor environment of Beato Angelico Building.2. To determine the level of concentrations of selected keyindicators of air pollution such as Total volatile organiccompounds (TVOCs), Total respirable dust(TRD), and Carbondioxide (CO2) .Materials and MethodsI. Walk-through InspectionThe building were surveyed and observed for signs of buildingdamage and microbial contaminations such as water stains.II. Determination of Fungal ContaminationsA. Agar Exposure MethodFive agar plates were exposed for one hour in each floor (nearthe stairs) of the building as well as in the three roomsidentified: Faculty room, Rooms 101 and 102 of the 8th Floor.The plates were placed on a table with a height of at least 1.5meter above the ground. Malt-extract agar (half-strength) plateswith pH maintained at 3.5 to specifically select for the moldswere prepared.
    • At the end of each exposure period, the plates were placed in anincubator with temperature maintained at room temperature for3-5 days. For identification of molds, each fungal isolate werecultured on MEA agar blocks on glass slides based on Henrici’sculture technique. Subsequent sporulating growth wereexamined with both stereoscopic and bright field microscopes.Fungal genera were identified using literatures on FungalTaxonomy and Mycology. During the agar exposure, otherparameters of the indoor air were also measured such astemperature and relative humidity. The number of occupants atthe time of exposure were also counted.B. Surface Sampling by Swab MethodSterilized cotton buds moistened with normal saline solutionwere swabbed gently on different surfaces (with an area 25 ofcm2 each) suspected with microbial contaminants like waterstain marks on the ceilings and walls, and including louvers ofthe airconditioners. The swabs were then streaked directly ontoplates of half-strength Malt Extract Agar (with pH 3.5 to inhibitbacteria). Prepared culture plates were incubated at roomtemperature for 3-5 days. Molds genera were identified using thesame procedures as in IIA.III. Determining the Levels of Indoor Air ChemicalPollutantsIn the absence of specific instruments to be used on this part ofthe study, the researcher commissioned the company FirstAnalytical Services and Technical Cooperative (F.A.S.T.
    • LABORATORIES) to conduct the sampling and analysis. Dueto budgetary constraints only few indicators of indoor airpollution were measured such as Carbon dioxide(CO2), Totalvolatile organic compounds (TVOCs), and Total respirable dusts(TRD).Aside from these other physical parameters of the indoor airwere also measured such as air velocity, temperature, andhumidity. For TRD and CO2, the Main Entrance/Exit and thearea 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 DiscussionsI. Walk-through Inspection of the BuildingDuring the inspection of the building last March 2, 2010, whichbegan at 2 O’clock in the afternoon and ended at around 5O’clock in the afternoon, the following things had beenobserved: a) several water stains on the ceiling of the facultyroom; b) intense smell of volatile organic chemicals at room101(ground floor), and room 1 and 2 (eight floor). It was laterfound that this volatile chemical at room 101(ground floor) wasdue to the adhesives that the students of the Industrial Designhad bee using, while at room 1 and 2 (eight floor), the volatilechemical was due to ‘turpentine’ that the Painting students hadbeen 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 notbeen cleaned for a long time.Furthermore, from ground floor up to the eight floor near thestairways, it was also observed that air was very hot and humid.Many students were also observed coming in and out thebuilding at that time.II. Determination of Fungal ContaminationsA. Agar Exposure Method or Settle Plate MethodAs indicated in Table 1, there was a generally slight decreasingtrend in the number of molds isolated from ground floor to the8th floor of the building. This could be attributed to the numberof people [55] who were present at the time of the sampling. Ithas been observed that majority of people were present at theground floor more than in the other floors because of its functionas entrance and exit. Next to ground floor, second floor werefound to have also a greater number of students. It was becausethis floor housed the offices and faculty rooms of both theCollege of Fine Arts and Design and the College ofArchitecture.The decreased number of molds isolated from third floor to eightfloor may also be attributed to the lesser number of studentsobserved to be present during the time of sampling. For room1(ground floor) and rooms 1 & 2 (eight floor), the numberof molds isolated showed almost similarly small. Reason for thiswas because these rooms were airconditioned and even though
    • there were occupants (mean 35) inside, they performed lesseractivity compared with those people in the ground floor.According to Flannigan [25] any activity in the building mightdisturb settled spores causing them to spread in the air.As for the temperature and relative humidity, Table 1 showed agenerally high values from ground floor to the eight floor withan exception for room 1(ground floor) and rooms 1 and 2 of theeight floor which were airconditioned.Increased temperatures and humidities in the environment areconducive to the growth of molds, causing them to multiplyfaster and produce spores in great amounts.Half-strength of Malt-Extract Agar was used in the experimentin order to delay the growth of some fast growing molds.As shown in Table 1 & Figure 1, of the 409 molds thatwere 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 andceilings [10]. Miller [42] stated that among the facultativepathogens of Interest, Aspergillus fumigatus, A terreus andsometimes A flavus cause aspergillosis, an invasive lungdisease. On the other hand Cladosporium is a dematiaceous(pigmented) mold widely distributed in air and rotten organicmaterial and frequently isolated as a contaminant on foods [23,
    • 24]. The genus Cladosporium includes over 30 species and themost common ones include Cladosporium elatum,Cladosporium herbarum, Cladosporium sphaerospermum, andCladosporium cladosporioides. Cladosporium spp. are causativeagents of skin lesions, keratitis, onychomycosis, sinusitis andpulmonary infections [20, 59]. Furthermore, Miller [42] had alsoaffirmed that most people diagnosed as allergic to mold aretested for allergy to Cladosporium cladosporiodes,Cladosporium herbarum and Alternara alternate. In anotherrelated study, it was found that hay fever has a significantcorrelation with indoor fungi, such as Cladosporium,Epicoccum, and Yeast [63]. Curvularia has three ubiquitousspecies which have been recovered from human infections,principally from cases of mycotic keratitis; C. lunata, C.pallescens and C. geniculata. Clinical manifestations ofphaeohyphomycosis include sinusitis, endocarditis, peritonitisand disseminated infection [60]. Neurospora is a common breadmold and has not been normally implicated in any humandisease. But its presence in the air can also possibly causeallergic rhinitis specially to a compromised individuals ifinhaled.Figure 3 is the experiment set-up for agar exposure method. Itshows a petri-dish placed on top of a stool with half-strengthMalt-Extract Agar(pH 3.5) being exposed for one hour to air atthe ground floor of the Beato Angelico building. Relativehumidity and temperature of the indoor air were also taken inthis site as well as in other 10 more sites. The area with thehighest number of molds isolated were the water stains on theceiling (Table 2 & Fig. 2) of the faculty room. While therest of the sampling areas had similarly small numbers of
    • isolated molds. But the mere fact that molds were isolated fromall the sampling areas was an indication that majority ofairconditioners were not being cleaned or not being cleaned asregularly as it should.A higher number of molds isolated in the water-stained ceilingcan be attributed more on the water that may have infiltrated thegypsum board ceiling and which made it a good breedingground for a variety of molds.This is a rather dangerous situation on the part of the occupantsof this room particularly those who stay there for quite sometimebecause if the contaminated tile ceiling is not replacedimmediately, prolong periods would generate thousands ofspores which when inhaled by a compromised person may causehim or her an allergic rhinitis or much worse a respiratorydisease such as aspergillosis.Differences in the size and sedimentation rate of spores alsoaffect what is detected in air samples. For instance, it has beenfound out that large Ulocladium spores released from moldpatches on walls in damp houses sediment rapidly [25] so that,even where growth is profuse, the mold is likely to be detectedin the air in quantity only shortly after disturbance of the growthor re-entrainment of settled spores as a result of activity.Out of 117 molds that were isolated through agar swab methodfrom four sampling locations (consisting of 13 aircon louversand three water stained gypsum ceiling boards), Aspergillusrevealed the highest percent occurrence at 60.7%, Cladosporiumwas next with 31.6% occurrence, and the least was Curvularia,
    • with 7.7% occurrence(figure 5 & table 2). This result isalmost similar as that of Agar exposure results in terms of thekind of fungal genera that were isolated. It was not impossiblebecause this population of molds after being suspended in the airfor a while would eventually fall on different surfaces due toearth’s gravitational pull.In order to calibrate the average number of molds in Table 1with that of the standards, the values in the table had to bemultiplied by 4. This was because in the standard, the exposuretime was 4 hours while in the experiment conducted theexposure period was only 1 hour.It can be seen in Table 3 that in general the number of moldsisolated from ground floor to eight floor were all beyond thethreshold limit value of 100 cfu/90mm/4hr except for room1(ground floor) and rooms 1 & 2 at the eight floor whichwere below the threshold limit values. Again these values abovethe threshold limit can be accounted for the presence of peopleat the sampling areas during the sampling time. The observedhigh temperature and high humidity were also possible reasonfor the high mold count since these could provide a conduciveenvironment for the growth of molds [11]. The mold count maybe reduced if only there were exhaust fans in the areas sampledon.Dampness can occur from existing leaks or new leaks from thewindows, building façade, leaking pipes above the ceiling, orleaking unit ventilators from the floor above.
    • It is generally recognized that the growth of mold on interiorsurfaces in buildings is unacceptable and that the amount ofgrowth (surface area) in a room is important in determining theprocedures used in mold remediation [ 3, 45, 46, 51, 67 ].According to Miller [42], fungal contamination of building air isalmost always caused by poor design and/or maintenance.Molds are transported into the indoor environment through aircirculation or are carried indoors by organisms, including humanbeings, or in the moving of inanimate objects that have moldsattached to their surfaces. When the food source, moisture,temperature, and so forth in the indoor environment arefavorable, molds can grow.Ghosh and Hines [27] said that fungi are introduced into anindoor environment, they can settle in amplification sites wherethey thrive and grow. Amplification sites include any site withthe proper pH, temperature, and moisture content.In some moisture damaged buildings, mold growth is hidden onconstruction materials within wall cavities or buildingassemblies and thus not readily evident during inspection.Microbial volatile organic compounds reportedly can diffusethrough building construction and may be useful in locatingconcealed mould growth [68].P. chrysogenum was the dominant culturable mold(concentrations about 200 cfu/m3) found in air samplescollected 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 higherthan those detected in the outdoor air [46] .According to a recent study of Bornehag et al. [13] earlydetection of water leakage was indicative of the extent of visiblemold growth subsequently found on biodegradable constructionmaterials hidden within exterior walls. The study also showedthat spores from hidden mould growth in exterior walls can enterthe indoor air in sufficient amounts to significantly degradeindoor air quality, e.g., by changing the rank order of taxa inroom air.Molds may grow on the stagnant water left in the humidifier andthen be aerosolized when the unit is reactivated [54].Currently, it is suggested by the American Conference ofGovernmental Industrial Hygiene [1] that bioaerosolconcentrations higher than 500 CFU/ m3 be considered as a signof the presence of a building-related air pollution source.The fungal concentrations found at most of the indoorenvironments should fall within the specified guidelines of theAmerican 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 moldsbased on surface swab method for all locations were above thestandard TLV of 50 cfu/25 cm2. These results were proof that ina natural way, the molds in the air may later on find its way ondifferent surfaces by gravity. However, high number of molds
    • found on the surfaces are also indicative of poor cleaningpractices.The standards set by ACGIH [2] which is between 100-1000CFU/m3 for the total fungi could not be applied in this studybecause the methods of sampling of indoor air were bothdifferent. In ACGIH standards, the method of sampling wasbased on an Andersen air sampler (impinger or impactorapparatus) while in this study, the indoor air was sampledthrough settling-plate method. Of course, the first one was muchmore accurate than the second one, however in the absence ofthe air sampling apparatus which is more expensive, Agarexposure method may still be used as an alternative. It’saccuracy however may be just increased by using higher numberof agar-exposure plates per sampling location, by increasing thetime of exposure (at least up to 4 hours), by being careful not tocontaminate the plates, and by using appropriate media forculturing the molds like malt-extract-agar, saboraud’s dextroseagar, etc…III. Determining the Levels of Indoor Air ChemicalPollutantsIn the chemical analysis of the indoor air of Beato Angelicobuilding, a private company (FAST Laboratories) wascommissioned to the job, the methods of sampling and analysiswere based on Occupational Safety and Health Standards-Department of Labor and Employment (OSHS-DOLE), 2005and the National Institute for Occupational Safety and Health(NIOSH).
    • Table 5 shows the summary of different parameters that weremeasured as well the different sampling methods and analyticalmethods 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 aPID RAE monitor.Presented in Table 6 were the levels of Total Volatile OrganicCompounds in the two identified locations namely Room F101and room F802. These two rooms were particularly selectedbecause of the observed presence of VOC smell in these rooms.In room F101, it was observed that there was a smell ofadhesives which the Industrial Design students were using.While in room F802, there was a recurring smell of turpentine inthe room which the Painting students were using when theyconduct oil painting sessions.Unfortunately, OSHS-DOLE had no existing Threshold LimitValue(TLV) for TVOCs, so the researcher conducted intensiveresearch on the reference standards from the library and theWorld Wide Web.Lucky enough, the researcher had found what he was lookingfor. He had found actually not only one but 3 different referencestandards, namely: WHO, OSHA, and NIOSH [32] . So,referring again to Table 6, the TVOC values of 4.2 ppm (forroom F101) and 5.4 ppm (for room F802) were very far highercompared with the 0.1 ppm TLV set by World Health
    • Organization [32]. In this case TVOC value in F101 was 42times higher than WHO TLV, while in room F802 the TVOCvalue was 54 times higher compared with WHO Threshold limitvalues for VOCs. Comparing still the measured TVOC valueswith OSHA [32] standard of 0.75 ppm, it was obvious that themeasured values for the two rooms were very much highercompared with the OSHA TLV.NIOSH [32] has even stricter standard when it recommendsworkers not be exposed to more than 0.016 ppm averaged over a10-hour day. If this would be applied to the two roomsmentioned then the students in these rooms, assuming they stayin that rooms for 10 hours, then they are exposed to 300 timesmore than the threshold limit value. This reminded me when onetime, Prof. Noel Escultura (Pers. Comm., March 7, 2010)admitted that he knew his Painting class were getting highalready on turpentine(VOC) when suddenly they began makingnoises and there was also a sudden change in his students’behavior.But actually, this problem may be easily remedied by puttingexhaust fans in the room. These fans can siphon out thesevolatile organic compounds that are present in the room.Requiring students to wear gas mask is also one solutionalthough, some may complain of uneasy feeling in using themask.Total Respirable Dust(TRD)The Threshold Limit Value(TLV) for Total respirableDust(TRD) set by OSHS-DOLE(2005) was 5 mg/m3. In this
    • study TRD was collected through filtration method and analysiswas done gravimetrically.Presented in Table 7 is the dust concentrations (TRD) measuredat Main Entrance/Exit and 2nd floor of Beato Angelico building.Comparing the two values with the OSHS-DOLE TLV of 5mg/m3 would show that they are within the threshold limitvalue. However, if we would apply the standard of Molhave [43]and Helmis et al. [28], the two values are much higher comparedwith threshold limit value of 50 microgram/m3 even if these twovalues are adjusted with that of the standard.Differences in standards are expected because one could decideto increase his standard in order to achieve higher quality indoorair while the other one could not increase yet the standardbecause of some considerations like inability of majority ofcompanies to follow yet a higher standard in terms of indoor airquality. Financial factor is also one reason because it alsorequires big amount of money to achieve or maintain a higherquality of indoor air.Particulate air pollution is a complex mixture of solid particlesand liquid droplets of different size, composition and origin.Particles with a diameter less than 10 micron are of specialinterest since they are inhalable. These particles are oftenreferred to us PM10 [52].According to Molhave [43] and Helmis et al. [28], the minimumacceptable concentration PM10 in the indoor environmentshould be 50 microgram (µg)/m3 at 24 continuous hourexposure.
    • RH has an effect on the formation and size of secondaryaerosols and therefore on the deposition. Low RH appears toenhance particle deposition of fine particles [36] and high RHlikewise [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 collectedusing gas sampling bag then analyzed through directmeasurement. As shown in Table 8, the results of CO2measurements were within Threshold Limit Value of 9,000mg/m3 required by OSHS-DOLE(2005). These findings showan adequacy of ventilations for the areas measured.Elevated CO2 concentrations suggest that other indoorcontaminants may also be increased. Carbon dioxide is a simpleasphyxiant, and can also act as a respiratory irritant [37]. Butexposure to an extremely high CO2 concentration (above30,000ppm) is required before significant health problems arelikely.Exposures above 30,000 ppm can lead to headaches, dizziness,and nausea [65]. Yang et al. [72] found that these concentrationsalso affect perception of motion. This may be because CO2 hasbeen shown to moderate the activity of cells within the visualcortex.Few studies are available about the ventilation levels and theCO2 concentration in schools. Most studies conclude that
    • schools do not meet the ventilation levels foreseen by theASHRAE standard 62-1999, while the indoor CO2concentration usually exceeds the threshold of 1000 ppm [21,40].Myhrvold, et al. [48] studied 22 classrooms in 5 Norwegianschools renovated with the objective of improving indoor airquality. Pre- and post-renovation measurements were made,including health symptom questionnaires and performance testsadministered to 550 students, and measurements of CO2concentrations. These investigators found a statisticallysignificant partial correlation (one way ANOVA, p< 0.001)between symptoms of headaches, dizziness, heavy headed,tiredness, difficulties concentrating, unpleasant odor, and highCO2 concentrations (1500-4000 ppm compared toconcentrations below 1500 ppm). Health symptomscharacterized as "irritations of the upper airways" were alsohigher at higher CO2 concentrations (p=0.024). Reducedperformance on the Swedish Performance Evaluation Systemtest was also observed at higher concentrations of CO2.On the other hand, an epidemiological study in 3 complaint and4 non-complaint Dutch schools (14 classrooms total) assessedrelationships between SBS symptom complaints of children andCO2 levels and indoor climate [58]. The complaint of “bad odorof the air” was associated with high CO2 levels.Air Velocity or Ventilation RatesVentilation rate was measured using thermo-anemometer. Airmovements were taken near the supply of air and students’
    • position. While monitoring was being conducted, the generalweather condition was taken into consideration and applicablestandards were used. In the sampling conducted, the generalweather condition was sunny.Results presented in Table 9 demonstrate air velocity (of fan)values for room F101 and room F802 were generally higher thanthe 150 ft./min (summer) standards of OSHS-DOLE(2005) .These higher values are interestingly indicative of a higherventilation rates in the two rooms sampled on. But it was alsoironic because it was in these two rooms where TVOCs werevery high. Well, even if the electric fans are put on but if thereare no exit points or no exhaust fans that would remove theVOCs, then these VOCs will still remain inside the room. Itwould just circulate inside the room and not come out becausethere is no exit point .Conclusion and RecommendationsMicrobiological analysis of the indoor air of Beato Angelicobuilding revealed the existence of high level of molds in the airwhich were beyond the standards. This implies therefore, theneed to conduct a more thorough clean-up process of theaffected areas. As for the chemical analysis of the selected areas,it was found out that a greater concern was on the Total volatileorganic compounds(TVOCs) values of the three rooms F101,F801 and F802 which were far beyond the threshold limit valuesset by the three respected institutions namely, World HealthOrganization(WHO), National Institute for Occupational Safetyand 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 thisway, for example, the turpentine released in the air will besiphoned out and is not going to stay inside the room.But to make sure that all the remedial measures are beingapplied effectively, it would be better if there will be a regularmonitoring of the indoor air.AcknowledgmentsThe researcher would like to thank the University of SantoTomas for extending financial support in order to make thisresearch a success. Special mentioned is given also to thefollowing persons for their guidance and unwavering support:Dr. Clarita M. de Leon Carillo, Director of UST AcademicAffairs & Research, Dr. Christina A. Binag, DirectorResearch Center for the Natural Sciences, and Dr. Cynthia B.Loza, Dean UST-College of Fine Arts and Design.References[1]. ACGIH (American Conference of Governmental IndustrialHygiene). Bioaerosols: Rationale for monitoring airborne viablemicroorganisms in the office environment. Appl. Ind. Hyg. 4:R19-R23; 1986.[2]. American Conference of Governmental IndustrialHygienists,(ACGIH), 1989. Guidelines for the Assessment ofBioaerosols in the Indoor Environment. Cincinnati, Ohio.
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    • List of Figures:
    • Acknowledgement: The author would like to thank the University of SantoTomas administrations for providing the funds needed for the above research.About the Author: Prof. Crisencio Paner has been teaching at the College of FineArts and Design,University of Santo Tomas Manila for more than 18 years now.He has also been restoring paintings and other artworks since 2000. Hisportfolio can be found in his blog, http://cmpaner.blogspot.com (The PaintingDoctor-Restorer/Conservator). He can be contacted at mobile nos. 0999-9401794 or at Tel. 02 416-2489)