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Öğe A comprehensive assessment of ambient air quality in Canakkale city: Emission inventory, air quality monitoring, source apportionment, and respiratory health indicators(Turkish Natl Committee Air Pollution Res & Control-Tuncap, 2020) Mentese, Sibel; Mirici, Nihal Arzu; Elbir, Tolga; Tuygun, Gizem Tuna; Bakar, Coskun; Otkun, Muserref Tatman; Oymak, SibelThis comprehensive study aims to examine the relationships between ambient air quality (AAQ) and respiratory health of the participants residing in three different towns of Canakkale city, Turkey between August 2013 and 2014. AAQ measurements for bioaerosols, volatile organic compounds (VOCs), total particulate matter (PM) count, carbon dioxide (CO2), and carbon monoxide (CO) were performed and monthly pulmonary function test (PFT) was applied to volunteer participants residing in the study sites (n = 121) for one year. Additionally, concentrations of air pollutants for PM2.5/PM10, sulfur dioxide (SO2), nitrogen oxides, and ozone were gathered from AAQ monitoring stations. To estimate the contributions of the emission sources and their effects on human health in the region, an emission inventory was also prepared in the region and AERMOD modelling system was applied for the year of 2013. Accordingly, the industry was the most polluting sector for NOx and SO2, while road traffic and residential heating were the most polluting sectors for CO and PM10. Factor analysis revealed that organics, combustion, bioaerosol propagation, and ozone accumulation contributed to AAQ, in agreement with AQ modelling results. Can had the worst air quality (industrialized site), which affected the respiratory health indicators of the participants. Generalized linear model estimated that PF of the participants varied according to the residing district, gender, suffering from asthma, and lifelong smoking or environmental tobacco smoke exposure (p < 0.05). Also, PF of the participants were linked with VOCs levels in the Central town, total PM count in Lapseki, and ozone levels in Can (p < 0.05).Öğe A long-term multi-parametric monitoring study: Indoor air quality (IAQ) and the sources of the pollutants, prevalence of sick building syndrome (SBS) symptoms, and respiratory health indicators(Turkish Natl Committee Air Pollution Res & Control-Tuncap, 2020) Mentese, Sibel; Mirici, Nihal Arzu; Elbir, Tolga; Palaz, Elif; Mumcuoglu, Deniz Tasdibi; Cotuker, Osman; Bakar, CoskunPoor indoor air quality (IAQ) can cause several respiratory diseases and symptoms. In this study, IAQ of 121 homes located in 3 different towns of Canakkale, Turkey was monitored throughout a year. Target air pollutants were particulate matter, volatile organic compounds (VOCs), bioaerosols, and Carbon dioxide (CO2), as well as air temperature and humidity. Moreover, pulmonary functions of the occupants were measured on a monthly basis. Also, occurrence of sick building syndrome (SBS) symptoms and other health related data were gathered from the occupants by a detailed questionnaire. The SBS is a situation related to indoor air pollution in which the occupants of a building experience health or comfort related adverse effects that appear to be associated directly to the time spent in the sick building. Results of this study showed that the highest indoor air pollutant levels were observed in Can town and the lowest levels were observed in Central town. Indoor levels of bioaerosols, particulate matter, benzene, Cladosporium spp., and Penicillium spp. as well as pulmonary functions of the occupants showed statistically significant differences between the locations of the homes (p < 0.001). Factor analysis implied that both indoor and outdoor originated sources contributed to IAQ. Even though the predominant SBS symptoms varied seasonally and spatially among the study sites, fatigue, cold-flu like symptoms, and difficulty in concentration occurred frequently. Correlations were found among the occurrence of SBS symptoms, measured IAQ parameters, and personal factors (p < 0.05). Performing more studies from the health and IAQ points of view improve public awareness.Öğe A Year - round motoring of ambient volatile organic compounds across Dardanelles strait(Acg Publications, 2020) Mentese, Sibel; Bas, BatuhanDardanelles strait has a crucial importance on marine transport, splitting canakkale city. Combustion-related anthropogenic sources emit volatile organic compounds (VOCs) into the air and they have public concern due to adverse health effects. In this study, composition of ambient VOCs across Dardanelles strait was monitored for 4 seasons over the year of 2018. A total of 12 sampling locations, including 5 locations on the European and 7 locations on the Asian seashores of Dardanelles strait were determined as sampling points. Standard methods were followed during the sampling and analysis of VOCs. VOCs samples were collected on thermal desorber tubes, containing sorbents of Tenax TA and Carbograph 1TD. Active VOC samples were collected by an air sampling pump and passive VOCs samples were exposed to air for 2 weeks. VOCs samples were analyzed by Thermal Desorber followed by Gas Chromatography - Flame Ionization Detector. Target VOCs in this study were paraffins and aromatic hydrocarbons. Limit of quantification was assessed as <= 0.1 mu g/m(3). According to the results of the study, VOCs concentrations varied both spatially and seasonally. The most abundant VOCs in the air were npentane, n-hexane, toluene, benzene, and 1,2,4-trichlorobenzene throughout the study. Furthermore, the highest VOCs levels mostly occurred at the locations that were close to the traffic sources and/or residential areas.Öğe Airborne bacteria levels in indoor urban environments: The influence of season and prevalence of sick building syndrome (SBS)(Sage Publications Ltd, 2016) Mentese, Sibel; Tasdibi, DenizThis study investigated levels of airborne bacteria in 90 indoor sampling sites with no known complaints such as kindergartens, schools, homes and dorms over three seasons. Airborne bacteria samples were collected before and during the heating season in Canakkale, Turkey. Also, a detailed occupant questionnaire was completed by one of the occupants (n=90) in each sampling site. Total bacteria counts (TBCs) were found to be higher in the sampling sites where coal was used as a heating source and in kindergartens where the occupancy rate was highest (p<0.05). Meteorological parameters were associated with outdoor TBC levels (p<0.001). Associations were found (p=0.05) for indoor TBC and other building factors (last floor covering/wall painting/renovation times, heating/cooking fuels and the age of the building). Indoor TBC levels together with the building-related factors (environmental tobacco smoke exposure, occupancy rate, distance to traffic, heating fuel, amount of carpet covering, and last wall painting time) and personal factors (gender and daily time spent indoors) were found to be associated with at least one group of the sick building syndrome (SBS) symptoms (p<0.05). In particular, general SBS symptoms (headache, fatigue and dizziness) were observed more often in female participants (p<0.05). In conclusion, there is a need to conduct more studies in larger populations to find the links between air pollutants and SBS symptoms.Öğe Are kindergartens healthy enough for the children?(Nova Science Publishers, Inc., 2010) Mentese, SibelEnvironmental conditions in kindergartens are of particular concern because of the children's health. In this chapter, effects of environmental parameters and the airborne pollutants on children in kindergartens according to the available studies done by the researchers are criticized in light of the author's professional experience on the issue. Several parameters may impact children's health in kindergartens individually as well as altogether, which is called combined-exposure. These parameters are occupant number, climatic factors (e.g., temperature, relative humidity, air exchange rate, etc.), ventilation rate and type (i.e., mechanical or HVAC), indoor material (e.g., furniture, carpet, toys, papers, etc.) loading rate, socio-economic features, volume of the classroom, cleaning frequency, geographic conditions and season. It is noteworthy that they are merely parameters that can generally trigger the reactions, producing the main pollutants that have more serious adverse health effects on children as well as staff of the kindergartens. However, this chapter is focused on children in the kindergartens rather than adults. These pollutants can be classified by both their sources (i.e., primary pollutants and secondary pollutants) and their characteristics (i.e., organic pollutants, inorganic pollutants, microbiological pollutants, etc.). Levels and composition of the pollutants are used to specify the adequacy of the environment for children's health and development. Some pollutants have a much more serious effect with even low concentrations, such as formaldehyde, benzene and molds, while the significant impact of certain other pollutants has not been documented yet. In this chapter, all possible pollutants that may influence children will be tackled, such as microbial agents (e.g., molds, bacteria, endotoxin, MVOCs, dust mites, cockroach allergens, etc.), organic compounds (e.g., VOCs, aldehydes, SVOCs, etc.), radon, particles (e.g., PM10, PM2.5, sub-micron particles, settled dust, etc.), CO2 levels, and CO levels along with the parameters given above. Due to various reasons, kindergartens are an important environment for children. First of all, children in kindergartens are more susceptible to the effects of poor or bad environmental conditions than the adults as their immune system hasn't maturated yet and the ratio of total volume of the air (i.e., including higher concentrations of air pollutants) breathed by children and their body weight is higher than adults. Recently, the increased rate of asthma among children living in non-industrial areas has been pointed out by WHO and the national health organizations of some countries. Similarly, available results show us inadequate environmental conditions, especially bad indoor air quality, are linked with childhood asthma and respiratory symptoms. Another issue of concern is occupancy load (i.e., area per person) of the room, which induces many problems such as infection by close contact and increased CO2 levels by breathing in a limited space for approximately 8 hours. © 2010 Nova Science Publishers, Inc. All rights reserved.Öğe Association between respiratory health and indoor air pollution exposure in Canakkale, Turkey(Pergamon-Elsevier Science Ltd, 2015) Mentese, Sibel; Mirici, Nihal A.; Otkun, Muserref T.; Bakar, Coskun; Palaz, Elif; Tasdibi, Deniz; Cevizci, SibelIndoor air quality (IAQ) measurements were conducted in three different towns (i.e. Centre, Lapseki, and Can) in Canakkale, Turkey (n = 121) throughout the year. All indoor environments were selected randomly among the volunteer participants of a previous health survey. Particulate matter (PM), Total Volatile Organic Compounds (TVOCs), Total Bacteria Concentration (TBC), Total Mold Concentration (TMC), and Carbon dioxide (CO2) together with temperature and relative humidity (RH) were measured monthly. Together with IAQ measurements, bronchial hyper-responsiveness indicators such as forced vital capacity (FVC) and forced expiration volume (FEV1) of the occupants of the homes were measured by monthly Pulmonary Function (PF) test. Furthermore, a comprehensive survey was given to the participants. The measured IAQ parameters showed seasonal and spatial variations (p < 0.05). Among them, the highest levels of TVOC, CO2, and PM were found in the winter, while the highest levels of both TBC and TMC were found in the summer. In general, levels of IAQ parameters and asthma prevalence were the highest in Can (i.e. industrial area). Also, IAQ adversely influenced the respiratory health of participants in Can (p < 0.05). Shortness of breath was the most prominent respiratory symptom. Negative associations between asthma and FEV1/FVC ratio, and between respiratory symptom score (RSS) and FEV1/FVC, support the idea that the PF test can be a good indicator for (early) prognosis of respiratory diseases. (C) 2015 Elsevier Ltd. All rights reserved.Öğe Associations among exposure to microbial, organic, and inorganic indoor/outdoor air pollution and respiratory problems in different towns of Canakkale, Turkey(Amer Chemical Soc, 2014) Mentese, Sibel; Otkun, Muserref Tatman; Bakar, Coskun; Mirici, Nihal Arzu; Cevizci, Sibel; Tasdibi, Deniz; Palaz, Elif[Anstract Not Available]Öğe Associations between respiratory health and ambient air quality in Canakkale, Turkey: a long-term cohort study(Springer Heidelberg, 2018) Mentese, Sibel; Bakar, Coskun; Mirici, Nihal Arzu; Oymak, Sibel; Otkun, Muserref TatmanFew epidemiological studies investigating the association between air pollution and health are available in Turkey. The aim of this cohort-type study is to examine the relationships between ambient air quality, respiratory diseases, and decreases in pulmonary function over a year in three different towns in Canakkale: Canakkale Central town (region I), Lapseki town center (region II), and Can town (region III). Region III had four different sub-regions, which were Can town center (region III-A), and the villages located around Can town, namely Durali (region III-B), Kulfal (region III-C), and Yuvalar (region III-D). In the first stage of the study, a detailed questionnaire was completed by the participants (n = 1152) in face-to-face interviews and pulmonary function test (PFT) was performed. In the second stage of the study, PFT measurements were repeated 1 year after the first stage. Particulate matter, SO2, NO2, and ozone were gathered from air quality monitoring stations located in the centers of the three regions. The most polluted area was region III, while region I and region II were the least polluted areas. The risk of pulmonary function decline throughout a year was 2.1 times higher in region III, 2.4 times higher both in regions III-B and III-C, and 1.6 times higher for smokers in all regions. In the present study, ambient air quality was worse in region III (industrialized region), which influenced PFT scores and the prognostics for chronic respiratory diseases. The findings of this study should be considered for future investment plans in this region related to human and environmental health needs.Öğe Calibration and performance of synchronous SIM/scan mode for simultaneous targeted and discovery (non-targeted) analysis of exhaled breath samples from firefighters(Elsevier Science Bv, 2017) Wallace, M. Ariel Geer; Pleil, Joachim D.; Mentese, Sibel; Oliver, Karen D.; Whitaker, Donald A.; Fent, Kenneth W.Traditionally, gas chromatography-mass spectrometry (GC/MS) analysis has used a targeted approach called selected ion monitoring (SIM) to quantify specific compounds that may have adverse health effects. Dueto method limitations and the constraints of preparing duplicate samples, the information that could be obtained from separately collecting the full scan chromatogram of the sample has often been sacrificed. However, the hybrid technique called synchronous SIM/scan mode alternates between the two acquisition modes, maintaining the accuracy and sensitivity of SIM for targeted analysis while also providing the full scan chromatogram for discovery of non-target compounds. This technology was assessed using calibration data and real-world breath samples from a joint EPA/NIOSH collaboration that investigated the safety of firefighters' protective gear during controlled structure burns. Collecting field samples is costly and must be performed strategically to ensure that time points and replicates are accurate and representative of the intended population. This is difficult to accomplish with firefighters who are working under volatile conditions. The synchronous SIM/scan method decreases the number of field samples that need to be collected by half and reduces error in trying to recreate time points since a breath sample from a single sorbent tube can be used to collect both the SIM and scan data simultaneously. As a practical demonstration of the method, we investigate thirty-six firefighter breath samples, document organic compounds of interest, and identify additional non-target compounds. Published by Elsevier B.V.Öğe Comparison of dichloran rose bengal chloramphenicol and Sabouraud dextrose agar with cycloheximide and chloramphenicol for airborne mold sampling(Springer, 2017) Mentese, Sibel; Otkun, Muserref Tatman; Palaz, ElifThe more the mold species isolated on a culture medium, the more the sampling environment is represented accurately. According to the sampling purpose, it is crucial to use the best culture medium for mold. However, no study is available regarding the comparison of dichloran rose bengal chloramphenicol (DRBC) and Sabouraud dextrose agar with cycloheximide and chloramphenicol (SDA-CHX-CHL) culture media in terms of their application for airborne sampling, isolation, and identification of fungi. Airborne mold samples were impacted onto both DRBC and SDA-CHX-CHL, simultaneously using single-stage Andersen sampler. The limit of detection (LOD) value for airborne mold count was 7 CFU m(-3) (1 colony growth on the Petri dish). The total mold counts (TMC) ranged between < 7 and 504 CFU m(-3) (med 56 CFU m(-3)) and < 7 and 1218 CFU m(-3) (med 259 CFU m(-3)), collected on SDA-CHX-CHL and DRBC, respectively. Significantly higher TMC were observed on DRBC than on SDA regardless of the sampling environment (i.e, indoor or outdoor) (p < 0.05). Among the most predominant mold genera, observation frequencies of Penicillium spp. and Aspergillus spp. on both culture media were found to be more than 70%. Observation frequencies of Cladosporium spp., Alternaria spp., and yeast were found to be higher in samples collected on DRBC than those on SDA-CHX-CHL. Finally, DRBC was found to be superior to SDA in terms of both number of colonies and number of genera isolated from the air.Öğe Comparison of exposure to indoor air pollution in different towns of Çanakkale, Turkey(International Society of Indoor Air Quality and Climate, 2014) Mentese, Sibel; Otkun, Muserref T.; Bakar, Coskun; Mirici, Nihal A.; Cevizci, Sibel; Cotuker, Osman; Tasdibi, Deniz[No abstract available]Öğe Comparison of indoor and ambient air quality perceptions in Can and Central provinces of Canakkale, Turkey(2012) Mentese, Sibel; Bulut, Mine; Sen, BeyzaA survey was applied to randomly selected 190 people, living in two different provinces of Canakkale city, Can and Central, to find out air quality perceptions of the participants' living in these two provinces as a preliminary part of an extensive study. The survey consists of 4 parts; information regarding the residential environment, socioeconomic situation, general medical condition including SBS symptoms observations, and concerns regarding the air quality of the participant. More than half of the participants were smoker and in some of the participant's houses more than 1 indoor smoker was present. Among half of the indoor smoker participants, daily cigarette consumption was >10. Thermal comfort of the houses and odour perception of the participants' had variations within the districts. The ratio of the participants' who had indoor air pollution concerns were almost equal to the ratio of the participants had odour problem indoors. In general, middle-age people were suffering from the SBS-symptoms.Öğe Contribution of Rotor-Turbine Ventilator (RTV) on indoor air quality of a cafeteria(International Society of Indoor Air Quality and Climate, 2014) Mentese, Sibel; Cotuker, Osman; Selcuk, Burak[No abstract available]Öğe Effects of humidity and temperature variations on the formaldehyde indoor air concentration(2012) Mentese, Sibel; Gunschera, Jan; Salthammer, Tunga[No abstract available]Öğe Estimation of sources and factors affecting indoor VOC levels using basic numerical methods(Amer Inst Mathematical Sciences-Aims, 2016) Mentese, Sibel; Tasdibi, Deniz; Orak, ErsinVolatile Organic Compounds (VOCs) are a concern due to their adverse health effects and extensive usage. Levels of indoor VOCs were measured in six homes located in three different towns in epsilon anakkale, Turkey. Monthly indoor VOC samples were collected by passive sampling throughout a year. The highest levels of total volatile organic compounds (TVOC), benzene, toluene, and xylenes occurred in industrial, rural, and urban sites in a descending order. VOC levels were categorized as average values annually, during the heating period, and non-heating period. Several building/environmental factors together with occupants' habits were scored to obtain a basic indoor air pollution index (IAPi) for the homes. Bivariate regression analysis was applied to find the associations between the pollutant levels and home scores. IAPi scores were found to be correlated with average indoor VOC levels. In particular, very strong associations were found for occupants' habits. Furthermore, observed indoor VOC levels were categorized by using self-organizing map (SOM) and two simple scoring approaches, rounded average and maximum value methods, to classify the indoor environments based on their VOC compositions (IAPvoc). Three classes were used for both IAPi and IAPvoc approaches, namely good, moderate, and bad. There is an urgent need for indexing studies to determine the potential sources and/or factors affecting observed VOCs. This study gives a basic but good start for further studies.Öğe Generation mechanism of secondary organic aerosols (SOAs) and aldehydes from ozone-initiated reactions in test chambers, close to typical room conditions(Amer Chemical Soc, 2014) Mentese, Sibel; Gunschera, Jan; Salthammer, Tunga[Anstract Not Available]Öğe Hot - Spot summertime levels and potential sources of volatile organic compounds (VOC) on roads around Canakkale and Kilitbahir Harbors across Dardanelles Strait(Turkish Natl Committee Air Pollution Res & Control-Tuncap, 2020) Mentese, Sibel; Akca, BaharOrganic air pollutants have considerable influence particularly on atmospheric chemistry, compared to other air pollutants. Traffic is one of the major sources of air pollutants occurred in Canakkale atmosphere by both remarkable road and marine traffic loads around the harbors. The aims of this study were finding the daily, week/weekend, and spatial variations of VOC at multiple sampling points of Canakkale and Kilitbahir. In this study, active air samples were collected from the major roads of Kilitbahir and Canakkale Harbors during rush hours and off-peak in 2018 summer. According to the measurement results, average levels of total volatile organic compounds (TVOC) were around 129 mu g/m(3) in Canakkale and 93 mu g/m(3) in Kilitbahir. Toluene was the most abundant compound. Average B: T: E: X ratio was calculated as 2.4:7.0:1:5.5 in Canakkale and 3.2:7.6:1:5.2 in Kilitbahir. According to the sampling points of both locations, levels of TVOC, benzene, toluene, and m,p-xylene in Canakkale and toluene levels in Kilitbahir showed statistically significant differences (p < 0.05). Also, benzene, which was already classified as a human carcinogen, varied diurnally in Kilitbahir (p < 0.05). Toluene levels varied between week and weekend days (p < 0.05). Moreover, measured VOC levels were compared with air quality monitoring station (AQMS) data and meteorological parameters. TVOC levels showed positive correlations with SO2 and PM10 (p < 0.05). Furthermore, a multivariate factor analysis applied to data set including VOC measurements, AQMS data, and meteorological parameters implied that traffic is the predominant factor influencing the air quality around the study sites.Öğe Impact of building materials on indoor formaldehyde levels: Effect of ceiling tiles, mineral fiber insulation and gypsum board(Pergamon-Elsevier Science Ltd, 2013) Gunschera, Jan; Mentese, Sibel; Salthammer, Tunga; Andersen, Jan RudMaterials like building products or furnishing present in climatically controlled or uncontrolled indoor environments influence the indoor air quality (IAQ) significantly. In this study, the contribution of formaldehyde emissions from building materials and influences of adsorption/desorption behavior to indoor air pollution is investigated in a custom-made test house environment, located in a climate-controlled 48 m(3) stainless steel chamber. The complete test house study comprised three experimental cycles applying different types of ceiling tiles as target building materials. In each cycle one type of ceiling tile was used, while the housing construction and fittings were left unchanged. One cycle was divided into three steps to differentiate the contribution of each material to the overall IAQ: after the background monitoring of the empty housing frame (Step I), ceiling tiles were installed in the house and the air quality was monitored for one week (Step II). Finally, furniture and carpet were introduced into the house and the air was again monitored for one week (Step III). Additionally, gypsum boards and ceiling tiles were characterized by determination of their emission, diffusion and adsorption/desorption rates with regard to formaldehyde. It is the most important finding of this study that the resulting formaldehyde concentration does not simply result from additive emissions from the materials involved. In fact, it can only be explained accurately when taking into account multiple parameters. (C) 2013 Elsevier Ltd. All rights reserved.Öğe INDOOR AIR QUALITY OF A CAFETERIA WITH A ROTOR TURBINE VENTILATOR (RTV) AND CROSS-CORRELATIONS BETWEEN INDOOR AIR POLLUTANTS, OCCUPANCY RATE AND METEOROLOGICAL PARAMETERS(Gh Asachi Technical Univ Iasi, 2018) Mentese, Sibel; Cotuker, Osman; Selcuk, BurakIndoor air quality (IAQ) improvement potential of rotor turbine ventilator (RTV) was researched by setting up an RTV on the outer part of the chimney of a kitchen, located in a windy city, Canakkale, Turkey. Efficiency of RTV was assessed by preliminary tests, conducted in a three-storey restaurant. After obtaining positive results in terms of airborne bacteria count (TBC) from these tests, long-term measurements were carried out in a cafeteria by air sampling before and after setting up the RTV. In addition to airborne bacteria measurements, concentrations of Total Volatile Organic Compounds (TVOC), Carbon monoxide (CO), Carbon dioxide (CO2), ozone and (fine and coarse) particulate matters (PM) were also measured before and after the RTV installation on the funnel of the cafeteria. Moreover, temperature and relative humidity were measured on-line, and the meteorological parameters were recorded. Furthermore, the number of people in the cafeteria during the air sampling was counted. After the RTV installation, levels of TBC, sum of PM, TVOC, and CO2 clearly decreased, while levels of ozone and CO showed no significant variation during the study. Overall, RTV has potential to improve IAQ, when combined with natural ventilation. In addition to examining the efficiency of RTV, cross-correlations were found among the air pollutants, meteorological/thermal comfort parameters, and the occupancy rate, regardless of the RTV installation. Moreover, statistically significant relationships (p<0.05) were found for number of people in the cafeteria and levels of both CO2 and TBC throughout the entire study.Öğe Multiple comparisons of organic, microbial, and fine particulate pollutants in typical indoor environments: Diurnal and seasonal variations(Taylor & Francis Inc, 2012) Mentese, Sibel; Rad, Abbas Yousefi; Arisoy, Munevver; Gullu, GulenThis study was performed to investigate the possible sources as well as seasonal and diurnal variations of indoor air pollutants in widely used four different environments (house, office, kindergarten, and primary school) in which people spend most of their time. Bioaerosol levels and species, volatile organic compound (VOC) levels, and PM2.5 (particulate matter with an aerodynamic diameter similar to 2.5 mu m) levels were determined in different parts of these environments in parallel with outdoor sampling. Air pollution samplings were carried out in each microenvironment during five subsequent days in both winter and summer in Ankara, Turkey. The results indicated that bioaerosol, VOC, and PM2.5 levels were higher in the winter than in the summer. Moreover, PM2.5 and bioaerosol levels showed remarkable daily and diurnal variations, whereas a good correlation was found between the VOC levels measured in the morning and in the afternoon. Bacteria levels were, in general, higher than fungi levels. Among the VOCs, toluene was the most predominant, whereas elevated n-hexane levels were also observed in the kindergarten and the primary school, probably due to the frequent wet cleaning during school days. According to factor analysis, several factors were found to be significantly influencing the indoor air quality (IAQ), and amongst them, VOC-based products used indoors ranked first. The overall results indicate that grab sampling in naturally ventilated places may overestimate or underestimate the IAQ due to the inhomogeneous composition of indoor air caused by irregular exchanges with the outdoor air according to the season and/or occupants' habits. Implications: Seasonal and diurnal variations of VOCs, PM2.5, bioaerosols in house, office, and schools were observed, in which PM2.5 and bioaeorosols showed marked both intra-and interday variability, but VOCs did not. VOC-containing products were the most common source of air pollutants affecting the indoor air quality. External factors affecting the indoor air quality were season and indirectly ventilation. A grab sample cannot be representative in evaluating the air quality of a naturally ventilated environment precisely.
