Investigation Of Indoor Air Quality Research Articles

Numerical investigation and analysis of indoor air quality in a room based on impinging jet ventilation

This study presents numerical investigation and analysis of carbon dioxide transport (CO2) within an isothermal three-dimensional room using impinging jet ventilation (IJV). The IJV is an effective strategy for use in buildings. The study is carried out under turbulent and transient flow regime. The URANS equations supplemented with energy and concentration equations are solved using the scStream code. We are targeting primarily the efficiency of the ventilation ɛC and the index of indoor air quality (IIAQ). The ventilation flow rate is 50 m3.h-1. Here, our ultimate aim is to analyse the behaviour of the flow and repartition of CO2 inside the room. The RNG k−ε model was adopted to handle the turbulence. CFD simulations were systematically checked through available experimental and/or numerical results. The obtained results indicated that the IJV ensures a homogeneous concentration distribution and a velocity of the ambient air less than 0.25 m.s-1. This is in agreement with the recommendations of ASHRAE Standard 55. The comparative results demonstrate that the IJV evacuates sufficiently the CO2 and ensures good air quality in an acceptable time.

The effect of positive pressure on indoor air quality in a deeply renovated school building – a case study

This paper is a case study of ventilation and indoor air quality (IAQ) investigations in an extensively repaired comprehensive school in Finland. Our main hypothesis is that positive pressure between air indoors and outdoors can be used for decreasing the concentration of harmful chemical and microbiological agents in indoor air, as well as occupants´ complaints about IAQ, in a building waiting for new repairs or with unsolved IAQ problems. Research was undertaken on a building consisting of 12 classrooms, and served by one air handling unit. It found that the ventilation system was crucially unbalanced. However, IAQ measurements did not explain occupants´ symptoms, which were suspected to be related to the impurities leaked through the building envelope caused by the high negative pressure. To eliminate the potential harmful effects of the building related sources and infiltration airflows, the air handling unit was adjusted to generate a 5-7 Pa positive pressure for a period of 4 months. In the next planned phase of the study, moisture content of the structures during the heating season will be measured, as well as potential changes in perceived IAQ and microbial contamination.

Investigation of Indoor Air Quality and the Identification of Influential Factors at Primary Schools in the North of China

Over 70% of a pupil’s school life is spent inside a classroom, and indoor air quality has a significant impact on students’ attendance and learning potential. Therefore, the indoor air quality in primary school buildings is highly important. This empirical study investigates the indoor air quality in four naturally ventilated schools in China, with a focus on four parameters: PM2.5, PM10, CO2, and temperature. The correlations between the indoor air quality and the ambient air pollution, building defects, and occupants’ activities have been identified and discussed. The results indicate that building defects and occupants’ activities have a significant impact on indoor air quality. Buildings with better air tightness have a relatively smaller ratio of indoor particulate matter (PM) concentrations to outdoor PM concentrations when unoccupied. During occupied periods, the indoor/outdoor (I/O) ratio could be larger than 1 due to internal students’ activities. The indoor air temperature in winter is mainly determined by occupants’ activities and the adiabatic ability of a building’s fabrics. CO2 can easily exceed 1000 ppm on average due to the closing of windows and doors to keep the inside air warmer in winter. It is concluded that improving air tightness might be a way of reducing outdoor air pollutants’ penetration in naturally ventilated school buildings. Mechanical ventilation with air purification could be also an option on severely polluted days.

Investigation of indoor air quality at urban schools in Qatar

Information about indoor conditions of classrooms in Qatari schools is very scarce and availability of indoor air quality (IAQ) data is important as children are vulnerable to health hazards and spend long times in classrooms. Therefore, IAQ was investigated in 16 mechanically ventilated schools in Qatar during the winter season. Parameters such as temperature, relative humidity, carbon monoxide (CO), carbon dioxide (CO2) and particulate matters (PM10 and PM2.5) were measured indoors and outdoors simultaneously. High indoor CO2 and PM concentrations were found in many classrooms and exceeded the ASHRAE standard and US-EPA air quality standards as there are currently no established IAQ standards in Qatar. The mean indoor CO2 concentration in all classrooms was 1776 ± 887 ppm with mean indoor/outdoor ratio of 3.89 ± 2.03. The mean indoor PM10 and PM2.5 concentrations were 93.2 ± 42.4 µg/m3 and 60.1 ± 28.8 µg/m3, respectively. High indoor PM concentrations were found to be highly influenced by outdoor levels. Mean indoor/outdoor ratios for PM10 and PM2.5 in all classrooms were 0.87 ± 0.43 and 0.80 ± 0.34, respectively. The current study also identified many factors associated with increased indoor levels of PM. According to results of this study, some recommendations were suggested to reduce exposure of school children to high indoor levels of these pollutants as well as to provide comfortable learning environments.

Investigations of indoor air quality of large department store buildings in China based on field measurements

This paper presents a large-scale field studies on the indoor air pollution in large multi-storey department store buildings in seven Chinese metropolitan cities. From the year 2013–2015, nine buildings equipped with centralized air-conditioning system were carefully selected for the onsite test. Results show that each building has diverse indoor thermal environment and concentrations of CO2, formaldehyde and TVOC. Mean concentrations of CO2, formaldehyde and TVOC in the measured buildings range from 560 to 997 ppm, 0.02–0.31 mg/m3 and 0.074–0.636 mg/m3 respectively. The highest rates of exceeding the standard limit in the tested buildings were found as 36.8% of CO2, 53.2% of formaldehyde and 40.3% of TVOC. There are significant correlations between indoor and outdoor concentrations of CO2, formaldehyde and TVOC. The pollutant concentrations are different in different merchandise sections. Furthermore, significant differences and colorations of the pollution concentration are revealed between that of aboveground and underground floors. A mathematical model for the calculation of the increment of fresh air for the underground floors of a department store building is proposed based on the theoretical analysis and the assumption of steady-state airflow condition. This model provides quantitative relations of a required amount of additional fresh air of the underground floor referencing to the aboveground floor of the same building. Based on this research, it is recommended that the factors of space functionality and usage as well as the location of under-aboveground floors of the department stores should be taken into account in the design and operation of the HVAC systems.

Investigation of Indoor Air Quality of Residential Buildings in Enugu, Nigeria

Consideration of indoor air quality is a known practice in building and home design in developed Countries, and appropriate measures are taken during design for residential health. This is not so in developing economies. There is a dearth of research work on indoor air quality. Yet there is high level of exposure of the population to indoor air pollutants in residential buildings in these regions of the world. Building designers are yet to consider this problem in their designs. A major cause of indoor air pollution is the traditional method of cooking using dirty fuels. At present, no designs in these regions take cognizance of the use of these dirty fuels. This study addresses the problem of indoor air pollution of residential buildings in these areas. The study adopts ‘International Environmental Protection Agencies’ Evaluation Methodology, involving the use of Building Physics Equipment; Light House Laser Particle Counters; Carbon Monoxide and Extech DCO 1001, that measures particulates, carbon monoxide, indoor relative humidity, indoor temperature, and carbon dioxide quality respectively. Subjective assessment using questionnaire is also adopted. The data were analyzed with Statistical Package for the Social Sciences (SPSS). The results reveal that indoor air quality problem is common in the study area. The major pollutants identified in the study included: gases, steam, particles of dust and fibers, most of which are from internal indoor combustions. The result of the analysis also reveals that the factor loadings yielded a high cumulative percentage of the measured variables, in other words, a high concentration of the pollutants in the indoor air mass. The study recommends a new approach in residential buildings design that ensures immediate removal of indoor air pollutants from their source of generation.

Investigation of Indoor Air Quality in Houses of Macedonia.

People who live in buildings are exposed to harmful effects of indoor air pollution for many years. Therefore, our research is aimed to investigate the indoor air quality in family houses. The measurements of indoor air temperature, relative humidity, total volatile organic compounds (TVOC), particulate matters (PM) and sound pressure level were carried out in 25 houses in several cities of the Republic of Macedonia. Mean values of indoor air temperature and relative humidity ranged from 18.9 °C to 25.6 °C and from 34.1% to 68.0%, respectively. With regard to TVOC, it can be stated that excessive occurrence was recorded. Mean values ranged from 50 μg/m3 to 2610 μg/m3. Recommended value (200 μg/m3) for human exposure to TVOC was exceeded in 32% of houses. Mean concentrations of PM2.5 (particular matter with diameter less than 2.5 µm) and PM10 (diameter less than 10 µm) are determined to be from 16.80 µg/m3 to 30.70 µg/m3 and from 38.30 µg/m3 to 74.60 µg/m3 individually. Mean values of sound pressure level ranged from 29.8 dB(A) to 50.6 dB(A). Dependence between characteristics of buildings (Year of construction, Year of renovation, Smoke and Heating system) and data from measurements (Temperature, Relative humidity, TVOC, PM2.5 and PM10) were analyzed using R software. Van der Waerden test shows dependence of Smoke on TVOC and PM2.5. Permutational multivariate analysis of variance shows the effect of interaction of Renovation and Smoke.

Measuring vapor intrusion: from source science politics to a transdisciplinary approach

Investigation of indoor air quality has been on the upswing in recent years. In this article, we focus on how the transport of subsurface vapors into indoor air spaces, a process known as ‘vapor intrusion’, (VI) is defined and addressed. For environmental engineers and physical scientists who specialize in this emerging indoor environmental exposure science, VI is notoriously difficult to characterize, leading the regulatory community to seek improved science-based understandings of VI pathways and exposures. Yet despite the recent growth in VI science and competition between environmental consulting companies, VI studies have largely overlooked the social and political field in which VI problems emerge and are experienced by those at risk. To balance and inform current VI studies, this article explores VI science and policy and develops a critique of what we call ‘source science politics’. Drawing inspiration from the creative synthesis of social and environmental science/engineering perspectives, the article offers a transdisciplinary approach to VI that highlights collaboration with social scientists and impacted communities and cultivates epistemic empathy.

Investigation of indoor air quality in shopping malls during summer in Western China using subjective survey and field measurement

Thermal parameters and concentrations of CO2, TVOC and formaldehyde were monitored in shopping malls in four western cities in China during summer. Simultaneously, questionnaire subjective surveys were carried out to investigate the indoor perception of air quality and Sick Building Syndrome (SBS) among staffs in the shopping malls. It was found that stuffy odor had significant correlation with the overall odors perception and staff in the shopping malls had noticeable SBS. Instrument measurement showed that mall C had higher pollution levels of TVOC, while formaldehyde concentrations were higher in mall X and L. Pollution level in the malls is influenced by many factors, and three factors (customer density, ventilation conditions, emission characteristic of merchandise) were discussed in the analysis of data from the four malls. For customer density, the concentrations of CO2 on weekends were higher than on weekdays. Daily CO2 concentration was positively correlated with customer flow rate, but there was no significant strong correlation between customer flow rate and TVOC/formaldehyde concentrations. Underground floors had poorer indoor air quality than over-ground because of lack of fresh air. As for the merchandise sections, the formaldehyde in the home textile section in mall X reached 1.15 mg/m3 with an over standard rate of 83.3% due to the new merchandise added. This paper makes a contribution to knowledge relating to the reasons for discomfort in shopping malls by contributing multiple investigations on contaminants together with information on human perception and the operation of air conditioning systems within the stores.

Indoor air quality investigation of the school environment and estimated health risks: Two-season measurements in primary schools in Kozani, Greece

Two primary schools and one kindergarten were selected in the city of Kozani, Greece in order to investigate the school environment, the indoor air pollutants that children are exposed to and possible health risks at school. In each school three classrooms and one outdoor position were monitored from Monday to Friday, in both non-heating (26/09/2011–14/10/2011) and heating (23/01/2012–10/02/2012) period. Temperature, relative humidity and CO2, were continuously monitored. Formaldehyde, benzene, trichloroethylene, pinene, limonene, NO2 and O3 were measured with diffusive samplers. CO was monitored every day (30 min/day). Radon was measured for four weeks with short term radon detectors. PM2.5 was gravimetrically determined while PM2.5 and PM10 fractions were measured using the optical light scattering technique. Building material emission testing for VOCs was performed using the Field and Laboratory Emission Cell (FLEC). The ventilation rate for each classroom was calculated based on the CO2 measurements.Results indicated that indoor air concentrations of the measured pollutants were within accepted limits with indicative ranges 1.5–9.4 μg/m3 for benzene, 2.3–28.5 μg/m3 for formaldehyde, 4.6–43 μg/m3 for NO2 and 0.1–15.6 μg/m3 for O3. Emissions from building materials seem to have a significant contribution to the indoor air quality. Very low ventilation rates (0.1–3.7 L/s per person) were observed, indicating inadequate ventilation and possible indoor air quality problems requiring intervention measures. The estimated average lifetime cancer risks for benzene, formaldehyde and trichloroethylene were very low.

Ventilation heat recovery jointed low-temperature heating in retrofitting—An investigation of energy conservation, environmental impacts and indoor air quality in Swedish multifamily houses

Sweden is actively engaged in accelerating the sustainable transformation of existing building and energy systems. Most traditional investigations of this subject have been based on final energy savings and CO2 emission analysis, while most existing evaluation methods for energy-retrofitting have not accurately taken into account the influences of flow temperature patterns of different low-temperature heating (LTH) radiators to operational energy. In addition, comprehensive environmental impact analyses by energy systems, as well as the contributions to indoor air quality (IAQ), have not been fully achieved. Moreover, critical mapping of the sustainability of energy-efficient retrofitting have not yet been done. This omission leads to inaccuracies and misleading estimates of the benefits of LTH retrofitting from system and primary energy perspective. In order to fill these knowledge gaps, the present study evaluated two types of LTH systems combined with ventilation retrofitting, namely heat recovery jointed ventilation radiators (VRs) and baseboard radiators (BRs). A typical Swedish multi-family house was selected for retrofitting practice. This study aims at evaluating ventilation heat recovery jointed low temperature heating (VJLTH) retrofitting on energy conservation, environmental impacts and indoor air quality (IAQ) in typical Swedish multifamily houses. The compatibility of building performance and sustainability contributions were critically analyzed by delivered/primary energy usage, life cycle assessment (LCA), and IAQ modeling. IDA ICE (indoor climate and energy simulation program), SimaPro (LCA environmental impact modeling program), analytical model and on-site measurement data provided by both radiator and heat pump manufactures were employed. The results showed that the studied VJLTH retrofitting can save up to 55% of the final energy. And the corresponding primary energy savings are more than 25%. Compared with conventional radiators, low-temperature heating radiators can improve the COP by 12–18% for air-source heat pumps. The studied retrofit can positively contribute 11 of 16 environmental indicators, 7 of which had environmental impacts reduced by more than 50%. However, neglecting the indicators with negative impacts will increase the risk of over-representing the environmental contributions. The sustainability improvements of retrofitting, particularly for future large-scale implementation, should be critically evaluated from a broader perspective than final energy savings.

Secondhand hookah smoke: an occupational hazard for hookah bar employees

BackgroundDespite the increasing popularity of hookah bars, there is a lack of research assessing the health effects of hookah smoke among employees. This study investigated indoor air quality in hookah...

Investigation of IAQ in Mechanically Ventilated Kindergartens and Elementary Schools in Korea

This study investigates the indoor pollutant levels in school buildings according to the operation of mechanical ventilation system. Three classrooms at two different elementary schools and four classrooms at two children's day care center in Korea were chosen for investigation of indoor air quality with mechanical ventilation systems. Measurements were conducted for particulate matter, formaldehyde, total volatile organic compounds, carbon monoxide, carbon dioxide, nitrogen dioxide, ozone, radon, and total bacteria counts. Differences in indoor pollutants concentrations with and without operation of ventilation systems in each classroom were analyzed. The results show that operation of ventilation systems could decrease the levels of indoor pollutants in the classrooms, especially showing the reduction of HCHO concentrations by 14.9-62.3%. representative samples in Singapore. This study reported that indoor CO 2 concentration levels were lower in Singapore child care centers when compared to child care centers from other cold climate countries due to the higher ventilation rate of child care centers in Singapore. St-Jean et al. (11) have assessed indoor air quality in 21 day care centers in Montreal, Canada and determined association between building characteristics and IAQ. They reported that over 85% of the day care centers had a mean CO 2 concentration higher than 1000 ppm. The mean formaldehyde concentration was 22.9 µg/m 3 . They also reported that the presence of a mechanical ventilation system and a large surface of play are per child were significantly associated with lower CO 2 levels. Chitra and Nagendra (4) have investigated indoor air quality parameters in a naturally ventilated school building located near an urban roadway in India. This study reported that the mean value of indoor PM 10 , PM 2.5 , PM 1 and CO concentrations were found to be 149 ± 69, 61 ± 29, 43 ± 24, 0.10 ± 0.18 and 95 ± 61, 32 ± 16, 18 ± 9 µg/m 3 , 0.11 ± 0.14 ppm, respectively for winter and summer seasons. Norback et al. (12) have studied the relationship between VOCs, respirable dust, and personal factors to prevalence and incidence of sick building syndrome in six primary schools. They reported that the average CO 2 concentrations in all sites were greater than 800 ppm and indicated inadequate ventilation. Lee and Chang (13) investigated IAQ of five classrooms in Hong Kong. This study showed that the average respirable suspended particulate matter (RSPM) concentrations were higher than the Hong Kong air quality objective (annual average, 55 µg/m 3

An investigation of indoor air quality, thermal comfort and sick building syndrome symptoms in UK energy efficient homes

Purpose – Concern of the deterioration of indoor environmental quality as a result of energy efficient building design strategies is growing. Apprehensions of the effect of airtight, super insulated envelopes, the reduction of infiltration, and the reliance on mechanical systems to provide adequate ventilation (air supply) is promoting emerging new research in this field. The purpose of this paper is to present the results of an indoor air quality (IAQ) and thermal comfort investigation in UK energy efficient homes, through a case study investigation. Design/methodology/approach – The case study dwellings consisted of a row of six new-build homes which utilize mechanical ventilation with heat recovery (MVHR) systems, are built to an average airtightness of 2m3/m2/hr at 50 Pascal’s, and constructed without a central heating system. Physical IAQ measurements and occupant interviews were conducted during the summer and winter months over a 24-hour period, to gain information on occupant activities, perception of the interior environment, building-related health and building use. Findings – The results suggest inadequate IAQ and perceived thermal comfort, insufficient use of purge ventilation, presence of fungal growth, significant variances in heating patterns, occurrence of sick building syndrome symptoms and issues with the MVHR system. Practical implications – The findings will provide relevant data on the applicability of airtight, mechanically ventilated homes in a UK climate, with particular reference to IAQ. Originality/value – IAQ data of this nature is essentially lacking, particularly in the UK context. The findings will aid the development of effective sustainable design strategies that are appropriate to localized climatic conditions and sensitive to the health of building occupants.

Unexpected increase in indoor pollutants after the introduction of a smoke-free policy in a correctional center.

Correctional centers (prisons) are one of the few non-residential indoor environments where smoking is still permitted. However, few studies have investigated indoor air quality (IAQ) in these locations. We quantified the level of inmate and staff exposure to secondhand smoke, including particle number (PN) count, and we assessed the impact of the smoking ban on IAQ. We performed measurements of indoor and outdoor PM2.5 and PN concentrations, personal PN exposure levels, volatile organic compounds (VOCs), and nicotine both before and after a complete indoor smoking ban in an Australian maximum security prison. Results show that the indoor 24-h average PM2.5 concentrations ranged from 6 (±1)μg/m(3) to 17 (±3)μg/m(3) pre-ban. The post-ban levels ranged from 7 (±2)μg/m(3) to 71 (±43)μg/m(3) . While PM2.5 concentrations decreased in one unit post-ban, they increased in the other two units. Similar post-ban increases were also observed in levels of PN and VOCs. We describe an unexpected increase of indoor pollutants following a total indoor smoking ban in a prison that was reflected across multiple pollutants that are markers of smoking. We hypothesise that clandestine post-ban smoking among inmates may have been the predominant cause.

Case study investigation of indoor air quality in mechanically ventilated and naturally ventilated UK social housing

There is a significant lack of indoor air quality research in low energy homes. This study compared the indoor air quality of eight newly built case study homes constructed to similar levels of air-tightness and insulation; with two different ventilation strategies (four homes with Mechanical Ventilation with Heat Recovery (MVHR) systems/Code level 4 and four homes naturally ventilated/Code level 3). Indoor air quality measurements were conducted over a 24 h period in the living room and main bedroom of each home during the summer and winter seasons. Simultaneous outside measurements and an occupant diary were also employed during the measurement period. Occupant interviews were conducted to gain information on perceived indoor air quality, occupant behaviour and building related illnesses. Knowledge of the MVHR system including ventilation related behaviour was also studied. Results suggest indoor air quality problems in both the mechanically ventilated and naturally ventilated homes, with significant issues identified regarding occupant use in the social homes.

Indoor air-quality investigation in code for sustainable homes and passivhaus dwellings

Purpose– Energy efficient building design strategies are growing in popularity, promoted through increased awareness of climate change, rising energy prices, global consciousness and a demand for energy security. To aid this design process, assessment tools such as Code for Sustainable Homes (CSHs) and Passivhaus were introduced in the UK. However, it is suggested that these tools prioritise energy efficiency over occupant health through a fundamental lack of attention to indoor air quality (IAQ). The purpose of this paper is to investigate IAQ in selected dwellings built using CSHs level 6, level 3 and Passivhaus homes in the UK.Design/methodology/approach– Using a case study approach, the investigation consisted of IAQ measurements during summer and winter months, occupant diaries and occupant interviews.Findings– The results from the IAQ measurements show the recommended maximum level of 1,000 ppm was breached in all three Code 6 and two Code 3 homes, with levels slightly below this limit in the two Passivhaus homes. Measurements found high levels of formaldehyde, carbon dioxide and low levels of relative humidity.Practical implications– There is a need for the adequate consideration of IAQ in sustainable assessment methods, including the use of mandatory credits to ensure occupant health is not disregarded in the drive towards zero carbon.Originality/value– These results can be used to recognise areas of improvement in the CSHs and Passivhaus standard, and the design of energy efficient homes in general. Research of this nature is essential to ensure occupant health is not sacrificed through the drive towards zero carbon.

Investigation of Indoor Air Quality in Primary School Classrooms

In recent IAQ studies, there is much concern about air quality in school buildings. This paper focuses on indoor air quality in classrooms of two primary schools in Beijing, China. Ventilation rates, CO2 and PM2.5 are measured and analyzed. The results show that ventilation rates in naturally ventilated classrooms with windows and doors closed are less than 1 l/s/p, and CO2 concentration during class hours can increase over 2500ppm within a class. And also, closing windows and doors can only partly prevent outdoor PM2.5 from entering into indoor air, and indoor PM2.5 concentrations are 60∼70% of outdoor. To insure good indoor air quality in primary schools, mechanical ventilation devices with air purification function should be introduced in.

A study of indoor air quality investigations in B.C health authorities


 Canadians spend 90 percent of their lifetime indoors and are currently aware that poor indoor air quality (IAQ) can negatively impact human health. If there are any IAQ problems, the Health Authorities will conduct IAQ investigations to respond to the complainants or resolve the conflicts. An online survey to Environmental Health Officers (EHOs) and specialists was used to understand the frequencies that B.C. Health Authorities conduct IAQ investigations, the locations Health Authorities encountered most IAQ queries, the different types of pollutants that IAQ instruments are used for and the preference for instruments chosen. Five common indoor air pollutants, such as mould, volatile organic compounds (VOCs), radon, particulate matters (PMs), CO and CO2, were chosen and the Chi-Square test was used to analyze the data in this study. This study showed that most EHOs had never conducted IAQ investigations since they had worked in the B. C Health Authorities. Mould problems between landlord and tenant were EHOs mostly encountered. The study found that EHOs referred to other agencies or consultants when they received complaints. The data showed that the method of managing IAQ problems was associated with the Health Authorities because few EHOs from Vancouver Coastal Health indicated they had used equipment to conduct IAQ investigations. The mostly encountered location and frequency of conducting radon investigations were significantly associated with the Health Authorities due to an on-going project in Northern Authority. Most EHOs and specialists had shown that they educated public regarding to the information of IAQ instead of monitoring the IAQ pollutants. The results of this study indicate that EHOs did not get involved in IAQ investigations often and also showed that mould problems were the mostly encountered IAQ problems between the Health Authorities. The most important role of EHOs and specialists in this area is to educate public to solve or prevent IAQ problems.

Investigation of indoor and outdoor air quality of the classrooms at a school in Serbia

The air inside schools can be more polluted than the air outside. The purpose of this study was to investigate the air quality in primary school placed in town at the east of Serbia. The characterization of air pollution concentration was performed with main goal to determine relationship between indoor and outdoor air pollution within five classrooms. The measurements were conducted continuously in indoor and outdoor environment for period of 10 days. The standard sampling and analytical methods were applied (gas chromatography coupled with mass spectrometry). This paper presents and analyses concentrations of different physical and chemical pollutants in the indoor and outdoor environment: respirable particulate matter with different diameters (up to 2.5 μm and 10 μm), polycyclic aromatic hydrocarbon in particulate matters up to 10 μm, volatile organic compounds, formaldehyde, ozone, carbon-dioxide and nitric-dioxide. It was found, in one class, that the concentration of particulate matter with diameter up to 10 and 2.5 microns as well as polycyclic aromatic hydrocarbon in particulate matters up to 10 μm were higher in indoor environment than in outdoor. The average value of formaldehyde in all classrooms was significantly higher than recommended value. On the basis of received results, extensive school renovation program can be recommended.