Air Quality In Schools Research Articles

Characteristics of air pollutants inside and outside a primary school classroom in Beijing and respiratory health impact on children

This study investigated the spatial and temporal distributions of particulate and gaseous air pollutants in a primary school in Beijing and assessed their health impact on the children. The results show that air quality inside the classroom was greatly affected by the input of outdoor pollutants; high levels of pollution were observed during both the heating and nonheating periods and indicate that indoor and outdoor air pollution posed a threat to the children's health. Traffic sources near the primary school were the main contributors to indoor and outdoor pollutants during both periods. Moreover, air quality in this primary school was affected by coal combustion and atmospheric reactions during the heating and nonheating periods, respectively. Based on the estimation by exposure-response functions and the weighting of indoor and outdoor pollutants during different periods, the levels of PM2.5, PM 10 and O3 at school had adverse respiratory health effects on children. Longer exposures during the nonheating period contributed to higher health risks. These results emphasized that emission sources nearby had a direct impact on air quality in school and children's respiratory health. Therefore, measures should be taken for double control on air pollution inside and outside the classroom to protect children from it.

Comparison of Indoor Air Quality in Schools: Urban vs. Industrial 'Oil & Gas' Zones in Akwa Ibom State – Nigeria

This study was carried out to assess indoor air quality (IAQ) in schools in Akwa Ibom State of Nigeria during the rainy (June – July) and dry (November – December) seasons of 2018. IAQ parameters were examined to assess pollutant levels in schools within Akwa Ibom State in single setting only (naturally ventilated classrooms). Schools were randomly selected from two zones: zone 1 which is located within the Capital City (Uyo metropolis) and represents the 'urban sector', and zone 2 which is located within the southern part of the state in close proximity to the oil and gas industrial region and represents the 'industrial sector'. Indoor air investigation included the following parameters: particulate matter (PM1, PM2, PM5, and PM10), carbon monoxide (CO), carbon dioxide (CO2) levels, temperature and relative humidity, which were simultaneously measured in fourteen (14) sampling days using Fluke 985 Particle Counter and Fluke 975 AirMeter. Multiple statistically analysis techniques were used to compare IAQ parameters and test for significant differences between the zones (urban vs. industrial) and annual seasonal variations. The concentrations of particulate matter (PM) in the naturally ventilated classroom in industrial zone during the rainy season ranged from 5152 – 5984 μg/m3 for PM1; 2744 – 3207 μg/m3 for PM2; 137 – 149 μg/m3 for PM5; 38 – 46 μg/m3 for PM10 and in urban zone, the concentrations of PM ranged from 1978 – 2491 μg/m3 for PM1; 1010 – 1311 μg/m3 for PM2; 38 – 56 μg/m3 for PM5; 15 – 24 μg/m3 for PM10. During the dry season, the concentrations of PM in the naturally ventilated classroom in industrial zone ranged from 6138 – 6999 μg/m3 for PM1; 2984 – 3980 μg/m3 for PM2; 146 – 159 μg/m3 for PM5; 47 – 59 μg/m3 for PM10 and in urban zone, the concentrations of PM ranged from 2556 – 3972 μg/m3 for PM1; 1911 – 2311 μg/m3 for PM2; 51 – 66 μg/m3 for PM5; 18 – 34 μg/m3 for PM10. Results of this study has revealed that the concentrations of PM1, PM2, PM5, and PM10 measured in the naturally ventilated classroom in industrial zone were significantly (p 10 measured were found to be much lower than the ambient maximum contaminant level for airborne PM10 standard promulgated by the United States Environmental Protection Agency (US–EPA) (150 μg/m3 daily average and 50 μg/m3 annual average) and World Health Organization (WHO) PM10 guidelines values (50 μg/m3 daily average and 20 μg/m3 annual average). Apart from re–suspension of atmospheric particles, anthropogenic activities in industrial zone significantly influenced the measured concentrations of PM compared to those measured in urban zone. In addition, the lower concentration of CO and CO2 measured indicated adequate air exchange at the time of the assessment in the naturally ventilated classrooms during the sampling period. The results obtained reveal important contributions towards understanding of airborne PM distribution patterns and the available data can be used for making public health policies.

The effect of the ventilation retrofit in a school on CO2, airborne particles, and energy consumptions

The energy retrofit of existing buildings is a key strategy to reduce the energy costs of the building sector. Amongst the retrofit solutions, the adoption of mechanical ventilation systems represents a necessary approach for buildings with high crowding index, such as schools.The air quality in schools is a main issue since children spend a significant fraction of the year in such microenvironments. To date, the scientific literature has carried out several studies concerning the air quality in naturally ventilated schools worldwide, nonetheless most of the studies performed a general evaluation of the air quality just using the CO2 as a comprehensive indicator. This is an oversimplified approach since the indoor air quality is affected by several pollutants, including airborne particles, whose behavior cannot be predicted by the CO2 one.The aim of the research is the evaluation of the effect of the ventilation retrofit in a classroom on different indoor air quality parameters and energy consumption. To this end a mechanical ventilation system with a heat recovery unit was installed in a test-classroom and tests with CO2-based demand controlled ventilation were performed. CO2 levels and indoor-to-outdoor particle concentrations were measured and compared to the pre-retrofit ventilation conditions (i.e. manual airing procedures).Results showed that mechanical ventilation systems have simultaneous positive effects on the different pollutants investigated as well as on ventilation heat losses: indeed, lower indoor-to-outdoor concentration ratios, with respect to the airing approach, were detected simultaneously for CO2, sub-micron particles and PM10.

Indoor Air Quality in Kindergartens in Poland

The universal ventilation system in Polish kindergartens is the natural ventilation system. This is due to the fact that these buildings are several or even several dozen years old. National regulation for natural ventilation define only general guidelines. There are in the legislation acts only the permissible tightness of the building joinery and the minimum value of the air infiltrate to the rooms. The amount of air is constant regardless of the room’s purpose or the number of people staying in them. Over the last decade, in such buildings incomplete thermomodernization treatments were carried out, as a result of which the inflow of air to the rooms was most often limited, and thus the indoor air quality decreased. While, the low indoor air quality may lead not only to the poor well-being of users, but also to low efficiency of work and insufficient learning of new messages. This problem is extremely important in the case of a group of people who are not be able to determine the requirements in relation to IAQ. As has been shown in the Scandinavian countries, in the rooms where children are staying there the proper ventilation system several times reduces the chance of allergic symptoms. At the same time, research carried out in Denmark showed that the low indoor air quality in school premises negatively affects the learning efficiency of children. That is why it is extremely important to ensure proper microclimate conditions in the rooms where the youngest children are staying. The article presents the results of research on the indoor air quality (IAQ) in 4 kindergartens in Poland, located in the city with 200,000 inhabitants. The buildings in which research was carried out were built in the years 1970-1993 and were equipped with a gravity ventilation system. The analysis covered the variability of the basic parameters describing the indoor air quality, i.e. temperature, relative humidity and concentration of carbon dioxide.

Indoor air quality in schools of a highly polluted south Mediterranean area.

This study aimed at surveying lower secondary schools in southern Italy, in a highly polluted area. A community close to an industrial area and three villages in rural areas was investigated. Indoor temperature, relative humidity (RH), gaseous pollutants (CO2 and NO2 ), selected biological pollutants in indoor dust, and the indoor/outdoor mass concentration and elemental composition of PM2.5 were ascertained. Temperature and RH were within, or close to, the comfort range, while CO2 frequently exceeded the threshold of 1000ppm, indicating inadequate air exchange rate. In all the classrooms, median NO2 levels were above the WHO threshold value. Dermatophagoides p. allergen concentration was below the sensitizing threshold, while high endotoxin levels were detected in the classrooms, suggesting schools may produce significant risks of endotoxin exposure. Concentration and solubility of PM2.5 elements were used to identify the sources of indoor particles. Indoor concentration of most elements was higher than outdoors. Resuspension was responsible for the indoor increase in soil components. For elements from industrial emission (Cd, Co, Ni, Pb, Sb, Tl, V), the indoor concentration depended on penetration from the outside. For these elements, differences in rural vs industrial concentrations were found, suggesting industrial sources may influence indoor air quality nearby schools.

Indoor air quality in inner-city schools and its associations with building characteristics and environmental factors

Indoor concentrations of fine particulate matter (PM2.5), nitrogen dioxide (NO2), and carbon monoxide (CO) were measured across 16 urban public schools in three different seasons. Exceedance of the WHO guidelines for indoor air was observed, mainly for the hourly average NO2 concentrations. Seasonal variability was statistically significant for indoor NO2 and CO concentrations, with higher exposures in fall and winter. An extensive list of potential factors at the outdoor environment, school, and room level that may explain the variability in indoor exposure was examined. Factors with significant contributions to indoor exposure were mostly related to the outdoor pollution sources. This is evidenced by the strong associations between indoor concentration of CO and NO2 and factors including outdoor PM2.5 and NO2 concentrations, including length of the nearby roads and the number of nearby industrial facilities. Additionally, we found that poor conditions of the buildings (a prevalent phenomenon in the studied urban area), including physical defects and lack of proper ventilation, contributed to poor air quality in schools. The results suggest that improving building conditions and facilities as well as a consideration of the school surroundings may improve indoor air quality in schools.

Sources of indoor air pollution at a New Zealand urban primary school; a case study

Children are particularly vulnerable to the health effects of air pollution and as they spend a large proportion of time at school, this is an important environment for children's exposure to air pollution. Understanding the factors that influence indoor air quality in schools is critical for the assessment and control of indoor air pollution. This study analysed the concentration and sources of air pollution at an urban primary school (5–11 years) in Wellington, the capital of New Zealand. Over a three-week period during spring, indoor measures of particulate matter (PM2.5, PM10), temperature, humidity, carbon dioxide (CO2) and nitrogen dioxide (NO2) were taken and hourly air particulate matter samples (PM2.5, PM10-2.5) were collected inside and outside for elemental speciation analysis. Indoor PM10 concentrations during the school day were significantly (p < 0.001) higher than outdoor concentrations 30.1 (range 10.0–75.0, SD 1.9) μg m−3 c.f. 8.9 (range <1.0–35.0, SD 6.8) μg m−3. Elemental analysis and receptor modelling of PM samples showed that indoor PM10 was primarily composed of crustal matter (soil) elements, possibly brought in on children's footwear. The primary driver of indoor PM2.5 was from the infiltration of outdoor pollutants inside, with by-products of motor vehicle emissions the main contributor to indoor PM2.5. There is a need for mitigation strategies to reduce exposure to indoor air pollution at school, such as improved cleaning methods, reducing the use of carpet in schools and improved ventilation. The findings from this study will be applicable to many other schools and public buildings with high foot traffic.

How to protect school children from the neurodevelopmental harms of air pollution by interventions in the school environment in the urban context

Recently, there has been a flurry of publications assessing the effect of air pollution on neurodevelopment. Here we present a summary of the results obtained within the BRain dEvelopment and Air polluTion ultrafine particles in scHool childrEn (BREATHE) Project, which aimed to evaluate the effects of the exposure to traffic related air pollutants in schoolchildren in Barcelona. To this end, we comprehensively characterised air quality in 39 urban schools from Barcelona and identified the main determinants of children's increased exposure. We propose a series of measures to be implemented to improve air quality in schools within the urban context and, consequently, minimise the negative effects on children's neurodevelopment that we found to be associated with the exposure to air pollution. We also aimed to list some of the actions pushed by governments and the society (including school managers, parents, and children) that have been taking place around Europe for promoting better high quality in the school and its surroundings.

Test-retest repeatability of child\u2019s respiratory symptoms and perceived indoor air quality \u2013 comparing self- and parent-administered questionnaires

BackgroundQuestionnaires can be used to assess perceived indoor air quality and symptoms in schools. Questionnaires for primary school aged children have traditionally been parent-administered, but self-administered questionnaires would be easier to administer and may yield as good, if not better, information. Our aim was to compare the repeatability of self- and parent-administered indoor air questionnaires designed for primary school aged pupils.MethodsIndoor air questionnaire with questions on child’s symptoms and perceived indoor air quality in schools was sent to parents of pupils aged 7–12 years in two schools and again after two weeks. Slightly modified version of the questionnaire was administered to pupils aged 9–12 years in another two schools and repeated after a week. 351 (52%) parents and 319 pupils (86%) answered both the first and the second questionnaire. Test-retest repeatability was assessed with intra-class correlation (ICC) and Cohen’s kappa coefficients (k).ResultsTest-retest repeatability was generally between 0.4–0.7 (ICC; k) in both self- and parent-administered questionnaire. In majority of the questions on symptoms and perceived indoor air quality test-retest repeatability was at the same level or slightly better in self-administered compared to parent-administered questionnaire. Agreement of self- and parent administered questionnaires was generally < 0.4 (ICC; k) in reported symptoms and 0.4–0.6 (ICC; k) in perceived indoor air quality.ConclusionsChildren aged 9–12 years can give as, or even more, repeatable information about their respiratory symptoms and perceived indoor air quality than their parents. Therefore, it may be possible to use self-administered questionnaires in future studies also with children.

Impact of School Air Quality on Children's Respiratory Health.

Background:Asthma is common in children with indoor pollutants influencing the development of the disease. Since children spend most of their time outside their homes within the school environment, school indoor air quality can directly influence their respiratory health.Aims:This study aims to analyze the indoor and outdoor air quality of Maltese schools and if an association exists between indoor pollutants and respiratory health in children.Settings and Design:Five primary schools were selected with 9- to 11-year-old students participating.Materials and Methods:Standardized health questionnaires and lung function tests were utilized. Indoor and outdoor air sampling together with traffic counts were carried out.Statistical Analysis Used:SPSS version 21 was used and the Chi-squared, logistic regression, and Pearson's correlation were used.Results:The mean indoor PM 2.5 level of 17.78 μg/m3 and CO (9.11 ppm) exceeded World Health Organization thresholds. Indoor ozone levels exceeded the mean European school's indoor ozone concentration of 8 μg/m3. High exposure to formaldehyde, NO2, and ozone was associated with atopy in children. Heavy vehicles passing near the schools were associated with current wheezing (P < 0.001) but not nocturnal cough (P = 0.34).Conclusions:School indoor and outdoor environment has a direct impact on children's respiratory health. This study has identified significant associations between high exposures to indoor air pollutants, school characteristics, and upper and lower airway inflammation.

Key Factors Determining Indoor Air PM10 Concentrations in Naturally Ventilated Primary Schools in Belgrade, Serbia.

IntroductionIndoor air quality (IAQ) is rated as a serious public health issue. Knowing children are accounted as more vulnerable to environmental health hazards, data are needed on air quality in schools.MethodsA project was conducted from 2007 until 2009 (SEARCH, School Environment and Respiratory Health of Children), aiming to verify links between IAQ and children’s respiratory health. Study was conducted in ten primary schools on 735 children, in 44 classrooms. Children were randomly selected. Research tools and indicators used for children’s exposure to school environment were indoor and outdoor pollutants, two standardized questionnaires for school and classroom characteristics. In both classroom air and ambient air in front of them we measured, during a 5-day exposure period for continuous 24h measuring: carbon monoxide, carbon dioxide, indoor air temperature, relative humidity, and PM10 during classes.ResultsPM10 concentrations were significantly most frequent in an interval of ≥80.1μg/m3, that is, in the interval above 50μg/m3. Mean PM10 value was 82.24±42.43 μg/m3, ranging from 32.00μg/m3 to of 197.00μg/m3.ConclusionThe increase of outdoor PM10 concentration significantly affects the increase of indoor PM10. A statistically significant difference exists for average IAQ PM10 concentrations vs. indicators of indoor thermal comfort zone (p<0.0001); they are lower in the classrooms with indicators within the comfort zone. Moreover, dominant factors for the increase of PM10 are: high occupancy rate in the classroom (<2m2 of space per child), high relative humidity (>75%), and indoor temperature beyond 23°C, as well as bad ventilation habits (keeping windows shut most of the time).

Teacher respiratory health symptoms in relation to school and home environment.

Few studies have evaluated teachers' respiratory health, especially its relationship with school/home environment, and school policies. This study assessed asthma and smoking prevalence among teachers in Romania, teacher's perception and knowledge of the school environment, policies and asthma management, and how school and home environment affected asthma, allergy, and respiratory infection symptoms. This cross-sectional study obtained information from 104 Romanian teachers utilizing teacher questionnaire data for Romania only, as part of the Schools Indoor Pollution and Health: Observatory Network in Europe (SINPHONIE) study, a multicenter European research project conducted between 2010 and 2012. The SINPHONIE questionnaire collected comprehensive information on school and home environment, respiratory symptoms, smoking, and school policies. We used unconditional logistic regression analysis to examine environment-outcome relationships while controlling for socio-demographics and co-exposures. Our results showed the prevalence of asthma-like symptoms and smoking among teachers in Romania was higher than in other SINPHONIE schools and among US teachers. Factors statistically associated with asthma, allergy, and respiratory infection (all p<0.05) include perception of health related to poor air quality in school, inappropriate cleaning of ventilation systems, dwelling proximity to busy traffic, and multiple school/home exposures. We also found lack of asthma management and environmental policies in the investigated Romanian schools. We concluded that multiple school and home environmental factors were related to respiratory and allergic symptoms. High asthma burden and smoking are important public health problems in Romania. Future studies including larger sample size and exposure measurements are needed to confirm our findings.

Comparison of indoor air quality in schools: Urban vs. Industrial 'oil & gas' zones in Kuwait

This study was conducted to assess indoor air quality during a complete school calendar year and covered all climatic seasons. IAQ parameters were examined to assess pollutant levels in Kuwait schools in multiple settings (classrooms, painting rooms, computer labs, science rooms, teachers' rooms, and roofs). Schools were randomly selected from two zones: zone 1 which is located close to downtown and represents the 'urban sector', and zone 2 which is located further south in close proximity to the oil and gas industrial region and represents the 'industrial sector'. Indoor air investigation included the following parameters: CO2, SO2, NO2, H2S, formaldehyde, acetaldehyde, TVOC, and nine elemental concentrations of PM10, namely: As, Co, Cr, Fe, Pb, V, Al, Cd, and Hg. Dust from air conditioning filters was also collected and analyzed for both PAHs and PBDEs. T-test, one-way ANOVA, Two-way ANOVA and linear regression were tested to identify seasonal, location, and zone variations. On-way ANOVA identified significant seasonal variation for NO2, H2S, formaldehyde and acetaldehyde. Factorial ANOVA demonstrated that the schools varied significantly on TVOCs. High concentrations of PAHs and BDE-209 cogener were also present in most schools. Analysis of dust from AC filter units along with measurements of indoor air pollutants can improve our understanding of the common sources of typical pollutants indoor. This study, to our knowledge, presents the first comprehensive analysis of indoor air parameters, including dust analysis from AC filters, in schools in the MENA region 'Middle East and North Africa'.

Trace element contents in fine particulate matter (PM2.5) in urban school microenvironments near a contaminated beach with mine tailings, Chañaral, Chile.

Air quality in schools is an important public health issue because children spend a considerable part of their daily life in classrooms. Particulate size and chemical composition has been associated with negative health effects. We studied levels of trace element concentrations in fine particulate matter (PM2.5) in indoor versus outdoor school settings from six schools in Chañaral, a coastal city with a beach severely polluted with mine tailings. Concentrations of trace elements were measured on two consecutive days during the summer and winter of 2012 and 2013 and determined using X-ray fluorescence. Source apportionment and element enrichment were measured using principal components analysis and enrichment factors. Trace elements were higher in indoor school spaces, especially in classrooms compared with outdoor environments. The most abundant elements were Na, Cl, S, Ca, Fe, K, Mn, Ti, and Si, associated with earth's crust. Conversely, an extremely high enrichment factor was determined for Cu, Zn, Ni and Cr; heavy metals associated with systemic and carcinogenic risk effects, whose probably origin sources are industrial and mining activities. These results suggest that the main source of trace elements in PM2.5 from these school microenvironments is a mixture of dust contaminated with mine tailings and marine aerosols. Policymakers should prioritize environmental management changes to minimize further environmental damage and its direct impact on the health of children exposed.

The effect of natural ventilation strategy on indoor air quality in schools

In order to reduce children's exposure to pollutants in classrooms a proper ventilation strategy need to be adopted. Such strategy is even more important in naturally ventilated schools where the air exchange rate is only based on the manual airing of classrooms. The present work aimed to evaluate the effect of the manual airing strategy on indoor air quality in Italian classrooms. For this aim, schools located in the Central Italy were investigated. Indoor air quality was studied in terms of CO2, particle number and PM concentrations and compared to corresponding outdoor levels. In particular two experimental analyses were performed: i) a comparison between heating and non heating season in different schools; ii) an evaluation of the effect of scheduled airing periods on the dilution of indoor-generated pollutants and the penetration of outdoor-generated ones. In particular, different airing procedures, i.e. different window opening periods (5 to 20min per hour) were imposed and controlled through contacts installed on classroom windows and doors. Results revealed that the airing strategy differently affect the several pollutants detected in indoors depending on their size, origin and dynamics. Longer airing periods may result in reduced indoor CO2 concentrations and, similarly, other gaseous indoor-generated pollutants. Simultaneously, higher ultrafine particle (and other vehicular-related pollutants) levels in indoors were measured due to infiltration from outdoors. Finally, a negligible effect of the manual airing on PM levels in classroom was detected. Therefore, a simultaneous reduction in concentration levels for all the pollutant metrics in classrooms cannot be obtained just relying upon air permeability of the building envelope and manual airing of the classrooms.

Source Apportionment of PM2.5 Particles: Influence of Outdoor Particles on Indoor Environment of Schools Using Chemical Mass Balance

ABSTRACTChildren have higher lung function than adults and they spend most of their day time in schools. Also, children studying at schools located in the vicinity of busy roadways are vulnerable to childhood asthma and respiratory disorders. The present study is focused on estimating the sources of PM2.5 particles present in the indoor air quality in schools which are located adjacent to urban and suburban roadways. The indoor PM2.5 samples from all the four schools were collected using fine dust sampler from 8 a.m. to 4 p.m. The sampling was carried out for one complete week during various seasons including both working and non-working days. The chemical compositions of the PM2.5 samples were analyzed for certain elements like Ba, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Sr, Ti, V and Zn using Inductively Coupled Plasma Optical Emission Spectrometry (ICP OES) and ions like F–, Cl–, NO3–, PO43–, SO42–, K+, Ca2+, Mg2+, NH4+, Na+ using Ion Chromatography (IC). Source apportionment study using Chemical Mass Balance was carried out using the species concentration of the collected samples. The major sources were found to be Paved Road Dust, Soil Dust, Gasoline Vehicle Emissions, Diesel Vehicle Emissions and Marine Source Emissions. Among these, vehicular emissions contribution was found to be higher for the schools located close to roadways rather than the school located at a considerable distance from highway. The difference in source type contribution at each school clearly depicts the difference in nature of location and type of activities in the vicinity of the sampling sites.

Chemical Composition of Indoor and Outdoor PM2.5 in Three Schools in the City of Rome

In Italy, children spend up to 30% of their time in school institutions; for this reason, the evaluation of indoor air quality in schools constitutes a necessary step forward in the direction of child health protection. In this study, we investigated the chemical composition of PM2.5 collected simultaneously indoor and outdoor in three primary schools in Rome. Seasonal variations between winter and spring/summer were evaluated, as well as the role of the main macro-sources of PM (soil, sea, traffic, secondary inorganics and organics). During winter periods, characterized by strong atmospheric stability, the main contributors were organics and combustion products, which accounted for more than 70% of the total mass both indoor and outdoor. Spring/summer period was characterized by very low outdoor concentrations (12 μg/m3 on average) and by a more balanced contribution of organic, traffic and secondary inorganic components. Indoor, the contribution of soil-related species from re-suspension of settled dust and secondary inorganic species from outdoor photochemical reactions became significant. Given that several indoor exceedances of the international air quality standards for PM2.5 were recorded during the most polluted days, the infiltration of outdoor air, due to the inadequate construction characteristics of the buildings and the absence of automated air filtration systems, seemed to be the main causes of the high PM concentrations measured indoor.

Real-time indoor and outdoor measurements of black carbon at primary schools

Epidemiological and toxicological studies have demonstrated the association between Black Carbon in indoor and outdoor air and the occurrence of health risks. Data on air quality in schools is of special interest, as children are more vulnerable to health hazards. In this context, indoor and outdoor measurements of real-time Equivalent Black Carbon (EBC) were collected at 39 primary schools located in Barcelona (Spain), with classrooms naturally ventilated under warm weather conditions. A main contribution of road traffic emissions to indoor and outdoor EBC levels was evidenced through different approaches. Simultaneous measurements of EBC levels at schools under different traffic conditions revealed concentrations by 30–35% higher at schools exposed to higher vehicles intensities. Moreover, a significant correlation was obtained between average outdoor EBC levels at different districts of the city and the percentage of surface area in each district used for the road network (R2 = 0.61). Higher indoor than outdoor levels were recorded at some instances when the indoor sampling location was relatively closer to road traffic, even under low outdoor temperatures. Indeed, the average indoor/outdoor EBC ratios for each school correlate moderately between campaigns in spite of significant differences in temperature between sampling periods. These two facts highlight the strong dependency of the EBC levels on the distance to traffic. The peaks of exposure inside the classrooms seemed to be determined by outdoor concentrations, as shown by the parallelism between indoor and outdoor mean EBC daily cycles and the similar contribution of traffic rush hours to indoor and outdoor daily mean levels. The airtightness of the classroom was suggested as the responsible for the indoor/outdoor ratios of EBC higher than 1 recorded at nights.

Indoor air quality in schools and its relationship with children's respiratory symptoms

A cross-sectional survey was conducted to characterize the indoor air quality (IAQ) in schools and its relationship with children's respiratory symptoms. Concentrations of volatile organic compounds (VOC), aldehydes, PM2.5, PM10, carbon dioxide, bacteria and fungi were assessed in 73 classrooms from 20 public primary schools located in Porto, Portugal. Children who attended the selected classrooms (n = 1134) were evaluated by a standardised health questionnaire completed by the legal guardians; spirometry and exhaled nitric oxide tests.The results indicated that no classrooms presented individual VOC pollutant concentrations higher than the WHO IAQ guidelines or by INDEX recommendations; while PM2.5, PM10 and bacteria levels exceeded the WHO air quality guidelines or national limit values. High levels of total VOC, acetaldehyde, PM2.5 and PM10 were associated with higher odds of wheezing in children. Thus, indoor air pollutants, some even at low exposure levels, were related with the development of respiratory symptoms. The results pointed out that it is crucial to take into account the unique characteristics of the public primary schools, to develop appropriate control strategies in order to reduce the exposure to indoor air pollutants and, therefore, to minimize the adverse health effects.

Association Between State Assistance on the Topic of Indoor Air Quality and School District-Level Policies That Promote Indoor Air Quality in Schools.

Nationally representative data from the 2012 School Health Policies and Practices Study examined whether state assistance on indoor air quality (IAQ) was associated with district-level policies and practices related to IAQ and integrated pest management (IPM). Districts in states that provided assistance on IAQ were more likely than districts not in such states to (1) have an IAQ management program (p < .001); (2) require schools to conduct periodic inspections of the heating, ventilation, and air conditioning system (p < .05); of the building for cracks, leaks, or past water damage (p < .01); for mold (p < .01); for clutter that prevents effective cleaning and maintenance (p < .05); of the plumbing system (p < .01); and for condensation in and around school facilities (p < .001); (3) have an engine idling reduction program ( < .001); (4) have a policy to purchase low-emitting products (p < .05); and (5) require IPM strategies (p < .05). Increasing the number of states that provide IAQ-related assistance to school districts and schools may improve school IAQ.