School Indoor Air Research Articles

Investigation of the Treatability of the Primary Indoor Volatile Organic Compounds on Activated Carbon Fiber Cloths at Typical Indoor Concentrations

Volatile organic compounds (VOCs) are a major concern for indoor air pollution because of the impacts on human health. In recent years, interest has increased in the development and design of activated carbon filters for removing VOCs from indoor air. Although extensive information is available on sources, concentrations, and types of indoor VOCs, there is little or no information on the performance of indoor air adsorption systems for removing low concentrations of primary VOCs. Filter designs need to consider various factors such as empty bed contact time, humidity effects, competitive adsorption, and feed concentration variations, whereas adsorption capacities of the indoor VOCs at the indoor concentration levels are important parameters for filter design. A preliminary assessment of the feasibility of using adsorption filters to remove low concentrations of primary VOCs can be performed. This work relates the information (including VOC classes in indoor air, the typical indoor concentrations, and the adsorption isotherms) with the design of a particular adsorbent/adsorbates system. As groundwork for filter design and development, this study selects the primary VOCs in indoor air of residences, schools, and offices in different geographical areas (North America, Europe, and Asia) on the basis of occurrence, concentrations, and health effects. Activated carbon fiber cloths (ACFCs) are chosen as the adsorbents of interest. It is demonstrated that the isotherm of a VOC (e.g., toluene on the ACFC) at typical indoor concentrations—parts per billion by volume (ppbv) level—is different than the isotherm at parts per million by volume (ppmv) levels reported in the publications. The isotherms at the typical indoor concentrations for the selected primary VOCs are estimated using the Dubinin–Radushkevitch equation. The maximum specific throughput for an indoor VOC removal system to remove benzene is calculated as a worst-case scenario. It is shown that VOC adsorption capacity is an important indicator of a filter’s lifetime and needs to be studied at the appropriate concentration range. Future work requires better understanding of the realistic VOC concentrations and isotherms in indoor environments to efficiently utilize adsorbents.

학교 실내공기질 및 건강 영향

Indoor air quality at classrooms is of special concern since students are susceptible and indoor air problems can be so subtle that it does not always produce easily recognizable health effects. The main objectives of the study were to investigate the time-activity pattern of school students, to determine the sources of poor indoor air quality in schools, and to demonstrate how indoor air quality in schools causes adverse health effects such as headache, upper airway irritation, fatigue, and lethargy. Recent articles ranging from 1987-2009 related to school indoor air quality were systematically reviewed. Building-associated health effects can increase student absences from school and degrade the performance of children while in school. The reduced ventilation rate was associated with a decreased ability to concentrate along with increased adverse health symptoms. There was an association between residential proximity to busy roads and a variety of adverse respiratory health outcomes in children. Consequently, the current findings suggest the need for control strategy for school indoor air pollutants with multidisciplinary approach methods because Korea has no other natural resources except manpower especially.

충남 지역 일부 학교의 PM10과 중금속 농도에 관한 연구

In this study, in order to analyze the air quality of the indoor environments of schools, we measured the indoor, outdoor and personal exposure concentration level of <TEX>$PM_{10}$</TEX> for 40 classrooms(20 old, 20 new) in chungnam area from June 22 to July 19 and from November 21 to December 30, 2003. 1. Old classrooms contained more dust than new classrooms; the average of respirable dust is <TEX>$43.27\;{\mu}g/m^3$</TEX> for new classrooms while <TEX>$53.38\;{\mu}g/m^3$</TEX> for old one. The exposure concentration level of respirable dust in new classrooms were in summer higher outdoors than indoors. The values were indoors <TEX>$46.71\;{\mu}g/m^3$</TEX>, outdoors <TEX>$50.46\;{\mu}g/m^3$</TEX>, and personal <TEX>$41.62\;{\mu}g/m^3$</TEX>. Meanwhile in winter indoors had a higher concentration level than outdoors, the values being indoors <TEX>$39.11\;{\mu}g/m^3$</TEX>, outdoors <TEX>$34.86\;{\mu}g/m^3$</TEX>, and personal <TEX>$49.01\;{\mu}g/m^3$</TEX>. 2. Cr concentration level within dust was slightly higher in summer indoors (<TEX>$101.50{\pm}32.10\;ng/m^3$</TEX>) and outdoors (<TEX>$100.89{\pm}35.18\;ng/m^3$</TEX>) than winter indoors (<TEX>$85.80{\pm}48.95\;ng/m^3$</TEX>) and outdoors (<TEX>$74.43{\pm}38.93\;ng/m^3$</TEX>), but in personal concentration level, winter was higher. The results of this research show insufficient understanding of health risks from indoor air pollution, and shows possible health problems to students from school indoor air pollution. As such, a logical and systematic education program for students about the importance of indoor air quality should be carried out. Also the results of <TEX>$PM_{10}$</TEX> concentration level measurements emphasize the need for regular measurements of indoor / outdoor and personal concentration level. New classrooms in particular needs to be used after measuring pollutants and safety, and requires installation of a ventilation device in all classrooms to improve air quality.

Sick Buildings or Not: Indoor Air Quality and Health Problems in Schools

Poor indoor air in schools has become a wide-spread problem with serious effects on occupant health. Resultant costs can be considerable at both local and national government levels. These include absenteeism and rehabilitation as well as building alterations and even demolition and rebuilding. This project aims to show factors contributing to health problems in Swedish schools. It includes a literature survey and particle measurements taken during various activities. Due to the fact that today there is no standard for indoor air quality (IAQ) in schools, in this project we used the outdoor air surrounding the building as an indicator. Results showed that indoor school environments had high airborne pollution levels, to a degree that probably causes health problems for many people. Regarding IAQ, this project shows the importance of taking into consideration choices in activities and furnishing of the building.

Asthma Prevalence, Management, and Education in New York State Elementary Schools: A Survey of School Nurses

A survey of school nurses was conducted in New York State elementary schools to assess asthma and asthma management in students. The survey contained questions about asthma morbidity, management and education, obstacles to management, and school indoor air quality. The reported prevalence of asthma among students was 8.5%. Of the students with asthma, 64% visited the health office, 26% were absent from school, 20% had physical limitations, and 7% needed urgent care. Only 28% had a written management plan at school, less than 25% of schools used asthma self-management programs, and obstacles to management included lack of time and funding. More than 25% rated school indoor air quality as "fair" or "poor." Schools need to adopt key components of asthma management, and school nurses should be encouraged to work with others in the school setting to address indoor air quality problems that might be affecting health.

Comparative overview of indoor air quality in Antwerp, Belgium

This comprehensive study, a first in Belgium, aimed at characterizing the residential and school indoor air quality of subgroups that took part in the European Community Respiratory Health Survey and the International Study of Asthma and Allergy in Childhood [Masoli M, Fabian D, Holt S, Beasley R. Global Burden of Asthma, Medical Research Institute of New Zealand, University of Southampton; 2004.] questionnaire-based asthma and related illnesses studies. The principal aim was to perform a base-line study to assess the indoor air quality in Antwerp in terms of various gaseous and particulate pollutants. Secondly, it aimed to establish correlations between these pollutants investigated, the pollutant levels in the indoor and outdoor micro-environments, findings of the previous questionnaire-based studies and an epidemiological study which ran in conjunction with this study. Lastly, these results were compared and evaluated with current indoor and ambient guidelines in various countries This paper presents selected results on PM1, PM2.5 and PM10 mass concentrations and elemental C estimates as black smoke, as well as gaseous NO 2, SO 2, O 3 and BTEX concentrations of 18 residences and 27 schools. These are related to current guidelines of Flanders, Germany, Norway, China and Canada and evaluated with reference to selected similar studies. It was found that indoor sources such as tobacco smoking and carpets, the latter causing re-suspension of dust, are responsible for elevated indoor respirable particulate matter and place school children and residents at risk. Both PM2.5 and PM10 equalled or exceeded the current guidelines adopted by Flanders, noting that 12-h and 24-h PM2.5 were compared with an annual limit value. Indoor and ambient NO 2 concentrations in the school campaign were higher than the annual EU ambient norm. The other studied pollutant levels were below the current guidelines.

PROJEKTO „MOKYKLOS PATALPŲ ORO MIKROBIOLOGINĖS BŪKLĖS ĮVERTINIMAS“ METODOLOGINIAI ASPEKTAI

The article presents methodological recommendations for the implementation of the project of a microbiological nature. The urgency of the project is undoubted, as it has been noticed that school classes were overcrowded with pupils and almost not ventilated in winter, thus, schoolchildren often suffered from respiratory illnesses. Besides, secondary school programs include many themes in which the concept of microorganisms is used, however, pupils usually lack practical knowledge about isolation of microorganisms in a laboratory and their distribution in the air. The main aim of this work was to evaluate microbial contamination of school premises as well as to provide pupils with knowledge about biological peculiarities of various systematic groups (bacteria, micromycetes and yeast-like fungi) and their macro- and micro-morphological peculiarities. To achieve the aim, the following tasks were set: 1) to develop pupils’ abilities to make experiments and develop their initial skills in research; 2) to form their cognitive experience of the surrounding world while performing team tasks; 3) to develop pupils’ creative-organizational abilities as an integral process of theoretical and practical actions. Due to lack of equipment and conditions, it is not easy to perform microbiological projects in schools. Furthermore, a teacher should have competence, though due to this, in the article much attention is paid to the methods of project performance. Necessary labware and nutritive media for project implementation are indicated. Possible variants of an experiment scheme are discussed and the stages of the experiment are presented coherently. Preparation of microscopical mounts and microscopy methods are described in detail. It is pointed out that the identification of microorganisms is a very hard work, so teachers should be trained in microbiological methods. Handbooks, which can be used for the identification of some microorganisms, are indicated. Much attention is paid to the presentation of experiment results, as pupils participating in the project get much information about microorganisms. Participants get familiarized with the size and shape of bacterial cells and fungal macro-morphological (colony colour, shape, size and colour of colony reverse) and micro-morphological (a shape of conidia and mycelium) peculiarities. Pupils observe reproduction ways of yeast-like fungi (budding and binary fission) and determine yeast cell shape, size and other characteristic properties. While describing microorganisms isolated from school indoor air, pupils indicate a systematic group to which a microorganism (a bacterium, micromycete and yeast-like fungus) belongs. When the opportunities to identify microorganisms exist, pupils point out a genus and a species to which a microorganism is ascribed. Possible variants of systematizing the obtained results (tables and pictures, etc.) are discussed. The implementation of the project in schools has undoubted theoretic and practical significance, because pursuing the project the pupil’s abilities to make an experiment are developed and initial skills in research and cognitive experience of the surrounding invisible world are formed. Execution of the project induces pupils’ creative-organizational abilities as an integral process of theoretical and practical actions. Later the pupils willingly participate in competitions and conferences of young researchers – naturalists, write papers, prepare a wall newspaper about microbial contamination of school indoor air and give recommendations about improvement of school sanitation. While performing team tasks, participants get knowledge about microorganisms of various systematic groups (bacteria, micromycetes and yeast-like fungi), their isolation under laboratory conditions and distribution in the indoor air. Pupils can use obtained knowledge in the lessons of the course “A Man and his Health” (9th grade) as well as in ecology and general biology (11th – 12th grades) lessons. Key words: microorganisms, distribution, air of school premises.

Monitoring of Fungi and Bacteria in the Indoor Air of Primary Schools in Edirne City, Turkey

We monitored levels of bacteria and fungi in the indoor air at selected sites of several public primary schools in the city of Edirne, Turkey. Sampling was by the Petri plate method onto both a Rose-Bengal streptomycin agar medium and a 5% sheep-blood agar medium exposed to the air for 10-minute periods. Samples were collected monthly over a period of 6 months between August 2001 and January 2002. A total of 941 microfungi and 2066 bacterial colonies were counted on 90 Petri plates. During this 6-month period, 19 bacterial genera, 15 fungal genera and 48 species of fungi were isolated from the air in the schools. Some bacteria, such as coagulase-negative Staphylococcus, Corynebacterium and Bacillus, were predominant (42.7%, 20.4% and 6.9% of the total, respectively). Penicillium, Cladosporium and Alternaria were the most common fungal genera (42.8%, 19.3% and 10.1% of the total, respectively). Staphylococcus, Acinetobacter, Corynebacterium, Propionibacterium and Pseudomonas genera were found in every month. Statistical analysis of the data showed a positive correlation between the concentrations of bacteria and air humidity (p 0.002, R2 0.726) and between bacterial concentrations and age of the schools ( p 0.045, R2 0.787). Also, that there was seasonal variation since the concentrations of fungi and bacteria varied according to the months ( p 0.001).

Elemental carbon and respirable particulate matter in the indoor air of apartments and nursery schools and ambient air in Berlin (Germany)

This study was performed to examine exposure to typical carcinogenic traffic air pollutants in the city center of an urban area. In all, 123 apartments and 74 nursery schools were analyzed with and without tobacco smoke interference and the households in two measuring periods. Simultaneously, the air outside 61 apartment windows as well as the average daily traffic volume were measured. Elemental carbon (EC), the marker for particulate diesel exhaust and respirable particulate matter (RPM) were determined. The thermographic EC analysis was conducted with and without prior solvent extraction of the soluble carbon fraction. Comparison of these two thermographic EC measurements clearly showed that method-related differences in the results, especially for indoor measurements, when high background loads of organic material were present (e.g. tobacco smoke), existed. Solvent extraction prior to EC determination was therefore appropriate. For the first winter measuring period, the EC concentration levels without solvent extraction in the indoor air were about 50% higher than those measured in the spring/summer period. In the second measuring period (i.e. spring/summer), the median EC concentrations after solvent extraction were 1.9 microg/m3 for smokers' apartments and 2.1 microg/m3 for non-smokers' apartments, with RPM concentrations of 57 and 27 microg/m3, respectively. Nursery schools showed high concentrations with median values of 53 microg/m3 for RPM and 2.9 microg/m3 for EC after solvent extraction. A significant correlation between the fine dust and EC concentrations (after solvent extraction) in the indoor and ambient air was determined. Outdoor EC values were also correlated with the average daily traffic volume. The EC ratios between indoor and ambient concentration showed a median of 0.8 (range: 0.3-4.2) in non-smoker households and 0.9 (range: 0.4-1.5) in smoker apartments. Furthermore, the EC/RPM ratio in indoor and ambient air was 0.01-0.15 (median 0.06) and 0.04-0.37 (median 0.09), respectively. In the absence of indoor sources a significant correlation with regard to respirable particulate matter (RPM) and elemental carbon concentrations between the indoor and ambient air of apartments was observed. The high degree of certainty resulting from this correlation underscores the importance of ambient air concentrations for indoor air quality. In nursery schools we found higher concentrations of RPM. An explanation of these results could be the high number of occupants in the room, their activity and the cleaning intensity.

Measures for Reducing the Levels of Chemical Compounds in the Indoor Air of Schools

Measures for Reducing the Levels of Chemical Compounds in the Indoor Air of Schools

Airborne rhinovirus detection and effect of ultraviolet irradiation on detection by a semi-nested RT-PCR assay.

BackgroundRhinovirus, the most common cause of upper respiratory tract infections, has been implicated in asthma exacerbations and possibly asthma deaths. Although the method of transmission of rhinoviruses is disputed, several studies have demonstrated that aerosol transmission is a likely method of transmission among adults. As a first step in studies of possible airborne rhinovirus transmission, we developed methods to detect aerosolized rhinovirus by extending existing technology for detecting infectious agents in nasal specimens.MethodsWe aerosolized rhinovirus in a small aerosol chamber. Experiments were conducted with decreasing concentrations of rhinovirus. To determine the effect of UV irradiation on detection of rhinoviral aerosols, we also conducted experiments in which we exposed aerosols to a UV dose of 684 mJ/m2. Aerosols were collected on Teflon filters and rhinovirus recovered in Qiagen AVL buffer using the Qiagen QIAamp Viral RNA Kit (Qiagen Corp., Valencia, California) followed by semi-nested RT-PCR and detection by gel electrophoresis.ResultsWe obtained positive results from filter samples that had collected at least 1.3 TCID50 of aerosolized rhinovirus. Ultraviolet irradiation of airborne virus at doses much greater than those used in upper-room UV germicidal irradiation applications did not inhibit subsequent detection with the RT-PCR assay.ConclusionThe air sampling and extraction methodology developed in this study should be applicable to the detection of rhinovirus and other airborne viruses in the indoor air of offices and schools. This method, however, cannot distinguish UV inactivated virus from infectious viral particles.

Perceptions of indoor air quality associated with ventilation system types in elementary schools.

With the increased utilization of school buildings on a year-round basis, school indoor air quality has become a national concern. The purpose of this study was to evaluate possible associations between ventilation system type and occupant perception of indoor air quality. Staff (n = 403) from 12 schools completed a self-administered questionnaire. Carbon dioxide (CO2) levels, air exchange rates, and particle counts were also measured for each school. Schools with unit ventilator (UV) systems had the lowest mean CO2 level at 637 ppm, followed by the variable air volume (VAV) systems with 664 ppm, and constant volume (CV) systems with a mean of 703 ppm. Schools with UV systems had the lowest mean air exchange rate at 2.67 air changes per hour (ACH), followed by the VAV system type at 2.80 ACH and the CV system type at 4.61 ACH. Indoor versus outdoor particle ratios were calculated for each ventilation system type. Particles with aerodynamic diameters ranging from 0.1-1.0 microm had a geometric mean ratio ranging from 0.38 to 0.68; particles with aerodynamic diameters ranging from 1-3 microm had ratios ranging from 1.39 to 5.47, and particles with aerodynamic diameters greater than 3 microm had ratios ranging from 3.20 to 14.76. Schools using VAV systems had a significantly lower prevalence of red and watery eyes while schools with UV systems had an elevated prevalence of nasal congestion, sore throat, headache, and dustiness complaints. This increased prevalence of complaints in buildings with UV systems may be due to the increased particulate levels.

The Mitochondrial Toxin Produced by Streptomyces griseus Strains Isolated from an Indoor Environment Is Valinomycin

Actinomycete isolates from indoor air and dust in water-damaged schools and children's day care centers were tested for toxicity by using boar spermatozoa as an indicator. Toxicity was detected in extracts of four strains which caused a loss of sperm motility, and the 50% effective concentrations (EC50) were 10 to 63 ng (dry weight) ml of extended boar semen-1. The four strains were identified as Streptomyces griseus strains by 16S ribosomal DNA and chemotaxonomic methods. The four S. griseus strains had similar effects on sperm cells, including loss of motility and swelling of mitochondria, but we observed no loss of plasma membrane integrity or depletion of cellular ATP. None of the effects was observed with sperm cells exposed to extracts of other indoor actinomycete isolates at concentrations of >/=5,000 to 72,000 ng ml-1. The toxin was purified from all four strains and was identified as a dodecadepsipeptide, and the fragmentation pattern obtained by tandem mass spectrometry was identical to that of valinomycin. Commercial valinomycin had effects in sperm cells that were identical to the effects of the four indoor isolates of S. griseus. The EC50 of purified toxin from the S. griseus strains were 1 to 3 ng ml of extended boar semen-1, and the EC50 of commercial valinomycin was 2 ng ml of extended boar semen-1. To our knowledge, this is the first report of the presence of ionophoric toxin producers in an indoor environment and the first report of valinomycin-producing strains identified as S. griseus.

Viable fungi in indoor air in homes and schools in the Sør-Varanger community during winter.

The present study investigated the content of fungal aerospores in homes and schools of house-dust-mite (HDM)-sensitized and control children in a subarctic area. During winter, airborne microfungi were collected from the homes and schools of 19 HDM-sensitized children and 19 nonatopic controls, all living in the community of Sør-Varanger, northern Norway. The samples were cultivated and microfungal growth was identified microscopically. Indoor humidity, temperature, and carbon dioxide (CO2) concentrations were measured. Housing conditions and sociodemographic and symptom data were obtained by a questionnaire. Penicillium was the most common microfungus in both homes and schools, followed by various yeasts, Aspergillus, Cladosporium, and Mucor. The number of infected homes was equal in the HDM-sensitized group and the control group, but aerospore counts were higher in the HDM-sensitized group than in the control group. The lowest aerospore counts were found in the schools. High aerospore counts also appeared to be related to high indoor humidity. The keeping of pets and damp indoor conditions were more frequent in homes of HDM-sensitized children than in the control group, whereas parental smoking and carpeting occurred with equal frequency in both groups. This indicates that no allergy sanitation measures had been undertaken, especially in the homes of the HDM-sensitized children.

Alpha-particle-induced cancer in humans.

Updated information is given on alpha-particle-induced cancer in persons internally exposed to 222Rn progeny, Thorotrast, long-lived 226Ra and 228Ra, and short-lived 224Ra. The lung cancer risk to persons breathing 222Rn progeny in the indoor air of offices, schools, and homes is of increasing concern. About half of the recent deaths among the German Thorotrast patients have been from liver cancer. Animal studies indicate that the liver cancer risk from Thorotrast is mainly from its radioactivity and that the risk coefficient for the Thorotrast patients can be used provisionally for other alpha emitters in the human liver. Six skeletal cancers have occurred in persons with average skeletal doses between 0.85 and 11.8 Gy from 226Ra and 228Ra. In the low-dose German 224Ra patients, two skeletal sarcomas have occurred at about 0.7 Gy compared to about six cases predicted by results from 224Ra patients at higher doses. The minimal appearance time for radiation-induced bone sarcomas in humans is about 4 y. Following brief irradiation, the vast majority of induced bone sarcomas are expressed by about 30 y. Recent evidence against the "practical threshold" hypothesis is given. With the downward revision of neutron doses to the atomic-bomb survivors, the follow-up of persons exposed to alpha particles may be the best opportunity to evaluate directly the effects of high LET radiation on humans.