Indoor Air Quality Complaints Research Articles

Perceived air quality and satisfaction during implementation of an automated indoor air quality monitoring and control system

Cooking and cleaning are among the largest sources of home pollutant emissions. To reduce these emissions, we developed an automated indoor air quality (IAQ) control intervention that operated based on real-time sensor readings of particulate matter (PM2.5) and evaluated the perceptual differences between this intervention and a baseline condition. We employed a 14-participant crossover study design in a one-bedroom apartment module. Participants experienced one of two conditions: (1) Advanced Control–automated IAQ interventions including a stove hood, two portable air cleaners, and a bathroom exhaust powered on/off based on predefined PM2.5 thresholds measured by environmental sensors; and (2) Standard Control–participants controlling IAQ interventions (e.g., stove hood) manually. Each condition lasted two weeks. Participants followed standardized cooking and cleaning protocols and filled out surveys assessing psychosocial and perceptual outcomes. Observations indicated that weekly IAQ satisfaction, perception, and preferences were similar between the two conditions—despite lower PM2.5 concentrations during cooking and cleaning for the Advanced Control versus Standard Control Condition. When pairing IAQ complaints with PM2.5 concentrations during cooking, we observed participants made complaints when PM2.5 concentrations >∼80 μg/m3 but few complaints when <∼60 μg/m3. Lower PM2.5 concentrations were observed for the Advanced Control versus Standard Control Condition during cleaning, but these lower concentrations did not appear perceivable by participants due to far lower PM2.5 concentrations during cleaning overall. Our observations suggest a connection between PM2.5 concentration and IAQ complaints made by participants, thereby providing possible thresholds for perceivable IAQ changes.

Indoor air quality and sick building syndrome in a university setting: a case study in Greece

ABSTRACT The perceived Indoor Air Quality (IAQ), the prevalence of Sick Building Syndrome (SBS) symptoms and its contributing risk factors were assessed in a university during the period of the economic crisis in Greece. Data was collected from 613 employees via questionnaires. Hierarchical linear regression analysis was performed. The most prevalent perceived IAQ complaints were ‘Dust and dirt’ (63.2%), ‘Room temperature too low’ (24.9%) and ‘Varying room temperature’ (24.4%). The most frequently reported SBS symptom was ‘Fatigue’ (34.1%). The prevalence of General, Mucosal and Dermal symptoms was 40.8%, 19.8% and 8.1%, respectively. Several contributing risk factors were identified, such as IAQ Discomfort Scale, atopy, sleep problems, female, exposure to biological and chemical agents, PC-use, Psychosocial Work Scale and job satisfaction. Poor perceived IAQ and high prevalence of SBS symptoms were reported from the university staff in a temperate climate country. SBS seemed to be multifactorial.

Exposure to indoor air contaminants in school buildings with and without reported indoor air quality problems

Reported indoor air quality (IAQ) complaints are common even in relatively new or renovated school buildings in Finland. However, detecting the causes for complaints with commonly used indoor air measurements is difficult. This study presents data on perceived and measured IAQ in six comprehensive school buildings in Finland. The aim of this study was to discover the possible differences of perceived and measured IAQ between schools with reported IAQ complaints and schools without reported IAQ complaints. The initial categorisation of schools with (‘problematic schools’) and without (‘comparison schools’) complaints was ensured via a validated indoor climate survey and a recently developed online questionnaire, which were completed by 186 teachers and 1268 students from the six schools. IAQ measurements of physical parameters, gaseous pollutants, particulate matter and bioaerosols were conducted in four problematic school buildings (26 classrooms) and two comparison school buildings (12 classrooms). Using air sampling as well as exhaust air filters and classroom settled dust to detect the presence of elevated concentrations of airborne cultivable microbes and pathogenic, toxigenic and mycoparasitic Trichoderma strains were the most indicative methods in distinguishing problematic schools from comparison schools. Other IAQ-related measurements did not detect clear differences between problematic and comparison schools, as the concentration levels were very low. The results indicate that the complaints reported by occupants could have been related to excess moisture or mould problems that had not been found or repaired. Ventilation pressure condition investigations and simultaneous exhaust and supply air filter dust culture should be addressed precisely in future studies.

Online Questionnaire as a Tool to Assess Symptoms and Perceived Indoor Air Quality in a School Environment

School environments are a complex entirety where various different exposure factors are related that contribute to the indoor air quality (IAQ) and may affect occupants’ health and well-being. Indoor air questionnaires are useful for collecting information about the occupants’ experiences and perceptions of the indoor air and for evaluating the results of the measures taken. A common way to implement health questionnaires is to ask the respondents to describe symptoms at certain time points, such as weeks or months. The aim of our study was to develop a short and easy online questionnaire to assess symptoms and perceived IAQ. We also aimed to test the usability of the questionnaire in school buildings and assess the differences between the online measurement data (CO2, T, and RH) and the IAQ complaints and symptoms reported by the pupils. A total of 105 teachers and 1268 pupils in 36 classrooms at six schools answered the questionnaires over a two-week period. The participants completed the questionnaire always after the lesson in the studied classroom. We received 719 answers from the teachers and 6322 answers from the pupils. The results demonstrated that the teachers reported more IAQ problems and symptoms than the pupils did. Differences between classrooms were observed in both the IAQ problem and reference schools. The most common significant differences (p-value &gt; 0.05) between the classrooms were among humidity, too cold air, and stuffy air, and among symptoms, dry/sore throat, tiredness, headache, and skin symptoms. Maximum values of CO2 measurements and the highest prevalence of stuffy air were relatively consistent. The testing process demonstrated that such a questionnaire was suitable for adults and children aged at least 12 years. The results of our study suggest that a quick and easy online questionnaire that is completed within a short period may be useful for gathering valuable knowledge about perceived IAQ. It could be used in combination with other indoor environment investigations to produce detailed results and restorative measures.

An evaluation of the knowledge and practices of Metro Vancouver residents regarding mould

&#x0D; Background: The average Canadian spends approximately 90% of their day indoors, a proportion of which may be in public spaces, thereby making Indoor Air Quality (IAQ) a pertinent topic for the fields of Public and Environmental Health. Mould complaints are one of the top IAQ complaints received by Environmental Health Officers (EHOs) in BC. Mould is ubiquitous in both the outdoor and indoor environment. However, once indoors, mould will grow unhindered on most surfaces as long as moisture is present. Accumulating evidence has established relationships between indoor environments and health. Thanks to the Internet, the amount of readily available information regarding mould today is vast but may not necessarily be valid nor reliable. It is important, therefore, to consider what the public does or does not know and where they are getting their information. This study evaluated the public perception of Metro Vancouver residents in regards to mould as an IAQ issue in order to provide Public and Environmental Health practitioners, including EHOs, with a deeper understanding of how to effectively address queries from the public regarding this topic. Methods: Data for this study was collected through a self-administered online questionnaire and disseminated using social media and the snowball effect. Questions were designed to collect demographic information and evaluate the knowledge and attitudes as well as the behaviour and practices of participants. Descriptive and inferential statistics, specifically the independent samples t-test and the analysis of variance (ANOVA), were used to analyze the results. Results: With an average 14.59 out of 20 points, respondent knowledge scores were, in general, fair. There was no statistically significant difference between respondent knowledge score and their gender, age, level of education, income or housing status. Conclusions: Although respondent knowledge scores were fair, a few gaps in knowledge were identified. Further, most of the sample population did not know specifically where to access reliable information on mould. These insights may be useful for Public and Environmental Health professionals when addressing queries from the public regarding this topic.&#x0D;

Identification of Mold and Dampness‐Associated Respiratory Morbidity in 2 Schools: Comparison of Questionnaire Survey Responses to National Data

Dampness and mold problems are frequently encountered in schools. Approximately one third of US public schools require extensive repairs or need at least 1 building replaced. This study illustrates how national data can be used to identify building-related health risks in school employees and students. School employees (n = 309) in 2 elementary schools (schools A and B) with dampness and mold problems completed standardized questionnaires. Responses were compared with participant responses from the 3rd National Health and Nutrition Examination Survey and were indirectly standardized for gender, age, smoking status, and (for school B) race. Uncontrolled comparisons were made to responses from a study of office workers, as well as between responses from school employees in different sections of the school buildings designated by decade of construction. Employees from both schools had excess work-related throat and lower respiratory symptoms, as well as eye, nasal, sinus, and wheezing symptoms. School B employees also had excess physician-diagnosed asthma and work-related fatigue, headache, and skin irritation. Employees in sections of the school buildings that were categorized as having greater dampness and mold contamination had more frequent upper and lower respiratory symptoms than employees working in other building sections. This noncostly type of analysis of indoor air quality complaints can be used to motivate and prioritize building remediation in public schools where funds for building remediation are usually limited.

Reduction of pulmonary toxicity of Stachybotrys chartarum spores by methanol extraction of mycotoxins.

The fungus Stachybotrys chartarum has been implicated in cases of nonspecific indoor air quality complaints in adults and in cases of pulmonary hemorrhaging in infants. The effects that have been described have been attributed to mycotoxins. Previous dose-effect studies focused on exposure to a single mycotoxin in a solvent, a strategy which is unlikely to accurately characterize the effects of inhaled spores. In this study we examined the role of mycotoxins in the pulmonary effects caused by S. chartarum spores and the dose dependency of these effects. S. chartarum spores were extracted in methanol to reduce the mycotoxin content of the spores. Then either untreated (toxin-containing) or methanol-extracted S. chartarum spores were intratracheally instilled into male 10-week-old Charles River-Dawley rats. After 24 h, the lungs were lavaged, and the bronchoalveolar lavage fluid was analyzed to determine differences in lactic dehydrogenase, albumin, hemoglobin, myeloperoxidase, and leukocyte differential counts. Weight change was also monitored. Our data show that methanol extraction dramatically reduced the toxicity of S. chartarum spores. No statistically significant effects were observed in the bronchoalveolar lavage fluids of the animals that were treated with methanol-extracted spores at any dose. Conversely, dose-dependent effects of the toxin-containing spores were observed when we examined the lactic dehydrogenase, albumin, and hemoglobin concentrations, the polymorphonuclear leukocyte counts, and weight loss. Our findings show that a single, intense exposure to toxin-containing S. chartarum spores results in pulmonary inflammation and injury in a dose-dependent manner. Importantly, the effects are related to methanol-soluble toxins in the spores.

A New Tool for Eliminating Indoor Air Quality Complaints

Poor indoor air quality (IAQ) can cause a variety of health problems for building occupants including headaches, respiratory problems, eye irritation and fatigue. Traditional IAQ measurements often fail to identify the root cause of the problems and solutions remain elusive. A new IAQ metric, ultrafine particles, is shown to have a high correlation with complaint areas. Researchers are studying the toxicology of these tiny pollutants on animals and humans. Ultrafine particles are defined as particles smaller than 100 nm diameter; ‘nanoparticles’, those smaller than 50 nm diameter, are a subset of ultrafine particles. A battery-powered, portable condensation particle counter (CPC) can be used to quickly identify the source and transport pathways of ultrafine particle contaminants so they can be eliminated or controlled. The CPC condenses isopropyl alcohol on the particles to grow them to an optically detectable size. The hand-held instrument is fast responding, has a wide concentration range, and can log data to detect trends and short-term excursions. Adding the metric of ultrafine particles may become very important to IAQ investigations in the future.

Continually measured fungal profiles in sick building syndrome.

Buildings with indoor air quality (IAQ) complaints frequently have high airborne concentrations of Penicillium species, while buildings with few IAQ complaints have an indoor air (IDA) fungal ecology similar to outdoor air (ODA), where Cladosporium species is usually the dominant microorganism. These studies compared fungal air profiles, measured continually over 6 h in a documented sick building, in IDA in a room experiencing IAQ problems with fungal profiles measured concurrently in ODA. The dominant species collected at both sites were Penicillium species, Cladosporium species, and Alternaria species. In the IDA, Penicillium species were always the dominant organisms, ranging from 150 to 567 cfu/m3 (89.8-100% of the total fungi). In the ODA, Cladosporium species were dominant in four samples (40.0-70.6%), while Penicillium species were dominant (52.7-79.6%) in two. These data demonstrate that, even though ODA fungal profiles are changing continuously, IDA fungal profiles in "sick" buildings tend to remain unchanged.

Microorganisms and Indoor Air Quality

Microorganisms can cause adverse human health effects and deterioration of building materials when they proliferate in indoor environments (1). While all types of microorganisms can cause problems indoors, bacteria and fungi are most commonly associated with indoor air quality complaints. Bacteria are generally found growing indoors in areas with standing water such as water spray and condensation areas of airhandling system components. Fungi, which have lower water activity (A,,,) requirements than bacteria, tend to colonize a wide variety of building materials wetted from floods, condensation, or plumbing leaks. When microbial amplification occurs, the indoor environment becomes a source of exposure to the occupants, especially when the organisms and/or their by-products are released into the air as bioaerosols (2).

The problem of the “sick” building-facts and implications: Identifying and measuring indoor nonbiologic agents

The problem of the “sick” building-facts and implications: Identifying and measuring indoor nonbiologic agents

Environmental control of chemical indoor air quality agents

Although the number and species of chemicals that can have a causal role in indoor air quality complaints can be enormous, the control methods are limited for most chemical emissions in a building. Because the causal chemical species is often not identified in indoor air quality evaluations, environmental controls for chemical contaminants are generally used. The type of control strategy can be divided into three major categories: emission source control; general dilution and local exhaust; and selective controls. Although general dilution ventilation is the most frequently used control for odors and background building-related chemicals, emission source control is quickly becoming a major control strategy of product manufacturers. As more product emission information becomes available, building interior specifications will soon begin to incorporate these data. In very limited situations, ″selective” controls can be used to remove specific contaminants. (J ALLERGYCLINIMMUNOL1994;94:401-3.)

Corrective options and implications Environmental control of chemical indoor air quality agents

Although the number and species of chemicals that can have a causal role in indoor air quality complaints can be enormous, the control methods are limited for most chemical emissions in a building. Because the causal chemical species is often not identified in indoor air quality evaluations, environmental controls for chemical contaminants are generally used. The type of control strategy can be divided into three major categories: emission source control; general dilution and local exhaust; and selective controls. Although general dilution ventilation is the most frequently used control for odors and background building-related chemicals, emission source control is quickly becoming a major control strategy of product manufacturers. As more product emission information becomes available, building interior specifications will soon begin to incorporate these data. In very limited situations, ″selective” controls can be used to remove specific contaminants. (J ALLERGYCLINIMMUNOL1994;94:401-3.)

Field studies on the sick building syndrome.

Field studies of the sick building syndrome have generally used questionnaires developed to define symptoms present over weeks and months, such as those asking ". . . do you usually . . .?" Although such studies have implicated ventilation systems as a major contributor to indoor air quality complaints, no specific exposures have been identified. An alternative approach is based on the short-term quantification of symptoms and characterization of the indoor environment with direct-reading or short-term sampling techniques. This paper summarizes the development of such a method in two studies in problem buildings and its subsequent application in a study in nonproblem buildings. The method correctly identified the postulated cause in a first building and generated a hypothesis for intervention in the second. In the nonproblem buildings, the levels of complaints appear related to the levels of VOCs, lighting, hours spent at desks, and crowding. This approach has suggested that dose-response relationships do exist in the sick building syndrome. Weaknesses of this approach include an inability to adequately address microbial characterization of indoor environments and the social and organizational predictors of complaints that are recognized to be of importance.

Indoor Air Quality Affected by Abandoned Gasoline Tanks

Abstract Exposures to petroleum hydrocarbons from leaking gasoline tanks were identified as a source of indoor air quality (IAQ) problems in a public office building. The total (gasoline) hydrocarbon concentrations measured in the building air ranged from 12 milligram per cubic meter (mg/m3) to 96 mg/m3. These area gasoline vapor concentrations, including most predominant vapor constituents, were measured in room air at concentrations below the personal exposure criteria/standards of the National Institute for Occupational Safety and Health, the American Conference of Governmental Industrial Hygienists, or the Occupational Safety and Health Administration. However, these gasoline vapors were a source of IAQ complaints and periodic worker exposures to the carcinogen benzene. The source of these petroleum hydrocarbon vapors was traced to three abandoned gasoline tanks buried beneath an adjacent building. These tanks were removed, averting potential for more serious health/safety hazards from continued gasol...

Federal epidemiologists link ills to environs

ABSTRACT Scientists at the Centers for Disease Control (CDC), Atlanta, understand the complexities of environment-health interactions. The CDC's Center for Environmental Health has investigated outbreaks of illness in which the causes ranged from rug shampoo to volcanic eruptions.In 1980, for example, symptoms of respiratory irritation among inhabitants of a city office building and a day-care center were traced to underdilution of commercial carpet cleaners. The dry residue, sodium dodecyl sulfate, turned out to be a potent respiratory irritant (Environ Int 1982;8:337-341). Henry Falk, MD, of the Center for Environmental Health, says the group has conducted a dozen such indoor air quality investigations.Indoor studies have more recently been taken over by the CDC's National Institute for Occupational Safety and Health. Its records indicate that the tally of indoor air quality complaints investigated now exceeds 200.Also in 1980, the Center for Environmental Health had the opportunity to study an outdoor