Indoor Air Quality Problems Research Articles

Assessing indoor air quality in New York City nail salons

ABSTRACTNail salons are an important business and employment sector for recent immigrants offering popular services to a diverse range of customers across the United States. However, due to the nature of nail products and services, salon air can be burdened with a mix of low levels of hazardous airborne contaminants. Surveys of nail technicians have commonly found increased work-related symptoms, such as headaches and respiratory irritation, that are consistent with indoor air quality problems. In an effort to improve indoor air quality in nail salons, the state of New York recently promulgated regulations to require increased outdoor air and “source capture” of contaminants. Existing indoor air quality in New York State salons is unknown. In advance of the full implementation of the rules by 2021, we sought to establish reliable and usable baseline indoor air quality metrics to determine the feasibility and effectiveness of the requirement. In this pilot study, we measured total volatile organic compounds (TVOC) and carbon dioxide (CO2) concentrations in 10 nail salons located in New York City to assess temporal and spatial trends. Within salon contaminant variation was generally minimal, indicating a well-mixed room and similar general exposure despite the task being performed. TVOC and CO2 concentrations were strongly positively correlated (ρ = 0.81; p < 0.01) suggesting that CO2 measurements could potentially be used to provide an initial determination of acceptable indoor air quality for the purposes of compliance with the standard. An almost tenfold increase in TVOC concentration was observed when the American National Standards Institute/American Society of Heating, Refrigerating and Air-Conditioning Engineers (ANSI/ASHRAE) target CO2 concentration of 850 ppm was exceeded compared to when this target was met.

The particles around us

The particles around us

Indoor Air Quality Police-Project: A New Practice to Assess Indoor Air Quality

Background/Aim: Pupils and teachers spend a lot of their times at school, thus the poor indoor air quality at schools may cause adverse health effects, absence at school and adversely affect student performance. In addition, school environments are particularly complex and have a lot of different and interconnected factors having effect to occupants’ health. We aimed 1) to develop the real-time questionnaire (discomfort and symptoms) method and 2) to assess associations between measured (real-time measurements) and perceived (online-questionnaires about discomfort and symptoms) indoor air quality in school buildings. Methods: Indoor Air Quality Police-project was conducted in six secondary schools with (4 schools) and without (2 schools) reported indoor air quality problems. Study involves six classrooms (6th- 9th grade) from each school where the measured and perceived indoor air quality were detected. Pupils and teachers completed the questionnaires in two weeks period at the end of the lessons in the studied classrooms. Following indoor air quality parameters were measured for two weeks periods: humidity, temperature, carbon dioxide, TVOC, ozone, arsine, ammonia, hydrogen sulfide, formaldehyde, particulate matter, dustiness, noise and lightness. Results: The fieldwork was build up due the autumn 2016 and end at the March of 2017. Preliminary results will be present at the conference. Conclusions: Indoor Air Quality Police-project will establish a new practice to assess the associations between measured and perceived indoor air quality. We have an opportunity to assess an information about possible indoor air related symptoms and discomfort simultaneously with real-time measured exposure factors. Information has been collected from the same indoor air space and from the same people for several times. There is potential to notice and determine new markers that are in key roles and have adverse effect on indoor air quality and on human.

Ventilation Positive Pressure Intervention Effect on Indoor Air Quality in a School Building with Moisture Problems.

This case study investigates the effects of ventilation intervention on measured and perceived indoor air quality (IAQ) in a repaired school where occupants reported IAQ problems. Occupants’ symptoms were suspected to be related to the impurities leaked indoors through the building envelope. The study’s aim was to determine whether a positive pressure of 5–7 Pa prevents the infiltration of harmful chemical and microbiological agents from structures, thus decreasing symptoms and discomfort. Ventilation intervention was conducted in a building section comprising 12 classrooms and was completed with IAQ measurements and occupants’ questionnaires. After intervention, the concentration of total volatile organic compounds (TVOC) and fine particulate matter (PM2.5) decreased, and occupants’ negative perceptions became more moderate compared to those for other parts of the building. The indoor mycobiota differed in species composition from the outdoor mycobiota, and changed remarkably with the intervention, indicating that some species may have emanated from an indoor source before the intervention.

Characterization of Odors of Wood by Gas Chromatography-Olfactometry with Removal of Extractives as Attempt to Control Indoor Air Quality.

Indoor air quality problems are usually revealed by occupants’ complaints. In this study, the odors of two types of hardwood species, namely, Cathy poplar (Populus cathayana Rehd.) and rubberwood (Hevea brasiliensis) were selected and extracted with ethanol-toluene for removal of extractives in an attempt to eliminate the odors. The odorous components of neat and extracted woods were identified by gas chromatography-mass spectrometry/olfactometry (GC-MS/O). The results showed that about 33 kinds of key volatile compounds (peak area above 0.2%) were detected from the GC-MS, and about 40 kinds of odorants were identified from GC-O. The components were concentrated between 15 and 33 min in GC-O, which was different from the concentration time in GC-MS. Lots of the odors identified from GC-O were unpleasant to humans, and variously described as stinky, burnt, leather, bug, herb, etc. These odors may originate from the thermos-oxidation of wood components. After extraction, the amounts and intensities of some odorants decreased, while some remained. However, the extraction process resulted in a benzene residue and led to increased benzene odor.

Need to repair moisture- and mould damage in different structures in finnish public buildings

Moisture- and mould damage and resulting impurities are related to complex indoor air quality problems. This study focuses on the need to repair moisture- and mould damage in different structures. The research material consists of 168 Finnish public buildings. Based on research material, the highest need for repair is in timber-framed ground floor with crawl-in space, slab-on-ground structures, external walls in concrete-framed buildings and walls in contact with soil. A need to repair these structures exists in 56–85% of the examined buildings. The study reveals that buildings are multi-problematic: on average 3.1 main category structures were damaged in every studied building.

Skin squames contribute to ammonia and volatile fatty acid production from bacteria colonizing in air-cooling units with odor complaints.

One of the most notable Indoor Air Quality problems is odor emission. This study investigated the potential contribution of skin squames to the production of ammonia (NH3 ) and volatile organic acids (VFAs) by 7 bacteria isolated from air-cooling (AC) units with complaints of urine and body odors. Our previous study showed that keratinolytic activity is higher in AC units with odor complaints than those without. In the offices where these units are located, the most likely source of keratins is from human skin squames. Most bacteria can produce NH3 and VFAs in the skin squame culture. Some correlations between the levels of NH3 , NH4+, VFAs, and keratinolytic activity were found. The odor production pathway with skin squames was proposed. Staphylococcus haemolyticus was abundant in the AC units with odor problems and had a high level of keratinolytic activity in addition to odor production. For long-term odor control, it is important to reduce the level of skin squames entering the AC units.

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 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.

Evaluation of Indoor Air Quality Screening Strategies: A Step-Wise Approach for IAQ Screening.

Conducting a full indoor air quality (IAQ) assessment in air-conditioned offices requires large-scale material and manpower resources. However, an IAQ index can be adopted as a handy screening tool to identify any premises (with poor IAQ) that need more comprehensive IAQ assessments to prioritize IAQ improvements. This study proposes a step-wise IAQ screening protocol to facilitate its cost-effective management among building owners and managers. The effectiveness of three IAQ indices, namely θ1 (with one parameter: CO2), θ2 (with two parameters: CO2 and respirable suspended particulates, RSP) and θ3 (with three parameters: CO2, RSP, and total volatile organic compounds, TVOC) are evaluated. Compared in a pairwise manner with respect to the minimum satisfaction levels as stated in the IAQ Certification Scheme by the Hong Kong Environmental Protection Department, the results show that a screening test with more surrogate IAQ parameters is good at identifying both lower and higher risk groups for unsatisfactory IAQ, and thus offers higher resolution. Through the sensitivity and specificity for identifying IAQ problems, the effectiveness of alternative IAQ screening methods with different monitoring parameters is also reported.

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.

Removal of carbon dioxide in the indoor environment with sorption-type air filters

Carbon dioxide in an indoor environment is one of the air pollutants monitored by the Indoor Air Quality Ordinance of Taiwan. It is necessary for people and the air-conditioning industry to take appropriate measures to minimize the emission and prevent creating an unacceptable indoor air quality (IAQ). This study presents the performance of sorption-type air filters to help people and the air-conditioning industry to understand and apply the best practical control to prevent CO2 emissions from causing IAQ problems. The adsorption of CO2 with a sorption-type filter with activated carbon before and after impregnating treatment has been investigated. It has been found that impregnation treatment with MgO and CaO can promote the adsorption of CO2 on a sorption-type filter, with MgO being the better of the two.

Detection of occupancy profile based on carbon dioxide concentration pattern matching

Abstract Occupancy is one of major factors influencing indoor microclimate. The aim of this work was to determine the influence of this factor on indoor air quality (IAQ) on the basis of CO 2 concentration measurements and statistical analysis. We wanted to identify periods of time when IAQ was strongly affected by the occupancy described by the given profile. The proposed approach consisted of several stages. The CO 2 concentration was measured and recorded in the form of univariate time series. Then, the relationship between occupancy and internal structure of the time series was disclosed. There were distinguished segments based on sample periodogram. Each segment was associated with a particular occupancy profile. In order to detect how human factor represented by a given occupancy profile influences IAQ we proposed to use pattern matching. In this approach there was examined the similarity between segments of the time series and the pattern of CO 2 variability, which represented a selected occupancy profile. The analysis was performed in time domain using moving time window technique. The similarity was judged based on two types of indexes, namely correlation coefficients and distance measures. It was shown that our approach may be applied to successfully detect a particular occupancy profile. The best performance was achieved when using angular distance as the similarity index. In this case we reached 82% true positive and 22% false positive detections. The proposed method may be applied in diagnostics problems to reveal sources of indoor air quality problems.

Optimum Installation of Sorptive Building Materials Using Contribution Ratio of Pollution Source for Improvement of Indoor Air Quality.

Reinforcing the insulation and airtightness of buildings and the use of building materials containing new chemical substances have caused indoor air quality problems. Use of sorptive building materials along with removal of pollutants, constant ventilation, bake-out, etc. are gaining attention in Korea and Japan as methods for improving such indoor air quality problems. On the other hand, sorptive building materials are considered a passive method of reducing the concentration of pollutants, and their application should be reviewed in the early stages. Thus, in this research, activated carbon was prepared as a sorptive building material. Then, computational fluid dynamics (CFD) was conducted, and a method for optimal installation of sorptive building materials was derived according to the indoor environment using the contribution ratio of pollution source (CRP) index. The results show that a method for optimal installation of sorptive building materials can be derived by predicting the contribution ratio of pollutant sources according to the CRP index.

Indoor air quality in green-renovated vs. non-green low-income homes of children living in a temperate region of US (Ohio)

Green eco-friendly housing includes approaches to reduce indoor air pollutant sources and to increase energy efficiency. Although sealing/tightening buildings can save energy and reduce the penetration of outdoor pollutants, an adverse outcome can be increased buildup of pollutants with indoor sources. The objective of this study was to determine the differences in the indoor air quality (IAQ) between green and non-green homes in low-income housing complexes. In one housing complex, apartments were renovated using green principles (n=28). Home visits were conducted immediately after the renovation, and subsequently at 6months and at 12months following the renovation. Of these homes, eight homes had pre-renovation home visits; this allowed pre- and post-renovation comparisons within the same homes. Parallel visits were conducted in non-green (control) apartments (n=14) in a nearby low-income housing complex. The IAQ assessments included PM2.5, black carbon, ultrafine particles, sulfur, total volatile organic compounds (VOCs), formaldehyde, and air exchange rate. Data were analyzed using linear mixed-effects models. None of the indoor pollutant concentrations were significantly different between green and non-green homes. However, we found differences when comparing the concentrations before and after renovation. Measured immediately after renovation, indoor black carbon concentrations were significantly lower averaging 682ng/m3 in post-renovation vs. 2364ng/m3 in pre-renovation home visits (p=0.01). In contrast, formaldehyde concentrations were significantly higher in post-renovated (0.03ppm) than in pre-renovated homes (0.01ppm) (p=0.004). Questionnaire data showed that opening of windows occurred less frequently in homes immediately post-renovation compared to pre-renovation; this factor likely affected the levels of indoor black carbon (from outdoor sources) and formaldehyde (from indoor sources) more than the renovation status itself. To reduce IAQ problems and potentially improve health, careful selection of indoor building materials and ensuring sufficient ventilation are important for green building designs.

Experimental and Numerical Study of Air Flow Diffusion and Contaminants Circulation in Room Ventilation Related with Iraqi Climate

Illnesses of many indoor air quality problems occur in office room. Ventilation is one way to control the contaminant transport and to provide better indoor air quality with in the office. In the evaluation of indoor air quality, CO₂ concentration is regarded as a good indicator to estimate the air quality level and to assess the performance of a mechanical ventilation system used by many designers, So the CO₂ concentration was used as the tracer gas in this study, also the humans respiration taken into account as CO₂ sources were the rate of production of carbon dioxide (CO₂) by human respiration. Experimental measurement and computational fluid dynamics (CFD) simulation methods were applied. The results from this study show that the floor-supply displacement ventilation can improve indoor air quality because the pollutant concentration in the breathing zone is lower than that of mixing system and the risk of cross contamination can be effectively reduced. Nevertheless, the indoor spaces with floor-supply displacement ventilation might have a higher risk of discomfort, because of high temperature stratification between the ankle and head levels when compared to traditional mixing ventilation. The results indicated that the contaminant distribution in a mechanically ventilated office room need to be studied individually according to different cases.

User evaluation of the indoor climate of the first passive house school in Norway

The indoor climate of the first passive house school in Norway was evaluated with the aid of a questionnaire (Orebro) with approximately 340 respondents, and three interview rounds with a total of 23 informants. The intention was to reveal whether the users experienced any problems or possibly better conditions than in a regular school building. The interviews showed that, overall, the users were satisfied with the building. The survey showed generally good results for the indoor climate. Questionnaire results were compared with reference material consisting of data for average school buildings. The indoor climate of Marienlyst School was better than the average for most of the symptoms of indoor air quality problems, for both pupils and teachers. The users did still experience some problems with the building, relating to the fine-tuning of the automatic systems: temperature control, solar control, static electricity, and pressure conditions in the building. The users also said they lacked information about the passive house concept, the building, and how to obtain optimal functionality of the automatic control systems. The reasons for the fine-tuning problems are discussed in relation to the passive house concept, and the problem indicators are probably not attributable to the concept.

Indoor air quality in Portuguese schools: levels and sources of pollutants.

Indoor air quality (IAQ) parameters in 73 primary classrooms in Porto were examined for the purpose of assessing levels of volatile organic compounds (VOCs), aldehydes, particulate matter, ventilation rates and bioaerosols within and between schools, and potential sources. Levels of VOCs, aldehydes, PM2.5 , PM10 , bacteria and fungi, carbon dioxide (CO2 ), carbon monoxide, temperature and relative humidity were measured indoors and outdoors and a walkthrough survey was performed concurrently. Ventilation rates were derived from CO2 and occupancy data. Concentrations of CO2 exceeding 1000ppm were often encountered, indicating poor ventilation. Most VOCs had low concentrations (median of individual species <5μg/m(3) ) and were below the respective WHO guidelines. Concentrations of particulate matter and culturable bacteria were frequently higher than guidelines/reference values. The variability of VOCs, aldehydes, bioaerosol concentrations, and CO2 levels between schools exceeded the variability within schools. These findings indicate that IAQ problems may persist in classrooms where pollutant sources exist and classrooms are poorly ventilated; source control strategies (related to building location, occupant behavior, maintenance/cleaning activities) are deemed to be the most reliable for the prevention of adverse health consequences in children in schools.

Chloroanisoles may explain mold odor and represent a major indoor environment problem in Sweden.

Indoor mold odor is associated with adverse health effects, but the microbial volatiles underlying mold odor are poorly described. Here, chloroanisoles were studied as potential key players, being formed by microbial metabolism of chlorophenols in wood preservatives. Using a three-stage approach, we (i) investigated the occurrence of chloroanisoles in buildings with indoor air quality problems, (ii) estimated their frequency in Sweden, and (iii) evaluated the toxicological risk of observed chloroanisole concentrations. Analyses of 499 building materials revealed several chloroanisole congeners in various types of buildings from the 1950s to 1970s. Evaluation of Swedish records from this time period revealed three coinciding factors, namely an unprecedented nationwide building boom, national regulations promoting wood preservatives instead of moisture prevention, and use of chlorophenols in these preservatives. Chlorophenols were banned in 1978, yet analysis of 457 indoor air samples revealed several chloroanisole congeners, but at median air levels generally below 15ng/m(3) . Our toxicological evaluation suggests that these concentrations are not detrimental to human health per se, but sufficiently high to cause malodor. Thereby, one may speculate that chloroanisoles in buildings contribute to adverse health effects by evoking odor which, enhanced by belief of the exposure being hazardous, induces stress-related and inflammatory symptoms.

FRAMEWORK FOR INTEGRATING INDOOR AIR QUALITY IMPACTS INTO LIFE CYCLE ASSESSMENTS OF BUILDINGS AND BUILDING RELATED PRODUCTS

Products used during construction and operation of a building can contribute to Indoor Air Quality (IAQ) problems that affect occupants' well-being. However, IAQ is conventionally not addressed in the life cycle assessments (LCAs) of buildings and building related products even though IAQ leads to one of the areas of protection under LCA - human health impacts. In this study, we proposed an overall framework for integrating IAQ into LCA using the standard steps of LCA. The framework focused on IAQ and LCA modeling from two categories of building related products: i) passive products that realize their function through initial installation and have long-term decayed emissions, and ii) active equipment that realize their function and cause emissions through daily operation. Dynamic and static life cycle inventory modeling approaches were proposed for passive products and active equipment, respectively. An indoor intake fraction equation and USEtox model effect factors were incorporated into the life cycle impact assessment. Three hypothetical examples were presented to illustrate the calculation procedure of the framework. We concluded that it was feasible to integrate IAQ into building related LCA studies. Development of IAQ related impact assessment methodologies can improve upon the limitations of this study. Further studies need to be carried out to compare the health impacts from IAQ related sources to other life cycle stages of building related products.