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Air exchange rate is a key determinant of indoor air quality which is highly variable within the rooms of a naturally ventilated terraced house (townhouse). Window opening can increase the air exchange rate, but internal door opening between rooms inside decreases the rate. Inert perfluorocarbon gas‐phase tracers demonstrated flow within the house, and the penetration of tracers released outside into the house showed a strong dependence on wind speed and wind direction. Between experiments, it was found that the tracer could be detected within certain parts of the house weeks after the initial release, with implications for pollutants and their impact on the indoor environment. A limited number of reactive tracer experiments suggested an upper limit for indoor [OH]~1 × 105 molecule cm-3 with up to 0.5 ppt of [NO3] estimated, leading to an estimated indoor lifetime for d5 isoprene of many hours. Ultrafine particulate matter generated in the kitchen travels throughout the house, and the persistence of elevated aerosol concentrations is seen even in well‐ventilated rooms, with implications for particle exposure in the evening and during the night. [ABSTRACT FROM AUTHOR]

The quality of the internal microclimate is a very important issue nowadays, considering that people in developed societies spend a good part of their day inside buildings and means of transport. But the poor quality of indoor air has a double effect; on the one hand, it can harm human health, and on the other hand, it can cause the degradation of materials. Thus, the current study considers the potential influence of a number of 20 pollutants on the exhibits, visitors, and employees of a synagogue that is over 140 years old in the Municipality of Oradea (Romania), which today is included in the list of historical monuments and is open to be visited. The monitoring period consisted of 9 months, during which parameters such as temperature, relative humidity, CO concentration, light intensity, concentration of particulate matter, and other pollutants were monitored. All the obtained values were then reported to the international standards in force for each indicator, both regarding the potential for human health and the integrity of the exhibits. The results indicate that the values of most pollutants respect the allowed thresholds, with more or less permitted exceptions. The most problematic are the values of temperature, relative humidity, HCHO, and VOC, which substantially exceed the allowed limits and vary a considerable difference. This can induce additional stress on the exhibits, leading over time to damage and premature aging; in terms of human health, the indoor microclimate can, in rare cases, cause discomfort associated with headaches, dizziness, and irritation, but the potential to cause persistent ailments is quite low. To maintain a clean internal microclimate, preventive conservation through the continuous monitoring of internal parameters as well as the establishment of long‐term strategies to stabilize the values of pollutants are necessary actions. [ABSTRACT FROM AUTHOR]

Indoor air quality has become a more prominent concern since the arrival of the COVID-19 pandemic. Manufacturing industries have always been prone to occupational health risks, which depend on the dynamics of the production shop floors. The furniture industry is one of these sectors with a unique work environment. Although a typical furniture manufacturing facility involves physical, chemical, and noise pollution-producing elements, this industry has been studied relatively less for indoor air quality and noise-related risks. This study investigated nine furniture manufacturing organizations’ indoor air quality and noise pollution levels through comprehensive quantitative techniques. The results of the measurements were compared against reference values set by specific guidelines to explore the degree of occupational health risk associated with the World Health Organization's (WHO) suggested levels. Repetitive measurements from five pre-designated workstations were taken at each facility. The study’s results indicated that organization size and department were significant factors for PM 2.5 and HCHO parameters, while only department type was substantial for noise exposure levels. However, across all departments and organization sizes, LAeq noise levels were below the safety threshold of 85 dB(A). Most organizations presented a lack of proper use of personal protective equipment and poor ventilation across shop floors.

Human beings experience a large fraction of their exposure to air pollutants in indoor environments. Air pollution is a large environmental health risk, and exposure to ambient air pollution and indoor air pollution contribute equally to the total number of fatalities worldwide. Although legislative authorities have established limit values for ambient outdoor air and stack emissions, there are inconsistent and variable national and regional limit values for gaseous substances and airborne particulate matter in the built environment (schools, homes, healthcare facilities, offices, and other public spaces). This lack of regulation is unsurprising, because indoor spaces are characterized by complex air chemistry, and their construction materials and types of activities vary significantly. The current understanding of indoor pollutants, including short-lived oxidants, degradation of VOCs, particle formation, and particle composition, is incomplete. It is necessary to identify and assess emerging pollutants and their toxicity, and to consider new consumer products and green construction materials and their impact on indoor air quality (IAQ). Learning from IAQ surveys and audit protocols, research methodologies should be regularized for cross-research comparisons. Some indoor air quality guidance and standards have been written, and several more are in development, with the international ISO 16000 series of indoor standards leading the way for improving indoor air data quality. The WHO has established some ambient air limit values which can mostly be translated into indoor limit values. The built environment needs to harmonize energy efficiency, thermal comfort and air quality standards and guidance. In this review, we discuss the next steps for improving international, regional and national standards and guidance, leading to better and more complete indoor air quality regulations.

Human beings experience a large fraction of their exposure to air pollutants in indoor environments. Air pollution is a large environmental health risk, and exposure to ambient air pollution and indoor air pollution contribute equally to the total number of fatalities worldwide. Although legislative authorities have established limit values for ambient outdoor air and stack emissions, there are inconsistent and variable national and regional limit values for gaseous substances and airborne particulate matter in the built environment (schools, homes, healthcare facilities, offices, and other public spaces). This lack of regulation is unsurprising, because indoor spaces are characterized by complex air chemistry, and their construction materials and types of activities vary significantly. The current understanding of indoor pollutants, including short-lived oxidants, degradation of VOCs, particle formation, and particle composition, is incomplete. It is necessary to identify and assess emerging pollutants and their toxicity, and to consider new consumer products and green construction materials and their impact on indoor air quality (IAQ). Learning from IAQ surveys and audit protocols, research methodologies should be regularized for cross-research comparisons. Some indoor air quality guidance and standards have been written, and several more are in development, with the international ISO 16000 series of indoor standards leading the way for improving indoor air data quality. The WHO has established some ambient air limit values which can mostly be translated into indoor limit values. The built environment needs to harmonize energy efficiency, thermal comfort and air quality standards and guidance. In this review, we discuss the next steps for improving international, regional and national standards and guidance, leading to better and more complete indoor air quality regulations. [ABSTRACT FROM AUTHOR]

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Introduction3D printing is increasingly present in research environments, and could pose health risks to users due to air pollution and particulate emissions. We evaluated the nanoparticulate emissions of two different 3D printers, utilizing either fused filament fabrication with polylactic acid, or stereolithography (SLA) with light curing resin.MethodsNanoparticulate emissions were evaluated in two different research environments, both by environmental measurements in the laboratory and by personal sampling.ResultsThe SLA printer had higher nanoparticulate emissions, with an average concentration of 4,091 parts/cm3, versus 2,203 particles/cm3 for the fused filament fabrication printer. The collected particulate matter had variable morphology and elemental composition with a preponderance of carbon, sulfur and oxygen, the main byproducts.DiscussionOur study implies that when considering the health risks of particulate emissions from 3D printing in research laboratories, attention should be given to the materials used and the type of 3D printer.

Recently, concerns about the effect of air pollution on school kids have increased. There is a growing body of evidence about asthma's development, as well as the worsening of symptoms of people with asthma, and exposure to air pollutants associated with traffic. For this reason, air quality control in the internal environment is considered one of the important things to monitor pollution levels, assess the appropriateness of the child's environment in the classroom, ensure a safe environment, activate the activities of air filtration, stimulate environmental awareness among the decision makers, and develop technologies according to data. Due to the absence of a standard tool for the data of indoor air quality of classrooms in The Hashemite Kingdom of Jordan schools, this research provides: a proposed system to measure air quality. It consists of: distributed sensors connected to a developed system and constitutes a wireless sensor network (WSN). Sensor nods are based on low energy ZigBee movements, and transmit field measurement data to the cloud through a portal. An improved cloud computing system has been applied, monitored, processed and visualized to store the data received from the sensor network.Data-processing shall be implemented and analyzed in the cloud through the application of artificial intelligence techniques, to improve pollutants and compounds technology. The proposed system is: low cost, small-scale, and low energy consumption which can enhance the effectiveness of air quality measurements, therefore a large number of nodes can be published, as well as the provision of the relevant information in order to distribute the air quality in different areas.Carbon dioxide is often considered as reference laboratories for measuring indoor air quality, because its high concentrations indicate that: Conditions of poor ventilation, probable accumulation of pollutants in indoor air. This is mainly related to technical difficulties in monitoring the quality of indoor air in classrooms, in contrast staff members and students inside the classroom relate ventilation to thermal comfort instead of the quality of indoor air (2: page 556), through the control of the mechanisms of direct exchange with the external air,regardless of the conditions of external air quality, and the exposure to pollutants, which arising from the surrounding environment in general, especially schools neighboring public roads.

Studies on indoor air quality are indispensable when considering that people spend approximately 85% of their time in confined environments. This short review mostly takes into consideration research that uses passive samplers to evaluate the quality of indoor environments (houses, school, cars, etc.). This short review summarizes most analytical methods to detect and quantify PAHs and PAEs in house dust used as a passive sampler. The objective of house dust analysis is to identify the presence, amount and distribution of specific hazardous substances in confined spaces and, if possible, to identify their sources. Household dust and the compounds present in it can enter the human body by inhalation, non-food ingestion and absorption through the skin. The observed differences in concentrations of house dust may also indicate important differences in the chemical and physical nature of pollutants caused by air filtration and absorption during the migration of ambient air into the indoor environment. [ABSTRACT FROM AUTHOR]

Atmospheres from indoor areas contain a range of volatile and semi-volatile compounds to which inhabitants are exposed through breathing. Despite different qualitative approaches have been proposed for the identification of compounds associated to the vapor phase of confined areas, active sampling remains as the preferred technique when quantitative data is required. Herein, we investigate the correlations existing between concentrations in air and water condensates obtained from indoor areas. To this end, samples of both matrices were simultaneously collected and analyzed by gas chromatography mass spectrometry. After validation of sample concentration approaches for a selection of compounds, the effect of different operational conditions, and environmental variables, in their concentrations in condensed water was assessed. Levels in this matrix were hardly affected by sampling time, air flow through the dehumidifier device, and the environmental temperature and humidity. Thus, air water distribution coefficients (K aw) could be estimated for fourteen out of sixteen pre-selected compounds. These values permitted a semiquantitative evaluation of their concentrations existing in air from different areas. In case of semi-volatile compounds (i.e. phenol, benzothiazole, phthalates), with log K aw below −4.8, analysis of 50 mL water samples permitted to achieve lower limits of quantification than active air sampling for 3 h at a flowrate of 1 m3 h−1. [Display omitted] • GC-MS quantification of volatile and semi-volatile species in water condensates. • Assessment of parameters controlling concentrations in condensed water. • Evaluation of air water partition coefficients for fourteen organic compounds. • Prediction of concentrations in air from water condensates analysis. [ABSTRACT FROM AUTHOR]

As humans spend more time indoors, ensuring acceptable indoor air quality (IAQ) through ubiquitous sensing systems has become a necessity. Although extensive studies have been conducted on the IAQ sensing systems, a holistic review of the performance and deployment of Ubiquitous IAQ Sensing (UIAQS) systems with associated requirements in IAQ sensing standards is still lacking. In this study, we first reviewed IAQ pollutants and other IAQ-related factors and the associated requirements in the prominent IAQ sensing standards. We found that while non-pollutant factors are influential on occupants' perception of IAQ and their satisfaction, they do not have evaluation metrics in the IAQ standards. Then, we systematically reviewed field studies on UIAQS technologies in the literature. Specific classes of information were recorded and analyzed further. We found that the majority of the UIAQS systems did not meet the requirements of the prominent IAQ sensing standards and identified four primary research gaps. We concluded that a new holistic and personalized approach that incorporates UIAQS measurements and subjective feedback is needed. This study provides valuable insights for researchers and policymakers to better improve UIAQS technologies by developing personalized IAQ sensors and sensing standards. [ABSTRACT FROM AUTHOR]

This narrative review article summarizes the strong available evidence that casually links indoor and outdoor air pollution to cardiovascular disease. It also discusses as a possible approach to mitigate this ubiquitous risk factor the use in the household of ornamental potted plants, and their variable degree of effectiveness for the removal of different indoor pollutants such as volatile organic compounds (formaldehyde, benzene, toluene, xylene). Thus, the choice of the plants should be tailored to the types and concentrations of the pollutants present in each household. Outdoor air is less polluted than indoor air in terms of concentrations of the gaseous (NO2) and particulate components (PM10, PM2.5, PM0.1), but it does hamper to a higher extent health because a large fraction of the population is inevitably exposed at the time of breezing. Being cognizant of the difficulties currently encountered in the attempts to mitigate the major sources of ambient air pollution (vehicle traffic and domestic heating) a strategy based upon a massive increase of green spaces in urban areas has been shown not only to positively mitigate air pollution but also improve life expectancy, general health and resilience.

Viral bronchiolitis is the most common lower respiratory tract infection in infants and children who are 2 years of age and younger. Aim: To analyse the identifiable risk factors for severity of bronchiolitis. Objectives: 1. To study the clinical profile and outcome of children with bronchiolitis. 2. Analysis of risk factors like gestational age, chronological age and indoor pollutants with severity of illness and hospital stay. Materials and Methods: A prospective descriptive cross-sectional study was done from August 2019-August 2020. A complete history was taken, with regards to risk factors like gestational age, birth weight, diet, socioeconomic status, overcrowding, passive smoking, indoor allergens and parental asthma was collected. A general physical examination was done and the severity of illness was assessed by Wood Downes score. Statistical analysis: The collected data were analyzed with IBM SPSS software version 23. A p value of <0.05 was considered as significant level. Results: A total of 120 children were enrolled in the study. Preterm babies and babies less than 6 months had more severe illness and required more duration of oxygen supplementation and hospital stay. In indoor pollutants like mosquito coil and incense stick smoke increased the severity of illness and need for oxygen. Conclusion: Oxygen support and hospitalization is required by mostly preterm babies and infants less than 6 months of age. Absence of fever is a good prognostic factor. Indoor pollutants especially mosquito coil and incense stick have a correlation with severity of illness at admission and duration of hospital stay. [ABSTRACT FROM AUTHOR]

Most of human exposure to atmospheric pollutants occurs indoors, and the components of outdoor aerosols may have been changed in the way before reaching indoor spaces. Here we conducted real‐time online measurements of mass concentrations and chemical composition of black carbon and the non‐refractory species in PM2.5 in an occupied office for approximately one month. The open‐close windows and controlled dampness experiments were also performed. Our results show that indoor aerosol species primarily originate from outdoors with indoor/outdoor ratio of these species typically less than unity except for certain organic aerosol (OA) factors. All aerosol species went through filtration upon transport indoors. Ammonium nitrate and fossil fuel OA underwent evaporation or particle‐to‐gas partitioning, while less oxidized secondary OA (SOA) underwent secondary formation and cooking OA might have indoor sources. With higher particulate matter (PM) mass concentration outdoors than in the office, elevated natural ventilation increased PM exposure indoors and this increased exposure was prolonged when outdoor PM was scavenged. We found that increasing humidity in the office led to higher indoor PM mass concentration particularly more oxidized SOA. Overall, our results highlight that indoor exposure of occupants is substantially different from outdoor in terms of mass concentrations and chemical species. [ABSTRACT FROM AUTHOR]

Studies on indoor air quality are indispensable when considering that people spend approximately 85% of their time in confined environments. This short review mostly takes into consideration research that uses passive samplers to evaluate the quality of indoor environments (houses, school, cars, etc.). This short review summarizes most analytical methods to detect and quantify PAHs and PAEs in house dust used as a passive sampler. The objective of house dust analysis is to identify the presence, amount and distribution of specific hazardous substances in confined spaces and, if possible, to identify their sources. Household dust and the compounds present in it can enter the human body by inhalation, non-food ingestion and absorption through the skin. The observed differences in concentrations of house dust may also indicate important differences in the chemical and physical nature of pollutants caused by air filtration and absorption during the migration of ambient air into the indoor environment.

As humans spend more time indoors, ensuring acceptable indoor air quality (IAQ) through ubiquitous sensing systems has become a necessity. Although extensive studies have been conducted on the IAQ sensing systems, a holistic review of the performance and deployment of Ubiquitous IAQ Sensing (UIAQS) systems with associated requirements in IAQ sensing standards is still lacking. In this study, we first reviewed IAQ pollutants and other IAQ-related factors and the associated requirements in the prominent IAQ sensing standards. We found that while non-pollutant factors are influential on occupants’ perception of IAQ and their satisfaction, they do not have evaluation metrics in the IAQ standards. Then, we systematically reviewed field studies on UIAQS technologies in the literature. Specific classes of information were recorded and analyzed further. We found that the majority of the UIAQS systems did not meet the requirements of the prominent IAQ sensing standards and identified four primary research gaps. We concluded that a new holistic and personalized approach that incorporates UIAQS measurements and subjective feedback is needed. This study provides valuable insights for researchers and policymakers to better improve UIAQS technologies by developing personalized IAQ sensors and sensing standards.

As an important indoor pollutant, nitrous acid (HONO) can contribute to the concentration of indoor OH radicals by photolysis via sunlight penetrating into indoor environments, thus affecting the indoor oxidizing capability. In order to investigate the concentration of indoor HONO and its impact factors, three different indoor environments and two different locations in urban and suburban areas were selected to monitor indoor and outdoor pollutants simultaneously, including HONO, NO, NO 2 , nitrogen oxides (NO x), O 3 , and particle mass concentration. In general, the concentration of indoor HONO was higher than that outdoors. In the urban area, indoor HONO with high average concentration (7.10 ppbV) was well-correlated with the temperature. In the suburban area, the concentration of indoor HONO was only about 1-2 ppbV, and had a good correlation with indoor relative humidity. It was mainly attributed to the heterogeneous reaction of NO 2 on indoor surfaces. The sunlight penetrating into indoor environments from outside had a great influence on the concentration of indoor HONO, leading to a concentration of indoor HONO close to that outdoors. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Chalconatronite, Na2[Cu(CO3)]2·3H2O, is formed as a corrosion product when copper alloys are exposed to sodium carbonate solutions in the air. This also happens when metals come into contact with corroding soda glass which forms alkaline surface films in reaction with humidity from clean air. More often, substantial amounts of formaldehyde are present indoors which react to formate via the Cannizzarro reaction and accumulate over time in the films. Twenty cases of chalconatronite (including two mentioned in the literature) are reported as occurring on heritage objects with glass in contact with copper alloys: Baroque reliquaries with set glass gems, enamel on metal (sixteenth century and a modern replica of intentionally unstable composition), Christmas tree glass baubles with wires, glass buttons with metal shanks, a glass figure with a wire support, miners' lamps, and a glass framed daguerreotype. These confirmed identifications might help conservators in investigating similar cases to shed more light on the formation conditions. [ABSTRACT FROM AUTHOR]

In this paper, we report on the indoor concentrations from a suite of full‐scale outdoor tracer‐gas point releases conducted in the downtown area of Oklahoma City in 2003. A point release experiment consisted of releases of sulfur hexafluoride (SF6) in multiple buildings and from different outdoor locations. From the measurements, we are able to estimate the concentration variations indoors for a building operating under "typical" operating conditions. The mean indoor spatial coefficients of variation are 30% to 45% from a daytime outdoor release are around 80% during an outdoor evening release. Having estimates of the spatial coefficient of variation provides stakeholders, including first responders, with the likely range of concentrations in the building when little is known about the building characteristics and operating behavior, such as developing urban‐scale hazard and consequence analyses. We show differences in indoor measurements at different distances to the release points, floors of the building, and heating, ventilation, and air conditioning system (HVAC) operation. We also show estimates at different time resolutions. The statistics show that in the studied medium to large commercial buildings, spatial differences would result in peak indoor concentrations in certain parts of the buildings that may be substantially higher than the building average. To our knowledge, very few tracer gas measurements have been conducted in buildings of this scope, particularly with measurements on multiple floors and within a floor. The resulting estimates of spatial variability provide a unique opportunity for hazard assessment, and comparison to multi‐zone models. [ABSTRACT FROM AUTHOR]

3D printing has been gaining popularity in the past few years for both personal and professional uses. However, recent results showed that desktop 3D printers emit particles and compounds, which have negative health effects. In this study, the emission from commercially available 3D printing polymers was evaluated. Volatile organic compounds (VOC) emission was studied by using commercial printer placed in gas tight chamber, but also in a very universal test, which simulates the condition in fused filament fabrication 3D printers and in the same time allows for comparison of various filaments without the impact of the 3D printer itself (ex vivo approach). VOC emission can be associated with thermal degradation of polymers as well as degradation of additives such as plasticizers, dyes or flame retardants, as confirmed by detailed FTIR analysis of filaments. The obtained results highlight the problem of emissions of harmful compounds, and the proposed testing methods can be a clue for plastic filament producers on how to test their products and make them safer. [ABSTRACT FROM AUTHOR]

With its increasing value as a means of public transportation, the health effects of the air in subway stations have attracted public concern. In the current study, we investigated the pulmonary toxicity of dust collected from an air purifier installed on the platform of the busiest subway station in Seoul. We found that the dust contained various elements which are attributable to the facilities and equipment used to operate the subway system. Particularly, iron (Fe), chromium (Cr), zirconium (Zr), barium (Ba), and molybdenum (Mo) levels were more notable in comparison with those in dust collected from the ventilation chamber of a subway station. To explore the health effects of inhaled dust, we first instilled via the trachea in ICR mice for 13 weeks. The total number of pulmonary macrophages increased significantly with the dose, accompanying hematological changes. Dust-laden alveolar macrophages and inflammatory cells accumulated in the perivascular regions in the lungs of the treated mice, and pulmonary levels of CXCL-1, TNF-α, and TGF-β increased clearly compared with the control. The CCR5 and CD54 level expressed on BAL cell membranes was also enhanced following exposure to dust, whereas the CXCR2 level tended to decrease in the same samples. In addition, we treated the dust to alveolar macrophages (known as dust cells), lysosomal and mitochondrial function decreased, accompanied by cell death, and NO production was rapidly elevated with concentration. Moreover, the expression of autophagy- (p62) and anti-oxidant (SOD-2)-related proteins increased, and the expression of inflammation-related genes was dramatically up-regulated in the dust-treated cells. Therefore, we suggest that dysfunction of alveolar macrophages may importantly contribute to dust-induced inflammatory responses and that the exposure concentrations of Cr, Fe, Mo, Zr, and Ba should be considered carefully when assessing the health risks associated with subway dust. We also hypothesize that the bound elements may contribute to dust-induced macrophage dysfunction by inhibiting viability. • Dust was collected from the platform of the busiest subway station in Seoul. • Subchronic pulmonary exposure increased the total number of pulmonary macrophages. • Dust-laden alveolar macrophages accumulated in the perivascular regions in the lungs. • The dust up-regulated expression of inflammation-related genes in alveolar macrophages. • The bound elements may be responsible for dust-induced macrophage dysfunction. [ABSTRACT FROM AUTHOR]

A sodium copper formate, first described in 2002, can also form on copper alloys with sodium originating from soda glass hydrolysis. The frequent occurrence (50% of 250 cases of glassinduced metal corrosion) is due to the presence of formaldehyde emissions in storage and its direct reaction to formate in the alkaline surface films. The compound can be produced without the presence of acetate when chalconatronite or metal coupons immersed in soda solution are exposed to formaldehyde vapours. The crystal structure, derived from X-ray powder diffraction, yielded the sum formula Cu4Na4O(HCOO)8(OH)2·4H2O. Except for the absence of acetate in the structure, this is in good agreement with the 2002 publication. To assess which kind of combined glass/metal objects are affected, a number of large museum collections were surveyed. Sodium copper formate was detected as a corrosion product using mainly micro-Raman spectroscopy, for instance, on 18 painted Limoges enamels, eight glass vessels with metal mountings, glass beads on metal wire from 11 bridal crowns, nine Christmas tree balls with wire decoration, 40 pieces of jewellery with glass gems, three daguerreotypes, and one miniature with cover glasses. [ABSTRACT FROM AUTHOR]

A field study on indoor thermal environment and pollutants was conducted in 10 households with 10–12 years old children in Changsha, a south-central city in China. The aim is to identify and examine the main indoor pollutants which affect schoolchildren's health. The households were divided into two groups: 1) Group A, households with apparently unhealthy children, 2) Group B, households with healthy children. The findings for autumn and winter indicated that the differences in temperature and relative humidity (RH) between Groups A and B were not significant. The average concentrations of CO 2 , HCHO and acetaldehyde of Group A were lower than those of Group B. However, the average concentrations of PM 2.5 and TVOCs of Group A were higher than those of Group B. In addition, the indoor PM 2.5 concentrations in ten households, exceeded the upper limit of the Chinese national standard (75 μg/m 3 ) and the TVOCs concentration in two households exceeded the upper limit (600 μg/m 3 ) in winter. The average concentrations of Di(2-ethylhexyl) Phthalate (DEHP) and Dibutyl Phthalate (DBP) which could harm children's health were significantly higher in the Group A household than those in that of Group B. Cladosporium, Aspergillus and Penicillium in indoor air and house dust which could have lead to children's allergy and respiratory diseases correlated with the seasonal climate variation. It was found that high-level indoor PM 2.5 , TVOCs, DEHP and DBP in house dust were possibly the main risk factors for children's health, with Cladosporium, Aspergillus and Penicillium possibly providing associated health risks. [ABSTRACT FROM AUTHOR]

Indoor air quality has been the object of interest for scientists and specialists from the fields of science such as chemistry, medicine and ventilation system design. This results from a considerable number of potential factors, which may influence the quality of the broadly understood indoor air in a negative way. Poor quality of indoor air in various types of public utility buildings may significantly affect an increase in the incidence of various types of civilisation diseases. This paper presents information about a broad spectrum of chemical compounds that were identified and determined in the indoor environment of various types of public utility rooms such as churches, museums, libraries, temples and hospitals. An analysis of literature data allowed for identification of the most important transport paths of chemical compounds that significantly influence the quality of the indoor environment and thus the comfort of living and the health of persons staying in it. [ABSTRACT FROM AUTHOR]

• Indoor thermal environment and air quality impact human health and comfort. • Evaluation was carried out via a questionnaire answered by apartment residents. • Indoor mold breeding was serious and the air quality was poor. • Air conditioning was the main source of indoor microbial pollution. • Indoor area with high humidity was the main site of microbial aggregation. Indoor air quality (IAQ) has a significant impact on human health and comfort. The impact of indoor microorganisms on IAQ has recently been taken into account. However, microbial contamination of microapartments in developed coastal cities, where microorganisms tend to breed, has rarely been investigated. Therefore, this study evaluated the IAQ of two microapartments in Shenzhen in spring, summer, and winter and conducted a questionnaire-based survey and pollution measurement on the residents of the microapartments to analyze the differences in their subjective evaluation. During the period of study, 863 answers to questionnaires were collected, including 403 in spring, 238 in winter, and 222 in summer. The IAQ of microapartments was evaluated and analyzed. It was found that indoor mold breeding was serious, and the air quality was poor. Through gene sequencing analysis, it was concluded that air conditioning was the main source of indoor microbial pollution, and the indoor area with high humidity was the main site of microbial aggregation. In addition, the types of indoor microorganisms were also correlated with seasons. The results of this study can promote the betterment of air quality to improve the comfort of residents. [ABSTRACT FROM AUTHOR]

Introduction: 3D printing is increasingly present in research environments, and could pose health risks to users due to air pollution and particulate emissions. We evaluated the nanoparticulate emissions of two different 3D printers, utilizing either fused filament fabrication with polylactic acid, or stereolithography (SLA) with light curing resin., Methods: Nanoparticulate emissions were evaluated in two different research environments, both by environmental measurements in the laboratory and by personal sampling., Results: The SLA printer had higher nanoparticulate emissions, with an average concentration of 4,091 parts/cm 3 , versus 2,203 particles/cm 3 for the fused filament fabrication printer. The collected particulate matter had variable morphology and elemental composition with a preponderance of carbon, sulfur and oxygen, the main byproducts., Discussion: Our study implies that when considering the health risks of particulate emissions from 3D printing in research laboratories, attention should be given to the materials used and the type of 3D printer., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The handling editor EO declared a past co-authorship with the authors JL, EC, LC, MC, and LL., (Copyright © 2023 Felici, Lachowicz, Milia, Cannizzaro, Cirrincione, Congiu, Jaremko, Campagna and Lecca.)

In rural areas of northeast China, residents often use a traditional Chinese kang for domestic heating. However, this heating method is associated with an uncomfortable thermal environment and poor indoor air quality. Therefore, this paper proposes a glazed transpired collector (GTC) based solar wall system, as a solution. Similar to air conditioning systems, the GTC is able to generate various airflow settings, which is one creative concept of the proposed system. Experimental and numerical studies were conducted to investigate the space heating and indoor air-quality improving performance of the system. The experimental results show that the average indoor temperatures can be increased from 12.12 °C to 16.17–18.19 °C, relevant to the various operating modes. The return-air mode reduces the concentrations of CO, CO 2 , PM 2.5 , and PM 10 by 34.8%, 20.3%, 14.4%, and 11.6%, respectively. The reductions relevant to the mixture mode are 69.6%, 28.0%, 45.0%, and 41.6%, respectively, and those to the fresh-air mode are 73.9%, 42.7%, 56.2%, and 58.1%, respectively. By numerically simulating the distributions of indoor air temperature and the concentrations of CO, CO 2 , PM 2.5 , and PM 10 , the GTC-based solar wall system is able to enhance the uniformity of temperature distribution and dilute indoor pollutant concentrations. To conclude, a summary of the simple and easy operating manual of the solar wall system is presented in this paper. The solar wall system can solve the problem of unacceptable indoor thermal comfort and indoor environmental pollution in rural dwellings in cold climates. [ABSTRACT FROM AUTHOR]

Diwali is great festival of India and it celebrated with full enthusiasm by Indian. But during this festival there is excessive use of fireworks which relate to short term variation in indoor air quality as well as outdoor concentration of pollutants which mainly affects the health of human beings. The present study aimed to estimate the concentration of PM10, SO2, NOx by measuring through AAS-127 Pm10 and AAS-118 Gaseous Sampler. For determine the Indoor air quality during Diwali two sites were selected on based of types of fuel used for cooking (Biomass Based site-1) and (LPG Based site-II). The average concentration of indoor pollutants PM10, NOX, SO2 on day of Diwali was 48.2 µg/m³, 87.65µg/m³,45.06 µg/m³ for site-1 and 28.46 µg/m³, 56.09 µg/m³, 38.9 µg/m³ for site-II was observed and it was 2 times and 2.5 times higher than the indoor concentration on normal day. The order of concentration on Diwali night NOX> PM10 >SO2 with pattern of post Diwali day> Diwali> pre Diwali while outdoor concentration of pollutants on post Diwali day was observed to be higher than the pre Diwali day which indicates a longer time stay of these pollutants in outdoor air, which accumulate on Diwali night due to fireworks. [ABSTRACT FROM AUTHOR]

Passive removal materials (PRMs) have recently gained great interest for their abilities in removing indoor pollutants without additional energy consumption and lower amounts of by-products formation. PRMs, based on their mechanism, can be categorized into two groups—photocatalytic oxidation-based and sorptive-based materials. Herein, a comprehensive literature review is conducted on the recent developments in PRMs as emerging building materials for eliminating indoors gaseous pollutants. Accordingly, a discussion about PRMs' performance for removing indoor air pollutants, followed by a detailed review on different types of PRMs and their destruction/sorption mechanisms is provided. Experimental results pertaining to the application of different PRMs for indoor pollutants removal, are compared. The impacts of various environmental and operational parameters on the PRMs' effectiveness are discussed. Finally, the cons and pros of the application of PRMs as an effective air cleaning method are discussed. • Exposure to indoor pollutants in airtight buildings is a threat to public health. • Applications of passive removal materials (PRMs) for improving IAQ are discussed. • Mechanisms of PCO-based PRMs and sorptive-based PRMs are summarized. • Effects of key controlling parameters on PRMs performance are reviewed. [ABSTRACT FROM AUTHOR]

A substantial disparity in asthma prevalence and morbidity among urban children compared with their nonurban counterparts has been recognized for more than two decades. Because of the nature of urban neighborhoods, pest allergens, such as cockroach and mouse, are present in high concentrations in US urban housing and have both repeatedly been linked to asthma morbidity in sensitized children. In addition, there is a growing body of evidence demonstrating that concentrations of many pollutants are higher indoors than outdoors in both US and European urban communities and that exposures to indoor pollutants such as particulate matter ( PM) and nitrogen dioxide ( NO2) are independently associated with symptoms in children with asthma. Although environmental interventions are challenging to implement, when they reduce relevant indoor allergen and pollutant exposures, they are associated with clear improvements in asthma. Other modifiable risk factors in urban childhood asthma that have emerged include dietary and nutritional factors. Overweight and obese children, for example, may be more susceptible to the pulmonary effects of pollutant exposure. Insufficiency of vitamin D and folate has also emerged as modifiable risk factors for asthma morbidity in children. The identification of these modifiable risk factors for urban childhood asthma morbidity offers a ripe opportunity for intervention. [ABSTRACT FROM AUTHOR]

Personal exposures of 65 primary school children to benzene, toluene, ethyl benzene, xylenes (BTEX), nitrogen dioxide (NO2) and ozone (O3) were measured during 24h by using organic vapor monitors and tailor-made passive samplers. Two schools were selected to represent students living in more polluted (urban) and less polluted (sub-urban) areas in the city of Eskişehir, Turkey. The pollutant concentrations were also measured in indoor and outdoor environments during the personal sampling to investigate the contribution of each micro-environment on measured personal concentrations. Socio-demographic and personal time–activity data were collected by means of questionnaires and half-hour-time resolution activity diaries. Personal exposure concentrations were found to be correlated with indoor home concentrations. Personal, indoor and outdoor concentrations of all studied pollutants except for ozone were found to be higher for the students living at the urban traffic site. Ozone, on the other hand, had higher concentrations at the sub-urban site for all three types of measurements (personal, indoor and outdoor). Analysis of the questionnaire data pointed out to environmental tobacco smoke, use of solvent based products, and petrol station nearby as factors that affect personal exposure concentrations. Cancer and non-cancer risks were estimated using the personal exposure concentrations. The mean cancer risk for the urban school children (1.7×10−5) was found to be higher than the sub-urban school children (0.88×10−5). Children living with smoking parents had higher risk levels (1.7×10−5) than children living with non-smoking parents (1.08×10−5). Overall, the risk levels were <1×10−4. All hazard quotient values for BTEX for the non-cancer health effects were <1 based on the calculations EPA's Risk Assessment Guidance for Superfund (RAGS) part F. [ABSTRACT FROM AUTHOR]

Fluorescent brighteners (FBs) are extensively used as important chemical additives in multiple industrial fields worldwide. The history of the use of global FBs spans over 60 years, but knowledge on their environmental occurrence and risks remains largely unknown. Here, we screened indoor dust and hand wipes from South China for a broad suite of 17 emerging FBs using a new comprehensive analytical method. All 17 FBs were detected in the indoor environment for the first time, most of them having been rarely investigated or never reported in prior environmental studies. Ionic FBs were found to be more abundant than nonionic ones. The median total concentrations of the 17 detectable FBs reached 11,000 ng/g in indoor dust and 2640 ng/m 2 in hand wipes, comparable to or higher than those of well-known indoor pollutants. Human exposure assessment indicated that hand-to-mouth contact is a significant pathway for exposure to FBs, with a comparable contribution to that of dust ingestion. Most of the newly identified FBs are predicted to have persistent, bioaccumulative, or toxic properties. Our work demonstrates that FBs are another class of highly abundant, hazardous, and ubiquitous indoor pollutants that have been overlooked for decades and points to an emerging concern.

Abstract: Prior research suggests that chemical processes taking place on the surface of particle filters employed in buildings may lead to the formation of harmful secondary byproducts. We investigated ozone reactions with fiberglass, polyester, cotton/polyester and polyolefin filter media, as well as hydrolysis of filter media additives. Studies were carried out on unused media, and on filters that were installed for 3 months in buildings at two different locations in the San Francisco Bay Area. Specimens from each filter media were exposed to ∼150 ppbv ozone in a flow tube under a constant flow of dry or humidified air (50% RH). Ozone breakthrough was recorded for each sample over periods of ∼1000 min; the ozone uptake rate was calculated for an initial transient period and for steady-state conditions. While ozone uptake was observed in all cases, we did not observe significant differences in the uptake rate and capacity for the various types of filter media tested. Most experiments were performed at an airflow rate of 1.3 L min−1 (face velocity = 0.013 m s−1), and a few tests were also run at higher rates (8–10 L min−1). Formaldehyde and acetaldehyde, two oxidation byproducts, were quantified downstream of each sample. Those aldehydes (m/z 31 and 45) and other volatile byproducts (m/z 57, 59, 61 and 101) were also detected in real-time using Proton-Transfer Reaction-Mass Spectrometry (PTR-MS). Low-ppbv byproduct emissions were consistently higher under humidified air than under dry conditions, and were higher when the filters were loaded with particles, as compared with unused filters. No significant differences were observed when ozone reacted over various types of filter media. Fiberglass filters heavily coated with impaction oil (tackifier) showed higher formaldehyde emissions than other samples. Those emissions were particularly high in the case of used filters, and were observed even in the absence of ozone, suggesting that hydrolysis of additives, rather than ozonolysis, is the main formaldehyde source in those filters. Emission rates of formaldehyde and acetaldehyde were not found to be large enough to substantially increase indoor concentrations in typical building scenarios. Nevertheless, ozone reactions on HVAC filters cannot be ignored as a source of low levels of indoor irritants. [Copyright &y& Elsevier]

We undertook this to determine the formaldehyde concentration in Japanese houses and the relationship between formaldehyde levels and the age and temperature of a house using a sensor element that we developed for time-integrated measurements of formaldehyde concentration in actual environments. We evaluated the correlation between the formaldehyde concentration estimated by the dinitrophenylhydrazine (DNPH)-derivatization method and that obtained with our sensor element. We found a linear relationship between the two results indicating that reliable measurements can be performed using the developed sensor element in actual environments. The indoor concentration of formaldehyde was determined in a study of 34 homes in the Kanto area of Japan, between September 28 and October 27, 2007. We obtained the highest formaldehyde concentrations of 92 ± 15 µg/m³ for apartments 0-2 years after their renovation, and a simple linear relationship was found between formaldehyde concentration and the age of the apartment. We also found that the formaldehyde concentration in a room containing furniture increased by 10% when the temperature increased by 1°C. [ABSTRACT FROM AUTHOR]

Abstract: We studied the synthesis and photocatalytic activity of small-sized TiO2 supported on hectorite and kaolinite. Deposition of TiO2 on the clay mineral surface was conducted by using a sol–gel method with titanium isopropoxide as precursor. Anatase TiO2 particles formation was achieved by hydrothermal treatment at 180 °C. Material characterization was conducted using XRD, SEM, XPS, ICP-OES, BET and porosimetry analysis. fficiency in synthesizing clay–TiO2 composites depended strongly on the clay mineral structure. Incorporation of anatase in hectorite, an expandable clay mineral, was found to be very significant (>36 wt.% Ti) and to be followed by important structural changes at the clay mineral surface. Instead, no major structural modifications of the clay were observed for kaolinite–TiO2, as compared with the untreated material. Photocatalytic performance of clay–TiO2 composites was evaluated with ATR-FTIR following the oxidation of adsorbed toluene and d-limonene, two model air pollutants. In either case, the photocatalytic removal efficiency of these hydrophobic substrates by the synthesized clay–TiO2 composites was comparable to that observed using pure commercial TiO2 (Degussa P25). [Copyright &y& Elsevier]

BACKGROUND: The effect of indoor nitrogen dioxide concentrations on asthma morbidity among inner-city preschool children is uncertain. OBJECTIVES: Our goal was to estimate the effect of indoor NO2 concentrations on asthma morbidity in an inner-city population while adjusting for other indoor pollutants. METHODS: We recruited 150 children (2--6 years of age) with physician-diagnosed asthma from inner-city Baltimore, Maryland. Indoor air was monitored over a 72-hr period in the children's bedrooms at baseline and 3 and 6 months. At each visit, the child's caregiver completed a questionnaire assessing asthma symptoms over the previous 2 weeks and recent health care utilization. RESULTS: Children were 58% male, 91% African American, and 42% from households with annual income < $25,000; 63% had persistent asthma symptoms. The mean (± SD) in-home NO2 concentration was 30.0 ± 33.7 (range, 2.9--394.0) ppb. The presence of a gas stove and the use of a space heater or oven/stove for heat were independently associated with higher NO2 concentrations. Each 20-ppb increase in NO2 exposure was associated significantly with an increase in the number of days with limited speech [incidence rate ratio (IRR) = 1.15; 95% confidence interval (CI), 1.05--1.25], cough (IRR = 1.10; 95% CI, 1.02--1.18), and nocturnal symptoms (IRR = 1.09; 95% CI, 1.02--1.16), after adjustment for potential confounders. NO2 concentrations were not associated with increased health care utilization. CONCLUSIONS: Higher indoor NO2 concentrations were associated with increased asthma symptoms in preschool inner-city children. Interventions aimed at lowering NO2 concentrations in inner-city homes may reduce asthma morbidity in this vulnerable population. [ABSTRACT FROM AUTHOR]

Abstract: Rationale: Outdoor nitrogen dioxide (NO2) is associated with reduced respiratory health. This could be due to a unique biological effect of this gaseous pollutant or because it serves as a surrogate of fine particles from incineration sources. Cooking with gas in small kitchens produces high concentrations of gaseous irritants (mainly nitrogen dioxide), but not fine particles. Objectives: To study the relative impact of cooking with gas on lung function parameters in a cross sectional study of school children. Methods: Nearly all elementary school children (2898 children aged 6–10 years) living in the city of Linz (capital of Upper Austria) underwent lung function testing. In a questionnaire administered simultaneously to their parents, information on household conditions including cooking and tobacco smoke exposure was collected. Impact of cooking with gas on lung function controlling for various confounders was analyzed using loglinear multiple regression. Results: Gas cooking reduced lung function parameters ranging from 1.1% (not significant) for MEF25 up to 3.4% () for peak expiratory flow (PEF). Conclusions: Gas stoves can have an adverse impact on children''s respiratory health. Parents and caretakers should be advised to insure good ventilation while and after cooking, especially in small and poorly ventilated rooms. This study adds to the growing evidence that gaseous pollutants from incineration sources affect respiratory health directly. [Copyright &y& Elsevier]

Abstract: Formaldehyde and acetaldehyde concentrations have been measured in indoor environments of various public spaces (railway station, airport, shopping center, libraries, underground parking garage, etc.) of Strasbourg area (east of France). In addition, formaldehyde, acetaldehyde propionaldehyde and hexanal concentrations have been measured in 22 private homes in the same area. In most of the sampling sites, indoor and outdoor formaldehyde and acetaldehyde concentrations were measured simultaneously. Gaseous aldehydes levels were quantified by a conventional DNHP-derivatization method followed by liquid chromatography coupled to UV detection. Outdoor formaldehyde and acetaldehyde concentrations were both in the range 1–10μgm−3, the highest values being measured at the airport and railway station. Indoor concentrations were strongly dependant upon the sampling sites. In homes, the average concentrations were 37μgm−3 (living rooms) and 46μgm−3 (bedrooms) for formaldehyde, 15μgm−3 (living rooms) and 18μgm−3 (bedrooms) for acetaldehyde, 1.2μgm−3 (living rooms) and 1.6μgm−3 (bedrooms) for propionaldehyde, 9μgm−3 (living rooms) and 10μgm−3 (bedrooms) for hexanal. However, concentrations as high as 123, 80 and 47μgm−3 have been found for formaldehyde, acetaldehyde and hexanal respectively. In public spaces, the highest formaldehyde concentration (62μgm−3) was found in a library and the highest concentration of acetaldehyde (26μgm−3) in the hall of a shopping center. Additional measurements of formaldehyde and acetaldehyde were made inside a car both at rest or in a fluid or heavy traffic as well as in a room where cigarettes were smoked. Our data have been discussed and compared with those of previous studies. [Copyright &y& Elsevier]

Chemicals present in indoor air can react with one another, either in the gas phase or on surfaces, altering the concentrations of both reactants and products. Such chemistry is often the major source of free radicals and other short-lived reactive species in indoor environments. To what extent do the products of indoor chemistry affect human health? To address this question, the National Institute for Occupational Safety and Health sponsored a workshop titled ‘Indoor Chemistry and Health’ on 12–15 July 2004 at the University of California-Santa Cruz. Approximately 70 experts from eight countries participated. Objectives included enhancing communications between researchers in indoor chemistry and health professionals, as well as defining a list of priority research needs related to the topic of the workshop. The ultimate challenges in this emerging field are defining exposures to the products of indoor chemistry and developing an understanding of the links between these exposures and various health outcomes. The workshop was a step toward meeting these challenges. This summary presents the issues discussed at the workshop and the priority research needs identified by the attendees. [ABSTRACT FROM AUTHOR]