Indoor Sources Research Articles

Partitioning indoor-generated and outdoor-generated PM2.5 from real-time residential measurements in urban and peri-urban Beijing

Limited number of projects have attempted to partition and quantify indoor- and outdoor-generated PM2.5 (PM2.5ig and PM2.5og) where strong indoor sources (e.g., solid fuel, tobacco smoke, or kerosene) exist. This study aimed to apply and refine a previous recursive model used to derive infiltration efficiency (Finf) to additionally partition pollution concentrations into indoor and outdoor origins within residences challenged by elevated ambient and indoor combustion-related sources. During the winter of 2016 and summer of 2017 we collected residential measurements in 72 homes in urban and peri-urban Beijing, 12 of which had additional paired residential outdoor measurements during the summer season. Local ambient measurements were collected throughout. We then compared the calculated PM2.5ig and using (i) outdoor and (ii) ambient measurements as model inputs. The results from outdoor and ambient measurements were not significantly different, which suggests that ambient measurements can be used as a model input for pollution origin partitioning when paired outdoor measurements are not available. From the results calculated using ambient measurements, the mean percentage contribution of indoor-generated PM2.5 was 19 % (σ = 22 %), and 7 % (11 %) of the total indoor PM2.5 for peri-urban and urban homes respectively during the winter; and 18 % (18 %) and 6 % (10 %) of the total indoor PM2.5 during the summer. Partitioning pollution into PM2.5ig and PM2.5og is important to allow investigation of distinct associations between health outcomes and particulate mixes, often with different physiochemical composition and toxicity. It will also inform targeted interventions that impact indoor and outdoor sources of pollution (e.g., domestic fuel switching vs. power generation), which are typically radically different in design and implementation.

A Pilot Study to Quantify Volatile Organic Compounds and Their Sources Inside and Outside Homes in Urban India in Summer and Winter during Normal Daily Activities

Indian cities have some of the poorest air quality globally but volatile organic compounds (VOCs)—many of which adversely affect health—and their indoor sources remain understudied in India. In this pilot study we quantified hundreds of VOCs inside and outside 26 homes in Ahmedabad and Gandhinagar, Gujarat, in May 2019 and in January 2020. We sampled in the morning and afternoon/evening to capture temporal variability. Total indoor VOCs were measured at higher concentrations in winter (327.0 ± 224.2 µgm−3) than summer (150.1 ± 121.0 µgm−3) and exceeded those measured outdoors. Using variable reduction techniques, we identified potential sources of compounds (cooking, plastics [with an emphasis on plasticizers], consumer products, siloxanes [as used in the production of consumer products], vehicles). Contributions differed by season and between homes. In May, when temperatures were high, plastics contributed substantially to indoor pollution (mean of 42% contribution to total VOCs) as compared to in January (mean of 4%). Indoor cooking and consumer products contributed on average 29% and 10% to all VOCs indoors in January and 16% and 4% in May. Siloxane sources contributed <4% to any home during either season. Cooking contributed substantially to outdoor VOCs (on average 18% in January and 11% in May) and vehicle-related sources accounted for up to 84% of VOCs in some samples. Overall, results indicate a strong seasonal dependence of indoor VOC concentrations and sources, underscoring the need to better understand factors driving health-harming pollutants inside homes to facilitate exposure reductions.

Sensitivity of modeled residential fine particulate matter exposure to select building and source characteristics: A case study using public data in Boston, MA

Many techniques for estimating exposure to airborne contaminants do not account for building characteristics that can magnify contaminant contributions from indoor and outdoor sources. Building characteristics that influence exposure can be challenging to obtain at scale, but some may be incorporated into exposure assessments using public datasets. We present a methodology for using public datasets to generate housing models for a test cohort, and examined sensitivity of predicted fine particulate matter (PM2.5) exposures to selected building and source characteristics. We used addresses of a cohort of children with asthma and public tax assessor's data to guide selection of floorplans of US residences from a public database. This in turn guided generation of coupled multi-zone models (CONTAM and EnergyPlus) that estimated indoor PM2.5 exposure profiles. To examine sensitivity to model parameters, we varied building floors and floorplan, heating, ventilating and air-conditioning (HVAC) type, room or floor-level model resolution, and indoor source strength and schedule (for hypothesized gas stove cooking and tobacco smoking). Occupant time-activity and ambient pollutant levels were held constant. Our address matching methodology identified two multi-family house templates and one single-family house template that had similar characteristics to 60 % of test addresses. Exposure to infiltrated ambient PM2.5 was similar across selected building characteristics, HVAC types, and model resolutions (holding all else equal). By comparison, exposures to indoor-sourced PM2.5 were higher in the two multi-family residences than the single family residence (e.g., for cooking PM2.5 exposure, by 26 % and 47 % respectively) and were sensitive to HVAC type and model resolution. We derived the influence of building characteristics and HVAC type on PM2.5 exposure indoors using public data sources and coupled multi-zone models. With the important inclusion of individualized resident behavior data, similar housing modeling can be used to incorporate exposure variability in health studies of the indoor residential environment.

Potential Health Benefit of NO2 Abatement in China's Urban Areas: Inspirations for Source-specific Pollution Control Strategy

Potential Health Benefit of NO2 Abatement in China's Urban Areas: Inspirations for Source-specific Pollution Control Strategy

Investigating aldehyde and ketone compounds produced from indoor cooking emissions and assessing their health risk to human beings

Aldehyde and ketone compounds are ubiquitous in the air and prone to adverse effects on human health. Cooking emission is one of the major indoor sources. Aiming to evaluate health risks associated with inhalation exposure to aldehyde and ketone compounds, 13 carbonyl compounds (CCs) released from heating 5 edible oils, 3 seasonings, and 2 dishes were investigated in a kitchen laboratory. For the scenarios of heating five types of oil, aldehydes accounted for 61.1%-78.0% of the total emission, mainly acetaldehyde, acrolein and hexanal. Comparatively, heating oil with added seasonings released greater concentrations of aldehyde and ketone compounds. The concentration enhancement of larger molecular aldehydes was significantly greater. The emission factors of aldehyde and ketone compounds for cooking the dish of chili fried meat were much greater compared to that of tomato fried eggs. Therefore, food materials also had a great impact on the aldehyde and ketone emissions. Acetone and acetaldehyde were the most abundant CCs in the kitchen. Acrolein concentrations ranged from 235.18 to 498.71 µg/m3, which was about 100 times greater compared to the guidelines provided by Office of Environmental Health Hazard Assessment (OEHHA). The acetaldehyde inhalation for adults was 856.83-1515.55 µg and 56.23-192.79 µg from exposure to chili fried meat and tomato fried eggs, respectively. This exceeds the reference value of 90 µg/day provided by OEHHA. The findings of this study provided scientific evidences for the roles of cooking emissions on indoor air quality and human health.

An alternative approach for estimating large-area indoor PM2.5 concentration – A case study of schools

BackgroundFor indoor air modelling, difficulties in collecting indoor parameters including life activity patterns and building characteristics are dilemmas when conducting a large-area study. Land-use/land cover information which is easier to obtain could represent as surrogates of emission sources for assessing indoor air quality. Moreover, low-cost sensors and machine learning provide a better way to enhance model accuracy. ObjectivesThis study proposed an alternative estimation approach to assess daily PM2.5 concentration for indoor environments of schools in a large area by integrating low-cost sensors, land-use/land cover predictors, and machine learning-based modelling approaches. MethodsIndoor PM2.5 data was collected from 145 indoor AirBox sensors in Kaohsiung and Pingtung Counties of Taiwan. Geospatial predictors were extracted from the circular buffers surrounding each AirBox sensor. Spearman correlation analysis and stepwise variable selection procedures were performed to select variables for land-use regression (LUR) and integrated with XGBoost, Random Forest (RF), and LGBM machine learning models. ResultsThe results revealed that outdoor PM2.5 and distance to the nearest thermal power plant were the main determinants of indoor estimation variations, when there were no indoor sources. When incorporating machine learning, the R2 increased from 0.59 for LUR to 0.85 for LUR-XGBoost while the RMSE decreased from 8.63 to 5.27 μg/m3, which performed better than both LUR-RF and LUR-LGBM. ConclusionsThis study demonstrates the value of the proposed alternative approach by incorporating data from a low-cost sensor with LUR model and machine learning algorithm in estimating the spatiotemporal variability of indoor PM2.5 for a large area.

Atmospheric iron particles in PM2.5 from a subway station, Beijing, China

Particulate matter pollution in the subway station's atmosphere can seriously influence the air quality and impacts on the health of subway workers and commuters. In this study, PM2.5 samples were collected from different locations within a subway station in Beijing, and the individual particles were analyzed for morphology and composition by Transmission Electron Microscopy with Energy Dispersive X-ray Spectrometry (TEM-EDX). The results showed that the concentration of PM2.5 in subway stations was affected by both indoor and outdoor sources. Particles generated by train-related sources such as resuspension, wheel, rail, brake and collector shoe abrasion were a significant source of airborne pollution in the subway atmosphere. Within the subway station PM2.5, Fe was the dominant element, and was detected in more than 75% of all particles analyzed. The Fe-rich particles were identified in railway carriages (79.4%), station concourse (65.3%), and platforms (61.3%). The geometric mean diameter of Fe-rich particles was 0.34 μm, which was smaller than that of all detected particles. Cr, Mn and other metals were often detected in the Fe-rich particles, reflecting metal alloys used in the wheels and tracks. A better understanding of the particle distribution around different areas of the subway system and the physicochemical characteristics of these Fe-rich particles is critical in developing a meaningful assessment of the risk posed by particles in the subway atmosphere.

Biomonitoring of BTEX in primary school children exposed to hookah smoke.

Hookah smoking is one of the major indoor sources of benzene, toluene, ethylbenzene, and xylenes (BTEX). This study aimed to investigate the potential exposure to BTEX among primary school children, particularly those exposed to hookah smoke. This cross-sectional study was conducted in Khesht, one of the southwestern cities in Iran, in mid-June 2020. Totally, 50 primary school children exposed to hookah smoke were chosen as the case group and 50 primary school children were selected as the control group. Urinary un-metabolized BTEX was measured by a headspace gas chromatography mass spectrometry (GC–MS). Additionally, a detailed questionnaire was used to gather data and information from the students’ parents. The mean levels of urinary benzene, toluene, ethylbenzene, m,p-xylene, and o-xylene were 1.44, 5.87, 2.49, 6.93, and 7.17 μg/L, respectively in the exposed children. Urinary BTEX was 3.93-folds higher in the case group than in the controls (p<0.05). Household cleaning products, the floor on which the house was located, children’s sleeping place, and playing outdoors were found to be important factors in predicting urinary BTEX levels. Overall, it was found necessary to avoid indoor smoking to prevent the emission of BTEX compounds via exhaled mainstream smoke and to protect vulnerable non-smokers, especially children, from exposure to second-hand and third-hand smoke.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11356-022-19882-9.

Restrictions on indoor and outdoor NO2 emissions to reduce disease burden for pediatric asthma in China: A modeling study

SummaryBackgroundEpidemiological studies have reported the associations between nitrogen dioxide (NO2) and pediatric asthma incidence, but unable to ascertain indoor NO2 sources. We estimated the pediatric asthma incidence and corresponding economic losses attributable to NO2 from indoor and outdoor sources in urban areas in China.MethodsExposure to NO2 from indoor and outdoor sources in 2019 were estimated separately with a source-specific model validated by measurements from different studies, and NO2 exposure after restricting emissions indoor (from cooking or second-hand smoking) and outdoor (to meet WHO interim targets and air quality guideline) were projected. Disease burden of NO2-attributable new-onset pediatric asthma were estimated based on NO2 exposure, concentration-response function from a meta-analysis, and number of pediatric asthma populations. Economic impacts were estimated based on the costs of pediatric asthma in China.FindingsIn China, NO2 is associated with an estimated 637,000 (95% uncertainty interval 358,000–851,000) new pediatric asthma cases and 1,358 million (674–2145) RMB economic losses in urban areas in 2019. 296,000 (222,000–523,000) new pediatric asthma cases would be prevented each year by restricting NO2 emissions indoor, i.e., switching from using gas stoves to electic stoves for cooking. 393,000 (119,000–463,000) new pediatric asthma cases would be prevented each year when outdoor air meets the air quality guideline for NO2 (< 10 µg/m3).InterpretationRestricting both indoor and outdoor NO2 emissions are necessary to reduce pediatric asthma incidence in urban areas. NO2 restrictions may be achieved through clean energy transition and adoption of climate change mitigation activities.FundingVanke School of Public Health, Tsinghua University (2021JC005).

Assessment of indoor and outdoor air quality in primary schools of Cyprus during the COVID–19 pandemic measures in May–July 2021

Combined pollutant effects from indoor and outdoor sources on children's health, while being at school have not been holistically tackled. The aim of the School Temperature and Environmental Pollutants Study (STEPS) was to perform a school population representative assessment of indoor air quality (IAQ) in primary schools of densely and intermediate populated areas of Cyprus (n = 42). The study took place during May–July 2021 when a school-specific COVID-19 protocol was in place. Questionnaire-based characteristics of schools/classrooms were collected along with 24/48-h long IAQ monitoring of air temperature, relative humidity (RH), particulate matter (PM), carbon dioxide (CO2) and volatile organic compounds (VOCs), using low-cost sensors. Mixed effect models assessed the IAQ determinants during school hours. Indoor PM, temperature, RH and VOCs increased with progressing school periods in the day, while indoor CO2 decreased. Indoor RH and CO2 were negatively associated with % open windows, while indoor PM2.5 was positively associated. Most of school time (85%), indoor air temperature exceeded the recommended upper limit (27 °C), while a third of indoor PM2.5 (24-h) measurements exceeded 15 μg/m3. The interplay of clean indoor air with adequate ventilation and adaptation to heat stress in schools is important and its comprehensive characterization requires holistic methodological approaches and tools.

Concentrations of indoor gaseous air pollutants and risk factors associated with childhood asthma in Benin City, Nigeria.

Pollutants from various indoor sources account for indoor air pollution mostly in developing countries and pose health risks to children. This study assessed the levels of indoor gaseous pollutants and environmental risk factors associated with asthma in children. A cross-sectional household survey was conducted among 304 children between the ages of 1 and 17years. Indoor pollution at home was investigated using a modified international survey on asthma and allergies in childhood (ISAAC) questionnaire. Concentrations of indoor gaseous pollutants (CO, SO2 and NO2) were measured in two hundred and twenty-five randomly selected households using a MultiRae lite gas meter. The data obtained were analysed using SPSS for windows version 21.0. The risk factors for childhood asthma were obtained as odds ratios (ORs) using multivariate logistic regression. Mean concentrations of indoor gaseous pollutants ranged between 2.34-3.14 and 2.21-2.61mg/m3 (CO), 0.02-0.05 and < 0.002-0.03mg/m3 (NO2) and < 0.002-0.03 and < 0.002-0.02mg/m3 (SO2) in the wet and dry seasons. The mean values of pollutants were within the WHO permissible limits. The morbidity rates of clinical asthma, physician-diagnosed asthma and recurrent wheeze in the past 12months among the respondents were 5.6%, 2.6% and 11.8% respectively. There was no association between asthma prevalence and air pollutant exposures except with CO (R = 0.130). However, the number of occupants, family history of asthma, current smoking, use of kerosene and proximity of residence to the highway with significant (p < 0.05) odds ratios (12.4, 3.51, 2.51, 7.20 and 3.46) were independent contributors to current asthma in children. The study showed that exposure to household risk factors contributed to increased asthma among children in the study locations.

Evaluating the applicability of the ratio of PM2.5 and carbon monoxide as source signatures

Air pollution is among the top risk faced by people around the world, and therefore combating it is among the top priorities. It begins with identifying the sources that contribute the most to local air pollution to prioritize their control. There are advanced methods for source identification and apportionment, but such methods are not available in many low-income countries and not everywhere in all high-income countries. We propose a simplified method by using source the signatures to help obtain information about the local source contribution if no other methods are available. Using low-cost monitors, particle mass (PM2.5) and carbon monoxide (CO) concentrations were measured and the ratio of CO/PM2.5 was determined. We investigated outdoor and indoor sources, including vehicular exhaust, combustion of biomass, incense and mosquito coil burning, and cigarette smoking. The results show that the ratios differed significantly between certain pollutant sources. Compressed natural gas (CNG) engines have a high ratio (mean value of 972 ± 419), which is attributed to relatively low PM2.5 emissions, while ship emissions and cigarette smoke recorded a relatively low ratio. Most traffic emissions recorded higher ratios than those of bushfire emissions, and ratios of most outdoor pollutant sources were much higher than those of indoor pollutant sources. There is a clear trend for ratios to decrease from high to low for CNG, petrol, diesel for buses, and fuel for ships. Our results suggest that the ratio of CO/PM2.5 can be used as an effective method to identify pollution sources.

Source apportionment of children daily exposure to particulate matter

The present study aims to investigate the sources of particulate pollution in indoor and outdoor environments, with focus on determining their contribution to the exposure of children to airborne particulate matter (PM). To this end, parallel indoor and outdoor measurements were carried out for a selection of 40 homes and 5 schools between September 2017 and October 2018. PM2.5 and PM2.5–10 samples were collected during five days in each microenvironment (ME) and analysed by X-Ray Fluorescence (XRF), for the determination of elements, and by a thermal-optical technique, for the measurement of organic and elemental carbon. The source apportionment analysis of the PM composition data, by means of the receptor model SoFi (Source Finder) 8 Pro, resulted in the identification of nine sources: exhaust and non-exhaust emissions from traffic, secondary particles, heavy oil combustion, industry, sea salt, soil, city dust, and an indoor source characterized by high levels of organic carbon. Integrated daily exposure to PM2.5 was on average 21 μg/m3. The organic matter, resulting from cleaning, cooking, smoking and biological material, was the major source contributing by 31% to the PM2.5 exposure. The source city dust, which was highly influenced by the resuspension of dust in classrooms, was the second main source (26%), followed by traffic (24%). The major sources affecting the integrated exposure to PM10, which was on average 33 μg/m3, were the city dust (39%), indoor organics (24%) and traffic (16%). This study provides important information for the design of measures to reduce the exposure of children to PM.

The association of indoor heat exposure with diabetes and respiratory 9-1-1 calls through emergency medical dispatch and services documentation

BackgroundPeople with pre-existing medical conditions, who spend a large proportion of their time indoors, are at risk of emergent morbidities from elevated indoor heat exposures. In this study, indoor heat of structures wherein exposed people received Grady Emergency Services based care in Atlanta, GA, U.S., was measured from May to September 2016. Methodology: In this case-control study, analyses were conducted to investigate the effect of indoor heat on the odds of 9-1-1 calls for diabetic (n = 90 cases) and separately, for respiratory (n = 126 cases), conditions versus heat-insensitive emergencies (n = 698 controls). Generalized Additive Models considered both linear and non-linear indoor heat and health outcome associations using thin-plate regression splines. ResultsHotter and more humid indoor conditions were non-linearly associated with an increasing likelihood of receiving emergency care for complications of diabetes and severe respiratory distress. Higher heat indices were associated with increased odds of a diabetes (odds ratio for change from 30 to 31 °C: 1.12, 95% CI: 1.08–1.16) or respiratory 9-1-1 medical call versus control (odds ratio for change from 34 to 35 °C: 1.18, 95% CI: 1.09–1.28) call. Both diabetic and respiratory distress patients were more likely to be African-American and/or have comorbidities. ConclusionsIn this study, the statistical association of indoor heat exposure with emergency morbidities (diabetic, respiratory) was demonstrated. The study also showcased the value and utility of data gathered by emergency medical dispatch and services from inaccessible private indoor sources (i.e., domiciles) for environmental health.

Advances in air quality research – current and emerging challenges

Abstract. This review provides a community's perspective on air quality research focusing mainly on developments over the past decade. The article provides perspectives on current and future challenges as well as research needs for selected key topics. While this paper is not an exhaustive review of all research areas in the field of air quality, we have selected key topics that we feel are important from air quality research and policy perspectives. After providing a short historical overview, this review focuses on improvements in characterizing sources and emissions of air pollution, new air quality observations and instrumentation, advances in air quality prediction and forecasting, understanding interactions of air quality with meteorology and climate, exposure and health assessment, and air quality management and policy. In conducting the review, specific objectives were (i) to address current developments that push the boundaries of air quality research forward, (ii) to highlight the emerging prominent gaps of knowledge in air quality research, and (iii) to make recommendations to guide the direction for future research within the wider community. This review also identifies areas of particular importance for air quality policy. The original concept of this review was borne at the International Conference on Air Quality 2020 (held online due to the COVID 19 restrictions during 18–26 May 2020), but the article incorporates a wider landscape of research literature within the field of air quality science. On air pollution emissions the review highlights, in particular, the need to reduce uncertainties in emissions from diffuse sources, particulate matter chemical components, shipping emissions, and the importance of considering both indoor and outdoor sources. There is a growing need to have integrated air pollution and related observations from both ground-based and remote sensing instruments, including in particular those on satellites. The research should also capitalize on the growing area of low-cost sensors, while ensuring a quality of the measurements which are regulated by guidelines. Connecting various physical scales in air quality modelling is still a continual issue, with cities being affected by air pollution gradients at local scales and by long-range transport. At the same time, one should allow for the impacts from climate change on a longer timescale. Earth system modelling offers considerable potential by providing a consistent framework for treating scales and processes, especially where there are significant feedbacks, such as those related to aerosols, chemistry, and meteorology. Assessment of exposure to air pollution should consider the impacts of both indoor and outdoor emissions, as well as application of more sophisticated, dynamic modelling approaches to predict concentrations of air pollutants in both environments. With particulate matter being one of the most important pollutants for health, research is indicating the urgent need to understand, in particular, the role of particle number and chemical components in terms of health impact, which in turn requires improved emission inventories and models for predicting high-resolution distributions of these metrics over cities. The review also examines how air pollution management needs to adapt to the above-mentioned new challenges and briefly considers the implications from the COVID-19 pandemic for air quality. Finally, we provide recommendations for air quality research and support for policy.

Characteristics, Source Contributions, and Source-Specific Health Risks of PM2.5-Bound Polycyclic Aromatic Hydrocarbons for Senior Citizens during the Heating Season in Tianjin, China.

Polycyclic aromatic hydrocarbons (PAHs) have carcinogenic impacts on human health. However, limited studies are available on the characteristics, sources, and source-specific health risks of PM2.5-bound PAHs based on personal exposure data, and comparisons of the contributions of indoor and outdoor sources are also lacking. We recruited 101 senior citizens in the winter of 2011 for personal PM2.5 sample collection. Fourteen PAHs were analyzed, potential sources were apportioned using positive matrix factorization (PMF), and inhalational carcinogenic risks of each source were estimated. Six emission sources were identified, including coal combustion, gasoline emission, diesel emission, biomass burning, cooking, and environmental tobacco smoking (ETS). The contribution to carcinogenic risk of each source occurred in the following sequence: biomass burning > diesel emission > gasoline emission > ETS > coal combustion > cooking. Moreover, the contributions of biomass burning, diesel emission, ETS, and indoor sources (sum of cooking and ETS) to PAH-induced carcinogenic risk were higher than those to the PAH mass concentration, suggesting severe carcinogenic risk per unit contribution. This study revealed the contribution of indoor and outdoor sources to mass concentration and carcinogenic risk of PM2.5-bound PAHs, which could act as a guide to mitigate the exposure level and risk of PM2.5-bound PAHs.

Inflammatory markers and lung function in relation to indoor and ambient air pollution.

Ambient air pollution causes a range of adverse health effects, whereas effects of indoor sources of air pollution are not well described in high-income countries. We compared hazards of ambient air pollution and indoor sources with respect to important biomarkers of cardiorespiratory effects in terms of lung function and systemic inflammation in a middle-aged Danish cohort. Our cohort comprised 5199 men and women aged 49-63 years at the recruitment during April 2009 to March 2011, with information on exposure to second-hand smoke (SHS) and use of candles, wood stove, kerosene heater and gas cooker as well as relevant covariates. Ambient air pollution exposure was assessed as 2-year mean nitrogen dioxide (NO2) at the address (mean±SD: 17.1±9.9μg/m3) and 4-day average levels of particulate matter with diameter <2.5μm (PM2.5; mean±SD: 12.5±6.0μg/m3) in urban background. Lung function was assessed as % predicted forced expiratory volume in the first second (FEV1) and inflammatory markers comprised interleukin-6 (IL-6), IL-10, IL-18, interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), and high sensitivity C-reactive protein (hs-CRP). We used random-effect regression models controlling for potential confounders as well as models with further adjustment for self-reported health or for all other exposures. In models adjusted for confounders FEV1 was inversely associated with exposure to NO2, (-0,83% per 10μg/m3; 95% CI: -1.26; -0.41%), SHS (-0.56% per 1 of 5 categories increment; 95% CI: -0.89; -0.23%), and gas cooker without hood (-0.89%; 95% CI: -1.62; -0.17%), whereas use of wood stove and candles showed positive associations, although these attenuated by mutual adjustment for all exposures or self-reported health. IL-6 showed positive associations with NO2 (6.30% increase in log-transformed values per 10μg/m3; 95% CI: 3.54; 9.05%), PM2.5 (7.82% per 10μg/m3; 95% CI: 3.35; 12.4%), SHS (4.38% per increase of 1 of 5 categories; 95% CI: 2.22; 6.54%) and use of kerosene (13.8%; 95% CI: 2.51; 25.1%), whereas the associations with use of wood stove and candles were inverse. PM2.5 and NO2 showed positive associations with IFN-γ and TNF-α, while PM2.5 further associated with IL-10 and IL-18. Hs-CRP was inversely associated with use of candles. These results suggest that the levels of exposure to ambient air pollution and SHS are more harmful than are the levels of exposure to indoor combustion sources from candles and wood stoves in a high-income setting.

An overview of indoor air pollution in the Malaysian kindergarten environment

Abstract The components of indoor air determine the quality of the indoor environment, which affects the health and well-being of inhabitants. Exposure to high levels of indoor air pollution in a kindergarten environment has a detrimental influence on children’s learning performance and increases the risk of respiratory problems that could lead to absenteeism. This paper explores and summarises the literature on indoor air pollution in kindergartens in the Malaysian environment. A review was done by analyzing papers taken from four electronic databases: Scopus, Science Direct, PubMed and Google Scholar. Information on indoor pollution levels and determinants sources were extracted from 17 studies. The most investigated pollutants were carbon dioxide (CO2), particulate matter (PM2.5 and PM10), volatile organic compounds (VOCs), carbon monoxide (CO), fungi and bacteria. Inadequate ventilation systems and overcrowded classrooms all contributed to excessive CO2 levels. Indoor PM2.5 sources are generated from cooking activities while cleaning, opening windows and movement activities of children were the primary sources of coarse particles. High concentrations of VOCs are emitted from a wide variety of indoor sources. Mobile vehicles and the proximity of kindergartens to busy roads were key contributors to higher CO concentrations. The findings highlight the importance of interventions to improve indoor air pollution in kindergarten premises in various settings.

Interior Design Students' Perception on Interior Health and Comfort in Shop House Design for New Normal Era

Objective – The 2020 Covid-19 outbreak has deeply redefined our relationship to public spaces. Public preference has shifted from indoor to outdoor areas which provide open-air spaces to reduce the possibility of Covid-19 transmission. Therefore, shop house foodservice retailers that operated in big cities may find it challenging to meet the new expectation. The Greenship (green building assessment tools in Indonesia) however, has made a checklist on how to achieve better indoor environment quality (IEQ) under the IHC (indoor health and comfort) category. Methodology – The method used for this research was the systematic literature review and typology studies with a proposed conceptual design made by students in Design Interior and Styling for Commercial and Retail Space studio academic year 2020/2021 as samples. Findings – The result shows that almost all students only took care of 5 categories out of 11 categories provided in the IHC category. The highest categories to get attention are indoor pollutant source control and outside view and daylight. The research shows attempts of students to achieve better IEQ but they are unaware that a guide and reference can as well be found in Greenship Interior Space. Novelty - This paper examines young interior designers' perceptions of healthy interior elements that need to be implemented for the purpose of adapting to the new normal. Type of Paper: Review JEL Classification: I23, I29.

Using Real Time Measurements to Derive the Indoor and Outdoor Contributions of Submicron Particulate Species and Trace Gases.

The indoor environment is usually more polluted than outdoors due to emissions of gas and particle-phase pollutants from multiple sources, leading to their accumulation on top of the infiltration of outdoor pollution. While it is widely recognized that negative health effects arise from the exposure to outdoor air pollution, exposure to indoor pollutants also needs to be well assessed since we spend most of our time (~90%) breathing indoors. Indoor concentrations of pollutants are driven by physicochemical processes and chemical transformations taking place indoors, acting as sources and/or sinks. While these basic concepts are understood, assessing the contribution of each process is still challenging. In this study, we deployed online instrumentation in an unoccupied room to test a methodology for the apportionment of indoor and outdoor pollutant sources. This method was successfully applied to the apportionment of PM1 and VOCs, however, there are limitations for reactive gases such as O3. The results showed that this unoccupied indoor environment acts as a source of VOCs and contributes 87% on OVOCs and 6% on CxHy, while it acts as a sink for particles, likely due to losses through volatilization up to 60%.