We investigated whether exposure to microbiome within the indoor environment is associated with risk of lower respiratory tract infections (LRTI) among children under five years of age. Electronic scientific repositories; PUBMED, SCOPUS, WEB OF SCIENCE, GREENFILE, EMBASE, and Cochrane library were searched and screened through July 2019 for published reports for inclusion in the meta‐analysis. Studies

Indoor air cleaning systems that incorporate CO2 sorbent materials enable HVAC load shifting and efficiency improvements. This study developed a bench‐scale experimental system to evaluate the performance of a sorbent under controlled operation conditions. A thermostatic holder containing 3.15 g sorbent was connected to a manifold that delivered CO2‐enriched air at a known temperature and relative

Indoor environmental quality (IEQ) is a general indicator of the quality of conditions inside a building. We investigated associations of perceived IEQ including air quality, thermal comfort, noise, and light quality with stress at work and the extent to which workplace location modifies these associations. We recruited 464 full‐time workers from four companies in Singapore. Data on socio‐demographic

This study examined indoor air pollutants and their health effects on allergic rhinitis in 3,194 employees of 226 bus station halls and then constructed a nomogram model to predict allergic rhinitis risk in those employees. Indoor air temperature, relative humidity, PM10 , PM2.5 , total bacteria, and total fungi were measured, and questionnaires were used to collect basic station information and employee

With the gradual reduction of emissions from building products, emissions from human occupants become more dominant indoors. The impact of human emissions on indoor air quality is inadequately understood. The aim of the Indoor Chemical Human Emissions and Reactivity (ICHEAR) project was to examine the impact on indoor air chemistry of whole-body, exhaled and dermally emitted human bioeffluents under

During 2010-2012, we surveyed 40,010 3- to 6-year-old children in seven Chinese cities (Beijing, Taiyuan, Urumqi, Shanghai, Nanjing, Changsha, and Chongqing). Their parents reported information on household renovation, including the timing of renovation and the choice of materials for walls and floors in the child's room, and the incidence of their child's rhinitis. Multivariate and two-level (city-child)

Resuspension of microbes in floor dust and subsequent inhalation by human occupants is an important source of human microbial exposure. Microbes in carpet dust grow at elevated levels of relative humidity, but rates of this growth are not well established, especially under changing conditions. The goal of this study was to model fungal growth in carpet dust based on indoor diurnal variations in relative

Data were collected in 70 detached houses built in 2011-2017 in compliance with the mechanical ventilation requirements of California's building energy efficiency standards. Each home was monitored for a 1-week period with windows closed and the central mechanical ventilation system operating. Pollutant measurements included time-resolved fine particulate matter (PM2.5 ) indoors and outdoors and formaldehyde

This study evaluated the interrelations between indoor and outdoor bioaerosols in a bedroom under a living condition. Two wideband integrated bioaerosol sensors were utilized to measure indoor and outdoor particulate matter (PM) and fluorescent biological airborne particles (FBAPs), which were within a size range of 0.5-20 μm. Throughout this one-month case study, the median proportion of FBAPs in

Seasonal influenza epidemics have been responsible for causing increased economic expenditures and many deaths worldwide. Evidence exists to support the claim that the virus can be spread through the air, but the relative significance of airborne transmission has not been well defined. Particle image velocimetry (PIV) and hot-wire anemometry (HWA) measurements were conducted at 1 m away from the mouth

Singapore is a tropical country with a high density of day-care facilities whose indoor environments may be adversely affected by outdoor fine particle (PM2.5 ) air pollution. To reduce this problem requires effective, evidence-based exposure-reduction strategies. Little information is available on the penetration of outdoor PM2.5 into day-care environments. Our study attempted to address the following

Recent studies reveal that the microbial diversity and composition in the respiratory tract are related to the susceptibility, development, and progression of respiratory infections. Indoor microorganisms can transmit into the respiratory tract through breathing, but their role in infections is unclear. Here, we present the first association study between the indoor microbiome and respiratory infections

This study investigated whether adjusting clothing to remain in neutral thermal comfort at moderately elevated temperature is capable of avoiding negative effects on perceived acute subclinical health symptoms, comfort, and cognitive performance. Two temperatures were examined: 23°C and 27°C. Twelve subjects were able to remain thermally comfortable at both temperatures by adjusting their clothing

Contamination of metals in household dust remains a concern for human health. However, few studies to date have been conducted on the contribution of both indoor and outdoor environments to the health risks posed by metals. This study was carried out to assess the potential health risks from both indoor and outdoor household dust and the respective contribution to the health risks for children. The

A new large-field, high-sensitivity, single-mirror coincident schlieren optical instrument has been installed at the Bauhaus-Universität Weimar for the purpose of indoor air research. Its performance is assessed by the non-intrusive measurement of the thermal plume of a heated manikin. The schlieren system produces excellent qualitative images of the manikin's thermal plume and also quantitative data

Bacterial transmission from contaminated surfaces via hand contact plays a critical role in disease spread. However, the fomite-to-finger transfer efficiency of microorganisms during multiple sequential surface contacts with and without gloves has not been formerly investigated. We measured the quantity of Escherichia coli on fingertips of participants after one-to-eight sequential contacts with inoculated

Close contact was first identified as the primary route of transmission for most respiratory infections in the early 20th century. In this review, we synthesize the existing understanding of the mechanisms of close contact transmission. We focus on two issues: the mechanism of transmission in close contact, namely the transmission of the expired particles between two people, and the physical parameters

We sought to investigate the association between active cigarette smoking (ex- and current smokers) with or without exposure to biomass fuels and respiratory symptoms/lung function in middle-aged adults and the elderly. In the chronic obstructive pulmonary disease surveillance conducted in six cities of Guangdong province, China, we surveyed 1986 residents aged 40-93 years. We recorded respiratory

The performance of ductless personalized ventilation (DPV) was compared to the performance of a typical desk fan since they are both stand-alone systems that allow the users to personalize their indoor environment. The two systems were evaluated using a validated computational fluid dynamics (CFD) model of an office room occupied by two users. To investigate the impact of DPV and the fan on the inhaled

Numerous acids and bases influence indoor air quality. The most abundant of these species are CO2 (acidic) and NH3 (basic), both emitted by building occupants. Other prominent inorganic acids are HNO3 , HONO, SO2 , H2 SO4 , HCl, and HOCl. Prominent organic acids include formic, acetic, and lactic; nicotine is a noteworthy organic base. Sources of N-, S-, and Cl-containing acids can include ventilation

Electronic (e)‐cigarette smoking is considered to be less harmful than traditional tobacco smoking because of the lack of a combustion process. However, e‐cigarettes have the potential to release harmful chemicals depending on the constituents of the vapor. To date, there has been significant evidence on the adverse health effects of e‐cigarette usage. However, what is less known are the impacts of

Physicochemical properties between colloidal engineered nanomaterials (ENMs) and aerosols released from consumer spray products were characterized. A dynamic light scattering (DLS), transmission electron microscopy (TEM), and inductively coupled plasma mass spectrometer (ICP‐MS) were used to evaluate the suspended ENMs in the products. Direct‐reading instruments, TEM, and ICP‐MS were used to characterize

Thermal adaptations, as feedbacks of occupants to physical stimuli, extend thermal comfort zone thereby reducing building energy consumption effectively. The rational approach models thermal comfort from the perspective of the body's heat balance, but is limited in explaining the thermal adaptations. The adaptive approach of modeling thermal comfort can fully account for the thermal adaptations, but

About 339 million people worldwide are suffering from asthma. We aimed to investigate whether exposure to formaldehyde (FA) is associated with asthma, which could provide clues for preventive and mitigation actions. This article provides a systematic review and meta-analysis of observational studies to assess the association between indoor FA exposure and the risk of asthma in children and adults.

Indoor surfaces are known to support organic films, but their thickness, composition, and variability between environments remain poorly characterized. Alkenes are expected to be a significant component of these films, with the reaction with O3 being a major sink for O3 and source of airborne chemicals. Here, we present a sensitive, microscale, nanospectrophotometric method for quantifying the alkene

A number of epidemiological studies find an association between indoor air dampness and respiratory health effects. This is often suggested to be linked to enhanced mold growth. However, the role of mold are obviously difficult to disentangle from other dampness related exposure including microbes as well as non-biological particles and chemical pollutants. The association may partly be due to visible

In order to create a healthy, comfortable, productive, and energy‐efficient indoor environment, the computational fluid dynamics (CFD)‐based adjoint method with an area‐constrained topology method can be used to inversely design the optimal number, size, location, and shape of air supply inlets and air supply parameters. However, this method is not very mature, and the distribution of retained inlets

BACKGROUND Household air pollution from biomass cookstoves is a major contributor to global morbidity and mortality, yet little is known about exposures to nitrogen dioxide (NO2 ). OBJECTIVE To characterize NO2 kitchen area concentrations and personal exposures among women with biomass cookstoves in the Peruvian Andes. METHODS We measured kitchen area NO2 concentrations at high-temporal resolution

Partitioning to surfaces is an important sink for volatile organic compounds (VOCs) indoors, but the mechanisms are not well understood or quantified. Here, a mass spectrometer was coupled to a portable surface reactor and a flow tube to measure partitioning of VOCs into paint films coated onto glass or wallboard, and their subsequent diffusion. A model was developed to extract values of the effective

Influenza transmission occurs through the air, but the relative importance of small droplets, or aerosols, in influenza transmission especially within healthcare facilities remains uncertain. Detections of influenza virus in aerosols in cough and exhaled breath from infected patients and from the air in outpatient or inpatient healthcare facilities have been studied, but most studies were done in adults

Exposure to elevated levels of certain volatile organic compounds (VOCs) in households has been linked to deleterious health effects. This study presents the first large-scale investigation of VOC levels in 169 energy-efficient dwellings in Switzerland. Through a combination of physical measurements and questionnaire surveys, we investigated the influence of diverse building characteristics on indoor

This paper presents a review on thermal comfort research that is informed by changes in occupant behavior, lifestyle, and income leading to rebound or pre-bound effect. It explores the current state of research in thermal comfort domain through a systematic review to identify the gaps and opportunities specifically focusing on energy-intensive developing countries. This review argues that adaptive

Electret filters are widely used in HVAC systems to decrease particulate matter in indoor environments. The previous standard in Europe for testing air filters for general ventilation was EN 779. In July 2018, it was replaced by the new international standard ISO 16890. One major change is the discharging process: It is now performed by treating the filters with saturated isopropyl alcohol (IPA) vapor

Volatile organic compounds (VOCs) emitted from personal care products (PCPs) can affect indoor air quality and outdoor air quality when ventilated. In this paper, we determine a set of simplified VOC species profiles and emission rates for a range of non-aerosol PCPs. These have been constructed from individual vapor analysis from 36 products available in the UK, using equilibrium headspace analysis

Monitoring improved cookstove adoption and usage in developing countries can help anticipate potential health and environmental benefits that may result from household energy interventions. This study explores stove-usage monitor (SUM)-derived usage data from field studies in China (52 stoves, 1422 monitoring days), Honduras (270 stoves, 630 monitoring days), India (19 stoves, 565 monitoring days)

BACKGROUND Exposure to black carbon indoors may be associated with blood pressure; however, evidence is limited to vulnerable subpopulations and highly exposed individuals. Our objective was to explore the relationship between indoor black carbon at various exposure windows on resting blood pressure in a general population sample. METHODS Black carbon was measured in the home of 76 individuals aged

Thermal comfort is an important factor for the design of buildings. Although it has been well recognized that many physiological parameters are linked to the state of thermal comfort or discomfort of humans, how to use physiological signal to judge the state of thermal comfort has not been well studied. In this paper, the feasibility of continuously determining feelings of personal thermal comfort

Persistent Organic Pollutants (POPs) are anthropogenic chemicals extensively used in the past for industrial and agricultural purposes, characterized by their lipophilicity, ubiquity, volatility and environmental persistence. By other hand, chlorpyrifos is the most widely used current pesticide (CUPs) being the main insecticide used for crops in Argentina. The aim of this work was to assess levels

Building materials and human activities are important sources of contamination indoors, but little information is available regarding contamination during construction process which could persist during the whole life of buildings. In this study, six construction stages on two construction sites were investigated regarding the emissions of 43 volatile organic compounds (VOCs), 46 semi-volatile organic

This study examined airborne emissions from cigarette butts for styrene, 2-methyl-2-cyclopenten-1-one, naphthalene, triacetin, and nicotine. Ten experiments were conducted by placing butts in a stainless steel chamber and measuring the chemical concentrations in chamber air. Emission rates were determined from the concentrations. Triacetin and nicotine concentrations were roughly 50% of initial concentrations

Many studies have shown that the use of laser printing devices (LPDs) contributes to the release of particles into the indoor environment. However, after more than two decades of research, the physicochemical properties of LPD-emitted particles and the possible health effects from exposure to particles are still heavily debated. We therefore carried out a critical review of the published studies around

This cross-sectional study analyzed the impact of occupational waste anesthetic gases on genetic material, oxidative stress, and inflammation status in young physicians exposed to inhalational anesthetics at the end of their medical residency. Concentrations of waste anesthetic gases were measured in the operating rooms to assess anesthetic pollution. The exposed group comprised individuals occupationally

Concentrations and emission rates of sixteen trace elements in emitted PM during heating soybean oil using three types of pans, including Teflon, granitium, and cast-iron, were investigated. Statistically significant decreases in Mn and Co emission rates were observed when the oil was heated in the cast-iron pan compared to Teflon and granitium pans. Among the released trace elements, Ni, Ba, Zn, and

Over half of schools surveyed in the United States reported one environmental problem affecting Indoor Air Quality. This study investigated environmental concerns in schools, teacher-reported symptoms, and performance in relation to thermal environment, lighting, and noise conditions in New York State classrooms. This cross-sectional study consisted of telephone surveys among teachers from 428 NYS

In vitro models mimicking the human respiratory system are essential when investigating the toxicological effects of inhaled indoor air particulate matter (PM). We present a pulmonary cell culture model for studying indoor air PM toxicity. We exposed normal human bronchial epithelial cells, grown on semi-permeable cell culture membranes, to four doses of indoor air PM in the air-liquid interface. We

Assessment of personal exposure to PM2.5 is critical for understanding intervention effectiveness and exposure-response relationships in household air pollution studies. In this pilot study, we compared PM2.5 concentrations obtained from two next-generation personal exposure monitors (the Enhanced Children MicroPEM or ECM; and the Ultrasonic Personal Air Sampler or UPAS) to those obtained with a traditional

A cross-sectional study was conducted to assess the prevalence of sick building syndrome symptoms and its associated factors among bank employees. Data were collected through a self-administered MM040NA questionnaire among 234 employees of commercial banks in Pokhara Metropolitan, Nepal. The prevalence of general, ocular, respiratory, and dermal sick building syndrome symptoms was 47.6%, 11.9%, 11

In this study, we investigated the effects of environmental factors such as airflow velocity, relative humidity (RH), temperature, and duct reflectance on the performance of in-duct UVC lamps. Staphylococcus epidermidis, Pseudomonas alcaligenes, and Escherichia coli were used as the test bacteria. The UV irradiance, disinfection efficacy, and UV susceptibility constant (Z value) of the test bacteria

The role of ventilation in preventing tuberculosis (TB) transmission has been widely proposed in infection control guidance. However, conclusive evidence is lacking. Modeling suggested the threshold of ventilation rate to reduce effective reproductive ratio (ratio between new secondary infectious cases and source cases) of TB to below 1 is corresponding to a carbon dioxide (CO2 ) level of 1000 parts

Biomass combustion for cooking and heating releases particulate matter (PM2.5 ) that contributes to household air pollution. Fuel and stove types affect the chemical composition of household PM, as does infiltration of outdoor PM. Characterization of these impacts can inform future exposure assessments and epidemiologic studies, but is currently limited. In this study, we measured chemical components

The presence of biofilms on the cooling coils of commercial air conditioning (AC) units can significantly reduce the heat transfer efficiency of the coils and may lead to the aerosolization of microbes into occupied spaces of a building. We investigated how climate and AC operation influence the ecology of microbial communities on AC coils. Forty large-scale commercial ACs were considered with representation

High-efficiency filtration in residential forced-air heating, ventilation, and air conditioning (HVAC) systems protects equipment and can reduce exposure to particulate matter. Laboratory tests provide a measure of the nominal efficiency, but they may not accurately reflect the in situ efficiency of the filters because of variations in system conditions and changes in filter performance over time.

This paper reviews the published literature on indoor thermal environment and air quality in Chinese-style residential kitchens (CRKs). The paper first discusses typical characteristics of CRKs, including kitchen layout, cooking methods, and ventilation systems used. Next, the paper describes the current state of the indoor thermal environment and air quality in CRKs. Finally, this paper summarizes

Chlorine-based disinfectants protect pool water from pathogen contamination but produce potentially harmful halogenated disinfection by-products (DBPs). This study characterized the bioaccumulation and elimination of exhaled DBPs post-swimming and investigated changes in exhaled breath profiles associated with chlorinated pool exposure. Nineteen participants provided alveolar-enriched breath samples