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Indoor air quality is closely related to human health, and increasing studies have highlighted that poor indoor air quality presents a threat to occupants' health in office and school buildings. This paper aims to analyze the exposure levels and health effects of indoor air pollutants in office and school buildings in the Yangtze River Delta, China. The published studies from 1980 to 2020 concerning indoor pollutants (including formaldehyde, PM2.5, PM10, CO2, TVOC, benzene, toluene, xylene, ammonia, microbial pollutants, and radon) in this zone were systematically reviewed. The Composite Index Method was used to evaluate indoor air quality, and DALYs (disability-adjusted life years) were evaluated by the IND and ID methods to quantify the health effects of inhaled air pollutants. The review found that PM2.5 concentrations exceeded current standards in China in 57% of the study samples in office buildings, while formaldehyde, benzene, TVOC, and ammonia exceeded existing standards in 60%, 62%, 61%, and 86% of the samples, respectively. In school buildings, 55% and 100% of the samples with the formaldehyde and ammonia concentrations exceeded the limits in standards, respectively. The evaluation of indoor air quality showed that office and school buildings in the Yangtze River Delta were at a medium and light pollution level, respectively. Furthermore, based on the DALYs value, the health risks of studied pollutants were ranked as PM2.5 > formaldehyde > ammonia > benzene > toluene > xylene. This review pointed out that in over half of the studies, the levels of pollutants (PM2.5, formaldehyde, benzene, TVOC, and ammonia) in office and school buildings exceeded the limits set by the current indoor air quality standard. PM2.5 and formaldehyde played important roles in impacting human health. Additionally, the levels of pollution varied among cities, and there were differences in health effects caused by different air pollutants, which should be noticed. This review provides valuable information on the levels and health effects of major pollutants, contributing to the control of main pollutants in school and office buildings. [ABSTRACT FROM AUTHOR]

Designing an economical, superior activity, excellent stability, and earth-rich catalysts is of crucial significance in the progress of electrochemical water splitting and still remains huge challenge to overcome. In this work, amorphous MoO2 with a porous nanostructure as a novel bifunctional electrocatalyst has been prepared by the hydrothermal method. This nanostructure has excellent HER/OER properties, in which the amorphous and porous states have a large number of vacancies and active sites exposed to the electrolyte. The as-prepared sample has been researched in detail via X-ray diffraction (XRD) and transmission electron microscopy (TEM). Electrochemical experiments show that when the current density reaches − 10 mA cm−2, the as-prepared samples need an overpotential of only about − 0.930 V (vs. RHE) in 1 M H2SO4 and − 0.777 V (vs. RHE) in 1 M KOH for HER, respectively. Furthermore, MoO2 exhibits an extremely overpotential of 2.414 V (vs. RHE) at 10 mA cm−2 in 1 M KOH for OER. It is believed that the amorphous and porous nanostructure remains a promising and efficient hydrolytic electrocatalyst. [ABSTRACT FROM AUTHOR]

Objective: Phthalate acid esters (PAEs) have been identified to be associated with children's health. Present study was conducted to assess associations between PAEs in household dust and childhood rhinitis. Methods: Based on phase II of CCHH study (China, Children, Home, Health) conducted in Shanghai, China, 266 indoor dust samples were collected from participants' families. Concentrations of PAEs in dust samples were measured by chemical treatment and gas chromatograph–mass spectrometer. Information about individuals and residences was surveyed by questionnaires. Logistic regression models were applied to obtain the associations between PAEs and childhood rhinitis. Results: Higher concentrations of benzyl butyl phthalate (BBP) were found in those families with children who had diagnosed rhinitis. Significantly higher concentrations of bis(2-ethylhexyl) phthalate (DEHP) and PAEs with high molecular weight (HMW-PAEs) were found in the positive group of lifetime rhinitis. Using the multiple and ordinal logistic regression models adjusted by covariates, dibutyl phthalate (DBP), DEHP, and HMW-PAEs were found to be significantly associated with diagnosed rhinitis. Boys who exposure to higher concentrations of DBP, DEHP, HMW-PAEs, and total PAEs have significant associations with diagnosed rhinitis compared with girls who exposure to lower concentration of PAEs. Conclusions: Present observational study indicated that exposure to high concentrations of DBP, DEHP, and HMW-PAEs in house settled dust was a risk factor for rhinitis for children, especially for boys. [ABSTRACT FROM AUTHOR]

Associations of household airborne fungi with allergies in childhood were inconsistent in the epidemiologic studies. During 2013–2014, we conducted a case-control study (phase two), which was nested in a cross-sectional study (phase one) during 2011–2012 in Shanghai, China. We inspected indoor air quality of 454 residences for 5–10 years old children. We defined cases as those children who were reported illnesses in the questionnaire of phase one or phase two and defined controls as those children who were not reported illnesses in both phases. A total of 436 living rooms and 445 bedrooms had valid data of household airborne fungi, and their mean concentrations were 301 cfu/m3 and 310 cfu/m3, respectively. In the multiple logistic regression analyses with adjusting for potential confounders, most associations of 16 studied illnesses with airborne fungi concentration were not statistically significant. Taking children in the 1st quartile that was stratified according to airborne fungi concentration in the living room as reference, only children in the 3rd quartile were significantly associated with a higher odd of lifetime-ever ear infections (adjusted OR, 95% CI 3.05, 1.29–7.21), and children in the 4th quartile were significantly associated with a higher odd of lifetime-ever wheeze (2.72, 1.28–5.75); but children in the 3rd quartile (0.33, 0.17–0.68) and in the 4th quartile (0.47, 0.23–0.97) were significantly associated with a lower odd of rhinitis in the past 12 months prior to the home inspection. Our results indicate that exposures to indoor airborne fungi in low concentrations seemingly have no significant impacts on the risks of most allergic and airway illnesses in childhood. Since families with sick participants might pay more attention to improve indoor air quality, effects of "avoidance behavior" on associations between indoor pollutants and childhood health should be considered in the data analysis and design of the nested case-control study. [ABSTRACT FROM AUTHOR]

Numerous research reports have demonstrated that the supply air volumes of cleanrooms areusuallyover-designed to satisfy air cleanliness classes, which may lead to enormous energy waste. In this study, five well-recognised international mathematical models for calculating cleanroom particle concentration were analysed, which are all based on uniform particle distribution in the cleanroom, indoor particle conservation, and mass airflow balance, and an improved and more general model has been established for calculating the minimum air change rates according to the expected air cleanliness class. Following the introduction of non-dimensional concentration correction factors, based on the least-squares method, the average relative error between the model-predicted and measured particle concentration is approximately 13.5%. Based on the improved model with correction factor, the test results demonstrate that the particle concentration depends mainly on the air change rate, particle emission rate and return airflow patterns, among others. When the air change rate per hour and ratio of particle concentrations between the return airflow and room average were varied from 40 h−1 to 120 h−1 and 0.7–1.3, respectively, the concentration consequently decreased by approximately 65% and 46%. The particle deposition caused by gravity can be neglected for small particles. [ABSTRACT FROM AUTHOR]

In this work, photoelectric responses of nanocrystalline WO film to humidity under UV light irradiation were investigated. Nanocrystalline WO film with porous structure was prepared on AlO substrate by the technology of screen printing and the subsequent heat treatment. The as-prepared nanocrystalline WO film was characterized with X-ray diffraction (XRD) and field-emission gun scanning electron microscopy (FE-SEM). The time-dependent photoelectric responses of nanocrystalline WO film were studied by exposing it to a wide humidity range of 20-80% relative humidity (RH) at room temperature under UV light irradiation. High performance photoelectric responses of nanocrystalline WO film to humidity were observed. To illustrate it, a possible explanation for the photoelectric responses to humidity was proposed. On the basis of the results, the high performance photoelectric responses of WO to humidity will provides a new insight into the design and fabrication of advanced photo-activated humidity sensors. [ABSTRACT FROM AUTHOR]

Purposes: We aim to investigate associations of the child's individual characteristics, building characteristics, home environmental exposures, family lifestyle behaviors, and dietary habits on childhood eczema during lifetime-ever and in the last year before the survey. Methods: During April 2011-April 2012, we conducted a cross-sectional study and collected 13,335 parents-reported questionnaires of 4-6-year-old children from 72 kindergartens in Shanghai, China. Logistic regression model was used to investigate associations. Results: After adjusted for sex, age, family history of atopy, and questionnaire reporter, the factors which were strongly associated (increased odds >30% and p value <0.05) with lifetime-ever eczema included mother employed during pregnancy (adjusted OR 1.33), residence renovated during pregnancy (1.49) and in the child's first year of life (1.31), using laminate (1.58) and solid (1.42) wood as material of floor covering (compared to using cement), residence located in urban district (1.38), and dampness-related exposures in the early residence (mold spots/stains: 1.41; mold odor: 1.41) and in the current residence (water damage: 1.33; damp stains: 1.34; mold spots: 1.32; and windows pane condensation: 1.31). Parental smoking, pet-keeping, and incense-burning had no significant associations with childhood eczema. Similar associations were found for eczema in the last year before the survey. Families with sick children likely changed lifestyle behaviors and dietary habits. Conclusions: Childhood eczema could be influenced by many household environmental and non-environmental factors. Exposures during early lifetime likely have greater impact on childhood eczema than current exposures. Associations of lifestyle behaviors and dietary habits with childhood eczema could be modified by family avoidance behaviors. [ABSTRACT FROM AUTHOR]

In this work, photoelectric responses of TiO and CdS/TiO devices to formaldehyde under UV light irradiation were investigated. Pure TiO film was firstly prepared by screen printing and CdS/TiO hybrid film by the subsequent successive ionic layer adsorption and reaction process. Fundamental characterizations of the as-prepared samples were measured by X-ray diffraction analysis, field-emission gun scanning electron microscopy, energy dispersive X-ray spectrum and high-resolution transmission electron microscope. Photocurrent measurements were utilized to study the photoelectric properties of the as-prepared devices. In comparison with pure TiO, CdS modified TiO hybrid device exhibited an improved UV-irradiated photoelectric response to formaldehyde. It is attributed to the hybrid structure which could increase the separation and restrain the recombination of photogenerated electron-hole pairs. On the basis of the results, the improved photoelectric response of CdS modified TiO should be valuable for the practical applications in fabricating photoelectric gas sensors working at room temperature. [ABSTRACT FROM AUTHOR]

In this paper, nanocrystalline ZnO film with porous structure was successfully prepared on alumina substrate by the technology of screen printing and the subsequent heat treatment. The fundamental characteristics of the as-prepared sample were examined through XRD, FE-SEM, EDX and PL spectra measurements. Meanwhile, photoelectric responses of it were tested under UV and white light irradiation, respectively. Different photocurrent curves were obtained. Under UV light, the photocurrent with comparatively high amplitude of each cycle could mostly recover upon the light off. While for white light, the photocurrent with low amplitude just partially recovered when the light was turned off. This phenomenon indicated that, after the white light off, a large number of free electrons still remained within the materials. To calculate the amount of the remained free electrons, three photocurrent parameters, which are related to the density of free electrons in ZnO, were defined for the first time. Furthermore, the explanations for the different photoelectric responses of ZnO based on the double Schottky barrier model were also proposed. [ABSTRACT FROM AUTHOR]

Whether indoor environmental smoke is harmful for preschool children’s respiratory health in a society where female smoking is rare has not been determined. This study is part of a cross-sectional study (CCHH study-phase one in Shanghai) and investigated associations between parental smoking and incense-burning and respiratory symptoms among 4–6 year old children in Shanghai, China. A number of 13335 valid questionnaires (response rate: 85.3%) were analyzed. A number of 56.1% (as reported by a parent) of preschool children in Shanghai are exposed to environmental tobacco smoke (ETS). A number of 40.3% of fathers and 0.9% of mothers are smokers. A number of 53.7% and 12.6% of Shanghai residents have used mosquito-repellent incense and incensation respectively. Children exposed to any parental smoking have higher prevalence of wheeze and croup than those not exposed. Current maternal smoking has a significant and positive association with wheeze (in the last 12 months, AOR, 95% CI: 1.83, 1.11–2.99). However, paternal smoking either currently or at child’s birth had only weak associations with wheeze and croup. Incense-burning (mosquito-repellent incense and incensation) had significant and negative association with doctor-diagnosed asthma (AOR, 95% CI: 0.85, 0.73–0.99) and hay fever (AOR, 95% CI: 0.80, 0.70–0.93). The results indicate that maternal smoking perhaps is a stronger risk factor for children’s respiratory health than paternal smoking. [ABSTRACT FROM AUTHOR]

Whether early pet-keeping is a risk factor for children’s asthma and allergies remains controversial. To investigate associations between asthma, allergies and airway symptoms among children and the indoor environment, a cross-sectional study was conducted in 5 districts of Shanghai. A number of 13335 questionnaires (response rate: 85.3%) of 4-6 year old children were analyzed. Families in urban areas have more pets except for dogs than families in suburbs. Fish are the most common pets in urban districts. The prevalence of doctor-diagnosed asthma was 10.3%, wheeze (ever) 28.3%, rhinitis (ever) 54.1%, doctor-diagnosed hay fever 12.6% and eczema (ever) 22.9%. In logistic regression analyses, early furred pet-keeping was positively associated with most of the symptoms and significantly with rhinitis (ever, adjusted OR=1.41, 95% CI=1.14–1.76) and doctor-diagnosed hay fever (1.38, 1.02–1.88). Current furred pet-keeping was significantly negatively associated with doctor-diagnosed asthma (0.57, 0.39–0.83). Persistent furred pet-keeping was significantly positively associated with rhinitis on pet or pollen exposure. However, current pet-keeping is not randomly distributed in the population. Children in families with “allergy” or with “pet avoidance behavior” (due to allergies in the family) have more symptoms, but have avoided cats and dogs, leading to the conclusion that such animals are “protective”, namely the “Healthy Pet-Keeping” effect. Moreover, rodents and birds are risks for children’s health. Fish-keeping is also seemingly a risk. This study indicates that early pet-keeping is a risk factor for asthma and allergies in families with a history of allergies, and part of residents in Shanghai have pet-avoidance behavior. [ABSTRACT FROM AUTHOR]

We studied plain TiO and CdS/TiO nanocomposite photoelectrode by testing their photocurrent response in gas phase. The CdS/TiO nanocomposite photoelectrode was prepared by the technology of screen printing and the successive ionic layer adsorption and reaction process. In comparison with the plain TiO photoelectrode, the CdS/TiO nanocomposite photoelectrode showed an extraordinary enhancement on the photocurrent amplitude. Under the irradiation of UV light and under 1, 5, and 10 V bias, respectively, the photocurrent amplitude of CdS/TiO nanocomposite photoelectrode was 37, 95, and 151 times higher than that of the plain TiO. To explain these distinctive phenomenon, we conclude that CdS not only acts as a sensitizer in the CdS/TiO nanocomposite, but also acts as a hole capturer. This conclusion was clearly demonstrated by the subsequent reproducible photocurrent response experiments of the on-off cycles of illumination. [ABSTRACT FROM AUTHOR]