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The aim was to study associations between dialkylphosphates (DAPs), organophosphate (OP) metabolites in urine, biomarkers of OP insecticide exposure, and respiratory symptoms among children in upper northern Thailand. We recruited junior high school children in randomly selected schools in four cities (N = 337), with repeated data collection in wet and dry seasons. Urine was collected and analyzed for six OP metabolites, with creatinine adjustment. Total DAP was expressed as sum of DAPs. Data on respiratory symptoms was collected by a standardized questionnaire. Associations were analyzed by multiple logistic regression. Totally 11.3 % lived in farm families. Total DAPs concentration was higher in dry season (p = 0.002) but did not differ between farm and non-farm children. Total DAPs in wet season was associated with current wheeze (p = 0.019), current asthma attacks (p = 0.012) and attacks of breathlessness in last 12 months (p = 0.021). Total DAPs in dry season was associated with current wheeze (p = 0.042), and associations between DAPs and respiratory symptoms were stronger for dimethylphosphate metabolites (DMPs) than for diethylphosphate metabolites (DEPs). DMPs are produced by certain OP pesticides. Biomass burning inside or outside the home, and dampness or mold at home, enhanced the association between total DAPs and attacks of breathlessness. In conclusion, OP pesticide exposure, measured as urinary DAPs, was higher in dry season and similar in farm and non-farm children. OPs exposure, especially to DMP related pesticides, can increase asthmatic symptoms, especially in wet season. Combined exposure to OP and smoke from biomass burning, or dampness and mold, can further increase the prevalence of attacks of breathlessness. There is a need to reduce OP insecticide and biomass smoke exposure among Thai children. Since different pesticides can be used in different seasons, studies on respiratory health effects of OPs pesticide exposure should be done in different seasons., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Objective: To study associations between fractional exhaled nitric oxide (FeNO) and asthma, airway symptoms, sensitization to common allergens, outdoor pollution and home environment among 380 students in eight junior high schools in two areas in Indonesia., Methods: Data on health and home were collected by a face-to face interview before measuring FeNO and performing skin prick test against common allergens. Exploratory linear mixed and logistic regression models were employed., Results: Geometric mean of FeNO was 17.8 ppb (GSD 2.09) and 139 students (36.6%) had elevated FeNO (>20 ppb). In total, 107 students (28.2%) were sensitized to house dust mite (HDM) (Der p1 or Der f1), 4 (1.1%) to cat and 3 (0.8%) to mold ( Cladosporium or Alternaria ). Moreover, 20 students (5.3%) had diagnosed asthma, 38 (10.0%) had current wheeze, and 107 (28.2%) had current rhinitis. HDM sensitization, diagnosed asthma, current wheeze, and current rhinitis were associated with FeNO. In total, 281 students (73.9%) had mold or dampness, 232 (61.1%) had environmental tobacco smoke (ETS) and 43 (11.3%) had other odor at home. Indoor mold or dampness and other odor at home were associated with FeNO. ETS was negatively associated with FeNO., Conclusion: HDM sensitization and elevated FeNO can be common among children in this part of Indonesia. The high prevalence of elevated FeNO indicate that undiagnosed childhood asthma is common. Dampness, mold and odor at home can be associated with increased FeNO while ETS can be associated with decreased FeNO.

The impact of early life exposure to residential greenness on childhood rhinitis and its interaction with particulate matter (PM) of different size fractions remain inconsistent. Herein, we recruited 40,486 preschool children from randomly selected daycare centers in 7 cities in China from 2019 to 2020, and estimated exposure to residential greenness by the normalized difference vegetation index (NDVI) with a 500 m buffer. Exposure to ambient PM (PM 1 , PM 2.5, and PM 10 ) was evaluated using a satellite-based prediction model (daily, at a resolution of 1 km × 1 km). By mixed-effect logistic regression, NDVI values during pregnancy, in the first (0-1 year old) and the second (1-2 years old) year of life were negatively associated with lifetime rhinitis (LR) and current rhinitis (CR) (P < 0.001). PM in the same time windows was associated with increased risks of LR and CR in children, with smaller size fraction of PM showing greater associations. The negative associations between prenatal and postnatal NDVI and LR and CR in preschool children remained robust after adjusting for concomitant exposure to PM, whereas the associations of postnatal NDVI and rhinitis showed significant interactions with PM. At lower levels of PM, postnatal NDVI remained negatively associated with rhinitis and was partly mediated by PM (10.0-40.9 %), while at higher levels of PM, the negative associations disappeared or even turned positive. The cut-off levels of PM were identified for each size fraction of PM. In conclusion, prenatal exposure to greenness had robust impacts in lowering the risk of childhood rhinitis, while postnatal exposure to greenness depended on the co-exposure levels to PM. This study revealed the complex interplay of greenness and PM on rhinitis in children. The exposure time window in prenatal or postnatal period and postnatal concomitant PM levels played important roles in influencing the associations between greenness, PM and rhinitis., Competing Interests: Declaration of competing interest None of the authors declares any conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Few studies focus on the associations of green space composition and configuration with children's allergic rhinitis (AR)., Methods: A multi-center population-based cross-sectional study was performed in 7 cities in mainland of China between 2019 and 2020, recruiting 36,867 preschool children. Information on the current AR symptoms and demographics were collected by questionnaire. Exposure to residential greenness was estimated by Normalized Difference Vegetation Index (NDVI, 1000 m buffer) around the residences. Greenness composition was estimated in 3 main categories: forest, grassland, shrubland. Configuration of each category and total greenness (a spatial resolution of 10 m × 10 m) was estimated by 6 landscape pattern metrics to quantify their area, shape complexity, aggregation, connectivity, and patch density. Exposure to daily ambient particulate matter (PM 1 , PM 2.5 and PM 10 , a spatial resolution of 1 km × 1 km) was estimated. Multilevel logistic regression models were applied to analyze the associations of greenness and its composition and configuration with AR, and mediation effects by PMs were examined by mediation analysis models., Results: The prevalence of self-reported current AR in preschool children was 33.1%. Two indicators of forest, Aggregation Index of forest patches (AIforest) (odds ratio (OR):0.92, 95% Confidential Interval (CI): 0.88-0.97), and Patch Cohesion of forest (COHESIONforest) (OR: 0.93, 95% CI:0.89-0.98) showed significantly negative associations with AR symptoms. Mediation analyses found the associations were partially mediated by PMs. Age, exclusive breastfeed duration and season were the potential effect modifiers. The associations varied across seven cities., Conclusion: Our findings suggest the inverse associations of the aggregation and connectivity of forest patches surrounding residence addresses with AR symptoms. Since the cross-sectional study only provides associations rather than causation, further studies are needed to confirm our results as well as the underlying mechanisms., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Zhuohui zhao reports financial support was provided by the Shanghai 3-year Public Health Action Plan [grant numbers GWVI-11.2-XD11]. Zhuohui zhao reports financial support was provided by Shanghai International Science and Technology Partnership Project (No. 21230780200). Zhuohui zhao reports financial support was provided by Shanghai B&R Joint Laboratory Project [grant numbers No.22230750300]., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Airborne particulate matter pollution has been linked to occurrence of childhood allergic rhinitis (AR). However, the relationships between exposure to particulate matter with an aerodynamic diameter ≤1 μm (PM 1 ) during early life (in utero and first year of life) and the onset of childhood AR remain largely unknown. This study aims to investigate potential associations of in utero and first-year exposures to size-segregated PMs, including PM 1 , PM 1-2.5 , PM 2.5 , PM 2.5-10 , and PM 10 , with childhood AR., Methods: We investigated 29286 preschool children aged 3-6 years in 7 Chinese major cities during 2019-2020 as the Phase II of the China Children, Families, Health Study. Machine learning-based space-time models were utilized to estimate early-life residential exposure to PM 1 , PM 2.5 , and PM 10 at 1 × 1-km resolutions. The concentrations of PM 1-2.5 and PM 2.5-10 were calculated by subtracting PM 1 from PM 2.5 and PM 2.5 from PM 10 , respectively. Multiple mixed-effects logistic models were used to assess the odds ratios (ORs) and 95% confidence intervals (CIs) of childhood AR associated with per 10-μg/m 3 increase in exposure to particulate air pollution during in utero period and the first year of life., Results: Among the 29286 children surveyed (mean ± standard deviation, 4.9 ± 0.9 years), 3652 (12.5%) were reported to be diagnosed with AR. Average PM 1 concentrations during in utero period and the first year since birth were 36.3 ± 8.6 μg/m 3 and 33.1 ± 6.9 μg/m 3 , respectively. Exposure to PM 1 and PM 2.5 during pregnancy and the first year of life was associated with an increased risk of AR in children, and the OR estimates were higher for each 10-μg/m 3 increase in PM 1 than for PM 2.5 (e.g., 1.132 [95% CI: 1.022-1.254] vs. 1.079 [95% CI: 1.014-1.149] in pregnancy; 1.151 [95% CI: 1.014-1.306] vs. 1.095 [95% CI: 1.008-1.189] in the first year of life). No associations were observed between AR and both pre- and post-natal exposure to PM 1-2.5 , indicating that PM 1 rather than PM 1-2.5 contributed to the association between PM 2.5 and childhood AR. In trimester-stratified analysis, childhood AR was only found to be associated with exposure to PM 1 (OR = 1.077, 95% CI: 1.027-1.128), PM 2.5 (OR = 1.048, 95% CI: 1.018-1.078), and PM 10 (OR = 1.032, 95% CI: 1.007-1.058) during the third trimester of pregnancy. Subgroup analysis suggested stronger PM-AR associations among younger (<5 years old) and winter-born children., Conclusions: Prenatal and postnatal exposures to ambient PM 1 and PM 2.5 were associated with an increased risk of childhood AR, and PM 2.5 -related hazards could be predominantly attributed to PM 1 . These findings highlighted public health significance of formulating air quality guideline for ambient PM 1 in mitigating children's AR burden caused by particulate air pollution., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Gas cooking is an important source of indoor air pollutants, and there is some limited evidence that it might adversely be associated with respiratory health. Using repeated cross-sectional data from the multi-centre international European Community Respiratory Health Survey, we assessed whether adults using gas cookers have increased risk of respiratory symptoms compared to those using electric cookers and tested whether there was effect modification by a priori selected factors., Methods: Data on respiratory symptoms and gas cooking were collected from participants at 26-55 and 38-67 years (median time between examinations 11.4 years) from interviewer-led questionnaires. Repeated associations between gas cooking (versus electric) and respiratory symptoms were estimated using multivariable mixed-effects logistic regression models adjusted for age, sex, study arm, smoking status, education level, and included random intercepts for participants within study centres. Analyses were repeated using a 3-level variable for type of cooker and gas source. Effect modification by ventilation habits, cooking duration, sex, age atopy, asthma, and study arm were examined., Results: The sample included 4337 adults (43.7% males) from 19 centres in 9 countries. Gas cooking increased the risk of "shortness of breath whilst at rest" (OR = 1.38; 95%CI: 1.06-1.79) and "wheeze with breathlessness" (1.32; 1.00-1.74). For several other symptoms, effect estimates were larger in those who used both gas hobs and ovens, had a bottled gas source and cooked for over 60 min per day. Stratifying results by sex and age found stronger associations in females and younger adults., Conclusion: This multi-centre international study, using repeat data, suggested using gas cookers in the home was more strongly associated than electric cookers with certain respiratory symptoms in adults. As gas cooking is common, these results may play an important role in population respiratory health., Competing Interests: Declaration of competing interest None., (Copyright © 2023 The Authors. Published by Elsevier GmbH.. All rights reserved.)

Previous studies have reported the association between particulate matter (PM) and childhood allergic rhinitis (AR). However, it is unclear whether food allergy (FA) modifies the PM-AR association. We aimed at evaluating the effect of the modification of FA on PM-AR association in preschool children. We adopted a cross-sectional study and conducted a questionnaire survey among preschool children aged 3-6 years in 7 cities in China from June 2019 to June 2020 to collect information on AR and FA. We used a combination of multilevel logistic regression and restricted cubic spline functions to quantitatively assess whether FA modifies the associations between size-specific PM exposure (1 × 1 km) and the risk of AR. The adjusted odds ratios (ORs) for AR among the children with FA as per a 10 μg/m 3 increase in early life PM 1 , PM 2.5 , and PM 10 were significantly higher than the corresponding ORs among the children without FA [e.g., OR: 1.58, 95% CI: (1.32, 1.90) vs 1.29, 95% CI: (1.18, 1.41), per 10 μg/m 3 increase in PM 1 ]. The interactions between FA and size-specific PM exposure and their effects on AR were statistically significant (all p -int < 0.001). FA, as an important part of the allergic disease progression, may modify the PM-AR association in preschool children.

We studied associations between fractional exhaled nitric oxide (FeNO), health and household exposure among school children (N = 348) in Penang, Malaysia. Multiple logistic regression and linear mixed models were applied. Overall, 46.0% had elevated FeNO (>20 ppb) and 10.6% diagnosed asthma. Male gender (p = 0.002), parental asthma or allergy (p = 0.047), cat allergy (p = 0.009) and seafood allergy (p < 0.001), diagnosed asthma (p = 0.001), wheeze (p = 0.001), ocular symptoms (p = 0.001), rhinitis (p = 0.002) and respiratory infections (p = 0.004) were all associated with FeNO. Students exposed to ETS had lower FeNO (p = 0.05). Dampness and mould was associated with wheeze (p = 0.038), especially in wooden homes (interaction p = 0.042) and among students with elevated FeNO (interaction p = 0.024). Cat keeping increased rhinitis (p = 0.041) and respiratory infections (p = 0.008) and modified the dampness associations. In conclusion, FeNO can be associated with ocular and respiratory symptoms. Elevated FeNO, cat keeping and a wooden house can enhance the risk of wheeze when exposed to dampness and mould.

We studied risk factors for rhinitis in Japanese homes and schools. A questionnaire was sent to students in four schools (12-15 y age), 1048 (99.2%) participated. Crowdedness and furry pet allergens were measured in their classrooms. Household environment data was collected by a questionnaire. Risk factors were identified by multi-level logistic regression with mutual adjustment. The prevalence of current rhinitis was 60.3%, current rhinoconjunctivitis 24.4% and weekly rhinitis 29.5%. Window condensation (AORs1.69-1.90) and indoor painting (AORs1.72-1.76) at home were associated with rhinitis. The association between painting and rhinitis was stronger in girls (interaction p  = 0.002) and in wooden homes (interaction p  = 0.05). Dog allergen (Can f 1) in classroom air was associated with rhinitis ( p  = 0.04). In conclusion, window pane condensation and indoor painting can be household risk factors for rhinitis and dog allergen may be a risk factor in Japanese schools. Girls can be more sensitive to emissions from indoor paint than boys.

Exposure to polycyclic aromatic hydrocarbons (PAHs) can be associated with different types of health effects. However, the systemic changes of health effects between fluctuations of PAHs exposure have not been established. In this study, urinary hydroxylated PAHs (OH-PAHs) and 12 biomarkers were determined among 36 students from the urban to the suburb in Taiyuan in 2019. The concentration of Σ 12 OH-PAHs in urban areas (28.2 and 21.4 μg/g Cr) was significantly higher than that in suburban area (16.8 μg/g Cr). The regression showed that hydroxy-phenanthrene (OH-Phe, 1/2/3/4/9-OH-Phe) was significantly positively correlated with lung function (PEF 25 and PEF 50 ), 8-hydroxydeoxyguanosine (8-OHdG), interleukin-8 (IL-8), and fractional exhaled nitric oxide (FeNO). Moreover, there were negative associations of 2-hydroxyfluorene (2-OH-Flu) with FVC and FEV 1 . 1 unit increase of 1-hydroxypyrene (1-OH-Pyr) was negatively associated with 18.8% FVC, 17.3% FEV 1 , and 26.4% PEF 25 in the suburban location, respectively. During urban 2 , each unit change of 2-OH-Flu was associated with 10.9% FVC and 10.5% FEV 1 decrease, which were higher than those in suburban location. 8-OHdG decreased by 32.0% with each unit increase in 3-hydroxyfluorene (3-OH-Flu) during urban 2 (p < 0.05), while 1.9% in the suburban location. During the suburban period, the increase in OH-Phe was correlated with the decrease in malondialdehyde (MDA). The respiratory damage caused by PAHs in the urban disappeared after backing to the urban from the suburban area. Notably, despite the total significant liner mixed regression association of FeNO with multiple OH-PAHs, the association of FeNO with OH-PAHs was not significant during different periods except for 2-OH-Flu. Our findings suggested that short-term exposure to different concentrations of PAHs might cause changes in health effects and called for further research to investigate possible alterations between health effects and PAH exposure., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: Few studies exist on environmental risk factors for respiratory infections in Thai school children., Aim: To study associations between home and outdoor environment and respiratory infections among school children in Northern Thailand in dry and wet season., Methods: A repeated questionnaire survey among the children (N = 1159). Data on ambient temperature and relative air humidity (RH) and PM 10 and ozone was collected from nearby monitoring stations. We used logistic regression to calculate odds ratios (OR)., Results: 14.1% had current respiratory infections (last 7 days), 32.1% had any respiratory infection last 3 months, and 26.1% had any respiratory infection last 12 months with antibiotic treatment. Students with diagnosed allergy (7.7%) and diagnosed asthma (4.7%) had more often respiratory infections (ORs 1.40-5.40; p < 0.05). Current respiratory infections were more common in dry (18.1%) than in wet season (10.4%) (p < 0.001) and was associated with indoor mould (OR 2.16; p = 0.024) and outdoor RH (OR 1.34 per 10% RH; p = 0.004.) in the total material. In wet season, mould (OR 2.32; p = 0.016), window pane condensation (OR 1.79; p = 0.050), water leakage (OR 1.82; p = 0.018), environmental tobacco smoke (ETS) (OR 2.34; p = 0.003) and outdoor RH (OR 2.70 per 10% RH; p = 0.01) were risk factors for current respiratory infections. In dry season, mould (OR 2.64; p = 0.004) and outdoor RH (OR 1.34 per 10% RH; p = 0.046) were associated with current respiratory infections. Irrespectively of season, biomass burning inside or outside the home was a risk factor for respiratory infections (ORs 1.32-2.34; p < 0.05). Living in a wooden house decreased the risk of respiratory infections (OR 0.56: p = 0.006)., Conclusions: Dry season, high outdoor RH, household dampness, indoor mould and ETS can increase childhood respiratory infections. Living in a traditional wooden house can reduce respiratory infections, possibly due to better natural ventilation. Smoke from biomass burning can increase childhood respiratory infections in northern Thailand., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Airborne bacteria and endotoxin may affect asthma and allergies. However, there is limited understanding of the environmental determinants that influence them. This study investigated the airborne microbiomes in the homes of 1038 participants from five cities in Northern Europe: Aarhus, Bergen, Reykjavik, Tartu, and Uppsala. Airborne dust particles were sampled with electrostatic dust fall collectors (EDCs) from the participants' bedrooms. The dust washed from the EDCs' clothes was used to extract DNA and endotoxin. The DNA extracts were used for quantitative polymerase chain (qPCR) measurement and 16S rRNA gene sequencing, while endotoxin was measured using the kinetic chromogenic limulus amoebocyte lysate (LAL) assay. The results showed that households in Tartu and Aarhus had a higher bacterial load and diversity than those in Bergen and Reykjavik, possibly due to elevated concentrations of outdoor bacterial taxa associated with low precipitation and high wind speeds. Bergen-Tartu had the highest difference (ANOSIM R = 0.203) in β diversity. Multivariate regression models showed that α diversity indices and bacterial and endotoxin loads were positively associated with the occupants' age, number of occupants, cleaning frequency, presence of dogs, and age of the house. Further studies are needed to understand how meteorological factors influence the indoor bacterial community in light of climate change.

We investigated associations between domestic exposure and respiratory health in students inNorthern Thailand in wet and dry season (1159 participants), calculating odds ratios (OR) with 95% confidence intervals (CI) by multilevel logistic regression. Totally 6.0% had wheeze, 23.0% dyspnoea, 4.0% current asthma, 54.6% rhinitis and 31.5% rhinoconjunctivitis. Girls had less wheeze (OR 0.66; 95% CI 0.43-1.00) and current asthma (OR 0.32; 95% CI 0.19-0.54). Water leakage was associated with wheeze (OR 2.35; 95% CI 1.09-5.06), dyspnea (OR 2.00; 95% CI 1.24-3.23) and rhinoconjunctivitis (OR 1.62; 95% CI 1.11-2.38). Mould was associated with rhinitis (OR 1.89; 95% CI 1.06-3.38). Window pane condensation was associated with wheeze (OR 2.60; 95% CI 1.13-5.98) and rhinoconjunctivitis (OR 1.70; 95% CI 1.08-2.67). Biomass burning was associated with wheeze, dyspnoea, rhinitis and rhinoconjunctivitis. In conclusion, household dampness and pollution from domestic biomass burning can increase asthma symptoms and rhinitis symptoms in students in northern Thailand.

Rhinitis is one of the most prevalent chronic diseases globally. Microbiome exposure affects the occurrence of rhinitis. However, previous studies did not differentiate allergic rhinitis (AR) and non-allergic rhinitis (NAR) in the microbial association analysis. In this study, we investigate 347 students in 8 junior high schools, Terengganu, Malaysia, who were categorized as healthy (70.9%), AR (13.8%) and NAR (15.3%) based on a self-administered questionnaire and skin prick tests of pollen, pet, mould and house dust mite allergens. Classroom microbial and metabolite exposure in vacuumed dust was characterized by PacBio long-read amplicon sequencing, quantitative PCR and LC-MS-based untargeted metabolomics. Our findings indicate a similar microbial association pattern between AR and NAR. The richness in Gammaproteobacteria was negatively associated with AR and NAR symptoms, whereas total fungal richness was positively associated with AR and NAR symptoms ( p < 0.05). Brasilonema bromeliae and Aeromonas enteropelogenes were negatively associated with AR and NAR, and Deinococcus was positively associated with AR and NAR ( p < 0.01). Pipecolic acid was protectively associated with AR and NAR symptoms (OR = 0.06 and 0.13, p = 0.009 and 0.045). A neural network analysis showed that B. bromeliae was co-occurring with pipecolic acid, suggesting that the protective role of this species may be mediated by releasing pipecolic acid. Indoor relative humidity and the weight of vacuum dust were associated with AR and NAR, respectively ( p < 0.05), but the health effects were mediated by two protective bacterial species, Aliinostoc morphoplasticum and Ilumatobacter fluminis . Overall, our study reported a similar microbial association pattern between AR and NAR and also revealed the complex interactions between microbial species, environmental characteristics, and rhinitis symptoms.

Associations between measured specific VOC reported to be associated with dampness and microbial growth in dwellings and asthma, lung function were investigated in 159 adults (one adult/home) from three North European cities (Reykjavik, Uppsala and Tartu). Spirometry was performed and forced vital capacity (FVC), forced expiratory volume in 1 s (FEV 1 ) and FEV 1 /FVC were measured. Among 159 participants, 58% were females, 24.5% atopics, 25.8% current smokers and 41% reported dampness or mold at home. Dimethyl disulphide (p = 0.004), ethyl isobutyrate (p = 0.021) and ethyl 2-methylbutyrate (p = 0.035) were associated with asthma. Isobutanol (p = 0.043), 3-methyl-1-butanol (p = 0.020), 2-hexanone (p = 0.033), 1-octen-3-ol (p = 0.027), 2-methyl-1-butanol (p = 0.022) and 2-ethyl-1-hexanol (p = 0.045) were associated with lower FEV 1 . Isobutanol (p = 0.004), 3-methyl-1-butanol (p = 0.001), 2-heptanone (p = 0.047) and 2-methyl-1-butanol (p = 0.002) were associated with lower FEV 1 /FVC. The association between dimethyl disulphide and asthma was more pronounced in females (p for interaction 0.099). The association between 1-butanol and lower FEV 1 was more pronounced in males (p for interaction 0.046). The associations between 3-octanone (p for interaction 0.064), 2-ethyl-1-hexanol (p for interaction 0.049) and lower FEV 1 , and between 2-heptanone (p for interaction 0.021), 3-octanone (p for interaction 0.008) and lower FEV 1 /FVC were stronger in homes with dampness/mold. Factor analysis identified one VOC factor related to asthma and two VOC factors related to lower lung function. Increased air concentrations of 2-heptanone, ethyl 2-methylbutyrate and ethyl isobutyrate were related to prescence of certain mold species (Aspergillus sp., Cladosporum sp. and Penicillium sp.) or building dampness. Some VOC were associated with type of dwelling, building age and pet keeping. In conclusion, some VOC reported to be associated with dampness and microbial growth can be associated with asthma and lower lung function in adults. Associations between these VOC and respiratory illness can be stronger in homes with dampness/mold. There can be gender differences in respiratory health effects when exposed to indoor VOC., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Passengers are at a higher risk of respiratory infections and chronic diseases due to microbial exposure in airline cabins. However, the presence of virulence factors (VFs), antimicrobial resistance genes (ARGs), metabolites, and chemicals are yet to be studied. To address this gap, we collected dust samples from the cabins of two airlines, one with textile seats (TSC) and one with leather seats (LSC), and analyzed the exposure using shotgun metagenomics and LC/MS. Results showed that the abundances of 17 VFs and 11 risk chemicals were significantly higher in TSC than LSC ( p < 0.01). The predominant VFs in TSC were related to adherence, biofilm formation, and immune modulation, mainly derived from facultative pathogens such as Haemophilus parainfluenzae and Streptococcus pneumoniae . The predominant risk chemicals in TSC included pesticides/herbicides (carbofuran, bromacil, and propazine) and detergents (triethanolamine, diethanolamine, and diethyl phthalate). The abundances of these VFs and detergents followed the trend of TSC > LSC > school classrooms ( p < 0.01), potentially explaining the higher incidence of infectious and chronic inflammatory diseases in aircraft. The level of ARGs in aircraft was similar to that in school environments. This is the first multi-omic survey in commercial aircraft, highlighting that surface material choice is a potential intervention strategy for improving passenger health.

Background: This study investigated associations of self-rated health (SRH), recovery from work, fatigue, and insomnia with working conditions, the psychosocial work environment, lifestyle, and sense of coherence (SOC) among commercial pilots., Methods: A standardized questionnaire was sent to all pilots in an airline company, of whom 354 (61%) responded. Associations were analyzed via ordinal and logistic regression with mutual adjustment., Results: Overall, 21.8% of participants reported low SRH, 13.0% reported not recovering from work during their free time, 61.9% experienced fatigue, and 70.6% experienced insomnia symptoms. A high level of demand at work was associated with poor SRH and more fatigue, and low social support at work was associated with insomnia and poorer recovery from work. Habits surrounding exercise and BMI were associated with SRH. Part-time pilots and captains reported experiencing better recovery from work than their counterparts, while female pilots and younger pilots reported less fatigue. Amount of free time after work and the type of airplane operated were associated with experience of insomnia symptoms. Finally, having a strong sense of coherence was protectively associated with all health outcomes., Conclusion: The psychosocial environment at work is essential for the health of pilots, and a strong sense of coherence can be protective. Occupational conditions may influence recovery from work, fatigue, and insomnia. Moreover, engaging in exercise, maintaining a healthy weight, working part-time, and having more free time after the working day could improve pilots' health., 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., (Copyright © 2023 Fu, Du, Chen, Norbäck, Lindgren, Janson and Runeson-Broberg.)

Background: The rapid increase of food allergy (FA) has become the "second wave" of allergy epidemic and is now a major global public health concern. Mounting evidence indicates that early life exposure to air pollution is associated with the "first wave" of allergy epidemic (including asthma, allergic rhinitis and eczema) in children, but little is known about its association with FA., Objectives: We hypothesize FA has triple exposure pathways, gut-skin-airway, and investigate the effects of airway exposure to outdoor and indoor air pollution on childhood FA., Methods: A cohort study of 2598 preschool children aged 3-6 years old was conducted in Changsha, China. The prevalence of FA was surveyed using a standard questionnaire by International Study of Asthma and Allergies in Childhood (ISAAC). Exposure to indoor air pollution was assessed by four indicators: new furniture, redecoration, mold or dampness, and window condensation. Exposure to outdoor air pollution was evaluated by the concentrations of PM10, SO2 and NO2, which were obtained from the monitored stations. Both prenatal and postnatal exposure windows were considered. The association between exposure to outdoor/indoor air pollution and childhood FA was estimated by multiple logistic regression models using odds ratio (OR) and a 95% confidence interval (CI)., Results: A total of 14.9% children reported FA. The prevalence was significantly associated with exposure to indoor air pollution, OR (95% CI) = 1.93 (1.35-2.75) for prenatal exposure to mold/dampness and 1.49 (1.07-2.10) and 1.41 (1.04-1.89) respectively for postnatal exposure to new furniture and window condensation. The prevalence of FA was also associated with prenatal and postnatal exposure to outdoor air pollution, particularly the traffic-related air pollutant NO2, with adjusted ORs (95% Cls) respectively 1.24 (1.00-1.54) and 1.38 (1.03-1.85) per interquartile range (IQR) increase. Sensitivity analysis showed that the association between outdoor/indoor air pollution and childhood FA was significant only in young children aged 3-4 years., Conclusion: Early-life exposure to high levels of outdoor and indoor air pollution in China due to the rapid economic growth and fast urbanization in the past decades may contribute to the rapid increase of food allergy (FA) in children. Our study indicates that, in addition to gut and skin, airway may be a new route of food sensitization. Air pollution leads to the first and second waves of allergy epidemics, suggesting a concept of 'one allergy' disease., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper, (Copyright © 2022 Elsevier Inc. All rights reserved.)

Fungi exposure has been significantly linked to respiratory illness. However, numerous fungi taxa that are potentially allergenic still undocumented and leave a barrier to establishing a clear connection between exposure and health risks. This study aimed to evaluate the association of fungi composition in settled dust with fractional exhaled nitric oxide (FeNO) levels among school children with doctor-diagnosed asthma. A cross-sectional study was undertaken among secondary school students in eight schools in the urban area of Hulu Langat, Selangor, Malaysia. A total of 470 school children (aged 14 years old) were randomly selected and their FeNO levels were measured and allergic skin prick tests were conducted. The settled dust samples were collected and analysed by using metagenomic technique to determine the fungi composition. The general linear regression with complex sampling was employed to determine the interrelationship. In total, 2645 fungal operational taxonomic units (OTUs) were characterised from the sequencing process which belongs to Ascomycota (60.7 %), Basidiomycota (36.4 %), Glomeromycota (2.9 %) and Chytridiomycota (0.04 %). The top five mostly abundance in all dust samples were Aspergillus clavatus (27.2 %), followed by Hyphoderma multicystidium (12.2 %), Verrucoconiothyrium prosopidis (9.4 %), Ganoderma tuberculosum (9.2 %), and Heterochaete shearii (7.2 %). The regression results indicated that A. clavatus, Brycekendrickomyces acaciae, Candida parapsilosis, Hazslinszkyomyces aloes, H. multicystidium, H. shearii, Starmerella meliponinorum, V. prosopidis were associated in increased of FeNO levels among the asthmatic group at 0.992 ppb (95 % CI = 0.34-1.68), 2.887 ppb (95 % CI = 2.09-3.76), 0.809 ppb (95 % CI = 0.14-1.49), 0.647 ppb (95 % CI = 0.36-0.94), 1.442 ppb (95 % CI = 0.29-2.61), 1.757 ppb (95 % CI = 0.59-2.87), 1.092 ppb (95 % CI = 0.43-1.75) and 1.088 ppb (95 % CI = 0.51-1.62), respectively. To our knowledge, this is a new finding. The findings pointed out that metagenomics profiling of fungi could enhance our understanding of a complex interrelation between rare and unculturable fungi with airway inflammation., Competing Interests: Declaration of competing interest The authors declare that they have no conflicts of interest., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

We studied home environment exposures in relation to asthma, allergic rhinitis and atopic dermatitis among offspring of participants (parents) in the Respiratory Health in Northern Europe (RHINE) study (age ≤ 30 y). Totally 17,881 offspring from Iceland, Norway, Sweden, Denmark and Estonia were included. Home environment exposures, including dampness and mold, type of dwelling, construction year and indoor painting were registered through a questionnaire answered by parents in the first follow up (RHINE II). The parents reported ten years later with in the frame of RHINE III offspring's birth year and offspring's asthma, allergic rhinitis, atopic dermatitis. They also reported dampness and mold at home from RHINE II to RHINE III. The prevalence of offspring's asthma before 10 y, asthma after 10 y, allergic rhinitis at any age and atopic dermatitis at any age were 9.7 %, 4.3 %, 15.6 % and 17.3 %, respectively. Asthma before 10 y was related to any indoor painting at RHINE II (OR = 1.14, 95%CI (1.02, 1.29)). Asthma after 10 y was associated with dampness/mold at home (OR = 1.33-1.62) and living in the newest buildings (constructed in 1986-2001) (OR = 1.30, 95%CI (1.02, 1.66)). Allergic rhinitis was associated with living in newer buildings (constructed in 1961-2001) (OR = 1.16-1.24). Atopic dermatitis was associated with visible mold (OR = 1.35, 95%CI(1.12, 1.62)), dampness/mold at home (OR = 1.18-1.38), living in apartments (OR = 1.22, 95%CI(1.10, 1.35)) and living in newer buildings (constructed in 1961-2001) (OR = 1.14-1.25). There were dose-response effects of dampness and mold on offspring's asthma after 10 y and atopic dermatitis (20 years exposure vs. 10 years exposure). Older offspring had increased risk of developing asthma after 10 y and atopic dermatitis. In conclusion, home dampness and mold, living in apartments, living in newer buildings and indoor painting were associated with offspring's asthma or allergic diseases. Stronger health effects were found among offspring with prolonged exposure of dampness/mold., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Indoor microbial exposure is associated with asthma, but the health effects of indoor metabolites and chemicals have not been comprehensively assessed., Methods: We collected classroom dust from 24 junior high schools in three geographically distanced areas in Malaysia (Johor Bahru, Terengganu and Penang), and conducted culture-independent high-throughput microbiome and untargeted metabolomics/chemical profiling., Results: 1290 students were surveyed for asthma symptoms (wheeze). In each centre, we found significant variation in the prevalence of wheeze among schools, which could be explained by personal characteristics and air pollutants. Large-scale microbial variations were observed between the three centres; the potential protective bacteria were mainly from phyla Actinobacteria in Johor Bahru, Cyanobacteria in Terengganu and Proteobacteria in Penang. In total, 2633 metabolites and chemicals were characterised. Many metabolites were enriched in low-wheeze schools, including plant secondary metabolites flavonoids/isoflavonoids (isoliquiritigenin, formononetin, astragalin), indole and derivatives (indole, serotonin, 1 H -indole-3-carboxaldehyde), and others (biotin, chavicol). A neural network analysis showed that the indole derivatives were co-occurring with the potential protective microbial taxa, including Actinomycetospora , Fischerella and Truepera , suggesting these microorganisms may pose health effects by releasing indole metabolites. A few synthetic chemicals were enriched in high-wheeze schools, including pesticides (2(3 H )-benzothiazolethione), fragrances (2-aminobenzoic acid, isovaleric acid), detergents and plastics (phthalic acid), and industrial materials (4,4-sulfonyldiphenol)., Conclusions: This is the first association study between high-throughput indoor chemical profiling and asthma symptoms. The consistent results from the three centres indicate that indoor metabolites/chemicals could be a better indicator than the indoor microbiome for environmental and health assessments, providing new insights for asthma prediction, prevention and control., Competing Interests: Conflicts of interest: The authors disclose no conflicts of interest., (Copyright ©The authors 2022.)

Importance: Exposure to particulate matter (PM) has been associated with childhood asthma and wheeze. However, the specific associations between asthma and PM with an aerodynamic equivalent diameter of 1 μm or less (ie, PM1), which is a contributor to PM2.5 and potentially more toxic than PM2.5, remain unclear., Objective: To investigate the association of early-life (prenatal and first year) exposure to size-segregated PM, including PM1, PM1-2.5, PM2.5, PM2.5-10, and PM10, with childhood asthma and wheeze., Design, Setting, and Participants: This cross-sectional study was based on a questionnaire administered between June 2019 and June 2020 to caregivers of children aged 3 to 6 years in 7 Chinese cities (Wuhan, Changsha, Taiyuan, Nanjing, Shanghai, Chongqing, and Urumqi) as the second phase of the China, Children, Homes, Health study., Exposures: Exposure to PM1, PM1-2.5, PM2.5, PM2.5-10, and PM10 during the prenatal period and first year of life., Main Outcomes and Measures: The main outcomes were caregiver-reported childhood asthma and wheeze. A machine learning-based space-time model was applied to estimate early-life PM1, PM2.5, and PM10 exposure at 1 × 1-km resolution. Concentrations of PM1-2.5 and PM2.5-10 were calculated by subtracting PM1 from PM2.5 and PM2.5 from PM10, respectively. Multilevel (city and child) logistic regression models were applied to assess associations., Results: Of 29 418 children whose caregivers completed the survey (15 320 boys [52.1%]; mean [SD] age, 4.9 [0.9] years), 2524 (8.6%) ever had wheeze and 1161 (3.9%) were diagnosed with asthma. Among all children, 18 514 (62.9%) were breastfed for more than 6 months and 787 (2.7%) had parental history of atopy. A total of 22 250 children (75.6%) had a mother with an educational level of university or above. Of the 25 422 children for whom information about cigarette smoking exposure was collected, 576 (2.3%) had a mother who was a current or former smoker during pregnancy and 7525 (29.7%) had passive household cigarette smoke exposure in early life. Early-life PM1, PM2.5, and PM10 exposure were significantly associated with increased risk of childhood asthma, with higher estimates per 10-μg/m3 increase in PM1 (OR, 1.55; 95% CI, 1.27-1.89) than in PM2.5 (OR, 1.14; 95% CI, 1.03-1.26) and PM10 (OR, 1.11; 95% CI, 1.02-1.20). No association was observed between asthma and PM1-2.5 exposure, suggesting that PM1 rather than PM1-2.5 contributed to the association between PM2.5 and childhood asthma. There were significant associations between childhood wheeze and early-life PM1 exposure (OR, 1.23; 95% CI, 1.07-1.41) and PM2.5 exposure (OR, 1.08; 95% CI, 1.01-1.16) per 10-μg/m3 increase in PM1 and PM2.5, respectively., Conclusions and Relevance: In this cross-sectional study, higher estimates were observed for the association between PM with smaller particles, such as PM1, vs PM with larger particles and childhood asthma. The results suggest that the association between PM2.5 and childhood asthma was mainly attributable to PM1.

To investigate the potential associations between household renovation and allergic diseases among preschool children in Wuhan, we conducted a large cross-sectional questionnaire survey among 9455 preschool children aged 3-6 years in Wuhan during November to December 2019. Data on demographics, health status, and home decoration conditions were analysed based on a questionnaire. Compared with tiles/stone/cement floor covering, the use of composite floor significantly increased the risk of diagnosed rhinitis and eczema among children (rhinitis: AOR, 95% CI: 1.36, 1.06-1.73; eczema: AOR, 95% CI: 1.47, 1.17-1.85). Household renovation had significant associations with diagnosed eczema (within 1 year before pregnancy: AOR, 95% CI: 1.34, 1.20-1.50; during pregnancy: AOR, 95% CI: 1.25, 1.08-1.44). This study suggests that use of artificial synthetic materials in home renovation during early childhood and pregnancy may be potential risk factors for childhood asthma, allergic rhinitis, and eczema.

Background: Northern China has severe air pollution, especially in winter. Fractional exhaled nitric oxide (FeNO) is an established biomarker of airway inflammation., Aim: To study associations between ambient temperature, air pollution and FeNO in university students in northern China., Methods: We performed a panel study in 67 university students without asthma diagnosis in the city of Taiyuan. FeNO was measured 6 times, over one heating season. Outdoor PM 10 , PM 2.5 , SO 2 , NO 2 and O 3 were measured at a fixed location in the campus. SO 2 , NO 2 and O 3 were measured 7 days (24 h/day) before the FeNO test. PM 2.5 and PM 10 were measured at different lag times (lag 1 day to lag 7 days). Temperature and carbon monoxide (CO) data were collected from a nearby monitoring station (lag 7). Linear mixed models were applied to study associations between exposure and FeNO, adjusting for gender, age, current smoking, height and furry pet or pollen allergy., Results: The overall geometric mean (GM) of FeNO was 17.2 ppb. GM of FeNO was lowest (12.9 ppb) in January and highest (20.0 ppb) in April. The range of lag 7 pollution was 105.0-339.0 μg/m 3 for PM 10 , 72.0-180.0 μg/m 3 for PM 2.5 , 36.0-347.0 μg/m 3 for SO 2 , 26.0-69.0 μg/m 3 for NO 2 , 31.0-163.0 μg/m 3 for O 3 and 0.93-3.14 mg/m 3 for CO. The lag 7 temperature ranged from -4.5 to 20.1 °C. FeNO was consistently higher at higher outdoor temperature (p < 0.001). In multi-pollutant models with temperature adjustment, PM 10 , PM 2.5 and SO 2 were associated with FeNO (all p-values <0.001). In contrast, CO was negatively associated (protective) with FeNO (p < 0.001). Associations between exposure and FeNO were similar in men and women., Conclusion: PM 10 , PM 2.5 and SO 2 and outdoor temperature can be associated with airway inflammation, measured as FeNO, in young adults in northern China while CO could be negatively associated with FeNO., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: There are few studies on fractional exhaled nitric oxide (FeNO) among children in subtropical areas. We studied associations between FeNO and respiratory symptoms, reported diagnosed allergies and indoor and outdoor environmental factors in first grade junior high school students ( N  = 270) in upper northern Thailand., Methods: Data on demographics, health and home environment were collected by a questionnaire distributed in dry season (February-March 2018). FeNO was measured when the research team visited the school. Daily outdoor pollution data (PM 10 and ozone) were collected from the nearest monitoring station 3 days (lag 3) and 7 days (lag 7) before the FeNO measurements. Two-level (student, school) linear mixed models were used to analyze associations, adjusting for gender and family education level., Results: In total, 29.6% had elevated FeNO level (>20 ppb) and 7.8% reported any allergy diagnosed by a doctor. Male gender ( p  = 0.02), diagnosed allergy ( p  = 0.001), especially to cat ( p  = 0.001) and house dust mite (HDM) allergies ( p  = 0.001) were associated with FeNO. Eye symptoms ( p  = 0.01), rhinitis symptoms ( p  = 0.03) and dyspnea ( p  = 0.05) in the last 3 days were associated with FeNO. Household indoor mold ( p  = 0.03), gas cooking ( p  = 0.03) and PM 10 (lag 3 and lag 7) were negatively (protective) associated with FeNO., Conclusions: Diagnosed allergy, especially to cat and HDM, can be associated with increased FeNO. Indoor mold and gas cooking can be associated with lower FeNO. Ocular, nasal and dyspnea symptoms reported by students in dry season in northern Thailand can be associated with FeNO, a biomarker of Th2 driven airway inflammation.

Background: Although mounting evidence has associated air pollution and environmental temperature with children's health problems, it is unclear whether there is an interaction between these factors on childhood asthma., Objectives: To explore the effects of temperature-pollution interactions during pre- and post-natal periods on asthma among pre-schoolers., Methods: A retrospective cohort study of 39,782 pre-schoolers was performed during 2010-2012, in seven cities in China. Exposure to three temperature indicators (TI) and three critical ambient air pollutants, including particulate matter with aerodynamic diameter ≤ 10 μm (PM 10 ), sulfur dioxide (SO 2 ) and nitrogen dioxide (NO 2 ) as proxies of industrial and vehicular air pollution, was estimated by an inverse distance weighted (IDW) method. Two-level logistical regression analysis was used to examine the association between both pre- and post-natal exposure and childhood asthma in terms of odds ratio (OR) and 95 % confidence interval (CI)., Results: Asthma prevalence in pre-schoolers at age of 3-6 years (6.9 %) was significantly associated with traffic-related air pollutant (NO 2 ) exposure, with ORs (95 % CI) of 1.17 (1.06, 1.28), 1.19 (1.05-1.34) and 1.16 (1.03-1.31) for an IQR increase in NO 2 exposure during lifetime, pregnancy, and entire postnatal period respectively. Furthermore, childhood asthma was positively associated with exposure to increased temperature during lifetime, pregnancy, and entire postnatal period with ORs (95 % CI) = 1.89 (1.66, 2.16), 1.47 (1.34, 1.61), and 1.15 (1.11, 1.18) respectively, while was negatively associated with decreased temperatures. Childhood asthma was positively related with exposure to extreme heat days (EHD) during postnatal period particularly in first year of life respectively with ORs (95 % CI) = 1.23 (1.04, 1.46) and 1.26 (1.07, 1.47), but was not related with extreme cold days (ECD) exposure. A combination of high air pollutant levels and high temperatures significantly increased the risk of asthma during both pre- and post-natal periods. Strikingly, we found a significantly positive interaction of temperature and PM 10 or SO 2 on asthma risk among boys and younger children., Conclusions: Prenatal and postnatal exposure to ambient air pollution and high temperatures are independently and jointly associated with asthma risk in early childhood., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

House dust mites produce well-known allergens for asthma and allergy among children. To study house dust mite allergen exposure level in northeast China and characterize its association with indoor environmental factors and cleaning habits, we inspected 399 homes in Tianjin area and collected dust from mattresses. Dermatophagoides farinae (Der f) and Dermatophagoides pteronyssinus (Der p) were detected by the enzyme-linked immunosorbent assay (ELISA) method. The medians of total allergen concentrations for spring, summer, autumn, and winter were 524 ng/g, 351 ng/g, 1022 ng/g, and 1010 ng/g. High indoor air relative humidity (RH), low air change rate, indoor dampness, and frequent changing of quilt cover/bedsheet/pillow case were significantly associated with high house dust mite allergen concentration (relative risk [RR]: RH, 1.18-1.34; air change rate, 0.97-1.00; dampness, 2.92-3.83; changing quilt cover/bedsheet/pillow case, 0.66-0.75). The decrease in the absolute humidity gradient between indoors and outdoors that occurs with increased air change rate may explain why a high ventilation reduces house dust mite allergen concentration. The findings of this study show the importance of ventilation and cleaning for controlling house dust mite allergens. We found that the decrease in additional absolute humidity (e.g., humidity indoor -humidity outdoor ) with increased air change rate may be the main reason that a high ventilation rate reduces house dust mite allergen concentration. Ventilation and cleaning should be both considered for creating a healthy home environment., (© 2022 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Emerging evidence suggests that early-life (in-utero and first-year since birth) exposure to ambient PM 2.5 is a risk factor for asthma onset and exacerbation among children, while the hazards caused by PM 2.5 compositions remain largely unknown., Objective: To examine potential associations of early-life exposures to PM 2.5 mass and its major chemical constituents with childhood asthma and wheezing., Methods: By conducting the Phase II of the China, Children, Homes, Health study, we investigated 30,325 preschool children aged 3-6 years during 2019-2020 in mainland China. Early-life exposure to PM 2.5 mass and its constituents (i.e., black carbon [BC], organic matter [OM], nitrate, ammonium, sulfate) were calculated based on monthly estimates at a 1 km × 1 km resolution from satellite-based models. We adopted a novel quantile-based g-computation approach to assess the effect of a mixture of PM 2.5 constituents on childhood asthma/wheezing., Results: The average PM 2.5 concentrations during in-utero and the first year since birth were 64.7 ± 10.6 and 61.8 ± 10.5 µg/m 3 , respectively. Early-life exposures to a mixture of major PM 2.5 constituents were significantly associated with increased risks of asthma and wheezing, while no evident compositions-wheezing associations were found in the first year. Each quintile increases in all five PM 2.5 components exposures in utero was accordingly associated with an odds ratio of 1.18 [95% confidence interval: 1.07-1.29] for asthma and 1.08 [1.01-1.16] for wheezing. BC, OM and SO 4 2- contributed more to risks of asthma and wheezing than the other PM 2.5 constituents during early life, wherein the effects of BC were only observed during pregnancy. Sex subgroup analyses suggested stronger associations among girls of first-year exposures to PM 2.5 components with childhood asthma., Conclusion: Early-life exposures to ambient PM 2.5 , particularly compositions of BC, OM and SO 4 2- , are associated with an increased risk of childhood asthma., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Pollen is the main factor causing asthma and allergic rhinitis (AR). However, the key indoor and outdoor factors associated with childhood symptoms of allergic rhinitis (SAR) to pollen are unclear. We investigate the association of exposure to outdoor air pollution and indoor environmental factors with childhood SAR to pollen and consider SAR to pollen in different seasons. A cross-sectional study of 2598 preschool children aged 3-6 was conducted in Changsha, China (2011-2012). The prevalence of SAR to pollen in children and information on indoor environmental factors were obtained by questionnaire. Children's exposure to outdoor air pollutants (PM 10 , SO 2, and NO 2 ) was estimated from the monitored concentrations. The association of exposure to indoor environmental factors and outdoor air pollution with childhood SAR to pollen was estimated by multiple logistic regression models using odds ratio (OR) and a 95% confidence interval (CI), and the relationship between outdoor air pollutants and childhood SAR to pollen was investigated using restricted cubic splines. We found that early-life and current exposure to outdoor air pollution were significantly associated with childhood SAR to pollen in autumn, including exposure to SO 2 one year before conception (OR = 1.60, 95% CI = 1.08-2.37) and during entire pregnancy (OR = 1.49, 95% CI = 1.01-2.20) periods, exposure to PM 10 during the current period (OR = 1.78, 95% CI = 1.07-2.96), and exposure to NO 2 during the early-life (one year before conception and entire pregnancy) and current periods with ORs (95% CI) of 1.72 (1.10-2.71), 1.82 (1.17-2.83), and 1.94 (1.11-3.40), respectively. Further, we found significant associations of both prenatal and postnatal exposure to window condensation with childhood SAR to pollen, with ORs (95% CI) = 1.37 (1.05-1.77) and 1.38 (1.02-1.88), respectively. We encourage SAR to pollen sufferers to stay indoors due to outdoor air pollution and higher pollen concentration outdoors, but indoor ventilation should be maintained.

Energy use in buildings can influence the indoor environment. Studies on green buildings, energy saving measures, energy use, fuel poverty, and ventilation have been reviewed, following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The database PubMed was searched for articles published up to 1 October 2020. In total, 68 relevant peer-reviewed epidemiological or exposure studies on radon, biological agents, and chemicals were included. The main aim was to assess current knowledge on how energy saving measures and energy use can influence health. The included studies concluded that buildings classified as green buildings can improve health. More efficient heating and increased thermal insulation can improve health in homes experiencing fuel poverty. However, energy-saving measures in airtight buildings and thermal insulation without installation of mechanical ventilation can impair health. Energy efficiency retrofits can increase indoor radon which can cause lung cancer. Installation of a mechanical ventilation systems can solve many of the negative effects linked to airtight buildings and energy efficiency retrofits. However, higher ventilation flow can increase the indoor exposure to outdoor air pollutants in areas with high levels of outdoor air pollution. Finally, future research needs concerning energy aspects of buildings and health were identified.

Common cold is usually considered to be associated with outdoor climate, but the evidence linking with indoor environmental factors is lacking. The role of indoor renovations during which critical timing window on childhood common cold remains unclear. Therefore, we investigated the effect of exposure to new furniture and/or redecoration during prenatal and postnatal periods on the occurrence and duration of common cold in preschool children. We conducted a retrospective cohort study of 39 782 children aged 3-6 years in seven cities of China. The occurrence and duration of common cold in children, and their lifetime exposures to indoor new furniture and redecoration (including pregnancy, the first year of life, and after one year old) were assessed using a questionnaire administered by the parents. Associations between high frequency (>5 colds) and long duration (≥2 weeks per cold) of common cold during past 12 months and exposure to indoor new furniture/redecoration were examined by logistic regression models in terms of odds ratio (OR) and 95% confidence interval (CI). We found that the prevalence of high frequency and long duration of common cold in preschool children in China were, respectively, 9.2% and 11.9%. Frequent common cold was significantly associated with exposure to indoor new furniture/redecoration during pregnancy, first year, and after 1 year old, respectively, with the ORs (95% CI) = 1.25 (1.12-1.39), 1.11 (1.00-1.25), and 1.09 (1.01-1.18). Furthermore, childhood long duration per cold was associated with exposure to indoor new furniture/redecoration during pregnancy with OR (95% CI) of 1.14 (1.03-1.25) but not with postnatal exposure. We identified that prenatal exposure to home renovation was more critical than postnatal exposure for an increased risk of high frequency and long duration of common cold. Sensitivity analysis showed that the association between prenatal exposure to indoor renovations and the risk of childhood common cold was consistent and robust, and the associations were modified by some personal and indoor environmental factors. Our findings indicated that prenatal and postnatal exposure to home renovation played an important role in the risk of childhood common cold, supporting the hypothesis of "fetal origin of childhood infection.", (© 2022 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Indoor microbiome exposure is associated with asthma, rhinitis and eczema. However, no studies report the interactions between environmental characteristics, indoor microbiome and health effects in a repeated cross-sectional framework., Methods: 1,279 and 1,121 preschool children in an industrial city (Taiyuan) of China were assessed for asthma, rhinitis and eczema symptoms in 2012 and 2019 by self-administered questionnaires, respectively. Bacteria and fungi in classroom vacuum dust were characterized by culture-independent amplicon sequencing. Multi-level logistic/linear regression was performed in two cross-sectional and two combined models to assess the associations., Results: The number of observed species in bacterial and fungal communities in classrooms increased significantly from 2012 to 2019, and the compositions of the microbial communities were drastically changed (p < 0.001). The temporal microbiome variation was significantly larger than the spatial variation within the city (p < 0.001). Annual average outdoor SO 2 concentration decreased by 60.7%, whereas NO 2 and PM 10 concentrations increased by 63.3% and 40.0% from 2012 to 2019, which were both associated with indoor microbiome variation (PERMANOVA p < 0.001). The prevalence of asthma (2.0% to 3.3%, p = 0.06) and rhinitis (28.0% to 25.3%, p = 0.13) were not significantly changed, but the prevalence of eczema was increased (3.6% to 7.0%; p < 0.001). Aspergillus subversicolor, Collinsella and Cutibacterium were positively associated with asthma, rhinitis and eczema, respectively (p < 0.01). Prevotella, Lactobacillus iners and Dolosigranulum were protectively (negatively) associated with rhinitis (p < 0.01), consistent with previous studies in the human respiratory tract. NO 2 and PM 10 concentrations were negatively associated with rhinitis in a bivariate model, but a multivariate mediation analysis revealed that Prevotella fully mediated the health effects., Conclusions: This is the first study to report the interactions between environmental characteristics, indoor microbiome and health in a repeated cross-sectional framework. The mediating effects of indoor microorganisms suggest incorporating biological with chemical exposure for a comprehensive exposure assessment., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Totally 1160 adults living in single-family houses in Sweden participated in a questionnaire survey on subjective indoor air quality (SIAQ). Inspectors investigated the dwellings and performed home measurements (mean indoor temperature 21.4 °C, mean indoor air humidity 34.2%, mean indoor air exchange rate 0.36 ac/h and mean moisture load indoor 1.7 g/m 3 ). Totally 15.5% perceived draught, 28.0% perceived too high room temperature, 42.4% unstable room temperature, 36.8% too low room temperature, 19.6% stuffy air, 19.8% dry air and 29.9% dust or dirt. Measured room temperature was related to perception of room temperature. Higher relative air humidity was related to perceived unstable room temperature (OR = 1.70) and too low room temperature (OR = 1.96). Higher absolute air humidity was related to too high room temperature (OR = 1.21), unstable room temperature (OR = 1.34) and too low room temperature (OR = 1.35). Higher measured relative humidity, absolute air humidity and moisture load were all associated with stuffy air and unpleasant odor (OR = 1.45-1.97). Higher air exchange rate was related to less perceived unstable room temperature (OR = 0.93). Higher U value was related to draught (OR = 1.17), too low room temperature (OR = 1.09), unpleasant odor (OR = 1.12) and dust and dirt (OR = 1.07). New concrete slab foundation was related to less stuffy air (OR = 0.39) (vs. basement). Damp foundation was associated with more stuffy air (OR = 1.44) and unpleasant odor (OR = 1.61). Window pane condensation was related to stuffy air (OR = 1.88). Moldy odor reported by inspector was related to stuffy air (OR = 1.73). Observed mold in the attic was associated with more stuffy air and unpleasant odor. In conclusion, complaints of room temperature can indicate poor thermal environment. Higher air exchange rate can create a more stable thermal sensation. Excess indoor humidity, lower degree of thermal insulation, presence of window pane condensation and indoor dampness/mold can impair SIAQ. Higher ventilation and concrete slab foundation with underlying thermal insulation can improve SIAQ., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

A questionnaire survey on dermal symptoms and home environment was performed in eight Chinese cities (40 279 participants). Data on city level temperature, precipitation, PM 10 , NO 2, and gross domestic product (GDP) per capita were collected. In total, 2.2% had eczema, 2.4% facial erythema (FE) and 2.6% seborrheic dermatitis symptoms (SD). Higher temperature was associated with eczema (OR = 1.09). Higher GDP per capita was related to less SD. Higher PM 10 was related to SD. Suburban living was protective for eczema (OR = 0.77) (vs. urban). Living in old buildings (built before 1991) was related to eczema (OR = 1.42). Living near heavily trafficked roads was related to FE (OR = 1.33) and SD (OR = 1.35). Having new furniture was related to all symptoms (OR = 1.26-1.47). Burning mosquito coils (OR = 1.37-1.57) and incense (OR = 1.33-1.37) were associated with eczema, FE, or SD. Presence of cockroaches and rats/mice was associated with FE or SD (OR = 1.31-1.40). Using air conditioner, daily cleaning and frequently exposing bedding to sunshine were protective (OR = 0.60-0.83). In conclusion, higher temperature, higher PM 10 , urban living, living near heavily trafficked roads, old buildings, new furniture, burning mosquito coils and incense, and presence of cockroaches/rats/mice increased the risk of eczema, FE, or SD. Higher GDP, air conditioner, daily cleaning, and exposing bedding to sunshine were protective., (© 2021 The Authors. Indoor Air published by John Wiley & Sons Ltd.)

Background: Indoor exposure to dry air during heating periods has been associated with dryness and irritation symptoms of the upper respiratory airways and the skin. The irritated or damaged mucous membrane poses an important entry port for pathogens causing respiratory infections., Objectives: To determine the effectiveness of interventions that increase indoor air humidity in order to reduce or prevent dryness symptoms of the eyes, the skin and the upper respiratory tract (URT) or URT infections, at work and in educational settings., Search Methods: The last search for all databases was done in December 2020. We searched Ovid MEDLINE, Embase, CENTRAL (Cochrane Library), PsycINFO, Web of Science, Scopus and in the field of occupational safety and health: NIOSHTIC-2, HSELINE, CISDOC and the In-house database of the Division of Occupational and Environmental Medicine, University of Zurich. We also contacted experts, screened reference lists of included trials, relevant reviews and consulted the WHO International Clinical Trials Registry Platform (ICTRP)., Selection Criteria: We included controlled studies with a parallel group or cross-over design, quasi-randomised studies, controlled before-and-after and interrupted time-series studies on the effects of indoor air humidification in reducing or preventing dryness symptoms and upper respiratory tract infections as primary outcomes at workplace and in the educational setting. As secondary outcomes we considered perceived air quality, other adverse events, sick leave, task performance, productivity and attendance and costs of the intervention., Data Collection and Analysis: Two review authors independently screened titles, abstracts and full texts for eligibility, extracted data and assessed the risks of bias of included studies. We synthesised the evidence for the primary outcomes 'dry eye', 'dry nose', 'dry skin', for the secondary outcome 'absenteeism', as well as for 'perception of stuffiness' as the harm-related measure. We assessed the certainty of evidence using the GRADE system., Main Results: We included 13 studies with at least 4551 participants, and extracted the data of 12 studies with at least 4447 participants. Seven studies targeted the occupational setting, with three studies comprising office workers and four hospital staff. Three of them were clustered cross-over studies with 846 participants (one cRCT), one parallel-group controlled trial (2395 participants) and three controlled before-and-after studies with 181 participants. Five studies, all CTs, with at least 1025 participants, addressing the educational setting, were reported between 1963 and 1975, and in 2018. In total, at least 3933 (88%) participants were included in the data analyses. Due to the lack of information, the results of the risk of bias assessment remained mainly unclear and the assessable risks of bias of included studies were considered as predominantly high. Primary outcomes in occupational setting:  We found that indoor air humidification at the workplace may have little to no effect on dryness symptoms of the eye and nose (URT). The only cRCT showed a significant decrease in dry eye symptoms among working adults (odds ratio (OR) 0.54, 95% confidence interval (CI) 0.37 to 0.79) with a low certainty of the evidence. The only cluster non-randomised cross-over study showed a non-significant positive effect of humidification on dryness nose symptoms (OR 0.87, 95% CI 0.53 to 1.42) with a low certainty of evidence. We found that indoor air humidification at the workplace may have little and non-significant effect on dryness skin symptoms. The pooled results of two cluster non-RCTs showed a non-significant alleviation of skin dryness following indoor air humidification (OR 0.66, 95% CI 0.33 to 1.32) with a low certainty of evidence. Similarly, the pooled results of two before-after studies yielded no statistically significant result (OR 0.69, 95% CI 0.33 to 1.47) with very low certainty of evidence No studies reported on the outcome of upper respiratory tract infections. No studies conducted in educational settings investigated our primary outcomes. Secondary outcomes in occupational setting: Perceived stuffiness of the air was increased during the humidification in the two cross-over studies (OR 2.18, 95% CI 1.47 to 3.23); (OR 1.70, 95% CI 1.10 to 2.61) with low certainty of evidence. Secondary outcomes in educational setting: Based on different measures and settings of absenteeism, four of the six controlled studies found a reduction in absenteeism following indoor air humidification (OR 0.54, 95% CI 0.45 to 0.65; OR 0.38, 95% CI 0.15 to 0.96; proportion 4.63% versus 5.08%)., Authors' Conclusions: Indoor air humidification at the workplace may have little to no effect on dryness symptoms of the eyes, the skin and the URT. Studies investigating illness-related absenteeism from work or school could only be summarised narratively, due to different outcome measures assessed. The evidence suggests that increasing humidification may reduce the absenteeism, but the evidence is very uncertain. Future RCTs involving larger sample sizes, assessing dryness symptoms more technically or rigorously defining absenteeism and controlling for potential confounders are therefore needed to determine whether increasing indoor air humidity can reduce or prevent dryness symptoms of the eyes, the skin, the URT or URT infections at work and in educational settings over time., (Copyright © 2021 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.)

Aim: The aim of this study was to investigate occupational, environmental, early life and other risk factors associated with respiratory infections and antibiotics use in a general population and among asthmatic individuals., Method: This study included 15 842 participants of the Respiratory Health in Northern Europe (RHINE) study aged 25-54 years from five Nordic countries, who answered a questionnaire covering respiratory outcomes, exposures, demographic characteristics and numbers of infections and courses of antibiotics in the last 12 months. Multiple logistic regression with and without adjustment for age, sex, smoking status, body mass index and centre were used to study the risk of infection and antibiotics in relation to asthma, and also the association between infection and antibiotics and occupations., Results: In the whole population, 11.6% reported having three or more respiratory infections, and 14.7% had used antibiotics because of respiratory tract infections within the last year. Asthmatic participants reported tripled odds for such infections (adjusted OR 2.98, 95% CI 2.53-3.52) and antibiotics use (adjusted OR 3.67, 95% CI 3.18-4.24) as compared to non-asthmatic participants. Both in the general and the asthmatic population, female sex, obesity and exposure to building dampness were associated with respiratory infections. Female sex and current smoking and living in Tartu were associated with antibiotic use. The use of antibiotics was doubled in people hospitalised for severe respiratory infection in childhood., Conclusion: In this study we identified several factors associated with increased respiratory infections and use of antibiotics in a general population and among asthmatic individuals. The frequency of respiratory infections and subsequent antibiotic treatment were increased among those with asthma., Competing Interests: Conflict of interest: M.A. Kisiel has nothing to disclose. Conflict of interest: X. Zhou has nothing to disclose. Conflict of interest: E. Björnsson has nothing to disclose. Conflict of interest: M. Holm has nothing to disclose. Conflict of interest: A. Dahlman-Höglund has nothing to disclose. Conflict of interest: J. Wang has nothing to disclose. Conflict of interest: C. Svanes has nothing to disclose. Conflict of interest: D. Norbäck has nothing to disclose. Conflict of interest: K.A. Franklin has nothing to disclose. Conflict of interest: A. Malinovschi has nothing to disclose. Conflict of interest: A. Johannessen has nothing to disclose. Conflict of interest: V. Schlünssen has nothing to disclose. Conflict of interest: C. Janson has nothing to disclose., (Copyright ©The authors 2021.)

Sick building symptoms (SBS) are defined as non-specific symptoms related to indoor exposures, including mucosal symptoms in eye, nose, throat, and skin, and general symptoms as headache and tiredness. Indoor microbial composition is associated with SBS symptoms, but the impact of microbial functional genes and potential metabolic products has not been characterized. We conducted a shotgun microbial metagenomic sequencing for vacuum dust collected in urban and rural schools in Shanxi province, China. SBS symptoms in students were surveyed, and microbial taxa and functional pathways related to the symptoms were identified using a multi-level linear regression model. SBS symptoms were common in students, and the prevalence of ocular and throat symptoms, headache, and tiredness was higher in urban than in rural areas (p < 0.05). A significant higher microbial α-diversity was found in rural areas than in urban areas (Chao1, p = 0.001; ACE, p = 0.002). Also, significant variation in microbial taxonomic and functional composition (β-diversity) was observed between urban and rural areas (p < 0.005). Five potential risk Actinobacteria species were associated with SBS symptoms (p < 0.01); students in the classrooms with a higher abundance of an unclassified Geodermatophilaceae, Geodermatophilus, Fridmanniella luteola, Microlunatus phosphovorus and Mycetocola reported more nasal and throat symptoms and tiredness. Students with a higher abundance of an unclassified flavobacteriaceae reported fewer throat symptoms and tiredness. The abundance of microbial metabolic pathways related to the synthesis of B vitamins (biotin and folate), gamma-aminobutyric acid (GABA), short-chain fatty acids (SCFAs), and peptidoglycan and were protectively (negatively) associated with SBS symptoms (FDR < 0.05). The result is consistent with human microbiota studies, which reported that these microbial products are extensively involved in immunological processes and anti-inflammatory effects. This is the first study to report the functional potential of the indoor microbiome and the occurrence of SBS, providing new insights into the potential etiologic mechanisms in chronic inflammatory diseases., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background: Poor acoustic conditions at home can have negative health impact. The aim was to investigate home environment factors and medical symptoms associated with noise disturbance., Methods: All adults (≥18 y) registered in selected apartments in Sweden were invited to participate in a questionnaire survey including medical questions and personal factors. Totally 5775 adults participated (response rate 46%). Information on home environment was obtained through an indoor environment questionnaire. Two-level logistic regression models (individual, municipality) were performed to estimate associations., Results: Totally 11.9% reported noise disturbance in general at home. Noise disturbance from voice/radio/TV/music/similar sounds from neighbours (13.2%), scraping sound/footsteps/thumping from neighbours (16.5%) and road traffic (16.1%) were common. Younger age and smoking were related to more noise disturbance and more medical symptoms. Noise disturbance was related to tiredness, headache and difficulty concentrating (OR = 1.70-8.19). Renting the apartment (OR = 2.53) and living above ground floor (OR = 1.37) were related to more noise disturbance in general. Living in newer buildings (constructed from 1986 to 2005) was related to less noise disturbance in general (OR = 0.40-0.59). A warmer climate (OR = 1.95), higher municipality population density (OR = 1.24), a longer living time (OR = 1.34), construction year (1961-1975) (OR = 2.42), renting (OR = 1.80-2.32), living above ground floor (OR = 1.45) and having a bathroom fan (OR = 1.84) were associated with increased noise disturbance from neighbours. Factors associated with increased noise disturbance from installations or ventilation/fans/heat pumps included a warmer climate, higher municipality population density, construction year (1961-1995), renting and any mechanical ventilation. Higher municipality population density, construction year (especially 1961-1985) and renting were associated with more noise disturbance from traffic (OR = 1.77-3.92). Renting the apartment (OR = 1.73) and living above ground floor (OR = 1.60) were related to more severe traffic noise disturbances. Noise disturbance in general was partly a mediator of the effects of old buildings, renting the apartment and lack of mechanical ventilation on medical symptoms (% of total effect mediated by noise disturbance: 19-44.8%)., Conclusions: Noise disturbance can be associated medical symptoms. Younger age, smoking, a warmer climate, higher municipality population density and different building factors (e.g. renting the apartment, construction period 1961-1985) can be associated with noise disturbance., (© 2021. The Author(s).)

We performed a repeated questionnaire study on home environment and health (six medical symptoms) in 1159 junior high school students (age 12.8 ± 0.7 years) in upper northern Thailand in wet and dry seasons. Data on outdoor temperature, relative humidity (RH), and air pollution were collected from nearest monitoring station. Odds ratios (OR) were calculated by multi-level logistic regression. Most common symptoms were rhinitis (62.5%), headache (49.8%), throat (42.8%), and ocular symptoms (42.5%). Ocular symptoms were more common at lower RH and rhinitis more common in dry season. Water leakage (28.2%), indoor mold (7.1%), mold odor (4.1%), and windowpane condensation (13.6%) were associated with all six symptoms (ORs: 1.3-3.5). Other risk factors included cat keeping, environmental tobacco smoke (ETS), other odor than mold odor, gas cooking, and cooking with biomass fire. Biomass burning inside and outside the home for other reasons than cooking was associated with all six symptoms (ORs: 1.5-2.6). Associations between home environment exposure and rhinitis were stronger in wet season. In conclusion, dampness-related exposure, windowpane condensation, cat keeping, ETS, gas cooking, and biomass burning can impair adolescent health in upper northern Thailand. In subtropical areas, environmental health effects should be investigated in wet and dry seasons., (© 2021 The Authors. Indoor Air published by John Wiley & Sons Ltd.)

The exposure of school children to indoor air pollutants has increased allergy and respiratory diseases. The objective of this study were to determine the toxicodynamic interaction of indoor pollutants exposure, biological and chemical with expression of adhesion molecules on eosinophil and neutrophil. A self-administered questionnaire, allergy skin test, and fractional exhaled nitric oxide (FeNO) analyser were used to collect information on health status, sensitization to allergens and respiratory inflammation, respectively among school children at age of 14 years. The sputum induced were analysed to determine the expression of CD11b, CD35, CD63 and CD66b on eosinophil and neutrophil by using flow cytometry technique. The particulate matter (PM 2.5 and PM 10 ), NO 2 , CO 2 , and formaldehyde, temperature, and relative humidity were measured inside the classrooms. The fungal DNA were extracted from settled dust collected from classrooms and evaluated using metagenomic techniques. We applied chemometric and regression in statistical analysis. A total of 1869 unique of operational taxonomic units (OTUs) of fungi were identified with dominated at genus level by Aspergillus (15.8%), Verrucoconiothyrium (5.5%), and Ganoderma (4.6%). Chemometric and regression results revealed that relative abundance of T. asahii were associated with down regulation of CD66b expressed on eosinophil, and elevation of FeNO levels in predicting asthmatic children with model accuracy of 63.6%. Meanwhile, upregulation of CD11b expressed on eosinophil were associated with relative abundance of A. clavatus and regulated by PM 2.5 . There were significant association of P. bandonii with upregulation of CD63 expressed on neutrophil and exposure to NO 2 . Our findings indicate that exposure to PM 2.5 , NO 2 , T. asahii, P.bandonii and A.clavatus are likely interrelated with upregulation of activation and degranulation markers on both eosinophil and neutrophil., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Risk factors at home for ocular, nasal, throat and dermal symptoms, headache, and fatigue were studied in a nationwide questionnaire survey in Sweden, the BETSI study in 2006. Totally, 5775 adults from a stratified random sample of multi-family buildings participated. Associations between home environment factors and weekly symptoms were analyzed by multi-level logistic regression. In total, 8.3% had ocular symptoms; 11.9% nasal symptoms; 7.1% throat symptoms; 11.9% dermal symptoms; 8.5% headache and 23.1% fatigue. Subjects in colder climate zones had more mucosal and throat symptoms but less fatigue and ocular symptoms. Rented apartments had poorer indoor environment than self-owned apartments. Those living in buildings constructed from 1961 to 1985 had most symptoms. Building dampness, mold and mold odor were risk factors, especially headache and ocular symptoms. Lack of mechanical ventilation system was another risk factor, especially for headache. Environmental tobacco smoke (ETS), electric radiators, and crowdedness were other risk factors. Oiled wooden floors, recent indoor painting, and new floor materials were negatively associated with symptoms. In conclusion, building dampness, mold, poor ventilation conditions, crowdedness, ETS, and emissions from electric radiators in apartments in Sweden can increase the risk of ocular, nasal, throat and dermal symptoms, headache, and fatigue., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Pathogens are commonly present in the human respiratory tract, but symptoms are varied among individuals. The interactions between pathogens, commensal microorganisms and host immune systems are important in shaping the susceptibility, development and severity of respiratory diseases. Compared to the extensive studies on the human microbiota, few studies reported the association between indoor microbiome exposure and respiratory infections. In this study, 308 students from 21 classrooms were randomly selected to survey the occurrence of respiratory infections in junior high schools of Johor Bahru, Malaysia. Vacuum dust was collected from the floor, chairs and desks of these classrooms, and high-throughput amplicon sequencing (16S rRNA and ITS) and quantitative PCR were conducted to characterize the absolute concentration of the indoor microorganisms. Fifteen bacterial genera in the classes Actinobacteria, Alphaproteobacteria, and Cyanobacteria were protectively associated with respiratory infections (p < 0.01), and these bacteria were mainly derived from the outdoor environment. Previous studies also reported that outdoor environmental bacteria were protectively associated with chronic respiratory diseases, such as asthma, but the genera identified were different between acute and chronic respiratory diseases. Four fungal genera from Ascomycota, including Devriesia, Endocarpon, Sarcinomyces and an unclassified genus from Herpotrichillaceae, were protectively associated with respiratory infections (p < 0.01). House dust mite (HDM) allergens and outdoor NO 2 concentration were associated with respiratory infections and infection-related microorganisms. A causal mediation analysis revealed that the health effects of HDM and NO 2 were partially or fully mediated by the indoor microorganisms. This is the first study to explore the association between environmental characteristics, microbiome exposure and respiratory infections in a public indoor environment, expanding our understanding of the complex interactions among these factors.

The indoor environment influences occupants' health. From March 1, 2018, to February 28, 2019, we continuously monitored indoor temperature (T), relative humidity (RH), and CO 2 concentration in bedrooms via an online system in 165 residences that covered all five climate zones of China. Meanwhile, we asked one specific occupant in each home to complete questionnaires about perceived air quality and sick building syndrome (SBS) symptoms at the end of each month. Higher CO 2 concentration was significantly associated with a higher percentage of perceived stuffy odor and skin SBS symptoms. Higher relative humidity was associated with higher percentage of perceived moldy odor and humid air, while lower RH was associated with a higher percentage of perceived dry air. Occupants who lived in residences with high RH were less likely to have mucosal and skin SBS symptoms (adjusted odds ratio (AOR): 0.73-0.78). However, the benefit of high humidity for perceived dry air and skin dryness symptoms is weaker if there is a high CO 2 concentration level., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Early life environment can affect asthma and allergies but few cohort studies on this issue are available from China. Our aim was to investigate reported onset of childhood wheeze, rhinitis and eczema symptoms in relation to prenatal, perinatal and postnatal home environment. Data on home environment and symptoms (ISAAC based questions) in first two years of life and in the past 12 months were reported by parents of the children (3-6 y) in a cross-sectional questionnaire survey in ten day care centers in Taiyuan, northern China (N = 3606). Changes of symptoms from the first 2 years of life to the past 12 months (recall period) were calculated retrospectively. Multilevel logistic regression analysis was applied. Reported onset of wheeze, rhinitis and eczema were 11.8%, 22.2% and 3.3%, respectively. Redecorating during pregnancy increased reported onset of rhinitis (OR = 2.29) and eczema (OR = 4.91). New furniture during pregnancy increased reported onset of rhinitis (OR = 1.47). Perinatal indoor mould increased reported onset of wheeze (OR = 1.51), rhinitis (OR = 1.65) and eczema (OR = 1.91). Perinatal mould odour increased reported onset of wheeze (OR = 1.85). Perinatal window pane condensation increased reported onset of wheeze (OR = 1.54) and rhinitis (OR = 1.24). Perinatal stuffy air and dry air in the home increased reported onset of all three symptoms (ORs 1.46-2.24). Dog keeping increased reported onset of wheeze (OR = 1.69) and eczema (OR = 2.13). Based on principal component analysis, four exposure scores were calculated (renovation, new furniture, mould and indoor air quality scores). Dose-response relationships were observed between these exposure scores and reported onset of symptoms. In conclusion, prenatal and postnatal exposure to emissions from renovation and new furniture can increase reported onset of childhood wheeze, rhinitis and eczema. Perinatal indoor mould, mould odour, condensation on window panes and impaired indoor air quality at home can be associated with reported development of wheeze, rhinitis and eczema in preschoolers in northern China., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Studies in developed countries have reported that the prevalence of asthma and rhinitis is higher in urban areas than in rural areas, and this phenomenon is associated with urbanization and changing indoor microbiome exposure. Developing countries such as China have experienced rapid urbanization in past years, but no study has investigated microbiome exposure and urban-rural health effects in these countries., Methods: Nine high schools from urban and rural areas were randomly selected in Shanxi Province, China, and classroom vacuum dust was collected for shotgun metagenomic sequencing. A self-administered questionnaire was collected from 1332 students for personal information and health data. Three-level logistic regression was performed between microbial richness/abundance/functional pathways and the occurrence of asthma and rhinitis symptoms., Results: Consistent with developed countries, the prevalence of wheeze and rhinitis was higher in urban areas than in rural areas (p < 0.05). Metagenomic profiling revealed 8302 bacterial, 395 archaeal, 744 fungal, 524 protist and 1103 viral species in classroom dust. Actinobacteria (mean relative abundance 49.7%), Gammaproteobacteria (18.4%) and Alphaproteobacteria (10.0%) were the most abundant bacterial classes. The overall microbiome composition was significantly different between urban and rural schools (p = 0.001, Adonis). Species from Betaproteobactera, Gammaproteobacteria and Bacilli were enriched in urban schools, and species from Actinobacteria and Cyanobacteria were enriched in rural schools. Potential pathogens were present in higher abundance in urban schools than in rural schools (p < 0.05). Pseudoalteromonas, Neospora caninum and Microbacterium foliorum were positively associated with the occurrence of wheeze, rhinitis and rhinoconjunctivitis, and Brachybacterium was protectively (negatively) associated with rhinitis (p < 0.01). The abundance of human endocrine and metabolic disease pathways was positively associated with rhinitis (p = 0.008), and butyrate and propionate metabolic genes and pathways were significantly enriched in rural schools (p < 0.005), in line with previous findings that these short-chain fatty acids protect against inflammatory diseases in the human gut., Conclusions: We conducted the first indoor microbiome survey in urban/rural environments with shotgun metagenomics, and the results revealed high-resolution microbial taxonomic and functional profiling and potential health effects. Video abstract.

Objective: Habitual snoring is associated with fatigue, headaches and low work performance. This cross-sectional study aimed to investigate if snoring is affected by environmental factors such as home dampness and exposure to air pollution., Setting: General population sample from four Swedish cities., Participants: 25 848 participants from the Swedish part of the epidemiological Global Asthma and Allergy and European network of excellence study carried out in 2008. The participants completed a postal questionnaire on snoring and, indoor and outdoor environmental exposure as well as potential confounders including smoking, weight, height and educational level., Results: Of the participants, 4211 (16.3%) were habitual snorers. Habitual snorers reported water damage (8.3% vs 7.0% p<0.0001), floor dampness (4.6% vs 3.8% % p<0.0001) and visible mould (5.2% vs 3.8% p<0.0001) in their homes more often than non-snorers. Habitual snorers stated being annoyed by air pollution more often than non-snorers with habitual snorers reporting being irritated with the air in their residential area to a higher extent (sometimes 16.2% vs 13.9%, and daily 4.6% vs 3.1%) as well as annoyance from traffic fumes (somewhat 19% vs 18.5% and very 5% vs 3.6%) (p<0.0001). These results remained significant after adjustment for age, body mass index, smoking history and educational level., Conclusion: Snoring is more prevalent in subjects reporting home dampness and air pollution. These association should be confirmed in further research using objective measurements and a longitudinal approach., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Little is known on respiratory effects of indoor chemicals in the tropics. We investigated associations between asthma and respiratory infections in Malaysian students and chemical exposure at home and at school. Moreover, we investigated differences in home environment between the three main ethnic groups in Malaysia (Malay, Chinese, Indian). Totally, 462 students from 8 junior high schools in Johor Bahru participated (96% participation rate). The students answered a questionnaire on health and home environment. Climate, carbon dioxide (CO 2 ), volatile organic compounds (VOC), formaldehyde and nitrogen dioxide (NO 2 ) were measured inside and outside the schools. Multilevel logistic regression was applied to study associations between exposure and health. Totally 4.8% were smokers, 10.3% had wheeze, 9.3% current asthma, and had 18.8% any respiratory infection in the past 3 months. Malay students had more dampness or mould (p < 0.001), more environmental tobacco smoke (ETS) (p < 0.001) and more cats (p < 0.001) at home as compared to Chinese or Indian students. Wheeze was associated with ethnicity (p = 0.02; lower in Indian), atopy (p = 0.002), current smoking (p = 0.02) and recent indoor painting at home (p = 0.03). Current asthma was associated with ethnicity (p = 0.001; lower in Chinese) and para-dichlorobenzene in classroom air (p = 0.008). Respiratory infections were related to atopy (p = 0.002), ethylbenzene (p = 0.02) and para-dichlorobenzene (p = 0.01) in classroom air. Para-dichlorobenzene is used in Asia against insects. In conclusion, chemical emissions from recent indoor painting at home can increase the risk of wheeze. In schools, para-dichlorobenzene can increase the risk of current asthma and respiratory infections while ethylbenzene can increase the risk of respiratory infections., (Copyright © 2021 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Cultivated buckwheat include two species originating from China: common buckwheat ( Fagopyrum esculentum ) and tartary buckwheat ( Fagopyrum tartaricum ). Buckwheat can cause IgE-mediated allergy, including severe allergic reactions and anaphylaxis. Exposure can occure when eating buckwheat food (food allergen), when producing or handling buckwheat food (occupational exposure) or when sleeping on buckwheat husk pillows (houeshold environmental exposure)., Methods: A search on buckwheat allergy in the medical datbase PubMed from 1970-2020., Result: A number of allergenic proteins have been identified in common buckwheat (e.g., Fag e 1, Fag e 2 and Fag e 3) and in tartary buckwheat (e.g., Fag t 1, Fag t 2, Fag t 3). Clinically relevant cross-reactivity has been described between buckwheat and peanut, latex, coconut, quinoa, and poppy seed. The prevalence of buckwheat allergy in the population can be estimated as 0.1-0.4% in Japan, Korea and buckwheat consuming areas of China. Among patients in allergy clinics in different countries, 2-7% has confirmed buckwheat allergy. School studies from Japan and Korea found 4-60 cases of buckwheat-related anaphylaxis per 100,000 school children. The incidence of severe allergic reactions to buckwheat, including anaphylaxis, can be estimated as 0.1-0.01 cases per 100,000 person-years., Conclusions: Buckwheat allergy is a neglected allegy deserving further attention but severe allergic reactions are rare.

Increasing evidence from the home environment indicates that indoor microbiome exposure is associated with asthma development. However, indoor microbiome composition can be highly diverse and dynamic, and thus current studies fail to produce consistent results. Chinese university dormitories are special high-density dwellings with similar building and occupants characteristics, which facilitate to disentangle the complex interactions between microbes, environmental characteristics and asthma. Settled air dust and floor dust was collected from 87 dormitory rooms in Shanxi University. Bacterial communities were characterized by 16 S rRNA amplicon sequencing. Students (n = 357) were surveyed for asthma symptoms and measured for fractional exhaled nitric oxide (FeNO). Asthma was not associated with the overall bacterial richness but associated with specific phylogenetic classes. Taxa richness and abundance in Clostridia, including Ruminococcus, Blautia, Clostridium and Subdoligranulum, were positively associated with asthma (p < 0.05), and these taxa were mainly derived from the human gut. Taxa richness in Alphaproteobacteria and Actinobacteria were marginally protectively associated with asthma, and these taxa were mainly derived from the outdoor environment. Bacterial richness and abundance were not associated with FeNO levels. Building age was associated with overall bacterial community variation in air and floor dust (p < 0.05), but not associated with the asthma-related microorganisms. Our data shows that taxa from different phylogenetic classes and derived habitats have different health effects, indicating the importance of incorporating phylogenetic and ecological concepts in revealing patterns in the microbiome asthma association analysis., (Copyright © 2020 Elsevier Inc. All rights reserved.)