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Introduction: Rhinitis is one of the most prevalent chronic respiratory diseases worldwide. There is emerging evidence suggesting that the indoor microbiome may contribute the onset and exacerbation of rhinitis symptoms, but comprehensive studies on this topic remain scarce. Methods: In this study, we assessed the microbiome assemblage of settled air dust collected in Petri dishes in 86 dormitory rooms of Shanxi University, China using 16s rRNA sequencing. A self-administered questionnaire, including questions about rhinitis symptoms and personal information, was completed by 357 students residing in these dormitories. Logistic and linear regression model was applied to examine the associations between environmental characteristics, indoor microbiome, and rhinitis. Results: The most abundant genera in the dormitories were Ralstonia (15.6%), Pelomonas (11.3%), Anoxybacillus (9.3%) and Ochrobactrum (6.2%). Taxa richness in the class of Actinobacteria and Fusobacteriia was negatively/protectively associated with rhinitis (p<0.05). Six bacterial genera, including those from Actinobacteria (Actinomyces), Fusobacteriia (Fusobacterium), and Bacteroidetes (Prevotella and Capnocytophaga), were negatively/protectively associated with rhinitis. Conversely, seven genera, predominantly from Alphaproteobacteria and Betaproteobacteria (Sphingomonas, Caulobacter, uncharacterized Caulobacteraceae and Comamonadaceae), were positively associated with rhinitis. Living in higher floor level and higher indoor PM2.5 concentrations were associated with a higher abundance of taxa potentially protective against rhinitis and a lower abundance of taxa potentially increasing the risk of rhinitis (P<0.01). However, having curtain indoor and higher indoor CO2 concentrations were associated with a lower abundance of taxa potentially protective against rhinitis and a higher abundance of taxa potentially increasing the risk of rhinitis (P<0.01). Discussion: This study enhances our understanding of the complex interactions between environmental characteristics, indoor microbiomes, and rhinitis, shedding light on potential strategies to manipulate indoor microbiome for disease prevention and control. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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." [ABSTRACT FROM AUTHOR]

A questionnaire survey on dermal symptoms and home environment was performed in eight Chinese cities (40 279 participants). Data on city level temperature, precipitation, PM10, NO2, 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 PM10 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 PM10, 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. [ABSTRACT FROM AUTHOR]

To investigate the role of different pattern of ambient air pollutants exposure during early life on childhood pneumonia, we conducted a retrospective cohort study of 3226 preschool children aged three to six years in Shenzhen, China during 2015 to 2016. Each child's exposure to three main air pollutants (PM10, SO2 and NO2) was calculated by the inverse distance weighted method. Multiple logistic regression analysis was used to investigate the pneumonia risk of early life exposure to air pollution. A relatively high prevalence of pneumonia (24.3%) among preschool children in Shenzhen was significantly associated with exposure to PM10 and SO2 during the first year of life, with adjusted odds ratios = 1.24 (1.05, 1.46) and 1.20 (1.05, 1.38) respectively. However, we observed no relationship between NO2 exposure and childhood pneumonia in pregnancy and first year of life. Sensitivity analysis suggested that boys, younger children (three to four years), non-preterm children, children without parental atopy and with exposure to environmental tobacco smoke were more susceptible to the impact of exposure to PM10 and SO2 on their suffering of pneumonia during their first year of life. Early-postnatal exposure to classical air pollution at low concentration during the first year of life can have an important role in enhancing the risk of childhood pneumonia, especially with the sensitive population. [ABSTRACT FROM AUTHOR]

The indoor environment influences occupants' health. From March 1, 2018, to February 28, 2019, we continuously monitored indoor temperature (T), relative humidity (RH), and CO2 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 CO2 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 CO2 concentration level. [ABSTRACT FROM AUTHOR]

Recent studies reveal that the microbial diversity and composition in the respiratory tract are related to the susceptibility, development, and progression of respiratory infections. Indoor microorganisms can transmit into the respiratory tract through breathing, but their role in infections is unclear. Here, we present the first association study between the indoor microbiome and respiratory infections. In total, 357 students living in 86 dormitory rooms in Shanxi University were randomly selected to survey symptoms of infections. Settled air dust was collected to characterize bacterial compositions by 16S rRNA sequencing. The overall microbial richness was not associated with respiratory infections, but microorganisms from specific phylogenetic classes showed various associations. Taxa richness and abundance of Actinobacteria were protectively associated with infections (P <.05). The abundance of several genera in Gammaproteobacteria, including Haemophilus, Klebsiella, Buttiauxella, and Raoultella, was positively associated with infections (P <.005). The role of these microorganisms was consistent with previous human microbiota studies. Building age was associated with the overall microbial composition variation in dormitories and negatively associated with three potential risk genera in Proteobacteria (P <.05). The weight of vacuum dust was positively associated with a protective genus, Micrococcus in Actinobacteria (P <.05). [ABSTRACT FROM AUTHOR]

From October 2010 to April 2012, we conducted a cross‐sectional study of associations between household environments and childhood health among preschool children in eight Chinese cities. Here, we analyze associations of early household renovation with preterm birth (PTB), low birthweight (LBW), term low birthweight (Term‐LBW), and small for gestational age (SGA). Parents responded to questions about household renovation and their children's gestational age and birthweight. In the multivariate logistic regression analyses, household renovation in the year before pregnancy was significantly associated with LBW (sample size: N = 25 813; adjusted odds ratio (OR) with 95% confidence intervals (CIs): 1.23, 1.01‐1.50) and Term‐LBW (N = 24 823; 1.29, 1.01‐1.67). Household renovation during pregnancy was significantly associated with PTB (N = 25 202; 1.28, 1.01‐1.69). These significant associations were also found in the two‐level (city‐child) logistic regression analyses and in the sensitivity analyses among 21 009 children with complete data in all studied variates. Stronger associations were found in certain subgroups. Our findings indicate that household renovation within one year before pregnancy might be a risk factor for LBW and Term‐LBW, while household renovation during pregnancy could be a risk factor for PTB. [ABSTRACT FROM AUTHOR]

We studied dampness and mold in China in relation to rhinitis, ocular, throat and dermal symptoms, headache and fatigue. A questionnaire study was performed in six cities including 36 541 randomized parents of young children. Seven self‐reported signs of dampness were evaluated. Multilevel logistic regression models were used to calculate odds ratios (ORs). Totally, 3.1% had weekly rhinitis, 2.8% eye, 4.1% throat and 4.8% skin symptoms, 3.0% headache and 13.9% fatigue. Overall, 6.3% of the homes had mold, 11.1% damp stains, 35.3% damp bed clothing, 12.8% water damage, 45.4% window pane condensation, 11.1% mold odor, and 37.5% humid air. All dampness signs were associated with symptoms (ORs from 1.2 to 4.6; P < 0.001), including rhinitis (ORs from 1.4 to 3.2; P < 0.001), and ORs increased by number of dampness signs. The strongest associations were for mold odor (ORs from 2.3 to 4.6) and humid air (ORs from 2.8 to 4.8). Associations were stronger among men and stronger in Beijing as compared to south China. In conclusion, dampness and mold are common in Chinese homes and associated with rhinitis and ocular, throat and dermal symptoms, headache and fatigue. Men can be more sensitive to dampness and health effects of dampness can be stronger in northern China. [ABSTRACT FROM AUTHOR]

Abstract Background Biomass burning is associated with childhood pneumonia but few studies exist on other indoor factors. Aim To study pneumonia in relation to pre-natal and post-natal exposure among children across China. Methods Children (3–6 y) (n = 39,782) from randomized day care centres in seven cities in China. Information on pneumonia and pre-natal and post-natal exposure to home environment factors were assessed by a parental questionnaire. Life-time outdoor temperature and GDP per capita were assessed on city level. Associations were calculated by multilevel logistic regression adjusting for fourteen co-variates. Results Totally 32.0% had ever had pneumonia diagnosed by a physician. Children of farmer mothers (OR = 0.65), with breastfeeding (OR = 0.91) and living in rural (OR = 0.85) or suburban (OR = 0.90) areas had less pneumonia. Buying new furniture one year before conception (OR = 1.11) and after first year of life (OR = 1.10) increased the risk. Redecoration one year before conception (OR = 1.20), during pregnancy (OR = 1.18) and after first year of life (OR = 1.17) increased pneumonia risk. Children with mould (OR = 1.17), window pane condensation (WPC) (OR = 1.20) and mould odour (OR = 1.15) at home at birth only had a higher risk of pneumonia. Similar associations were seen for dampness and mould in the current home. Children in the oldest and newest homes had less pneumonia. Cockroaches (OR = 1.08), mosquitos or flies in the current home (OR = 1.18), an exhaust fan in the bathroom (OR = 1.10) and higher economic development level, measured as GDP per capita on city level (OR 1.11 per 10,000 RMB/year) were associated with childhood pneumonia. Conclusions Perinatal and postnatal exposure to mould, mould odour and window pane condensation at home can be early life risk factors for childhood pneumonia in China. Moreover, pre-natal and post-natal exposure to chemical emissions from new furniture and renovation could increase the risk of childhood pneumonia. Breastfeeding, farm exposure, and living in rural or suburban areas could be protective. Highlights • Childhood pneumonia can be influenced by prenatal and perinatal indoor exposure. • Mould and window condensation at birth is a risk factor for childhood pneumonia. • Prenatal exposure to redecoration and new furniture can increase the risk. • Cockroaches, mosquitos and flies are other risk factors in the home environment. • Farm exposure, breastfeeding and suburban or rural environment can be protective. [ABSTRACT FROM AUTHOR]

The previous studies reported inconsistent associations of early residential decoration with childhood allergies and respiratory diseases. In this study, we conducted a 10-year retrospective observational survey among preschoolers from three urban districts in Chongqing of China in 2010 and in 2019, to investigate the associations of the prenatal and postnatal residential decorations with the childhood asthma, allergic rhinitis, eczema, wheeze, rhinitis, and pneumonia. We collected data from 4976 to 3971 of 3-6-year-olds preschoolers in the 2010 and 2019 surveys, respectively. The results showed that proportions of prenatal and postnatal residential decorations in different durations in 2010 were significantly higher than in 2019 (4.1%–19.6% vs. 2.1–5.3%). Except for allergic rhinitis (6.1% vs. 9.5%), prevalences of the studied diseases in 2010 also were significantly higher than in 2019 (for example: asthma: 8.2% vs. 6.1%; wheeze: 17.1% vs. 7.7%; rhinitis: 40.6% vs. 24.0%). In the two-level (district-child) logistic regression analyses, surveys in both 2010 and 2019 revealed that residential renovation and buying new furniture in prenatal and postnatal periods consistently increased odds of most studied diseases (ranges of adjusted odds ratio (AOR): 1.31–1.86). The prenatal decoration exposures had stronger associations with childhood allergies and respiratory diseases than the postnatal decoration exposures. The early residential decoration activities had stronger associations with allergies and respiratory diseases among girls and preschoolers without history of family allergy. Our findings indicate that prenatal and postnatal household decoration behaviors are risk factors for childhood airway diseases and allergies. Girls and children without family history of allergy are vulnerability groups. • A 10-years repeated survey was conducted in 2010 and 2019 in Chongqing. • Early home decoration was consistently associated with childhood allergy. • Prenatal decoration has stronger effect on these diseases than postnatal. • The associations were stronger in girls and children without history of atopy. [ABSTRACT FROM AUTHOR]

Food allergy increased in the recent years causing heavy disease burden worldwide, yet the unique factors for the second-wave allergy epidemic since a rise of allergic diseases are unclear. To examine the impact of introduction timing of complementary foods on childhood food allergy and whether ambient air pollution modify this association. A retrospective cohort study of 2,598 preschoolers was conducted at 36 kindergartens at Changsha of China during 2011–2012. A standard questionnaire was developed to survey each preschooler's introduction timing of complementary foods, food allergy, and home environments. Each subject's exposure to ambient air pollutants including PM 10 , SO 2 , and NO 2 was estimated for pregnancy and postnatal period. Association between food allergy and introduction timing of complementary foods as well as its modification by ambient pollution were evaluated by multiple logistic regression model. Childhood total food allergy (14.6%) was significantly positively associated with early introduction to fruit or vegetable before 3 months with OR = 1.97 (1.25–3.11), especially for egg and milk allergies. Food allergy was also significantly associated with NO 2 exposure in pregnancy especially during the 1st trimester with ORs (95% CI) = 1.24 (1.00–1.54) and 1.27 (1.03–1.58) and postnatal period with OR of 1.30 (1.01–1.66) respectively for per IQR increase in their exposure. We observed that living near traffic-main road and other areas significantly increased food allergy risk of early introduction of fruit and vegetable. We further detected that early introduction of milk powder or porridge significantly decreased the risk of food allergy at the condition of light outdoor air pollution exposure during postnatal period. Sensitivity analysis showed that children living at urban area, male sex, younger age, and having breast-feeding were more susceptible to the effect of early introduction of fruit and vegetable on food allergy. Our study indicates that the role of introduction timing of complementary foods on food allergy could be adjusted by air pollution exposure level, which may partly explain the second-wave allergy epidemic and provide a potential preventive strategy. [Display omitted] • Childhood food allergy was associated with early introduction of fruit and vegetable before 3 months. • Food allergy was related to NO 2 exposure in pregnancy especially 1st trimester and postnatal stage. • Living near traffic area increased food allergy risk of early introduction of fruits and vegetables. • Low air pollution increased protective effect of early introduction of food allergens on food allergy. • Air pollution modified effect of solid food addition at different time on food allergy development. [ABSTRACT FROM AUTHOR]

Microbial exposure has been indicated as significant in the development of asthma and allergy among children. The aim of the study was to test whether microbial exposure and allergens in the school environment are associated with asthmatic symptoms in pupils. Data on asthmatic symptoms and respiratory infections were collected through a questionnaire survey among 1993 pupils aged 11–15 yr in 10 randomly selected schools in Taiyuan, China. Settled dust in classrooms was analysed using tandem gas chromatography-mass spectrometry for 3-hydroxy fatty acids, marker of lipopolysaccharide (LPS) from endotoxin, muramic acid (MuA), marker of bacteria and ergosterol (Erg) for fungi, quantifying both culturable and non-culturable microbes. A total of 29.8% reported daytime attacks of breathlessness, 8.4% wheeze and 1.2% had doctor’s diagnosed asthma. Generally, MuA was negatively associated with wheeze and daytime attacks of breathlessness, the latter of which was negatively associated with Erg to a weaker extent. Total concentration of LPS was positively associated with daytime attacks of breathlessness, but shorter lengths of LPS, C10, C12 and C14 LPS were negatively associated with either wheezing or daytime attacks of breathlessness. For MuA and C10 and C12 of LPS, the associations were independent of airborne allergens and classroom crowdedness, and even independent of the other two microbial markers for MuA. Microbial exposure indicated by certain chemical markers (e.g. MuA) could be protective for asthmatic symptoms, but for LPS (endotoxin), the picture is more complex, varying by different lengths of fatty acids of LPS. [ABSTRACT FROM AUTHOR]

BACKGROUND: There are few studies on associations between children's respiratory heath and air pollution in schools in China. The industrial development and increased traffic may affect the indoor exposure to air pollutants in school environment. Moreover, there is a need to study respiratory effects of environmental tobacco smoke (ETS) and emissions from new building materials in homes in China. OBJECTIVES: We studied the associations between pupils' asthmatic symptoms and indoor and outdoor air pollution in schools, as well as selected home exposures, in a coal-burning city in north China. METHODS: A questionnaire survey was administered to pupils (11-15 years of age) in 10 schools in urban Taiyuan, collecting data on respiratory health and selected home environmental factors. Indoor and outdoor school air pollutants and climate factors were measured in winter. RESULTS: A total of 1,993 pupils (90.2%) participated; 1.8% had cumulative asthma, 8.4% wheezing, 29.8% had daytime attacks of breathlessness. The indoor average concentrations of sulfur dioxide, nitrogen dioxide, ozone, and formaldehyde by class were 264.8, 39.4, 10.1, and 2.3 μg/m³, respectively. Outdoor levels were two to three times higher. Controlling for possible confounders, either wheeze or daytime or nocturnal attacks of breathlessness were positively associated with SO2, NO2, or formaldehyde. In addition, ETS and new furniture at home were risk factors for wheeze, daytime breathlessness, and respiratory infections. CONCLUSIONS: Indoor chemical air pollutants of mainly outdoor origin could be risk factors for pupils' respiratory symptoms at school, and home exposure to ETS and chemical emissions from new furniture could affect pupils' respiratory health. [ABSTRACT FROM AUTHOR]

There is mounting evidence that exposure to household dampness/mold (D/M) is the cause of respiratory, allergic diseases for children. While few research focuses on the effects caused by building environment changes, from a longitudinal investigation perspective, especially for China experiencing a rapid development in recent years. This study aimed to explore the changes of D/M in Chinese homes over the past 10 years and identify the impacts of climate, building energy efficiency and residents' behaviors. The cross-sectional surveys were repeatedly conducted in children' residences in 2010 (Period I) and 2019 (Period II), among Taiyuan, Urumqi in northern China, and Nanjing, Shanghai, Wuhan, Changsha, Chongqing in southern China. Finally, 23465 children in Period I and 34720 children in Period II were involved, with no changes of residences since birth. The results showed that the proportions for reported D/M indicators were significantly reduced in Period II: e.g., 93.8% and 84.1% residents respectively answered no visible mold spots and damp stains in current residences, compared to only 78.3% and 62.2% in Period I. Southern homes accounted for high proportions for D/M indicator occurrences; warm-humid climate, annual higher precipitation and lower sunshine hours, etc., exacerbated the indoor D/M exposure risks. While residents' behaviors like ventilation, airing quilt/beddings, regular cleaning ameliorated the reported D/M significantly. The findings, from a temporal and spacious dimension perspective, advance our understanding of indoor D/M changes, precisely improvement in children' homes over the past 10 years, benefiting to promote indoor air quality standards in China. • Epidemiological surveys for household environment and children health were repeated in China. • Temporal and spacious comparisons of Dampness/Mold were stratified by Period-District. • Proportions of D/M were reduced in residents regardless of district difference. • Southern homes reported higher proportions for D/M indicators due to climates. • Residents' behaviors like ventilation modified the D/M exposure risks significantly. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

• Prenatal air pollution (PM 2.5 and PM 10) can increase furry pet related symptoms among pre-school children in China. • Indoor mould, dampness and window pane condensation can increase furry pet related symptoms and diagnosed rhinitis. • Early life cat and dog keeping can increase furry pet related symptoms and diagnosed rhinitis. • Prenatal farm exposure and living in less urbanized areas can protect against rhinitis not related to furry pets. Few Chinese population studies exist on early life risk factors for furry pet allergy. We studied childhood respiratory symptoms when in contact with furry pets in relation to early life exposure. Moreover, we studied similar environmental associations for rhinitis not related to furry pets. Children aged 3–6 y from day care centres in seven Chinese cities participated (N = 39,782). Parents answered a questionnaire on home environment and children's health, including rhinoconjunctivitis and wheeze when in contact with furry pets, and diagnosed rhinitis. Prenatal and postnatal outdoor temperature, PM 2.5 , PM 10 , and NO 2 were calculated using data from monitoring stations. Associations were estimated by multilevel logistic regression. Totally 2% had cats, 4% dogs, and 3.2% had rhinoconjunctivitis or wheeze when in contact with furry pets (FP symptoms). Moreover, 1.1% had furry pet related diagnosed rhinitis and 7.5% had diagnosed rhinitis not related to furry pets (other diagnosed rhinitis). Prenatal PM 2.5 and PM 10 , especially in second trimester, and a colder climate were risk factors for FP symptoms. ETS, dampness and mould, condensation on windows in wintertime, and cats and dog keeping were associated with FP symptoms. Breast feeding and frequent window opening were protective. Similar indoor associations were found for furry pet related diagnosed rhinitis. ETS, dampness and mould, window condensation, urbanization and mechanical exhaust ventilation were risk factors for other diagnosed rhinitis. Cooking with an electric stove and early life exposure to animals (cats, dogs, farm environment during pregnancy) were protective for diagnosed rhinitis not related to furry pets. Prenatal outdoor PM 10 and PM 2.5 can be risk factors for symptoms suggestive of furry pet allergy. Early life dampness and mould can be risk factors for rhinitis related and not related to furry pets. Exposure to animals (cats, dogs, farm environment) may reduce diagnosed rhinitis not related to furry pets. [ABSTRACT FROM AUTHOR]

Although mounting evidence have linked traffic-related air pollution (TRAP) with increased risk of preterm birth (PTB), whether it can interact with indoor environmental factors remains unknown, and its window(s) susceptibility at the stage of gestation is unclear. To explore PTB risk for prenatal exposure to traffic-related air pollution and home environmental factors during pregnancy, so as to identify critical window(s) in the combined effect of traffic air pollution and main home environmental factor(s) on PTB development. A retrospective cohort study of 3,509 preschool children was performed in Changsha, China during 2011–2012. The PTB prevalence was reported by the parents based on a questionnaire. We estimated each mother's exposure to traffic-related air pollutant NO 2 in different windows of gestation, including conception month, three trimesters, birth month, and whole gestation. Maternal exposure to home environmental factors was considered by renovation (new furniture/redecoration) in pregnancy, and mold/damp stains and window condensation during perinatal period. Associations of PTB with both ambient NO 2 and home environmental factors, and their interactions on PTB were evaluated by logistic regression models using odds ratio (OR) with 95% confidence interval (CI). Traffic air pollutant NO 2 exposure in utero was significantly associated with PTB, with adjusted odds ratio (OR) (95% CI) of 1.41 (1.00–1.98) for an IQR increase in NO 2 exposure during whole pregnancy, particularly in the conception month and 1st trimester. We further found a positive relationship between perinatal exposure to mold/damp stains in the homes and PTB, OR (95% CI) = 1.73 (1.04–2.90). Especially, we detected a significant interaction between outdoor NO 2 and indoor mold/damp stains on PTB risk. Male and female foetus were respectively more susceptible to perinatal mold/dampness at home and outdoor NO 2 exposure in early gestation. Our finding indicates that both outdoor traffic air pollutant and indoor mold/dampness play key roles in PTB development, and their interaction effect in early pregnancy significantly increases PTB risk. Image 1 • PTB was significantly associated with traffic air pollutant NO 2 exposure during pregnancy. • The effect of NO 2 exposure in the conception month and 1st trimester was more important. • Indoor mold/damp stains in pregnancy was also related with an increased risk of PTB. • There is a significant interaction between outdoor NO 2 and indoor mold/damp stains on PTB. • Sensitive populations were more susceptible to the PTB risk of outdoor and indoor air pollution. [ABSTRACT FROM AUTHOR]

Background Early life is suggested to be a critical time in determining subsequent asthma development, but the extent to which the effect of early-life exposure to ambient air pollution on childhood asthma is unclear. Objectives We investigated doctor-diagnosed asthma in preschool children due to exposure to ambient air pollution in utero and during the first year of life. Methods In total 2490 children aged 3–6 years participated in a questionnaire study regarding doctor-diagnosed asthma between September 2011 and January 2012 in China. Children’s exposure to critical air pollutants, sulfur dioxide (SO 2 ) as proxy of industrial air pollution, nitrogen dioxide (NO 2 ) as proxy of traffic pollution, and particulate matter≤10 µm in diameter (PM 10 ) as a mixture, was estimated from the concentrations measured at the ambient air quality monitoring stations by using an inverse distance weighted (IDW) method. Logistic regression analysis was employed to determine the relationship between early-life exposure and childhood asthma in terms of odds ratio (OR) and 95% confidence interval (CI). Results Association between early-life exposure to air pollutants and childhood asthma was observed. SO 2 and NO 2 had significant associations with adjusted OR (95% CI) of 1.45 (1.02–2.07) and 1.74 (1.15–2.62) in utero and 1.62 (1.01–2.60) and 1.90 (1.20–3.00) during the first year for per 50 µg/m 3 and 15 µg/m 3 increase respectively. Exposure to the combined high level of SO 2 and NO 2 in China significantly elevated the asthmatic risk with adjusted OR (95% CI) of 1.76 (1.18–2.64) in utero and 1.85 (1.22–2.79) during the first year compared to the low level exposure. The associations were higher for males and the younger children aged 3–4 than females and the older children aged 5–6. Conclusions Early-life exposure to ambient air pollution is associated with childhood asthma during which the level and source of air pollution play important roles. The high level and nature of combined industrial and traffic air pollution in China may contribute to the recent rapid increase of childhood asthma. [ABSTRACT FROM AUTHOR]

Few studies focus on the associations of green space composition and configuration with children's allergic rhinitis (AR). 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. 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. 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. • Forest aggregation and connectivity were negatively associated with AR symptoms. • Particulate matters mediated the inverse association of forest configuration with AR. • Age, exclusive breastfeed duration and season were the effect modifiers. [ABSTRACT FROM AUTHOR]

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. 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/m3 increase in exposure to particulate air pollution during in utero period and the first year of life. 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/m3 and 33.1 ± 6.9 μg/m3, 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/m3 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. 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. • The first study evaluated early-life exposure to ambient PM 1 and childhood AR. • Increased childhood AR risk associated with prenatal and postnatal exposures to ambient PM 1 and PM 2.5. • Later trimesters of gestation might be the sensitive window for early-life PM exposure and childhood AR. • Enhanced effect of early-life PM exposure on childhood AR was observed among younger and winter-born children. [ABSTRACT FROM AUTHOR]

Abstract During 2010–2012, we conducted an observational study on household environment and health outcomes among 40,010 preschool children from seven cities of China. Here we examined associations of six dampness-related indicators (visible mold spots, visible damp stains, damp clothing and/or bedding, water damage, condensation on windowpane, moldy odor) in the current residence and three dampness-related indicators (visible mold spots, condensation on windowpane, moldy odor) in the early residence with childhood asthma and rhinitis. In the multi-level logistic regression analyses, visible mold spots and visible damp stains in the current residence were significantly associated with the increased odds of doctor-diagnosed asthma and allergic rhinitis during lifetime-ever (adjusted odd ratios (AORs) range: 1.18–1.35). All dampness-related indicators were significantly associated with increased odds of wheeze and rhinitis during lifetime-ever and in the past 12 months (AORs range: 1.16–2.64). The cumulative numbers of damp indicators had positively dose-response relationships with the increased odds of the studied diseases. These associations for wheeze and rhinitis were similar between northern children and southern children. Similar results were found in the sensitive analyses among children without a family history of allergies and among children without asthma and allergic rhinitis. For 3–6 years-old children in mainland of China in 2011, we speculated that about 90,000 (2.02%) children with asthma and about 59,000 (1.09%) children with allergic rhinitis could be attributable to exposing to visible mold spots in the current residence. Our results suggested that early and lifetime exposures to household dampness indicators are risk factors for childhood asthma and rhinitis. Graphical abstract Unlabelled Image Highlights • We studied associations of dampness with asthma and rhinitis in children from seven cities. • Home dampness significantly associated and dose-response related with asthma and rhinitis. • The associations had no substantial differences in children from different climate zones. • We estimated burdens of the studied diseases attributable to home visible mold spots. [ABSTRACT FROM AUTHOR]

Background Although air pollution and social stress may independently increase childhood asthma, little is known on their synergistic effect on asthma, particularly in China with high levels of stress and air pollution. Objectives To examine associations between exposure to a combination of parental stress and air pollution and asthma prevalence in children. Methods We conducted a cohort study of 2406 preschool children in Changsha (2011–2012). A questionnaire was used to collect children’s lifetime prevalence of asthma and their parental stress. Parental socioeconomic and psychosocial stresses were respectively defined in terms of housing size and difficulty concentrating. Children’s exposure to ambient air pollutants was estimated using concentrations measured at monitoring stations. Associations between exposure to parental stress and air pollution and childhood asthma were estimated by multiple logistic regression models using odds ratio (OR) and 95% confidence interval (CI). Results Life time prevalence of asthma in preschool children (6.7%) was significantly associated with parental socioeconomic and psychosocial stresses with OR (95% CI) respectively 1.48 (1.02–2.16) and 1.64 (1.00–2.71). Asthma was also associated with exposure to air pollutants, with adjusted OR (95% CI) during prenatal and postnatal periods respectively 1.43 (1.10–1.86) and 1.35 (1.02–1.79) for SO 2 and 1.61 (1.19–2.18) and 1.76 (1.19–2.61) for NO 2 . The association with air pollution was significant only in children exposed to high parental stress, the association with parental stress was significant only in children exposed to high air pollution, and the association was the strongest in children exposed to a combination of parental stress and air pollution. Sensitivity analysis showed that the synergistic effects of parental stress and air pollution on childhood asthma were stronger in boys. Conclusions Parental stress and air pollution were synergistically associated with increased childhood asthma, indicating a common biological effect of parental stress and air pollution during both prenatal and postnatal periods. [ABSTRACT FROM AUTHOR]

Background Otitis media (OM) is a common infection in early childhood with repeated attacks that lead to long-term complications and sequelae, but its etiology still remains unclear. Objective To examine the association between early life exposure to air pollution and childhood OM, with the purpose of identifying critical windows of exposure and key components of air pollution in the development of OM. Methods We conducted a prospective cohort study of 1617 children aged 3–4 years in Changsha, China (2011–2012). The prevalence of OM was assessed by a questionnaire administered by the parents. Individual exposures to nitrogen dioxide (NO 2 ), sulfur dioxide (SO 2 ) and particulate matter with an aerodynamic diameter ≤ 10 μm (PM 10 ) during prenatal, postnatal, and current windows were estimated using the measured concentrations at monitoring stations. We used logistic regression model to examine the OM risk in terms of odds ratio (OR) and 95% confidence interval (CI) for exposure to different air pollutants during different timing windows, adjusting for covariates, multi-pollutants, and multi-windows. Results Life-time prevalence of doctor-diagnosed OM in preschool children in Changsha was 7.3%. Childhood OM was associated only with prenatal exposure to the industrial air pollution with adjusted OR (95% CI) = 1.44 (1.09–1.88) for a 27 μg/m3 increase in SO 2 , particularly during the first trimester of pregnancy. We further found that prenatal SO 2 exposure was not associated with the repeated attacks but was associated with the onset of OM, adjusted OR (95% CI) = 1.47 (1.10–1.96). The association between prenatal SO 2 exposure and early childhood OM was robust after adjusting for other pollutants and windows. Sensitivity analysis indicated that the association was stronger in females, children with parental atopy, and children living in houses with cockroaches, new redecoration, and condensation on window pane during winter. Conclusion We provide new evidence that prenatal exposure to industrial air pollution is associated with early childhood OM in China and may contribute to the onset of childhood OM. Our findings are helpful in developing more effective preventative strategies for childhood OM. [ABSTRACT FROM AUTHOR]

Evidence from developed countries on the association between greenspace and childhood respiratory health has been inconsistent whilst such evidence is largely lacking in the developing world where rapid urbanization is occurring. This study aimed to investigate the associations between surrounding greenness, air pollution and respiratory health among pre-school children in a rapidly developing city in China. We recruited 2920 pre-school children in Taiyuan city. Greenness exposure was represented by the Normalized Difference Vegetation Index (NDVI) which combined estimations based on a weighted mean that children spend time both in kindergarten and home (75% home, 25% kindergarten). Air pollution exposures were estimated from a land-use-regression model which was also calculated based on a weighted mean as with greenness. Logistic regression was performed to assess the relationships between greenness, air pollution and respiratory symptoms. Greenness had negatively impacted respiratory health among pre-school children in Taiyuan city, particularly for current dry cough at night. A 0.1-unit increment for NDVI 300m was associated with an Odds Ratio (OR) of 2.45 (95%CI: 1.33–4.53) for dry cough at night. The associations were robust after adjusting for air pollution and road condition. No statistically significant associations were found between air pollution and any symptoms. The mediating effect of air pollution on dry cough at night with greenness was not observed. Our study found that within different buffers, a higher level of greenness was consistently associated with a higher risk of dry cough at night among pre-school children. This finding has indicated that environmental policies on urban greening should be scientifically justified to protect respiratory health among young children. [Display omitted] • Surrounding greenness negatively impacted respiratory health in pre-school children. • Higher greenness may be linked to higher risk of dry cough at night. • Exposing to different levels of PM 2.5 , NO 2 and O 3 can increase the associations. [ABSTRACT FROM AUTHOR]

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. 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. 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). 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. 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. [Display omitted] • The association between air pollution and food allergy (FA) in children is unclear. • Airway is a new pathway contributing to FA, in addition to gut and skin. • Prenatal exposure to both outdoor and indoor air pollution increased FA risk. • High levels of outdoor and indoor air pollution may cause the rapid increase of FA in China. • Air pollution leads to the first and second waves of allergy epidemics. [ABSTRACT FROM AUTHOR]

Indoor environment is associated with the sick building syndrome (SBS), but little is known about the contribution of outdoor air pollution and meteorological conditions to SBS. We studied associations between outdoor air pollution, meteorological parameters and selected indoor exposure and building characteristics at home and weekly SBS symptoms in a standardized questionnaire study among 3485 randomly selected adults in China. Outdoor factors included particulate matters with diameter < 10 μm (PM 10 ), sulfur dioxide (SO 2 ), nitrogen dioxide (NO 2 ), outdoor temperature (T), relative air humidity (RH), and wind speed (WS) during last three months. Multiple logistic regression was applied calculating odds ratios (OR) with 95% confidence interval (95% CI). Asthma or allergic rhinitis (atopy) was associated with all types of SBS symptoms except fatigue. Indoor factors played a major role in SBS symptoms. Mold/dampness on the floor/ceiling was associated with fatigue OR = 1.60 (1.11–2.30) and headache OR = 1.80 (1.07–3.04). Moldy odor was associated with fatigue OR = 1.59 (1.07–2.37) and dermal symptoms OR = 1.91 (1.21–3.02). Window pane condensation in winter was associated with fatigue OR = 1.73 (1.30–2.31) and throat symptoms OR = 1.53 (1.01–2.31). Damp bed clothing was related with throat symptom OR = 1.62 (1.09–2.40). Home redecoration was associated with fatigue OR = 1.49 (1.07–2.06). Frequent window opening was associated with less nose symptoms OR = 0.54 (0.36–0.82) and mechanical ventilation in the bathroom reduced dermal symptoms OR = 0.66 (0.44–0.99). Females were more susceptible to redecoration and window pane condensation than men. No associations with SBS were observed for outdoor air pollutants or meteorological parameters in the final models combining indoor and outdoor factors, although SO 2 , T, and RH were associated with some SBS symptoms (fatigue, eyes and nose symptoms) in the separate outdoor models. In conclusion, indoor mold/dampness, air pollution from redecoration and poorer ventilation conditions in dwellings can be risk factors for SBS symptoms in an adult Chinese population, especially among females. [ABSTRACT FROM AUTHOR]

Northern China has severe air pollution, especially in winter. Fractional exhaled nitric oxide (FeNO) is an established biomarker of airway inflammation. To study associations between ambient temperature, air pollution and FeNO in university students in northern China. 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. 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/m3 for PM 10 , 72.0–180.0 μg/m3 for PM 2.5 , 36.0–347.0 μg/m3 for SO 2 , 26.0–69.0 μg/m3 for NO 2 , 31.0–163.0 μg/m3 for O 3 and 0.93–3.14 mg/m3 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. 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. • PM 10 , PM 2.5 and SO 2 can be associated with higher FeNO in Chinese university students. • Outdoor carbon monoxide (CO) in northern China can be associated with lower FeNO. • Higher ambient temperature can be associated with higher FeNO in northern China. • Outdoor air pollution in northern China can be associated with airway inflammation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Early life exposure to traffic pollutant nitrogen dioxide (NO 2) plays a key role in childhood asthma. • Pre- or post-natal exposure to increased temperature and extreme hot day elevates asthma risk. • Co-exposure to both high temperatures and air pollution significantly increases risk of asthma. • Boys and younger children are more susceptible to postnatal heat-particle interaction on asthma. • Our study suggests a hypothesis of "fetal origin of asthma" via temperature-pollution interaction. 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. To explore the effects of temperature-pollution interactions during pre- and post-natal periods on asthma among pre-schoolers. 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). 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. Prenatal and postnatal exposure to ambient air pollution and high temperatures are independently and jointly associated with asthma risk in early childhood. [ABSTRACT FROM AUTHOR]

[Display omitted] 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. To examine potential associations of early-life exposures to PM 2.5 mass and its major chemical constituents with childhood asthma and wheezing. 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. 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/m3, 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. 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. [ABSTRACT FROM AUTHOR]

[Display omitted] 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. 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. 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. 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. [ABSTRACT FROM AUTHOR]

The main aim was to study associations between asthma, allergic rhinitis and eczema among adults across China and dampness and mold at home. Young adults (N = 40,279) in eight cities in China answered a questionnaire in 2010–2012 (response rate 75.0%). Data on asthma, allergic rhinitis, eczema and the home environment was assessed by the questionnaire. Climate data was obtained from China Meteorological Administration and the website of Weather Underground. Health associations were analyzed by two-level logistic regression models, adjusting for covariates. Totally 1.6% had asthma, 6.6% allergic rhinitis and 2.2% eczema. Mold odor was associated with asthma (OR = 1.90) and allergic rhinitis (OR = 1.25–1.44). Window pane condensation in winter was associated with asthma (OR = 1.39), allergic rhinitis (OR = 1.26–1.58) and eczema (OR = 1.36–1.77). Presence of mold spots or damp stains was related to asthma (OR = 1.58–2.49), allergic rhinitis (OR = 1.35–1.76) and eczema (OR = 1.47–1.70). Water damage was related to asthma (OR = 1.69–1.82), allergic rhinitis (OR = 1.40–1.45) and eczema (OR = 1.44–1.96). Damp bed clothing was related to asthma (OR = 1.23), allergic rhinitis (OR = 1.23) and eczema (OR = 1.35). A higher dampness score was associated with increased odds ratios for diseases. Those living in older buildings had more asthma (OR = 1.39–1.76) and allergic rhinitis (OR = 1.16–1.21). Those living in suburban or rural areas had less asthma, allergic rhinitis and eczema as compared to those living in urban areas (OR values from 0.24 to 0.66). Stronger health associations with dampness and mold were found in southern China and in newer buildings (constructed after 2005). In conclusion, dampness and mold at home can be risk factors for asthma, allergic rhinitis and eczema among adults in China. Living in older buildings can be risk factors for asthma or allergic rhinitis while living in less urbanized areas can be protective. • Dampness/mold can be risk factors for adult asthma, allergic rhinitis or eczema. • Living in old buildings can be a risk factor for adult asthma and allergic rhinitis. • Less urbanized areas have less adult asthma, allergic rhinitis and eczema. • High ambient temperature and high precipitation can influence eczema. [ABSTRACT FROM AUTHOR]

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.)

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.

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.

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.

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.

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.)

We investigated associations between prenatal and postnatal environmental factors and onset and remission of preschool childhood eczema across China. The study population was preschoolers in randomized day care centers in seven cities (N = 39,782). Data on eczema and prenatal and postnatal indoor and outdoor environment were obtained from a cross-sectional questionnaire sent to parents or other guardians. Reports on eczema in the first 2 years and in the past year was used to retrospectively calculate onset and remission (changes of reported eczema). Prenatal and postnatal outdoor temperature, NO 2 and PM 10 were modelled from official air pollution data. Associations were estimated by two-level logistic regression. Calculated onset rate was 3.2%/y and remission rate 29.2%/y. Exposure to NO 2 during pregnancy was associated with onset of eczema, similarly for all trimesters. Postnatal PM 10 and NO 2 were related to decreased remission. Postnatal outdoor temperature was associated with onset of eczema. Pre-natal and current redecoration or buying new furniture, and perinatal as well as current dampness and indoor mould, were associated with increased onset and decreased remission. Cockroaches in current home was another indoor risk factors. Prenatal exposure to farm environment and large family size were all negatively associated with eczema. In conclusion, a warmer climate and prenatal NO 2 can be associated with increased onset of eczema in Chinese preschoolers. Postnatal PM 10 and NO 2 can be associated with reduced remission. Perinatal and current dampness, indoor mould and cockroaches may increase onset and decrease remission. Exposure to chemical emissions from indoor materials after first year of life may increase onset. Prenatal exposure to farm environment and large family size could be protective., 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 © 2020 The Author(s). Published by Elsevier B.V. All rights reserved.)

We estimated associations between ambient air pollution, home environment and asthma as well as rhinitis among adults across China. A total of 40,279 young adults from eight Chinese cities participated in a questionnaire survey (participation rate 75%). There were questions on health and home environment. Information on city level gross domestic product (GDP) per capita, ambient temperature and PM 10 and NO 2 were collected from registers. Two-level logistic regression models were used to study health associations. Totally 1.6% reported asthma and 6.6% reported allergic rhinitis (AR). Higher temperature was associated with more asthma but less AR. Higher GDP was associated with less asthma but more AR. Higher degree of urbanization, higher level of NO 2 and living near heavily trafficked road were risk factors for asthma and AR. Participants in older buildings reported more asthma. Redecoration and buying new furniture were related to more asthma and AR (OR = 1.15-1.91). Using natural gas (OR = 1.34) and biomass (OR = 1.35) for cooking were risk factors for AR. Burning mosquito coils and incense increased the risk of asthma and AR. Cat keeping (OR = 2.88), dog keeping (OR = 2.04), cockroaches (OR = 1.54) and rats or mice (OR = 1.46) were associated with asthma. Cockroaches increased the risk of AR (OR = 1.22). Air humidifier and air cleaner were linked to asthma and AR. Frequent cleaning and exposing bedding to sunshine were protective. In conclusion, urbanization, NO 2 and traffic exhaust can increase the risk of adult asthma and AR. Higher ambient temperature was related to more asthma but less AR. Indoor animals such as cats, dogs, rats/mice and presence of cockroaches were associated with asthma or AR. Indoor chemical sources such as redecoration and new furniture were other risk factors. Cooking with natural gas or biomass and burning mosquito coils and incense were associated with asthma or AR. Frequent cleaning and exposing bedding to sunshine were protective., Competing Interests: Declaration of competing interest The authors declare that they have no known competing interest., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

This paper studied associations between reported common cold and home dampness and mould, cleaning habits and ventilation, climate and outdoor air pollution in China among young adults without asthma or allergic rhinitis. Parents of children attending day care in eight Chinese cities answered a questionnaire on their health and home environment (75% response rate). We restricted the population to subject without asthma or allergic rhinitis (N = 37,275). Temperature and air pollution data was obtained from monitoring stations. Associations were estimated by multilevel logistic regression. Totally 12.5% reported common cold (≥3 colds) and 1.6% frequent common cold (≥5 colds) in the past 12 months. Female gender (OR = 1.53; 95% CI 1.37-1.71), residents in southern China (OR = 1.89; 95% CI 1.16-3.07) and living in homes with water leakage (OR = 1.32; 95% CI 1.16-1.50), mould odour (OR = 1.48; 95% CI 1.28-1.72), indoor mould (OR = 1.47; 95% CI 1.28-1.70), condensation on window panes (OR = 1.42; 95% CI 1.32-1.52) and damp bed clothing (OR = 1.19; 95% CI 1.11-1.28) were associated with common cold. Having many signs of dampness increased ORs. Daily cleaning (OR = 0.91; 95% CI 0.85-0.97) and mechanical ventilation in kitchen or bathroom (OR = 0.75; 95% CI 0.64-0.89) were protective. Higher mean ambient temperature (OR = 1.11 per °C; 95% CI 1.02-1.21), PM 10 (OR = 1.17 per 10 μg/m 3 ; 95% CI 1.14-1.21) and PM 2.5 (OR = 1.28 per 10 μg/m 3 ; 95% CI 1.20-1.37) were associated with common cold. The association with particulate air pollution was stronger in southern China. Similar associations were found for frequent common cold. In conclusion, indoor dampness and mould, a warmer climate and PM 10 and PM 2.5 can be associated with reported common cold. Further intervention and prospective studies are needed to verify causality of observed association in this cross-sectional study., 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 © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

Introduction: Although mounting evidence has linked environmental factors with childhood allergies, some specific key issues still remain unclear: what is the main environmental factor? what is the critical timing window? And whether these contribute to the development of disease?, Areas Covered: This selective review summarizes recent epidemiological studies on the association between early-life exposure to indoor/outdoor air pollution and childhood allergic diseases. A literature search was conducted in the PubMed and Web of Science for peer-reviewed articles published until April 2020. Exposure to the traffic-related air pollutant, NO 2 , exposure during pregnancy and early postnatal periods is found to be associated with childhood allergies, and exposure during different trimesters causes different allergic diseases. However, exposure to classical air pollutants (PM 10 and SO 2 ) also contributes to childhood allergy in developing countries. In addition, early-life exposure to indoor renovation and mold/dampness significantly increases the risk of allergy in children. A synergistic effect between indoor and outdoor air pollution is found in the development of allergic diseases., Expert Opinion: Early-life exposure to outdoor air pollution and indoor environmental factors plays an important role in the development of childhood allergic diseases, and the synergy between indoor and outdoor exposures increases allergy risk. The available findings support the hypothesis of the 'fetal origins of childhood allergy,' with new implications for the effective control and early prevention of childhood allergies.

Few studies exist from China on associations between home environment and adult health. We studied associations between home environment factors (other than dampness and mould) and rhinitis, throat and dermal symptoms and headache and fatigue among young parents in six cities across China (N = 36,541). They were recruited as parents from day care centers selected randomly and answered a questionnaire on medical symptoms and the home environment. Odds ratios (OR) were calculated by multilevel logistic regression adjusting for gender, atopy, smoking, home size and dampness/mould. Overall, 4.8% had skin symptoms 3.1% rhinitis, 2.8% eye, 4.1% throat symptoms, 3.0% headache and 13.9% had fatigue (all as weekly symptoms). Redecoration was associated with rhinitis, eye and skin symptoms, headache and fatigue. New furniture was associated with eye, throat and skin symptoms and fatigue. Gas cooking was associated with eye and throat symptoms, headache and fatigue. Biomass cooking was associated with eye and throat symptoms and headache. Burning incense was associated with eye, throat and skin symptoms, headache and fatigue. Presence of cockroaches and mosquitos or flies was associated with all six symptoms. Rats or mice were associated with eye and dermal symptoms. Cat keeping was associated with eye symptoms while dog keepers had less fatigue. Living near major roads was associated with rhinitis, eye, throat and skin symptoms and fatigue. Daily cleaning, a mechanical ventilation system in the kitchen or in the bathroom, living in older buildings and living in less urbanized areas were protective factors. In conclusion, urbanization, traffic exhaust, indoor emissions from redecoration and new furniture, gas cooking and air pollution from burning incense and biomass may cause dermal and mucosal symptoms, headache and fatigue among adults in China. Indoor animals (cats, mice/rats, cockroaches) were other risk factors. Daily cleaning, mechanical ventilation and living in older buildings can be protective., (Copyright © 2019. Published by Elsevier B.V.)

We studied indoor sources of indoor particulate matter (PM), outdoor air pollution and antibiotic use in relation to asthma, rhinitis and eczema among pre-school children and investigated synergistic effects between PM and antibiotics use. Children (3-6y) from randomly selected day care centres in seven cities across China were included (n = 39,782). Data on ambient temperature and air pollution were collected from local monitoring stations. Data on indoor PM sources (ETS, burning of incense or mosquito coils and biomass for cooking), antibiotics use and health (doctor diagnosed asthma and rhinitis, lifetime eczema, current wheeze and current rhinitis) were assessed by a parental questionnaire. Associations were calculated by multilevel logistic regression. Asthma diagnosis was associated with outdoor temperature, NO 2 and burning mosquito coils. Rhinitis diagnosis was associated with NO 2 , ETS, gas cooking and burning biomass for cooking. Lifetime eczema was associated with temperature, PM 10, NO 2 , ETS, biomass cooking and burning mosquito coils. Burning incense was associated with current wheeze and current rhinitis. Children using antibiotics had more asthma, wheeze, rhinitis, and eczema. Excluding children with respiratory infections did not change associations with antibiotics use. Antibiotics use enhanced the effects of ETS and PM 10 (a synergistic effect). In conclusion, a warmer climate, outdoor NO 2 and PM 10, ETS, gas cooking and burning biomass, incense and mosquito coils can increase the risk of asthma, wheeze, rhinitis and eczema among pre-school children in China. Antibiotics use is a risk factor for childhood asthma, wheeze, rhinitis and eczema and ETS and outdoor PM 10 can enhance the effect., (Copyright © 2019 The Authors. Published by Elsevier Ltd.. All rights reserved.)

From October 2010 to April 2012, we conducted a cross-sectional study of associations between household environments and childhood health among preschool children in eight Chinese cities. Here, we analyze associations of early household renovation with preterm birth (PTB), low birthweight (LBW), term low birthweight (Term-LBW), and small for gestational age (SGA). Parents responded to questions about household renovation and their children's gestational age and birthweight. In the multivariate logistic regression analyses, household renovation in the year before pregnancy was significantly associated with LBW (sample size: N = 25 813; adjusted odds ratio (OR) with 95% confidence intervals (CIs): 1.23, 1.01-1.50) and Term-LBW (N = 24 823; 1.29, 1.01-1.67). Household renovation during pregnancy was significantly associated with PTB (N = 25 202; 1.28, 1.01-1.69). These significant associations were also found in the two-level (city-child) logistic regression analyses and in the sensitivity analyses among 21 009 children with complete data in all studied variates. Stronger associations were found in certain subgroups. Our findings indicate that household renovation within one year before pregnancy might be a risk factor for LBW and Term-LBW, while household renovation during pregnancy could be a risk factor for PTB., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objective: Few longitudinal studies exist on childhood exposure to indoor and outdoor air pollution and respiratory illness in China. We studied associations between indoor and outdoor environment and prevalence, onset and remission of wheeze and rhinitis among children across China., Methods: Children (3-6 y) were recruited from randomized day care centres in six cities. The main data analysis was restricted to children not moving since birth (N = 17,679). Data on wheeze, rhinitis and the home environment were assessed by a parental questionnaire. Prevalence in the first two years of life (baseline) and the last year (follow-up) was used to calculate onset and remission. Outdoor PM 2.5 , PM 10 , and NO 2 at the day care centre were modelled from monitoring station data. Associations were calculated by multilevel logistic regression., Results: Prenatal NO 2 was associated with decreased remission of wheeze and increased prevalence and increased onset of rhinitis. Prenatal PM 2.5 was associated with increased prevalence of wheeze. Postnatal NO 2 and postnatal PM 10 were associated with increased prevalence and lower remission of wheeze and rhinitis. Mould, window pane condensation, renovation and cockroaches at home were associated with increased prevalence and increased onset of wheeze and rhinitis. Gas cooking was associated with increased onset of rhinitis. Children of mothers with industrial work had more wheeze., Conclusions: Outdoor PM 2.5 , PM 10 and NO 2 can increase childhood wheeze and rhinitis. Dampness and mould can increase onset and decrease remission. Crowdedness, cockroaches at home and emissions from new building materials and gas cooking can be risk factors for wheeze and rhinitis., (Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Few data exist on asthma and rhinitis across China in relation to indoor and outdoor air pollution, climate and socioeconomic factors. The main aim was to study associations between asthma, rhinitis and current respiratory symptoms among pre-school children across China and selected indoor and outdoor exposure and indicators of socio-economic status (SES) in mutually adjusted models., Methods: Chinese children (3-6 yr.) (n = 39,782) were recruited from randomly selected day care centres in seven cities in China. Data on asthma, respiratory symptoms, rhinitis, indoor and outdoor exposure at home and SES were assessed by a parentally administered questionnaire. Lifetime mean ambient temperature, PM 10 , NO 2, and GDP per capita on city level were calculated., Results: Totally 7.4% had ever doctors' diagnosed (DD) asthma and 8.7% DD-rhinitis, 19.7% had current wheeze, 45.0% rhinitis and 16.9% cough. DD-asthma was associated with ambient temperature (OR = 1.15, 95% CI 1.11-1.20 per °C), NO 2 (OR = 1.16, 95% CI 1.02-1.33 per 10 μg/m 3 ), indoor mould/dampness (OR = 1.25, 95% CI 1.13-1.39) and living near major roads (OR = 1.13, 95% CI 1.02-1.25). DD-rhinitis was associated with ambient temperature (OR = 1.07, 95% CI 1.05-1.10 per °C), NO 2 (OR = 1.20, 95% CI 1.09-1.32 per 10 μg/m 3 ), GDP (OR = 1.03, 95% CI 1.01-1.06 per 10,000 RenMinBi/year), indoor mould/dampness (OR = 1.23, 95% CI 1.11-1.35), passive smoking (OR = 1.11, 95% CI 1.01-1.21), and living near major roads (OR = 1.14, 95% CI 1.03-1.25). Children in suburban or rural areas, in larger families (≥5 persons) and with prenatal farm exposure had less DD-asthma and DD-rhinitis., Conclusions: Economic development level of the city, higher SES, ambient temperature, NO 2 , PM 10 , traffic air pollution and mould/dampness can be risk factors for asthma and rhinitis and respiratory symptoms among pre-school children in China. Breastfeeding, large family size and early-life farm exposure could be protective factors., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

It is well known that exposure to thermal stress during pregnancy can lead to an increased incidence of premature births. However, there is little known regarding window(s) of susceptibility during the course of a pregnancy. We attempted to identify possible windows of susceptibility in a cohort study of 3604 children in Changsha with a hot-summer and cold winter climatic characteristics. We examined the association between PTB and ambient temperature during different timing windows of pregnancy: conception month, three trimesters, birth month and entire pregnancy. We found a U-shaped relation between the prevalence of PTB and mean ambient temperature during pregnancy. Both high and low temperatures were associated with PTB risk, adjusted OR (95% CI) respectively 2.57 (1.98-3.33) and 2.39 (1.93-2.95) for 0.5 °C increase in high temperature range (>18.2°C) and 0.5°C decrease in low temperature range (< 18.2°C). Specifically, PTB was significantly associated with ambient temperature and extreme heat/cold days during conception month and the third trimester. Sensitivity analysis indicated that female fetus were more susceptible to the risk of ambient temperature. Our study indicates that the risk of preterm birth due to high or low temperature may exist early during the conception month., (Copyright © 2018 Elsevier Ltd. All rights reserved.)