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Despite mounting evidence linking indoor and outdoor environments to eczema, the role of indoor and outdoor environmental pollutant(s) exposure during critical time window(s) on eczema remains unknown. To investigate the correlations between childhood eczema and itchy rashes and exposure to outdoor air pollution and the home environment. A combined cross-sectional and retrospective cohort study of 8689 kindergarten students was conducted. We collected information about each child's health outcomes and home environment, as well as calculated individual exposure to air pollutants. Multiple logistic regression models were used to investigate the links between indoor and outdoor environments and childhood eczema and itchy rashes. Childhood ever doctor-diagnosed eczema (DDE) was linked to NO 2 , CO, PM 2.5 , PM 2.5-10 and PM 10 exposure during the preconceptional, pregnant, and postnatal periods, with ORs (95 % CI) ranging from 1.06 (1.00–1.13) to 1.21 (1.08–1.37). Ever doctor-diagnosed itchy rash (DDIR) was associated with SO 2 , CO, PM 2.5 , PM 2.5-10 and PM 10 exposure during preconceptional and postnatal periods, with ORs (95 % CI) ranging from 1.11 (1.02–1.20) to 1.31 (1.13–1.52). Preconceptional outdoor air pollution was associated with a higher risk of ever, early, and late DDE and DDIR. Indoor smoke, renovation, and dampness were all associated with DDE and DDIR. Postnatal exposure to plants has been linked to both ever and early DDE. There was no link between indoor environments and late DDE. Furthermore, pregnancy has been identified as a critical indoor exposure time window for DDE and DDIR. Early-life exposure to outdoor air pollutants and indoor environments, particularly before birth, played important roles in childhood eczema. [Display omitted] • Preconceptional, prenatal, and postnatal exposures to CO, NO 2 , PM 2.5 and PM 10 increase the risk of eczema. • Preconception and the first year are critical time windows for CO or PM 2.5 exposure in relation to itchy rashes. • Prenatal and postnatal indoor factors are important for early and late eczema and itchy rashes. • Postnatal indoor factors exposure played a key role in the development of later and current itchy rashes. • Our findings lend credence to the "fetal origin of childhood atopic dermatitis" hypothesis. [ABSTRACT FROM AUTHOR]

Doctor-diagnosed plant allergy (DPA) in children has emerged as a significant global public health concern. However, the role of antibiotics and indoor environmental factors (IEFs) in childhood DPA remains unknown. To investigate the correlations between childhood DPA and exposure to antibiotics and IEFs during different time periods. A retrospective cohort study of 8,689 preschoolers was performed in Changsha, China. We collected data on each child's health outcomes, antibiotics use and home environment by a questionnaire, as well as temperature and air pollutants in Changsha, and calculated personal exposure to temperature and pollutants. Multiple logistic regression models were used to assess the independent and joint effects of antibiotics and IEFs on childhood DPA. Life-time and early-life antibiotics use was associated with childhood DPA with ORs (95% CI) = 1.58 (1.15–2.17) and 1.33 (1.04–1.69), with a higher risk for early-life exposure than later-life exposure. Renovation-specific indoor air pollution (IAP) during pre-birth (1 year before pregnancy and pregnancy) and smoke-specific IAP during early life (pregnancy and first year) had significantly impacts on childhood DPA. Furthermore, dampness-specific allergens throughout lifetime elevated the risk of DPA, with ORs ranging from 1.34 (1.00–1.81) to 1.93 (1.44–2.59). Moreover, life-time and early-life antibiotic use significantly increased the DPA risk attributed to some specific IEFs, such as ETS especially grandparental smoking, exposure during first year and previous year, with a significant interaction. Life-time and early-life exposure to antibiotics and IEFs independently and jointly played key roles in the development of DPA , supporting the "fetal origin of childhood PA" hypothesis. [Display omitted] • Life-time and early-life antibiotic use increased the risk of childhood plant allergy (PA). • Renovation-specific indoor air pollution (IAP) exposure before birth elevated the risk of PA. • Smoke-specific IAP exposure during early life was associated with increased risk of PA. • Dampness-specific indoor allergens exposure throughout lifetime was related with PA risk. • Antibiotic use significantly increased childhood PA risk attributed to smoke-specific IAP. [ABSTRACT FROM AUTHOR]

We studied time trends in home environment and sick building syndrome (SBS) symptoms in a repeat study in five cities in southern China. Moreover, we studied associations between home environment exposure and SBS symptoms. Parents from randomly selected day care centers were invited. One parent per family answered a questionnaire on the home environment and their own SBS symptoms. Data collection was performed in two surveys in 2010 and 2019 (27,292 participants in 2010 and 32,073 in 2019). We used two-level logistic regression to analyze health associations. Asthma decreased from 1.7% to 1.5% (P < 0.05) but allergic rhinitis increased from 6.5% to 16.4% (P < 0.001). All SBS symptoms decreased from 2010 to 2019 (all P < 0.001). Most aspects of the home environment improved from 2010 to 2019 but there were less cleaning, more cats, dogs, and urbanization in 2019. Redecoration, new furniture, and pests were associated with most types of SBS symptoms, similarly in 2010 and 2019. Environmental tobacco smoke (ETS) was associated with SBS symptoms in 2019 only. In conclusion, prevalence of SBS symptoms among young parents in southern China decreased from 2010 to 2019 but allergic rhinitis increased. Cockroaches, rats, mice, mosquitoes or flies can be consistent biological risk factors for SBS symptoms. Redecoration, buying new furniture and traffic air pollution are other risk factors for SBS symptoms. Daily cleaning, frequently putting bedding to sunshine, and having a fan in the bathroom can be protective factors. ETS is an emerging risk factor for SBS symptoms. [Display omitted] • The home environment was improved and SBS symptoms decreased from 2010 to 2019. • Redecoration, new furniture, traffic pollution and ETS can increase SBS symptoms. • Cockroaches, rats, mice, mosquitoes and flies at home can increase SBS symptoms. • Daily cleaning and exposing bedding outdoors to sunshine can reduce the symptoms. • Installing mechanical exhaust ventilation in the bathroom can reduce SBS symptoms. [ABSTRACT FROM AUTHOR]

We investigated associations between dampness in Chinese homes and sick building syndrome (SBS) symptoms and studied the role of climate, family size, cleaning and ventilation for dampness, mould and SBS. A questionnaire survey was done in 2019–2020 among adults in five cities (32349 participants) and data on outdoor climate was collected. Multilevel logistic regression was used to calculate adjusted odds ratios (ORs). In total, 2.2% had rhinitis, 1.8% eye, 1.6% throat and 2.9% skin symptoms, 2.1% headache and 8.7% fatigue (weekly symptoms). Overall, 12.1% reported indoor mould, 5.7% damp bedding, 5.3% mould odour and 33.8% humid air in current home. Mould was associated with all symptoms (ORs 1.86–2.15 for minor mold growth and 1.65–3.45 for major mould growth). Damp bedding was associated with all symptoms (ORs 2.18–2.80 for minor dampness and 2.51–8.03 for major dampness). Mould odour was associated with all symptoms (ORs 1.84–2.77 for sometimes odour and ORs 3.78–7.80 for weekly odour). Perception of humid air was associated with all symptoms. ORs increased by number of dampness signs. Precipitation, outdoor relative air humidity and temperature increased dampness, mould and SBS symptoms. Large family size increased dermal symptoms. Daily floor cleaning, airing in winter, putting bedding to sunshine and mechanical ventilation in the bathroom reduced dampness, mould and SBS symptoms. In conclusion, mould and dampness in Chinese homes can increase rhinitis and SBS-symptoms in a dose-response manner. A warmer and more humid climate can increase, and cleaning and ventilation in the home can decrease dampness, mould and SBS symptoms. • Mould and dampness can increase medical symptoms in adults in a dose-response manner. • Precipitation, temperature and air humidity can increase domestic dampness and mould. • Precipitation, temperature and relative air humidity can increase medical symptoms. • Cleaning and putting bedding to sunshine can reduce dampness, mould and symptoms. • Airing and mechanical ventilation can reduce dampness, mould and medical symptoms. [ABSTRACT FROM AUTHOR]

Despite mounting evidence linking asthma to air pollution, it remains unclear which specific pollutant(s) exposure during critical time window(s) plays a pivotal role in the development of asthma. The objective of this study is to investigate the effects of intrauterine and postnatal air pollution exposure on children's asthma. From 2019 to 2020, a retrospective cohort study was conducted in Changsha, China. The inverse distance weighted (IDW) method was used to estimate each child's personal exposure to outdoor air pollutants at their home address. Associations between personal air pollution exposure and asthma were comprehensively examined. The occurrence of children's asthma was found to be linked to exposure to PM 2.5 and NO 2 during both the intrauterine and current periods, with significant ORs (95% CI) of 1.44 (1.08–1.93) and 1.29 (1.00–1.68) for IQR increase in intrauterine exposure particularly during the 2nd trimester, and 1.26 (1.01–1.57) and 1.26 (1.04–1.51) for exposure in previous year. Post-natal PM 10 exposure was linked to asthma, with an OR (95% CI) of 1.28 (1.01–1.62). Higher risks of asthma were associated with intrauterine exposure to PM 2.5 and postnatal exposure to PM 10. The critical time windows for PM 2.5 , PM 2.5-10 , and PM 10 exposure were identified as the entire pregnancy, the second trimester, and the entire postnatal period, respectively. Cumulative exposure to PM 2.5 and NO 2 during gestational weeks had a notable impact on asthma. Additionally, exposure to traffic-related air pollution (TRAP) at all timing stages, as well as PM 2.5-10 and SO 2 at night, increased the risk of asthma. Certain subgroups were more vulnerable to asthma risk due to air pollution. Children's asthma was predominantly influenced by exposure to particulate matters and TRAP during both the intrauterine and postnatal periods. [Display omitted] • Traffic-related air pollution (TRAP) exposure was related with childhood asthma. • Pregnancy, 2nd trimester, and postnatal period were critical widows for PM exposure. • Daytime and nighttime TRAP exposure played an important role in the risk of asthma. • There were cumulative effects of PM 2.5 and NO 2 over gestation in relation to asthma. • Our study supports and develops the "fetal origin of childhood asthma" hypothesis. [ABSTRACT FROM AUTHOR]

Childhood pneumonia remains a major public health concern worldwide, but the critical meteorological factors that contribute to it are unknown. To investigate the relationship between childhood pneumonia and prenatal and postnatal exposure to meteorological factors to identify the critical factors and vulnerable timing windows. We conducted a retrospective cohort study of 8689 preschoolers in China. We gathered information on personal factors, health status, and indoor environment through questionnaires. We considered meteorological factors including temperature (mean, maximum, minimum), diurnal temperature variation (DTV), relative humidity, wind speed, rainfall, pressure and sunshine during early life. Using multiple logistic regression models, we investigated the links between childhood pneumonia and early life exposure to meteorological factors. Exposure to mean, maximum, and minimum temperatures was associated with childhood pneumonia in the first month and first trimester, with ORs (95% CI) of 1.32 (1.07–1.62), 1.26 (1.04–1.52) and 1.33 (1.08–1.64) in the first month, and 1.42 (1.12–1.81), 1.36 (1.08–1.71) and 1.47 (1.15–1.88) in the first trimester for per IQR increase in each meteorological factor exposure. Wind speed, rainfall, and sunshine exhibited significant associations with pneumonia during the first, second, and third trimesters, respectively. Exposure to various temperatures, DTV, relative humidity, rainfall, air pressure, and sunshine were linked to childhood pneumonia in the postnatal period, particularly in the previous year. The sensitivity analysis revealed that boys are more vulnerable to meteorological factors. Keeping dogs or plants may offer protection against the pneumonia risk of prenatal and postnatal meteorological exposure. Exposure to meteorological factors during both the prenatal and postnatal periods, especially in early pregnancy, was found to elevate the risk of childhood pneumonia. [Display omitted] • Effect of climatic factors on childhood pneumonia in different windows is unclear. • Pneumonia in children was associated with prenatal exposure to ambient temperature. • Early pregnancy was identified as a critical time window for climatic exposure. • Postnatal exposure to climatic factors had the highest risk of childhood pneumonia. • Our study support "Fetal origin of pneumonia" hypothesis by meteorological factors. [ABSTRACT FROM AUTHOR]

Despite numerous studies demonstrating a link between asthma and meteorological parameters, the role of maternal exposure in pregnancy on childhood asthma remains unknown. To investigate the association of meteorological factors during pregnancy with childhood asthma and identify key exposure windows. In central China's Changsha city, we carried out a retrospective cohort study involving 8,689 preschoolers. We used questionnaires to collect information about childhood health, personal factors, socioeconomic status (SES), and indoor environment. We considered meteorological parameters including temperature (mean, maximum, minimum), diurnal temperature variation (DTV), relative humidity, wind speed (mean, extreme), rainfall, pressure, and sunshine during early life. We investigated the links between childhood asthma and meteorological factors using logistic regression models. Doctor-diagnosed asthma (D-DA) in preschoolers was associated with exposure to increased temperatures (mean, maximum, and minimum) by per IQR increment in the first month with ORs (95% CI) of 2.03 (1.21–3.40), 1.86 (1.15–3.00) and 2.08 (1.23–3.50) as well as in the first trimester with ORs of 2.40 (1.36–4.24), 2.20 (1.26–3.83) and 2.54 (1.43–4.53), respectively. D-DA was inversely related to wind speed in the first month and first two trimesters. Compared to an increased risk of D-DA when exposed to pressure in the third trimester, exposure to DTV during pregnancy, particularly in the third trimester, significantly decreased the risk. Some preschoolers with certain personal factors and high SES were more vulnerable to pre-natal meteorological exposure. Prenatal exposure to meteorological factors, especially high temperatures and low wind speeds in early pregnancy, contributes to childhood asthma. [Display omitted] • The impact of meteorological factors in pregnancy on childhood asthma is unclear. • Asthma was linked to higher temperatures and lower wind speed in pregnancy. • Early pregnancy was identified as a critical window for climatic susceptibility. • Personal and socioeconomic factors modified asthma risk of climate exposure. • Our study supports "Fetal origins of asthma" hypothesis by meteorological factors. [ABSTRACT FROM AUTHOR]

Building envelope dampness exposure is correlated with children's respiratory and allergic diseases. However, little research has compared the variation in the health impact of dampness exposure across multiple cities from a longitudinal perspective. A cross-sectional survey and a repeated one were conducted in children's residences in six cities: Chongqing, Shanghai, Nanjing, Wuhan, Changsha and Taiyuan, China, in 2010 (Phase I) and 2019 (Phase II). We selected 17,810 preschoolers during Phase I and 26,001 preschoolers during Phase II aged 3–6 years without changing residence since birth in the study. The proportion of residences with building envelope dampness exposure and the prevalence of respiratory and allergic diseases, except allergic rhinitis, in preschoolers significantly declined from Phase I to Phase II. Dampness exposure increased the risk for most childhood respiratory diseases in Phase II, with a 34% greater risk of lifetime-ever asthma in early residences and a 36% greater risk of current eczema in current residences. Most diseases showed a significantly positive exposure-response relationship to the cumulative period of building envelope dampness exposure (p < 0.05). The risk of developing current eczema was approximately 1.35 and 1.73 times higher in children exposed to both early and current dampness in Phase I and Phase II, respectively, than in children who had never been exposed. These findings provide new insights into the respiratory and allergic diseases in Chinese preschoolers because of building envelope dampness exposure over the last decade. The increased risk in Phase II raises concerns about the household's dampness environment. [Display omitted] • Building envelope dampness exposure has decreased over the last decade. • Prevalence of childhood respiratory diseases has declined over the last decade. • The risk of dampness exposure on respiratory diseases has increased in 2019. • Accumulated dampness exposure has a higher risk of current eczema in 2019. [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]

Cervical, endometrial, and ovarian cancers are three major gynecological cancers (GCs) leading to heavy disease burden and high mortality among women worldwide, which are associated with environmental exposure. However, the role of air pollution and temperature on GCs remains unclear. To assess the combined effects of short-term, medium-term, and long-term exposure to ambient air pollution and temperature indicators on GCs in women. A case-control study was conducted in XiangYa Hospital from 2010 to 2018 at Changsha, China. A standard questionnaire was designed to collect the health status and personal factors of 305 cases with GCs including cervical, endometrial, and ovarian cancers and 399 healthy women as control group. Personal exposure to ambient air pollution (PM 10 , SO 2 , and NO 2), temperature, and diurnal temperature variation (DTV) during past one year, past five years, and past ten years was calculated by inverse distance weighted (IDW) method based on each subject's home address. Multiple logistic regression model was used to analyse the relationship of GCs with outdoor air pollution and temperature indicators. Exposure to NO 2 during past five years and past ten years was significantly associated with GCs, with adjusted ORs (95% CI) of 1.40 (1.02–1.91) and 1.41 (1.03–1.93). Furthermore, an increase in temperature during past ten years was related with GCs, with OR (95% CI) = 1.95 (1.16–3.25). We strikingly found that high temperature increased the effect of long-term exposure to PM 10 and NO 2 during past ten years on GCs, while low DTV elevated GCs risk of air pollution exposure. Sensitivity analysis suggests that some specific subjects were more susceptible to the effect of air pollution and temperature indicators on GCs. Relatively long-term exposure to traffic-related air pollution (NO 2) and increased temperature played important roles in the development of women's GCs. There may be interactions between air pollution and temperature indicators on GCs. [Display omitted] • Exposure to NO 2 longer than 5 and 10 years was associated with gynecological cancers (GCs). • Long-term exposure to an increase in temperature elevated GC risk. • High temperature significantly increased effect of long-term exposure to NO 2 on GCs. • Low diurnal temperature variation elevated GT risk of PM 10 and/or NO 2 exposure. • There are interactions of traffic-related air pollution and temperature indicators on risk of GCs. [ABSTRACT FROM AUTHOR]

Otitis media (OM) is a common pediatric infectious disease worldwide. Increasing evidence have associated indoor environment with OM, yet the role of home environmental factor(s) exposure during which critical window(s) on childhood OM are unclear. To examine the association between indoor environmental factors exposure and childhood OM, to identify main indoor factor(s) and key window(s). A retrospective cohort study involving 8689 preschoolers aged 3–6 was performed in Changsha, China. The data about each child's health outcome and home environments was obtained through a standard questionnaire. Exposure timing windows included 1 year before pregnancy, pregnancy, first year of life, and past year. Multiple logistic regression models were used to analyze the association between indoor environmental factors and childhood OM. We found that exposure to mold/damp stains and mold/damp clothes or bedding during preconceptional, prenatal, and postnatal periods was consistently associated with childhood OM, with ORs ranged from 1.25 (1.02–1.54) to 1.38 (1.13–1.68). Past year was identified as a critical time window for mold/damp stains exposure in relation to OM risk. We further found that exposures to new furniture during pregnancy and environmental tobacco smoke (ETS) and grandparental smoking during first year were significantly associated with an increase in childhood OM, with ORs (95% CI) = 1.28 (1.00–1.64), 1.20 (1.01–1.42), and 1.21 (1.00–1.48). Moreover, current exposure to total plants especially for non-flowering plants significantly increased OM risk, with ORs (95% CI) = 1.23 (1.05–1.44) and 1.25 (1.06–1.46). The association between early life exposure to indoor environmental factors and OM was stronger among children living near traffic roads. Outdoor air pollution and temperature could modify the effect of indoor environmental exposure on childhood OM. Our sensitivity analysis indicated that some subgroups were more susceptible to OM risk of indoor exposure. Our findings suggest that exposure to home environmental factors played an important role in childhood OM, and the association can be interacted by outdoor air pollution and temperature. [Display omitted] • Both pre- and post-birth exposure to home environmental factors increase risk of childhood OM. • Dampness related indoor allergen plays a key role in the development of otitis media. • Renovation exposure in pregnancy was associated with an increase in childhood otitis media. • Current period was identified as the critical time window for OM risk of home environment. • Our study supports a hypothesis of "Fetal origin of childhood OM" by indoor exposure. [ABSTRACT FROM AUTHOR]

A questionnaire survey was performed in eight Chinese cities (40,279 adults participated; response rate 75%). There were questions on demographic information of the participants, allergic rhinitis, asthma, perceived odors and home environment. The majority were women (74.7%) and 12.2% were smokers; 6.6% reported allergic rhinitis and 1.6% reported asthma. Totally 38% reported stuffy odor; 24.6% unpleasant odor; 11.5% pungent odor and 10.4% mold odor. Reporting of condensation on window panes were common (62.1%); visible mold or dampness stains (21.9%) and water damage (14.7%) were less common. All dampness indicators were associated with allergic rhinitis and asthma (OR = 1.34–1.87) and all odors (OR = 1.79–6.17). All odors were associated with allergic rhinitis and asthma (OR = 1.23–4.51). Odor perception was partly a mediator of the effects of mold and dampness on allergic rhinitis (% of total effect mediated: 2.7–9.8%) and asthma (2.2–10.7%) when adjusting for other home environment factors. Increased mediation effects for allergic rhinitis (% of total effect mediated: 11.2–17.4%) and asthma (% of total effect mediated: 5.5–14.7%) were found for total odor score (0–8) as compared to the mediation effects for four single odors. In conclusion, mold and dampness in dwellings were associated with adult allergic rhinitis, asthma and odors. Different odors were related to allergic rhinitis and asthma. Some of the effects of mold/dampness on allergic rhinitis and asthma were indirect effect mediated by odors from damp buildings, but most of the effects were direct effects. • Mold and dampness were associated with allergic rhinitis and asthma. • Mold and dampness were related to odor perceptions. • Different types of odors were associated with allergic rhinitis and asthma. • Odors were partly mediators of the effects of indoor dampness on rhinitis and asthma. [ABSTRACT FROM AUTHOR]

Mounting studies have associated asthma with environmental and climatic factors, but their interaction during pregnancy on childhood asthma are unclear. This study aims to investigate the interaction of in utero air pollution and environmental temperature exposure on childhood asthma, to identify key timing windows for exposure. A retrospective cohort study with 2,598 pre-schoolers was conducted during 2011–2012 in Changsha, China. Maternal exposure to three critical ambient air pollutants (PM 10 , SO 2 and NO 2 , as proxies of industrial and vehicular air pollution) and temperature (T), was assessed for the 40 gestational weeks, three trimesters of gestation, and entire pregnancy by an inverse distance weighted (IDW) method. Logistic regression analysis was used to examine the association of childhood asthma with air pollution and temperature exposure. Our results showed that pre-schooler's asthma was significantly associated with SO 2 and NO 2 exposure in utero, ORs = 1.46 (95% CI: 1.12–1.89) and 1.67 (95% CI: 1.24–2.26) by inter quartile range (IQR) increase of their exposure respectively. Significant risk was observed for exposure of SO 2 and NO 2 particularly during the 1st and 2nd trimesters and their specific gestational weeks. Pre-schooler's asthma was related with high temperature exposure during 1st trimester, OR = 2.33 (95% CI: 1.11–4.90) by IQR increase of T exposure. Low T and high T respectively increased the asthma risk of NO 2 exposure in the 1st and 3rd trimester. Boys were more susceptible to the temperature-pollution interaction on asthma development. Our study indicates that low and high temperature respectively during early and late pregnancy significantly increased the impact of air pollution exposure in utero on pre-schooler's asthma. [Display omitted] • Childhood asthma was mainly associated with prenatal exposure to SO 2 and NO 2 in pregnancy. • Asthma was related with high temperature (T) and more summer days in the 1st trimester. • Low T in 1st trimester and high T in 3rd trimester increased asthma risk of NO 2 exposure. • Boys were more susceptible to the temperature-pollution interaction on asthma risk. • Our study supports the hypothesis of "fetal origin of allergy" via temperature-pollution interaction. [ABSTRACT FROM AUTHOR]

Recent rapid increase of childhood asthma in China should be associated with exposure to the high air pollution, but it is unclear to which exposure window, to which kind of air pollution, and to what extent the effect. We investigated the effect of early life exposure to both outdoor and indoor air pollution on childhood asthma. Questionnaire survey was administered to 2490 children aged 3–6 years in Changsha. Early life exposure of each child in utero and during the first year of life was evaluated based on three outdoor air pollutants, i.e. particulate matters (PM 10 ), industry-related SO 2 and traffic-related NO 2 , and two kinds of indoor air pollution represented by new furniture and redecoration. Multivariate logistic regression method was used to estimate the effect of exposure on asthma. Results indicated that exposure to both industry- and traffic-related air pollutants (SO 2 and NO 2 ) significantly increased childhood asthma with odds ratio = 1.07 (95% CI: 1.03–1.12) and 1.16 (1.00–1.35) in utero and 1.09 (1.04–1.15) and 1.26 (1.06–1.50) during the first year for 10 μg/m 3 increase in concentration. Exposure to new furniture and home redecoration during pregnancy significantly increased childhood asthma with odds ratio 2.34 (1.16–4.74) and 2.21 (1.29–3.81) respectively. The effects of outdoor and indoor exposures were independent to each other. We conclude that early life exposures to both outdoor air pollution and indoor renovation contributes to the rapid development of childhood asthma in China, the former stronger after birth but the latter stronger before birth. [ABSTRACT FROM AUTHOR]

Low birth weight (LBW), as a major concern in public health, is now increasing worldwide, but its main indoor environmental factors remain unclear. We examined whether LBW including term-LBW (T-LBW) and preterm-LBW (P-LBW) was associated with maternal exposure to indoor environmental factors, with a purpose to identify the key indoor environmental factor(s) contributing to LBW. A nationwide retrospective cohort study of 30,735 pre-schoolers in six Chinese cities was performed from 2010 to 2012. One questionnaire survey was conducted to collect information on the pre-schoolers' birth outcomes and their maternal exposure of indoor environmental factors including new furniture, house redecoration, cooking fuels, mould/damp stains, and mouldy odour during pregnancy. Maternal exposure of traffic-related air pollutant (NO 2), industrial pollutant (SO 2), and inhalable particulate matter (PM 10), as well as meteorological parameters, was estimated in pregnancy. Associations of LBW, T-LBW and P-LBW with indoor environmental factors were evaluated by two-level (city-child) logistic regression models with an odds ratio (OR) and 95% confidence interval (CI). We found that P-LBW (1.0%) and T-LBW (1.4%) prevalence were respectively associated with persistent mould/damp stains and mouldy odour exposure in utero, ORs = 1.81 (95% CI: 1.01–3.24) and 1.49 (95% CI: 1.01–2.21). Exposure to high temperature and PM 2.5 in pregnancy significantly enhanced the effect of persistent mould/damp stains and/or mouldy odour on P-LBW and LBW, ORs (95% CI) = 2.92 (1.40–6.07) and 1.78 (1.00–3.15) with significant interaction p values of 0.067 and 0.094 respectively. Sensitivity analysis suggested that raising cats and dogs significantly increased LBW risk of persistent mould/damp stains and mouldy odour exposure. Our findings indicate that long-term exposure to indoor mould/damp stains and mouldy odour in utero plays a key role in LBW, and this association can be significantly modified by some specific personal, indoor, and outdoor factors. [Display omitted] • Mould/damp stains exposure was significantly associated with term-low birth weight (LBW). • Maternal exposure to residential mouldy odour significantly increased the risk of preterm-LBW. • High temperature and PM 2.5 enhanced LBW risk of mould/damp stains and mouldy odour. • Families with pets were more susceptible to LBW risk of mould/damp stains and mouldy odour. • Our study has a new implication for the effective reduction and early prevention of LBW. [ABSTRACT FROM AUTHOR]

Small for gestational age (SGA) is a major public health problem that affects 32.4 million infants worldwide and its prevalence is increasing rapidly in new-borns. However, the key risk factors and their exposure time window on the development of SGA are unclear. We aim to investigate the association between exposure to outdoor air pollution and indoor environmental factors during which critical timing window and SGA, and to evaluate which specific personal factors modify this association. A retrospective cohort study of 3509 infants was conducted in Changsha, China during 2011–2012. A questionnaire survey was performed to obtain the formation on infant's birth outcomes and prenatal exposure of indoor environmental factors containing parental (maternal and/or paternal) smoking, new furniture, house redecoration, mold or dampness, window condensation, and keeping dogs in gestational age. Intrauterine exposure to industrial air pollutant (SO 2), traffic-related air pollutant (NO 2) and inhalable particulate matter (PM 10) was estimated during three trimesters and entire pregnancy. Associations between outdoor air pollutants and indoor environmental factors and SGA, term SGA (TSGA) and preterm SGA (PSGA) were assessed by multiple logistic regression model in terms of odds ratio (OR) and 95% confidence interval (CI). Prevalence of SGA (5.2%) and TSGA (4.9%) were significantly associated with intrauterine exposure to outdoor SO 2 during the entire gestational age with adjusted ORs (95% CI) of 1.08 (1.01–1.15) and 1.08 (1.00–1.15) for per 10 μg/m3 increase in SO 2 exposure after adjusting for the covariates, indoor environmental factors, and outdoor air temperature, and PSGA prevalence (0.3%) was significantly related with PM 10 exposure during whole pregnancy with odds = 2.21 (1.08–4.51). However, no association was observed for traffic-related air pollutant NO 2 exposure. Specifically, the association was more significant for SO 2 exposure during the 1st and/or 2nd trimester. We further found that TSGA and PSGA were associated with indoor exposure to parental smoking and new furniture, respectively, ORs (95% CI) = 1.46 (1.00–2.11) and 10.95 (1.46–81.95). We observed that the odds of SGA and TSGA attributed to SO 2 exposure in the first two trimesters was only significant among families with parental smoking and new furniture in gestation. Sensitivity analysis showed that infants with female sex and born in cold months were more susceptible to the effect of outdoor SO 2 exposure during the first two trimesters and entire gestational age on SGA and TSGA. On the other hand, infants born in the cold season and by a younger mother were more sensitive to the effect of indoor parental smoking in utero on SGA and TSGA. Maternal exposure to industry-related air pollution and indoor environmental risk factors during pregnancy, particularly during the first two trimesters, significantly increased SGA risk, and some specific personal factors could modify these associations. [Display omitted] • Industrial air pollution was associated with small for gestational age (SGA). • We identified the first two trimesters as critical windows for SGA development. • Parental smoking and new furniture in utero increased risk of term and preterm SGA. • Parental smoking amplifies the effect of outdoor industrial air pollution on SGA. • Personal factors could interact with air pollution in critical windows on SGA risk. [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]