Childhood Airway Research Articles

Predictors of lung function in early adulthood: A population-based cohort study.

Lung function reaches a peak/plateau in early adulthood before declining with age. Lower early adult lung function may increase the risk for chronic obstructive pulmonary disease (COPD) in mid-late adult life. Understanding the effects of multiple childhood/adolescent exposures and their potential interactions on plateau lung function would provide insights into the natural history of COPD. Longitudinal spirometry data from 688 participants with complete data from a population-based birth cohort (original n = 1037) were used to investigate associations between a wide range of childhood/adolescent exposures and repeated measures of FEV1, FVC and FEV1/FVC during the early-adult plateau phase. Generalized estimating equations were used to accommodate the multiple timepoints per participant. FEV1 reached a peak/plateau between ages 18 and 26 and FVC from 21 to 32 years, whereas FEV1/FVC declined throughout early adulthood. Childhood asthma and airway hyperresponsiveness were associated with lower early adult FEV1 and FEV1/FVC. Smoking by age 18 was associated with lower FEV1/FVC. Higher BMI during early adulthood was associated with lower FEV1 and FVC and lower FEV1/FVC. Physical activity during adolescence was positively associated with FEV1 and FEV1/FVC but this was only statistically significant in men. There was no convincing evidence of interactions between exposures. Childhood asthma and airway hyperresponsiveness are associated with lower lung function in early adulthood. Interventions targeting these may reduce the risk of COPD in mid-late adult life. Promotion of physical activity during adolescence, prevention of cigarette smoking and maintenance of a healthy body weight in early adulthood are also priorities.

Distinct trajectories of lung function from childhood to mid-adulthood

RationaleLife course trajectories of lung function development and decline influence the risk for lung disease but are poorly documented.ObjectiveTo document lung function trajectories from childhood to mid-adult life.MethodsWe modelled forced...

Risk Factors for Asthma Among Preschool Children Attending Allergy Clinic at Benghazi Children’ Hospital, Libya

Introduction: Bronchial asthma is a common heterogeneous chronic inflammatory disorder of the lower respiratory airways in childhood. Aim: This study aimed to examine different recognized risk factors of asthma. Methods: A total of 420 children sample of case-control groups of matched age (1-5 years) and gender were randomly selected and recruited in this study. The number of children in each group was (210). The cross-sectional study was conducted at Benghazi children’s hospital for six months period from 1st of June 2021 to 31st of December 2021. The data were collected using a self-administrated. The collected data were analyzed using SPSS (version 22). The chi-square test used to compare proportions. Whereas, the binary logistic regression was used to calculate the odds ratios (OR) and 95% confidence intervals (CI). Results: The result of cross-tabulation using chi-square of all different recognized factors showed a statistically significant different of p-value>0.05 were age, the family history of asthma and atopy, personal history of asthma, pet in the house, maternal medication intake, maternal treatment for the common cold, mode of delivery, preterm delivery, low birth weight, and recurrent respiratory tract infections. On other hand, the analysis of all substantial risk factors for asthma using a binary logistic regression showed age (being older (>3-5 Years)) had a protective effect against asthma (OR=0.800, (95% CI)=(0.492-1.302)), gender (being female had a protective effect against asthma (OR=0.886, (95% CI) = (0.544-1.443)), paternal (OR=0.698, (95% CI) = (0.400-1.217), not maternal educational levels had a protective against asthma, none of the personal and environmental factors affected the development of asthma in our studied children. While, the greatest contribution in this study was from natal and post natal factors including mode of delivery (OR= 0.621, (95% CI) = (0.383-1.006), and type of feeding (OR=0.854, (95% CI) = (0.515-1.416) that are a

Longitudinal analysis of the impact of smoking exposure on atopic indices and allergies in early childhood

BackgroundExposure to smoking is recognized as a health hazard; however, a longitudinal analysis of the impact of smoking exposure in families on the allergic reactions related to childhood atopic diseases has not been well addressed. MethodsChildren who completed a three-year follow-up period from the birth cohort were included in this study. The history of smoking exposure was recorded, and the urine cotinine levels were measured at 1 and 6 months, and 1, 2, and 3 years of age. Specific IgE levels against food and mite allergens were measured at age 6 months, and 1, 2, and 3 years. Their relevance to family smoking exposure and the subsequent development of atopic diseases was also analyzed. This study was approved by the Ethics Committee of Chang Gung Memorial Hospital (No. 102-1842C) ResultsA total of 198 infants were enrolled in this study. The prevalence of passive smoking exposure among these children was as high as 45%. The urine cotinine levels were significantly higher in children with history of smoking exposure (P < 0.001). At 6 months of age, the food-specific IgE levels and the prevalence of eczema were significantly higher in children with smoking exposure than in those without smoking exposure (P < 0.05). By contrast, the urine cotinine levels were significantly higher in children with IgE sensitization (>100 kU/L, P < 0.05) at 3 years of age, which was also significantly associated with a higher prevalence of allergic rhinitis and development of asthma (P < 0.01). ConclusionFamily smoking exposure appears to be strongly associated with food sensitization in infancy and with IgE production in later childhood. This could potentially increase the susceptibility of developing infantile eczema and subsequent childhood airway allergies.

Prenatal and postnatal decoration in residence are associated with childhood allergies and respiratory diseases: A 10-year repeated retrospective observational study

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.

Phenotype-specific signatures of systems-level gut microbiome associated with childhood airway allergies.

Perturbation of gut symbiosis has been linked to childhood allergic diseases. However, the underlying host-microbe interaction connected with specific phenotypes is poorly understood. To address this, integrative analyses of stool metagenomic and metabolomic profiles associated with IgE reactions in 56 children with mite-sensitized airway allergies (25 with rhinitis and 31 with asthma) and 28 nonallergic healthy controls were conducted. We noted a decrease in the number and abundance of gut microbiome-encoded carbohydrate-active enzyme (CAZyme) genes, accompanied with a reduction in species richness, in the asthmatic gut microflora but not in that from allergic rhinitis. Such loss of CAZymes was consistent with the observation that a CAZyme-linked decrease in fecal butyrate was found in asthmatics and negatively correlated with mite-specific IgE responses. Different from the CAZymes, we demonstrated an increase in α diversity at the virulome levels in asthmatic gut microbiota and identified phenotype-specific variations of gut virulome. Moreover, use of fecal metagenomic and metabolomic signatures resulted in distinct effects on differentiating rhinitis and asthma from nonallergic healthy controls. Overall, our integrative analyses reveal several signatures of systems-level gut microbiome in robust associations with fecal metabolites and disease phenotypes, which may be of etiological and diagnostic implications in childhood airway allergies.

Effect of Vitamin C Supplementation for Pregnant Smokers on Offspring Airway Function and Wheeze at Age 5 Years

Vitamin C supplementation (500 mg/d) for pregnant smokers has been reported to increase offspring airway function as measured by forced expiratory flow (FEF) through age 12 months; however, its effects on airway function at age 5 years remain to be assessed. To assess whether vitamin C supplementation in pregnant smokers is associated with increased and/or improved airway function in their offspring at age 5 years and whether vitamin C decreases the occurrence of wheeze. This study followed up the Vitamin C to Decrease the Effects of Smoking in Pregnancy on Infant Lung Function (VCSIP) double-blind, placebo-controlled randomized clinical trial conducted at 3 centers in the US (in Oregon, Washington, and Indiana) between 2012 and 2016. Investigators and participants remain unaware of the treatment assignments. Forced expiratory flow measurements at age 5 years were completed from 2018 to 2021. Pregnant smokers were randomized to vitamin C (500 mg/d) or placebo treatment. The primary outcome was the prespecified measurement of FEF between 25% and 75% expired volume (FEF25-75) by spirometry at age 5 years. Secondary outcomes included FEF measurements at 50% and 75% of expiration (FEF50 and FEF75), forced expiratory volume in 1 second (FEV1), and occurrence of wheeze. Of the 251 pregnant smokers included in this study, 125 (49.8%) were randomized to vitamin C and 126 (50.2%) were randomized to placebo. Of 213 children from the VCSIP trial who were reconsented into this follow-up study, 192 (90.1%) had successful FEF measurements at age 5 years; 212 (99.5%) were included in the analysis of wheeze. Analysis of covariance demonstrated that offspring of pregnant smokers allocated to vitamin C compared with placebo had 17.2% significantly higher mean (SE) measurements of FEF25-75 at age 5 years (1.45 [0.04] vs 1.24 [0.04] L/s; adjusted mean difference, 0.21 [95% CI, 0.13-0.30]; P < .001). Mean (SE) measurements were also significantly increased by 14.1% for FEF50 (1.59 [0.04] vs 1.39 [0.04] L/s; adjusted mean difference, 0.20 [95% CI, 0.11-0.30]; P < .001), 25.9% for FEF75 (0.79 [0.02] vs 0.63 [0.02] L/s; 0.16 [95% CI, 0.11-0.22]; P < .001), and 4.4% for FEV1 (1.13 [0.02] vs 1.09 [0.02] L; 0.05 [95% CI, 0.01-0.09]; P = .02). In addition, offspring of pregnant smokers randomized to vitamin C had significantly decreased wheeze (28.3% vs 47.2%; estimated odds ratio, 0.41 [95% CI, 0.23-0.74]; P = .003). In this follow-up study of offspring of pregnant smokers randomized to vitamin C vs placebo, vitamin C supplementation during pregnancy resulted in significantly increased airway function of offspring at age 5 years and significantly decreased the occurrence of wheeze. These findings suggest that vitamin C supplementation for pregnant smokers may decrease the effects of smoking in pregnancy on childhood airway function and respiratory health. ClinicalTrials.gov Identifier: NCT03203603.

Cohort profile: the ECHO prenatal and early childhood pathways to health consortium (ECHO-PATHWAYS)

PurposeExposures early in life, beginning in utero, have long-term impacts on mental and physical health. The ECHO prenatal and early childhood pathways to health consortium (ECHO-PATHWAYS) was established to examine...

HSP70 upregulation in nasal mucosa of symptomatic children with allergic rhinitis and potential risk of asthma development

Allergic rhinitis and asthma are the most common causes of chronic inflammation of the upper and lower airways in childhood. However, a nasal biomarker that can link to pulmonary inflammation is yet to be found. The present paper aims to investigate the possible role in inflammation of two inducible 70-kDa Heat Shock Proteins (HSP70) members, HSPA1A/B and HSPA6, in nasal mucosa cells of allergic children through their mRNA expression analysis, and their correlation to both spirometric and FeNO values. The relationship between FeNO in lower airways and ∆Cts of HSPA1A/B in nasal mucosa seems to be influenced by clinical symptoms regardless of age, sex, and sensitization patterns. Therefore, HSP70 expression, as well as FeNO levels, could have a predictive capability to identify lower airways inflammation and thus to recognize rhinitic children having a potential risk of asthma development.

Phenotype‐specific signatures of gut microbiome, resistome, virulome, and metabolome associated with childhood airway allergies

Perturbation of gut dysbiosis has been linked to childhood allergic diseases. However, the association of fecal microbiome and metabolite profiles with specific phenotypes is poorly understood. To address this, we performed shotgun sequencing of intestinal microbiome and untargeted metabolomics profiling of fecal samples in a cohort of children mite‐sensitized airway allergies (25 with rhinitis and 31 with asthma) and 28 non‐allergic healthy controls. An integrative analysis of stool metagenomic and metabolomic profiles associated with IgE reactions in childhood allergic rhinitis and asthma was conducted. We noted a decrease in the number and abundance of gut microbiome‐encoded carbohydrate‐active enzyme (CAZyme) genes, accompanied with a reduction of within‐sample species richness (α diversity), in the asthmatic gut microbiome but not in that from allergic rhinitis. Such loss of CAZymes was consistent with the observation that decreased levels of butyrate and fumarate (a metabolic precursor of propionate) were detected in the fecal samples of asthmatics. In addition, genes related to rifamycin resistance were significantly enriched in fecal samples of cases with asthma, suggesting that altered resistome in gut microbiota may contribute to respiratory health in asthmatics. Further analysis of gut virulome identified differentially abundant virulence functions in asthmatic microbiome, such as enrichments for fibrinogen binding protein, magnesium uptake, and Ebp pili genes, and depletions for flagella‐mediated motility genes. Moreover, we demonstrated an inverse correlation between the abundance of Galactobacillus timonensis and serum IgE levels of the host. Our dual‐omics analyses reveal several microbial gene functions and species‐level clades derived from gut dysbiosis in robust associations with fecal metabolites and disease phenotypes, which may be of etiological and diagnostic implications in childhood airway allergies.

Phenotype-specific signatures of fecal metabolome and systems-level gut microbiome associated with childhood airway allergies

Phenotype-specific signatures of fecal metabolome and systems-level gut microbiome associated with childhood airway allergies

Phenotype-specific signatures of fecal metabolome and systems-level gut microbiome associated with childhood airway allergies

Phenotype-specific signatures of fecal metabolome and systems-level gut microbiome associated with childhood airway allergies

Prenatal polycyclic aromatic hydrocarbon (PAH) exposure and early childhood asthma in a diverse US pregnancy cohort

Background/AimExposure to polycyclic aromatic hydrocarbons (PAH) may increase risk of pediatric asthma. Effects of prenatal PAH exposure, specifically, are hypothesized but understudied. The ECHO PATHWAYS Consortium investigated these relationships in a large, diverse prospective cohort study.MethodsWe included 919 mother-child dyads from the CANDLE Study, a longitudinal pregnancy cohort set in Shelby County, TN. PAH metabolites were measured in second trimester urine and adjusted for specific gravity. Seven metabolites detected in &gt;80% of women were included in analysis. When children were 4-6 years old, mothers completed the International Study on Allergies and Asthma in Childhood survey. Poisson regression with robust standard errors was used to estimate relative risk of current wheeze, current asthma, and ever asthma associated with each metabolite in separate models, adjusted for maternal age, race, education and other asthma risk factors. Effect modification by child sex and maternal asthma was assessed using interaction models. We did not adjust for multiple comparisons.ResultsParticipants were 66% Black, 44% White; 58% with high school education or less. On average, urinary PAH metabolite concentrations were higher than in other US cohorts. Mean (SD) child age at assessment was 4.3 (0.4) years. Prevalence of reported current wheeze and asthma and ever asthma was 19.4%, 16.1%, and 14.6%, respectively. In multivariable models, we observed no evidence that any metabolite was associated with any outcome. No differences by child sex were observed. Maternal asthma modified associations between 1/9-hydroxyphenanthrene and current asthma (RRmaternal asthma = 0.88; 95%CI: 0.78, 0.99 versus RRwithout maternal asthma = 1.09; 95%CI: 0.97, 1.23 per two-fold increase in exposure; pinteraction=0.012).ConclusionsResults of our analysis, the largest cohort study of prenatal PAH and childhood airway outcomes conducted to date, did not support the hypothesis that prenatal PAHs increases risk of early childhood asthma.

Vitamin D levels in children with bronchial asthma

Background: Bronchial asthma is a common chronic inflammatory disorder of the airways in childhood. Vitamin D, initially described as a vitamin that regulated calcium homeostasis, has also been shown to exert important antimicrobial effects and is also a potent immune system regulator having a potential role in various allergic diseases. The main objective of this study was to look the levels of vitamin D in children with bronchial asthma and to study the co relationship between vitamin D levels and severity of asthma.Methods: This study included 80 (40 asthmatic children and 40 healthy controls) children aged between 4 and 15 year. Serum vitamin D levels where determined and compared between the two groups. The association between vitamin D levels and severity of asthma was studied in the asthmatic children.Results: Among 40 asthmatic children the mean serum vitamin D level was 16.6±11.56 ng/ml, while as the mean vitamin D levels in healthy control subjects was 24.225±2.764 ng/ml and the difference between the two groups was statistically significant (p=0.001). Vitamin D deficiency was highly prevalent in asthmatic patients and there was a direct and a significant relationship between serum vitamin D levels and severity of asthma.Conclusion: In this study, vitamin D levels were considerably lower in children with asthma than in healthy children. Also, in this study vitamin D deficient asthma patients have more severe asthma than the patients who have sufficient vitamin D levels.

Cross-talk between airway and gut microbiome links to IgE responses to house dust mites in childhood airway allergies

A connection between airway and gut microbiota related to allergen exposure in childhood allergies was not well addressed. We aimed to identify the microbiota alterations in the airway and gut related to mite-specific IgE responses in young children with airway allergies. This study enrolled 60 children, including 38 mite-sensitized children (20 rhinitis and 18 asthma), and 22 non-mite-sensitized healthy controls. Microbiome composition analysis of the throat swab and stool samples was performed using bacterial 16S rRNA sequencing. An integrative analysis of the airway and stool microbial profiling associated with IgE reactions in childhood allergic rhinitis and asthma was examined. The Chao1 and Shannon indices in the airway were significantly lower than those in the stool. Additionally, an inverse association of the airway microbial diversity with house dust mite (HDM) sensitization and allergic airway diseases was noted. Fecal IgE levels were positively correlated with the serum Dermatophagoides pteronyssinus- and Dermatophagoides farinae-specific IgE levels. Airway Leptotrichia spp. related to asthma were strongly correlated with fecal Dorea and Ruminococcus spp., which were inversely associated with fecal IgE levels and risk of allergic rhinitis. Moreover, four airway genera, Campylobacter, Selenomonas, Tannerella, and Atopobium, were negatively correlated with both serum mite-specific and fecal IgE levels. Among them, the airway Selenomonas and Atopobium spp. were positively correlated with stool Blautia and Dorea spp. related to asthma and allergic rhinitis, respectively. In conclusion, airway microbial dysbiosis in response to HDM and its cross-talk with the gut microbial community is related to allergic airway diseases in early childhood.

First-Year Antibiotics Exposure in Relation to Childhood Asthma, Allergies, and Airway Illnesses.

Background: Associations of early antibiotics exposures with childhood asthma, allergies, and airway illnesses are debated. Objectives: We aimed to investigate associations of first-year antibiotics exposure with childhood asthma, allergies, and airway illnesses. Methods: A cross-sectional study was conducted among preschoolers in Shanghai, China during 2011–2012. A questionnaire regarding household environment and lifestyles and childhood health outcomes was reported by the child’s parents. Results: In total, 13,335 questionnaires (response rate: 85.3%) were analyzed and 3049 (24.1%) children had first-year antibiotics exposure. In the multivariate logistic regression analyses, first-year antibiotics exposure had significant associations with the higher odds of lifetime-ever pneumonia (adjusted OR, 95% CI: 2.15, 1.95–2.37), croup (1.46, 1.24–1.73), wheeze (1.44, 1.30–1.60), asthma (1.38, 1.19–1.61), food allergy (1.29, 1.13–1.46), and allergic rhinitis (1.23, 1.07–1.41), and as well as current (one year before the survey) common cold (≥3 times) (1.38, 1.25–1.52), dry cough (1.27, 1.13–1.42), atopic dermatitis (1.25, 1.09–1.43), wheeze (1.23, 1.10–1.38), and rhinitis symptoms (1.15, 1.04–1.26). These associations were different in children with different individual characteristics (age, sex, family history of atopy, and district) and other early exposures (breastfeeding, home decoration, pet-keeping, and environmental tobacco smoke). Conclusions: Our results indicate that first-year antibiotics exposure could be a strong risk factor for childhood pneumonia, asthma, allergies, and their related symptoms. The individual characteristics and other early exposures may modify effects of early antibiotic exposure on childhood allergies and airway illnesses.

Damp indicators in different areas of residence in different periods are strongly associated with childhood asthma and wheeze

During June 2019, we conducted a cross-sectional study among 4534 preschoolers 3–7 years old in Chongqing, China. Here, we investigated associations of home dampness exposures with childhood allergies and airway diseases among the selected 2563 preschoolers who never changed residence. Compared to children without dampness exposures, children exposed to any of five damp indicators (water damage, condensation on windowpane, moldy odor, visible mold spots, visible damp stains) in any areas (living room, bedroom, and bathroom) during any periods (one year before pregnancy, during pregnancy, first year of lifetime, in the past year before the survey) had significantly higher prevalences of asthma, allergic rhinitis, pneumonia, eczema, wheeze, and rhinitis. In the two-level (district-child) logistic regression analyses, five damp indicators in the different areas during different periods were significantly associated with the increased odds of the studied diseases in most cases. The cumulative scores of damp indicators, scores of areas with damp indicators, and scores of periods with dampness exposures had number-response relationships with the studied diseases, particularly for asthma, wheeze, allergic rhinitis in lifetime-ever, and current wheeze. These associations and number-response relationships were more notable for visible mold spots and visible damp stains in living room and bedroom than other damp indicators, and for during pregnancy and first year of lifetime than for one year before pregnancy and in the past year before the survey. Our results provide strong evidences for the impacts of indoor dampness exposures on pediatric asthma and wheeze and seemingly suggest their potential causal relationships.

Predictive value of childhood airway hyper-responsiveness to indirect stimuli: 10-year longitudinal study.

Airway hyper-responsiveness (AHR) is a common feature in asthma. The use of AHR in predicting active asthma or the persistence of AHR in childhood is poorly understood. By analyzing longitudinal connections including different measures of AHR, lung function, and inflammation markers, we sought to identify the best available method for predicting persistence of AHR and identification of later active asthma. We tested 105 asthmatic children aged 3-7years with fractional exhaled nitric oxide (FeNO), impulse oscillometry (IOS), and AHR evaluated by indirect methods (hypertonic saline and exercise challenge). Ten years later, 64 children participated in the follow-up visit and were tested with FeNO, IOS, spirometry, and methacholine challenge. At both study visits, blood samples were collected, and a questionnaire was completed. Asthma was in remission in 66% of patients at adolescence. AHR measured by hypertonic saline challenge at preschool age was associated with asthma symptoms (OR 10.2; 95% CI 2.8, 37.3) but not with AHR estimated with methacholine challenge 10years later. AHR measured by exercise challenge was not associated with AHR or recent asthma symptoms in adolescence. Preschool eosinophilia continued until adolescence in 87% of patients but was not associated with AHR or subjective signs of asthma 10years later. Wheezy preschoolers with atopy had a higher risk for AHR in adolescence (OR 4.1; 95% CI 1.0, 16.2). Results from hypertonic saline challenge are associated with persistent asthma symptoms even after a decade. AHR measured by indirect methods at preschool age did not predict AHR in adolescence.

Prenatal and postnatal exposures to ambient air pollutants associated with allergies and airway diseases in childhood: A retrospective observational study

It’s inconsistent about associations of early exposures to outdoor air pollutants with allergies and airway diseases in childhood. Here, we investigated associations of prenatal and postnatal exposures to outdoor nitrogen dioxide (NO2), sulphur dioxide (SO2), and PM10 (particulate matter with an aerodynamic diameter ≤ 10 μm) with asthma, wheeze, hay fever, rhinitis, pneumonia, and eczema in childhood. We surveyed 3,177 preschoolers who never change residences since birth in Shanghai, China. Parents reported information regarding children’s health status. Daily-averaged concentrations of these pollutants in the children’s gestation and in the first year of lifetime for district where children lived were collected by Shanghai Environmental Monitoring Center. After adjusting for covariates, exposures to higher level of NO2 during different trimesters of gestation and of the first year of lifetime had significant associations with the increased odds of asthma, hay fever, rhinitis, pneumonia, and eczema in childhood. Associations of NO2 exposures in the early trimesters of gestation and of the first year of lifetime with pneumonia were stronger than in the later trimesters, whereas associations of NO2 exposures in the early trimesters with hay fever and eczema were weaker than in the later trimesters. Our results indicated that prenatal and postnatal exposures to outdoor NO2 could be risk factors for allergies and airway diseases in childhood. Both dose and duration were related with the influence degree of early NO2 exposure on childhood allergies and airway diseases.

Associations of ambient air pollutants with airway and allergic symptoms in 13,335 preschoolers in Shanghai, China

Findings are inconsistent in studies for impacts of outdoor air pollutants on airway health in childhood. In this paper, we collected data regarding airway and allergic symptoms in the past year before a survey in 13,335 preschoolers from a cross-sectional study. Daily averaged concentrations of ambient sulphur dioxide (SO2), nitrogen dioxide (NO2), and particulate matter with an aerodynamic diameter ≤10 μm (PM10) in the past year before the survey were collected in the kindergarten-located district. We investigated associations of 12-month average concentrations of these pollutants with childhood airway and allergic symptoms. In the two-level (district-child) logistic regression analyses, exposure to higher level of NO2 and of PM10 increased odds of wheeze symptoms (adjusted OR, 95%CI: 1.03, 1.01–1.05 for per 3.0 μg/m3 increase in NO2; 1.22, 1.09–1.39 for per 7.6 μg/m3 increase in PM10), wheeze with a cold (1.03, 1.01–1.06; 1.22, 1.08–1.39), dry cough during night (1.05, 1.03–1.08; 1.23, 1.09–1.40), rhinitis symptoms (1.11, 1.08–1.13; 1.32, 1.07–1.63), rhinitis on pet (1.11, 1.05–1.18; 1.37, 0.95–1.98) and pollen (1.12, 1.03–1.21; 1.23, 0.84–1.82) exposure, eczema symptoms (1.09, 1.05–1.12; 1.22, 0.98–1.52), and lack of sleep due to eczema (1.12, 1.07–1.18; 1.58, 1.25–1.98). Exposures to NO2 and PM10 were also significantly and positively associated with the accumulative score of airway symptoms. Similar positive associations were found of NO2 and of PM10 with the individual symptoms and symptom scores among preschoolers from different kindergarten-located district. These results indicate that ambient NO2 and PM10 likely are risk factors for airway and allergic symptoms in childhood in Shanghai, China.