Early-life exposure to PM2.5 constituents and childhood asthma and wheezing: Findings from China, Children, Homes, Health study

Air pollution associated with cardiopulmonary disease and mortality among participants with preserved ratio impaired spirometry

BACKGROUND

Epidemiological evidence regarding the association between air pollutants and cardiopulmonary disease, mortality in individuals with preserved ratio impaired spirometry (PRISm), and their combined effects remains unclear.

METHODS

We followed 36,149 participants with PRISm in the UK Biobank study. Annual concentrations of PM2.5, PM10, NO2, NOx, and SO2 at residential addresses were determined using a bilinear interpolation method, accounting for address changes. A multistate model assessed the dynamic associations between air pollutants and cardiopulmonary diseases and mortality in PRISm. Quantile g-computation was used to investigate the joint effects of air pollutants.

RESULTS

Long-term exposure to PM2.5, PM10, NO2, NOx, and SO2 was significantly associated with the risk of cardiopulmonary disease in PRISm. The corresponding hazard ratios (HRs) [95 % confidence intervals (95 % CIs)] per interquartile range (IQR) were 1.49 (1.43, 1.54), 1.52 (1.46, 1.57), 1.34 (1.30, 1.39), 1.30 (1.26, 1.34), and 1.44 (1.41, 1.48), respectively. For mortality, the corresponding HRs (95 % CIs) per IQR were 1.36 (1.25, 1.47), 1.35 (1.24, 1.46), 1.27 (1.18, 1.36), 1.23 (1.15, 1.31), and 1.29 (1.20, 1.39), respectively. In PRISm, quantile g-computation analysis demonstrated that a quartile increase in exposure to a mixture of all air pollutants was positively associated with the risk of cardiopulmonary disease and mortality, with HRs (95 % CIs) of 1.84 (1.76, 3.84) and 1.45 (1.32, 1.57), respectively.

CONCLUSION

Long-term individual and joint exposure to air pollutants (PM2.5, PM10, NO2, NOx, and SO2) might be an important risk factor for cardiopulmonary disease and mortality in high-risk populations with PRISm.

Association of Long-Term Exposure to PM2.5 Constituents and Green Space With Arthritis and Rheumatoid Arthritis

There is limited evidence regarding the effects of long-term exposure to PM2.5 constituents on the risk of arthritis and rheumatoid arthritis, and the interaction between PM2.5 and green space remains unclear. This study examined the relationship between long-term exposure to PM2.5 constituents and the risk of arthritis and rheumatoid arthritis, with the exposure period extending from recruitment until self-reported outcomes, death, loss to follow-up, or end of follow-up. Additionally, the study assessed whether there was an interactive effect between PM2.5 and green space on these risks. We gathered cohort data on 18,649 individuals aged ≥45 years. We applied generalized linear mixed-effects models to estimate the effects of PM2.5 constituents, NDVI, and their interaction on arthritis and rheumatoid arthritis. The quantile g-computation and weighted quantile sum regression model were applied to estimate the combined effect of PM2.5 constituents. Our results showed that exposure to single and mixed PM2.5 constituents adversely affected arthritis and rheumatoid arthritis, and was mainly attributed to the black carbon component. We observed "U" or "J" shaped exposure-response curves for the effects of PM2.5, OM, NO3 - and NH4 + exposure on the development of arthritis/rheumatoid arthritis. Additionally, the odds ratio of arthritis for per interquartile range (IQR) increase in PM2.5 was 1.209 (95% CI:1.198, 1.221), per 0.1-unit decrease in NDVI was 1.091 (95% CI:1.033, 1.151), and the interaction term was 1.005 (95% CI:1.002, 1.007). These findings flesh out the existing evidence for PM2.5 constituents, NDVI and arthritis, rheumatoid arthritis, but the underlying mechanisms still require further exploration.

Glycolysis mediates the association between phthalate exposure and the prevalence of childhood asthma: The National Health and Nutrition Examination Survey 2009-2018

Identified as a critical risk factor for childhood asthma, environmental pollution plays a pivotal role. However, research on the effects and mechanisms of phthalates mixture and their interactions in relation to childhood asthma is still lacking. In the National Health and Nutrition Examination Survey (NHANES) conducted from 2009 to 2018, our research explored the link between phthalates in urine and the prevalence of childhood asthma. In this study, which involved 810 participants, we used four different statistical analysis methods to investigate the association between urinary phthalate levels and childhood asthma. Additionally, we conducted a mediation analysis to explore whether the impact mechanism of phthalate exposure on childhood asthma operates through the glycolysis. Among the participants, 525 (64.81 %) individuals were diagnosed with asthma, with 330 (40.74 %) individuals undergoing testing for glycolytic markers. Through Spearman correlation analysis and weighted principal component analysis (W-PCA), it was found that mono-2-ethyl-5-carboxypentyl phthalate (MECPP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono-(2-ethyl)-hexyl phthalate (MEHP) and mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP) are the four most highly correlated phthalates. In addition, comprehensive analysis by the weighted generalized linear models (W-GLM), weighted quantile sum (WQS) and Bayesian kernel machine regression (BKMR) models showed that phthalates mixture were positively associated with the prevalence of childhood asthma, especially MECPP, MEHHP and MEOHP. More importantly, glycolysis participated as a mediator in the relationship between MECPP, MEHHP and MEOHP exposure and the prevalence of childhood asthma, explaining 41.194 %, 38.322 % and 39.871 % of the effects respectively. Therefore, our study revealed that phthalate exposure is a risk factor for asthma in children, and glycolysis may be involved as a potential mediator in this process. This conclusion will be verified through more prospective studies in the future.

Air pollution exposure, chemical compositions, and risk of expiratory airflow limitation in youth in Northeast China

BACKGROUND

Expiratory airflow limitation (EAL) is closely associated with respiratory health in youth and adulthood. Owing to limited evidence, we aim to estimate the association between air pollutants, both individually and in combination, along with their chemical compositions, and the risk of EAL in youth based on data obtained from Northeast China Biobank.

METHODS

Pulmonary function was evaluated using a medical-grade pulmonary function analyzer, with EAL defined as a forced expiratory flow in 1 s/ forced vital capacity ratio of < 0.8. Land use regression models were used to predict exposure to six air pollutants. Air pollution score (APS) for each participant was constructed as combined exposure. The chemical composition of particulate matter with an aerodynamic diameter of ≤ 2.5 µm (PM2.5) was determined using a validated machine-learning algorithm. Logistic regression models were employed to estimate effect sizes, and odds ratio (OR) and 95 % confidence intervals (CI) were calculated.

RESULTS

In total, 905 EAL cases were identified among the 4301 participants, with a prevalence of 21.04 %. Each inter-quartile range increase in APS was associated with a 25 % higher risk of EAL (OR = 1.25, 95 % CI: 1.12, 1.39). Among the pollutants analyzed, PM2.5 exposure had the strongest association with the risk of EAL (OR = 1.33, 95 % CI: 1.18, 1.52). Out of the five chemical components, sulfate (SO2-4) (OR = 1.39, 95 % CI: 1.24, 1.57) and ammonium (NH+4) (OR = 1.39, 95 % CI: 1.23, 1.57) exhibited the strongest associations with the risk of EAL.

CONCLUSIONS

Overall, combined effects of air pollution increased the risk of EAL in youth, with SO2-4 and NH+4 emerging as the predominant contributing chemical components in Northeast China.

Individual and joint exposures to PM2.5 constituents and mortality risk among the oldest-old in China

Cohort evidence linking long-term survival of older adults with exposure to fine particulate matter (PM2.5) constituents remains scarce in China. By constructing a dynamic cohort based on the Chinese Longitudinal Healthy Longevity Study, we aimed to assess the individual and joint associations of major PM2.5 constituents with all-cause death in Chinese oldest-old (.80 years) adults. Time-dependent Cox proportional hazards models were adopted to estimate death risks of long-term exposure to PM2.5 constituents. Among 14,884 participants, totaling 56,342 person-years of follow-up, 12,346 deaths were identified. The highest mortality risk associated with an interquartile range (IQR) increase in exposure was 1.081 (95% confidence interval [CI]: 1.055-1.108) for sulfate (IQR=4.1 μg m-3), followed by 1.078 (95% CI: 1.056-1.101) for black carbon (IQR=1.6 μg m-3), 1.056 (95% CI: 1.028-1.084) for ammonium (IQR=3.2 μg m-3), 1.050 (95% CI: 1.021-1.080) for nitrate (IQR=5.8 μg m-3), and 1.049 (95% CI: 1.024-1.074) for organic matter (IQR=10.3 μg m-3). In joint exposure, each IQRequivalent rise of all five PM2.5 constituents was associated with an 8.2% (95% CI: 4.0%-12.6%) increase in mortality risk. The weight analysis indicated the predominant role of sulfate and black carbon in driving PM2.5-related mortality. Octogenarians (aged 80-89 years) and rural dwellers were at significantly greater risk of mortality from individual and joint exposures to PM2.5 constituents. This study suggests that later-life exposure to PM2.5 constituents, particularly sulfate and black carbon, may curtail long-term survival of the oldest-old in China.

Selective capture of PM2.5 by urban trees: The role of leaf wax composition and physiological traits in air quality enhancement

Human health risks from particles with a diameter of less than 2.5 µm (PM2.5) highlight the role of urban trees as bio-filters in air pollution control. However, whether the size and composition of particles captured by various tree species differ or not remain unclear. This study investigates how leaf attributes affect the capture of PM2.5, which can penetrate deep into the lungs and pose significant health risks. Using a self-developed particulate matter (PM) resuspension chamber and single-particle aerosol mass spectrometer, we measured the size distribution and mass spectra of particles captured by ten tree species. Notably, Cinnamomum camphora (L.) J.Presl and Osmanthus fragrans Lour. are more effective at capturing particles under 1 µm, which are most harmful because they can reach the alveoli, whereas Ginkgo biloba L. and Platanus × acerifolia (Aiton) Willd. tend to capture larger particles, up to 1.6 µm, which are prone to being trapped in the upper respiratory tract. Leaf physiological traits such as stomatal conductance and water potential significantly enhance the capture of larger particles. The Adaptive Resonance Theory neural network (ART-2a) algorithm classified a large number of single particles to determine their composition. Results indicate distinct inter-species variations in chemical composition of particles captured by leaves. Moreover, we identified how specific leaf wax compositions-beyond the known sticky nature of hydrophobic waxes-contribute to particle adhesion, particularly highlighting the roles of fatty acids and alkanes in adhering particles rich in organic carbon and heavy metals, respectively. This research advances our understanding by linking leaf physiological and wax characteristics to the selective capture of PM2.5, providing actionable insights for urban forestry management. The detailed exploration of particle size and composition, tied to specific tree species, enriches the current literature by quantifying how and why different species contribute variably to air quality improvement. This adds a crucial layer of specificity to the general knowledge that trees serve as bio-filters, offering a refined strategy for planting urban trees based on their particulate capture profiles.

The short-term association between environmental variables and daily pediatric asthma patient visits in Hangzhou, China: A time-series study

Background

To date, a large number of studies have shown correlations between environmental variables and pediatric asthma in short-term lag time. However, their results are inconsistent. Therefore, we aimed to evaluate the short-term impact of environmental variables on daily pediatric asthma patients' visits (DPAPV) in Hangzhou, China, and find the most important risk factor.

Methods

Generalized additive distribution lag non-linear model (GAM-DLNM) was applied to explore the effect of environmental variables on DPAPV in single- and multi-variable models in Hangzhou, China from 2014 to 2021. Then, risk factors of pediatric asthma were selected (p < 0.05 both in single- and multi-variable models) and used weighted quantile sum (WQS) regression model to evaluate their relative importance.

Results

There were 313,296 pediatric asthma patient records between 2014 and 2021. Both in single- and multi-variable models, PM2.5, PM10, and NO2 exhibited significant positive correlations in short-term lag time and these correlations reached their maximum in lag day 2 (RR = 1.00, 95%CI:1.00 to 1.01), lag day 2 (RR = 1.00, 95%CI:1.00 to 1.01), and lag day 3 (RR = 1.04, 95%CI:1.02 to1.05), respectively. The WQS index showed that NO2 had the greatest relative importance (weight over 70 %). The relative importance of NO2 increased with time passing. Males were more susceptible to the adverse effects of NO2.

Conclusion

PM2.5, PM10, and NO2 had significant adverse effects on pediatric asthma. Among them, NO2 presented the greatest and most important adverse effect on the disease. Therefore, parents could give priority to paying attention to NO2 to control children's asthma.

Associations of Insecticide Exposure with Childhood Asthma and Wheezing: A Population-Based Cross-Sectional Study in Sanya, China

Insecticide exposure may affect childhood asthma/wheezing, but evidence is scarce in low- and middle-income countries. We conducted a population-based cross-sectional study in Sanya, China. Generalized linear models were adopted to assess the associations of insecticide exposure with childhood asthma/wheezing, reported as odds ratios (ORs) and 95% confidence intervals (CIs). A subgroup analysis was performed to explore the possible effects of sociodemographic and environmental factors on these associations. The median age of the 9754 children was 6.7 years, and 5345 (54.8%) were boys. The prevalences of ever asthma (EA), ever wheezing (EW), and current wheezing (CW) were 7.4%, 5.3%, and 2.9%, respectively. We found a greater prevalence of childhood EA with insecticide exposure (OR = 1.18, 95% CI: 1.00, 1.38). Outdoor insecticide exposure was associated with elevated ORs for EA (1.24, 95% CI: 1.03, 1.50), EW (1.27, 95% CI: 1.03, 1.57), and CW (1.38, 95% CI: 1.04, 1.81). The p for the trend in insecticide exposure frequency was significant for EA (p = 0.001) and CW (p = 0.034). These adverse impacts were pronounced in girls who were exposed to low temperatures. Our findings suggest adverse effects of insecticide use, especially outdoors, on childhood asthma/wheezing. Further studies are warranted to verify this association and develop tailored prevention measures.

Mutual Associations of Exposure to Ambient Air Pollutants in the First 1000 Days of Life With Asthma/Wheezing in Children: Prospective Cohort Study in Guangzhou, China

BACKGROUND

The first 1000 days of life, encompassing pregnancy and the first 2 years after birth, represent a critical period for human health development. Despite this significance, there has been limited research into the associations between mixed exposure to air pollutants during this period and the development of asthma/wheezing in children. Furthermore, the finer sensitivity window of exposure during this crucial developmental phase remains unclear.

OBJECTIVE

This study aims to assess the relationships between prenatal and postnatal exposures to various ambient air pollutants (particulate matter 2.5 [PM2.5], carbon monoxide [CO], sulfur dioxide [SO2], nitrogen dioxide [NO2], and ozone [O3]) and the incidence of childhood asthma/wheezing. In addition, we aimed to pinpoint the potential sensitivity window during which air pollution exerts its effects.

METHODS

We conducted a prospective birth cohort study wherein pregnant women were recruited during early pregnancy and followed up along with their children. Information regarding maternal and child characteristics was collected through questionnaires during each round of investigation. Diagnosis of asthma/wheezing was obtained from children's medical records. In addition, maternal and child exposures to air pollutants (PM2.5 CO, SO2, NO2, and O3) were evaluated using a spatiotemporal land use regression model. To estimate the mutual associations of exposure to mixed air pollutants with the risk of asthma/wheezing in children, we used the quantile g-computation model.

RESULTS

In our study cohort of 3725 children, 392 (10.52%) were diagnosed with asthma/wheezing. After the follow-up period, the mean age of the children was 3.2 (SD 0.8) years, and a total of 14,982 person-years were successfully followed up for all study participants. We found that each quartile increase in exposure to mixed air pollutants (PM2.5, CO, SO2, NO2, and O3) during the second trimester of pregnancy was associated with an adjusted hazard ratio (HR) of 1.24 (95% CI 1.04-1.47). Notably, CO made the largest positive contribution (64.28%) to the mutual effect. After categorizing the exposure according to the embryonic respiratory development stages, we observed that each additional quartile of mixed exposure to air pollutants during the pseudoglandular and canalicular stages was associated with HRs of 1.24 (95% CI 1.03-1.51) and 1.23 (95% CI 1.01-1.51), respectively. Moreover, for the first year and first 2 years after birth, each quartile increment of exposure to mixed air pollutants was associated with HRs of 1.65 (95% CI 1.30-2.10) and 2.53 (95% CI 2.16-2.97), respectively. Notably, SO2 made the largest positive contribution in both phases, accounting for 50.30% and 74.70% of the association, respectively.

CONCLUSIONS

Exposure to elevated levels of mixed air pollutants during the first 1000 days of life appears to elevate the risk of childhood asthma/wheezing. Specifically, the second trimester, especially during the pseudoglandular and canalicular stages, and the initial 2 years after birth emerge as crucial susceptibility windows.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR-ROC-17013496; https://tinyurl.com/2ctufw8n.

Intrauterine and early postnatal exposures to submicron particulate matter and childhood allergic rhinitis: A multicity cross-sectional study in China

BACKGROUND

Airborne particulate matter pollution has been linked to occurrence of childhood allergic rhinitis (AR). However, the relationships between exposure to particulate matter with an aerodynamic diameter ≤1 μm (PM1) 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 PM1, PM1-2.5, PM2.5, PM2.5-10, and PM10, with childhood AR.

METHODS

We investigated 29286 preschool children aged 3-6 years in 7 Chinese major cities during 2019-2020 as the Phase II of the China Children, Families, Health Study. Machine learning-based space-time models were utilized to estimate early-life residential exposure to PM1, PM2.5, and PM10 at 1 × 1-km resolutions. The concentrations of PM1-2.5 and PM2.5-10 were calculated by subtracting PM1 from PM2.5 and PM2.5 from PM10, 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.

RESULTS

Among the 29286 children surveyed (mean ± standard deviation, 4.9 ± 0.9 years), 3652 (12.5%) were reported to be diagnosed with AR. Average PM1 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 PM1 and PM2.5 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 PM1 than for PM2.5 (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 PM1-2.5, indicating that PM1 rather than PM1-2.5 contributed to the association between PM2.5 and childhood AR. In trimester-stratified analysis, childhood AR was only found to be associated with exposure to PM1 (OR = 1.077, 95% CI: 1.027-1.128), PM2.5 (OR = 1.048, 95% CI: 1.018-1.078), and PM10 (OR = 1.032, 95% CI: 1.007-1.058) during the third trimester of pregnancy. Subgroup analysis suggested stronger PM-AR associations among younger (<5 years old) and winter-born children.

CONCLUSIONS

Prenatal and postnatal exposures to ambient PM1 and PM2.5 were associated with an increased risk of childhood AR, and PM2.5-related hazards could be predominantly attributed to PM1. These findings highlighted public health significance of formulating air quality guideline for ambient PM1 in mitigating children's AR burden caused by particulate air pollution.

Effect of air pollution on asthma

Asthma is a chronic inflammatory airway disease characterized by respiratory symptoms, variable airflow obstruction, bronchial hyperresponsiveness, and airway inflammation. Exposure to air pollution has been linked to an increased risk of asthma development and exacerbation. This review aims to comprehensively summarize recent data on the impact of air pollution on asthma development and exacerbation. Specifically, we reviewed the effects of air pollution on the pathogenic pathways of asthma, including type 2 and non-type 2 inflammatory responses, and airway epithelial barrier dysfunction. Air pollution promotes the release of epithelial cytokines, driving TH2 responses, and induces oxidative stress and the production of proinflammatory cytokines. The enhanced type 2 inflammation, furthered by air pollution-induced dysfunction of the airway epithelial barrier, may be associated with the exacerbation of asthma. Disruption of the TH17/regulatory T cell balance by air pollutants is also related to asthma exacerbation. As the effects of air pollution exposure may accumulate over time, with potentially stronger impacts in the development of asthma during certain sensitive life periods, we also reviewed the effects of air pollution on asthma across the lifespan. Future research is needed to better characterize the sensitive period contributing to the development of air pollution-induced asthma and to map air pollution-associated epigenetic biomarkers contributing to the epigenetic ages onto asthma-related genes.

The Associations of Prenatal Exposure to Fine Particulate Matter and Its Chemical Components with Allergic Rhinitis in Children and the Modification Effect of Polyunsaturated Fatty Acids: A Birth Cohort Study

BACKGROUND

Polyunsaturated fatty acids (PUFAs) have been shown to protect against fine particulate matter < 2.5 μ m in aerodynamic diameter (PM 2.5 )-induced hazards. However, limited evidence is available for respiratory health, particularly in pregnant women and their offspring.

OBJECTIVES

We aimed to investigate the association of prenatal exposure to PM 2.5 and its chemical components with allergic rhinitis (AR) in children and explore effect modification by maternal erythrocyte PUFAs.

METHODS

This prospective birth cohort study involved 657 mother-child pairs from Guangzhou, China. Prenatal exposure to residential PM 2.5 mass and its components [black carbon (BC), organic matter (OM), sulfate (SO 4 2 - ), nitrate (NO 3 - ), and ammonium (NH 4 + )] were estimated by an established spatiotemporal model. Maternal erythrocyte PUFAs during pregnancy were measured using gas chromatography. The diagnosis of AR and report of AR symptoms in children were assessed up to 2 years of age. We used Cox regression with the quantile-based g-computation approach to assess the individual and joint effects of PM 2.5 components and examine the modification effects of maternal PUFA levels.

RESULTS

Approximately 5.33 % and 8.07% of children had AR and related symptoms, respectively. The average concentration of prenatal PM 2.5 was 35.50 ± 5.31   μ g / m 3 . PM 2.5 was positively associated with the risk of developing AR [hazard ratio ( HR ) = 1.85 ; 95% confidence interval (CI): 1.16, 2.96 per 5   μ g / m 3 ] and its symptoms (HR = 1.79 ; 95% CI: 1.22, 2.62 per 5   μ g / m 3 ) after adjustment for confounders. Similar associations were observed between individual PM 2.5 components and AR outcomes. Each quintile change in a mixture of components was associated with an adjusted HR of 3.73 (95% CI: 1.80, 7.73) and 2.69 (95% CI: 1.55, 4.67) for AR and AR symptoms, with BC accounting for the largest contribution. Higher levels of n-3 docosapentaenoic acid and lower levels of n-6 linoleic acid showed alleviating effects on AR symptoms risk associated with exposure to PM 2.5 and its components.

CONCLUSION

Prenatal exposure to PM 2.5 and its chemical components, particularly BC, was associated with AR/symptoms in early childhood. We highlight that PUFA biomarkers could modify the adverse effects of PM 2.5 on respiratory allergy. https://doi.org/10.1289/EHP13524.

Prenatal Exposure to Air Pollutants Associated with Allergic Diseases in Children: Which Pollutant, When Exposure, and What Disease? A Systematic Review and Meta-analysis

This systematic review aims to identify the association between prenatal exposure to air pollutants and allergic diseases in children, focusing on specific pollutants, timing of exposure, and associated diseases. We searched PubMed, Scopus, and Web of Science for English articles until May 1, 2023, examining maternal exposure to outdoor air pollutants (PM1, PM2.5, PM10, NO, NO2, SO2, CO, and O3) during pregnancy and child allergic diseases (atopic dermatitis (AD), food allergy (FA), asthma (AT) and allergic rhinitis (AR)/hay fever (HF)). The final 38 eligible studies were included in the meta-analysis. Exposure to PM2.5 and NO2 during pregnancy was associated with the risk of childhood AD, with pooled ORs of 1.34 (95% confidence interval (CI), 1.10-1.63) and 1.10 (95%CI, 1.05-1.15) per 10 µg/m3 increase, respectively. Maternal exposure to PM1, PM2.5, and NO2 with a 10 µg/m3 increase posed a risk for AT, with pooled ORs of 1.34 (95%CI, 1.17-1.54), 1.11 (95%CI, 1.05-1.18), and 1.07 (95%CI, 1.02-1.12), respectively. An increased risk of HF was observed for PM2.5 and NO2 with a 10 µg/m3 increase, with ORs of 1.36 (95%CI, 1.17-1.58) and 1.26 (95%CI, 1.08-1.48), respectively. Traffic-related air pollutants (TRAP), particularly PM2.5 and NO2, throughout pregnancy, pose a pervasive risk for childhood allergies. Different pollutants may induce diverse allergic diseases in children across varying perinatal periods. AT is more likely to be induced by outdoor air pollutants as a health outcome. More research is needed to explore links between air pollution and airway-derived food allergies.

Association of residential land cover and wheezing among children and adolescents: A cross-sectional study in five provinces of China

The association between residential land cover (RLC) and wheezing remains poorly understood. This study aimed to investigate the association between RLC and wheezing in childhood and adolescence. A cross-sectional survey was conducted among children and adolescents in five provinces of China. Land cover data were obtained from the Cross-Resolution Land-Cover mapping framework based on noisy label learning, classifying land cover into five categories: cropland, forest, grass/shrubland, wetland, and impervious. Generalized linear mixed models were employed to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the risk of wheezing. Mediation analysis was employed to investigate whether ambient particulate matter (PM2.5) acts as a mediator in the association between RLC and wheezing. A total of 12,875 participants were included in the study, comprising 318 patients and 12,557 controls. Cropland500m was significantly associated with decreased odds of wheezing (OR: 0.929, 95% CI: 0.879-0.982), while impervious surfaces500m significantly was associated with increased odds of wheezing (OR: 1.056, 95% CI: 1.019-1.096) in all participants. In the stratified analysis, significant differences were found in the main outcomes between the adolescence group (age ≥10 years) and the childhood group (age <10 years) (Pinteraction < 0.05), while no significant differences were observed between the southern and northern regions, or between male and female respondents. Mediation analysis revealed that PM2.5 partially mediated the association between cropland500m and impervious surfaces500m with wheezing. RLC plays a significant role in wheezing during childhood and adolescence, with cropland offering protection and impervious surfaces posing a heightened risk.

Prenatal exposure to PM2.5 components and the risk of different types of preterm birth and the mediating effect of pregnancy complications: a cohort study

OBJECTIVES

This study aims to reveal the single and mixed associations of PM2.5 and its components with very, moderately, and late preterm births and to explore the potential mediating role of pregnancy complications in PM2.5-induced preterm birth.

STUDY DESIGN

This was a retrospective cohort study.

METHODS

We enrolled 168,852 mothers and matched the concentrations of PM2.5 and its five components (OM, SO42-, BC, NO3-, and NH4+) based on their geographical location. Next, we used generalized linear models, quantile g-computation, and mediation analysis to evaluate the associations of PM2.5 and its components with very, moderately, and late preterm births and the mediating role of pregnancy complications.

RESULTS

Prenatal exposure to PM2.5 and its components was associated with preterm birth, and the association was strongest in the third trimester. Preterm birth was associated with co-exposure to a mixture of PM2.5 components in the third trimester, and the contributions of NO3-, NH4+, and BC to the risk of preterm birth were positive. Meanwhile, pregnancy complications mediated PM2.5-induced preterm birth. Moreover, very and moderately preterm births were associated with PM2.5 and its components in the second and third trimesters, and very and late preterm births were associated with co-exposure to a mixture of PM2.5 components in the third trimester.

CONCLUSIONS

Later exposure to PM2.5 during pregnancy will cause earlier preterm birth. Targeted and positive interventions for anthropogenic sources of specific PM2.5 components and pregnancy complications are helpful for preterm birth prevention.

Associations between combined urban and lifestyle factors and respiratory health in European children

INTRODUCTION

Previous studies identified some environmental and lifestyle factors independently associated with children respiratory health, but few focused on exposure mixture effects. This study aimed at identifying, in pregnancy and in childhood, combined urban and lifestyle environment profiles associated with respiratory health in children.

METHODS

This study is based on the European Human Early-Life Exposome (HELIX) project, combining six birth cohorts. Associations between profiles of pregnancy (38 exposures) and childhood (84 exposures) urban and lifestyle factors, identified by clustering analysis, and respiratory health were estimated by regression models adjusted for confounders.

RESULTS

Among the 1033 included children (mean ± standard-deviation (SD) age: 8.2 ± 1.6 years old, 47% girls) the mean ± SD forced expiratory volume in 1s (FEV1) and forced vital capacity (FVC) were 99 ± 13% and 101 ± 14%, respectively, and 12%, 12% and 24% reported ever-asthma, wheezing and rhinitis, respectively. Four profiles of pregnancy exposures and four profiles of childhood exposures were identified. Compared to the reference childhood exposure profile (low exposures), two exposure profiles were associated with lower levels of FEV1. One profile was characterized by few natural spaces in the surroundings and high exposure to the built environment and road traffic. The second profile was characterized by high exposure to meteorological factors and low levels of all other exposures and was also associated with an increased risk of ever-asthma and wheezing. A pregnancy exposure profile characterized by high exposure levels to all risk factors, but a healthy maternal lifestyle, was associated with a lower risk of wheezing and rhinitis in children, compared to the reference pregnancy profile (low exposures).

CONCLUSION

This comprehensive approach revealed pregnancy and childhood profiles of urban and lifestyle exposures associated with lung function and/or respiratory conditions in children. Our findings highlight the need to pursue the study of combined exposures to improve prevention strategies for multifactorial diseases such as asthma.

Exposure to ambient fine particulate matter components during pregnancy and early childhood and its association with asthma, allergies, and sensitization in school-age children

BACKGROUND

Exposure to fine particulate matter (PM2.5) has been associated with allergic diseases, including asthma. However, information about the effects of specific PM2.5 components is limited. This study aimed to investigate the relationship of exposure to chemical components of PM2.5 during pregnancy and early childhood with the development of asthma, allergies, and sensitization in school-age children.

METHODS

This study included 2,408 children in the second grade of elementary school. Questionnaire surveys of respiratory/allergic symptoms and measurements of serum total IgE and specific IgE levels to house dust mite (HDM) and animal proteins were conducted. Exposures to ambient PM2.5 mass, sulfate (SO42-), nitrate (NO3-), ammonium (NH4+), elemental carbon (EC), and organic carbon (OC) of PM2.5 in participants' residences from conception to age six were estimated using predictive models. Multiple logistic regression analysis was used to analyze the association of respiratory/allergic symptoms and allergen sensitization with estimated exposure concentrations, after adjustment for survey year, sex, season of birth, feeding method during infancy, presence of siblings, history of lower respiratory tract infection, use of childcare facilities, passive smoking, presence of pets, mother's age, history of allergic diseases, smoking during pregnancy, and annual household income.

RESULTS

No significant association was found between PM2.5 and its component concentrations and asthma. However, wheezing significantly increased with mean NO3- concentrations during pregnancy (odds ratio of 1.64 [95% confidence interval: 1.10, 2.47] for an interquartile range increase). Significant associations were also found between EC in the second trimester of pregnancy and PM2.5, NO3-, EC, and OC concentrations in early childhood. Higher PM2.5, SO4-, and NH4+ concentrations during the second trimester increased the risk of rhinitis. Sensitizations to HDM and animal proteins were significantly associated with exposure to components such as SO42- and NH4+ during pregnancy but not with postnatal exposure.

CONCLUSIONS

Exposures to NO3-, EC, and OC during pregnancy and early childhood were associated with wheezing. SO42- and NH4+ exposures during pregnancy were associated with sensitization to HDM and animal proteins. Asthma was not associated with exposure to PM2.5 and its main components at any period.

Associations between long-term exposure to PM2.5 chemical constituents and allergic diseases: evidence from a large cohort study in China

BACKGROUND

Exposure to air pollutants may cause immune responses and further allergic diseases, but existing studies have mostly, if not all, focused on effects of short-term exposure to PM2.5 on allergic diseases.

OBJECTIVES

We estimated associations of long-term exposure to PM2.5 chemical constituents with allergic disease risks and effect modification.

METHODS

We used the baseline of a newly established, provincially representative cohort of 51,480 participants in southwest China. The presence of allergic rhinitis, allergic asthma, urticaria, and allergic conjunctivitis was self-reported by following a formed questionnaire in face-to-face interviews. The average concentrations of PM2.5 chemical constituents (NO3-, SO42-, NH4+, organic matter [OM], and black carbon [BC]) over participants' residence were estimated using machine learning models. Logistic regression with double robust estimator and weighted quantile sum regression were used to estimate the effects of PM2.5 chemical constituents on allergic disease risks, as well as relative importance of each PM2.5 chemical constituent.

RESULTS

Per interquartile range increase in the concentration of all PM2.5 chemical constituents was associated with the elevated risks for allergic asthma (OR = 1.79 [1.41-2.26]), allergic conjunctivitis (1.54 [1.19-2.00]), urticaria (1.36 [1.25-1.48]), and allergic rhinitis (1.18 [1.11-1.26]). NO3- contributed more to risks for allergic asthma (weight = 46.05 %), urticaria (72.29 %), and allergic conjunctivitis (47.65 %), while NH4+ contributed more to allergic rhinitis (78.07 %). OM contributed most to the risks for allergic asthma (30.81 %) and allergic conjunctivitis (31.40 %). BC was also associated with allergic rhinitis, urticaria, and allergic conjunctivitis, only with a considerable weight for urticaria (24.59 %). Joint effects of PM2.5 chemical constituents on risks for allergic rhinitis and urticaria were stronger in minorities and farmers than their counterparts.

CONCLUSION

Long-term exposure to PM2.5 chemical constituents was associated with the increased allergic disease risks, with NO3- and NH4+ accounting for the largest variance of the associations. Our findings would serve as scientific evidence for developing more explicit strategies of air pollution control.

The combined effects of exposure to multiple PM2.5 components on overweight and obesity in middle-aged and older adults: a nationwide cohort study from 125 cities in China

The prevalence of overweight or obesity increased rapidly over the past decades in most countries, including China. However, little evidence exists about the effects of long-term exposure to PM2.5 components on overweight or obesity, particularly in developing countries. We measured different weight stages according to body mass index (BMI), and investigated the effects of exposure to PM2.5 components (ammonium [[Formula: see text]], sulfate [[Formula: see text]], nitrate [[Formula: see text]], black carbon and organic matter) on different BMI levels in middle-aged and elderly people of China. Our study explored the effects of single and multiple air pollution exposures on overweight and obesity by using the Generalized Linear Model and Quantile g-Computation model (QgC). This study found a significantly positive association between five PM2.5 components and overweight/obesity. In the QgC model, there was still a positive association between multiple exposure to PM2.5 components and overweight when all PM2.5 components were considered as a whole. In addition, males, the elderly, and urban residents were also more sensitive to five PM2.5 components.

Study of the Impact of Air Pollution on Convulsions in Children: A Hospital-Based Retrospective Study in Hangzhou, China

BACKGROUND

To investigate the relationship between the occurrence of convulsions in children and air pollution in Hangzhou.

METHODS

From January 1, 2018, to December 31, 2020, 775 children admitted with convulsion to the pediatric outpatient clinic of The Affiliated Hospital of Hangzhou Normal University (Hangzhou, China) were enrolled in this study. The clinical data and the corresponding weather data of the day in Hangzhou were collected and analyzed. Also, the monthly etiological classification of convulsions and the monthly average air data of Hangzhou were statistically analyzed.

RESULTS

The highest incidence of convulsion was observed in children 1 to 2 years old, and higher in boys than in girls. The top three main causes were febrile seizure, benign infantile convulsion with mild gastroenteritis, and epilepsy. Among the meteorological factors, the increase in the level of 2.5 micron particulate matter (PM 2.5) in the air per month led to an increase in the number of patients with febrile seizure, benign infantile convulsion with mild gastroenteritis, and epilepsy, where the increase of ozone in 8 hours (O3-8h) per month led to a decrease in the number of patients with such conditions.

CONCLUSIONS

PM2.5, PM10, and SO2 are the main meteorological factors affecting the occurrence of convulsions in children in Hangzhou, and PM2.5 and SO2 are risk factors. The increase in the level of PM2.5 in the air per month could increase occurrence of child convulsions, but the increase of O3-8h per month could decrease occurrence of child convulsions.

Association of Fine Particulate Matter Constituents with the Predicted 10-Year Atherosclerotic Cardiovascular Disease Risk: Evidence from a Large-Scale Cross-Sectional Study

Little is known concerning the associations of fine particulate matter (PM2.5) and its constituents with atherosclerotic cardiovascular disease (ASCVD). A total of 31,162 participants enrolled from the Henan Rural Cohort were used to specify associations of PM2.5 and its constituents with ASCVD. Hybrid machine learning was utilized to estimate the 3-year average concentration of PM2.5 and its constituents (black carbon [BC], nitrate [NO3-], ammonium [NH4+], inorganic sulfate [SO42-], organic matter [OM], and soil particles [SOIL]). Constituent concentration, proportion, and residual models were utilized to examine the associations of PM2.5 constituents with 10-year ASCVD risk and to identify the most hazardous constituent. The isochronous substitution model (ISM) was employed to analyze the substitution effect between PM2.5 constituents. We found that each 1 μg/m3 increase in PM2.5, BC, NH4+, NO3-, OM, SO42-, and SOIL was associated with a 3.5%, 49.3%, 19.4%, 10.5%, 21.4%, 14%, and 28.5% higher 10-year ASCVD risk, respectively (all p < 0.05). Comparable results were observed in proportion and residual models. The ISM found that replacing BC with other constituents will generate the greatest health benefits. The results indicated that long-term exposure to PM2.5 and its constituents were associated with increased risks of ASCVD, with BC being the most attributable constituent.

Association of the components of ambient fine particulate matter (PM2.5) and chronic kidney disease prevalence in China

Previous research has implicated PM_2.5 as a potential environmental risk factor for CKD, but little is known about the associations between its components and CKD. We conducted a nationwide cross-sectional study using the updated air pollution data in the nationwide population (N = 2,938,653). Using generalized additive models, we assessed the association between long-term exposure to PM_2.5 and its components (i.e., black carbon [BC], organic matter [OM], nitrate [NO₃^-], ammonium [NH₄⁺], sulfate [SO₄^2-]), and CKD prevalence. The air pollution data was estimated using high-resolution and high-quality spatiotemporal datasets of ground-level air pollutants in China. Besides, we adopted a novel quantile-based g-computation approach to assess the effect of a mixture of PM_2.5 constituents on CKD prevalence. The average concentration of PM_2.5 was 78.67 ± 22.5 μg/m³, which far exceeded WHO AQG. In the fully adjusted generalized additive model, at a 10 km × 10 km spatial resolution, the ORs per IQR increase in previous 1-year average PM_2.5 exposures was 1.380 (95%CI: 1.345-1.415), for NH₄⁺ was 1.094 (95%CI: 1.062-1.126), for BC was 1.604 (95%CI: 1.563-1.646), for NO₃^- was 1.094 (95%CI: 1.060-1.130), for SO₄^2- was 1.239 (95%CI: 1.208-1.272), and for the OM was 1.387 (95%CI: 1.354-1.421), respectively. Subgroup analysis showed females, younger, and healthier were more vulnerable to this effect. In the further exploration of the joint effect of PM_2.5 compositions (OR 1.234 [95%CI 1.222-1.246]) per quartile increase in all 5 PM_2.5 components, we found that PM_2.5SO₄^2- contributed the most. These findings provide important evidence for the positive relationship between long-term exposure to PM_2.5 and its chemical constituents and CKD prevalence in a Chinese health check-up population, and identified PM_2.5SO₄^2- has the highest contribution to this relationship. This study provides clinical and public health guidance for reducing specific air particle exposure for those at risk of CKD.

Post-birth exposure contrasts for children during the Household Air Pollution Intervention Network randomized controlled trial

Exposure to household air pollution is a leading cause of ill-health globally. The Household Air Pollution Intervention Network (HAPIN) randomized controlled trial evaluated the impact of a free liquefied petroleum gas stove and fuel intervention on birth outcomes and maternal and child health. As part of HAPIN, an extensive exposure assessment was conducted. Here, we report on PM 2.5 and CO exposures of young children (≤ 15 months old) reconstructed using a Bluetooth-beacon based time-activity monitoring system coupled with microenvironmental pollutant monitors. Median (IQR) exposures to PM 2.5 were 65.1 (33 - 128.2) µg/m 3 in the control group and 22.9 (17.2 - 35.3) µg/m3 in the intervention group; for CO, median (IQR) exposures were 1.1 (0.3 - 2.9) ppm and 0.2 (0 - 0.7) ppm for control and intervention group, respectively. Exposure reductions were stable over time and consistent with previous findings for the children's mothers. In the intervention group, 75% of children's reconstructed exposures were below the WHO interim target guideline value of 35 µg/m 3 , while 26% were below the standard in the control group. Our findings suggest that an LPG fuel and stove intervention can substantially reduce children's exposure to household air pollution.

Long-term exposure to air pollution and increased risk of atrial fibrillation prevalence in China

BACKGROUND

Atrial fibrillation (AF) is the most common type of treated heart arrhythmia contributing to adverse cardiovascular events. The association between short-term air pollution exposure and AF episodes has been recognized. But the evidence of the association between long-term air pollution exposure and AF was limited, especially in developing countries.

METHODS

We performed a nationwide cross-sectional study among 1,374,423 individuals aged ≥35 years from 13 health check-up centers. Using logistic regression models, we assessed the association between long-term exposure to single air pollution and AF prevalence, including particulate matter (PM_2.5 and PM₁₀), ozone (O₃) and PM_2.5 compositions, which were estimated by high-resolution and high-quality spatiotemporal datasets of ground-level air pollutants for China. The quantile g-computation model was used to explore the joint effect of all exposures to air pollution and the contribution of an individual component to the mixture.

RESULTS

In single-pollutant models, an increase of 10 μg/m³ in PM_2.5 (OR 1.031[95%CI 1.010,1.053]) and PM₁₀ (OR = 1.021 [95%CI 1.009,1.033]) was positively associated with AF prevalence. The stratified analyses revealed that these associations were significantly stronger in females, people <65 years old, and those with hypertension and diabetes. In the further exploration of the joint effect of PM_2.5 compositions (OR 1.060 [95%CI 1.022,1.101]) per quintile increase in all five PM_2.5 components), we found that PM_2.5 sulfate contributed the most.

CONCLUSIONS

These findings provide important evidence for the positive relationship between long-term exposure to air pollution and AF prevalence in China and identify sulfate particles of PM_2.5 as having the highest contribution to the overall mixture effects among all PM2.5 chemical constituents.

Long-term exposure to PM2.5 constituents in relation to glucose levels and diabetes in middle-aged and older Chinese

BACKGROUND

Previous studies have indicated the associations between fine particulate matter (PM_2.5) exposure and diabetes or glucose levels. However, evidence linking PM_2.5 constituents and diabetes or glucose levels was extensively scarce, particularly in developing countries. This study aimed to investigate the associations of exposure to PM_2.5 and its five constituents (black carbon [BC], organic matter [OM], nitrate [NO₃^-], sulfate [SO₄^2-], and ammonium [NH₄⁺]) with diabetes and glucose levels among the middle-aged and elderly Chinese populations.

METHODS

A national cross-sectional sample of participants aged 45+ years was enrolled from 28 provinces across China's mainland. Health examination and questionnaire survey for each respondent were performed during 2011-2012. Diabetes was determined by alternative definitions, and the main definition (MD) was self-report diabetes or antidiabetic medicine use or HbA_1c ≥6.5 or fasting glucose ≥7 mmol/L or random glucose ≥11.1 mmol/L. Monthly exposure to PM_2.5 mass and its five constituents (BC, OM, NO₃^-, SO₄^2-, and NH₄⁺) for each participant at residence were estimated using satellite-based spatiotemporal prediction models. Generalized linear models and linear mixed-effects models were used to assess the effects of exposure to PM_2.5 and its constituents on diabetes or glucose levels, respectively. Stratification analyses were done by sex and age.

RESULTS

We included a total of 17,326 adults over 45 years in this study. The 3-year mean (interquartile range [IQR]) concentrations of PM_2.5, BC, OM, NO₃^-, SO₄^2-, and NH₄⁺ were 47.9 (27.4) µg/m³, 2.9 (2.2) µg/m³, 9.2 (6.6) µg/m³, 10.2 (9.4) µg/m³, 11.0 (5.2) µg/m³, and 7.1 (4.4) µg/m³, respectively. Per IQR rise in exposure to PM_2.5 was significantly associated with an increase of 0.133 mmol/L (95% confidence interval, 0.048-0.219) in glucose concentrations. Similar positive associations were observed for BC (0.097 mmol/L [0.012-0.181]), OM (0.160 mmol/L [0.065-0.256]), NO₃^- (0.145 mmol/L [0.039-0.251]), SO₄^2- (0.111 mmol/L [0.026-0.196]), and NH₄⁺ (0.135 mmol/L [0.041-0.230]). Under different diabetes definitions, PM_2.5 mass and selected constituents with the exception of SO₄^2- were all associated with a higher risk of prevalent diabetes. In MD-based analysis, similar positive associations were observed for four constituents, with corresponding odds ratios of 1.180 (1.097-1.270) for PM_2.5, 1.154 (1.079-1.235) for BC, 1.170 (1.079-1.270) for OM, 1.200 (1.098-1.312) for NO₃^-, and 1.123 (1.037-1.215) for NH₄⁺. Stratified analyses showed a significantly higher risk of diabetes in males (1.225 [1.064-1.411]) than females (1.024 [0.923-1.136]) when exposed to PM_2.5. Participants under 65 years were generally more vulnerable to diabetes hazards related to PM_2.5 constituents exposure.

CONCLUSIONS

Exposures to PM_2.5 and its constituents (i.e., BC, OM, NO₃^-, and NH₄⁺) were positively associated with increased risks of prevalent diabetes and elevated glucose levels in middle-aged and older adults.

The Correlation of PM2.5 Exposure with Acute Attack and Steroid Sensitivity in Asthma

Bronchial asthma is a common chronic inflammatory disease of the respiratory system. Asthma primarily manifests in reversible airflow limitation and airway inflammation, airway remodeling, and persistent airway hyperresponsiveness. PM2.5, also known as fine particulate matter, is the main component of air pollution and refers to particulate matter with an aerodynamic diameter of ≤2.5 μm. PM2.5 can be suspended in the air for an extensive time and, in addition, can contain or adsorb heavy metals, toxic gases, polycyclic aromatic hydrocarbons, bacterial viruses, and other harmful substances. Epidemiological studies have demonstrated that, in addition to increasing the incidence of asthma, PM2.5 exposure results in a significant increase in the incidence of hospital visits and deaths due to acute asthma attacks. Furthermore, PM2.5 was reported to induce glucocorticoid resistance in asthmatic individuals. Although various countries have implemented strict control measures, due to the wide range of PM2.5 sources, complex components, and unknown pathogenic mechanisms involving the atmosphere, environment, chemistry, and toxicology, PM2.5 damage to human health still cannot be effectively controlled. In this present review, we summarized the current knowledge base regarding the relationship between PM2.5 toxicity and the onset, acute attack prevalence, and steroid sensitivity in asthma.