Association of improved air quality with lung development in children

Emerging evidence for the impact of Electric Vehicle sales on childhood asthma: Can ZEV mandates help?

Growing epidemiological studies indicate a significant fraction of asthma cases can be attributed to traffic-related air pollution (TRAP). Zero emission vehicle (ZEV) mandates - one of the most forward-looking climate policies in the United States - aim to reduce TRAP by mandating automakers to sell a certain fraction of Electric Vehicles (EVs) annually; however, their public health benefits are largely unknown. We conduct the screening step of the health impact assessment (HIA) of real-world EV sales to estimate the impact of ZEV mandates in reducing childhood asthma. Using publicly available US state and national datasets, we isolate the burden of childhood asthma attributable to TRAP from 2013 to 2019 and examine the influence of EV and non-EV vehicle sales and fleets on asthma incidence and prevalence using a generalized linear mixed model. Our analyses indicate that new EV sales have reduced asthma, with one asthma case prevented for every 264 (95% CI: 113-401) new EVs on the road. The rise of new childhood asthma cases from new car sales can be prevented when non-EV sales are replaced with EV sales at an annual market share of 21.4% (7.1-41.6%). Extending our analysis to the entire vehicle fleet, we project that when EVs reach 53.0% (35.5%-76.9%), childhood asthma due to tailpipe emissions can be eradicated completely. Screening results conclude that ZEV mandates implemented over the past decade are already exhibiting measurable public health benefits, suggesting that a broader adoption could significantly reduce the asthma burden, thus we recommend a full HIA for ZEV mandates to fully assess their potential.

Ambient exposure to nitrogen dioxide and lung function: a multi-metric approach

Most studies evaluating chronic ambient exposure to nitrogen dioxide (NO2) have used averages as the exclusive exposure metric. However, this approach may lead to an underestimation of potential health effects. The objective of this study is to evaluate the association between ambient exposure to NO2 assessed by various metrics, and lung function in a cohort of healthy male youth. A cross-sectional analysis of 5,462 subjects was conducted using multivariate linear regression. Exposure to NO₂ was assessed by spatial interpolation using Empirical Bayesian Kriging (EBK). Five different exposure metrics were evaluated over two years, including average concentration, the number and intensity of exceedances of the 24-h NO2 World Health Organization air quality guideline (AQG), and the number and intensity of 1-h NO2 peaks. Lung function indices, including percent predicted forced expiratory volume in one second (FEV1), forced vital capacity (FVC), forced expiratory flow between 25% and 75% of vital capacity (FEF25-75), and FEV1/FVC ratio, were assessed. The intensity of the 24-h AQG exceedances was associated with the largest reductions in FEV1 (-0.82%, 95% CI: -1.61%, -0.03%) and FVC (-1.03%, 95% CI: -1.86%, -0.20%), while FEF25-75 showed a significant decline only with the 1-h peak intensity metric (-2.78%, 95% CI: -5.02%, -0.54%). The study results support integrating diverse exposure metrics as part of NO2 chronic exposure assessment, as these metrics may capture a wider range of potential health effects that could be underestimated or overlooked when relying only on average concentrations.

The impact of climate change on respiratory health: current understanding and knowledge gaps

PURPOSE OF REVIEW

To present an overview of the impact of climate change upon human respiratory health.

RECENT FINDINGS

Climate change is directly impacting air quality. Particulate matter clearly increases mortality rates. Ozone, a longstanding suspect in climate-related injury, turns out not to have the major impact that had been projected at current levels of exposure. The key factors in global warming have been clearly identified, but while these factors collectively cause deleterious changes, a close look at the literature shows that it is unclear to what extent each factor individually is a driver of a specific process. This article summarizes some of those studies.

SUMMARY

A better understanding of which components of climate change most impact human health is needed in order to re-define environmental standards. PM 2.5 needs to be broken down by chemical composition to study the differential impacts of different sources of PM 2.5 . The detection and study of climate-related changes in respiratory infectious diseases is in a state of relative infancy.

Proximity to petrochemical industry and risk of childhood asthma occurrence

Adverse effects on the respiratory system were associated with intensive petroleum-related industrial activities. The study aimed to assess the impact of petrochemical exposure on childhood asthma using various surrogate indices. A singleton birth cohort from 2004 to 2017 was conducted, leveraging two linked nationwide databases in Taiwan. The distance from the nearest petrochemical industrial parks (PIPs), the probability for PIPs exposure, and benzene exposure level were used as surrogate petrochemical exposure indices. Both prenatal and postnatal exposure window were considered. The Cox proportional hazard models were applied to evaluate the effects. A total of 461,343 asthma cases were identified in this cohort by December 31, 2018. Certain risk factors such as being male, preterm birth, low birth weight, Caesarean delivery, maternal gestational hypertension, and gestational diabetes, were more prevalent in children with asthma than in those without. The results indicated an increased risk of asthma for those living near PIPs or with a higher probability for PIPs exposure during prenatal and/or postnatal periods. Increased asthma risks were also observed with higher levels of benzene exposure during either the prenatal or postnatal periods. Proximity to PIPs is associated with an increased risk of childhood asthma, as indicated by three different exposure surrogate exposure indices. This underscores the significant impact of petrochemical exposure on the occurrence of childhood asthma.

Environmental Issues in Global Pediatric Health: Technical Report

Pediatricians and pediatric trainees in North America are increasingly involved in caring for children and adolescents in or from low- and middle-income countries (LMICs). In many LMICs, toxic environmental exposures-notably outdoor and household air pollution, water pollution, lead, hazardous waste disposal, pesticides, and other manufactured chemicals-are highly prevalent and account for twice as great a proportion of disease and deaths among young children as in North America. Climate change will likely worsen these exposures. It is important that pediatricians and other pediatric health professionals from high-income countries who plan to work in LMICs be aware of the disproportionately severe impacts of environmental hazards, become knowledgeable about the major toxic threats to children's health in the countries and communities where they will be working, and consider environmental factors in their differential diagnoses. Likewise, pediatricians in high-income countries who care for children and adolescents who have emigrated from LMICs need to be aware that these children may be at elevated risk of diseases caused by past exposures to toxic environmental hazards in their countries of origin as well as ongoing exposures in products such as traditional foods, medications, and cosmetics imported from their original home countries. Because diseases of toxic environmental origin seldom have unique physical signatures, the environmental screening history, supplemented by laboratory testing, is the principal diagnostic tool. The goal of this technical report is to enhance pediatricians' ability to recognize, diagnose, and manage disease caused by hazardous environmental exposures, especially toxic chemical exposures, in all countries and especially in LMICs.

Environmental Issues in Global Pediatric Health: Policy Statement

Pediatricians and pediatric trainees in North America are increasingly involved in caring for children and adolescents in or from low- and middle-income countries (LMICs). In many LMICs, hazardous environmental exposures-notably outdoor and household air pollution, water pollution, lead, pesticides, and other manufactured chemicals-are highly prevalent and account for twice the proportion of disease and deaths among young children as in North America. Climate change will likely worsen these exposures. It is important that pediatricians and other pediatric health professionals from high-income countries who work in LMICs be aware of the disproportionately severe impacts of toxic environmental hazards, become knowledgeable about the major local/regional environmental threats, and consider environmental factors in their differential diagnoses. Likewise, pediatricians in high-income countries who care for patients who have emigrated from LMICs need to be aware that these children may be at elevated risk of toxic environmental diseases from past exposures to toxic environmental hazards in their countries of origin as well as ongoing exposures in products imported from their home countries, including traditional foods, medications, and cosmetics. Because diseases of toxic environmental origin seldom have unique physical signatures, pediatricians can utilize the environmental screening history, supplemented by laboratory testing, as a diagnostic tool. To prepare pediatricians to care for children in and from LMICs, pediatric organizations could increase the amount of environmental health and climate change content offered in continuing medical education (CME) credits, maintenance of certification (MOC) credits, and certification and recertification examinations. Broadly, it is important that governments and international agencies increase resources directed to pollution prevention, strengthen the environmental health workforce, and expand public health infrastructure in all countries.

Respiratory Benefits of Multisetting Air Purification in Children: A Cluster Randomized Crossover Trial

Importance

Particulate matter exposure has been linked to impaired respiratory health in children, but the respiratory benefits of air purification have not been fully elucidated.

Objectives

To assess the respiratory health outcomes among children exposed to multisetting air purification vs sham purification.

Design, Setting, and Participants

This cluster randomized, double-blind, crossover trial was conducted among healthy school-aged children (10-12 years) in China from April to December 2021. Data were analyzed from December 2021 to July 2024.

Interventions

A multisetting (both in classrooms and bedrooms) air purification intervention compared with sham purification in a 2-stage intervention with more than 2 months (76 days) for each period and a washout period (88 days) to estimate the respiratory benefits of air purification.

Main Outcomes and Measures

The primary outcomes were pulmonary function, airway inflammation markers, and metabolites in exhaled breath condensate (EBC) before and after the air purification intervention. Linear mixed-effects models were used to estimate the respiratory benefits of children related to air purification. Differential metabolites in EBC were identified using metabolomics analysis to explore their possible mediation roles.

Results

A total of 79 children (38 male [48%]; mean [SD] age, 10.3 [0.5] years) were included in the statistical analyses. During the study period, the mean (SD) concentration of outdoor fine particulate matter (PM2.5) at the school site was 32.53 (24.06) μg/m3. The time-weighted personal PM2.5 concentration decreased by 45.14% during the true air purification period (mean [SD], 21.49 [8.72] μg/m3) compared with the sham air purification period (mean [SD], 39.17 [14.25] μg/m3). Air purification improved forced expiratory volume in 1 second by 8.04% (95% CI, 2.15%-13.93%), peak expiratory flow by 16.52% (95% CI, 2.76%-30.28%), forced vital capacity (FVC) by 5.73% (95% CI, 0.48%-10.98%), forced expiratory flow at 25% to 75% of FVC by 17.22% (95% CI, 3.78%-30.67%), maximal expiratory flow at 75% of FVC by 14.60% (95% CI, 0.35%-28.85%), maximal expiratory flow at 50% of FVC by 17.86% (95% CI, 3.65%-32.06%), and maximal expiratory flow at 25% of FVC by 18.22% (95% CI, 1.73%-34.70%). Fractional exhaled nitric oxide in the true air purification group decreased by 22.38% (95% CI, 2.27%-42.48%). Several metabolites in EBC (eg, L-tyrosine and β-alanine) were identified to mediate the effect of air purification on respiratory health.

Conclusions and Relevance

This randomized clinical trial provides robust and holistic evidence that indoor air purification notably improved pulmonary health in children, highlighting the importance of intensified indoor air purification in regions with high air pollution levels.

Trial Registration

ClinicalTrials.gov Identifier: NCT04835337.

Long-Term Exposure to Nitrogen Dioxide and Ozone and Respiratory Health in Children

Rationale: Further evaluation of the impact of long-term exposure to the gaseous air pollutants nitrogen dioxide (NO2) and ozone (O3) on child lung function and of NO2 or O3 on eosinophilic airway inflammation is needed. Objectives: To determine whether NO2 and O3 are associated with lung function and fractional exhaled nitric oxide (FeNO) in children. Methods: We measured lung function (forced expiratory volume in 1 second [FEV1] and forced vital capacity [FVC]) at midchildhood (mean age, 7.9 yr; n = 703), early teens (13.2 yr; n = 976), and midteens (17.6 yr; n = 624) study visits, and FeNO at the early and midteens study visits in Project Viva, a cohort of mother-child pairs in the Boston area. Long-term exposure to NO2 and O3 was estimated at the home address using geospatial models. We examined associations of home address NO2 and O3 exposure and proximity to roadway with lung function and FeNO using linear regression models, adjusting for age, sex, height, weight, season, relative humidity, temperature, parental smoking, and measures of socioeconomic status. We examined for effect modification of the midteen associations by blood eosinophil concentration, physical activity, aeroallergen sensitization, and parental atopy. Results: Median exposure to NO2 was 33.1 ppb (interquartile range [IQR], 10.4 ppb) and to O3 was 35.3 ppb (IQR, 3.4) in the first year of life. Exposure to NO2 was associated with lower FEV1 and FVC across all age groups and exposure time intervals: For example, an IQR increment of NO2 exposure from birth through the early teen visit was associated with 189.9 ml lower FEV1 (95% confidence interval, -273.3, -106.5) at the midteen visit. Lifetime NO2 exposure at was associated with higher FeNO at the early teen visit: for example, 16.2% higher FeNO (95% confidence interval, 7.1-26.4%) per IQR of lifetime NO2 through the early teen visit. O3 exposure was not associated with lung function or FeNO. Aeroallergen sensitization (measured in a subset of participants) modified associations of NO2 and O3 with FeNO. Conclusions: Exposure to NO2 was associated with lower lung function and higher FeNO among generally healthy children and teenagers. Because NO2 exposure levels were within the annual U.S. Environmental Protection Agency standard, these findings suggest a need to reduce exposure to this pollutant to optimize child respiratory health.

Impact of a 10-year shift in ambient air quality on mortality in Canada: a causal analysis of multiple pollutants

BACKGROUND

The impact of past air quality improvements on health and equity at low pollution levels near the revised WHO air quality guidelines remains largely unknown. Less is known about the influence of simultaneous reductions in multiple major pollutants. Leveraging real-world improvements in air quality across Canada, we sought to directly evaluate their health benefits by quantifying the impact of a joint shift in three criteria pollutants on mortality in a national cohort.

METHODS

In this population-based cohort study, we assembled a cohort of 2·7 million adults living in Canada in 2007 who were followed up through 2016. Annual mean concentrations of fine particulate matter (PM2·5), nitrogen dioxide (NO2), and ozone (O3) were assigned to participants' residential locations. For each pollutant individually and combined, we conducted a causal analysis of the impact of the decadal shift in annual exposure from the pre-baseline level (2004-06) on the risk of non-accidental mortality using the parametric g-formula, a structural causal model. To check the robustness of our results, we conducted multiple sensitivity analyses, including exploring alternative exposure scenarios. We also evaluated differential benefits across regions and socio-demographic subgroups.

FINDINGS

Between 2007 and 2016, annual mean exposures to PM2·5 and NO2 decreased (from 7·1 μg/m3 [SD 2·3] to 5·5 μg/m3 [1·9] for PM2·5 and from 11·1 ppb [SD 6·6] to 8·0 ppb [4·9] for NO2), whereas O3 declined initially and then rebounded (from 38·6 [SD 8·3] ppb to 36·0 [6·0] ppb and then 38·1 [5·4] ppb). Compared to pre-baseline (2004-06) levels, the joint change in the pollution exposures beginning in 2007 resulted in, per million population, 70 (95% CI 29-111) fewer deaths by 2009, 416 (283-549) fewer deaths by 2012, and 609 (276-941) fewer deaths by 2016, corresponding to a -0·7% change in mortality risk over the decade. Stratified analyses showed greater beneficial impacts in men, adults aged 50 years and older, low income-earners, and residents in regions undergoing substantial air quality improvements. Had all regions experienced pollution reductions similar to the most improved region, approximately three times as many deaths would have been averted (2191 fewer deaths per million). Conversely, if the observed air quality improvements had been delayed in all regions by 3 years, there would have been 429 more deaths per million by 2016.

INTERPRETATION

In Canada, substantial health gains were associated with air quality improvements at levels near the revised WHO guidelines between 2007 and 2016, with notable heterogeneity observed across socio-demographic subgroups and regions. These findings indicate that modest declines in air pollution can considerably improve health and equity, even in low-exposure environments.

FUNDING

Health Canada.

Spatiotemporal modeling of long-term PM2.5 concentrations and population exposure in Greece, using machine learning and statistical methods

The lack of high-resolution, long-term PM2.5 observations in Greece and the Eastern Mediterranean hampers the development of spatial models that are crucial for providing representative exposure estimates to health studies. This work presents a spatial modeling approach to address this gap and assess PM2.5 spatial variability for the first time on a national level in Greece, by integrating in situ observations, meteorology, emissions and satellite AOD data among others. A high-resolution (1 km2) gridded dataset of PM2.5 concentrations across Greece from 2015 to 2022 was developed, and seven statistical, machine learning, and hybrid models were evaluated under different prediction scenarios. Random Forest (RF) models demonstrated superior performance, (R2 = 0.73, MAE = 2.2 μg m-3), validated against ground-based measurements. Winter months consistently showed the highest PM2.5 levels, averaging 16.8 μg m-3, over the domain, due to residential biomass burning (BB) and limited atmospheric dispersion. Summer months had the lowest concentrations, averaging 10.3 μg m-3, while substantial decreases nationwide were observed during the 2020 COVID-19 lockdown. Population exposure analysis indicated that the entire Greek population was exposed to long-term PM2.5 concentrations exceeding the WHO air quality guideline (AQG) of 5 μg m-3. Moreover, the dataset revealed elevated PM2.5 levels across several regions of mainland Greece. Notably, 70 % to 90 % of the population experience levels exceeding 10 μg m-3 in Central and Northern regions of continental Greece like Thessaly, Central Macedonia, and Ioannina. The Ioannina region, which is severely impacted by residential BB, recorded pollution levels up to five times the WHO AQG highlighting the urgent need for targeted interventions. The high-resolution RF model's superior performance for monthly average concentrations, compared to the Copernicus Atmosphere Monitoring Service (CAMS) dataset, renders it a reliable tool for long-term PM2.5 assessment in Greece that can support air quality management and health studies.

Gene-Air Pollution Interaction and Diversity of Genetic Sampling: The Southern California Children's Health Study

Gene-environment interactions have been observed for childhood asthma, however few have been assessed in ethnically diverse populations. Thus, we examined how polygenic risk score (PRS) modifies the association between ambient air pollution exposure (nitrogen dioxide [NO2], ozone, particulate matter < 2.5 and < 10 μm) and childhood asthma incidence in a diverse cohort. Participants (n = 1794) were drawn from the Southern California Children's Health Study, a multi-wave prospective cohort followed from 4th to 12th grade. PRS was developed using single nucleotide polymorphisms previously associated with childhood asthma. PRS-asthma associations and PRS-air pollutant interactions were estimated using Poisson regression. An interquartile range PRS increase was associated with 36% (95% CI: 9%, 70%) higher asthma incidence among non-Hispanic children, but not associated with asthma among Hispanic children (rate ratio: 0.81 [95% CI: 0.62, 1.04]). NO2-PRS interaction was borderline significant in the overall sample (coefficient: 0.23 [95% CI: -0.03, 0.49]). Limited evidence was observed for a positive interaction between PRS and NO2 exposure associated with asthma incidence; however, the literature-based PRS was not associated with asthma among Hispanic participants. Equitable, diverse genetic sampling approaches are needed to better identify clinically relevant SNPs in this population.

Clinical Characteristics of Chronic Obstructive Pulmonary Disease according to Smoking Status

Chronic obstructive pulmonary disease (COPD) can be caused by various factors, including lung infections, asthma, air pollution, childhood growth disorders, and genetic factors, though smoking is the predominant risk factor. The main pathological mechanisms in COPD involve small airway disease, emphysema, mucus hypersecretion, and vascular disorders. COPD in non-smokers is characterized by a normal 1-second forced expiratory volume decline, equal sex distribution, younger age of onset, fewer comorbidities, milder airflow obstruction, preserved diffusing capacity of the lungs for carbon monoxide, and radiological features such as more air-trapping and less severe emphysema compared to COPD in smokers. Nevertheless, non-smokers with COPD still experience a high prevalence of acute exacerbations, nearly equal to that of smokers with COPD. Moreover, COPD itself is an independent risk factor for developing lung cancer, regardless of smoking status. Given that COPD coexists with numerous comorbidities, effectively managing these comorbidities is crucial, requiring multifaceted efforts for comprehensive treatment.

Impact of childhood exposure to traffic related air pollution on adult cardiometabolic health: Exploring the role of perceived stress

BACKGROUND

Little is known about how childhood exposure to traffic-related air pollution (TRAP) and stress interact to affect adults' cardiometabolic health. We examined this interaction and assessed the impact of over 10 years of childhood TRAP exposure on cardiometabolic health.

METHODS

From 2018 to 2023, 313 young adults from the Southern California Children's Health Study were enrolled in a follow-up assessment. Using CALINE4 line source dispersion model, average childhood TRAP exposures (from pregnancy to age 13) were estimated for nitrogen oxides (NOx) from all roads. Traffic density was calculated within a 300-m residential buffer. Cardiometabolic health was assessed in adulthood (mean age 24 ± 1.7) based on blood lipids (total cholesterol, high- and low-density lipoprotein [HDL, LDL], triglycerides), glucose metabolism (fasting glucose, fasting insulin, HbA1c), body composition (BMI, android/gynoid ratio [AG ratio], percent body fat), and blood pressure. A PDAY (Pathobiologic Determinants of Atherosclerosis in Youth) score was generated to evaluate overall cardiometabolic health. Participants' perceived stress was assessed in childhood and adulthood (ages 13 and 24 years, respectively).

RESULTS

Results of mixed effects linear models, adjusted for demographics and smoking status, suggested that each standard deviation increase in childhood exposure to traffic-related total NOx was associated with 0.62 increase in PDAY score (95% Confidence Interval [CI]:0.10,1.14), 0.09% increase in HbA1c (95%CI: 0.04, 0.15), 1.19% increase in percent body fat (95%CI: 0.18, 2.20), and 0.96 kg/m2 increase in BMI (0.11, 1.80) in adulthood. Among participants with higher childhood stress levels, we observed significant associations of traffic-related total NOx with total cholesterol, HDL, LDL, HbA1c, insulin, and BMI. None of these associations were significant among people with lower stress levels. We observed similar statistically significant associations of traffic density.

CONCLUSION

Long-term childhood exposure to TRAP in childhood may have lasting adverse impacts on cardiometabolic health, especially for children with higher stress levels.

The Health Impacts of Air Pollution in the Context of Changing Climate in Africa: A Narrative Review with Recommendations for Action

Introduction: Despite the broad improvement in air quality, air pollution remains a major leading global risk factor for ill health and deaths each year. Air pollution has a significant impact on both health and economic growth in Africa. This paper reviews the health impacts of air pollution and the benefits of air pollution mitigation and prevention on climate change. Methods: We conducted a narrative review and synthesized current literature on the health impact of air pollution in the context of changing climate in Africa. Results: Particulate matter (PM2.5) concentrations in Africa pose significant health risks due to various sources, including household fuels and industrial emissions. Limited air quality monitoring hampers accurate assessment and public health planning. Africa's rapid urbanization exacerbates air pollution, impacting vulnerable populations disproportionately. Renewable energy adoption and improved monitoring infrastructure are crucial for mitigating air pollution's economic and health impacts. Recommendations include adopting air quality standards, identifying pollution sources, and prioritizing interventions for vulnerable groups. Integrating renewable energy into development plans is essential for sustainable growth. African leaders must prioritize environmental policies to safeguard public health amid ongoing industrialization. Conclusions: Air pollution prevention remains a vital concern that requires leaders to engage stakeholders, and other opinion leaders in society. African leaders should proactively explore new avenues to integrate non‑polluting renewable energy sources such as solar power, wind and hydropower into their national development plans.

Air pollution exposure during pregnancy and lung function in childhood: The LUIS study

BACKGROUND

The adverse effects of high air pollution levels on childhood lung function are well-known. Limited evidence exists on the effects of moderate exposure levels during early life on childhood lung function. We investigated the association of exposure to moderate air pollution during pregnancy, infancy, and preschool time with lung function at school age in a Swiss population-based study.

METHODS

Fine-scale spatiotemporal model estimates of particulate matter with a diameter <2.5 µm (PM2.5) and nitrogen dioxide (NO2) were linked with residential address histories. We compared air pollution exposures within different time windows (whole pregnancy, first, second, and third trimester of pregnancy, first year of life, preschool age) with forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) measured cross-sectionally using linear regression models adjusted for potential confounders.

RESULTS

We included 2182 children, ages 6-17 years. Prenatal air pollution exposure was associated with reduced lung function at school age. In children aged 12 years, per 10 µg·m-3 increase in PM2.5 during pregnancy, FEV1 was 55 mL lower (95% CI -84 to -25 mL) and FVC 62 mL lower (95% CI -96 to -28 mL). Associations were age-dependent since they were stronger in younger and weaker in older children. PM2.5 exposure after birth was not associated with reduced lung function. There was no association between NO2 exposure and lung function.

CONCLUSION

In utero lung development is most sensitive to air pollution exposure, since even modest PM2.5 exposure during the prenatal time was associated with reduced lung function, most prominent in younger children.

Pollution exposure in the first 3 months post transplant is associated with lower baseline FEV1 and higher CLAD risk

BACKGROUND

Exposure to air pollution post-lung transplant has been shown to decrease graft and patient survival. This study examines the impact of air pollution exposure in the first 3 months post-transplant on baseline (i.e., highest) forced expiratory volume in 1 second (FEV1) achieved and development of chronic lung allograft dysfunction (CLAD).

METHODS

Double-lung transplant recipients (n = 82) were prospectively enrolled for comprehensive indoor and personal environmental monitoring at 6- and 12-week post transplant and followed for >4 years. Associations between clinical and exposure variables were investigated using an exposomics approach followed by analysis with a Cox proportional hazards model. Multivariable analyses were used to examine the impact of air pollution on baseline % predicted FEV1 (defined as the average of the 2 highest values post transplant) and risk of CLAD.

RESULTS

Multivariable analysis revealed a significant inverse relationship between personal black carbon (BC) levels and baseline % FEV1. The multivariable model indicated that patients with higher-than-median exposure to BC (>350 ng/m3) attained a baseline % FEV1 that was 8.8% lower than those with lower-than-median BC exposure (p = 0.019). Cox proportional hazards model analysis revealed that patients with high personal BC exposure had a 2.4 times higher hazard risk for CLAD than patients with low BC exposure (p = 0.045).

CONCLUSIONS

Higher personal BC levels during the first 3 months post-transplant decrease baseline FEV1 and double the risk of CLAD. Strategies to reduce BC exposure early following a lung transplant may help improve lung function and long-term outcomes.

Protecting our future: environmental hazards and children's health in the face of environmental threats: a comprehensive overview

Children face the excitement of a changing world but also encounter environmental threats to their health that were neither known nor suspected several decades ago. Children are at particular risk of exposure to pollutants that are widely dispersed in the air, water, and food. Children and adolescents are exposed to chemical, physical, and biological risks at home, in school, and elsewhere. Actions are needed to reduce these risks for children exposed to a series of environmental hazards. Exposure to a number of persistent environmental pollutants including air pollutants, endocrine disruptors, noise, electromagnetic waves (EMWs), tobacco and other noxious substances, heavy metals, and microplastics, is linked to damage to the nervous and immune systems and affects reproductive function and development. Exposure to environmental hazards is responsible for several acute and chronic diseases that have replaced infectious diseases as the principal cause of illnesses and death during childhood. Children are disproportionately exposed to environmental toxicities. Children drink more water, eat more food, and breathe more frequently than adults. As a result, children have a substantially heavier exposure to toxins present in water, food, or air than adults. In addition, their hand-to-mouth behaviors and the fact that they live and play close to the ground make them more vulnerable than adults. Children undergo rapid growth and development processes that are easily disrupted. These systems are very delicate and cannot adequately repair thetional development in children's environmental health was the Declaration of the Environment Leaders of the Eight on Children's Environmental Health by the Group of Eight. In 2002, the World Health Organization launched an initiative to improve children's environmental protection effort. Here, we review major environmental pollutants and related hazards among children and adolescents.

Development of over 30-years of high spatiotemporal resolution air pollution models and surfaces for California

California's diverse geography and meteorological conditions necessitate models capturing fine-grained patterns of air pollution distribution. This study presents the development of high-resolution (100 m) daily land use regression (LUR) models spanning 1989-2021 for nitrogen dioxide (NO2), fine particulate matter (PM2.5), and ozone (O3) across California. These machine learning LUR algorithms integrated comprehensive data sources, including traffic, land use, land cover, meteorological conditions, vegetation dynamics, and satellite data. The modeling process incorporated historical air quality observations utilizing continuous regulatory, fixed site saturation, and Google Streetcar mobile monitoring data. The model performance (adjusted R2) for NO2, PM2.5, and O3 was 84 %, 65 %, and 92 %, respectively. Over the years, NO2 concentrations showed a consistent decline, attributed to regulatory efforts and reduced human activities on weekends. Traffic density and weather conditions significantly influenced NO2 levels. PM2.5 concentrations also decreased over time, influenced by aerosol optical depth (AOD), traffic density, weather, and land use patterns, such as developed open spaces and vegetation. Industrial activities and residential areas contributed to higher PM2.5 concentrations. O3 concentrations exhibited no significant annual trend, with higher levels observed on weekends and lower levels associated with traffic density due to the scavenger effect. Weather conditions and land use, such as commercial areas and water bodies, influenced O3 concentrations. To extend the prediction of daily NO2, PM2.5, and O3 to 1989, models were developed for predictors such as daily road traffic, normalized difference vegetation index (NDVI), Ozone Monitoring Instrument (OMI)-NO2, monthly AOD, and OMI-O3. These models enabled effective estimation for any period with known daily weather conditions. Longitudinal analysis revealed a consistent NO2 decline, regulatory-driven PM2.5 decreases countered by wildfire impacts, and spatially variable O3 concentrations with no long-term trend. This study enhances understanding of air pollution trends, aiding in identifying lifetime exposure for statewide populations and supporting informed policy decisions and environmental justice advocacy.

Childhood Air Pollution Exposure Associated with Self-reported Bronchitic Symptoms in Adulthood

Rationale: Few studies have examined the effects of long-term childhood air pollution exposure on adult respiratory health, including whether childhood respiratory effects underlie this relation. Objectives: To evaluate associations between childhood air pollution exposure and self-reported adult bronchitic symptoms while considering child respiratory health in the Southern California Children's Health Study. Methods: Exposures to nitrogen dioxide (NO2), ozone, and particulate matter <2.5 μm and <10 μm in diameter (PM10) assessed using inverse-distance-squared spatial interpolation based on childhood (birth to age 17 yr) residential histories. Bronchitic symptoms (bronchitis, cough, or phlegm in the past 12 mo) were ascertained via a questionnaire in adulthood. Associations between mean air pollution exposure across childhood and self-reported adult bronchitic symptoms were estimated using logistic regression. We further adjusted for childhood bronchitic symptoms and asthma to understand whether associations operated beyond childhood respiratory health impacts. Effect modification was assessed for family history of asthma, childhood asthma, and adult allergies. Measurements and Main Results: A total of 1,308 participants were included (mostly non-Hispanic White [56%] or Hispanic [32%]). At adult assessment (mean age, 32.0 yr; standard deviation [SD], 4.7), 25% reported bronchitic symptoms. Adult bronchitic symptoms were associated with NO2 and PM10 childhood exposures. Odds ratios per 1-SD increase were 1.69 (95% confidence interval, 1.14-2.49) for NO2 (SD, 11.1 ppb) and 1.51 (95% confidence interval, 1.00-2.27) for PM10 (SD, 14.2 μg/m3). Adjusting for childhood bronchitic symptoms or asthma produced similar results. NO2 and PM10 associations were modified by childhood asthma, with greater associations among asthmatic individuals. Conclusions: Childhood NO2 and PM10 exposures were associated with adult bronchitic symptoms. Associations were not explained by childhood respiratory health impacts; however, participants with childhood asthma had stronger associations.

Lung function in children residents in the largest coal region in Brazil

Coal mining activities release harmful air pollutants, which affect children's health, particularly the lung function. Brazil has a large coal reserve in the southern region, where a coal-fired power plant and two coal mines are located. The study aimed to evaluate the prevalence of altered respiratory function and associated factors in children living in this region. A cross-sectional study was conducted in seven cities. It collected socioeconomic and demographic, prenatal and postnatal care, neonatal outcomes, child health information as well as lung function and air quality. The study included 396 children who lived in a high socio-environmental vulnerability due to low education levels and family income, high percentage of unemployed and families with a high bedroom density. There was a high prevalence of preterm birth, low birth weight and long-term exposure to environmental conditions. The most common respiratory problem in the parents was rhinitis, while in the children was wheezing and pneumonia. The prevalence of respiratory function alteration in the region was 7.78%. Variables associated with altered respiratory function were passive smoking, low birth weight, history of wheezing. The concentration of pollutants was equivalent when comparing stations within the coal mining host town (Candiota) and surrounding towns.

Ambient Air Pollution Exposure and Outcomes in Patients Receiving Lung Transplant

Importance

Elevated ambient fine particulate matter (PM2.5) air pollution exposure has been associated with poor health outcomes across several domains, but its associated outcomes among lung transplant recipients are poorly understood.

Objective

To investigate whether greater PM2.5 exposure at the zip code of residence is associated with a higher hazard for mortality and graft failure in patients with lung transplants.

Design, Setting, and Participants

This retrospective cohort study used panel data provided by the United Network for Organ Sharing, which includes patients receiving transplants across all active US lung transplant programs. Adult patients who received lung transplants between May 2005 and December 2016 were included, with a last follow-up of September 10, 2020. Data were analyzed from September 2022 to May 2023.

Exposure

Zip code-level annual PM2.5 exposure was constructed using previously published North American estimates.

Main Outcomes and Measures

The primary outcome was time to death or lung allograft failure after lung transplant. A gamma shared frailty Cox proportional hazards model was used to produce unadjusted and adjusted hazard ratios (HRs) to estimate the association of zip code PM2.5 exposure at the time of transplant with graft failure or mortality.

Results

Among 18 265 lung transplant recipients (mean [SD] age, 55.3 [13.2] years; 7328 female [40.2%]), the resident zip code's annual PM2.5 exposure level was greater than or equal to the Environmental Protection Agency (EPA) standard of 12μg/m3 for 1790 patients (9.8%) and less than the standard for 16 475 patients (90.2%). In unadjusted analysis, median graft survival was 4.87 years (95% CI, 4.57-5.23 years) for recipients living in high PM2.5 areas and 5.84 years (95% CI, 5.71-5.96 years) for recipients in the low PM2.5 group. Having an annual PM2.5 exposure level greater than or equal to the EPA standard 12 μg/m3 was associated with an increase in the hazard of death or graft failure (HR, 1.11; 95% CI, 1.05-1.18; P < .001) in the unadjusted analysis and after adjusting for covariates (HR, 1.08; 95% CI, 1.01-1.15; P = .02). Each 1 μg/m3 increase in exposure was associated with an increase in the hazard of death or graft failure (adjusted HR, 1.01; 95% CI, 1.00-1.02; P = .004) when treating PM2.5 exposure as a continuous variable.

Conclusions and Relevance

In this study, elevated zip code-level ambient PM2.5 exposure was associated with an increased hazard of death or graft failure in lung transplant recipients. Further study is needed to better understand this association, which may help guide risk modification strategies at individual and population levels.

Cleaning indoor air-what works for respiratory health: An updated literature review and recommendations

Indoor air pollution is a growing public health concern globally and is associated with increased respiratory symptoms and morbidity. Individuals spend most of their time indoors, and pollutant-related health effects are often driven by the indoor environment. Understanding effective interventions to improve indoor air quality and their impact on respiratory outcomes is key to decreasing the burden of air pollution for high-risk populations across the life-span. This review applies a hierarchy of interventions framework specific to respiratory health effects and focuses on recent studies of interventions to improve indoor air quality among high-risk populations with chronic respiratory disease published in the past 3 years. While policy and source control interventions are likely the most effective and equitable approaches to improve indoor air quality and benefit population health, these were less extensively investigated. Engineering interventions, such as air cleaner interventions, were the most widely studied. Several studies, including those focused on asthma and chronic obstructive pulmonary disease, demonstrated improvement in symptoms and medication receipt with interventions in both home- and school-based settings. Combined multilevel interventions with engineering and behavioral interventions led to improved respiratory outcomes in some, but not all, studies. Placing the recent work in the context of the broader literature, we identify gaps in research. Further research is needed to understand intervention effectiveness over time and an increased focus on policy and source control interventions that can mitigate risk in vulnerable populations.

Navigating COPD in Aging Populations: Insights Into Pathophysiology and Comprehensive Care

Chronic obstructive pulmonary disease (COPD) poses a significant and growing health burden among aging populations, marked by increasing prevalence and complex management challenges specific to elderly patients. This review explores the multifaceted interplay between COPD and aging, highlighting overlapping pathophysiological processes and comorbidities that complicate diagnosis and treatment. We examine age-specific management strategies, emphasizing the need for tailored approaches that account for the unique physical, cognitive, and health-related quality of life impacts on older adults. Additionally, we discuss preventive treatments and the critical roles of mental health, end-of-life care, and caregiver support in comprehensive disease management. The importance of integrative approaches to enhancing health care delivery is also underscored. Finally, we outline future directions, focusing on novel treatment pathways and the identification of biomarkers for early detection. Addressing these elements is essential for optimizing care in this vulnerable population and alleviating the significant societal and economic impacts of COPD among aging patients.

Environmental exposures associated with early childhood recurrent wheezing in the mother and child in the environment birth cohort: a time-to-event study

BACKGROUND

Antenatal factors and environmental exposures contribute to recurrent wheezing in early childhood.

AIM

To identify antenatal and environmental factors associated with recurrent wheezing in children from birth to 48 months in the mother and child in the environment cohort, using time-to-event analysis.

METHOD

Maternal interviews were administered during pregnancy and postnatally and children were followed up from birth to 48 months (May 2013-October 2019). Hybrid land-use regression and dispersion modelling described residential antenatal exposure to nitrogen dioxide (NO2) and particulate matter of 2.5 µm diameter (PM2.5). Wheezing status was assessed by a clinician. The Kaplan-Meier hazard function and Cox-proportional hazard models provided estimates of risk, adjusting for exposure to environmental tobacco smoke (ETS), maternal smoking, biomass fuel use and indoor environmental factors.

RESULTS

Among 520 mother-child pairs, 85 (16%) children, had a single wheeze episode and 57 (11%) had recurrent wheeze. Time to recurrent wheeze (42.9 months) and single wheeze (37.8 months) among children exposed to biomass cooking fuels was significantly shorter compared with children with mothers using electricity (45.9 and 38.9 months, respectively (p=0.03)). Children with mothers exposed to antenatal ETS were 3.8 times more likely to have had recurrent wheeze compared with those not exposed (adjusted HR 3.8, 95% CI 1.3 to 10.7). Mean birth month NO2 was significantly higher among the recurrent wheeze category compared with those without wheeze. NO2 and PM2.5 were associated with a 2%-4% adjusted increased wheezing risk.

CONCLUSION

Control of exposure to ETS and biomass fuels in the antenatal period is likely to delay the onset of recurrent wheeze in children from birth to 48 months.

Convolutional Neural Networks Facilitate Process Understanding of Megacity Ozone Temporal Variability

Ozone pollution is profoundly modulated by meteorological features such as temperature, air pressure, wind, and humidity. While many studies have developed empirical models to elucidate the effects of meteorology on ozone variability, they predominantly focus on local weather conditions, overlooking the influences from high-altitude and broader regional meteorological patterns. Here, we employ convolutional neural networks (CNNs), a technique typically applied to image recognition, to investigate the influence of three-dimensional spatial variations in meteorological fields on the daily, seasonal, and interannual dynamics of ozone in Shenzhen, a major coastal urban center in China. Our optimized CNNs model, covering a 13° × 13° spatial domain, effectively explains over 70% of daily ozone variability, outperforming alternative empirical approaches by 7 to 62%. Model interpretations reveal the crucial roles of 2-m temperature and humidity as primary drivers, contributing 16% and 15% to daily ozone fluctuations, respectively. Regional wind fields account for up to 40% of ozone changes during the episodes. CNNs successfully replicate observed ozone temporal patterns, attributing -5-6 μg·m-3 of interannual ozone variability to weather anomalies. Our interpretable CNNs framework enables quantitative attribution of historical ozone fluctuations to nonlinear meteorological effects across spatiotemporal scales, offering vital process-based insights for managing megacity air quality amidst changing climate regimes.

Birth Cohort Studies of Long-Term Exposure to Ambient Air Pollution in Early Life and Development of Asthma in Children and Adolescents from Denmark

INTRODUCTION

Exposure to ambient air pollution from combustion-source emissions contributes to the prevalence of asthma, but the role of early-life exposure in asthma development is not well understood. The objective was to examine the effects of early-life exposure to multiple specific ambient air pollutants on incidence and prevalence of asthma and to determine the mechanistic basis for these effects.

METHODS

The study included all live-born singletons in Denmark during 1998-2016 (N = 1,060,154), participants in the Danish National Birth Cohort (DNBC3, N = 22,084), and participants in the Copenhagen Prospective Studies on Asthma in Childhood (COPSAC, N = 803). We modeled the concentrations of particulate matter ≤2.5 and ≤10 μm in aerodynamic diameter (PM2.5 and PM10), PM-related elemental carbon (EC), organic carbon (OC), sulfate (SO42-), nitrate (NO3-), ammonium (NH4+), secondary organic aerosols (SOA), and sea salt as well as nitrogen dioxide (NO2), nitrogen oxides (NOx), sulfur dioxide (SO2), and ozone (O3) - from all sources. Prenatal and postnatal time-weighted mean exposures were calculated for all residential addresses.

We defined asthma incidence as the first registered asthma diagnosis for all and used parental recall at child aged 7 to determine the prevalence of doctor-diagnosed asthma ever and active asthma for the DNBC participants. For the COPSAC participants, we analyzed inflammatory markers in blood collected at 6 months of age; at 6 years of age, we analyzed nasal epithelial deoxyribonucleic acid (DNA) methylation, gene expression, immune mediators, and forced expiratory volume in 1 second (FEV1).

Cox proportional hazard models were fitted with fixed prenatal means and time-varying running annual means of a year before the event for the postnatal follow-up period for asthma incidence. Logistic regression models with cluster-robust standard errors and generalized estimating equations for dependence between women being included more than once were used for asthma prevalence. Mixed-effect linear regression models with random intercept for cohort were used to examine changes in lung function, and linear regression models were used to examine changes in biomarkers.

RESULTS

The prenatal mean and interquartile range (IQR) concentrations of PM2.5 and NO2 were 10.5 (2.4) and 17.5 (8.7) μg/m3. In the nationwide study the risk of asthma incidence increased with increasing prenatal exposure to all pollutants except for O3 and sea salt. An IQR increase in prenatal exposure was associated with an adjusted hazard ratio (HR) and 95% confidence interval (CI) of 1.06 (95% CI: 1.04-1.08) for PM2.5 and 1.04 (1.02-1.05) for NO2. The corresponding estimates for postnatal exposures were 1.08 (1.05-1.10) and 1.02 (1.01-1.04), respectively.

In the DNBC participants, the asthma incidence results from models further adjusted with cohort-specific covariates were similar to models adjusted for register-based covariates only. Prenatal exposure to PM2.5, PM10, NO2, NOx, EC, SO42-, and sea salt were weakly associated with elevated risk for asthma incidence. There was no evidence of associations with asthma prevalence.

For the COPSAC children, an IQR of PM2.5 and of NH4+ was each associated with a 2%-3% (95% CI: 1%-5%) reduction in mean FEV1, consistently for prenatal and postnatal exposures. Prenatal exposure to PM and NO2 was associated with immunological changes in blood and the airways but not with DNA methylation or gene expression changes.

CONCLUSIONS

The results of these studies strengthen the evidence that long-term exposure to ambient air pollution contributes to the development of asthma in early life through an altered immune profile, even at these relatively low concentrations.

Outdoor Air Pollution and Pediatric Respiratory Disease

Outdoor air pollution is ubiquitous, and no safe level of exposure has been identified for the most common air pollutants such as ozone and particle pollution. Children are uniquely more susceptible to the harms of outdoor air pollution, which can cause and exacerbate respiratory disease. Although challenging to identify the effects of outdoor air pollution on individual patients, understanding the basics of outdoor air pollution is essential for pediatric respiratory health care providers. This review covers basic information regarding outdoor air pollution, unique considerations for children, mechanisms for increased susceptibility, and association with incident and exacerbation of respiratory disease in children.

Carotid Artery Wall Echogenicity Measured by Gray Scale Median of the Intima-Media Complex From Childhood to Young Adulthood

BACKGROUND

Echogenicity of the carotid arterial wall, measured by gray scale median of the intima-media complex (IM-GSM), is a novel subclinical atherosclerosis marker with lower values indicating greater lipid deposition. Our longitudinal study investigated IM-GSM from childhood to adulthood and its associated risk factors.

METHODS AND RESULTS

A total of 240 participants from the Southern California CHS (Children's Health Study) underwent carotid artery ultrasounds in 2008 (mean age±SD): (11.2±0.6 years), and again around 2022 (24.2±1.6 years) to assess IM-GSM, carotid artery intima-media thickness, and carotid artery distensibility. Questionnaires and anthropometric and blood pressure measurements were completed by participants at both times. Mean and SD of IM-GSM were 108.2±24.6 in childhood and 75.6±15.8 in adulthood. Each 1-year increase in age was associated with -2.52 change in IM-GSM (95% CI, -2.76 to -2.27). Childhood and adulthood IM-GSMs were highly correlated (β=0.13 [95% CI, 0.05-0.22]). In childhood, Hispanic ethnicity, lower parental education levels and prenatal father smoking were significantly associated with lower IM-GSM. In adulthood, higher systolic blood pressure, carotid artery intima-media thickness, hypertension, and lower distensibility were significantly associated with lower IM-GSM. Weight status exhibited a consistent association with both childhood and adulthood IM-GSM. During the transition from childhood to adulthood, individuals who shifted from normal weight to overweight/obese or normal blood pressure to hypertension or experienced an increase in carotid artery intima-media thickness displayed lower levels of IM-GSM in adulthood.

CONCLUSIONS

IM-GSM decreases with age. Maintaining healthy weight and blood pressure levels in children could potentially aid in preventing subclinical atherosclerosis.

Association Between Cardiovascular Health and Subclinical Atherosclerosis Among Young Adults Using the American Heart Association's "Life's Essential 8" Metrics

BACKGROUND

This study investigated the association of American Heart Association's cardiovascular health guidelines Life's Essential 8 (LE8) and Life's Simple 7 (LS7) with carotid artery outcomes among young adults.

METHODS AND RESULTS

This cross-sectional study included 240 young adults (age 24.2±1.6 years) who underwent a carotid ultrasound between 2018 and 2022. LE8 score was calculated from 4 health factors (body mass index, non-high-density lipoprotein cholesterol, fasting glucose, and blood pressure), and 4 health behaviors (dietary intake, physical activity, tobacco use, and sleep). LS7 was calculated from 7 metrics (all LE8 metrics, except for sleep) with a simpler algorithm. Higher LE8 and LS7 scores both indicate better health and better adherence to American Heart Association guidelines. Carotid artery outcomes included carotid artery intima-media thickness, arterial stiffness (eg, distensibility), and echogenicity determined by grayscale median of the intima media complex. Results of linear regression analyses, adjusting for age, sex, ethnicity, and parents' highest degree, indicated that a 1-SD increase in LE8 score was associated with 12.14 μm lower carotid artery intima-media thickness (95% CI, -20.93 to 3.35), 1.17 (10-6×m2/N) greater distensibility (95% CI, 0.09-2.24), suggesting less arterial stiffness, and 2.66 μm greater grayscale median of the intima media complex (95% CI, 0.58-4.75), suggesting less lipid deposition. Analyses using LS7 score demonstrated comparable findings. Health factor metrics demonstrated stronger association with carotid artery outcomes, as compared with behavior metrics.

CONCLUSIONS

Greater adherence to the American Heart Association's cardiovascular health guidelines is associated with lower risk for subclinical atherosclerosis in young adults. LE8 and LS7 demonstrated comparable associations with carotid artery outcomes.

Impact of environmental air pollution on respiratory health and function

Environmental air pollution presents a considerable risk to global respiratory health. If critical levels are exceeded, inhaled pollutants can lead to the development of respiratory dysfunction and provoke exacerbation in those with pre-existing chronic respiratory disease. Over 90% of the global population currently reside in areas where environmental air pollution is considered excessive-with adverse effects ranging from acute airway irritation to complex immunomodulatory alterations. This narrative review provides an up-to-date perspective concerning the impact of environmental air pollution on respiratory health and function and describes the underpinning mechanisms that contribute to the development and progression of chronic respiratory disease.

The role of environmental pollution in the development of pulmonary exacerbations in cystic fibrosis: a narrative review

Cystic fibrosis is the most common autosomal recessive disease in the Caucasian race. Its course is chronic and progressive, with pulmonary involvement being associated with greater morbidity and mortality. One of the factors most related to worse prognosis in these patients is respiratory exacerbations. Although limited, there is evidence demonstrating that increased exposure to environmental pollution, both acute and chronic, is associated with an increase in these exacerbations. It is crucial to fully understand this relationship in order to attempt to improve the respiratory health of these patients. That is why the available evidence is reviewed and measures are established to reduce exposure to pollutants.

Near-fatal and fatal asthma and air pollution: are we missing an opportunity to ask key questions?

There is an increasing body of evidence supporting the link between asthma attacks and air pollution in children. To our knowledge, there has only been one reported case of a fatal asthma attack in a child associated with air pollution and this was in the UK. This article considers why there is a lack of evidence on fatal/near-fatal asthma and air pollution. We also explore three challenges. First, fatal and near-fatal asthma events are rare and not yet well understood. Second, measuring and interpreting personal exposure to air pollution with sufficient temporal and spatial detail are challenging to interpret in the context of individual fatal or near-fatal asthma attacks. Third, current studies are not designed to answer the question of whether or to what extent air pollution is associated with fatal/near-fatal asthma attacks in children. Conclusive evidence is not yet available and systems of data collection for both air pollution and fatal and near-fatal asthma attacks should be enhanced to ensure risk can be determined and impact minimised.

Forced vital capacity and body mass index of Xinjiang children and adolescents: an analysis based on seven successive national surveys, 1985-2014

BACKGROUND

Pulmonary function is very important for the healthy development of children and adolescents. However, fewer studies have been conducted on pulmonary function trends in children and adolescents in remote areas. The aim of this study was to estimate the forced vital capacity (FVC) trend and its relationship with body mass index (BMI) among young people in Xinjiang during 1985-2014 using data from seven successive national surveys.

METHODS

A total of 19,449 Xinjiang children and adolescents aged 7-18 years were extracted from the Chinese National Survey on Students' Constitution and Health. Height, weight, and FVC were measured repeatedly in each survey. FVC comparisons between adjacent surveys by age and sex were conducted by nonparametric Kruskal-Wallis after Kolmogorov-Smirnov of normality. One-way ANOVA and least significant difference(LSD) method was used to compare differences in FVC levels of Xinjiang children and adolescents with different BMI. The relationship between BMI and FVC was investigated using a nonlinear regression model.

RESULTS

The FVC levels of Xinjiang children and adolescents peaked in 2000, with overall FVC levels being 8.7% higher in 2000 than in 1985. Since then, a substantial decline occurred, contrasting to 2000, with FVC levels decreasing by 27% in 2014, which was still lower than that in 1985 by 20.73%. The proportion of overnutrition boys increased from 0.2% in 1985 to 22.1% in 2014, and girls from 0.5% in 1985 to 14.5% in 2014. An inverted U-shape association between FVC and BMI values was obtained for Xinjiang children and adolescents.

CONCLUSIONS

Targeted measures should be carried out in schools to control BMI levels to ensure good lung function in children and adolescents in Xinjiang. Future studies should pay more attention to other factors affecting FVC, such as dietary behaviour, physical activity, and racial differences among children and adolescents.

Impact of ambient air pollution on lung function in preterm-born school-aged children

RATIONALE

Increased outdoor air pollution worsens lung function in children. However, these associations are less well studied in preterm-born individuals.

OBJECTIVES

We assessed associations between ambient air pollutants and spirometry measures in preterm-born children.

METHODS

The Respiratory Health Outcomes in Neonates study recruited preterm-born children aged 7-12 years who were born at ≤34 week's gestation. We associated four ambient air pollutants (particulate matter with aerodynamic diameter ≤2.5 µm (PM2.5), PM10, nitrogen dioxide (NO2) and sulfur dioxide) at time of birth and spirometry assessment and averaged exposure between these two time points with spirometry measures, using linear regression analyses. Gestational age was banded into 23-28, 29-31 and 32-34 week's. Regression models estimated spirometry values against pollutant levels at birth and at the time of spirometry.

MEASUREMENTS AND MAIN RESULTS

From 565 preterm-born children, 542 (96%) had satisfactory data. After adjustments for early and current life factors, significant detrimental associations were noted between PM10 at birth and per cent predicted forced vital capacity (%FVC) for the 23-28 and 29-31 week's gestation groups and between current PM2.5 and NO2 exposure and %FVC for the 23-28 week's gestation group. No associations with spirometry were noted for the averaged pollution exposure between birth and spirometry. Predictive models showed 5.9% and 7.4% differences in %FVC between the highest and lowest current pollution exposures for PM2.5 and NO2, respectively, in the 23-28 week group.

CONCLUSIONS

Birth and current exposures to road-traffic-associated pollutants detrimentally affected %FVC in preterm-born school-aged children, who already have compromised lung function.

Sampling, composition, and biological effects of Mexico City airborne particulate matter from multiple periods

Air pollution is a worldwide environmental problem with an impact on human health. Particulate matter of ten micrometers or less aerodynamic diameter (PM10) as well as its fine fraction (PM2.5) is related to multiple pulmonary diseases. The impact of air pollution in Mexico City, and importantly, particulate matter has been studied and considered as a risk factor for two decades ago. Previous studies have reported the composition of Mexico City particulate matter, as well as the biological effects induced by this material. However, material collected and used in previous studies is a limited resource, and sampling and particle recovery techniques have been improved. In this study, we describe the methods used in our laboratory for Mexico City airborne particulate matter PM10 and PM2.5 sampling, considering the years 2017, 2018 and 2019. We also analyzed the PM10 and PM2.5 samples obtained to determine their composition. Finally, we exposed lung cell line cultures to PM10 and PM2.5 to evaluate the biological effect of the material in terms of cell viability, cell death, inflammatory response, and cytogenetic alterations. Our results showed that PM10 composition includes inorganic, organic and biological compounds, while PM2.5 is a mixture of more enriched organic compounds. PM10 and PM2.5 treatment in lung cells does not significantly impact cell viability/cell death. However, PM10 and PM2.5 increase the secretion levels of IL-6. Moreover, PM10 as well as PM2.5 induce cytogenetic alterations, such as micronuclei, anaphase bridges, trinucleated cells and apoptotic cells in lung cells. Our results update the evidence of the composition and biological effects of Mexico City particulate matter and provide us a reliable basis for future approaches.

Prevalence, Medicaid use and mortality risk of low FEV1 in adults aged 20-35 years old in the USA: evidence from a population-based retrospective cohort study

BACKGROUND

The prevalence, Medicaid use and mortality risk associated with low forced expiratory volume in 1 s (FEV1) among young adults aged 20-35 years are not well understood, despite its potential implications for the development of chronic pulmonary disease and overall prognosis.

METHODS

A retrospective cohort study was conducted among young adults aged 20-35 years old, using data from the National Health and Nutrition Examination Survey, National Death Index and Centers for Medicare & Medicaid Services. Participants were categorised into a low FEV1 group (pre-bronchodilator FEV1%pred <80%) and a normal FEV1 group (FEV1%pred ≥80%). Weighted logistic regression analysis was employed to identify the risk factors associated with low FEV1, while Cox proportional hazard models were used to calculate the hazard ratio (HR) for Medicaid use and the all-cause mortality between the two groups.

RESULTS

A total of 5346 participants aged 20-35 were included in the study, with 329 in the low FEV1 group and 5017 in the normal group. The weighted prevalence of low FEV1 among young adults was 7.1% (95% CI 6.0 to 8.2). Low body mass index (OR=3.06, 95% CI 1.79 to 5.24), doctor-diagnosed asthma (OR=2.25, 1.28 to 3.93), and wheezing or whistling (OR=1.57, 1.06 to 2.33) were identified as independent risk factors for low FEV1. Over a 15-year follow-up, individuals in the low FEV1 group exhibited a higher likelihood of Medicaid use compared with those in the normal group (HR=1.73, 1.07 to 2.79). However, there was no statistically significant increase in the risk of all-cause mortality over a 30-year follow-up period (HR=1.48, 1.00 to 2.19).

CONCLUSIONS

A considerable portion of young adults demonstrated low FEV1 levels, a characteristic that was associated with a higher risk of Medicaid use over a long-term follow-up, yet not linked to an augmented risk of all-cause mortality.

Analysis of gasoline-related pollutant exposures and risks in California between 1996 and 2014

BACKGROUND

Gasoline-powered vehicles and equipment are an important source of air pollution in California. Many gasoline-related pollutants pose significant health concerns. The California Air Resources Board strictly regulates the state's gasoline formulation and vehicle emissions.

OBJECTIVE

To investigate exposure trends for gasoline-related air pollutants between 1996 and 2014, capturing the period before and after the removal of methyl t-butyl ether (MTBE).

METHODS

We identified gasoline-related chemicals with known or suspected health concerns and adequate ambient air monitoring data. Average exposures to the general public were estimated from 1996 to 2014 in five major air basins and statewide. We determined the fractions of exposures attributable to gasoline use and evaluated cancer and non-cancer risks for chemicals with available cancer potencies and health reference values.

RESULTS

We found that average gasoline-attributable cancer risks for the general California population from the most highly emitted carcinogens (acetaldehyde, benzene, 1,3-butadiene, and formaldehyde) declined by over 80% between 1996 and 2014. This decline occurred despite roughly constant statewide gasoline sales, an increase in vehicle miles traveled, and an approximately 10% increase in vehicle registrations over this same period. Naphthalene, measured as a volatile organic compound (VOC), was the most abundant gasoline-related polycyclic aromatic hydrocarbon (PAH). From 1996 to 2014, gasoline-attributable cancer risks for naphthalene were estimated to drop approximately threefold in the South Coast Air Basin. Exposures to gasoline-related chemicals associated with non-cancer health effects, such as chronic respiratory toxicity or neurotoxicity, were generally below levels of concern. The exception was acrolein, with gasoline-related exposures in 2014 estimated to be high enough to pose risks for respiratory toxicity.

IMPACT STATEMENT

Our historical analysis demonstrated the success of California's regulatory efforts to reduce gasoline-related air pollutant exposures and risks to the general public. New efforts are focused on addressing gasoline-related and other air pollution in heavily impacted communities affected by multiple environmental and social stressors.

Exosome-encapsulated lncRNA HOTAIRM1 contributes to PM2.5-aggravated COPD airway remodeling by enhancing myofibroblast differentiation

Emphysema, myofibroblast accumulation and airway remodeling can occur in the lungs due to exposure to atmospheric pollution, especially fine particulate matter (PM2.5), leading to chronic obstructive pulmonary disease (COPD). Specifically, bronchial epithelium-fibroblast communication participates in airway remodeling, which results in COPD. An increasing number of studies are now being conducted on the role of exosome-mediated cell-cell communication in disease pathogenesis. Here, we investigated whether exosomes generated from bronchial epithelial cells could deliver information to normal stromal fibroblasts and provoke cellular responses, resulting in airway obstruction in COPD. We studied the mechanism of exosome-mediated intercellular communication between human bronchial epithelial (HBE) cells and primary lung fibroblasts (pLFs). We found that PM2.5-induced HBE-derived exosomes promoted myofibroblast differentiation in pLFs. Then, the exosomal lncRNA expression profiles derived from PM2.5-treated HBE cells and nontreated HBE cells were investigated using an Agilent Human LncRNA Array. Combining coculture assays and direct exosome treatment, we found that HBE cell-derived exosomal HOTAIRM1 facilitated the myofibroblast differentiation of pLFs. Surprisingly, we discovered that exosomal HOTAIRM1 enhanced pLF proliferation to secrete excessive collagen secretion, leading to airway obstruction by stimulating the TGF-β/SMAD3 signaling pathway. Significantly, PM2.5 reduced FEV1/FVC and FEV1 and increased the level of serum exosomal HOTAIRM1 in healthy people; moreover, serum exosomal HOTAIRM1 was associated with PM2.5-related reductions in FEV1/FVC and FVC. These findings show that PM2.5 triggers alterations in exosome components and clarify that one of the paracrine mediators of myofibroblast differentiation is bronchial epithelial cell-derived HOTAIRM1, which has the potential to be an effective prevention and therapeutic target for PM2.5-induced COPD.

Lung function benefits of traditional Chinese medicine Qiju granules against fine particulate air pollution exposure: a randomized controlled trial

Introduction

Multiple targets are considered as the causes of ambient fine particulate matter [aerodynamic diameters of < 2.5 μm (PM2.5)] induced lung function injury. Qiju granules are derived from the traditional Chinese medicine (TCM) formula known as Qi-Ju-Di-Huang-Wan (Lycium, Chrysanthemum, and Rehmannia Formula, QJDHW), which has been traditionally used to treat symptoms such as cough with phlegm, dry mouth and throat, and liver heat. This treatment approach involves attenuating inflammation, oxidative stress, and fibrosis response. This study investigated the effects of Qiju granules on protecting lung function against PM2.5 exposure in a clinical trial.

Methods

A randomized, double-blinded, and placebo-controlled trial was performed among 47 healthy college students in Hangzhou, Zhejiang Province in China. The participants were randomly assigned to the Qiju granules group or the control group based on gender. Clinical follow-ups were conducted once every 2 weeks during a total of 4 weeks of intervention. Real-time monitoring of PM2.5 concentrations in the individually exposed participants was carried out. Data on individual characteristics, heart rate (HR), blood pressure (BP), and lung function at baseline and during the follow-ups were collected. The effects of PM2.5 exposure on lung function were assessed within each group using linear mixed-effect models.

Results

In total, 40 eligible participants completed the scheduled follow-ups. The average PM2.5 level was found to be 64.72 μg/m3 during the study period. A significant negative correlation of lung function with PM2.5 exposure concentrations was observed, and a 1-week lag effect was observed. Forced expiratory volume in one second (FEV1), peak expiratory flow (PEF), maximal mid-expiratory flow (MMEF), forced expiratory flow at 75% of forced vital capacity (FVC) (FEF75), forced expiratory flow at 50% of FVC (FEF50), and forced expiratory flow at 25% of FVC (FEF25) were significantly decreased due to PM2.5 exposure in the control group. Small airway function was impaired more seriously than large airway function when PM2.5 exposure concentrations were increased. In the Qiju granules group, the associations between lung function and PM2.5 exposure were much weaker, and no statistical significance was observed.

Conclusion

The results of the study showed that PM2.5 exposure was associated with reduced lung function. Qiju granules could potentially be effective in protecting lung functions from the adverse effects of PM2.5 exposure.

Clinical Trial Registration

identifier: ChiCTR1900021235.

Impact of climate change on paediatric respiratory health: pollutants and aeroallergens

Paediatric populations are particularly vulnerable to respiratory diseases caused and exacerbated by aeroallergens, pollutants and infectious agents. Worsening climate change is expected to increase the prevalence of pollutants and aeroallergens while amplifying disease severity and causing disproportionate effects in under-resourced areas. The purpose of this narrative review is to summarise the role of anthropogenic climate change in the literature examining the future impact of aeroallergens, pollutants and infectious agents on paediatric respiratory diseases with a focus on equitable disease mitigation. The aeroallergens selected for discussion include pollen, dust mites and mould as these are prevalent triggers of paediatric asthma worldwide. Human rhinovirus and respiratory syncytial virus are key viruses interacting with climate change and pollution and are primary causal agents of viral respiratory disease. Within this review, we present the propensity for aeroallergens, climate change and pollution to synergistically exacerbate paediatric respiratory disease and outline measures that can ameliorate the expected increase in morbidity and severity of disease through a health equity lens. We support shifting from fossil fuels to renewable energy worldwide, across sectors, as a primary means of reducing increases in morbidity.

Lung function changes in children exposed to mine fire smoke in infancy

BACKGROUND AND OBJECTIVE

Chronic, low-intensity air pollution exposure has been consistently associated with reduced lung function throughout childhood. However, there is limited research regarding the implications of acute, high-intensity air pollution exposure. We aimed to determine whether there were any associations between early life exposure to such an episode and lung growth trajectories.

METHODS

We conducted a prospective cohort study of children who lived in the vicinity of the Hazelwood coalmine fire. Lung function was measured using respiratory oscillometry. Z-scores were calculated for resistance (R5 ) and reactance at 5 Hz (X5 ) and area under the reactance curve (AX). Two sets of analyses were conducted: (i) linear regression to assess the cross-sectional relationship between post-natal exposure to mine fire-related particulate matter with an aerodynamic diameter of less than 2.5 micrometres (PM2.5 ) and lung function at the 7-year follow-up and (ii) linear mixed-effects models to determine whether there was any association between exposure and changes in lung function between the 3- and 7-year follow-ups.

RESULTS

There were no associations between mine fire-related PM2.5 and any of the lung function measures, 7-years later. There were moderate improvements in X5 (β: -0.37 [-0.64, -0.10] p = 0.009) and AX (β: -0.40 [-0.72, -0.08] p = 0.014), between the 3- and 7-year follow-ups that were associated with mean PM2.5 , in the unadjusted and covariance-adjusted models. Similar trends were observed with maximum PM2.5 .

CONCLUSION

There was a moderate improvement in lung stiffness of children exposed to PM2.5 from a local coalmine fire in infancy, consistent with an early deficit in lung function at 3-years after the fire that had resolved by 7-years.

Air pollutants contribute to epithelial barrier dysfunction and allergic diseases

Air pollution is a global problem associated with various health conditions, causing elevated rates of morbidity and mortality. Major sources of air pollutants include industrial emissions, traffic-related pollutants, and household biomass combustion, in addition to indoor pollutants from chemicals and tobacco. Various types of air pollutants originate from both human activities and natural sources. These include particulate matter, pollen, greenhouse gases, and other harmful gases. Air pollution is linked to allergic diseases, including atopic dermatitis, allergic rhinitis, allergic conjunctivitis, food allergy, and bronchial asthma. These pollutants lead to epithelial barrier dysfunction, dysbiosis, and immune dysregulation. In addition, climate change and global warming may contribute to the exacerbation and the development of allergic diseases related to air pollutants. Epigenetic changes associated with air pollutants have also been connected to the onset of allergic diseases. Furthermore, these changes can be passed down through subsequent generations, causing a higher prevalence of allergic diseases in offspring. Modulation of the aryl hydrocarbon receptor could be a valuable strategy for alleviating air pollutant-induced epidermal barrier dysfunction and atopic dermatitis. A more effective approach to preventing allergic diseases triggered by air pollutants is to reduce exposure to them. Implementing public policies aimed at safeguarding individuals from air pollutant exposure may prove to be the most efficient solution. A pressing need exists for global policy initiatives that prioritize efforts to reduce the production of air pollutants.

Climate Change and Children's Health: Building a Healthy Future for Every Child

The warming of our planet matters to every child. Driven by fossil fuel-generated greenhouse gas emissions, climate conditions stable since the founding of modern pediatrics in the mid-nineteenth century have shifted, and old certainties are falling away. Children's physical and mental health are threatened by climate change through its effects on temperature, precipitation, and extreme weather; ecological disruption; and community disruption. These impacts expose and amplify existing inequities and create unprecedented intergenerational injustice. Fossil fuel extraction and combustion cause harm today and reach centuries into the future, jeopardizing the health, safety, and prosperity of today's children and future generations. Appreciating the unique vulnerability of their patients, pediatricians have become leading health advocates for climate actions necessary to protect all living and future children. Policies that reduce reliance on fossil fuels and promote cleaner air, facilitate walking and bicycling, encourage more sustainable diets, increase access to nature, and develop more connected communities lead to immediate gains in child health and equity, and build a foundation for generations of children to thrive.

Climate Change and Children's Health: Building a Healthy Future for Every Child

Observed changes in temperature, precipitation patterns, sea level, and extreme weather are destabilizing major determinants of human health. Children are at higher risk of climate-related health burdens than adults because of their unique behavior patterns; developing organ systems and physiology; greater exposure to air, food, and water contaminants per unit of body weight; and dependence on caregivers. Climate change harms children through numerous pathways, including air pollution, heat exposure, floods and hurricanes, food insecurity and nutrition, changing epidemiology of infections, and mental health harms. As the planet continues to warm, climate change's impacts will worsen, threatening to define the health and welfare of children at every stage of their lives. Children who already bear higher burden of disease because of living in low-wealth households and communities, lack of access to high quality education, and experiencing racism and other forms of unjust discrimination bear greater risk of suffering from climate change hazards. Climate change solutions, advanced through collaborative work of pediatricians, health systems, communities, corporations, and governments lead to immediate gains in child health and equity and build a foundation for generations of children to thrive. This technical report reviews the nature of climate change and its associated child health effects and supports the recommendations in the accompanying policy statement on climate change and children's health.

Perceived Stress From Childhood to Adulthood and Cardiometabolic End Points in Young Adulthood: An 18-Year Prospective Study

BACKGROUND

We investigated how childhood-to-adulthood perceived stress patterns predict adult cardiometabolic risk.

METHODS AND RESULTS

This study included 276 participants from the Southern California Children's Health Study (2003-2014), and a follow-up assessment (2018-2021). Perceived stress (Perceived Stress Scale) was initially reported by participants' parents for themselves during early childhood (mean age, 6.3 years), and later self-reported during adolescence (13.3 years) and young adulthood (23.6 years). Participants were grouped into 4 stress patterns: consistently high, decreasing, increasing, and consistently low. Cardiometabolic risk was assessed in young adulthood by carotid artery intima-media thickness, systolic and diastolic blood pressure, obesity, percent body fat, android/gynoid ratio, and glycated hemoglobin. A cardiometabolic risk score was generated by summing the clinically abnormal markers. Multivariable linear and logistic regression models were used to (1) examine the associations between Perceived Stress Scale at 3 time points and adult cardiometabolic risk, and (2) assess the impact of stress pattern on adult cardiometabolic risk. Findings suggested that in adulthood, higher Perceived Stress Scale score was associated with increased overall cardiometabolic risk (β=0.12 [95% CI, 0.01-0.22]), carotid artery intima-media thickness (β=0.01 [95% CI, 0.0003-0.02]), systolic blood pressure (β=1.27 [95% CI, 0.09-2.45]), and diastolic blood pressure (β=0.94 [95% CI, 0.13-1.75]). Individuals with a consistently high adolescence-to-adulthood stress pattern had greater overall cardiometabolic risk (β=0.31 [95% CI, 0.02-0.60]), android/gynoid ratio (β=0.07 [95% CI, 0.02-0.13]), percent body fat (β=2.59 [95% CI, 0.01-5.17]), and greater odds of obesity (odds ratio, 5.57 [95% CI, 1.62-19.10]) in adulthood, compared with those with a consistently low Perceived Stress Scale score.

CONCLUSIONS

Consistently high perceived stress from adolescence to adulthood may contribute to greater cardiometabolic risk in young adulthood.

How Schools Can Help Address Social Determinants of Health in Asthma Management

Schools are in a unique position to address social determinants of health (SDOHs) in pediatric asthma management because of their potential to provide resources and facilitate collaboration with health care providers and services for children at risk within their community. SDOHs include economic factors, educational attainment and health literacy, neighborhood factors and the built environment, social and community aspects including discrimination and racism, and health care access and quality. These factors have a significant impact on asthma health in children, and certain populations such as minoritzed populations and those living in high-poverty environments have been shown to be at greater risk for adverse effects of SDOHs on asthma outcomes. School-based asthma programs address several SDOHs including health literacy, the built environment, and health care quality and access and have been shown to improve asthma outcomes. Key components include connection between the school and the health care team, self-management education, and directly observed therapy. School nurses play a key role in directing and managing effective programs because they can evaluate and support a student's health while considering the effect of SDOHs at interpersonal, institutional, community, and policy levels.