External Environmental Pollution as a Risk Factor for Asthma

Effects of climate and environmental factors on childhood and adolescent asthma: A systematic review based on spatial and temporal analysis evidence

BACKGROUND

Asthma is a prevalent chronic respiratory disease among children, influenced by various climate and environmental factors. Despite its prevalence, the specific effects of these factors on asthma remain unclear. This study aims to systematically assess the epidemiological evidence using spatial and temporal methods on the impact of climate and environmental factors on childhood asthma.

METHODS

A systematic review was conducted to analyse the impact of climate and environmental factors on childhood asthma and wheezing, focusing on spatial and temporal trends. Searches were carried out in PubMed, Embase, and CINAHL databases for studies published from January 2000 to April 2024, using key search terms 'asthma/wheezing', 'extreme weather, 'green space', 'air pollution' and 'spatial or temporal analyses".

RESULTS

The systematic review analysed 28 studies, with six employing spatial and 22 using temporal analysis methods; however, none incorporated spatio-temporal analysis in their models. The findings reveal that extreme weather events, including heatwaves and heavy rainfall, elevate childhood asthma risks across various climates, with significant effects observed during summer and winter months. Dust storms in arid and subtropical regions are linked to immediate spikes in hospital admissions due to asthma exacerbations. The effects of green spaces on childhood asthma are mixed, with some studies indicating protective effects while others suggest increased risks, influenced by local environmental factors. Air pollutants such as PM2.5, NO2, and ozone can exacerbate asthma symptoms and along with other environmental factors, contribute to seasonal effects. High temperatures generally correlate with increased asthma risks, though the effects vary by age, sex, and climate.

CONCLUSION

Future research should integrate spatial and temporal methods to better understand the effects of environmental and climate changes on childhood asthma.

The Effects of Turmeric and Mangosteen Pericarp Ethanol Extract on Eosinophil Count, TNF-α and TGF-β1 Gene Expression in Asthmatic Rat Model

Background

Asthma is a chronic respiratory disease that is characterized by inflammation, bronchial hyperreactivity, and airway remodeling. The long-term use of corticosteroids at high doses causes various side effects. Traditional herbal medicine has been suggested as an alternative therapy that is safe and effective in dealing with asthma. Natural plants such as turmeric and mangosteen are known to treat asthma and reduce inflammation.

Objective

The purpose of this study was to investigate the effects of turmeric and mangosteen pericarp ethanol extracts on the eosinophil counts, TNF-α and TGF-β1 gene expression, and inflammatory cell counts in the histopathology of an asthmatic rat model.

Methods

The preliminary study used 30 rats, which were divided into a normal group, negative control group (OVA-sensitized), turmeric normal group, mangosteen group, and positive control group. Blood samples were collected after the sensitization period to determine eosinophil counts. TNF-α and TGF-β1 gene expression, and histopathology were observed in the rat's lungs. The follow-up study used 30 rats divided into a normal group, negative control group (OVA-sensitized), combination of turmeric and mangosteen group (54m/200gr rats, 36mg/200gr rats, and 36mg/200gr rats), and positive control group. The examination procedures were the same as in the preliminary study.

Results

The administration of single ethanol extracts of turmeric and mangosteen significantly decreased eosinophils and improved the histopathological features of the lungs (inflammatory cell counts, bronchial inflammatory score, and bronchial smooth muscle thickness) (p<0.05). The combination of turmeric and mangosteen extracts at all doses significantly decreased eosinophils and improved the histopathological features of the lungs (inflammatory cell counts, bronchial inflammatory score, and bronchial smooth muscle thickness) (p<0.05). Both the single and combined administration of turmeric and mangosteen ethanol extracts did not cause significant changes in TNF-alpha and TGF-beta (p>0.05).

Conclusion

Turmeric ethanol extract and mangosteen pericarp ethanol extract have a reductional effect on the parameters of asthma based on the eosinophil counts, the inflammatory cell counts and score, and bronchial smooth muscle thickness.

Clearing the air: A systematic review of studies on air pollution and childhood brain outcomes to mobilize policy change

Climate change, wildfires, and environmental justice concerns have drawn increased attention to the impact of air pollution on children's health and development. Children are especially vulnerable to air pollution exposure, as their brains and bodies are still developing. The objective of this systematic review was to synthesize available empirical evidence on the associations between air pollution exposure and brain outcomes in developmental samples (ages 0-18 years old). Studies were identified by searching the PubMed and Web of Science Core Collection databases and underwent a two-phase screening process before inclusion. 40 studies were included in the review, which included measures of air pollution and brain outcomes at various points in development. Results linked air pollution to varied brain outcomes, including structural volumetric and cortical thickness differences, alterations in white matter microstructure, functional network changes, metabolic and molecular effects, as well as tumor incidence. Few studies included longitudinal changes in brain outcomes. This review also suggests methodologies for incorporating air pollution measures in developmental cognitive neuroscience studies and provides specific policy recommendations to reduce air pollution exposure and promote healthy brain development by improving access to clean air.

Chemical composition, mutagenicity, and cytotoxicity of urban submicron particulate matter (PM1) in Agra, India

This study, conducted in Agra, India, examined the mass concentrations, chemical compositions, and seasonal variations of submicron particles (PM1). The concentrations of metals, water-soluble inorganic ions (WSIs) including anions (F-, Cl-, NO₃-, SO₄2-) and cations (Ca2+, K+, Mg2+, NH₄+, Na+), organic carbon (OC) and elemental carbon (EC) and polycyclic aromatic hydrocarbons (PAHs) in PM1 extract were determined using Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES), Ion Chromatography, Thermogravimetric Analysis and Gas Chromatography-Mass Spectrometry (GC-MS) respectively. For morphological observation of PM1 particles, Field Emission Scanning Electron Microscopy-Energy Dispersive X-ray spectrometry (FESEM-EDS) was used. The annual average concentration of PM1 was 82.9 ± 33.4 μg/m3, which exceeds the World Health Organisation's (WHO) safe limit for PM2.5 of 5 μg/m3 by a factor of 17. The PM1 mass composition included metals (31 %), WSIs (28 %), OC and EC (9.8 %), and PAHs (0.4 %). Winter recorded the highest PM1 concentration (96.1 ± 25.8 μg/m3), followed by post-monsoon, summer, and monsoon seasons. The average concentration of PAHs was 364.6 ± 226.6 ng/m3. Positive Matrix Factorization (PMF) identified traffic, emissions from biomass/coal and wood combustion, industrial/stationary sources, and secondary aerosols as potential contributors. The Ames test revealed the presence of frameshift mutations and base pair substitutions, especially in winter and post-monsoon. Additionally, PM1 exhibited cytotoxic effects on V-79 cells, with heightened toxicity during winter and prolonged exposure in other seasons. This study underscores the urgent need to address local emission sources and establish regulatory standards for PM1 in urban areas.

Public health impacts of air pollution from the spatiotemporal heterogeneity perspective: 31 provinces and municipalities in China from 2013 to 2020

Air pollution has long been a significant environmental health issue. Previous studies have employed diverse methodologies to investigate the impacts of air pollution on public health, yet few have thoroughly examined its spatiotemporal heterogeneity. Based on this, this study investigated the spatiotemporal heterogeneity of the impacts of air pollution on public health in 31 provinces in China from 2013 to 2020 based on the theoretical framework of multifactorial health decision-making and combined with the spatial durbin model and the geographically and temporally weighted regression model. The findings indicate that: (1) Air pollution and public health as measured by the incidence of respiratory diseases (IRD) in China exhibit significant spatial positive correlation and local spatial aggregation. (2) Air pollution demonstrates noteworthy spatial spillover effects. After controlling for economic development and living environment factors, including disposable income, population density, and urbanization rate, the direct and indirect spatial impacts of air pollution on IRD are measured at 3.552 and 2.848, correspondingly. (3) China's IRD is primarily influenced by various factors such as air pollution, economic development, living conditions, and healthcare, and the degree of its influence demonstrates an uneven spatiotemporal distribution trend. The findings of this study hold considerable practical significance for mitigating air pollution and safeguarding public health.

Immunological Effects of Diesel Particles in a Murine Model of Healthy Mice

Introduction: Exposure to environmental pollutants such as diesel exhaust particles (DEP) increases the risk of respiratory disease exacerbation. However, the possible effects of these particles on the general population remain poorly understood. The present study aimed to assess the immunomodulatory and inflammatory effects of the inhalation of DEP in a model of healthy mice undergoing short-, mid- and long-term exposure. Materials and Methods: BALB/c ByJ mice were randomly divided into five experimental groups. The control group received three intranasal instillations of saline over 8 days while the other four groups received intranasal instillations of 150 µg of DEP 3 days per week for 8, 17, 26, and 53 days. Lung function assessment and flow cytometry were performed. Results: In lung tissue, intranasal exposure to DEP decreased total monocytes (p < 0.015 in all groups). At 26 days, a reduction in inflammatory monocytes and an increase in resident monocytes were observed, p = 0.001 and 0.0001, respectively. Eosinophils and neutrophils decreased at 26 days (p = 0.017 and p = 0.041, respectively). The intranasal challenges of DEP increased the total population of dendritic cells (DC) at 26 and 53 days (p = 0.017 and p = 0.022, respectively) and decreased the total and alveolar populations of macrophages (p < 0.003 for all groups compared to control), while interstitial macrophage populations increased over the time period (p = 0.0001 for all groups compared to control). Conclusions: Continuous DEP exposure triggers immune mechanisms that predispose healthy individuals to a pro-inflammatory and hyper-reactive microenvironment. This mouse model provides evidence of the capacity of DEP to increase DC, interstitial macrophages, and resident monocytes.

EAACI guidelines on environmental science for allergy and asthma: The impact of short-term exposure to outdoor air pollutants on asthma-related outcomes and recommendations for mitigation measures

The EAACI Guidelines on the impact of short-term exposure to outdoor pollutants on asthma-related outcomes provide recommendations for prevention, patient care and mitigation in a framework supporting rational decisions for healthcare professionals and patients to individualize and improve asthma management and for policymakers and regulators as an evidence-informed reference to help setting legally binding standards and goals for outdoor air quality at international, national and local levels. The Guideline was developed using the GRADE approach and evaluated outdoor pollutants referenced in the current Air Quality Guideline of the World Health Organization as single or mixed pollutants and outdoor pesticides. Short-term exposure to all pollutants evaluated increases the risk of asthma-related adverse outcomes, especially hospital admissions and emergency department visits (moderate certainty of evidence at specific lag days). There is limited evidence for the impact of traffic-related air pollution and outdoor pesticides exposure as well as for the interventions to reduce emissions. Due to the quality of evidence, conditional recommendations were formulated for all pollutants and for the interventions reducing outdoor air pollution. Asthma management counselled by the current EAACI guidelines can improve asthma-related outcomes but global measures for clean air are needed to achieve significant impact.

The relationship between neighborhood economic deprivation and asthma-associated emergency department visits in Maryland

Background

Asthma represents a substantial public health challenge in the United States, affecting over 25 million adults. This study investigates the impact of neighborhood economic deprivation on asthma-associated Emergency Department (ED) visits in Maryland, using the Distressed Communities Index (DCI) for analysis.

Methods

A retrospective analysis of Maryland's Emergency Department Databases from January 2018 to December 2020 was conducted, focusing on asthma-associated ED visits.

Results

The study involved 185,317 ED visits, majority of which were females (56.3%) and non-Hispanic whites (65.2%). A significant association was found between increased neighborhood socioeconomic deprivation and asthma-related ED visits. The poorest neighborhoods showed the highest rates of such visits. Compared to prosperous areas, neighborhoods classified from Comfortable to Distressed had progressively higher odds for asthma-related ED visits (Comfortable: OR = 1.14, Distressed OR = 1.65). Other significant asthma predictors included obesity, female gender, tobacco smoking, and older age.

Conclusion

There is a substantive association between higher asthma-related ED visits and high neighborhood economic deprivation, underscoring the impact of socioeconomic factors on health outcomes.

Public health implications

Addressing healthcare disparities and improving access to care in economically distressed neighborhoods is crucial. Targeted interventions, such as community health clinics and asthma education programs, can help mitigate the impact of neighborhood disadvantage.

Environmental pollutants and exosomes: A new paradigm in environmental health and disease

This study investigates the intricate interplay between environmental pollutants and exosomes, shedding light on a novel paradigm in environmental health and disease. Cellular stress, induced by environmental toxicants or disease, significantly impacts the production and composition of exosomes, crucial mediators of intercellular communication. The heat shock response (HSR) and unfolded protein response (UPR) pathways, activated during cellular stress, profoundly influence exosome generation, cargo sorting, and function, shaping intercellular communication and stress responses. Environmental pollutants, particularly lipophilic ones, directly interact with exosome lipid bilayers, potentially affecting membrane stability, release, and cellular uptake. The study reveals that exposure to environmental contaminants induces significant changes in exosomal proteins, miRNAs, and lipids, impacting cellular function and health. Understanding the impact of environmental pollutants on exosomal cargo holds promise for biomarkers of exposure, enabling non-invasive sample collection and real-time insights into ongoing cellular responses. This research explores the potential of exosomal biomarkers for early detection of health effects, assessing treatment efficacy, and population-wide screening. Overcoming challenges requires advanced isolation techniques, standardized protocols, and machine learning for data analysis. Integration with omics technologies enhances comprehensive molecular analysis, offering a holistic understanding of the complex regulatory network influenced by environmental pollutants. The study underscores the capability of exosomes in circulation as promising biomarkers for assessing environmental exposure and systemic health effects, contributing to advancements in environmental health research and disease prevention.

Adverse Childhood Experiences and Related Events are Associated with Asthma Symptoms in Children

OBJECTIVE

To examine the association between adverse childhood experiences (ACEs) and related events and asthma symptom burden in children.

METHODS

This is a cross-sectional study of baseline data from 147 participants with asthma from a cohort of children enrolled in the Pediatric ACEs Screening and Resiliency Study. Participants completed the PEdiatric ACEs and Related Life Events Screener (PEARLS) tool, a 17-item questionnaire, capturing 3 domains of childhood adversity-child maltreatment, household challenges, and social context. Asthma symptom burden was assessed using the International Study of Asthma and Allergies in Childhood core questionnaire, which asks participants to identify the presence and frequency of severe wheezing that limits speech, wheezing with exercise, nocturnal wheezing, and nocturnal cough in the last 12 months. Using multivariable logistical regression models, we examined the relationship between reported PEARLS and asthma symptoms.

RESULTS

Of children with asthma, 86% reported at least 1 adversity, with 48% reporting 4 or more. The odds of severe wheeze limiting speech increased by 19% with each additional reported adversity captured by the PEARLS tool (95% confidence intervals (CI) 1.01-1.41). Increasing PEARLS scores were also associated with 16% increased odds of reporting wheeze with exercise (95% CI 1.03-1.31). Wheezing with exercise was associated with the household challenges domain (odds ratio (OR) 1.34; 95% CI 1.05-1.72), while severe wheeze limiting speech was associated with the social context domain (OR 1.75; 95%CI 1.02-3.02).

CONCLUSIONS

Childhood adversities are associated with increased asthma symptom burden, suggesting the tool may be helpful in identifying children at risk for poorly controlled asthma.

Examining the impact of air pollution, climate change, and social determinants of health on asthma and environmental justice

PURPOSE OF REVIEW

In this review, we discuss the current literature examining the impact air pollution and climate change has on asthma onset, control, and exacerbation. This review also addresses the risk of exposure to specific disproportionately affected communities, highlighting health disparities in exposure and asthma outcomes.

RECENT FINDINGS

Recent studies have shifted from highlighting the associations between asthma exacerbations and indoor and outdoor air pollution. Studies are now focused on confirming the association of asthma incidence from these same exposures. Many studies have linked particulate matter to adverse asthma outcomes, however, the pollutant exposures that pose the greatest risk and the effect of natural disasters fueled by climate change are under current study. Some studies have observed that the true burden that pollutant exposures have on asthma outcomes occurs at the intersection of exposure and vulnerability. Future studies in this area will address social determinants of health, societal factors such as redlining and other systemic racism practices.

SUMMARY

Although decades of research support the causal link between gaseous and particulate air pollution and the exacerbation of preexisting asthma, recent studies suggest air pollution can cause incident (new onset) asthma. Studies have started to focus on the underlying drivers of poor outcomes in asthma. Many of the structural impediments to high quality asthma care at the society level (e.g. poverty, redlining, systemic racism) also are risk factors for worsened climate events and air pollution exposure. The individuals in these disproportionately affected groups are doubly affected by worsened exposure and worsened access to care for the resultant asthma exacerbations or incident asthma. More research is needed to understand the specific climate and air pollution mitigation efforts where disproportionately affected communities would derive the most benefit.

The Influence of Fine Particulate Matter and Cold Weather on Emergency Room Interventions for Childhood Asthma

(1) Background: Children are the most vulnerable to pollution due to their decreased stature, heightened respiratory rate, and frequent outdoor engagement. PM2.5, nitrogen dioxide (NO2), ozone, and cold weather are associated with pediatric asthma. In this study, we investigated the nexus between air pollution, climate factors, and pediatric asthma emergency room visits (ERVs). (2) Method: Pediatric asthma ERV data for healthcare quality from the Taiwanese National Insurance in the Taipei area were obtained from 2015 to 2019. Air pollution and climate factor data were also collected. Poisson regression was employed to determine the relationships with relative risks (RRs). (3) Results: The incidence of pediatric asthma ERVs decreased, with a crude RR of 0.983 (95% CI: 0.98-0.986, p < 0.001). Fine particulate matter (PM2.5) had an adjusted RR of 1.102 (95% CI: 1.037-1.172, p = 0.002) and a 7.7 µg/m3 increase, and air temperature had an adjusted RR of 0.813 (95% CI: 0.745-0.887, p < 0.001) comparing between the highest and lowest quarter air temperature associated with pediatric asthma ERVs. (4) Conclusions: This inquiry underscores the positive associations of PM2.5 and cold weather with pediatric asthma ERVs. The findings could guide the government to establish policies to reduce air pollution and promote children's health.

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.

Exercise-Mediated Protection against Air Pollution-Induced Immune Damage: Mechanisms, Challenges, and Future Directions

Air pollution, a serious risk factor for human health, can lead to immune damage and various diseases. Long-term exposure to air pollutants can trigger oxidative stress and inflammatory responses (the main sources of immune impairment) in the body. Exercise has been shown to modulate anti-inflammatory and antioxidant statuses, enhance immune cell activity, as well as protect against immune damage caused by air pollution. However, the underlying mechanisms involved in the protective effects of exercise on pollutant-induced damage and the safe threshold for exercise in polluted environments remain elusive. In contrast to the extensive research on the pathogenesis of air pollution and the preventive role of exercise in enhancing fitness, investigations into exercise resistance to injury caused by air pollution are still in their infancy. In this review, we analyze evidence from humans, animals, and cell experiments on the combined effects of exercise and air pollution on immune health outcomes, with an emphasis on oxidative stress, inflammatory responses, and immune cells. We also propose possible mechanisms and directions for future research on exercise resistance to pollutant-induced damage in the body. Furthermore, we suggest strengthening epidemiological studies at different population levels and investigations on immune cells to guide how to determine the safety thresholds for exercise in polluted environments.

Modulatory Effects of Vitamin D: A Possible Approach to Mitigate Air Pollution Related Pregnancy Complications

Approximately 99% of people on the planet breathe air that exceeds the World Health Organization's permitted threshold for pollution. South Asia is home to the world's most polluted cities. Population-based studies have suggested that women's reproductive health outcomes are worsening due to air pollution. Preeclampsia, miscarriage, gestational diabetes, high blood pressure, and unfavorable birth outcomes, including preterm birth, low birth weight, or even stillbirth are all linked to exposure to air pollution during pregnancy. It is estimated that 0.61 million deaths in India alone were related to indoor air pollution. Females frequently cook in the household using solid fuel as a primary combustion source. Women in the regions with the highest population density are disproportionately affected by high levels of poor-quality indoor air. Recently, it has been proposed that air pollution has a distinct role in the onset of vitamin D deficiency. Numerous studies have explored associations between low vitamin D level and various female reproductive health conditions since the discovery of the vitamin D receptor. It is worthy to note that some of these reproductive health conditions positively correlate with the severity of air pollution. In this study, the evidence has been synthesized on vitamin D's protective properties and dietary and pharmaceutical interventions have been discussed to show their beneficial effects in decreasing the long-term negative impacts of air pollution on women's health.

Medium-term exposure to size-fractioned particulate matter and asthma exacerbations in China: A longitudinal study of asthmatics with poor medication adherence

BACKGROUND

Studies have shown that short- and long-term exposure to particulate matter (PM) can increase the risk of asthma morbidity and mortality. However, the effect of medium-term exposure remains unknown. We aim to examine the effect of medium-term exposure to size-fractioned PM on asthma exacerbations among asthmatics with poor medication adherence.

METHODS

We conducted a longitudinal study in China based on the National Mobile Asthma Management System Project that specifically and routinely followed asthma exacerbations in asthmatics with poor medication adherence from April 2017 to May 2019. High-resolution satellite remote-sensing data were used to estimate each participant's medium-term exposure (on average 90 days) to size-fractioned PM (PM1, PM2.5, and PM10) based on the residential address and the date of the follow-up when asthma exacerbations (e.g., hospitalizations and emergency room visits) occurred or the end of the follow-up. The Cox proportional hazards model was employed to examine the hazard ratio of asthma exacerbations associated with each PM after controlling for sex, age, BMI, education level, geographic region, and temperature.

RESULTS

Modelling results revealed nonlinear exposure-response associations of asthma exacerbations with medium-term exposure to PM1, PM2.5, and PM10. Specifically, for emergency room visits, we found an increased hazard ratio for PM1 above 22.8 µg/m3 (1.060, 95 % CI: 1.025-1.096, per 1 µg/m3 increase), PM2.5 above 38.2 µg/m3 (1.032, 95 % CI: 1.010-1.054), and PM10 above 78.6 µg/m3 (1.019, 95 % CI: 1.006-1.032). For hospitalizations, we also found an increased hazard ratio for PM1 above 20.3 µg/m3 (1.055, 95 % CI: 1.001-1.111) and PM2.5 above 39.2 µg/m3 (1.038, 95 % CI: 1.003-1.074). Furthermore, the effects of PM were greater for a longer exposure window (90-180 days) and among participants with a high BMI.

CONCLUSION

This study suggests that medium-term exposure to PM is associated with an increased risk of asthma exacerbations in asthmatics with poor medication adherence, with a higher risk from smaller PM.

Tropical high altitude and severe asthma in adults: house dust mite sensitization and phenotypic distribution

BACKGROUND

There is a lack of information on house dust mite (HDM) sensitization and phenotype distribution in patients with severe asthma (SA) living permanently at high-altitude (HA) in tropical regions, which may be different.

OBJECTIVE

The aim of this study was to characterize adults with SA in a tropical high altitude city (2,640 m): Bogotá, Colombia.

MATERIAL AND METHODS

This observational cross-sectional study included severe asthmatic outpatients (n = 129) referred to the ASMAIRE program of the Fundación Neumológica Colombiana in Bogotá (2,640 m). Clinical history, spirometry, total IgE, blood eosinophils, and skin prick test (SPT), including HDM allergens, were performed. Phenotype definitions: Allergic/atopic (AA): IgE ≥100 IU/mL and/or at least one positive SPT; eosinophilic (EOS): blood eosinophils ≥300 cells/µL; type 2-high: AA and/or EOS phenotype; type 2-low: non-AA/non-EOS phenotype (IgE <100 IU/mL, negative SPT, and blood eosinophils <300 cells/µL).

RESULTS

A total of 129 adults with SA were included, 79.8% female. Phenotype distribution: AA: 61.2%; EOS: 37.2%; type 2-high: 72.1%; type 2-low: 27.9%. Among AA patients, HDM sensitization was present in 87% and 34.9% were non-eosinophilic. There was a significant overlap between the phenotypes.

CONCLUSIONS

In contrast to non-tropical high-altitude regions, we found a high frequency of HDM sensitization in patients with AA phenotype living in a tropical high-altitude city. We also found a discrete lower frequency of EOS phenotype with no other significant differences in the phenotypic distribution compared to that described at low altitudes. We propose that tropical location may modify the effect of high altitude on HDM concentrations and allergenicity.

A systematic review and meta-analysis of field studies of portable air cleaners: Performance, user behavior, and by-product emissions

Indoor air quality is important for the health of building occupants, and public interest in controlling indoor airborne pathogens increased dramatically with the COVID-19 pandemic. Pollutant concentrations can be controlled locally using portable air cleaners (sometimes called air purifiers), which allow occupants to apply air cleaning technology to meet their needs in the location and times that they find appropriate. This paper provides a systematic review of scientific literature that describes field studies of the effectiveness of portable air cleaners. Over 500 papers were considered, and 148 were reviewed in detail, to extract 35 specific research results (e.g., particulate removal performance) or characteristics (e.g., type of building). These were aggregated to provide an overview of results and approaches to this type of research, and to provide meta-analyses of the results. The review includes: descriptions of the geographical location of the research; rate of publications over time; types of buildings and occupants in the field study; types of air cleaner technology being tested; pollutants being measured; resulting pollutant removal effectiveness; patterns of usage and potential barriers to usage by occupants; and the potential for by-product emissions in some air cleaner technologies. An example result is that 83 of the 148 papers measured reductions in fine particulates (PM2.5) and found a mean reduction of 49 % with standard deviation of 20 %. The aggregated results were approximately normally distributed, ranging from finding no significant reduction up to a maximum above 90 % reduction. Sixteen of the 148 papers considered gaseous pollutants, such as volatile organic compounds, nitrogen dioxide, and ozone; 36 papers considered biological pollutants, such as bacteria, viruses, pollen, fungi, etc. An important challenge, common to several studies, is that occupants run the air cleaners for shorter periods and on low airflow rate settings, because of concerns about noise, drafts, and electricity cost, which significantly reduces air cleaning effectiveness.

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.

Prevalence and Risk Factors of Childhood Asthma in Jazan Region, Saudi Arabia

Background

The prevalence of asthma among children has been on the rise worldwide, leading to significant morbidity and mortality. Our study was conducted to determine the prevalence of asthma and its related risk factors among school-age children in the Jazan Region, Saudi Arabia.

Materials and Method

The study was a cross-sectional prospective study that used Phase I ISAAC protocol and was conducted from March to June 2023. The sample size was calculated to be 1600 among school-age children in the Jazan Region Saudi Arabia. This study complies with the Declaration of Helsinki. Data was analyzed using SPSS version 23.0, Descriptive statistics were calculated for study variables, and appropriate tests of significance were performed to determine statistical significance.

Results

The total study population was 1368 the majority of them, 96.6% (n=1321), were Saudi nationals, and most of them lived in rural areas (70.6%, n=966). The prevalence of life-long wheezing, wheezing in the last 12 months, and exercise-induced wheezing was 28.0%, 29.2%, and 30.9%, respectively. Risk factors such as having indoor plants, having a pet, and a smoker in the household were reported by 48.0%, 24.6%, and 36.4% of participants, respectively. Living near an industrial area was determined as a risk factor in 98 (7.2%) of the children. Asthma-related symptoms were strongly correlated with all risk factors based on the chi-square test, and some risk factors based on multivariate linear regression.

Conclusion

The prevalence of asthma among children in the Jazan Region is higher than previously reported, and the reported risk factors are significantly correlated with symptoms of asthma.

Air pollution and oxidative stress in adults suffering from airway diseases. Insights from the Gene Environment Interactions in Respiratory Diseases (GEIRD) multi-case control study

Air pollution is a leading risk factor for global mortality and morbidity. Oxidative stress is a key mechanism underlying air-pollution-mediated health effects, especially in the pathogenesis/exacerbation of airway impairments. However, evidence lacks on subgroups at higher risk of developing more severe outcomes in response to air pollution. This multi-centre study aims to evaluate the association between air pollution and oxidative stress in healthy adults and in patients affected by airway diseases from the Italian GEIRD (Gene Environment Interactions in Respiratory Diseases) multi-case control study. Overall, 1841 adults (49 % females, 20-83 years) were included from four Italian centres: Pavia, Sassari, Turin, and Verona. Following a 2-stage screening process, we identified 1273 cases of asthma, chronic bronchitis, rhinitis, or COPD and 568 controls. Systemic oxidative stress was quantified by urinary 8-isoprostane and 8-OH-dG. Individual residential exposures to NO2, PM10, PM2.5, and O3 were derived using an innovative five-stage machine-learning-based approach. Linear mixed regression models tested the association between oxidative stress biomarkers and air pollution tertiles, adjusting by age, sex, BMI, smoking, education and season, with recruiting centres as random intercept. Only cases exhibited higher levels of log-transformed 8-isoprostane and 8-OH-dG in association with NO2 (β: 0.30 95 % CI: 0.08-0.52 and 0.20 95 % CI: 0.03-0.37), PM10 (0.34 95 % CI: 0.12-0.55 and 0.21 95 % CI: 0.05-0.37) and PM2.5 (0.27 95 % CI: 0.09-0.49 and 0.18 95 % CI: 0.02-0.34) as compared to the first tertile of exposure. No significant associations were observed for summer O3. Our findings suggest that exposure to air pollution may increase systemic oxidative stress levels in people suffering from airway diseases. This introduces a potential novel approach available for future epidemiological studies and Public Health for effective prevention strategies oriented at the quantification of early biological effects in susceptible people, whose additional risk level might be currently underrated. Air-pollution-mediated exacerbations, driven by oxidative stress, still deserve our attention.

Suppression of SPARC Ameliorates Ovalbumin-induced Airway Remodeling via TGFβ1/Smad2 in Chronic Asthma

PURPOSE

Airway remodeling is a critical feature of asthma. Secreted protein acidic and rich in cysteine (SPARC), which plays a cardinal role in regulating cell-matrix interactions, has been implicated in various fibrotic diseases. However, the effect of SPARC in asthma remains unknown.

METHODS

We studied the expression of SPARC in human bronchial epithelial cells and serum of asthmatics as well as in the lung tissues of chronic asthma mice. The role of SPARC was examined by using a Lentivirus-mediated SPARC knockdown method in the ovalbumin (OVA)-induced asthma mice. The biological processes regulated by SPARC were identified using RNA sequencing. The function of SPARC in the remodeling process induced by transforming growth factor β1 (TGFβ1) was conducted by using SPARC small interfering RNA (siRNA) or recombinant human SPARC protein in 16HBE cells.

RESULTS

We observed that SPARC was up-regulated in human bronchial epithelia of asthmatics and the asthmatic mice. The levels of serum SPARC in asthmatics were also elevated and negatively correlated with the forced expiratory volume in one second (FEV1) to forced vital capacity ratio (FVC) (r = -0.485, P < 0.01) and FEV1 (%predicted) (r = -0.425, P = 0.001). In the chronic asthmatic mice, Lentivirus-mediated SPARC knockdown significantly decreased airway remodeling and airway hyper-responsiveness. According to gene set enrichment analysis, negatively enriched pathways found in the OVA + short hairpin-SPARC group included ECM organization and collagen formation. In the lung function studies, knockdown of SPARC by siRNA reduced the expression of remodeling-associated biomarkers, cell migration, and contraction by blocking the TGFβ1/Smad2 pathway. Addition of human recombinant SPARC protein promoted the TGFβ1-induced remodeling process, cell migration, and contraction in 16HBE cells via the TGFβ1/Smad2 pathway.

CONCLUSIONS

Our studies provided evidence for the involvement of SPARC in the airway remodeling of asthma via the TGFβ1/Smad2 pathway.

Analytical methods employed in the identification and quantification of per- and polyfluoroalkyl substances in human matrices - A scoping review

Persistent organic pollutants (POPs) represent a possible hazard for the ecosystems, with adverse outcomes on wildlife and humans. POPs have always received interest from the scientific community, and they have also been subject to legal restrictions worldwide on their application and commercialization. Among the broad spectrum of POPs, per- and polyfluoroalkyl substances (PFASs) are considered emerging contaminants due to their potential effect on the ecosystem and human health. These contaminants are widely employed in countless applications, from surfactants and building materials to food packaging. On the other hand, their chemical structure gives them the ability to interact with the environment, causing possible toxic effects for humans and environment. Human biomonitoring is a necessary instrument to indagate the impact of PFASs on human health: in recent years several studies have found detectable levels of PFASs in several biological matrices in humans (blood, hair, nails, and urine). Here, we review the most recent scientific literature concerning analytical methods employed in the identification and quantification of PFASs focusing on biological matrices. It has been noted that liquid chromatography coupled with mass spectrometry is the main analytical instrumentation employed, while blood and/or serum samples are the main employed human matrices whereas the use of non-invasive matrices is still at the beginning. Various issues directly related to human metabolism of PFASs and the effective amount of PFAS absorbed from the environment still need to be investigated.

Inactivation of airborne pathogenic microorganisms by plasma-activated nebulized mist

The airborne microorganisms in the aerosols are one main transmission way of pathogenic microorganisms and therefore inactivation of microorganisms in aerosols could effectively prevent the transmission of pathogenic microorganisms to control epidemics. The mist nebulized by plasma-activated air could effectively inactivate bacteria and could be developed for the sterilization of microorganisms in aerosols. In this study, the plasma-activated nebulized mist (PANM) was applied for the inactivation of microorganisms in aerosols and efficiently inactivated the bacteria, yeast, and viruses in aerosols after 2-min treatment. The PANM treatment caused morphologic changes and damage to the bacteria cells in aerosols. The PANM could also inactivate the microorganisms attached to the surface of the treatment chamber and the bacteria attached to the skin of mice within 6-min treatment. The biosafety assays demonstrated that the PANM treatment exhibited no effects on the behavior, hematological and serum biochemical parameters of blood, and organs from the mice. This study would supply an efficient, broad-spectrum, and safe aerosol sterilization strategy based on plasma technology to prevent the transmission of airborne microorganisms.

Spatial variance and estimation of nitrogen dioxide levels as a contributing factor to asthma epidemiology in Rawalpindi, Pakistan

Asthma prevalence and morbidity are increasing rapidly worldwide, especially in developing countries. Previous studies have shown nitrogen dioxide as an important contributor to asthma prevalence along with extreme temperatures, relative humidity, and land use change. The present study aimed to assess the asthma epidemiology and association of nitrogen dioxide, temperature, and land use as a contributing factor for increasing asthma prevalence in Rawalpindi, Pakistan. Secondary data related to the frequency of asthmatics hospital visits were analyzed to figure out the hotspots of asthma by using Getis ord Gi* statistics in ArcGIS 10.2. Moreover, intraurban variation of nitrogen dioxide concentration was analyzed by passive sampling method and its association with the rate of asthmatics hospital visits in Rawalpindi, Pakistan was also researched. Results revealed the random distribution of disease with significant hotspots along with spatial variability of nitrogen dioxide in urban and rural locations. Indoor and outdoor levels of nitrogen dioxide exceed the national and world health organization standards on asthma high risk areas especially in winter season. Congested housing with poor ventilation, unplanned urbanization, cold temperature, and unclean fuel use are revealed as strong determinants of asthma prevalence in Rawalpindi, Pakistan. Extensive monitoring and interventions are needed for the reduction of both indoor and outdoor nitrogen dioxide levels to overcome the increasing rate of asthma prevalence.

Association between air pollution exposure and outpatient visits for dermatomyositis in a humid subtropical region of China: a time-series study

In recent years, a growing number of studies have found that air pollution plays critical roles in the onset and development of autoimmune diseases, but few studies have shown an association between air pollutants and dermatomyositis (DM). We sought to investigate the relationship between short-term exposure to air pollution and outpatient visits for DM and to quantify the burden of DM due to exposure to air pollutants in Hefei, China. Daily records of hospital outpatient visits for DM, air pollutants and meteorological factors data in Hefei from January 1, 2018 to December 31, 2021 were obtained. We used a distributed lag non-linear model (DLNM) in conjunction with a generalized linear model (GLM) to explore the association between air pollution and outpatient visits for DM, and conducted stratified analyses by gender, age and season. Moreover, we used attributable fraction (AF) and attributable number (AN) to reflect the burden of disease. A total of 4028 DM clinic visits were recorded during this period. High concentration nitrogen dioxide (NO2) exposure was associated with increased risk of DM outpatient visits (relative risk (RR) 1.063, 95% confidence interval (CI) 1.015-1.114, lag 0-5). Intriguingly, exposure to high concentration ozone (O3) was associated with reduced risk of outpatient visits for DM (RR 0.974, 95% CI 0. 0.954-0.993, lag 0-6). The results of stratified analyses showed that the cold season (vs. warm season) were more susceptible to outpatient visits for DM associated with NO2 and O3 exposure. In addition, we observed that an increased risk of DM outpatient visits was attributable to high concentration NO2 exposure, while high concentration O3 exposure was associated with a decreased risk of DM outpatient visits. This study provided a scientific basis for the etiology research and health protection of DM.

The Footprint of Microbiome in Pediatric Asthma-A Complex Puzzle for a Balanced Development

Considered to be of greater complexity than the human genome itself, the microbiome, the structure of the body made up of trillions of bacteria, viruses, and fungi, has proven to play a crucial role in the context of the development of pathological processes in the body, starting from various infections, autoimmune diseases, atopies, and culminating in its involvement in the development of some forms of cancer, a diagnosis that is considered the most disabling for the patient from a psychological point of view. Therefore, being a cornerstone in the understanding and optimal treatment of a multitude of ailments, the body's microbiome has become an intensively studied subject in the scientific literature of the last decade. This review aims to bring the microbiome-asthma correlation up to date by classifying asthmatic patterns, emphasizing the development patterns of the microbiome starting from the perinatal period and the impact of pulmonary dysbiosis on asthmatic symptoms in children. Likewise, the effects of intestinal dysbiosis reflected at the level of homeostasis of the internal environment through the intestine-lung/vital organs axis, the circumstances in which it occurs, but also the main methods of studying bacterial variability used for diagnostic purposes and in research should not be omitted. In conclusion, we draw current and future therapeutic lines worthy of consideration both in obtaining and maintaining remission, as well as in delaying the development of primary acute episodes and preventing future relapses.

Ambient particulate matter associates with asthma in high altitude region: A population-based study

Background

Exposure to particulate matter (PM) has been a major public health threat, but the potentially differential effects on asthma of PM remain largely unknown in high altitude settings. We evaluated the effects of ambient PM on asthma in high altitude settings.

Methods

The study recruited a representative sample from high altitude settings using a multistage stratified sampling procedure. Asthma was defined by a self-reported history of diagnosis by a physician or by wheezing symptoms in the preceding 12 months. The annual mean PM_2.5 and PM₁₀ concentrations were calculated for each grid cell at 1-km spatial resolution based on the geographical coordinates.

Results

We analyzed data for participants (mean age 39.1 years, 51.4% female) and 183 (3.7%, 95% confidence interval (CI): 3.2-4.2) of the participants had asthma. Prevalence was higher in women (4.3%, 95% CI 3.5-5.1) than in men (3.1%, 2.4-3.8) and increasing with higher concentration of PM exposures. For an interquartile range (IQR) difference (8.77 μg/m³) in PM_2.5 exposure, the adjusted odds ratio (OR) was 1.64 (95% CI 1.46-1.83, P < 0.001) for risk of asthma. For PM₁₀, there was evidence for an association with risk of asthma (OR 2.34, 95% CI: 1.75-3.15, P < 0.001 per IQR of 43.26 μg/m³). Further analyses showed that household mold or damp exposure may aggravate PM exposure associated risks of asthma.

Conclusions

This study identified that PM exposure could be a dominate environmental risk factor for asthma but largely unconsidered in the high-altitude areas. The association between PM exposure and asthma should be of interest for planners of national policies and encourage programs for prevention of asthma in residents living at high altitudes.

Social Inequities in Exposure to Traffic-Related Air and Noise Pollution at Public Schools in Texas

Although children are particularly vulnerable to the adverse impacts of vehicular pollution and spend significant portions of their time at school, previous studies have not examined or compared school-level social inequities in exposure to both traffic-related air and noise pollution in the same study area. We addressed this gap through a case study in Texas-the second-largest US state based on total population and number of children. Vehicular pollution exposure was measured using: (1) outdoor concentrations of nitrogen dioxide (NO₂), a widely used proxy for traffic-related air pollution; and (2) road noise estimates from the US Department of Transportation's National Transportation Noise Mapping Tool. These variables were linked to data on locations and sociodemographic characteristics of children enrolled in Texas public schools. We found children attending schools with the highest exposure to both NO₂ and road noise (top 25%) were significantly more likely to be Black, Hispanic, and eligible for free/reduced lunches (socioeconomically deprived). Results from multivariable generalized estimating equations that control for spatial clustering and other relevant factors revealed that schools with greater NO₂ exposure were significantly more likely to serve racial/ethnic minority and younger students, while schools with greater exposure to road noise were significantly more likely to serve socioeconomically deprived and older students. These findings underscore the urgent need to reduce both air pollution and noise exposure at school locations, especially in schools attended by higher proportions of socially disadvantaged children that are often additionally burdened with other challenges.

Long-term effect of intermediate particulate matter (PM1-2.5) on incident asthma among middle-aged and elderly adults: A national population-based longitudinal study

BACKGROUND

There is insufficient evidence about the long-term effects of intermediate particulate matter (PM_1-2.5) on asthma development in adults aged 45 years and above. This study aimed to investigate the relationship between long-term exposure to PM_1-2.5 and the incidence of asthma in adults aged 45 years and above.

METHODS

A cohort study based on the China Health and Retirement Longitudinal Study (CHARLS) database was conducted to investigate the long-term effects of PM_1-2.5 on self-reported asthma incidence in adults aged 45 years and above in China from 2011 to 2018. The PM concentrations were estimated using a high-resolution (1 km²) satellite-based spatiotemporal model. A covariate-adjusted generalized linear mixed model was used to analyze the relationship between long-term exposure to PM_1-2.5 and the incidence of asthma. Effect modifications and sensitivity analysis were conducted.

RESULTS

After a 7-year follow-up, 103 (1.61 %) of the 6400 participants developed asthma. Each 10 μg/m³ increment in the 1-, 2-, 3-, and 4-year moving average concentrations of PM_1-2.5 corresponded to a 1.82 [95 % confidence interval (CI):1.11-2.98], 1.95 (95 % CI: 1.24-3.07), 1.95 (95 % CI: 1.26-3.03) and 1.88 (95 % CI: 1.26-2.81) fold risk for incident asthma, respectively. A significant multiplicative interaction was observed between socioeconomic level and long-term exposure to PM_1-2.5. Stratified analysis showed that smokers and those with lower socioeconomic levels were at higher risk of incident asthma related to PM_1-2.5. Restricted cubic splines showed an increasing trend in asthma incidence with increasing PM_1-2.5. Sensitivity analyses showed that our model was robust.

CONCLUSION

Long-term exposure to PM_1-2.5 was positively associated with incident asthma in middle-aged and elderly individuals. Participants with a history of smoking and lower socioeconomic levels had a higher risk. More studies are warranted warrant to establish an accurate reference value of PM_1-2.5 to mitigate the growing asthma burden.

Outdoor air pollution exposure and the risk of asthma and wheezing in the offspring

According to the "fetal origin of disease" hypothesis, air pollution exposure in pregnancy may play an important role in stimulating the early programming of asthma and allergies. However, previous studies reported inconsistent findings. The aim of this meta-analysis was to provide higher grade evidence and quantitatively analyze the link between prenatal exposure to outdoor air pollutants and childhood asthma and wheezing. Databases (Web of Science and PubMed) were extensively searched for articles published from the start of the database to September 15, 2021. Either random-effect model or fixed-effect model was used to estimate the disease-specific relative risks (RR) with the corresponding 95% confidence intervals (CIs) to estimate the association. Newcastle-Ottawa Quality Score (NOS) was used to assess the quality of studies. This study finally included 13 cohort studies, and the findings showed that NO₂ and SO₂ exposure during entire pregnancy was significantly associated with wheezing (RR = 1.032, 95% CI: 1.000, 1.066) and asthma (RR = 1.114, 95% CI: 1.066, 1.164), respectively. Further analyses showed that PM_2.5 were positively associated with asthma in the second (RR = 1.194, 95% CI: 1.143, 1.247) and third trimester (RR = 1.050, 95% CI: 1.007, 1.094), while NO₂ (RR = 1.060, 95% CI: 1.021, 1.101) and SO₂ (RR = 1.067, 95% CI: 1.013, 1.123) were shown positively associated with asthma only in the second trimester. The relationship between wheezing and outdoor air pollutants was not significant in any of the pregnancy subgroups. This study suggests that prenatal exposure of outdoor air pollution may increase the asthma and wheezing risk in the offspring and that the second trimester may be a sensitive period for air pollution exposure. But the interpretation of the causal association is hampered by limited number of studies on dose response.

Di-(2-ethylhexyl) phthalate aggravates fine particulate matter-induced asthma in weanling mice due to T follicular helper cell-dependent response

Environmental pollutants fine particulate matter and di-(2-ethylhexyl) phthalate (DEHP) are believed to be the risk factors for childhood asthma. Allergic asthma is basically an immediate hypersensitivity mediated by IgE, the product of humoral immune response. T follicular helper cells (Tfh) have been newly identified as the crucial T helper cells for supporting B cells to produce immunoglobulins in humoral immunity. Tfh cells are therefore potentially to serve as the diagnostic marker and therapeutic target of immune diseases. In this study, we examined the joint effects of fine particulate matter and DEHP on the initiation and progression of asthma and explored the fundamental role of Tfh cells during the process. Weanling C57BL/6 mice (both sexes) were concurrently exposed to DEHP (intragastric administration at 300 μg/kg) and fine atmospheric particulate matter (mean particle diameter < 4 µm, PM4) (oropharyngeal instillation at 2 mg/kg) once every three days for 30 days (10 times). We found that DEHP displayed adjuvant effects to potentiate PM4 allergen-induced expansion of Tfh and plasma cells, production of serum IgE and IgG1, and occurrence of airway hyper-responsiveness and inflammation. Then PM4 and DEHP co-exposure was performed to Cd4 knock-out mice reconstituted with normal wild-type adoptive Tfh cells or non-Tfh cells. The results of immune adoptive transfusion indicated that the joint immunotoxic effects of PM4 and DEHP were dependent on Tfh cells. We further proved that DEHP could adjuvantly boost PM4-induced expression of BCL-6 and c-MAF and secretion of IL-13 and IL-4 in Tfh cells. In conclusion, these data suggest that DEHP metabolites act in an adjuvant-like manner to aggravate PM4 allergen-induced asthma based on anaphylactic IgE response, resulting from excessive IL-13 and IL-4 synthesized by abnormally differentiated Tfh cells.

Long-term exposure to ambient air pollution and asthma symptom score in the CONSTANCES cohort

BACKGROUND

The asthma symptom score allows to consider asthma as a continuum and to investigate its risk factors. One previous study has investigated the association between asthma score and air pollution and only for nitrogen dioxide (NO₂). We aimed to study the associations between particulate matter with an aerodynamic diameter lower than 2.5 µm (PM_2.5), black carbon (BC) and NO₂ and the asthma symptom score in adults from CONSTANCES, a French population-based cohort.

METHODS

Asthma symptom score (range: 0-5) was based on the number of five self-reported symptoms of asthma in the last 12 months. Annual individual exposure to PM_2.5, BC and NO₂ was estimated at participants' residential address using hybrid land-use regression models. Cross-sectional associations of each pollutant with asthma symptom score were estimated using negative binomial regressions adjusted for age, sex, smoking status and socioeconomic position. Associations with each symptom were estimated using logistic regression. The effect of BC independent of total PM_2.5 was investigated with a residual model.

RESULTS

Analyses were conducted on 135 165 participants (mean age: 47.2 years, 53.3% women, 19.0% smokers, 13.5% ever asthma). The ratio of mean score was 1.12 (95% CI 1.10 to 1.14), 1.14 (95% CI 1.12 to 1.16) and 1.12 (95% CI 1.10 to 1.14) per one IQR increase of PM_2.5 (4.86 µg/m³), BC (0.88 10^-5 m^-1) and NO₂ (17.3 µg/m³). Positive and significant associations were also found for each asthma symptom separately. BC effect persisted independently of total PM_2.5.

CONCLUSION

Exposure to each pollutant was associated with increased asthma symptom score in adults. This study highlights that BC could be one of the most harmful particulate matter components.

Juvenile arsenic exposure aggravates goblet cell hyperplasia and airway mucus secretion in ovalbumin-sensitized mice

Gestational arsenic (As) exposure has been associated with adverse developmental outcomes. The purpose of this study was to explore the impacts of As exposure in different periods on susceptibility to allergic asthma. In model 1, dams were administered with NaAsO₂ (0.1 or 1 ppm) by drinking water throughout pregnancy and lactation. In model 2, newly weaned pups were exposed to NaAsO₂ (1 ppm) through drinking water. Pups were sensitized and challenged with ovalbumin (OVA). Inflammatory cell infiltration and pulmonary T helper 2 (Th2) cytokine upregulation were shown in OVA-sensitized and challenged pups. Goblet cell hyperplasia and airway mucus secretion were observed in OVA-sensitized and challenged pups. Maternal As exposure throughout pregnancy and lactation did not aggravate inflammatory cell infiltration, airway mucus secretion and pulmonary Th2 cytokine upregulation in OVA-sensitized and challenged pups. Although airway hyperreactivity, inflammatory cell infiltration and Th2 cytokine weren't influenced, OVA-evoked Goblet cell hyperplasia and airway mucus secretion were aggravated in pups who were exposed to NaAsO₂ after weaning. In conclusion, juvenile As exposure increases susceptibility to allergic asthma through aggravating Goblet cell hyperplasia and airway mucus secretion. The impacts of maternal As exposure during pregnancy and lactation on susceptibility to allergic asthma needs to be further evaluated in other animal experiments.

Health threat of PM2.5-bound trace elements exposure on asthma hospital admission: A time-stratified case-crossover study

Environmental pollution of trace elements has become of main concern due to the adverse effects. To estimate the impact of PM_2.5-bound trace elements on human health, a time-stratified case-crossover study has been designed to examine the short-term associations between 28 elements and asthma hospitalizations from January 2019 to November 2021 in Xiamen, China. This research summarized the major components that pose health risks in different seasons and took risk assessment for different groups. We found that an inter-quartile range (IQR) increase of Ca, Fe, Mn, Pd, Si, and Ti was positively associated with the incidence of asthma in the lag of 0-4 days. In winter, the elements that predisposed the population to asthma attack were the most, such as Al, Ba, Ca, Cr, Cu, Fe, K, Mn, Pd, Si, and Ti, and these elements are at higher risk for longer periods of time. The discrepancy in risk levels and major elements of asthma diagnosis among various age groups were also found in this work. Our results provided insights into the development of specific policies to reduce the risk of asthma attacks due to exposure to PM_2.5-bound trace elements.

Disparities in Air Pollutants Across Racial, Ethnic, and Poverty Groups at US Public Schools

We investigate socioeconomic disparities in air quality at public schools in the contiguous US using high resolution estimates of fine particulate matter (PM2.5) and nitrogen dioxide (NO2) concentrations. We find that schools with higher proportions of people of color (POC) and students eligible for the federal free or reduced lunch program, a proxy for poverty level, are associated with higher pollutant concentrations. For example, we find that the median annual NO2 concentration for White students, nationally, was 7.7 ppbv, compared to 9.2 ppbv for Black and African American students. Statewide and regional disparities in pollutant concentrations across racial, ethnic, and poverty groups are consistent with nationwide results, where elevated NO2 concentrations were associated with schools with higher proportions of POC and higher levels of poverty. Similar, though smaller, differences were found in PM2.5 across racial and ethnic groups in most states. Racial, ethnic, and economic segregation across the rural-urban divide is likely an important factor in pollution disparities at US public schools. We identify distinct regional patterns of disparities, highlighting differences between California, New York, and Florida. Finally, we highlight that disparities exist not only across urban and non-urban lines but also within urban environments.

Prospects of Probiotic Adjuvant Drugs in Clinical Treatment

In modern society, where new diseases and viruses are constantly emerging, drugs are still the most important means of resistance. However, adverse effects and diminished efficacy remain the leading cause of treatment failure and a major determinant of impaired health-related quality of life for patients. Clinical studies have shown that the disturbance of the gut microbial structure plays a crucial role in the toxic and side effects of drugs. It is well known that probiotics have the ability to maintain the balance of intestinal microecology, which implies their potential as an adjunct to prevent and alleviate the adverse reactions of drugs and to make medicines play a better role. In addition, in the past decade, probiotics have been found to have excellent prevention and alleviation effects in drug toxicity side effects, such as liver injury. In this review, we summarize the development history of probiotics, discuss the impact on drug side effects of probiotics, and propose the underlying mechanisms. Probiotics will be a new star in the world of complementary medicine.

Neighborhood environmental factors linked to hospitalizations of older people for viral lower respiratory tract infections in Spain: a case-crossover study

BACKGROUND

Lower respiratory tract viral infection (LRTI) is a significant cause of morbidity-mortality in older people worldwide. We analyzed the association between short-term exposure to environmental factors (climatic factors and outdoor air pollution) and hospital admissions with a viral LRTI diagnosis in older adults.

METHODS

We conducted a bidirectional case-crossover study in 6367 patients over 65 years of age with viral LRTI and residential zip code in the Spanish Minimum Basic Data Set. Spain's State Meteorological Agency was the source of environmental data. Associations were assessed using conditional logistic regression. P-values were corrected for false discovery rate (q-values).

RESULTS

Almost all were hospital emergency admissions (98.13%), 18.64% were admitted to the intensive care unit (ICU), and 7.44% died. The most frequent clinical discharge diagnosis was influenza (90.25%). LRTI hospital admissions were more frequent when there were lower values of temperature and O₃ and higher values of relative humidity and NO₂. The regression analysis adjusted by temperatures and relative humidity showed higher concentrations at the hospital admission for NO₂ [compared to the lag time of 1-week (q-value< 0.001) and 2-weeks (q-value< 0.001)] and O₃ [compared to the lag time of 3-days (q-value< 0.001), 1-week (q-value< 0.001), and 2-weeks (q-value< 0.001)] were related to a higher odds of hospital admissions due to viral LRTI. Moreover, higher concentrations of PM₁₀ at the lag time of 1-week (q-value = 0.023) and 2-weeks (q-value = 0.002), and CO at the lag time of 3-days (q-value = 0.023), 1-week (q-value< 0.001) and 2-weeks (q-value< 0.001)], compared to the day of hospitalization, were related to a higher chances of hospital admissions with viral LRTI.

CONCLUSION

Unfavorable environmental factors (low temperatures, high relative humidity, and high concentrations of NO₂, O₃, PM₁₀, and CO) increased the odds of hospital admissions with viral LRTI among older people, indicating they are potentially vulnerable to these environmental factors.

Is dietary intake of antioxidant vitamins associated with reduced adverse effects of air pollution on diabetes? Findings from a large cohort study

INTRODUCTION

It remains unknown whether higher dietary intake of antioxidant vitamins could reduce the harmful effects of air pollution on incident diabetes mellitus.

METHODS

A total of 156,490 participants free of diabetes mellitus in the UK Biobank data were included in this analysis. Antioxidant vitamin intake was measured using a 24-h food intake questionnaire, and results were categorized as sufficient or insufficient according to the British Recommended Nutrient Intake. Exposure to fine particles (PM_2.5), thoracic particles (PM₁₀), nitrogen dioxide (NO₂), and nitrogen oxide (NO_x) was estimated using land use regression models at participants' residences. Incident diabetes mellitus was identified using health administrative datasets. Cox regression models were used to assess the associations.

RESULTS

A total of 4271 incident diabetes mellitus cases were identified during a median follow-up of 11.7 years. Compared with participants with insufficient intake of antioxidant vitamins, those with sufficient consumption had a weaker association between air pollution (PM_2.5, PM₁₀ and NO₂) and diabetes mellitus [sufficient vs. insufficient: HR = 1.12 (95 % CI: 0.87, 1.45) vs. 1.69 (95 % CI: 1.42, 2.02) for PM_2.5, 1.00 (95 % CI: 0.88, 1.14) vs. 1.21 (95 % CI: 1.10, 1.34) for PM₁₀, and 1.01 (95 % CI: 0.98, 1.04) vs. 1.05 (95 % CI: 1.03, 1.07) for NO₂ (all p for comparison < 0.05)]. Among different antioxidant vitamins, we observed stronger effects for vitamin C and E.

CONCLUSION

Our study suggests that ambient air pollution is one important risk factor of diabetes mellitus, and sufficient intake of antioxidant vitamins may reduce such adverse effects of air pollution on diabetes mellitus.

Cinnamomum cassia (L.) J.Presl Alleviates Allergic Responses in Asthmatic Mice via Suppression of MAPKs and MMP-9

The prevalence of asthma is gradually increasing, and endangers human health. Many therapeutic agents have been developed to address this concern. Cinnamomum cassia (L.) J.Presl is a traditional herbal remedy in China, Japan, and Korea and used mainly to control common cold, cough, pneumonitis and fever in Donguibogam, a medical encyclopedia of Korea. Therefore, we investigated whether C. cassia (L.) J.Presl extract (CCE) confers protective effects on asthma model induced by ovalbumin (OVA). The animals were received intraperitoneal administration of OVA on day 1 and 14, and then subjected to OVA inhalation from day 21–23. They were orally treated CCE (30 and 100 mg/kg) from day 18–23. CCE administration decreased allergic responses, including airway hyperresponsiveness, eosinophilia, inflammatory cytokine production, and immunoglobulin E in OVA-exposed mice, along with the decline in inflammatory cell count and mucus secretion in respiratory tract. Additionally, CCE suppressed MAPK phosphorylation and MMP-9 expression in OVA-exposed mice. Overall, CCE treatment attenuated allergic responses induced by OVA exposure, which may be connected to the suppression of MAPK phosphorylation.

Impact of air pollutants on hospital visits for pediatric asthma in Fuzhou city, southeast China

Rapid social development in China has resulted in severe air pollution and adverse impacts on people's health. Although studies have been conducted on the relationship between exposure to air pollutants and asthma exacerbation, most studies were performed in relatively heavily polluted areas, while little is known about the effect of air pollutants in less polluted areas. We assessed the effects of air pollutants on the risk of asthma-related outpatient and emergency visits of infants and children aged from 0 to 13 years during 2018 to 2020 in Fuzhou city, southeast China. Data of six air pollutants: sulfur dioxide (SO₂), nitrogen dioxides (NO₂), carbon monoxide (CO), daily maximum 8-h average ozone (O₃-8 h), particulate matter with an aerodynamic diameter ≤ 10 μm (PM₁₀), and particulate matter with an aerodynamic diameter ≤ 2.5 μm (PM_2.5), were obtained from the Environmental Protection Administration of Fuzhou. Data of temperature, humidity, and wind speed were provided by the Meteorological Bureau of Fuzhou. Results revealed that on lag day 6, NO₂, SO₂, and CO were positively associated with the number of outpatient and emergency visits. Among the pollutants, SO₂ had the highest effects on both outpatient visits (RR = 1.672, 95%CI 1.545, 1.809) and emergency visits (RR = 1.495, 95%CI 1.241, 1.800), and its effect on outpatient visits was stronger in children aged 0-4 years than in those aged 5-13 years (RR = 2.331 vs. 1.439). In conclusion, SO₂ contributes substantially to the adverse effects of air pollutants on pediatric respiratory health in Fuzhou. Younger children were more affected by air pollution than their older counterparts.

Ozone-Induced Models of Airway Hyperreactivity and Epithelial Injury

Ozone (O₃), a criterion air pollutant produced as a product of internal combustion, generates increased inflammation, lung permeability, and airway hyperreactivity when exposed to rodents in laboratory settings. Airway hyperreactivity is defined as an exaggerated acute obstructive response of the airways to one or more nonspecific stimuli. Lung permeability is a measure of barrier functions that separate internal and external environments to limit access of pathogens and other noxious material. By modeling in vivo O₃ exposure in rodents, this allows investigators to explore pulmonary and nonpulmonary O₃ effects as a means of understanding its impact on human health and lung function. Furthermore, direct effects of O₃ on epithelial permeability can be defined using in vitro exposures to airway epithelial cells. This chapter will focus on methods of generating O₃ and then exposing rodents and cultured epithelial cells in laboratory settings.

Analysis of Environmental and Pathogenic Bacteria Attached to Aerosol Particles Size-Separated with a Metal Mesh Device

Metal mesh devices (MMDs) are novel materials that enable the precise separation of particles by size. Structurally, MMDs consist of a periodic arrangement of square apertures of characteristic shapes and sizes on a thin nickel membrane. The present study describes the separation of aerosol particles using palm-top-size collection devices equipped with three types of MMDs differing in pore size. Aerosols were collected at a farm located in the suburbs of Nairobi, Kenya; aerosol particles were isolated, and pathogenic bacteria were identified in this microflora by next-generation sequencing analysis. The composition of the microflora in aerosol particles was found to depend on particle size. Gene fragments were obtained from the collected aerosols by PCR using primers specific for the genus Mycobacterium. This analysis showed that Mycobacterium obuense, a non-tuberculous species of mycobacteria that causes lung diseases, was present in these aerosols. These findings showed that application of this MMD analytical protocol to aerosol particles can facilitate the investigation of airborne pathogenic bacteria.

Ozone Exposure and Asthma Attack in Children

Background

Increasing evidence indicated that ozone (O3) exposure could trigger asthma attacks in children. However, the effect of O3 at low concentrations is uncertain.

Purpose

This study aimed to explore the effects of O3 exposure at low concentrations on asthma attacks in children.

Methods

A total of 3,475 children with asthma attacks from the First Affiliated Hospital of Xiamen University were available for the analyses. Air pollution data and meteorological data in Xiamen during 2016-2019 were also collected. A case-crossover design and conditional logistic regression models were conducted to evaluate the association between asthma attacks and outdoor air pollution with lag structures (from lag 0 to lag 6) in both single and multi-pollutant models. Furthermore, we estimated the influence of various levels of O3 exposure on an asthma attack in three groups categorized by maximum daily 8-h sliding average ozone (O3-8 h) (O3-8 h ≥ 100 μg/m3, O3-8 h: 80-99 μg/m3, O3-8 h < 80 μg/m3).

Results

For both single-pollutant models and multi-pollutant models, when O3-8 h was higher than 80 μg/m3, O3 exposure was increased the risk of acute asthma attacks on each day of lag. The effect of O3 on children with asthma was significant when O3 concentration was higher than 100 μg/m3.

Conclusion

O3 concentration above 80 μg/m3 contributed to an increased risk of asthma attacks in children.

Air pollution and hospital admissions for critical illness in emergency department: a tertiary-center research in Changsha, China, 2016-2020

We aimed to comprehensively investigate the associations of air pollutants with hospital admissions for critical illness in ED. Patients with critical illness including level 1 and level 2 of the Emergency Severity Index admitted in ED of Changsha Central Hospital from January 2016 to December 2020 were enrolled. Meteorological and air pollutants data source were collected from the National Meteorological Science Data Center. A Poisson generalized linear regression combined with a polynomial distributed lag model (PDLM) was utilized to explore the effect of air pollution on hospital admissions for critical illness in ED. Benchmarks as references (25th) were conducted for comparisons with high levels of pollutant concentrations (75th). At first, lagged effects of all different air pollutants were analyzed. Then, based on the most significant factor, analyses in subgroups were performed by gender (male and female), age (< 45, 45-65, and > 65), disorders (cardiovascular, neurological, respiratory), and seasons (spring, summer, autumn, and winter). A total of 47,290 patients with critical illness admitted in ED were included. The effects of air pollutants (PM_2.5, PM₁₀, SO₂, NO₂, O₃ and CO) on critical illness ED visits were statistically significant. Strong collinearity between PM_2.5 and PM₁₀ (r = 0.862) was found. Both single-day lag and cumulative-day lag day models showed that PM_2.5 had the strongest effects (lag 0, RR = 1.025, 95% CI 1.008-1.043, and lag 0-14, RR = 1.067, 95% CI 1.017-1.120, respectively). In both PM_2.5 and PM₁₀, the risks of critical illness in male, > 65 ages, respiratory diseases, and winter increased the most significant. Air pollutants, especially PM_2.5 and PM₁₀ exposure, could increase the risk of critical illness admission.

Identifying Louisiana communities at the crossroads of environmental and social vulnerability, COVID-19, and asthma

The COVID-19 pandemic has disproportionately affected the socially and environmentally vulnerable, including through indirect effects on other health conditions. Asthma is one such condition, which may be exacerbated by both prolonged adverse in-home exposures if quarantining in unhealthy homes and prolonged outdoor exposures if the ambient air quality is unhealthy or hazardous. As both are often the case in Environmental Justice (EJ) communities, here we have analyzed data at the census tract (CT) level for Louisiana to assess any correlation between social and environmental vulnerability, and health issues like COVID-19 and asthma. Higher Social Vulnerability Index (SVI), Particulate Matter less than 2.5 μm in diameter (PM2.5) and Ozone levels were associated with higher rates of cumulative COVID-19 incidence at various time points during the pandemic, as well as higher average annual asthma hospitalization rates and estimated asthma prevalence. Further, cumulative COVID-19 incidence during the first three months of the pandemic was moderately correlated with both asthma hospitalizations and estimated prevalence, suggesting similar underlying factors may be affecting both conditions. Additionally, 137 CTs were identified where social and environmental vulnerabilities co-existed, of which 75 (55%) had high estimated prevalence of asthma. These areas are likely to benefit from asthma outreach that considers both social and environmental risk factors. Fifteen out of the 137 CTs (11%) not only had higher estimated prevalence of asthma but also a high burden of COVID-19. Further research in these areas may help to elucidate any common social determinants of health that underlie both asthma and COVID-19 burdens, as well as better clarify the possible role of the environment as related to the COVID-19 burden in Louisiana.

Modeling Air Pollution Health Risk for Environmental Management of an Internationally Important Site: The Salt Range (Kallar Kahar), Pakistan

This study aimed to assess the health effects of emissions released by cement industries and allied activities, such as mining and transportation, in the salt range area of district Chakwal, Pakistan. DISPER was used to estimate dispersion and contribution of source emission by cement industries and allied activities to surface accumulation of selected pollutants (PM2.5, PM10, NOx, and O3). To assess the long-term effects of pollutants on human health within the radius of 500 m to 3 km, Air Q+ software was used, which was designed by the World Health Organization (WHO). One-year average monitoring data of selected pollutants, coordinates, health data, and population data were used as input data for the model. Data was collected on lung cancer mortality among different age groups (25+ and 30+), infant post-neonatal mortality, mortality due to respiratory disease, and all-cause mortality due to PM2.5 and NO2. Results showed that PM2.5 with the year-long concentration of 27.3 µg/m3 contributes a 9.9% attributable proportion (AP) to lung cancer mortality in adults aged 25+, and 13.8% AP in adults age 30+. Baseline incidence is 44.25% per 100,000 population. PM10 with the year-long concentration of 57.4 µg/m3 contributes 16.96% AP to infant post-neonatal mortality and baseline incidence is 53.86% per 1000 live births in the country. NO2 with the year-long concentration of 14.33 µg/m3 contributes 1.73% AP to all-cause mortality. Results obtained by a simulated 10% reduction in pollutant concentration showed that proper mitigation measures for reduction of pollutants’ concentration should be applied to decrease the rate of mortalities and morbidities. Furthermore, the study showed that PM2.5 and PM10 are significantly impacting the human health in the nearby villages, even after mitigation measures were taken by the selected cement industries. The study provides a roadmap to policymakers and stakeholders for environmental and health risk management in the area.

Current Insights into Atopic March

The incidence of allergic diseases is increasing, and research on their epidemiology, pathophysiology, and the prevention of onset is urgently needed. The onset of allergic disease begins in infancy with atopic dermatitis and food allergy and develops into allergic asthma and allergic rhinitis in childhood; the process is defined as “atopic march”. Atopic march is caused by multiple immunological pathways, including allergen exposure, environmental pollutants, skin barrier dysfunction, type 2 inflammation, and oxidative stress, which promote the progression of atopic march. Using recent evidence, herein, we explain the involvement of allergic inflammatory conditions and oxidative stress in the process of atopic march, its epidemiology, and methods for prevention of onset.