The effects of traffic-related air pollutants on chronic obstructive pulmonary disease in the community-based general population

Prevalence and etiotypes of persistent airflow obstruction in the general population across the lifetime

BACKGROUND AND OBJECTIVES

Different factors (etiotypes) can lead to persistent airflow obstruction (PAO) across the lifetime, including genetic factors, abnormal lung development, cigarette smoking, traffic pollution exposure, respiratory infections and asthma. Here we explore the prevalence of PAO and associated etiotypes in the general population in different age bins.

METHODS

We studied 664 individuals with PAO (FEV1/FVC post bronchodilation (post-BD) below the lower limit of normal (LLN)) and 11,522 with normal lung function (FEV1/FVC, FEV1 and FVC ≥ LLN and ≤ upper limit of normal (ULN) post-BD) included in the LEAD Study (NCT01727518), a general population cohort in Vienna (Austria). For analysis, participants were stratified in three age bins (<25, 25-<50 and ≥ 50 years of age).

RESULTS

PAO occurred in 3.8 % in females and 5.6 % in males of the cohort, and it increased with age. Most participants with PAO (57.5 %) reported respiratory symptoms, indicating a high burden of disease. PAO was associated with male sex (25-<50 years), ever smoking (>50 years), increased number of pack years (25-<50 years, >50 years), not being breastfed (<25 years) and ever diagnosis of asthma (in all age bins). Etiotypes varied by age bins with cigarette smoking being the most prevalent one, often in combination with traffic pollution exposure.

CONCLUSION

In the general population PAO occurs in about 5 % of participants with a higher prevalence in older individuals. Etiotypes and associated factors for PAO accumulate with age.

Controlled human exposures: a review and comparison of the health effects of diesel exhaust and wood smoke

One of the most pressing issues in global health is air pollution. Emissions from traffic-related air pollution and biomass burning are two of the most common sources of air pollution. Diesel exhaust (DE) and wood smoke (WS) have been used as models of these pollutant sources in controlled human exposure (CHE) experiments. The aim of this review was to compare the health effects of DE and WS using results obtained from CHE studies. A total of 119 CHE-DE publications and 25 CHE-WS publications were identified for review. CHE studies of DE generally involved shorter exposure durations and lower particulate matter concentrations, and demonstrated more potent dysfunctional outcomes than CHE studies of WS. In the airways, DE induces neutrophilic inflammation and increases airway hyperresponsiveness, but the effects of WS are unclear. There is strong evidence that DE provokes systemic oxidative stress and inflammation, but less evidence exists for WS. Exposure to DE was more prothrombotic than WS. DE generally increased cardiovascular dysfunction, but limited evidence is available for WS. Substantial heterogeneity in experimental methodology limited the comparison between studies. In many areas, outcomes of WS exposures tended to trend in similar directions to those of DE, suggesting that the effects of DE exposure may be useful for inferring possible responses to WS. However, several gaps in the literature were identified, predominantly pertaining to elucidating the effects of WS exposure. Future studies should strongly consider performing head-to-head comparisons between DE and WS using a CHE design to determine the differential effects of these exposures.

APOE-ε4 Alleles Modify the Decline of MMSE Scores Associated With Time-Dependent PM2.5 Exposure: Findings From a Community-Based Longitudinal Cohort Study

OBJECTIVE

Limited research has explored the long-term effect of reduced PM2.5 exposure on cognitive function. This study aimed to investigate the effects of time-dependent PM2.5 exposure and the interactions of PM2.5 and aging on declines in Mini-Mental State Examination (MMSE) scores, in carriers and non-carriers of the APOE-ε4 allele.

METHODS

Participants aged over 60 were recruited for this cohort study, undergoing MMSE tests twice from the Taiwan Biobank Program from 2008 to 2020. Participants with dementia or baseline MMSE scores <24 were excluded. Annual PM2.5 levels were estimated using a hybrid kriging/land use regression model with extreme gradient boosting, treated as a time-dependent variable. Generalized estimating equations were used to assess the impacts of repeated PM2.5 on MMSE decline, further stratified by the presence of APOE-ε4 alleles.

RESULTS

After follow-up, 290 participants out of the overall 7,000 community residents in the Biobank dataset demonstrated incidences of MMSE declines (<24), with an average MMSE score decline of 1.11 per year. Participants with ε4/ε4 alleles in the APOE gene had significantly 3.68-fold risks of MMSE decline. High levels of PM2.5 across all visits were significantly associated with worsening of scores on the overall MMSE. As annual levels of PM2.5 decreased over time, the impact of PM2.5 on MMSE decline also slowly diminished.

CONCLUSION

Long-term PM2.5 exposure may be associated with increased risk of MMSE decline, despite improvements in ambient PM2.5 levels over time. Validation of these results necessitates a large-scale prospective cohort study with more concise cognitive screening tools.

The impact of air pollution on respiratory diseases in an era of climate change: A review of the current evidence

The impacts of climate change and air pollution on respiratory diseases present significant global health challenges. This review aims to investigate the effects of the interactions between these challenges focusing on respiratory diseases. Climate change is predicted to increase the frequency and intensity of extreme weather events amplifying air pollution levels and exacerbating respiratory diseases. Air pollution levels are projected to rise due to ongoing economic growth and population expansion in many areas worldwide, resulting in a greater burden of respiratory diseases. This is especially true among vulnerable populations like children, older adults, and those with pre-existing respiratory disorders. These challenges induce inflammation, create oxidative stress, and impair the immune system function of the lungs. Consequently, public health measures are required to mitigate the effects of climate change and air pollution on respiratory health. The review proposes that reducing greenhouse gas emissions contribute to slowing down climate change and lessening the severity of extreme weather events. Enhancing air quality through regulatory and technological innovations also helps reduce the morbidity of respiratory diseases. Moreover, policies and interventions aimed at improving healthcare access and social support can assist in decreasing the vulnerability of populations to the adverse health effects of air pollution and climate change. In conclusion, there is an urgent need for continuous research, establishment of policies, and public health efforts to tackle the complex and multi-dimensional challenges of climate change, air pollution, and respiratory health. Practical and comprehensive interventions can protect respiratory health and enhance public health outcomes for all.

Comparison of the association between different ozone indicators and daily respiratory hospitalization in Guangzhou, China

Background

Epidemiological studies have widely proven the impact of ozone (O₃) on respiratory mortality, while only a few studies compared the association between different O₃ indicators and health.

Methods

This study explores the relationship between daily respiratory hospitalization and multiple ozone indicators in Guangzhou, China, from 2014 to 2018. It uses a time-stratified case-crossover design. Sensitivities of different age and gender groups were analyzed for the whole year, the warm and the cold periods. We compared the results from the single-day lag model and the moving average lag model.

Results

The results showed that the maximum daily 8 h average ozone concentration (MDA8 O₃) had a significant effect on the daily respiratory hospitalization. This effect was stronger than for the maximum daily 1 h average ozone concentration (MDA1 O₃). The results further showed that O₃ was positively associated with daily respiratory hospitalization in the warm season, while there was a significantly negative association in the cold season. Specifically, in the warm season, O₃ has the most significant effect at lag 4 day, with the odds ratio (OR) equal to 1.0096 [95% confidence intervals (CI): 1.0032, 1.0161]. Moreover, at the lag 5 day, the effect of O₃ on the 15-60 age group was less than that on people older than 60 years, with the OR value of 1.0135 (95% CI: 1.0041, 1.0231) for the 60+ age group; women were more sensitive than men to O₃ exposure, with an OR value equal to 1.0094 (95% CI: 0.9992, 1.0196) for the female group.

Conclusion

These results show that different O₃ indicators measure different impacts on respiratory hospitalization admission. Their comparative analysis provided a more comprehensive insight into exploring associations between O₃ exposure and respiratory health.

The Effects and Pathogenesis of PM2.5 and Its Components on Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD), a heterogeneous disease, is the leading cause of death worldwide. In recent years, air pollution, especially particulate matter (PM), has been widely studied as a contributing factor to COPD. As an essential component of PM, PM2.5 is associated with COPD prevalence, morbidity, and acute exacerbations. However, the specific pathogenic mechanisms were still unclear and deserve further research. The diversity and complexity of PM2.5 components make it challenging to get its accurate effects and mechanisms for COPD. It has been determined that the most toxic PM2.5 components are metals, polycyclic aromatic hydrocarbons (PAHs), carbonaceous particles (CPs), and other organic compounds. PM2.5-induced cytokine release and oxidative stress are the main mechanisms reported leading to COPD. Nonnegligibly, the microorganism in PM 2.5 may directly cause mononuclear inflammation or break the microorganism balance contributing to the development and exacerbation of COPD. This review focuses on the pathophysiology and consequences of PM2.5 and its components on COPD.

Mechanisms of Lung Damage and Development of COPD Due to Household Biomass-Smoke Exposure: Inflammation, Oxidative Stress, MicroRNAs, and Gene Polymorphisms

Chronic exposure to indoor biomass smoke from the combustion of solid organic fuels is a major cause of disease burden worldwide. Almost 3 billion people use solid fuels such as wood, charcoal, and crop residues for indoor cooking and heating, accounting for approximately 50% of all households and 90% of rural households globally. Biomass smoke contains many hazardous pollutants, resulting in household air pollution (HAP) exposure that often exceeds international standards. Long-term biomass-smoke exposure is associated with Chronic Obstructive Pulmonary Disease (COPD) in adults, a leading cause of morbidity and mortality worldwide, chronic bronchitis, and other lung conditions. Biomass smoke-associated COPD differs from the best-known cigarette smoke-induced COPD in several aspects, such as a slower decline in lung function, greater airway involvement, and less emphysema, which suggests a different phenotype and pathophysiology. Despite the high burden of biomass-associated COPD, the molecular, genetic, and epigenetic mechanisms underlying its pathogenesis are poorly understood. This review describes the pathogenic mechanisms potentially involved in lung damage, the development of COPD associated with wood-derived smoke exposure, and the influence of genetic and epigenetic factors on the development of this disease.

Reductions in NO2 and emergency room visits associated with California's goods movement policies: A quasi-experimental study

INTRODUCTION

This study examines whether the "Emission Reduction Plan for Ports and Goods Movement" in California reduced air pollution exposures and emergency room visits among California Medicaid enrollees with asthma and/or chronic obstructive pulmonary disease.

METHOD

We created a retrospective cohort of 5608 Medicaid enrollees from ten counties in California with data from 2004 to 2010. We grouped the patients into two groups: those living within 500 m of goods movement corridors (ports and truck-permitted freeways), and control areas (away from the busy truck or car permitted highways). We created annual air pollution surfaces for nitrogen dioxide and assigned them to enrollees' home addresses. We used a quasi-experimental design with a difference-in-differences method to examine changes before and after the policy for cohort beneficiaries in the two groups.

RESULTS

The reductions in nitrogen dioxide exposures and emergency room visits were greater for enrollees in goods movement corridors than those in control areas in post-policy years. We found that the goods movement actions were associated with 14.8% (95% CI, -24.0% to -4.4%; P = 0.006) and 11.8% (95% CI, -21.2% to -1.2%; P = 0.030) greater reduction in emergency room visits for the beneficiaries with asthma and chronic obstructive pulmonary disease, respectively, in the third year after California's emission reduction plan.

CONCLUSION

These findings indicate remarkable health benefits via reduced emergency room visits from the significantly improved air quality due to public policy interventions for disadvantaged and susceptible populations.

Establishment of Repeated In Vitro Exposure System for Evaluating Pulmonary Toxicity of Representative Criteria Air Pollutants Using Advanced Bronchial Mucosa Models

There is mounting evidence that shows the association between chronic exposure to air pollutants (particulate matter and gaseous) and onset of various respiratory impairments. However, the corresponding toxicological mechanisms of mixed exposure are poorly understood. Therefore, in this study, we aimed to establish a repeated exposure setting for evaluating the pulmonary toxicological effects of diesel exhaust particles (DEP), nitrogen dioxide (NO2), and sulfur dioxide (SO2) as representative criterial air pollutants. Single, combined (DEP with NO2 and SO2), and repeated exposures were performed using physiologically relevant human bronchial mucosa models developed at the air−liquid interface (bro-ALI). The bro-ALI models were generated using human primary bronchial epithelial cells (3−4 donors; 2 replicates per donor). The exposure regime included the following: 1. DEP (12.5 µg/cm2; 3 min/day, 3 days); 2. low gaseous (NO2: 0.1 ppm + SO2: 0.2 ppm); (30 min/day, 3 days); 3. high gaseous (NO2: 0.2 ppm + SO2: 0.4 ppm) (30 min/day, 3 days); and 4. single combined (DEP + low gaseous for 1 day). The markers for pro-inflammatory (IL8, IL6, NFKB, TNF), oxidative stress (HMOX1, GSTA1, SOD3,) and tissue injury/repair (MMP9, TIMP1) responses were assessed at transcriptional and/ or secreted protein levels following exposure. The corresponding sham-exposed samples under identical conditions served as the control. A non-parametric statistical analysis was performed and p < 0.05 was considered as significant. Repeated exposure to DEP and single combined (DEP + low gaseous) exposure showed significant alteration in the pro-inflammatory, oxidative stress and tissue injury responses compared to repeated exposures to gaseous air pollutants. The study demonstrates that it is feasible to predict the long-term effects of air pollutants using the above explained exposure system.