Associations of ambient air pollution with chronic obstructive pulmonary disease hospitalization and mortality

Global associations between long-term exposure to PM2.5 constituents and health: A systematic review and meta-analysis of cohort studies

Existing studies on the most impactful component remain controversial, hindering the optimization of future air quality standards that concerns particle composition. We aimed to summarize the health risk associated with PM2.5 components and identify those components with the greatest health risk. We performed a meta-analysis to quantify the combined health effects of PM2.5 components, and used the meta-smoothing to produce the pooled concentration-response (C-R) curves. Out of 8954 initial articles, 80 cohort studies met the inclusion criteria, including a total of 198.08 million population. The pooled C-R curves demonstrated approximately J-shaped association between total mortality and exposure to BC, and NO3-, but U-shaped and inverted U-shaped relationship withSO42- and OC, respectively. In addition, this study found that exposure to various elements, including BC,SO42-NO3-, NH4+, Zn, Ni, and Si, were significantly associated with an increased risk of total mortality, with Ni presenting the largest estimate. And exposure to NO3-, Zn, and Si was positively associated with an increased risk of respiratory mortality, while exposure to BC, SO42-, and NO3- showed a positive association with risk of cardiovascular mortality. For health outcome of morbidity, BC was notably associated with a higher incidence of asthma, type 2 diabetes and stroke. Subgroup analysis revealed a higher susceptibility to PM2.5 components in Asia compared to Europe and North America, and females showed a higher vulnerability. Given the significant health effects of PM2.5 components, governments are advised to introduce them in regional monitoring and air quality control guidelines. ENVIRONMENTAL IMPLICATION: PM2.5 is a complex mixture of chemical components from various sources, and each component has unique physicochemical properties and uncertain toxicity, posing significant threat to public health. This study systematically reviewed cohort studies on the association between long-term exposure to 13 PM2.5 components and the risk of morbidity and mortality. And we applied the meta-smoothing approach to establish the pooled concentration-response associations between PM2.5 components and mortality globally. Our findings will provide strong support for PM2.5 components monitoring and the improvement of air quality-related regulations. This will aid in helping to enhance health intervention strategies and mitigating public exposure to detrimental particulate matter.

Long-term exposure to air pollution on cardio-respiratory, and lung cancer mortality: a systematic review and meta-analysis

Air pollution is a major cause of specific deaths worldwide. This review article aimed to investigate the results of cohort studies for air pollution connected with the all-cause, cardio-respiratory, and lung cancer mortality risk by performing a meta-analysis. Relevant cohort studies were searched in electronic databases (PubMed/Medline, Web of Science, and Scopus). We used a random effect model to estimate the pooled relative risks (RRs) and their 95% CIs (confidence intervals) of mortality. The risk of bias for each included study was also assessed by Office of Health Assessment and Translation (OHAT) checklists. We applied statistical tests for heterogeneity and sensitivity analyses. The registration code of this study in PROSPERO was CRD42023422945. A total of 88 cohort studies were eligible and included in the final analysis. The pooled relative risk (RR) per 10 μg/m3 increase of fine particulate matter (PM2.5) was 1.080 (95% CI 1.068-1.092) for all-cause mortality, 1.058 (95% CI 1.055-1.062) for cardiovascular mortality, 1.066 (95%CI 1.034-1.097) for respiratory mortality and 1.118 (95% CI 1.076-1.159) for lung cancer mortality. We observed positive increased associations between exposure to PM2.5, PM10, black carbon (BC), and nitrogen dioxide (NO2) with all-cause, cardiovascular and respiratory diseases, and lung cancer mortality, but the associations were not significant for nitrogen oxides (NOx), sulfur dioxide (SO2) and ozone (O3). The risk of mortality for males and the elderly was higher compared to females and younger age. The pooled effect estimates derived from cohort studies provide substantial evidence of adverse air pollution associations with all-cause, cardiovascular, respiratory, and lung cancer mortality.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40201-024-00900-6.

Fine particulate matter aggravates smoking induced lung injury via NLRP3/caspase-1 pathway in COPD

BACKGROUND

Exposure to noxious particles, including cigarette smoke and fine particulate matter (PM2.5), is a risk factor for chronic obstructive pulmonary disease (COPD) and promotes inflammation and cell death in the lungs. We investigated the combined effects of cigarette smoking and PM2.5 exposure in patients with COPD, mice, and human bronchial epithelial cells.

METHODS

The relationship between PM2.5 exposure and clinical parameters was investigated in patients with COPD based on smoking status. Alveolar destruction, inflammatory cell infiltration, and pro-inflammatory cytokines were monitored in the smoking-exposed emphysema mouse model. To investigate the mechanisms, cell viability and death and pyroptosis-related changes in BEAS-2B cells were assessed following the exposure to cigarette smoke extract (CSE) and PM2.5.

RESULTS

High levels of ambient PM2.5 were more strongly associated with high Saint George's respiratory questionnaire specific for COPD (SGRQ-C) scores in currently smoking patients with COPD. Combined exposure to cigarette smoke and PM2.5 increased mean linear intercept and TUNEL-positive cells in lung tissue, which was associated with increased inflammatory cell infiltration and inflammatory cytokine release in mice. Exposure to a combination of CSE and PM2.5 reduced cell viability and upregulated NLRP3, caspase-1, IL-1β, and IL-18 transcription in BEAS-2B cells. NLRP3 silencing with siRNA reduced pyroptosis and restored cell viability.

CONCLUSIONS

PM2.5 aggravates smoking-induced airway inflammation and cell death via pyroptosis. Clinically, PM2.5 deteriorates quality of life and may worsen prognosis in currently smoking patients with COPD.

COPD Exposed to Air Pollution: A Path to Understand and Protect a Susceptible Population

TOPIC IMPORTANCE

Air pollution poses a risk to the respiratory health of individuals with COPD. Long- and short-term exposures to higher levels of particulate-rich air pollution are associated with increased COPD exacerbation, hospitalization, and mortality, collectively implicating air pollution as a cause of adverse COPD-related outcomes.

REVIEW FINDINGS

This review summarizes the evidence for COPD as a phenotype that confers susceptibility for adverse health outcomes in the face of common air pollution. We highlight how typical contributors to compromised urban air quality, including that from traffic, wildfire smoke, and indoor biomass combustion, adversely affect the COPD patient population. Evidence underscoring the burden of ongoing air pollution exposure on patients with COPD is discussed. We then detail the detrimental impact of that exposure on COPD pathophysiology, which in turn increases the patient's susceptibility. We specifically propose that indoor air is a particularly rational target for increased monitoring and remediation to protect patients with COPD. Because COPD is a heterogeneous disease with several endotypes, future intervention studies need to better include control populations, to highlight COPD-specific risks and identify subpopulations within patients with COPD who will benefit the most from improved indoor air quality.

SUMMARY

Regulatory efforts must continue to broadly lower emission standards to protect this susceptible population from the negative health impacts of air pollution.

Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2023 Guidelines Reviewed

The Global Initiative for Chronic Obstructive Lung Disease (GOLD) report is an essential resource for all clinicians who strive to provide optimal care to patients with chronic obstructive lung disease (COPD). The annual report of GOLD makes few revisions and updates besides including data from the preceding year. At an interval, GOLD comes up with a significant modification in its guidelines, which is generally a major overhaul of the pre-existing guidelines. According to the latest 2023 updates, published in November 2022, there have been significant advancements made in the field of COPD. These include the development of more precise definitions for COPD and its exacerbations, the introduction of a new set of parameters to measure exacerbation severity, and updating the COPD assessment tool. Additionally, revisions have been made to the initial and follow-up treatment guidelines. The report also simplifies the treatment algorithm and sheds light on new findings that suggest the use of pharmacological triple therapy can reduce mortality rates. Furthermore, the report includes discussions on inhaler device selection and adherence to COPD medications. These improvements demonstrate a continued effort to enhance COPD treatment and management. Although there are some areas that could benefit from more detailed guidance and explanation, such as the proper utilization of blood eosinophil counts for treatment decisions, and the establishment of treatment protocols post-hospitalization, the latest modifications to the GOLD recommendations will undoubtedly aid healthcare providers in addressing any gaps in patient care. We aim to highlight key changes in the GOLD 2023 report and present a viewpoint about their potential implications in a real-world clinical scenario.

Biomarkers of the relationship of particulate matter exposure with the progression of chronic respiratory diseases

A high level of particulate matter (PM) in air is correlated with the onset and development of chronic respiratory diseases. We conducted a systematic literature review, searching the MEDLINE, EMBASE, and Cochrane databases for studies of biomarkers of the effect of PM exposure on chronic respiratory diseases and the progression thereof. Thirty-eight articles on biomarkers of the progression of chronic respiratory diseases after exposure to PM were identified, four of which were eligible for review. Serum, sputum, urine, and exhaled breath condensate biomarkers of the effect of PM exposure on chronic obstructive pulmonary disease (COPD) and asthma had a variety of underlying mechanisms. We summarized the functions of biomarkers linked to COPD and asthma and their biological plausibility. We identified few biomarkers of PM exposure-related progression of chronic respiratory diseases. The included studies were restricted to those on biomarkers of the relationship of PM exposure with the progression of chronic respiratory diseases. The predictive power of biomarkers of the effect of PM exposure on chronic respiratory diseases varies according to the functions of the biomarkers.

Exposure to outdoor particulate matter and risk of respiratory diseases: a systematic review and meta-analysis

According to epidemiological studies, particulate matter (PM) is an important air pollutant that poses a significant threat to human health. The relationship between particulate matter and respiratory diseases has been the subject of numerous studies, but these studies have produced inconsistent findings. The purpose of this systematic review was to examine the connection between outdoor particulate matter (PM2.5 and PM10) exposure and respiratory disorders (COPD, lung cancer, LRIs, and COVID-19). For this purpose, we conducted a literature search between 2012 and 2022 in PubMed, Web of Science, and Scopus. Out of the 58 studies that were part of the systematic review, meta-analyses were conducted on 53 of them. A random effect model was applied separately for each category of study design to assess the pooled association between exposure to PM2.5 and PM10 and respiratory diseases. Based on time-series and cohort studies, which are the priorities of the strength of evidence, a significant relationship between the risk of respiratory diseases (COPD, lung cancer, and COVID-19) was observed (COPD: pooled HR = 1.032, 95% CI: 1.004-1.061; lung cancer: pooled HR = 1.017, 95% CI: 1.015-1.020; and COVID-19: pooled RR = 1.004, 95% CI: 1.002-1.006 per 1 μg/m3 increase in PM2.5). Also, a significant relationship was observed between PM10 and respiratory diseases (COPD, LRIs, and COVID-19) based on time-series and cohort studies. Although the number of studies in this field is limited, which requires more investigations, it can be concluded that outdoor particulate matter can increase the risk of respiratory diseases.

Health burden associated with tillage-related PM2.5 pollution in the United States, and mitigation strategies

Exposure to airborne particulate matter of diameter less than 2.5 μm (PM2.5) is associated with cardiovascular diseases (CVD) and chronic obstructive pulmonary disease (COPD). In agriculture, the practice of tilling generates PM2.5 emissions that can jeopardize human health. This paper estimates the annual deaths and disability-adjusted life years (DALYs) from CVD and COPD attributable to PM2.5 emissions from corn, soybean, cotton, and wheat tillage in the contiguous United States. Primary PM2.5 from crop-tillage combination was calculated using values obtained from the Environmental Protection Agency's National Emissions Inventory, 2017, while deaths and DALYs estimates were calculated using data from the Institute of Health Metrics and Evaluation's global burden of risk factors study, the US decennial census, and the US Centers for Disease Control. We also propose and implement a conceptual framework for identifying the optimal subsidy upon accounting for health benefits arising from reducing conventional tillage, and we discuss strategies to achieve conservation tillage. Annual PM2.5 emissions from crop tillage is about 0.25 million tons. We estimate that approximately 1000 annual deaths and 22,000 DALYs from CVD, as well as 300 annual deaths and 7400 DALYs from COPD, were attributable to tillage-related PM2.5 emissions. Tillage related primary PM2.5 emissions contribute about 0.002 % of total CVD and COPD deaths in the United States, and its related health economic value loss is about 12.9 billion USD annually. About 350 annual deaths may be averted upon a shift from conventional to conservation tillage. Conservation tillage is generally adopted when the pecuniary and soil health benefits exceed those from adopting intensive tillage. Agricultural policies and on-farm measures that may help reduce intensive tillage, and the related PM2.5 emissions, include subsidies for adopting conservation tillage and carbon capture credits, use of herbicides and herbicide-tolerant crops, protecting herbicide-tolerance traits, planting cover crops, and use of windbreaks.

Computational Tools for Handling Molecular Clusters: Configurational Sampling, Storage, Analysis, and Machine Learning

Computational modeling of atmospheric molecular clusters requires a comprehensive understanding of their complex configurational spaces, interaction patterns, stabilities against fragmentation, and even dynamic behaviors. To address these needs, we introduce the Jammy Key framework, a collection of automated scripts that facilitate and streamline molecular cluster modeling workflows. Jammy Key handles file manipulations between varieties of integrated third-party programs. The framework is divided into three main functionalities: (1) Jammy Key for configurational sampling (JKCS) to perform systematic configurational sampling of molecular clusters, (2) Jammy Key for quantum chemistry (JKQC) to analyze commonly used quantum chemistry output files and facilitate database construction, handling, and analysis, and (3) Jammy Key for machine learning (JKML) to manage machine learning methods in optimizing molecular cluster modeling. This automation and machine learning utilization significantly reduces manual labor, greatly speeds up the search for molecular cluster configurations, and thus increases the number of systems that can be studied. Following the example of the Atmospheric Cluster Database (ACDB) of Elm (ACS Omega, 4, 10965-10984, 2019), the molecular clusters modeled in our group using the Jammy Key framework have been stored in an improved online GitHub repository named ACDB 2.0. In this work, we present the Jammy Key package alongside its assorted applications, which underline its versatility. Using several illustrative examples, we discuss how to choose appropriate combinations of methodologies for treating particular cluster types, including reactive, multicomponent, charged, or radical clusters, as well as clusters containing flexible or multiconformer monomers or heavy atoms. Finally, we present a detailed example of using the tools for atmospheric acid-base clusters.

Indoor (residential) and ambient particulate matter associations with urinary oxidative stress biomarkers in a COPD cohort

OBJECTIVES

Oxidative stress contributes to chronic obstructive pulmonary disease (COPD) pathophysiology. Associations between indoor (residential) exposure to particulate matter ≤2.5 μm in diameter (PM2.5) and one of its components, black carbon (BC), and oxidative stress are ill-defined.

METHODS

Between 2012 and 2017, 140 patients with COPD completed in-home air sampling over one week intervals, followed by collection of urine samples to measure oxidative stress biomarkers, malondialdehyde (MDA), a marker of lipid peroxidation, and 8-hydroxy-2' -deoxyguanosine (8-OHdG), a marker of oxidative DNA damage. Ambient (central site) BC and PM2.5 were measured, and the ratio of indoor/ambient sulfur in PM2.5, a surrogate for residential ventilation and particle infiltration, was used to estimate indoor BC and PM2.5 of outdoor origin. Mixed effects linear regression models with a participant-specific random intercept were used to assess associations with oxidative biomarkers, adjusting for personal characteristics.

RESULTS

There were positive associations (% increase per IQR; 95 % CI) of directly measured indoor BC with total MDA (6.96; 1.54, 12.69) and 8-OHdG (4.18; -0.67, 9.27), and similar associations with both indoor BC of outdoor origin and ambient BC. There were no associations with directly measured indoor PM2.5, but there were positive associations between indoor PM2.5 of outdoor origin and total MDA (5.40; -0.91, 12.11) and 8-OHdG (8.02; 2.14, 14.25).

CONCLUSIONS

In homes with few indoor combustion sources, directly measured indoor BC, estimates of indoor BC and PM2.5 of outdoor origin, and ambient BC, were positively associated with urinary biomarkers of oxidative stress. This suggests that the infiltration of particulate matter from outdoor sources, attributable to traffic and other sources of combustion, promotes oxidative stress in COPD patients.

The association of long-term exposure to outdoor air pollution with all-cause GP visits and hospital admissions by ethnicity and country of birth in the United Kingdom

BACKGROUND

Air pollution is associated with poor health. Yet, more research is needed to reveal the association of long-term exposure to outdoor air pollution with less studied health outcomes like hospital admissions and general-practitioner (GP) visits and whether this association is stronger for ethnic minorities compared to the rest of population. This study investigates the association between air pollution and all-cause GP visits and hospital admissions by ethnicity in the United-Kingdom (UK).

METHODS

We used individual-level longitudinal data from the "UK Household Longitudinal Study" including 46,442 adult individuals who provided 140,466 responses across five years (2015-2019). This data was linked to yearly concentrations of NO2, SO2, and particulate-matter (PM10, PM2.5) outdoor pollution using the Lower Super Output Area (LSOA) of residence for each individual. Multilevel mixed-effects ordered logistic models were used to assess the association between air pollution and all-cause GP visits and hospital admissions.

RESULTS

We found higher odds of hospital admissions per 1 μg/m3 increase in annual concentrations of NO2 (OR = 1.008; 95%CI = 1.004-1.012), SO2 (OR = 1.048; 95%CI = 1.014-1.083), PM10 (OR = 1.011; 95%CI = 1.003-1.018), and PM2.5 (OR = 1.018; 95%CI = 1.007-1.029) pollutants. Higher odds of GP visits were also observed with increased exposure to NO2 (OR = 1.010; 95%CI = 1.006-1.014) and SO2 (OR = 1.114; 95%CI = 1.077-1.152) pollutants. The observed associations did not differ across ethnic groups, but by country of birth, they were more pronounced in individuals born outside UK than those born in UK.

CONCLUSION

This study supports an association between higher exposure to outdoor air pollution and increased all-cause hospital admissions and GP visits. Further longitudinal studies with longer follow-up time periods may be able to reveal more definite conclusions on the influence of ethnicity on the association between long-term outdoor air pollution and both hospital admissions and GP visits.

Evaluation of Potential Effects of Increased Outdoor Temperatures Due to Global Warming on Cerebral Blood Flow Rate and Respiratory Function in Chronic Obstructive Disease and Anemia

Global warming due to increased outdoor carbon dioxide (CO2) levels may cause several health problems such as headaches, cognitive impairment, or kidney dysfunction. It is predicted that further increases in CO2 levels will increase the morbidity and mortality of patients affected by a variety of diseases. For instance, patients with Chronic Obstructive Pulmonary Disease (COPD) may suffer cognitive impairments or intracranial bleeding due to an increased cerebral blood flow rate. Predicting the harmful effects of global warming on human health will help to take measures for potential problems. Therefore, the quantification of physiological parameters is an essential step to investigate the effects of global warming on human health. In this study, the effects of increased outdoor temperatures due to climate change on cerebral blood flow rate and respiratory function in healthy subjects and COPD patients with anemia and respiratory acidosis are evaluated utilizing numerical simulations. The numerical model simulates cardiac function and blood circulation in systemic, pulmonary and cerebral circulations, cerebral autoregulatory functions, respiratory function, alveolar gas exchange, oxygen (O2) and CO2 contents, and hemoglobin levels in the blood. The simulation results show that although the cardiovascular function is not significantly altered, the respiratory function and cerebral blood flow rates are altered remarkably.

Air pollution induces pyroptosis of human monocytes through activation of inflammasomes and Caspase-3-dependent pathways

According to the World Health Organization (WHO), air pollution is one of the most serious threats for our planet. Despite a growing public awareness of the harmful effects of air pollution on human health, the specific influence of particulate matter (PM) on human immune cells remains poorly understood. In this study, we investigated the effect of PM on peripheral blood monocytes in vitro. Monocytes from healthy donors (HD) were exposed to two types of PM: NIST (SRM 1648a, standard urban particulate matter from the US National Institute for Standards and Technology) and LAP (SRM 1648a with the organic fraction removed). The exposure to PM-induced mitochondrial ROS production followed by the decrease of mitochondrial membrane potential and activation of apoptotic protease activating factor 1 (Apaf-1), Caspase-9, and Caspase-3, leading to the cleavage of Gasdermin E (GSDME), and initiation of pyroptosis. Further analysis showed a simultaneous PM-dependent activation of inflammasomes, including NLRP3 (nucleotide-binding oligomerization domain-like receptor pyrin domain containing 3) and Caspase-1, followed by cleavage of Gasdermin D (GSDMD) and secretion of IL-1β. These observations suggest that PM-treated monocytes die by pyroptosis activated by two parallel signaling pathways, related to the inorganic and organic PM components. The release of IL-1β and expression of danger-associated molecular patterns (DAMPs) by pyroptotic cells further activated the remnant viable monocytes to produce inflammatory cytokines (TNF-α, IL-6, IL-8) and protected them from death induced by the second challenge with PM.In summary, our report shows that PM exposure significantly impacts monocyte function and induces their death by pyroptosis. Our observations indicate that the composition of PM plays a crucial role in this process-the inorganic fraction of PM is responsible for the induction of the Caspase-3-dependent pyroptotic pathway. At the same time, the canonical inflammasome path is activated by the organic components of PM, including LPS (Lipopolysaccharide/endotoxin). PM-induced pyroptosis of human monocytes. Particulate matter (PM) treatment affects monocytes viability already after 15 min of their exposure to NIST or LAP in vitro. The remnant viable monocytes in response to danger-associated molecular patterns (DAMPs) release pro-inflammatory cytokines and activate Th1 and Th17 cells. The mechanism of PM-induced cell death includes the increase of reactive oxygen species (ROS) production followed by collapse of mitochondrial membrane potential (ΔΨm), activation of Apaf-1, Caspase-9 and Caspase-3, leading to activation of Caspase-3-dependent pyroptotic pathway, where Caspase-3 cleaves Gasdermin E (GSDME) to produce a N-terminal fragment responsible for the switch from apoptosis to pyroptosis. At the same time, PM activates the canonical inflammasome pathway, where activated Caspase-1 cleaves the cytosolic Gasdermin D (GSDMD) to produce N-terminal domain allowing IL-1β secretion. As a result, PM-treated monocytes die by pyroptosis activated by two parallel pathways-Caspase-3-dependent pathway related to the inorganic fraction of PM and the canonical inflammasome pathway dependent on the organic components of PM.

The effect of "smoky" coal bans on chronic lung disease among older people in Ireland

Globally, coal is still widely used for heating. However, there are concerns about its effect on ambient air quality and health. We estimated the effect of bans prohibiting the sale and use of so-called "smoky coal" on the prevalence of chronic lung disease in older people. Our identification strategy relied on the phased extension of smoky coal bans to Irish towns after 2010. We examined five waves of The Irish Longitudinal Study on Ageing (TILDA), a large nationally representative survey containing detailed information on health, housing, and socio-economic status. Controlling for relevant factors, smoky coal bans reduced the probability that an older person reports being diagnosed with chronic lung disease by between three and five percentage points. In models where we estimated the effect of the ban on the incidence of new cases of chronic lung disease, rather than existing cases, we found the effect was between -0.96 and -2.5 percentage points. Our findings were robust to estimating the model using different sub-samples and control variables. Furthermore, to address potential endogeneity of the ban, we examined subsamples defined by whether participants lived in towns within a range of the population threshold at which the ban was imposed. Estimating our model using these subsamples showed a consistently negative effect of the ban. We also showed parallel trends in health outcomes before the treatment, and that the treatment did not affect attrition from the sample.

Exposure to ultrafine particles and cognitive decline among older people in the United States

BACKGROUND

Some studies suggest that ambient particulate air pollution is associated with cognitive decline. However, the findings are mixed, and there is no relevant research examining the influences of ultrafine particles (UFP), which may have more toxicity than larger particles. We therefore conducted this study to investigate whether residential UFP exposure is associated with cognitive decline using data from the Alzheimer's Disease Research Centers in the United States.

METHODS

This is a longitudinal study of participants who were aged 65 years and older and had normal cognitive status at baseline. Residential UFP exposure, expressed as particle number concentrations (PNC), was assessed in 2016-2017 using a nationwide land use regression model, and was assigned to each participant using their 3-digit residential ZIP codes. Cognitive functions including memory, attention, language, executive function, and global function were assessed annually using 15 neuropsychological tests from March 2015 to February 2022. Linear mixed-effects models were used to examine the associations after adjustment for covariates including baseline age, sex, APOE ε4 status, race, education, smoking status, history of diabetes, quartiles of neighborhood median household income, and interaction terms of follow-up time with each covariate.

RESULTS

This study included 5646 participants (mean age 76 years, 65% female). On average, each participant had 4 annual visits. When PNC was treated as a continuous variable, there were no statistically or clinically significant changes in annual decline of each cognitive function in relation to an interquartile range elevation in PNC (4026 particles/cm3). Similarly, when PNC was treated as a categorical variable including five exposure groups, there were no linear exposure-response trends in annual decline of each cognitive function across the five exposure groups.

CONCLUSIONS

This study found no meaningful associations between residential UFP exposure and cognitive decline in global and domain-specific functions. There is a need for further research that assigns UFP exposure at a finer geographic scale.

Personal air pollution exposure and metals in the nasal epithelial lining fluid of COPD patients

Sampling of the nasal epithelial lining fluid is a potential method to assess exposure to air pollution within the respiratory tract among high risk populations. We investigated associations of short- and long-term particulate matter exposure (PM) and pollution-related metals in the nasal fluid of people with chronic obstructive pulmonary disease (COPD). This study included 20 participants with moderate-to-severe COPD from a larger study who measured long-term personal exposure to PM2.5 using portable air monitors and short-term PM2.5 and black carbon (BC) using in-home samplers for the seven days preceding nasal fluid collection. Nasal fluid was sampled from both nares by nasosorption, and inductively coupled plasma mass spectrometry was used to determine the concentration of metals with major airborne sources. Correlations of selected elements (Fe, Ba, Ni, Pb, V, Zn, Cu) were determined within the nasal fluid. Associations between personal long-term PM2.5 and seven day home PM2.5 and BC exposure and nasal fluid metal concentrations were determined by linear regression. Within nasal fluid samples, concentrations of vanadium and nickel (r = 0.8) and lead and zinc (r = 0.7) were correlated. Seven day and long-term PM2.5 exposure were both associated with higher levels of copper, lead, and vanadium in the nasal fluid. BC exposure was associated with higher levels of nickel in the nasal fluid. Levels of certain metals in the nasal fluid may serve as biomarkers of air pollution exposure in the upper respiratory tract.

Personal and community-level exposure to air pollution and daily changes in respiratory symptoms and oxygen saturation among adults with COPD

Background

Air pollution exposure is associated with hospital admissions for Chronic Obstructive Pulmonary Disease (COPD). Few studies have investigated whether daily personal exposure to air pollutants affects respiratory symptoms and oxygenation among COPD patients.

Methodology

We followed 30 former smokers with COPD for up to 4 non-consecutive 30-day periods in different seasons. Participants recorded worsening of respiratory symptoms (sub-categorized as breathing or bronchitis symptoms) by daily questionnaire, and oxygen saturation by pulse oximeter. Personal and community-level exposure to fine particulate matter (PM_2.5), nitrogen dioxide (NO₂), and ozone (O₃) were measured by portable air quality monitors and stationary monitors in the Boston area. We used generalized and multi-level linear mixed-effects models to estimate associations of the 24-hour average of each pollutant in the previous day with changes in respiratory symptoms and oxygen saturation.

Results

Higher community-level exposure to air pollutants was associated with worsening respiratory symptoms. An interquartile range (IQR) higher community-level O₃ was associated with a 1.35 (95%CI: 1.07-1.70) higher odds of worsening respiratory symptoms. The corresponding ORs for community-level PM_2.5 and NO₂ were 1.18 (95%CI: 1.02-1.37) and 1.06 (95%CI: 0.90-1.25), respectively. Community-level NO₂ was associated with worsening bronchitis symptoms (OR=1.25, 95%CI: 1.00-1.56), but not breathing symptoms. Personal PM_2.5 exposure was associated with lower odds of worsening respiratory symptoms (OR=0.91; 95%CI: 0.81-1.01). Personal exposure to NO₂ was associated with 0.11% lower oxygen saturation (95%CI: -0.22, 0.00) per IQR.

Conclusions

In this COPD population, there was a pattern of worsening respiratory symptoms associated with community-level exposure to O₃ and PM_2.5, and worsening oxygenation associated with personal exposure to NO₂.

Determinants of indoor carbonaceous aerosols in homes in the Northeast United States

BACKGROUND

Little is known about sources of residential exposure to carbonaceous aerosols, which include black carbon (BC), the elemental carbon core of combustion particles, and organic compounds from biomass combustion (delta carbon).

OBJECTIVE

Assess the impact of residential characteristics on indoor BC and delta carbon when known sources of combustion (e.g., smoking) are minimized.

METHODS

Between November 2012-December 2014, 125 subjects (129 homes) in Northeast USA were recruited and completed a residential characteristics questionnaire. Every 3 months, participants received an automated sampler to measure fine particulate matter (PM2.5) in their home during a weeklong period (N = 371 indoor air samples) and were also questioned about indoor exposures. The samples were analyzed using a transmissometer at 880 nm (reflecting BC) and at 370 nm. The difference between the two wavelengths estimates delta carbon. Outdoor BC and delta carbon were measured using a central site aethalometer.

RESULTS

Geometric mean indoor concentrations of BC and delta carbon (0.65 µg/m³ and 0.19 µg/m³, respectively), were greater than central site concentrations (0.53 µg/m³ and 0.02 µg/m³, respectively). Multivariable analysis showed that greater indoor concentrations of BC were associated with infrequent candle use, multi-family homes, winter season, lack of air conditioning, and central site BC. For delta carbon, greater indoor concentrations were associated with apartments, spring season, and central site concentrations.

SIGNIFICANCE

In addition to outdoor central site concentrations, factors related to the type of housing, season, and home exposures are associated with indoor exposure to carbonaceous aerosols. Recognition of these characteristics should enable greater understanding of indoor exposures and their sources.

Air pollution and COPD: GOLD 2023 committee report

Exposure to air pollution is a major contributor to the pathogenesis of COPD worldwide. Indeed, most recent estimates suggest that 50% of the total attributable risk of COPD may be related to air pollution. In response, the Global Initiative for Chronic Obstructive Lung Disease (GOLD) Scientific Committee performed a comprehensive review on this topic, qualitatively synthesised the evidence to date and proffered recommendations to mitigate the risk. The review found that both gaseous and particulate components of air pollution are likely contributors to COPD. There are no absolutely safe levels of ambient air pollution and the relationship between air pollution levels and respiratory events is supra-linear. Wildfires and extreme weather events such as heat waves, which are becoming more common owing to climate change, are major threats to COPD patients and acutely increase their risk of morbidity and mortality. Exposure to air pollution also impairs lung growth in children and as such may lead to developmental COPD. GOLD recommends strong public health policies around the world to reduce ambient air pollution and for implementation of public warning systems and advisories, including where possible the use of personalised apps, to alert patients when ambient air pollution levels exceed acceptable minimal thresholds. When household particulate content exceeds acceptable thresholds, patients should consider using air cleaners and filters where feasible. Air pollution is a major health threat to patients living with COPD and actions are urgently required to reduce the morbidity and mortality related to poor air quality around the world.

Perturbation of arachidonic acid and glycerolipid metabolism promoted particulate matter-induced inflammatory responses in human bronchial epithelial cells

Particulate matter (PM) has become the main risk factor for public health, being linked with an increased risk of respiratory diseases. However, the potential mechanisms underlying PM-induced lung injury have not been well elucidated. In this study, we systematically integrated the metabolomics, lipidomics, and transcriptomics data obtained from the human bronchial epithelial cells (HBECs) exposed to PM to reveal metabolic disorders in PM-induced lung injury. We identified 170 differentially expressed metabolites (82 upregulated and 88 downregulated metabolites), 218 differentially expressed lipid metabolites (125 upregulated and 93 downregulated lipid metabolites), and 1417 differentially expressed genes (643 upregulated and 774 downregulated genes). Seven key metabolites (prostaglandin E2, inosinic acid, L-arginine, L-citrulline, L-leucine, adenosine, and adenosine monophosphate), and two main lipid subclasses (triglyceride and phosphatidylcholine) were identified in PM-exposed HBECs. The amino acid metabolism, lipid metabolism, and carbohydrate metabolism were the significantly enriched pathways of identified differentially expressed genes. Then, conjoint analysis of these three omics data and further qRT-PCR validation showed that arachidonic acid metabolism, glycerolipid metabolism, and glutathione metabolism were the key metabolic pathways in PM-exposed HBECs. The knockout of AKR1C3 in arachidonic acid metabolism or GPAT3 in glycerolipid metabolism could significantly inhibit PM-induced inflammatory responses in HBECs. These results revealed the potential metabolic pathways in PM-exposed HBECs and provided a new target to protect from PM-induced airway damage.

Short and long-term association of exposure to ambient black carbon with all-cause and cause-specific mortality: A systematic review and meta-analysis

Black carbon (BC) is a product of incomplete or inefficient combustion and may be associated with a variety of adverse effects on human health. The objective of this study was to analyze the association between various mortalities and long-/short-term exposure to BC as an independent pollutant. In this systematic review, we searched 4 databases for original research in English up to 6^th October 2022, that investigated population-wide mortality due to BC exposure. We pooled mortality estimates and expressed them as relative risk (RR) per 10 μg/m³ increase in BC. We used a random-effect model to derive the pooled RRs. Of the 3186 studies identified, 29 articles met the eligibility criteria, including 18 long-term exposure studies and 11 short-term exposure studies. In the major meta-analysis and sensitivity analysis, positive associations were found between BC and total mortality and cause-specific disease mortalities. Among them, the short-term effects of BC on total mortality, cardiovascular disease mortality, respiratory disease mortality, and the long-term effects of BC on total mortality, ischemic heart disease mortality, respiratory disease mortality and lung cancer mortality were found to be statistically significant. The heterogeneity of the meta-analysis results was much lower for short-term studies than for long-term. Few studies were at a high risk of bias in any domain. The certainty of the evidence for most of the exposure-outcome pairs was moderate. Our study showed a significantly positive association between short-/long-term BC exposure and various mortalities. We speculate that BC has a higher adverse health effect on the respiratory system than on the cardiovascular system. This is different from the effect of PM_2.5. Therefore, more studies are needed to consider BC as a separate pollutant, and not just as a component of PM_2.5.

Disparities in ambient nitrogen dioxide pollution in the United States

Average ambient concentrations of nitrogen dioxide (NO2), an important air pollutant, have declined in the United States since the enactment of the Clean Air Act. Despite evidence that NO2 disproportionately affects racial/ethnic minority groups, it remains unclear what drives the exposure disparities and how they have changed over time. Here, we provide evidence by integrating high-resolution (1 km × 1 km) ground-level NO2 estimates, sociodemographic information, and source-specific emission intensity and location for 217,740 block groups across the contiguous United States from 2000 to 2016. We show that racial/ethnic minorities are disproportionately exposed to higher levels of NO2 pollution compared with Whites across the United States and within major metropolitan areas. These inequities persisted over time and have worsened in many cases, despite a significant decrease in the national average NO2 concentration over the 17-y study period. Overall, traffic contributes the largest fraction of NO2 disparity. Contributions of other emission sources to exposure disparities vary by location. Our analyses offer insights into policies aimed at reducing air pollution exposure disparities among races/ethnicities and locations.

Exploring the impact of particulate matter on mortality in coastal Mediterranean environments

Air pollution is one of the most important problems the world is facing nowadays, adversely affecting public health and causing millions of deaths every year. Particulate matter is a criteria pollutant that has been linked to increased morbidity, as well as all-cause and cause-specific mortality. However, this association remains under-investigated in smaller-size cities in the Eastern Mediterranean, which are also frequently affected by heat waves and dust storms. This study explores the impact of particulate matter with an aerodynamic diameter ≤ 10 μm (PM₁₀) and ≤ 2.5 μm (PM_2.5) on mortality (all-cause, cardiovascular, respiratory) in two coastal cities in the Eastern Mediterranean; Thessaloniki, Greece and Limassol, Cyprus. Generalized additive Poisson models were used to explore overall and gender-specific associations, controlling for long- and short-term patterns, day of week and the effect of weather variables. Moreover, the effect of different lags, season, co-pollutants and dust storms on primary associations was investigated. A 10 μg/m³ increase in PM_2.5 resulted in 1.10 % (95 % CI: -0.13, 2.34) increase in cardiovascular mortality in Thessaloniki, and in 3.07 % (95 % CI: -0.90, 7.20) increase in all-cause mortality in Limassol on the same day. Additionally, significant positive associations were observed between PM_2.5 as well as PM₁₀ and mortality at different lags up to seven days. Interestingly, an association with dust storms was observed only in Thessaloniki, having a protective effect, while the gender-specific analysis revealed significant associations only for the males in both cities. The outcome of this study highlights the need of city- or county-specific public health interventions to address the impact of climate, population lifestyle behaviour and other socioeconomic factors that affect the exposure to air pollution and other synergistic effects that alter the effect of PM on population health.

Long-term exposure to particulate matter and COPD mortality: Insights from causal inference methods based on a large population cohort in southern China

BACKGROUND

Evidence of the association between long-term exposure to particulate matter (PM) and chronic obstructive pulmonary disease (COPD) mortality from large population-based cohort study is limited and often suffers from residual confounding issues with traditional statistical methods. We hereby assessed the casual relationship between long-term PM (PM_2.5, PM₁₀ and PM_10-2.5) exposure and COPD mortality in a large cohort of Chinese adults using state-of-the-art causal inference approaches.

METHODS

A total of 580,757 participants in southern China were enrolled in a prospective cohort study from 2009 to 2015 and followed up until December 2020. Exposures to PM at each residential address were obtained from the Long-term Gap-free High-resolution Air Pollutant Concentration dataset. Marginal structural Cox models were used to investigate the association between COPD mortality and annual average exposure levels of PM exposure.

RESULTS

During an average follow-up of 8.0 years, 2250 COPD-related deaths occurred. Under a set of causal inference assumptions, the hazard ratio (HR) for COPD mortality was estimated to be 1.046 (95 % confidence interval: 1.034-1057), 1.037 (1.028-1.047), and 1.032 (1.006-1.058) for each 1-μg/m³ increase in annual average concentrations of PM_2.5, PM₁₀, and PM_10-2.5 respectively. Additionally, the detrimental effects appeared to be more pronounced among the elderly (age ≥ 65) and inactive participants. The effect estimates of PM_2.5, PM₁₀, and PM_10-2.5 tend to be greater among participants who were generally exposed to PM₁₀ concentrations below 70 μg/m³ than that among the general population.

CONCLUSION

Our results support causal links between long-term PM exposure and COPD mortality, highlighting the urgency for more effective strategies to reduce PM exposure, with particular attention on protecting potentially vulnerable groups.

Are air quality perception and PM2.5 exposure differently associated with cardiovascular and respiratory disease mortality in Brussels? Findings from a census-based study

BACKGROUND

There is ample evidence that air pollution increases mortality risk, but most studies are based on modelled estimates of air pollution, while the subjective perception of air quality is scarcely assessed. We aimed to compare the effects of objective and subjective exposure to air pollution on cardiorespiratory mortality in Brussels, Belgium.

METHODS

Data consisted of the 2001 Belgian census linked to registry-based mortality data for the follow-up period 2001-2014. We included individuals aged >30 years of age residing in Brussels at baseline (2001). Air pollution exposure was assessed with objective (modelled annual mean concentrations of PM_2.5 in micrograms per cubic metre, μg/m³) and subjective indicators (poor self-reported air quality perception in the census). We used Cox Proportional Hazard models with age as the underlying time scale to evaluate associations with cardiovascular disease (CVD) and respiratory disease mortality, and separately, ischaemic heart disease (IHD), cerebrovascular disease, and COPD excluding asthma mortality. We specified single- and two-exposure models and evaluated effect modification by neighbourhood unemployment rate.

RESULTS

437,340 individuals were included at baseline. During follow-up (2001-2014), 22,821 (5%) individuals had died from CVDs and 8572 (2%) from respiratory diseases. In single-exposure models, PM_2.5 was significantly associated with an increased risk in CVD and IHD mortality (e.g. for IHD, per 5 μg/m³ increase: Hazard Ratio, HR:1.22, 95%CI:1.08-1.37), and poor air quality perception with COPD excluding asthma mortality (HR:1.23, 95%CI:1.15-1.33). Associations remained significant in the two-exposure models, and additionally, perception was associated with respiratory disease mortality. Associations became gradually stronger with increasing neighbourhood unemployment rate [e.g. in the highest, Q3: PM_2.5 and cerebrovascular disease mortality (HR:1.53, 95%CI:1.04-2.24)].

CONCLUSION

Our findings suggest that objective and subjective exposure to air pollution increased the risk of dying from cardiovascular and respiratory diseases respectively in Brussels. These results encourage policies reducing pollution load in Brussels whilst considering socio-economic inequalities.

Long-term PM2.5 exposure in association with chronic respiratory diseases morbidity: A cohort study in Northern China

Several literatures have examined the risk of chronic respiratory diseases in association with short-term ambient PM2.5 exposure in China. However, little evidence has examined the chronic impacts of PM2.5 exposure on morbidity of chronic respiratory diseases in cohorts from high pollution countries. Our study aims to investigate the associations. Based on a retrospective cohort among adults in northern China, a Cox regression model with time-varying PM2.5 exposure and a concentration-response (C-R) curve model were performed to access the relationships between incidence of chronic respiratory diseases and long-term PM2.5 exposure during a mean follow-up time of 9.8 years. Individual annual average PM2.5 estimates were obtained from a satellite-based model with high resolution. The incident date of a chronic respiratory disease was identified according to self-reported physician diagnosis time and/or intake of medication for treatment. Among 38,047 urban subjects analyzed in all-cause chronic respiratory disease cohort, 482 developed new cases. In CB (38,369), asthma (38,783), and COPD (38,921) cohorts, the onsets were 276, 89, and 14, respectively. After multivariable adjustment, hazard ratio and 95% confidence interval for morbidity of all-cause chronic respiratory disease, CB, asthma, and COPD were 1.15 (1.01, 1.31), 1.20 (1.00, 1.42), 0.76 (0.55, 1.04), and 0.66 (0.29, 1.47) with each 10 μg/m3 increment in PM2.5, respectively. Stronger effect estimates were suggested in alcohol drinkers across stratified analyses. Additionally, the shape of C-R curve showed an increasing linear relationship before 75.00 μg/m3 concentrations of PM2.5 for new-onset all-cause chronic respiratory disease, and leveled off at higher levels. These findings indicated that long-term exposure to high-level PM2.5 increased the risks of incident chronic respiratory diseases in China. Further evidence of C-R curves is warranted to clarify the associations of adverse chronic respiratory outcomes involving air pollution.

Effect of particulate matter 2.5 on QT dispersion in patients with chronic respiratory disease

PM2.5 air pollutants increased risk of ventricular arrhythmias. The prolonged corrected QT interval (QTc) and QT dispersion (QTd) is common in patients with chronic airway disease and is associated with heightened risk of ventricular tachyarrhythmia. We sought to examine the effect of PM2.5 exposure on QTc and QTd in patients with chronic airway disease. We enrolled 73 patients with chronic airway disease into the study. The 12-lead ECGs were recorded during high-exposure and low-exposure periods of PM2.5. QTc and QTd were compared between 2 periods. Mean age was 70 ± 10 years. Mean FEV1/FVC was 63 ± 14%. There was no difference in QTc between PM2.5 high-exposure and low-exposure periods. However, QTd was significantly increased during PM2.5 high-exposure compared to low-exposure periods in male patients (43.5 ± 15.0 vs. 38.2 ± 12.1 ms, P = 0.044) but no difference was found in females. We found that patients who worked mostly indoor had less QTd than those working outdoor during PM2.5 low-exposure period. In addition, those who wore face mask tended to have less QTd during low-exposure period than those who did not. High PM2.5 exposure increased QTd in male patients with chronic airway disease. Working indoors and wearing face mask were associated with less QTd.

Beyond the COPD-tobacco binomium: New opportunities for the prevention and early treatment of the disease

Chronic obstructive pulmonary disease (COPD) has been traditionally understood as a self-inflicted disease cause by tobacco smoking occurring in individuals older than 50-60 years. This traditional paradigm has changed over the last decade because new scientific evidence showed that there are many genetic (G) and environmental (E) factors associated with reduced lung function, that vary, accumulate, and interact over time (T), even before birth (G×E×T). This new perspective opens novel windows of opportunity for the prevention, early diagnosis, and personalized treatment of COPD. This review presents the evidence that supports this proposal, as well as its practical implications, with particular emphasis on the need that clinical histories in patients with suspected COPD should investigate early life events and that spirometry should be used much more widely as a global health marker.

Ambient Air Pollution and Dysanapsis: Associations with Lung Function and Chronic Obstructive Pulmonary Disease in the Canadian Cohort Obstructive Lung Disease Study

Rationale: Outdoor air pollution is a potential risk factor for lower lung function and chronic obstructive pulmonary disease (COPD). Little is known about how airway abnormalities and lung growth might modify this relationship. Objectives: To evaluate the associations of ambient air pollution exposure with lung function and COPD and examine possible interactions with dysanapsis. Methods: We made use of cross-sectional postbronchodilator spirometry data from 1,452 individuals enrolled in the CanCOLD (Canadian Cohort Obstructive Lung Disease) study with linked ambient fine particulate matter (PM_2.5) and nitrogen dioxide (NO₂) air pollution estimates. Dysanapsis, or the ratio of the airway-to-lung volume calculated from thoracic computed tomography images, was used to examine possible interactions. Measurements and Main Results: In adjusted models, 101.7 ml (95% confidence interval [CI], -166.2 to -37.2) and 115.0 ml (95% CI, -196.5 to -33.4) lower FEV₁ were demonstrated per increase of 2.4 ug/m³ PM_2.5 and 9.2 ppb NO₂, respectively. Interaction between air pollution and dysanapsis was not statistically significant when modeling the airway-to-lung ratio as a continuous variable. However, a 109.8 ml (95% CI, -209.0 to -10.5] lower FEV₁ and an 87% (95% CI, 12% to 213%) higher odds of COPD were observed among individuals in the lowest, relative to highest, airway-to-lung ratio, per 2.4 μg/m³ increment of PM_2.5. Conclusions: Ambient air pollution exposure was associated with lower lung function, even at relatively low concentrations. Individuals with dysanaptic lung growth might be particularly susceptible to inhaled ambient air pollutants, especially those at the extremes of dysanapsis.

Systematic characterization of the effective constituents and molecular mechanisms of Ardisiae Japonicae Herba using UPLC-Orbitrap Fusion MS and network pharmacology

Objective

Ardisiae Japonicae Herba (AJH), the dried whole herb of Ardisia japonica (Thunb.) Blume [Primulaceae], has been used in treating chronic obstructive pulmonary disease (COPD) in China. However, the material basis and molecular mechanisms of AJH against COPD remain unclear. Therefore, in this study, we attempt to establish a systematic approach to elucidate the material basis and molecular mechanisms through compound identification, network analysis, molecular docking, and experimental validation.

Methods

Ultra-high performance liquid chromatography-Orbitrap Fusion mass spectrometry (UPLC-Orbitrap Fusion MS) was used to characterize the chemical compounds of AJH. The SwissTargetPrediction, String and Metascape databases were selected for network pharmacology analysis, including target prediction, protein-protein interaction (PPI) network analysis, GO and KEGG pathway enrichment analysis. Cytoscape 3.7.2 software was used to construct a component-target-pathway network to screen out the main active compounds. Autodock Vina software was used to verify the affinity between the key compounds and targets. TNF-α-stimulated A549 cell inflammation model was built to further verify the anti-inflammatory effects of active compounds.

Results

Altogether, 236 compounds were identified in AJH, including 33 flavonoids, 21 Phenylpropanoids, 46 terpenes, 7 quinones, 27 steroids, 71 carboxylic acids and 31 other compounds. Among them, 41 compounds were selected as the key active constituents, which might exhibit therapeutic effects against COPD by modulating 65 corresponding targets primarily involved in inflammation/metabolism/immune-related pathways. The results of molecular docking showed that the key compounds could spontaneously bind to the receptor proteins with a strong binding ability. Finally, the anti-inflammatory effects of the three active compounds were validated with the decreased levels of Interleukin-6 (IL-6) and Matrix Metalloproteinase 9 (MMP9) in TNF-α-induced A549 cells model.

Conclusion

This study clarified that AJH may exert therapeutic actions for COPD via regulating inflammation/immune/metabolism-related pathways using UPLC-Orbitrap Fusion MS technology combined with network pharmacology for the first time. This study had a deeper exploration of the chemical components and pharmacological activities in AJH, which provided a reference for the further study and clinical application of AJH in the treatment of COPD.

Modification of associations between indoor particulate matter and systemic inflammation in individuals with COPD

RATIONALE

Little is known about personal characteristics and systemic responses to particulate pollution in patients with COPD.

OBJECTIVES

Assess whether diabetes, obesity, statins and non-steroidal anti-inflammatory medications (NSAIDs) modify associations between indoor black carbon (BC) and fine particulate matter ≤2.5 μm in diameter (PM_2.5) on systemic inflammation and endothelial activation.

METHODS

144 individuals with COPD without current smoking and without major in-home combustion sources were recruited at Veterans Affairs Boston Healthcare System. PM_2.5 and BC were measured in each participant's home seasonally for a week (up to 4 times; 482 observations) and plasma biomarkers of systemic inflammation [C-reactive protein (CRP); interleukin-6 (IL-6)] and endothelial activation [soluble vascular adhesion molecule-1 (sVCAM-1)] measured. Linear mixed effects regression with a random intercept was used, and effect modification assessed with multiplicative interaction terms and stratum specific estimates.

RESULTS

Median (25%ile, 75%ile) indoor BC and PM_2.5 were 0.6 (0.5,0.7) μg/m³ and 6.8 (4.8,10.4) μg/m³, respectively. Although p-values for effect modification were not statistically significant, there were positive associations (%-increase/interquartile range; 95% CI) between CRP and BC greater among non-statin (18.8%; 3.6-36.3) than statin users (11.1%; 2.1-20.9). There were also positive associations greater among non-statin users between PM_2.5 and CRP. For IL-6, associations with BC and PM_2.5 were also greater among non-statin users. Associations between CRP and BC were greater (20.3%; 4.5-38.5) in persons with diabetes than without diabetes (10.3%; 0.92-20.6) with similar effects of PM_2.5. There were no consistent associations that differed based on obesity. Effect modification was not observed for NSAID use, or with any factor considered with sVCAM-1.

CONCLUSIONS

Associations between indoor BC and PM_2.5 and CRP were greater in patients with diabetes and those not taking statins, and with IL-6 if not taking statins. These results suggest that these characteristics may modify the systemic response to indoor BC and PM_2.5 in persons with COPD.

Is short-term and long-term exposure to black carbon associated with cardiovascular and respiratory diseases? A systematic review and meta-analysis based on evidence reliability

OBJECTIVE

Adverse health effects of fine particles (particulate matter_2.5) have been well documented by a series of studies. However, evidences on the impacts of black carbon (BC) or elemental carbon (EC) on health are limited. The objectives were (1) to explored the effects of BC and EC on cardiovascular and respiratory morbidity and mortality, and (2) to verified the reliability of the meta-analysis by drawing p value plots.

DESIGN

The systematic review and meta-analysis using adapted Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach and p value plots approach.

DATA SOURCES

PubMed, Embase and Web of Science were searched from inception to 19 July 2021.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Time series, case cross-over and cohort studies that evaluated the associations between BC/EC on cardiovascular or respiratory morbidity or mortality were included.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently selected studies, extracted data and assessed risk of bias. Outcomes were analysed via a random effects model and reported as relative risk (RR) with 95% CI. The certainty of evidences was assessed by adapted GRADE. The reliabilities of meta-analyses were analysed by p value plots.

RESULTS

Seventy studies met our inclusion criteria. (1) Short-term exposure to BC/EC was associated with 1.6% (95% CI 0.4% to 2.8%) increase in cardiovascular diseases per 1 µg/m³ in the elderly; (2) Long-term exposure to BC/EC was associated with 6.8% (95% CI 0.4% to 13.5%) increase in cardiovascular diseases and (3) The p value plot indicated that the association between BC/EC and respiratory diseases was consistent with randomness.

CONCLUSIONS

Both short-term and long-term exposures to BC/EC were related with cardiovascular diseases. However, the impact of BC/EC on respiratory diseases did not present consistent evidence and further investigations are required.

PROSPERO REGISTRATION NUMBER

CRD42020186244.

Long-term exposure to ambient fine particulate matter (PM2.5) and associations with cardiopulmonary diseases and lung cancer in Taiwan: a nationwide longitudinal cohort study

BACKGROUND

Although a number of studies have reported on the health effects of fine particulate matter (PM2.5) exposure, particularly in North American and European countries as well as China, the evidence about intermediate to high levels of PM2.5 exposures is still limited. We aimed to investigate the associations between long-term exposure to PM2.5 and risk of cardiopulmonary disease incidence in Taiwan with intermediate levels of PM2.5 exposure.

METHODS

A cohort of Taiwanese adults, who participated in the 2001, 2005, 2009 and 2013 National Health Interview Surveys, was followed through 2016 to identify cardiopulmonary disease onset. Exposure to PM2.5 was estimated by incorporating a widespread monitoring network of air quality monitoring stations and microsensors. We used time-dependent Cox regression models to examine the associations between the PM2.5 exposures and health outcomes, adjusting for individual characteristics and ecological covariates. The natural cubic spline functions were used to explore the non-linear effects of the PM2.5 exposure.

RESULTS

A total of 62 694 adults from 353 towns were enrolled. Each 10-μg/m3 increase in 5-year average exposure to PM2.5 was associated with a 4.8% increased risk of incident ischaemic heart disease (95% CI: -3.3, 13.6), 3.9% increased risk of incident stroke (95% CI: -2.9, 11.1), 6.7% increased risk of incident diabetes (95% CI: 1.1, 12.7), 15.7% increased risk of incident lung cancer (95% CI: -0.9, 35.1) and 11.5% increased risk of incident chronic obstructive pulmonary disease (95% CI: -0.8, 25.2). The concentration-response curve showed that there was no statistical evidence of non-linearity for most of the disease outcomes except for ischaemic heart disease (P for non-linearity = 0.014).

CONCLUSIONS

Long-term exposure to intermediate levels of ambient PM2.5 was associated with cardiopulmonary health outcomes. Our study adds value to future application and national burden of disease estimation in evaluating the health co-benefits from ambient air pollution reduction policy in Asian countries.

Genetic Polymorphism of Matrix Metalloproteinase 9 and Susceptibility to Chronic Obstructive Pulmonary Disease: A Meta-analysis

Background

To systematically analyze the influence of genetic polymorphisms of matrix metalloproteinase 9 (MMP9) on susceptibility to chronic obstructive pulmonary disease (COPD).

Methods

Relevant literatures reporting MMP9 and susceptibility to COPD in PubMed, Web of Science, VIP, Wanfang and CNKI databases were searched using the key words "matrix metalloproteinases 9/MMP9, COPD/chronic obstructive pulmonary disease". Data of eligible literatures were extracted and analyzed for the odds ratio (OR) and corresponding 95% CI.

Results

A total of 16 independent studies reporting MMP9-1562C/T and COPD patients were enrolled and analyzed. None of the genetic models revealed the relationship between MMP9-1562C/T and susceptibility to COPD. Subgroup analyses identified lower risk of COPD in Chinese population carrying the TT genotype for theMMP9 rs3918242 relative to those carrying CT and CC genotypes (P=0.03, OR=0.67, 95% CI=0.46-0.97).

Conclusions

Chinese population carrying the TT genotype for the MMP-9 rs3918242 present lower susceptibility to COPD relative to those carrying CT and CC genotypes.

Neighborhood environmental exposures and incidence of attention deficit/hyperactivity disorder: A population-based cohort study

BACKGROUND

Emerging studies have associated low greenspace and high air pollution exposure with risk of child attention deficit/hyperactivity disorder (ADHD). Population-based studies are limited, however, and joint effects are rarely evaluated. We investigated associations of ADHD incidence with greenspace, air pollution, and noise in a population-based birth cohort.

METHODS

We assembled a cohort from administrative data of births from 2000 to 2001 (N ∼ 37,000) in Metro Vancouver, Canada. ADHD was identified by hospital records, physician visits, and prescriptions. Cox proportional hazards models were applied to assess associations between environmental exposures and ADHD incidence adjusting for available covariates. Greenspace was estimated using vegetation percentage derived from linear spectral unmixing of Landsat imagery. Fine particulate matter (PM_2.5) and nitrogen dioxide (NO₂) were estimated using land use regression models; noise was estimated using a deterministic model. Exposure period was from birth until the age of three. Joint effects of greenspace and PM_2.5 were analysed in two-exposure models and by categorizing values into quintiles.

RESULTS

During seven-year follow-up, 1217 ADHD cases were diagnosed. Greenspace was associated with lower incidence of ADHD (hazard ratio, HR: 0.90 [0.81-0.99] per interquartile range increment), while PM_2.5 was associated with increased incidence (HR: 1.11 [1.06-1.17] per interquartile range increment). NO₂ (HR: 1.01 [0.96, 1.07]) and noise (HR: 1.00 [0.95, 1.05]) were not associated with ADHD. There was a 50% decrease in the HR for ADHD in locations with the lowest PM_2.5 and highest greenspace exposure, compared to a 62% increase in HR in locations with the highest PM_2.5 and lowest greenspace exposure. Effects of PM_2.5 were attenuated by greenspace in two-exposure models.

CONCLUSIONS

We found evidence suggesting environmental inequalities where children living in greener neighborhoods with low air pollution had substantially lower risk of ADHD compared to those with higher air pollution and lower greenspace exposure.

Controlled human exposure to diesel exhaust: a method for understanding health effects of traffic-related air pollution

Diesel exhaust (DE) is a major component of air pollution in urban centers. Controlled human exposure (CHE) experiments are commonly used to investigate the acute effects of DE inhalation specifically and also as a paradigm for investigating responses to traffic-related air pollution (TRAP) more generally. Given the critical role this model plays in our understanding of TRAP's health effects mechanistically and in support of associated policy and regulation, we review the methodology of CHE to DE (CHE-DE) in detail to distill critical elements so that the results of these studies can be understood in context. From 104 eligible publications, we identified 79 CHE-DE studies and extracted information on DE generation, exposure session characteristics, pollutant and particulate composition of exposures, and participant demographics. Virtually all studies had a crossover design, and most studies involved a single DE exposure per participant. Exposure sessions were typically 1 or 2 h in duration, with participants alternating between exercise and rest. Most CHE-DE targeted a PM concentration of 300 μg/m3. There was a wide range in commonly measured co-pollutants including nitrogen oxides, carbon monoxide, and total organic compounds. Reporting of detailed parameters of aerosol composition, including particle diameter, was inconsistent between studies, and older studies from a given lab were often cited in lieu of repeating measurements for new experiments. There was a male predominance in participants, and over half of studies involved healthy participants only. Other populations studied include those with asthma, atopy, or metabolic syndrome. Standardization in reporting exposure conditions, potentially using current versions of engines with modern emissions control technology, will allow for more valid comparisons between studies of CHE-DE, while recognizing that diesel engines in much of the world remain old and heterogeneous. Inclusion of female participants as well as populations more susceptible to TRAP will broaden the applicability of results from CHE-DE studies.

Controlled human exposure to diesel exhaust: results illuminate health effects of traffic-related air pollution and inform future directions

Air pollution is an issue of increasing interest due to its globally relevant impacts on morbidity and mortality. Controlled human exposure (CHE) studies are often employed to investigate the impacts of pollution on human health, with diesel exhaust (DE) commonly used as a surrogate of traffic related air pollution (TRAP). This paper will review the results derived from 104 publications of CHE to DE (CHE-DE) with respect to health outcomes. CHE-DE studies have provided mechanistic evidence supporting TRAP’s detrimental effects on related to the cardiovascular system (e.g., vasomotor dysfunction, inhibition of fibrinolysis, and impaired cardiac function) and respiratory system (e.g., airway inflammation, increased airway responsiveness, and clinical symptoms of asthma). Oxidative stress is thought to be the primary mechanism of TRAP-induced effects and has been supported by several CHE-DE studies. A historical limitation of some air pollution research is consideration of TRAP (or its components) in isolation, limiting insight into the interactions between TRAP and other environmental factors often encountered in tandem. CHE-DE studies can help to shed light on complex conditions, and several have included co-exposure to common elements such as allergens, ozone, and activity level. The ability of filters to mitigate the adverse effects of DE, by limiting exposure to the particulate fraction of polluted aerosols, has also been examined. While various biomarkers of DE exposure have been evaluated in CHE-DE studies, a definitive such endpoint has yet to be identified. In spite of the above advantages, this paradigm for TRAP is constrained to acute exposures and can only be indirectly applied to chronic exposures, despite the critical real-world impact of living long-term with TRAP. Those with significant medical conditions are often excluded from CHE-DE studies and so results derived from healthy individuals may not apply to more susceptible populations whose further study is needed to avoid potentially misleading conclusions. In spite of limitations, the contributions of CHE-DE studies have greatly advanced current understanding of the health impacts associated with TRAP exposure, especially regarding mechanisms therein, with important implications for regulation and policy.

A systematic review on solid fuel combustion exposure and respiratory health in adults in Europe, USA, Canada, Australia and New Zealand

Epidemiological studies performed in low- and middle-income countries have shown a positive association between solid fuel burning exposure and adverse health effects, including respiratory effects in adults. However, the evidence is less clear in other countries. We performed a systematic review of epidemiological studies conducted in Europe, North America (Canada and USA only), Australia and New Zealand on the association between outdoor and indoor exposure to solid fuel (biomass and coal) combustion and respiratory outcomes in adults. We identified 34 articles. The epidemiological evidence is still limited. Positive associations were found between indoor coal, wood and combined solid fuel combustion exposure and lung cancer risk, although based on a limited number of studies. A significant association was found between indoor solid fuel exposure and COPD risk. Inconsistent results were found considering indoor coal, wood and mixed solid fuel burning exposure and other respiratory outcomes (i.e. lower respiratory infections, upper respiratory infections and other upper respiratory tract diseases, asthma and respiratory symptoms). Inconsistent results were found considering the relationship between the exposure to outdoor wood burning exposure and overall respiratory mortality, asthma, COPD and respiratory symptoms in adults. The available epidemiological evidence between outdoor exposure to residential coal burning and respiratory outcomes suggests an increased risk of adverse respiratory effects. The studies considering the impact of the introduction of measures in order to reduce solid fuel burning on air quality and health showed an improvement in air quality resulting in a reduction of adverse respiratory effects. The identified epidemiological studies have several limitations. Additional and better conducted epidemiological studies are needed to establish whether exposure occurring indoors and outdoors to solid fuel combustion pollutants is associated with adverse respiratory outcomes in adults.

Characteristics of PM2.5 Pollution in Osorno, Chile: Ion Chromatography and Meteorological Data Analyses

Over the decades, air pollution has become a serious problem in Osorno, Chile. This study aims to clarify the source of PM2.5 by comprehensively analyzing its chemical composition and comparing it with meteorological conditions. The PM2.5 and filter samples were collected during April 2019–August 2019 using a continuous particulate monitor. The analyses were conducted using Image J software, ion chromatography, and backward trajectory. The ion composition and the PM2.5 were compared. The results on the PM2.5 and potassium (K+) concentrations indicated a correlation factor of 0.93, indicating that biomass combustion, such as wood burning, is the dominant source of PM2.5 in Osorno. High PM2.5 concentrations of over 170 to 1124 µg/m3 were observed in low temperature, low precipitation, and low wind speed periods—meteorological conditions contributed to the development of a thermal inversion layer. In addition, correlations of 0.61 to 0.67 were found among the detected ions that are often found in seawater. The backward trajectory analyses showed dominant air mass transport from the South Pacific Ocean, suggesting that part of the detected PM2.5 was derived from the marine environment. Continuous monitoring and mitigation strategies focusing on wood combustion activities are necessary to alleviate the current air pollution problem in Osorno city.

Chronic exposure to biomass ambient particulate matter triggers alveolar macrophage polarization and activation in the rat lung

The role of alveolar macrophages (AMs) in chronic obstructive pulmonary disease is unclear. We characterized the function of AMs in rats chronically exposed to biomass fuel smoke (BMF) and studied the signal pathways that regulate AMs polarization. One hundred and eighty male Sprague‐Dawley rats were divided into BMF group and clean air control (CON) group. After BMF smoke exposure for 4 days, 1 month and 6 months, the cytokine secretion and function of AMs were determined by flow cytometry, quantitative polymerase chain reaction, Western blotting and immunofluorescence. Bone marrow‐derived macrophages were cultured and exposed to particulate matter (PM) from the smoke. Exposure initially promoted pro‐inflammatory factors, but pro‐inflammatory macrophages shared features of anti‐inflammatory macrophages. Consistent with IL‐4 upregulated in bronchoalveolar lavage fluid, p‐Stat6 and peroxisome proliferator‐activated receptor γ (PPARγ) in AMs elevated at 4 days of exposure. After 6 months of exposure, CD206, TGF‐β1 and p‐Smad3 were significantly higher than the control groups. PPARγ reversed the M1 phenotype induced by PM in vitro and drove the macrophages into the M2 phenotype. Altogether, the study demonstrates the dynamic phenotype and functional changes in AMs during exposure to BMF smoke.

Investigating the association between long-term exposure to air pollution and greenness with mortality from neurological, cardio-metabolic and chronic obstructive pulmonary diseases in Greece

Long-term exposure to air pollution has been associated with increased natural-cause mortality, but the evidence on diagnoses-specific mortality outcomes is limited. Few studies have examined the potential synergistic effects of exposure to pollutants and greenness. We investigated the association between exposure to air pollution and greenness with nervous system related mortality, cardiometabolic and chronic obstructive pulmonary diseases (COPD) mortality in Greece, using an ecological study design. We collected socioeconomic and mortality data for 1035 municipal units from the 2011 Census. Annual PM_2.5, NO₂, BC and O₃ concentrations for 2010 were predicted at 100 × 100 m grids by hybrid land use regression models. The normalized difference vegetation index (NDVI) was used for greenness. We applied single and two-exposure Poisson regression models on standardized mortality rates accounting for spatial autocorrelation. We assessed interactions between pollutants and greenness. An interquartile range increase in PM_2.5, NO₂ and BC was associated with increased risk in mortality from diseases of the nervous system (relative risk (RR): 1.14, 95% confidence interval (CI): 1.01, 1.28); 1.03 (95% CI: 0.99, 1.07); 1.05 (95% CI: 1.00, 1.10) respectively) and from cerebrovascular disease (RR: 1.14, 95% CI: 1.10, 1.18); 1.02 (95% CI: 1.01, 1.04); 1.02 (95% CI: 1.00, 1.04) respectively). PM_2.5 was associated with ischemic heart disease mortality (RR: 1.05, 95% CI: 1.01, 1.10). We estimated inverse associations for all outcomes with O₃ and for mortality from diseases of the nervous system or COPD with greenness. Estimates were mostly robust to co-exposure adjustment. Interactions were identified between NDVI and O₃ or PM_2.5 on mortality from the diseases of the nervous system, with higher effect estimates in greener areas. Our findings support the adverse effects of air pollution and the beneficial role of greenness on cardiovascular and nervous system related mortality. Further research is needed on diabetes mellitus.

FIZZ2 as a Biomarker for Acute Exacerbation of Chronic Obstructive Pulmonary Disease

PURPOSE

Found in inflammatory zone 2 (FIZZ2) is associated with lung inflammation. The aim of the study was to investigate the expression and utility of FIZZ2 as a marker for chronic obstructive pulmonary disease (COPD).

METHODS

Immunohistochemistry was used to detect the expression of FIZZ2 in COPD. The serum concentration of FIZZ2 was measured by enzyme-linked immunosorbent assay and the episodes of acute exacerbations of COPD (AECOPD) in the following year were recorded.

RESULTS

FIZZ2 expression was elevated in bronchial epithelial cells (0.217 ± 0.021 vs 0.099 ± 0.010, p < 0.0001) and negatively correlated with the pulmonary function (FEV1/FVC%) (p = 0.0149) and positively correlated with the smoking index (p = 0.0241). Serum level of FIZZ2 in COPD were significantly higher than that in healthy controls (561.6 ± 70.71 vs 52.24 ± 20.52 pg/ml, p < 0.0001) and increased with the COPD severity. Serum levels of FIZZ2 negatively correlated with the pulmonary function [Forced Vital Capacity (FVC), Forced Expiratory Volume (FEV1), FEV1%, FEV1/FVC) (r =  - 0.3086, - 0.3529, - 0.3343, and - 0.2676, respectively, p = 0.0003, p < 0.0001, p < 0.0001, p = 0.0014). The expression of human serum FIZZ2 was positively correlated with the smoking index (r = 0.2749, p = 0.0015). There was a positive correlation between the FIZZ2 concentration and the frequency of AECOPD episodes in the following year (r = 0.7291, p < 0.0001).

CONCLUSION

FIZZ2 expression was elevated in patients with COPD and its serum concentration might be a potential biomarker for AECOPD.

Effects of exposure to ambient air pollution on pulmonary function impairment in South Korea: Korea National Health and Nutritional Examination Survey

OBJECTIVES

This study aimed to investigate the association between pulmonary function and air pollution using 2007–2017 data from the Korea National Health and Nutrition Examination Survey, a nationwide cross-sectional representative survey.

METHODS

A total of 27,378 participants that had sampling weights from a complex sample survey were included in this study. Using the data for forced expiratory volume in 1 second and forced vital capacity, the participants with pulmonary function impairment were classified according to the criteria of restrictive lung disease and chronic obstructive pulmonary disease (COPD). Exposure to ambient air pollution was estimated using the Community Multiscale Air Quality model. Multivariate linear and logistic regression analyses with complex samples were used to determine the associations between pulmonary function and air pollution after adjusting for covariates.

RESULTS

In total, 13.2% of the participants aged >40 years had COPD, and 10.7% were classified as being in the restrictive lung disease group. According to the multivariate logistic regression model, the odds ratios for the fourth quartiles of particulate matter less than 10 μm in diameter (PM₁₀), particulate matter less than 2.5 μm in diameter (PM_2.5) and carbon monoxide (CO) with a 2-year lag period were 1.203 (95% confidence interval [CI], 1.036 to 1.396), 1.283 (95% CI, 1.101 to1.495), and 1.292 (95% CI, 1.110 to 1.504), respectively, using the restrictive lung disease group as an event after adjusting for covariates in the complex sample.

CONCLUSIONS

Long-term exposure to PM₁₀, PM_2.5, and CO was significantly associated with pulmonary function, especially restrictive lung disease.

Risk and Resilience: How Is the Health of Older Adults and Immigrant People Living in Canada Impacted by Climate- and Air Pollution-Related Exposures?

BACKGROUND

In the rapidly shifting Canadian climate, an ageing population, and increased migration, a greater understanding of how local climate and air pollution hazards impact older adults and immigrant populations will be necessary for mitigating and adapting to adverse health impacts.

OBJECTIVES

To explore the reported health impacts of climate change and air pollution exposures in older adults and immigrant people living in Canada, identify known factors influencing risk and resilience in these populations and gaps in the literature.

METHODS

We searched for research focused on older adults and immigrants living in Canada, published from 2010 onward, where the primary exposures were related to climate or air pollution. We extracted data on setting, exposures, health outcomes, and other relevant contextual factors.

RESULTS AND DISCUSSION

We identified 52 eligible studies, most focused in Ontario and Quebec. Older people in Canada experience health risks due to climate and air pollution exposures. The extent of the risk depends on multiple factors. We found little information about the climate- and air pollution-related health impacts experienced by immigrant communities.

CONCLUSIONS

Further research about climate- and air pollution-related exposures, health, and which factors promote or reduce resiliency in Canada's older adults and immigrant communities is necessary.

Respiratory symptoms, lung function, and fraction of exhaled nitric oxide before and after assignment in a desert environment-a cohort study

BACKGROUND

Inhalation of small particulate matter (PM 2.5) may be associated with development of respiratory disease. Increased respiratory symptoms have been reported among military staff after service in countries with recurrent desert storms.

OBJECTIVE

The aim was to investigate whether an assignment in a desert environment and exposure to desert storms are associated with negative effects on respiratory health.

METHODS

In two cohorts of Swedish soldiers serving in Mali as part of the United Nations stabilization forces, examination with spirometry, determination of fraction of exhaled nitric oxide (FeNO), and a questionnaire including participant characteristics, symptoms, and exposure was performed before and after service. Ambient air sampling was conducted on-site. Paired t-test was used to compare pre- and post-variables on lung function data, FeNO and symptom level.

RESULTS

Most indoor and outdoor air measurements of dust and silica were within the Swedish occupational exposure limit for PM2.5 and silica (<0.10-2.7 mg/m³ and <0.002-0.40 mg/m³, respectively) as well as for respirable dust and silica (0.056-0.078 mg/m³and 0.0033-0.025 mg/m³, respectively). In the subgroup of participants with reported exposure to desert storms during the stay in Mali, forced expiratory volume in 1 s (FEV₁) was significantly lower after exposure than before the mission (mean litres (SD) 4.21 ± 0.66 vs 4.33 ± 0.72, p = 0.021).

CONCLUSION

Exposure to a desert storm was associated with a decrease in FEV₁. Exposure to small particulate matter may contribute to the development of respiratory disease and thus spirometry should be performed after occupational exposure to desert storms.

Effects of PM2.5 on Chronic Airway Diseases: A Review of Research Progress

The adverse effects of polluted air on human health have been increasingly appreciated worldwide. It is estimated that outdoor air pollution is associated with the death of 4.2 million people globally each year. Accumulating epidemiological studies indicate that exposure to ambient fine particulate matter (PM2.5), one of the important air pollutants, significantly contributes to respiratory mortality and morbidity. PM2.5 causes lung damage mainly by inducing inflammatory response and oxidative stress. In this paper, we reviewed the research results of our group on the effects of PM2.5 on chronic obstructive pulmonary disease, asthma, and lung cancer. And recent research progress on epidemiological studies and potential mechanisms were also discussed. Reducing air pollution, although remaining a major challenge, is the best and most effective way to prevent the onset and progression of respiratory diseases.

Specialist Care in Individuals With Asthma Who Required Hospitalization: A Retrospective Population-Based Study

BACKGROUND

Patients who are at risk for severe asthma exacerbations should receive specialist care. However, the care pattern for such patients in the real world is unclear.

OBJECTIVE

To describe the pattern of care among individuals with asthma who required hospitalization, and to identify factors associated with receiving asthma specialist care.

METHODS

This was a retrospective population-based study using health administrative data from two Canadian provinces. Individuals aged 14 to 45 years who were newly diagnosed with asthma between 2006 and 2016 and had at least one hospitalization for asthma at or within 5 years after the initial asthma diagnosis were included. First, we calculated frequencies of primary and specialist care around the asthma diagnosis: 1 year before and 2 years after in a 6-month period. Next, among individuals diagnosed with asthma by a primary care physician, we used multivariable Cox regressions to identify factors associated with receiving specialist care.

RESULTS

For 1862 individuals included, we found that most (≥71% per time period) were cared for by primary care physicians 1 year before and 2 years after the asthma diagnosis; the percentage of individuals seen at least once by a specialist for asthma and/or asthma-related respiratory conditions during the first 6 months since the diagnosis did not exceed 40%. Among 1411 of 1862 individuals who were under primary care before the asthma diagnosis (76%), controlling for covariates, living in a rural area or a low-income neighborhood was associated with less likelihood of receiving specialist care.

CONCLUSIONS

Despite recommendations, more than half of individuals with asthma who required hospitalization did not receive specialist care during the first 2 years since the diagnosis. Identified factors associated with receiving asthma specialist care suggested that access is an important barrier to receiving recommended care.

Relationship Between Air Pollution and the Concentration of Nitric Oxide in the Exhaled Air (FeNO) in 8-9-Year-Old School Children in Krakow

The consequences of air pollution pose one of the most serious threats to human health, and especially impact children from large agglomerations. The measurement of nitric oxide concentration in exhaled air (FeNO) is a valuable biomarker in detecting and monitoring airway inflammation. However, only a few studies have assessed the relationship between FeNO and the level of air pollution. The study aims to estimate the concentration of FeNO in the population of children aged 8–9 attending the third grade of public primary schools in Krakow, as well as to determine the relationship between FeNO concentration and dust and gaseous air pollutants. The research included 4580 children aged 8–9 years who had two FeNO measurements in the winter–autumn and spring–summer periods. The degree of air pollution was obtained from the Regional Inspectorate of Environmental Protection in Krakow. The concentration of pollutants was obtained from three measurement stations located in different parts of the city. The FeNO results were related to air pollution parameters. The study showed weak but significant relationships between FeNO and air pollution parameters. The most significant positive correlations were found for CO8h (r = 0.1491, p < 0.001), C₆H₆ (r = 0.1420, p < 0.001), PM₁₀ (r = 0.1054, p < 0.001) and PM_2.5 (r = 0.1112, p < 0.001). We suggest that particulate and gaseous air pollutants impact FeNO concentration in children aged 8–9 years. More research is needed to assess the impact of air pollution on FeNO concentration in children. The results of such studies could help to explain the increase in the number of allergic and respiratory diseases seen in children in recent decades.

Cancer risk assessment for exposure to hazardous volatile organic compounds in Calgary, Canada

Oil and natural gas (O&G) extraction operations emit hazardous volatile organic compounds (VOCs) in quantities that have adverse effects on human health. Our current understanding of the exposure risks associated with upstream O&G exploitations remains limited, and very few quantitative on-site remediation strategies have been proposed. To this end, we assessed the health risks associated with the emission of hazardous VOCs and presented a set of remediation goals for the city of Calgary, which is a major center of the Canadian oil industry. Results from probabilistic risk assessment (PRA) suggested that although VOCs had a negligible impact on chronic non-cancer-associated risk, inhalation-associated cancer risk remained a significant concern. Carbon tetrachloride, benzene, and 1,3-butadiene were the dominant VOCs, representing 88% of the integrated inhalation cancer risk (= 7.8 × 10^-5); background, solid fuel combustion, and O&G extraction were among the primary sources that posed the greatest threat to human health. Results of a Monte Carlo simulation revealed that the probability of developing cancer due to inhalation of hazardous VOCs was ∼13.1% on clean air days and 45.9% on days with significant levels of air pollution. Preliminary remediation goals (PRGs) included reductions of 24.2-65.1% and 11.4-50.9% targeting priority VOCs and their sources, respectively. Taken together, our findings suggest that stringent control of the sources of VOCs, particularly fossil fuel combustion, is an urgent priority. PRA coupled with PRGs provides informative risk assessments and suggests quantitative remediation strategies that can be applied toward improved management of hazardous pollutants.