Air pollution and respiratory infections: the past, present, and future

Altered cytokine release of airway epithelial cells in vitro by combinations of respiratory syncytial virus, Streptococcus pneumoniae, Printex 90 and diesel exhaust particles

Air pollution exposure has been linked to an increased severity of respiratory infections. Studying the cellular mechanisms behind a potential interaction between biological infectious agents, like viruses or bacteria, and the chemical constituent of air pollution could provide more understanding of this finding. In vitro models allow assessment of the mechanisms leading to such increased severity of respiratory infections. The response of primary respiratory bronchial epithelial cells was investigated after combined exposure to biological agents (Respiratory Syncytial Virus (RSV), the bacterium Streptococcus pneumoniae), and chemical agents (Printex 90 or diesel exhaust particles (DEP)). Multiple combinations of exposures to these agents were tested and the effect on cell viability and cytotoxicity were assessed. The secretion levels of 24 pro- and anti-inflammatory cytokines were assessed at levels that did not cause cytotoxicity. Infection with RSV resulted in decreased metabolic activity and an increase in cytokine levels compared to the other exposures. Exposures to the bacterial and chemical agents, in addition to an RSV infection, resulted in a further increase in cytokine levels. We found a cluster of cytokines that responded similarly to the performed exposures which were CXCR3 ligands CXCL9, CXCL10 and CXCL11 and CCR5 ligand CCL5. Even though the data suggests that combined exposures result in a further increase of cytokine levels, this was not confirmed by statistical analysis. Together, this information may help to understand the cellular effects of combined exposure in an in vitro setting and the biological responses to these exposures in vivo.

Short-term exposure to ultrafine particles and respiratory infection hospital admissions in children in Copenhagen, Denmark

INTRODUCTION

Short-term exposure to ultrafine particles (UFP; <100 nm) may trigger respiratory hospitalizations, potentially even more so among children than adults, but available evidence is limited. We examined the association between short-term UFP exposure and respiratory infection hospital admissions in children in Copenhagen, Denmark.

METHODS

Daily concentrations of UFP were monitored at an urban background station during 2002-2018. Hospital admissions for lower and upper respiratory infections (LRTIs/URTIs), pneumonia, bronchitis, and influenza in children (0-18 years) were obtained from the Danish National Patient Register. Associations between UFP concentrations up to one week prior to admission and hospital admissions were examined using case-crossover design. Relative risks (RR) with 95 % confidence intervals (CI) were estimated per interquartile range (IQR) increase in UFP for the total population, and by sex, age (0-4/5-14/15-18 years) and socio-economic status (income, mother's education).

RESULTS

We observed 109,585 hospital admissions for respiratory infections. We found positive associations of UFP with total respiratory infections, URTIs, and pneumonia with RRs of 1.04 (95 % CI: 1.01, 1.06), 1.04 (1.01, 1.08), and 1.06 (1.01, 1.12), respectively, per IQR increase in three-day mean UFP (lag 0-2), that were robust to PM2.5 and NO2 adjustment. Associations were stronger in boys and children younger than 15 years, with no differences between socio-economic groups.

CONCLUSION

Short-term exposure to UFP triggered hospital admissions for respiratory infections, especially URTIs and pneumonia, in children in Copenhagen independently from PM2.5 and NO2. Our findings emphasize the need for policies and regulations aimed at improving urban air quality to protect children's health.

Effects of Long-Term Air Pollution Exposure on Disease Outcomes and Hybrid Immune Responses in SARS-CoV-2 Breakthrough Infections: A Study of the Yichang COVID-19 Antibody Longitudinal Survey (YC-CALS) in China

BACKGROUND

As immunity wanes and viral mutations continue, the risk of endemic SARS-CoV-2 breakthrough infections (BTIs) remains. Air pollution is considered a risk factor for respiratory infection, but evidence of its association with SARS-CoV-2 BTIs is limited.

OBJECTIVES

We aimed to examine the effects of long-term exposure to air pollution on disease outcomes, immune responses, and antibody dynamics of SARS-CoV-2 BTIs.

METHODS

We gathered data on self-reported SARS-CoV-2 infections through questionnaires and measured IgG antibody levels using serological assays from a total of 6,875 participants from the Yichang COVID-19 Antibody Longitudinal Survey cohort in China. Air pollutant exposure [particulate matter (PM) with an aerodynamic diameter ≤ 2.5 μ m (PM 2.5 ), PM with an aerodynamic diameter ≤ 10 μ m (PM 10 ), PM with an aerodynamic diameter ≤ 1 μ m (PM 1 ), SO 2 , NO 2 , O 3 , and CO] was quantified using validated models for the past 5 y (2018-2022). Logistic and linear regression models were applied to analyze the associations between air pollutant levels and SARS-CoV-2 BTIs, Long COVID, COVID-19 hospitalization, and antibody responses. Quantile g-computation was used to assess the combined effects of pollutant mixtures. A linear mixed model was used to evaluate the effect of air pollution on antibody dynamics.

RESULTS

Per interquartile range (IQR) increase in PM 2.5 , SO 2 , NO 2 , and CO, the adjusted odds ratios (ORs) for SARS-CoV-2 BTIs were 1.65 [95% confidence interval (CI): 1.30, 2.08], 1.30 (95% CI: 1.12, 1.50), 1.63 (95% CI: 1.20, 2.20), and 1.24 (95% CI: 1.06, 1.45). The ORs for PM 2.5 were 1.78 (95% CI: 1.07, 3.02) and 2.02 (95% CI: 1.18, 3.54) for Long COVID and hospitalization. Per IQR increase in PM 1 and NO 2 , IgG antibody percentages decreased by - 2.31 % (95% CI: - 4.49 % , - 0.13 % ) and - 2.69 % (95% CI: - 5.35 % , - 0.03 % ). Effects were stronger in older adults, those with comorbidities, and the undervaccinated. The combined effect on SARS-CoV-2 BTIs was mainly driven by PM 2.5 (59.4%), and the impact on IgG response was largely attributed to NO 2 (63.7%). Exposure to the highest levels of PM 2.5 (p = 0.002 ), PM 1 (p < 0.001 ), and NO 2 (p = 0.002 ) was associated with a faster IgG decline than the lowest.

DISCUSSION

Long-term exposure to air pollution increases the risk of SARS-CoV-2 BTIs and disease severity while weakening the immune response, particularly for vulnerable populations. https://doi.org/10.1289/EHP15660.

Association between long-term PM2.5 exposure and risk of infectious diseases - acute otitis media, sinusitis, pharyngitis, and tonsillitis in children: A nationwide longitudinal cohort study

BACKGROUND

Air pollution, particularly particulate matter, has been linked to various health issues, including respiratory infections in children. This study investigates the impact of long-term PM2.5 exposure on acute otitis media (AOM), sinusitis, pharyngitis, and tonsillitis in a large Korean cohort. While children are known to be more vulnerable due to anatomical factors, the relationship between prolonged PM2.5 exposure and these infections has been insufficiently explored in large populations.

METHODS

We aimed to examine the association of long-term exposure to PM2.5 with the first hospital visit of four infectious diseases - acute otitis media, sinusitis, pharyngitis, and tonsillitis - using a population-based cohort from National Health Insurance Service-National Sample Cohort data from 2002 to 2019. To ensure a minimum follow-up period of five years, individuals who enrolled in 2016 or later were excluded. A time-varying Cox model was applied to adjust for age, sex, income status, residential areas and district-level socioeconomic indicators. Annually updated residential addresses and related PM2.5 concentrations based on mean annual predictions from a machine learning-based ensemble prediction model were assigned.

RESULTS

Our study included 364,227 people aged 0-18 years at enrollment and total of onset of each disease was 196,762 with acute otitis media, 253,248 with sinusitis, 275,160 with pharyngitis, and 315,367 with tonsillitis. Estimated hazard ratios (HR) per 5 μg/m3 increase in PM2.5 were noticeably associated with acute otitis media (HR = 1.06; 95% confidence interval [CI]: 1.05-1.08), sinusitis (HR = 1.01; 95% CI: 1.01-1.02), pharyngitis (HR = 1.02; 95% CI: 1.01-1.03), and tonsillitis (HR = 1.05; 95% CI: 1.05-1.06).

CONCLUSIONS

This study demonstrates a significant link between long-term PM2.5 exposure and increased risks of AOM, sinusitis, pharyngitis, and tonsillitis, especially in younger individuals. Highlighting the effects of prolonged exposure, it emphasizes the importance of public health strategies to protect vulnerable populations and provides insights for policies addressing air pollution-related health risks.

Particulate Matter Exposure and Viral Infections: Relevance to Highly Polluted Settings such as Ulaanbaatar, Mongolia

PURPOSE OF REVIEW

Particulate matter (PM), a ubiquitous significant component of the ambient air pollution mixture, significantly contributes to increased global risk for chronic cardiopulmonary diseases, acute hospitalizations, and deaths. One of the causes of this increased risk is because PM exposure increases the incidence and severity of respiratory infections. The respiratory system is particularly vulnerable to air pollution and its impact on infection as it is a key site for exposure both to inhaled pollutants and infectious microbes or viruses. This review examines the current understanding of how PM affects antiviral host defense responses and possible underlying mechanisms.

RECENT FINDINGS

While numerous studies have associated adverse health outcomes with combined or sequential exposure to inhaled pollutants and viruses, defining causal relationships and mechanisms remains limited. Particularly limited, are contemporary data focuses on low- and middle-income countries, including heavily polluted regions such as Ulaanbaatar, Mongolia. This manuscript focuses on how (1) PM, serving as a carrier for viruses, enhances the transmission of viruses; (2) PM impairs immune defense to viruses; and (3) PM impacts epithelial cell functions to exacerbate viral infections. Given the significant public health hazards on PM, particularly in heavily polluted regions such as Southeast Asia, Middle East and Africa, it is critical to define specific mechanisms of PM on respiratory infection and how their impact may differ in these highly polluted regions. Ultimately, this could devise future public health measures and interventions to limit this substantial public health risk.

Time series analysis of the impact of air pollutants on influenza-like illness in Changchun, China

BACKGROUND

Emerging evidence links air pollution to respiratory infections, yet systematic assessments in cold regions remain limited. This study evaluates the short-term effects of six major air pollutants on influenza-like illness (ILI) incidence in Changchun, Northeast China, with implications for air quality management and respiratory disease prevention.

METHODS

ILI surveillance data from Changchun were extracted from "China Influenza Surveillance Network" and the ambient air quality monitoring data of the city were collected from 2017 to 2022. A generalized additive model (GAM) with quasi-Poisson regression analysis was employed to quantify pollutant-ILI associations, adjusting for meteorological factors and temporal trends.

RESULTS

Among 84,010 ILI cases, immediate exposure effects were observed: each 10 µg/m³ increase in PM2.5 (ER = 1.00%, 95% CI: 0.63-1.37%), PM10 (0.90%, 0.57-1.24%), and O3 (1.05%, 0.44-1.67%) significantly elevated ILI risks. Young and middle-aged individuals (25-59 years old) exhibited the highest susceptibility to five pollutants (PM2.5, PM10, SO2, O3, and CO), and age subgroups under 15 years old exhibited susceptibility to NO2. Post-COVID-19 outbreak showed amplified effects across all pollutants (p < 0.05 vs. pre-outbreak). The effects of PM2.5, PM10, SO2 and O3 on ILI cases were greater in the cold season (October to March) (p < 0.05).

CONCLUSIONS

PM2.5, PM10, and O3 exposure significantly increases ILI risks in Changchun, particularly among young/middle-aged populations during cold seasons and post-pandemic periods. These findings underscore the urgency for real-time air quality alerts and targeted protection strategies during high-risk periods to mitigate respiratory health burdens.

Short-term air pollution exposure and risk of respiratory pathogen infections: an 11-year case-crossover study in Guangzhou, China

BACKGROUND

Limited epidemiological evidence exists on the relationship between short-term exposure to air pollutants and respiratory pathogen infections. This study investigates the association between short-term air pollution exposure and respiratory pathogen infections in Guangzhou, southern China.

METHODS

A time-stratified case-crossover study design was applied. Data from 96,927 patients with suspected respiratory pathogen infections between 2013 and 2023 were collected. The daily air pollutant concentration is obtained from the local environmental monitoring station. Logistic regression was used to assess the effect of air pollutant exposure included in the equation on the risk of respiratory pathogen infection. Generalized additive models were used to analyze the relationship between pollutant exposure and hospital visits, adjusting for potential confounders such as temperature and precipitation. Sub-group analysis was performed to estimate the reliability of the correlations among the subgroups.

RESULTS

The logistic regression model shows that PM2.5, NO2 and CO are included in the variable equation. Single-pollutant models indicate that there is a significant association between short-term exposure to NO2 and CO and an increased risk of hospital visits for respiratory infections, especially on lag day 0, while PM2.5 shows a non-linear relationship. In the multi-pollutant model, for each unit increase in NO2, the risk of hospital visits increased by 11.66%, and for CO, the risk increased by 0.64%. Subgroup analysis showed the effects were more pronounced in minors (< 18 years), while no significant gender differences were observed. Additionally, CO and NO2 interacted with PM2.5, amplifying the risk of infection.

CONCLUSION

This large-scale epidemiological study demonstrates significant associations between short-term air pollutant exposure and respiratory infections, particularly highlighting the risks of NO2 and CO exposure. The findings underscore the critical need for strengthening air quality monitoring and protection strategies in rapidly urbanizing regions, with special attention to vulnerable populations such as minors. These results provide evidence-based support for enhancing environmental health policies in metropolitan areas to better protect public health through improved air quality standards and early warning systems.

Comparison of the rate of healthcare encounters for influenza from source-specific PM2.5 before and after tier 3 vehicle standards in New York state

BACKGROUND

Influenza healthcare encounters in adults associated with specific sources of PM2.5 is an area of active research.

OBJECTIVE

Following 2017 legislation requiring reductions in emissions from light-duty vehicles, we hypothesized a reduced rate of influenza healthcare encounters would be associated with concentrations of PM2.5 from traffic sources in the early implementation period of this regulation (2017-2019).

METHODS

We used the Statewide Planning and Research Cooperative System (SPARCS) to study adult patients hospitalized (N = 5328) or treated in the emergency department (N = 18,247) for influenza in New York State. Using a modified case-crossover design, we estimated the excess rate (ER) of influenza hospitalizations and emergency department visits associated with interquartile range increases in source-specific PM2.5 concentrations (e.g., spark-ignition emissions [GAS], biomass burning [BB], diesel [DIE]) in lag day(s) 0, 0-3 and 0-6. We then evaluated whether ERs differed after Tier 3 implementation (2017-2019) compared to the period prior to implementation (2014-2016).

RESULTS

Each interquartile range increase in DIE in lag days 0-6 was associated with a 21.3% increased rate of influenza hospitalization (95% CI: 6.9, 37.6) in the 2014-2016 period, and a 6.3% decreased rate (95% CI: -12.7, 0.5) in the 2017-2019 period. The GAS/influenza excess rates were larger in the 2017-2019 period than the 2014-2016 period for emergency department visits. We also observed a larger ER associated with increased BB in the 2017-2019 period compared to the 2014-2016 period.

IMPACT STATEMENT

We present an accountability study on the impact of the early implementation period of the Tier 3 vehicle emission standards on the association between specific sources of PM2.5 air pollution on influenza healthcare encounters in New York State. We found that the association between gasoline emissions and influenza healthcare encounters did not lessen in magnitude between periods, possibly because the emissions standards were not yet fully implemented. The reduction in the rates of influenza healthcare encounters associated with diesel emissions may be reflective of past policies to reduce the toxicity of diesel emissions. Accountability studies can help policy makers and environmental scientists better understand the timing of pollution changes and associated health effects.

Mitochondrial fusion protein: a new therapeutic target for lung injury diseases

Mitochondria are essential organelles responsible for cellular energy supply. The maintenance of mitochondrial structure and function relies heavily on quality control systems, including biogenesis, fission, and fusion. Mitochondrial fusion refers to the interconnection of two similar mitochondria, facilitating the exchange of mitochondrial DNA, metabolic substrates, proteins, and other components. This process is crucial for rescuing damaged mitochondria and maintaining their normal function. In mammals, mitochondrial fusion involves two sequential steps: outer membrane fusion, regulated by mitofusin 1 and 2 (MFN1/2), and inner membrane fusion, mediated by optic atrophy 1 (OPA1). Dysfunction in mitochondrial fusion has been implicated in the development of various acute and chronic lung injuries. Regulating mitochondrial fusion, maintaining mitochondrial dynamics, and improving mitochondrial function are effective strategies for mitigating lung tissue and cellular damage. This study reviews the expression and regulatory mechanisms of mitochondrial fusion proteins in lung injuries of different etiologies, explores their relationship with lung injury diseases, and offers a theoretical foundation for developing novel therapeutic approaches targeting mitochondrial fusion proteins in lung injury.

All-Cause and Cause-Specific Mortality Associated with Long-Term Exposure to Fine Particulate Matter in Japan: The Ibaraki Prefectural Health Study

AIMS

Long-term exposure to fine particulate matter (PM2.5) is causally associated with mortality and cardiovascular disease. However, in terms of cardiovascular cause-specific outcomes, there are fewer studies about stroke than about coronary heart disease, particularly in Asia. Furthermore, there remains uncertainty regarding the PM2.5-respiratory disease association. We examined whether long-term exposure to PM2.5 is associated with all-cause, cardiovascular and respiratory disease mortality in Japan.

METHODS

We used data of 46,974 participants (19,707 men; 27,267 women), who were enrolled in 2009 and followed up until 2019, in a community-based prospective cohort study (the second cohort of the Ibaraki Prefectural Health Study). We estimated PM2.5 concentrations using the inverse distance weighing methods based on ambient air monitoring data, and assigned each participant to administrative area level concentrations. A Cox proportional hazard model was applied to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of mortality.

RESULTS

During the average follow-up of 10 years, we confirmed 2,789 all-cause deaths. All outcomes including stroke mortality did not significantly increase as the PM2.5 concentration increased. For non-malignant respiratory disease mortality, the multivariable adjusted HR per 1 µg/m3 increase in the PM2.5 concentration was 1.09 (95% CI = 0.97-1.23).

CONCLUSIONS

In this population exposed to PM2.5 at concentrations of 8.3-13.1 µg/m3, there was no evidence that long-term exposure to PM2.5 had adverse effects on mortality. Weak evidence of positive association observed for non-malignant respiratory disease mortality needs further studies in other populations.

Long-term exposure to air pollution and lower respiratory infections in a large population-based adult cohort in Catalonia

BACKGROUND

Evidence is limited regarding the role of air pollution in acute lower respiratory infections among adults. We assessed the influence of long-term air pollution exposure on hospital admission for lower respiratory infections and whether there are vulnerable subgroups.

METHODS

We used a populational cohort in Catalonia, Spain, comprising 3,817,820 adults residing in Catalonia as of January 1, 2015. Air pollution exposure was assigned to individuaĺs residential address using locally-developed models. We characterized the concentration-response functions between long-term air pollution exposure and hospital admission for lower respiratory infections between 2015 and 2019. We assessed interaction between exposure and clinical and socio-economic factors on multiplicative and additive scales.

RESULTS

An interquartile range exposure increase was associated with an 8 % (95 % Confidence Interval: 5 %-11 %) for Nitrogen Dioxide, 10 % (95 % Confidence Interval: 8 %-13 %) for Particulate Matter with diameter equal to or smaller than 2.5 µm, 5 % (95 % Confidence Interval: 3 %-7%) for Particulate Matter with diameter equal to or smaller than 10 µm and 18 % (95 % Confidence Interval: 14 %-22%) for ozone (adjusted by Nitrogen Dioxide) increase in hospital admissions for respiratory infections. Concentration-response functions were non-linear, with steeper slopes at exposures below the median or at most extreme high values. Associations were consistently greater for individuals over 65 years or with hypertension diagnosis and males.

CONCLUSIONS

Long-term exposure to air pollution was positively associated with hospital admission for lower respiratory infections. Individuals who were older than 65 years, hypertensive or male were most vulnerable.

Combined health effects of air pollutant mixtures on respiratory mortality using BKMR in Hangzhou, China

Previous research on respiratory system mortality primarily focused on understanding their combined effects and have neglected the fact that air pollution mixtures are interrelated. This study used Bayesian kernel machine regression (BKMR) to analyze the relationship between air pollutant mixtures and respiratory mortality in Hangzhou, China from 2014 to 2018. The results showed a significant association between pollutant mixtures and respiratory system mortality primarily driven by PM2.5 and SO2. The joint exposure of air pollutants was positively correlated with respiratory system mortality at lag 01 and lag 02 days. The estimated joint effects of log-transformed mixture air pollution exposure on log-transformed respiratory system mortality increased from -0.02 (95% CI: -0.08-0.02) and -0.01 (95% CI: -0.05-0.04) at the 25th percentile to 0.06 (95% CI: 0.01-0.12) and 0.04 (95% CI: -0.001, 0.09) at the 75th percentile. Additionally, there was evidence of an interaction between O3 and PM10. This study confirms that exposure to multiple pollutants is a significant public health problem facing the Hangzhou population given the compounded effect proven with regression analysis, while furthermore, the control of PM2.5 and SO2 also represents a serious concern.Implications: Evidence indicates interactions between O3 and PM10. This study demonstrates that exposure to multiple pollutants exerts combined effects on the public health of the Hangzhou population, highlighting the importance of controlling PM2.5 and SO2.

Air Pollution as an Environmental Risk Factor for Alzheimer's Disease and Related Dementias

Alzheimer's disease and related dementias are a leading cause of morbidity in our aging populations. Although influenced by genetic factors, fewer than 5% of Alzheimer's disease and related dementia cases are due solely to genetic causes. There is growing scientific consensus that these dementias arise from complex gene by environment interactions. The 2020 Lancet Commission on dementia prevention, intervention, and care identified 12 modifiable risk factors of dementia, including lifestyle, educational background, comorbidities, and environmental exposures to environmental contaminants. In this review, we summarize the current understanding and data gaps regarding the role(s) of environmental pollutants in the etiology of Alzheimer's disease and related dementias with a focus on air pollution. In addition to summarizing findings from epidemiological and experimental animal studies that link airborne exposures to environmental contaminants to increased risk and/or severity of Alzheimer's disease and related dementias, we discuss currently hypothesized mechanism(s) underlying these associations, including peripheral inflammation, neuroinflammation and epigenetic changes. Key data gaps in this rapidly expanding investigative field and approaches for addressing these gaps are also addressed.

Air pollution, dysbiosis and diseases: pneumonia, asthma, COPD, lung cancer and irritable bowel syndrome

With substantial effects on human health, air pollution has become a major global concern. Air pollution has been linked to numerous gastrointestinal and respiratory diseases with increasing mortalities. The gut and respiratory dysbiosis brought about by air pollution has recently received much attention. This review attempts to provide an overview of the types of air pollutants, their sources, their impact on the respiratory and gut dysbiotic patterns and their correlation with five major diseases including pneumonia, asthma, COPD, lung cancer and irritable bowel syndrome. Deeper insights into the links between pollutants, dysbiosis and disease may pave the way for novel diagnostic biomarkers for prognosis and early detection of these diseases, as well as ways to ease the disease burden.

Air Pollution in Relation to COVID-19 Morbidity and Mortality: A Large Population-Based Cohort Study in Catalonia, Spain (COVAIR-CAT)

INTRODUCTION

Evidence from epidemiological studies based on individual-level data indicates that air pollution may be associated with coronavirus disease 2019 (COVID-19) severity. We aimed to test whether (1) long-term exposure to air pollution is associated with COVID-19-related hospital admission or mortality in the general population; (2) short-term exposure to air pollution is associated with COVID-19-related hospital admission following COVID-19 diagnosis; (3) there are vulnerable population subgroups; and (4) the influence of long-term air pollution exposure on COVID-19-related hospital admissions differed from that for other respiratory infections.

METHODS

We constructed a cohort covering nearly the full population of Catalonia through registry linkage, with follow- up from January 1, 2015, to December 31, 2020. Exposures at residential addresses were estimated using newly developed spatiotemporal models of nitrogen dioxide (NO23), particulate matter ≤2.5 μm in aerodynamic diameter (PM2.5), particulate matter ≤10 μm in aerodynamic diameter (PM10), and maximum 8-hr-average ozone (O3) at a spatial resolution of 250 m for the period 2018-2020.

RESULTS

The general population cohort included 4,660,502 individuals; in 2020 there were 340,608 COVID-19 diagnoses, 47,174 COVID-19-related hospital admissions, and 10,001 COVID-19 deaths. Mean (standard deviation) annual exposures were 26.2 (10.3) μg/m3 for NO2, 13.8 (2.2) μg/m3 for PM2.5, and 91.6 (8.2) μg/m3 for O3. In Aim 1, an increase of 16.1 μg/m3 NO2 was associated with a 25% (95% confidence interval [CI]: 22%-29%) increase in hospitalizations and an 18% (10%-27%) increase in deaths. In Aim 2, cumulative air pollution exposure over the previous 7 days was positively associated with COVID-19-related hospital admission in the second pandemic wave (June 20 to December 31, 2020). Associations of exposure were driven by exposure on the day of the hospital admission (lag0). Associations between short-term exposure to air pollution and COVID-19-related hospital admission were similar in all population subgroups. In Aim 3, individuals with lower individual- and area-level socioeconomic status (SES) were identified as particularly vulnerable to the effects of long-term exposure to NO2 and PM2.5 on COVID-19-related hospital admission. In Aim 4, long-term exposure to air pollution was associated with hospital admission for influenza and pneumonia: (6%; 95% CI: 2-11 per 16.4-μg/m3 NO2 and 5%; 1-8 per 2.6-μg/m3 PM2.5) as well as for all lower respiratory infections (LRIs) (18%; 14-22 per 16.4-μg/m3 NO2 and 14%; 11-17 per 2.6-μg/m3 PM2.5) before the COVID-19 pandemic. Associations for COVID-19-related hospital admission were larger than those for influenza or pneumonia for NO2, PM2.5, and O3 when adjusted for NO2.

CONCLUSIONS

Linkage across several registries allowed the construction of a large population-based cohort, tracking COVID-19 cases from primary care and testing data to hospital admissions, and death. Long- and short-term exposure to ambient air pollution were positively associated with severe COVID-19 events. The effects of long-term air pollution exposure on COVID-19 severity were greater among those with lower individual- and area-level SES.

Effects of Community Assets on Major Health Conditions in England: A Data Analytic Approach

INTRODUCTION

The broader determinants of health including a wide range of community assets are extremely important in relation to public health outcomes. Multiple health conditions, multimorbidity, is a growing problem in many populations worldwide.

METHODS

This paper quantified the effect of community assets on major health conditions for the population of England over six years, at a fine spatial scale using a data analytic approach. Community assets, which included indices of the health system, green space, pollution, poverty, urban environment, safety, and sport and leisure facilities, were quantified in relation to major health conditions. The health conditions examined included high blood pressure, obesity, dementia, diabetes, mental health, cardiovascular conditions, musculoskeletal conditions, respiratory conditions, kidney and liver disease, and cancer. Cluster analysis and dendrograms were calculated for the community assets and major health conditions. For each health condition, a statistical model with all community assets was fitted, and model selection was performed. The number of significant community assets for each health condition was recorded. The unique variance, explained by each significant community asset per health condition, was quantified using hierarchical variance partitioning within an analysis of variance model.

RESULTS

The resulting data indicate major health conditions are often clustered, as are community assets. The results suggest that diversity and richness of community assets are key to major health condition outcomes. Primary care service waiting times and distance to public parks were significant predictors of all health conditions examined. Primary care waiting times explained the vast majority of the variances across health conditions, with the exception of obesity, which was better explained by absolute poverty.

CONCLUSIONS

The implications of the combined findings of the health condition clusters and explanatory power of community assets are discussed. The vast majority of determinants of health could be accounted for by healthcare system performance and distance to public green space, with important covariate socioeconomic factors. Emphases on community approaches, significant relationships, and asset strengths and deficits are needed alongside targeted interventions. Whilst the performance of the public health system remains of key importance, community assets and local infrastructure remain paramount to the broader determinants of health.

Breathing in danger: Understanding the multifaceted impact of air pollution on health impacts

Air pollution, a pervasive environmental threat that spans urban and rural landscapes alike, poses significant risks to human health, exacerbating respiratory conditions, triggering cardiovascular problems, and contributing to a myriad of other health complications across diverse populations worldwide. This article delves into the multifarious impacts of air pollution, utilizing cutting-edge research methodologies and big data analytics to offer a comprehensive overview. It highlights the emergence of new pollutants, their sources, and characteristics, thereby broadening our understanding of contemporary air quality challenges. The detrimental health effects of air pollution are examined thoroughly, emphasizing both short-term and long-term impacts. Particularly vulnerable populations are identified, underscoring the need for targeted health risk assessments and interventions. The article presents an in-depth analysis of the global disease burden attributable to air pollution, offering a comparative perspective that illuminates the varying impacts across different regions. Furthermore, it addresses the economic ramifications of air pollution, quantifying health and economic losses, and discusses the implications for public policy and health care systems. Innovative air pollution intervention measures are explored, including case studies demonstrating their effectiveness. The paper also brings to light recent discoveries and insights in the field, setting the stage for future research directions. It calls for international cooperation in tackling air pollution and underscores the crucial role of public awareness and education in mitigating its impacts. This comprehensive exploration serves not only as a scientific discourse but also as a clarion call for action against the invisible but insidious threat of air pollution, making it a vital read for researchers, policymakers, and the general public.

In-Utero exposure to potential sources of indoor air pollution and umbilical cord blood leukocyte telomere length

Indoor air pollution (IAP) has been associated with various adverse health effects. However, the evidence regarding such an association with leukocyte telomere length (LTL) in cord blood samples is still scarce. Therefore, the present study aimed to assess the relationship between exposure to indicators of IAP and LTL in umbilical cord blood samples. This cross-sectional study was based on 188 mother-newborn pairs who participated in our study between 2020 and 2022 in Isfahan, Iran. Umbilical LTL was measured by quantitative real-time polymerase chain reaction (qRT-PCR) technique. Linear mixed-effect models were used to assess the relationship between IAP indicators and umbilical LTL, adjusted for relevant covariates. The median (interquartile range (IQR)) of umbilical LTL was 0.92 (0.47). In fully adjusted models, frequency of using degreasing spray during pregnancy (times per month) (β = -0.047, 95% CI:0.09, -0.05, P-value = 0.02), using air freshener spray during pregnancy (β = -0.26, 95% CI: -0.5, -0.02, P-value = 0.03) and frequency of using insecticides during pregnancy (times per month) (β = -0.025, 95% CI: -0.047, -0.003, P-value = 0.02) were significantly associated with shorter umbilical LTL. There was a positive significant relationship between the frequency of using cleaning spray during pregnancy (times per month) with umbilical LTL (β = 0.019, 95% CI: 0.005, 0.033, P-value = 0.01). Furthermore, the direct connection of the parking with home and the frequency of using barbecue (times per week) were marginally associated with shorter umbilical LTL. For other indicators of IAP, we did not observe any statistically significant associations. Overall, this study suggested a negative association between prenatal exposure to IAP during pregnancy and umbilical LTL.

Acid etching post-treatment enhanced fungal sterilization performance of copper-manganese-cerium oxide in liquid and aerosol: Materials and molecular biological mechanisms

Bioaerosol is one of the main ways to spread respiratory infectious diseases. In order to further improve the sterilization efficiency of copper-manganese-cerium oxide (CuMnCeOx), the post-treatment method based on acid etching was adopted. The results showed that sterilization efficiency of the treated CuMnCeOx could reach 99% in aerosol with space velocity of 1400 h-1. L(+)-ascorbic acid successfully promoted the formation of Cu+, oxygen vacancies and the generation of reactive oxygen species (ROS) on the surface of the treated CuMnCeOx. During sterilization in liquid system, the transcriptome identified 316 differentially expressed genes, including 270 up-regulated genes and 46 down-regulated genes. Differentially expressed genes were significantly enriched in cell wall (GO:0005618) and external encapsulating structure (GO:0030312). Up-regulated genes were shown in regulation of reactive oxygen species biosynthetic processes (GO:1903409, GO:1903426, GO:1903428) and positive regulation all of reactive oxygen species metabolic process (GO:2000379), indicating that ROS induced cell death by destroying cell wall.

Projecting non-communicable diseases attributable to air pollution in the climate change era: a systematic review

OBJECTIVES

Climate change is a major global issue with significant consequences, including effects on air quality and human well-being. This review investigated the projection of non-communicable diseases (NCDs) attributable to air pollution under different climate change scenarios.

DESIGN

This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 flow checklist. A population-exposure-outcome framework was established. Population referred to the general global population of all ages, the exposure of interest was air pollution and its projection, and the outcome was the occurrence of NCDs attributable to air pollution and burden of disease (BoD) based on the health indices of mortality, morbidity, disability-adjusted life years, years of life lost and years lived with disability.

DATA SOURCES

The Web of Science, Ovid MEDLINE and EBSCOhost databases were searched for articles published from 2005 to 2023.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

The eligible articles were evaluated using the modified scale of a checklist for assessing the quality of ecological studies.

DATA EXTRACTION AND SYNTHESIS

Two reviewers searched, screened and selected the included studies independently using standardised methods. The risk of bias was assessed using the modified scale of a checklist for ecological studies. The results were summarised based on the projection of the BoD of NCDs attributable to air pollution.

RESULTS

This review included 11 studies from various countries. Most studies specifically investigated various air pollutants, specifically particulate matter <2.5 µm (PM2.5), nitrogen oxides and ozone. The studies used coupled-air quality and climate modelling approaches, and mainly projected health effects using the concentration-response function model. The NCDs attributable to air pollution included cardiovascular disease (CVD), respiratory disease, stroke, ischaemic heart disease, coronary heart disease and lower respiratory infections. Notably, the BoD of NCDs attributable to air pollution was projected to decrease in a scenario that promotes reduced air pollution, carbon emissions and land use and sustainable socioeconomics. Contrastingly, the BoD of NCDs was projected to increase in a scenario involving increasing population numbers, social deprivation and an ageing population.

CONCLUSION

The included studies widely reported increased premature mortality, CVD and respiratory disease attributable to PM2.5. Future NCD projection studies should consider emission and population changes in projecting the BoD of NCDs attributable to air pollution in the climate change era.

PROSPERO REGISTRATION NUMBER

CRD42023435288.

Air pollution and bronchiolitis: a case-control study in Antwerp, Belgium

This case-control study aimed to investigate the association between short-term (1 to 5 days) and medium-term (31 days) exposure to air pollutants (PM2.5, PM10, BC, NO2) at home/daycare and the risk of 'severe bronchiolitis' (defined as 'requiring hospitalization for bronchiolitis') in children under 2 years in Antwerp, Belgium. We included 118 cases and 79 controls admitted to three general hospitals from October 2020 to June 2021. Exposure levels were predicted using an interpolation model based on fixed measuring stations. We used unconditional logistic regression analysis to assess associations, with adjustment for potential confounders. There were hardly any significant differences in the day-to-day air pollution values between cases and controls. Medium-term (31 days) exposure to PM2.5, PM10, and NO2 was however significantly higher in cases than controls in univariate analysis. Logistic regression revealed an association between severe bronchiolitis and interquartile range (IQR) increases of PM2.5 and PM10 at home and in daycare, as well as IQR increases of NO2 in daycare. Controls were however overrepresented in low pollution periods. Time-adjustment reduced the odds ratios significantly at home for PM2.5 and PM10 (aOR 1.54, 95%CI 0.51-4.65; and 2.69, 95%CI 0.94-7.69 respectively), and in daycare for. PM2.5 (aOR 2.43, 95%CI 0.58-10.1). However, the association between severe bronchiolitis and medium-term air pollution was retained in daycare for IQR increases of PM10 (aOR 5.13, 95%CI 1.24-21.28) and NO2 (aOR 3.88, 95%CI 1.56-9.61) in the time-adjusted model.  Conclusion: This study suggests a possible link between severe bronchiolitis and medium-term (31 days) air pollution exposure (PM10 and NO2), particularly in daycare. Larger studies are warranted to confirm these findings. What is Known: • Bronchiolitis is a leading cause of hospitalization in infants globally and causes a yearly seasonal wave of admissions in paediatric departments worldwide. • Existing studies, mainly from the USA, show heterogeneous outcomes regarding the association between air pollution and bronchiolitis. What is New: • There is a possible link between severe bronchiolitis and medium-term (31 days) air pollution exposure (PM10 and NO2), particularly in daycare. • Larger studies are needed to validate these trends.

Respiratory Health Effects of Air Pollutants

Air pollution is a risk factor for asthma and respiratory infection. Avoidance of air pollution is the best approach to mitigating the impacts of pollution. Personal preventive strategies are possible, but policy interventions are the most effective ways to prevent pollution and its effect on asthma and respiratory infection.

Long-Term Exposure to AIR Pollution and COVID-19 Mortality and Morbidity in DENmark: Who Is Most Susceptible? (AIRCODEN)

INTRODUCTION

Early ecological studies have suggested a link between air pollution and Coronavirus Diseases 2019 (COVID-19); however, the evidence from individual-level prospective cohort studies is still sparse. Here, we have examined, in a general population, whether long-term exposure to air pollution is associated with the risk of contracting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and developing severe COVID-19, resulting in hospitalization or death and who is most susceptible. We also examined whether long-term exposure to air pollution is associated with hospitalization or death due to COVID-19 in those who have tested positive for SARS-CoV-2.

METHODS

We included all Danish residents 30 years or older who resided in Denmark on March 1, 2020. and followed them in the National COVID-19 Surveillance System until first positive test (incidence), COVID-19 hospitalization, or death until April 26, 2021. We estimated mean levels of nitrogen dioxide (NO2), particulate matter with an aerodynamic diameter <2.5 μm (PM2.5), black carbon (BC), and ozone (O3) at cohort participants' residence in 2019 by the Danish Eulerian Hemispheric Model/Urban Background Model. We used Cox proportional hazard models to estimate the associations of air pollutants with COVID-19 incidence, hospitalization, and mortality adjusting for age, sex, and socioeconomic status (SES) at the individual and area levels. We examined effect modification by age, sex, SES (education, income, wealth, employment), and comorbidities with cardiovascular disease, respiratory disease, acute lower respiratory infections, diabetes, lung cancer, and dementia. We used logistic regression to examine association of air pollutants with COVID-19-related hospitalization or death among SARS-CoV-2 positive patients, adjusting for age, sex, individual- and area-level SES.

RESULTS

Of 3,721,810 people, 138,742 were infected, 11,270 hospitalized, and 2,557 died from COVID-19 during 14 months of follow-up. We detected strong positive associations with COVID-19 incidence, with hazard ratio (HR) and 95% confidence interval (CI) of 1.10 (CI: 1.05-1.14) per 0.5-μg/m3 increase in PM2.5 and 1.18 (CI: 1.14-1.23) per 3.6-μg/m3 increase in NO2. For COVID-19 hospitalizations and for COVID-19 deaths, corresponding HRs and 95% CIs were 1.09 (CI: 1.01-1.17) and 1.19 (CI: 1.12-1.27), respectively for PM2.5, and 1.23 (CI: 1.04-1.44) and 1.18 (CI: 1.03-1.34), respectively for NO2. We also found strong positive and statistically significant associations with BC and negative associations with O3. Associations were strongest in those aged 65 years old or older, participants with the lowest SES, and patients with chronic cardiovascular, respiratory, metabolic, lung cancer, and neurodegenerative disease. Among 138,742 individuals who have tested positive for SARS-Cov-2, we detected positive association with COVID-19 hospitalizations (N = 11,270) with odds ratio and 95% CI of 1.04 (CI: 1.01- 1.08) per 0.5-μg/m3 increase in PM2.5 and 1.06 (CI: 1.01-1.12) per 3.6-μg/m3 increase in NO2, but no association with PM with an aerodynamic diameter <10 μm (PM10), BC, or O3, and no association between any of the pollutants and COVID-19 mortality (N = 2,557).

CONCLUSIONS

This large nationwide study provides strong new evidence in support of association between long-term exposure to air pollution and COVID-19.

Air pollution exposure, SARS-CoV-2 infection, and immune response in a cohort of healthcare workers of a large university hospital in Milan, Italy

Several studies have examined the possible relationship between air pollutants and the risk of COVID-19 but most returned controversial findings. We tried to assess the association between (short- and long-term) exposure to particulate and gaseous pollutants, SARS-CoV-2 infections, and immune response in a population of healthcare workers (HCWs) with well-characterized individual data. We collected occupational and clinical characteristics of all HCWs who performed a nasopharyngeal swab (NPS) for detecting SARS-CoV-2 at the Policlinico Hospital in Milan (Lombardy, Italy) between February 24, 2020 (day after first documented case of COVID-19 in our hospital) and December 26, 2020 (day before start of the vaccination campaign). Each subject was assigned daily average levels of particulate matter ≤10 μm (PM10), nitrogen dioxide (NO2), and ozone (O3) retrieved from the air quality monitoring station closest to his/her residential address. Air pollution data were treated as time-dependent variables, generating person-days at risk. Multivariate Poisson regression models were fit to evaluate the rate of positive NPS and to assess the association between air pollution and antibody titer among NPS-positive HCWs. Among 3712 included HCWs, 635 (17.1%) had at least one positive NPS. A 10 μg/m3 increase in NO2 average concentration in the four days preceding NPS was associated with a higher risk of testing positive [Incidence Rate Ratio (IRR) = 1.08, 95% confidence interval (CI): 1.01; 1.16)]. When considering a 1 μg/m3 increase in 2019 annual NO2 average, we observed a higher risk of infection (IRR: 1.02, 95%CI: 1.00; 1.03) and an increased antibody titer (+2.4%, 95%CI: 1.1; 3.6%). Findings on PM10 and O3 were less consistent and, differently from NO2, were not confirmed in multipollutant models. Our study increases the body of evidence suggesting an active role of air pollution exposure on SARS-CoV-2 infection and confirms the importance of implementing pollution reduction policies to improve public health.

Resolution of inflammation in xenobiotic-induced mucosal injury and chronic disease

It has been appreciated for decades that exposure to toxicants can induce injury and inflammation leading to multiple pathologies in many organ systems. However, recently the field has begun to recognize that toxicants can cause chronic pathologies and diseases by impairing processes known to promote the resolution of inflammation. This process is comprised of dynamic and active responses including pro-inflammatory mediator catabolism, dampening of downstream signaling, production of pro-resolving mediators, apoptosis, and efferocytosis of inflammatory cells. These pathways promote the return to local tissue homeostasis and prevent chronic inflammation that can lead to disease. The aim of this special issue was to identify and report on the potential hazards of toxicant exposure on the resolution of inflammation responses. Papers included in the issue also provide insights into biological mechanisms by which toxicants perturb these resolution processes and identify potential therapeutic targets.

Cytokine fields and the polarization of the immune response

Certain cells that participate in the immune response are known to become polarized in their production of cytokines. It is postulated that, after initial polarization at the site of antigenic encounter, the different types of cell arriving at this site are induced to conform to the local cytokine field, implying that they share common regulatory circuits. As they migrate, these cells might, in turn, spread the particular cytokine field. Therefore, the field is 'infectious' in nature. Propagation of the cytokine field must be regulated somehow. The invasion of the cytokine field into an organ or the entire body could have major immunological consequences.