Air pollution and public health: emerging hazards and improved understanding of risk

The mediating effect of maternal blood lipids on the association between maternal exposure to PM2.5 and birth weight: a retrospective birth cohort study in Zhejiang, China

BACKGROUND

Maternal PM2.5 exposure and lipid levels during pregnancy were independently detected associated with birth weight. Potential mediating factors still remain unclear.

METHODS

This study aimed to examine the association of maternal PM2.5 exposure and birth weight, and explore the potential mediation effect of maternal blood lipids in the relationship between PM2.5 exposure and birth weight. 5,162 pregnant women from Zhejiang, China were included in the study during 2013-2014. We measured blood lipids for each participant in the second and third trimesters. Air pollution exposure in residential districts was estimated based on satellite data for each individual throughout three trimesters in pregnancy. Linear mixed-effects models were employed to examine associations between PM2.5 and birth weight. Using a mediation analysis approach, we decomposed the total effect of PM2.5 on birth weight into natural direct and indirect effects via blood lipid concentration.

RESULTS

After adjusting for covariates, a 10 µg/m3 increment in PM2.5 during the second trimester was directly associated with an 11.65 g increase in birth weight (95% CI: 2.99, 20.31 g). The indirect effects of PM2.5 exposure (each 10 µg/m3 increase) on birth weight, mediated through elevated maternal lipid levels, were - 2.35 g (95% CI: -4.07, -0.63 g) for total cholesterol to high-density lipoprotein cholesterol ratio (TC: HDL ratio), -0.69 g (95% CI: -1.16, -0.22 g) for Triglycerides (TG), and - 1.80 g (95% CI: -3.19, -0.41 g) for HDL-C, during the second trimester.

CONCLUSIONS

Findings suggest prenatal PM2.5 exposure may impact term birth weight via direct biological effects and lipid-mediated pathways, underscoring the importance of incorporating air pollution mitigation into perinatal care and advancing biomarker-driven fetal monitoring. Future research should clarify PM2.5 component-specific effects, decode placental-fetal lipid regulatory mechanisms, and validate pollution-metabolism-outcome relationships through multi-regional cohorts to inform precision environmental health interventions and clinical risk management.

Computational insights into exploring the potential effects of environmental contaminants on human health

With rapid industrialization and urbanization, the increasing prevalence of air and water pollutants poses a significant threat to public health. Traditional research methods, such as epidemiological studies and in vitro/in vivo experiments, provide valuable biological insights but are often costly, time-consuming, and limited in scale. To address this gap, this study develops a machine learning-based approach to predict the carcinogenicity of pollutants. Using the dataset of carcinogenic and non-carcinogenic molecules that we collected, the pretrained KPGT model trained with molecular fingerprints and descriptors achieved an AUC of 0.83, surpassing traditional machine learning models. To validate this model, common pollutants from air and water sources were analyzed. Further clustering classified these pollutants into five distinct groups. Target prediction analysis identified key genes associated with representative pollutant molecules, such as MAPK1, MTOR, and PTPN11. GO and KEGG pathway analyses, along with survival analysis, revealed potential carcinogenic mechanisms and prognostic implications. Our findings contribute to improved pollution risk assessment and evidence-based environmental policy development, ultimately aiding in the mitigation of pollutant-related health risks.

Effects of particulate air pollution exposure on lung-brain axis and related miRNAs modulation in mouse models

Particulate matter exposure is linked to numerous health issues, including respiratory, cardiovascular, and neurodegenerative diseases. This review focuses on the biological mechanisms through which air pollution influences the lung-brain axis, highlighting the role of miRNAs in regulating gene pathways affected by PM. Some microRNAs (miRNAs) are identified as key modulators of cellular processes, including inflammation, epithelial-to-mesenchymal transition (EMT), and blood-brain barrier integrity. Using mice models to study these effects allows for controlled experimentation on the systemic distribution of PM across biological barriers. Among the imaging technologies, Positron Emission Tomography is the best approach to monitor the distribution and effects of PM in vivo. The research underscores the importance of miRNA profiles as potential markers for the health effects of PM exposure, suggesting that specific miRNAs could serve as early indicators of damage to the lung-brain axis.

Healthful Plant-Based Dietary Patterns Associated with Reduced Adverse Effects of Air Pollution on COPD: Findings from a Large Cohort Study

OBJECTIVES

The potential of a plant-based diet (PD) to mitigate the adverse effects of long-term air pollution exposure on chronic obstructive pulmonary disease (COPD) remains uncertain. This study aims to explore both the independent and synergistic impacts of air pollution components and PD on COPD risk.

METHODS

Annual concentrations of air pollutants, including particulate matter (PM2.5, PM2.5-10, and PM10), as well as nitrogen oxides (NOX) and nitrogen dioxide (NO2), were estimated using a land-use regression model. We calculated the plant-based diet index (PDI), healthy plant-based diet index (hPDI), and unhealthy plant-based diet index (uPDI) by evaluating scores of 17 food categories. Cox regression was performed to evaluate their individual and combined effects on COPD risk.

RESULTS

This prospective cohort study included 162,741 participants. Every standard deviation increase in PM2.5, NO2, and NOX exposure was associated with an increased risk of COPD, with an adjusted HR (95% CI) of 1.049 (1.019, 1.079), 1.065 (1.034, 1.096), and 1.063 (1.035, 1.092), respectively. Compared with low-quality hPDI, moderate- and high-quality hPDI were associated with a lower risk of COPD with an adjusted HR (95% CI) of 0.884 (0.827, 0.946) and 0.758 (0.697, 0.825), respectively. For the combined effects, with the level of hPDI increasing, the joint effects of hPDI with PM2.5, NO2, and NOX showed a gradually increasing negative impact on COPD risk (p-interaction = 0.001, 0.005, and 0.005, respectively).

CONCLUSIONS

Exposure to PM2.5, NO2, and NOx may elevate the risk of chronic obstructive pulmonary disease (COPD), whereas adherence to a high-quality hPDI could potentially counteract this association. Future research should explore the underlying biological mechanisms, assess the long-term effects of diet, and evaluate the effectiveness of dietary modifications in diverse populations to inform targeted prevention policies.

Air pollution and systemic immune biomarkers in early life: A systematic review

INTRODUCTION

Children's rapid development and immature immune systems place them at a higher risk of adverse health outcomes associated with air pollution exposure. However, the specific mechanisms in which air pollution mediates immune dysregulation in youth are poorly understood. Thus, we aimed to systematically review the available epidemiological evidence surrounding the effects of indoor and ambient air pollution exposure on systemic immune biomarkers in early life (from birth to 18 years old).

METHODS

based on PRISMA guidelines, we developed a systematic search strategy and defined inclusion and exclusion criteria to retrieve publications from PubMed, SCOPUS and Web of Science published up to August 10th, 2024. Quality assessment and evidence evaluation were also performed. Five independent reviewers participated in the process.

RESULTS

In total, 96 studies were included. We found limited evidence of a causal relationship between prenatal ambient PM2.5 and reduced T-cells (CD3+ and CD8+), as well as between postnatal PM exposure and increased IgE levels or allergic sensitization. For the rest of exposure-outcome combinations we classified the evidence as inadequate, mainly due to the limited number of studies available or the lack of consistency in the results obtained among them. This was particularly the case for indoor air pollution research, for which only 12 studies were available.

CONCLUSION

the present systematic review highlights the need for further research on the impacts of air pollution on youth's immune system. We provided recommendations for future studies in order to better understand the early subclinical and clinical effects of air pollution and the underlying biological pathways, and identify the dynamics of the innate and adaptive immune responses to environmental threats. Considering the significance of childhood immunity on health outcomes within all stages of life, and the globally extensive burden of air pollution exposure, further research on this topic should be prioritized.

Importance of sub-23 nm particles in traffic environments: Particle number emission factors and extrathoracic deposition doses

New research suggests that exposure to ultrafine particles (UFPs; particle diameter dp < 100 nm) is particularly harmful to brain health. One pathway into the body is via deposition in the respiratory system, where the smallest UFPs deposit efficiently in human extrathoracic airways. Traffic is a major source of these particles, yet sub-23 nm (dp < 23 nm) particles are currently unregulated in engine emission testing worldwide, including the stringent requirements of the European Union, nor are there requirements for ambient monitoring. In this study, we report size-resolved particle number emission factors (EFs) for traffic and estimates of extrathoracic dose rates of sub-23 nm particles. The EFs and dose rates are based on measurements conducted in different urban environments, including roads, tunnels, an airport, and a riverside, in two Central European cities (Düsseldorf and Prague) from March to April 2022. A key difference between the cities is that Düsseldorf has a low-emission zone in its central area and a newer vehicle fleet compared to Prague. Overall, traffic-influenced sites had large EFs for sub-23 nm particles. In the highway and tunnel environments, EFs of particles with dp > 2.5 nm were between 2 and 18 times greater than the EFs of particles with dp > 23 nm. Near the airport, the EF of particles with dp > 23 nm was already high, being 2-9 times higher than in other environments. The number concentrations of sub-23 nm particles varied significantly within the studied cities, and dose rates (measured in billions of particles per hour) differed by up to a factor of ten or more depending on the location.

Green infrastructure and its influence on urban heat island, heat risk, and air pollution: A case study of Porto (Portugal)

Green infrastructure plays a fundamental role in mitigating the effects of urban heat island. Vegetation may trap particulates and absorb pollutants like ozone, thus improving air quality. Understanding how green infrastructure reduces urban heat island and air pollution within specific urban zones can provide valuable insights for better urban design, improved environmental quality, and increased resident well-being. This study addresses the impact of green infrastructure deprivation on urban heat island effects, air pollution, and heat-related health risks in Porto, Portugal. The study employs a monitoring network to analyse the spatial distribution of air temperature and humidity throughout the city, although with specific gaps in coverage. With a focus on the role of urban green infrastructure in mitigating air urban heat island effects, this paper uses the data from Porto Digital's monitoring network between 2019 and 2022. Heat risk index assesses vulnerability to heat-related health risks by integrating land surface temperature, land cover, and demographic data through remote sensing. Green infrastructure mapping is conducted to quantify the spatial distribution of vegetation elements in the study area. The data analysis from 2019 to 2022 reveals that urban heat island intensity is more pronounced during the summer and at night. Approximately 32.6% of Porto is in areas with a high heat risk index, indicating increased vulnerability to heat-related health risks. The study finds that limited green infrastructure exacerbates this vulnerability, particularly in socioeconomically disadvantaged areas. Additionally, persistent air pollution hotspots, including elevated levels of ozone and particulate matter, contribute to the intensity of urban heat island. These findings underscore the need for integrating green infrastructure into urban planning to mitigate urban heat island and air pollution, improve urban resilience, and promote environmental justice.

The impaired response of nasal epithelial cells to microplastic stimulation in asthma and COPD

Microplastic particles from the air are inhaled and accumulate in the lungs, potentially causing immunological reactions and airway tissue injury. This study aimed to evaluate the biological effects of polyamide fibres on nasal epithelium co-cultivated with macrophages in control, asthma, and COPD groups. Nasal epithelial cells alone or in co-culture with monocyte-derived macrophages were exposed to polyamide fibres for 48 h. We identified 8 differentially expressed genes (DEGs) in controls, 309 DEGs in asthma (including ANKRD36C, BCL2L15, FCGBP, and IL-19), and 22 DEGs in COPD (e.g., BCL2L15, IL-19, CAPN14, PGBD5, PTPRH), particularly in epithelial/moMφ co-cultures. Microplastic exposure induced inflammatory cytokine secretion only for IL-8 production in controls (epithelial/ moMφs co-culture) and asthmatic (monoculture) epithelial cells in contrast to PM2.5, which was a strong inflammatory inducer. Gene Ontology analysis revealed that microplastic exposure affected sterol and cholesterol biosynthesis, secondary alcohol metabolism, and acetyl-CoA metabolism in asthma, and cell motility, chemokine signaling, leukocyte migration, and chemotaxis in COPD. Microplastic stimulation altered the response of airway epithelial cells in obstructive lung diseases differently than in controls, linking to Th2 inflammation, stress response modulation, and carcinogenesis. Asthmatic and COPD epithelial cells are more susceptible to damage from microplastic fibre exposure.

Investigation of the expression of Cis P-tau and Pin1 proteins following air pollution induction in the brain tissue of C57BL/6 mice

Alzheimer's disease (AD) is a multifactorial disease in which environmental factors play a role. Among environmental factors, air pollution is a vital issue in modern life. Despite extensive considerations, it remains uncertain how pollution mediates neurodegeneration in AD. Beta-amyloids and hyperphosphorylated tau proteins are the two main pathological markers that have been studied in AD so far. Tau protein is basically a phosphoprotein whose functions are controlled by phosphorylation. The function of tau protein is to be located on the surface of microtubules and stabilize them. Studies have shown that phosphorylated tau protein (p-tau) exists in cis and trans conformations at Thr231, among which cis is highly neurotoxic. The Pin1 enzyme performs the conversion of cis to trans or vice versa. In this study, an experimental mouse model was designed to investigate the formation of cis p-tau by inducing air pollution. In this way, mice were randomly exposed to pollution at 2-week, 1-month, and 2-month intervals. We investigated the formation of phosphorylated cis tau form during air pollution on mouse brains using Western blots and immunofluorescence. The fluorescent imaging results and Western blotting analysis of mouse brains revealed a significant accumulation of cis p-tau in pollution-treated mice models compared to the healthy control mice. According to Western blot results, air pollution induction caused a significant decrease in Pin1 protein. The results clearly show that the tauopathy observed during air pollution is mediated through the formation of cis tau. Our findings unravel tauopathy mysteries upon pollution and would help find a possible therapeutic target to fight the devastating disorder caused by modern life.

Ambient PM2.5 orchestrates M1 polarization of alveolar macrophages via activating glutaminase 1-mediated glutaminolysis in acute lung injury

The temporary explosive growth events of atmospheric fine particulate matter (PM2.5) pollution during late autumn and winter seasons still frequently occur in China. High-concentration exposure to PM2.5 aggravates lung inflammation, leading to acute lung injury (ALI). Alveolar macrophages (AMs) participate in PM2.5-induced pulmonary inflammation and injury. The polarization of AMs is dependent on metabolic reprogramming. However, the mechanism underlying the PM2.5-induced glutaminase-mediated glutaminolysis in AM polarization is still largely obscure. In this study, we found that PM2.5-treated mice exhibited pulmonary dysfunction and inflammation. The concentrations of glutamate and succinate were increased in PM2.5-treated lungs and AMs compared with the controls, whereas glutamine and α-ketoglutarate (α-KG) levels were decreased, indicating that glutaminolysis in AMs was aberrantly activated as evidenced by increased mRNA and protein levels of GLS1 after PM2.5 exposure. Moreover, we determined that the GLS1/nuclear factor kappa-B (NF-κB)/hypoxia-inducible factor-1α (HIF-1α) pathway regulated M1 polarization of AMs upon PM2.5 exposure. Inhibition of glutaminolysis by GLS1 specific inhibitor CB-839 and GLS1 siRNA significantly decreased PM2.5-induced M1 macrophage polarization and attenuated pulmonary damage. Taken together, our findings reveal a novel mechanism by which a metabolic program regulates M1 polarization of AMs and suggest that GLS1-mediated glutaminolysis is a potential therapeutic target for treating PM2.5-induced ALI.

The Role of Air Pollution and Olfactory Dysfunction in Alzheimer's Disease Pathogenesis

The escalating issue of air pollution contributes to an alarming number of premature fatalities each year, thereby posing a significant threat to global health. The focus of recent research has shifted towards understanding its potential association with neurodegenerative diseases, specifically Alzheimer's disease (AD). AD is recognised for its characteristic deposition of toxic proteins within the brain, leading to a steady deterioration of cognitive capabilities, memory failure, and, ultimately, death. There is burgeoning evidence implying that air pollution may be a contributing factor to this protein build up, thereby intensifying the course of AD. It has been demonstrated that the olfactory system, responsible for smell perception and processing, acts as a potential gateway for airborne pollutants to inflict brain damage. This review aims to elucidate the relationship between air pollution, olfactory deterioration, and AD. Additionally, this review aims to highlight the potential mechanisms through which pollutants might instigate the development of AD and the role of the olfactory system in disease pathogenesis. Moreover, the diverse model systems employed in exploring the correlation, public health policy ramifications, and prospective directions for future research will be discussed.

Next-generation air filtration nanotechnology for improved indoor air quality

Indoor air quality (IAQ) significantly affects human health, with pollutants such as organic, inorganic substances, and biological contaminants contributing to various respiratory, neurological, and immunological diseases. In this review, we highlighted the need for advanced air filtration technologies to mitigate these pollutants, which are emitted from household products, building materials, combustion processes, and bioaerosols. While traditional HVAC systems and mechanical filtration methods have been effective, they are often energy-intensive and limited in their ability to capture specific pollutants. To address these limitations, nanotechnology-based air filtration technologies, particularly those utilizing electrospinning processes, offer promising alternatives. This review classifies pollutants and details the working principles of next-generation filters, focusing on passive, self-powered, and externally powered mechanisms. These advanced filters achieve high filtration efficiency with minimal pressure drop, enhanced pollutant capture, and in some cases, health monitoring capabilities. This review emphasizes the significance of ongoing research into eco-friendly and sustainable filtration systems to enhance IAQ and minimize health risks linked to long-term exposure to indoor air pollutants.

Does industrial robot adoption inhibit environmental pollution in China? An empirical study on energy consumption and green technology innovation

In this research, we develop a theoretical model to examine the relationship between the adoption of industrial robots and environmental pollution. Additionally, we explore the mechanisms through which the implementation of industrial robots influences pollutant emissions. Our findings indicate that the adoption of industrial robots has a negative effect on environmental pollution. This conclusion is drawn from a panel data analysis of 283 cities in China from 2006 to 2020, utilizing a double fixed effect model. Further mechanism tests reveal that the use of industrial robots contributes to a reduction in pollution emissions by optimizing the energy consumption structure and enhancing energy efficiency. Meanwhile, industrial robot usage decreases pollution emissions by enhancing pollution treatment capabilities and boosting green technological innovation. Furthermore, regions characterized by heightened environmental awareness demonstrate a more significant improvement in environmental pollution levels when industrial robots are applied to their production process. This study ultimately demonstrates that integrating industrial robots can lead to a reduction in pollutant emissions, thereby yielding sustainable benefits for the environment.

Aerosol Fluorescent Labeling via Probe Molecule Volatilization

The physicochemical properties of aerosols, including hygroscopicity, phase state, pH, and viscosity, influence important processes ranging from virus transmission and pulmonary drug delivery to atmospheric light scattering and chemical reactivity. Despite their importance, measurements of these key properties in aerosols remain experimentally challenging due to small particle sizes and low mass densities in air. Fluorescence probe spectroscopy is one of the only analytical techniques that is capable of experimentally determining these properties in situ in a nondestructive and minimally perturbative manner. However, the application of fluorescence probe spectroscopy to important classes of aerosols including exhaled respiratory and ambient atmospheric aerosols has been limited due to a typical reliance on premixing the probe molecule with particle constituents prior to particle generation, which is not always possible. Here, a method for aerosol fluorescent labeling based on probe molecule volatilization is developed. The method is first applied to label model polyethylene glycol (PEG) aerosols with two different polarity-sensitive probes, Nile red and Prodan. The similarity of the relative humidity-dependent fluorescent emission of each probe between prelabeled and volatilized-probe PEG particles validated the methodology. A preliminary application of the technique to indicate the hygroscopicity of artificial saliva respiratory particles and model atmospheric secondary organic aerosol particles is demonstrated. The methodology developed here paves the way for future studies applying powerful fluorescent probe-based analytical techniques to study exhaled or natural aerosols for which fluorescent prelabeling is not possible.

Untargeted metabolomic analysis reveals a time-course hepatic metabolism disorder induced by short-term 6PPD exposure in rats

The tire antioxidant 6PPD has garnered extensive attention due to its widespread presence in the environment and the harmful effects of its transformation products on aquatic organisms. 6PPD has been detected in airborne dust, and it can enter mammals through inhalation exposure. While the toxic effects of 6PPD exposure have been reported in mammals, its effects on hepatic metabolism still remain poorly understood. Here, we collected the serum and liver samples at 1, 6, and 72 h following a single oral exposure of 100 mg/kg body weight (bw) 6PPD, respectively. We also investigated changes in serum and hepatic physiological indicators and metabolites, correspondingly. Results indicated that single time oral exposure a high dose of 6PPD did not significantly affect the physiological indexes of rats within a short time frame. However, untargeted metabolomics analysis of the metabolites in the liver at 1, 6, and 72 h revealed that the number of differential expression metabolites gradually increased over time and the most affected substances were lipids and lipid-like molecules. Interestingly, the KEGG pathway enrichment analysis indicated that 6PPD disrupted the riboflavin metabolism, leading to a significant decrease in FMN levels at all time points. In addition, the hepatic glucose metabolism was significantly affected at 6 and 72 h after oral administration. Taken together, short-term exposure to 6PPD disturbed lipid and riboflavin metabolism and gradually affected glucose metabolism in the liver of rats. These findings revealed the impacts of 6PPD on the hepatic metabolism in animals, and also offered some important insights into its toxicology and health risk.

Combining Cold Atmospheric Plasma and Environmental Nanoparticle Removal Device Reduces Neurodegenerative Markers

Ageing leads to a gradual deterioration of the organs, with the brain being particularly susceptible, often leading to neurodegeneration. This process includes well-known changes such as tau hyperphosphorylation and beta-amyloid deposition, which are commonly associated with neurodegenerative diseases but are also present in ageing. These structures are triggered by earlier cellular changes such as energy depletion and impaired protein synthesis, both of which are essential for cell function. These changes may in part be induced by environmental pollution, which has been shown to accelerate these processes. Cold Atmospheric Plasma (CAP) or atmospheric pressure gas discharge plasmas have shown promise in activating the immune system and improving cellular function in vitro, although their effects at the organ level remain poorly understood. Our aim in this work is to investigate the effect of a device that combines CAP treatment with the effective removal of environmental nanoparticles, typical products of pollution, on the activity of aged mouse brains. The results showed an increase in energy capacity, a reduction in reticulum stress and an activation of cellular autophagic clearance, minimising aggresomes in the brain. This leads to a reduction in key markers of neurodegeneration such as tau hyperphosphorylation and beta-amyloid deposition, demonstrating the efficacy of the tested product at the brain level.

The temporal trend and disparity in short-term health impacts of fine particulate matter in California (2006-2019)

Most epidemiological studies assume that the relationship between short-term air pollution exposure and health outcomes is constant over time, which ignores potential changes in population composition and particulate matter emission sources. Limited studies have assessed changes in the relationship between fine particulate matter (PM2.5) and adverse health outcomes over time, with mixed results. Additionally, there is a need to identify which subgroups are disproportionately impacted over time by PM2.5-related health consequences. Therefore, we aimed to examine whether temporal trends exist in the relationships between daily PM2.5 exposure and circulatory and respiratory acute care utilization in California from 2006 to 2019. We further assessed whether certain subpopulations are more susceptible to PM2.5 exposure by demographic characteristics and extreme wildfire frequency. Daily PM2.5 concentrations estimated from a stacked ensemble model and daily cause-specific acute care utilization and demographic data from the California Department of Health Care Access and Information. We analyzed this relationship using modified two-stage Bayesian hierarchical models, where we first did not consider temporal trends, then stratified by two periods, and finally flexibly considered non-linear changes over time. Increases in circulatory (0.56 %; 95 % credible interval (CI): 0.17 %, 0.96 %) and respiratory acute care utilization risk (2.61 %; 95%CI: 2.29 %, 2.94 %) were found with every 10 μg/m3 increase in PM2.5 on the same day and previous two days. These risks were found to increase over time, where 0.13 % (95%CI: 0.02 %, 0.22 %) and 1.40 % (95%CI: 1.24 %, 1.54 %) increases were identified for circulatory and respiratory acute care utilizations, respectively, from the first (2006-2012) to second period (2013-2019). Differences by age, sex, race/ethnicity, and extreme wildfire frequency were noted. These findings confirm that air pollution guidelines should consider the dynamic nature of epidemiological dose-response and can provide insight for targeted air pollution control and adaptation policies designed to reduce PM2.5 exposure, particularly for the most susceptible subpopulations.

Association of exposure to air pollutants and risk of mortality among people living with HIV: a systematic review

BACKGROUND

People living with HIV (PLWH) are more vulnerable to infectious and non-infectious comorbidities due to chronic inflammation and immune dysfunction. Air pollution is a major global health risk, contributing to millions of deaths annually, primarily from cardiovascular and respiratory diseases. However, the link between air pollution and mortality risk in PLWH is underexplored. This systematic review assesses the association between exposure to pollutants such as particulate matter (PM), nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3), and carbon monoxide (CO) and mortality risk in PLWH.

METHODS

A systematic search of PubMed, Web of Science, and Embase was conducted for studies published up to August 2024. Eligibility criteria included cohort, case-control, and cross-sectional studies assessing air pollution exposure and mortality in PLWH. Nested-Knowledge software was used for screening and data extraction. The Newcastle-Ottawa Scale was applied for quality assessment. A narrative approach and tabular summarization were used for data synthesis and presentation.

RESULTS

Nine studies, mostly from China, demonstrated a significant association between long-term exposure to PM1, PM2.5, and PM10 and increased risks of AIDS-related and all-cause mortality in PLWH. Hazard ratios for mortality increased by 2.38-5.13% per unit increase in PM concentrations, with older adults (> 60), females, and those with lower CD4 counts (< 500 cells/µL) being more vulnerable. Short-term exposure to ozone and sulfur dioxide also increased mortality risks, particularly during the warm season and in older populations. Specific pollutants like ammonium (NH4⁺) and sulfate (SO4²⁻) had the strongest links to elevated mortality.

CONCLUSION

Air pollution, especially fine particulate matter and ozone, is associated with a higher risk of mortality in PLWH. Targeted interventions to reduce pollution exposure in vulnerable subgroups are crucial. Further research is needed to confirm these findings in diverse regions and develop effective mitigation strategies.

Time-Series analysis of short-term exposure to air pollutants and daily hospital admissions for stroke in Tabriz, Iran

BACKGROUND

Air pollution is considered one of the risk factors for stroke prevalence in the long term and incidence in the short term. Tabriz is one of the most important industrial cities in Iran. Hence, air pollution has always been one of the main concerns in environmental health in the region.

METHOD

The patient data were retrieved from electronic health records of the primary tertiary hospital of the city (Imam Reza Hospital). Air pollution data was obtained from the Environmental Protection Agency and is generated by 8 sensor stations spread across the city. Average daily values were calculated for CO, NO, NO, NOx, O3, SO2, PM2.5, and PM10 from hourly measurement data. Autoregressive integrated moving average (ARIMA-X) model with 3 lag days was developed to assess the correlation.

RESULTS

Air pollutants and hospital admission data were collected for 1821 day and includes 4865 stroke cases. our analysis showed no statistically significant association between the daily concentrations of CO (p = 0.41), NOx (p = 0.96), O3 (p = 0.65), SO2 (p = 0.91), PM2.5 (p = 0.44), and PM10 (p = 0.36). Only the binary COVID variable which was used to distinguish between COVID-19 era and other days, was significant (p value = 0.042). The goodness of fit measures, Root Mean Squared Error (RMSE), and Median Absolute Error (MAE) were 1.81 and 1.19, respectively.

CONCLUSION

In contrast to previous reports on the subject, we did not find any pollutant significantly associated with an increased number of stroke patients.

'Incense is the one that keeps the air fresh': indoor air quality perceptions and attitudes towards health risk

BACKGROUND

Air pollution is of significant environmental and public health concern globally. While much research has historically focused on outdoor air pollution, indoor air pollution has been relatively under-explored despite its strong connection with health outcomes, particularly respiratory health. Studies on air pollution exposure mitigation consistently reveal a significant knowledge gap between the understanding of air pollution as a health risk among lay individuals and expert scientists. This study aimed to assess how people define and understand the concept of 'clean air' within their home setting.

METHODS

We adopted a mixed-methods approach which used a guided questionnaire designed to elicit both quantitative and qualitative data, collected as digital voice notes. The total sample (n = 40) comprised data from two socially different sites of science and non-science events. We compared whether the notion of clean air inside homes differs between these two different social contexts and how views and 'sense' of indoor air pollution are formed. The concept of 'place' facilitated fluidity in our explorative analysis. Insights allowed us to assess the extent to which context mediates individuals' perceptions of indoor air pollution and attitudes towards health risk.

RESULTS

We found that individuals' insights were embodied in repetitive day-to-day activities (e.g. cleaning and cooking). Three key themes emerged (1) Stimulative Effects, (2) Contextual Conditions, and (3) Risk Attitudes. Sensory perceptions such as sight, smell and temperature primarily motivated participants to assess air quality inside their homes. These perceptions were shaped by contextual conditions, influencing how individuals perceived their health risk and were subsequently motivated to spend personal time considering or seeking information about household air pollution, or improving their home air quality.

CONCLUSIONS

Our insights revealed that social, geographical, and contextual factors play a crucial role in individuals' understandings of indoor air pollution. These dimensions should be integrated into designs of effective public health risk communication strategies. Our findings highlight that common lay perceptions and practices intended to improve air quality may pose health risks. Therefore, risk communication about household air pollution must extend beyond objective information by considering contextual factors that shape how people interpret and respond to air quality issues.

CLINICAL TRIAL NUMBER

Not applicable.

Mechanistic insights regarding neuropsychiatric and neuropathologic impacts of air pollution

Air pollution is a significant environmental health risk for urban areas and developing countries. Air pollution may contribute to the incidence of cardiopulmonary and metabolic diseases. Evidence also points to the role of air pollution in worsening or developing neurological and neuropsychiatric conditions. Inhaled pollutants include compositionally differing mixtures of respirable gaseous and particulate components of varied sizes, solubilities, and chemistry. Inhalation of combustibles and volatile organic compounds (VOCs) or other irritant particulate matter (PM) may trigger lung sensory afferents which initiate a sympathetic stress response via activation of the hypothalamic-pituitary-adrenal (HPA) and sympathetic-adrenal-medullary (SAM) axes. Activation of SAM and HPA axes are associated with selective inhibition of hypothalamic-pituitary-gonadal (HPG) and hypothalamic-pituitary-thyroid (HPT) axes following exposure. Regarding chronic exposure in susceptible hosts, these changes may become pathological by causing neuroinflammation, neurotransmitter, and neuroendocrine imbalances. Soluble PM, such as metals and nano-size particles may translocate across the olfactory, trigeminal, or vagal nerves through retrograde axonal transport, or through systemic circulation which may disrupt the blood-brain barrier (BBB) and deposit in neural tissue. Neuronal deposition of metallic components can have a negative impact through multiple molecular mechanisms. In addition to systemic translocation, the release of pituitary and stress hormones, altered metabolic hormonal status and resultant circulating metabolic milieu, and sympathetically and HPA-mediated changes in immune markers, may secondarily impact the brain through a variety of regulatory adrenal hormone-dependent mechanisms. Several reviews covering air pollution as a risk factor for neuropsychiatric disorders have been published, but no reviews discuss the in-depth intersection between molecular and stress-related neuroendocrine mechanisms, thereby addressing adaptation and susceptibility variations and link to peripheral tissue effects. The purpose of this review is to discuss evidence regarding neurochemical, neuroendocrine, and molecular mechanisms which may contribute to neuropathology from air pollution exposure. This review also covers bi-directional neural and systemic interactions which may raise the risk for air pollution-related systemic illness.

Air-Pollution-Mediated Microbial Dysbiosis in Health and Disease: Lung-Gut Axis and Beyond

Growing evidence suggests physiological and pathological functions of lung and gut microbiomes in various pathologies. Epidemiological and experimental data associate air pollution exposure with host microbial dysbiosis in the lungs and gut. Air pollution through increased reactive oxygen species generation, the disruption of epithelial barrier integrity, and systemic inflammation modulates microbial imbalance. Microbiome balance is crucial in regulating inflammation and metabolic pathways to maintain health. Microbiome dysbiosis is proposed as a potential mechanism for the air-pollution-induced modulation of pulmonary and systemic disorders. Microbiome-based therapeutic approaches are increasingly gaining attention and could have added value in promoting lung health. This review summarizes and discusses air-pollution-mediated microbiome alterations in the lungs and gut in humans and mice and elaborates on their role in health and disease. We discuss and summarize the current literature, highlight important mechanisms that lead to microbial dysbiosis, and elaborate on pathways that potentially link lung and lung microbiomes in the context of environmental exposures. Finally, we discuss the lung-liver-gut axis and its potential pathophysiological implications in air-pollution-mediated pathologies through microbial dysbiosis.

Ambient Air Pollution and Incident Cardiovascular Disease in People With Type 2 Diabetes Mellitus: A Cohort Study

OBJECTIVES

We aimed to assess the effect of air pollution on incident cardiovascular disease (CVD) in people with type 2 diabetes mellitus (T2DM).

METHODS

We tracked 486 T2DM patients from 2012 to 2021. Cox regression models were applied to assess the hazard of exposure to particulate matter, carbon monoxide (CO), ozone, nitrogen dioxide, and sulfur dioxide (SO 2 ) on incident CVD, revealing hazard ratios (HRs).

RESULTS

CVD incidents occurred in 73 individuals. Among men, each 1-ppm increase in CO levels raised the risk of CVD (HR: 2.66, 95% CI: 1.30-5.44). For women, a 5-ppb rise in SO 2 increased CVD risk (HR: 1.60, 95% CI: 1.11-2.30). No notable impact of particulate pollutants was found.

CONCLUSIONS

Persistent exposure to gaseous air pollutants, specifically CO and SO 2 , is linked to the development of CVD in men and women with T2DM.

Diesel exhaust particle extract elicits an oxPAPC-like transcriptomic profile in macrophages across multiple mouse strains

Air pollution is a prominent cause of cardiopulmonary illness, but uncertainties remain regarding the mechanisms mediating those effects as well as individual susceptibility. Macrophages are highly responsive to particles, and we hypothesized that their responses would be dependent on their genetic backgrounds. We conducted a genome-wide analysis of peritoneal macrophages harvested from 24 inbred strains of mice from the Hybrid Mouse Diversity Panel (HMDP). Cells were treated with a DEP methanol extract (DEPe) to elucidate potential pathways that mediate acute responses to air pollution exposures. This analysis showed that 1247 genes were upregulated and 1383 genes were downregulated with DEPe treatment across strains. Pathway analysis identified oxidative stress responses among the most prominent upregulated pathways; indeed, many of the upregulated genes included antioxidants such as Hmox1, Txnrd1, Srxn1, and Gclm, with NRF2 (official gene symbol: Nfe2l2) being the most significant driver. DEPe induced a Mox-like transcriptomic profile, a macrophage subtype typically induced by oxidized phospholipids and likely dependent on NRF2 expression. Analysis of individual strains revealed consistency of overall responses to DEPe and yet differences in the degree of Mox-like polarization across the various strains, indicating DEPe × genetic interactions. These results suggest a role for macrophage polarization in the cardiopulmonary toxicity induced by air pollution.

Understanding the impact of distance and disadvantage on lung cancer care and outcomes: a study protocol

BACKGROUND

Lung cancer is the third most common cancer in the UK and the leading cause of cancer mortality globally. NHS England guidance for optimum lung cancer care recommends management and treatment by a specialist team, with experts concentrated in one place, providing access to specialised diagnostic and treatment facilities. However, the complex and rapidly evolving diagnostic and treatment pathways for lung cancer, together with workforce limitations, make achieving this challenging. This place-based, behavioural science-informed qualitative study aims to explore how person-related characteristics interact with a person's location relative to specialist services to impact their engagement with the optimal lung pathway, and to compare and contrast experiences in rural, coastal, and urban communities. This study also aims to generate translatable evidence to inform the evidence-based design of a patient engagement intervention to improve lung cancer patients' and informal carers' participation in and experience of the lung cancer care pathway.

METHODS

A qualitative cross-sectional interview study with people diagnosed with lung cancer < 6 months before recruitment (in receipt of surgery, radical radiotherapy, or living with advanced disease) and their informal carers. Participants will be recruited purposively from Barts Health NHS Trust and United Lincolnshire Hospitals NHS Trusts to ensure a diverse sample across urban and rural settings. Semi-structured interviews will explore factors affecting individuals' capability, opportunity, and motivation to engage with their recommended diagnostic and treatment pathway. A framework approach, informed by the COM-B model, will be used to thematically analyse facilitators and barriers to patient engagement.

DISCUSSION

The study aligns with the current policy priority to ensure that people with cancer, no matter where they live, can access the best quality treatments and care. The evidence generated will be used to ensure that lung cancer services are developed to meet the needs of rural, coastal, and urban communities. The findings will inform the development of an intervention to support patient engagement with their recommended lung cancer pathway.

PROTOCOL REGISTRATION

The study received NHS Research Ethics Committee (Ref: 23/SC/0255) and NHS Health Research Authority (IRAS ID 328531) approval on 04/08/2023. The study was prospectively registered on Open Science Framework (16/10/2023; https://osf.io/njq48 ).

Respiratory Diseases Associated With Wildfire Exposure in Outdoor Workers

Wildfires, including forest fires, bushfires, and landscape fires, have become increasingly prevalent, fueled by climate change and environmental factors and posing significant challenges to both ecosystems and public health. This review article examines the relationship between wildfires and respiratory diseases in outdoor workers, with a main focus on airway disease. In addition to the expected effects of direct thermal respiratory injuries and possible carbon monoxide poisoning, there are associations between wildfires and upper and lower respiratory effects, including infections as well as exacerbations of asthma and chronic obstructive pulmonary disease. A few studies have also shown an increased risk of new-onset asthma among wildfire firefighters. Outdoor workers are likely to have greater exposure to wildfire smoke with associated increased risks of adverse effects. As wildfires become increasingly prevalent globally, it is crucial to understand the various dimensions of this association. Furthermore, this review addresses preventive measures and potential interventions to alleviate the airway burden on individuals during and after work with wildfires events.

Respiratory conditions and health symptoms associated with air pollution amongst children aged six years and below in Melusi Informal Settlement, Tshwane Metropolitan Municipality, South Africa: a cross-sectional study

BACKGROUND

Respiratory conditions and health symptoms associated with air pollution in children are a major public health concern, as their immune systems and lungs are not yet fully developed. This study aimed to assess self-reported respiratory conditions and health symptoms associated with air pollution sources amongst children aged six years and below in Melusi informal settlement, Tshwane Metropolitan Municipality, South Africa.

METHODS

With a quantitative cross-sectional study design, parents/caregivers of children aged six years and below (n = 300) from eight Early Childhood Development Centres were invited to participate in the study. This study employed complete sampling, and data was collected using the modified International Study of Asthma and Allergies in Children. The chi-square and multiple logistic regression models were used to analyze data, with p < 0.05 in the adjusted odds ratios considered as being statistically significant.

RESULTS

Three models were run to examine the predictors of wheezing in the past 12 months, dry cough, and itchy-watery eyes. The model for asthma was excluded, as only seven participants reported having asthma. Wheeze in the past 12 months was associated with participants living in the area for more than three years (OR 2.96 95%CI: 1.011-8.674). Furthermore, having a dog in the house in the past 12 months was associated with wheeze in the past 12 months (OR 5.98 95%CI: 2.107-16.967). There was an association between duration of stay in a residence and dry cough prevalence (OR 5.63 95%CI: 2.175-14.584). Trucks always or frequently passing near homes was associated with itchy-watery eyes (OR 3.27 95%CI: 1.358-7.889). 59% (59%) of participants perceived the indoor air quality in their homes to be good, while 6% perceived it as poor. In contrast, 36% of participants perceived the outdoor air quality to be good, and 19.7% perceived it as poor.

CONCLUSION

The association between perceived air pollution exposure, self-reported respiratory conditions, and health symptoms amongst children is complex. Further research is required to better understand the multifaceted nature of air pollution and its impact on the health of children.

Microscopic and spectroscopic analysis of atmospheric iron-containing single particles in Lhasa, Tibet

The Tibetan Plateau, known as the "Third Pole", is currently in a state of perturbation caused by intensified human activity. In this study, 56 samples were obtained at the five sampling sites in typical area of Lhasa city and their physical and chemical properties were investigated by TEM/EDS, STXM, and NEXAFS spectroscopy. After careful examination of 3387 single particles, the results showed that Fe should be one of the most frequent metal elements. The Fe-containing single particles in irregular shape and micrometer size was about 7.8% and might be mainly from local sources. Meanwhile, the Fe was located on the subsurface of single particles and might be existed in the form of iron oxide. Interestingly, the core-shell structure of iron-containing particles were about 38.8% and might be present as single-, dual- or triple-core shell structure and multi-core shell structure with the Fe/Si ratios of 17.5, 10.5, 2.9 and 1.2, respectively. Meanwhile, iron and manganese were found to coexist with identical distributions in the single particles, which might induce a synergistic effect between iron and manganese in catalytic oxidation. Finally, the solid spherical structure of Fe-containing particles without an external layer were about 53.4%. The elements of Fe and Mn were co-existed, and might be presented as iron oxide-manganese oxide-silica composite. Moreover, the ferrous and ferric forms of iron might be co-existed. Such information can be valuable in expanding our understanding of Fe-containing particles in the Tibetan Plateau atmosphere.

Association of anaemia with indoor air pollution among older Indian adult population: multilevel modelling analysis of nationally representative cross-sectional study

INTRODUCTION

Anaemia is a disease of public health importance with multi-causal pathways. Previous literature suggests the role of indoor air pollution (IAP) on haemoglobin levels, but this has been studied less due to logistic constraints. A high proportion of the population in developing countries, including India, still depends on unclean fuel, which exacerbates IAP. The objective was to study the association between anaemia and IAP among the older Indian adult population (≥ 45 years) as per gender.

METHODS

Our study analysed the nationally representative dataset of the Longitudinal Ageing Study in India (LASI 2017-18, Wave-1). We have documented the association of anaemia (outcome variable) with IAP (explanatory variable). To reduce the confounding effects of demographic and socioeconomic; health related and behavioural covariates; propensity score matching (PSM) was conducted. Nested multilevel regression modelling was conducted. States and union territories were categorised cross tabulated as low, middle and high as per anaemia and IAP exposure. P value < 0.05 was considered statistically significant. SATA version 17 was used for analysis.

RESULTS

More than half (52.52%) of the participants were exposed to IAP (male (53.55%) > female (51.63%)). The odds of having anaemia was significantly 1.19 times higher (AOR 1.19 (1.09-1.31)) among participants using unclean/ solid fuel. The adjusted odds were significantly higher among participants exposed to pollution-generating sources (AOR 1.30; 1.18-1.43), and household indoor smoking (AOR 1.17 (1.07-1.29). The odds of having anaemia were significantly higher (AOR 1.26; 1.15-1.38) among participants exposed to IAP, which was higher in males (AOR 1.36; 1.15-1.61) than females (AOR 1.21; 1.08-1.35). Empowered Action Group (EAG) states like Uttar Pradesh, Chhattisgarh, Madhya Pradesh, Bihar had both high anaemia and IAP exposure.

CONCLUSION

This study established the positive association of anaemia with indoor air pollution among older Indian adults through a nationally representative large dataset. The association was higher among men. Further research is recommended to understand detailed causation and to establish temporality. It is a high time to implement positive intervention nationally to decrease solid/ unclean fuel usage, vulnerable ventilation, indoor smoking, IAP and health hazards associated with these with more focused actions towards EAG states.

Knowledge, Attitudes, and Practices Regarding Air Pollution among Medical Students

Background: Air pollution has emerged as a global public health concern. Specifically, in Medellín, Colombia, episodes of elevated air pollution have been documented. Medical students' knowledge of air pollution is paramount for implementing future interventions directed toward patients. The aim of this research was to delineate the knowledge, attitudes, and practices regarding air pollution among medical students at a private university in Medellín. Methods: A cross-sectional study involving 352 medical students was conducted. A questionnaire was administered, generating scores ranging from 0 to 100, where a higher score signified better knowledge, attitudes, and practices. Data were analyzed using frequencies, summary measures, non-parametric tests, and linear regression. Results: In total, 31% rated the education received at the university on the relationship between health and air quality as fair to poor, and 81% perceived the air quality in the city as poor. The knowledge score was 77.8 (IQR 71.1-85.6), with 90% acknowledging that exposure to air pollution increases the risk of various diseases. The attitudes score was 82.1 (IQR 71.8-87.2), and 25.9% believed that air pollution is a multifactorial problem, rendering their actions ineffective. In terms of practices, the score was 50 (IQR 42.9-57.1), indicating that students either did not employ protective measures against pollution or used inappropriate practices such as masks or air purifiers. Regression analysis revealed no association between knowledge and practices. Conclusion: The findings of this study underscore that medical students possess commendable knowledge regarding the health effects of air pollution. However, their adoption of inappropriate practices for self-protection is evident. The lack of correlation between knowledge and practices highlights the necessity of educational initiatives to be complemented by regulatory and cultural interventions.

Study of secondary organic aerosol formation and aging using ambient air in an oxidation flow reactor during high pollution events over Delhi

Secondary aerosols constitute a significant fraction of atmospheric aerosols, yet our understanding of their formation mechanism and fate is very limited. In this work, the secondary organic aerosol (SOA) formation and aging of ambient air of Delhi are studied using a potential aerosol mass (PAM) reactor, an oxidation flow reactor (OFR), coupled with aerosol chemical speciation monitor (ACSM), proton transfer reaction time of flight mass spectrometer (PTR-ToF-MS), and scanning mobility particle sizer with counter (SMPS + C). The setup mimics atmospheric aging of up to several days with the generation of OH radicals. Variations in primary volatile organic compounds (VOCs) and oxygenated volatile organic compounds (OVOCs) as a function of photochemical age were investigated. Primary VOCs such as benzene, toluene, xylene, trimethyl benzene, etc. decrease and OVOCs like formic acid, formaldehyde, acetone, ethanol, etc. increase substantially upon oxidation in OFR. The highest organic aerosol (OA) enhancement was observed for the 4.2 equivalent photochemical days of aging i.e., 1.84 times the ambient concentration, and net OA loss was observed at very high OH exposure, typically after 8.4 days of photochemical aging due to heterogeneous oxidation followed by fragmentation/evaporation. In ambient air, OA enhancement is highest during nighttime due to the high concentrations of precursor VOCs in the atmosphere. SMPS + C results demonstrated substantial new particle formation upon aging and decrement in preexisting aerosol mass. This is the first experimental study conducting an in-situ evaluation of potential SOA mass generated from the ambient aerosols in India.

Decreased air quality shows minimal influence on peak summer attendance at forested Pacific West national parks

Wildfires are increasing in duration and intensity across the United States' Pacific West region, resulting in heightened particulate matter from smoke in the atmosphere. Levels of peak particulate matter are concurrent to peak visitor attendance at National Parks, given seasonal alignment with summer vacation travel and heightened forest fire conditions. Particulate matter threatens visitor health and safety and contributes to poor visibility and a deteriorated visitor experience. To assess visitation response to diminished air quality, we utilized wildfire-generated particulate matter (PM2.5) data in conjunction with monthly attendance records for three ecoregions containing eight national parks in Washington, Oregon, and California from 2009 to 2019. We analyzed daily PM2.5 levels from data gridded at the 10 km scale for National Park Service units by Level III forest ecoregions within the National Park Service's Pacific West Unit. Data were then compared to normalized monthly visitation trends for each of the ecoregions using two statistical methods Kendall's Tau and Analysis of Variance (ANOVA) with post-hoc Tukey tests. Results demonstrate that attendance at these national parks does not decrease in response to increased PM2.5 levels. Instead, we see several statistically significant increases in attendance across these ecoregions during periods of reduced air quality. Of 115 shifts between air quality categories during the busy season of July to September, there are no significant decreases in attendance as air quality worsens. These findings suggest that visitors are willing to tolerate reduced air quality compared to other factors such as temperature or precipitation. Given that park units within each ecoregion feature diverse historical contexts, varied built environments, and unique ecological systems, our discussion specifically addresses managerial concerns associated with maintained high levels of visitation during suboptimal, and potentially dangerous, conditions. There is substantial need for specific, scalable approaches to mitigate adverse health and experiential impacts as visitors are exposed to increased risks during a range of exertional activities associated with diverse settings.

Costs of Air Pollution in California's San Joaquin Valley: A Societal Perspective of the Burden of Asthma on Emergency Departments and Inpatient Care

Introduction

The San Joaquin Valley (SJV) is often recognized as one of the most polluted regions in the US. Periods of pollution exposure are associated with increased health burden related to respiratory inflammation and undermined lung function, which aggravates respiratory diseases such as asthma and leads to symptoms such as coughing, wheezing, or difficulty breathing. Asthma costs US$ 82 billion annually in healthcare costs, missed work and school in the US.

Methods

Employing a societal perspective, a cost of illness design was combined with environmental epidemiological methods to analyze the economic impact of O3, NO2, and PM2.5-related adverse respiratory health outcomes amongst SJV residents who attended the emergency department (ED) or were hospitalized in 2016.

Results

Asthma exacerbations monetized value ranged from US$ 3353 to US$ 5003 per ED visit and for hospital admissions US$ 2584 per inpatient day for adults 65 years and older to US$ 3023 per child. The estimated value to society in healthcare costs, productivity losses, school absences, and opportunity costs from air pollution adverse health outcomes totaled US$ 498,014,124 in ED visits and US$ 223,552,720 in hospital admissions for the SJV population in 2016. The marginal reduction in the background concentrations of pollutants would avert 21,786 ED adverse events and 19,328 hospitalizations from the health burden on the SJV population or US$ 8,024,505 cost savings due to O3, US$ 82,482,683 from NO2 reductions, and US$ 46,214,702 from decreased concentration of PM2.5.

Conclusion

This study provides evidence that air pollution is a negative externality that imposes substantial social, environmental, and healthcare costs on the SJV. Furthermore, the region would avert significant adverse health outcomes realizing economic savings by reducing air pollution and exposures.

The Effect of Diesel Exhaust Particles on Adipose Tissue Mitochondrial Function and Inflammatory Status

Air pollution poses a significant global health risk, with fine particulate matter (PM2.5) such as diesel exhaust particles (DEPs) being of particular concern due to their potential to drive systemic toxicities through bloodstream infiltration. The association between PM2.5 exposure and an increased prevalence of metabolic disorders, including obesity, metabolic syndrome, and type 2 diabetes mellitus (T2DM), is evident against a backdrop of rising global obesity and poor metabolic health. This paper examines the role of adipose tissue in mediating the effects of PM2.5 on metabolic health. Adipose tissue, beyond its energy storage function, is responsive to inhaled noxious stimuli, thus disrupting metabolic homeostasis and responding to particulate exposure with pro-inflammatory cytokine release, contributing to systemic inflammation. The purpose of this study was to characterize the metabolic response of adipose tissue in mice exposed to either DEPs or room air (RA), exploring both the adipokine profile and mitochondrial bioenergetics. In addition to a slight change in fat mass and a robust shift in adipocyte hypertrophy in the DEP-exposed animals, we found significant changes in adipose mitochondrial bioenergetics. Furthermore, the DEP-exposed animals had a significantly higher expression of adipose inflammatory markers compared with the adipose from RA-exposed mice. Despite the nearly exclusive focus on dietary factors in an effort to better understand metabolic health, these results highlight the novel role of environmental factors that may contribute to the growing global burden of poor metabolic health.

Ambient PM2.5 and productivity-adjusted life years lost in Brazil: a national population-based study

Enormous health burden has been associated with air pollution and its effects continue to grow. However, the impact of air pollution on labour productivity at the population level is still unknown. This study assessed the association between premature death due to PM2.5 exposure and the loss of productivity-adjusted life years (PALYs), in Brazil. We applied a novel variant of the difference-in-difference (DID) approach to assess the association. Daily all-cause mortality data in Brazil were collected from 2000-2019. The PALYs lost increased by 5.11% (95% CI: 4.10-6.13%), for every 10 µg/m3 increase in the 2-day moving average of PM2.5. A total of 9,219,995 (95% CI: 7,491,634-10,921,141) PALYs lost and US$ 268.05 (95% CI: 217.82-317.50) billion economic costs were attributed to PM2.5 exposure, corresponding to 7.37% (95% CI: 5.99-8.73%) of the total PALYs lost due to premature death. This study also found that 5,005,306 PALYs could be avoided if the World Health Organization (WHO) air quality guideline (AQG) level was met. In conclusion, this study demonstrates that ambient PM2.5 exposure is associated with a considerable labour productivity burden relating to premature death in Brazil, while over half of the burden could be prevented if the WHO AQG was met. The findings highlight the need to reduce ambient PM2.5 levels and provide strong evidence for the development of strategies to mitigate the economic impacts of air pollution.

A conceptional model integrating geographic information systems (GIS) and social media data for disease exposure assessment

Although previous studies have acknowledged the potential of geographic information systems (GIS) and social media data (SMD) in assessment of exposure to various environmental risks, none has presented a simple, effective and user-friendly tool. This study introduces a conceptual model that integrates individual mobility patterns extracted from social media, with the geographic footprints of infectious diseases and other environmental agents utilizing GIS. The efficacy of the model was independently evaluated for selected case studies involving lead in the ground; particulate matter in the air; and an infectious, viral disease (COVID- 19). A graphical user interface (GUI) was developed as the final output of this study. Overall, the evaluation of the model demonstrated feasibility in successfully extracting individual mobility patterns, identifying potential exposure sites and quantifying the frequency and magnitude of exposure. Importantly, the novelty of the developed model lies not merely in its efficiency in integrating GIS and SMD for exposure assessment, but also in considering the practical requirements of health practitioners. Although the conceptual model, developed together with its associated GUI, presents a promising and practical approach to assessment of the exposure to environmental risks discussed here, its applicability, versatility and efficacy extends beyond the case studies presented in this study.

How can the Sendai framework be implemented for disaster risk reduction and sustainable development? A qualitative study in Iran

BACKGROUND

The Sendai Framework is the United Nations' most significant approach to reducing the risk of disasters from 2015 to 2030. This framework designed for all communities. However, communities should create operational and remedial strategies based on their unique circumstances. Considering the gaps in the implementation of Sendai framework strategies in Iran, as a developing country, the present study was designed.

METHOD

This study was conducted by using a qualitative direct content analysis method to find out the expert's opinions on the implementation of the Sendai framework in Iran from 2021 to 2023. 35 experts in the focus group discussion and 9 experts in the interview were the participants of the study.

RESULTS

Study findings were merged and reported as one main theme entitled Executive actions for implementing the Sendai Framework, four categories, and 37 codes. Eleven codes for the strategy of understanding disaster risk, 11 codes for the strategy of strengthening disaster risk governance to manage disaster risk, eight codes for the strategy of Investing in disaster risk reduction for resilience, and finally, seven codes for the strategy of enhancing disaster preparedness for effective response and to "Build Back Better" in recovery, rehabilitation, and reconstruction were identified as implementation solutions.

CONCLUSION

The Sendai Framework has not provided any detailed implementation solutions because the countries' economic, social, level of development, etc., are different. The study's findings can be used as a guide for other developing countries.

Effects of fine particulate matter on bone marrow-conserved hematopoietic and mesenchymal stem cells: a systematic review

The harmful effects of fine particulate matter ≤2.5 µm in size (PM2.5) on human health have received considerable attention. However, while the impact of PM2.5 on the respiratory and cardiovascular systems has been well studied, less is known about the effects on stem cells in the bone marrow (BM). With an emphasis on the invasive characteristics of PM2.5, this review examines the current knowledge of the health effects of PM2.5 exposure on BM-residing stem cells. Recent studies have shown that PM2.5 enters the circulation and then travels to distant organs, including the BM, to induce oxidative stress, systemic inflammation and epigenetic changes, resulting in the reduction of BM-residing stem cell survival and function. Understanding the broader health effects of air pollution thus requires an understanding of the invasive characteristics of PM2.5 and its direct influence on stem cells in the BM. As noted in this review, further studies are needed to elucidate the underlying processes by which PM2.5 disturbs the BM microenvironment and inhibits stem cell functionality. Strategies to prevent or ameliorate the negative effects of PM2.5 exposure on BM-residing stem cells and to maintain the regenerative capacity of those cells must also be investigated. By focusing on the complex relationship between PM2.5 and BM-resident stem cells, this review highlights the importance of specific measures directed at safeguarding human health in the face of rising air pollution.

Fabrication of slag/CKD one-mix geopolymer cement reinforced by low-cost nano-particles, mechanical behavior and durability performance

CKD is a byproduct of the cement industry, and its accumulation in the surrounding represents one of many issues associated with this industry. In this study, CKD was utilized in the fabrication of one-mix geopolymer cement (GP) composite as an economical and environmental solution for disposal of this byproduct. The mechanical properties and durability behavior during various deterioration actions were inspected. The obtained findings demonstrated that, replacing slag by CKD in the fabricated GP could cause an elongation in the setting times and reduction in the compression strength of approximately 50%. However, GPs containing CKD offered an accepted resistance to irradiation by γ-rays and to firing action. Reinforcing the GPs with nano Fe3O4 (NF) or nano TiO2 (NT) accelerated the geopolymerization reaction and offered mechanical properties surprising the control mix, this was related to the micro-filling and catalytic actions of the NPs which supported the formation of symmetrical and organized clusters of CSHs and CASH gel as shown in SEM micrographs. The reinforcing mixes surpassing the control mix in the protection against intrusion of sulfate ions which they could retain about 92% of their strength after 4 months of exposure while the control mix retained 80%. Furthermore, they showed a superior resistance to the destructive effect of irradiation by high dose gamma rays up to 1500 kGy and they retained ~ 75% of their strength after irradiation while the control mix was kept at only 35%. The fabricated composites are recommended for usage in many applied construction fields.

Assessment of diesel fuel quality

Diesel is an essential energy source in the transportation and industrial sectors worldwide; hence, the quality of this commodity is crucial. This study compares various fuel samples to understand the quality of the fuels in terms of sulphur content, density, surface tension, viscosity, and calorific value. The properties of diesel fuel samples from eight (8) Filling Stations (Marketing Companies (MC)) were examined and compared with GSA 141:2022 and ISO 8217:2017 standards. Fuel from two companies, MC-A and MC-G had slightly lower densities than the standard, indicative of a possible contamination with lower-density fuels such as kerosene. The surface tension of all samples, except one was within the standard range. The only sample with the lower than the standard value also displayed high sulphur content. Although all the fuel samples met the minimum requirement for calorific value, the viscosities of the fuels from three companies were slightly higher than the specified standard value which can potentially result in higher emissions. In the case of sulphur content, fuel samples from only three companies were in compliance with the maximum 50 ppm standard. This means 62.5 % of the diesel fuel within the study area at the time contained more than the acceptable amount of sulphur. The findings in this research highlight the need to re-examine the quality of fuels along the distribution chain.

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.

When and where to exercise: An assessment of personal exposure to urban tropical ambient airborne pollutants in Singapore

BACKGROUND

Physical activity is associated with health benefits and has been shown to reduce mortality risk. However, exposure to high levels of ambient fine particulate matter (PM2.5) during exercise can potentially reduce the health benefits of physical activity. This study aims to assess and compare the PM2.5 concentrations of different exercise venues in Singapore by their location attributes and time of day.

METHODS

Personal PM2.5 exposures (μg/m3) at 24 common outdoor exercise venues in Singapore over 49 sampling days were collected using real-time personal sensors from September 2017 to January 2020. Wilcoxon rank-sum test and Kruskal-Wallis test were used to compare PM2.5 concentrations between different timings (peak (0700-0900; 1800-2000) vs. non-peak (0600-0700; 0900-1800; 2000-2300); weekend vs. weekday), and location attributes (near major roads (<50 m) vs. away from major roads (≥50 m)). Multivariable linear regression models were used to assess the associations between location attributes, timings and ambient PM2.5 with personal PM2.5 concentration, adjusting for potential confounders.

RESULTS

Compared with peak hours, exercising during non-peak hours was associated with a significantly lower PM2.5 exposure (median, 17.8 μg/m3 during peak vs. 14.5 μg/m3 during non-peak; P = 0.006). Exercise venues away from major roads have significantly lower PM2.5 concentrations as compared to those located next to major roads (median, 14.4 μg/m3 away from major roads vs. 18.5 μg/m3 next to major roads; P < 0.001). Individuals who exercised in parks experienced the highest PM2.5 exposure (median, 55.0 μg/m3) levels in the afternoon during 1400-1500. Furthermore, ambient PM2.5 concentration was significantly and positively associated with personal PM2.5 exposure (β = 0.85, P < 0.001).

CONCLUSIONS

Our findings suggest that exercising outdoors in the urban environment exposes individuals to differential levels of PM2.5 at different times of the day. Further research should investigate a wider variety of outdoor exercise venues, explore different types of air pollutants, and consider the varying activity patterns of individuals.

Empowering community health professionals for effective air pollution information communication

BACKGROUND

Air pollution remains a significant public health risk, particularly in urban areas. Effective communication strategies remain integral to overall protection by encouraging the adoption of personal air pollution exposure reduction behaviours. This study aims to explore how community health professionals can be empowered to communicate air pollution information and advice to the wider community, to encourage the uptake of desired behaviours in the population.

METHODS

The study adopted a qualitative methodology, where four homogenous Focus Group Discussions (FGDs) were held with a range of community health professionals, including Health Care Professionals, Community Health and Wellbeing Workers (CHWWs) and Social Prescribing Link Workers (SPLW). A classical content analysis was conducted with the Structural Empowerment Theory (SET) and Psychological Empowerment Theory (PET) as guiding concepts.

RESULTS

Five key themes were identified: from a structural empowerment perspective: [1] resources and support, [2] knowledge. From a psychological empowerment perspective: [3] confidence as advisor, [4] responsibility as advisor, and [5] residents' receptiveness to advice. It was concluded that advice should be risk stratified, clear, easy to follow and provide alternatives.

CONCLUSION

This study identified ways for community health professionals to be empowered by local councils or other organisations in providing advice on air pollution, through the provision of essential structural support and opportunities to enhance their knowledge and confidence in the subject. Implementing recommendations from this study would not only empower community health professionals to advise on air pollution to the wider community but also increase adherence to health advice.

Knowledge, attitudes, and perception of air pollution in Ireland

Aim

Air pollution remains a major global public health challenge; and Ireland is no exception to the human health implications of exposure ambient air pollutants. Accurate and timely information can be critical to mitigate the harmful effects of air pollution. This study aimed to assess the knowledge, perceptions, and attitudes to poor air quality in Ireland to assist stakeholders in developing and implementing effective communication pieces and policies about the management of air pollution.

Study design

Cross-sectional population-based cohort.

Method

Quantitative data on knowledge, attitudes, and perceptions (KAP) were collected from respondents living across Ireland, and the results were analysed with SPSS (Version 28.0).

Results

Among the 1005 respondents included in this study, the mean [SD] age was 46.1 [15.3] years; 53% were female (n = 530); and 66% and 35% of respondents were aware of air pollution and its adverse effects on health at a national and local level respectively (n = 668 and n = 353 respectively). In addition, there were significant relationships between socio-demographic and air pollution awareness. There were correlation between respondent's age, gender, socio-economic group, and locality in Ireland.

Conclusion

This study demonstrates that environmental health literacy around air pollution in critically lacking among respondents. Given that air pollution is an increasingly important global priority, opportunities need to create to improve reach and impact of communication of air quality health risk and mitigation measures.

The impact of air pollution on asthma: clinical outcomes, current epidemiology, and health disparities

INTRODUCTION

Air pollution has been shown to have a significant impact on morbidity and mortality of respiratory illnesses including asthma.

AREAS COVERED

Outdoor air pollution consists of a mixture of individual pollutants including vehicle traffic and industrial pollution. Studies have implicated an array of individual components of air pollution, with PM2.5, NO2, SO2, and ozone being the most classically described, and newer literature implicating other pollutants such as black carbon and volatile organic compounds. Epidemiological and cohort studies have described incidence and prevalence of pollution-related asthma and investigated both acute and chronic air pollution exposure as they relate to asthma outcomes. There is an increasing body of literature tying disparities in pollution exposure to clinical outcomes. In this narrative review, we assessed the published research investigating the association of pollution with asthma outcomes, focusing on the adult population and health care disparities.

EXPERT OPINION

Pollution has multiple deleterious effects on respiratory health but there is a lack of data on individualized pollution monitoring, making it difficult to establish a temporal relationship between exposure and symptoms, thereby limiting our understanding of safe exposure levels. Future research should focus on more personalized monitoring and treatment plans for mitigating exposure.

MicroRNAs as Potential Biomarkers of Environmental Exposure to Polycyclic Aromatic Hydrocarbons and Their Link with Inflammation and Lung Cancer

Exposure to atmospheric air pollution containing volatile organic compounds such as polycyclic aromatic hydrocarbons (PAHs) has been shown to be a risk factor in the induction of lung inflammation and the initiation and progression of lung cancer. MicroRNAs (miRNAs) are small single-stranded non-coding RNA molecules of ~20-22 nucleotides that regulate different physiological processes, and their altered expression is implicated in various pathophysiological conditions. Recent studies have shown that the regulation of gene expression of miRNAs can be affected in diseases associated with outdoor air pollution, meaning they could also be useful as biomarkers of exposure to environmental pollution. In this article, we review the published evidence on miRNAs in relation to exposure to PAH pollution and discuss the possible mechanisms that may link these compounds with the expression of miRNAs.

Effect of a single one-hour teaching session about environmental pollutants and climate change on the understanding and behavioral choices of adolescents: The BREATHE pilot randomized controlled trial

BACKGROUND

Despite the wealth of scientific information on the health effects of air pollution, the adult public's lifestyle continues to be largely detrimental towards the environment.

OBJECTIVE

The purpose of the study was to determine whether a short interactive teaching session on air pollution could shift reported behavioral choices of adolescents towards environmentally friendlier options.

METHODS

We performed a pilot randomized control trial in which eighth-grade students were randomized to receive a one-hour script-based teaching on either the effects of air pollution on lung health (intervention group) or the role of vaccination in public health (active control group). The enrolled students completed a survey (15 multiple-choice questions; five targeting understanding (score range 5 to 20); ten targeting behavioral choices (score range 10 to 38) newly designed for this study to evaluate their understanding and predict their future behavior towards air pollution immediately before, immediately after, and one month after the teaching sessions.

RESULTS

Seventy-seven students (age = 13.5±0.6 years; 50.4% female; median annual family income = $25K-$50K with 70.1% <$50K; 39 assigned to intervention group) were enrolled in the study. The teaching sessions did not result in any significant change in the participants' understanding domain scores in either the intervention or the control groups. However, the intervention (air pollution) teaching session resulted in a statistically significant increase in behavior domain score from baseline to immediately post-teaching, which continued to be present at one-month follow-up (mean ± standard deviation of score change immediately after = 1.7±3.3; score change 1-month after = 2.5±3.2; P<0.001; minimally important difference = 1.0).

DISCUSSION

This pilot study highlights the potential of a short one-time teaching session in promoting environmentally friendly behavior choices among adolescents.

Source apportionment, health risk assessment, and trajectory analysis of black carbon and light absorption properties of black and brown carbon in Delhi, India

Black Carbon (BC) is an important atmospheric pollutant, well recognized for adverse health and climatic effects. The present work discusses the monthly and seasonal variations of BC sources, health risks, and light absorption properties. The measurement was done from January to December 2021 using a seven wavelength aethalometer. Annual average BC concentration during the study period was 12.2 ± 8.8 μg/m3 (ranged from 1.9 - 52.2 μg/m3). Results represent highest BC concentration during winter (W), followed by post-monsoon (P-M), summer (S), and monsoon (M) seasons where the fossil fuel (FF) combustion is the major source during W, S, and M seasons and biomass burning (BB) during the P-M season. The health risk assessment revealed that individuals in Delhi are exposed to BC levels equivalent to inhaling the smoke from 36 passively smoked cigarettes (PSC) everyday. The risk is highest during W reaching upto 71 PSC and minimum during M i.e., 9 PSC. The light absorption properties were calculated for BC (AbsBC) and Brown carbon (AbsBrC). AbsBC and varied from 229-89 Mm-1 between 370-950 nm and AbsBrC varied from 87-12 Mm-1 between 370-660 nm. AbsBC contributed substantially to total absorption at all wavelengths, while AbsBrC contribution is quite significant in the UV region only. Trajectory analysis confirmed significant influence of regional sources (e.g., biomass-burning aerosols from northwest and east direction) on air quality, health risks, and light absorption properties of BC over Delhi especially during the P-M season. The BB events of Punjab, Haryana, Uttar Pradesh, and eastern Pakistan seems to have significant influence on Delhi's air quality predominantly during P-M season.

Climate change, air quality, and respiratory health: a focus on particle deposition in the lungs

This review article delves into the multifaceted relationship between climate change, air quality, and respiratory health, placing a special focus on the process of particle deposition in the lungs. We discuss the capability of climate change to intensify air pollution and alter particulate matter physicochemical properties such as size, dispersion, and chemical composition. These alterations play a significant role in influencing the deposition of particles in the lungs, leading to consequential respiratory health effects. The review paper provides a broad exploration of climate change's direct and indirect role in modifying particulate air pollution features and its interaction with other air pollutants, which may change the ability of particle deposition in the lungs. In conclusion, climate change may play an important role in regulating particle deposition in the lungs by changing physicochemistry of particulate air pollution, therefore, increasing the risk of respiratory disease development.

Machine Learning Big Data Analysis of the Impact of Air Pollutants on Rhinitis-Related Hospital Visits

This study seeks to elucidate the intricate relationship between various air pollutants and the incidence of rhinitis in Seoul, South Korea, wherein it leveraged a vast repository of data and machine learning techniques. The dataset comprised more than 93 million hospital visits (n = 93,530,064) by rhinitis patients between 2013 and 2017. Daily atmospheric measurements were captured for six major pollutants: PM10, PM2.5, O3, NO2, CO, and SO2. We employed traditional correlation analyses alongside machine learning models, including the least absolute shrinkage and selection operator (LASSO), random forest (RF), and gradient boosting machine (GBM), to dissect the effects of these pollutants and the potential time lag in their symptom manifestation. Our analyses revealed that CO showed the strongest positive correlation with hospital visits across all three categories, with a notable significance in the 4-day lag analysis. NO2 also exhibited a substantial positive association, particularly with outpatient visits and hospital admissions and especially in the 4-day lag analysis. Interestingly, O3 demonstrated mixed results. Both PM10 and PM2.5 showed significant correlations with the different types of hospital visits, thus underlining their potential to exacerbate rhinitis symptoms. This study thus underscores the deleterious impacts of air pollution on respiratory health, thereby highlighting the importance of reducing pollutant levels and developing strategies to minimize rhinitis-related hospital visits. Further research considering other environmental factors and individual patient characteristics will enhance our understanding of these intricate dynamics.