Cardiovascular effects of air pollution

Chemically Resolved Respiratory Deposition of Ultrafine Particles Characterized by Number Concentration in the Urban Atmosphere

Ultrafine particles (UFPs) dominate the atmospheric particles in number concentration, impacting human health and climate change. However, existing studies primarily rely on mass-based approaches, leading to a restricted understanding of the number-based and chemically resolved health effects of atmospheric UFPs. In this study, we utilized a high-mass-resolution single-particle aerosol mass spectrometer to investigate the online chemical composition and number size distribution of ultrafine, fine, and coarse particles during the summertime in urban Shenzhen, China. Human respiratory deposition dose assessments of particles with varying chemical compositions were further conducted by a respiratory deposition model. The results showed that during our observation, particles containing elemental carbon (EC) were the dominant components in UFPs (0.05-0.1 μm). Compared to fine and coarse particles, UFPs can deposit more deeply into the respiratory tract with a daily dose of ∼2.08 ± 0.67 billion particles. Among the deposited UFPs, EC-cluster particles constituted ∼85.7% in number fraction, accounting for a daily number dose of ∼1.78 billion particles, which poses a greater impact on human health. Simultaneously, we found discrepancies in the chemically resolved particle depositions among number-, surface area-, and mass-based approaches, emphasizing the importance of an appropriate metric for particle health-risk evaluation.

Elevated Leukocyte Count and Platelet-Derived Thrombogenicity Measured Using the Total Thrombus-Formation Analysis System in Patients with ST-Segment Elevation Myocardial Infarction

AIMS

High platelet-derived thrombogenicity during the acute phase of ST-segment elevation myocardial infarction (STEMI) is associated with poor outcomes; however, the associated factors remain unclear. This study aimed to examine whether acute inflammatory response after STEMI affects platelet-derived thrombogenicity.

METHODS

This retrospective observational single-center study included 150 patients with STEMI who were assessed for platelet-derived thrombogenicity during the acute phase. Platelet-derived thrombogenicity was assessed using the area under the flow-pressure curve for platelet chip (PL-AUC), which was measured using the total thrombus-formation analysis system (T-TAS). The peak leukocyte count was evaluated as an acute inflammatory response after STEMI. The patients were divided into two groups: the highest quartile of the peak leukocyte count and the other three quartiles combined.

RESULTS

Patients with a high peak leukocyte count (＞15,222/mm3; n=37) had a higher PL-AUC upon admission (420 [386-457] vs. 385 [292-428], p=0.0018), higher PL-AUC during primary percutaneous coronary intervention (PPCI) (155 [76-229] vs. 96 [29-170], p=0.0065), a higher peak creatine kinase level (4200±2486 vs. 2373±1997, p＜0.0001), and higher PL-AUC 2 weeks after STEMI (119 [61-197] vs. 88 [46-122], p=0.048) than those with a low peak leukocyte count (≤ 15,222/mm3; n=113). The peak leukocyte count after STEMI positively correlated with PL-AUC during primary PPCI (r=0.37, p＜0.0001). A multivariable regression analysis showed the peak leukocyte count to be an independent factor for PL-AUC during PPCI (β=0.26, p=0.0065).

CONCLUSIONS

An elevated leukocyte count is associated with high T-TAS-based platelet-derived thrombogenicity during the acute phase of STEMI.

Analysis of particulate matter-induced alteration of genes and related signaling pathways in the respiratory system

Airborne particulate matter (PM) is a global environmental risk factor threatening human health and is a major cause of cardiovascular and respiratory disease-associated death. Current studies on PM exposure have been limited to large-scale cohort and epidemiological investigations, emphasizing the need for detailed individual-level studies to uncover specific differentially expressed genes and their associated signaling mechanisms. Herein, we revealed that PM exposure significantly upregulated inflammatory and immune responses, such as cytokine-mediated signaling pathways, complement system, and the activation and migration of immune cells in gene set enrichment analysis of our RNA sequencing (RNAseq) data. Remarkably, we discovered that the broad gene expression and signaling pathways mediated by macrophages were predominantly expressed in the respiratory system following PM exposure. Consistent with these observations, individual PMs, classified by aerodynamic size and origin, significantly promoted macrophage recruitment to the lungs in the mouse lung inflammation model. Additionally, we confirmed that RNAseq observations from the respiratory system were reproduced in murine bone marrow-derived macrophages and the alveolar macrophage cell line MH-S after individual PM exposure. Our findings demonstrated that PM exposure augmented broad inflammatory and immune responses in the respiratory system and suggested the reinforcement of global strategies for reducing particulate air pollution to prevent respiratory diseases and their exacerbation.

Modelling environmental life cycle performance of alternative marine power configurations with an integrated experimental assessment approach: A case study of an inland passenger barge

There is pressure on the global shipping industry to move towards greener propulsion and fuel technologies to reduce greenhouse gas emissions. Hydrogen and electricity are both recognised as pathways to achieve a net-zero. However, in the evaluation of the environmental performance of these alternative marine power configurations, conventional life cycle assessment (LCA) methods have limitations reflecting the varied nature of ship design and operational modes. The integration of LCA with experimental assessment could remedy the shortcoming of conventional approaches to data generation. The system energy demand data in this study was generated based on specific ship design and directly fed into life cycle assessment. To demonstrate the effectiveness and potential the approach was applied to a case study of inland waterway vessel. Suitable hybrid PV/electricity/diesel and hydrogen powered fuel cell systems for the case vessel were modelled; and hydrodynamic testing and dynamic system simulation was undertaken to provide ship performance data under various operational/environmental profiles. Lifecycle assessment (LCA) indicated hydrogen and electrical propulsion technologies have the potential for 85.7 % and 56.2 % emissions reduction against an MGO base case, respectively. The results highlight that implementation of both technologies is highly dependent on energy production pathways. Hydrogen systems reliant on fossil feedstocks risk an increase in emissions of up to 6.3 % against the MGO base case. Sensitivity analysis indicated an electrical system with electricity production from 79.5 % renewables could achieve savings of 82.2 % in GHG emissions compared to the MGO base case. Crucially, the results demonstrate a further development of the LCA approach which can enable a more accurate environmental performance evaluation of alternative marine power configurations considering specific ship design and operational characteristics. Ultimately this addition makes the results more meaningful for commercial operations and decision making in the selection of alternative marine power systems to support the transition to net-zero.

Increased vascular stiffness in children exposed in utero but not children exposed postnatally to emissions from a coal mine fire

Background

Chronic, low-intensity air pollution exposure has been consistently associated with increased atherosclerosis in adults. However, there was limited research regarding the implications of acute, high-intensity air pollution exposure during childhood. We aimed to determine whether there were any associations between early-life exposure to such an episode and early-life vascular function changes.

Methods

We conducted a prospective cohort study of children (<9 years old) who lived in the vicinity of the Hazelwood coal mine fire (n = 206). Vascular function was measured using noninvasive diagnostic methods including carotid intima-media thickness and pulse wave velocity (PWV). Exposure estimates were calculated from prognostic models and location diaries during the exposure period completed by each participant's parent. Linear mixed-effects models were used to determine whether there were any associations between exposure and changes in vascular outcomes at the 3- and 7-year follow-ups and over time.

Results

At the 7-year follow-up, each 10 μg/m3 increase in daily PM2.5 in utero was associated with increased PWV (β = 0.13 m/s; 95% confidence interval [CI] = 0.02, 0.24; P = 0.02). The association between in utero exposure to daily PM2.5 was not altered by adjustment for covariates, body mass index, and maternal fire stress. Each 1 µg/m3 increase in background PM2.5 was associated with increased PWV (β = 0.68 m/s; 95% CI = 0.10, 1.26; P = 0.025), in children from the in utero exposure group. There was a trend toward smaller PWV (β = -0.17 m/s; 95% CI = -0.366, 0.02) from the 3- to 7-year follow-up clinic suggesting that the deficits observed previously in children exposed postnatally did not persist.

Conclusion

There was a moderate improvement in vascular stiffness of children exposed to PM2.5 from a local coal mine fire in infancy. There was a mild increase in vascular stiffness in children exposed to PM2.5 from a local coal mine fire while their mothers were pregnant.

Influence of gestational hypertension and maternal air pollutant exposure on birth outcomes

The relationship between exposure to air pollutants and fetal growth outcomes has shown inconsistency, and only a limited number of studies have explored the impact of air pollution on gestational hypertension and birth outcomes. This study aimed to evaluate how maternal exposure to air pollutants and blood pressure could influence fetal birth outcomes. A total of 55 women with gestational hypertension and 131 healthy pregnant women were enrolled in this study. Data pertaining to personal characteristics, prenatal examinations, outdoor air pollutant exposure, and fetal birth outcomes were collected. The study revealed that fetal birth weight and abdominal circumference exhibited a significant reduction among women with gestational hypertension compared to healthy pregnant women, even after adjustments for body mass index, gestational age, and exposure to air pollutants had been made. Moreover, maternal exposure to outdoor air pollutants displayed a notable correlation with decreased birth length of fetuses. Consequently, the study concluded that maternal blood pressure and exposure to outdoor air pollutants during pregnancy potentially stand as pivotal factors influencing fetal birth outcomes.

Epidemiology, Mechanisms and Prevention in the Etiology of Environmental Factor-Induced Cardiovascular Diseases

Cardiovascular diseases are a significant cause of mortality worldwide, and their prevalence can be amplified by a range of environmental factors. This review article critically evaluated the published information on the epidemiology and pathophysiological mechanisms of various environmental factors such as air indoor and outdoor air pollution, water pollution, climate change, and soil pollution. Preventative measures to mitigate these effects including public health responses are discussed with gaps in our knowledge for future studies.

Burden of cardiovascular disease attributed to air pollution: a systematic review

BACKGROUND

Cardiovascular diseases (CVDs) are estimated to be the leading cause of global death. Air pollution is the biggest environmental threat to public health worldwide. It is considered a potentially modifiable environmental risk factor for CVDs because it can be prevented by adopting the right national and international policies. The present study was conducted to synthesize the results of existing studies on the burden of CVDs attributed to air pollution, namely prevalence, hospitalization, disability, mortality, and cost characteristics.

METHODS

A systematic search was performed in the Scopus, PubMed, and Web of Science databases to identify studies, without time limitations, up to June 13, 2023. Exclusion criteria included prenatal exposure, exposure to indoor air pollution, review studies, conferences, books, letters to editors, and animal and laboratory studies. The quality of the articles was evaluated based on the Agency for Healthcare Research and Quality Assessment Form, the Newcastle-Ottawa Scale, and Drummond Criteria using a self-established scale. The articles that achieved categories A and B were included in the study.

RESULTS

Of the 566 studies obtained, based on the inclusion/exclusion criteria, 92 studies were defined as eligible in the present systematic review. The results of these investigations supported that chronic exposure to various concentrations of air pollutants, increased the prevalence, hospitalization, disability, mortality, and costs of CVDs attributed to air pollution, even at relatively low levels. According to the results, the main pollutant investigated closely associated with hypertension was PM2.5. Furthermore, the global DALY related to stroke during 2016-2019 has increased by 1.8 times and hospitalization related to CVDs in 2023 has increased by 8.5 times compared to 2014.

CONCLUSION

Ambient air pollution is an underestimated but significant and modifiable contributor to CVDs burden and public health costs. This should not only be considered an environmental problem but also as an important risk factor for a significant increase in CVD cases and mortality. The findings of the systematic review highlighted the opportunity to apply more preventive measures in the public health sector to reduce the footprint of CVDs in human society.

Cardiovascular disease, mortality and exposure to particulate matter (PM): a systematic review and meta-analysis

One of the main factors that causes health effects in humans such as hospital admissions for cardiovascular disease (HACVD), respiratory disease (RD), lung function, cardiovascular mortality (MCVD), lung cancer, and increased mortality is air pollution especially particulate matter (PM). This a systematic review and meta-analysis aims to investigate the effects of particulate matter on the occurrence of cardiovascular disease and mortality. A systematic review and meta-analysis of the literature was done from 2011 to 2021 based on various databases. Based on the result of this study, subgroup analysis based on temperature conditions showed a different estimation in cold cities (6.24, UR (4.36-8.12)), moderate cities (4.86, UR (3.57-6.15)) and warm cities (8.96, UR (7.06-10.86)). Test of group differences showed a significant difference (Q=12.22, p-value<0.001). There was publication bias among the studies (the Egger's test; (Z=14.18, p<0.001)). According result study pooled estimation of AP% for MCVD from the random-effect meta-analysis based on DerSimonian-Laird model, overall is 5.04, UR (3.65-6.43) (Figure 4). Subgroup analysis based on temperature conditions showed the estimation in cold cities (5.47, UR (3.97-6.97)) and moderate cities (4.65, UR (0.54-8.77)). Test of group differences showed a non-significant difference (Q=0.13, p-value=0.71). There was no publication bias among the studies (the Egger's test; (Z=0.82, p=0.376)). Exposed to air pollutants and particulate matter can be increase the risk of cardiovascular disease, respiratory disease, and cardiovascular mortality.

Short-term effects of ambient gaseous air pollution on blood platelet mitochondrial DNA methylation and myocardial ischemia

BACKGROUND

The potential effects of short-term exposure to major ambient gaseous pollutants (ozone: O3, carbon monoxide: CO, and sulfur dioxide: SO2) on platelet mitochondrial DNA (mtDNA) methylation have been uncertain and no studies have examined whether platelet mtDNA methylation levels could modify the associations between ambient gaseous pollutants and the risks of ST-segment depression (STDE) and T-wave inversion events (TIE), two indicators of myocardial ischemia.

METHODS

This study used data from a randomized, double-blind, placebo-controlled intervention study with a standardized 24-hour exposure protocol among 110 participants in Beijing. Absolute changes in platelet mtDNA methylation (ACmtDNAm) levels were determined by two repeated measurements on platelet mtDNA methylation levels in blood samples collected before and after the 24-hour exposure period. A multivariable linear regression model and a generalized linear model with a Poisson link function were used to investigate the associations of ambient gaseous pollutants with platelet mtDNA methylation levels, STDE, and TIE, respectively.

RESULTS

Short-term O3 exposure was significantly associated with decreased ACmtDNAm at ATP6_P1 but increased ACmtDNAm at mt12sRNA, MT-COX1, and MT-COX1_P2; short-term CO and SO2 exposures were significantly associated with decreased ACmtDNAm at D-loop, MT-COX3- and ATP-related genes. Moreover, short-term O3 exposure was significantly associated with increased risks of STDE and TIE, and ACmtDNAm at MT-COX1 and MT-COX1_P2 modified the association between short-term O3 exposure and STDE events. L-Arg supplementation attenuated the effects of ambient gaseous pollutants, particularly O3, on ACmtDNAm and STDE.

CONCLUSIONS

Platelet mtDNA methylation levels are promising biomarkers of short-term exposure to ambient gaseous air pollution, and are likely implicated in the mechanism behind the association of ambient O3 pollution with adverse cardiovascular effects. L-Arg supplementation showed the potential to mitigate the adverse effects of ambient O3 pollution.

The effects of technological developments in transportation vehicles on air pollution mitigation of metropolitan cities: A case study of Istanbul

This study investigates the impact of transportation vehicles on air pollution emissions in Istanbul, a metropolitan city in Türkiye. The TIMES (The Integrated MARKAL-EFOM System) Model has been used to determine the current level of air pollutants coming from the transportation sector, make future estimates, and assess the impact of various scenarios on air pollution emissions. Air pollutants such as carbon monoxide, nitrogen oxides, sulfur oxides, particulate matter, and non-methane volatile organic compounds are included in the model. The amount of air pollution emissions discussed in this research were 74, 68, 13, 5, and 2 kt for NOx, CO, VOC, SO2, and PM, respectively, in the base year of 2016. In 2055, these emissions have shifted to 190, 98, 26, 8, and 5 kt, respectively. This means that emissions are predicted to increase between 1.4 and 2.6 times. According to model results, individual measures could decrease potential air pollution emissions for 2055 by up to 13 %. When all of the actions done within the pollutants of the study are combined, the total amount of emissions has decreased by 30.2 %, 24.3 %, 18.8 %, 5.3 % and 21.4 % for NOx, CO, VOC, SO2, and PM, respectively. This research emphasizes how critical it is to address metropolitan areas' transportation-related air pollution. The number of such studies dealing with air pollution parameters using the TIMES Model is very few, and it is expected that this study will create important outputs for similar studies.

From Local Issues to Global Impacts: Evidence of Air Pollution for Romania and Turkey

Air pollution significantly threatens human health and natural ecosystems and requires urgent attention from decision makers. The fight against air pollution begins with the rigorous monitoring of its levels, followed by intelligent statistical analysis and the application of advanced machine learning algorithms. To effectively reduce air pollution, decision makers must focus on reducing primary sources such as industrial plants and obsolete vehicles, as well as policies that encourage the adoption of clean energy sources. In this study, data analysis was performed for the first time to evaluate air pollution based on the SPSS program. Correlation coefficients between meteorological parameters and particulate matter concentrations (PM1, PM2.5, PM10) were calculated in two urban regions of Romania (Craiova and Drobeta-Turnu Severin) and Turkey (Adana). This study establishes strong relationships between PM concentrations and meteorological parameters with correlation coefficients ranging from -0.617 (between temperature and relative humidity) to 0.998 (between PMs). It shows negative correlations between temperature and particulate matter (-0.241 in Romania and -0.173 in Turkey) and the effects of humidity ranging from moderately positive correlations with PMs (up to 0.360 in Turkey), highlighting the valuable insights offered by independent PM sensor networks in assessing and improving air quality.

Evaluating low-cost monitoring designs for PM2.5 exposure assessment with a spatiotemporal modeling approach

Determining the most feasible and cost-effective approaches to improving PM2.5 exposure assessment with low-cost monitors (LCMs) can considerably enhance the quality of its epidemiological inferences. We investigated features of fixed-site LCM designs that most impact PM2.5 exposure estimates to be used in long-term epidemiological inference for the Adult Changes in Thought Air Pollution (ACT-AP) study. We used ACT-AP collected and calibrated LCM PM2.5 measurements at the two-week level from April 2017 to September 2020 (N of monitors [measurements] = 82 [502]). We also acquired reference-grade PM2.5 measurements from January 2010 to September 2020 (N = 78 [6186]). We used a spatiotemporal modeling approach to predict PM2.5 exposures with either all LCM measurements or varying subsets with reduced temporal or spatial coverage. We evaluated the models based on a combination of cross-validation and external validation at locations of LCMs included in the models (N = 82), and also based on an independent external validation with a set of LCMs not used for the modeling (N = 30). We found that the model's performance declined substantially when LCM measurements were entirely excluded (spatiotemporal validation R2 [RMSE] = 0.69 [1.2 μg/m3]) compared to the model with all LCM measurements (0.84 [0.9 μg/m3]). Temporally, using the farthest apart measurements (i.e., the first and last) from each LCM resulted in the closest model's performance (0.79 [1.0 μg/m3]) to the model with all LCM data. The models with only the first or last measurement had decreased performance (0.77 [1.1 μg/m3]). Spatially, the model's performance decreased linearly to 0.74 (1.1 μg/m3) when only 10% of LCMs were included. Our analysis also showed that LCMs located in densely populated, road-proximate areas improved the model more than those placed in moderately populated, road-distant areas.

Climate Change and Human Health in Africa in Relation to Opportunities to Strengthen Mitigating Potential and Adaptive Capacity: Strategies to Inform an African "Brains Trust"

Background

Africa faces diverse and complex population/human health challenges due to climate change. Understanding the health impacts of climate change in Africa in all its complexity is essential for implementing effective strategies and policies to mitigate risks and protect vulnerable populations. This study aimed to outline the major climate change-related health impacts in Africa in the context of economic resilience and to seek solutions and provide strategies to prevent or reduce adverse effects of climate change on human health and well-being in Africa.

Methods

For this narrative review, a literature search was conducted in the Web of Science, Scopus, CAB Abstracts, MEDLINE and EMBASE electronic databases. We also searched the reference lists of retrieved articles for additional records as well as reports. We followed a conceptual framework to ensure all aspects of climate change and health impacts in Africa were identified.

Results

The average temperatures in all six eco-regions of Africa have risen since the early twentieth century, and heat exposure, extreme events, and sea level rise are projected to disproportionately affect Africa, resulting in a larger burden of health impacts than other continents. Given that climate change already poses substantial challenges to African health and well-being, this will necessitate significant effort, financial investment, and dedication to climate change mitigation and adaptation. This review offers African leaders and decision-makers data-driven and action-oriented strategies that will ensure a more resilient healthcare system and safe, healthy populations-in ways that contribute to economic resiliency.

Conclusions

The urgency of climate-health action integrated with sustainable development in Africa cannot be overstated, given the multiple economic gains from reducing current impacts and projected risks of climate change on the continent's population health and well-being. Climate action must be integrated into Africa's development plan to meet the Sustainable Development Goals, protect vulnerable populations from the detrimental effects of climate change, and promote economic development.

Spatiotemporal distribution characteristics and influencing factors of the rate of cardiovascular hospitalization in Ganzhou city of China

Aims

The objective of this study was to analyze hospitalization rates for cardiovascular diseases (CVD) in Ganzhou City, Jiangxi Province of China from 2015 to 2020 and to uncover the spatiotemporal distribution characteristics and influencing factors, and thus to provide reference for the prevention and control of CVD and public health resources planning.

Methods

The hospitalization data for CVDs from 2016 to 2020 was obtained from the First Affiliated Hospital of Gannan Medical University, and ArcGIS 10.8, SaTScan 9.5, and Matlab 20.0 were used to analyze the spatial autocorrelation, spatiotemporal scan statistics, and potential affecting factors of the hospitalization rates.

Results

The hospitalization rate for CVDs in Ganzhou City showed a slightly increasing trend from 2016 to 2020, with higher rates in winter and summer than that in spring and autumn, and the individuals aged 61 and above constitute a higher proportion compared to other age groups. Additionally, there was a positive correlation between hospitalization rates for CVDs and the counties and districts in Ganzhou City, with high-high aggregation areas mainly distributed in Nankang District, the western urban area of Ganzhou City. The spatial scan analysis identified three different types of significant aggregation areas: high-risk, low-risk, and middle-risk areas. The high-risk area was mainly centered around Zhanggong District or Shangyu County in the central and western regions, with a disease hospitalization rate 2-3 times higher than the rest areas. The study also found that environmental meteorological factors such as the annual average concentration of NO2, O3, average annual temperature, and annual maximum temperature diurnal range had a significant positive effect on hospitalization rates for CVDs in Ganzhou City, with O3 concentration and average annual temperature having significant positive indirect spatial spillover effects.

Conclusion

Winter and summer are the seasons with high hospitalization rate of cardiovascular diseases. County residents aged 61 and above are the higher-risk population that needs to pay more attention on for prevention and control of CVD in Ganzhou City, which exhibits significant spatiotemporal clustering. The urban areas of Zhanggong and Nankang in Ganzhou City are the key areas for prevention and control of CVD. The hospitalization rate of CVD in Ganzhou City is influenced by the aforementioned four environmental meteorological factors, with the annual maximum temperature diurnal range showing the most significant positive direct effect.

Methylomic, Proteomic, and Metabolomic Correlates of Traffic-Related Air Pollution in the Context of Cardiorespiratory Health: A Systematic Review, Pathway Analysis, and Network Analysis

A growing body of literature has attempted to characterize how traffic-related air pollution (TRAP) affects molecular and subclinical biological processes in ways that could lead to cardiorespiratory disease. To provide a streamlined synthesis of what is known about the multiple mechanisms through which TRAP could lead to cardiorespiratory pathology, we conducted a systematic review of the epidemiological literature relating TRAP exposure to methylomic, proteomic, and metabolomic biomarkers in adult populations. Using the 139 papers that met our inclusion criteria, we identified the omic biomarkers significantly associated with short- or long-term TRAP and used these biomarkers to conduct pathway and network analyses. We considered the evidence for TRAP-related associations with biological pathways involving lipid metabolism, cellular energy production, amino acid metabolism, inflammation and immunity, coagulation, endothelial function, and oxidative stress. Our analysis suggests that an integrated multi-omics approach may provide critical new insights into the ways TRAP could lead to adverse clinical outcomes. We advocate for efforts to build a more unified approach for characterizing the dynamic and complex biological processes linking TRAP exposure and subclinical and clinical disease and highlight contemporary challenges and opportunities associated with such efforts.

Gas cooking and respiratory outcomes in children: A systematic review

The most recent meta-analysis of gas cooking and respiratory outcomes in children was conducted by Lin et al. [93] in 2013. Since then, a number of epidemiology studies have been published on this topic. We conducted the first systematic review of this epidemiology literature that includes an in-depth evaluation of study heterogeneity and study quality, neither of which was systematically evaluated in earlier reviews. We reviewed a total of 66 relevant studies, including those in the Lin et al. [93] meta-analysis. Most of the studies are cross-sectional by design, precluding causal inference. Only a few are cohort studies that could establish temporality and they have largely reported null results. There is large variability across studies in terms of study region, age of children, gas cooking exposure definition, and asthma or wheeze outcome definition, precluding clear interpretations of meta-analysis estimates such as those reported in Lin et al. [93]. Further, our systematic study quality evaluation reveals that a large proportion of the studies to date are subject to multiple sources of bias and inaccuracy, primarily due to self-reported gas cooking exposure or respiratory outcomes, insufficient adjustment for key confounders (e.g., environmental tobacco smoke, family history of asthma or allergies, socioeconomic status or home environment), and unestablished temporality. We conclude that the epidemiology literature is limited by high heterogeneity and low study quality and, therefore, it does not provide sufficient evidence regarding causal relationships between gas cooking or indoor NO2 and asthma or wheeze. We caution against over-interpreting the quantitative evidence synthesis estimates from meta-analyses of these studies.

Hourly Air Pollution Exposure and Emergency Hospital Admissions for Stroke: A Multicenter Case-Crossover Study

BACKGROUND

Daily exposure to ambient air pollution is associated with stroke morbidity and mortality; however, the association between hourly exposure to air pollutants and risk of emergency hospital admissions for stroke and its subtypes remains relatively unexplored.

METHODS

We obtained hourly concentrations of fine particulate matter (PM2.5), respirable particulate matter (PM10), nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3), and carbon monoxide (CO) from the China National Environmental Monitoring Center. We conducted a time-stratified case-crossover study among 86 635 emergency hospital admissions for stroke across 10 hospitals in 3 cities (Jinhua, Hangzhou, and Zhoushan) in Zhejiang province, China, between January 1, 2016 and December 31, 2021. Using a conditional logistic regression combined with a distributed lag linear model, we estimated the association between hourly exposure to multiple air pollutants and risk of emergency hospital admissions for total stroke, ischemic stroke, hemorrhagic stroke, and undetermined type.

RESULTS

Hourly exposure to PM2.5, PM10, NO2, and SO2 was associated with an increased risk of hospital admissions for total stroke and ischemic stroke. The associations were most pronounced during the concurrent hour of exposure and lasted for ≈2 hours. We found that the risk was more pronounced among male patients or those aged <65 years old.

CONCLUSIONS

Our findings suggest that exposure to PM2.5, PM10, NO2, and SO2, but not CO and O3, is associated with emergency hospital admissions for total stroke or ischemic stroke shortly after exposure. Implementing targeted pollution emission reduction measures may have significant public health implications in controlling and reducing the burden of stroke.

Effect of temperature on fast transmission of COVID-19 in low per capita GDP Asian countries

An abrupt outbreak of COVID-19 caused enormous global concerns. Although all countries around the world are severely affected, developing Asian countries faced more difficulties due to their low per capita GDP. The temperature was considered a leading variable in spreading viral diseases, including COVID-19. The present study aimed to assess the relationship between temperature and the spread of COVID-19, with a focus on developing Asian countries. In a few Asian countries, COVID-19 spread rapidly in the summer, while in some countries, there is an increase in winter. A linear correlation was developed between COVID-19 cases/deaths and temperature for the selected countries, which were very weak. A coefficient of determination of 0.334 and 0.365 was observed between cases and average monthly max/min temperatures. A correlation of R2 = 0.307 and 0.382 was found between deaths and average max/min monthly temperatures, respectively. There is no scientific reason to assume that COVID-19 is more dominant at low than high temperatures. Therefore, it is believed that the results may be helpful for the health department and decision-makers to understand the fast spread of COVID-19.

Long-Term Exposure to Air Pollution Below Regulatory Standards and Cardiovascular Diseases Among US Medicare Beneficiaries: A Double Negative Control Approach

Growing evidence suggests that long-term air pollution exposure is a risk factor for cardiovascular mortality and morbidity. However, few studies have investigated air pollution below current regulatory limits, and causal evidence is limited. We used a double negative control approach to examine the association between long-term exposure to air pollution at low concentrations and three major cardiovascular events among Medicare beneficiaries aged ≥ 65 years across the contiguous United States between 2000 and 2016. We derived ZIP code-level estimates of ambient fine particulate matter (PM 2.5 ), nitrogen dioxide (NO 2 ), and warm-season ozone (O 3 ) from high-resolution spatiotemporal models. The outcomes of interest were hospitalizations for stroke, heart failure (HF), and atrial fibrillation and flutter (AF). The analyses were restricted to areas with consistently low pollutant levels on an annual basis (PM 2.5 <10 µg/m³, NO 2  < 45 or 40 ppb, warm-season O 3  < 45 or 40 ppb). For each 1 µg/m 3 increase in PM 2.5 , the hospitalization rates increased by 2.25% (95% confidence interval (CI): 1.96%, 2.54%) for stroke and 3.14% (95% CI: 2.80%, 3.94%) for HF. Each ppb increase in NO 2 increased hospitalization rates for stroke, HF, and AF by 0.28% (95% CI: 0.25%, 0.31%), 0.56% (95% CI: 0.52%, 0.60%), and 0.45% (95% CI: 0.41%, 0.49%), respectively. For each ppb increase in warm-season O 3 , there was a 0.32% (95% CI: 0.21%, 0.44%) increase in hospitalization rate for stroke. The associations for NO 2 and warm-season O 3 became stronger under a more restrictive upper threshold. Using an approach robust to omitted confounders, we concluded that long-term exposure to low-level PM 2.5 , NO 2 , and warm-season O 3 was associated with increased risks of cardiovascular diseases in the US elderly. Stricter national air quality standards should be considered.

Mendelian-randomization study reveals causal relationships between nitrogen dioxide and gut microbiota

Exposure to nitrogen dioxide might potentially change the makeup and operation of gut microbes. Nitrogen dioxide data was procured from the IEU Open GWAS (N = 456 380). Subsequently, a two-sample Mendelian randomization study was executed, utilizing summary statistics of gut microbiota sourced from the most expansive available genome-wide association study meta-analysis, conducted by the MiBioGen consortium (N = 13 266). The causal relationship between nitrogen dioxide and gut microbiota was determined using inverse variance weighted, maximum likelihood, MR-Egger, Weighted Median, Weighted Model, Mendelian randomization pleiotropy residual sum and outlier, and constrained maximum likelihood and model averaging and Bayesian information criterion. The level of heterogeneity of instrumental variables was quantified by utilizing Cochran's Q statistic. The colocalization analysis was used to examine whether nitrogen dioxide and the identified gut microbiota shared casual variants. Inverse variance weighted estimate suggested that nitrogen dioxide was causally associated with Akkermansia (β = -1.088, 95% CI: -1.909 to -0.267, P = 0.009). In addition, nitrogen dioxide presented a potential association with Bacteroides (β = -0.938, 95% CI: -1.592 to -0.284, P = 0.005), Barnesiella (β = -0.797, 95% CI: -1.538 to -0.055, P = 0.035), Coprococcus 3 (β = 1.108, 95% CI: 0.048-2.167, P = 0.040), Eubacterium hallii group (E. hallii) (β = 0.776, 95% CI: 0.090-1.463, P = 0.027), Holdemania (β = -1.354, 95% CI: -2.336 to -0.372, P = 0.007), Howardella (β = 1.698, 95% CI: 0.257-3.139, P = 0.021), Olsenella (β = 1.599, 95% CI: 0.151-3.048, P = 0.030) and Sellimonas (β = -1.647, 95% CI: -3.209 to -0.086, P = 0.039). No significant heterogeneity of instrumental variables or horizontal pleiotropy was found. The associations of nitrogen dioxide with Akkermansia (PH4 = 0.836) and E. hallii (PH4 = 0.816) were supported by colocalization analysis. This two-sample Mendelian randomization study found that increased exposure to nitrogen dioxide had the potential to impact the human gut microbiota.

The relationship between PM10 and SO2 exposure and Covid-19 infection rates in Turkey using nomenclature of territorial units for statistics level 1 regions

The Covid-19 pandemic, which has been affecting the world since December 2019, has become one of the biggest problems of the 21st century. There are studies stating that the contagiousness of the Covid-19 pandemic, which is transmitted from person to person, increases more with environmental factors such as air pollution, and accordingly, there is an increase in the number of cases. In this study, a panel regression model to investigate the effect of air pollution concentrations such as PM10 and SO2 as environmental factors and population density on the monthly mean number of Covid-19 cases for 12 regions at the nomenclature of territorial units for statistics (NUTS) level 1 in Turkey between June 2020 and November 2020, and a linear regression model to investigate the effect at the regional level. we used. Based on the model results, we concluded that a small increase in air pollution indicators led to an increase in the number of Covid-19 cases in Turkey and its regions. It is very important to identify preventable environmental factors in order to prevent and minimize the effects of respiratory tract diseases and rapidly spreading pandemic diseases such as Covid-19. Accordingly, we can conclude that countries should take some measures, especially on air pollution, in order to develop public health and pandemic/disease management strategies and to reduce the risk of respiratory diseases.

Short-term exposure to various ambient air pollutants and emergency department visits for cause-stable ischemic heart disease: a time-series study in Shanghai, China

Studying the impact of local meteorological conditions and air pollution on cardiovascular disease is crucial for reducing the burden of cardiovascular disease. However, there have been few studies on the acute effects of various air pollutants on stable ischemic heart disease (SIHD), and the effects of these factors are not well defined and require further investigation. We performed a time-series study aimed at exploring the association between short-term exposure to various air pollutants and emergency department (ED) visits for SIHD during 2013-2020 in Baoshan District Renhe Hospital of Shanghai, China. The associations between air pollution (NO2, PM2.5, PM10, SO2 O3-8 h and CO) and ED visits were analyzed using quasi-Poisson regression. Subgroup and sensitivity analyses were conducted. From 2013 to 2020, a total of 18,241 ED visits for SIHD were recorded. Elevated PM2.5, PM10, NO2, SO2 and CO were significantly associated with increased ED visits for SIHD at lag (0, 5), lag 0, lag (0-4, 01-03), lag (0-3, 5, 01-03) and lag (3-5). When the concentration of O3-8 h was lower than the threshold recommended by the WHO, exposure to O3-8 h was associated with a slightly decreased risk of SIHD. Moreover, the relationship between different types of air pollution and the frequency of ED visits exhibited variations based on gender, age, and seasonality. This study suggests that short-term exposure to PM2.5, PM10, NO2, SO2 and CO might induce SIHD, especially in old females. Air pollution control measures should be encouraged to prevent the occurrence and development of SIHD.

Methylomic, proteomic, and metabolomic correlates of traffic-related air pollution: A systematic review, pathway analysis, and network analysis relating traffic-related air pollution to subclinical and clinical cardiorespiratory outcomes

A growing body of literature has attempted to characterize how traffic-related air pollution (TRAP) affects molecular and subclinical biological processes in ways that could lead to cardiorespiratory disease. To provide a streamlined synthesis of what is known about the multiple mechanisms through which TRAP could lead cardiorespiratory pathology, we conducted a systematic review of the epidemiological literature relating TRAP exposure to methylomic, proteomic, and metabolomic biomarkers in adult populations. Using the 139 papers that met our inclusion criteria, we identified the omic biomarkers significantly associated with short- or long-term TRAP and used these biomarkers to conduct pathway and network analyses. We considered the evidence for TRAP-related associations with biological pathways involving lipid metabolism, cellular energy production, amino acid metabolism, inflammation and immunity, coagulation, endothelial function, and oxidative stress. Our analysis suggests that an integrated multi-omics approach may provide critical new insights into the ways TRAP could lead to adverse clinical outcomes. We advocate for efforts to build a more unified approach for characterizing the dynamic and complex biological processes linking TRAP exposure and subclinical and clinical disease, and highlight contemporary challenges and opportunities associated with such efforts.

Effect of short-term exposure to air pollution on daily cardio- and cerebrovascular hospitalisations in areas with a low level of air pollution

Exposure to air pollution is associated with increased cardio- and cerebrovascular diseases. However, the evidence regarding the short-term effect of air pollution on cardio- and cerebrovascular hospitalisations in areas with relatively low air pollution levels is limited. This study aims to examine the effect of short-term exposure to different air pollutants on hospital admissions due to cardio- and cerebrovascular diseases in rural and regional Australia with low air pollution. The study was conducted in five local Government areas of Hunter New England Local Health District (HNE-LHD). Hospitalisation data from January 2018 to February 2020 (820 days) were accessed from the HNE-LHD admitted patients' dataset. Poisson regression model was used to examine the association between the exposure (air pollutants) and outcome variables (hospitalisation due to cardio- and cerebrovascular disease). The concentrations of gaseous air pollutants, Sulphur Dioxide (SO2), Nitrogen Dioxide (NO2), Ozone (O3), Carbon Monoxide (CO), and Ammonia (NH3) were below national benchmark concentrations for every day of the study period. In single pollutant models, SO2 and NO2 significantly increased the daily number of cardio- and cerebrovascular hospitalisations. The highest cumulative effect for SO2 was observed across lag 0-3 days (Incidence Rate Ratio, IRR: 1.77; 95% Confidence Interval, CI: 1.18-2.65; p-value: 0.01), and for NO2, it was across lag 0-2 days (IRR: 1.13; 95% CI: 1.02-1.25; p-value: 0.02). In contrast, higher O3 was associated with decreased cardio- and cerebrovascular hospitalisations, with the largest effect observed at lag 0 (IRR: 0.94; 95% CI: 0.89-0.98; p-value: 0.02). In the multi-pollutant model, the effect of NO2 remained significant at lag 0 and corresponded to a 21% increase in cardio- and cerebrovascular hospitalisation (95% CI: 1-44%; p-value = 0.04). Thus, the study revealed that gaseous air pollutants, specifically NO2, were positively related to increased cardio- and cerebrovascular hospitalisations, even at concentrations below the national standards.

Changes in air pollution exposure after residential relocation and body mass index in children and adolescents: A natural experiment study

Air pollution exposure may affect child weight gain, but observational studies provide inconsistent evidence. Residential relocation can be leveraged as a natural experiment by studying changes in health outcomes after a sudden change in exposure within an individual. We aimed to evaluate whether changes in air pollution exposure due to residential relocation are associated with changes in body mass index (BMI) in children and adolescents in a natural experiment study. This population-based study included children and adolescents, between 2 and 17 years, who moved during 2011-2018 and were registered in the primary healthcare in Catalonia, Spain (N = 46,644). Outdoor air pollutants (nitrogen dioxides (NO2), particulate matter <10 μm (PM10) and <2.5 μm (PM2.5)) were estimated at residential census tract level before and after relocation; tertile cut-offs were used to define changes in exposure. Routinely measured weight and height were used to calculate age-sex-specific BMI z-scores. A minimum of 180 days after moving was considered to observe zBMI changes according to changes in exposure using linear fixed effects regression. The majority of participants (60-67% depending on the pollutant) moved to areas with similar levels of air pollution, 15-49% to less polluted, and 14-31% to more polluted areas. Moving to areas with more air pollution was associated with zBMI increases for all air pollutants (β NO2 = 0.10(95%CI 0.09; 0.12), β PM2.5 0.06(0.04; 0.07), β PM10 0.08(0.06; 0.10)). Moving to similar air pollution areas was associated with decreases in zBMI for all pollutants. No associations were found for those moving to less polluted areas. Associations with moving to more polluted areas were stronger in preschool- and primary school-ages. Associations did not differ by area deprivation strata. This large, natural experiment study suggests that increases in outdoor air pollution may be associated with child weight gain, supporting ongoing efforts to lower air pollution levels.

Association between long-term exposure to low level air pollutants and incident end-stage kidney disease in the UK Biobank: A prospective cohort

BACKGROUND

Previous studies suggest that air pollution can increase the risk of incident chronic kidney disease (CKD). However, the association between end-stage kidney disease (ESKD) and co-exposure to relatively low-level air pollutants remains unclear.

METHODS

A prospective cohort was designed based on UK Biobank. From 1 January 2010 to 12 November 2021, 453,347 participants were followed up over a median of 11.87 years. Principal component analysis was used to identify major patterns of five air pollutants, including PM2.5, PM2.5-10, PM10, NO2, and NOx. Sub-distribution hazards models were used to estimate the associations between air pollution, individually or jointly, and incident ESKD, CKD, and all-cause death, respectively.

RESULTS

Principal component analysis identified two principal components, namely RC1 (PM2.5, NO2, and NOx) and RC2 (PM2.5-10 and PM10). An elevated risk of incident ESKD was associated with an interquartile range (IQR) increase in PM2.5 (hazard ratio: 1.11, 95% confidence interval: 1.02-1.22), NO2 (1.16, 1.04-1.30), NOx (1.08, 1.00-1.17), and RC1 (1.12, 1.02-1.23). An elevated risk of incident CKD was associated with an IQR increase in PM2.5 (1.05, 1.03-1.07), NO2 (1.04, 1.02-1.06), NOx (1.03, 1.02-1.05), and RC1 (1.04, 1.02-1.06). An increased risk of all-cause mortality was associated with an IQR increase in PM2.5 (1.02, 1.00-1.04). Restricted cubic spline analyses indicated a monotonic elevating association of PM2.5, NO2, NOx, and RC1 with ESKD incidence.

CONCLUSIONS

Long-term exposure to PM2.5, NO2, NOx, and their complex was associated with elevated ESKD incidence, even at relatively lower levels of air pollution.

Maintaining brain health across the lifespan

Across the lifespan, the human body and brain endure the impact of a plethora of exogenous and endogenous factors that determine the health outcome in old age. The overwhelming inter-individual variance spans between progressive frailty with loss of autonomy to largely preserved physical, cognitive, and social functions. Understanding the mechanisms underlying the diverse aging trajectories can inform future strategies to maintain a healthy body and brain. Here we provide a comprehensive overview of the current literature on lifetime factors governing brain health. We present the growing body of evidence that unhealthy alimentary regime, sedentary behaviour, sleep pathologies, cardio-vascular risk factors, and chronic inflammation exert their harmful effects in a cumulative and gradual manner, and that timely and efficient intervention could promote healthy and successful aging. We discuss the main effects and interactions between these risk factors and the resulting brain health outcomes to follow with a description of current strategies aiming to eliminate, treat, or counteract the risk factors. We conclude that the detailed insights about modifiable risk factors could inform personalized multi-domain strategies for brain health maintenance on the background of increased longevity.

Sex Associations Between Air Pollution and Estimated Atherosclerotic Cardiovascular Disease Risk Determination

Objective: The purpose of this study was to investigate the sex correlations of particulate matters (PM2.5, PM10, PM2.5-10), NO2 and NOx with ASCVD risk in the UK Biobank population. Methods: Among 285,045 participants, pollutants were assessed and correlations between ASCVD risk were stratified by sex and estimated using multiple linear and logistic regressions adjusted for length of time at residence, education, income, physical activity, Townsend deprivation, alcohol, smocking pack years, BMI and rural/urban zone. Results: Males presented higher ASCVD risk than females (8.63% vs. 2.65%, p < 0.001). In males PM2.5, PM10, NO2, and NOx each were associated with an increased ASCVD risk >7.5% in the adjusted logistic models, with ORs [95% CI] for a 10 μg/m3 increase were 2.17 [1.87-2.52], 1.15 [1.06-1.24], 1.06 [1.04-1.08] and 1.05 [1.04-1.06], respectively. In females, the ORs for a 10 μg/m3 increase were 1.55 [1.19-2.05], 1.22 [1.06-1.42], 1.07 [1.03-1.10], and 1.04 [1.02-1.05], respectively. No association was observed in both sexes between ASCVD risk and PM2.5-10. Conclusion: Our findings may suggest the possible actions of air pollutants on ASCVD risk.

Research progress of different components of PM2.5 and ischemic stroke

PM2.5 is a nonhomogeneous mixture of complex components produced from multiple sources, and different components of this mixture have different chemical and biological toxicities, which results in the fact that the toxicity and hazards of PM2.5 may vary even for the same mass of PM2.5. Previous studies on PM2.5 and ischemic stroke have reached different or even opposing conclusions, and considering the heterogeneity of PM2.5 has led researchers to focus on the health effects of specific PM2.5 components. However, due to the complexity of PM2.5 constituents, assessing the association between exposure to specific PM2.5 constituents and ischemic stroke presents significant challenges. Therefore, this paper reviews and analyzes studies related to PM2.5 and its different components and ischemic stroke, aiming to understand the composition of PM2.5 and identify its harmful components, elucidate their relationship with ischemic stroke, and thus provide some insights and considerations for studying the biological mechanisms by which they affect ischemic stroke and for the prevention and treatment of ischemic stroke associated with different components of PM2.5.

γ-Oryzanol ameliorates fine dust-induced premature endothelial senescence and dysfunction via attenuating oxidative stress

Various cardiovascular diseases are associated with endothelial senescence, and a recent study showed that fine dust (FD)-induced premature endothelial senescence and dysfunction is associated with increased oxidative stress. The aim of the present study was to investigate protective effect of rice bran extract (RBE) and its major component of γ-Oryzanol (γ-Ory) against FD-induced premature endothelial senescence. Porcine coronary artery endothelial cells (PCAECs) were treated with FD alone or with RBE or γ-Ory. Senescence-associated β-galactosidase (SA-β-gal) activity, expression of cell cycle regulatory proteins, and oxidative stress levels were evaluated. The results indicated that SA-β-gal activity in the FD-treated PCAECs was attenuated by RBE and γ-Ory. Additionally, γ-Ory inhibited FD-induced cell cycle arrest, restored cell proliferation, and reduced the expression of cell cycle regulatory proteins. γ-Ory also inhibited oxidative stress and prevented senescence-associated NADPH oxidase and LAS activity in FD-exposed ECs suggesting that γ-Ory could protect against FD-induced ECs senescence and dysfunction.

Causality of particulate matter on cardiovascular diseases and cardiovascular biomarkers

Background

Previous observational studies have shown that the prevalence of cardiovascular diseases (CVDs) is related to particulate matter (PM). However, given the methodological limitations of conventional observational research, it is difficult to identify causality conclusively. To explore the causality of PM on CVDs and cardiovascular biomarkers, we conducted a Mendelian randomization (MR) analysis.

Method

In this study, we obtained summary-level data for CVDs and cardiovascular biomarkers including atrial fibrillation (AF), heart failure (HF), myocardial infarction (MI), ischemic stroke (IS), stroke subtypes, body mass index (BMI), lipid traits, fasting glucose, fasting insulin, and blood pressure from several large genome-wide association studies (GWASs). Then we used two-sample MR to assess the causality of PM on CVDs and cardiovascular biomarkers, 16 single nucleotide polymorphisms (SNPs) for PM2.5 and 6 SNPs for PM10 were obtained from UK Biobank participants. Inverse variance weighting (IVW) analyses under the fixed effects model were used as the main analytical method to calculate MR Estimates, followed by multiple sensitivity analyses to confirm the robustness of the results.

Results

Our study revealed increases in PM2.5 concentration were significantly related to a higher risk of MI (odds ratio (OR), 2.578; 95% confidence interval (CI), 1.611-4.127; p = 7.920 × 10-5). Suggestive evidence was found between PM10 concentration and HF (OR, 2.015; 95% CI, 1.082-3.753; p = 0.027) and IS (OR, 2.279; 95% CI,1.099-4.723; p = 0.027). There was no evidence for an effect of PM concentration on other CVDs. Furthermore, PM2.5 concentration increases were significantly associated with increases in triglyceride (TG) (OR, 1.426; 95% CI, 1.133-1.795; p = 2.469 × 10-3) and decreases in high-density lipoprotein cholesterol (HDL-C) (OR, 0.779; 95% CI, 0.615-0.986; p = 0.038). The PM10 concentration increases were also closely related to the decreases in HDL-C (OR, 0.563; 95% CI, 0.366-0.865; p = 8.756 × 10-3). We observed no causal effect of PM on other cardiovascular biomarkers.

Conclusion

At the genetic level, our study suggested the causality of PM2.5 on MI, TG, as well HDL-C, and revealed the causality of PM10 on HF, IS, and HDL-C. Our findings indicated the need for continued improvements in air pollution abatement for CVDs prevention.

Sources, Degradation, Ingestion and Effects of Microplastics on Humans: A Review

Celluloid, the predecessor to plastic, was synthesized in 1869, and due to technological advancements, plastic products appear to be ubiquitous in daily life. The massive production, rampant usage, and inadequate disposal of plastic products have led to severe environmental pollution. Consequently, reducing the employment of plastic has emerged as a pressing concern for governments globally. This review explores microplastics, including their origins, absorption, and harmful effects on the environment and humans. Several methods exist for breaking down plastics, including thermal, mechanical, light, catalytic, and biological processes. Despite these methods, microplastics (MPs, between 1 and 5 mm in size) continue to be produced during degradation. Acknowledging the significant threat that MPs pose to the environment and human health is imperative. This form of pollution is pervasive in the air and food and infiltrates our bodies through ingestion, inhalation, or skin contact. It is essential to assess the potential hazards that MPs can introduce. There is evidence suggesting that MPs may have negative impacts on different areas of human health. These include the respiratory, gastrointestinal, immune, nervous, and reproductive systems, the liver and organs, the skin, and even the placenta and placental barrier. It is encouraging to see that most of the countries have taken steps to regulate plastic particles. These measures aim to reduce plastic usage, which is essential today. At the same time, this review summarizes the degradation mechanism of plastics, their impact on human health, and plastic reduction policies worldwide. It provides valuable information for future research on MPs and regulatory development.

PM2.5 induces alterations in gene expression profile of platelet-derived extracellular vesicles and mediates cardiovascular injury in rats

Platelet-derived extracellular vesicles (P-EVs), as the most abundant vesicles in blood, have been proven to play cardinal roles in cardiovascular injury. RNAs (especially miRNAs) carried by P-EVs can be transferred to the receptor, which plays a critical role in regulating vascular endothelial function. PM2.5 is one of the most well-known risk factors that cause cardiovascular disease. Therefore, the objective of the current study was to explore whether exposure to PM2.5 would alter the gene expression profile of P-EVs, and to further elucidate the role of RNAs (especially miRNAs) carried by P-EVs in cardiovascular injury induced by PM2.5 exposure. P-EVs were isolated from the platelet-rich plasma which was exposed and unexposed to PM2.5, and the differentially expressed target genes were evaluated using whole-transcriptome gene sequencing. Rats were treated with P-EVs under different exposure conditions (a protein concentration of 50 µg/mL) and an equal volume of normal saline. The pathological damage of the thoracic aorta and cardiac tissue was evaluated and the coagulation function of the rats was detected. The differentially expressed genes were shown to be mainly concentrated in inflammation, angiogenesis, and apoptosis-related pathways. Moreover, P-EVs extracted from PM2.5-exposed plasma had the potential to trigger an inflammatory response, impair vascular endothelial function, disrupt the normal coagulation process, and promote a prothrombotic state. Our study indicated that PM2.5 induces cardiovascular injury in rats by interfering with the gene expression of P-EVs. It will provide new targets for studying the mechanism involved in PM2.5-induced cardiovascular injury.

Incident risk and burden of cardiovascular diseases attributable to long-term NO2 exposure in Chinese adults

BACKGROUND

A number of studies suggested a nexus between long-term exposure to nitrogen dioxide (NO2) and the incidence of cardiovascular disease (CVD), while population-based cohort evidence in low- and middle-income countries was extensively sparse.

METHODS

We carried out an 8-year longitudinal study (2010-2018) in a nationwide dynamic cohort of 36,948 Chinese adult participants, who were free of CVD at baseline. Annual average estimates of NO2 exposure were predicted using a well-validated spatiotemporal model and assigned to study participants based on their residential counties. Considering death as a competing risk event, Fine-Gray competing risk models with time-varying exposures at an annual scale were used to quantify incident risks of overall CVD, hypertension, and stroke associated with a 10-μg/m3 rise in NO2 exposure. Using the meta-analysis approach, we performed a pooled analysis of hazard ratio (HR) drawn from this and prior multinational cohort studies for the assessment of attributable burden. NO2-attributable overall CVD incidents in China were evaluated by city and province for years 2010 and 2018, referring to a counterfactual exposure level of 10 μg/m3 (2021 World Health Organization [WHO] air quality guidelines). A decomposition method was used to decompose net change in NO2-attributable CVD incidents during 2010 and 2018 into 3 primary contributions of driving factors (i.e., changes in NO2 exposure, population size, and incidence rate).

RESULTS

A total of 4428 overall CVD events (hypertension 2448, stroke 1044) occurred during a median follow-up period of 6.1 years. Annual mean NO2 concentration from 2010 to 2018 was 20.0 μg/m3 (range: 6.9-57.4 μg/m3). An increase of 10-µg/m3 in NO2 was associated with an HR of 1.558 (95% confidence interval [CI]: 1.477, 1.642) for overall CVD, 1.521 (95% CI: 1.419, 1.631) for hypertension, and 1.664 (95% CI: 1.485, 1.865) for stroke. Longitudinal associations of NO2 exposure with incident CVD were nearly linear over the exposure range, suggesting no discernible thresholds. Subgroup analyses indicated significantly higher NO2-associated risks of incident CVD among urban residents and overweight/obese individuals. According to pooled HR of NO2-CVD association (1.108, 95% CI: [1.007, 1.219]) from 10 multinational cohort studies, we estimated totally 1.44 million incident CVD cases attributable to NO2 exposure in 2018, representing a substantial decrease of 0.41 million compared to the estimate in 2010 (1.85 million) in mainland of China. Nationally, from 2010 to 2018, the attributable incident cases greatly dropped by 22.4%, which was dominantly driven by declined NO2 concentration (-47.1%) that had offset far from the rise of CVD incidence rate (+19.6%) and population growth (+5.1%).

CONCLUSIONS

This study provided nationwide cohort evidence for elevated risks of CVD incidence associated with long-term ambient NO2 exposure among Chinese adults, particularly in urban areas and among overweight/obese individuals. Our findings highlighted that reducing NO2 exposure below 2021 WHO guideline could help prevent a substantial portion of incident CVD cases in China.

Associations between air pollution and mental health service use in dementia: a retrospective cohort study

BACKGROUND

Little is known about the role of air pollution in how people with dementia use mental health services.

OBJECTIVE

We examined longitudinal associations between air pollution exposure and mental health service use in people with dementia.

METHODS

In 5024 people aged 65 years or older with dementia in South London, high resolution estimates of nitrogen dioxide (NO2) and particulate matter (PM2.5 and PM10) levels in ambient air were linked to residential addresses. Associations between air pollution and Community Mental Health Team (CMHT) events (recorded over 9 years) were examined using negative binomial regression models. Cognitive function was measured using the Mini Mental State Examination (MMSE) and health and social functioning was measured using the Health of the Nation Outcomes Scale (HoNOS65+). Associations between air pollution and both MMSE and HoNOS65+ scores were assessed using linear regression models.

FINDINGS

In the first year of follow-up, increased exposure to all air pollutants was associated with an increase in the use of CMHTs in a dose-response manner. These associations were strongest when we compared the highest air pollution quartile (quartile 4: Q4) with the lowest quartile (Q1) (eg, NO2: adjusted incidence rate ratio (aIRR) 1.27, 95% CI 1.11 to 1.45, p<0.001). Dose-response patterns between PM2.5 and CMHT events remained at 5 and 9 years. Associations were strongest for patients with vascular dementia. NO2 levels were linked with poor functional status, but not cognitive function.

CONCLUSIONS

Residential air pollution exposure is associated with increased CMHT usage among people with dementia.

CLINICAL IMPLICATIONS

Efforts to reduce pollutant exposures in urban settings might reduce the use of mental health services in people with dementia, freeing up resources in already considerably stretched psychiatric services.

Determinants of knowledge associated with occupational hazards and perceived health problems among dye workers in Abeokuta, Nigeria

Background

Identification of potential hazards, their adverse health effects, and predisposing factors in the workplace are critical to improving safety. The objective of the study was to assess the knowledge of occupational hazards, the prevalence of perceived health problems and their predictors among textile dye workers in Abeokuta Nigeria who work in unsupervised settings.

Materials and Methods

In this cross-sectional study, data were collected from 199 participants using a validated semi-structured interviewer-administered questionnaire. Multiple linear regression analysis was used to determine the predictors of knowledge while Pearson Chi-square was employed to test the association between perceived health problems, sociodemographics and work environment characteristics.

Results

The mean age of the respondents was 40 (SD=12) years with an average work experience of 19 years. The majority of respondents 139 (69.8%) had lower than average scores on knowledge of 25 questions on chemical hazards. There was no correlation between knowledge score and work experience (P=0.492) or age (P=0.462) but the knowledge was significantly associated with exposure score (P=0.004), gender (P=0.002) and adherence to instructions on chemicals usage (P=0.041) after adjusting for safe practice. The most frequent health problems among the dye workers were respiratory disorders (53.8%), allergies (51.8%), and skin disorders (24.1%). Airborne gaseous pollutants from the mixing of chemicals were associated with allergies (P=0.045), circulatory (P=0.02) and skin disorders (P=0.049) while air-borne textile fiber/dye particles could predict allergies (P=0.028).

Conclusions

Findings revealed that exposure, gender and adherence to instruction labels on dye/chemical containers could determine knowledge of chemical hazards while physical work environment characteristics could determine health problems.

Long-term cardiometabolic effects of ambient ozone pollution in a large Chinese population

Limited studies investigated the effects of long-term ozone exposure on cardiometabolic health. We aimed to examine the association of long-term ozone exposure with a range of cardiometabolic diseases, as well as the subclinical indicators in Eastern China. The study included 202,042 adults living in 11 prefecture-level areas in Zhejiang Province between 2014 and 2021. Using a satellite-based model with a 1 × 1 km spatial resolution, we estimated residential 5-year average ozone exposures for each subject. Mixed-effects logistic and linear regression models were applied to explore the associations of ozone exposure with cardiometabolic diseases and subclinical indicators, respectively. We found that a 9% [95% confidence interval (95% CI): 7-12%] higher in odds of cardiometabolic disease per 10 μg/m³ increase in ozone exposure. Specifically, we also found higher prevalence of cardiovascular diseases (15%), stroke (19%), hypertension (7%), dyslipidemia (15%), and hypertriglyceridemia (9%) associated with ozone exposure. However, we did not find significant associations between ozone exposure and coronary heart disease, myocardial infarction, or diabetes mellitus. Long-term ozone exposures were also significantly associated with adverse changes in systolic blood pressure, diastolic blood pressure, total serum cholesterol, triglyceride, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, glucose concentration, and body mass index. Our results showed that people with lower education levels, those over 50 years old, and those who were overweight or obese were more susceptible to the effects of ozone on cardiometabolic diseases. Our findings demonstrated the detrimental effects of long-term ozone exposure on cardiometabolic health, emphasizing the need for ozone control strategies to reduce the burden of cardiometabolic diseases.

Air quality and respiratory health in children

Air pollution is a leading modifiable risk factor for various cardio-respiratory outcomes globally, both for children and for adults. Children are particularly susceptible to the adverse effects of air pollution due to various physiological and behavioural factors. Children are at a higher risk of outcomes such as acute respiratory infections, asthma and decreased lung function due to air pollution exposure; the risk varies in different geographical regions, depending on the source of air pollution, duration of exposures and concentration. Prenatal exposure to air pollution may also contribute to adverse respiratory outcomes later in life.

Association between First Trimester Exposure to Ambient PM2.5 and NO2 and Congenital Heart Defects: A Population-Based Cohort Study of 1,342,198 Live Births in Canada

BACKGROUND

The extent to which ambient air pollution contributes to the pathogenesis of congenital heart defects remains uncertain.

OBJECTIVE

We investigated whether first trimester exposure to ambient fine particulate matter (PM2.5) and nitrogen dioxide (NO2) was associated with the risk of critical and noncritical heart defects in a large population-based cohort of births.

METHODS

We carried out a retrospective cohort study of children conceived between 2000 and 2016 in Quebec, Canada. Heart defects were identified via data from the Maintenance and Use of Data for the Study of Hospital Clientele registry. The main exposures were average concentration of PM2.5 and NO2 in a) the first trimester and b) the month of conception. Exposures were estimated at the residential postal code. Associations with critical and noncritical heart defects were assessed using logistic regression models, adjusted for maternal and infant characteristics. We considered single- and two-pollutant models and assessed modifying effects of maternal comorbidity, including preexisting hypertension, preeclampsia, anemia, and diabetes.

RESULTS

The cohort comprised 1,342,198 newborns, including 12,715 with heart defects. Exposure in the first trimester and month of conception yielded similar results; both were associated with a greater risk of heart defects. Adjusted odds ratios (OR) for any heart defect per interquartile range increase were 1.02 (95% CI: 1.00, 1.05) for PM2.5 and 1.10 (95% CI: 1.07, 1.13) for NO2. Associations with atrial septal defects were 1.08 (95% CI: 1.03, 1.14) for PM2.5 and 1.19 (95% CI: 1.12, 1.25) for NO2. Corresponding ORs for ventricular septal defects and individual critical heart defects were not significant. PM2.5 (OR=1.11; 95% CI: 1.06, 1.17) and NO2 (OR=1.23; 95% CI: 1.17, 1.31) exposure were associated with a greater risk of heart defects in mothers with comorbidity.

DISCUSSION

In this population-based cohort, prenatal exposure to ambient air pollution during the first trimester was associated with an increased risk of heart defects, particularly atrial septal defects. The association with heart defects was greater in mothers with comorbidity. https://doi.org/10.1289/EHP11120.

Air pollution exposure and heart failure: A systematic review and meta-analysis

While the literature strongly supports a positive association between particulate matter with diameter ≤ 2.5 μm (PM_2.5) exposure and heart failure (HF), there is uncertainty regarding the other pollutants and the dose and duration of exposure that triggers an adverse response. To comprehensively assess and quantify the association of air pollution exposure with HF incidence and mortality, we performed separate meta-analyses according to pollutant types [PM_2.5, PM₁₀, sulfur dioxide (SO₂), nitrogen dioxide (NO₂), carbon monoxide (CO), ozone (O₃)], and exposure duration (short- and long-term). We systematically searched PubMed, EMBASE, and Web of Science for relevant articles with publication dates up to July 12, 2022, identifying 35 eligible studies. Random-effects models were used to summarize the pooled odds ratios (ORs) and 95 % confidence intervals (95 % CIs). For long-term exposure, the growing risk of HF was significantly associated with each 10 μg/m³ increase in PM_2.5 (OR = 1.196, 95 % CI: 1.079-1.326; I² = 76.8 %), PM₁₀ (1.190, 1.045-1.356; I² = 76.2 %), and NO₂ (1.072, 1.028-1.118; I² = 78.3 %). For short-term exposure, PM_2.5, PM₁₀, NO₂, and O₃ (per 10 μg/m³ increment) increased the risk of HF, with estimated ORs of 1.019 (1.008-1.030; I² = 39.9 %), 1.012 (1.007-1.017; I² = 28.3 %), 1.016 (1.005-1.026; I² = 53.7 %), and 1.006 (1.002-1.010; I² = 0.0 %), respectively. No significant effects of SO₂ and CO exposure on the risk of HF were observed. In summary, our study powerfully highlights the deleterious impact of PM_2.5, PM₁₀, and NO₂ exposure (either short- or long-term) on HF risk. Serious efforts should be made to improve air quality through legislation and interdisciplinary cooperation.

Tailoring the microstructure of BiVO4 sensing electrode by nanoparticle decoration and its effect on hazardous NH3 sensing

Real-time monitoring and quantification of exhaust pollutants is crucial but is troublesome because of extremely harsh thermochemical conditions, and in this regard mixed-potential sensing technology can be a realistic solution. In this study, BiVO₄ nanoparticles are decorated onto the preformed porous sensing electrode (SE) backbone by homogeneous infiltration process to improve the sensing performance in mixed-potential sensor. The influence of nanoparticle decoration on phase composition, microstructure and sensing performance are analyzed by physical and electrochemical techniques. Corresponding results indicate that the microstructure tailoring enhances the sensor performance, by extending the triple phase boundary (TPB) and surface area of SE itself. The sensitivity (-119.47 mV/decade) and response time (20 s) of i-BVO SE-based sensor at 600 ℃ are 20 % higher and 8 s faster than bare BiVO₄ SE-based sensor (99.24 mV/decade and 28 s). Additionally, the i-BVOǀYSZǀPt cell exhibits good selectivity and cross-sensitivity toward NH₃ without any dependency on oxygen partial pressure (pO₂). The fabricated sensor is also found stable towards cyclic and long-term operations. Electrochemical Impendence Spectroscopy (EIS) and DC polarization studies were performed to confirm the mixed-potential behavior. Conclusively, the superior sensing performance of i-BVO SE compared to various oxide based SEs highlights its suitability for mixed-potential NH₃ sensing.

A case study on occupational exposure assessment and characterization of particles in a printing shop in China

Printers can release numerous particles to contaminate indoor environments and pose health risks. Clarifying the exposure level and physicochemical properties of printer-emitted particles (PEPs) will help to evaluate the health risks of printer operator. In our study, the particles concentration in the printing shop was monitored in real time for a long time (12 h/day, total 6 days), and the PEPs were collected to characterize their physicochemical properties including shape, size and compositions. The result showed that the concentration of PEPs is closely related to the printing workload and the highest particle mass concentration of PM₁₀ and PM_2.5 was 212.73 μg m^-3 and 91.48 μg m^-3, respectively. The concentration of PM₁ in the printing shop was in the range of 11.88-80.59 μg m^-3 for mass value, and 174.83-1348.84 P cm^-3 for count value which changed with the printing volume. The particle sizes of PEPs were less than 900 nm, 47.99% of PEPs was less than 200 nm, and 14.21% of the particles were at the nanoscale. PEPs contained 68.92% organic carbon (OC), 5.31% elemental carbon (EC), 3.17% metal elements, and 22.60% other inorganic additives, which contained more OC and metal elements than toners. Total polycyclic aromatic hydrocarbons (PAHs) levels were 18.95 ng/mg in toner and 120.70 ng/mg in PEPs. The carcinogenic risk of PAHs in PEPs was 1.40 × 10^-7. These findings suggested future studies should pay more attention to the health effects of printing workers exposed to nanoparticles.

A State-of-the-Science Review on High-Resolution Metabolomics Application in Air Pollution Health Research: Current Progress, Analytical Challenges, and Recommendations for Future Direction

BACKGROUND

Understanding the mechanistic basis of air pollution toxicity is dependent on accurately characterizing both exposure and biological responses. Untargeted metabolomics, an analysis of small-molecule metabolic phenotypes, may offer improved estimation of exposures and corresponding health responses to complex environmental mixtures such as air pollution. The field remains nascent, however, with questions concerning the coherence and generalizability of findings across studies, study designs and analytical platforms.

OBJECTIVES

We aimed to review the state of air pollution research from studies using untargeted high-resolution metabolomics (HRM), highlight the areas of concordance and dissimilarity in methodological approaches and reported findings, and discuss a path forward for future use of this analytical platform in air pollution research.

METHODS

We conducted a state-of-the-science review to a) summarize recent research of air pollution studies using untargeted metabolomics and b) identify gaps in the peer-reviewed literature and opportunities for addressing these gaps in future designs. We screened articles published within Pubmed and Web of Science between 1 January 2005 and 31 March 2022. Two reviewers independently screened 2,065 abstracts, with discrepancies resolved by a third reviewer.

RESULTS

We identified 47 articles that applied untargeted metabolomics on serum, plasma, whole blood, urine, saliva, or other biospecimens to investigate the impact of air pollution exposures on the human metabolome. Eight hundred sixteen unique features confirmed with level-1 or -2 evidence were reported to be associated with at least one or more air pollutants. Hypoxanthine, histidine, serine, aspartate, and glutamate were among the 35 metabolites consistently exhibiting associations with multiple air pollutants in at least 5 independent studies. Oxidative stress and inflammation-related pathways-including glycerophospholipid metabolism, pyrimidine metabolism, methionine and cysteine metabolism, tyrosine metabolism, and tryptophan metabolism-were the most commonly perturbed pathways reported in > 70 % of studies. More than 80% of the reported features were not chemically annotated, limiting the interpretability and generalizability of the findings.

CONCLUSIONS

Numerous investigations have demonstrated the feasibility of using untargeted metabolomics as a platform linking exposure to internal dose and biological response. Our review of the 47 existing untargeted HRM-air pollution studies points to an underlying coherence and consistency across a range of sample analytical quantitation methods, extraction algorithms, and statistical modeling approaches. Future directions should focus on validation of these findings via hypothesis-driven protocols and technical advances in metabolic annotation and quantification. https://doi.org/10.1289/EHP11851.

Meandered and muddled: a systematic review on the impact of air pollution on ocular health

From the years 1970-2023, a systematic overview of the diverse consequences of particulate matter on eye health and a disease classification according to acute, chronic, and genetic are presented using the PubMed, Research Gate, Google Scholar, and Science Direct databases. Various studies on medical aspects correlate with the eye and health. However, from an application perspective, there is limited research on the ocular surface and air pollution. The main objective of the study is to uncover the relationship between eye health and air pollution, particularly particulate matter, along with other external factors acting as aggravators. The secondary goal of the work is to examine the existing models for mimicking human eyes. The study is followed by a questionnaire survey in a workshop, in which the exposure-based investigation was tagged based on their activity. This paper establishes a relationship between particulate matter and its influence on human health, leading to numerous eye diseases like dry eyes, conjunctivitis, myopia, glaucoma, and trachoma. The results of the questionnaire survey indicate that about 68% of the people working in the workshop are symptomatic with tears, blurred vision, and mood swings, while 32% of the people were asymptomatic. Although there are approaches for conducting experiments, the evaluation is not well defined; empirical and numerical solutions for particle deposition on the eye are needed. There prevails a broad gap in the arena of ocular deposition modeling.

Health Impacts of Long-Term NO2 Exposure and Inequalities among the Chinese Population from 2013 to 2020

Nitrogen dioxide (NO₂) is associated with mortality and many other adverse health outcomes. In 2021, the World Health Organization established a new NO₂ air quality guideline (AQG) (annual average <10 μg/m³). However, the burden of diseases attributable to long-term NO₂ exposure above the AQG is unknown in China. Nitrogen oxide is a major air pollutant in populous cities, which are disproportionately impacted by NO₂; this represents a form of environmental inequality. We conducted a nationwide risk assessment of premature deaths attributable to long-term NO₂ exposure from 2013 to 2020 based on the exposure-response relationship, high-resolution annual NO₂ concentrations, and gridded population data (considering sex, age, and residence [urban vs rural]). We calculated health metrics including attributable deaths, years of life lost (YLL), and loss of life expectancy (LLE). Inequality in the distribution of attributable deaths and YLLs was evaluated by the Lorenz curve and Gini index. According to the health impact assessments, in 2013, long-term NO₂ exposure contributed to 315,847 (95% confidence interval [CI]: 306,709-319,269) premature deaths, 7.90 (7.68-7.99) million YLLs, and an LLE of 0.51 (0.50-0.52) years. The high-risk subgroup (top 20%) accounted for 85.7% of all NO₂-related deaths and 85.2% of YLLs, resulting in Gini index values of 0.81 and 0.67, respectively. From 2013 to 2020, the estimated health impact from NO₂ exposure was significantly reduced, but inequality displayed a slightly increasing trend. Our study revealed a considerable burden of NO₂-related deaths in China, which were disproportionally frequent in a small high-risk subgroup. Future clean air initiatives should focus not only on reducing the average level of NO₂ exposure but also minimizing inequality.

A comprehensive overview of genotoxicity and mutagenicity associated with outdoor air pollution exposure in Brazil

This review examined the mutagenicity and genotoxicity associated with exposure to outdoor air pollutants in Brazil. A search was performed on the Web of Science database using a combination of keywords that resulted in 134 articles. After applying exclusion criteria, a total of 75 articles were obtained. The articles were classified into three categories: (1) studies with plants and animals, (2) in vitro studies, and (3) human biomonitoring. The investigations were conducted in 11 of 27 Brazilian states with the highest prevalence in the southeast and south regions. Only 5 investigations focused on the effects of burning biomass on the quality of outdoor air. Plants, especially Tradescantia pallida, were the main air pollution biomonitoring tool. When available, a significant association between levels of air pollutants and genetic damage was described. Among the in vitro studies, Salmonella/microsome is the most used test to evaluate mutagenesis of outdoor air in Brazil (n = 26). Human biomonitoring studies were the least frequent category (n = 18). Most of the investigations utilized micronucleus bioassay, in oral mucosa cells (n = 15) and lymphocytes (n = 5), and the comet assay (n = 6). The analysis in this study points to the existence of gaps in genotoxicity studies and our findings indicate that future studies need to address the variety of potential sources of pollution existing in Brazil. In addition to extent of the impacts, consideration should be given to the enormous Brazilian biodiversity, as well as the determination of the role of socioeconomic inequality of the population in the observed outcomes.

Acute Effects of Ambient Air Pollution on Asthma Emergency Department Visits in Ten U.S. States

BACKGROUND

Previous studies of short-term ambient air pollution exposure and asthma morbidity in the United States have been limited to a small number of cities and/or pollutants and with limited consideration of effects across ages.

OBJECTIVES

To estimate acute age group-specific effects of fine and coarse particulate matter (PM), major PM components, and gaseous pollutants on emergency department (ED) visits for asthma during 2005-2014 across the United States.

METHODS

We acquired ED visit and air quality data in regions surrounding 53 speciation sites in 10 states. We used quasi-Poisson log-linear time-series models with unconstrained distributed exposure lags to estimate site-specific acute effects of air pollution on asthma ED visits overall and by age group (1-4, 5-17, 18-49, 50-64, and 65+ y), controlling for meteorology, time trends, and influenza activity. We then used a Bayesian hierarchical model to estimate pooled associations from site-specific associations.

RESULTS

Our analysis included 3.19 million asthma ED visits. We observed positive associations for multiday cumulative exposure to all air pollutants examined [e.g., 8-d exposure to PM2.5: rate ratio of 1.016 with 95% credible interval (CI) of (1.008, 1.025) per 6.3-μg/m3 increase, PM10-2.5: 1.014 (95% CI: 1.007, 1.020) per 9.6-μg/m3 increase, organic carbon: 1.016 (95% CI: 1.009, 1.024) per 2.8-μg/m3 increase, and ozone: 1.008 (95% CI: 0.995, 1.022) per 0.02-ppm increase]. PM2.5 and ozone showed stronger effects at shorter lags, whereas associations of traffic-related pollutants (e.g., elemental carbon and oxides of nitrogen) were generally stronger at longer lags. Most pollutants had more pronounced effects on children (<18 y old) than adults; PM2.5 had strong effects on both children and the elderly (>64 y old); and ozone had stronger effects on adults than children.

CONCLUSIONS

We reported positive associations between short-term air pollution exposure and increased rates of asthma ED visits. We found that air pollution exposure posed a higher risk for children and older populations. https://doi.org/10.1289/EHP11661.

Contributions of various driving factors to air pollution events: Interpretability analysis from Machine learning perspective

The air quality in China has been improved substantially, however fine particulate matter (PM_2.5) still remain at a high level in many areas. PM_2.5 pollution is a complex process that is attributed to gaseous precursors, chemical, and meteorological factors. Quantifying the contribution of each variable to air pollution can facilitate the formulation of effective policies to precisely eliminate air pollution. In this study, we first used decision plot to map out the decision process of the Random Forest (RF) model for a single hourly data set and constructed a framework for analyzing the causes of air pollution using multiple interpretable methods. Permutation importance was used to qualitatively analyze the effect of each variable on PM_2.5 concentrations. The sensitivity of secondary inorganic aerosols (SIA): SO₄^2-, NO₃^- and NH₄⁺ to PM_2.5 was verified by Partial dependence plot (PDP). Shapley Additive Explanation (Shapley) was used to quantify the contribution of drivers behind the ten air pollution events. The RF model can accurately predict PM_2.5 concentrations, with determination coefficient (R²) of 0.94, root mean square error (RMSE) and mean absolute error (MAE) of 9.4 μg/m³ and 5.7 μg/m³, respectively. This study revealed that the order of sensitivity of SIA to PM_2.5 was NH₄⁺＞NO₃^-＞SO₄^2-. Fossil fuel and biomass combustion may be contributing factors to air pollution events in Zibo in 2021 autumn-winter. NH₄⁺ contributed 19.9-65.4 μg/m³ among ten air pollution events (APs). K, NO₃^-, EC and OC were the other main drivers, contributing 8.7 ± 2.7 μg/m³, 6.8 ± 7.5 μg/m³, 3.6 ± 5.8 μg/m³ and 2.5 ± 2.0 μg/m³, respectively. Lower temperature and higher humidity were vital factors that promoted the formation of NO₃^-. Our study may provide a methodological framework for precise air pollution management.

How does particulate air pollution affect barrier functions and inflammatory activity of lung vascular endothelium?

Both particulate matter and gaseous components of air pollution have already been shown to increase cardiovascular mortality in numerous studies. It is, however, important to note that on their way to the bloodstream the polluting agents pass the lung barrier. Inside the alveoli, particles of approximately 0.4-1 μm are most efficiently deposited and commonly undergo phagocytosis by lung macrophages. Not only the soluble agents, but also particles fine enough to leave the alveoli enter the bloodstream in this finite part of the endothelium, reaching thus higher concentrations in close proximity of the alveoli and endothelium. Additionally, deposits of particulate matter linger in direct proximity of the endothelial cells and may induce inflammation, immune responses, and influence endothelial barrier dysfunction thus increasing PM bioavailability in positive feedback. The presented discussion provides an overview of possible components of indoor PM and how endothelium is thus influenced, with emphasis on lung vascular endothelium and clinical perspectives.