Extrapulmonary translocation of intratracheally instilled fine and ultrafine particles via direct and alveolar macrophage-associated routes

The effects of direct and macrophage-mediated exposure to aqueous fine particulate matter on vascular endothelial dysfunction

Fine particulate matter (PM2.5) is an independent risk factor for vascular diseases. In this context, activated macrophages release inflammatory molecules that can contribute to endothelial dysfunction. While the effects of PM2.5's solid fraction on vascular endothelial cells are well-documented, the effect of its polar compounds circulating in the bloodstream remains unclear. In this study, we examined the effects of direct and indirect (macrophage-mediated) exposure to aqueous PM2.5 on the endothelium. CF-1 mice received intranasal instillations of PM2.5 (30 μg in 10 μL) or saline, 5 days per week for two weeks. These animals exhibited considerable endothelial dysfunction linked to oxidative stress. Similarly, macrophages (RAW264.7 lineage) exposed to aqueous PM2.5 (10-fold dilution) exhibited oxidative stress and inflammation, indicating that their reactive phenotype may contribute to the outcomes observed in vivo. Interestingly, their conditioned medium (10 % v/v) enhanced endothelial cell function (EOMA lineage) by reducing reactive oxygen species (ROS) production and promoting an endothelial nitric oxide synthase (eNOS)-dependent increase in nitrite levels, with the exact opposite effect observed in cells directly exposed to aqueous PM2.5. These findings suggest that the macrophage secretome, rather than residual metals, may be responsible for these effects. Consistent with these findings, incubation with the animals' plasma (1 % v/v) also stimulated nitrite production. Additionally, caveolin-1, a key mediator of vesicle uptake, was overexpressed in endothelial cells exposed to conditioned medium, suggesting its involvement in monocyte-endothelium crosstalk. Finally, our results indicated that the macrophage secretome might serve as a mild stimulus, activating protective mechanisms in endothelial cells, whereas direct exposure to aqueous PM2.5 induces dysfunction.

A systematic review of air pollution exposure and brain structure and function during development

OBJECTIVES

Air pollutants are known neurotoxicants. In this updated systematic review, we evaluate new evidence since our 2019 systematic review on the effect of outdoor air pollution exposure on childhood and adolescent brain structure and function as measured by magnetic resonance imaging (MRI).

METHODS

Using PubMed, Web of Science, and Scopus we conducted an updated literature search and systematic review of articles published through January 2025, using key terms for air pollution and functional and/or structural MRI. Two raters independently screened all articles using Covidence and implemented the risk of bias instrument for systematic reviews used to inform the World Health Organization Global Air Quality Guidelines.

RESULTS

We identified 29 relevant papers, and 20 new studies met our inclusion criteria. Including six studies from our 2019 review, the 26 publications to date include study populations from the United States, Netherlands, Spain, and United Kingdom. Studies investigated exposure periods spanning pregnancy through early adolescence, and estimated air pollutant exposure levels via personal monitoring, geospatial residential estimates, or school courtyard monitors. Brain MRI occurred when children were on average 6-14.7 years old; however, one study assessed newborns. Several MRI modalities were leveraged, including structural morphology, diffusion tensor imaging, restriction spectrum imaging, arterial spin labeling, magnetic resonance spectroscopy, as well as resting-state and task-based functional MRI. Air pollutants were associated with widespread brain differences, although the magnitude and direction of findings are largely inconsistent, making it difficult to draw strong conclusions.

CONCLUSION

Prenatal and childhood exposure to outdoor air pollution is associated with structural and functional brain variations. Compared to our initial 2019 review comprised of only cross-sectional studies, the current literature now includes longitudinal studies and more advanced neuroimaging methods. Further research is needed to clarify the effects of developmental timing, along with the downstream implications of outdoor air pollution exposure on children's cognitive and mental health.

Particulate matter and co-occurring genetic risk induce oxidative stress and cardiac and brain Alzheimer's pathology

Amyloid-beta (Aβ) aggregates, an Alzheimer's disease (AD) pathological hallmark, extend beyond the brain to the heart of heart failure (HF) and AD patients. Being diseases of the elderly, increased prevalence is expected as the population ages. However, changes in the incidence and prevalence of dementia over the past decades, and the independent association of exposure to air particulate matter (PM) with poor cognitive function, adverse cardiovascular effects, and oxidative stress hint to the contribution of other factors beyond senescence. Therefore we evaluate whether, and by which mechanism(s), PM exposure affects heart and brain proteinopathy with/without genetic predisposition.AD-prone and control mice are exposed for three months to filtered air (FA) or concentrated ambient PM < 2.5μm in diameter (PM2.5), and evaluated for Aβ pathology, cognitive and cardiac function, and markers of oxidative stress. Aβ pathology become noticeable in AD hearts and worsens with PM2.5 in AD brains. Functionally, PM2.5 lead to anxiety and memory deficits and worsens diastolic function. Redox homeostasis is negatively impacted by genotype and PM2.5. This study identifies environmental pollution as a potential key contributor to early progression of heart and brain proteinopathy, delineating a crucial timepoint for early interventions to limit multiorgan damage in vulnerable patients.

Relationship between air pollution exposure and insulin resistance in Chinese middle-aged and older populations: evidence from Chinese cohort

Aims

This study aimed to determine the relationships between mixed exposure to six air pollutants, namely, particulate matter with an aerodynamic diameter of 2.5 micrometers or less (PM2.5), PM with an aerodynamic diameter of 10 micrometers or less (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), cobalt (CO) and ozone (O3), and insulin resistance (IR) indices in Chinese middle-aged and older populations.

Methods

A total of 2,219 participants from the China Health and Retirement Longitudinal Study (CHARLS), who are followed from 2011 to 2015, were included. Surface air pollutant concentration data were obtained from the China High Air Pollutants (CHAP) database. Multivariable linear regression analysis was used to examine the longitudinal associations between different air pollutants and various IR indices. Additionally, Bayesian kernel machine regression (BKMR), weighted quantile sum (WQS) regression, and quantile-based g computation (Qgcomp) were further utilized to assess the mixed effects of the six air pollutants.

Results

Fully adjusted linear models revealed that increases in the levels of the six air pollutants (in μg/m3) were associated with higher triglyceride-glucose-body mass index (TyG-BMI; Beta = 0.027-0.128), triglyceride-glucose-waist circumference (TyG-WC; Beta = 0.155-0.674), and metabolic score for insulin resistance (METS-IR; Beta = 0.001-0.029) values during the four-year follow-up period. Further mixture analysis indicated that combined exposure to the six air pollutants had a significant cumulative effect on the increases in these three IR indices. Among the pollutants, NO2 and O3 were identified as the primary contributor to the cumulative effect. The result of mediation analysis supported the mediating role of BMI in the relationship between air pollution and IR (mediation proportion: 49.1%-93.5%). The results from both subgroup analysis and sensitivity analysis supported the detrimental effects of air pollution on IR.

Conclusion

Both individual and mixed exposures to air pollution were significantly associated with IR in Chinese middle-aged and older individuals, with our study providing new evidence.

Nanomedicines for Pulmonary Drug Delivery: Overcoming Barriers in the Treatment of Respiratory Infections and Lung Cancer

The pulmonary route for drug administration has garnered a great deal of attention in therapeutics for treating respiratory disorders. It allows for the delivery of drugs directly to the lungs and, consequently, the maintenance of high concentrations at the action site and a reduction in systemic adverse effects compared to other routes, such as oral or intravenous. Nevertheless, the pulmonary administration of drugs is challenging, as the respiratory system tries to eliminate inhaled particles, being the main responsible mucociliary escalator. Nanomedicines represent a primary strategy to overcome the limitations of this route as they can be engineered to prolong pulmonary retention and avoid their clearance while reducing drug systemic distribution and, consequently, systemic adverse effects. This review analyses the use of pulmonary-administered nanomedicines to treat infectious diseases affecting the respiratory system and lung carcinoma, two pathologies that represent major health threats.

Nanotechnology in healthcare, and its safety and environmental risks

Nanotechnology holds immense promise in revolutionising healthcare, offering unprecedented opportunities in diagnostics, drug delivery, cancer therapy, and combating infectious diseases. This review explores the multifaceted landscape of nanotechnology in healthcare while addressing the critical aspects of safety and environmental risks associated with its widespread application. Beginning with an introduction to the integration of nanotechnology in healthcare, we first delved into its categorisation and various materials employed, setting the stage for a comprehensive understanding of its potential. We then proceeded to elucidate the diverse healthcare applications of nanotechnology, spanning medical diagnostics, tissue engineering, targeted drug delivery, gene delivery, cancer therapy, and the development of antimicrobial agents. The discussion extended to the current situation surrounding the clinical translation and commercialisation of these cutting-edge technologies, focusing on the nanotechnology-based healthcare products that have been approved globally to date. We also discussed the safety considerations of nanomaterials, both in terms of human health and environmental impact. We presented the in vivo health risks associated with nanomaterial exposure, in relation with transport mechanisms, oxidative stress, and physical interactions. Moreover, we highlighted the environmental risks, acknowledging the potential implications on ecosystems and biodiversity. Lastly, we strived to offer insights into the current regulatory landscape governing nanotechnology in healthcare across different regions globally. By synthesising these diverse perspectives, we underscore the imperative of balancing innovation with safety and environmental stewardship, while charting a path forward for the responsible integration of nanotechnology in healthcare.

A Systematic Review of Air Pollution Exposure and Brain Structure and Function during Development

Objectives

Air pollutants are known neurotoxicants. In this updated systematic review, we evaluate new evidence since our 2019 systematic review on the effect of outdoor air pollution exposure on childhood and adolescent brain structure and function as measured by magnetic resonance imaging (MRI).

Methods

Using PubMed and Web of Science, we conducted an updated literature search and systematic review of articles published through March 2024, using key terms for air pollution and functional and/or structural MRI. Two raters independently screened all articles using Covidence and implemented the risk of bias instrument for systematic reviews informing the World Health Organization Global Air Quality Guidelines.

Results

We identified 222 relevant papers, and 14 new studies met our inclusion criteria. Including six studies from our 2019 review, the 20 publications to date include study populations from the United States, Netherlands, Spain, and United Kingdom. Studies investigated exposure periods spanning pregnancy through early adolescence, and estimated air pollutant exposure levels via personal monitoring, geospatial residential estimates, or school courtyard monitors. Brain MRI occurred when children were on average 6-14.7 years old; however, one study assessed newborns. Several MRI modalities were leveraged, including structural morphology, diffusion tensor imaging, restriction spectrum imaging, arterial spin labeling, magnetic resonance spectroscopy, as well as resting-state and task-based functional MRI. Air pollutants were associated with widespread brain differences, although the magnitude and direction of findings are largely inconsistent, making it difficult to draw strong conclusions.

Conclusion

Prenatal and childhood exposure to outdoor air pollution is associated with structural and functional brain variations. Compared to our initial 2019 review, publications doubled-an increase that testifies to the importance of this public health issue. Further research is needed to clarify the effects of developmental timing, along with the downstream implications of outdoor air pollution exposure on children's cognitive and mental health.

Aqueous PM2.5 promotes lipid accumulation, classical macrophage polarisation and heat shock response

Fine particulate matter (PM2.5) is an air pollutant that enhances susceptibility to cardiovascular diseases. Macrophages are the first immune cells to encounter the inhaled particles and orchestrate an inflammatory response. Given their role in atherosclerosis development, we investigated whether aqueous PM2.5 could elicit atherogenic effects by polarising macrophages to a pro-oxidative and pro-inflammatory phenotype and enhancing foam cell formation. The RAW264.7 macrophage cell line was exposed to PM2.5 for 48 h, with PBS as the control. Aqueous PM2.5 induced apoptosis and reduced cell proliferation. In surviving cells, we observed morphological, phagocytic, oxidative, and inflammatory features (i.e. enhanced iNOS, Integrin-1β, IL-6 expression), indicative of classical macrophage activation. We also detected an increase in total and surface HSP70 levels, suggesting macrophage activation. Further, exposure of high-cholesterol diet-fed mice to PM2.5 resulted in aortic wall enlargement, indicating vascular lesions. Macrophages exposed to PM2.5 and non-modified low-density lipoprotein (LDL) showed exacerbated lipid accumulation. Given the non-oxidised LDL used and the evidence linking inflammation to disrupted cholesterol negative feedback, we hypothesise that PM2.5-induced inflammation in macrophages enhances their susceptibility to transforming into foam cells. Finally, our results indicate that exposure to aqueous PM2.5 promotes classical macrophage activation, marked by increased HSP70 expression and that it potentially contributes to atherosclerosis.

Improving agglomeration efficiency of aerosols with sizes less than 2.5 µm by generation of vortex streams in inhomogeneous ultrasonic field

In this paper a new approach to increase the agglomeration efficiency of finely dispersed aerosols by generating toroidal vortex streams in inhomogeneous ultrasonic field is proposed and studied. From the obtained experimental results (for two types of emitters) it could be established that the toroidal vortex streams generated in an inhomogeneous ultrasonic field provide an increase of the agglomeration efficiency when exposed to a gas-dispersed flow injected into the agglomeration chamber at a speed of up to 0.2 m/s. Further increase of the injected flow velocity leads to disruption of the structure of the generated vortex streams and agglomeration efficiency decreases. In the course of the analysis, it was found that the efficiency of agglomeration by toroidal vortex streams increases in direct proportion to the increase of the sound pressure level up to 165 dB. After that, no further increase in agglomeration efficiency is observed. By analyzing the agglomeration efficiency depending on particle size, it was possible to verify that the efficiency of agglomeration in comparison with agglomeration in a homogeneous ultrasonic field for droplets with a size of 0.2 … 0.6 μm is increased by 25 %, for 1.8 μm droplets by 20 %; and for droplets larger than 2.5 μm, the increase in efficiency is no more than 17 %.

Carbon Nanotube Immunotoxicity in Alveolar Epithelial Type II Cells Is Mediated by Physical Contact-Independent Cell-Cell Interaction with Macrophages as Demonstrated in an Optimized Air-Liquid Interface (ALI) Coculture Model

There is a need for the assessment of respiratory hazard potential and mode of action of carbon nanotubes (CNTs) before their approval for technological or medical applications. In CNT-exposed lungs, both alveolar macrophages (MФs), which phagocytose CNTs, and alveolar epithelial type II cells (AECII cells), which show tissue injury, are impacted but cell-cell interactions between them and the impacted mechanisms are unclear. To investigate this, we first optimized an air-liquid interface (ALI) transwell coculture of human AECII cell line A549 (upper chamber) and human monocyte cell line THP-1 derived macrophages (lower chamber) in a 12-well culture by exposing macrophages to CNTs at varying doses (5-60 ng/well) for 12-48 h and measuring the epithelial response markers for cell differentiation/maturation (proSP-C), proliferation (Ki-67), and inflammation (IL-1β). In optimal ALI epithelial-macrophage coculture (3:1 ratio), expression of Ki-67 in AECII cells showed dose dependence, peaking at 15 ng/well CNT dose; the Ki-67 and IL-1β responses were detectable within 12 h, peaking at 24-36 h in a time-course. Using the optimized ALI transwell coculture set up with and without macrophages, we demonstrated that direct interaction between CNTs and MФs, but not a physical cell-cell contact between MФ and AECII cells, was essential for inducing immunotoxicity (proliferative and inflammatory responses) in the AECII cells.

Long-term exposure to particulate matter is associated with elevated blood pressure: Evidence from the Chinese plateau area

Background

Ambient air pollution could increase the risk of hypertension; however, evidence regarding the relationship between long-term exposure to particulate matter and elevated blood pressure in plateau areas with lower pollution levels is limited.

Methods

We assessed the associations of long-term exposure to particulate matter (PM, PM1, PM2.5, and PM10) with hypertension, diastolic blood pressure (DBP), systolic blood pressure (SBP) and pulse pressure (PP) in 4.235 Tibet adults, based on the baseline of the China multi-ethnic cohort study (CMEC) in Lhasa city, Tibet from 2018-19. We used logistic regression and linear regression models to evaluate the associations of ambient PM with hypertension and blood pressure, respectively.

Results

Long-term exposure to PM1, PM2.5, and PM10 is positively associated with hypertension, DBP, and SBP, while negatively associated with PP. Among these air pollutants, PM10 had the strongest effect on hypertension, DBP, and SBP, while PM2.5 had the strongest effect on PP. The results showed for hypertension odds ratio (OR) = 1.99; 95% confidence interval (CI) = 1.58, 2.51 per interquartile range (IQR) μg/m3 increase in PM1, OR = 1.93; 95% CI = 1.55, 2.40 per IQR μg/m3 increase in PM2.5, and OR = 2.12; 95% CI = 1.67, 2.68 per IQR μg/m3 increase in PM10.

Conclusions

Long-term exposure to ambient air pollution was associated with an increased risk of hypertension, elevated SBP and DBP levels, and decreased PP levels. To reduce the risk of hypertension and PP reduction, attention should be paid to air quality interventions in plateau areas with low pollution levels.

Micro- and nano-plastics in the atmosphere: A review of occurrence, properties and human health risks

The ubiquitous occurrence of micro/nano plastics (MNPs) poses potential threats to ecosystem and human health that have attracted broad concerns in recent decades. Detection of MNPs in several remote regions has implicated atmospheric transport as an important pathway for global dissemination of MNPs and hence as a global health risk. In this review, the latest research progress on (1) sampling and detection; (2) origin and characteristics; and (3) transport and fate of atmospheric MNPs was summarized. Further, the current status of exposure risks and toxicological effects from inhaled atmospheric MNPs on human health is examined. Due to limitations in sampling and identification methodologies, the study of atmospheric nanoplastics is very limited today. The large spatial variation of atmospheric MNP concentrations reported worldwide makes it difficult to compare the overall indoor and outdoor exposure risks. Several in vitro, in vivo, and epidemiological studies demonstrate adverse effects of immune response, apoptosis and oxidative stress caused by MNP inhalation that may induce cardiovascular diseases and reproductive and developmental abnormalities. Given the emerging importance of atmospheric MNPs, the establishment of standardized sampling-pretreatment-detection protocols and comprehensive toxicological studies are critical to advance environmental and health risk assessments of atmospheric MNPs.

circRNAs deregulation in exosomes derived from BEAS-2B cells is associated with vascular stiffness induced by PM2.5

As an environmental pollutant, ambient fine particulate matter (PM2.5) was linked to cardiovascular diseases. The molecular mechanisms underlying PM2.5-induced extrapulmonary disease has not been elucidated clearly. In this study the ambient PM2.5 exposure mice model we established was to explore adverse effects of vessel and potential mechanisms. Long-term PM2.5 exposure caused reduced lung function and vascular stiffness in mice. And chronic PM2.5 induced migration and epithelial-mesenchymal transition (EMT) phenotype in BEAS-2B cells. After PM2.5 treatment, the circRNAs and mRNAs levels of exosomes released by BEAS-2B cells were detected by competing endogenous RNA (ceRNA) array, which contained 1664 differentially expressed circRNAs (DE-circRNAs) and 308 differentially expressed mRNAs (DE-mRNAs). By bioinformatics analysis on host genes of DE-circRNAs, vascular diseases and some pathways related to vascular diseases including focal adhesion, tight junction and adherens junction were enriched. Then, ceRNA network was constructed, and DE-mRNAs in ceRNA network were conducted functional enrichment analysis by Ingenuity Pathway Analysis, which indicated that hsa_circ_0012627, hsa_circ_0053261 and hsa_circ_0052810 were related to vascular endothelial dysfunction. Furthermore, it was verified experimentally that ExoPM2.5 could induce endothelial dysfunction by increased endothelial permeability and decreased relaxation in vitro. In present study, we investigated in-depth knowledge into the molecule events related to PM2.5 toxicity and pathogenesis of vascular diseases.

Long-term exposure to several constituents and sources of PM2.5 is associated with incidence of upper aerodigestive tract cancers but not gastric cancer: Results from the large pooled European cohort of the ELAPSE project

It is unclear whether cancers of the upper aerodigestive tract (UADT) and gastric cancer are related to air pollution, due to few studies with inconsistent results. The effects of particulate matter (PM) may vary across locations due to different source contributions and related PM compositions, and it is not clear which PM constituents/sources are most relevant from a consideration of overall mass concentration alone. We therefore investigated the association of UADT and gastric cancers with PM2.5 elemental constituents and sources components indicative of different sources within a large multicentre population based epidemiological study. Cohorts with at least 10 cases per cohort led to ten and eight cohorts from five countries contributing to UADT- and gastric cancer analysis, respectively. Outcome ascertainment was based on cancer registry data or data of comparable quality. We assigned home address exposure to eight elemental constituents (Cu, Fe, K, Ni, S, Si, V and Zn) estimated from Europe-wide exposure models, and five source components identified by absolute principal component analysis (APCA). Cox regression models were run with age as time scale, stratified for sex and cohort and adjusted for relevant individual and neighbourhood level confounders. We observed 1139 UADT and 872 gastric cancer cases during a mean follow-up of 18.3 and 18.5 years, respectively. UADT cancer incidence was associated with all constituents except K in single element analyses. After adjustment for NO2, only Ni and V remained associated with UADT. Residual oil combustion and traffic source components were associated with UADT cancer persisting in the multiple source model. No associations were found for any of the elements or source components and gastric cancer incidence. Our results indicate an association of several PM constituents indicative of different sources with UADT but not gastric cancer incidence with the most robust evidence for traffic and residual oil combustion.

Cardiovascular diseases burden attributable to ambient PM2.5 pollution from 1990 to 2019: A systematic analysis for the global burden of disease study 2019

BACKGROUND

Ambient PM2.5 pollution (APMP2.5) was the leading environmental risk factor for cardiovascular diseases (CVDs) worldwide. An up-to-date comprehensive study is needed to provide global epidemiological patterns.

METHODS

Detailed data on CVDs burden attributable to APMP2.5 were obtained from the Global Burden of Disease Study (GBD) 2019. We calculated the estimated annual percentage change (EAPC) to assess temporal trends in age-standardized rates of deaths and disability-adjusted life years (DALYs) over 30 years.

RESULTS

Globally, CVDs attributable to APMP2.5 resulted in 2.48 million deaths and 60.91 million DALYs, with an increase of 122%, respectively from 1990 to 2019. In general, men suffered markedly higher burden than women, but the gap will likely turn narrow. As for age distribution, CVDs deaths and DALYs attributable to APMP2.5 mainly occurred in the elder group (>70 years). Low- and middle-income regions endured the higher CVDs burden due to the higher exposure to APMP2.5, and the gap may potentially expand further compared with high-income regions. For regions, the highest age-standardized rates of APMP2.5-related CVDs deaths and DALYs were observed mainly in Central Asia, while the lowest was observed in Australasia. At the national level, countries with the largest ASDR decline were clustered in western Europe, while Equatorial Guinea, Timor-Leste and Bhutan exhibited relatively rapid increases over this period.

CONCLUSIONS

The global CVDs burden attributable to APMP2.5 has contributed to the heterogeneity of spatial and temporal distribution. APMP2.5-related CVDs deaths have largely shifted from higher SDI regions to those with a lower SDI. Globally, APMP2.5-attributable CVDs pose a significant threat to public health and diseases burden has increased over time, particularly in male, old-aged populations. The governments and health systems should take measures to reduce air pollution to impede this rising trend.

Adverse effects of cigarette filter silica on lungs: Comparison with natural crystalline silica particles

As a common additive in cigarette filters, nanosilica has been implemented to reduce the release of harmful substances in cigarette smoke. However, the potential risk of occupational exposure for cigarette factory workers is unknown. We collected physical examination data from 710 cigarette factory workers to evaluate the adverse effects of cigarette filter silica exposure. We also established mouse models induced by cigarette filter silica and crystalline silica separately to compare the lung inflammation, pulmonary function, apoptosis, and fibrosis of the two models. Workers in the rolling and packing workshop exposed to cigarette filter silica had a higher rate of abnormal lung function (17.75%) than those in the cutting workshop (0.87%). Animal experiments showed that compared with the same dose of crystalline silica, cigarette filter silica resulted in higher levels of inflammatory factors in the bronchoalveolar lavage fluid (BALF) of mice at day 7, and lower levels of total lung capacity (TLC), inspiratory capacity (IC), vital capacity (VC), and forced vital capacity (FVC) in mice at day 28. Additionally, both exposed groups of mice showed increased levels of caspase 3, collagen I (Col-Ⅰ), α-smooth muscle actin (α-SMA) and hydroxyproline (HYP) in the lungs, as well as collagen accumulation and fibrous nodules at day 28, with no significant difference between the two groups. The results suggested that cigarette filter silica caused more severe early lung inflammation and late ventilation impairment than the same dose of crystalline silica. In the future, we need to pay more attention to nanosilica protection in cigarette factories to prevent pulmonary dysfunction in workers.

Human milk EV-miRNAs: a novel biomarker for air pollution exposure during pregnancy

Exposure to ambient and near-roadway air pollution during pregnancy has been linked with several adverse health outcomes for pregnant women and their babies. Emerging research indicates that microRNA (miRNA) expression can be altered by exposure to air pollutants in a variety of tissues. Additionally, miRNAs from breast tissue and circulating miRNAs have previously been proposed as a biomarker for breast cancer diagnosis and prognosis. Therefore, this study sought to evaluate the associations between pregnancy exposures to ambient (PM10, PM2.5, NO2, O3) and near-roadway air pollution (total NOx, freeway NOx, non-freeway NOx) with breast milk extracellular vesicle miRNA (EV-miRNA), measured at 1-month postpartum, in a cohort of 108 Latina women living in Southern California. We found that PM10 exposure during pregnancy was positively associated with hsa-miR-200c-3p, hsa-miR-200b-3p, and hsa-let-7c-5p, and was negatively associated with hsa-miR-378d. We also found that pregnancy PM2.5 exposure was positively associated with hsa-miR-200c-3p and hsa-miR-200b-3p. First and second trimester exposure to PM10 and PM2.5 was associated with several EV-miRNAs with putative messenger RNA targets related to cancer. This study provides preliminary evidence that air pollution exposure during pregnancy is associated with human milk EV-miRNA expression.

The bio-distribution, clearance pathways, and toxicity mechanisms of ambient ultrafine particles

Ambient particles severely threaten human health worldwide. Compared to larger particles, ultrafine particles (UFPs) are highly concentrated in ambient environments, have a larger specific surface area, and are retained for a longer time in the lung. Recent studies have found that they can be transported into various extra-pulmonary organs by crossing the air-blood barrier (ABB). Therefore, to understand the adverse effects of UFPs, it is crucial to thoroughly investigate their bio-distribution and clearance pathways in vivo after inhalation, as well as their toxicological mechanisms. This review highlights emerging evidence on the bio-distribution of UFPs in pulmonary and extra-pulmonary organs. It explores how UFPs penetrate the ABB, the blood-brain barrier (BBB), and the placental barrier (PB) and subsequently undergo clearance by the liver, kidney, or intestine. In addition, the potential underlying toxicological mechanisms of UFPs are summarized, providing fundamental insights into how UFPs induce adverse health effects.

Determinants and mechanisms of inorganic nanoparticle translocation across mammalian biological barriers

Biological barriers protect delicate internal tissues from exposures to and interactions with hazardous materials. Primary anatomical barriers prevent external agents from reaching systemic circulation and include the pulmonary, gastrointestinal, and dermal barriers. Secondary barriers include the blood-brain, blood-testis, and placental barriers. The tissues protected by secondary barriers are particularly sensitive to agents in systemic circulation. Neurons of the brain cannot regenerate and therefore must have limited interaction with cytotoxic agents. In the testis, the delicate process of spermatogenesis requires a specific milieu distinct from the blood. The placenta protects the developing fetus from compounds in the maternal circulation that would impair limb or organ development. Many biological barriers are semi-permeable, allowing only materials or chemicals, with a specific set of properties, that easily pass through or between cells. Nanoparticles (particles less than 100 nm) have recently drawn specific concern due to the possibility of biological barrier translocation and contact with distal tissues. Current evidence suggests that nanoparticles translocate across both primary and secondary barriers. It is known that the physicochemical properties of nanoparticles can affect biological interactions, and it has been shown that nanoparticles can breach primary and some secondary barriers. However, the mechanism by which nanoparticles cross biological barriers has yet to be determined. Therefore, the purpose of this review is to summarize how different nanoparticle physicochemical properties interact with biological barriers and barrier products to govern translocation.

Cold-induced adaptive thermogenesis is impaired by exposure of Asian sand dust in mice

Desertification and desert sandstorms caused by the worsening global warming pose increasing risks to human health. In particular, Asian sand dust (ASD) exposure has been related to an increase in mortality and hospital admissions for respiratory diseases. In this study, we investigated the effects of ASD on metabolic tissues in comparison to diesel particulate matter (DPM) that is known to cause adverse health effects. We found that larger lipid droplets were accumulated in the brown adipose tissues (BAT) of ASD-administered but not DPM-administered mice. Thermogenic gene expression was decreased in these mice as well. When ASD-administered mice were exposed to the cold, they failed to maintain their body temperature, suggesting that the ASD administration had led to impairments in cold-induced adaptive thermogenesis. However, impaired thermogenesis was not observed in DPM-administered mice. Furthermore, mice fed a high-fat diet that were chronically administered ASD demonstrated unexplained weight loss, indicating that chronic administration of ASD could be lethal in obese mice. We further identified that ASD-induced lung inflammation was not exacerbated in uncoupling protein 1 knockout mice, whose thermogenic capacity is impaired. Collectively, ASD exposure can impair cold-induced adaptive thermogenic responses in mice and increase the risk of mortality in obese mice.

Association of joint exposure to various ambient air pollutants during adolescence with blood pressure in young adulthood

The association of various air pollutants exposure during adolescence with blood pressure (BP) in young adulthood is uncertain. We intended to evaluate the long-term association of individual and joint air pollutants exposure during adolescence with BP in young adulthood. This cross-sectional study of incoming students was conducted in five geographically disperse universities in China during September and October 2018. Mean concentrations of particulate matter with diameters ≤2.5 μm (PM2.5 ), ≤10 μm (PM10 ), nitrogen dioxides (NO2 ), carbon monoxide (CO), sulfur dioxide (SO2 ), and ozone (O3 ) at participants' residential addresses during 2013-2018 were collected from the Chinese Air Quality Reanalysis dataset. Generalized linear mixed models (GLM) and quantile g-computation (QgC) models were utilized to estimate the association between individual and joint air pollutants exposure and systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse pressure (PP). A total of 16,242 participants were included in the analysis. The GLM analyses showed that PM2.5 , PM10 , NO2 , CO, and SO2 were significantly positively associated with SBP and PP, while O3 was positively associated with DBP. The QgC analyses indicated that long-term exposure to a mixture of the six air pollutants had a significant positive joint association with SBP and PP. In conclusion, air pollutant co-exposure during adolescence may influence BP in young adulthood. The findings of this study emphasized the impacts of multiple air pollutants interactions on potential health and the need of minimizing pollution exposures in the environment.

Utilization of endogenous albumin trafficking pathways in the lungs has potential to modestly increase the lung interstitial access and absorption of drug delivery systems after inhaled administration

OBJECTIVES

Drug delivery systems typically show limited access to the lung interstitium and absorption after pulmonary delivery. The aim of this work was to undertake a proof-of-concept investigation into the potential of employing endogenous albumin and albumin absorption mechanisms in the lungs to improve lung interstitial access and absorption of inhaled drug delivery systems that bind albumin.

METHODS

The permeability of human albumin (HSA) through monolayers of primary human alveolar epithelia, small airway epithelia, and microvascular endothelium were investigated. The pulmonary pharmacokinetics of bovine serum albumin (BSA) was also investigated in efferent caudal mediastinal lymph duct-cannulated sheep after inhaled aerosol administration.

RESULTS

Membrane permeability coefficient values (Papp) of HSA increased in the order alveolar epithelia

CONCLUSION

Drug delivery systems that bind endogenous albumin may show a modest increase in lung permeability and absorption after inhaled delivery compared to systems that do not efficiently bind albumin.

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Key Words

• Albumin
• inhaled
• lung permeability
• nebulized
• pharmacokinetics
• sheep

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MESH Headings

• Humans
• Animals
• Sheep
• Lung/metabolism
• Albumins/metabolism
• Drug Delivery Systems
• Aerosols
• Lymph/metabolism

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Affiliation(s)

Jibriil P Ibrahim School of Biomedical Sciences, University of Queensland, St Lucia, QLD, Australia
Neville J Butcher School of Biomedical Sciences, University of Queensland, St Lucia, QLD, Australia
Ashok Kothapalli School of Biomedical Sciences, University of Queensland, St Lucia, QLD, Australia
Christopher N Subasic School of Biomedical Sciences, University of Queensland, St Lucia, QLD, Australia
Joanne T Blanchfield School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, QLD, Australia
Andrew K Whittaker Australian Institute of Bioengineering and Nanotechnology, University of Queensland, St Lucia, QLD, Australia Australian Research Council Centre of Excellence for Green Electrochemical Transformation of Carbon Dioxide, University of Queensland, St Lucia, QLD, Australia
Michael R Whittaker Drug Delivery Disposition Dynamics, Monash Institute of Pharmaceutical Sciences, Parkville, VIC, Australia
Lisa M Kaminskas School of Biomedical Sciences, University of Queensland, St Lucia, QLD, Australia

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Effects of Gallic Acid on Memory Deficits and Electrophysiological Impairments Induced by Cerebral Ischemia/Reperfusion in Rats Following Exposure to Ambient Dust Storm

We aimed to investigate the probable protective effects of gallic acid (GA) on cognitive deficits, hippocampal long term potentiation (LTP) impairments, and molecular changes induced by cerebral ischemia/reperfusion (I/R) in rats following exposure to ambient dust storm. After pretreatment with GA (100 mg/kg), or vehicle (Veh) (normal saline, 2 ml/kg) for ten days, and 60 minutes' exposure to dust storm including PM (PM, 2000-8000 g/m3) every day, 4-vessel occlusion (4VO) type of I/R was induced. Three days after I/R induction, we evaluated behavioral, electrophysiological, histopathological, molecular and brain tissue inflammatory cytokine changes. Our findings indicated that pretreatment with GA significantly reduced cognitive impairments caused by I/R (P < 0.05) and hippocampal LTP impairments caused by I/R after PM exposure (P < 0.001). Additionally, after exposure to PM, I/R significantly elevated the tumor necrosis factor α content (P < 0.01) and miR-124 level (P < 0.001) while pre-treatment with GA reduced the level of miR-124 (P < 0.001). Histopathological results also revealed that I/R and PM caused cell death in the hippocampus CA1 area (P < 0.001) and that GA decreased the rate of cell death (P < 0.001). Our findings show that GA can prevent brain inflammation, and thus cognitive and LTP deficits caused by I/R, PM exposure, or both.

Organic Semiconducting Nanoparticles for Biosensor: A Review

Highly bio-compatible organic semiconductors are widely used as biosensors, but their long-term stability can be compromised due to photo-degradation and structural instability. To address this issue, scientists have developed organic semiconductor nanoparticles (OSNs) by incorporating organic semiconductors into a stable framework or self-assembled structure. OSNs have shown excellent performance and can be used as high-resolution biosensors in modern medical and biological research. They have been used for a wide range of applications, such as detecting small biological molecules, nucleic acids, and enzyme levels, as well as vascular imaging, tumor localization, and more. In particular, OSNs can simulate fine particulate matters (PM_2.5, indicating particulate matter with an aerodynamic diameter less than or equal to 2.5 μm) and can be used to study the biodistribution, clearance pathways, and health effects of such particles. However, there are still some problems that need to be solved, such as toxicity, metabolic mechanism, and fluorescence intensity. In this review, based on the structure and design strategies of OSNs, we introduce various types of OSNs-based biosensors with functional groups used as biosensors and discuss their applications in both in vitro and in vivo tracking. Finally, we also discuss the design strategies and potential future trends of OSNs-based biosensors. This review provides a theoretical scaffold for the design of high-performance OSNs-based biosensors and highlights important trends and future directions for their development and application.

Air pollution combined with high-fat feeding aggravates metabolic and cardiovascular diseases: A dangerous, oxidative, and immune-inflammatory association

Obesity and particulate air pollutant (PM_2.5) are important risk factors for cardiometabolic diseases. PM_2.5 exacerbates insulin resistance and lipid ectopic deposition in obese animals. The inorganic fraction of PM_2.5, the Residual Oil Fly Ash (ROFA), is related to cardiovascular events, by enhancing the generation of reactive species, inflammatory cytokines, and leukocyte activation. However, the synergistic effects of ROFA and a high-fat diet (HFD) are still poorly described, and the studies were mainly conducted with males.

AIMS

To investigate if ROFA could potentiate the cardiometabolic effects of diet-induced obesity in female rats.

MATERIAL AND METHODS

Wistar female rats were divided into four groups: Control (n = 6), Polluted (n = 6), HFD (n = 6), and HFD + Polluted (n = 6). HFD and HFD + Polluted received a high-fat diet (HFD) (58.3 % as fats), whilst Control and Polluted groups received a standard diet (Nuvilab CR-1). In addition, Polluted and HFD + Polluted groups received intranasal instillation of ROFA (250 μg/50 μL), while Control and HFD groups received saline solution (50 μL) daily, five days per week. Both interventions occurred 24 weeks after the animals were euthanized.

KEY FINDINGS

HFD combined with ROFA exposure impaired lipid profile challenged systemic and cardiac antioxidant defense, and presented a synergistic effect in inducing an immune-inflammatory condition. We found that the lipid profile disturbance is associated with HFD-induced hepatic, but not cardiac, deposition of triglycerides in female animals.

SIGNIFICANCE

Our results support the hypothesis that ROFA exposure combined with bad feeding can exacerbate metabolic and cardiovascular diseases.

Exposure to ambient air pollution and lipid levels and blood pressure in an adult, Danish cohort

BACKGROUND

Air pollution is a well-recognized risk factor for cardiovascular disease. However, the mechanistic pathways underlying the association are not completely understood. Hence, further studies are required to shed light on potential mechanisms, through which air pollution may affect the development from subclinical to clinical cardiovascular disease.

OBJECTIVES

To investigate associations between short-term exposure to air pollution and high-density lipoprotein (HDL), non-high density lipoprotein (non-HDL), systolic and diastolic blood pressure.

METHODS

The study was conducted among 32,851 Danes from the Diet, Cancer and Health - Next Generations cohort, who had a blood sample taken and blood pressure measured. We measured HDL and non-HDL in the blood samples. We modelled exposure to fine particulate matter (PM_2.5), ultrafine particles (UFP), elemental carbon (EC) and nitrogen dioxide (NO₂) in time-windows from 24 h up to 90 days before blood sampling. Pollutants were modelled as total air pollution from all sources, and apportioned into contributions from non-traffic and traffic sources. We analyzed data using linear and logistic regression, with adjustment for socio-economic and lifestyle factors.

RESULTS

Air pollution exposure over 24 h to 30 days was generally adversely associated with lipid profile and blood pressure, e.g. for 30-day UFP-exposure, adjusted β-estimates were: -0.025 (-0.043; -0.006) for HDL, 0.086 (0.042; 0.130) for non-HDL, 2.45 (1.70; 3.11) for systolic and 1.56 (1.07; 20.4) for diastolic blood pressure, per 10,000 particles/cm³. The strongest associations were found for the non-traffic components of air pollution, and among those who were overweight/obese.

DISCUSSION

In this large study of air pollution and lipid levels and blood pressure, we found that 24-h to 30-day PM_2.5, UFP, EC and NO₂ concentrations were generally adversely associated with lipid profile and blood pressure, two important cardiovascular risk factors. The study suggests potential pathways, through which air pollution could affect the development of cardiovascular disease.

Moderate aerobic training is safe and improves glucose intolerance induced by the association of high fat diet and air pollution

Obesity and exposure to fine particulate matter (PM_2.5) are risk factors for insulin resistance, to which physical exercise is the most powerful non-pharmacological strategy. However, public concern over whether exercise could be protective in a polluted environment exists. Therefore, evaluating the possible benefits of exercise in polluted conditions in different contexts (age, gender, and cardiometabolic health) is imperative. In this sense, muscle plays a major role in maintaining glucose homeostasis, and its oxidative status is closely affected during exercise. This study tested whether moderate aerobic training could alleviate the metabolic and oxidative impairment in the gastrocnemius induced by the combination of a high-fat diet (HFD) and PM_2.5 exposure. Female mice (B6129SF2/J) received HFD (58.3% of fat) or standard diet, intranasal instillation of 20 μg residual oil fly ash (ROFA: inorganic portion of PM_2.5), or saline seven times per week for 19 weeks. In the 13th week, animals were submitted to moderate training or remained sedentary. Trained animals followed a progressive protocol for 6 weeks, ending at swimming with 5% body weight of workload for 60 min, while sedentary animals remained in shallow water. Aerobic moderate training attenuated weight gain and glucose intolerance and prevented muscle and pancreatic mass loss induced by a HFD plus ROFA exposure. Interestingly, a HFD combined with ROFA enhanced the catalase antioxidant activity, regardless of physical exercise. Therefore, our study highlights that, even in polluted conditions, moderate training is the most powerful non-pharmacological treatment for obesity and insulin resistance.

Penetration and translocation of functional inorganic nanomaterials into biological barriers

With excellent physicochemical properties, inorganic nanomaterials (INMs) have exhibited a series of attractive applications in biomedical fields. Biological barriers prevent successful delivery of nanomedicine in living systems that limits the development of nanomedicine especially for sufficient delivery of drugs and effective therapy. Numerous researches have focused on overcoming these biological barriers and homogeneity of organisms to enhance therapeutic efficacy, however, most of these strategies fail to resolve these challenges. In this review, we present the latest progress about how INMs interact with biological barriers and penetrate these barriers. We also summarize that both native structure and components of biological barriers and physicochemical properties of INMs contributed to the penetration capacity. Knowledge about the relationship between INMs structure and penetration capacity will guide the design and application of functional and efficient nanomedicine in the future.

The macrophage senescence hypothesis: the role of poor heat shock response in pulmonary inflammation and endothelial dysfunction following chronic exposure to air pollution

INTRODUCTION

Cardiovascular diseases (CVD) have been associated with high exposure to fine particulate air pollutants (PM_2.5). Alveolar macrophages are the first defense against inhaled particles. As soon as they phagocytize the particles, they reach an inflammatory phenotype, which affects the surrounding cells and associates with CVD. Not coincidentally, CVD are marked by a depleted heat shock response (HSR), defined by a deficit in inducing 70-kDa heat shock protein (HSP70) expression during stressful conditions. HSP70 is a powerful anti-inflammatory chaperone, whose reduced levels trigger a pro-inflammatory milieu, cellular senescence, and a senescence-associated secretory phenotype (SASP). However, whether macrophage senescence is the main mechanism by which PM_2.5 propagates low-grade inflammation remains unclear.

OBJECTIVE AND DESIGN

In this article, we review evidence supporting that chronic exposure to PM_2.5 depletes HSR and determines the ability to solve the initial stress.

RESULTS AND DISCUSSION

When exposed to PM_2.5, macrophages increase the production of reactive oxygen species, which activate nuclear factor-kappa B (NF-κB). NF-κB is naturally a pro-inflammatory factor that drives prostaglandin E2 (PGE2) synthesis and causes fever. PGE2 can be converted into prostaglandin A2, a powerful inducer of HSR. Therefore, when transiently activated, NF-κB can trigger the anti-inflammatory response through negative feedback, by inducing HSP70 expression. However, when chronically activated, NF-κB heads a set of pathways involved in mitochondrial dysfunction, endoplasmic reticulum stress, unfolded protein response, inflammasome activation, and apoptosis. During chronic exposure to PM_2.5, cells cannot properly express sirtuin-1 or activate heat shock factor-1 (HSF-1), which delays the resolution phase of inflammation. Since alveolar macrophages are the first immune defense against PM_2.5, we suppose that the pollutant impairs HSR and, consequently, induces cellular senescence. Accordingly, senescent macrophages change its secretory phenotype to a more inflammatory one, known as SASP. Finally, macrophages' SASP would propagate the systemic inflammation, leading to endothelial dysfunction and atherosclerosis.

Long-term respiratory exposure to amorphous silica nanoparticles promoted systemic inflammation and progression of fibrosis in a susceptible mouse model

Exposure to amorphous silica nanoparticles (SiNPs) has increased dramatically, and concerns are growing about their potential health effects. However, their long-term systemic toxicity profile and underlying mechanisms following respiratory exposure still remains unexplored. It is well documented that the inhalation of ultrafine particles is firmly associated with adverse effects in humans. Environmental pollutants may contribute to diverse adverse effect or comorbidity in susceptible individuals. Thereby, we examined the long-term systemic effects of inhaled SiNPs using a sensitive mouse model (ApoE^-/-) fed by a western diet. Male ApoE^-/- mice were intratracheally instilled with SiNPs suspension at a dose of 1.5, 3.0 and 6.0 mg/kg·bw, respectively, once per week, 12 times in total. The histological analysis was conducted. The serum cytokine levels were quantified by RayBiotech antibody array. As a result, systemic histopathological alterations were noticed, mainly characterized by inflammation and fibrosis. More importantly, cytokine array analysis indicated the key role of mast cells accumulation in systemic inflammation and fibrosis progression induced by inhaled SiNPs. Collectively, our study firstly demonstrated that long-term exposure to inhaled SiNPs promoted the mast cell-dominated activation of inflammatory response, not only in the lung but also in heart, liver and kidney, etc., eventually leading to the progression of tissue fibrosis in ApoE^-/- mice.

Environmental Toxicants and NAFLD: A Neglected yet Significant Relationship

The liver is an organ of vital importance in the body; it is the center of metabolic activities and acts as the primary line of defense against toxic compounds. Exposure to environmental toxicants is an unavoidable fallout from rapid industrialization across the world and is even higher in developing countries. Technological development and industrialization have led to the release of toxicants such as pollutant toxic gases, chemical discharge, industrial effluents, pesticides and solvents, into the environment. In the last few years, a growing body of evidence has shed light on the potential impact of environmental toxicants on liver health, in particular, on non-alcoholic fatty liver disease (NAFLD) incidence and progression. NAFLD is a multifactorial disease linked to metabolic derangement including diabetes and other complications. Environmental toxicants including xenobiotics and pollutants may have a direct or indirect steatogenic/fibrogenic impact on the liver and should be considered as risk factors associated with NAFLD. This review discusses the contribution of environmental toxicants toward the increasing disease burden of NAFLD.

Chemical Composition and Toxicity of PM10 and PM0.1 Samples near Open-Pit Mines and Coal Power Stations

Particulate matter (PM) <10 μm in size represents an extremely heterogeneous and variable group of objects that can penetrate the human respiratory tract. The present study aimed to isolate samples of coarse and ultrafine PM at some distance from polluting industries (1−1.5 km from the border of open-cast mines). PM was collected from snow samples which allowed the accumulation of a relatively large amount of ultrafine particles (UFPs) (50−60 mg) from five objects: three open-cast mines, coal power plants, and control territories. The chemical composition of PM was examined using absorption spectroscopy, luminescence spectroscopy, high-performance liquid chromatography, X-ray diffraction (XRD), and X-ray fluorescence (XRF) analyses of solid particle material samples. Toxicity was assessed in human MRC-5 lung fibroblasts after 6 h of in vitro exposure to PM samples. The absorption spectra of all the samples contained a wide non-elementary absorption band with a maximum of 270 nm. This band is usually associated with the absorption of dissolved organic matter (DOM). The X-ray fluorescence spectra of all the studied samples showed intense lines of calcium and potassium and less intense lines of silicon, sulfur, chlorine, and titanium. The proliferation of MRC-5 cells that were exposed to PM0.1 samples was significantly (p < 0.01) lower than that of MRC-5 cells exposed to PM10 at the same concentration, except for PM samples obtained from the control point. PM0.1 samples—even those that were collected from control territories—showed increased genotoxicity (micronucleus, ‱) compared to PM10. The study findings suggest that UFPs deserve special attention as a biological agent, distinct from larger PMs.

Indirect mediators of systemic health outcomes following nanoparticle inhalation exposure

The growing field of nanoscience has shed light on the wide diversity of natural and anthropogenic sources of nano-scale particulates, raising concern as to their impacts on human health. Inhalation is the most robust route of entry, with nanoparticles (NPs) evading mucociliary clearance and depositing deep into the alveolar region. Yet, impacts from inhaled NPs are evident far outside the lung, particularly on the cardiovascular system and highly vascularized organs like the brain. Peripheral effects are partly explained by the translocation of some NPs from the lung into the circulation; however, other NPs largely confined to the lung are still accompanied by systemic outcomes. Omic research has only just begun to inform on the complex myriad of molecules released from the lung to the blood as byproducts of pulmonary pathology. These indirect mediators are diverse in their molecular make-up and activity in the periphery. The present review examines systemic outcomes attributed to pulmonary NP exposure and what is known about indirect pathological mediators released from the lung into the circulation. Further focus was directed to outcomes in the brain, a highly vascularized region susceptible to acute and longer-term outcomes. Findings here support the need for big-data toxicological studies to understand what drives these health outcomes and better predict, circumvent, and treat the potential health impacts arising from NP exposure scenarios.

Long-term effects of PM2.5 components on blood pressure and hypertension in Chinese children and adolescents

Growing evidence has linked fine particulate matter (PM_2.5) exposure to elevated blood pressure, but the effects of PM_2.5 components are unclear, particularly in children and adolescents. Based on a cross-sectional investigation in China, we analyzed the associations between long-term exposure to PM_2.5 and its major components with elevated blood pressure in children and adolescents. A representative sample (N = 37,610) of children and adolescents with age 7-18 years was collected in seven Chinese provinces. Exposures to PM_2.5 and five of its major components, including black carbon (BC), organic matter (OM), inorganic nitrate (NO₃^-), sulfate (SO₄^2-), and soil particles (SOIL), were estimated using satellite-based spatiotemporal models. The associations between long-term exposures to PM_2.5 and its components and diastolic blood pressure (DBP), systolic blood pressure (SBP), and hypertension were investigated using mixed-effects logistic and linear regression models. Within the populations, 11.5 % were classified as hypertension. After adjusting for a variety of covariates, per interquartile range (IQR) increment in PM_2.5 mass and BC levels were significantly associated with a higher hypertension prevalence with odds ratios (ORs) of 1.56 (95% confidence interval (CI): 1.08, 2.25) for PM_2.5 and 1.19 (95% CI: 1.04, 1.35) for BC. Long-term exposures to PM_2.5 and BC have also been associated with elevated SBP and DBP. Additionally, OM and NO₃^- were significantly associated with increased SBP, while SOIL was significantly associated with increased DBP. In the subgroup analysis, the associations between long-term exposures to BC and blood pressure vary significantly by urbanicity of residential area and diet habits. Our study suggests that long-term exposure to PM_2.5 mass and specific PM_2.5 components, especially for BC, are significantly associated with elevated blood pressure and a higher hypertension prevalence in Chinese children and adolescents.

Association between long-term exposure to PM2.5 and hypertension: A systematic review and meta-analysis of observational studies

BACKGROUND

Numerous studies have examined the association between long-term exposure to particulate matter with an aerodynamic diameter of ≤2.5 μm (PM_2.5) and hypertension. However, the results are inconsistent.

OBJECTIVES

Considering the limitations of previous meta-analyses and the publication of many new studies in recent years, we conducted this meta-analysis to assess the relationship between long-term PM_2.5 exposure and the incidence and prevalence of hypertension in a healthy population.

METHODS

We searched PubMed, Web of Science, Embase, and Scopus for relevant studies published until April 2, 2021 and reviewed the reference lists of previous reviews. A total of 28 observational studies reporting RR or OR with 95% CI for the association between long-term PM_2.5 exposure and the risk of hypertension were included.

RESULTS

After the sensitivity analysis, we excluded one study with a high degree of heterogeneity, resulting in 27 studies and 28 independent reports. Approximately 42 million participants were involved, and the cases of hypertension in cohort and cross-sectional studies were 508,749 and 1,793,003, respectively. The meta-analysis showed that each 10 μg/m³ increment in PM_2.5 was significantly associated with the risks of hypertension incidence (RR = 1.21, 95% CI: 1.07, 1.35) and prevalence (OR = 1.06, 95% CI: 1.03, 1.09). Subgroup analyses showed that occupational exposure had a significant effect on the association of PM_2.5 and hypertension incidence (p for interaction = 0.042) and that the PM_2.5 concentration level and physical activity had a noticeable effect on the association of PM_2.5 and hypertension prevalence (p for interaction = 0.005; p for interaction = 0.022).

CONCLUSIONS

A significantly positive correlation was observed between long-term PM_2.5 exposure and risks of hypertension incidence and prevalence, and a high PM_2.5 concentration resulted in an increased risk of hypertension.

HSP70 as a biomarker of the thin threshold between benefit and injury due to physical exercise when exposed to air pollution

Physical exercise has acute and chronic effects on inflammatory balance, metabolic regulation, and redox status. Exercise-induced adaptations are mediated by enhanced 70-kDa heat shock protein (HSP70) levels and an improved heat shock response (HSR). Therefore, exercise could be useful against disease conditions [obesity, diabetes mellitus (DM), and exposure to atmospheric pollutants] marked by an impaired HSR. However, exercise performed by obese or diabetic subjects under pollution conditions might also be dangerous at certain intensities. Intensity correlates with an increase in HSP70 levels during physical exercise until a critical point at which the effort becomes harmful and impairs the HSR. Establishing a unique biomarker able to indicate the exercise intensity on metabolism and cellular fatigue is essential to ensure adequate and safe exercise recommendations for individuals with obesity or DM who require exercise to improve their metabolic status and live in polluted regions. In this review, we examined the available evidence supporting our hypothesis that HSP70 could serve as a biomarker for determining the optimal exercise intensity for subjects with obesity or diabetes when exposed to air pollution and establishing the fine threshold between anti-inflammatory and pro-inflammatory exercise effects.

Association of long-term exposure to ambient particulate pollution with stage 1 hypertension defined by the 2017 ACC/AHA Hypertension Guideline and cardiovascular disease: The CHCN-BTH cohort study

BACKGROUND

Evidence regarding the effects of ambient air pollution on new stage 1 hypertension defined by the 2017 ACC/AHA Hypertension Guideline remains sparse.

OBJECTIVES

To investigate the association of long-term exposure to ambient PM_2.5 with stage 1 hypertension and to explore the mediating and modifying effects of PM_2.5 on cardiovascular disease (CVD).

METHODS

A total of 32,135 participants aged 18-80 years were recruited in 2017. The three-year (2014-2016) average PM_2.5 concentrations were assessed by a spatial statistical model. Blood pressure (BP) was divided into four categories according to the 2017 ACC/AHA Hypertension Guideline: normal BP (SBP<120 mmHg and DBP<80 mmHg), elevated BP (SBP 120-129 mmHg and DBP<80 mmHg), stage 1 hypertension (SBP 130-139 mmHg or DBP 80-89 mmHg), and stage 2 hypertension (SBP≥140 mmHg or DBP≥90 mmHg or taking antihypertensive medications). The associations of PM_2.5 with BP categories were estimated by two-level generalized linear mixed models. Analyses stratified by age, mediation and interaction analyses of PM_2.5 and stage 1 hypertension with CVD were performed.

RESULTS

We detected a positive significant association between long-term exposure to PM_2.5 and stage 1 hypertension. Compared to normal BP, the OR was 1.05 (95% CI: 1.02, 1.08) per 10 μg/m³ increase in PM_2.5. The association was stronger than that of elevated BP but weaker than that of stage 2 hypertension. Stage 1 hypertension only partially mediated the association between PM_2.5 and CVD, and the mediation proportions ranged from 1.55% to 11.00%. However, it modified the association between PM_2.5 and CVD, which was greater in participants with stage 1 hypertension (OR: 1.66; 95% CI: 1.43, 1.93) than in participants with normal BP (OR: 1.32; 95% CI: 1.11, 1.57), with P_interaction<0.001. In the analysis stratified by age, the above associations were age-specific, and significant associations were only observed in the young and middle-aged (<60 years) groups.

CONCLUSIONS

Long-term exposure to ambient PM_2.5 was significantly associated with stage 1 hypertension. This earlier stage of hypertension may be a trigger BP range for adverse effects of air pollution in the development of hypertension and CVD, especially in young and middle-aged individuals.

Carbon Monoxide-Releasing Molecule-2 Ameliorates Particulate Matter-Induced Aorta Inflammation via Toll-Like Receptor/NADPH Oxidase/ROS/NF-κB/IL-6 Inhibition

Particulate matter (PM), a major air pollutant, may be associated with adverse cardiovascular effects. Reactive oxygen species- (ROS-) dependent proinflammatory cytokine production, such as interleukin-6 (IL-6), is a possible underlying mechanism. Carbon monoxide- (CO-) releasing molecule-2 (CORM-2) which liberates exogenous CO can exert many beneficial effects, particularly anti-inflammation and antioxidant effects. The purpose of this study was to explore the protective effects and underpinning mechanisms of CORM-2 on PM-induced aorta inflammation. Here, human aortic vascular smooth muscle cells (HASMCs) were utilized as in vitro models for the assessment of signaling pathways behind CORM-2 activities against PM-induced inflammatory responses, including Toll-like receptors (TLRs), NADPH oxidase, ROS, nuclear factor-kappa B (NF-κB), and IL-6. The modulation of monocyte adherence and HASMC migration, that are two critical cellular events of inflammatory process, along with their regulators, including intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and matrix metalloproteinase-2 (MMP-2) and MMP-9, in response to PM by CORM-2, were further evaluated. Finally, mice experiments under different conditions were conducted for the in vivo evaluation of CORM-2 benefits on the expression of inflammatory molecules including IL-6, ICAM-1, VCAM-1, MMP-2, and MMP-9. Our results found that PM could induce aorta inflammation in vitro and in vivo, as evidenced by the increase of IL-6 expression that was regulated by the TLR2 and TLR4/NADPH oxidase/ROS/NF-κB signaling pathway, thereby promoting ICAM-1- and VCAM-1-dependent monocyte adhesion and MMP-2- and MMP-9-dependent HASMC migration. Importantly, our experimental models demonstrated that CORM-2-liberated CO effectively inhibited the whole identified PM-induced inflammatory cascade in HASMCs and tissues. In conclusion, CORM-2 treatment may elicit multiple beneficial effects on inflammatory responses of aorta due to PM exposure, thereby providing therapeutic value in the context of inflammatory diseases of the cardiovascular system.

The Association Between Short-term Exposure to Ambient Air Pollution and Patient-Level Home Blood Pressure Among Patients With Chronic Cardiovascular Diseases in a Web-Based Synchronous Telehealth Care Program: Retrospective Study

BACKGROUND

The association between short-term exposure to ambient air pollution and blood pressure has been inconsistent, as reported in the literature.

OBJECTIVE

This study aimed to investigate the relationship between short-term ambient air pollution exposure and patient-level home blood pressure (HBP).

METHODS

Patients with chronic cardiovascular diseases from a telehealth care program at a university-affiliated hospital were enrolled as the study population. HBP was measured by patients or their caregivers. Hourly meteorological data (including temperature, relative humidity, wind speed, and rainfall) and ambient air pollution monitoring data (including CO, NO₂, particulate matter with a diameter of <10 µm, particulate matter with a diameter of <2.5 µm, and SO₂) during the same time period were obtained from the Central Weather Bureau and the Environmental Protection Administration in Taiwan, respectively. A stepwise multivariate repeated generalized estimating equation model was used to assess the significant factors for predicting systolic and diastolic blood pressure (SBP and DBP).

RESULTS

A total of 253 patients and 110,715 HBP measurements were evaluated in this study. On multivariate analysis, demographic, clinical, meteorological factors, and air pollutants significantly affected the HBP (both SBP and DBP). All 5 air pollutants evaluated in this study showed a significant, nonlinear association with both home SBP and DBP. Compared with demographic and clinical factors, environmental factors (meteorological factors and air pollutants) played a minor yet significant role in the regulation of HBP.

CONCLUSIONS

Short-term exposure to ambient air pollution significantly affects HBP in patients with chronic cardiovascular disease.

Effect of Seasonal Variation on the Relationship of Indoor Air Particulate Matter with Measures of Obesity and Blood Pressure in Children

BACKGROUND

Particulate matter (PM) air pollution is an important environmental health risk factor. Although some studies have shown PM to be associated with obesity and hypertension, very few studies have assessed the association of indoor PM specifically with obesity and blood pressure measures in children with respect to seasonal variation.

OBJECTIVES

The present study investigated the relationship of PM with obesity and blood pressure variables in children across the winter and summer seasons.

METHODS

A comparative descriptive approach was adopted and school children from 10-14 years of age from selected rural and urban localities of the Eastern Cape Province of South Africa were assessed in winter and summer. Anthropometric measurements were taken, including height, weight, waist circumference, body mass index (BMI), and total fat mass (TFM), while blood pressure variables including systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) were measured. Indoor air PM concentrations were measured in the classrooms in the presence of children.

RESULTS

The prevalence of obesity and hypertension in children were 13.4% and 5.1% in winter and 12.9% and 1.0% in summer, respectively. High blood pressure was more prevalent in children in rural areas, while the prevalence of obesity in children was higher in urban areas. Particulate matter was significantly (p<0.05) higher in rural areas compared to urban areas. Obese children in summer had a greater than 3-fold association (AOR: 3.681, p=0.005) with 4th interquartile range (IQR) of PM5 and a greater than 3- and 4-fold association (AOR: 3.08; 4.407; p<0.05) with 2nd and 4th IQR of PM10, respectively, than their overweight, normal weight or underweight counterparts. High blood pressure was not associated (p< 0.05) with PM.

CONCLUSIONS

High concentrations of indoor PM were positively associated with obesity in children in summer, particularly among rural children. This association could be accounted for by location and seasonal differences.

PARTICIPANT CONSENT

Obtained.

ETHICS APPROVAL

Ethics approval was obtained from the Health Sciences Ethics Committee of Walter Sisulu University, South Africa (Ref No: CHI011SCHU01).

COMPETING INTERESTS

The authors declare no competing financial interests.

Spatially and size-resolved analysis of gold nanoparticles in rat spleen after intratracheal instillation by laser ablation-inductively coupled plasma-mass spectrometry

In a dual approach, laser ablation-inductively coupled plasma-mass spectrometry was applied to investigate spleen samples of rats after intratracheal instillation of polyvinylpyrrolidone-coated gold nanoparticles. First, spatially resolved imaging analysis was deployed to investigate gold translocation from the lungs to the spleen and to investigate the distribution pattern of gold in the spleen parenchyma itself. Using the same instrumental setup, laser ablation-inductively coupled plasma-mass spectrometry in single particle mode was applied to determine the species of translocated gold. Single particle analysis allows the determination of particle size distributions and therefore to distinguish between ionic species, intact nanoparticles, and agglomerates. A translocation of instilled gold from the lungs to the spleen was demonstrated for gold nanoparticles of 30 and 50 nm diameter. Furthermore single particle analysis revealed the translocation of intact gold nanoparticles in a non-agglomerated state.

Effects of Ambient Air Pollution on Blood Pressure Among Children and Adolescents: A Systematic Review and Meta-Analysis

Background

Previous studies have investigated the association of ambient air pollution with blood pressure (BP) in children and adolescents, however, the results are not consistent. We conducted a systematic review and meta‐analysis to assess the relationship between short‐term and long‐term ambient air pollutant exposure with BP values among children and adolescents.

Methods and Results

We searched PubMed, Web of Science, and Embase before September 6, 2020. Two reviewers independently searched and selected studies, extracted data, and assessed study quality. The studies were divided into groups by composition of air pollutants (NO₂, particulate matter (PM) with diameter ≤10 μm or ≤2.5 μm) and length of exposure. The beta regression coefficients (β) and their 95% CIs were calculated to evaluate the strength of the effect with each 10 μg/m³ increase in air pollutants. Out of 36 650 articles, 14 articles were included in this meta‐analysis. The meta‐analysis showed short‐term exposure to PM with diameter ≤10 μm (β=0.267; 95% CI, 0.033‒0.501) was significantly associated with elevated systolic BP values. In addition, long‐term exposure to PM with diameter ≤2.5 μm (β=1.809; 95% CI, 0.962‒2.655), PM with diameter ≤10 μm (β=0.526; 95% CI, 0.095‒0.958), and NO₂ (β=0.754; 95% CI, 0.541‒0.968) were associated with systolic BP values and long‐term exposure to PM with diameter ≤2.5 μm (β=0.931; 95% CI, 0.157‒1.705), and PM with diameter ≤10 μm (β=0.378; 95% CI, 0.022‒0.735) was associated with diastolic BP.

Conclusions

Our study indicates that both short‐term and long‐term exposure to some ambient air pollutants may increase BP values among children and adolescents.

Ovariectomy reduces the cardiac cytoprotection in rats exposed to particulate air pollutant

Fine particulate matter (PM_2.5) has been considered a risk factor for cardiovascular diseases by inducing an oxidative and inflammatory phenotype. Besides, the reduction of 17β-estradiol (E2) levels during menopause is a natural risk for cardiovascular outcomes. During the E2 downfall, there is a high requirement of the 70-kDa heat shock proteins (HSP70), which present essential antioxidant, anti-inflammatory, and anti-senescence roles. We investigated if the ovariectomy, an animal model for menopause, could induce additional effects in cardiac health by impairing oxidative and heat shock response parameters of female rats chronically exposed to residual oil fly ash (ROFA; an inorganic fraction of PM_2.5). Thus, ROFA was obtained from São Paulo (Brazil) and solubilized it in saline. Further, female Wistar rats were exposed to 50 μL of saline (control group) or ROFA solution (250 μg) (polluted) by intranasal instillation, 5 days/week, 12 weeks. At the 12th week, animals were subdivided into four groups (n = 6 p/group): control, OVX, polluted, and polluted + OVX. Control and polluted were submitted to false surgery, while OVX and polluted + OVX were ovariectomized. ROFA or saline exposure continued for 12 weeks. Ovariectomy reduced the cardiac catalase activity and iHSP70 expression in female rats exposed to ROFA. Neither plasma eHSP72 levels nor H-index (eHSP72 to cardiac iHSP70 ratio) was affected. In conclusion, ovariectomy reduces the cardiac cytoprotection and antioxidant defense, and enhances the susceptibility to premature cellular senescence in rats exposed to ROFA.

Emerging role of air pollution and meteorological parameters in COVID-19

Exposure to air pollutants has been associated with respiratory viral infections. Epidemiological studies have shown that air pollution exposure is related to increased cases of SARS-COV-2 infection and COVID-19-associated mortality. In addition, the changes of meteorological parameters have also been implicated in the occurrence and development of COVID-19. However, the molecular mechanisms by which pollutant exposure and changes of meteorological parameters affects COVID-19 remains unknown. This review summarizes the biology of COVID-19 and the route of viral transmission, and elaborates on the relationship between air pollution and climate indicators and COVID-19. Finally, we envisaged the potential roles of air pollution and meteorological parameters in COVID-19.

Hypertension in Low- and Middle-Income Countries

In recent decades low- and middle-income countries (LMICs) have been witnessing a significant shift toward raised blood pressure; yet in LMICs, only 1 in 3 are aware of their hypertension status, and ≈8% have their blood pressure controlled. This rising burden widens the inequality gap, contributes to massive economic hardships of patients and carers, and increases costs to the health system, facing challenges such as low physician-to-patient ratios and lack of access to medicines. Established risk factors include unhealthy diet (high salt and low fruit and vegetable intake), physical inactivity, tobacco and alcohol use, and obesity. Emerging risk factors include pollution (air, water, noise, and light), urbanization, and a loss of green space. Risk factors that require further in-depth research are low birth weight and social and commercial determinants of health. Global actions include the HEARTS technical package and the push for universal health care. Promising research efforts highlight that successful interventions are feasible in LMICs. These include creation of health-promoting environments by introducing salt-reduction policies and sugar and alcohol tax; implementing cost-effective screening and simplified treatment protocols to mitigate treatment inertia; pooled procurement of low-cost single-pill combination therapy to improve adherence; increasing access to telehealth and mHealth (mobile health); and training health care staff, including community health workers, to strengthen team-based care. As the blood pressure trajectory continues creeping upward in LMICs, contextual research on effective, safe, and cost-effective interventions is urgent. New emergent risk factors require novel solutions. Lowering blood pressure in LMICs requires urgent global political and scientific priority and action.

Toxic effect and mechanism of ultrafine carbon black on mouse primary splenocytes and two digestive enzymes

This paper investigated the toxic effect and mechanism of ultrafine carbon black (UFCB) on splenocytes and enzymes in the digestive system. It was found that the toxicity of UFCB to splenocytes was dose-dependent. UFCB with a low concentration (<15 μg/mL) had no significant effect on splenocytes while UFCB with high concentration (>15 μg/mL) induced significant oxidative damage with increased content of reactive oxygen species (ROS) (134%) and malonaldehyde (MDA) (222.3%) along with the decreased activity of superoxide dismutase (SOD) (55.63%) and catalase (CAT) (87.73%). Analysis combined cellular and molecular levels indicated that UFCB induced splenocyte toxicity through oxidative stress. The interactions of UFCB with two important digestive enzymes, α-amylase and lipase, were also studied respectively. Results showed that the interaction of UFCB and the two enzymes altered the particle size and fluorescence intensity in both experimental systems. The formation of protein corona also resulted in the contraction of the polypeptide skeleton in both enzymes, which further inhibited their activity. Our work provided basic data on the toxicity of UFCB in the spleen and digestive system and fills the gap in the study of UFPs toxicity. CAPSULE: UFCB induced splenocyte toxicity and enzyme dysfunction through oxidative stress and protein corona formation respectively.

Cardiovascular health impacts of wildfire smoke exposure

In recent years, wildland fires have occurred more frequently and with increased intensity in many fire-prone areas. In addition to the direct life and economic losses attributable to wildfires, the emitted smoke is a major contributor to ambient air pollution, leading to significant public health impacts. Wildfire smoke is a complex mixture of particulate matter (PM), gases such as carbon monoxide, nitrogen oxide, and volatile and semi-volatile organic compounds. PM from wildfire smoke has a high content of elemental carbon and organic carbon, with lesser amounts of metal compounds. Epidemiological studies have consistently found an association between exposure to wildfire smoke (typically monitored as the PM concentration) and increased respiratory morbidity and mortality. However, previous reviews of the health effects of wildfire smoke exposure have not established a conclusive link between wildfire smoke exposure and adverse cardiovascular effects. In this review, we systematically evaluate published epidemiological observations, controlled clinical exposure studies, and toxicological studies focusing on evidence of wildfire smoke exposure and cardiovascular effects, and identify knowledge gaps. Improving exposure assessment and identifying sensitive cardiovascular endpoints will serve to better understand the association between exposure to wildfire smoke and cardiovascular effects and the mechanisms involved. Similarly, filling the knowledge gaps identified in this review will better define adverse cardiovascular health effects of exposure to wildfire smoke, thus informing risk assessments and potentially leading to the development of targeted interventional strategies to mitigate the health impacts of wildfire smoke.

Global burden of ischemic heart disease attributable to ambient PM2.5 pollution from 1990 to 2017

OBJECTIVES

We aimed to estimate the spatial and temporal variation in the PM_2.5 associated ischemic heart disease (IHD) burden on a global scale between 1990 and 2017.

METHODS

We obtained data on IHD attributable to PM_2.5 from the Global Burden of Disease Study (GBD) 2017. We used the numbers and age-standardized mortality rate (ASMR) and disability-adjusted life years (DALYs) rate (ASDR) of IHD attributable to PM_2.5 by sex, socio-demographic index (SDI), and countries. We calculated the estimated annual percentage changes (EAPCs) to assess the trends of ASMR and ASDR between 1990 and 2017. We further calculated the contribution of population growth, population aging, and mortality or DALYs changes to the total IHD deaths and DALYs attributable to PM_2.5 between 1990 and 2017.

RESULTS

In 2017, IHD attributable to PM_2.5 resulted in 977,140 (95% UI: 838,900-1123,240) deaths and 21.93 million (95% UI: 18.88-25.37) DALYs globally. There has been a significant change of attributable IHD burden, from being a common burden to one that mainly affects low and middle-SDI countries in Asia, Oceania and sub-Saharan Africa. This global change has occurred as a consequence of opposing trends in high-SDI countries and in Asia, Oceania and sub-Saharan Africa, which has led to some Asian countries having the highest IHD burden attributable to PM_2.5 in 2017.

CONCLUSIONS

Although the global age-standardized burden of IHD attributable to PM_2.5 has decreased from 1990 to 2017, there has been an unpleasant increase in some low and middle-income countries, mainly in Asia, Oceania, and Africa.

Ovariectomy enhances female rats' susceptibility to metabolic, oxidative, and heat shock response effects induced by a high-fat diet and fine particulate matter

Obesity and exposure to fine particulate matter (air pollutant PM_2.5) are important risk factors for metabolic and cardiovascular diseases. They are also related to early menopause. The reduction of 17β-estradiol (E2) levels during female climacteric, marked by menopause, is of significant concern because of its imminent influence on metabolism, redox and inflammatory status. This complex homeostasis-threatening scenario may induce a heat shock response (HSR) in cells, enhancing the expression of the 70 kDa heat shock protein (HSP70). A failure in this mechanism could predispose women to cardiovascular diseases. In this study, we evaluated if the climacteric could represent an additional risk among obese rats exposed to PM_2.5 by worsening lipid, oxidative, and inflammatory parameters and HSP70 in cardiac tissue. We induced obesity in female Wistar rats using a high-fat diet (HFD) (58.3% as fats) and exposed them to 50 μL of saline 0.9% (control, n = 15) or 250 μg residual oil fly ash (ROFA, the inorganic portion of PM_2.5) (polluted, n = 15) by intranasal instillation, 5 days/w for 12 weeks. At the 12th week, we subdivided these animals into four groups: control (n = 6), OVX (n = 9), polluted (n = 6) and polluted + OVX (n = 9). OVX and polluted + OVX were submitted to a bilateral ovariectomy (OVX), a surgical model for menopause, while control and polluted received a false surgery (sham). ROFA exposure and HFD consumption were continued for 12 additional weeks, after which the animals were euthanized. ROFA enhanced the susceptibility to ovariectomy-induced dyslipidemia, while ovariectomy predisposed female rats to the ROFA-induced decrease of cardiac iHSP70 expression. Ovariectomy also decreased the IL-6 levels and IL-6/IL-10 in obese animals, reinforcing a metabolic impairment and a failure to respond to unfavorable conditions. Our results support the hypothesis that obese ovariectomized animals are predisposed to a metabolic worsening under polluted conditions and are at higher risk of cardiovascular diseases.