Persistent endothelial dysfunction in humans after diesel exhaust inhalation

Association between weather conditions and migraine: a systematic review and meta-analysis

BACKGROUND

Previous studies have linked migraine to weather conditions, but variations in the factors examined and inconsistent focus have complicated comparisons. This underscores the need for a more comprehensive and clearer analysis.

METHODS

Studies published before December 2024 on the association between weather and migraine were searched from PubMed, Embase, Web of Science, and Cochrane. Meta-analyses based on effect sizes were performed using Review Manager version 5.4.1.

RESULTS

A total of 31 studies were included in the meta-analyses. It revealed a significant association between migraine attack and weather changes reported as a trigger factor (RD = 0.47, 95% CI = 0.40-0.54). Additionally, specific weather factors, such as temperature (OR = 1.15, 95% CI = 1.02-1.29) and ambient pressure (OR = 1.07, 95% CI = 1.01-1.15), were significantly associated with migraine attacks, while humidity (OR = 1.04, 95% CI = 0.97-1.11) did not show a significant association. Moreover, increased levels of air pollutants, including PM10 (OR = 1.07, 95% CI = 1.03-1.11), PM2.5 (OR = 1.04, 95% CI = 1.01-1.06), NO2 (OR = 1.08, 95% CI = 1.03-1.14), CO (OR = 1.08, 95% CI = 1.01-1.16), and O3 (OR = 1.12, 95% CI = 1.03-1.21), were significantly associated with an increased risk of migraine clinical visits, whereas SO2 (OR = 1.02, 95% CI = 1.00-1.04) was not.

CONCLUSIONS

This meta-analysis revealed that weather changes are significant trigger factors for migraine, with temperature and ambient pressure playing notable roles in this association. Additionally, increased levels of air pollutants are linked to a higher risk of migraine attacks. These findings could lead to new interventions for patients who are weather-sensitive and offer fresh perspectives for future research into the pathogenesis of migraine.

The effect of short-term exposure to air pollution on the admission of ischemic stroke and its interaction with meteorological factors

OBJECTIVES

The aim of this study was to investigate the associations, potential effects, and interactions between short-term exposure to air pollution and the risk of ischemic stroke (IS).

STUDY DESIGN

An ecological study.

METHODS

Daily data on IS incidents, air pollution, and meteorological conditions were collected from 2017 to 2021 in Gannan. A time-stratified case-crossover design, combined with a distributional lag nonlinear model, was employed to analyze the relationship between air pollution exposure and the admission of IS. Additionally, the interaction between air pollutants and meteorological factors was examined using bivariate response surface modeling. The study also conducted stratified analyses based on gender, age, marital status, medical insurance purchase status, and season of admission.

RESULTS

In the single lag day structure, extremely low levels of PM2.5 (RR = 1.11, 95 % CI: 1.03-1.20) and PM10 (RR = 1.10, 95 % CI: 1.02-1.20) peaked on lag 3. Conversely, extremely high levels of NO2 (RR = 1.05, 95 % CI: 1.01-1.10), CO (RR = 1.19, 95 % CI: 1.03-1.37), and extremely low levels of O3 (RR = 1.09, 95 % CI: 1.01-1.19) exhibited a greater relative risk on lag 4. In the cumulative lag-day structure, extremely high levels of NO2 exhibited the most significant hazard effect at lag 05 (RR = 1.27, 95 % CI: 1.01-1.52), while extremely low levels of CO at lag 02 (RR = 1.15, 95 % CI: 1.05-1.24) and extremely low levels of O3 at lag 01 (RR = 1.20, 95 % CI: 1.04-1.40) also demonstrated notable associations. In the subgroup stratum, the association between air pollution and IS was found to be more significant in patients who were male, aged <65 years, married, had medical insurance, and were admitted during the cold season. The lowest number of IS hospitalisations occurred under low relative humidity conditions alongside increasing concentrations of CO.

CONCLUSIONS

Short-term exposure to air pollution was positively associated with an increased risk of IS. This association was influenced by factors such as being male, aged <65 years, married, having medical insurance, and admissions during the cold season. Additionally, an interaction was observed between air pollutants and meteorological factors. These findings carry significant public health implications for the prevention of IS.

Acute airway inflammation following controlled biodiesel exhaust exposure in healthy subjects

BACKGROUND

Exposure to standard petrodiesel exhaust is linked to adverse health effects. Moreover, there is a mounting request to replace fossil-based fuels with renewable and sustainable alternatives and, therefore, rapeseed methyl ester (RME) and other biofuels have been introduced. However, recent toxicological research has indicated that biodiesel exhaust may also induce adverse health-related events.

AIM

To determine whether exposure to 100% RME biodiesel (BD100) exhaust would cause an acute airway neutrophilic recruitment in humans.

METHODS

Fourteen healthy subjects underwent exposure to diluted BD100 exhaust and filtered air for 1-h, in a blinded, random fashion. Bronchoscopy with endobronchial mucosal biopsies, bronchial wash (BW) and bronchoalveolar lavage (BAL) was performed six hours after exposure. Differential cell counts and inflammatory markers were determined in the supernatant and biopsies were stained immunohistochemically.

RESULTS

Compared with filtered air, BD100 exhaust exposure increased bronchial mucosal endothelial P-selectin adhesion molecule expression, as well as neutrophil, mast cell and CD68 + macrophage numbers. An increased influx of neutrophils and machrophages was also seen in BW.

CONCLUSION

Exposure to biodiesel exhaust was associated with an acute airway inflammation that appeared similar to preceding petrodiesel exposure studies. The present findings, together with the recently reported adverse cardiovascular effects after similar biodiesel exposure, indicate that biodiesel is not free of toxicity and may affect human health.

Controlled human exposures: a review and comparison of the health effects of diesel exhaust and wood smoke

One of the most pressing issues in global health is air pollution. Emissions from traffic-related air pollution and biomass burning are two of the most common sources of air pollution. Diesel exhaust (DE) and wood smoke (WS) have been used as models of these pollutant sources in controlled human exposure (CHE) experiments. The aim of this review was to compare the health effects of DE and WS using results obtained from CHE studies. A total of 119 CHE-DE publications and 25 CHE-WS publications were identified for review. CHE studies of DE generally involved shorter exposure durations and lower particulate matter concentrations, and demonstrated more potent dysfunctional outcomes than CHE studies of WS. In the airways, DE induces neutrophilic inflammation and increases airway hyperresponsiveness, but the effects of WS are unclear. There is strong evidence that DE provokes systemic oxidative stress and inflammation, but less evidence exists for WS. Exposure to DE was more prothrombotic than WS. DE generally increased cardiovascular dysfunction, but limited evidence is available for WS. Substantial heterogeneity in experimental methodology limited the comparison between studies. In many areas, outcomes of WS exposures tended to trend in similar directions to those of DE, suggesting that the effects of DE exposure may be useful for inferring possible responses to WS. However, several gaps in the literature were identified, predominantly pertaining to elucidating the effects of WS exposure. Future studies should strongly consider performing head-to-head comparisons between DE and WS using a CHE design to determine the differential effects of these exposures.

Long-term exposure to particulate matter pollution and incidence of ischemic and hemorrhagic stroke: A prospective cohort study in Eastern China

Although epidemiological studies have demonstrated significant associations of long-term exposure to particulate matter (PM) air pollution with stroke, evidence on the long-term effects of PM exposure on cause-specific stroke incidence is scarce and inconsistent. We incorporated 33,282 and 33,868 individuals aged 35-75 years without a history of ischemic or hemorrhagic stroke at the baseline in 2014, who were followed up till 2021. Residential exposures to particulate matter with an aerodynamic diameter less than 2.5 μm (PM2.5) and particulate matter with an aerodynamic diameter less than 10 μm (PM10) for each participant were predicted using a satellite-based model with a spatial resolution of 1 × 1 km. We employed time-varying Cox proportional hazards models to assess the long-term effect of PM pollution on incident stroke. We identified 926 cases of ischemic stroke and 211 of hemorrhagic stroke. Long-term PM exposure was significantly associated with increased incidence of both ischemic and hemorrhagic stroke, with almost 2 times higher risk on hemorrhagic stroke. Specifically, a 10 μg/m³ increase in 3-year average concentrations of PM2.5 was linked to a hazard ratio (HR) of 1.35 (95% confidence interval (CI): 1.18-1.54) for incident ischemic stroke and 1.79 (95% CI: 1.36-2.34) for incident hemorrhagic stroke. The HR related to PM10, though smaller, remained statistically significant, with a HR of 1.25 for ischemic stroke and a HR of 1.51 for hemorrhagic stroke. The excess risks are larger among rural residents and individuals with lower educational attainment. The present cohort study contributed to the mounting evidence on the increased risk of incident stroke associated with long-term PM exposures. Our results further provide valuable evidence on the heightened sensitivity of hemorrhagic stroke to air pollution exposures compared with ischemic stroke.

Genetic polymorphisms in genes involved in the type I interferon system (STAT4 and IRF5): association with Asian SLE patients

Systemic lupus erythematosus (SLE) is a common autoimmune disease with a polymorphic clinical presentation involving multisystem damages with significant differences in prevalence and disease severity among different ethnic groups. Although genetic, hormonal, and environmental factors have been demonstrated to contribute a lot to SLE, the pathogenesis of SLE is still unknown. Numerous evidence revealed that gene variants within the type I interferons (IFN) signaling pathway performed the great genetic associations with autoimmune diseases including SLE. To date, through genome-wide association studies (GWAS), genetic association studies showed that more than 100 susceptibility genes have been linked to the pathogenesis of SLE, among which TYK2, STAT1, STAT4, and IRF5 are important molecules directly connected to the type I interferon signaling system. The review summarized the genetic associations and the detailed risk loci of STAT4 and IRF5 with Asian SLE patients, explored the genotype distributions associated with the main clinical manifestations of SLE, and sorted out the potential reasons for the differences in susceptibility in Asia and Europe. Moreover, the therapies targeting STAT4 and IRF5 were also evaluated in order to propose more personalized and targeted treatment plans in SLE.

Exposure to occupational air pollution and vascular endothelial dysfunction in workers of the steel industry in Iran

Air pollution is recognized as a risk factor for cardiovascular diseases; however, the precise underlying mechanisms remain unclear. This study investigated the impact of occupational air pollution exposure on endothelial function in workers within the steel industry. Specifically, we examined male employees in the coke-making division of the Isfahan Steel Company in Iran, as well as those in administrative roles with no known history of cardiovascular risk. Data on age, body mass index, duration of employment, blood pressure, fasting blood sugar, and lipid profile were collected. To assess endothelial function, flow-mediated dilation (FMD) was measured. The baseline brachial artery diameter was greater (mean difference [95% CI] = 0.068 mm [0.008 to 0.128]), while the FMD was lower (mean difference [95% CI] = -0.908 % [-1.740 to -0.075]) in the coke-making group than in the control group. After controlling for potential confounding variables, it was observed that working in the coke-making sector of the industry was associated with lower FMD (F = 3.954, p = .049). These findings indicated that occupational air pollution exposure among workers in the steel industry is linked to impaired endothelium-dependent vasodilation.

Recent Advances in Thiourea Based Colorimetric and Fluorescent Chemosensors for Detection of Anions and Neutral Analytes: A Review

Thioureas and their derivatives are organosulfur compounds having excellent biological and non-biological applications. These compounds contain S- and N-, which are nucleophilic and allow for establishing inter-and intramolecular hydrogen bonding. These characteristics make thiourea moiety a very important chemosensor to detect various environmental pollutants. This article covers a broad range of thioureas and their derivatives that are used for highly sensitive, selective, and simple fluorimetric (turn-off and turn-on), and colorimetric chemosensors for the detection and determination of different types of anions, such as CN-, AcO-, F-, ClO- and citrate ions, etc., and neutral analytes such as ATP, DCP, and Amlodipine, etc., in biological, environmental, and agriculture samples. Further, the sensing performances of thioureas-based chemosensors have been compared and discussed, which could help the readers for the future design of organic fluorescent and colorimetric sensors to detect anions and neutral analytes. We hope this study will support the new thoughts to design highly efficient, selective, and sensitive chemosensors to detect different analytes in biological, environmental, and agricultural samples.

The stress-responsive cytotoxic effect of diesel exhaust particles on lymphatic endothelial cells

Diesel exhaust particles (DEPs) are very small (typically < 0.2 μm) fragments that have become major air pollutants. DEPs are comprised of a carbonaceous core surrounded by organic compounds such as polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs. Inhaled DEPs reach the deepest sites in the respiratory system where they could induce respiratory/cardiovascular dysfunction. Additionally, a previous study has revealed that a portion of inhaled DEPs often activate immune cells and subsequently induce somatic inflammation. Moreover, DEPs are known to localize in lymph nodes. Therefore, in this study we explored the effect of DEPs on the lymphatic endothelial cells (LECs) that are a constituent of the walls of lymph nodes. DEP exposure induced cell death in a reactive oxygen species (ROS)-dependent manner. Following exposure to DEPs, next-generation sequence (NGS) analysis identified an upregulation of the integrated stress response (ISR) pathway and cell death cascades. Both the soluble and insoluble components of DEPs generated intracellular ROS. Three-dimensional Raman imaging revealed that DEPs are taken up by LECs, which suggests internalized DEP cores produce ROS, as well as soluble DEP components. However, significant cell death pathways such as apoptosis, necroptosis, ferroptosis, pyroptosis, and parthanatos seem unlikely to be involved in DEP-induced cell death in LECs. This study clarifies how DEPs invading the body might affect the lymphatic system through the induction of cell death in LECs.

First-in-human controlled inhalation of thin graphene oxide nanosheets to study acute cardiorespiratory responses

Graphene oxide nanomaterials are being developed for wide-ranging applications but are associated with potential safety concerns for human health. We conducted a double-blind randomized controlled study to determine how the inhalation of graphene oxide nanosheets affects acute pulmonary and cardiovascular function. Small and ultrasmall graphene oxide nanosheets at a concentration of 200 μg m-3 or filtered air were inhaled for 2 h by 14 young healthy volunteers in repeated visits. Overall, graphene oxide nanosheet exposure was well tolerated with no adverse effects. Heart rate, blood pressure, lung function and inflammatory markers were unaffected irrespective of graphene oxide particle size. Highly enriched blood proteomics analysis revealed very few differential plasma proteins and thrombus formation was mildly increased in an ex vivo model of arterial injury. Overall, acute inhalation of highly purified and thin nanometre-sized graphene oxide nanosheets was not associated with overt detrimental effects in healthy humans. These findings demonstrate the feasibility of carefully controlled human exposures at a clinical setting for risk assessment of graphene oxide, and lay the foundations for investigating the effects of other two-dimensional nanomaterials in humans. Clinicaltrials.gov ref: NCT03659864.

The effect of indoor air filtration on biomarkers of inflammation and oxidative stress: a review and meta-analysis of randomized controlled trials

Improvement of indoor air quality is beneficial for human health. However, previous studies have not reached consistent conclusions regarding the effects of indoor air filtration on inflammation and oxidative stress. This study aims to determine the relationship between indoor air filtration and inflammation and oxidative stress biomarkers. We conducted an electronic search that evaluated the association of indoor air filtration with biomarkers of inflammation and oxidative stress in five databases (PubMed, Cochrane Library, EMBASE, Web of Science, and Scopus) from the beginning to April 23, 2023. Outcomes included the following markers: interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), C-reactive protein (CRP), malondialdehyde (MDA), 8-hydroxy-2deoxyguanosine (8-OHdG), and 8-iso-prostaglandinF2α (8-isoPGF2α). We extracted data from the included studies according to the system evaluation and the preferred reporting item for meta-analysis (PRISMA) guidelines and used the Cochrane risk of bias tool to assess bias risk. Our meta-analysis included 15 studies with 678 participants to assess the combined effect size. The meta-analysis demonstrated that indoor air filtration could have a marked reduction in IL-6 (SMD: -0.275, 95% CI: -0.545 to -0.005, p = 0.046) but had no significant effect on other markers of inflammation or oxidative stress. Subgroup analysis results demonstrated a significant reduction in 8-OHdG levels in the subgroup with < 1 day of duration (SMD: -0.916, 95% CI: -1.513 to -0.320; p = 0.003) and using filtrete air filter (SMD: -5.530, 95% CI: -5.962 to -5.099; p < 0.001). Our meta-analysis results depicted that indoor air filtration can significantly reduce levels of inflammation and oxidative stress markers. Considering the adverse effects of air pollution on human health, our study provides powerful evidence for applying indoor air filtration to heavy atmospheric pollution.

Association between Ambient Volatile Organic Compounds Exposome and Emergency Hospital Admissions for Cardiovascular Disease

The limited research on volatile organic compounds (VOCs) has not taken into account the interactions between constituents. We used the weighted quantile sum (WQS) model and generalized linear model (GLM) to quantify the joint effects of ambient VOCs exposome and identify the substances that play key roles. For a 0 day lag, a quartile increase of WQS index for n-alkanes, iso/anti-alkanes, aromatic, halogenated aromatic hydrocarbons, halogenated saturated chain hydrocarbons, and halogenated unsaturated chain hydrocarbons were associated with 1.09% (95% CI: 0.13, 2.06%), 0.98% (95% CI: 0.22, 1.74%), 0.92% (95% CI: 0.14, 1.69%), 1.03% (95% CI: 0.14, 1.93%), 1.69% (95% CI: 0.48, 2.91%), and 1.85% (95% CI: 0.93, 2.79%) increase in cardiovascular disease (CVD) emergency hospital admissions, respectively. Independent effects of key substances on CVD-related emergency hospital admissions were also reported. In particular, an interquartile range increase in 1,1,1-trichloroethane, methylene chloride, styrene, and methylcyclohexane is associated with a greater risk of CVD-associated emergency hospital admissions [3.30% (95% CI: 1.93, 4.69%), 3.84% (95% CI: 1.21, 6.53%), 5.62% (95% CI: 1.35, 10.06%), 8.68% (95% CI: 3.74, 13.86%), respectively]. We found that even if ambient VOCs are present at a considerably low concentration, they can cause cardiovascular damage. This should prompt governments to establish and improve concentration standards for VOCs and their sources. At the same time, policies should be introduced to limit VOCs emission to protect public health.

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

TOPIC IMPORTANCE

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

REVIEW FINDINGS

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

SUMMARY

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

Epithelial MAPK signaling directs endothelial NRF2 signaling and IL-8 secretion in a tri-culture model of the alveolar-microvascular interface following diesel exhaust particulate (DEP) exposure

BACKGROUND

Particulate matter 2.5 (PM2.5) deposition in the lung's alveolar capillary region (ACR) is significantly associated with respiratory disease development, yet the molecular mechanisms are not completely understood. Adverse responses that promote respiratory disease development involve orchestrated, intercellular signaling between multiple cell types within the ACR. We investigated the molecular mechanisms elicited in response to PM2.5 deposition in the ACR, in an in vitro model that enables intercellular communication between multiple resident cell types of the ACR.

METHODS

An in vitro, tri-culture model of the ACR, incorporating alveolar-like epithelial cells (NCI-H441), pulmonary fibroblasts (IMR90), and pulmonary microvascular endothelial cells (HULEC) was developed to investigate cell type-specific molecular responses to a PM2.5 exposure in an in-vivo-like model. This tri-culture in vitro model was termed the alveolar capillary region exposure (ACRE) model. Alveolar epithelial cells in the ACRE model were exposed to a suspension of diesel exhaust particulates (DEP) (20 µg/cm2) with an average diameter of 2.5 µm. Alveolar epithelial barrier formation, and transcriptional and protein expression alterations in the directly exposed alveolar epithelial and the underlying endothelial cells were investigated over a 24 h DEP exposure.

RESULTS

Alveolar epithelial barrier formation was not perturbed by the 24 h DEP exposure. Despite no alteration in barrier formation, we demonstrate that alveolar epithelial DEP exposure induces transcriptional and protein changes in both the alveolar epithelial cells and the underlying microvascular endothelial cells. Specifically, we show that the underlying microvascular endothelial cells develop redox dysfunction and increase proinflammatory cytokine secretion. Furthermore, we demonstrate that alveolar epithelial MAPK signaling modulates the activation of NRF2 and IL-8 secretion in the underlying microvascular endothelial cells.

CONCLUSIONS

Endothelial redox dysfunction and increased proinflammatory cytokine secretion are two common events in respiratory disease development. These findings highlight new, cell-type specific roles of the alveolar epithelium and microvascular endothelium in the ACR in respiratory disease development following PM2.5 exposure. Ultimately, these data expand our current understanding of respiratory disease development following particle exposures and illustrate the utility of multicellular in vitro systems for investigating respiratory tract health.

Biological effects of diesel exhaust inhalation. III cardiovascular function

OBJECTIVE

Inhalation of diesel exhaust (DE) has been shown to be an occupational hazard in the transportation, mining, and gas and oil industries. DE also contributes to air pollution, and therefore, is a health hazard to the general public. Because of its effects on human health, changes have been made to diesel engines to reduce both the amounts of particulate matter and volatile fumes they generate. The goal of the current study was to examine the effects of inhalation of diesel exhaust.

MATERIALS AND METHODS

The study presented here specifically examines the effects of exposure to 0.2 and 1.0 mg/m3 DE or filtered air (6h/d for 4 d) on measures of peripheral and cardio-vascular function, and biomarkers of heart and kidney dysfunction in male rats. A Tier 2 engine used in oil and gas fracking operations was used to generate the diesel exhaust.

RESULTS

Exposure to 0.2 mg/m3 DE resulted in an increase in blood pressure 1d following the last exposure, and increases in dobutamine-induced cardiac output and stroke volume 1 and 27d after exposure. Changes in peripheral vascular responses to norepinephrine and acetylcholine were minimal as were changes in transcript expression in the heart and kidney. Exposure to 1.0 mg/m3 DE did not result in major changes in blood pressure, measures of cardiac function, peripheral vascular function or transcript expression.

DISCUSSION AND CONCLUSIONS

Based on the results of this study, we suggest that exposure to DE generated by a Tier 2 compliant diesel engine generates acute effects on biomarkers indicative of cardiovascular dysfunction. Recovery occurs quickly with most measures of vascular/cardiovascular function returning to baseline levels by 7d following exposure.

[Global environmental changes and the epithelial barrier hypothesis]

BACKGROUND

The global burden of noncommunicable diseases (NCD) has seen a strong increase in recent decades and attributable to the influence of environmental factors. For a multitude of diseases an association with epithelial barrier damage has been reported.

OBJECTIVE

This article provides an overview of the health effects of environmental pollution in the context of the epithelial barrier hypothesis of Cezmi Akdis. Additionally, exemplary mechanisms of a barrier damage are described. Finally, possible preventive and therapeutic consequences are discussed.

MATERIAL AND METHODS

The PubMed database was searched for the relevant topics and selected literature was reviewed.

RESULTS

A wide variety of substances can damage the epithelial barriers of the skin, lungs and gastrointestinal tract. The rise in the prevalences of atopic diseases could (partly) be due to an increased exposure to barrier-damaging substances, such as particulate matter and laundry detergents. A possible pathogenetic mechanism is the initiation and maintenance of an immune response by subepithelial penetration of microorganisms through damaged epithelia.

CONCLUSION

Based on the epithelial barrier hypothesis new therapeutic and prevention strategies can be developed. The regulation of hazardous chemicals and the fight against environmental pollution and climate change are necessary to reduce the burden of disease.

Long-term air pollution exposure and markers of cardiometabolic health in the National Longitudinal Study of Adolescent to Adult Health (Add Health)

BACKGROUND

Air pollution exposure is associated with cardiovascular morbidity and mortality. Although exposure to air pollution early in life may represent a critical window for development of cardiovascular disease risk factors, few studies have examined associations of long-term air pollution exposure with markers of cardiovascular and metabolic health in young adults.

OBJECTIVES

By combining health data from the National Longitudinal Study of Adolescent to Adult Health (Add Health) with air pollution data from the Fused Air Quality Surface using Downscaling (FAQSD) archive, we: (1) calculated multi-year estimates of exposure to ozone (O3) and particulate matter with an aerodynamic diameter ≤ 2.5 µm (PM2.5) for Add Health participants; and (2) estimated associations between air pollution exposures and multiple markers of cardiometabolic health.

METHODS

Add Health is a nationally representative longitudinal cohort study of over 20,000 adolescents aged 12-19 in the United States (US) in 1994-95 (Wave I). Participants have been followed through adolescence and into adulthood with five in-home interviews. Estimated daily concentrations of O3 and PM2.5 at census tracts were obtained from the FAQSD archive and used to generate tract-level annual averages of O3 and PM2.5 concentrations. We estimated associations between average O3 and PM2.5 exposures from 2002 to 2007 and markers of cardiometabolic health measured at Wave IV (2008-09), including hypertension, hyperlipidemia, body mass index (BMI), diabetes, C-reactive protein, and metabolic syndrome.

RESULTS

The final sample size was 11,259 individual participants. The average age of participants at Wave IV was 28.4 years (range: 24-34 years). In models adjusting for age, race/ethnicity, and sex, long-term O3 exposure (2002-07) was associated with elevated odds of hypertension, with an odds ratio (OR) of 1.015 (95% confidence interval [CI]: 1.011, 1.029); obesity (1.022 [1.004, 1.040]); diabetes (1.032 [1.009,1.054]); and metabolic syndrome (1.028 [1.014, 1.041]); PM2.5 exposure (2002-07) was associated with elevated odds of hypertension (1.022 [1.001, 1.045]).

CONCLUSION

Findings suggest that long-term ambient air pollution exposure, particularly O3 exposure, is associated with cardiometabolic health in early adulthood.

Single inhalation exposure to polyamide micro and nanoplastic particles impairs vascular dilation without generating pulmonary inflammation in virgin female Sprague Dawley rats

BACKGROUND

Exposure to micro- and nanoplastic particles (MNPs) in humans is being identified in both the indoor and outdoor environment. Detection of these materials in the air has made inhalation exposure to MNPs a major cause for concern. One type of plastic polymer found in indoor and outdoor settings is polyamide, often referred to as nylon. Inhalation of combustion-derived, metallic, and carbonaceous aerosols generate pulmonary inflammation, cardiovascular dysfunction, and systemic inflammation. Additionally, due to the additives present in plastics, MNPs may act as endocrine disruptors. Currently there is limited knowledge on potential health effects caused by polyamide or general MNP inhalation.

OBJECTIVE

The purpose of this study is to assess the toxicological consequences of a single inhalation exposure of female rats to polyamide MNP during estrus by means of aerosolization of MNP.

METHODS

Bulk polyamide powder (i.e., nylon) served as a representative MNP. Polyamide aerosolization was characterized using particle sizers, cascade impactors, and aerosol samplers. Multiple-Path Particle Dosimetry (MPPD) modeling was used to evaluate pulmonary deposition of MNPs. Pulmonary inflammation was assessed by bronchoalveolar lavage (BAL) cell content and H&E-stained tissue sections. Mean arterial pressure (MAP), wire myography of the aorta and uterine artery, and pressure myography of the radial artery was used to assess cardiovascular function. Systemic inflammation and endocrine disruption were quantified by measurement of proinflammatory cytokines and reproductive hormones.

RESULTS

Our aerosolization exposure platform was found to generate particles within the micro- and nano-size ranges (thereby constituting MNPs). Inhaled particles were predicted to deposit in all regions of the lung; no overt pulmonary inflammation was observed. Conversely, increased blood pressure and impaired dilation in the uterine vasculature was noted while aortic vascular reactivity was unaffected. Inhalation of MNPs resulted in systemic inflammation as measured by increased plasma levels of IL-6. Decreased levels of 17β-estradiol were also observed suggesting that MNPs have endocrine disrupting activity.

CONCLUSIONS

These data demonstrate aerosolization of MNPs in our inhalation exposure platform. Inhaled MNP aerosols were found to alter inflammatory, cardiovascular, and endocrine activity. These novel findings will contribute to a better understanding of inhaled plastic particle toxicity.

Unique regulatory roles of ncRNAs changed by PM2.5 in human diseases

PM_2.5 is a type of particulate matter with an aerodynamic diameter smaller than 2.5 µm, and exposure to PM_2.5 can adversely damage human health. PM_2.5 may impair health through oxidative stress, inflammatory reactions, immune function alterations and chromosome or DNA damage. Through increasing in-depth studies, researchers have found that noncoding RNAs (ncRNAs), particularly microRNAs (miRNAs), circular RNAs (circRNAs) as well as long noncoding RNAs (lncRNAs), might play significant roles in PM_2.5-related human diseases via some of the abovementioned mechanisms. Therefore, in this review, we mainly discuss the regulatory function of ncRNAs altered by PM_2.5 in human diseases and summarize the potential molecular mechanisms. The findings reveal that these ncRNAs might induce or promote diseases via inflammation, the oxidative stress response, cell autophagy, apoptosis, cell junction damage, altered cell proliferation, malignant cell transformation, disruption of synaptic function and abnormalities in the differentiation and status of immune cells. Moreover, according to a bioinformatics analysis, the altered expression of potential genes caused by these ncRNAs might be related to the development of some human diseases. Furthermore, some ncRNAs, including lncRNAs, miRNAs and circRNAs, or processes in which they are involved may be used as biomarkers for relevant diseases and potential targets to prevent these diseases. Additionally, we performed a meta-analysis to identify more promising diagnostic ncRNAs as biomarkers for related diseases.

Long-term exposure to ambient fine particulate matter chemical composition and in-hospital case fatality among patients with stroke in China

Background

There is little evidence on the association between PM_2.5 chemical components and fatality among hospitalized stroke patients.

Methods

This study used an inpatient discharge database from 2013 to 2019 in four provinces (Sichuan, Shanxi, Guangxi, and Guangdong) in China. Annual average exposure to PM_2.5 and its five chemical components [black carbon (BC), organic matter (OM), sulphate ( S O 4 2 - ), nitrate ( N O 3 - ), and ammonium ( N H 4 + )] were estimated using bilinear interpolation at patient's residential address. Mixed-effects logistic regression models were conducted to estimate the odds ratios (ORs). Counterfactual analyses were used to estimate the population attributable burden (PAF).

Findings

Among 3,069,093 hospitalized patients with stroke, each interquartile (IQR) increment in PM_2.5 and its chemical components was significantly associated with stroke fatality: the ORs were 1.137 [95% confidence interval (CI): 1.118-1.157; IQR: 15.14 μg/m³] for PM_2.5, 1.108 (95% CI: 1.091-1.126; IQR: 0.71 μg/m³) for BC, 1.086 (95% CI: 1.069-1.104; IQR: 3.47 μg/m³) for OM, and 1.065 (95% CI: 1.048-1.083; IQR: 2.81 μg/m³) for S O 4 2 - . We did not find significant associations for N O 3 - (OR: 0.991, 95% CI: 0.975-1.008; IQR: 3.30 μg/m³). The associations were larger among patients with ischemic stroke than those with hemorrhagic stroke. The PAFs were 10.6% (95% CI: 9.1-12.2%) for BC, 9.9% (95% CI: 8.2-11.7%) for OM, and 6.6% (4.9-8.3%) for S O 4 2 - .

Interpretation

Ambient BC, OM, and S O 4 2 - might be important risk factors for stroke fatality. The findings advocate the need to develop tailored guidelines for PM chemical components and curb the emissions of the most hazardous chemical components.

Funding

Bill & Melinda Gates Foundation (INV-016826).

Impacts of long-term ambient particulate matter and gaseous pollutants on circulating biomarkers of inflammation in male and female health professionals

BACKGROUND

Systemic inflammation may serve as a biological mechanism linking air pollution to poor health but supporting evidence from studies of long-term pollutant exposure and inflammatory cytokines is inconsistent.

OBJECTIVE

We studied associations between multiple particulate matter (PM) and gaseous air pollutants and pro- and anti-inflammatory cytokines within two nationwide cohorts of men and women.

METHODS

Data were obtained from 16,151 women in the Nurses' Health Study and 7,930 men in the Health Professionals' Follow-up Study with at least one measure of circulating adiponectin, C-Reactive Protein (CRP), Interleukin-6 (IL-6) or soluble tumor necrosis-factor receptor-2 (sTNFR-2). Exposure to PM with aerodynamic diameter ≤2.5, 2.5-10, and ≤10 μm (PM2.5, PM2.5-10, PM10) and nitrogen dioxide (NO2) was estimated using spatio-temporal models and were linked to participants' addresses at the time of blood draw. Averages of the 1-, 3-, and 12-months prior to blood draw were examined. Associations between each biomarker and pollutant were estimated from linear regression models adjusted for individual and contextual covariates.

RESULTS

In adjusted models, we observed a 2.72% (95% CI: 0.43%, 5.95%), 3.11% (-0.12%, 6.45%), and 3.67% (0.19%, 7.26%) increase in CRP associated with a 10 μg/m3 increase in 1-, 3-, and 12- month averaged NO2 in women. Among men, there was a statistically significant 5.96% (95% CI: 0.07%, 12.20%), 6.99% (95% CI: 0.29%, 14.15%), and 8.33% (95% CI: 0.35%, 16.94%) increase in CRP associated with a 10 μg/m3 increase in 1-, 3-, and 12-month averaged PM2.5-10, respectively. Increasing PM2.5-10 was associated with increasing IL-6 and sTNFR-2 among men over shorter exposure durations. There were no associations with exposures to PM2.5 or PM10, or with adiponectin. Findings were robust to sensitivity analyses restricting to disease-free controls and non-movers.

CONCLUSIONS

Across multiple long-term pollutant exposures and inflammatory markers, associations were generally weak. Focusing on specific pollutant-inflammatory mechanisms may clarify pathways.

Exposure to ambient gaseous pollutant and daily hospitalizations for Sjögren's syndrome in Hefei: A time-series study

OBJECTIVE

Increasing evidence suggested that gaseous pollutants were associated with the development of autoimmune diseases, while there were few studies on the association between gaseous pollutants and Sjögren's syndrome (SS). This study sought to assess the relationship between exposure to several gaseous pollutants and the hospitalizations for SS.

METHODS

The data regarding SS hospitalizations, gaseous pollutants, and meteorological factors in Hefei from 2016 to 2021 were collected. A distributed lag non-linear model combined with a generalized linear model were adopted to analyze the association between gaseous pollutants and SS hospitalizations, and stratified analyses were also conducted.

RESULTS

We detected significant associations between gaseous pollutants (NO2, SO2, O3, CO) and SS hospitalizations. Exposure to NO2 was linked with the elevated risk of hospitalizations for SS (RR=1.026, lag1 day). A positive correlation between CO exposure and hospitalizations for SS was found (RR=1.144, lag2 day). In contrast, exposure to SO2, O3 was respectively related to the decreased risk of hospitalizations for SS (SO2: RR=0.897, lag14 day; O3: RR=0.992, lag9 day). Stratified analyses found that female patients were more vulnerable to these gaseous pollutants. SS patients ≥ 65 years were more susceptible to NO2, CO exposure, and younger patients were more vulnerable to O3 exposure. In addition, exposure to O3, CO in cold season were more likely to affect hospitalizations for SS.

CONCLUSION

Our results demonstrated a significant association between exposure to NO2, CO and elevated risk of hospitalizations for SS, and SO2, O3 exposure might be linked to reduced risk of SS hospitalizations.

The effect of air pollution on systemic lupus erythematosus: A systematic review and meta-analysis

BACKGROUND

Systemic lupus erythematosus (SLE) is an autoimmune disease resulting from impaired inflammatory responses. Given the role of air pollution on increasing inflammatory mediators, thus, we aimed to systematically review and meta-analyze evidence regarding an association between short-term exposure to air pollution and SLE onset, activity, and hospitalization.

METHODS

Electronic databases including Web of Science, PubMed, Scopus, and Embase were searched for all published articles until July 5, 2021. Newcastle Ottawa Scale (NOS) checklist was used to assess the quality of individual studies. Relevant demographic data and the intended results of the selected studies were extracted, and their adjusted risk ratios (RRs) were pooled using random and fixed effect analysis based on the heterogeneity index.

FINDINGS

Twelve studies were entered in our systematic review, and finally, six publications were enrolled in meta-analysis. Overall, Meta-analysis showed no significant association between an increase of PM_2.5 on the third day and SLEDAI score with pooled adjusted RR of 1.212 (95% CI, 0,853-1.721), p-value = 0.284. However, there was a positive relationship between 6 days increase of Particulate matter (PM) 2.5 and the systemic lupus erythematosus disease activity Index (SLEDAI) score (pooled adjusted RR 1.112; 95% CI, 1.005-1.231), p-value = 0.040. There was no significant association between carbon monoxide (CO), nitrogen dioxide (NO₂), PM_2.5, and PM₁₀ increase in the air and hospitalization of SLE patients with pooled RR of 1.021 (95% CI, 0,986-1.1.057), p-value = 0.249, 1.034 (95% CI, 0.996-1.068); p-value = 0.079, 1.042 (95% CI, 0.994-1.092); p-value = 0.084 and 1.004 (95% CI, 0.996-1.013); p-value = 0.323, respectively. Also, analysis showed a significant relation between ozone (O₃) increase and hospitalization with a pooled RR of 1.076 (95% CI, 1.009-1.147); p-value = 0.025. Finally, analysis of SO₂ increase and risk of hospitalization demonstrated no significant relationship with the pooled RR of 1.011; (95% CI, 0.962-1.062), p-value = 0.0.671.

CONCLUSION

Our findings prove that PM_2.5 was associated with increased SLE risk. We also showed that only O₃ was associated with increased hospital admissions of SLE patients.

Fine and ultrafine airborne PM influence inflammation response of young adults and toxicological responses in vitro

Little evidence is available regarding the impact of different sizes of inhaled particulate matter (PM) on inflammatory responses in healthy young adults in connection with toxicological responses. We conducted a five-time repeated measurement panel study on 88 healthy young college students in Guangzhou, China from December 2017 to January 2018. Blood samples were collected from each participant and tested for tumor necrosis factor alpha (TNF-α) levels every week for 5 consecutive weeks. Mass concentrations of ambient PM_2.5, PM₁, PM_0.5 and number concentrations of ambient PM_0.1 were measured. RAW 264.7 macrophages were exposed to PM (PM_10-2.5, PM_2.5-1, PM_1-0.2, PM_0.2) collected at the same time as the panel study. Cytotoxicity, oxidation and inflammatory parameters, cell cycle and genotoxicity were tested. Particles were characterized for their chemical composition. The trends of associations between PM_2.5, PM₁, PM_0.5 and TNF-α level were consistent in lag 0 and 3 days, and the relative risk decreased as the particle size decreased. All the ambient air pollutants had the similar change trends in lag 1, 4 and 5 days. Similar results in RAW 264.7 macrophages were found; PM_10-2.5 induced the greatest TNF-α and macrophage inflammatory protein 2 (MIP-2) productions and oxidative damage. PM_1-0.2 and PM_0.2 induced more significant dose-dependent increases of cell cycle and genotoxic response. In the component concentrations of PM samples, metal elements were PM_10-2.5 > PM_2.5-1 > PM_0.2 ≥ PM_1-0.2; ions and polycyclic aromatic hydrocarbons (PAHs) were PM_0.2 > PM_1-0.2 > PM_2.5-1 > PM_10-2.5. Our results suggested that exposure to all particle sizes was significantly associated with inflammation among healthy young adults and toxicological responses in RAW 264.7 macrophages. Different human and toxicological reactions caused by PM samples indicated the importance of investigating various particle sizes.

Exposure to Long-Term Air Pollution and Incidence of Peripheral Arterial Disease in the General Population: A Korean National Population-Based Retrospective Cohort Study

This study aimed to evaluate the causal relationship between long-term outdoor air pollutants and incidence of peripheral arterial disease (PAD) using the Korean National Health Insurance Service-National Sample Cohort (NHIS-NSC) database. We included 292,091 subjects from the general population who had previously not been diagnosed with PAD by the NHIS-NSC between 2008 and 2014. Hourly air pollutant data (particulate and gaseous) and climate data were collected. Correlation analysis of the collected data confirmed the relationship between air pollution and PAD incidence. For 1,836,965.4 person-years, incident cases of PAD were observed in 5243 subjects (285.4/100,000 person-years). In the Cox proportional hazard analysis, exposure to long-term average concentration of sulfur dioxide (SO2) [hazard ratio (HR), 1.686; (95% confidence interval (CI), 1.108–2.565) for .01ppm] and nitrogen dioxide (NO2) [HR, 1.200; (95% CI, 1.077–1.336) for .01 ppm] significantly increased the risk of PAD occurrence after the adjustment for several variables. This study demonstrated that SO2 and NO2 exposure are independent predictors of PAD.

Cardiovascular effects of traffic-related air pollution: A multi-omics analysis from a randomized, crossover trial

A system-wide cardiovascular response to traffic-related air pollution (TRAP) has been rarely described. To systemically understand the mechanisms underlying cardiovascular effects of TRAP, we conducted a randomized, crossover trial in 56 young adults, who engaged in two 4-hour exposure sessions on a main road and in a park, alternately. We measured personal exposures to traffic-related air pollutants (TRAPs), including fine and ultrafine particulate matter, black carbon, nitrogen dioxide, and carbon monoxide. Lipidomics, targeted proteomics, urine metabolomics, targeted biomarkers, ambulatory blood pressure and electrocardiogram were measured. We used linear mixed-effects models to estimate the associations. The exposures to TRAPs except for fine particulate matter in the road session were 2-3 times higher. We observed elevated blood pressure and decreased heart rate variability (HRV) after TRAP exposure, accompanied by dozens of molecular alterations involving systemic inflammation, oxidative stress, endothelial dysfunction, coagulation, and lipid metabolism. Pathways like vascular smooth muscle cell proliferation and biomarkers like trimethylamine N-Oxide might also be disturbed. Some of these TRAP-related molecular biomarkers were also associated with changes of blood pressure or HRV. Our results provided systematical mechanistic profiling for the cardiovascular effects of TRAP using multi omics, which may have implications in TRAP control.

The Impact of Fine Particulate Matter 2.5 on the Cardiovascular System: A Review of the Invisible Killer

Air pollution exerts several deleterious effects on the cardiovascular system, with cardiovascular disease (CVD) accounting for 80% of all premature deaths caused by air pollution. Short-term exposure to particulate matter 2.5 (PM_2.5) leads to acute CVD-associated deaths and nonfatal events, whereas long-term exposure increases CVD-associated risk of death and reduces longevity. Here, we summarize published data illustrating how PM_2.5 may impact the cardiovascular system to provide information on the mechanisms by which it may contribute to CVDs. We provide an overview of PM_2.5, its associated health risks, global statistics, mechanistic underpinnings related to mitochondria, and hazardous biological effects. We elaborate on the association between PM_2.5 exposure and CVD development and examine preventive PM_2.5 exposure measures and future strategies for combating PM_2.5-related adverse health effects. The insights gained can provide critical guidelines for preventing pollution-related CVDs through governmental, societal, and personal measures, thereby benefitting humanity and slowing climate change.

Long-Term Inhalation of Ultrafine Zinc Particles Deteriorated Cardiac and Cardiovascular Functions in Rats of Myocardial Infarction

Substantial ultrafine zinc particles exist in air pollutions. The level of Zn concentrations in serum and tissue could affect patients with myocardial infarction (MI). The aim of the study is to investigate the change of cardiac functions and peripheral hemodynamics in MI rats after long-term inhalation of ultrafine Zn particles. Coronary artery ligation surgery was performed to induce MI in Wistar rats. The inhalation of ultrafine Zn particles was carried out for 6 weeks after the operation. Physiological and hemodynamic measurements and computational biomechanics analysis were demonstrated in eight groups of rats at postoperative 4 and 6 weeks. There was no statistical significance between shams and shams with inhalation of ultrafine Zn particles. There were significant impairments of cardiac and hemodynamic functions in MI rats. In comparison with MI rats, the inhalation of ultrafine Zn particles for 4 weeks slowed down the progression from MI to heart failure, but the inhalation for 6 weeks accelerated the process. The long-term inhalation of ultrafine zinc particles induced excessive accumulation of zinc in serum and tissue, which deteriorated cardiac and hemodynamic dysfunctions in MI rats. The findings suggested the importance for regulating Zn intake of MI patients as well as looking at ways to lower zinc concentrations in air pollutions.

Short-term exposure to nitrogen dioxide and ischemic stroke incidence in Shenzhen, China: Modification effects by season and temperature

BACKGROUND AND OBJECTIVES

China has experienced a serious public health burden because of the increased incidence of ischemic stroke. Evidence describing the association between short-term exposure to nitrogen dioxide (NO₂) and ischemic stroke morbidity is limited, and few studies have focused on the effects of season and temperature. This study aimed to evaluate the acute effects of NO₂ on ischemic stroke incidence in Shenzhen, a southeastern city of China, considering the modified effects of season and temperature.

METHODS

A time-stratified case-crossover study was conducted between 2003 and 2014 among 98,482 ischemic stroke hospitalizations. Conditional quasi-Poisson regression was used to estimate the percentage changes in ischemic stroke admissions in relation to each 10 μg/m³ increment in NO₂.

RESULTS

NO₂ was positively associated with ischemic stroke onset over the full year, as well as in the cold season (November through April) and on cold days (ambient temperature≤median temperature), with significant single-day effects within 3 days after the exposure, and significant cumulative effects within the delayed five days. The maximum percentage changes were obtained at lag0-5, with 1.81% (95% confidence interval (CI) was 0.86-2.76%) over the full year, 2.75% (1.48-4.03%) in the cold season, and 3.04% (1.74-4.35%) on cold days. Additionally, the effects of exposure were found to be greater in males and people with higher education, and were lasting longer in subgroups of older individuals.

CONCLUSIONS

Our findings provide evidence that reductions in NO₂ levels might decrease ischemic stroke morbidity, and enhance the understanding of ischemic stroke occurrence associated with NO₂ modified by season and temperature.

Protective actions of nuclear factor erythroid 2-related factor 2 (NRF2) and downstream pathways against environmental stressors

Environmental risk factors, including noise, air pollution, chemical agents, ultraviolet radiation (UVR) and mental stress have a considerable impact on human health. Oxidative stress and inflammation are key players in molecular pathomechanisms of environmental pollution and risk factors. In this review, we delineate the impact of environmental risk factors and the protective actions of the nuclear factor erythroid 2-related factor 2 (NRF2) in connection to oxidative stress and inflammation. We focus on well-established studies that demonstrate the protective actions of NRF2 and its downstream pathways against different environmental stressors. State-of-the-art mechanistic considerations on NRF2 signaling are discussed in detail, e.g. classical concepts like KEAP1 oxidation/electrophilic modification, NRF2 ubiquitination and degradation. Specific focus is also laid on NRF2-dependent heme oxygenase-1 induction with detailed presentation of the protective down-stream pathways of heme oxygenase-1, including interaction with BACH1 system. The significant impact of all environmental stressors on the circadian rhythm and the interactions of NRF2 with the circadian clock will also be considered here. A broad range of NRF2 activators is discussed in relation to environmental stressor-induced health side effects, thereby suggesting promising new mitigation strategies (e.g. by nutraceuticals) to fight the negative effects of the environment on our health.

Registered human trials addressing environmental and occupational toxicant exposures: Scoping review of immunological markers and protective strategies

Exposure to pollution is a worldwide societal challenge participating in the etiology and progression of different diseases. However, the scarce information hinders our understanding of the actual level of human exposure and its specific effects. Inadequate and excessive immune responses underlie diverse chronic diseases. Yet, it is unclear which and how toxicant exposures affect the immune system functions. There is a multiplicity of immunological outcomes and biomarkers being studied in human trials related to exposure to different toxicants but still without clear evidence of their value as biomarkers of exposure or effect. The main aim of this study was to collect scientific evidence and identify relevant immunological biomarkers used at the clinical level for toxicant exposures. We used the platform clinical trials.gov as a database tool. First, we performed a search combining research items related to toxicants and immunological parameters. The resulting117 clinical trials were examined for immune-related outcomes and specific biomarkers evaluated in subjects exposed to occupational and environmental toxicants. After categorization, relevant immunological outcomes and biomarkers were identified related to systemic and airway inflammation, modulation of immune cells, allergy and autoimmunity. In general, the immune markers related to inflammation are more frequently investigated for exposure to pollutants, namely IL-6, C-reactive protein (CRP) and nitric oxide (NO). Nevertheless, the data also indicated that prospective biomarkers of effect are gaining ground and a guiding representation of the established and novel biomarkers is suggested for upcoming trials. Finally, potential protective strategies to mitigate the adverse effects of specific toxicants are underlined for future studies.

A controlled chamber study of effects of exposure to diesel exhaust particles and noise on heart rate variability and endothelial function

BACKGROUND

Adverse cardiovascular effects are associated with both diesel exhaust and road traffic noise, but these exposures are hard to disentangle epidemiologically. We used an experimental setup to evaluate the impact of diesel exhaust particles and traffic noise, alone and combined, on intermediary outcomes related to the autonomic nervous system and increased cardiovascular risk.

METHODS

In a controlled chamber 18 healthy adults were exposed to four scenarios in a randomized cross-over fashion. Each exposure scenario consisted of either filtered (clean) air or diesel engine exhaust (particle mass concentrations around 300 µg/m³), and either low (46 dB(A)) or high (75 dB(A)) levels of traffic noise for 3 h at rest. ECG was recorded for 10-min periods before and during each exposure type, and frequency-domain heart rate variability (HRV) computed. Endothelial dysfunction and arterial stiffness were assessed after each exposure using EndoPAT 2000.

RESULTS

Compared to control exposure, HRV in the high frequency band decreased during exposure to diesel exhaust, both alone and combined with noise, but not during noise exposure only. These differences were more pronounced in women. We observed no synergistic effects of combined exposure, and no significant differences between exposure scenarios for other HRV indices, endothelial function or arterial stiffness.

CONCLUSION

Three-hour exposure to diesel exhaust, but not noise, was associated with decreased HRV in the high frequency band. This indicates activation of irritant receptor-mediated autonomic reflexes, a possible mechanism for the cardiovascular risks of diesel exposure. There was no effect on endothelial dysfunction or arterial stiffness after exposure.

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

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

The pro-inflammatory effects of combined exposure to diesel exhaust particles and mineral particles in human bronchial epithelial cells

BACKGROUND

People are exposed to ambient particulate matter (PM) from multiple sources simultaneously in both environmental and occupational settings. However, combinatory effects of particles from different sources have received little attention in experimental studies. In the present study, the pro-inflammatory effects of combined exposure to diesel exhaust particles (DEP) and mineral particles, two common PM constituents, were explored in human lung epithelial cells.

METHODS

Particle-induced secretion of pro-inflammatory cytokines (CXCL8 and IL-1β) and changes in expression of genes related to inflammation (CXCL8, IL-1α, IL-1β and COX-2), redox responses (HO-1) and xenobiotic metabolism (CYP1A1 and CYP1B1) were assessed in human bronchial epithelial cells (HBEC3-KT) after combined exposure to different samples of DEP and mineral particles. Combined exposure was also conducted using lipophilic organic extracts of DEP to assess the contribution of soluble organic chemicals. Moreover, the role of the aryl hydrocarbon receptor (AhR) pathway was assessed using an AhR-specific inhibitor (CH223191).

RESULTS

Combined exposure to DEP and mineral particles induced increases in pro-inflammatory cytokines and expression of genes related to inflammation and redox responses in HBEC3-KT cells that were greater than either particle sample alone. Moreover, robust increases in the expression of CYP1A1 and CYP1B1 were observed. The effects were most pronounced after combined exposure to α-quartz and DEP from an older fossil diesel, but enhanced responses were also observed using DEP generated from a modern biodiesel blend and several stone particle samples of mixed mineral composition. Moreover, the effect of combined exposure on cytokine secretion could also be induced by lipophilic organic extracts of DEP. Pre-incubation with an AhR-specific inhibitor reduced the particle-induced cytokine responses, suggesting that the effects were at least partially dependent on AhR.

CONCLUSIONS

Exposure to DEP and mineral particles in combination induces enhanced pro-inflammatory responses in human bronchial epithelial cells compared with exposure to the individual particle samples. The effects are partly mediated through an AhR-dependent pathway and lipophilic organic chemicals in DEP appear to play a central role. These possible combinatory effects between different sources and components of PM warrant further attention and should also be considered when assessing measures to reduce PM-induced health effects.

Environmental exposure to volatile organic compounds is associated with endothelial injury

OBJECTIVE

Volatile organic compounds (VOCs) are airborne toxicants abundant in outdoor and indoor air. High levels of VOCs are also present at various Superfund and other hazardous waste sites; however, little is known about the cardiovascular effects of VOCs. We hypothesized that ambient exposure to VOCs exacerbate cardiovascular disease (CVD) risk by depleting circulating angiogenic cells (CACs).

APPROACH AND RESULTS

In this cross-sectional study, we recruited 603 participants with low-to-high CVD risk and measured 15 subpopulations of CACs by flow cytometry and 16 urinary metabolites of 12 VOCs by LC/MS/MS. Associations between CAC and VOC metabolite levels were examined using generalized linear models in the total sample, and separately in non-smokers. In single pollutant models, metabolites of ethylbenzene/styrene and xylene, were negatively associated with CAC levels in both the total sample, and in non-smokers. The metabolite of acrylonitrile was negatively associated with CD45^dim/CD146⁺/CD34⁺/AC133⁺ cells and CD45⁺/CD146⁺/AC133⁺, and the toluene metabolite with AC133⁺ cells. In analysis of non-smokers (n = 375), multipollutant models showed a negative association with metabolites of ethylbenzene/styrene, benzene, and xylene with CD45^dim/CD146⁺/CD34⁺ cells, independent of other VOC metabolite levels. Cumulative VOC risk score showed a strong negative association with CD45^dim/CD146⁺/CD34⁺ cells, suggesting that total VOC exposure has a cumulative effect on pro-angiogenic cells. We found a non-linear relationship for benzene, which showed an increase in CAC levels at low, but depletion at higher levels of exposure. Sex and race, hypertension, and diabetes significantly modified VOC associated CAC depletion.

CONCLUSION

Low-level ambient exposure to VOCs is associated with CAC depletion, which could compromise endothelial repair and angiogenesis, and exacerbate CVD risk.

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

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

Travelling with heart failure: risk assessment and practical recommendations

Patients with heart failure are at a higher risk of cardiovascular events compared with the general population, particularly during domestic or international travel. Patients with heart failure should adhere to specific recommendations during travel to lower their risk of developing heart failure symptoms. In this Review, we aim to provide clinicians with a set of guidelines for patients with heart failure embarking on national or international travel. Considerations when choosing a travel destination include travel distance and time, the season upon arrival, air pollution levels, jet lag and altitude level because all these factors can increase the risk of symptom development in patients with heart failure. In particular, volume depletion is of major concern while travelling given that it can contribute to worsening heart failure symptoms. Pre-travel risk assessment should be performed by a clinician 4-6 weeks before departure, and patients should receive advice on potential travel-related illness and on strategies to prevent volume depletion. Oxygen supplementation might be useful for patients who are very symptomatic. Upon arrival at the destination, potential drug-induced photosensitivity (particularly in tropical destinations) and risks associated with the local cuisine require consideration. Special recommendations are needed for patients with cardiac implantable electronic devices or left ventricular assist devices as well as for those who have undergone major cardiac surgery.

The Relationship Between Ambient Air Pollution and Hospitalizations for Gout in a Humid Subtropical Region of China

Objective

Gout is a chronic disease caused by the deposition of sodium urate (MSU) crystals. Available data on the association between environmental hazards and gout are scarce. The present study was present to investigate the relationship between short-term exposure to air pollution and hospitalizations for acute gout from 2016 to 2020 in Anqing City, China.

Methods

Daily records of hospital admissions for acute gout in Anqing from 1 January 2016 to 31 December 2020 were retrieved from the tertiary first-class hospitals in Anqing. Air pollutants and meteorological data were obtained from the China Environmental Monitoring Station and China Meteorological Data Service Center respectively. We used a time-series analysis to explore the association between air pollution (NO₂, O₃, and CO) and hospitalizations for acute gout, and conducted stratified analyses by gender, age and season.

Results

We observed an association between NO₂ and hospitalizations for gout (lag 0, relative risk (RR):1.022, 95% confidence interval (CI):1.004-1.041). For every 1 mg/m³ increase in CO concentration, hospitalizations for gout increased by 3.9% (lag 11 days, RR=1.039, 95% CI: 1.004-1.076). Intriguingly, there was a negative association between O₃ and hospitalizations for gout (lag0, RR=0.986, 95% CI: 0.976-0.996). Stratified analyses showed that exposure to high levels of NO₂ was considered to be more vulnerable to gout in cold season.

Conclusion

Our study showed that short-term exposure to NO₂ and CO has a significant effect on hospitalizations for acute gout.

Short-Term Association of Air Pollutant Levels and Hospital Admissions for Stroke and Effect Modification by Apparent Temperature: Evidence From Shanghai, China

The epidemiological evidence on relationships between air pollution, temperature, and stroke remains inconclusive. Limited evidence is available for the effect modification by apparent temperature, an indicator reflecting reactions to the thermal environment, on short-term associations between air pollution and hospital admissions for stroke. We used a generalized additive model with Poisson regression to estimate the relative risk (RR) of stroke admissions in Shanghai, China, between 2014 and 2016 associated with air pollutants, with subgroup analyses by age, sex, apparent temperature, and season. During the study period, changes in the daily number of stroke admissions per 10 μg/m³ increase in nitrogen dioxide (at lags 0, 1, 0–1, and 0–2) ranged from 1.05 (95% CI: 0.82%, 2.88%) to 2.24% (95% CI: 0.84%, 3.65%). For each 10 μg/m³ increase in sulfur dioxide concentrations at lags 1, 2, 0–1, and 0–2, the RR of daily stroke admissions increased by 3.34 (95% CI: 0.955%, 5.79%), 0.32 (95% CI: −1.97%, 2.67%), 3.33 (95% CI: 0.38%, 6.37%), and 2.86% (95% CI: −0.45%, 6.28%), respectively. The associations of same-day exposure to nitrogen dioxide with stroke admissions remained significant after adjustment for ozone levels. These associations were not modified by sex, age, apparent temperature, or season. More research is warranted to determine whether apparent temperature modifies the associations between air pollution and stroke admissions.

Environmental risk factors and cardiovascular diseases: a comprehensive review

Noncommunicable diseases (NCDs) are fatal for more than 38 million people each year and are thus the main contributors to the global burden of disease accounting for 70% of mortality. The majority of these deaths are caused by cardiovascular disease. The risk of NCDs is strongly associated with exposure to environmental stressors such as pollutants in the air, noise exposure, artificial light at night and climate change, including heat extremes, desert storms and wildfires. In addition to the traditional risk factors for cardiovascular disease such as diabetes, arterial hypertension, smoking, hypercholesterolemia and genetic predisposition, there is a growing body of evidence showing that physicochemical factors in the environment contribute significantly to the high NCD numbers. Furthermore, urbanization is associated with accumulation and intensification of these stressors. This comprehensive expert review will summarize the epidemiology and pathophysiology of environmental stressors with a focus on cardiovascular NCDs. We will also discuss solutions and mitigation measures to lower the impact of environmental risk factors with focus on cardiovascular disease.

Acute exposure to diesel affects inflammation and vascular function

Background

Diesel exhaust fumes represent one of the most common toxic pollutants. The prolonged effects of acute exposure to this pollutant on inflammatory status and vascular properties are unknown.

Methods

During a 2-h session, 40 healthy subjects were exposed to diesel exhaust fumes and/or filtered air. Endothelial function was assessed with flow mediated dilation, arterial stiffness with pulse wave velocity and reflected waves with augmentation index. C-reactive protein, fibrinogen, protein C levels and protein S activity were also measured. Standard deviation of normal to normal R–R intervals (SDNN) was used to assess heart rate variability. Measurements were assessed before exposure and 2 and 24 h after diesel exposure.

Results

Compared with filtered air, exposure to diesel exhaust fumes decreased flow mediated dilation and increased pulse wave velocity and augmentation index up to 24 h after the exposure (p &lt; 0.001 for all). Similarly, compared with filtered air, diesel exhaust exposure impaired SDNN during the 24-h study period (p = 0.007). C-reactive protein and fibrinogen levels were significantly increased after diesel exhaust exposure while protein C levels and protein S activity decreased (p &lt; 0.01 for all). Exposure to diesel exhaust fumes resulted in higher C-reactive protein concentration in smokers compared with non-smokers (p &lt; 0.001).

Conclusion

Short-term exposure to diesel exhaust fumes has a prolonged adverse impact on endothelial function and vascular wall properties, along with impaired heart rate variability, abnormal fibrinolytic activity and increased markers of inflammation. These findings give insights into the mechanisms underlining the increased cardiovascular risk of subjects regularly exposed to diesel exhaust fumes.

Air pollution and cardiovascular disease: Can the Australian bushfires and global COVID-19 pandemic of 2020 convince us to change our ways?

Air pollution is a major global challenge for a multitude of reasons. As a specific concern, there is now compelling evidence demonstrating a causal relationship between exposure to airborne pollutants and the onset of cardiovascular disease (CVD). As such, reducing air pollution as a means to decrease cardiovascular morbidity and mortality should be a global health priority. This review provides an overview of the cardiovascular effects of air pollution and uses two major events of 2020-the Australian bushfires and COVID-19 pandemic lockdown-to illustrate the relationship between air pollution and CVD. The bushfires highlight the substantial human and economic costs associated with elevations in air pollution. Conversely, the COVID-19-related lockdowns demonstrated that stringent measures are effective at reducing airborne pollutants, which in turn resulted in a potential reduction in cardiovascular events. Perhaps one positive to come out of 2020 will be the recognition that tough measures are effective at reducing air pollution and that these measures have the potential to stop thousands of deaths from CVD.

Alterations to the urinary metabolome following semi-controlled short exposures to ultrafine particles at a major airport

BACKGROUND

Inflammation, oxidative stress and reduced cardiopulmonary function following exposure to ultrafine particles (UFP) from airports has been reported but the biological pathways underlying these toxicological endpoints remain to be explored. Urinary metabolomics offers a robust method by which changes in cellular pathway activity can be characterised following environmental exposures.

OBJECTIVE

We assessed the impact of short-term exposures to UFP from different sources at a major airport on the human urinary metabolome.

METHODS

21 healthy, non-smoking volunteers (aged 19-27 years) were repeatedly (2-5 visits) exposed for 5h to ambient air at Amsterdam Airport Schiphol, while performing intermittent, moderate exercise. Pre- to-post exposure changes in urinary metabolite concentrations were assessed via 1H NMR spectroscopy and related to total and source-specific particle number concentrations (PNC) using linear mixed effects models.

RESULTS

Total PNC at the exposure site was on average, 53,500 particles/cm3 (range 10,500-173,200) and associated with significant reductions in urinary taurine (-0.262 AU, 95% CI: -0.507 to -0.020) and dimethylamine concentrations (-0.021 AU, 95% CI: -0.040 to -0.067). Aviation UFP exposure accounted for these changes, with the reductions in taurine and dimethylamine associating with UFP produced during both aircraft landing and take-off. Significant reductions in pyroglutamate concentration were also associated with aviation UFP specifically, (-0.005 AU, 95% CI: -0.010 - <0.000) again, with contributions from both landing and take-off UFP exposure. While non-aviation UFPs induced small changes to the urinary metabolome, their effects did not significantly impact the overall response to airport UFP exposure.

DISCUSSION

Following short-term exposures at a major airport, aviation-related UFP caused the greatest changes to the urinary metabolome. These were consistent with a heightened antioxidant response and altered nitric oxide synthesis. Although some of these responses could be adaptive, they appeared after short-term exposures in healthy adults. Further study is required to determine whether long-term exposures induce injurious effects.

Oxidative Stress Biomarkers in the Relationship between Type 2 Diabetes and Air Pollution

The incidence and prevalence of type 2 diabetes have increased in the last decades and are expected to further grow in the coming years. Chronic hyperglycemia triggers free radical generation and causes increased oxidative stress, affecting a number of molecular mechanisms and cellular pathways, including the generation of advanced glycation end products, proinflammatory and procoagulant effects, induction of apoptosis, vascular smooth-muscle cell proliferation, endothelial and mitochondrial dysfunction, reduction of nitric oxide release, and activation of protein kinase C. Among type 2 diabetes determinants, many data have documented the adverse effects of environmental factors (e.g., air pollutants) through multiple exposure-induced mechanisms (e.g., systemic inflammation and oxidative stress, hypercoagulability, and endothelial and immune responses). Therefore, here we discuss the role of air pollution in oxidative stress-related damage to glycemic metabolism homeostasis, with a particular focus on its impact on health. In this context, the improvement of new advanced tools (e.g., omic techniques and the study of epigenetic changes) may provide a substantial contribution, helping in the evaluation of the individual in his biological totality, and offer a comprehensive assessment of the molecular, clinical, environmental, and epidemiological aspects.

The health effects of wearing facemasks on cardiopulmonary system of healthy young adults: A double-blinded, randomized crossover trial

BACKGROUND

Facemask had increasingly been utilized as a personal protective measure to reduce exposure to ambient particulate matter (PM) during heavily-polluted days and routine life. However, evidence on the potential effects on cardiovascular system by wearing particulate-filtering facemask was limited.

METHODS

We conducted a double-blinded randomized crossover trial (RCT) to evaluate the effects of wearing N95 facemasks on the molecular responses of cardiopulmonary system among 52 healthy college students in Beijing, China. We measured cardiopulmonary health indicators and collected biological samples before and after (up to 5 h at multiple time points) a 2-h walk to examine the changes in lung function, biomarkers of respiratory and systemic oxidative stress/inflammation. We applied linear mixed-effect models to evaluate the effect of the facemask-intervention on the health of cardio-pulmonary system.

RESULTS

In the trial wearing real facemasks, FEV₁ increased by 2.05% (95% CI: 0.27%-3.87%), 2.80% (95% CI: 1.00%-4.63%), and 2.87% (95% CI: 1.07%-4.70%) at V1 (30-min), V2 (3-h), and V3 (5-h) after the 2-h walk outsides, respectively. Compared with participants wearing the sham mask, the percentage change of nitrate in EBC was lower among those wearing the real mask. After the 2-h exposure, urinary MDA levels increased compared to the baseline in both trials. Real trial was lower than sham trial for 6 cytokines (i.e., IL-6, IL-10, IL-13, IL-17A, IFN-γ and TNF-α) in serum at 5-h post-exposure. Wearing facemasks on polluted days produced better improvement, however, on cleaner days, the improvement was weaker.

CONCLUSIONS

Short-term use of N95 facemasks appeared to effectively reduce the levels of lung function declines, the respiratory oxidative stress, and the systemic inflammation/oxidative stress which may be induced by short-term exposure to PM. Wearing facemasks on polluted days (PM_2.5 > 75 μg/m³) presented larger beneficial effects on the cardiopulmonary health than in clean days (PM_2.5 < 75 μg/m³).

Acute cardiovascular effects of controlled exposure to dilute Petrodiesel and biodiesel exhaust in healthy volunteers: a crossover study

BACKGROUND

Air pollution derived from combustion is associated with considerable cardiorespiratory morbidity and mortality in addition to environmental effects. Replacing petrodiesel with biodiesel may have ecological benefits, but impacts on human health remain unquantified. The objective was to compare acute cardiovascular effects of blended and pure biodiesel exhaust exposure against known adverse effects of petrodiesel exhaust (PDE) exposure in human subjects. In two randomized controlled double-blind crossover studies, healthy volunteers were exposed to PDE or biodiesel exhaust for one hour. In study one, 16 subjects were exposed, on separate occasions, to PDE and 30% rapeseed methyl ester biodiesel blend (RME30) exhaust, aiming at PM10 300 μg/m3. In study two, 19 male subjects were separately exposed to PDE and exhaust from a 100% RME fuel (RME100) using similar engine load and exhaust dilution. Generated exhaust was analyzed for physicochemical composition and oxidative potential. Following exposure, vascular endothelial function was assessed using forearm venous occlusion plethysmography and ex vivo thrombus formation was assessed using a Badimon chamber model of acute arterial injury. Biomarkers of inflammation, platelet activation and fibrinolysis were measured in the blood.

RESULTS

In study 1, PDE and RME30 exposures were at comparable PM levels (314 ± 27 μg/m3; (PM10 ± SD) and 309 ± 30 μg/m3 respectively), whereas in study 2, the PDE exposure concentrations remained similar (310 ± 34 μg/m3), but RME100 levels were lower in PM (165 ± 16 μg/m3) and PAHs, but higher in particle number concentration. Compared to PDE, PM from RME had less oxidative potential. Forearm infusion of the vasodilators acetylcholine, bradykinin, sodium nitroprusside and verapamil resulted in dose-dependent increases in blood flow after all exposures. Vasodilatation and ex vivo thrombus formation were similar following exposure to exhaust from petrodiesel and the two biodiesel formulations (RME30 and RME100). There were no significant differences in blood biomarkers or exhaled nitric oxide levels between exposures.

CONCLUSIONS

Despite differences in PM composition and particle reactivity, controlled exposure to biodiesel exhaust was associated with similar cardiovascular effects to PDE. We suggest that the potential adverse health effects of biodiesel fuel emissions should be taken into account when evaluating future fuel policies.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01337882 /NCT01883466. Date of first enrollment March 11, 2011, registered April 19, 2011, i.e. retrospectively registered.

Exposure to ambient air pollution during pregnancy and inflammatory biomarkers in maternal and umbilical cord blood: The Healthy Start study

BACKGROUND

Air pollution exposure during pregnancy has been associated with adverse pregnancy and birth outcomes. Inflammation has been proposed as a potential link. We estimated associations between air pollution exposure during pregnancy and inflammatory biomarkers in maternal and cord blood. We evaluated whether maternal inflammation was associated with infant outcomes.

METHODS

Among 515 mother-infant dyads in the Healthy Start study (2009-2014), trimester-long, 7- and 30-day average concentrations of particulate matter ≤2.5 μm (PM2.5) and ozone (O3) during pregnancy were estimated, using inverse-distance-weighted interpolation. Inflammatory biomarkers were measured in maternal blood in mid-pregnancy (C-reactive protein [CRP], Interleukin [IL]-6, and tumor necrosis factor-α [TNFα]) and in cord blood at delivery (CRP, IL-6, IL-8, IL-10, monocyte chemoattractant protein-1 [MCP-1], and TNFα). We used linear regression to estimate associations between pollutants and inflammatory biomarkers and maternal inflammatory biomarkers and infant weight and body composition.

RESULTS

There were positive associations between PM2.5 during certain exposure periods and maternal IL-6 and TNFα. There were negative associations between recent O3 and maternal CRP, IL-6, and TNFα and positive associations between trimester-long O3 exposure and maternal inflammatory biomarkers, though some 95% confidence intervals included the null. Patterns were inconsistent for associations between PM2.5 and O3 and cord blood inflammatory biomarkers. No consistent associations between maternal inflammatory biomarkers and infant outcomes were identified.

CONCLUSIONS

Air pollution exposure during pregnancy may impact maternal inflammation. Further investigations should examine the health consequences for women and infants of elevated inflammatory biomarkers associated with air pollution exposure during pregnancy.

A Rare Presentation of Posterior Cerebral Artery Stroke With Monocular Hemianopia After Diesel Exposure

Acute ischemic stroke of the posterior cerebral artery (PCA) presents with variable symptoms that may initially make it challenging to diagnose. Common etiologies of PCA stroke include large and small artery disease, atherosclerosis, and cardioembolism. We present a 69-year-old male, initially diagnosed with sinusitis at an urgent care facility, who presented with worsening headache and peripheral vision loss following exposure to diesel vapor and exhaust. Physical examination revealed a right monocular temporal hemianopia and subsequent imaging showed infarction of the left occipital lobe. Due to the length of time between the onset of the infarct and medical treatment, angiography and physical intervention were not indicated and management was done medically. This case presents a unique exposure prior to the development of a PCA stroke, as well as an atypical visual defect and suggests that physicians should consider neuroimaging in patients with nonspecific neurological findings such as new-onset headache and vision changes.