Short time exposure to ambient ozone and associated cardiovascular effects: A panel study of healthy young adults

Physical activity alleviated associations of oxidation capacity of the atmosphere with platelet-based inflammatory indicators: findings from the Henan Rural Cohort Study

Background: several adverse effects of ozone (O3) and nitrogen dioxide (NO2) are assessed using combined oxidant capacity (Ox) and redox-weighted oxidant capacity (Owtx) as surrogates. However, the associations of oxidant capacity (Ox and Owtx) with platelet-based inflammatory indicators and the potential modifying role of physical activity (PA) remain unclear. Methods: 31 318 participants were selected from the baseline survey of the Henan Rural Cohort Study. The Ox and Owtx were calculated based on O3 and NO2. The International Physical Activity Questionnaire was used to evaluate PA. Platelet-based inflammatory indicators were obtained from the data of physical examination. Generalized linear models were applied to explore associations between atmospheric oxidation capacity indicators (O3, Ox, Owtx, and NO2) and platelet-based inflammatory indicators and whether PA modified these associations. Results: O3, Ox, and Owtx were positively associated with platelet-based inflammatory indicators (PCT, PLT, PLR, SII, MLR and SIRI). The estimated β values and 95% confidence intervals (CIs) for PLT in response to a 5 μg m-3 increment in O3, Ox, and Owtx were 19.267 × 109 L-1 (95% CI: 17.493, 21.041 × 109 L-1), 6.226 × 109 L-1 (95% CI: 5.502, 6.950 × 109 L-1), and 14.664 × 109 L-1 (95% CI: 13.101, 16.227 × 109 L-1), respectively. The corresponding values for SIRI were 0.134 × 109 L-1 (95% CI: 0.111, 0.156 × 109 L-1), 0.064 × 109 L-1 (95% CI: 0.055, 0.073 × 109 L-1), and 0.135 × 109 L-1 (95% CI: 0.115, 0.155 × 109 L-1). And similar results were observed for NO2. Furthermore, we observed positive associations of O3, Ox, Owtx, and NO2 with platelet-based inflammatory indicators attenuated by increased PA levels. Conclusions: exposure to O3, Ox, Owtx, and NO2 was positively associated with platelet-based inflammatory indicators, and these associations were modified by PA. The findings suggested that a healthy lifestyle of PA might be an effective measure against early adverse effects of air pollution.

Interactive effects of short-term ozone exposure and plasma biomarkers related to nitric oxide pathway and inflammation on myocardial ischemia

BACKGROUND

No study has explored the possible interactive effects of short-term ozone (O3) exposure and plasma endothelial and inflammatory biomarkers, including cyclic guanosine monophosphate (cGMP), nitric oxide metabolite (NOx), myeloperoxidase (MPO), and high-sensitive C-reactive protein (hs-CRP), on myocardial ischemia, indicated by ST-segment depression events (STDE) recorded in ambulatory electrocardiograms.

METHODS

A L-arginine (L-Arg) intervention study with 118 participants was carried out using a standardized 24-h exposure protocol, employing a multivariable linear regression model to assess the effects of O3 exposure on plasma biomarkers, and a generalized linear model to investigate the effects on 24-hour STDE. The possible interactive effects of short-term O3 exposure and plasma biomarkers on indicators of myocardial ischemia were also investigated by including product interaction terms between ambient O3 and plasma biomarkers in the models. We also explored whether L-Arg supplementation could alleviate the adverse effects of ambient O3 exposure.

RESULTS

Data from 107 participants were included in final analysis. Short-term O3 exposure was associated with significantly decreased plasma cGMP and MPO levels, and increased 24-h STDE risk, with plasma cGMP and MPO modifying the O3-STDE associations. Participants with lower plasma levels of cGMP or higher MPO demonstrated increased vulnerability to the harmful effects of ambient O3 on 24-h STDE in inferior leads. L-Arg supplementation attenuated the effects of short-term O3 exposure on plasma MPO and hs-CRP.

CONCLUSIONS

Plasma biomarkers (cGMP and MPO) are likely involved in the potential pathways connecting ambient O3 exposure and harmful cardiac effects. Supplementation with L-Arg showed the potential to mitigate the inverse effects of ambient O3 exposure on inflammation.

Multiphase Radical Chemical Processes Induced by Air Pollutants and the Associated Health Effects

Air pollution is increasingly recognized as a significant health risk, yet our understanding of its underlying chemical and physiological mechanisms remains incomplete. Fine particulate matter (PM2.5) and ozone (O3) interact with biomolecules in intracellular and microenvironments, such as the epithelial lining fluid (ELF), leading to the generation of reactive oxygen species (ROS). These ROS trigger cellular inflammatory responses and oxidative stress, contributing to a spectrum of diseases affecting the respiratory, cardiovascular, and central nervous systems. Extensive epidemiological and toxicological research highlights the pivotal role of ROS in air pollution-related diseases. It is crucial to comprehend the intricate chemical processes and accompanying physiological effects of ROS from air pollutants. This review aims to systematically summarize ROS generation mechanisms in the ELF and measurement techniques of oxidative potential (OP), taking the kinetic reactions of ROS cycling in the ELF as an example, and discusses the general health implications of ROS in respiratory, cardiovascular, and central nervous systems. Understanding these processes through interdisciplinary research is essential to develop effective and precise strategies as well as air quality standards to mitigate the public health impacts of air pollution globally.

Short-term exposure to air pollution on peripheral white blood cells and inflammation biomarkers: a cross-sectional study on rural residents

Effects of short-term exposure to ambient air pollution on systemic immunological and inflammatory biomarkers in rural population have not been adequately characterized. From May to July 2021, 5816 participants in rural villages of northern Henan Province, China, participated in this cross-sectional study. Blood biomarkers of systemic inflammation were determined including peripheral white blood cells (WBC), eosinophils (EOS), basophils (BAS), monocytes (MON), lymphocytes (LYM), neutrophils (NEU), neutrophil-lymphocyte ratio (NLR), and serum high-sensitivity C-reactive protein (hs-CRP). The concentrations of ambient fine particulate matter (PM2.5), PM10, nitrogen dioxide (NO2), carbon monoxide (CO), and ozone (O3) were assessed up to 7 days prior to the blood draw. A generalized linear model was used to analyze the associations between air pollution exposure and the above-mentioned blood biomarkers. Significantly positive associations were revealed between PM2.5, CO and WBC; CO, O3 and LYM; PM2.5, PM10, SO2, CO and NEU; PM2.5, PM10, SO2, CO and NLR; PM2.5, PM10, SO2, NO2, CO, O3 and hs-CRP. Meanwhile, negative associations were found between SO2 and WBC; PM2.5, PM10, NO2, CO, or O3 and EOS; PM2.5, SO2, or CO and BAS; SO2, NO2 or O3 and MON; PM2.5, PM10, SO2, or NO2 and LYM. Moreover, men, individuals with normal body mass index (BMI), current smokers, and those older than 60 years were found vulnerable to air pollution effects. Taken together, short-term exposure to air pollution was associated with systemic inflammatory responses, providing insight into the potential mechanisms for air pollution-induced detrimental systemic effects in rural residents.

Association between short-term exposure to ambient air pollutants and biomarkers indicative of inflammation and oxidative stress: a cross-sectional study using KoGES-HEXA data

BACKGROUND

Air pollution-induced systemic inflammation and oxidative stress are hypothesized to be the major biological mechanisms underlying pathological outcomes. We examined the association between short-term exposure to ambient air pollutants and biomarkers of inflammation and oxidative stress in 2199 general middle-aged Korean population residing in metropolitan areas.

METHODS

Serum levels of inflammatory cytokines (interleukin [IL]-1β, IL-6, IL-8, IL-10, and tumor necrosis factor [TNF]-α) and urinary levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) were measured. Daily concentrations of a series of air pollutants (particulate matter [PM]10, PM2.5, SO2, NO2, CO, and O3) were predicted using the Community Multiscale Air Quality modeling system, and participant-level pollutant exposure was determined using geocoded residential addresses. Short-term exposure was defined as the 1- to 7-day moving averages.

RESULTS

The multivariable-adjusted linear models controlling for the sociodemographic, lifestyle, temporal, and meteorological factors identified positive associations of PM with IL-1β, IL-8, IL-10, TNF-α, and 8-OHdG levels; SO2 with IL-10 levels, CO with IL-1β, IL-10, and TNF-α levels; and O3 with IL-1β, IL-8, and 8-OHdG levels. O3 levels were inversely associated with IL-10 levels. For each pollutant, the strongest associations were observed for the 7-day average PM and CO with IL-1β (per 10-µg/m3 increase in PM10: 2.7%, 95% confidence interval [CI] = 0.6-4.8; per 10-µg/m3 increase in PM2.5: 6.4%, 95% CI = 2.4-10.5; per 0.1-ppm increase in CO: 3.3%, 95% CI = 0.3-6.5); the 2-day average SO2 with IL-10 levels (per 1-ppb increase in SO2: 1.1%, 95% CI = 0.1-2.1); and the 7-day average O3 with IL-8 levels (per 1-ppb increase in O3: 1.3%, 95% CI = 0.7-1.9).

CONCLUSIONS

Short-term exposure to ambient air pollutants may induce oxidative damage and pro-inflammatory roles, together with counter-regulatory anti-inflammatory response.

Short-term ozone exposure and serum neural damage biomarkers in healthy elderly adults: Evidence from a panel study

BACKGROUND

Although converging lines of research have pointed to the adverse neural effects of air pollution, evidence linking ozone (O3) and neural damage remains limited.

OBJECTIVES

To investigate the subclinical neural effects of short-term ozone (O3) exposure in elderly adults.

METHODS

A panel of healthy elderly individuals was recruited, and five repeated measurements were conducted from December 2018 to April 2019 in Xinxiang, China. Serum neural damage biomarkers, including brain-derived neurotrophic factor (BDNF), neurofilament light chain (NfL), neuron-specific enolase (NSE), protein gene product 9.5 (PGP9.5), and S100 calcium-binding protein B (S100B) were measured at each follow-up session. Personal O3 exposure levels were calculated based on outdoor monitoring and sampling times. A linear mixed-effects model was adopted to quantify the acute effect of O3 on serum neural damage biomarkers. Stratification analysis based on sex, education level, physical activity, and glutathione S-transferases (GST) gene polymorphism analysis was performed to explore their potential modifying effects.

RESULTS

A total of 34 healthy volunteers aged 63.7 ± 5.7 y were enlisted and completed the study. The concentration of the daily maximum 8-h average O3 (O3-8h) ranged from 19.5 to 160.5 μg/m3 during the study period. Regression analysis showed that short-term O3 exposure was associated positively with serum concentrations of neural damage biomarkers. A 10 μg/m3 increase in O3-8h exposure was associated with an increment of 74 % (95 % CI:1 %-146 %) and 197 % (95 % CI:39 %-356 %) in BDNF (lag 2 d) and NfL (lag 1 d), respectively. The stratification results suggest that males, people with lower education levels, lower physical activity, and GST theta 1 (GSTT1)-sufficient genotype might be marginally more vulnerable.

CONCLUSIONS

This study provides new evidence for the neural damage risk posed by O3 exposure, even at relatively low concentrations, which, therefore, requires that stringent air quality standards be developed and implemented.

Mortality Burden of Cardiovascular Disease Attributable to Ozone in China: 2019 vs 2050

Due to a combination of lifestyle risk factors, the burden of cardiovascular disease (CVD) has been increasing in China, affecting an estimated 330 million people. Environmental risk factors can exacerbate these risks or independently contribute to CVD. Ozone is an overlooked and invisible risk factor, and it plays a significant role in the development of CVD. Our study provides a novel quantification of the ozone-attributable CVD mortality burden based on daily maximum 8-h average ozone concentration during May to October (6mDMA8) in Chinese adults in 2050, projected under Shared Socioeconomic Pathways 585 and 126, and using the updated WHO air quality guideline level. The study also considers the contributions made by changes in ozone exposure, population aging, population size, and baseline death rates of CVD between 2019 and 2050. While adopting a sustainable and green pathway (SSP 126) can reduce the projected magnitude of premature CVD deaths to 359,200 in 2050, it may not be sufficient to reduce the CVD mortality burden significantly. Therefore, it is crucial to implement strategies for stricter ozone control and reducing the baseline death rate of CVD to mitigate the impacts of ozone on Chinese adults.

Cross-sectional and longitudinal relationships between ozone exposure and glucose homeostasis: Exploring the role of systemic inflammation and oxidative stress in a general Chinese urban population

The adverse health effects of ozone pollution have been a globally concerned public health issue. Herein we aim to investigate the association between ozone exposure and glucose homeostasis, and to explore the potential role of systemic inflammation and oxidative stress in this association. A total of 6578 observations from the Wuhan-Zhuhai cohort (baseline and two follow-ups) were included in this study. Fasting plasma glucose (FPG) and insulin (FPI), plasma C-reactive protein (CRP, biomarker for systemic inflammation), urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG, biomarker for oxidative DNA damage), and urinary 8-isoprostane (biomarker for lipid peroxidation) were repeatedly measured. After adjusting for potential confounders, ozone exposure was positively associated with FPG, FPI, and homeostasis model assessment of insulin resistance (HOMA-IR), and negatively associated with HOMA of beta cell function (HOMA-β) in cross-sectional analyses. Each 10 ppb increase in cumulative 7-days moving average ozone was associated with a 13.19%, 8.31%, and 12.77% increase in FPG, FPI, and HOMA-IR, respectively, whereas a 6.63% decrease in HOMA-β (all P < 0.05). BMI modified the associations of 7-days ozone exposure with FPI and HOMA-IR, and the effects were stronger in subgroup whose BMI ≥24 kg/m². Consistently high exposure to annual average ozone was associated with increased FPG and FPI in longitudinal analyses. Furthermore, ozone exposure was positively related to CRP, 8-OHdG, and 8-isoprostane in dose-response manner. Increased CRP, 8-OHdG, and 8-isoprostane could dose-dependently aggravate glucose homeostasis indices elevations related to ozone exposure. Increased CRP and 8-isoprostane mediated 2.11-14.96% of ozone-associated glucose homeostasis indices increment. Our findings suggested that ozone exposure could cause glucose homeostasis damage and obese people were more susceptible. Systemic inflammation and oxidative stress might be potential pathways in glucose homeostasis damage induced by ozone exposure.

Mixed exposure effect of seminal metals on semen quality, mediation of total antioxidant capacity, and moderation of GSTM1/GSTT1 gene deletion in Chinese reproductive-aged men

BACKGROUND

The effects of metal exposure on semen quality and the role of oxidative damage in this process remain unclear.

METHODS

We recruited 825 Chinese male volunteers, and 12 seminal metals (Mn, Cu, Zn, Se, Ni, Cd, Pb, Co, Ag, Ba, Tl, and Fe), the total antioxidant capacity (TAC), and reduced glutathione were measured. Semen parameters and GSTM1/GSTT1-null genotypes were also detected. Bayesian kernel machine regression (BKMR) was applied to evaluate the effect of the mixed exposure to metals on semen parameters. The mediation of TAC and moderation of GSTM1/GSTT1 deletion were analyzed.

RESULTS

Most seminal metal concentrations were correlated with each other. The BKMR models revealed a negative association between the semen volume and metal mixture, with Cd (cPIP = 0.60) and Mn (cPIP = 0.10) as the major contributors. Compared to fixing all scaled metals at their median value (50th percentiles), fixing the scaled metals at their 75th percentiles decreased the TAC by 2.17 units (95%CI: -2.60, -1.75). Mediation analysis indicated that Mn decreased the semen volume, with 27.82% of this association mediated by TAC. Both the BKMR and multi-linear models showed that seminal Ni was negatively correlated with sperm concentration, total sperm count, and progressive motility, which was modified by GSTM1/GSTT1. Furthermore, Ni and the total sperm count showed a negative association in GSTT1 and GSTM1 null males (β[95%CI]: 0.328 [-0.521, -0.136]) but not in males with GSTT1 and/or GSTM1. Although Fe and the sperm concentration and total sperm count were positively correlated, they showed inverse "U" shapes in univariate analysis.

CONCLUSION

Exposure to the 12 metals was negatively associated with semen volume, with Cd and Mn as the major contributors. TAC may mediate this process. GSTT1 and GSTM1 can modify the reduction in the total sperm count caused by seminal Ni exposure.

Association between short-term exposure to PM2.5 and nasal microbiota dysbiosis, inflammation and oxidative stress: A panel study of healthy young adults

Fine particulate matter (PM_2.5) is the primary environmental stressor and a significant threat to public health. However, the effect of PM_2.5 exposure on human nasal microbiota and its pathophysiological implication remain less understood. This study aimed to explore the associations of PM_2.5 exposure with indices of nasal microbiota and biomarkers of nasal inflammation and oxidative stress. We conducted a panel study with 75 students in Xinxiang, Henan Province, China, from September to December 2017. Biomarkers of nasal inflammation and oxidative stress including interleukin-6 (IL-6), IL-8, tumor necrosis factor-α (TNF-α), 8-epi-prostaglandin F2 alpha (8-epi-PGF2α) and indices of nasal microbiota diversity and phenotypes were measured. Linear mixed-effect models and bioinformatic analyses were performed to assess the association of PM_2.5 concentrations with the abovementioned biomarkers and indices. It was found that per 1 μg/m³ increase in PM_2.5 was associated with increments of 13.15% (95 % CI: 5.53-20.76 %) and 78.98 % (95 % CI: 21.61-136.36 %) in TNF-α on lag2 and lag02. Indices of microbial diversity and phenotypes including equitability, Shannon index, biofilm forming, and oxidative stress tolerant decreased to different extent with the increment in PM_2.5. Notably, thirteen differential microbes in Clostridia, Bacilli, and Gammaproteobacteria classes were recognized as keystone taxa and eight of them were associated with TNF-α, IL-6, or 8-epi-PGF2α. Moreover, environmental adaptation was the most critical functional pathway of nasal microbiota associated with PM_2.5 exposure. In summary, short-term exposure to PM_2.5 is associated with nasal inflammation, microbiota diversity reduction, and the microbiota phenotype alterations.

Oxidative Stress Sensing System for 8-OHdG Detection Based on Plasma Coupled Electrochemistry by Transparent ITO/AuNTAs/PtNPs Electrode

8-Hydroxydeoxyguanosine (8-OHdG) is the most widely used oxidative stress biomarker of the free radical-induced oxidative damage product of DNA, which may allow a premature assessment of various diseases. This paper designs a label-free, portable biosensor device to directly detect 8-OHdG by plasma-coupled electrochemistry on a transparent and conductive indium tin oxide (ITO) electrode. We reported a flexible printed ITO electrode made from particle-free silver and carbon inks. After inkjet printing, the working electrode was sequentially assembled by gold nanotriangles (AuNTAs) and platinum nanoparticles (PtNPs). This nanomaterial-modified portable biosensor showed excellent electrochemical performance for 8-OHdG detection from 10 μg/mL to 100 μg/mL by our self-developed constant voltage source integrated circuit system. This work demonstrated a portable biosensor for simultaneously integrating nanostructure, electroconductivity, and biocompatibility to construct advanced biosensors for oxidative damage biomarkers. The proposed nanomaterial-modified ITO-based electrochemical portable device was a potential biosensor to approach 8-OHdG point-of-care testing (POCT) in various biological fluid samples, such as saliva and urine samples.

Air pollution associated acute respiratory inflammation and modification by GSTM1 and GSTT1 gene polymorphisms: a panel study of healthy undergraduates

Epidemiological evidence has linked air pollution with adverse respiratory outcomes, but the mechanisms underlying susceptibility to air pollution remain unclear. This study aimed to investigate the role of glutathione S-transferase (GST) polymorphism in the association between air pollution and lung function levels. A total of 75 healthy young volunteers aged 18-20 years old were recruited for six follow-up visits and examinations. Spirometry was conducted to obtain lung function parameters such as forced vital capacity (FVC), and forced expiratory volume in 1 s (FEV₁). Nasal fluid concentrations of interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor-α (TNF-α), and 8-epi-prostaglandin F2α (8-epi-PGF2a) were measured using ELISA kits. Linear mixed-effect models were used to evaluate the association of air pollutants with respiratory outcomes. Additionally, polymorphisms of glutathione S-transferase mu 1 (GSTM1) and glutathione S-transferase theta 1 (GSTT1) were estimated to explore its role in the association between air pollutants and lung function. We found that short-term exposure to atmospheric particulates such as PM_2.5 and PM₁₀ can cause an increase in nasal biomarkers of inflammation, oxidative stress, and lung function, while air gaseous pollutant exposure is linked with decreased lung function, except for CO. Stratification analyses showed that an increase in nasal inflammatory cytokines caused by exposure to atmospheric particulates is more obvious in subjects with GSTM1-sufficient (GSTM1⁺) than GSTM1-null (GSTM1^-), while elevated lung function levels due to air particles are more significant in subjects with the genotype of GSTM1^- when compared to GSTM1⁺. As for air gaseous pollutants, decreased lung function levels caused by O₃, SO₂, and NO₂ exposure is more manifest in subjects with the genotype of GSTM1^- compared to GSTM1⁺. Taken together, short-term exposure to air pollutants is associated with alterations in nasal biomarkers and lung function levels in young healthy adults, and susceptible genotypes play an important mediation role in the association between exposure to air pollutants and inflammation, oxidative stress, and lung function levels.

Joint effect of multiple air pollutants on cardiometabolic health in normal-weight and obese adults: A novel insight into the role of circulating free fatty acids

The cardiometabolic effects of air pollution in the context of mixtures and the underlying mechanisms remain not fully understood. This study aims to investigate the joint effect of air pollutant mixtures on a broad range of cardiometabolic parameters, examine the susceptibility of obese individuals, and determine the role of circulating fatty acids. In this panel study, metabolically healthy normal-weight (MH-NW, n = 49) and obese (MHO, n = 39) adults completed three longitudinal visits (257 person-visits in total). Personal exposure levels of PM_2.5, PM₁₀, O₃, NO₂, SO₂, CO and BC were estimated based on fixed-site monitoring data, time-activity logs and infiltration factor method. Blood pressure, glycemic homeostasis, lipid profiles, systematic inflammation and coagulation biomarkers were measured. Targeted metabolomics was used to quantify twenty-eight plasma free fatty acids (FFAs). Bayesian kernel machine regression models were applied to establish the exposure-response relationships and identify key pollutants. Significant joint effects of measured air pollutants on systematic inflammation and coagulation biomarkers were observed in the MHO group, instead of the MH-NW group. Lipid profiles showed the most significant changes in both groups and O₃ contributed the most to the total effect. Specific FFA patterns were identified, and de novo lipogenesis (DNL)-related pattern was most closely related to blood lipid profiles. In particular, interaction analysis suggested that DNL-related FFA pattern augmented the effects of O₃ on triglyceride (TG, P_interaction = 0.040), high-density lipoprotein cholesterol (HDL-C, P_interaction = 0.106) and TG/HDL-C (P_interaction = 0.020) in the MHO group but not MH-NW group. This modification was further confirmed by interaction analysis with estimated activity of SCD1, a key enzyme in the DNL pathway. Therefore, despite being metabolically healthy, obese subjects have a higher cardiometabolic susceptibility to air pollution, especially O₃, and the DNL pathway may represent an intrinsic driver of lipid susceptibility. This study provides new insights into the cardiometabolic susceptibility of obese individuals to air pollution.

Acute effects of ambient nitrogen dioxide exposure on serum biomarkers of nervous system damage in healthy older adults

Ambient nitrogen dioxide (NO₂)-induced adverse health effects have been studied, but documented evidence on neural systems is limited. This study aimed to determine the acute effect of NO₂ exposure on nervous system damage biomarker levels in healthy older adults. Five rounds of follow-up among 34 healthy retired people were scheduled from December 2018 to April 2019 in Xinxiang, China. The real-time NO₂ concentrations were measured using a fixed site monitor. Serum samples were acquired during each round to measure nervous system damage biomarker levels: brain-derived neurotrophic factor (BDNF), neurofilament light chain (NfL), neuron-specific enolase (NSE), protein gene product 9.5 (PGP9.5), and S100 calcium-binding protein B (S100B). A linear mixed-effect model was incorporated to analyze the association between short-term NO₂ exposure and serum concentrations of the above-mentioned biomarkers. Stratification analysis based on sex, educational attainment, glutathione S-transferase theta 1 gene (GSTT1) polymorphism, and physical activity intensity was conducted to explore their potential modification effect. The NO₂ concentration ranged from 34.7 to 59.0 µg/m³ during the study period. Acute exposure to ambient NO₂ was significantly associated with elevated serum levels of NfL, PGP9.5, and BDNF. In response to a 10 µg/m³ increase in NO₂ concentration, NfL and PGP9.5 levels increased by 76 % (95 % confidence interval [CI]: 12-140 %) and 54 % (95 % CI: 1-107 %) on the lag0 day, respectively, while BDNF levels increased by 49 % (95 % CI: 2-96 %) at lag4 day. The estimated effect of NO₂ on NSE levels in GSTT1-sufficient participants was significantly higher than that in GSTT1-null participants. Intriguingly, the estimation of NO₂ on PGP9.5 levels in females was significantly higher than that in males. Most two-pollutant models showed robust results, except for O₃, which might have had confounding effects on NO₂-induced BDNF stimulation. In summary, acute exposure to NO₂ was associated with increased levels of serum nervous system damage biomarker levels including NFL, PGP9.5, and BDNF. The present study provided insights into NO₂ exposure-induced adverse neural effects.

Association between short-term exposure to ambient air pollution and biomarkers of coagulation: A systematic review and meta-analysis

Ambient air pollution is one of the major global risk factors for cardiovascular health, and coagulation changes have been proposed to mediate this risk. Plasminogen activator inhibitor-1 (PAI-1), von Willebrand factor (vWF), soluble P-selectin (sP-selectin) and tissue plasminogen activator (t-PA) are major coagulation biomarkers. However, there has been no systematic meta-analysis to summarize associations of ambient air pollution with these coagulation biomarkers. To assess the overall associations between ambient particulate matter (PM_2.5, PM₁₀), ozone (O₃), nitrogen dioxide (NO₂), carbon monoxide (CO) and major coagulation biomarkers including PAI-1, vWF, sP-selectin and t-PA based on the existing epidemiological research. We performed a systematic literature search of publications reporting the associations of ambient air pollutants (PM_2.5, PM₁₀, O₃, NO_2, and CO) with coagulation biomarkers (PAI-1, vWF, sP-selectin and t-PA) in PubMed, Web of Science, EMBASE, and Scopus databases as of April 5, 2022. Then, we performed a random-effect meta-analysis, which included 27 articles, and then identified the potential sources of heterogeneity. The pooled percent changes of coagulation biomarkers per 10 μg/m³ increase in short-term exposure to ambient PM_2.5 were 2.43% (95% CI: 0.59%, 4.29%) in PAI-1, 1.08% (95% CI: 0.21%, 1.96%) in vWF and 1.14% (95% CI: 0.59%, 1.68%) in sP-selectin, respectively. We also found significant associations of short-term exposure to ambient O₃ with PAI-1 (1.62%, 95% CI: 0.01%, 3.25%), sP-selectin (9.59%, 95% CI:2.78%, 16.86%) and t-PA (0.45%, 95% CI: 0.02%, 0.88%), respectively. Short-term exposures to ambient PM₁₀, NO₂ and CO were not significantly associated with changes in coagulation biomarkers. In conclusion, short-term exposures to PM_2.5 and O₃ are associated with significant increases in coagulation biomarkers, suggesting an activated coagulation state upon air pollution exposure.

Subclinical cardiovascular outcomes of acute exposure to fine particulate matter and its constituents: A glutathione S-transferase polymorphism-based longitudinal study

To explore the acute subclinical cardiovascular effects of fine particulate matter (PM_2.5) and its constituents, a longitudinal study with 61 healthy young volunteers was conducted in Xinxiang, China. Linear mixed-effect models were used to analyze the association of PM_2.5 and its constituents with cardiovascular outcomes, respectively, including blood pressure (BP), heart rate (HR), serum levels of high-sensitivity C-reactive protein (hs-CRP), 8-hydroxy-2'-deoxyguanosine (8-OHdG), tissue-type plasminogen activator (t-PA), and platelet-monocyte aggregation (PMA). Additionally, the modifying effects of glutathione S-transferase mu 1 (GSTM1) and glutathione S-transferase theta 1 (GSTT1) polymorphisms were examined. A 10 μg/m³ increase in PM_2.5 was associated with -1.04 (95 % CI: -1.86 to -0.22) mmHg and -0.90 (95 % CI: -1.69 to -0.11) mmHg decreases in diastolic BP (DBP) and mean arterial BP (MABP) along with 1.83 % (95 % CI: 0.59-3.08 %), 5.93 % (95 % CI: 0.70-11.16 %) increases in 8-OHdG and hs-CRP, respectively. Ni content was positively associated with the 8-OHdG levels whereas several other metals presented negative association with 8-OHdG and HR. Intriguingly, GSTT1+/GSTTM1+ subjects showed higher susceptibility to PM_2.5-induced alterations of DBP and PMA, and GSTT1-/GSTM1+ subjects showed higher alteration on t-PA. Taken together, our findings indicated that short-term PM_2.5 exposure induced oxidative stress, systemic inflammation, autonomic alterations, and fibrinolysis in healthy young subjects. Among multiple examined metal components Ni appeared to positively associated with systematic oxidative stress. In addition, GST-sufficient subjects might be more prone to PM_2.5-induced autonomic alterations.

Effect of ozone on allergic airway inflammation

Background

Exposure to ozone (O₃) is associated with increased risk of exacerbations of asthma, but the underlying mechanisms are not well studied.

Objective

We sought to determine whether O₃ exposure would enhance airway inflammatory responses to allergen and the GSTM1-null genotype would modulate this enhancement.

Methods

In a crossover design, 10 asthmatic participants (5 with GSTM1-null genotype) who had specific sensitization to Dermatophagoides pteronyssinus (DP) were exposed to 160 ppb O₃ or filtered air (FA) control for 4 hours on 2 separate days at least 3 weeks apart. At 20 hours after exposure, endobronchial challenge with DP allergen, and sham normal saline (NS) instillation, were performed in separate bronchi. Six hours later, a second bronchoscopy was performed to collect bronchoalveolar lavage (BAL) from the DP- and NS-challenged segments for analyses of inflammatory biomarkers. Linear regression compared cell and cytokine responses across the 4 exposure groups (FA-NS, O₃-NS, FA-DP, O₃-DP). Effect modification by GSTM1 genotype was assessed in stratified regressions.

Results

BAL eosinophil counts were increased in segments challenged with DP compared to sham-challenged segments (P < .01). DP challenge compared to sham also caused a significant increase in BAL concentrations of the T_H2 cytokines IL-4, IL-5, IL-10, and IL-13 (P < .03 for all comparisons). O₃ exposure did not significantly affect BAL cells or cytokine after DP challenge. Compared to GSTM1-present participants, GSTM1-null participants had significantly lower eosinophil (P < .041) and IL-4 (P < .014) responses to DP challenge after O₃ exposure.

Conclusions

While O₃ did not cause a clear differential effect on airway inflammatory responses to allergen challenge, those responses did appear to be modulated by the antioxidant enzyme, GSTM1.

Long-Term Effects of Ambient Particulate and Gaseous Pollutants on Serum High-Sensitivity C-Reactive Protein Levels: A Cross-Sectional Study Using KoGES-HEXA Data

Ambient air pollutants reportedly increase inflammatory responses associated with multiple chronic diseases. We investigated the effects of long-term exposure to ambient air pollution on high-sensitivity C-reactive protein (hs-CRP) using data from 60,581 participants enrolled in the Korean Genome and Epidemiology Study-Health Examinees Study between 2012 and 2017. Community Multiscale Air Quality System with surface data assimilation was used to estimate the participants' exposure to criteria air pollutants based on geocoded residential addresses. Long-term exposure was defined as the 2-year moving average concentrations of PM₁₀, PM_2.5, SO₂, NO₂, and O₃. Multivariable linear and logistic regression models were utilized to estimate the percent changes in hs-CRP and odds ratios of systemic low-grade inflammation (hs-CRP > 3 mg/L) per interquartile range increment in air pollutants. We identified positive associations between hs-CRP and PM₁₀ (% changes: 3.75 [95% CI 2.68, 4.82]), PM_2.5 (3.68, [2.57, 4.81]), SO₂ (1.79, [1.10, 2.48]), and NO₂ (3.31, [2.12, 4.52]), while negative association was demonstrated for O₃ (-3.81, [-4.96, -2.65]). Elevated risks of low-grade inflammation were associated with PM₁₀ (odds ratio: 1.07 [95% CI 1.01, 1.13]), PM_2.5 (1.08 [1.02, 1.14]), and SO₂ (1.05 [1.01, 1.08]). The odds ratios reported indicated that the exposures might be risk factors for inflammatory conditions; however, they did not reflect strong associations. Our findings suggest that exposure to air pollutants may play a role in the inflammation process.

Associations of long-term exposure to ambient ozone with hypertension, blood pressure, and the mediation effects of body mass index: A national cross-sectional study of middle-aged and older adults in China

BACKGROUND

The associations between long-term exposure to ozone (O₃) and respiratory diseases are well established. However, its association with cardiovascular disease (CVD) remains controversial. In this study, we examined the associations between O₃ and the prevalence of hypertension and blood pressure, and the mediation effects of body mass index (BMI) in Chinese middle-aged and older adults.

METHODS

In this national cross-sectional study, we estimated the O₃ exposure of 12,028 middle-aged and older adults from 126 county-level cities in China, using satellite-based spatiotemporal models. Generalized linear mixed models were used to evaluate the associations of long-term exposure to O₃ with hypertension and blood pressure, including systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and pulse pressure (PP). Mediation effect models were applied to examine the mediation effects of BMI among O₃-induced hypertension and elevated blood pressure.

RESULTS

Each 10 μg/m³ increase in O₃ concentration was significantly associated with an increase of 13.7% (95% confidence interval (CI): 4.8%, 23.3%) in the prevalence of hypertension, an increase of 1.128 mmHg (95% CI: 0.248, 2.005), 0.679 mmHg (95% CI: 0.059, 1.298), 0.820 mmHg (95%CI: 0.245, 1.358) in SBP, DBP, and MAP, respectively. Mediation effect models showed that BMI played 40.08%, 37.25%, 39.95%, and 33.51% mediation roles in the effects of long-term exposure to O₃ on hypertension, SBP, DBP, and MAP, respectively.

CONCLUSIONS

Long-term exposure to O₃ can increase the prevalence of hypertension and blood pressure levels of middle-aged and older adults, and an increase of BMI would be an important modification effect for O₃-induced hypertension and blood pressure increase.

Associations of Short-Term Exposure to Fine Particulate Matter with Neural Damage Biomarkers: A Panel Study of Healthy Retired Adults

Exposure to fine particulate matter (PM_2.5) is associated with various adverse health effects, such as respiratory and cardiovascular diseases. This study aimed to evaluate the association of PM_2.5 with neural damage biomarkers. A total of 34 healthy retirees were recruited from Xinxiang Medical University from December 2018 to April 2019. Concentrations of PM_2.5 constituents including 24 metals and nonmetallic elements and 6 ions, and 5 biomarkers of neural damage including brain-derived neurotrophic factor (BDNF), neurofilament light chain (NfL), neuron-specific enolase (NSE), protein gene product 9.5 (PGP9.5), and S100 calcium-binding protein B (S100B) in serum were measured. A linear mixed-effect model was employed to estimate the association of PM_2.5 and its constituents with neural damage biomarkers. Modification effects of glutathione S-transferase theta 1 gene (GSTT1) polymorphism, sex, education, and physical activity on PM_2.5 exposure with neural damage were explored. PM_2.5 and its key constituents were significantly associated with neural damage biomarkers. A 10 μg/m³ increase in PM_2.5 concentration was associated with 2.09% (95% CI, 39.3-76.5%), 100% (95% CI, 1.73-198%), and 122% (95% CI, 20.7-222%) increments in BDNF, NfL, and PGP9.5, respectively. Several constituents such as Cu, Zn, Ni, Mn, Sn, V, Rb, Pb, Al, Be, Cs, Co, Th, U, Cl^-, and F^- were significantly associated with NfL. The estimated association of PM_2.5 with NSE in GSTT1-sufficient volunteers was significantly higher than that in GSTT1-null volunteers. Therefore, short-term PM_2.5 exposure was associated with neural damage, and GSTT1 expression levels modified the PM_2.5-induced adverse neural effects.

Synergistic effects of gaseous pollutants on hospital admissions for cardiovascular disease in Liuzhou, China

Previous studies demonstrated that short-term exposure to gaseous pollutants (nitrogen dioxide (NO₂), sulfur dioxide (SO₂), and ozone (O₃)) had a greater adverse effect on cardiovascular disease. However, little evidence exists regarding the synergy between gaseous pollutants and cardiovascular disease (CVD). Therefore, we aimed to estimate the effect of individual gaseous pollutants on hospital admissions for CVD and to explore the possible synergistic effects between gaseous pollutants. Daily hospitalization counts for CVD were collected from January 1, 2014, to December 31, 2015. We also collected daily time series on gaseous pollutants from the Environment of the People's Republic of China, including NO₂, SO₂, and O₃. We used distributed lag nonlinear models (DLNMs) to assess the association of individual gaseous pollutants on CVD hospitalization, after controlling for seasonality, day of the week, public holidays, and weather variables. Then, we explored the variability across age and sex groups. In addition, we analyzed the synergistic effects between gaseous pollutants on CVD. Extremely low NO₂ and SO₂ increase the risk of CVD in all subgroup at lag 7 days. The greatest effect of high concentration of SO₂ was observed in male and the elderly (≥ 65 years) at lag 3 days. Greater effects of high concentration of O₃ were more pronounced in the young (< 65 years) and female at lag 3 days, while the effect of low concentration of O₃ was greater in male and the young (< 65 years) at lag 0 day. We found a synergistic effect between NO₂ and SO₂ for CVD, as well as between SO₂ and O₃. The synergistic effects of NO₂ and SO₂ on CVD were stronger in the elderly (≥ 65) and female. The female was sensitive to synergistic effects of SO₂-O₃ and NO₂-O₃. Interestingly, we found that there was a risk of CVD in the susceptible population even for gaseous pollutant concentrations below the National Environmental Quality Standard. The synergy between NO₂ and SO₂ was significantly associated with cardiovascular disease hospitalization in the elderly (≥ 65). This study provides evidence for the synergistic effect of gaseous pollutants on hospital admissions for cardiovascular disease.

Association between gaseous air pollutants and biomarkers of systemic inflammation: A systematic review and meta-analysis

BACKGROUND

Studies have linked gaseous air pollutants to multiple health effects via inflammatory pathways. Several major inflammatory biomarkers, including C-reactive protein (CRP), fibrinogen, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) have also been considered as predictors of cardiovascular disease. However, there has been no meta-analysis to evaluate the associations between gaseous air pollutants and these typical biomarkers of inflammation to date.

OBJECTIVES

To evaluate the overall associations between short-term and long-term exposures to ambient ozone (O₃), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), carbon dioxide (CO) and major inflammatory biomarkers including CRP, fibrinogen, IL-6 and TNF-α.

METHODS

A meta-analysis was conducted for publications from PubMed, Web of Science, Scopus and EMBASE databases up to Feb 1st, 2021.

RESULTS

The meta-analysis included 38 studies conducted among 210,438 participants. Generally, we only observed significant positive associations between short-term exposures to gaseous air pollutants and inflammatory biomarkers. For a 10 μg/m³ increase in short-term exposure to O₃, NO₂, and SO₂, there were significant increases of 1.05% (95%CI: 0.09%, 2.02%), 1.60% (95%CI: 0.49%, 2.72%), and 10.44% (95%CI: 4.20%, 17.05%) in CRP, respectively. Meanwhile, a 10 μg/m³ increase in NO₂ was also associated with a 4.85% (95%CI: 1.10%, 8.73%) increase in TNF-α. Long-term exposures to gaseous air pollutants were not statistically associated with these biomarkers, but the study numbers were relatively small. Subgroup analyses found more apparent associations in studies with better study design, higher quality, and smaller sample size. Meanwhile, the associations also varied across studies conducted in different geographical regions.

CONCLUSION

Short-term exposure to gaseous air pollutants is associated with increased levels of circulating inflammatory biomarkers, suggesting that a systemic inflammatory state is activated upon exposure. More studies on long-term exposure to gaseous air pollutants and inflammatory biomarkers are warranted to verify the associations.

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.

Acute ozone exposure can cause cardiotoxicity: Mitochondria play an important role in mediating myocardial apoptosis

OBJECTIVE

To clarify the cardiotoxicity induced by acute exposure to different concentrations of ozone in both gender rats and explore the underlying mechanisms.

METHODS

A total of 240 rats were randomly sorted into 6 groups with equal numbers of male and female rats in each group. The rats were subjected to ozone inhalation at concentrations of 0, 0.12, 0.5, 1.0, 2.0 and 4.0 ppm, respectively, for 6 h. After ozone exposure, function indicators, myocardial injury indexes and risk factors of cardiovascular disease in blood were assayed.

RESULTS

High ozone exposure resulted in sustained ventricular tachycardia in male and female rats. Myocardial apoptosis in male rats started from 1.0 ppm ozone, and that in female rats started from 2.0 ppm ozone (p < 0.05). Caspase-9 increased significantly from 0.12 ppm ozone (p < 0.01) in both gender rats, while caspase-3 was initially activated at 0.5 ppm ozone. From 1.0 ppm ozone, mitochondrial cristae and myofilaments dissolved. The ratio of Bcl-2/Bax decreased significantly from 0.12 ppm and MRCC-IV decreased significantly from 2.0 ppm by ozone.

CONCLUSION

Acute ozone exposure can cause paroxysmal ventricular tachycardia in rats. Moreover, the changes of inflammatory factors in the heart tissues of female and male rats after ozone exposure were greater than those of oxidative stress. This study reported for the first time that 6 h ozone exposure does not cause acute cardiomyocyte necrosis, but promotes cardiomyocyte apoptosis in a mitochondrial-dependent manner. Ozone could regulate caspases-3 dependent cardiomyocyte apoptosis by affecting the balance between caspase-9 and XIAP.

Sperm mtDNA copy number, telomere length, and seminal spermatogenic cells in relation to ambient air pollution: Results of a cross-sectional study in Jing-Jin-Ji region of China

Evidences on the association of air pollutants and semen quality were limited and mechanism-based biomarkers were sparse. We enrolled 423 men at a fertility clinic in Shijiazhuang, China to evaluate associations between air pollutants and semen quality parameters including the conventional ones, sperm mitochondrial DNA copy number (mtDNAcn), sperm telomere length (STL) and seminal spermatogenic cells. PM_2.5, PM₁₀, CO, SO₂, NO₂ and O₃ exposure during lag0-90, lag0-9, lag10-14 and lag70-90 days were evaluated with ordinary Kringing model. The exposure-response correlations were analyzed with multiple linear regression models. CO, PM_2.5 and PM₁₀ were adversely associated with conventional semen parameters including sperm count, motility and morphology. Besides, CO was positively associated with seminal primary spermatocyte (lag70-90, 0.49; 0.14, 0.85) and mtDNAcn (lag0-90, 0.37; 0.12, 0.62, lag10-14, 0.31; 0.12, 0.49), negatively associated with STL (lag0-9, -0.30; -0.57, -0.03). PM_2.5 was positively associated with mtDNAcn (0.50; 0.24, 0.75 and 0.38; 0.02, 0.75 for lag0-90 and lag70-90) while negatively associated with STL (lag70-90, -0.49; -0.96, -0.01). PM₁₀ and NO₂ were positively associated with mtDNAcn. Our findings indicate CO and PM might impair semen quality testicularly and post-testicularly while seminal spermatogenic cell, STL and mtDNAcn change indicate necessity for more attention on these mechanisms.

Circadian Deregulation as Possible New Player in Pollution-Induced Tissue Damage

Circadian rhythms are 24-h oscillations driven by a hypothalamic master oscillator that entrains peripheral clocks in almost all cells, tissues and organs. Circadian misalignment, triggered by industrialization and modern lifestyles, has been linked to several pathological conditions, with possible impairment of the quality or even the very existence of life. Living organisms are continuously exposed to air pollutants, and among them, ozone or particulate matters (PMs) are considered to be among the most toxic to human health. In particular, exposure to environmental stressors may result not only in pulmonary and cardiovascular diseases, but, as it has been demonstrated in the last two decades, the skin can also be affected by pollution. In this context, we hypothesize that chronodistruption can exacerbate cell vulnerability to exogenous damaging agents, and we suggest a possible common mechanism of action in deregulation of the homeostasis of the pulmonary, cardiovascular and cutaneous tissues and in its involvement in the development of pathological conditions.

Fish oil and olive oil-enriched diets alleviate acute ozone-induced cardiovascular effects in rats

Fish oil (FO) and olive oil (OO) supplementations attenuate the cardiovascular responses to inhaled concentrated ambient particles in human volunteers. This study was designed to examine the cardiovascular effects of ozone (O₃) exposure and the efficacy of FO and OO-enriched diets in attenuating the cardiovascular effects from O₃ exposure in rats. Rats were fed either a normal diet (ND), a diet enriched with 6% FO or OO starting at 4 weeks of age. Eight weeks following the start of these diet, animals were exposed to filtered air (FA) or 0.8 ppm O₃, 4 h/day for 2 consecutive days. Immediately after exposure, cardiac function was measured as the indices of left-ventricular developed pressure (LVDP) and contractility (dP/dt_max and dP/dt_min) before ischemia. In addition, selective microRNAs (miRNAs) of inflammation, endothelial function, and cardiac function were assessed in cardiac tissues to examine the molecular alterations of diets and O₃ exposure. Pre-ischemic LVDP and dP/dt_max were lower after O₃ exposure in rats fed ND but not FO and OO. Cardiac miRNAs expressions were altered by both diet and O₃ exposure. Specifically, O₃-induced up-regulation of miR-150-5p and miR-208a-5p were attenuated by FO and/or OO. miR-21 was up-regulated by both FO and OO after O₃ exposure. This study demonstrated that O₃-induced cardiovascular responses appear to be blunted by FO and OO diets. O₃-induced alterations in miRNAs linked to inflammation, cardiac function, and endothelial dysfunction support these pathways are involved, and dietary supplementation with FO or OO may alleviate these adverse cardiovascular effects in rats.