Short-term PM2.5 exposure and circulating von Willebrand factor level: a meta-analysis

PM2.5-mediated cardiovascular disease in aging: Cardiometabolic risks, molecular mechanisms and potential interventions

Air pollution, particularly fine particulate matter (PM2.5) with <2.5 μm in diameter, is a major public health concern. Studies have consistently linked PM2.5 exposure to a heightened risk of cardiovascular diseases (CVDs) such as ischemic heart disease (IHD), heart failure (HF), and cardiac arrhythmias. Notably, individuals with pre-existing age-related cardiometabolic conditions appear more susceptible. However, the specific impact of PM2.5 on CVDs susceptibility in older adults remains unclear. Therefore, this review addresses this gap by discussing the factors that make the elderly more vulnerable to PM2.5-induced CVDs. Accordingly, we focused on physiological aging, increased susceptibility, cardiometabolic risk factors, CVDs, and biological mechanisms. This review concludes by examining potential interventions to reduce exposure and the adverse health effects of PM2.5 in the elderly population. The latter includes dietary modifications, medications, and exploration of the potential benefits of supplements. By comprehensively analyzing these factors, this review aims to provide a deeper understanding of the detrimental effects of PM2.5 on cardiovascular health in older adults. This knowledge can inform future research and guide strategies to protect vulnerable populations from the adverse effects of air pollution.

Association Between Long-Term Exposure to Ambient Air Pollution and Fasting Blood Glucose: A Systematic Review and Meta-Analysis

Increasing studies are indicating a potential association between ambient air pollution exposure and fasting blood glucose (FBG), an indicator of prediabetes and diabetes. However, there is inconsistency within the existing literature. The aim of this study was to summarize the associations of exposures to particulate matters (PMs) (with aerodynamic diameters of ≤1 μm (PM1), ≤2.5 μm (PM2.5), and ≤10 μm (PM10), respectively) and gaseous pollutants (sulfur dioxide (SO2), nitrogen dioxide (NO2) and ozone (O3)) with FBG based on the existing epidemiological research for a better understanding of the relationship between air pollution and diabetes. Up to 2 July 2024, we performed a comprehensive literature retrieval from various electronic databases (PubMed, Web of Science, Scopus, and Embase). Random-effect and fixed-effect models were utilized to estimate the pooled percent changes (%) and 95% confidence intervals (CIs). Then, subgroup meta-analyses and meta-regression analyses were applied to recognize the sources of heterogeneity. There were 33 studies eligible for the meta-analysis. The results showed that for each 10 μg/m3 increase in long-term exposures to PM1, PM2.5, PM10, and SO2, the pooled percent changes in FBG were 2.24% (95% CI: 0.54%, 3.96%), 1.72% (95% CI: 0.93%, 2.25%), 1.19% (95% CI: 0.41%, 1.97%), and 0.52% (95% CI:0.40%, 0.63%), respectively. Long-term exposures to ambient NO2 and O3 were not related to alterations in FBG. In conclusion, our findings support that long-term exposures to PMs of various aerodynamic diameters and SO2 are associated with significantly elevated FBG levels.

The association between cadmium exposure and the risk of chronic obstructive pulmonary disease: A systematic review and meta-analysis

According to the World Health Organization, chronic obstructive pulmonary disease (COPD) was one of the top ten causes of death worldwide in 2019. The ratio of forced expiratory volume in the first second to forced vital capacity (FEV1/FVC) provides a useful indicator for the diagnosis of COPD. Existing data have demonstrated that cadmium (Cd) exposure is associated with COPD. However, data concerning the incidence and progression of cadmium-induced COPD is inconsistent. To explore the relationship between cadmium exposure and the risk of COPD in humans, through January 12, 2023, we conducted a thorough search of the PubMed, Cochrane, Web of Science, Embase and Scopus databases for relevant material. In this study, a meta-analysis was conducted to evaluate the association between cadmium and COPD. This meta-analysis indicated that exposure to cadmium (per 1 μg/L increase) was associated with reduced FEV1/FVC (% change = -47.54%, 95% CI: -54.99% to -40.09%). Subgroup analysis showed that the combined effect estimates were significantly higher in the COPD patient group (% change = -54.66%, 95% CI: -83.32% to -26.00%) than in the general population (% change = -52.11%, 95%CI: -60.53% to -43.70%). Therefore, we conclude that cadmium exposure is associated with reduced FEV1/FVC, which suggests a risk for COPD.

Long-term exposure to air pollution and risk of insulin resistance: A systematic review and meta-analysis

OBJECTIVE

The effects of air pollution on metabolism have become a popular research topic, and a large number of studies had confirmed that air pollution exposure could induce insulin resistance (IR) to varying degrees, but the results were inconsistent, especially for the long-term exposures. The aim of the current study was to further investigate the potential effects of air pollution on IR.

METHODS

A systematic review and meta-analysis of four electronic databases, including PubMed, Embase, Web of Science and Cochrane were conducted, searching for relevant studies published before June 10, 2023, in order to explore the potential relationships between long-term exposure to air pollution and IR. A total of 10 studies were included for data analysis, including seven cohort studies and three cross-sectional studies. Four major components of air pollution, including PM2.5 (particulate matter with an aerodynamic diameter of 2.5 µm or less), PM10 (particulate matter with an aerodynamic diameter of 10 µm or less), NO2, and SO2 were selected, and each analyzed for the potential impacts on insulin resistance, in the form of adjusted percentage changes in the homeostasis assessment model of insulin resistance (HOMA-IR).

RESULTS

This systematic review and meta-analysis showed that for every 1 μg/m³ increase in the concentration of selected air pollutants, PM2.5 induced a 0.40% change in HOMA-IR (95%CI: -0.03, 0.84; I2 =67.4%, p = 0.009), while PM10 induced a 1.61% change (95%CI: 0.243, 2.968; I2 =49.1%, p = 0.001). Meanwhile, the change in HOMA-IR due to increased NO2 or SO2 exposure concentration was only 0.09% (95%CI: -0.01, 0.19; I2 =83.2%, p = 0.002) or 0.01% (95%CI: -0.04, 0.06; I2 =0.0%, p = 0.638), respectively.

CONCLUSIONS

Long-term exposures to PM2.5, PM10, NO2 or SO2 are indeed associated with the odds of IR. Among the analyzed pollutants, inhalable particulate matters appear to exert greater impacts on IR.

Association of urinary arsenic with the oxidative DNA damage marker 8-hydroxy-2 deoxyguanosine: A meta-analysis

BACKGROUND

The International Agency for Research on Cancer has classified arsenic as a class I carcinogen. Oxidative DNA damage is a typical early precursor to recognized malignancies. The most sensitive early independent marker of oxidative DNA damage is believed to be 8-hydroxy-2 deoxyguanosine (8-OHdG). To date, research on the link between urinary arsenic and 8-OHdG has not been consistent.

OBJECTIVE

This study was aimed at exploring the effects of urinary arsenic on 8-OHdG in human urine.

METHODS

A literature search until January 2023 was performed on the PubMed, Cochrane Library, Web of Science, Embase, and Scopus databases through a combination of computer and manual retrieval. Stata 12.0 was used to examine the degree of heterogeneity among included studies. The percentage change and 95 % confidence interval (95 % CI) of 8-OHdG were calculated between populations exposed to different doses. We used a random effect model because the degree of heterogeneity exceeded 50 %. Sensitivity analysis and testing for publication bias were performed.

RESULTS

This meta-analysis included nine studies, most of which were performed in China. After exposure to arsenic, urinary arsenic (per 10 μg/g creatinine increase) was associated with the increased 8-OHdG (% change = 41.49 %, 95 % CI: 19.73 %, 63.25 %). Subgroup analysis indicated that the percentage change in 8-OHdG in urine was more pronounced in people exposed to arsenic <50 μg/L (% change = 24.60 %, 95 % CI: 17.35 %, 37.85 %). In studies using total urinary arsenic content as an indicator, the percentage change in 8-OHdG in urine was more significant (% change = 60.38 %, 95 % CI: 15.08 %, 105.68 %).

CONCLUSION

The 8-OHdG levels in human urine significantly increased after exposure to environmental arsenic, thus suggesting that arsenic exposure is correlated with oxidative DNA damage.

Air pollution exposure and vascular endothelial function: a systematic review and meta-analysis

Vascular endothelial dysfunction is an early stage to cardiovascular diseases (CVDs), but whether air pollution exposure has an effect on it remains unknown. We conducted a systematic review and meta-analysis to summarize epidemiological evidence between air pollution and endothelial dysfunction. We searched the database of PubMed, EMBASE, the Cochrane Library, and Web of Science up to November 10, 2022. Fixed and random effect models were used to pool the effect change or percent change (% change) and 95% confidence interval (95% CI) of vascular function associated with particulate matter (PM) and gaseous pollutants. I² statistics, funnel plot, and Egger's test were used to evaluate heterogeneity and publication bias. There were 34 articles included in systematic review, and 25 studies included in meta-analysis. For each 10 µg/m³ increment in short-term PM_2.5 exposure, augmentation index (AIx) and pulse wave velocity (PWV) increased by 2.73% (95% CI: 1.89%, 3.57%) and 0.56% (95% CI: 0.22%, 0.89%), and flow-mediated dilation (FMD) decreased by 0.17% (95% CI: - 0.33%, - 0.00%). For each 10 µg/m³ increment in long-term PM_2.5 exposure, FMD decreased by 0.99% (95% CI: - 1.41%, - 0.57%). The associations between remaining pollutants and outcomes were not statistically significant. The effect of short-term PM_2.5 exposure on FMD change was stronger in population with younger age, lower female proportion, higher mean body mass index and higher PM_2.5 exposure. Cardiac or vasoactive medication might attenuate this effect. Our study provides evidence that PM_2.5 exposure had adverse impact on vascular endothelial function, indicating the importance of air quality improvement for early CVD prevention.

Potential Biological Mediators of Myocardial and Vascular Complications of Air Pollution-A State-of-the-Art Review

Ambient air pollution is recognised globally as a significant contributor to the burden of cardiovascular diseases. The evidence from both human and animal studies supporting the cardiovascular impact of exposure to air pollution has grown substantially, implicating numerous pathophysiological pathways and related signalling mediators. In this review, we summarise the list of activated mediators for each pathway that lead to myocardial and vascular injury in response to air pollutants. We performed a systematic search of multiple databases, including articles between 1990 and Jan 2022, summarising the evidence for activated pathways in response to each significant air pollutant. Particulate matter <2.5 μm (PM_2.5) was the most studied pollutant, followed by particulate matter between 2.5 μm-10 μm (PM₁₀), nitrogen dioxide (NO₂) and ozone (O₃). Key pathogenic pathways that emerged included activation of systemic and local inflammation, oxidative stress, endothelial dysfunction, and autonomic dysfunction. We looked at how potential mediators of each of these pathways were linked to both cardiovascular disease and air pollution and included the overlapping mediators. This review illustrates the complex relationship between air pollution and cardiovascular diseases, and discusses challenges in moving beyond associations, towards understanding causal contributions of specific pathways and markers that may inform us regarding an individual's exposure, response, and likely risk.

The pathophysiological and molecular mechanisms of atmospheric PM2.5 affecting cardiovascular health: A review

BACKGROUND

Exposure to ambient fine particulate matter (PM2.5, with aerodynamic diameter less than 2.5 µm) is a leading environmental risk factor for global cardiovascular health concern.

OBJECTIVE

To provide a roadmap for those new to this field, we reviewed the new insights into the pathophysiological and cellular/molecular mechanisms of PM2.5 responsible for cardiovascular health.

MAIN FINDINGS

PM2.5 is able to disrupt multiple physiological barriers integrity and translocate into the systemic circulation and get access to a range of secondary target organs. An ever-growing body of epidemiological and controlled exposure studies has evidenced a causal relationship between PM2.5 exposure and cardiovascular morbidity and mortality. A variety of cellular and molecular biology mechanisms responsible for the detrimental cardiovascular outcomes attributable to PM2.5 exposure have been described, including metabolic activation, oxidative stress, genotoxicity, inflammation, dysregulation of Ca2+ signaling, disturbance of autophagy, and induction of apoptosis, by which PM2.5 exposure impacts the functions and fates of multiple target cells in cardiovascular system or related organs and further alters a series of pathophysiological processes, such as cardiac autonomic nervous system imbalance, increasing blood pressure, metabolic disorder, accelerated atherosclerosis and plaque vulnerability, platelet aggregation and thrombosis, and disruption in cardiac structure and function, ultimately leading to cardiovascular events and death. Therein, oxidative stress and inflammation were suggested to play pivotal roles in those pathophysiological processes.

CONCLUSION

Those biology mechanisms have deepen insights into the etiology, course, prevention and treatment of this public health concern, although the underlying mechanisms have not yet been entirely clarified.

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.

Effects of ambient air pollution on glycosylated hemoglobin: a systematic review and meta-analysis

Air pollution is one of the biggest environmental health problems in the world; accumulative studies have shown that air pollution was closely related to metabolism disorders. HbA1c is a stable indicator for blood glucose level monitoring. However, studies on the impact of ambient air pollution on HbA1c have inconsistent conclusions. The objective of the study is to explore the influence of ambient air pollution on HbA1c. By searching keywords, a systematic literature retrieval was carried out on PubMed, Cochrane Library, Web of Science, and Embase databases up to April 2022. Pooled percentage change (%-change) and 95% confidence intervals (95% CI) were estimated using random effect models for particulate matter (PM) and nitrogen dioxide (NO₂). A subgroup analysis of body mass index (BMI), study region, exposure period, sample size, sensitivity analysis, and publication bias detection was also performed. There were 8, 12, and 6 studies included in this meta-analysis to explore the association between PM₁₀, PM_2.5, NO₂, and HbA1c, respectively. The results showed that for every increase of 10 μg/m³ in PM₁₀, PM_2.5, and NO₂, the %-changes in HbA1c were 0.13%, 0.814%, and 0.02%, respectively. The subgroup analysis showed that exposure period, sample size, and BMI were associated with HbA1c in response to air pollution. PM₁₀, PM_2.5, and NO₂ exposure were significantly associated with increased HbA1c levels.

A Real-Time Comparison of Four Particulate Matter Size Fractions in the Personal Breathing Zone of Paris Subway Workers: A Six-Week Prospective Study

We developed a Bayesian spline model for real-time mass concentrations of particulate matter (PM10, PM2.5, PM1, and PM0.3) measured simultaneously in the personal breathing zone of Parisian subway workers. The measurements were performed by GRIMM, a gravimetric method, and DiSCmini during the workers’ work shifts over two consecutive weeks. The measured PM concentrations were analyzed with respect to the working environment, the underground station, and any specific events that occurred during the work shift. Overall, PM0.3 concentrations were more than an order of magnitude lower compared to the other PM concentrations and showed the highest temporal variation. The PM2.5 levels raised the highest exposure concern: 15 stations out of 37 had higher mass concentrations compared to the reference. Station PM levels were not correlated with the annual number of passengers entering the station, the year of station opening or renovation, or the number of platforms and tracks. The correlation with the number of station entrances was consistently negative for all PM sizes, whereas the number of correspondence concourses was negatively correlated with PM0.3 and PM10 levels and positively correlated with PM1 and PM2.5 levels. The highest PM10 exposure was observed for the station platform, followed by the subway cabin and train, while ticket counters had the highest PM0.3, PM1, and PM2.5 mass concentrations. We further found that compared to gravimetric and DiSCmini measurements, GRIMM results showed some discrepancies, with an underestimation of exposure levels. Therefore, we suggest using GRIMM, calibrated by gravimetric methods, for PM sizes above 1μm, and DiSCmini for sizes below 700 nm.

Omega-3 fatty acids attenuate cardiovascular effects of short-term exposure to ambient air pollution

Background

Exposure to air pollution is associated with elevated cardiovascular risk. Evidence shows that omega-3 polyunsaturated fatty acids (omega-3 PUFA) may attenuate the adverse cardiovascular effects of exposure to fine particulate matter (PM_2.5). However, it is unclear whether habitual dietary intake of omega-3 PUFA protects against the cardiovascular effects of short-term exposure to low-level ambient air pollution in healthy participants. In the present study, sixty-two adults with low or high dietary omega-3 PUFA intake were enrolled. Blood lipids, markers of vascular inflammation, coagulation and fibrinolysis, and heart rate variability (HRV) and repolarization were repeatedly assessed in 5 sessions separated by at least 7 days. This study was carried out in the Research Triangle area of North Carolina, USA between October 2016 and September 2019. Daily PM_2.5 and maximum 8-h ozone (O₃) concentrations were obtained from nearby air quality monitoring stations. Linear mixed-effects models were used to assess the associations between air pollutant concentrations and cardiovascular responses stratified by the omega-3 intake levels.

Results

The average concentrations of ambient PM_2.5 and O₃ were well below the U.S. National Ambient Air Quality Standards during the study period. Significant associations between exposure to PM_2.5 and changes in total cholesterol, von Willebrand factor (vWF), tissue plasminogen activator, D-dimer, and very-low frequency HRV were observed in the low omega-3 group, but not in the high group. Similarly, O₃-associated adverse changes in cardiovascular biomarkers (total cholesterol, high-density lipoprotein, serum amyloid A, soluable intracellular adhesion molecule 1, and vWF) were mainly observed in the low omega-3 group. Lag-time-dependent biphasic changes were observed for some biomarkers.

Conclusions

This study demonstrates associations between short-term exposure to PM_2.5 and O₃, at concentrations below regulatory standard, and subclinical cardiovascular responses, and that dietary omega-3 PUFA consumption may provide protection against such cardiovascular effects in healthy adults.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12989-022-00451-4.

An Integration Method for Regional PM2.5 Pollution Control Optimization Based on Meta-Analysis and Systematic Review

PM_2.5 pollution in China is becoming increasingly severe, threatening public health. The major goal of this study is to evaluate the mortality rate attributed to PM_2.5 pollution and design pollution mitigation schemes in a southern district of China through a two-objective optimization model. The mortality rate is estimated by health effect evaluation model. Subjected to limited data information, it is assumed that the meta-analysis method, through summarizing and combining the research results on the same subject, was suitable to estimate the percentage of deaths caused by PM_2.5 pollution. The critical parameters, such as the total number of deaths and the background concentration of PM_2.5, were obtained through on-site survey, data collection, literature search, policy analysis, and expert consultation. The equations for estimating the number of deaths caused by PM_2.5 pollution were established by incorporating the relationship coefficient of exposure to reaction, calculated residual PM_2.5 concentration of affected region, and statistical total base number of deaths into a general framework. To balance the cost from air quality improvement and human health risks, a two-objective optimization model was developed. The first objective is to minimize the mortality rate attributable to PM_2.5 pollution, and the second objective is to minimize the total system cost over three periods. The optimization results demonstrated that the combination of weights assigned to the two objectives significantly influenced the model output. For example, a high weight value assigned to minimizing the number of deaths results in the increased use of treatment techniques with higher efficiencies and a dramatic decrease in pollutant concentrations. In contrast, a model weighted more toward minimizing economic loss may lead to an increase in the death toll due to exposure to higher air pollution levels. The effective application of this model in the Nanshan District of Shenzhen City, China, is expected to serve as a basis for similar work in other parts of the world in the future.

Inhalation of particulate matter containing free radicals leads to decreased vascular responsiveness associated with an altered pulmonary function

Airborne particulate matter (PM) is associated with an increased risk for cardiovascular diseases. Although the goal of thermal remediation is to eliminate organic wastes through combustion, when incomplete combustion occurs, organics chemisorb to transition metals to generate PM-containing environmentally persistent free radicals (EPFRs). Similar EPFR species have been detected in PM found in diesel and gasoline exhaust, woodsmoke, and urban air. Prior in vivo studies demonstrated that EPFRs reduce cardiac function secondary to elevations in pulmonary arterial pressures. In vitro studies showed that EPFRs increase ROS and cytokines in pulmonary epithelial cells. We thus hypothesized that EPFR inhalation would promote lung inflammation and oxidative stress, leading to systemic inflammation, vascular endothelial injury, and a decline in vascular function. Mice were exposed to EPFRs for either 4 h or for 4 h/day for 10 days and lung and vascular function were assessed. After a 4-h exposure, plasma nitric oxide (NO) was reduced while endothelin-1 (ET-1) was increased, however lung function was not altered. After 10 day, plasma NO and ET-1 levels were again altered and lung tidal volume was reduced. These time course studies suggested the vasculature may be an early target of injury. To test this hypothesis, an intermediate time point of 3 days was selected. Though the mice exhibited no marked inflammation in either the lung or the blood, we did note significantly reduced endothelial function concurrent with a reduction in lung tidal volume and an elevation in annexin V protein levels in the lung. Although vascular dysfunction was not dependent upon inflammation, it may be associated with an injury at the air-blood interface. Gene expression analysis suggested roles for oxidative stress and aryl hydrocarbon receptor (Ahr) signaling. Studies probing the relationship between pulmonary oxidative stress and AhR signaling at the air-blood interface with vascular dysfunction seem warranted.NEW & NOTEWORTHY Particulate matter (PM) resulting from the combustion of organic matter is known to contribute to cardiopulmonary disease. Despite hypotheses that cardiovascular dysfunction occurring after PM exposures is secondary to lung or systemic inflammation, these studies investigating exposures to PM-containing environmentally persistent free radicals (EPFRs) demonstrate that cardiovascular dysfunction precedes pulmonary inflammation. The cardiopulmonary health consequences of EPFRs have yet to be thoroughly evaluated, especially in healthy, adult mice. Our data suggest the vasculature as a direct target of PM exposure, and our studies aimed to elucidate the mechanisms contributing to EPFR-induced vascular dysfunction.

Association between exposure to different stone aggregates from asphalt and blood coagulability: A human exposure chamber study

A large fraction of particulate matter (PM)_, especially PM₁₀, concentrations are due to non-exhaust emissions, such as road abrasion and wear on tires and brake pads. Concentrating on road abrasion, we aimed to investigate blood coagulability in healthy adults after exposure to two types of stone materials commonly used in asphalt on Norwegian roads. This study followed a randomized, double-blind, cross-over study design. Using an exposure chamber, 24 healthy young volunteers were exposed to aggregates of two different types of rocks and placebo dust: quartz diorite, rhomb porphyry, and lactose (placebo dust). Each exposure session lasted for 4 hours (h), and blood samples were collected before exposure (baseline), 4 h post-exposure, and 24 h post-exposure to analyse potential changes in the von Willebrand factor (vWF) as well as of fibrinogen, d-dimer, leukocytes, and thrombocytes. The dust concentration in the exposure chamber was measured with real-time instruments and gravimetric samples of total dust, respirable dust, PM₁₀, PM_2.5, and ultrafine particles (UFP). The results were analysed using a linear mixed-effect model. Leukocyte blood counts increased post-exposure for all exposure materials; however, none of the increases were statistically significant. The concentration of fibrinogen increased after exposure to quartz diorite, while it decreased after exposures to rhomb porphyry and lactose. Type of material was a statistically significant explanatory variable for the concentration of fibrinogen, with the most significant increase occurring 24 h post-exposure to quartz diorite. After exposure to the three materials, vWF decreased. For the thrombocytes, an increase in blood count was observed 24 h post-exposure to quartz diorite and rhomb porphyry, with a modest (p = 0.09) positive association for quartz diorite. Although the results are limited, we conclude that the different effects observed post-exposure to quartz diorite support considering potential health effects when choosing materials in the production of asphalt.

The short- and long-term associations of particulate matter with inflammation and blood coagulation markers: A meta-analysis

Inflammation and the coagulation cascade are considered to be the potential mechanisms of ambient particulate matter (PM) exposure-induced adverse cardiovascular events. Tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-8 (IL-8), and fibrinogen are arguably the four most commonly assayed markers to reflect the relationships of PM with inflammation and blood coagulation. This review summarized and quantitatively analyzed the existing studies reporting short- and long-term associations of PM2.5(PM with an aerodynamic diameter ≤2.5 μm)/PM10 (PM with an aerodynamic diameter≤10 μm) with important inflammation and blood coagulation markers (TNF-α, IL-6, IL-8, fibrinogen). We reviewed relevant studies published up to July 2020, using three English databases (PubMed, Web of Science, Embase) and two Chinese databases (Wang-Fang, China National Knowledge Infrastructure). The OHAT tool, with some modification, was applied to evaluate risk of bias. Meta-analyses were conducted with random-effects models for calculating the pooled estimate of markers. To assess the potential effect modifiers and the source of heterogeneity, we conducted subgroup analyses and meta-regression analyses where appropriate. The assessment and correction of publication bias were based on Begg's and Egger's test and "trim-and-fill" analysis. We identified 44 eligible studies. For short-term PM exposure, the percent change of a 10 μg/m3 PM2.5 increase on TNF-α and fibrinogen was 3.51% (95% confidence interval (CI): 1.21%, 5.81%) and 0.54% (95% confidence interval (CI): 0.21%, 0.86%) respectively. We also found a significant short-term association between PM10 and fibrinogen (percent change = 0.17%, 95% CI: 0.04%, 0.29%). Overall analysis showed that long-term associations of fibrinogen with PM2.5 and PM10 were not significant. Subgroup analysis showed that long-term associations of fibrinogen with PM2.5 and PM10 were significant only found in studies conducted in Asia. Our findings support significant short-term associations of PM with TNF-α and fibrinogen. Future epidemiological studies should address the role long-term PM exposure plays in inflammation and blood coagulation markers level change.