Markers of inflammation and coagulation after long-term exposure to coarse particulate matter: a cross-sectional analysis from the multi-ethnic study of atherosclerosis

Coarse Particulate Matter and Markers of Inflammation and Coagulation in the Multi-Ethnic Study of Atherosclerosis (MESA) Population: A Repeat Measures Analysis

BACKGROUND

In contrast to fine particles, less is known of the inflammatory and coagulation impacts of coarse particulate matter (PM 10 - 2.5 , particulate matter with aerodynamic diameter ≤ 10 μ m  and > 2.5 μ m ). Toxicological research suggests that these pathways might be important processes by which PM 10 - 2.5 impacts health, but there are relatively few epidemiological studies due to a lack of a national PM 10 - 2.5 monitoring network.

OBJECTIVES

We used new spatiotemporal exposure models to examine associations of both 1-y and 1-month average PM 10 - 2.5 concentrations with markers of inflammation and coagulation.

METHODS

We leveraged data from 7,071 Multi-Ethnic Study of Atherosclerosis and ancillary study participants 45-84 y of age who had repeated plasma measures of inflammatory and coagulation biomarkers. We estimated PM 10 - 2.5 at participant addresses 1 y and 1 month before each of up to four exams (2000-2012) using spatiotemporal models that incorporated satellite, regulatory monitoring, and local geographic data and accounted for spatial correlation. We used random effects models to estimate associations with interleukin-6 (IL-6), C-reactive protein (CRP), fibrinogen, and D-dimer, controlling for potential confounders.

RESULTS

Increases in PM 10 - 2.5 were not associated with greater levels of inflammation or coagulation. A 10 - μ g / m 3 increase in annual average PM 10 - 2.5 was associated with a 2.5% decrease in CRP [95% confidence interval (CI): - 5.5 , 0.6]. We saw no association between annual average PM 10 - 2.5 and the other markers (IL-6: - 0.7 % , 95% CI: - 2.6 , 1.2; fibrinogen: - 0.3 % , 95% CI: - 0.9 , 0.3; D-dimer: - 0.2 % , 95% CI: - 2.6 , 2.4). Associations consistently showed that a 1 0 - μ g / m 3 increase in 1-month average PM 10 - 2.5 was associated with reduced inflammation and coagulation, though none were distinguishable from no association (IL-6: - 1.2 % , 95% CI: - 3.0   , 0.5; CRP: - 2.5 % , 95% CI: - 5.3 , 0.4; fibrinogen: - 0.4 % , 95% CI: - 1.0 , 0.1; D-dimer: - 2.0 % , 95% CI: - 4.3 , 0.3).

DISCUSSION

We found no evidence that PM 10 - 2.5 is associated with higher inflammation or coagulation levels. More research is needed to determine whether the inflammation and coagulation pathways are as important in explaining observed PM 10 - 2.5 health impacts in humans as they have been shown to be in toxicology studies or whether PM 10 - 2.5 might impact human health through alternative biological mechanisms. https://doi.org/10.1289/EHP12972.

Particulate matter, traffic-related air pollutants, and circulating C-reactive protein levels: The Multiethnic Cohort Study

Inhaled particles and gases can harm health by promoting chronic inflammation in the body. Few studies have investigated the relationship between outdoor air pollution and inflammation by race and ethnicity, socioeconomic status, and lifestyle risk factors. We examined associations of particulate matter (PM) and other markers of traffic-related air pollution with circulating levels of C-reactive protein (CRP), a biomarker of systemic inflammation. CRP was measured from blood samples obtained in 1994-2016 from 7,860 California residents participating in the Multiethnic Cohort (MEC) Study. Exposure to PM (aerodynamic diameter ≤2.5 μm [PM2.5], ≤10 μm [PM10], and between 2.5 and 10 μm [PM10-2.5]), nitrogen oxides (NOx, including nitrogen dioxide [NO2]), carbon monoxide (CO), ground-level ozone (O3), and benzene averaged over one or twelve months before blood draw were estimated based on participants' addresses. Percent change in geometric mean CRP levels and 95% confidence intervals (CI) per standard concentration increase of each pollutant were estimated using multivariable generalized linear regression. Among 4,305 females (55%) and 3,555 males (45%) (mean age 68.1 [SD 7.5] years at blood draw), CRP levels increased with 12-month exposure to PM10 (11.0%, 95% CI: 4.2%, 18.2% per 10 μg/m3), PM10-2.5 (12.4%, 95% CI: 1.4%, 24.5% per 10 μg/m3), NOx (10.4%, 95% CI: 2.2%, 19.2% per 50 ppb), and benzene (2.9%, 95% CI: 1.1%, 4.6% per 1 ppb). In subgroup analyses, these associations were observed in Latino participants, those who lived in low socioeconomic neighborhoods, overweight or obese participants, and never or former smokers. No consistent patterns were found for 1-month pollutant exposures. This investigation identified associations of primarily traffic-related air pollutants, including PM, NOx, and benzene, with CRP in a multiethnic population. The diversity of the MEC across demographic, socioeconomic, and lifestyle factors allowed us to explore the generalizability of the effects of air pollution on inflammation across subgroups.

Significant Decrease in Glycated Hemoglobin, 2h-Post-Load Glucose and High-Sensitivity C-Reactive Protein Levels in Patients with Abnormal Body Mass Index after Therapy with Manual Lymphatic Drainage

The objective of this study was to investigate the effect of manual lymphatic drainage (MLD) on the insulin resistance parameter (HOMA-IR), glycated hemoglobin (HbA1c), C-peptide, insulin, fasting plasma glucose (FPG), 2h-post-loadglucose (2h-PG) and the concentration of high-sensitivity C-reactive protein (hsCRP) in patients with abnormal body mass index. The study involved 30 patients, including patients with normal body weight (as a control group; group I; n = 14), overweight patients (group II; n = 9) and obese patients (group III; n = 7). Each patient underwent 10 sessions of MLD therapy, 3 times a week for 30 min. In addition, we measured body mass index (BMI) and waist-to-hip ratio (WHR) and performed body composition analysis as well as biochemical tests before MLD therapy (stage 0′) and after MLD therapy (stage 1′). A statistically significant correlation was demonstrated between the concentration of C-peptide, BMI, the amount of visceral adipose tissue (r = 0.87, p = 0.003; r = 0.76, p = 0.003, respectively), and the HOMA-IR index, BMI and the amount of visceral adipose tissue (r = 0.86, p = 0.005; r = 0.84, p = 0.042, respectively), before and after MLD therapy. In overweight patients (group II), a statistically significant (p = 0.041) decrease in the hsCRP level by 2.9 mg/L and a significant (p = 0.050) decrease in the 2h-PG level by 12 mg/dL after the MLD therapy was detected. Moreover, in the group of obese patients (group III), a statistically significant (p = 0.013) decrease in HbA1c level by 0.2% after MLD therapy was demonstrated. Our results indicate that MLD may have a positive effect on selected biochemical parameters, with the most favorable changes in overweight patients. Further studies in a larger number of patients are warranted to confirm our findings, to test in-depth their mechanism, and to investigate clinical benefits of this alternative therapy in patients with abnormal body mass index.

Clinical and biological risk factors associated with inflammation in patients with type 2 diabetes mellitus

BACKGROUND

Chronic inflammation has been associated with insulin resistance and related metabolic dysregulation, including type 2 diabetes mellitus (T2DM). Several non modifiable (i.e. genetic predisposition) and modifiable (i.e. sedentary lifestyle, energy-dense food) risk factors were suggested to explain the mechanisms involved in the development of inflammation, but are difficult to assess in clinical routine. The present study aimed to identify easy to asses clinical and biological risk factors associated with inflammation in patients with T2DM.

METHODS

One hundred nine patients (51 men, 58 women), 28-60 years old, from seven primary healthcare centers in Gaza City, Palestine, took part to the cross-sectional study (November 2013-May 2014). Study participants had T2DM with no history of inflammatory diseases, cardiovascular diseases, medication and/or any health condition that might affect the inflammatory markers, interleukin 6 (IL-6) and C-reactive protein (CRP). Inflammation was defined for IL-6 ≥ 2 pg/mL and CRP ≥ 6 mg/L. Multivariable logistic regressions were used to identify the relationship between inflammation and clinical and biological risk factors.

RESULTS

After adjustment for age and gender, inflammation seems to increase with increased body mass index (BMI) (OR: 1.427 [1.055-1.931]), increased fasting blood glucose (OR: 1.029 [1.007-1.052]) and decreased adiponectin values (OR: 0.571 [0.361-0.903]). There were also significant relationships between inflammation and BMI (OR: 1.432 [1.042-1.968]), fasting blood glucose (OR: 1.029 [1.006-1.052]) and adiponectin (OR: 0.569 [0.359-0.902]), after adjustment for smoking habits and physical activity.

CONCLUSION

Managing obesity and associated complications (i.e. hyperglycemia, high adiponectin levels) might help decreasing inflammation in individuals with T2DM.

Effect of urban air pollution on CRP and coagulation: a study on inpatients with acute exacerbation of chronic obstructive pulmonary disease

PURPOSE

Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is an important event in the course of chronic obstructive pulmonary disease that negatively affects patients' quality of life and leads to higher socioeconomic costs. While previous studies have demonstrated a significant association between urban air pollution and hospitalization for AECOPD, there is a lack of research on the impact of particulate matter (PM) on inflammation and coagulation in AECOPD inpatients. Therefore, this study investigated the association of changes in coagulation function and C-reactive protein (CRP) with PM levels in the days preceding hospitalization.

PATIENTS AND METHODS

We reviewed the medical records of AECOPD patients admitted to Putuo Hospital, Shanghai University of Traditional Chinese Medicine, between March 2017 and September 2019. We analyzed the association of coagulation function and CRP level in AECOPD patients with PM levels in the days before hospitalization. Multivariate unconditional logistic regression analyses were used to evaluate the adjusted odds ratio (OR) and 95% confidence interval (CI) for the association of CRP data with hospitalization day. Kruskal-Wallis tests were used to evaluate mean aerodynamic diameter of ≥ 2.5 μm (PM_2.5) exposure on the day before hospitalization; we assessed its association with changes in prothrombin time (PT) in AECOPD inpatients with different Global Initiative for Chronic Obstructive Lung Disease (GOLD) classes.

RESULTS

The peripheral blood PT of AECOPD patients with PM_2.5 ≥ 25 mg/L on the day before hospitalization were lower than those of patients with PM_2.5 < 25 mg/L (t = 2.052, p = 0.041). Patients with severe GOLD class exposed to greater than 25 mg/L of PM_2.5on the day before hospitalization showed significant differences in PT (F = 9.683, p = 0.008). Peripheral blood CRP levels of AECOPD patients exposed to PM_2.5 ≥ 25 mg/L and PM₁₀ ≥ 50 mg/L on the day before hospitalization were higher than those of patients exposed to PM_2.5 < 25 mg/L and PM₁₀ < 50 mg/L (t = 2.008, p = 0.046; t = 2.637, p = 0.009). Exposure to < 25 mg/L of PM_2.5 on the day before hospitalization was significantly associated with CRP levels (adjusted OR 1.91; 95% CI 1.101, 3.315; p = 0.024).

CONCLUSION

Exposure of patients with AECOPD to high PM levels on the day before hospitalization was associated with an increased CRP level and shortened PT. Moreover, PM_2.5 had a greater effect on CRP level and PT than mean aerodynamic diameter of ≥ 10 μm (PM₁₀). AECOPD patients with severe GOLD class were more sensitive to PM_2.5-induced shortening of PT than those with other GOLD classes.

Associations of long-term exposure to air pollution with blood pressure and homocysteine among adults in Beijing, China: A cross-sectional study

BACKGROUND

Studies on the hypertensive effect of long-term exposure to air pollution are mixed, and sparse evidence exists regarding its effects on homocysteine (Hcy), another crucial risk factor for cardiovascular disease (CVD).

METHODS

We collected data from 23,256 participants aged 18-74 years at baseline (years 2017-2018) from a community-based cohort in China. A linear combination of concentrations from monitoring stations at the participants' home and work addresses, weighted by the time, was used to estimate two-year exposures to particulate matter with fine particles≤2.5 μm (PM_2.5), aerodynamic diameter≤10 μm (PM₁₀), nitrogen dioxide (NO₂) and sulfur dioxide (SO₂). Generalized linear regressions and logistic regressions were conducted to examine the associations between air pollution and systolic blood pressure (SBP), diastolic blood pressure (DBP), Hcy, hypertension and co-occurrence of hypertension and hyperhomocysteinemia (HHcy).

RESULTS

The results showed that each interquartile range (IQR) increase in PM_2.5 (16.1 μg/m³), PM₁₀ (19.3 μg/m³) and SO₂ (3.9 μg/m³) was significantly associated with SBP (changes: 0.64-1.86 mmHg), DBP (changes: 0.35-0.70 mmHg) and Hcy (changes: 0.77-1.04 μmol/L) in the fully adjusted model. These air pollutants were also statistically associated with the prevalence of co-occurrence of hypertension and HHcy (ORs: 1.22-1.32), which were stronger than associations with the prevalence of hypertension (ORs: 1.09-1.19). The hypertensive effects of exposure to PM_2.5, PM₁₀ and SO₂ were more pronounced among elder participants, obese participants, those with established CVD or a high 10-year CVD risk and those with a family history of hypertension. However, interaction analyses of Hcy showed different patterns. Additionally, moderate level of physical activity and active travel mode benefited individuals in resisting the health impacts of air pollution on both blood pressure (BP) and Hcy.

CONCLUSIONS

Our study supports a positive relationship between air pollution and BP and Hcy among adults in Beijing, and close attention to vulnerable populations and healthy lifestyles could effectively benefit further cardiovascular health.

Differential inflammatory potential of particulate matter (PM) size fractions from Imperial Valley, CA

Particulate matter (PM) in Imperial Valley originates from a variety of sources such as agriculture, traffic at the border crossing, emissions from the cross-border city of Mexicali, and the drying lakebed of the Salton Sea. Dust storms in Imperial Valley, California regularly lead to exceedances of the federal air quality standards for PM10 (diameter less than 10 microns). To determine if there are differences in the composition and biological response to Imperial County PM by size, ambient PM samples were collected from a sampling unit stationed in the northern-most part of the valley, South of the Salton Sea. Ultrafine, fine, and coarse PM samples were collected and extracted separately. Chemical composition of each size fraction was obtained after extraction by using several analytical techniques, and biological response was measured by exposing a cell line of macrophages to particles and quantifying subsequent gene expression. Biological measurements demonstrated coarse PM induced an inflammatory response in macrophages measured in increases of inflammatory markers IL-1β, IL-6, IL-8 and CXCL2 expression, whereas ultrafine and fine PM only demonstrated significant increases in expression of CYP1a1. These differential responses were due not only to particle size, but to the distinct chemical profiles of each size faction as well. Community groups in Imperial Valley have already completed several projects to learn more about local air quality, giving residents access to data that provides real-time levels of PM2.5 and PM10 as well as recommendations on health-based practices dependent on the current AQI (air quality index). However, to date there is no information on the composition or toxicity of ambient PM from the region. The data presented here could provide more definitive information on the toxicity of PM by size, and further inform the community on local air quality.

A case-crossover study of short-term air pollution exposure and the risk of stillbirth in California, 1999-2009

BACKGROUND

Associations between ambient air pollution and stillbirth have recently been explored, but most studies have focused on long-term (trimester or gestational averages) rather than short-term (within one week) air pollution exposures.

OBJECTIVE

To evaluate whether short-term exposures to criteria air pollutants are associated with increased risk of stillbirth.

METHODS

Using air pollution and fetal death certificate data from 1999 to 2009, we assessed associations between acute prenatal air pollution exposure and stillbirth in California. In a time-stratified case-crossover study, we analyzed single day and/or cumulative average days (up to a 6 day lag) of exposure to fine (PM_2.5) and coarse particles (PM_10-2.5), ozone (O₃), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), and carbon monoxide (CO) for mothers estimated to reside within 10 km of a pollution monitor based on reported zip code. We also examined potential confounding by apparent temperature or co-pollutants, and effect modification by maternal demographic factors, fetal sex, gestational age, and cause of stillbirth.

RESULTS

Stillbirth cases in the primary analyses ranged between 1,203 and 13,018, depending on the pollutant. For an IQR increase in SO₂ (lag 4), O₃ (lag 4), and PM_10-2.5 (lag 2), we found a 2.8% (95% confidence interval (CI) 0.2%, 5.5%), 5.8% (95% CI 1.6%, 10.1%), and 6.1% (95% CI 0.1%, 12.4%) increase in the odds of stillbirth, respectively. Additional adjustment by apparent temperature had little effect on the SO₂ association but slightly attenuated O₃ (adjusted % change: 4.2% (95% CI -0.2%, 8.9%) and PM_10-2.5 (5.7% (95% CI -1.1%, 13.0%)) associations, while other co-pollutants had minimal impact. Associations were observed specifically for stillbirths from obstetric complications and in women with higher educational attainment.

CONCLUSIONS

This study provides evidence for associations between prenatal short-term air pollution exposure, specifically SO₂, O_3, and PM_10-2.5, and stillbirth in California and warrants replication of findings in other settings.

Air Pollution and Asthma: Critical Targets for Effective Action

Evidence to advocate for cleaner air for people with asthma is not in short supply. We know that air pollution is associated with the development and worsening of the condition and that mitigating interventions can improve respiratory outcomes. We have clear targets, particularly traffic emissions, especially in urban areas, and plenty of potentially effective actions. Road traffic must be reduced, and what remains should be cleaner and greener. Urban green spaces, safe cycle networks and wider pavements will promote active travel and leisure time exercise. Healthcare professionals must ensure people are aware of their air quality, its impact on asthma and the appropriate behaviour to safeguard health. What remains are realistic policies and effective measures, based on the correct scientific evidence, to be taken forth with political courage and investment so that air pollution no longer contributes to the development or worsening of respiratory ill health.

Association between coarse particulate matter and inflammatory and hemostatic markers in a cohort of midlife women

BACKGROUND

Exposure to particulate matter air pollution has been associated with cardiovascular disease (CVD) morbidity and mortality; however, most studies have focused on fine particulate matter (PM_2.5) exposure and CVD. Coarse particulate matter (PM_10-2.5) exposure has not been extensively studied, particularly for long-term exposure, and the biological mechanisms remain uncertain.

METHODS

We examined the association between ambient concentrations of PM_10-2.5 and inflammatory and hemostatic makers that have been linked to CVD. Annual questionnaire and clinical data were obtained from 1694 women (≥ 55 years old in 1999) enrolled in the longitudinal Study of Women's Health Across the Nation (SWAN) at six study sites from 1999 to 2004. Residential locations and the USEPA air monitoring network measurements were used to assign exposure to one-year PM_10-2.5, as well as co-pollutants. Linear mixed-effects regression models were used to describe the association between PM_10-2.5 exposure and markers, including demographic, health and other covariates.

RESULTS

Each interquartile (4 μg/m³) increase in one-year PM_10-2.5 exposure was associated with a 5.5% (95% confidence interval [CI]: 1.8, 9.4%) increase in levels of plasminogen activator inhibitor-1 (PAI-1) and 4.1% (95% CI: - 0.1, 8.6%) increase in high-sensitivity C-creative Protein (hs-CRP). Stratified analyses suggested that the association with PAI-1 was particularly strong in some subgroups, including women who were peri-menopausal, were less educated, had a body mass index lower than 25, and reported low alcohol consumption. The association between PM_10-2.5 and PAI-1 remained unchanged with adjustment for PM_2.5, ozone, nitrogen dioxide, and carbon monoxide.

CONCLUSIONS

Long-term PM_10-2.5 exposure may be associated with changes in coagulation independently from PM_2.5, and thus, contribute to CVD risk in midlife women.

Ambient air pollution and homocysteine: Current epidemiological evidence and a call for further research

Elevated blood homocysteine (Hcy) is an independent risk factor for cardiovascular disease. A growing number of studies have evaluated the link between air pollution and blood Hcy levels, but the results are inconsistent. To date, no systematic review of the published studies has been conducted yet. We aimed to provide a comprehensive overview of these studies. We systematically searched three international databases (PubMed, Web of Science, and Embase) and four Chinese databases (Wanfang, CNKI, CBM, and VIP) for peer-reviewed epidemiological studies investigating associations between ambient air pollutants and Hcy levels published before December 2019. We screened literature, extracted data, assessed methodological quality, and evaluated the risk of bias of the included studies. Of 1157 identified articles, 10 were finally included in this systematic review. Most were cross-sectional studies and were performed in developed countries. Particulate matter with aerodynamic diameters less than 2.5 μm (PM_2.5) and/or 10 μm (PM₁₀) were investigated in all of the included studies. Overall, the evidence generally supports a positive association between higher PM concentrations and elevated Hcy levels. However, high heterogeneity in terms of study participants, study design, exposure duration, and particle components and sources, low methodological quality and probable high risk of bias in some studies, and limited literature number precluded us from drawing a robust conclusion. Associations between Hcy and gaseous pollutants were explored in only one or two studies, and the results were inconclusive. Additional, well-designed studies remain required to validate the association between air pollution and Hcy.

Identifying the contributions of multiple driving forces to PM10-2.5 pollution in urban areas in China

Economic development and urban expansion have accelerated particulate matter pollution in urban areas in China. Particulate matter-driven haze poses a serious threat to human beings from a public health point of view. Substantial evidences had linked adverse health effects with exposures to PM_2.5, but recent research indicated that PM_10-2.5 also had great risk. However, the relative contributions of driving forces to PM_10-2.5 pollution are not well understood in the urban areas in China, and no targeted policies have been regulated to control the pollution. In this study, we quantified the contributions of potential driving factor across China with the structural equation model (SEM). Our results showed that in 2015 and 2016, the annual average concentrations of PM_10-2.5 in the 290 prefecture-level cities with a mean value of 36 and 35 μg/m³, respectively. Industrial scale contributed more to PM_10-2.5 pollution than city size and residents' activities in urban areas based on SEM results. Driving forces included in our model could explain 42% of variations in PM_10-2.5 pollution, which indicated that there existed influences from other anthropogenic sources and natural sources. Eleven targeted recommendations were then proposed to control PM_10-2.5 pollution based on our mechanism analysis. Findings from our study are beneficial to control PM_10-2.5 pollution on a national scale, and also can provide a theoretical basis for the formulation of PM_10-2.5 pollution control policy in China.

Is long-term particulate matter and nitrogen dioxide air pollution associated with incident monoclonal gammopathy of undetermined significance (MGUS)? An analysis of the Heinz Nixdorf Recall study

BACKGROUND

Exposure to air pollution activates the innate immune system and influences the adaptive immune system in experimental settings. We investigated the association of residential long-term exposure to particulate matter (PM) and NO₂ air pollution with monoclonal gammopathy of undetermined significance (MGUS) as a marker of adaptive immune system activation.

METHODS

We used data from the baseline (2000-2003), 5-year (2006-2008) and 10-year (2011-2015) follow-up examinations of the German Heinz Nixdorf Recall cohort study of 4814 participants (45-75years). Residential exposure to PM size fractions and NO₂ was estimated by land-use regression (ESCAPE-LUR, annual mean 2008/2009) and dispersion chemistry transport models (EURAD-CTM, 3-year mean at baseline). We used logistic regression to estimate the effects of air pollutants on incident MGUS, adjusting for age, sex, education, smoking status, physical activity, and BMI. As a non-linear approach, we looked at quartiles (2-4) of the air pollutants in comparison to quartile 1.

RESULTS

Of the 3949 participants with complete data, 100 developed MGUS during the 10-year follow-up. In the main model, only PM_coarse was associated with incident MGUS (OR per IQR (1.9μg/m³): 1.32, 95% CI 1.04-1.67). We further found positive associations between PM size fractions estimated by ESCAPE-LUR and incident MGUS by quartiles of exposure (OR Q4 vs Q1: PM_2.5 2.03 (1.08-3.80); PM₁₀ 1.97 (1.05-3.67); PM_coarse 1.98 (1.09-3.60)).

CONCLUSIONS

Our results indicate that an association between long-term exposure to PM and MGUS may exist. Further epidemiologic studies are needed to corroborate this possible link.

Airborne endotoxin concentrations in indoor and outdoor particulate matter and their predictors in an urban city

Endotoxins are an important biological component of particulate matter and have been associated with adverse effects on human health. There have been some recent studies on airborne endotoxin concentrations. We collected fine (PM_2.5 ) and coarse (PM_10-2.5 ) particulate matter twice on weekdays and weekends each for 48 hour, inside and outside 55 homes in an urban city in Japan. Endotoxin concentrations in both fractions were measured using the kinetic Limulus Amebocyte Lysate assay. The relationships between endotoxin concentrations and household characteristics were evaluated for each fraction. Both indoor and outdoor endotoxin concentrations were higher in PM_2.5 than in PM_10-2.5 . In both PM_2.5 and PM_10-2.5 , indoor endotoxin concentrations were higher than outdoor concentrations, and the indoor endotoxin concentrations significantly correlated with outdoor concentrations in each fraction (R² =0.458 and 0.198, respectively). Indoor endotoxin concentrations in PM_2.5 were significantly higher in homes with tatami or carpet flooring and in homes with pets, and lower in homes that used air purifiers. Indoor endotoxin concentrations in PM_10-2.5 were significantly higher in homes with two or more children and homes with tatami or carpet flooring. These results showed that the indoor endotoxin concentrations were associated with the household characteristics in addition to outdoor endotoxin concentrations.

Long-term exposure to high air pollution induces cumulative DNA damages in traffic policemen

The specific effects of long-term exposure to high air pollution on human health and biological remain unclear. To explore the adverse health effects as well as biological mechanisms and biomarkers for durative exposure to air pollution, 183 traffic policemen and 88 office policemen were enrolled in this study. The concentration of PM2.5 in both the traffic and office policemen's working environments were obtained. Detailed personal questionnaires were completed and levels of inflammation, oxidative stress and DNA damage markers of all participants were analyzed in this study. The average PM2.5 concentration of the intersections of main roads and the offices of control group were 132.4±48.9μg/m³ and 50.80±38.6μg/m³, respectively. The traffic policemen, who stably exposed to at least 2 times higher PM2.5 in their work area as compared with the control group, have a median average duration of 7.00years, and average cumulative intersection duty time reached 8030h. No statistically significant differences in the levels of inflammation markers were observed between the traffic and office policemen. However, the DNA damage markers in traffic policemen shared significant positive correlation with cumulative intersection duty time and higher than those in the office policemen. Multiple linear regression analysis demonstrated that the increase of cumulative intersection duty time by 1h per day for one year was associated with the increase in 8-hydroxy-20-deoxyguanosine of 0.329% (95% CI: 0.249% to 0.409%), tail DNA of 0.051% (95% CI: 0.041% to 0.061%), micronucleus frequency of 0.036‰ (95% CI: 0.03‰ to 0.043‰), and a decrease in glutathione of 0.482% (95% CI: -0.652% to -0.313%). These findings suggest that long-term exposure to high air pollution could induce cumulative DNA damages, supporting the hypothesis that durative exposure to air pollution is associated with an increased risk of cancer.

Ambient Coarse Particulate Matter and the Right Ventricle: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Coarse particulate matter (P10-2.5) is primarily mechanically generated and includes crustal material, brake and tire wear, and biological particles. PM10-2.5 is associated with pulmonary disease, which can lead to right ventricular (RV) dysfunction. Although RV characteristics have been associated with combustion-related pollutants, relationships with PM10-2.5 remain unknown.

OBJECTIVES

To quantify cross-sectional associations between RV dysfunction and PM10-2.5 mass and components among older adults and susceptible populations.

METHODS

We used baseline cardiac magnetic resonance images from 1,490 participants (45-84 y old) from the Multi-Ethnic Study of Atherosclerosis and assigned 5-y residential concentrations of PM10-2.5 mass, copper, zinc, phosphorus, silicon, and endotoxin, using land-use regression models. We quantified associations with RV mass, end-diastolic volume, and ejection fraction after control for risk factors and copollutants using linear regression. We further examined personal susceptibility.

RESULTS

We found positive associations of RV mass and, to a lesser extent, end diastolic volume with PM10-2.5 mass among susceptible populations including smokers and persons with emphysema. After adjustment for copollutants, an interquartile range increase in PM10-2.5 mass (2.2 μg/m3) was associated with 0.5 g (95% CI: 0.0, 1.0), 0.9 g (95% CI: 0.1, 1.7), and 1.4 g (95% CI: 0.4, 2.5) larger RV mass among former smokers, current smokers, and persons with emphysema, respectively. No associations were found with healthy individuals or with ejection fraction.

CONCLUSIONS

Alterations to RV structure may represent a mechanism by which long-term PM10-2.5 exposure increases risks for adverse respiratory and cardiovascular outcomes, especially among certain susceptible populations. https://doi.org/10.1289/EHP658.

Obesity and inflammation: the linking mechanism and the complications

Obesity is the accumulation of abnormal or excessive fat that may interfere with the maintenance of an optimal state of health. The excess of macronutrients in the adipose tissues stimulates them to release inflammatory mediators such as tumor necrosis factor α and interleukin 6, and reduces production of adiponectin, predisposing to a pro-inflammatory state and oxidative stress. The increased level of interleukin 6 stimulates the liver to synthesize and secrete C-reactive protein. As a risk factor, inflammation is an imbedded mechanism of developed cardiovascular diseases including coagulation, atherosclerosis, metabolic syndrome, insulin resistance, and diabetes mellitus. It is also associated with development of non-cardiovascular diseases such as psoriasis, depression, cancer, and renal diseases. On the other hand, a reduced level of adiponectin, a significant predictor of cardiovascular mortality, is associated with impaired fasting glucose, leading to type-2 diabetes development, metabolic abnormalities, coronary artery calcification, and stroke. Finally, managing obesity can help reduce the risks of cardiovascular diseases and poor outcome via inhibiting inflammatory mechanisms.

Fine particulate air pollution and premature ventricular contractions: The REasons for Geographic And Racial Differences in Stroke (REGARDS) Study

BACKGROUND

It is unknown if higher levels of ambient particulate matter (PM) exposure increase the risk for premature ventricular contractions (PVC) in a population-based study of men and women, and if this relationship varies by race or sex.

METHODS

We examined the association of PM <2.5µm in diameter (PM_2.5) concentration with PVCs in 26,121 (mean age=64±9.3 years; 55% female; 41% black) participants from the REasons for Geographic And Racial Differences in Stroke (REGARDS) study. Estimates of short- (2-week) and long-term (1-year) PM_2.5 exposures were computed prior to the baseline visit using geographic information system data on the individual level at the coordinates of study participants' residences. PVCs were identified from baseline electrocardiograms.

RESULTS

PVCs were detected in 1719 (6.6%) study participants. Short- (OR=1.08, 95%CI=1.03, 1.14) and long- (OR=1.06, 95%CI=1.01, 1.12) term PM_2.5 exposures were associated with PVCs. Interactions were not detected by race or sex. An interaction between short-term PM_2.5 exposure and PVCs was detected for those with cardiovascular disease (OR=1.16, 95%CI=1.06, 1.27) compared with those without cardiovascular disease (OR=1.05, 95%CI=0.99, 1.12; p-interaction=0.027).

CONCLUSION

Our findings suggest that PM_2.5 exposure is associated with an increased risk for PVCs in a biracial population-based study of men and women. We also have identified persons with cardiovascular disease as an at-risk population for PVCs when increases in short-term PM_2.5 concentration occur.

Short-term effects of particle size fractions on circulating biomarkers of inflammation in a panel of elderly subjects and healthy young adults

Systemic inflammation biomarkers have been associated with risk of cardiovascular morbidity and mortality. We aimed to clarify associations of acute exposure to particulate matter (PM₁₀ (PM < 10 μm), PM_2.5-10 (PM 2.5-10 μm), PM_2.5 (PM < 2.5 μm), PM_1-2.5 (PM 1-2.5 μm), and PM1 (PM < 1 μm)) with systemic inflammation using panels of elderly subjects and healthy young adults. We followed a panel of 44 nonsmoking elderly subjects living in a retirement home and a panel of 40 healthy young adults living in a school dormitory in Tehran city, Iran from May 2012 to May 2013. Blood biomarkers were measured one every 7-8 weeks and included white blood cells (WBC), high sensitive C-reactive protein (hsCRP), tumor necrosis factor-soluble receptor-II (sTNF-RII), interleukin-6 (IL-6), and von Willebrand factor (vWF). We measured hourly indoor and outdoor exposure to PM₁₀, PM_2.5-10, PM_2.5, PM_1-2.5, and PM₁ mass concentration to derive weighted averages of personal exposure based on simultaneously collected time-activity data. The random intercept linear mixed effects model was used for data analysis. We observed significant positive associations for WBC and IL-6 with exposure to PM₁₀, PM_2.5-10, PM_2.5, PM_1-2.5, and PM₁; sTNF-RII with PM_2.5, PM_1-2.5, and PM₁; hsCRP with PM_2.5 and PM₁; and vWF with PM₁₀ and PM_2.5-10, PM_2.5, and PM_1-2.5 mass concentration in elderly subjects from the current-day and multiday averages. For healthy young adults, we found significant positive associations for WBC and IL-6 with exposure to PM₁₀, PM_2.5-10, PM_2.5, and PM_1-2.5, but no with PM₁. The results showed that increase of hsCRP, sTNF-RII, and vWF were not significantly associated with any of the PM sizes investigated in the healthy young subjects. Our results provided some evidence that short-term exposure to PM₁₀, PM_2.5-10, PM_2.5, PM_1-2.5, and PM₁ was associated with inflammation and coagulation blood markers, but associations were depended on PM size and also differed across the various time lag.

Environmental Exposures and Cardiovascular Disease: A Challenge for Health and Development in Low- and Middle-Income Countries

Environmental exposures in low- and middle-income countries lie at the intersection of increased economic development and the rising public health burden of cardiovascular disease. Increasing evidence suggests an association of exposure to ambient air pollution, household air pollution from biomass fuel, lead, arsenic, and cadmium with multiple cardiovascular disease outcomes, including hypertension, coronary heart disease, stroke, and cardiovascular mortality. Although populations in low- and middle-income countries are disproportionately exposed to environmental pollution, evidence linking these exposures to cardiovascular disease is derived from populations in high-income countries. More research is needed to further characterize the extent of environmental exposures.

Biomarkers of the health outcomes associated with ambient particulate matter exposure

Epidemiologic evidence supports the positive association of cardiopulmonary morbidity and mortality, and lung cancer risk with exposure to airborne particulate matter (PM). Oxidative stress and inflammation have been proposed to be the major causal factors involved in mediating PM effects on both cardiovascular and pulmonary health outcomes. However, the mechanism whereby PM causes the health effects is not fully elucidated. To evaluate and investigate human exposure to PM, it is essential to have a specific, sensitive and robust characterization of individual exposure to PM. Biomarkers may mark important intermediate steps leading to overt health effects after PM exposure. Thus biomarkers are promising indicators, which could serve as representative measures of the exposure to PM for assessing the health impacts and understanding the mechanism. Indeed, a number of biomarkers are already in use in the field of epidemiological studies and toxicological research. However, we are facing now the challenges to select robust, specific and sensitive biomarkers, which can be employed in large-scale of population to assess the health risk and to monitor the effectiveness of interventions. In this review, we describe a range of biomarkers that are associated with air pollution exposure, particularly markers of oxidative stress, inflammatory factors, and microRNAs, as well as markers of pollutants metabolites. Understanding the nature of the association of these biomarkers with PM exposure may shed some light on the process of selecting biomarkers for large-scale population studies, developing novel preventative and therapeutic strategies.

Long- and Short-term Exposure to Air Pollution and Inflammatory/Hemostatic Markers in Midlife Women

BACKGROUND

Studies have reported associations between long-term air pollution exposures and cardiovascular mortality. The biological mechanisms connecting them remain uncertain.

METHODS

We examined associations of fine particles (PM2.5) and ozone with serum markers of cardiovascular disease risk in a cohort of midlife women. We obtained information from women enrolled at six sites in the multi-ethnic, longitudinal Study of Women's Health Across the Nation, including repeated measurements of high-sensitivity C-reactive protein, fibrinogen, tissue-type plasminogen activator antigen, plasminogen activator inhibitor type 1, and factor VIIc (factor VII coagulant activity). We obtained residence-proximate PM2.5 and ozone monitoring data for a maximum five annual visits, calculating prior year, 6-month, 1-month, and 1-day exposures and their relations to serum markers using longitudinal mixed models.

RESULTS

For the 2,086 women studied from 1999 to 2004, PM2.5 exposures were associated with all blood markers except factor VIIc after adjusting for age, race/ethnicity, education, site, body mass index, smoking, and recent alcohol use. Adjusted associations were strongest for prior year exposures for high-sensitivity C-reactive protein (21% increase per 10 μg/m³ PM2.5, 95% confidence interval [CI]: 6.6, 37), tissue-type plasminogen activator antigen (8.6%, 95% CI: 1.8, 16), and plasminogen activator inhibitor (35%, 95% CI: 19, 53). An association was also observed between year prior ozone exposure and factor VIIc (5.7% increase per 10 ppb ozone, 95% CI: 2.9, 8.5).

CONCLUSIONS

Our findings suggest that prior year exposures to PM2.5 and ozone are associated with adverse effects on inflammatory and hemostatic pathways for cardiovascular outcomes in midlife women.

Advances in Understanding Air Pollution and CVD

The MESA Air (Multi-Ethnic Study of Atherosclerosis and Air Pollution) leveraged the platform of the MESA cohort into a prospective longitudinal study of relationships between air pollution and cardiovascular health. MESA Air researchers developed fine-scale, state-of-the-art air pollution exposure models for the MESA Air communities, creating individual exposure estimates for each participant. These models combine cohort-specific exposure monitoring, existing monitoring systems, and an extensive database of geographic and meteorological information. Together with extensive phenotyping in MESA-and adding participants and health measurements to the cohort-MESA Air investigated environmental exposures on a wide range of outcomes. Advances by the MESA Air team included not only a new approach to exposure modeling, but also biostatistical advances in addressing exposure measurement error and temporal confounding. The MESA Air study advanced our understanding of the impact of air pollutants on cardiovascular disease and provided a research platform for advances in environmental epidemiology.

Current Methods and Challenges for Epidemiological Studies of the Associations Between Chemical Constituents of Particulate Matter and Health

Epidemiological studies have been critical for estimating associations between exposure to ambient particulate matter (PM) air pollution and adverse health outcomes. Because total PM mass is a temporally and spatially varying mixture of constituents with different physical and chemical properties, recent epidemiological studies have focused on PM constituents. Most studies have estimated associations between PM constituents and health using the same statistical methods as in studies of PM mass. However, these approaches may not be sufficient to address challenges specific to studies of PM constituents, namely assigning exposure, disentangling health effects, and handling measurement error. We reviewed large, population-based epidemiological studies of PM constituents and health and describe the statistical methods typically applied to address these challenges. Development of statistical methods that simultaneously address multiple challenges, for example, both disentangling health effects and handling measurement error, could improve estimation of associations between PM constituents and adverse health outcomes.

Obesity can predict and promote systemic inflammation in healthy adults

BACKGROUND

To find out the differences on biomedical data between obese and non-obese participants, and to identify risk factors associated with systemic inflammation in healthy Palestinian adults.

METHODOLOGY

A cross-sectional study involved 105 apparently healthy adults. Interview questionnaire was used to collect personal information. Participants were excluded if they suffered from acute or chronic inflammatory diseases, or continued using medicines, which might affect the biomedical results.

RESULTS

In association with increased Body Mass Index (BMI), the obese group displayed significant higher markers including: interleukin 6 (IL-6), high sensitivity C reactive protein (hs-CRP), total cholesterol (TC), systolic blood pressure (SBP), and diastolic blood pressure (DBP). Obese group in association with increased waist circumference (WC) was higher significantly in inflammatory markers (IL-6, hs-CRP), lipid profile (TC) and triglyceride (TG), and blood pressure (SBP, DBP). A tertile of a feature of systemic inflammation (hs-CRP) was created, by Ordinal Logistic Regression, after adjusting for the age, gender, smoking habits, physical activity pattern, father and mother's health history; risk factors were the increased BMI [OR: 1.24] (95% CI: 1.005-1.548, P=0.050), IL-6 [OR: 3.35] (95% CI: 1.341-8.398, P=0.010), DBP [OR: 1.19] (95% CI: 1.034-1.367, P=0.015), and reduced Adiponectin [OR: 0.59] (95% CI: 0.435-0.820, P=0.001). Finally, BMI correlated with IL-6 and hs-CRP (r=0.326, P=0.005; r=0.347, P<0.001; respectively), and hs-CRP correlated with IL-6 (r=0.303, P=0.010), and inversely with Adiponectin (r=-0.342, P=0.001).

CONCLUSION

The increased level of IL-6 and reduced Adiponectin, which strongly associated with obesity, indicated that having high BMI is a useful marker in association with IL-6 and further developed systemic inflammation.

Atmospheric metallic and arsenic pollution at an offshore drilling platform in the Bo Sea: A health risk assessment for the workers

To investigate the ambient metal pollution at the offshore drilling platform in the Bo Sea, which few studies have focused on, PM2.5 samples were collected and ten heavy metals, as well as As, were analyzed. High concentration levels of metals were observed, and the heavy metal pollution was quite serious compared to air quality standards and other marine areas. Back trajectories and wind dependent and PCA analyses showed that the marine sources included ship traffic emissions and corrosive stainless steels from the equipment at the platform as well as industrial emissions from stainless steel production and coal combustion sources, which were transported from the surrounding mainland. Both contributed greatly to the ambient metallic particles at the offshore platform. The Hazard Index values of the metals, which were much less than 1, the Carcinogenic Risk data, which were lower than the EPA's acceptable range, and the fact that the metal concentrations did not the exceed the permissible exposure limits of OSHA, indicated that the health risks from the ambient metallic particles for the oil-drilling workers were not significant.

Particulate matter (PM₁₀) induces metalloprotease activity and invasion in airway epithelial cells

Airborne particulate matter with an aerodynamic diameter ≤ 10 μm (PM10) is a risk factor for the development of lung diseases and cancer. The aim of this work was to identify alterations in airway epithelial (A549) cells induced by PM10 that could explain how subtoxic exposure (10 μg/cm(2)) promotes a more aggressive in vitro phenotype. Our results showed that cells exposed to PM10 from an industrial zone (IZ) and an urban commercial zone (CZ) induced an increase in protease activity and invasiveness; however, the cell mechanism is different, as only PM10 from CZ up-regulated the activity of metalloproteases MMP-2 and MMP-9 and disrupted E-cadherin/β-catenin expression after 48 h of exposure. These in vitro findings are relevant in terms of the mechanism action of PM10 in lung epithelial cells, which could be helpful in understanding the pathogenesis of some human illness associated with highly polluted cities.