A cross-sectional analysis of polycyclic aromatic hydrocarbons and diesel particulate matter exposures and hypertension among individuals of Mexican origin

Associations among urinary 1-hydroxypyrene level, oxidative stress, and high blood pressure: A panel study among elderly Koreans

Polycyclic aromatic hydrocarbons (PAHs) are environmental carcinogens. However, there is limited evidence for the relations between PAHs exposure and blood pressure (BP) with the mediating role of oxidative stress. Therefore, in this study, we evaluated relations among PAHs exposure, oxidative stress, and BP in the elderly population. We measured the levels of 1-hydroxypyrene (1-OHP), an indicator of PAHs exposure, and malondialdehyde (MDA), an oxidative stress marker, in urine samples repeatedly collected from 560 elderly persons aged ≥60 years, and then evaluated the relations among 1-OHP level, MDA level, and systolic or diastolic BP (SBP or DBP) measured on the day of urine collection. Urinary 1-OHP level was significantly associated with both MDA level (β = 0.19 and p < 0.0001) and BP (β = 1.72 and p < 0.0001 for SBP; and β = 1.24 and p < 0.0001 for DBP). Furthermore, urinary MDA level was also significantly associated with BP (β = 4.35 and p < 0.0001 for SBP; and β = 2.51 and p < 0.0001 for DBP). The trend for the change of SBP and DBP by 1-OHP quartile was more apparent in the elderly female participants (ptrend<0.0001 for SBP; and ptrend<0.0001 for DBP) compared with the elderly male participants (ptrend = 0.8351 for SBP; and ptrend = 0.3736 for DBP). To explore the mediating role of oxidative stress in the relation between 1-OHP level and SBP or DBP, we repeated these analyses after adjustment for the MDA levels. The increase in BP by 1-OHP exposure was largely mediated by the production of MDA (96.3% for SBP and 94.7% for DBP). These results revealed that PAHs exposure may increase BP through the mediation of oxidative stress.

Effect and interaction of PINK1 genetic polymorphisms and environmental factors on blood pressure in COEs-exposed workers

Coke oven emissions (COEs) contain a variety of polycyclic aromatic hydrocarbons (PAHs), which can cause damage to the human cardiovascular system. In addition, myocardial mitochondria are susceptible to damage in hypertensive patients. However, it is not clear whether genetic variation, in single nucleotide polymorphisms (SNPs) in PINK1 affects COEs exposure-induced abnormal blood pressure. We surveyed and tested 518 workers exposed to COEs and statistically analyzed them with SPSS 21.0 software. SBP was greater in the high-exposure group than in the low-exposure group. Generalized linear model analysis showed that the interaction of PINK1 rs3738136 (GA+AA) and COEs had an effect on SBP [β(95%CI) = -6.537(-12.072, -1.002), p = 0.021] and DBP [β(95%CI) = -4.811(-8.567, -1.056), p = 0.012]. This study is the first to identify the role of PINK1 rs3738136 in COE- induced abnormal blood pressure, and to prove that the abnormal blood pressure of workers is the result of environmental and genetic factors.

Waterpipe smoking is associated with presence and severity of coronary artery disease: a propensity score-matched study

BACKGROUND

The prevalence of waterpipe smoking (WPS) has been increasing worldwide. This trend is alarming as WPS can negatively impact cardiovascular health. In the present study, we explored the association between WPS and the presence and severity of CAD.

METHODS

This study was a retrospective analysis of patients who underwent diagnostic coronary angiography at Tehran Heart Center between April 2021 and May 2022. Patients with a previous history of percutaneous coronary intervention and coronary surgery were excluded. Waterpipe smokers were matched with non-smokers based on age, gender, and cigarette smoking using a 1:4 propensity score matching model. Stenosis ≥ 50% in any coronary artery was considered a CAD diagnosis. Gensini score was also calculated to measure the severity of the CAD.

RESULTS

We reviewed the medical records of 8699 patients, including 380 waterpipe smokers. After matching, 1520 non-smokers with similar propensity scores to the waterpipe smokers were selected. Waterpipe smokers were more likely to have CAD than non-smokers (OR: 1.29; 95% CI: 1.04-1.60, P = 0.021). In addition, WPS increased the natural logarithm of the Gensini score by 1.24 (95% CI: 1.04-1.48, P = 0.014) in patients with atherosclerotic coronary disease.

CONCLUSION

WPS may increase the risk of CAD independent of age, gender, and cigarette smoking. In addition, among patients with any degree of atherosclerosis in coronary arteries (GS > 0), WPS may lead to higher average GS, suggesting more severe atherosclerosis.

Inflammatory biomarkers mediate the association between polycyclic aromatic hydrocarbon exposure and dyslipidemia: A national population-based study

Exploring the association between exposure to polycyclic aromatic hydrocarbons (PAHs) and the risk of dyslipidemia and possible mediating effects is essential for conducting epidemiological health studies on related lipid disorders. Therefore, our study aimed to elucidate the potential association between PAH exposure and dyslipidemia risk and further identify the mediating effects based on blood cell-based inflammatory biomarkers. This cross-sectional study was conducted on 8380 individuals with complete survey data from the National Health and Nutrition Examination Survey (2001-2016). Multiple models (generalized linear regression model, restricted cubic spline model, Bayesian kernel machine regression, weighted quantiles sum regression) were used to assess the relationship between PAH co-exposure and the dyslipidemia risk and further identify potential mediating effects. Among the 8380 subjects, 2886 (34.44 %) had dyslipidemia. After adjusting for the confounding factors, the adjusted OR and 95% CI for dyslipidemia in the highest quartile of subjects were 1.30 (1.11, 1.51), 1. 22 (1.04, 1.43), 1.21 (1.03, 1.42), 1.29 (1.10, 1.52), 1.18 (1.01, 1.37), and 1.04 (0.89, 1.23) for 1-hydroxynaphthalene, 2-hydroxynaphthalene, 3-hydroxyfluorene, 2-hydroxyfluorene (2-FLU), 1-hydroxyphenanthrene, and 1-hydroxypyrene. The Bayesian kernel machine regression model also showed a positive correlation between PAH mixtures and dyslipidemia, and 2-FLU has the highest contribution. Mediation effect analyses showed that white blood cells and neutrophils were statistically significant in the association between PAHs and dyslipidemia. The present study suggests that individual and mixed PAH exposures may increase the risk of dyslipidemia in adults. Inflammatory biomarkers significantly mediated the relationship between PAH exposure and dyslipidemia. Environmental pollutants and their mechanisms should be more intensively monitored and studied.

Association of urinary polycyclic aromatic hydrocarbon metabolites with gestational diabetes mellitus and gestational hypertension among pregnant women in Southwest China: A cross-sectional study

The association of polycyclic aromatic hydrocarbons (PAHs) with gestational diabetes mellitus (GDM) and gestational hypertension during pregnancy has not yet been established. To investigate the association between PAH exposure and GDM and gestational hypertension, we conducted a cross-sectional study of 4206 pregnant women from the Zunyi birth cohort in southwestern China. Gas chromatography/mass spectrometry was used to detect the urinary levels of 10 monohydroxylated PAHs (OH-PAHs). GDM and gestational hypertension were diagnosed and the relevant information was documented by specialist obstetricians and gynecologists. Logistic regression and restricted cubic spline regression were employed to investigate their single and nonlinear associations. Stratified analyses of pregnancy and body mass index data were conducted to determine their moderating effects on the abovementioned associations. Compared with the first quartile of urinary ∑OH-PAHs, the third or fourth quartile in all study participants was associated with an increased risk of GDM (quartile 3: odds ratio [OR] = 1.35, 95% confidence interval [CI]: 1.03-1.77) and gestational hypertension (quartile 3: OR = 1.88, 95% CI: 1.26-2.81; quartile 4: OR = 1.58, 95% CI: 1.04-2.39), respectively. Nonlinear associations of 1-OH-PYR with GDM (cutoff level: 0.02 μg/g creatinine [Cr]) and 1-OH-PHE with gestational hypertension (cutoff level: 0.06 μg/g Cr) were also observed. In pregnant women with overweight or obesity, 1-OH-PHE and 3-OH-PHE were more strongly associated with gestational hypertension. Our results indicate that exposure to PAH during pregnancy may significantly increase the maternal risks of GDM and gestational hypertension; however, this finding still needs to be confirmed through larger-scale prospective studies and biological evidence.

Quantification, characterization and risk assessment of microplastics from five major estuaries along the northern Bay of Bengal coast

Microplastics (MPs) as hazardous contaminants has drawn the rapid attention of the general public due to their omnipresence and adverse impacts on ecosystems and human health. Despite this, understanding of MPs contamination levels in the estuarine ecosystems along the Bay of Bengal coast remains very limited. This research focused on the presence, spatial distribution, morpho-chemical characteristics and ecological implications of MPs in water and sediment from five key estuaries (Meghna, Karnaphuli, Matamuhuri, Bakkhali, and Naf rivers) within the Bengal delta. Out of the five estuaries, the Meghna exhibited the least amount of MPs in both surface water (150.00 ± 65.62 items/m3) and sediment (30.56 ± 9.34 items/kg). In contrast, the highest occurrence of MPs was recorded in Karnaphuli river water (350.00 ± 69.22 items/m3) and Matamuhuri river sediment (118.33 ± 26.81 items/kg). ANOVA indicated a statistically significant distinction (p < 0.01) among the examined estuaries. Most identified MPs were fibers and < 0.5 mm in size in both water and sediment samples. Transparent MPs were dominant in both water (42.28%) and sediment (45.22%). Besides violet, red, blue, pink and green colored MPs were also observed. Various polymer types, including PE, PP, PET, PS, Nylon, EVA, and ABS, were detected, with PE being the dominant one. Based on the polymer risk index (PHI), the estuaries were classified as hazard level V, signifying a severe level of MP contamination. However, the potential ecological hazardous index (PHI), potential ecological risk index (RI), and pollution load index (PLI) indicated moderate pollution levels. This study offers initial insights into the pollution caused by MPs in major estuaries of Bengal delta, which policymakers can utilize to implement suitable management strategies.

Fossil-fuel and combustion-related air pollution and hypertension in the Sister Study

Hypertension is a leading risk factor for disease burden, with more than 200 million disability-adjusted life-years attributed to high blood pressure in 2015. While outdoor air pollution is associated with cardiovascular disease, the joint effect of exposure to air pollution from combustion products on hypertension has rarely been studied. We conducted a cross-sectional analysis to explore the association between combustion-related air pollution and hypertension. Census-tract levels of ambient concentrations of nine fossil-fuel and combustion-related air toxics (biphenyl, naphthalene, polycyclic organic matter, diesel emissions, 1,3-butadiene, acetaldehyde, benzene, acrolein, and formaldehyde) from the 2005 National Air Toxics Assessment database and NO2 from 2005 monitoring data were linked to baseline residential addresses of 47,467 women in the Sister Study cohort. Hypertension at enrollment (2003-2009) was defined as high systolic (≥140 mm Hg) or diastolic (≥90 mm Hg) blood pressure or taking antihypertensive medication. We used log-binomial regression and quantile-based g-computation to estimate the individual and joint effects of fossil-fuel and combustion-related air pollution on hypertension. Comparing the highest to lowest quartiles, diesel emissions (prevalence ratio (PR) = 1.05, 95% confidence interval (CI) = 1.01,1.08), 1,3-butadiene (PR = 1.04, 95%CI = 1.00,1.07), acetaldehyde (PR = 1.08, 95%CI = 1.04,1.12), benzene (PR = 1.05, 95%CI = 1.02,1.08), formaldehyde (PR = 1.08, 95%CI = 1.04,1.11), and NO2 (PR = 1.08, 95%CI = 1.05,1.12) were individually associated with higher prevalence of hypertension. The PR for the joint effect of increasing all ambient air toxics and NO2 by one quartile was 1.02 (95%CI = 1.01,1.04). Associations varied by race/ethnicity, with stronger associations observed among women reporting races/ethnicities (Hispanic/Latina, non-Hispanic Black and other) other than non-Hispanic White. In conclusion, we found that air pollution from fossil fuel and combustion may be a risk factor for hypertension.

Urinary polycyclic aromatic hydrocarbon metabolites were associated with hypertension in US adults: data from NHANES 2009-2016

Polycyclic aromatic hydrocarbons (PAHs) are widely existing organic pollutants in the environment, and their persistence in the environment makes us have to pay continuous attention to their health effects. However, since the American Heart Association updated its definition of hypertension in 2017, few studies have explored the relationship. This study aimed to investigate the relationship between PAH exposure and hypertension after the updated definition of hypertension and explore whether body mass index (BMI) moderates this relationship. A total of 6332 adult participants from the 2009-2016 National Health and Nutrition Examination Survey (NHANES) were examined. Multiple logistic regression and restricted cubic splines were used to analyze the association between urinary polycyclic aromatic hydrocarbon metabolites and hypertension, and the dose-response relationship. Weighted quantile sum (WQS) regression was applied to blood pressure to reveal multiple exposure effects and the relative weights of each PAH. The prevalence of hypertension in the study population was 48.52%. There was a positive dose-response relationship between high exposure to 1-hydroxynaphthalene, 2&3-hydroxyphenanthrene, and the risk of hypertension. Naphthalene metabolites accounted for the most significant proportion of systolic blood pressure, and phenanthrene metabolites accounted for the most significant proportion of diastolic blood pressure. Obese individuals with high PAH exposure were at greater risk for hypertension than individuals with low PAH exposure and normal BMI. Higher prevalence rate and stronger association of metabolites with outcomes were obtained in the general population of the USA under the new guideline. High levels of exposure to PAHs were positively associated with the risk of hypertension, and these effects were modified by BMI.

The interaction effects of secondhand smoke exposure and overweight on the prevalence of hypertension in Chinese coke oven workers and NHANES participants (2013-2016)

BACKGROUND

The prevalence of hypertension may be affected by environmental pollution and personal behavior.

OBJECTIVES

We aimed to evaluate the interaction effects of secondhand smoke exposure and overweight on hypertension.

METHODS

In this cross-sectional study, a total of 627 workers from a coking plant in China and 1011 individuals from the NHANES database in the United States from 2013 to 2016 were selected as the research participants. The concentrations of 11 urinary polycyclic aromatic hydrocarbons (PAHs) metabolites and 3 tobacco metabolites were measured. An interaction effect was tested in the modified Poisson regression models.

RESULTS

For smokers among Chinese coke oven workers, the only statistically significant positive association was with hypertension in the highest tertile of nicotine metabolized ratio (NMR) (PR: 1.539, 95% CI: 1.013-2.337). Nonsmoking Chinese workers with 3rd tertile urinary nicotine levels were associated with a 114.8% significantly increased prevalence of hypertension (PR: 2.148, 95% CI: 1.025-4.500) compared to nonsmokers 1st tertile with nicotine levels. Association between tobacco exposure and hypertension is possibly modified by PAHs exposure (PR: 2.335, 95% CI: 0.933-5.841). Nonsmokers in the NHANES database with high urinary nicotine levels were associated with a 17.3% significantly increased prevalence of hypertension (PR: 1.173, 95% CI: 1.028-1.338) compared to those with low nicotine levels. We observed that overweight people with high nicotine levels had a significantly higher likelihood of hypertension than no overweight people with low nicotine levels among nonsmoking Chinese coke oven workers and NHANES participants (PR = 4.686, 95% CI: 1.488-14.754; PR = 1.251, 95% CI: 1.039-1.506).

CONCLUSIONS

Tobacco exposure and overweight are important risk factors for hypertension, and secondhand smoke exposure and overweight have an interactive effect on the incidence of hypertension in nonsmoking Chinese coke oven workers and NHANES participants.

Relationship of polycyclic aromatic hydrocarbons exposure with vascular damages among sanitation workers

Chronic exposure to polycyclic aromatic hydrocarbons (PAHs) leads to a high incidence of cardiovascular diseases. To assess the effects of PAHs exposure on vascular damages in occupationally exposed populations, 196 sanitation workers were recruited. According to the differences of occupation or operation, they were divided into exposure group (n = 115) and control group (n = 81). Sixteen serum PAHs were determined by gas chromatography-tandem mass spectrometery. Tumor necrosis factor ɑ (TNF-ɑ) and angiotensin II (ANG-II) in serum, blood lipids and blood pressure were also measured. Results showed that, except for indeno(1,2,3-cd)pyrene, dibenzo(a,h)anthracene and benzo(g,h,i)perylene, the detection frequencies of other PAHs were above 85%, showing that subjects are generally exposed to PAHs. The top three compounds in serum concentrations of PAHs were phenanthrene, acenaphthylene and anthracene. Moreover, the concentrations of total serum PAHs in the exposure group were significantly higher than those in the control (p < 0.05), suggesting a higher PAHs exposure in the former. Though there was no significant difference in blood lipids and blood pressure between groups (p > 0.05), TNF-ɑ and ANG-II levels in the exposure group were significantly higher than those in the control group (p < 0.05), suggesting that PAHs exposure may be related to pro-inflammatory effects and vascular endothelial damages.

Polycyclic aromatic hydrocarbon and its effects on human health: An overeview

Polycyclic aromatic hydrocarbons (PAHs) are a class of chemicals of considerable environmental significance. PAHs are chemical contaminants of fused carbon and hydrogen aromatic rings, basically white, light-yellow, or solid compounds without color. Natural sources of pollution are marginal or less significant, such as volcanic eruptions, natural forest fires, and moorland fires that trigger lightning bursts. The significant determinants of PAH pollution are anthropogenic pollution sources, classified into four groups, i.e., industrial, mobile, domestic, and agricultural pollution sources. Humans can consume PAHs via different routes, such as inhalation, dermal touch, and ingestion. The Effect of PAHs on human health is primarily based on the duration and route of exposure, the volume or concentration of PAHs to which one is exposed, and the relative toxicity of PAHs. Many PAHs are widely referred to as carcinogens, mutagens, and teratogens and thus pose a significant danger to human health and the well-being of humans. Skin, lung, pancreas, esophagus, bladder, colon, and female breast are numerous organs prone to tumor development due to long-term PAH exposure. PAH exposure may increase the risk of lung cancer as well as cardiovascular disease (CVD), including atherosclerosis, thrombosis, hypertension, and myocardial infarction (MI). Preclinical studies have found a relationship between PAH exposure, oxidative stress, and atherosclerosis. In addition, investigations have discovered a relationship between PAH exposure at work and CVD illness and mortality development. This review aims to explain PAH briefly, its transportation, its effects on human health, and a relationship between environmental exposures to PAHs and CVD risk in humans.

Exposure to polycyclic aromatic hydrocarbon-induced oxidative stress in Shiraz, Iran: urinary levels, health risk assessment and mediation effect of MDA on the risk of metabolic syndromes

PURPOSE

Polycyclic Aromatic Hydrocarbons (PAHs) have been identified as carcinogenic and endocrine disrupter compounds that cause Metabolic Syndrome (MetS). Oxidative stress can lead to carcinogenesis and MetS in exposed people. Therefore, the relationship between urinary metabolite of PAH (OH-PAHs) level and the oxidative stress biomarker (Malondialdehyde) effect as the mediator in increasing the risk of MetS due to PAH exposure and risk assessment was investigated in Shiraz, Iran.

METHODS

The first morning void urinary and blood samples were obtained from participants and analyzed. Physical examinations and anthropometric measurements were performed on the day of sampling. An automatic biochemistry analyzer was used to measure the blood cells. The participants' socio-demographic information was gathered using a questionnaire and direct interviews with participants.

RESULTS

The MetS prevalence was 26%. Malondialdehyde could act as a mediator between exposure to 1-HydroxyPyrene and increase in fast blood sugar, exposure to 2-HydroxyNaphthalene and increase in systolic blood pressure and exposure to 2-HydroxyFluorene and increase in SBP. Hazard quotients varied from 0.009 to 14.92 in women, and from 0.005 to 8.43 for Fluorene and Naphthalene in men, respectively. The Hazard Indexes were greater than one meaning that the non-cancer health risk related to the PAH exposure could be identified in the participants.

CONCLUSION

Although oxidative stress has been suggested to lead to MetS and the high HI levels obtained in the current study, future researches are essential to achieve more reliable findings and monitoring the environmental influencing factors in PAH exposure.

The association between urinary metabolites of polycyclic aromatic hydrocarbons (PAHs) and cardiovascular diseases and blood pressure: a systematic review and meta-analysis of observational studies

Although epidemiological studies have discerned the association between polycyclic aromatic hydrocarbons (PAHs) exposure and hypertension and/or cardiovascular disease in the general population, the possible mechanisms for this association are not well understood. We sought to examine the association between urinary metabolites of PAHs and cardiovascular diseases (CVDs) and blood pressure in adults, by conducting a meta-analysis of observational studies. We searched PubMed, Scopus, Embase, and Web of science, up to July 2021, for observational studies that investigated the association between urinary metabolites of PAHs and CVDs and blood pressure in adults. Nine prospective studies, including 27,280 participants, were included. Based on overall pooled results, there was a significant positive association between all types of urinary metabolites of PAH and blood pressure (OR: 1.32; 95%, CI: 1.19 to 1.48, p < 0.0001) (I2 = 62.4%, p < 0.0001). There was no significant association between any urinary metabolite of PAH and CHD (OR: 0.93; 95%, CI: 0.83 to 1.03, p = 0.174) (I2 = 0%, p = 0.653). Overall, there was a significant positive association between all urinary metabolites of PAH and CVD (OR: 1.23; 95%, CI: 1.16 to 1.30, p < 0.0001) (I2 = 59.7%, p < 0.0001). The results of the present meta-analysis suggest that different metabolites PAHs are associated with an increased risk of CVD and HTN. Further studies, including randomized clinical trials, are needed to confirm the veracity of our findings.

Relationship Between Polycyclic Aromatic Hydrocarbons and Cardiovascular Diseases: A Systematic Review

Objective: The primary aim of this systematic review was to examine the relationship of polycyclic aromatic hydrocarbon (PAH) exposure with cardiovascular diseases (CVDs) and elaborate the current knowledge and recent advances in the area of PAH and its effects on CVDs and discuss the growing epidemiological evidence linking PAH to CVDs on the health of human populations. In this systematic review, the increased risk of cardiovascular diseases and their relationship with PAHs were discussed in detail.

Methods: On 05th April 2021, a systematic literature search was conducted using PubMed/Medline and Web of Science search engines in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. The search was limited to articles that were written in English and dealt with human issues. All original peer-review publications were considered for inclusion. Comments, case reports, reviews, duplicated papers, and conference reports were excluded. Data was collected from included papers by two independent reviewers.

Results: Conclusively, 20 research articles published between 2005 and 2021 were chosen for the final analysis. The systemic review included 20 studies with a variety of geographical studies. The most common research category among the nominated studies were time-series studies followed by retrospective cohort, cross-sectional, quasi-experimental, panel, and case-control studies. Most of the studies were conducted in the United States, whereas others were showed in various geographical countries around the world, such as Denmark, Germany, Finland, Netherlands, France, China, Norway, Korea, Sweden, Saudi Arabia, and Belgium. Eight studies assessed the association between PAH exposure and CVDs, four articles observed this relationship with blood pressure (BP), two observed association between atherosclerotic CVD and PAH, one congenital heart disease, cardiovascular events, and two with obesity. Furthermore, in some investigations, a favorable association between PAH exposure and hypertension as well as PAH exposure and obesity was found.

Conclusion: In conclusion, this systematic review examined the relationship of PAH exposure with CVDs and CVD-related risk factors by searching several digital databases. After a comprehensive literature searches and summarizing findings from 20 articles, the authors concluded that a positive relationship was observed between PAH exposure and CVD risks.

Metabolic Syndrome and Endocrine Disrupting Chemicals: An Overview of Exposure and Health Effects

Increasing prevalence of metabolic syndrome (MetS) is causing a significant health burden among the European population. Current knowledge supports the notion that endocrine-disrupting chemicals (EDCs) interfere with human metabolism and hormonal balance, contributing to the conventionally recognized lifestyle-related MetS risk factors. This review aims to identify epidemiological studies focusing on the association between MetS or its individual components (e.g., obesity, insulin resistance, diabetes, dyslipidemia and hypertension) and eight HBM4EU priority substances (bisphenol A (BPA), per- and polyfluoroalkyl substances (PFASs), phthalates, polycyclic aromatic hydrocarbons (PAHs), pesticides and heavy metals (cadmium, arsenic and mercury)). Thus far, human biomonitoring (HBM) studies have presented evidence supporting the role of EDC exposures on the development of individual MetS components. The strength of the association varies between the components and EDCs. Current evidence on metabolic disturbances and EDCs is still limited and heterogeneous, and mainly represent studies from North America and Asia, highlighting the need for well-conducted and harmonized HBM programmes among the European population. Rigorous and ongoing HBM in combination with health monitoring can help to identify the most concerning EDC exposures, to guide future risk assessment and policy actions.

The association between the urinary biomarkers of polycyclic aromatic hydrocarbons and risk of metabolic syndromes and blood cell levels in adults in a Middle Eastern area

PURPOSE

Limited studies have been published on the association between the urinary biomarkers of Polycyclic Aromatic Hydrocarbons (PAHs) and risk of Metabolic Syndromes (MetS) and blood cell levels in adults in the Middle East. The present study aimed to evaluate the exposure to PAHs and the distribution of urinary OH-PAH levels in the general population of Shiraz, Iran, as well as, the association between OH-PAHs and the prevalence of MetS and blood cell levels.

METHODS

In this study, 200 participants were randomly selected from the adult population, and their first-morning void urine samples were collected.

RESULTS

The mean concentrations of 1-OHNap, 2-OHNap, 2-OHFlu, 9-OHPhe, and 1-OHP were 639.8, 332.1, 129, 160.3, and 726.9 ng/g creatinine, respectively. The prevalence of MetS was 26% according to the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) criteria. The results showed that urinary OH-PAHs, especially 1-OHP, were positively and significantly associated with higher waist circumstance (p < 0.001), triglyceride level (p < 0.001), systolic blood pressure (p < 0.001), diastolic blood pressure (p < 0.001), number of white blood cells (p = 0.041) and red blood cells (p < 0.001). It also caused lower levels of High Density Lipoprotein-Cholesterol (HDL-C). In conclusion, the results emphasized the adverse health effects of PAHs on human health, including obesity, hypertension, dyslipidemia, and decreased number of blood cells.

CONCLUSION

Therefore, in order to identify the PAHs sources and to develop methods for decreasing the amount of emissions to the environment, broader researches are needed.

Cellular Mechanisms Involved in the Combined Toxic Effects of Diesel Exhaust and Metal Oxide Nanoparticles

Diesel exhaust particles (DEPs) and non-exhaust particles from abrasion are two main representative sources of air pollution to which humans are exposed daily, together with emerging nanomaterials, whose emission is increasing considerably. In the present work, we aimed to investigate whether DEPs, metal oxide nanoparticles (MeO-NPs), and their mixtures could affect alveolar cells. The research was focused on whether NPs induced different types of death in cells, and on their effects on cell motility and migration. Autophagy and cell cycles were investigated via cytofluorimetric analyses, through the quantification of the autophagic biomarker LC3B and PI staining, respectively. Cellular ultrastructures were then observed via TEM. Changes in cell motility and migration were assessed via transwell migration assay, and by the cytofluorimetric analysis of E-cadherin expression. A colony-forming efficiency (CFE) assay was performed in order to investigate the interactions between cells inside the colonies, and to see how these interactions change after exposure to the single particles or their mixtures. The results obtained suggest that NPs can either reduce the toxicity of DEPs (CuO) or enhance it (ZnO), through a mechanism that may involve autophagy as cells' response to stressors and as a consequence of particles' cellular uptake. Moreover, NPs can induce modification of E-cadherin expression and, consequentially, of colonies' phenotypes.

Concentrations of selected monohydroxy polycyclic aromatic hydrocarbons across various stages of glomerular function

The objective of this study was to evaluate the variabilities in the concentrations of selected monohydroxy polycyclic aromatic hydrocarbons (OH-PAH) in urine across various stages of glomerular function. Data from National Health and Nutrition Examination Survey for US adult smokers (N = 3125) and nonsmokers (N = 6793) were selected for analysis to meet the objectives of the study. OH-PAHs selected for analysis were as follows: 1-hydroxynaphthalene, 2-hydroxynaphthalene, 2-hydroxyfluorene, 3-hydroxyfluorene, 9-hydroxyfluorene, 1-hydroxyphenanthrene, 2-hydroxyphenanthrene, 3-hydroxyphenanthrene, and 1-hydroxypyrene. Stages of glomerular function (GF) considered were as follows: hyperfiltrators (GF-1A, eGFR ≥ 110 mL/min/1.73 m²), normal filtrators (GF-1B, 90 < eGFR < 110 mL/min/1.73 m²), GF-2 (60 ≤ eGFR < 90 mL/min/1.73 m²), GF-3A (45 ≤ eGFR < 60 mL/min/1.73 m²), and GF-3B/4 (15 ≤ eGFR < 45 mL/min/1.73 m²). For the analysis of data for smokers, however, data for GF-3A and GF-3B/4 were merged because of small sample sizes for these GF stages for smokers. Among nonsmokers, (i) there was almost a straight-line decrease in adjusted concentrations of 2-hydroxyfluorene, 3-hydroxyfluorene, 9-hydroxyfluorene, 1-hydroxyphenanthrene, 2-hydroxyphenanthrene, 3-hydroxyphenanthrene, and 1-hydroxypyrene over GF-1A through GF-3B/4; (ii) concentrations of these OH-PAHs at GF-3B/4 varied from being 37.5% for 1-hydroxypyrene to being 87% for 9-hydroxyfluorene of what they were at GF-1A; and (iii) while concentrations of 1-hydroxynaphthalene were located on an inverted U-shaped curve, concentrations of 2-hydroxynaphthalene were located on a U-shaped curve with pints of inflections at GF-3A. Among smokers, concentrations of all nine OH-PAHs in urine were located on inverted U-shaped curves with points of inflections located at GF-2 and concentrations of these OH-PAHs at GF-3/4 varied from being 48.7% for 1-hydroxypyrene to being 116.1% for 9-hydroxyfluorene of what they were at GF-1A. The kidneys differ in how they process urinary metabolites of PAHs among smokers and nonsmokers.

Contributions of dietary, demographic, disease, lifestyle and other factors in explaining variabilities in concentrations of selected monohydroxylated polycyclic aromatic hydrocarbons in urine: Data for US children, adolescents, and adults

Data from National Health and Nutrition Examination Survey for 2003-2014 for US children aged 6-11 years (N = 2097), adolescents aged 12-19 ears (N = 2642), and adults aged ≥ 20 years (N = 9170) were analyzed to investigate the effects of dietary, demographic, disease, lifestyle, and other factors on concentrations of nine metabolites of polycyclic aromatic hydrocarbons (PAH) in urine. PAHs analyzed were: 1-hydroxynaphthalene, 2-hydroxynaphthalene, 2-hydroxyfluorene, 3-hydroxyfluorene, 9-hydroxyfluorene, 1-hydroxyphenanthrene, 2-hydroxyphenanthrene, 3-hydroxyphenanthrene, and 1-hydroxypyrene. Adults with diabetes were found to have higher adjusted levels of 1-hydroxynaphthalene (4139 vs. 3622 ng/L, p < 0.01) than nondiabetics. Adults with albuminuria had higher adjusted levels of 1-hydroxynaphthalene (4140 vs.3621 ng/L, p < 0.01) and 2-hydroxynaphthalene (6039 vs. 5468 ng/L, p < 0.01) than those without albuminuria. Children with albuminuria had lower adjusted levels of 9-hydroxyfluorene (162 vs. 187 ng/L, p = 0.04), 1-hydroxyphenanthrene (92 vs. 108 ng/L, p < 0.01), and 1-hydroxypyrene (118 vs. 138 ng/L, p < 0.01) than those without albuminuria. The ratios of smoker to nonsmoker adjusted levels for adults varied from a low of 1.4 for 2-hydroxyphenanthrene to a high of 5.6 for 3-hydroxyfluorene. Exposure to environmental tobacco smoke at home was associated with higher levels of most OH-PAHs among children, adolescents, and adults. Consumption of red meat not processed at high temperatures was associated with increased levels of 1-hydroxypyrene (β = 0.00040, p = 0.01), 1-, 2-, and 3-hydroxyphenanthrene, 3-, and 9-hydroxyfluorene. Consumption of red meat processed at high temperatures was associated with increased levels of 2-hydroxynaphthalene (β = 0.00046, p = 0.02) among adults. Consumption of fish processed at high temperatures was associated with decreased levels of 1-hydroxynaphtahlene (β = - 0.00088, p < 0.01), 2-, 3-, and 9-hydroxyfluorene, 1-, 2-, and 3-hydroxyphenanthrene. Among adults, alcohol consumption and caffeine may be associated with increased levels of certain OH-PAHs. Oxidative stress and inflammation associated with exposure to PAHs are associated with albuminuria and have the potential to lead to the development of diabetes.

Association between urinary polycyclic aromatic hydrocarbons and hypertension in the Korean population: data from the Second Korean National Environmental Health Survey (2012-2014)

Polycyclic aromatic hydrocarbons (PAHs) are environmental and occupational pollutants derived from incomplete combustion of organic materials, including wood and fossil fuels. Epidemiological studies have evaluated the association between PAH exposure and hypertension or cardiovascular disease in the general population, but the evidence is limited. In this study, we evaluated the association between urinary PAH metabolites and hypertension in the Korean adult population. A total of 6478 adults who participated in the Second Korean National Environmental Health Survey (2012–2014) were included. The differences in urinary concentrations of four PAH metabolites, including 1-hydroxypyrene, 2-hydroxyfluorene, 1-hydroxyphenanthrene, and 2-naphthol, were compared according to hypertension status using a general linear model. Adjusted odds ratios (aORs) for hypertension were calculated according to the quartile groups of urinary PAH metabolites after adjusting for age, sex, body mass index (BMI), smoking, and alcohol consumption in multiple logistic regression analyses. The estimated mean concentrations of urinary 1-hydroxyphenanthrene were significantly higher in the hypertension group than in the non-hypertension group. In 1-hydroxyphenanthrene, the OR for hypertension was significantly higher in the third and fourth quartile groups than in the first quartile group (third: OR 1.707, 95% CI 1.203–2.423, fourth: OR 1.604, 95% CI 1.158–2.223). No significant associations were detected for the other metabolites. Our results suggest an association between exposure to PAHs and hypertension in a Korean adult population. Further studies are required to evaluate the effects of low-dose long-term exposure to PAHs on hypertension and cardiovascular disease.

Measurement of urinary 1-aminopyrene and 1-hydroxypyrene as biomarkers of exposure to diesel particulate matter in gold miners

Metabolites of polycyclic aromatic hydrocarbons measured in human samples are often used as biomarkers of exposure to diesel engine exhaust (DEE). The aim of this study was to assess the changes in urinary levels of 1-aminopyrene (1-AP) and 1-hydroxypyrene (1-OHP) and their relationship with Elemental Carbon (EC), as a component of diesel engine exhaust exposure, among a hard-rock gold-mining population. Urine samples were collected at the beginning and end of a 12-hour work shift from 100 underground and above ground gold miners. Miners were fitted with personal exposure monitoring equipment to quantify exposure to DEE, measured as Elemental Carbon (EC), across their 12-hour work shift. General linear regression assessed associations of the post-shift urinary 1-AP and 1-OHP concentrations with EC, controlling for age, gender, the pre-shift biomarker level, Body Mass Index (BMI), days on current shift, time in mining, smoking status and second-hand smoke exposure. The concentrations of 1-AP and 1-OHP increased significantly across a 12-hour mining work shift. Moreover, consistent with the sensitivity analysis, the concentration of 1-AP was significantly associated with EC after adjustments. Urinary 1-OHP, but not 1-AP was significantly associated with current smoking. Urinary 1-AP may be a more robust and specific biomarker of DEE than 1-OHP.

Potential role of polycyclic aromatic hydrocarbons as mediators of cardiovascular effects from combustion particles

Air pollution is the most important environmental risk factor for disease and premature death, and exposure to combustion particles from vehicles is a major contributor. Human epidemiological studies combined with experimental studies strongly suggest that exposure to combustion particles may enhance the risk of cardiovascular disease (CVD), including atherosclerosis, hypertension, thrombosis and myocardial infarction.In this review we hypothesize that adhered organic chemicals like polycyclic aromatic hydrocarbons (PAHs), contribute to development or exacerbation of CVD from combustion particles exposure. We summarize present knowledge from existing human epidemiological and clinical studies as well as experimental studies in animals and relevant in vitro studies. The available evidence suggests that organic compounds attached to these particles are significant triggers of CVD. Furthermore, their effects seem to be mediated at least in part by the aryl hydrocarbon receptor (AhR). The mechanisms include AhR-induced changes in gene expression as well as formation of reactive oxygen species (ROS) and/or reactive electrophilic metabolites. This is in accordance with a role of PAHs, as they seem to be the major chemical group on combustion particles, which bind AhR and/or is metabolically activated by CYP-enzymes. In some experimental models however, it seems as PAHs may induce an inflammatory atherosclerotic plaque phenotype irrespective of DNA- and/or AhR-ligand binding properties. Thus, various components and several signalling mechanisms/pathways are likely involved in CVD induced by combustion particles.We still need to expand our knowledge about the role of PAHs in CVD and in particular the relative importance of the different PAH species. This warrants further studies as enhanced knowledge on this issue may amend risk assessment of CVD caused by combustion particles and selection of efficient measures to reduce the health effects of particular matters (PM).

Benzo[a]pyrene alters vascular function in rat aortas ex vivo and in vivo

Benzo[a]pyrene (BaP) is a polycyclic aromatic hydrocarbon found in tobacco smoke and air pollution products. BaP exposure has been recently suggested to be a risk factor for hypertension in coke oven workers. The mechanisms of BaP on vascular smooth muscle function remain unclear. Here, we examined the influence and possible mechanism of BaP on vasoconstriction in rat thoracic aortas ex vivo and in vivo. In vivo exposure of rats to BaP (20 mg/kg) for 8 weeks caused a significant enhancement in the systolic blood pressure and enhanced aortic hyperreactivity to α1-adrenoceptor selective agonist phenylephrine in aortas. BaP (1 and 10 μM) treatment for 18 h induced an enhancement of phenylephrine-induced vasoconstriction in the organ cultures of aortas. Aryl hydrocarbon receptor antagonist α-naphthoflavone, protein kinase C (PKC) inhibitor chelerythrine, mitogen-activated protein kinases (MAPK) inhibitor PD98059, myosin light chain kinase (MLCK) inhibitor ML-9, and Rho-kinase inhibitor Y-27632 significantly suppressed BaP-enhanced vasoconstriction. BaP time-dependently triggered reactive oxygen species (ROS) production in primary vascular smooth muscle cells. Both antioxidant N-acetylcysteine and NAD(P)H oxidase inhibitor diphenyleneiodonium significantly inhibited BaP-triggered ROS production and vasoconstriction. These results suggest that BaP enhances aortic vasoconstriction via the activation of ROS and muscular signaling molecules PKC, MAPK, MLCK, and Rho-kinase.

A Mixed-Methods Study to Examine the Role of Psychosocial Stress and Air Pollution on Hypertension in Mexican-Origin Hispanics

PURPOSE

Independent and combined effects of air pollution and psychosocial stressors on hypertension, a risk factor for cardiovascular disease, among Hispanics are not well studied.

METHODS

We administered a pilot-tested questionnaire on individual- and neighborhood-level psychosocial stressors, developed with community input, to nearly 2500 individuals from the MD Anderson Cancer Center cohort of Mexican-Americans. We used data from local air quality monitors to estimate individual exposures to ozone (O3) and fine particulate matter (PM2.5) for the 12-month period preceding enrollment using inverse distance interpolation. We applied logistic regression models to examine relationships between exposures to psychosocial stressors and air pollution with prevalent hypertension and used stratified analyses to examine the interacting effects of these two exposures on hypertension. RESULTS: There was a positive association between prevalent hypertension and a high frequency of feeling anxious or depressed (prevalence odds ratio (POR) = 1.36, 95% CI [1.06-1.75]) and experiencing aches and pains (POR = 1.29, 95% CI [1.01-1.64]). The odds of having hypertension were also elevated among those worrying about their own health (POR = 1.65, 95% CI [1.30-2.06]) or about not having enough money (POR = 1.27, 95% CI [1.01-1.6]). We observed an inverse association between O3 and hypertension. There was no interaction between psychosocial stressors and O3 on hypertension.

CONCLUSION

Our findings add to the evidence of a positive association between individual and family stressors on hypertension among Hispanics and other racial/ethnic groups. Contrary to previous studies reporting positive associations, our results suggest that long-term exposure to O3 may be inversely related to prevalent hypertension.

PM2.5 Filter Extraction Methods: Implications for Chemical and Toxicological Analyses

Toxicology research into the global public health burden of fine particulate matter (PM_2.5) exposures frequently requires extraction of PM_2.5 from filters. A standardized method for these extractions does not exist, leading to inaccurate interlaboratory comparisons. It is largely unknown how different filter extraction methods might impact the composition and bioactivity of the resulting samples. We characterized the variation in these metrics by using equal portions of a single PM_2.5 filter, with each portion undergoing a different extraction method. Significant differences were observed between extraction methods for concentrations of elements and polycyclic aromatic hydrocarbons (PAHs) for the PM_2.5 tested following its preparation for biological response studies. Importantly, the chemical profiles differed from those observed when we used standard protocols for chemical characterization of the ambient sample, demonstrating that extraction can alter both chemical component amounts and species profiles of the extracts. The impact of these chemical differences on sensitive end points of zebrafish development was investigated. Significant differences in the percent incidence and timing of mortality were associated with the PM_2.5 extraction method. This research highlights the importance of and rationale for considering the extraction method when interlaboratory comparisons of PM_2.5 toxicology research are made.

Methods for Evaluating the Combined Effects of Chemical and Nonchemical Exposures for Cumulative Environmental Health Risk Assessment

Cumulative risk assessment (CRA) has been proposed as a means of evaluating possible additive and synergistic effects of multiple chemical, physical and social stressors on human health, with the goal of informing policy and decision-making, and protecting public health. Routine application of CRA to environmental regulatory and policy decision making, however, has been limited due to a perceived lack of appropriate quantitative approaches for assessing combined effects of chemical and nonchemical exposures. Seven research projects, which represented a variety of disciplines, including population health science, laboratory science, social sciences, geography, statistics and mathematics, were funded by the US Environmental Protection Agency (EPA) to help address this knowledge gap. We synthesize key insights from these unique studies to determine the implications for CRA practice and priorities for further research. Our analyses of these seven projects demonstrate that the necessary analytical methods to support CRA are available but are ultimately context-dependent. These projects collectively provided advancements for CRA in the areas of community engagement, characterization of exposures to nonchemical stressors, and assessment of health effects associated with joint exposures to chemical and psychosocial stressors.

Longitudinal Analysis of Long-Term Air Pollution Levels and Blood Pressure: A Cautionary Tale from the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Air pollution exposures are hypothesized to impact blood pressure, yet few longitudinal studies exist, their findings are inconsistent, and different adjustments have been made for potentially distinct confounding by calendar time and age.

OBJECTIVE

We aimed to investigate the associations of long- and short-term [Formula: see text] and [Formula: see text] concentrations with systolic and diastolic blood pressures and incident hypertension while also accounting for potential confounding by age and time.

METHODS

Between 2000 and 2012, Multi-Ethnic Study of Atherosclerosis participants were measured for systolic and diastolic blood pressure at five exams. We estimated annual average and daily [Formula: see text] and [Formula: see text] concentrations for 6,569 participants using spatiotemporal models and measurements, respectively. Associations of exposures with blood pressure corrected for medication were studied using mixed-effects models. Incident hypertension was examined with Cox regression. We adjusted all models for sex, race/ethnicity, socioeconomic status, smoking, physical activity, diet, season, and site. We compared associations from models adjusting for time-varying age with those that adjusted for both time-varying age and calendar time.

RESULTS

We observed decreases in pollution and blood pressures (adjusted for age and medication) over time. Strong, positive associations of long- and short-term exposures with blood pressure were found only in models with adjustment for time-varying age but not adjustment for both time-varying age and calendar time. For example, [Formula: see text] higher annual average [Formula: see text] concentrations were associated with 2.7 (95% CI: 1.5, 4.0) and [Formula: see text] (95% CI: [Formula: see text] 1.0) mmHg in systolic blood pressure with and without additional adjustment for time, respectively. Associations with incident hypertension were similarly weakened by additional adjustment for time. Sensitivity analyses indicated that air pollution did not likely cause the temporal trends in blood pressure.

CONCLUSIONS

In contrast to experimental evidence, we found no associations between long- or short-term exposures to air pollution and blood pressure after accounting for both time-varying age and calendar time. This research suggests that careful consideration of both age and time is needed in longitudinal studies with trending exposures. https://doi.org/10.1289/EHP2966.

Benzo[a]pyrene activates interleukin-6 induction and suppresses nitric oxide-induced apoptosis in rat vascular smooth muscle cells

Benzo[a]pyrene, a ubiquitous environmental pollutant, has been suggested to be capable of initiating and/or accelerating atherosclerosis. Accumulation of vascular smooth muscle cells (VSMCs) in vessel intima is a hallmark of atherosclerosis. Nitric oxide (NO) can suppress VSMCs proliferation and induce VSMCs apoptosis. NO plays a compensatory role in the vascular lesions to reduce proliferation and/or accelerate apoptosis of VSMCs. The aim of this study was to investigate whether benzo[a]pyrene can affect VSMCs growth and apoptosis induced by NO. Benzo[a]pyrene (1–30 μmol/L) did not affect the cell number and cell cycle distribution in VSMCs under serum deprivation condition. Sodium nitroprusside (SNP), a NO donor, decreased cell viability and induced apoptosis in VSMCs. Benzo[a]pyrene significantly suppressed SNP-induced cell viability reduction and apoptosis. VSMCs cultured in conditioned medium from cells treated with benzo[a]pyrene could also prevent SNP-induced apoptosis. Benzo[a]pyrene was capable of inducing the activation of nuclear factor (NF)-κB and phosphorylation of p38 mitogen-activated protein kinase (MAPK) in VSMCs. Both NF-κB inhibitor and p38 MAPK inhibitor significantly reversed the anti-apoptotic effect of benzo[a]pyrene on SNP-treated VSMCs. Incubation of VSMCs with benzo[a]pyrene significantly and dose-dependently increased interleukin (IL)-6 production. A neutralizing antibody to IL-6 effectively reversed the anti-apoptotic effect of benzo[a]pyrene on SNP-treated VSMCs. Taken together, these results demonstrate for the first time that benzo[a]pyrene activates IL-6 induction and protects VSMCs from NO-induced apoptosis. These findings propose a new mechanism for the atherogenic effect of benzo[a]pyrene.

A Systematic Review on the Effects of Polycyclic Aromatic Hydrocarbons on Cardiometabolic Impairment

Background:

Various epidemiological studies have shown that exposure to environmental pollutants including polycyclic aromatic hydrocarbons (PAHs) might increase the risk of cardiovascular diseases (CVDs) and their risk factors. This study aims to systematically review the association of PAH exposure with metabolic impairment.

Methods:

Data were collected by searching for relevant studies in international databases using the following keywords: “polycyclic aromatic hydrocarbon” + “cardiovascular disease,” PAH + CVD, polycyclic aromatic hydrocarbon and “air pollutant” + “CVD,” and the desired data were extracted and included in the study according to the systematic review process.

Results:

From the 14 articles included in the present systematic review, eight articles were conducted on the relationship between PAH and CVDs, four articles were conducted to examine the association of PAH exposure with blood pressure (BP), and two articles investigated the link between PAH and obesity.

Conclusions:

Most studies included in this systematic review reported a significant positive association of PAH exposure with increased risk of CVDs and its major risk factors including elevated BP and obesity. These findings should be confirmed by longitudinal studies with long-term follow-up.

Polycyclic aromatic hydrocarbon exposure, miR-146a rs2910164 polymorphism, and heart rate variability in coke oven workers

BACKGROUND

Exposure to ubiquitous polycyclic aromatic hydrocarbons (PAHs) has been associated with decreased heart rate variability (HRV). Evidence accumulates that microRNAs (miRNAs) might be the intermediate factors between environmental exposures and their adverse health effects. Single nucleotide polymorphisms (SNPs) in miRNA genes may affect phenotypes and disease morbidity.

OBJECTIVE

We sought to investigate the influences of four well-studied SNPs in miRNA genes (rs2910164, rs11614913, rs2292832, and rs3746444) on HRV, and their modifying effects on the associations between PAH exposure and HRV.

METHODS

We measured the concentrations of ten urinary monohydroxy PAHs (OH-PAHs), seven HRV parameters, and genotypes of these four SNPs in 1222 coke oven workers.

RESULTS

There were significant differences among different rs2910164 genotype carriers in terms of all seven HRV indices: workers with rs2910164 CC genotype had significant lower HRV than those with GG or GC genotype (P<0.05). The number of rs2910164 C allele was negatively associated with HRV indices in the high PAH exposure group (β<0, P<0.05), and the association between rs2910164 and high-frequency (HF) power was significantly stronger in high exposure group (Pinteraction=0.042). Interestingly, the negative associations between the sum of 10 OH-PAHs and HRV (β<0, P<0.05) were significantly or marginally significantly stronger in workers with rs2910164 CC genotype (Pinteraction≤0.050).

CONCLUSIONS

Coke oven workers with miR-146a rs2910164 CC genotype may be more susceptible to decreased HRV. The modifying effect of rs2910164 on the PAHs-HRV associations suggested miR-146a may mediate the effects of PAH exposure on HRV.