Atherosclerotic process in taxi drivers occupationally exposed to air pollution and co-morbidities

Associations of Long-Term Exposure to Fine Particulate Constituents With Cardiovascular Diseases and Underlying Metabolic Mediations: A Prospective Population-Based Cohort in Southwest China

BACKGROUND

The health effects of particulate matter with an aerodynamic diameter ≤2.5 μm (PM2.5) might differ depending on compositional variations. Little is known about the joint effect of PM2.5 constituents on metabolic syndrome and cardiovascular disease (CVD). This study aims to evaluate the combined associations of PM2.5 components with CVD, identify the most detrimental constituent, and further quantify the mediation effect of metabolic syndrome.

METHODS AND RESULTS

A total of 14 427 adults were included in a cohort study in Sichuan, China, and were followed to obtain the diagnosis of CVD until 2021. Metabolic syndrome was defined by the simultaneous occurrence of multiple metabolic disorders measured at baseline. The concentrations of PM2.5 chemical constituents within a 1-km2 grid were derived based on satellite- and ground-based detection methods. Cox proportional hazard models showed that black carbon, organic matter (OM), nitrate, ammonium, chloride, and sulfate were positively associated with CVD risks, with hazard ratios (HRs) ranging from 1.24 to 2.11 (all P<0.05). Quantile g-computation showed positive associations with 4 types of CVD risks (HRs ranging from 1.48 to 2.25, all P<0.05). OM and chloride had maximum weights for CVD risks. Causal mediation analysis showed that the positive association of OM with total CVD was mediated by metabolic syndrome, with a mediation proportion of 1.3% (all P<0.05).

CONCLUSIONS

Long-term exposure to PM2.5 chemical constituents is positively associated with CVD risks. OM and chloride appear to play the most responsible role in the positive associations between PM2.5 and CVD. OM is probably associated with CVD through metabolic-related pathways.

Associations of polycyclic aromatic hydrocarbons mixtures with cardiovascular diseases mortality and all-cause mortality and the mediation role of phenotypic ageing: A time-to-event analysis

The associations of polycyclic aromatic hydrocarbons (PAHs) with cardiovascular diseases (CVDs) and all-cause mortality are unclear, especially the joint effects of PAHs exposure. Meanwhile, no studies have examined the effect of phenotypic ageing on the relationship between PAHs and mortality. Therefore, this study aimed to investigate the independent and joint associations between PAHs and CVDs, all-cause mortality, and assess whether phenotypic age acceleration (PhenoAgeAccel) mediate this relationship. We retrospectively collected data of 11,983 adults from the National Health and Nutrition Examination Survey database. Firstly, Cox proportional hazards regression and restricted cubic splines were applied to evaluate the independent association of single PAH on mortality. Further, time-dependent Probit extension of Bayesian Kernel Machine Regression and quantile-based g-computation models were conducted to test the joint effect of PAHs on mortality. Then, difference method was used to calculate the mediation proportion of PhenoAgeAccel in the association between PAHs and mortality. Our results revealed that joint exposure to PAHs showed positive association with CVDs and all-cause mortality. By controlling potential confounders, 1-Hydroxynapthalene (1-NAP) (HR = 1.24, P = 0.035) and 2-Hydroxyfluorene (2-FLU) (HR = 1.25, P < 0.001) showed positive association with CVDs mortality, and they were the top 2 predictors (weight: 0.82 for 1-NAP, 0.14 for 2-FLU) of CVDs mortality. 1-NAP (HR = 1.15, P < 0.001) and 2-FLU (HR = 1.13, P < 0.001) also showed positive association with all-cause mortality, and they were also the top 2 predictors of all-cause mortality (weight: 0.66 for 1-NAP, 0.34 for 2-FLU). PhenoAgeAccel mediated the relationship between 1-NAP, 2-FLU and CVDs, all-cause mortality, with a mediation proportion of 10.00 % to 24.90 % (P < 0.05). Specifically, the components of PhenoAgeAccel including C-reactive protein, lymphocyte percent, white blood cell count, red cell distribution width, and mean cell volume were the main contributors of mediation effects. Our study highlights the hazards of joint exposure of PAHs and the importance of phenotypic ageing on the relationship between PAHs and mortality.

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.

New insight into PAH4 induced hepatotoxicity and the dose-response assessment in rats model

PAH4 (sum of benzo[a]pyrene, chrysene, benz[a]anthracene and benzo[b]fluoranthene) has been proposed as better marker than benzo[a]pyrene to assess total PAHs exposure in foodstuffs. However, the toxicological behaviors of PAH4 combined exposure remain unclear. This study aimed to investigate PAH4 toxicity effects with non-targeted metabolomics approach and evaluate the external and internal dose-response relationships based on benchmark dose (BMD) analysis. Male Sprague-Dawley rats were treated by gavage with vehicle (corn oil) or four doses of PAH4 (10, 50, 250, 1000 μg/kg·bw) for consecutive 30 days. After the final dose, the liver, blood and urine samples of rats were subsequently collected for testing. The concentrations of urinary mono-hydroxylated PAHs metabolites (OH-PAHs) including 3-hydroxybenzo[a]pyrene (3-OHB[a]P), 3-hydroxychrysene (3-OHCHR) and 3-hydroxybenz[a]anthracene (3-OHB[a]A) were determined to reflect internal PAH4 exposure. Our results showed PAH4 exposure increased relative liver weight and serum aspartate aminotransferase (AST) activity and caused hepatocyte swelling and degeneration, implying hepatotoxicity induced by PAH4. Serum metabolomics suggested PAH4 exposure perturbed lipid metabolism through upregulating the expression of glycerolipids metabolites, which was evidenced by markedly increased serum triglyceride (TG) level and hepatic TG content. Additionally, urinary OH-PAHs concentrations presented strong positive correlations with the external dose, indicating they were able to reflect PAH4 exposure. Furthermore, PAH4 exposure led to a dose-response increase of hepatic TG content, based on which the 95% lower confidence value of BMDs for external and internal doses were estimated as 5.45 μg/kg·bw and 0.11 μmol/mol·Cr, respectively. In conclusion, this study suggested PAH4 exposure could induce hepatotoxicity and lipid metabolism disorder, evaluating the involved dose-response relationships and providing a basis for the risk assessment of PAHs.

Aromatic Hydrocarbon Receptor Repressor (AHRR) is a biomarker of ambient air pollution exposure and Coronary Artery Disease (CAD)

Two hundred and twenty subjects were recruited while undergoing cardiac catheterization. AHRR cg05575921 methylation was shown to be significantly decreased in ever smokers compared to never smokers (Mean± SD = 64.2 ± 17.2 vs 80.1 ± 11.1 respectively; P < 0.0001). In addition, higher urinary levels of 2-OHNAP and 2-OHFLU were significantly associated with more AHRR cg05575921 hypomethylation, even after correcting for smoking (β[95%CI]= -4.161[-7.553, -0.769]; P = 0.016 and -5.190[-9.761, -0.618]; P = 0.026, respectively) but not 1-OHPYR (β[95%CI]= -3.545 [-10.935, 3.845]; P = 0.345). Additionally, hypomethylation of AHRR ROI was significantly associated with obstructive coronary artery disease (CAD) after adjusting for smoking, age, sex, diabetes and dyslipidemia (OR [95%CI] = 1.024[1.000 - 1.048]; P = 0.046). Results of this study necessitate further validation to potentially consider clinical incorporation of AHRR methylation status as an early predictive biomarker for the potential association between ambient air pollution and CAD.

Research progress of different components of PM2.5 and ischemic stroke

PM2.5 is a nonhomogeneous mixture of complex components produced from multiple sources, and different components of this mixture have different chemical and biological toxicities, which results in the fact that the toxicity and hazards of PM2.5 may vary even for the same mass of PM2.5. Previous studies on PM2.5 and ischemic stroke have reached different or even opposing conclusions, and considering the heterogeneity of PM2.5 has led researchers to focus on the health effects of specific PM2.5 components. However, due to the complexity of PM2.5 constituents, assessing the association between exposure to specific PM2.5 constituents and ischemic stroke presents significant challenges. Therefore, this paper reviews and analyzes studies related to PM2.5 and its different components and ischemic stroke, aiming to understand the composition of PM2.5 and identify its harmful components, elucidate their relationship with ischemic stroke, and thus provide some insights and considerations for studying the biological mechanisms by which they affect ischemic stroke and for the prevention and treatment of ischemic stroke associated with different components of PM2.5.

Firefighters and the liver: Exposure to PFAS and PAHs in relation to liver function and serum lipids (CELSPAC-FIREexpo study)

INTRODUCTION

Firefighting is one of the most hazardous occupations due to exposure to per- and polyfluoroalkyl substances (PFAS) and polycyclic aromatic hydrocarbons (PAHs). Such exposure is suspected to affect the cardiometabolic profile, e.g., liver function and serum lipids. However, only a few studies have investigated the impact of this specific exposure among firefighters.

METHODS

Men included in the CELSPAC-FIREexpo study were professional firefighters (n = 52), newly recruited firefighters in training (n = 58), and controls (n = 54). They completed exposure questionnaires and provided 1-3 samples of urine and blood during the 11-week study period to allow assessment of their exposure to PFAS (6 compounds) and PAHs (6 compounds), and to determine biomarkers of liver function (alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and total bilirubin (BIL)) and levels of serum lipids (total cholesterol (CHOL), low-density lipoprotein cholesterol (LDL) and triglycerides (TG)). The associations between biomarkers were investigated both cross-sectionally using multiple linear regression (MLR) and Bayesian weighted quantile sum (BWQS) regression and prospectively using MLR. The models were adjusted for potential confounders and false discovery rate correction was applied to account for multiplicity.

RESULTS

A positive association between exposure to PFAS and PAH mixture and BIL (β = 28.6%, 95% CrI = 14.6-45.7%) was observed by the BWQS model. When the study population was stratified, in professional firefighters and controls the mixture showed a positive association with CHOL (β = 29.5%, CrI = 10.3-53.6%) and LDL (β = 26.7%, CrI = 8.3-48.5%). No statistically significant associations with individual compounds were detected using MLR.

CONCLUSIONS

This study investigated the associations between exposure to PFAS and PAHs and biomarkers of cardiometabolic health in the Czech men, including firefighters. The results suggest that higher exposure to a mixture of these compounds is associated with an increase in BIL and the alteration of serum lipids, which can result in an unfavourable cardiometabolic profile.

Health Impact Assessment of Short-Term Exposure to Particulate Matter (PM10) in Northern Thailand

In northern Thailand, in recent decades, particulate pollution from the burning of biomass has become a serious issue with toxicological implications for human health, especially during the winter months of January to April. The purpose of this study was to explore short-term exposure to particulate matter (PM₁₀) in northern Thailand. The high PM₁₀ concentration in 2012 was used as a case study. We used the EPA's Benefits Mapping and Analysis Program-Community Edition (BenMAP-CE) for the health impact assessment, along with ground-based measurement data. The annual average observed PM₁₀ concentration was in the range of 43-61 μg/m³, with a maximum observed PM₁₀ concentration of 300 μg/m³ in March. We then assessed the impacts of PM₁₀ exposure in northern Thailand. When the PM₁₀ concentration was reduced to 120 μg/m³, the undesirable effects on respiratory mortality decreased by 5%-11%. When the concentration of PM₁₀ was reduced to 45 μg/m³, the deleterious effects on respiratory mortality decreased by 11-30%. In conclusion, adherence to the WHO-AQG, particularly for PM₁₀ (45 μg/m³), tends to result in considerable reductions in respiratory disease mortality in northern Thailand.

The Association between Replacement Drivers and Depressive Symptoms

A replacement driver is a type of gig worker who provides driving services to the target point with the drunk driver's own car. This study aimed to examine the association of replacement drivers (ref: paid workers) with depressive symptoms. Information on replacement drivers was collected through online/offline surveys. Data from the 8th Korea National Health and Nutrition Examination Survey were applied to construct the control group. The Patient Health Questionnaire-9; ≥5 points was defined as depressive symptoms. Adjusted odds ratios (aOR) and 95% confidence intervals (CI) were calculated by performing multivariable logistic regression analysis. The mean age of replacement drivers was 56.11. The prevalence of depressive symptoms in replacement drivers and controls were 49.63% and 12.64%, respectively. Replacement drivers showed a higher association with depressive symptoms than paid workers (aOR 7.89, 95% CI [5.53-11.26]). This relationship was prominent in the older, low-education, and low-income groups. Linear discriminant analysis was the most effective in predicting depressive symptoms among the machine learning models. Using the replacement driver feature increased the AUC values of the models. Given the strong association between depressive symptoms and replacement drivers, in-depth studies to establish guidelines to prevent mental diseases among replacement drivers are required.

Associations between short-term exposure of PM2.5 constituents and hospital admissions of cardiovascular diseases among 18 major Chinese cities

Previous studies showed different risk effects on exposure of fine particulate matter (PM_2.5) mass for cardiovascular disease (CVD) globally, which is likely due to different constituents of PM_2.5. This study aimed to investigate the association between short-term exposure of PM_2.5 constituents and hospital admissions of CVD. Daily counts of city-specific hospital admissions for CVD in 18 cities in China between 2014 and 2017 were extracted from the national Urban Employee Basic Medical Insurance database and the Beijing Municipal Commission of Health and Family Planning Information Center database. Directly measured PM_2.5 constituents, including ions and polycyclic aromatic hydrocarbons, were collected by the Chinese Environmental Public Health Tracking system. We used the time-stratified case-crossover design to estimate the association between PM_2.5 constituents and hospital admissions of CVD. Concentrations of ions accounted for the majority of the detected constituents. Excess risk (ER) of average ions concentrations for CVD was highest as 2.30% (95% CI: 1.62-2.99%) for NH₄⁺, whose major sources are residential and agricultural emissions. This was followed by 1.85% (1.30-2.41%) for NO₃^- (generally from vehicles), 0.95% (0.28-1.63%) for SO₄^2- (often from fossil fuel burning) respectively. The association for ions were generally consistent with ischemic heart disease (IHD) and ischemic stroke, e.g., NH₄⁺ was associated with IHD (2.50%; 1.52-3.48%) and ischemic stroke (1.77%; 0.65-2.9%). For polycyclic aromatic hydrocarbons (PAHs), mainly from coal and vehicle-related oil combustion, the constituents were all associated with ischemic stroke but not for IHD. The ER for ischemic stroke was highest at 1.69% (0.99-2.39%) for indeno (123-cd) pyrene. Thus, in terms of the subtypes of CVD, the risks of hospital admissions varied with exposure to different PM_2.5 constituents. Exposed to NH₄⁺ had the highest risk to IHD and ischemic stroke, whereas PAHs were predominately associated with ischemic stroke only.

Opinions of taxi drivers regarding occupational risks and prevention strategies: A cross- sectional study in Turkey

BACKGROUND: Taxi drivers are prone to musculoskeletal problems and can suffer from cardiovascular disease, respiratory disease, and psychosocial problems. For occupational health and safety it is crucial to know the risk factors and initiatives to be taken for protection. OBJECTIVES: This study was carried out to evaluate the opinions of taxi drivers regarding occupational risks and prevention strategies. METHODS: This was a descriptive and cross-sectional study including 524 taxi drivers. A questionnaire was developed to determine the opinions of taxi drivers regarding occupational risks and intervention strategies. For the analysis of data, Mann-Whitney U (Z-table value), descriptive statistics (number, percentage) and Chi-square (χ2) test between dependent and independent variables were used. RESULTS: Among the taxi drivers, the occupation was reported to be risky for musculoskeletal system disorders by 67%, for cardiovascular diseases by 68.3%, for respiratory diseases by 46.9% and for psychosocial problems by 63.3%. When the opinions of taxi drivers regarding prevention from these risks were examined, 30.2% of them stated prevention from musculoskeletal system disorders, 34.0% from cardiovascular diseases, 31.3% from respiratory diseases and 40.1% from psychosocial problems. It was a prominent finding to see a decrease in the number of drivers who stated to show prevention behavior towards these risks compared to their states of recognizing them. CONCLUSİON: Drivers were insufficient both in recognizing health risks of their jobs and implementing intervention strategies. Education concerning health risks of their jobs and prevention from these risks is required.

The interplay between exposure to PAHs and MTHFR C677T polymorphism on cardiovascular risk biomarkers in Mexican women

Cardiovascular diseases (CVDs) are the leading cause of morbidity and mortality worldwide. Environmental and genetic factors are recognized as risk determinants in the onset and development of CVDs. However, the interaction between both factors on CVDs risk is not still completely clarified. Therefore, the objective of this study was to evaluate the effect of the interaction between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and polycyclic aromatic hydrocarbon (PAH) exposure (gene-environment interaction) on cardiovascular risk biomarkers in Mexican women. A cross-sectional study was completed with the participation of 390 healthy women. For all enrolled women, anthropometric measurements, serum biochemical analyses, atherogenic indexes, and serum concentrations of biomolecules used as CVD risk biomarkers were obtained. 1-Hydroxypyrene (1-OHP) was measured in urine, as an exposure biomarker of PAHs. The mean urinary level of 1-OHP in the assessed population was 1.23 ± 1.40 μmol/mol creatinine. The allelic frequency (MTHFR C677T polymorphism) identified in the registered individuals was 68.0% for the mutant allele (T-allele). Significant positive associations were detected between urinary 1-OHP levels and serum asymmetric dimethylarginine (ADMA) concentrations (p < 0.05) and atherogenic index of plasma (AIP) values (p < 0.05). Also, women with the TT genotype of the MTHFR C677T enzyme have the highest serum ADMA levels (p < 0.05) and AIP values (p < 0.05) compared to women grouped as CC genotype and CT genotype. Besides, the findings in this study suggest an interaction between environmental (PAHs exposure) and genetic (MTHFR C677T polymorphism) factors on cardiovascular risk markers (ADMA and AIP). According to the usefulness of AIP and ADMA, an increased cardiovascular risk is notable in highly exposed individuals to PAHs with the polymorphic genotype (TT) of the MTHFR enzyme. Therefore, intervention programs in the target communities are required to diminish the cardiovascular risk of the assessed individuals.

Human Health, Environmental Quality and Governance Quality: Novel Findings and Implications From Human Health Perspective

Human health and wellbeing are intimately linked to the state of the environment. The current study emphasizes the role of environmental quality, government policies, and human health. This paper provides a detailed literature review of existing findings regarding our key variables of interest. The results argue that the implications of poor government policies and environmental pollution for rising economic development have led to poor environmental quality and health issues for humans. Based on earlier investigations, the present study reviewed the state-of-the-art review and determined innovative insights for outdoor and indoor environment difficulties. This study provides a detailed review of human health, environmental quality, and governance quality. In addition, the study conducts an empirical analysis using the annual data of low-income countries from 1996 to 2020. Government actions and health systems must be modified immediately to address these rising concerns successfully. The report offers policy recommendations for addressing health, governance, and environmental change mitigation issues, all of which are directly or indirectly related to the study. This article presents an overview of environmental change's health impacts and explores how health hazards may be reduced or eliminated through effective adaptation strategies.

Staphylococcus epidermidis WF2R11 Suppresses PM2.5-Mediated Activation of the Aryl Hydrocarbon Receptor in HaCaT Keratinocytes

The skin supports a diverse microbiome whose imbalance is related to skin inflammation and diseases. Exposure to fine particulate matter (PM_2.5), a major air pollutant, can adversely affect the skin microbiota equilibrium. In this study, the effect and mechanism of PM_2.5 exposure in HaCaT keratinocytes were investigated. PM_2.5 stimulated the aryl hydrocarbon receptor (AhR) to produce reactive oxygen species (ROS) in HaCaT cells, leading to mitochondrial dysfunction and intrinsic mitochondrial apoptosis. We observed that the culture medium derived from a particular skin microbe, Staphylococcus epidermidis WF2R11, remarkably reduced oxidative stress in HaCaT cells caused by PM_2.5-mediated activation of the AhR pathway. Staphylococcus epidermidis WF2R11 also exhibited inhibition of ROS-induced inflammatory cytokine secretion. Herein, we demonstrated that S. epidermidis WF2R11 could act as a suppressor of AhRs, affect cell proliferation, and inhibit apoptosis. Our results highlight the importance of the clinical application of skin microbiome interventions in the treatment of inflammatory skin diseases.

Association of urinary polycyclic aromatic hydrocarbon metabolites and cardiovascular disease among US population: A cross-sectional study

OBJECTIVE

The main aim of the study was to illustrate the association between urinary polycyclic aromatic hydrocarbons (PAHs) and their metabolites with cardiovascular diseases (CVDs), including congestive heart failure (CHF), coronary heart disease (CHD), angina, heart attack, and stroke among the US population.

METHODS

The National Health and Nutritional Examination Survey (NHANES) 2003-16, nationally representative data were utilized for this study. A cross-sectional observational study was designed to assess the strength of the association between urinary PAH and CVDs. The NHANES survey used a stratified multistage probability sample strategy for obtaining representative samples. Logistic regression analysis was performed to evaluate the association between PAH and the prevalence of CVDs.

RESULTS

In our study, the average ages of the three different PAHs tertiles were 42.56 ± 19.68, 42.21 ± 19.51, and 43.39 ± 17.99 years, respectively. A positive association was found between the second and third tertile of urinary PAH and increased prevalence of coronary heart disease (tertile-2: OR = 1.24, 95% CI = 1.09-1.42; tertile-3: OR = 1.97, 95% CI = 1.69-2.28), angina (tertile-2: OR = 1.3, 95% CI = 1.13-1.49; tertile-3: OR = 2.07, 95% CI = 1.76-2.42), heart attack (tertile-2: OR = 1.28, 95% CI = 1.12-1.47; tertile-3: OR = 1.71, 95% CI = 1.48-1.96) and stroke (tertile-2: OR = 1.17, 95% CI = 1.02-1.33; tertile-3: OR = 1.66, 95% CI = 1.43-1.93) in total participants, respectively, with p-values less than 0.05.

CONCLUSION

In conclusion, this study found a positive association between urinary PAHs and the prevalence of various CVDs among the US population.

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.

Oxidative stress generated by polycyclic aromatic hydrocarbons from ambient particulate matter enhance vascular smooth muscle cell migration through MMP upregulation and actin reorganization

Background

Epidemiological studies have suggested that elevated concentrations of particulate matter (PM) are strongly associated with the incidence of atherosclerosis, however, the underlying cellular and molecular mechanisms of atherosclerosis by PM exposure and the components that are mainly responsible for this adverse effect remain to be established. In this investigation, we evaluated the effects of ambient PM on vascular smooth muscle cell (VSMC) behavior. Furthermore, the effects of polycyclic aromatic hydrocarbons (PAHs), major components of PM, on VSMC migration and the underlying mechanisms were examined.

Results

VSMC migration was significantly increased by treatment with organic matters extracted from ambient PM. The total amount of PAHs contained in WPM was higher than that in SPM, leading to higher ROS generation and VSMC migration. The increased migration was successfully inhibited by treatment with the anti-oxidant, N-acetyl-cysteine (NAC). The levels of matrix metalloproteinase (MMP) 2 and 9 were significantly increased in ambient PM-treated VSMCs, with MMP9 levels being significantly higher in WPM-treated VSMCs than in those treated with SPM. As expected, migration was significantly increased in all tested PAHs (anthracene, ANT; benz(a)anthracene, BaA) and their oxygenated derivatives (9,10-Anthraquinone, AQ; 7,12-benz(a)anthraquinone, BAQ, respectively). The phosphorylated levels of focal adhesion kinase (FAK) and formation of the focal adhesion complex were significantly increased in ambient PM or PAH-treated VSMCs, and these effects were blocked by administration of NAC or α-NF, an inhibitor of AhR, the receptor that allows PAH uptake. Subsequently, the levels of phosphorylated Src and NRF, the downstream targets of FAK, were altered with a pattern similar to that of p-FAK.

Conclusions

PAHs, including oxy-PAHs, in ambient PM may have dual effects that lead to an increase in VSMC migration. One is the generation of oxidative stress followed by MMP upregulation, and the other is actin reorganization that results from the activation of the focal adhesion complex.

Epigenetic Regulation in Exposome-Induced Tumorigenesis: Emerging Roles of ncRNAs

Environmental factors, including pollutants and lifestyle, constitute a significant role in severe, chronic pathologies with an essential societal, economic burden. The measurement of all environmental exposures and assessing their correlation with effects on individual health is defined as the exposome, which interacts with our unique characteristics such as genetics, physiology, and epigenetics. Epigenetics investigates modifications in the expression of genes that do not depend on the underlying DNA sequence. Some studies have confirmed that environmental factors may promote disease in individuals or subsequent progeny through epigenetic alterations. Variations in the epigenetic machinery cause a spectrum of different disorders since these mechanisms are more sensitive to the environment than the genome, due to the inherent reversible nature of the epigenetic landscape. Several epigenetic mechanisms, including modifications in DNA (e.g., methylation), histones, and noncoding RNAs can change genome expression under the exogenous influence. Notably, the role of long noncoding RNAs in epigenetic processes has not been well explored in the context of exposome-induced tumorigenesis. In the present review, our scope is to provide relevant evidence indicating that epigenetic alterations mediate those detrimental effects caused by exposure to environmental toxicants, focusing mainly on a multi-step regulation by diverse noncoding RNAs subtypes.

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.

Association between blood ethylene oxide levels and the risk of cardiovascular diseases in the general population

Ethylene oxide (EtO) is a highly reactive organic compound that is mainly used as a sterilizing agent. However, to date, the effects of EtO on the cardiovascular system are not clear. We aimed to explore the association between blood EtO levels and the risk of cardiovascular disease (CVD) in the general US population. We obtained information on blood levels of EtO and CVD outcomes in 3,410 participants from the National Health and Nutritional Examination Survey (NHANES) 2013-2014 and 2015-2016. Logistic regression models were applied to calculate the odds ratios (ORs) and 95% confidence intervals (95% CIs) for the association between EtO and risk of all CVD as well as subtypes of CVD. Linear regression analyses were used to estimate the associations of EtO with potential mechanistic parameters of CVD, including blood pressure, blood lipid levels and inflammatory parameters. Higher blood levels of EtO were associated with an increased risk of all CVD (p for trend = 0.003), with an adjusted OR (95% CI) in the highest quartile of 1.94 (1.24, 3.02) compared with the lowest quartile as a reference. Higher concentrations of EtO were positively associated with the risk of angina (p for trend = 0.04) and heart attack (p for trend = 0.011). In addition, the concentration of EtO was positively associated with the levels of triglycerides, white blood cells, lymphocytes, monocytes, neutrophils and eosinophils (p = 0.003 for eosinophils and p < 0.001 for the others) and negatively associated with the level of high-density lipoprotein cholesterol (p < 0.001). We found that exposure to EtO was associated with angina, heart attack and all CVD in a large representative US population. Furthermore, EtO may induce CVD through the inflammatory response and abnormal fatty acid metabolism.

Taxi drivers' exposure to black carbon and nitrogen dioxide in electric and diesel vehicles: A case study in London

Nitrogen dioxide (NO₂) and black carbon (BC) concentrations were measured inside London taxicabs across 40 work shifts in a real-world occupational study. The shifts were measured across five plug-in hybrid range-extender electric taxicabs (TXe City) and five diesel taxicabs (TX4 Diesel). The aim of this study was to characterise the impact of fuel and cabin design on professional drivers' air pollution exposures. Personal exposure was monitored using portable BC, NO₂ and GPS devices. A controlled study replicating a typical taxi drivers' route in central London was conducted. Simultaneous inside and outside BC concentrations were measured to assess infiltration rates. The drivers were instructed to keep the BC devices with them at all times, providing a comparison of exposures at work and outside of work. The driver's average BC and NO₂ exposure while working was nearly twice as high for diesel taxicab drivers (6.8 ± 7.0 μg/m³, 101.9 ± 87.8 μg/m³) compared with electric drivers (3.6 ± 4.9 μg/m³, 55.3 ± 53.0 μg/m³, respectively). The exposure to BC while not working was 1.6 μg/m³ for diesel drivers and 1.1 μg/m³ for electric drivers, highlighting the very high exposures experienced by this occupational sector. The analysis of vehicle type on BC concentrations showed that the airtight cabin design and presence of an in-built filter in the electric TXe City reduced the exposure to BC substantially; indoor to outdoor ratios being 0.63 on the electric taxi compared to 0.99 on the diesel taxi with recirculate ventilation mode off and 0.07 to 0.44 with recirculate on. These findings provide important evidence for occupational health of professional drivers through exposure reduction measures in vehicle design.

Cardiovascular health status of taxi/for-hire vehicle drivers in the United States: A systematic review

BACKGROUND

Taxi/for-hire vehicle (FHV) drivers are a predominantly immigrant, male, and growing population in large, metropolitan cities in the U.S. at risk for cardiovascular conditions.

OBJECTIVE

This review sought to systematically investigate the literature given mounting evidence of poor taxi/FHV driver health.

METHODS

A systematic search of peer-reviewed journal articles that included a range of cardiovascular risks and conditions among taxi/FHV drivers in the U.S. was conducted.

RESULTS

8800 journal articles were initially found. 14 eligible articles were included: 3 mixed methods articles, 1 qualitative article, and 10 quantitative articles. Articles spanned 13 cardiovascular risks and conditions, including tobacco, nutrition, physical activity, stress, depression, body mass index/waist circumference, cholesterol, blood glucose/diabetes, air pollution, sleep, blood pressure/hypertension, heart disease, and stroke. The majority of studies were cross-sectional and utilized convenience samples.

CONCLUSIONS

Rigorous and high quality research is needed to further investigate rates of cardiovascular health in this population. The complexity of data collection in this group presents challenges to this endeavor. The high prevalence of poor nutrition, limited physical activity, diabetes, and blood pressure across studies indicates an urgent need to address low rates of health care access at a policy level and to design targeted workplace interventions.

Polycyclic aromatic hydrocarbon metabolites and mortality risk in an adult population

Occupational polycyclic aromatic hydrocarbons (PAHs) exposure has been shown to increase the risk of various cancers and may be associated with carcinogenic mortality. However, no study has explored the relationship between environmental PAH exposure and mortality in general population. The aim of our study was to explore the association between PAH exposure and all-cause, cardiovascular, and cancer mortality in a general US adult population. We analyzed data from the National Health and Nutrition Examination Survey (NHANES 2001-2006) based on the information in this dataset on 692 males and 717 females. PAH exposure was detected using biomarkers from urine samples. Follow-up data on mortality were derived from initial examination of the subjects until death or 31 December 2006 in the NHANES database. We calculated hazard ratios (HRs) of PAH metabolites among all-cause, cardiovascular, and cancer mortality using the multivariate Cox proportional hazards regression model after adjusting for covariates. Among males, 3-phenanthrene was positively associated with increased risk of all-cause mortality (HR 1.043, 95%CI 1.019-1.066). Female participants with higher 2-napthol (HR 1.043, 95%CI 1.014-1.072), 3-fluorene (HR 2.159, 95%CI 1.233-3.779), and 1-phenanthrene (HR = 1.259, 95%CI 1.070-1.481) levels had increased all-cause mortality. In addition, high 3-phenanthrene (HR 1.333, 95%CI 1.008-1.763) and 1-phenanthrene (HR 1.463, 95%CI 1.126-1.900) levels increased the risk of cardiovascular mortality. However, there were no significant findings for cancer mortality in both genders. Environmental PAH exposure among the adult population is associated with non-carcinogenic but not cancer mortality. Future studies are warranted to determine the underlying mechanisms related to these findings.

Cellular response to chemicals present in air pollution in occupationally exposed workers and its potential cancer susceptibility

The study aimed to evaluate the potential effects of the chronic exposure to chemical agents from air pollution on phenotypic and genotypic expressions of peripheral biomarkers and tumor-related proteins in mononuclear cells. This study evaluates 85 taxi drivers (outdoor workers) and 55 non-occupationally exposed persons (NOE) to air pollution (indoor workers). The biomarkers were urinary 1-hydroxypyrene (1-OHP), for organic agents, and blood As and Ni, for inorganic agents. Oxidative stress biomarkers; protein expression of ICAM-1 (CD54), β2-integrin, L-selectin (CD62-L), and MCP1; gene expression of ICAM-1, p53 and CD26 were performed. Urinary 1-OHP and blood As and Ni levels were increased in taxi drivers and were associated with inflammatory and oxidative stress biomarkers. These exposure biomarkers were also associated with each other, suggesting a common source of exposure. The gene expression of p53, CD26 and ICAM-1 were decreased in taxi drivers and were strongly associated between them, indicating a commom regulation point. The antioxidant non-protein thiols and lycopene were negatively associated with inflammatory biomarkers, maybe regulating the immune-response. We demonstrated, for the first time, that in occupational exposure to air pollution chemicals, oxidative and inflammatory processes are involved in the immune-regulatory process, and indirectly contribute to suppressing the p53 and CD26 expressions, increasing the risk of cancer development. On the other hand, antioxidants could contribute to improving the immune-regulation, but more studies are needed.

Polycyclic aromatic hydrocarbon exposure results in altered CRH, reproductive, and thyroid hormone concentrations during human pregnancy

Polycyclic aromatic hydrocarbons (PAHs) are byproducts of incomplete combustion reactions and are ubiquitous in the environment, leading to widespread human exposure via inhalation and ingestion pathways. PAHs have been implicated as endocrine disrupting compounds in previous animal and in vitro studies, but human studies are currently lacking. Pregnant women and their developing fetuses are particularly susceptible populations to environmental contaminants, in part because alterations in hormone physiology during gestation can have adverse consequences on the health of the pregnancy. We utilized data on 659 pregnant women from the PROTECT longitudinal birth cohort in Puerto Rico to assess associations between repeated measures of 8 urinary hydroxylated PAH (OH-PAH) metabolites and 9 serum hormones during gestation. Urine samples were collected at 3 study visits (median gestational ages of 18, 22, and 26 weeks at each visit, respectively) and serum samples were collected at the first and third study visits. Linear mixed effects models were used to ascertain longitudinal associations between OH-PAHs and hormones, and sensitivity analyses were employed to assess potential nonlinearity and differences in associations on the basis of fetal sex and timing of biomarker measurement. Among the multiple positive associations we observed between OH-PAHs and CRH, estriol, progesterone, T3, and the ratio of T3 to T4, and inverse associations with testosterone, the most notable are a 24.3% increase (95% CI: 13.0, 36.7) in CRH with an interquartile range (IQR) increase in 1-hydroxyphenanthrene and a 17.2% decrease (95% CI: 8.13, 25.4) in testosterone with an IQR increase in 1-hydroxynapthalene. Many associations observed were dependent on fetal sex, and some relationships showed evidence of nonlinearity. These findings demonstrate the importance of studying PAH exposures during pregnancy and highlight the potential complexity of their impacts on the physiology of human pregnancy.

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.

Polycyclic aromatic hydrocarbon exposure and atherosclerotic cardiovascular disease risk in urban adults: The mediating role of oxidatively damaged DNA

Polycyclic aromatic hydrocarbon (PAH) exposure has been considered a risk factor for cardiovascular diseases (CVD), whereas possible mechanisms for this association have not been fully understood. This study focused on exploring the potential effect of oxidatively damaged DNA on the relationships between PAH exposure and the 10-year atherosclerotic CVD (ASCVD) risk. Urinary levels of monohydroxy PAH metabolites (OH-PAHs) and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG, the typical biomarker for oxidatively damaged DNA) were measured among 3052 subjects in the baseline of the Wuhan-Zhuhai cohort. The relationships between urinary OH-PAHs, 8-oxodG and 10-year risk of ASCVD were analyzed by linear mixed models and logistic regression models, respectively. The mediation analysis was further applied to explore the role of 8-oxodG in the relationship between urinary OH-PAHs and 10-year ASCVD risk. After controlling for potential confounders, the log-transformed level of total urinary low molecular weight OH-PAHs (∑LMW OH-PAHs) was significantly associated with an elevated risk of 10-year ASCVD [odds ratio (OR) = 1.222, 95% confidence interval (CI): 1.065-1.402]. More specifically, significantly positive dose-response relationships between total urinary hydroxynaphthalene (∑OHNa), hydroxyfluorene (∑OHFlu), hydroxyphenanthrene (∑OHPh) and 10-year ASCVD risk were observed (all P for trend <0.05). We also found positive relationships between urinary OH-PAH levels and 8-oxodG, as well as between urinary 8-oxodG levels and 10-year risk of ASCVD. Moreover, mediation analyses indicated that urinary 8-oxodG mediated 14.49%, 12.62% and 10.55% of the associations between urinary ∑LMW OH-PAHs, ∑OHNa, ∑OHFlu and 10-year ASCVD risk, respectively. These findings suggest that the oxidatively damaged DNA pathway may be a possible mechanism underlying PAH-associated ASCVD risk elevation.

Thermogravimetric analysis of soot combustion in the presence of ash and soluble organic fraction

Soot (Printex U, PU) combustion in the presence of ash and soluble organic fraction (SOF) was studied by thermogravimetric analysis (TGA). The comprehensive combustion index, combustion stability index and peak temperature were collected to evaluate the combustion performance of soot/ash/SOF mixtures. Compared with SiO₂, Fe₂O₃ and CaSO₄ nanoparticles, ZnO nanoparticles efficiently accelerate soot combustion with excellent oxygen carrying abilities. When the weight ratio of the PU/ZnO mixture is 1 : 1, this acceleration effect is maximized in the soot combustion process. The comprehensive combustion and combustion stability indices increase from 0.667 × 10⁻⁷%² min⁻² °C⁻³ and 23.53 × 10⁵ to 1.296 × 10⁻⁷%² min⁻² °C⁻³ and 39.53 × 10⁵, compared to pure PU, respectively. Compared with the PU/ZnO mixture, the soot combustion had inferior results after adding two oils as the simulative SOF. The 15W lubricant had the minimum negative impact compared to 0# diesel fuel. The comprehensive combustion and combustion stability indices reach the maximum values of 1.074 × 10⁻⁷%² min⁻² °C⁻³ and 33.29 × 10⁵ at the 1 : 1 : 0.1 weight ratio of PU/ZnO/15W, which grew by 62% and 42% compared to pure PU, respectively. This work contributes to an understanding of the combined effect of ash and SOF on soot combustion.

Soot (Printex U, PU) combustion in the presence of ash and soluble organic fraction (SOF) was studied by thermogravimetric analysis (TGA).

Oxygenated polycyclic aromatic hydrocarbons from ambient particulate matter induce electrophysiological instability in cardiomyocytes

Background

Epidemiologic studies have suggested that elevated concentrations of particulate matter (PM) are strongly associated with an increased risk of developing cardiovascular diseases, including arrhythmia. However, the cellular and molecular mechanisms by which PM exposure causes arrhythmia and the component that is mainly responsible for this adverse effect remains to be established. In this study, the arrhythmogenicity of mobilized organic matter from two different types of PM collected during summer (SPM) and winter (WPM) seasons in the Seoul metropolitan area was evaluated. In addition, differential effects between polycyclic aromatic hydrocarbons (PAHs) and oxygenated PAHs (oxy-PAHs) on the induction of electrophysiological instability were examined.

Results

We extracted the bioavailable organic contents of ambient PM, measuring 10 μm or less in diameter, collected from the Seoul metropolitan area using a high-volume air sampler. Significant alterations in all factors tested for association with electrophysiological instability, such as intracellular Ca²⁺ levels, reactive oxygen species (ROS) generation, and mRNA levels of the Ca²⁺-regulating proteins, sarcoplasmic reticulum Ca²⁺ATPase (SERCA2a), Ca²⁺/calmodulin-dependent protein kinase II (CaMK II), and ryanodine receptor 2 (RyR2) were observed in cardiomyocytes treated with PM. Moreover, the alterations were higher in WPM-treated cardiomyocytes than in SPM-treated cardiomyocytes. Three-fold more oxy-PAH concentrations were observed in WPM than SPM. As expected, electrophysiological instability was induced higher in oxy-PAHs (9,10-anthraquinone, AQ or 7,12-benz(a) anthraquinone, BAQ)-treated cardiomyocytes than in PAHs (anthracene, ANT or benz(a) anthracene, BaA)-treated cardiomyocytes; oxy-PAHs infusion of cells mediated by aryl hydrocarbon receptor (AhR) was faster than PAHs infusion. In addition, ROS formation and expression of calcium-related genes were markedly more altered in cells treated with oxy-PAHs compared to those treated with PAHs.

Conclusions

The concentrations of oxy-PAHs in PM were found to be higher in winter than in summer, which might lead to greater electrophysiological instability through the ROS generation and disruption of calcium regulation.

Formaldehyde, Oxidative Stress, and FeNO in Traffic Police Officers Working in Two Cities of Northern Italy

Personal air formaldehyde (air-FA) was measured as risk factor of airways inflammation and oxidative stress (SO) induction. Overall, 154 police officers were enrolled from two differently urbanised Italian cities, Turin and Pavia. Urinary F2t-isoprostane (15-F2t-IsoP), a prostaglandin-like compound, was quantified as a biomarker of general OS in vivo and fractional exhaled nitric oxide (FeNO) was measured for monitoring local inflammatory processes. Urinary cotinine was quantified as a biomarker of tobacco smoking exposure. Traffic police officers living in Turin showed an increased level of log air-FA (p < 0.001), equal to +53.6% (p < 0.001). Log air-(FA) mean values were 3.38 (C.I. 95% 3.33–3.43) and 2.84 (C.I. 95% 2.77–2.92) in Turin and Pavia, respectively. Log (air-FA) was higher in “outdoor workers” (3.18, C.I. 95% 3.13–3.24, p = 0.035) compared to “indoor workers”, showing an increase of +9.3%, even controlling for sex and city. The analyses on 15-F2t-IsoP and FeNO, both adjusted for log air-FA, highlighted that OS and inflammation were higher (+66.8%, p < 0.001 and +75%, p < 0.001, respectively) in Turin traffic police officers compared to those from Pavia. Our findings suggest that even low exposures to traffic-related emissions and urbanisation may influence both general oxidative stress levels and local inflammation.

Biomarkers of exposure, effect, and susceptibility in occupational exposure to traffic-related air pollution: A review

There is a well-recognized association between environmental air pollution exposure and several human diseases. However, the relationship between diseases related to occupational air pollution exposure on roads and high levels of traffic-related air pollutants (TRAPs) is less substantiated. Biomarkers are essential tools in environmental and occupational toxicology, and studies on new biomarkers are increasingly relevant due to the need to determine early biomarkers to be assessed in exposure conditions. This review aimed to investigate the main advances in the biomonitoring of subjects occupationally exposed to air pollution, as well as to summarize the biomarkers of exposure, effect, and susceptibility. Furthermore, we discuss how biomarkers could be used to complement the current application of methods used to assess occupational exposures to xenobiotics present in air pollution. The databases used in the preparation of this review were PubMed, Scopus, and Science Direct. Considering the significant deleterious effects on health associated with chronic occupational exposure to xenobiotics, this topic deserves attention. As it is difficult to avoid occupational exposure to TRAPs, biomonitoring should be applied as a strategy to reduce the toxic effects of workplace exposure.

Association of Urinary Polycyclic Aromatic Hydrocarbons and Diabetes in Korean Adults: Data from the Korean National Environmental Health Survey Cycle 2 (2012-2014)

PURPOSE

To investigate the associations between the urinary levels of polycyclic aromatic hydrocarbons (PAHs) and diabetes mellitus in Korean adults.

MATERIALS AND METHODS

We examined the data of 6478 participants aged ≥19 years from the Korean National Environmental Health Survey (KoNEHS) cycle 2 (2012-2014). The urinary levels of 1-hydroxypyrene (1-OHP), 2-naphthol (2-NAP), 1-hydroxyphenathrene (1-OHPhe), and 2-hydroxyfluorene (2-OHFlu) were measured by gas chromatography-mass spectrometry. Diabetes mellitus was defined as a self-report of physician-diagnosed diabetes mellitus or the use of oral hypoglycemics or insulin. Analyses were adjusted for sex, age, body mass index, household income, alcohol consumption, physical activity, urinary creatinine and cotinine, menopausal status, and quartiles of all other PAHs.

RESULTS

The prevalence of diabetes was 6.5% in the study population. In men, the geometric means of the 2-NAP and 2-OHFlu levels were higher in participants with diabetes mellitus than in those without diabetes mellitus [4.11 vs 3.26 μg/L (P <0.05) and 0.45 vs 0.40 μg/L (P <0.05), respectively]. In women, the geometric mean of 2-NAP levels was also higher in participants with diabetes mellitus than in those without diabetes mellitus (1.81 vs 0.56 μg/L, P <0.05), but there were no significant differences in geometric means for other PAHs. A higher odds ratio (OR) of diabetes was found in participants with the highest quartiles of urinary 2-NAP [OR 1.83, 95% confidence interval (CI) 1.29-2.60] and 2-OHFlu (OR 1.81, 95% CI 1.10-2.98) than in those with the lowest quartiles.

CONCLUSION

The urinary 2-NAP and 2-OHFlu levels were associated with diabetes mellitus in Korean adults. Further studies are needed to determine a potential causal relationship between PAH exposure and diabetes mellitus and its underlying mechanism.

Association between a urinary biomarker for exposure to PAH and blood level of the acute phase protein serum amyloid A in coke oven workers

BACKGROUND

Coke oven workers are exposed to both free and particle bound PAH. Through this exposure, the workers may be at increased risk of cardiovascular diseases. Systemic levels of acute phase response proteins have been linked to cardiovascular disease in epidemiological studies, suggesting it as a marker of these conditions. The aim of this study was to assess whether there was association between PAH exposure and the blood level of the acute phase inflammatory response marker serum amyloid A (SAA) in coke oven workers.

METHODS

A total of 87 male Polish coke oven workers from two different plants comprised the study population. Exposure was assessed by means of the individual post-shift urinary excretion of 1-hydroxypyrene, as internal dose of short-term PAH exposure, and by anti-benzo[a]pyrene diolepoxide (anti-B[a]PDE)-DNA), as a biomarker of long-term PAH exposure. Blood levels of acute phase proteins SAA and CRP were measured by immunoassay. C-reactive protein (CRP) levels were included to adjust for baseline levels of SAA.

RESULTS

Multiple linear regression showed that the major determinants of increased SAA levels were urinary 1-hydroxypyrene (beta = 0.56, p = 0.030) and serum CRP levels (beta = 7.08; p < 0.0001) whereas anti-B[a]PDE-DNA, the GSTM1 detoxifying genotype, diet, and smoking were not associated with SAA levels.

CONCLUSIONS

Urinary 1-hydroxypyrene as biomarker of short-term PAH exposure and serum levels of CRP were predictive of serum levels of SAA in coke oven workers. Our data suggest that exposure of coke oven workers to PAH can lead to increased systemic acute response and therefore potentially increased risk of cardiovascular disease.

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).

Expression levels of circulating microRNAs-126, -155, and -145 in Mexican women exposed to polycyclic aromatic hydrocarbons through biomass fuel use

Human exposure to polycyclic aromatic hydrocarbons (PAHs) has been considered a risk determinant for the development of cardiovascular diseases (CVD). Therefore, the aim of this study was to assess expression levels of vascular-related miRNAs, miR-126, miR-155, and miR-145, in plasma from women (aged 19-81 years) exposed (n = 100) and non-exposed (n = 20) to PAHs via biomass combustion smoke.1-hydroxypyrene (1-OHP) was determined in urine as a biomarker of exposure to PAHs using high-resolution liquid chromatography. Plasma expression levels of proposed miRNAs were determined by quantitative real-time PCR. Additionally, traditional risk factors (age, blood pressure, serum lipid profile, blood glucose, and among others) associated with CVD were evaluated. Urinary 1-OHP concentrations and plasma expression levels of miR-126 and miR-155 were significantly higher (P < 0.05) in women using wood as a fuel source in their homes (indoor) compared to women from the reference group (non-exposed to biomass smoke). Besides, multivariate linear regression analyses revealed that miR-126[β = 0.61; 95% confidence interval (0.32-0.90)] and miR-155 [β = 0.45; 95% confidence interval (0.13-0.84)] expression levels were significantly associated with urinary 1-OHP concentrations after being adjusted by traditional risk factors (P < 0.05). In contrast, no significant relationship was found between miR-145 and urinary 1-OHP levels. Furthermore, miRNAs assessed in this investigation are associated with CVD events. Consequently, actions to reduce exposure to PAHs in the evaluated population are warranted. Environ. Mol. Mutagen. 60:546-558, 2019. © 2019 Wiley Periodicals, Inc.

A Cross-Sectional Study of Prevalence of Depression, Anxiety and Stress among Professional Cab Drivers in New Delhi

Background

The profession of drivers is one of the occupational groups exposed to very poor working conditions. This study aimed to establish the prevalence of depression, anxiety and stress among cab drivers.

Materials and Methods

This cross-sectional study included 134 cab drivers. Their mental health status was assessed with the help of a screening tool - Depression Anxiety Stress Scale (DASS-21). Their demographic details, working conditions, lifestyle factors and use of habit-forming substances were also assessed with the help of a semi-structured questionnaire.

Results

It was revealed that all cab drivers were male and between 20 to 64 years of age. Eighty two (62%) drivers said they are sometimes irritated at work, 29 (21.5%) said they feel irritated daily and rest 23 (17.2%) said that they were never irritated at work. When screened for depression, anxiety and stress, it was found out that 81 (60.5%) were suffering from depression, 63 (47%) from anxiety and 49 (36.5%) had variable degree of stress.

Conclusion

Cab drivers are at high risk of acquiring mental health diseases, yet the mental health of this large workforce is ignored.

Obesity mediated the association of exposure to polycyclic aromatic hydrocarbon with risk of cardiovascular events

Exposure to polycyclic aromatic hydrocarbons (PAHs) could cause high blood pressure (BP) and increased risk for atherosclerotic cardiovascular disease (ASCVD). However, the mechanisms underlying the relationship between them were unclear. We investigated potential mediation effect of obesity on the association of exposure to PAHs with high BP and increased risk for ASCVD. In the repeated measures study, 106 community-dwelling residents in Wuhan, China finished the physical examination in the winter and summer seasons, eight urinary PAHs metabolites were measured. Associations of urinary PAHs with high BP and increased risk for ASCVD were assessed using either linear mixed effect models or generalized estimating equations models. Mediation analysis was performed to evaluate the mediating effect of obesity on the association of urinary PAHs metabolites with high BP or increased risk of ASCVD. We observed the positive association between urinary PAHs metabolites and BP or the odds ratios for high BP (all P<0.05). Additionally, each one-unit increase in ln-transformed urinary levels of 4-hydroxyphenanthrene or the total of PAH metabolites was associated with a 12.63% or 11.91% increase in the estimated 10-year ASCVD risk (both P<0.05). The waist-to-height ratio mediated 29.0% of the association of urinary 4-hydroxyphenanthrene with increased risk of ASCVD (P<0.05). The findings suggest that PAHs exposure may be associated with elevated BP and an increased risk of ASCVD. Obesity may partially mediate the association between PAHs exposure and higher BP or increased risk of ASCVD.

Long-term high air pollution exposure induced metabolic adaptations in traffic policemen

OBJECTIVE

To assess the adverse physiological changes induced by long-term exposure to PM2.5.

METHODS

Totally 183 traffic policemen and 88 office policemen as the control group, were enrolled in this study. The concentrations of PM2.5 in both the working places of traffic and office policemen were obtained. Detailed personal questionnaires and conventional laboratory tests including hematology, fasting blood glucose, blood lipids, liver, kidney, immunity and tumor-related markers were conducted on all participants of this study.

RESULTS

A dose-response relationship between the FBG, HDL-c and CEA values and the PM2.5 exposure duration was observed. Multivariate analysis confirmed that one hour on duty outdoor per day for one year was associated with an increase in FBG of 0.005% (95% CI: 0.0004% to 0.009%), CEA of 0.012% (95% CI: 0.006% to 0.017%), and a decrease in HDL-C of 0.001% (95% CI: 0.00034% to 0.002%).

CONCLUSION

Long-term high air pollution exposure may lead to metabolism adaptation and it is likely involved in the development of cardiovascular disease and diabetes mellitus.

Are metals and pyrene levels additional factors playing a pivotal role in air pollution-induced inflammation in taxi drivers?

This study aimed to evaluate which xenobiotic (As, Hg, Pb or pyrenes) is primarily responsible for the inflammatory process in taxi drivers. Multiple regression analysis showed that Hg is the main xenobiotic responsible for the increase of cytokine levels. These associations suggest that co-exposure to pollutants could be a risk factor for health effects.

Distribution and predictors of urinary polycyclic aromatic hydrocarbon metabolites in two pregnancy cohort studies

Pregnant women and their fetuses represent susceptible populations to environmental contaminants. Exposure to polycyclic aromatic hydrocarbons (PAHs) among pregnant women may contribute to adverse birth outcomes such as preterm birth. Multiple previous studies have assessed airborne sources of PAHs among pregnant women but few have measured urinary PAH metabolites which can capture total exposure through multiple routes. The aim of this study was to bridge this knowledge gap by assessing longitudinal urinary PAH metabolite concentrations over two time points in pregnancy cohorts in Boston (N = 200) and Puerto Rico (N = 50) to better understand exposure distributions throughout pregnancy and how they relate to demographic factors. Urine samples were analyzed for 1-NAP, 2-NAP, 2-FLU, 1-PHE, 2,3-PHE, 4-PHE, 9-PHE, and 1-PYR. Concentrations of 2-NAP, 1-PYR, and 4-PHE were higher in Puerto Rico, while all other metabolites were present in higher concentrations in Boston. In Puerto Rico, intraclass correlation coefficients (ICC) were weak to moderate, ranging from 0.06 to 0.42. PAH metabolite concentrations were significantly higher among younger, heavier (except 1-NAP and 9-PHE), and less educated individuals in Boston only. Consistent significant associations between PAH concentrations and measured covariates were not found in Puerto Rico. Our results suggest that potentially important differences in PAH exposure exist between these two populations. Additionally, our results indicate that multiple urinary measurements are required to accurately assess PAH exposure throughout pregnancy.

Influence on serum asymmetric dimethylarginine (ADMA) concentrations of human paraoxonase 1 polymorphism (Q192R) and exposure to polycyclic aromatic hydrocarbons (PAHs) in Mexican women, a gene-environment interaction

It has been demonstrated that Cardiovascular Diseases (CVD) are a consequence of the combination of genetic and environmental factors and/or the interaction between them. Therefore, the aim of this study was to evaluate the impact of polycyclic aromatic hydrocarbon (PAHs) exposure and PON1 Q192R polymorphism (genetic susceptibility) on serum asymmetric dimethylarginine (ADMA) levels in Mexican women (n = 206). Urinary 1-hydroxypyrene concentrations (1-OHP; exposure biomarker for PAHs) were quantified using a high-performance liquid chromatography technique, PON1 Q192R polymorphism was genotyped using TaqMan probes and serum ADMA concentrations were evaluated using a commercially available ELISA kit. Urinary 1-OHP levels detected in this study ranged from 0.07 to 9.37 μmol/mol of creatinine (0.13-18.0 μg/g of creatinine). Regarding allele frequency (PON1 Q192R polymorphism), the 192Q-allele frequency was 0.43 and for the 192R-allele it was 0.57. In relation to serum ADMA levels, the levels ranged from 0.06 to 1.46 μmol/L. Moreover, multiple linear regression analysis was performed and associations between urinary 1-OHP levels (β = 0.05, p = 0.002), PON1 Q192R polymorphism (β = 0.04, p = 0.003) and serum ADMA concentrations were found. Besides, an interaction (gene-environment interaction) of both independent variables (1-OHP and PON1 polymorphism) on serum ADMA levels was found (β = 0.04, p = 0.02) in the constructed multiple linear model. Therefore, according to the significance of this research, it is necessary to execute health programs to reduce cardiovascular risk in the assessed population.

Occupational exposure of firefighters to polycyclic aromatic hydrocarbons in non-fire work environments

This work aims to characterize personal exposure of firefighters to polycyclic aromatic hydrocarbons (PAHs) in non-fire work environments (fire stations), and assesses the respective risks. Eighteen PAHs (16 considered by USEPA as priority pollutants, dibenzo[a,l]pyrene and benzo[j]fluoranthene) were monitored in breathing zones of workers at five Portuguese fire stations during a normal shift. The obtained levels of PAHs fulfilled all existent occupational exposure limits as well as air quality guidelines with total concentrations (ΣPAHs) in range of 46.8-155ngm^-3. Light compounds (2-3 rings) were the most predominant congeners (74-96% of ΣPAHs) whereas PAHs with 5-6 rings accounted 3-9% of ΣPAHs. Fuel and biomass combustions, vehicular traffic emissions, and use of lubricant oils were identified as the main sources of PAHs exposure at the studied fire corporations. Incremental lifetime cancer risks were below the recommend USEPA guideline of 10^-6 and thus negligible for all the studied subjects, but WHO health-based guideline level of 10^-5 was exceeded (9-44 times) at all fire corporations. These results thus show that even during non-fire situations firefighters are exposed to PAHs at levels that may promote some adverse health outcomes; therefore the respective occupational exposures to these compounds should be carefully controlled.

Ambient levels of concentrated PM2.5 affects cell kinetics in adrenal glands: an experimental study in mice

We evaluated the effects of air pollution on the adrenal cortex using 30 female mice divided into two groups of fifteen animals each. One group was conditioned daily in a chamber with exposure to particulate matter (PM) 2.5 μm (GExp). Animals were exposed on daily basis in an ambient particles concentrator during the period of time enough to reach an accumulated dose of 600 μg/m³, which corresponds to a 24-h exposure of 25 μg/m³ that approximates to the annual mean of PM2.5 in São Paulo. The other group was allocated to another chamber with filtered air (GCrt). After euthanasia, the adrenals underwent histological processing and immunohistochemistry staining for Ki-67 and cleaved caspase-3. Histomorphometry of the adrenal glands in GExp showed increased thickness of the zona glomerulosa, while in GCrt; the adrenal glands from GExp had higher Ki-67 immunostaining scores in the zona reticularis than those from GCrt. The adrenal from GExp showed higher cleaved caspase-3 immunoreactivity in the zona fasciculata than the unexposed group (GCrt). The homeostasis index indicated higher cell proliferation in the zona glomerulosa and zona reticularis in GExp than in GCrt. Our data indicate that PM2.5 air pollution induces alterations on cell kinetics in mouse adrenal glands.

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.

Serum adipocyte-fatty acid binding protein (FABP4) levels in women from Mexico exposed to polycyclic aromatic hydrocarbons (PAHs)

Recent studies indicate that exposure to polycyclic aromatic hydrocarbons (PAHs) is a very important risk factor for the development of cardiovascular diseases (CVDs). Correspondingly, adipocyte-fatty acid binding protein (FABP4, also known as aP2 and AFABP) has been proposed as a new, meaningful and useful biomarker to predict metabolic and cardiovascular diseases. Therefore, the aim of this study was to evaluate serum FABP4 levels in Mexican women exposed to PAHs. Urinary 1-hydroxypyrene ((1-OHP), exposure biomarker for PAHs) levels were quantified using a high-performance liquid chromatography (HPLC) technique, and serum FABP4 concentrations were analyzed using a commercially available ELISA kit. The mean urinary 1-OHP level found in women participating in this study was 1.30 ± 1.10 μmol/mol creatinine (2.45 ± 2.10 μg/g creatinine). Regarding serum FABP4 concentrations, the levels ranged from 3.80 to 62.5 ng/mL in the assessed population. Moreover, a significant association (p < 0.001) was found between urinary 1-OHP levels and serum FABP4 concentrations in women after adjusting for potential confounding variables. The presented data in this study can be considered only as a starting point for further studies. Then, in order to elucidate whether FABP4 represents a risk factor for CVD disease in humans exposed to air contaminants (such as PAHs), large epidemiological studies are necessary.

Association between inflammation processes, DNA damage, and exposure to environmental pollutants

Environmental exposure to pollutants, especially polycyclic aromatic hydrocarbons (PAHs), could lead to carcinogenesis development. However, there is a gap on the mechanisms involved in this effect. Therefore, the aim of this study was to investigate the potential relationship between exposure to environmental air pollution and inflammation process in DNA damage in taxi drivers. This study included 45 taxi drivers and 40 controls; non-smokers composed both groups. Biological monitoring was performed through quantification of urinary 1-hydroxypyrene (1-OHP). ICAM-1 (CD54) expression, NTPDase activity, inflammatory cytokine (IL-1β, IL-6, IL-10, TNF-α and IFN-γ) levels, and comet and micronucleus assays were evaluated. The results demonstrated that 1-OHP levels, ICAM-1 expression, NTPDase activity, and DNA damage biomarkers (% tail DNA and micronucleus frequency) were increased in taxi drivers compared to the control group (p < 0.01). Moreover, significant associations were found between 1-OHP levels and ICAM-1 expression, % tail DNA, and micronucleus frequency (p < 0.05). Besides, pro-inflammatory cytokine levels were positively correlated to % tail DNA and micronucleus frequency (p < 0.001). Our findings suggest an important association between environmental exposure to air pollution with increase of ICAM-1 expression and NTPDase activity in taxi drivers. Additionally, the multiple regression linear-analysis demonstrated association between IL-6 and DNA damage. Thus, the present study has provided important evidence that, in addition to environmental exposure to air pollutants, the inflammation process may contribute to DNA damage.

Plasma asymmetric dimethylarginine (ADMA) levels in Mexican women exposed to polycyclic aromatic hydrocarbons (PAHs): A preliminary study

Recent studies indicate that exposure to environmental pollutants (as polycyclic aromatic hydrocarbons) is a very important risk factor for development of cardiovascular diseases (CVDs). Correspondingly, in recent times asymmetric dimethylarginine (ADMA) has been proposed as a new and meaningful biomarker predictor for the risk of CVDs. Therefore, the objective of this study was to evaluate plasma ADMA concentrations in Mexican women (n=155) exposed to polycyclic aromatic hydrocarbons (PAHs). Urinary 1-hydroxypyrene [(1-OHP), exposure biomarker for PAHs] levels were quantified using a high performance liquid chromatography (HPLC) technique and plasma ADMA concentrations were analyzed using a commercially available ELISA kit. Urinary 1-OHP levels in all women assessed ranged from <LOD to 8.80μmol/mol creatinine. Regarding plasma ADMA concentrations, the mean levels ranged from 0.66 to 1.00μmol/L. Moreover, a significantly relationship was found between plasma ADMA concentrations and urinary 1-OHP levels (p=0.005; r=0.390). In conclusion, the results showed in this study demonstrated that the urinary 1-OHP levels were significant predictors of plasma ADMA concentrations in Mexican women exposed to PAHs. Although with due caution regarding the low representativeness of the present screening, it can be considered as a preliminary work to perform prospective studies including greater number of individuals and focusing in a more complete characterization of the effects produced by PAHs exposure on cardiovascular health.

Hematocrit levels as cardiovascular risk among taxi drivers in Bangkok, Thailand

In Thailand, taxi drivers employed in the informal sector often experience hazardous working conditions. Previous studies revealed that elevated Hematocrit (HCT) is a predictor of cardiovascular disease (CVD) risk. This study assessed factors associated with HCT in taxi drivers to predict their occupational CVD risk factors. A cross-sectional study was conducted on 298 male taxi drivers who joined a health check-up campaign in Bangkok, Thailand. HCT and body mass index were retrieved from participant health check-up files. Self-administered questionnaires assessed demographics, driving mileage, working hours, and lifestyle. Statistical associations were analyzed using stepwise linear regression. Our results showed that obesity (p=0.007), daily alcohol drinking (p=0.003), and current or past smoking (p=0.016) were associated with higher HCT levels. While working hours were not directly associated with HCT levels in the current study, the effect on overworking is statistically arguable because most participants worked substantially longer hours. Our findings suggest that taxi drivers' CVD risk may be increased by their unhealthy work styles. Initiatives to improve general working conditions for taxi drivers should take into account health promotion and CVD prevention. The policy of providing periodic health check-ups is important to make workers in the informal sector aware of their health status.

Effects of air pollution on human health and practical measures for prevention in Iran

Air pollution is a major concern of new civilized world, which has a serious toxicological impact on human health and the environment. It has a number of different emission sources, but motor vehicles and industrial processes contribute the major part of air pollution. According to the World Health Organization, six major air pollutants include particle pollution, ground-level ozone, carbon monoxide, sulfur oxides, nitrogen oxides, and lead. Long and short term exposure to air suspended toxicants has a different toxicological impact on human including respiratory and cardiovascular diseases, neuropsychiatric complications, the eyes irritation, skin diseases, and long-term chronic diseases such as cancer. Several reports have revealed the direct association between exposure to the poor air quality and increasing rate of morbidity and mortality mostly due to cardiovascular and respiratory diseases. Air pollution is considered as the major environmental risk factor in the incidence and progression of some diseases such as asthma, lung cancer, ventricular hypertrophy, Alzheimer's and Parkinson's diseases, psychological complications, autism, retinopathy, fetal growth, and low birth weight. In this review article, we aimed to discuss toxicology of major air pollutants, sources of emission, and their impact on human health. We have also proposed practical measures to reduce air pollution in Iran.