Polycyclic Aromatic Hydrocarbons Metabolites Research Articles

Urinary Metabolites of Polycyclic Aromatic Hydrocarbons of Rural Population in Northwestern China: Oxidative Stress and Health Risk Assessment.

Polycyclic aromatic hydrocarbon (PAH) exposure is suspected to be linked to oxidative damage. Herein, ten PAH human exposure biomarkers [hydroxylated PAH metabolites (OH-PAHs)] and five oxidative stress biomarkers (OSBs) were detected in urine samples collected from participants living in a rural area (n = 181) in Northwestern China. The median molar concentration of ΣOH-PAHs in urine was 47.0 pmol mL-1. The 2-hydroxynaphthalene (2-OHNap; median: 2.21 ng mL-1) was the dominant OH-PAH. The risk assessment of PAH exposure found that hazard index (HI) values were <1, indicating that the PAH exposure of rural people in Jingyuan would not generate significant cumulative risks. Smokers (median: 0.033) obtained higher HI values than nonsmokers (median: 0.015, p < 0.01), suggesting that smokers face a higher health risk from PAH exposure than nonsmokers. Pearson correlation and multivariate linear regression analysis revealed that ΣOH-PAH concentrations were significant factors in increasing the oxidative damage to deoxyribonucleic acid (DNA) (8-hydroxy-2'-deoxyguanosine, 8-OHdG), ribonucleic acid (RNA) (8-oxo-7,8-dihydroguanine, 8-oxoGua), and protein (o, o'-dityrosine, diY) (p < 0.05). Among all PAH metabolites, only 1-hydroxypyrene (1-OHPyr) could positively affect the expression of all five OSBs (p < 0.05), suggesting that urinary 1-OHPyr might be a reliable biomarker for PAH exposure and a useful indicator for assessing the impacts of PAH exposure on oxidative stress. This study is focused on the relation between PAH exposure and oxidative damage and lays a foundation for the study of the health effect mechanism of PAHs.

The Maternal and Infant Environmental Health Riskscape study of perinatal disparities in greater Houston: rationale, study design and participant profiles.

The Maternal and Infant Environmental Health Riskscape (MIEHR) Center was established to address the interplay among chemical and non-chemical stressors in the biological, physical, social, and built environments that disproportionately impact perinatal health among Black pregnant people in a large and diverse urban area with documented disparities in the U.S. The MIEHR cohort is recruiting non-Hispanic Black and non-Hispanic white pregnant people who deliver their infants at major obstetric hospitals in Houston, Texas. At enrollment, all participants are asked to provide urine samples for chemical [metals, cotinine, and polycyclic aromatic hydrocarbons (PAHs)] analyses and blood samples. A subset of the cohort is asked to provide oral and vaginal swabs, and fecal samples. Questionnaire and electronic health record data gather information about residential address history during pregnancy, pregnancy history and prenatal care, sociodemographic and lifestyle factors, experiences of discrimination and stress, and sources of social support. Using information on where a participant lived during their pregnancy, features of their neighborhood environment are characterized. We provide summaries of key individual- and neighborhood-level features of the entire cohort, as well as for Black and white participants separately. Between April 2021 and February 2023, 1,244 pregnant people were recruited. Nearly all participants provided urine samples and slightly less than half provided blood samples. PAH exposure patterns as assessed on 47% of participants thus far showed varying levels depending on metabolite as compared to previous studies. Additionally, analyses suggest differences between Black and white pregnant people in experiences of discrimination, stress, and levels of social support, as well as in neighborhood characteristics. Our findings to date highlight racial differences in experiences of discrimination, stress, and levels of support, as well as neighborhood characteristics. Recruitment of the cohort is ongoing and additional neighborhood metrics are being constructed. Biospecimens will be analyzed for metals and PAH metabolites (urine samples), miRNAs (plasma samples) and the microbiome (oral swabs). Once enrollment ends, formal assessments are planned to elucidate individual- and neighborhood-level features in the environmental riskscape that contribute to Black-White disparities in perinatal health.

Activity-Based Protein Profiling to Probe Relationships between Cytochrome P450 Enzymes and Early-Age Metabolism of Two Polycyclic Aromatic Hydrocarbons (PAHs): Phenanthrene and Retene.

A growing body of literature has linked early-life exposures to polycyclic aromatic hydrocarbons (PAH) with adverse neurodevelopmental effects. Once in the body, metabolism serves as a powerful mediator of PAH toxicity by bioactivating and detoxifying PAH metabolites. Since enzyme expression and activity vary considerably throughout human development, we evaluated infant metabolism of PAHs as a potential contributing factor to PAH susceptibility. We measured and compared rates of phenanthrene and retene (two primary PAH constituents of woodsmoke) metabolism in human hepatic microsomes from individuals ≤21 months of age to a pooled sample (n = 200) consisting primarily of adults. We used activity-based protein profiling (ABPP) to characterize cytochrome P450 enzymes (CYPs) in the same hepatic microsome samples. Once incubated in microsomes, phenanthrene demonstrated rapid depletion. Best-fit models for phenanthrene metabolism demonstrated either 1 or 2 phases, depending on the sample, indicating that multiple enzymes could metabolize phenanthrene. We observed no statistically significant differences in phenanthrene metabolism as a function of age, although samples from the youngest individuals had the slowest phenanthrene metabolism rates. We observed slower rates of retene metabolism compared with phenanthrene also in multiple phases. Rates of retene metabolism increased in an age-dependent manner until adult (pooled) metabolism rates were achieved at ∼12 months. ABPP identified 28 unique CYPs among all samples, and we observed lower amounts of active CYPs in individuals ≤21 months of age compared to the pooled sample. Phenanthrene metabolism correlated to CYPs 1A1, 1A2, 2C8, 4A22, 3A4, and 3A43 and retene metabolism correlated to CYPs 1A1, 1A2, and 2C8 measured by ABPP and vendor-supplied substrate marker activities. These results will aid efforts to determine human health risk and susceptibility to PAHs exposure during early life.

Prepubertal exposure to polycyclic aromatic hydrocarbons are associated with early pubertal development onset in boys: A longitudinal study

ObjectiveTo investigate the effects of polycyclic aromatic hydrocarbons(PAHs) on puberty in boys. Methods695 subjects were selected from four primary schools in Chongqing, China. 675 urine samples from these boys were collected four PAH metabolites: 1-hydroxypyrene, 2-hydroxynaphthoic, 2-hydroxyfluorene, and 9-hydroxyphenanthrene. Pubertal development of 695 boys was assessed at follow-up visits starting in December 2015 and occurring every six months thereafter until now, data used in this article ending in June 2021. A total of 12 follow-up visits were performed. Cox proportional hazards regression models were used to analyze the relationship between PAH metabolite concentrations and indicators of pubertal timing. ResultsThe mean age at puberty onset of testicular volume, facial hair, pubic hair, first ejaculation, and axillary hair in boys was 11.66, 12.43, 12.51, 12.72 and 13.70 years, respectively. Cox proportional hazards regression models showed that boys with moderate level of 1-OHPyr exposure was associated with earlier testicular development (HR: 1.276, 95%CI: 1.006-1.619), with moderate level of 2-OHNap were at higher risk of early testicular development (HR: 1.273, 95%CI: 1.002-1.617) and early axillary hair development (HR: 1.355, 95%CI: 1.040-1.764), with moderate level of 2-OHFlu was associated with earlier pubic hair development (HR: 1.256, 95%CI: 1.001-1.577), with high level of 9-OHPhe were at higher risk of early fisrt ejaculation (HR: 1.333, 95%CI: 1.005-1.767) and early facial hair development (HR: 1.393, 95%CI: 1.059-1.831). ConclusionPrepubertal exposure to PAHs may be associated with earlier pubertal development in boys. Environmental ImplicationPolycyclic aromatic hydrocarbons(PAHs) are a widespread group of persistent organic pollutants that are ubiquitous in the air, have potential carcinogenicity and teratogenicity. As environmental endocrine disruptors (EEDs), PAHs may enter children’s bodies before and after birth in various ways, potentially causing functional disorders of the reproductive system and abnormal development. That’s why we considered PAHs as "hazardous material". By exploring the association between PAH metabolites and pubertal development onset(testicular volume, pubic hair, axillary hair, facial hair and first ejaculation) in boys, we expected to provide scientific evidence for reducing exposure to PAHs in various pathways.

Association of mixed polycyclic aromatic hydrocarbons exposure with oxidative stress in Korean adults

Polycyclic aromatic hydrocarbons (PAHs) are widespread pollutants associated with several adverse health effects and PAH-induced oxidative stress has been proposed as a potential mechanism. This study evaluated the associations of single and multiple PAHs exposure with oxidative stress within the Korean adult population, using serum gamma glutamyltransferase (GGT) as an oxidative stress marker. Data from the Second Korean National Environmental Health Survey (2012–2014) were analyzed. For analysis, 5225 individuals were included. PAH exposure was assessed with four urinary PAH metabolites: 1-hydroxyphenanthrene, 1-hydroxypyrene, 2-hydroxyfluorene, and 2-naphthol. After adjusting for age, sex, body mass index, drinking, passive smoking, and current smoking (model 1), as well as the presence of diabetes and hepatobiliary diseases (model 2), complex samples general linear model regression analyses for each metabolite revealed a significant positive association between Ln(1-hydroxyphenanthrene) and Ln(GGT) (model 1: β = 0.040, p < 0.01 and model 2: β = 0.044, p < 0.05). For the complete dataset (n = 4378), a significant positive association was observed between mixture of four urinary PAH metabolites and serum GGT in both the quantile g-computation and the Bayesian kernel machine regression analysis. Our study provides evidence for the association between mixed PAH exposure and oxidative stress.

PAH bioremediation with Rhodococcus rhodochrous ATCC 21198: Impact of cell immobilization and surfactant use on PAH treatment and post-remediation toxicity

Polycyclic aromatic hydrocarbons (PAHs) are prevalent environmental contaminants that are harmful to ecological and human health. Bioremediation is a promising technique for remediating PAHs in the environment, however bioremediation often results in the accumulation of toxic PAH metabolites. The objectives of this research were to demonstrate the cometabolic treatment of a mixture of PAHs by a pure bacterial culture, Rhodococcus rhodochrous ATCC 21198, and investigate PAH metabolites and toxicity. Additionally, the surfactant Tween ® 80 and cell immobilization techniques were used to enhance bioremediation. Total PAH removal ranged from 70–95% for fluorene, 44–89% for phenanthrene, 86–97% for anthracene, and 6.5–78% for pyrene. Maximum removal was achieved with immobilized cells in the presence of Tween ® 80. Investigation of PAH metabolites produced by 21198 revealed a complex mixture of hydroxylated compounds, quinones, and ring-fission products. Toxicity appeared to increase after bioremediation, manifesting as mortality and developmental effects in embryonic zebrafish. 21198′s ability to rapidly transform PAHs of a variety of molecular structures and sizes suggests that 21198 can be a valuable microorganism for catalyzing PAH remediation. However, implementing further treatment processes to address toxic PAH metabolites should be pursued to help lower post-remediation toxicity in future studies.

Prenatal exposure to polycyclic aromatic hydrocarbons and growth parameters.

It has long been known that airborne polycyclic aromatic hydrocarbons (PAHs) can negatively affect pregnancy and birth outcomes, such as birth weight, fetal development, and placental growth factors. However, similar studies yield divergent results. Our goal was to estimate the amount of monohydroxylated PAH (OH-PAH) metabolites in the urine of pregnant women/mothers and their newborns in relation to birth outcomes, such as placenta weight, Apgar 5', and the growth parameters of children up to the age of two. Two cohorts of children born in 2013 and 2014 during the summer and winter seasons in the Czech Republic in the cities Karviná (N = 144) and České Budějovice (N = 198), which differ significantly in the level of air pollution, were studied. PAH exposure was assessed by the concentration of benzo[a]pyrene (B[a]P) in the air and the concentration of 11 OH-PAH metabolites in the urine of newborns and mothers. Growth parameters and birth outcomes were obtained from medical questionnaires after birth and from pediatric questionnaires during the following 24 months of the child's life. Concentrations of B[a]P were significantly higher in Karviná (p < 0.001). OH-PAH metabolites were significantly higher in the mothers' as well as in the newborns' urine in Karviná and during the winter season. Neonatal length was shorter in newborns in Karviná (p < 0.001), but this difference evened out during the next 3 to 24 months. Compared to České Budějovice, newborns in Karviná showed significantly lower weight gain between birth and three months after delivery. The OH-PAH metabolites in mothers' or newborns' urine did not affect birth weight. The presence of seven OH-PAH (top 25% of values of concentrations higher than the median) metabolites in the newborns' urine is associated with decreased length of newborn. Nine OH-PAH metabolites decreased placenta weight, which was the most significant, while seven OH-PAH metabolites decreased Apgar 5'. We have shown a possible connection between higher concentration of OH-PAH metabolites in newborns' urine and decreased length, head circumference, placenta weight, and Apgar 5', but not birth weight.

Prenatal polycyclic aromatic hydrocarbon exposure and asthma at age 8–9 years in a multi-site longitudinal study

Background and aimStudies suggest prenatal exposure to polycyclic aromatic hydrocarbons (PAHs) may influence wheezing or asthma in preschool-aged children. However, the impact of prenatal PAH exposure on asthma and wheeze in middle childhood remain unclear. We investigated these associations in socio-demographically diverse participants from the ECHO PATHWAYS multi-cohort consortium.MethodsWe included 1,081 birth parent–child dyads across five U.S. cities. Maternal urinary mono-hydroxylated PAH metabolite concentrations (OH-PAH) were measured during mid-pregnancy. Asthma at age 8–9 years and wheezing trajectory across childhood were characterized by caregiver reported asthma diagnosis and asthma/wheeze symptoms. We used logistic and multinomial regression to estimate odds ratios of asthma and childhood wheezing trajectories associated with five individual OH-PAHs, adjusting for urine specific gravity, various maternal and child characteristics, study site, prenatal and postnatal smoke exposure, and birth year and season in single metabolite and mutually adjusted models. We used multiplicative interaction terms to evaluate effect modification by child sex and explored OH-PAH mixture effects through Weighted Quantile Sum regression.ResultsThe prevalence of asthma in the study population was 10%. We found limited evidence of adverse associations between pregnancy OH-PAH concentrations and asthma or wheezing trajectories. We observed adverse associations between 1/9-hydroxyphenanthrene and asthma and persistent wheeze among girls, and evidence of inverse associations with asthma for 1-hydroxynathpthalene, which was stronger among boys, though tests for effect modification by child sex were not statistically significant.ConclusionsIn a large, multi-site cohort, we did not find strong evidence of an association between prenatal exposure to PAHs and child asthma at age 8–9 years, though some adverse associations were observed among girls.

Cardiolipin Membranes Promote Cytochrome c Transformation of Polycyclic Aromatic Hydrocarbons and Their In Vivo Metabolites.

The catalytic properties of cytochrome c (Cc) have captured great interest in respect to mitochondrial physiology and apoptosis, and hold potential for novel enzymatic bioremediation systems. Nevertheless, its contribution to the metabolism of environmental toxicants remains unstudied. Human exposure to polycyclic aromatic hydrocarbons (PAHs) has been associated with impactful diseases, and animal models have unveiled concerning signs of PAHs' toxicity to mitochondria. In this work, a series of eight PAHs with ionization potentials between 7.2 and 8.1 eV were used to challenge the catalytic ability of Cc and to evaluate the effect of vesicles containing cardiolipin mimicking mitochondrial membranes activating the peroxidase activity of Cc. With moderate levels of H2O2 and at pH 7.0, Cc catalyzed the oxidation of toxic PAHs, such as benzo[a]pyrene, anthracene, and benzo[a]anthracene, and the cardiolipin-containing membranes clearly increased the PAH conversions. Our results also demonstrate for the first time that Cc and Cc-cardiolipin complexes efficiently transformed the PAH metabolites 2-hydroxynaphthalene and 1-hydroxypyrene. In comparison to horseradish peroxidase, Cc was shown to reach more potent oxidizing states and react with PAHs with ionization potentials up to 7.70 eV, including pyrene and acenaphthene. Spectral assays indicated that anthracene binds to Cc, and docking simulations proposed possible binding sites positioning anthracene for oxidation. The results give support to the participation of Cc in the metabolism of PAHs, especially in mitochondria, and encourage further investigation of the molecular interaction between PAHs and Cc.

Polycyclic Aromatic Hydrocarbons and Pancreatic Cancer: An Analysis of the Blood Biomarker, r-1,t-2,3,c-4-Tetrahydroxy-1,2,3,4-tetrahydrophenanthrene and Selected Metabolism Gene SNPs.

Exposure to polycyclic aromatic hydrocarbons (PAHs), byproducts of incomplete combustion, and their effects on the development of cancer are still being evaluated. Recent studies have analyzed the relationship between PAHs and tobacco or dietary intake in the form of processed foods and smoked/well-done meats. This study aims to assess the association of a blood biomarker and metabolite of PAHs, r-1,t-2,3,c-4-tetrahydroxy-1,2,3,4-tetrahydrophenanthrene (PheT), dietary intake, selected metabolism SNPs, and pancreatic cancer. Demographics, food-frequency data, SNPs, treatment history, and levels of PheT in plasma were determined from 400 participants (202 cases and 198 controls) and evaluated based on pancreatic adenocarcinoma diagnosis. Demographic and dietary variables were selected based on previously published literature indicating association with pancreatic cancer. A multiple regression model combined the significant demographic and food items with SNPs. Final multivariate logistic regression significant factors (p-value < 0.05) associated with pancreatic cancer included: Type 2 Diabetes [OR = 6.26 (95% CI = 2.83, 14.46)], PheT [1.03 (1.02, 1.05)], very well-done red meat [0.90 (0.83, 0.96)], fruit/vegetable servings [1.35 (1.06, 1.73)], recessive (rs12203582) [4.11 (1.77, 9.91)], recessive (rs56679) [0.2 (0.06, 0.85)], overdominant (rs3784605) [3.14 (1.69, 6.01)], and overdominant (rs721430) [0.39 (0.19, 0.76)]. Of note, by design, the level of smoking did not differ between our cases and controls. This study does not provide strong evidence that PheT is a biomarker of pancreatic cancer susceptibility independent of dietary intake and select metabolism SNPs among a nonsmoking population.

Natural hydrophobic deep eutectic solvent based dispersive liquid-liquid microextraction followed by liquid chromatography with tandem mass spectrometry analysis of multi-class metabolites of pesticides, phthalates, and polycyclic aromatic hydrocarbons in animal-originated foods

Demonstrated a new natural hydrophobic deep eutectic solvent (NADES) based dispersive liquid-liquid microextraction (DLLME) approach/method to extract and enrich 37 multi-class metabolites (MCM) such as pesticides, phthalates, and polycyclic aromatic hydrocarbons metabolites from a complex animal- originated food matrices. The extraction solvent (NADES) synthesized from an equimolar mixture of the terpenes, thymol and menthol. The analysis was performed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) employing electrospray ionization, and an enzymatic deconjugation of metabolites was carried out with β-glucuronidase. The parameters were optimized using the design of experiments (DoE). Further, the method was validated, and measurement uncertainty was also calculated. The detection and quantitation limits of the method were 0.03 to 0.4 ng/mL and 0.1 to 1.32 ng/mL, respectively. Recovery and expanded uncertainty ranged from 81.3 to 112.3 % and 8.9 to 19.7 %. The pertinence of the method was proven in identifying/finding metabolites in egg and meat samples ranging from 0.31 to 7.83 ng/g and 0.51 to 9.78 ng/mL in milk samples.

Assessment of PAH exposure and health risks among South Korean firefighters based on urinary PAH metabolites

Polycyclic aromatic hydrocarbons (PAHs) comprise a group of compounds resulting from the incomplete combustion of organic matter. Firefighters engaged in fire suppression are highly exposed to PAHs. This study centered on evaluating the exposure levels and health risks of PAHs in South Korean firefighters involved in firefighting activities. The concentrations of 10 PAH metabolites in the urine of firefighters were measured immediately after, and two weeks post their engagement in extinguishing a large tire factory fire. The levels of OH-PAHs in urine samples immediately after fire suppression were elevated by a factor of 1.01–1.84 compared to urine samples from non-exposed period. The median concentration of total PAH metabolites (OH-PAHs) was higher in urine samples immediately after fire suppression (5910 ng/g creatinine) than in urine samples from non-exposed periods (5020 ng/g creatinine). However, the ∑OH-PAH levels in firefighters’ urine were related to personal habits such as smoking. The concentrations of all individual OH-PAHs in the urine samples of nonsmokers exhibited a substantial increase, ranging from 1.37 to 2.3 times, clearly demonstrating that firefighting activities were a substantial source of PAH exposure. The calculated values associated with the health risks stemming from exposure to PAHs, including carcinogenic risk, total estimated daily intake (TEDI), and hazard quotients/index (HQs/HI), all fell within acceptable limits, indicating negligible risk. However, the HQ/HI values and TEDI for individual and total PAH exposures, except those for naphthalene, were 1.36–2.00 times higher in firefighters' samples taken after firefighting operations compared to those during regular duty. This underscores the need for more comprehensive investigations to comprehend the singular impact of firefighting activities due to the diverse sources of PAH emissions in the environment.

Dyslexia is associated with urinary polycyclic aromatic hydrocarbon metabolite concentrations of children from China: Data from the READ program

It has been found that exposure to polycyclic aromatic hydrocarbons (PAHs) is associated with the risk of certain childhood neurodevelopmental disorders. However, no research has investigated the relationship between exposure to PAHs and children's dyslexia odds. The objective of this research was to investigate whether urinary mono-hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) are associated with increased dyslexia odds in Chinese children. We recruited 1,089 children (542 dyslexic children and 547 non-dyslexic children) for this case-control study. Ten OH-PAHs were measured in the participants' urine samples, which were collected between November 2017 and March 2023. Odds ratios (ORs) of the associations between the OH-PAHs and dyslexia were calculated using logistic regression models, after adjustment for the potential confounding factors. A significant association was found between urinary concentrations of 2-hydroxynaphthalene (2-OHNap) and the elevated odds of dyslexia. The children in the highest quartile of 2-OHNap had a higher OR of dyslexia (1.87, 95% CI: 1.07–3.27) than those in the lowest quartile (P-trend = 0.02) after adjustment for the covariates. After excluding children with maternal disorders during pregnancy, logistic regression analyses showed similar results. Our results suggested a possible association between PAH exposure and the elevated odds of dyslexia.

Association between exposure to polycyclic aromatic hydrocarbons and endometriosis: data from the NHANES 2001-2006.

To evaluate the association between urinary polycyclic aromatic hydrocarbon (PAH) metabolites and the risk of endometriosis. This cross-sectional study obtained data on women aged 20-54 years from the National Health and Nutrition Examination Survey (NHANES) 2001-2006. The weighted multivariate logistic regression model was established to assess the association between the eight urinary PAH metabolites and the risk of endometriosis. In this multivariate analysis, the eight urinary PAH metabolites were adjusted with urinary creatinine, and were divided into three groups according to tertiles: Tertile 1, Tertile 2 and Tertile 3. To evaluate the overall association of mixed PAH metabolites with endometriosis, the Bayesian kernel machine regression (BKMR) model was applied. Totally 1,291 women were included, of which 90 (6.97%) had endometriosis and 1,201 (93.03%) did not have endometriosis. After adjusting for age, race, smoking, age at menarche, hysterectomy, ovary removed, female hormone use, and menopause, compared with the Tertile 1 group, the Tertile 2 and Tertile 3 groups of all PAH metabolites demonstrated no significant risk of endometriosis. A positive tendency was found between mixed PAH metabolites and endometriosis when all the metabolites were at their 60th percentile levels or above compared with their median levels. When all the other metabolites were fixed at their median levels, 1-hydroxynaphthalene was positively correlated with endometriosis. Potential interactions existed between 1-hydroxynaphthalene and 2-hydroxynaphthalene and between 2-hydroxyfluorene and 3-hydroxyfluorene. No significant association was found between individual PAH metabolites and endometriosis. A positive association existed between mixed PAH metabolites and the risk of endometriosis.

Association between polycyclic aromatic hydrocarbons exposure with red cell width distribution and ischemic heart disease: insights from a population-based study.

This study investigates the association between polycyclic aromatic hydrocarbon (PAH) exposure, red blood cell distribution width (RDW), and ischemic heart disease (IHD) in a sample of 3003 participants from the National Health and Nutrition Examination Survey (NHANES). We hypothesize that RDW may mediate the effect of hydroxylated PAHs (OH-PAH) on IHD. Logistic regression models reveal significant associations between increased urinary PAH metabolite concentrations and IHD, as well as positive associations between PAH metabolites and RDW. Weighted Quantile Sum (WQS) regression and Bayesian Kernel Machine Regression (BKMR) analyses confirm the significant associations of the OH-PAH mixture with IHD and RDW. Mediation analysis demonstrates that RDW partially mediates the relationship between PAH exposure and IHD, accounting for 2-4.6% of the total effects. Our findings highlight the potential underlying mechanisms linking PAH exposure, RDW, and IHD and emphasize the importance of addressing environmental pollutants like PAHs in maintaining cardiovascular health and informing public health policies.

Baseline data and associations between urinary biomarkers of polycyclic aromatic hydrocarbons, blood pressure, hemogram, and lifestyle among wildland firefighters.

Available literature has found an association between firefighting and pathologic pathways leading to cardiorespiratory diseases, which have been linked with exposure to polycyclic aromatic hydrocarbons (PAHs). PAHs are highlighted as priority pollutants by the European Human Biomonitoring Initiative in occupational and non-occupational contexts. This cross-sectional study is the first to simultaneously characterize six creatinine-adjusted PAHs metabolites (OHPAHs) in urine, blood pressure, cardiac frequency, and hemogram parameters among wildland firefighters without occupational exposure to fire emissions (> 7 days), while exploring several variables retrieved via questionnaires. Overall, baseline levels for total OHPAHs levels were 2 to 23-times superior to the general population, whereas individual metabolites remained below the general population median range (except for 1-hydroxynaphthalene+1-hydroxyacenaphtene). Exposure to gaseous pollutants and/or particulate matter during work-shift was associated with a 3.5-fold increase in total OHPAHs levels. Firefighters who smoke presented 3-times higher total concentration of OHPAHs than non-smokers (p < 0.001); non-smoker females presented 2-fold lower total OHPAHs (p = 0.049) than males. 1-hydroxypyrene was below the recommended occupational biological exposure value (2.5 μg/L), and the metabolite of carcinogenic PAH (benzo(a)pyrene) was not detected. Blood pressure was above 120/80 mmHg in 71% of subjects. Firefighters from the permanent intervention team presented significantly increased systolic pressure than those who performed other functions (p = 0.034). Tobacco consumption was significantly associated with higher basophils (p = 0.01-0.02) and hematocrit (p = 0.03). No association between OHPAHs and blood pressure was found. OHPAHs concentrations were positively correlated with monocyte, basophils, large immune cells, atypical lymphocytes, and mean corpuscular volume, which were stronger among smokers. Nevertheless, inverse associations were observed between fluorene and pyrene metabolites with neutrophils and eosinophils, respectively, in non-smokers. Hemogram was negatively affected by overworking and lower physical activity. This study suggests possible associations between urinary PAHs metabolites and health parameters in firefighters, that should be further assessed in larger groups.

Association between polycyclic aromatic hydrocarbons and periodontitis: Results from a large population-based study.

To explore the association between polycyclic aromatic hydrocarbons (PAHs) (measured using urinary metabolites) and periodontitis using data from the National Health and Nutrition Examination Survey 2009-2014. Weighted binary logistic regression, Bayesian kernel machine regression (BKMR) and weighted quantile sum (WQS) regression were used to evaluate independent and joint associations between the six urinary monohydroxylated metabolites of PAHs (OH-PAHs) and periodontitis. In all, 3413 participants were included in this study. All six urinary OH-PAHs were present at higher levels in the periodontitis group compared with the non-periodontitis group (p < .001). Fully adjusted multivariable logistic regressions showed positive associations between the six urinary OH-PAHs and periodontitis (p < .05). Higher concentrations of OH-PAHs were also positively associated with attachment loss, periodontal pocket depth (PPD) and the number of tooth loss. BKMR and WQS regression yielded similar positive associations between OH-PAH mixtures and periodontitis. PAHs and their mixture are positively associated with periodontitis, which may provide novel insights into periodontitis prevention from an environmental exposure perspective.

Association of co-exposure to polycyclic aromatic hydrocarbons and phthalates with oxidative stress and inflammation

Exposure to multiple environmental pollutants is ubiquitous and inevitable, but studies investigating their exposure effects on oxidative stress or inflammation have mainly been restricted to single-pollutant models. This study investigated the association of co-exposure to polycyclic aromatic hydrocarbons and phthalates with oxidative stress and inflammation. Using a cross-sectional study in adults, we measured urinary concentrations of metabolites of polycyclic aromatic hydrocarbons (OH-PAHs) and phthalates (mPAEs), urinary oxidative stress biomarker 8-hydroxy-2′-deoxyguanosine, and 9 inflammatory biomarkers in paired blood samples. The associations of urinary OH-PAHs and mPAEs with oxidative stress and inflammation biomarkers were evaluated by different statistical models. The Bayesian kernel machine regression and quantile g-computation was used to examine the joint effects, and increased levels of urinary concentrations of OH-PAHs and mPAEs were associated with elevated 8-hydroxy-2′-deoxyguanosine level and white blood cell counts. Exposure to polycyclic aromatic hydrocarbons contributed more significantly to inflammation, while exposure to phthalates contributed more to oxidative stress. Monoisobutyl phthalate was identified as the most significant metabolite contributing to elevated oxidative stress levels. 1-Hydroxypyrene was negatively associated with platelet, and monomethyl phthalate was significantly positively associated with interleukin 6 in multivariate linear regression. The restricted cubic spline analysis revealed non-linear patterns of 3-hydroxyfluorene with white blood cell, lymphocyte, neutrophil, and C-reactive protein. The results indicated significant associations between increased co-exposure to polycyclic aromatic hydrocarbons and phthalates with elevated oxidative stress and inflammation. Further investigation is needed to elucidate the underlying biological mechanisms and to determine the potential public health implications.

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.

Insight into the interactions between surfactants and microorganisms for the biodegradation of polycyclic aromatic hydrocarbons: Enhancing efficiency, cellular response, and elucidating mechanisms

The response mechanisms of polycyclic aromatic hydrocarbons (PAHs)-degrading strains to Tween 80 concentrations are key elements of microbial remediation efficacy. The degradation characteristics, cell morphology, and microbial metabolic activities of three strains (Arthrobacter (SZ-3), Pseudomonas putida (B6-2), and Klebsiella (CW-D3T)) at different Tween 80 concentrations (0∼2000 mg/L) were investigated. The results showed that the three PAHs degrading strains grow well with the maximum cell activity of 8.75–8.81 log CFU/ml and the electron transfer system activity (ETSA) of 0.341–0.655 μg O2 g−1min−1 at a Tween 80 concentrations range of 1000–2000 mg/L. The best degradation of PAHs by SZ-3 was achieved at a Tween 80 concentration of 500 mg/L. The degradation rates of phenanthrene (PHE), fluoranthene (FLU), and pyrene (PYR) were 91.42%, 54.62%, and 50.76%, respectively. For strains B6-2 and CW-D3T, the highest degradation rates for PHE were achieved at a Tween 80 concentration of 500 mg/L, and the highest degradation rates for FLU and PYR were reached in the absence of Tween 80. The changes of catechol 1,2-dioxygenase were consistent with the PAHs degradation efficiency. The cell surface hydrophobicity (CSH) of SZ-3 and CW-D3T increased with the increase of Tween 80, while that of B6-2 decreased. In addition, the detection of PAHs metabolites showed that SZ-3 had two metabolic pathways, salicylic acid, and phthalic acid. B6-2 metabolized PAHs mainly through the phthalic acid pathway, and CW-D3T mainly through the salicylic acid pathway. Tween 80 did not affect the metabolic pathway of PAHs by each strain.