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

Recent advances in bioassays for assessing the toxicity of environmental contaminants in effect-directed analysis

Chemical cocktails in the environment can cause adverse impacts on ecosystems and human health even at low concentrations. Effect-directed analysis (EDA) has proven to be very valuable in identifying key toxic substances in environmental mixtures. For this, it is important to carefully select accurate bioassays from a wide range of tests for EDA when applying it to actual environmental samples. This article reviews studies published from 2014 to 2023 that have applied EDA and summarizes the bioassays and their corresponding biological effects. A total of 127 studies were selected from 591 publications evaluating the toxic effects of environmental samples, including wastewater, surface water, and sediments. Here, bioassays used in EDA are summarized, including the assays that measure specific receptor-mediated modes of action (MOA), induction of xenobiotic metabolism pathways, and induction of adaptive stress response pathways using either in vitro or in vivo bioassays. Also, the identified substances using EDA are discussed based on their MOA. The importance of EDA in establishing a comprehensive approach for the detection of environmental contaminants using bioanalytical methods is emphasized. The current limitations and benefits of using EDA in practical applications are outlined and strategies for moving forward are proposed.

Effects of mono-substituents on the polarity-sensitive fluorescent probe properties of pyrene

This study investigates the effects of mono-substituents (i.e., hydroxyl, methyl, amino and nitro groups) on the polarity-sensitive fluorescent probe properties of pyrene (Pyr) using fluorescence, UV-vis, and circular dichroism absorption spectroscopy. The results indicate that the four mono-substituents altered the fluorescence spectral characteristics of Pyr to varying degrees, with the most to least influential order being: nitro, amino, hydroxyl, and methyl. 1-Aminopyrene (1-APyr) and 1-nitropyrene (1-NPyr) are deemed unsuitable for use as polarity-sensitive fluorescent probes due to their limited or absent spectral characteristics. The I386/I406 and I376/I396 ratios of 1-HPyr and 1-MPyr decrease as solvents polarity increases, contrasting with the I372/I384 ratio of Pyr. Thus, 1-hydroxypyrene (1-HPyr) and 1-methylpyrene (1-MPyr) also exhibit polarity-sensitive characteristics similar to Pyr, and their solubility in PBS buffer surpasses that of Pyr at 298 K. Moreover, 1-HPyr and 1-MPyr are practicable for detecting the polarity of human serum albumin (HSA) under simulated physiological conditions. The results underscore the potential of the polarity-sensitive mono-substituents of Pyr in biological applications, particularly in probing protein polarity and conformational changes, and further providing a potential tool for the related research in biochemistry and pathology.

Comparative toxicity analysis of benzo[a]pyrene and PAH4 on HepG2 cells using transcriptomics and metabolomics

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants posing potential health risks. PAH4 (sum of benzo[a]pyrene (BaP), chrysene, benz[a]anthracene and benzo[b]fluoranthene) has been proposed as a marker to evaluate the occurrence of total PAHs. However, toxicity effects of exposure to PAH4 mixture and its toxicity differences with single PAH are little-known. Here, we systematically investigated the hepatotoxicity mechanisms of PAH4 and compare its toxicity with BaP using HepG2 cell model. Our results showed that BaP and PAH4 exposure induced cytotoxicity and oxidative stress. Furthermore, both BaP and PAH4 activated P53 signaling pathway, leading to cell apoptosis, and disrupted peroxisome proliferator-activated receptor (PPAR) signaling and induced lipid metabolism disorder. Integrated analysis of transcriptomics and metabolomics indicated that BaP and PAH4 shared similar toxicity mechanisms, commonly affecting the metabolic pathways including glycerolipid and glycerophospholipid metabolism. Moreover, the integrated biomarker response (IBR) analysis demonstrated that BaP and PAH4 exhibited similar global toxicity on HepG2 cells. We further found that the toxicity effects of PAH4 could be partially alleviated by an aryl hydrocarbon receptor (AHR) antagonist, indicating a potential role of AHR signaling in PAH4-induced hepatotoxicity. Overall, these findings provided insights into the toxicological mechanisms and interaction effects of PAHs mixtures.

Physiological responses and adaptive mechanisms of the harmful algal bloom species Heterosigma akashiwo to naphthalene exposure

Polycyclic aromatic hydrocarbons (PAHs), especially naphthalene (Nap), pose a significant threat to coastal ecosystems and may contribute to the occurrence of harmful algal blooms (HABs). However, the response mechanisms of HAB species to PAH pollution remain unclear. This study investigated the physiological and molecular responses of the HAB species Heterosigma akashiwo to varying Nap concentrations. Low concentrations (1-10 μg/L) promoted growth, while high concentrations (20-1000 μg/L) inhibited growth, causing abnormal cell morphology and oxidative stress. Within 96 h, H. akashiwo removed 82.38 % (10 μg/L) and 88.93 % (100 μg/L) of Nap, mainly through biodegradation and intracellular accumulation. Transcriptomic analysis revealed that H. akashiwo employs a multifaceted adaptive strategy to cope with Nap stress. Key mechanisms include the upregulation of calcium signaling, transcription factors (e.g., zinc finger protein C2H2, myeloblastosis transcription factor, basic leucine zipper transcription factor), heat shock proteins (e.g., HSP40), and fatty acid desaturase (FAD), enhancing stress tolerance through detoxification, antioxidant responses, and membrane integrity. Activation of peroxisomal and oxidative phosphorylation genes indicates improved detoxification and energy metabolism. Differential expression of genes in the PI3K-Akt pathway reveals dose-dependent growth responses, with low concentrations promoting proliferation and high concentrations inhibiting growth. These findings offer insights into H. akashiwo's adaptive responses to Nap, aiding ecological risk assessment and bioremediation strategies for PAH pollution in marine environments.

Mechanistic insights into fluoranthene degradation: Activation of peroxymonosulfate by mackinawite and pyrite in aqueous solution and soil slurry

The slow regeneration of Fe(II) in conventional Fenton and Fenton-like systems poses significant limitations for sustained and continuous generation of reactive oxygen species (ROS), which is critical for effective pollutant degradation. This study investigates the use of iron sulfide minerals-specifically, mackinawite (FeS) and pyrite (FeS2)-as both activators and reductants in peroxymonosulfate (PMS)-based Fenton-like systems to enhance Fe(II) regeneration and improve pollutant degradation efficiency. Results demonstrate that over 90 % of fluoranthene (FLT) was degraded within 60 min using the PMS/FeS and PMS/FeS2 systems. Reactive species including SO4-•, HO•, and 1O2 were generated in both systems, with SO4-• playing a primary role in FLT degradation, while 1O2 contributed partially to the process. Both FeS and FeS2 maintained structural stability during PMS activation, with surface Fe(II) oxidized to Fe(III) and reductive sulfur species (S2- in FeS and S22- in FeS2) facilitating the Fe(III)/Fe(II) cycle before ultimately converting to SO42-. These systems demonstrated robust performance across diverse water matrices, achieving excellent FLT degradation in actual groundwater and soil slurry, underscoring the promising application potential of PMS/FeS and PMS/FeS2 systems for remediating FLT-contaminated environments.

Associations between urinary polycyclic aromatic hydrocarbon biomarker concentrations and birth outcomes in the LIFECODES cohort

Environmental exposure to polycyclic aromatic hydrocarbons (PAH) is ubiquitous and may impact fetal development leading to adverse birth outcomes. PAHs result from incomplete combustion and exposure sources include inhalation of cigarette smoke and car exhaust, ingestion of charred meat, and many others. The purpose of this study was to determine associations between prenatal PAH biomarker concentrations and birth outcomes. Our nested case-control study included 123 preterm birth cases and 335 term controls from the LIFECODES cohort between 2006 and 2008 (n = 458). Eight urinary PAH metabolites were measured in urine samples collected at up to four study visits (median 12, 18, 24, 34 weeks gestation). Linear and logistic regression were used to model gestational geometric mean PAH biomarker concentrations in relation to preterm birth, birth weight z-score, and small or large for gestational age with adjustment for potential confounders. Effect modification by infant sex was also explored. Odds ratios for preterm birth were elevated for most PAH metabolites but confidence intervals included the null. For most PAH metabolites, a significant inverse association was observed for birth weight for gestational age z-score, and a corresponding increase in the odds of small for gestational age (SGA). For example, an interquartile range increase in 2-hydroxynapthalene (2-NAP) was associated with a significantly lower birth weight z-score (β: 0.22; 95 % CI: 0.36, -0.08) and 1.90 times the odds of SGA (95 %CI: 1.41, 2.55). Further study should aim to determine the extent and mechanisms by which PAH exposure impacts fetal growth.

Vascular toxicity of benzene series released from decorative materials

The health risks associated with benzene series emissions from decorative materials have become a paramount concern in indoor air quality assessments, particularly given their established link with cardiovascular diseases, such as hypertension and atherosclerosis. Despite epidemiological evidence supporting this correlation, the underlying mechanisms remain under debate. This research comprehensively reviewed contemporary epidemiological studies on the cardiovascular impacts of benzene series emissions. It concentrated on the elucidation of their vascular toxicity, encompassing structural damage to vascular tissues, impaired vasoconstrictive-diastolic function, and abnormal lipid accumulation. By illuminating these research advancements, this study aimed to outline directions for future investigations and furnish insights into mitigating the risk of cardiovascular diseases stemming from benzene-contaminated decorative materials, ultimately contributing to public health protection.

Transforming beef quality through healthy breeding: a strategy to reduce carcinogenic compounds and enhance human health: a review

The presence of carcinogenic substances in beef poses a significant risk to public health, with far-reaching implications for consumer safety and the meat production industry. Despite advancements in food safety measures, traditional breeding methods have proven inadequate in addressing these risks, revealing a substantial gap in knowledge. This review aims to fill this gap by evaluating the potential of healthy breeding techniques to significantly reduce the levels of carcinogenic compounds in beef. We focus on elucidating the molecular pathways that contribute to the formation of key carcinogens, such as heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs), while exploring the transformative capabilities of advanced genomic technologies. These technologies include genomic selection, CRISPR/Cas9, base editing, prime editing, and artificial intelligence-driven predictive models. Additionally, we examine multi-omics approaches to gain new insights into the genetic and environmental factors influencing carcinogen formation. Our findings suggest that healthy breeding strategies could markedly enhance meat quality, thereby offering a unique opportunity to improve public health outcomes. The integration of these innovative technologies into breeding programs not only provides a pathway to safer beef production but also fosters sustainable livestock management practices. The improvement of these strategies, along with careful consideration of ethical and regulatory challenges, will be crucial for their effective implementation and broader impact.

Air pollutants and lung regeneration: impact on the fate of lung stem cells

Inhalable airborne pollutants, including particulate matter, ozone, cigarette smoke, and emerging microparticles and nanoparticles can initiate or exacerbate various lung diseases. Their toxicological impact depends not only on their chemical composition, but also on the host's capacity for clearance and post-injury repair mechanisms. Studies have identified region-specific stem cells within the lung epithelial-mucosal barrier, which are pivotal for mucosal repair after damage. This review delineates the roles of airway and alveolar key stem cells in lung epithelial mucosal repair, details how traditional and emerging airborne pollutants affect their regenerative capabilities. Additionally, it discusses the transformative contributions of organoids and single-cell sequencing technologies to advance our understanding of how inhaled pollutants affect lung tissue toxicity. A tissue regeneration perspective on the interplay between inhaled pollutants and lung stem cells is crucial for developing comprehensive strategies to prevent and control lung diseases associated with exposure to airborne pollutants.

A gold-silver nanostar 2D array composite structure for rapid SERS determination of PAHs

This study developed a portable multi-ring aromatic hydrocarbon (PAH) detection tool using a dual-metal surface-enhanced Raman scattering (SERS) substrate. Gold-silver nanostars (AuNS@Ag) were synthesized by a secondary seed-mediated growth method and assembled into a two-dimensional array by a liquid-phase interface self-assembly method, uniformly deposited on a silicon wafer. The PAHs in water samples were identified using a portable Raman spectrometer. The SERS detection platform has high sensitivity and stability, and can detect pyrene and phenanthrene with concentrations of 10-8 M and 0.5 × 10-8 M, respectively. The stable dual-metal nanomaterial AuNS@Ag 2D array has potential application prospects and can be used for environmental monitoring.

Downregulation of MGAT3 Promotes Benzo[a]pyrene-Mediated Lung Carcinogenesis by Regulating Cell Invasion and Migration Activity

Environmental chemical carcinogens are major factors in the induction of lung cancer, with benzo[a]pyrene (B[a]P) being one of the most widespread and highly carcinogenic among them. Although studies have reported that B[a]P exerts its carcinogenic effects by causing mutations, inducing cytotoxicity, and inhibiting DNA synthesis, the early molecular regulatory events and mechanisms involved in B[a]P-induced tumor initiation remain unclear. This study found that the MGAT3 gene was significantly downregulated in B[a]P-induced mouse lung tumorigenesis, suggesting its important tumor-suppressive function. Further investigation revealed that suppression of MGAT3 expression promoted the invasion and migration abilities of lung cancer cells, while overexpression of MGAT3 in these cells inhibited these effects. Western blot analysis also showed that MGAT3 regulated the expression of epithelial-mesenchymal transition markers, thereby affecting the motility of lung cancer cells. Xenograft assay also confirmed the inhibitory effect of MGAT3 overexpression on tumor proliferation. Analysis of lung cancer tissue expression further validated that MGAT3 is significantly downregulated in lung cancer tissues, and this decrease in expression is associated with a poor prognosis in lung cancer patients. Our research indicates that the suppression of MGAT3 expression and its downstream regulatory molecules plays a crucial role in lung cancer development induced by environmental chemical carcinogens.

Polycyclic Aromatic Hydrocarbons Regulate the Occurrence and Development of Nasopharyngeal Carcinoma by Regulating Aryl Hydrocarbon Receptor

Nasopharyngeal carcinoma (NPC) has hidden onset, low rate of early diagnosis, and most of them have metastases at the time of diagnosis. The specific pathogenesis of NPC is still unclear. Polycyclic aromatic hydrocarbons (PAHs) are a large group of contaminants produced by the incomplete combustion of organic matter and widespread in the air. Many of these compounds are mutagenic and carcinogenic. PAHs plays an important role in mutagenic and carcinogenic, while its role in NPC still needs further elucidation. In this study, CNE-2 cells were stimulated by PAHs, then the expression of aryl hydrocarbon receptor (AhR) and CYP1A2 were respectively examined using Real-Time fluorescence quantitative PCR (qRT-PCR) and Western Blot. CNE-2 cells proliferation, migration, invasion and apoptosis were examined by CCK-8, Wound-Healing Assay, Transwell, Flow Cytometry, respectively. We found that AhR expression was increased while the level of apoptosis was inhibited by PAHs. While the ability of cell invasion was weakened, proliferation and migration were not significantly different. After treated by PAHs and ITE, the effect of PAHs on promoting AhR expression was significantly inhibited and apoptosis was up-regulated. The present study found that, PAHs inhibit apoptosis of NPC cells and promote the expression of AhR. Besides, PAHs participates in NPC occurrence and development by regulating AhR expression. Collectively, these findings may provide a possible strategy for the clinical treatment of NPC.

Polycyclic aromatic hydrocarbon-aryl hydrocarbon receptor signaling regulates chronic inflammation in lung-gut axis

Polycyclic aromatic hydrocarbons (PAHs) are broadly identified in environmental pollutants and also formed during the heat processing of meat, including grilling, roasting, smoking, and frying, particularly at high temperatures. Besides, the PAHs influence inflammatory response through activation of aryl hydrocarbon receptor (AhR) signaling. Recently, the role of the PAHs/AhR axis in inflammatory diseases has attracted major attention in the regulation of lung function, gut barrier function, and systemic inflammation. Many experiments have been conducted to determine the role of the PAHs/AhR/cytochrome P450 1A1 signaling activation on elevation of inflammation in the lung-gut axis. In contrast, several dietary AhR ligands can improve inflammatory function by modulating the AhR signaling, thereby strengthening the intestinal barrier. This review includes the pivotal roles of xenobiotic and diet-derived AhR ligands in the regulation of chronic lung diseases and systemic inflammation and their relevance in the lung-gut axis.

Unraveling the immunotoxic effects of benzo[a]pyrene on Mytilus coruscus through histopathological, enzymatic, and transcriptomic analyses

Benzo[a]pyrene (BaP) is a representative polycyclic aromatic hydrocarbon (PAH) known for its significant toxicity and environmental persistence, capable of causing mutations, deformities, and cancer in aquatic organisms. However, systematic studies on the effects of BaP exposure on histological damage, cell apoptosis, enzyme activity changes, and gene expression in Mytilus coruscus (M. coruscus), an important ecological indicator species, remain scarce. In this study, the biological effects of BaP on M. coruscus and the immunotoxic mechanisms following BaP exposure were evaluated using histological analysis, TUNEL assay, enzyme activity assays, and transcriptome sequencing. Our findings revealed notable histopathological changes due to BaP exposure, including hemocyte infiltration, atrophy, and deformation of digestive tubules in the digestive glands, as well as epithelial cell detachment and deformation in gills. Antioxidant enzyme activities (CAT, GSH-Px, SOD, T-AOC) varied significantly across tissues under BaP stress. Additionally, significant DNA fragmentation and increased apoptosis were observed in BaP-exposed groups compared to controls. Transcriptome analysis showed that after BaP exposure, nucleotide excision repair and innate immune response pathways were suppressed, while the metabolism of xenobiotics by cytochrome P450, glutathione biosynthesis, and apoptosis pathways were upregulated. These results elucidate the toxic mechanisms of BaP on M. coruscus and the immunotoxic responses of the mussels. This study enhances our understanding of how BaP and similar pollutants affect marine bivalves, providing valuable insights for environmental monitoring and pollutant management strategies.

Xenobiotics mediated modulation of gut microbiota and its role in lifestyle diseases: a critical appraisal on exposomics

Gastrointestinal tract of humans provides a niche to thousands of microbes, referred as gut microbiota (GM). GM establishes an intricate relationship with other organs via gut-organ axis, and modulates host health. The structure and functioning of these gut microbes can be influenced by the type of external exposome an individual experiences. Depending upon GM perturbations and host genotype, this can result in variable health implications. On the other hand, the huge arsenal of enzymes possessed by GM can chemically alter the xenobiotic structure. Its consequences can be numerous, including formation of harmful metabolites that cause organ damage, reversal of host detoxification pathways, or favourable health effects. Additionally, GM-mediated bio-transformation of pharmaceuticals can alter their pharmacokinetics and pharmacodynamics, potentially yielding variable drug responses, resulting into prolonged or ineffective treatments. To address this bi-facial relationship and the pivotal role of GM, this review incorporates recent in vitro, in vivo, and multiomics studies. It also suggests the need of machine learning approaches to decode the complex host-microbiota-xenobiotics interactions. These knowledge will aid in comprehending recent rise in chronic lifestyle-diseases which poses a huge burden on the health sector, and can also be a learning curve in making formulations and therapies for personalized treatment.

Unraveling the connection between endocrine-disrupting chemicals and anxiety: An integrative epidemiological and bioinformatic perspective

BACKGROUND

The evidence linking endocrine-disrupting chemicals (EDCs) to anxiety in adults is currently sparse, while the effects of various categories of EDCs on the risk of anxiety, along with the underlying mechanisms, remain poorly understood.

METHODS

Four EDCs-polycyclic aromatic hydrocarbons (PAHs), phenols, pesticides, and phthalates-were quantified in 3927 adults from the National Health and Nutrition Examination Survey (NHANES) (2007-2012). We employed five statistical models to assess the individual and joint impacts of EDCs on anxiety risk. Causal mediation analysis frameworks were constructed to explore the mediating role of oxidative stress (OS). We identified potential biological mechanisms linking analytes to outcomes using the Comparative Toxicogenomics Database (CTD), MalaCards, and Open Targets, followed by enrichment analyses with Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG).

RESULTS

In individual chemical analyses, nine PAHs were significantly associated with increased anxiety risk (P < 0.05). Mixed-effects analyses showed that co-exposure to EDCs positively correlated with anxiety, primarily due to 2-hydroxyfluorene (2-FLU) and 3-hydroxyfluorene (3-FLU). Bilirubin mediated 5.42 % of the anxiety linked to the PAH mixture. The inflammatory genes TNF and IL-6 were identified as key biological stressors, with enrichment analysis indicating significant involvement in reactive oxygen species metabolic processes and the AGE-RAGE signaling pathway.

CONCLUSION

This study highlights the association between EDCs and anxiety in a representative U.S. population, indicating that exposure to PAHs may elevate anxiety risk through OS, inflammation, and the AGE-RAGE signaling pathway. Further longitudinal study were merited to support our results.

Molecular cloning, characterization, and structural stability analysis of a rare acidic catechol 2,3-dioxygenase from the metagenome of coal-polluted soil

Polycyclic Aromatic Hydrocarbons (PAHs) are ubiquitous environmental pollutants that pose substantial health hazards, especially in coal-mining areas. This study presented the metagenomic identification and comprehensive characterization of a novel acidic catechol 2,3-dioxygenase, C23O927, derived from a coal-contaminated soil metagenome. Optimal enzymatic activity for C23O927 was observed at pH 4.0 and 55 °C, with remarkable stability across a wide pH spectrum (2.0-10.0) and temperature range (30 °C-60 °C). The enzyme displayed robust tolerance to various organic solvents and salts, and its activity was notably activated by diverse metal ions. Distinct from other catechol 2,3-dioxygenases, C23O927 exhibited oxygen tolerance and maintained robust activity after purification at 4 °C for up to three days. The structural stability of C23O927 is attributed to its unique extended β-sheet structure and increased α-helices. These characteristics help enhance rigidity and reduce the exposure of the hydrophobic core, thereby conferring greater stability on C23O927. The unique properties of C23O927, which include an optimal pH for acidic environments, salt tolerance, resistance to metal ions and organic solvents, and thermal stability, render it a promising candidate for industrial waste management and soil bioremediation.

Global Geographic Patterns of Soil Microbial Degradation Potential for Polycyclic Aromatic Hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) are toxic and persistent pollutants that are widely distributed in the environment. PAHs are toxic to microorganisms and pose ecological risks. Bacteria encode enzymes for PAH degradation through specific genes, thereby mitigating PAH pollution. However, due to PAHs' complexity, information on the global degradation potential, diversity, and associated risks of PAH-degrading microbes in soils is lacking. In this study, we analyzed 121 PAH-degrading genes and selected 33 as marker genes to predict the degradation potential within the soil microbiome. By constructing a Hidden Markov Model, we identified 4990 species carrying PAH-degrading genes in 40,039 soil metagenomic assembly genomes, with Burkholderiaceae and Stellaceae emerging as high-potential degraders. We demonstrated that the candidate PAH degraders predominantly emerged in artificial soil and farmland, with significantly fewer present in extreme environments, driven by factors such as average annual rainfall, organic carbon, and human modification of terrestrial systems. Furthermore, we comprehensively quantified the potential risks of each potential host in future practical applications using three indicators (antibiotic resistance genes, virulence factors, and pathogenic bacteria). We found that the degrader Stellaceae has significant application prospects. Our research will help determine the biosynthetic potential of PAH-degrading enzymes globally and further identify potential PAH-degrading bacteria at lower risk.

Exposure to polycyclic aromatic hydrocarbons and bone mineral density in children and adolescents: results from the 2011-2016 National Health and Nutrition Examination Survey

Introduction

Identifying factors that hinder bone development in children and adolescents is crucial for preventing osteoporosis. Exposure to polycyclic aromatic hydrocarbons (PAHs) has been linked to reduced bone mineral density (BMD), although available data, especially in children and adolescents, are limited. We examined the associations between urinary hydroxylated-PAHs (OH-PAHs) and lumbar spine BMD, pelvic BMD, and total BMD among 8-19 years participants (N = 1,332) of the 2011-2016 National Health and Nutrition Examination Survey.

Methods

Weighted linear regressions were employed to assess the associations between urinary OH-PAHs and BMD. Additionally, Bayesian kernel machine regression (BKMR) and quantile g-computation (Qgcomp) models were utilized to investigate the effect of co-exposure of PAHs on BMD.

Results

Several urinary OH-PAHs exhibited negative associations with lumbar spine BMD, pelvic BMD, and total BMD in children and adolescents. For instance, an increase of one unit in the natural log-transformed levels of urinary 1-hydroxypyrene and 2&3-Hydroxyphenanthrene was linked with a decrease of -0.014 g/cm2 (95% CI: -0.026, -0.002) and -0.018 g/cm2 (95% CI: -0.032, -0.004) in lumbar spine BMD, a decrease of -0.021 g/cm2 (95% CI: -0.039, -0.003) and -0.017 g/cm2 (95% CI: -0.033, -0.001) in pelvic BMD, and a decrease of -0.013 g/cm2 (95% CI: -0.023, -0.002) and -0.016 g/cm2 (95% CI: -0.026, -0.006) in total BMD. The body mass index modified the associations between urinary OH-PAHs and BMD, revealing negative effects on BMD primarily significant in overweight/obese individuals but not significant in underweight/normal individuals. Both the BKMR model and the Qgcomp model indicated a significant negative correlation between the overall effects of seven urinary OH-PAHs and lumbar spine BMD, pelvic BMD, and total BMD.

Conclusion

Our findings revealed that exposure to PAHs might hinder bone development in children and adolescents, potentially impacting peak bone mass-an essential factor influencing lifelong skeletal health.

Elucidating the synergistic role of hybrid peptide from Burkholderia cepacia enzymes in biodegradation of polycyclic aromatic hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) are hazardous environmental contaminants emerging from industrial activities and fossil fuel combustion, posing risks to human health and ecosystems. Biodegradation offers a sustainable approach to mitigating PAH pollution, and here we investigated the efficacy of a peptide hybrid of laccase and O-methyltransferase enzymes from the bacterium Burkholderia cepacia in PAH degradation. Both enzymes demonstrated stability with an instability index below 40, indicating suitability for environmental application. Following active site prediction, the 3D structure of the peptide hybrid, consisting of 71 amino acids, was modelled using trRosetta, achieving a high-quality structure with an ERRAT score above 97%. Further bioinformatic analysis confirmed the hybrid's non-allergenic and non-virulent properties. Molecular docking studies revealed a robust binding affinity above - 9 kcal/mol, highlighting this peptide hybrid's potential for effective PAH degradation and suggesting its promise as an eco-friendly bioremediation agent for PAH-contaminated sites.

Urinary metabolic alterations associated with occupational exposure to metals and polycyclic aromatic hydrocarbons based on non-target metabolomics

Long-term occupational exposure to metals and organics have been reported to be under great health risks. However, limited data are available on the molecular mechanism between combined exposure to metals and polycyclic aromatic hydrocarbons (PAHs) and harmful health effects. In present work, non-target metabolomics study was conducted based on urine samples from nonferrous metal smelting workers (n = 207), surrounding residents (n = 180), and the control residents (n = 187) by using ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS). Differential and correlation analyses among metabolic features indicate that total 22 differential metabolites in smelting workers were associated (p < 0.05) with metal and PAH exposure. Particularly, amino acid metabolism was strongly disturbed, and other metabolic pathways, including steroid hormone biosynthesis, citrate cycle, and pantothenate and coenzyme A (CoA) biosynthesis were also perturbed. Among them, steroid hormone biosynthesis was more affected by PAH exposure than metals, especially for hydroxyphenanthrene. These altered pathways were closely associated with oxidative stress, inflammation, and energy metabolism disorder. Additionally, our results indicate that endogenous metabolism in surrounding residents were also affected by nonferrous metal smelting activities to some extent. Our work provides valuable insights into molecular mechanisms of adverse health effects probably induced by combined exposure to metals and PAHs.

Explainable no-code OECD-compliant machine learning models to predict the mutagenic activity of polycyclic aromatic hydrocarbons and their radical cation metabolites

Polycyclic aromatic hydrocarbons (PAHs) are persistent pollutants with well-known genotoxic and mutagenic effects, posing risks to ecosystems and human health. Their hydrophobic nature promotes accumulation in soils and aquatic environments, increasing exposure risks. Upon metabolic activation, PAHs generate reactive species that form DNA adducts, driving their mutagenic potential. This study presents an OECD-compliant methodology that integrates conceptual density functional theory (CDFT) calculations at the GFN2-xTB level with machine learning models to predict PAH mutagenicity. Using quantum chemical descriptors of procarcinogens and radical cation metabolites alongside Ames test data, key electronic properties linked to mutagenicity were identified. Feature selection consistently highlighted radical cation descriptors as key indicators of metabolic activation pathways. Machine learning models - including SPAARC, Random Tree, and JCHAID - achieved validation accuracies exceeding 89 %, with minimal false-negative rates, ensuring conservative predictions for environmental risk assessment. The PSL and CDP electrophilicity frameworks proved particularly effective in modeling DNA damage-related processes. This no-code, freeware-based methodology provides a scalable and cost-effective tool for assessing mutagenic risks in environmentally relevant conditions. The findings reinforce the importance of metabolic activation, validate the radical cation as a reliable proxy for this process, and demonstrate the predictive value of electronic properties in QSAR modeling. These insights support advances in environmental toxicology and contribute to improved strategies for regulatory risk assessment.

Recycling process of decoration and demolition waste is a neglected source for emerging concerns in particulate phase: PAHs as an example

Decoration and demolition waste (DDW) has been widely studied because of its annual surge in output, complex composition, and high utilization potential. DDW recycling is a key element of circular economy, with the potential for emerging pollutants in the particulate phase. Thus, this study selected polycyclic aromatic hydrocarbons (PAHs) as the representative and investigated their emission characteristics and occupational risk in the particulate phase, including 2.5-μm (PM2.5), inhalable (PM10), total suspended particles (TSP), and dust samples of different sizes (75-100 μm, 50-75 μm, and < 50 μm), from dust collectors during DDW recycling. Acenaphthylene (Acy), chrysene (Chr), benz[a]anthracene (BaA), fluoranthene (Fla), pyrene (Pyr), phenanthrene (Phe) were detected in all samples. PM2.5 and dust in 75-100 μm own the highest total occupation risk of 1.51 × 10-13 and 2.07 × 10-15, respectively. Chr and BaA had the control priority with the converted toxicity of 162.82 ng/g and 233.35 ng/g. Moreover, nontarget screening was applied to mining out isophorone, benzophenone, and other carcinogenic micropollutants in the PM2.5, PM10, TSP, and dust samples. Global PAHs from DDW recycling production can reach 193.44 ± 241.80 kg/a under reasonable estimation. This study provides strong evidence that DDW recycling is a neglected source of concern in the particulate phase.

Current levels, sources, and risks of human exposure to PAHs, PBDEs and PCBs in South American outdoor air: A critical review

This study provides a comprehensive overview of the current levels, sources and human exposure risks to hazardous polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs) in South American outdoor air. Research documents were obtainable for only 6 countries within the target period (2014-2024). For all contaminants, urban concentrations exceeded that of rural/remote locations. PAHs were extensively reported with concentration reaching 1100 ∑16PAHs/m3 in Southwest of Buenos Aires province, Argentina. The health risk data also exceeded the threshold level in several locations. The profiles and seasonal fluctuations across all studies were widely influenced by the prevalent local/domestic sources. Biomass combustion (particularly of sugar cane/agricultural wastes and wood/coal for residential heating), vehicular emission, and industrial emission were accounted for most PAH sources. Regulations targeting biomass combustion for improved air quality seem not to currently have significant impacts on current PAH levels. PBDEs were widely reported within 0.3-55 pg ∑4-14BDE/m3, albeit high concentrations were documented in Concepción Bay, Chile (maximum = 1100 pg ∑4BDE/m3) and Córdoba, Argentina (maximum = 120 pg ∑4BDE/m3). Most notable source of PBDEs is solid municipal wastes. Similar to other global studies, BDE-47, 99 and 209 dominated the congeners reported. PCBs were reported with the highest concentrations measured in Córdoba, Argentina (maximum = 1700 pg ∑30PCBs/m3), but data remain limited in other important locations such as São Paulo, Brazil. Sources of PCBs were broadly associated with solid wastes, electric transformers, and re-volatilization from polluted environment. PAHs, PCBs and PBDEs were all within average to top global concentrations. This study underscores potential rise in atmospheric level of the target contaminants without sustainable regulatory structure and the need for continuous monitoring of these contaminants as a measure of policy impacts. We provide sustainable recommendations.

Associations of endocrine-disrupting chemicals mixtures with serum lipid and glucose metabolism among overweight/obese and normal-weight children: A panel study

BACKGROUND

Endocrine-disrupting chemicals (EDCs) can disturb lipid and glucose metabolism, but few studies have explored the effects of EDC mixtures and underlying inflammation mechanisms in weight-specific children.

METHODS

We conducted a panel study with 3 repeated visits among 144 children aged 4-12 years. For each visit, participants provided morning urine samples for 4 consecutive days and fasting blood samples on day 4. A total of 36 EDCs were measured, including 10 per- and polyfluoroalkyl substances (PFAS), 3 phenols, 3 parabens, 10 phthalates, and 10 polycyclic aromatic hydrocarbons. We used quantile g-computation, grouped weighted quantile sum (GWQS) regression, and linear mixed-effect models to evaluate and validate the associations of the mixture and individual effects of EDCs on lipid and fasting blood glucose (FBG). Further, mediation models were applied to explore the potential role of cytokines in the relationships of EDCs and outcomes.

RESULTS

A quantile increase in EDC mixtures was associated with elevated triglyceride (TG) (β = 0.18, 95 % CI: 0.04, 0.33) and FBG (β = 0.02, 95 % CI: 0.01, 0.04). Also, GWQS regression revealed that PFAS contributed the most to the overall effects for TG and FBG, followed by phenols. These associations were more pronounced in overweight/obese children. Regarding individual pollutants, we observed positive relationships of several PFAS with TG and FBG. Furthermore, chemokine ligand 2 mediated the associations of PFAS with TG among overweight/obese children.

CONCLUSIONS

The present study suggested that the EDC mixtures were associated with elevated lipid and glucose levels among children, particularly for those with overweight/obesity.

Medicago sativa L. Root Exudation of Phenolic Compounds and Effect of Flavonoids on Phenanthrene Degradation by Two Rhizobacteria

BACKGROUND

Plant-microbial degradation of organic pollutants occurs in the rhizosphere under the influence of plant root exudates. Similarities in chemical structure to polycyclic aromatic hydrocarbons (PAHs), phenolic compounds and flavonoids released with exudates can determine the ability of rhizosphere microorganisms to degrade hazardous aromatic pollutants.

METHODS

Here, we analyzed phenolic compounds in the root exudates of alfalfa (Medicago sativa L.) grown in quartz sand uncontaminated and phenanthrene-contaminated quartz sand, a model PAH pollutant, under axenic conditions. The effect of six flavonoids (naringenin, rutin, morin, quercetin, apigenin, and luteolin) on phenanthrene degradation by two PAH-degrading bacteria, Ensifer meliloti P221 and Mycolicibacterium gilvum PAM1, previously isolated from the rhizosphere of alfalfa was also investigated. Ultraviolet (UV)-vis spectroscopy and high-performance liquid chromatography (HPLC) were applied to assay flavonoid and phenanthrene content in cultivation media.

RESULTS

The quantitative and qualitative characteristics of the root-exuded phenolic compounds changed under the influence of phenanthrene. The impact of the flavonoids on PAH biodegradation varied from neutral or even inhibitory to stimulatory. The same flavonoid (quercetin) had opposite effects on the growth of the two bacteria and on phenanthrene degradation. The effect of the flavonoids on bacterial growth did not depend on the presence of PAHs. Using naringenin as an example, we showed that increased PAH degradations could not accompany bacterial growth promotion by any flavonoid. Except for rutin, all flavonoids were subject to bacterial degradation. Inoculation of alfalfa with the competent rhizobacterium Ensifer meliloti increased the contents phenolic compounds in the plant root exudate, promoted qualitative changes in their profile, and increased the rhizodegradation of phenanthrene from 6% and 22% to 57% and 34% at initial phenanthrene concentrations of 50 and 100 mg/L respectively.

CONCLUSION

Our data suggest a the role for plant flavonoids in the rhizome-mediated degradation of PAHs. The microbe-induced qualitative and quantitative changes in root exudation illustrate the induction of PAH-mediated catabolic activity in the rhizosphere.

Occurrence, formation mechanism, and health risk of polycyclic aromatic hydrocarbons in barbecued food

Polycyclic aromatic hydrocarbons (PAHs) show negative impacts on human health. Dietary intake is the predominant way for PAH exposure, of which barbecued food is a crucial contributor. This review aims to provide a comprehensive insight into the formation mechanism, influencing factors, mitigation strategies, and health risks of PAHs in barbecued food. PAHs in barbecued food are formed by Hydrogen abstraction and acetylene addition (HACA) mechanism, Diels-Alder reaction and Maillard reaction, which was influenced by heat source, temperature, cooking time, and the meat type. There are significant differences in PAH concentrations in different barbecued foods, where chrysene dominates among the selected PAH species. To reduce PAHs formation, adding marinades and adopting alternative cooking methods are suggested, which effectively reduce PAH levels by 53 -89 %. In addition, it is estimated that people in countries such as Pakistan has an incremental lifetime cancer risk (ILCR) over 10-5 via barbecued food consumption, indicating potential health risk. This work highlighted that regular monitoring of PAH levels in barbecued food and dynamic modification of relevant safety limits are recommended to ensure food safety.

Prenatal polycyclic aromatic hydrocarbons exposure and child growth and adiposity: A longitudinal study

BACKGROUND

Exposure to polycyclic aromatic hydrocarbons (PAHs) during childhood has been associated with altered growth and adiposity in children. The effects of prenatal exposure to PAHs on developmental programming of growth and adiposity are still unknown.

OBJECTIVE

To study the association of prenatal exposure to PAHs with early childhood growth and adiposity measures.

METHODS

In NYU Children's Health and Environment Study (2016-2019), we studied 880 mother-child pairs for maternal urinary PAH metabolites in early, mid, and late pregnancy and measured child weight, length/height, triceps, and subscapular skinfold thicknesses at 1, 2, 3, and 4 years. We used linear mixed models to investigate associations between average pregnancy exposure to PAHs and the z-scores of child repeated measures. The models were adjusted for sociodemographic and health-related factors.

RESULTS

Children prenatally exposed to higher levels of PAHs had greater weight and length/height z scores. We found an interaction with time-point of child assessment, showing stronger associations at later ages. For instance, PAH exposure was associated with higher weight z-scores at 3 years: coefficient per Ln-unit increase in 2-NAP = 0.25 (95%CI: 0.13, 0.37), 2-PHEN = 0.25 (95%CI: 0.11, 0.39), 1-PYR = 0.13 (95%CI: 0.02, 0.24), and 4-PHEN = 0.09 (95%CI: 0.02, 0.15). Higher concentrations of 2-NAP (coefficient = 0.21, 95%CI: 0.11, 0.31), 2-PHEN (coefficient = 0.24, 95%CI: 0.12, 0.35), 3-PHEN (coefficient = 0.13, 95%CI: 0.02, 0.24]), 4-PHEN (coefficient = 0.09, 95%CI: 0.04, 0.15), and 1-PYR (coefficient = 0.11, 95%CI: 0.02, 0.21) were associated with higher weight z-score at 4 years.

CONCLUSION

Prenatal PAH exposure may contribute to the developmental programming of growth in childhood.

Atmospheric polycyclic aromatic hydrocarbon concentrations in a semi-urban site: temporal variation, risk assessment, source identification, and estimation of levels in diverse environments

This study evaluates atmospheric polycyclic aromatic hydrocarbon (PAH) concentrations in a semi-urban area, Görükle, Turkey, from June 2021 to February 2022. The average concentration of ∑16 PAHs was 24.85 ± 19.16 ng/m3, ranging from 6.70 to 59.11 ng/m3. Seasonal variations were observed, with winter concentrations approximately five times higher than those in summer, driven by increased residential heating emissions and adverse meteorological effects. The results were compared to literature values, revealing lower PAH levels than those found in other urban and industrial areas. Meteorological factors were statistically analyzed. Polycyclic aromatic hydrocarbon concentrations exhibited an inverse relationship with temperature and mixing height, while relative humidity showed a positive linear correlation. The study also estimated PAH concentrations in various environmental media using gas-particle partitioning and equilibrium models. The concentrations of PAHs in the particulate phase were minimal, suggesting that most PAHs were present in the gas phase. Additionally, the equilibrium concentrations of PAHs in soil, leaves, bark, and water were modeled, emphasizing the accumulation of heavier PAHs in these media yet 2- and 3-ring PAHs were predominant in the ambient air samples. Source apportionment and principal component analysis studies identified vehicle emissions and combustion for heating purposes as the primary sources of pollution. However, air mass trajectory analysis indicated contributions from Kocaeli, an area with significant industrial activity. The cancer risk assessment yielded low risks for both adults and children.

Co-exposure to polycyclic aromatic hydrocarbons and nicotine and their associations with cognitive impairment risk in older adults from southern China

Exposure to polycyclic aromatic hydrocarbons (PAHs) and tobacco smoke is widespread and linked to various adverse health outcomes. Their potential to disturb the neurological system has raised much concern, particularly among older adults. Thus, we conducted a case-control study to assess the associations between co-exposure to PAHs and nicotine, and the risk of cognitive impairment and oxidative stress in older adults. A total of 384 adults aged 60 years and older were recruited from 2017 to 2018 in Shenzhen, China. Morning spot urine samples were collected for the analysis of 6 mono-hydroxylated PAHs, 8 nicotine metabolites, and a typical biomarker for oxidative stress, 8-hydroxy-2'-deoxyguanosine (8-OHdG). The Mini-Mental State Examination was used to assess the cognitive function of participants. Quantile-based g-computation (QGC), weighted quantile sum regression, and Bayesian kernel machine regression were used to analyze the associations between the exposure mixture and outcomes. QGC showed co-exposure to PAHs and nicotine were positively associated with cognitive impairment risk (OR: 1.66, 95% CI: 1.36-2.03, P < 0.001) and 8-OHdG (β:11.19, 95% CI: 3.90-18.48, P < 0.001). The primary contributors to cognitive impairment risk were (S)-nicotine-N-β-glucuronide (NicGluc), cotinine N-β-D-glucuronide (CotGluc) and (S)-cotinine N-oxide (CNO) and Cotinine (Cot), with no-linear dose-response relationships. However, 8-OHdG did not mediate the association between PAHs, nicotine and cognitive impairment risk.

Geographic heterogeneity of polycyclic aromatic hydrocarbons in Yangtze River sediments: Evidence from the longest river in Asia

This work is the first comprehensive survey of the Yangtze River, covering its origin to the estuary mouth. It focuses on the geographical and industrial factors influencing the distribution of polycyclic aromatic hydrocarbons (PAHs) in sediments, along with their contamination levels, sources, and ecological risks. The total concentrations of PAHs ranged from 2.14 to 796 (mean 179 ± 179) ng/g, which falls within the low-to-middle range compared to global levels. Four-ring PAHs were observed with the highest proportion (34.0%), followed by three-rings (24.7%), five-rings (16.0%), two-rings (16.6%), and six-rings (8.62%). PAH levels were significantly higher downstream of the confluences of the Yangtze mainstream and its major tributaries, as well as in areas with frequent industrial activity. Heavy metals (Zn, Pb, and Cd) and industry output values were positively correlated with PAHs concentrations, especially three-ring PAHs. The results of source analysis, based on molecular diagnostics and principal component analysis, identified coal, biomass, and petroleum combustion as the main sources of PAHs. Among these, industrial coal combustion and vehicle emissions were dominant, contributing 39% and 64% of the PAHs pollution in top and bottom sediments, respectively. The toxicity equivalence (TEQ) evaluation results showed that the total TEQ of ∑16PAHs (mean: 14 ng/g) was below the 600 ng/g TEQBaP standard established by the Canadian Council of Ministers of the Environment. BaP had the highest TEQBaP, followed by DahA and BbF. The risk assessment indicated that Nap and Pyr were the two congeners with the highest risk, accounting for 24-33% and 21-28% of the Risk Quotient for negligible concentration values (RQNCs) and maximum Permissible Concentration values (RQMPCs) of ∑16PAHs, respectively. Despite the overall low to moderate risks of PAHs in the region, the above-mentioned major compounds (e.g., BaP, DahA, BbF, Nap, and Pyr) should be of continued concern.

Advances in environmental pollutant detection techniques: Enhancing public health monitoring and risk assessment

Accurate detection and monitoring of environmental pollutants are of paramount importance for disease prevention and public health. In recent years, the ever-expanding human activities and industrial production have given rise to a sharp increase in the complexity and variety of these pollutants, which pose significant threats to human well - being. Environmental pollutants stem from multiple sources, such as heavy metals, persistent organic pollutants, inorganic non - metallic pollutants, emerging pollutants, and biological contaminants. Traditional detection technologies, though valuable for their sensitivity and accuracy, are constrained by complex sample preparation, poor selectivity, and the absence of standardized detection methods. On the other hand, emerging technologies, including nanotechnology, molecular detection methods, biosensors, Surface-Enhanced Raman Spectroscopy (SERS), multi-omics, and big data analysis, offer promising solutions for rapid and sensitive pollutant detection. The establishment of environmental monitoring networks and data - sharing platforms further enhances real - time pollutant monitoring and provides solid data support for public health initiatives. Nonetheless, challenges persist, including data integration, exposure assessment, and the development of cost-effective and portable detection solutions. Future progress in interdisciplinary approaches and technology integration will be crucial for advancing environmental pollutant detection and facilitating comprehensive disease prevention. This review systematically classifies environmental pollutants and showcases the latest advancements in detection technologies, offering critical insights for environmental monitoring and public health protection.

Levels of exposure markers among residents in environmentally vulnerable areas in Korea, the general population in Korea, and Asians in the United States

This study compares biomarker levels among environmentally vulnerable residents in Korea, the general Korean population, and Asians in the United States. We selected 953 exposed residents and 204 controls from the Forensic Research via Omics Markers in Environmental Health Vulnerable Areas (FROM) study (2021-2023), 4,239 participants from the fourth Korean National Environmental Health Survey (2018-2020), and 996 Asians from the U.S. National Health and Nutrition Examination Survey (2017-March 2020). The analyzed biomarkers included blood and urinary metals, urinary metabolites of polycyclic aromatic hydrocarbons, nicotine, volatile organic compounds, and serum perfluorocarbon metabolites. The highest median biomarker levels varied by pollution source among older adults. In refineries, blood lead and cadmium (Cd), as well as urinary Cd and 2-hydroxyfluorene, were highest. Abandoned metal mines exhibited the highest blood and urinary mercury, urinary Cd, total arsenic (As), 2-naphthol, and cotinine levels. Coal-fired power plants showed the highest urinary 1- hydroxyphenanthrene levels, while cement factories had the highest urinary As3+ levels. Sprawls demonstrated the highest urinary monomethylarsonic acid, 1-hydroxypyrene, and phenylglyoxylic acid levels, and industrial areas recorded the highest levels of trans, trans-muconic acid, benzylmercapturic acid, and 2-methylhippuric acid. In general, biomarker levels were higher among exposed residents in the FROM study than in the general population; however, urinary 2-hydroxyfluorene and As5+ levels did not differ significantly. Exposure to pollution sources in environmentally vulnerable areas may elevate biomarker levels in residents.

Polycyclic Aromatic Hydrocarbons (PAHs) in the Environment: Occupational Exposure, Health Risks and Fertility Implications

Polycyclic aromatic hydrocarbons (PAHs) are a group of organic compounds with fused aromatic rings, primarily derived from combustion processes and environmental pollutants. This narrative review discusses the most relevant studies on PAHs, focusing on their sources, environmental and occupational exposure, and effects on human health, emphasizing their roles as carcinogenic, mutagenic, and teratogenic agents. The primary pathways for human exposure to PAHs are through the ingestion of contaminated food (mainly due to some food processing methods, such as smoking and high-temperature cooking techniques), the inhalation of ambient air, and the smoking of cigarettes. Coke oven workers are recognized as a high-risk occupational group for PAH exposure, highlighting the need for appropriate strategies to mitigate these risks and safeguard worker health. PAHs are metabolized into reactive intermediates in the body, which can lead to DNA damage and promote the development of various health conditions, particularly in environments with high exposure levels. Chronic PAH exposure has been linked to respiratory diseases, as well as cardiovascular problems and immune system suppression. Furthermore, this review underscores the significant impact of PAHs on reproductive health. The results of the reported studies suggest that both male and female fertility can be compromised due to oxidative stress, DNA damage, and endocrine disruption caused by PAH exposure. In males, PAHs impair sperm quality, while, in females, they disrupt ovarian function, potentially leading to infertility, miscarriage, and birth defects. Fetal exposure to PAHs is also associated with neurodevelopmental disorders. Given the extensive and detrimental health risks posed by PAHs, this review stresses the importance of stringent environmental regulations, occupational safety measures, and public health initiatives to mitigate exposure and safeguard reproductive and overall health.

Rapid and On-Site Approaches for Determination of Polycyclic Aromatic Hydrocarbons in Water and Air by Surface-Enhanced Raman Spectroscopy

Polycyclic aromatic hydrocarbons (PAHs) represent a class of carcinogenic, teratogenic, and mutagenic aromatic organic pollutants that are ubiquitous in the environment. The rapid and on-site detection of PAHs remains a challenge. This study proposes point-of-use (POU) surface-enhanced Raman spectroscopy (SERS)-based strategies for the qualitative and quantitative analyses of PAHs in environmental water and air. The results demonstrate clear correlations between the signal intensity and the logarithmic concentration of PAHs in water (ranging from 2.5 to 100 ppb), with satisfactory recovery and reproducibility. A similar trend was observed for PAHs on glass fiber filters modified with silver nanoparticles (AgNPs@GF filter). Specifically, the limits of detection (LOD) for fluoranthene, phenanthrene, and pyrene in water were 0.7, 1.0, and 0.1 ppb, respectively, while the LOD for fluoranthene, phenanthrene, and pyrene on the AgNPs@GF filter were 9.11, 18.18, and 14.59 ppb. Recovery rates in spiked real water and filters ranged from 83% to 126%, and the entire detection process was completed within 1 min. These findings highlight the significant potential of this method as a powerful tool for rapid on-site analysis of PAHs in various environmental matrices.

Association of urinary metabolites of polycyclic aromatic hydrocarbons with urinary incontinence in adults: A cross-sectional study

This study aims to investigate the association between polycyclic aromatic hydrocarbon (PAH) metabolites and urinary incontinence (UI) in the general adult population. This study analyzed six urinary PAH metabolites in the general adult population from the 2005-2016 National Health and Nutrition Examination Survey (NHANES). UI was distinguished into stress UI (SUI), urgency UI (UUI), mixed UI (MUI), and any UI by self-reported questionnaires. Multiple logistic regression, restricted cubic spline (RCS) regression, and quantile g-computation (QG-C) were applied to assess the association between PAHs (individual and mixture exposure) and the prevalence of UI. A total of 8,136 participants were included in our study. The participants had a median age of 45.9 years, and 48.7 % of individuals were female. Most ln-transformed PAHs were positively and linearly related to the prevalence of SUI and any UI in women (P < 0.05). Increasing prevalence of SUI was associated with the highest quantiles of 3-hydroxyfluorene (3-FLU) (OR = 1.72, 95%CI = 1.27-2.33, P for trend = 0.002), 2-hydroxyfluorene (2-FLU) (OR = 1.75, 95%CI = 1.29-2.38, P for trend = 0.008), and 1-hydroxypyrene (1-PYR) (OR = 1.44, 95%CI = 1.05-1.96, P for trend = 0.012) compared with the lowest quantiles in women. The mixture of urinary PAH metabolites was significantly associated with an increased prevalence of SUI (OR = 1.09, 95%CI: 1.01-1.19, P = 0.038) in women. Urinary 2-FLU had the greatest positive contribution to the overall effect, while 2-hydroxynapthalene (2-NAP) was the major negative contributor. Our study demonstrated that mixture exposure to PAHs is associated with the prevalence of SUI in adult women, which might be primarily driven by 2-FLU.

Exploring the association between exposure to pesticides, polycyclic aromatic hydrocarbons, and phthalates and metabolic syndrome in National Health and Nutrition Examination Survey in the USA, 2007-2012: utilizing a multi-step statistical strategy

BACKGROUND

Pesticides, polycyclic aromatic hydrocarbons (PAHs), and phthalates are recognized as potential contributors to metabolic disorders. Nevertheless, the combined effect of simultaneous exposure to these chemicals on the metabolic syndrome (MetS) remains elusive.

OBJECTIVES

To explore the impacts of simultaneous exposure to pesticides, PAHs and phthalates and identify critical chemicals on MetS.

METHODS

Based on the National Health and Nutrition Examination Survey (NHANES) database from 2007-2012, our study included 4030 non-pregnant individuals aged 20 years or older. We used the weighted linear regression model, variable selection models (including LASSO regression and BMA models), as well as a mixture exposure model (WQS model) to investigate the correlation between chemicals and MetS. Additionally, stratified analyses were performed based on gender and age.

RESULTS

The weighted generalized linear regression model revealed a positive correlation of 2-hydroxyphenanthrene (2-PHEN) with MetS (OR: 1.37, 95% CI: 1.19-1.59, P < 0.001). Both the LASSO regression and BMA models identified 2-PHEN as a significant chemical positively associated with MetS. Additionally, the WQS model showed a positive association between overall exposure to the three chemical categories and MetS, with the highest weighted chemicals being 2-PHEN. Stratified analyses demonstrated a significant correlation between 2-PHEN and MetS between different subgroups. Notably, the WQS regression model revealed a significant association in the subgroup of female (OR = 1.40, 95% CI: 1.08-1.83, P < 0.05), with 2-PHEN, 2,5-dichlorophenol (2,5-DCP), 2-hydroxynaphthalene (2-NAP), and mono-ethyl phthalate (MEP) identified as the primary contributions to MetS.

CONCLUSION

Combined exposure to the three chemical groups was associated with an increased risk of MetS, with the PAHs group exhibiting the most pronounced effect and 2-PHEN emerging as a key chemical, underscoring significant public health concerns regarding the potential health risks of endocrine-disrupting chemicals (EDCs) exposure to metabolic diseases.

Identification of Dihydropentalenes as Products of the Molecular-Weight Growth Reaction of Cyclopentadienyl Plus Propargyl

The resonance-stabilized cyclopentadienyl (C5H5) and propargyl (C3H3) radicals are important precursors for polycyclic aromatic hydrocarbons (PAHs) and thus play a significant role in molecular-weight growth and soot formation processes under combustion conditions. In this work, we describe an experimental and theoretical investigation of the C5H5 + C3H3 reaction. Experimentally, we studied this reaction in a resistively heated microtubular SiC reactor at a controlled temperature of ∼1150 K and a pressure of 10-20 mbar. The reactants C5H5 and C3H3 were pyrolytically generated from anisole (C6H5OCH3) and propargyl bromide (C3H3Br). We identified the reactants and the C8H8 products isomer-selectively utilizing photoion mass-selected threshold photoelectron spectroscopy (ms-TPES). The experimentally observed predominant formation of dihydropentalenes over the ring-enlargement reaction to styrene is consistent with our theoretical predictions of the kinetics on the newly calculated C8H8 potential energy surface. This work highlights dihydropentalenes as reactants in molecular-weight growth reactions and as potential building blocks in versatile routes for the formation of curved PAHs.

Assessment of polycyclic aromatic hydrocarbons (PAHs) and heavy metal contamination in Shitalakshya River water: ecological and health risk implications

The Shitalakshya River, vital to the Dhaka district, faces severe pollution challenges due to industrial discharges, urban runoff, and other anthropogenic activities. This study investigated the concentration of polycyclic aromatic hydrocarbons (PAHs) and heavy metals in the river water, utilizing GC-MS/MS and ICP-MS techniques. The results revealed a total PAH concentration ranging from 4.97 to 5.87 ng/mL, with 3-ring PAHs being the most prevalent. Heavy metals such as Fe, As, Ni, and Zn were found in significant concentrations, exceeding international standards for drinking water and aquatic life. The ecological risk assessment identified benzo(b)fluoranthene, benzo(k)fluoranthene, and indeno(1,2,3-cd)pyrene as the highest threats to aquatic organisms. Health risk assessments indicated substantial risks from dermal and ingestion exposures, particularly due to arsenic, highlighting potential long-term health implications for local residents. The study underscores the urgent need for comprehensive monitoring, pollution source identification, and stringent regulatory measures to mitigate these risks.

Wildfire Smoke Contributions to Polycyclic Aromatic Hydrocarbon Loadings in Western Canadian Urban Surface Grime

Wildfires emit large amounts of polycyclic aromatic hydrocarbons (PAHs) into the atmosphere. As PAHs emitted from anthropogenic sources are known to accumulate in urban surface grime present on building exteriors and windows, we hypothesized that PAH-containing wildfire smoke plumes could similarly increase PAH grime loadings. To explore this hypothesis, we coupled analysis of PAHs in grime samples collected from August to November 2021 in two historically smoke-affected Canadian cities, Calgary and Kamloops, with contemporaneous field- and model-based indicators of wildfire influence. In Calgary, a single wildfire smoke day contributed over 20% of total grime PAH loadings during this study's 3-month sampling period, which implies that wildfire inputs have the potential to dominate the grime composition during a typical wildfire season. In Kamloops, although the PAH congener profile displayed a sustained background wildfire influence, total PAH loadings were dominated by a hyper-local combustion event, which highlights that even small-scale urban combustion activities have the potential to control pollutant loadings on nearby surfaces. In both locations, temporal PAH congener profiles showed no evidence of reactive loss, implying that biomass burning contributes to the presence of a persistent PAH reservoir available for direct exposure or runoff-mediated contamination of downstream environmental compartments.

Metabolomics, Genetics, and Environmental Factors: Intersecting Paths in Abdominal Aortic Aneurysm

Abdominal aortic aneurysm represents a significant public health concern, particularly in men aged 55 to 64, where it occurs in about 1%. We investigated the metabolomics and genetics of AAA by analyzing a cohort including 76 patients with AAA and randomly selected 228 controls. Utilizing the Metabolon DiscoveryHD4 platform for non-targeted metabolomics profiling, we identified several novel metabolites significantly associated with AAA. These metabolites were primarily related to environmental and lifestyle factors, notably smoking and pesticide exposure, which underscores the influence of external factors on the progression of AAA. Additionally, several genetic variants were associated with xenobiotics, highlighting a genetic predisposition that may exacerbate the effects of these environmental exposures. The integration of metabolomic and genetic data provides compelling evidence that lifestyle, environmental, and genetic factors are intricately linked to the etiology of AAA. The results of our study not only deepen the understanding of the complex pathophysiology of AAA but also pave the way for the development of targeted therapeutic strategies.

Predictive value and mediating effect analysis of the AHR-ARNT-CYP1A1 axis for missed abortion related to polycyclic aromatic hydrocarbons exposure

This study aimed to determine the predictive value of aryl hydrocarbon receptor (AHR) signaling pathway genes, and to detect the mediating effect of AHR that may mediate the influence of polycyclic aromatic hydrocarbons (PAHs) on missed abortion. The present study was conducted using a 1:2 matched case-control study, a total of 94 cases of women with missed abortion and 188 matched women controls with normal pregnancy but voluntarily abortion were included. The receiver operating characteristic curve (ROC) and the area under the ROC curve (AUC) were used to evaluate the predictive value of AHR signaling pathway genes for missed abortion. The mediating role of AHR within the effect pathway between PAHs exposure and missed abortion was performed using the mediation package of the R language. The results showed that the level of PAH-DNA adducts in the case group (487.61 ± 6.29) pg/ml was higher than that in the control group (446.86 ± 5.95) pg/ml (P < 0.001). There were significant differences in the expression levels of AHR, aryl hydrocarbon receptor nuclear translocator (ARNT), aryl hydrocarbon receptor repressor (AHRR), cytochrome P450 enzymes 1A1 (CYP1A1) and glutathione S-transferase P1 (GSTP1) genes between the case group and the control group (P < 0.01). After adjusting for covariates, high exposure of PAH-DNA adducts levels increased AHR and CYP1A1 expression. The 5-fold cross-validation results revealed that the mean value of the area under the ROC curve (AUC) of AHR-ARNT-CYP1A1 axis was 0.931 (95%CI: 0.858 ~ 0.999), which had good predictive performance in assessing the risk of prevalence of missed abortion. AHR gene might play a partial mediating effect in the association between PAHs exposure and missed abortion, and the percentage of mediating effect was 36.56%.

Fugacity-based multimedia transport modeling and risk assessment of PAHs in Urumqi

Currently, there is a lack of a comprehensive understanding of the behavior of polycyclic aromatic hydrocarbons (PAHs) in complex multimedia urban environmental systems. Taking Urumqi City as a case study, we developed an integrated multimedia urban environmental model to simulate the inter-media transport processes of PAHs across air, water, soil, sediment, vegetation, and impervious surfaces. The predictive results of this model were in good agreement with the actual monitoring data from 2021, confirming its accuracy. Notably, the simulated data for 2021 indicate that the total amount of PAHs in the soil reached 1.06 × 106 kg, accounting for 97.44% of the total PAHs in Urumqi City, highlighting soil as the primary sink for PAHs. Further analysis of transport fluxes revealed that atmospheric transfer pathways to soil and vegetation are the main mechanisms driving the distribution of PAHs in urban environments. Additionally, sensitivity analysis identified temperature, soil, and vegetation-related parameters as the primary factors influencing PAHs. Based on the simulated concentration, the risk assessment results showed that soil PAHs had a higher risk of carcinogenesis to human body. This study deepens our understanding of the behavior of PAHs in urban environments and provides insights into how human activities affect the fate and transformation of these contaminants in multimedia urban systems.

Developmental toxicity of alkylated PAHs and substituted phenanthrenes: Structural nuances drive diverse toxicity and AHR activation

Polycyclic aromatic hydrocarbons (PAHs) are a diverse class of chemicals that occur in complex mixtures including parent and substituted PAHs. To understand the hazard posed by complex environmental PAH mixtures, we must first understand the structural drivers of activity and mode of action of individual PAHs. Understanding the toxicity of alkylated PAHs is important as they often occur in higher abundance in environmental matrices and can be more biologically active than their parent compounds. 104 alkylated PAHs were screened from 11 different parent compounds with emphasis on substituted phenanthrenes and their structurally dependent toxicity differences. Using a high-throughput early life stage zebrafish assay, embryos were exposed to concentrations between 0.1 and 100 μM and assessed for morphological and behavioral outcomes. The aryl hydrocarbon receptor (AHR) is often implicated in the toxicity of PAHs and the induction of cytochrome P4501A (cyp1a) is an excellent biomarker of Ahr activation. Embryos were evaluated for cyp1a induction using a fluorescence reporter line. Alkyl and polar phenanthrene derivatives were further assessed for spatial cyp1a expression and Ahr dependence of morphological effects. In the alkyl PAH screen 35 (33.7%) elicited a morphological or behavioral response and of those 23 (65%) also induced cyp1a. 31 (29.8%) of the chemicals only induced cyp1a. Toxicity varied substantially in response to substitution location, the amount of ring substitutions and alkyl chain length. Cyp1a induction varied by parent compound group and was a poor indicator of morphological or behavioral outcomes. Polar phenanthrenes were more biologically active than alkylated phenanthrene derivatives and their toxicity was not dependent upon the Ahr2, Ahr1a or Ahr1b when tested individually, despite cyp1a induction by 50% of polar phenanthrenes. Our results demonstrated that induction of cyp1a did not always correlate with PAH toxicity or Ahr dependence and that the type and location of phenanthrene substitution determined potency.

Associations of coke oven emission exposure with pulmonary function, blood pressure, blood cell parameters, and biochemical indices in coking workers: a cross-sectional pilot study

Background and objective: Coke oven emissions (COEs) are formed in the process of coking production, mainly composed of polycyclic aromatic hydrocarbons (PAHs) and benzene; however, the health impacts of COE exposure in coking workers are not fully clear so far. We aimed to explore the associations of occupational COE exposure with pulmonary function, blood pressure, blood cell parameters, and blood biochemical indices, and to bolster health surveillance and disease prevention and control in coking workers. Methods: We investigated 566 coking workers at a large state-owned enterprise coking plant in Taiyuan, Shanxi, China, measured the concentrations of plasma 16 PAHs and urinary phenol, assessed the health outcomes including pulmonary function, blood pressure, the levels of peripheral hematologic parameters and biochemical indices, and examined the associations of PAH and phenol concentrations with the health outcomes using multiple linear regressions, least absolute shrinkage and selection operator regression (LASSO), and Bayesian kernel machine regression (BKMR). Results: After adjustment for confounders, plasma ∑15PAH concentration was significantly associated with increases in hemoglobin (HGB) and triglyceride (TG) levels in coking workers, and urinary phenol concentration was significantly associated with increases in the diastolic blood pressure (DBP) level, and decreases in platelet (PLT) count. When phenol concentration and PAH concentration were simultaneously included in the multiple linear regression model, both of them were associated with the level of HGB. LASSO and BKMR indicated that the PAHs with four rings and above contributed to the HGB level. Conclusion: PAH exposure could damage hematological parameters and blood lipids, and benzene exposure could increase blood pressure and decrease PLT count.

PAH-Finder: A Pattern Recognition Workflow for Identification of PAHs and Their Derivatives

Polycyclic aromatic hydrocarbons (PAHs) are pervasive environmental pollutants with significant health risks due to their carcinogenic, mutagenic, and teratogenic properties. Traditional methods for PAH identification, primarily relying on gas chromatography-mass spectrometry (GC-MS), utilize spectral library searches together with other techniques, such as mass defect analysis. However, these methods are limited by incomplete spectral libraries and a high false positive rate. Here, we present PAH-Finder, a data-driven workflow that integrates machine learning with high-resolution mass spectrometry (HRMS). PAH-Finder introduces a novel approach to evaluate the fragment distribution of PAH backbones in MS spectra by normalizing fragment m/z values to a 0-100% range relative to the molecular ion peak. Seven machine learning features capture PAH fragmentation characteristics, and a random forest model trained on 98 PAH spectra and 1003 background spectra achieved an F1 score of ∼0.9 in 5-fold cross validation. Additionally, PAH-Finder leverages the presence of doubly charged fragments and molecular formula prediction to enhance the identification accuracy. In a case study, PAH-Finder identified 135 PAHs, including 7 types of previously unreported PAH formulas in particulate matter samples, demonstrating a 246% increase in annotation efficiency compared to the NIST20 library search. It also identified 32 heteroatom-doped PAHs not included in the training data set, showcasing its robustness of generalization. PAH-Finder's high accuracy in detecting a broad spectrum of PAHs facilitates efficient data processing and interpretation for nontargeted analysis, enhancing our understanding of air pollution and public health protection. PAH-Finder is freely available at Github (https://github.com/FangLabNTU/PAH-Finder).

Benefits of Immobilized Bacteria in Bioremediation of Sites Contaminated with Toxic Organic Compounds

Although bioremediation is considered the most environmentally friendly and sustainable technique for remediating contaminated soil and water, it is most effective when combined with physicochemical methods, which allow for the preliminary removal of large quantities of pollutants. This allows microorganisms to efficiently eliminate the remaining contaminants. In addition to requiring the necessary genes and degradation pathways for specific substrates, as well as tolerance to adverse environmental conditions, microorganisms may perform below expectations. One typical reason for this is the high toxicity of xenobiotics present in large concentrations, stemming from the vulnerability of bacteria introduced to a contaminated site. This is especially true for planktonic bacteria, whereas bacteria within biofilms or microcolonies have significant advantages over their planktonic counterparts. A physical matrix is essential for the formation, maintenance, and survival of bacterial biofilms. By providing such a matrix for bacterial immobilization, the formation of biofilms can be facilitated and accelerated. Therefore, bioremediation combined with bacterial immobilization offers a comprehensive solution for environmental cleanup by harnessing the specialized metabolic activities of microorganisms while ensuring their retention and efficacy at target sites. In many cases, such bioremediation can also eliminate the need for physicochemical methods that are otherwise required to initially reduce contaminant concentrations. Then, it will be possible to use microorganisms for the remediation of higher concentrations of xenobiotics, significantly reducing costs while maintaining a rapid rate of remediation processes. This review explores the benefits of bacterial immobilization, highlighting materials and processes for developing an optimal immobilization matrix. It focuses on the following four key areas: (i) the types of organic pollutants impacting environmental and human health, (ii) the bacterial strains used in bioremediation processes, (iii) the types and benefits of immobilization, and (iv) the immobilization of bacterial cells on various carriers for targeted pollutant degradation.

Physical Health Symptoms and Perceptions of Air Quality among Residents of Smoke-Damaged Homes from a Wildland Urban Interface Fire

The Marshall Fire was a wildland urban interface (WUI) fire that destroyed more than 1000 structures in two communities in Colorado. High winds carried smoke and ash into an unknown number of buildings that, while not incinerated, were significantly damaged. We aimed to understand whether smoke or ash damage to one's home was associated with physical health impacts of the fire event for people living in and around the fire zone whose homes were not completely destroyed. We analyzed data collected from participants who responded to Wave 1 (six months postfire; N = 642) or Wave 2 (one-year postfire; N = 413) of the Marshall Fire Unified Research Survey. We used self-reported exposure to smells and ash in their homes as measures of exposure and also created spatial exposure measures based on proximity to destroyed structures. Reporting a headache was statistically significantly associated with all exposure metrics (self-reported and spatial proximity), and reporting a strange taste in one's mouth was also significantly associated with having more destroyed buildings within 250 m of the home. Study findings can inform response planning for future WUI fires to protect the health of residents of smoke-damaged homes.

Association between polycyclic aromatic hydrocarbons exposure and current asthma: a population-based study

BACKGROUND

Polycyclic aromatic hydrocarbons (PAHs) are environmental contaminants that can cause a variety of health problems. This study sought to determine whether there was a relationship between PAHs and current asthma in adults.

METHODS

This cross-sectional study utilized data from the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2016 and employed multifactor logistic regression, subgroup analyses, and smoothed curve fitting to examine the linear and nonlinear associations between PAHs and current asthma.

RESULTS

A total of 8729 adult participants were included in the study. We found a linear positive association between current asthma and the six PAHs. In the fully adjusted model, log 3-Hydroxyfluorene, log 2-Hydroxyfluorene, and log 1-Hydroxypyrene remained significantly associated with current asthma. Subgroup analyses stratified by smoking status, gender, age, and body mass index (BMI) showed consistent associations between PAHs and current asthma, with some subgroups displaying stronger positive correlations. Specifically, positive correlations between log 1-Hydroxynaphthalene, log 3-Hydroxyfluorene, and log 2-Hydroxyfluorene with current asthma were independently significant in smokers. Among women, log 3-Hydroxyfluorene and log 2-Hydroxyfluorene were also significantly associated with current asthma. In participants with a BMI ≥ 30 kg/m2, log 1-Hydroxynaphthalene, log 2-Hydroxynaphthalene, and log 1-Hydroxypyrene were significantly correlated with current asthma. For individuals aged 20-40 years, log 3-Hydroxyfluorene and log 1-Hydroxypyrene showed independent associations with current asthma, with age modifying the relationship between log 1-Hydroxypyrene and current asthma (p for interaction < 0.05), while p for interaction values in other subgroups were not statistically significant. Additionally, a variable relationship between log 1-Hydroxypyrene and current asthma was identified by smoothing curve fitting. The data suggested that below the inflection point of 1.87, the association fluctuates, while above this point, a linear increase in current asthma is observed, as indicated by a two-piecewise linear regression model.

CONCLUSIONS

We found a positive association between PAHs and current asthma in adults, with a variable relationship between log 1-Hydroxypyrene and current asthma, suggesting that high levels of 1-Hydroxypyrene exposure may increase the risk of current asthma. More prospective studies are needed to confirm our findings.

Fabrication of MOF-on-MOF composites by surfactant-assisted growth strategy for SPME of polycyclic aromatic hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) are a class of persistent organic pollutants with strong carcinogenicity and mutagenicity, which cause great harm to the environment and food. Herein, a composite (NH2-MIL-88@PCN-224) was prepared through a guest PCN-224 in situ grown on the host NH2-MIL-88 by a surfactant-assisted growth strategy, and successfully applied for solid-phase microextraction (SPME) of PAHs from milk samples. The prepared SPME coatings exhibited high extraction and adsorption capacity for PAHs due to their porous structure, ultra-large specific surface area, strong π-π stacking, hydrophobic interactions and size-matching effects. The SPME-GC-FID method based on NH2-MIL-88@PCN-224 coated fibers has the significant advantages of wide linear range (1-200 ng mL-1), low detection limit (0.003-0.020 ng mL-1), high recoveries (92.15-106.64 %) and good reproducibility. This work overcomes the lattice-matching limitation by adopting a surfactant-assisted growth strategy, which offers a new direction for the preparation of ultra-high-performance SPME coatings with extremely high extraction efficiency, exceptional thermal stability, and long service life, and greatly expands the variety of MOF SPME coatings.