Lung cancer risk assessment for workers exposed to polycyclic aromatic hydrocarbons in various industries

Proteogenomic analysis of air-pollution-associated lung cancer reveals prevention and therapeutic opportunities

Air pollution significantly impacts lung cancer progression, but there is a lack of a comprehensive molecular characterization of clinical samples associated with air pollution. Here, we performed a proteogenomic analysis of lung adenocarcinoma (LUAD) in 169 female never-smokers from the Xuanwei area (XWLC cohort), where coal smoke is the primary contributor to the high lung cancer incidence. Genomic mutation analysis revealed XWLC as a distinct subtype of LUAD separate from cases associated with smoking or endogenous factors. Mutational signature analysis suggested that Benzo[a]pyrene (BaP) is the major risk factor in XWLC. The BaP-induced mutation hotspot, EGFR-G719X, was present in 20% of XWLC which endowed XWLC with elevated MAPK pathway activations and worse outcomes compared to common EGFR mutations. Multi-omics clustering of XWLC identified four clinically relevant subtypes. These subgroups exhibited distinct features in biological processes, genetic alterations, metabolism demands, immune landscape, and radiomic features. Finally, MAD1 and TPRN were identified as novel potential therapeutic targets in XWLC. Our study provides a valuable resource for researchers and clinicians to explore prevention and treatment strategies for air-pollution-associated lung cancers.

Benzo(a)pyrene promotes the malignant progression of malignant-transformed BEAS-2B cells by regulating YTH N6-methyladenosine RNA binding protein 1 to inhibit ferroptosis

Benzo[a]pyrene (BaP) is associated with the development of lung cancer, but the underlying mechanism has not been completely clarified. Here, we used 10 μM BaP to induce malignant transformation of human bronchial epithelial BEAS-2B cells, named BEAS-2B-T. Results indicated that BaP (6.25, 12.5 and 25 μM) treatment significantly promoted the migration and invasion of BEAS-2B-T cells. Meanwhile, BaP exposure inhibited ferroptosis in BEAS-2B-T, ferroptosis-related indexes Fe2+, malondialdehyde (MDA), lipid peroxidation (LPO) and reactive oxygen species (ROS) decreased significantly. The protein level of ferroptosis-related molecule transferrin receptor (TFRC) decreased significantly, while solute carrier family 7 membrane 11 (SLC7A11), ferritin heavy chain 1 (FTH1) and glutathione peroxidase 4 (GPX4) increased significantly. The intervention of ferroptosis dramatically effected the migration and invasion of BEAS-2B-T induced by BaP. Furthermore, the expression of YTH N6-methyladenosine RNA binding protein 1 (YTHDF1) was markedly increased after BaP exposure. YTHDF1 knockdown inhibited BEAS-2B-T migration and invasion by promoting ferroptosis. In the meantime, the contents of Fe2+, MDA, LPO and ROS increased significantly, TFRC was markedly increased, and SLC7A11, FTH1, and GPX4 were markedly decreased. Moreover, overexpression of YTHDF1 promoted BEAS-2B-T migration and invasion by inhibiting ferroptosis. Importantly, knockdown of YTHDF1 promoted ferroptosis and reduced BEAS-2B-T migration and invasion during BaP exposure, and overexpression of YTHDF1 increased migration and invasion of BEAS-2B-T by inhibiting ferroptosis during BaP exposure. RNA immunoprecipitation assays indicated that the binding of YTHDF1 to SLC7A11 and FTH1 markedly increased after YTHDF1 overexpression. Therefore, we concluded that BaP promotes the malignant progression of BEAS-2B-T cells through YTHDF1 upregulating SLC7A11 and FTH1 to inhibit ferroptosis. This study reveals new epigenetic and ferroptosis markers for preventing and treating lung cancer induced by environmental carcinogens.

Utilizing biological experimental data and molecular dynamics for the classification of mutational hotspots through machine learning

Motivation

Benzo[a]pyrene, a notorious DNA-damaging carcinogen, belongs to the family of polycyclic aromatic hydrocarbons commonly found in tobacco smoke. Surprisingly, nucleotide excision repair (NER) machinery exhibits inefficiency in recognizing specific bulky DNA adducts including Benzo[a]pyrene Diol-Epoxide (BPDE), a Benzo[a]pyrene metabolite. While sequence context is emerging as the leading factor linking the inadequate NER response to BPDE adducts, the precise structural attributes governing these disparities remain inadequately understood. We therefore combined the domains of molecular dynamics and machine learning to conduct a comprehensive assessment of helical distortion caused by BPDE-Guanine adducts in multiple gene contexts. Specifically, we implemented a dual approach involving a random forest classification-based analysis and subsequent feature selection to identify precise topological features that may distinguish adduct sites of variable repair capacity. Our models were trained using helical data extracted from duplexes representing both BPDE hotspot and nonhotspot sites within the TP53 gene, then applied to sites within TP53, cII, and lacZ genes.

Results

We show our optimized model consistently achieved exceptional performance, with accuracy, precision, and f1 scores exceeding 91%. Our feature selection approach uncovered that discernible variance in regional base pair rotation played a pivotal role in informing the decisions of our model. Notably, these disparities were highly conserved among TP53 and lacZ duplexes and appeared to be influenced by the regional GC content. As such, our findings suggest that there are indeed conserved topological features distinguishing hotspots and nonhotpot sites, highlighting regional GC content as a potential biomarker for mutation.

Availability and implementation

Code for comparing machine learning classifiers and evaluating their performance is available at https://github.com/jdavies24/ML-Classifier-Comparison, and code for analysing DNA structure with Curves+ and Canal using Random Forest is available at https://github.com/jdavies24/ML-classification-of-DNA-trajectories.

Increased mortality risk from airborne exposure to polycyclic aromatic hydrocarbons

BACKGROUND

The potential health effects of airborne polycyclic aromatic hydrocarbons (PAHs) among general population remained extensively unstudied. This study sought to investigate the association of short-term exposure to low-level total and 7 carcinogenic PAHs with mortality risk.

METHODS

We conducted an individual-level time-stratified case-crossover study in Jiangsu province of eastern China, by investigating over 2 million death cases during 2016-2019. Daily concentrations of total PAH and its 7 carcinogenic species including benzo[a]anthracene (BaA), benzo[a]pyrene (BaP), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), chrysene (Chr), dibenz[a,h]anthracene (DahA), and indeno[1,2,3-cd]pyrene (IcdP), predicted by well-validated spatiotemporal models, were assigned to death cases according to their residential addresses. We estimated mortality risk associated with short-term exposure to increase of an interquartile range (IQR) for aforementioned PAHs using conditional logistic regression.

RESULTS

An IQR increase (16.9 ng/m3) in 2-day (the current and prior day) moving average of total PAH concentration was associated with risk increases of 1.90% (95% confidence interval [CI]: 1.71-2.09) in all-cause mortality, 1.90% (95% CI: 1.70-2.10) in nonaccidental mortality, 2.01% (95% CI: 1.72-2.29) in circulatory mortality, and 2.53% (95% CI: 2.03-3.02) in respiratory mortality. Risk increases of cause-specific mortality ranged between 1.42-1.90% for BaA (IQR: 1.6 ng/m3), 1.94-2.53% for BaP (IQR: 1.6 ng/m3), 2.45-3.16% for BbF (IQR: 2.8 ng/m3), 2.80-3.65% for BkF (IQR: 1.0 ng/m3), 1.36-1.77% for Chr (IQR: 1.8 ng/m3), 0.77-1.24% for DahA (IQR: 0.8 ng/m3), and 2.96-3.85% for IcdP (IQR: 1.7 ng/m3).

CONCLUSIONS

This study provided suggested evidence for heightened mortality risk in relation to short-term exposure to airborne PAHs in general population. Our findings suggest that airborne PAHs may pose a potential threat to public health, emphasizing the need of more population-based evidence to enhance the understanding of health risk under the low-dose exposure scenario.

The concentration and probabilistic health risk assessment attribute to PAHs in indoor air of Hormozgan aluminum plant, Iran

We measured PAHs concentrations to understand the potential short and long-term health risks to workers. In the anode cooking area, the lowest and highest concentrations of PAHs were found for DahA (dibenzo[a,h]anthracene) at 0.373 ± 0.326 µg/m3 and Chry (chrysene) at 1.923 ± 1.258 µg/m3, respectively. In the anode-making area, these concentrations were higher, with DahA at 0.435 ± 0.221 µg/m3 and Chry peaking at 3.841 ± 1.702 µg/m3. Risk assessment based on these concentrations indicates a hierarchical order of individual PAHs risks in the anode cooking area, led by BaP (benzo[a]pyrene), followed by other specific PAHs compounds. The total hazard quotient (THQ) for PAH exposure in both anode-making and cooking areas significantly exceeds the threshold for considered cancer risk, emphasizing the considerable danger to workers. This study underscores the urgent need to mitigate exposure to PAHs in industrial settings to protect worker health from the carcinogenic risks of such hazardous compounds.

Molecular Characteristics of Aberrant Gene Mutations and Expression Profiles Induced by Benzo(a)pyrene in Hepatocellular Carcinoma Cells

Benzo(a)pyrene (BaP) is a prevalent food and environmental carcinogen. Chronic low-dose BaP exposure can promote the migratory and invasive capacities of human hepatocellular carcinoma (HCC) cells, yet its intricate molecular mechanisms remain elusive. Utilizing the established BaP-exposed HCC cell model, we analyzed the gene expression alteration, exosomal RNA cargo, and genetic variants induced by BaP through transcriptomic and whole-genome sequencing. Transcriptomic analysis revealed significant dysregulation in genes and pathways associated with tumor metastasis, particularly those involved in steroidal lipid metabolism and cell migration. BaP exposure enriched PI3K-AKT, mTOR, and NF-κB signaling pathways and disrupted genes implicated in cellular secretory processes, suggesting the potential involvement of exosomes in metastasis. Exosome analysis depicted the RNA profiling in exosomes of HCC cells altered by BaP, and the exosomal circRNA-miRNA-mRNA interaction network was constructed. Finally, whole-genome sequencing delineated BaP-induced gene mutations and genomic instability in HCC cells. In summary, prolonged low-dose BaP exposure induces intricate molecular alterations in gene mutation and expression profiles in HCC cells, notably those secreted in exosomes, which may potentially remodel the tumor microenvironment and foster HCC metastasis. Our findings offer new insights into the molecular underpinnings of BaP-induced HCC metastasis, thereby advancing the comprehensive understanding of BaP toxicity.

Metabolomics perspectives of the ecotoxicological risks of polycyclic aromatic hydrocarbons: A scoping review

Polycyclic Aromatic Hydrocarbons (PAHs) represent persistent environmental pollutants ubiquitously distributed in the environment. Their presence alongside various other contaminants gives rise to intricate interactions, culminating in profound deleterious consequences. The combination effects of different PAH mixtures on biota remains a relatively unexplored domain. Recent studies have harnessed the exceptional sensitivity of metabolomic techniques to unveil the significant ecotoxicological perils of PAH pollution confronting both human populations and ecosystems. This article furnishes a comprehensive overview of current literature focused on the metabolic repercussions stemming from exposure to complex mixtures of PAHs or PAH-pollution sources using metabolomics approaches. These insights are obtained through a wide range of models, including in vitro assessments, animal studies, investigations on human subjects, botanical specimens, and soil environments. The findings underscore that PAH mixtures induce cellular stress responses and systemic effects, leading to metabolic dysregulations in amino acids, carbohydrates, lipids, and other key metabolites (e.g., organic acids, purines), with specific variations observed based on the organism and PAH compounds involved. Additionally, the ecological consequences of PAH pollutants on plant and soil microbial responses are emphasized, revealing significant changes in stress-related metabolites and nutrient cycling in soil ecosystems. The complex interplay of various PAHs and their metabolic effects on several models, as elucidated through metabolomics, highlight the urgency of further research and the need for comprehensive strategies to mitigate the risks posed by these widespread environmental pollutants.

Enhanced photocatalytic degradation of polycyclic aromatic hydrocarbon by graphitic carbonitride-nickel (g-C3N4-Ni) nanocomposite

The objective of the present study is to synthesize g-C3N4-Ni nanocomposites composed of graphitic carbon nitride and magnetic nickel nanoparticles for benzopyrene degradation, which is one of the most potent polycyclic aromatic hydrocarbons (PAH) molecules. The concocted g-C3N4-Ni nanocomposites contained confined nanospheres with a mean particle dimension of 22 nm. Batch adsorption studies revealed that a rise in adsorbent dosage elevates benzopyrene degradation percentage in both water and soil samples with respect to time. The increase in the benzopyrene concentration did not have much influence on the degradation efficiency, and hence, the minimal concentration of PAH molecule is essential for the effective adsorption by g-C3N4-Ni nanocomposites. The rise in pH tends to increase the degradation of Benzopyrene till 3 h of the incubation period, and beyond 3 h, the degradation percentage declines. With regard to the effect of light source, UV light has been shown to accelerate the degradation of benzopyrene by g-C3N4-Ni nanocomposites than sunlight. The adsorption kinetic and isotherm investigations have proven that the Pseudo-second order kinetic model and Freundlich isotherm model were appropriate for our study. Thus, the g-C3N4-Ni nanocomposites were found to be efficient as a photocatalyst for the adsorption of benzopyrene from environmental samples.

Functional polymorphisms in Benzo(a)Pyrene-induced toxicity pathways associated with the risk on laryngeal squamous cell carcinoma

Benzo(a)Pyrene (BaP) is a well-known environmental carcinogen that poses a significant risk to human health. The pivotal genes and toxicity pathways have been identified as key events to construct the mode of action (MOA) of BaP. In this study, we focused on evaluating the association between genetic variants in BaP-disturbed toxicity pathways and the susceptibility of laryngeal squamous cell carcinoma (LSCC), based on the data of our previous genome-wide association analysis (GWAS). In addition, we investigated the biological roles of these significant polymorphisms by integrating bioinformatic annotation and experimental validation. Our findings revealed that 15 functional polymorphisms in AHR signaling, p53 signaling, NRF2 signaling, TGF-β signaling, STAT3 signaling, and IL-8 signaling pathways were significantly associated with susceptibility to LSCC. Our study provides a novel approach for identifying novel risk genetic loci utilizing GWAS data, and suggests potential targets for early detection of LSCC in the future.

Hazards of polycyclic aromatic hydrocarbons: a review on occurrence, detection, and role of green nanomaterials on the removal of PAH from the water environment

Organic pollutant contamination in the environment is a serious and dangerous issue, especially for developing countries. Among all organic pollutants, polycyclic aromatic hydrocarbons (PAHs) are the more frequently discovered ones in the environment. PAH contamination is caused chiefly by anthropogenic sources, such as the disposal of residential and industrial waste and automobile air emissions. They are gaining interest due to their environmental persistence, toxicity, and probable bioaccumulation. The existence of PAHs may result in damage to the environment and living things, and there is widespread concern about the acute and chronic threats posed by the release of these contaminants. The detection and elimination of PAHs from wastewater have been the focus of numerous technological developments during recent decades. The development of sensitive and economical monitoring systems for detecting these substances has attracted a lot of scientific attention. Using several nanomaterials and nanocomposites is a promising treatment option for the identification and elimination of PAHs in aquatic ecosystems. This review elaborated on the sources of origin, pathogenicity, and widespread occurrence of PAHs. In addition, the paper highlighted the use of nanomaterial-based sensors in detecting PAHs from contaminated sites and nanomaterial-based absorbents in PAH elimination from wastewater. This review also addresses the development of Graphene and Biofunctionalized nanomaterials for the elimination of PAHs from the contaminated sites.

Removal of organic and inorganic contaminants from the air, soil, and water by algae

Rapid increases in human populations and development has led to a significant exploitation of natural resources around the world. On the other hand, humans have come to terms with the consequences of their past mistakes and started to address current and future resource utilization challenges. Today's primary challenge is figuring out and implementing eco-friendly, inexpensive, and innovative solutions for conservation issues such as environmental pollution, carbon neutrality, and manufacturing effluent/wastewater treatment, along with xenobiotic contamination of the natural ecosystem. One of the most promising approaches to reduce the environmental contamination load is the utilization of algae for bioremediation. Owing to their significant biosorption capacity to deactivate hazardous chemicals, macro-/microalgae are among the primary microorganisms that can be utilized for phytoremediation as a safe method for curtailing environmental pollution. In recent years, the use of algae to overcome environmental problems has advanced technologically, such as through synthetic biology and high-throughput phenomics, which is increasing the likelihood of attaining sustainability. As the research progresses, there is a promise for a greener future and the preservation of healthy ecosystems by using algae. They might act as a valuable tool in creating new products.

Bitumen fumes and PAHs in asphalt road paving: Emission characteristics, determinants of exposure and environmental impact

BACKGROUND

Asphalt road paving and its subsequent complex airborne emissions have raised concerns about occupational exposures and environmental impacts. Although several studies described bitumen fumes or Polycyclic Aromatic Hydrocarbons (PAH) emissions at specific worksites, no comprehensive studies have characterised road paving emissions and identified the main determinants of exposure.

METHODS

A 10-year study from 2012 to 2022 was performed to examine the pollutants resulting from bitumen fume emissions and covering the main processes used in road paving (asphalt production, mechanical rolled asphalt paving, manual paving, mastic asphalt paving, emulsion paving, and coal-tar asphalt milling). A total of 623 air samples were collected at 63 worksites (on 290 workers, in the environment and near emission sources), and bitumen fumes, PAHs, aldehydes and volatile organic compounds were analysed. Biomonitoring campaigns were performed on 130 workers to assess internal exposure to PAHs.

RESULTS

Fume emissions revealed complex mixtures of C₁₀-C₃₀ compounds, including linear saturated hydrocarbons (C₆-C₁₂), alicyclic hydrocarbons and aliphatic ketones. PAHs were dominated by 2-3 aromatic ring compounds (naphthalene, fluorene, and phenanthrene), and C₁-C₁₃ aldehydes were identified. Binder proportion, paving temperature, outdoor temperature, workload and job category influenced airborne concentrations. A significant temporal trend was observed over the time period of the study, with decreasing BF and PAH exposures. PAH biomonitoring was consistent with air samples, and urinary metabolites of 2-3 ring PAHs dominated over 4-5 ring PAHs. Occupational exposures were generally far lower than exposure limits, except coal-tar asphalt milling activities. Very low environmental concentrations were measured, which highlights a negligible contribution of paving emissions to global environmental pollution.

CONCLUSION

The present study confirmed the complex nature of bitumen fumes and characterised the main determinants of exposure. The results highlight the need to reduce the paving temperature and binder proportion. Recycled asphalt pavement use was not associated with higher emissions. The impact of paving activities on environmental airborne pollution was deemed negligible.

Understanding population exposure to size-segregated aerosol and associated trace elements during residential cooking in northeastern India: Implications for disease burden and health risk

Mass-size distribution of respirable aerosol and 13 associated trace elements (TEs) were investigated in rural kitchens using liquefied petroleum gas (LPG), firewood and mixed biomass fuels across three northeastern Indian states. The averaged PM10 (particulate matter with aerodynamic diameter ≤ 10 μm) and ΣTE concentrations were 403 and 30 μg m-3 for LPG, 2429 and 55 μg m-3 for firewood, and 1024 and 44 μg m-3 for mixed biomass-using kitchens. Mass-size distributions were tri-modal with peaks in the ultrafine (0.05-0.08 μm), accumulation (0.20-1.05 μm), and coarse (3.20-4.57 μm) modes. Respiratory deposition, estimated using the multiple path particle dosimetry model, ranged from 21 % to 58 % of the total concentration across fuel types and population age categories. Head, followed by pulmonary and tracheobronchial, was the most vulnerable deposition region, and children were the most susceptible age group. Inhalation risk assessment of TEs revealed significant non-carcinogenic as well as carcinogenic risk, especially for biomass fuel users. The potential years of life lost (PYLL) was the highest for chronic obstructive pulmonary disease (COPD: 15.9 ± 3.8 years) followed by lung cancer (10.3 ± 0.3 years) and pneumonia (10.1 ± 0.1 years), while the PYLL rate was also highest for COPD, with Cr(VI) being the major contributor. Overall, these findings reveal the significant health burden faced by the northeastern Indian population from indoor cooking using solid biomass fuels.

How Does Environmental and Occupational Exposure Contribute to Carcinogenesis in Genitourinary and Lung Cancers?

Environmental and occupational exposures have been associated with an increased risk of different types of cancers, although the exact mechanisms of higher carcinogenesis risk are not always well understood. Lung cancer is the leading cause of global cancer mortality, and, also, genitourinary neoplasms are among the main causes of cancer-related deaths in Western countries. The purpose of this review is to describe the main environmental and occupational factors that increase the risk of developing lung and genitourinary cancers and to investigate carcinogenesis mechanisms that link these agents to cancer onset. Further objectives are to identify methods for the prevention or the early detection of carcinogenic agents and, therefore, to reduce the risk of developing these cancers or to detect them at earlier stages.

Internal exposure risk based on urinary metabolites of PAHs of occupation and non-occupation populations around a non-ferrous metal smelting plant

The emission of various metals from non-ferrous metal smelting activities is well known. However, relative investigations on potential occupational exposure of organic pollutants are still limited. Herein, total of 619 human urine samples were collected from workers engaged in smelting activities and residents living near and/or far from the smelting sites, and ten mono-hydroxylated metabolites of polycyclic aromatic hydrocarbons (OH-PAHs) in human urine were determined. The median levels of Σ₁₀OH-PAHs in smelting workers (25.6 ng/mL) were significantly higher (p < 0.01) than that of surrounding residents (9.00 ng/mL) and rural residents as the control (8.17 ng/mL), indicating an increase in occupational PAH exposure in non-ferrous metal smelting activities. The composition profiles of OH-PAH congeners were similar in three groups, in which naphthalene metabolites accounted for 76-82% of the total. The effects of smoking, drinking, gender, BMI, and occupational categories on urinary OH-PAHs were considered. The partial correlation analysis showed an insignificant effect of non-ferrous metal smelting activities on PAH exposure for surrounding residents. In the health risk assessments, almost all smelting workers had cancer risks exceeded the acceptable level of 10^-6. This study provides a reference to occupational PAH exposure and reinforce the necessary of health monitoring among smelting workers.

Chemical fingerprints and implicated cancer risks of Polycyclic aromatic hydrocarbons (PAHs) from fine particulate matter deposited in human lungs

Exposure to fine particles (PM_2.5) and associated PAHs are frequently linked with lung cancer, which makes the understanding of their occurrence and health risk in human lungs urgently important. Using the ultrasonic treatment and sequencing centrifugation (USC) extraction method coupled with gas chromatography-tandem mass spectrometry (GC - MS/MS) analysis, we revealed the molecular fingerprints of PM-accumulated PAHs in human lungs from a cohort of 68 patients with lung cancer in a typical air-polluted region, China. Sixteen priority PAHs can be grouped by concentrations as ∼ 1 × 10⁴ ng/g (ANT/BkF/ACE/DBA/BgP/PHN/PYR), 2-5 × 10³ ng/g (BaP/FLE/NaP/BbF), and ∼ 1 × 10³ ng/g (IND/Acy/CHR/FLT/BaA). The sum concentration of 16 PAHs was approximately equaled to 13% of those in atmospheric PM_2.5, suggesting significant pulmonary leaching of PAHs deposited in lungs. Low- and high-molecular weight PAHs accounted for ∼ 41.8% and ∼ 45.1% of the total PAHs, respectively, which indicated that atmospheric PM_2.5, tobacco and cooking smoke were likely to be important sources of pulmonary PAHs. The evident increasing concentrations of NaP and FLE in pulmonary PM were significantly correlated with smoking history among smokers. The implicated carcinogenic potency of PM-accumulated PAHs among the participants aged 70-80 was 17 times that among participants aged 40-50 on the basis of BaP equivalent concentration (BaPeq) evaluation. The particulate enrichment factor (EF_P), the PAH content in pulmonary PM relative to the bulk lung tissue, was equaled to 54 ∼ 835 and averaged at 436. The high value of EF_P suggested that PAHs were essentially accumulated in pulmonary PM and exhibited a pattern of "hotspot" distribution in the lungs, which would likely increase the risk of monoclonal tumorigenesis. The chemical characteristics of PM-accumulated PAHs in human lungs together with their implicated lung cancer risks could provide significant information for understanding health effects of particulate pollution in the human body.

Polycyclic aromatic hydrocarbons exposure was associated with microRNA differential expression and neurotransmitter changes: a cross-sectional study in coal miners

Exposure to polycyclic aromatic hydrocarbons (PAHs) may cause neurobehavioral changes. This study aimed to explore the underlying mechanism of PAH neurotoxicity in coal miners. Urinary PAH metabolites, neurotransmitters, and oxidative stress biomarkers of 652 coal miners were examined. Subjects were divided into high and low-exposure groups based on the median of total urinary PAH metabolites. Differentially expressed miRNAs were screened from 5 samples in the low-exposure group (≤ 4.88 μmol/mol Cr) and 5 samples in the high-exposure group (> 4.88 μmol/mol Cr) using microarray technology, followed by bioinformatics analysis of the potential molecular functions of miRNA target genes. Reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) was used to validate differentially expressed miRNAs. Restricted cubic splines (RCS) were applied to assess the possible dose-response relationships. Compared to the low PAH exposure group, the high-exposure group had higher levels of 5-hydroxytryptamine (5-HT), epinephrine (E), and acetylcholine (ACh), and lower levels of acetylcholinesterase (AChE). 1-OHP had a dose-response relationship with malondialdehyde (MDA), dopamine (DA), 5-HT, and AChE (P for overall associations < 0.05). There were 19 differentially expressed microRNAs in microarray analysis, significantly enriched in the cell membrane, molecular binding to regulate transcription, and several signaling pathways such as PI3K-Akt. And in the validation stage, miR-885-5p, miR-20a-5p, and let-7i-3p showed differences in the low and high-exposure groups (P < 0.05). Changes in neurotransmitters and microRNA expression levels among the coal miners were associated with PAH exposure. Their biological functions are mainly related to the transcriptional regulation of nervous system diseases or signaling pathways of disorders. These findings provide new insights for future research of PAH neurotoxicity.

Rapid detection of four polycyclic aromatic hydrocarbons in drinking water by constant-wavelength synchronous fluorescence spectrometry

Based on the advantages of the good selectivity and high sensitivity of the synchronous fluorescence method, an efficient method using constant-wavelength synchronous fluorescence spectrometry (CWSFS) for simultaneous and rapid determination of four polycyclic aromatic hydrocarbons (PAHs) (acenaphthene, phenanthrene, benzo[a]anthracene and fluoranthene) in drinking water was established in this study. When the difference in wavelength (Δλ) at 100 nm was chosen for CWSFS scanning, the synchronous fluorescence spectra of the four PAHs could be well separated with only one single scan. Different from conventional fluorescence analysis, the established method can avoid the interference among the four PAHs each other and the interference of the drinking water sample matrix, so the four PAHs in drinking water could be well distinguished and determined. The concentrations of four PAHs in the range of 0.05-100 μg/L, 0.1-400 μg/L, 0.05-100 μg/L and 0.5-2000 μg/L showed a good linear relationship with fluorescence intensity. The limits of detection were 0.0058 μg/L, 0.021 μg/L, 0.0061 μg/L and 0.056 μg/L, respectively. The recoveries were in the range of 86.55-98.74%. Overall, the established CWSFS had the characteristics of simple, rapid, sensitive and accuracy, and had been applied to the determination of the four PAHs in various drinking water with satisfactory results.

Effects of H19/SAHH/DNMT1 on the oxidative DNA damage related to benzo[a]pyrene exposure

The mechanisms that long noncoding RNA (lncRNA) H19 binding to S-adenosylhomocysteine hydrolase (SAHH) interacted with DNA methyltransferase 1 (DNMT1) and then regulated DNA damage caused by polycyclic aromatic hydrocarbons (PAHs) remain unclear. A total of 146 occupational workers in a Chinese coke-oven plant in 2014 were included in the final analyses. We used high-performance liquid chromatography mass spectrometry (HPLC-MS) equipped to detect urine biomarkers of PAHs exposure, including 2-hydroxynaphthalene (2-NAP), 2-hydroxyfluorene (2-FLU), 9-hydroxyphenanthrene (9-PHE) and 1-hydroxypyrene (1-OHP). The levels of SAM and SAH in plasma were detected by HPLC-ultraviolet. By constructing various BEAS-2B cell models exposed to 16 μM benzo[a]pyrene (BaP) for 24 h, toxicological parameters reflecting distinct mechanisms were evaluated. We documented that urinary 1-hydroxypyrene (1-OHP) levels were positively associated with blood H19 RNA expression (OR: 1.51, 95% CI: 1.03-2.19), but opposite to plasma SAHH activity (OR: 0.63, 95% CI: 0.41-0.98) in coke oven workers. Moreover, by constructing various BEAS-2B cell models exposed to benzo[a]pyrene (BaP), we investigated that H19 binding to SAHH exaggerated DNMT1 expressions and activity. Suppression of H19 enhanced the interaction of SAHH and DNMT1 in BaP-treated cells, decreased eight-oxoguanine DNA glycosylase 1 (OGG1) methylation, reduced oxidative DNA damage and lessened S phase arrest. However, SAHH or DNMT1 single knockdown and SAHH/DNMT1 double knockdown showed the opposite trend. A H19/SAHH/DNMT1 axis was involved in OGG1 methylation, oxidative DNA damage and cell cycle arrest by carcinogen BaP.

Lung cancer risk in workers occupationally exposed to polycyclic aromatic hydrocarbons with emphasis on the role of DNA repair gene

OBJECTIVE

Workers in secondary aluminum production plants are occupationally exposed to polycyclic aromatic hydrocarbons (PAHs). We aimed to monitor the concentrations of PAHs in air and in serum of workers at two secondary aluminum production plants. We also investigated the potential risk of lung cancer development among PAHs exposed workers with emphasis on the role of A1AT mutation and APEX1 gene polymorphisms.

METHODS

This study included 177 workers from administrative departments and production lines. Blood samples were obtained for estimation of benzo(a)pyrene diol epoxide albumin adduct (BPDE-Alb adduct), anti-Cyclin-B1 marker (CCNB1) and squamous cell carcinoma antigen (SCCAg). Genes' polymorphism for human apurinic/apyrimidinic endonuclease (APEX1) and alpha-1-anti-trypsin (A1AT) gene mutation were detected.

RESULTS

There was a significant increase in the level of BPDE-Alb adduct among exposed workers in comparison to non-exposed group. Moreover, 41.67% of exposed workers in El Tebbin had BPDE-Alb adduct level ≥ 15 ng/ml versus 29.6% of workers in Helwan factory. There was a significant increase in tumor markers (SCCAg and CCNB1) among workers whose BPDE-Alb adduct ≥ 15 ng/ml. There was a significant increase in the level of BPDE-Alb adducts in exposed workers carrying homozygous APEX1 genotype Glu/Glu. Furthermore, exposed workers with the Glu/Glu genotype had high tumor markers levels. There was a significant increase in levels of BPDE-Alb adducts in workers carrying A1AT mutant allele. Moreover, workers with mutant A1AT genotype had significantly high tumor markers (SCCAg and CCNB1) levels.

CONCLUSION

Therefore, we conclude that aluminum workers may be at a potential risk of lung cancer development due to PAHs exposure. Although PAHs concentrations in air were within the permissible limits, yet evidence of DNA damage was present as expressed by high BPDE-albumin adduct level in exposed workers. Also, elevation of tumor markers (SCCAg and CCNB1) in exposed workers points to the importance of periodic biological monitoring of such workers to protect them from cancer risk.

Trace Metals and Polycyclic Aromatic Hydrocarbons in the Snow Cover of the City of Nizhnevartovsk (Western Siberia, Russia)

The city of Nizhnevartovsk is one of the centers of oil production in Western Siberia (Russia). A survey of the contents of trace metals and metalloids (TMMs) and polycyclic aromatic hydrocarbons (PAHs) in the snow cover was conducted there. It was aimed to study insoluble particles in the snow where the predominant fraction of pollutants in urban areas is concentrated. In contrast to the background area, the deposition of TMMs in Nizhnevartovsk increases by 1-2 orders of magnitude. The deposition of V and Mn increases by 37 and 88 times, respectively, and the deposition of W increases at most (by 98 times). Abrasion of spikes of winter tires, abrasion of metal parts of vehicles, and combustion of motor fuels cause the pollution with W, Co, and V, respectively. The total content of 12 EPA PAHs in the particulate fraction of snow in the urban area averaged 148.2 ng l^-1, and the deposition rate was 17.0 μg/m². In contrast to the background area, the fraction of high molecular weight 5-6-ring PAHs significantly increases in the city, especially dibenzo(a,h)anthracene (DahA). The indicative ratios of PAHs showed that the snowpack composition was influenced by both petrogenic and pyrogenic sources. The proportion of pyrogenic sources is the highest in the low-rise residential area due to fuel combustion to produce heat and burning of household waste. The impact of motor transport is also major and is manifested in the maximum pollution in areas of heavy traffic. No emissions of PAHs from oil spills from the nearby Samotlor oil field have been identified. It is concluded that the hydrocarbon pollution of the atmosphere from the field weakens during the winter period compared to the warm season. Application of the integral TDF index characterizes the majority (72%) of the studied samples as lowly polluted, 24% of the observation sites are classified as moderately polluted, and one (4%), as highly polluted. The maximum TDF values are observed in the industrial area. The data obtained during the study allowed us to identify the central areas and sites along the roads with the heaviest traffic as the most contaminated areas of the city. This study can be a reference for air pollution monitoring in Nizhnevartovsk.

Associations between urinary biomarkers of oxidative stress and biomarkers of tobacco smoke exposure in smokers

Oxidative stress can contribute to the development of diseases, and may originate from exposures to toxicants commonly found in air pollution and cigarette smoke such as polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs). Yet, associations between these exposures and oxidative stress biomarkers are poorly characterized. We report here novel associations between 14 exposure biomarkers of PAHs and VOCs, and two oxidative stress biomarkers; 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) and 8-isoprostaglandin F_2α (8-isoprostane) in urine obtained from smokers participating in an ongoing clinical study (ESTxENDS, NCT03589989). We also assessed associations between six biomarkers of tobacco smoke exposure (metabolites of nicotine and tobacco-specific nitrosamines (TSNAs)) and both oxidative stress biomarkers. We then quantified the relative importance of each family of the 20 exposure biomarkers on oxidative stress. Participating smokers (153 men and 117 women, median age 44 years) had on average smoked 25 [2-62] years and smoked about 17 [5-40] cigarettes per day at the time of the study. Multiple linear regression results showed an association between 8-oxodG concentrations and the following metabolites in decreasing relative importance: PAHs (beta coefficient β = 0.105, p-value <0.001, partial R² = 0.15) > VOCs (β = 0.028, p < 0.001, partial R² = 0.09) > nicotine (β = 0.226, p < 0.001, partial R² = 0.08); and between 8-isoprostane concentrations and metabolites of PAHs (β = 0.117, p < 0.001, partial R² = 0.14) > VOCs (β = 0.040, p < 0.001, partial R² = 0.14) > TSNAs (β = 0.202, p = 0.003, partial R² = 0.09) > nicotine (β = 0.266, p < 0.001, partial R² = 0.08). Behavioral factors known to contribute to oxidative stress, including sleep quality, physical activity, and alcohol consumption, did not play a significant role. Exposures to PAHs and VOCs among smokers were significantly associated with oxidative stress.

Reprogramming of glycolysis by chemical carcinogens during tumor development

Indiscriminate usage and mismanagement of chemicals in the agricultural and industrial sectors have contaminated different environmental compartments. Exposure to these persistent and hazardous pollutants like heavy metals, endocrine disruptors, aromatic hydrocarbons, and pesticides can result in various health adversities, including cancer. Chemical carcinogens follow a similar pattern of carcinogenesis, like oxidative stress, chromosomal aberration, DNA double-strand break, mismatch repair, and misregulation of oncogenic and/or tumor suppressors. Out of several cancer-associated endpoints, cellular metabolic homeostasis is the commonest to be deregulated upon chemical exposure. Chemical carcinogens hamper glycolytic reprogramming to fuel the malignant transformation of the cells and/or promote cancer progression. Several regulators like Akt, ERK, Ras, c-Myc, HIF-1α, and p53 regulate glycolysis in chemical-induced carcinogenesis. However, the deregulation of the anabolic biochemistry of glucose during chemical-induced carcinogenesis remains to be uncovered. This review comprehensively covers the environmental chemical-induced glycolytic shift during carcinogenesis and its mechanism. The focus is also to fill the major gaps associated with understanding the fairy tale between environmental carcinogens and metabolic reprogramming. Although evidence from studies regarding glycolytic reprogramming in chemical carcinogenesis provides valuable insights into cancer therapy, exposure to a mixture of toxicants and their mechanism of inducing carcinogenesis still needs to be studied.

Polycyclic Aromatic Hydrocarbons in the Snow Cover in the City of Tyumen (Western Siberia, Russia)

Some of Russia's large industrial cities are sources of hazardous contamination in the environment. Tyumen is one of the most rapidly developing cities in Siberia due to oil and gas extraction in the northern Tyumen Region. Concentrations of 14 polycyclic aromatic hydrocarbons (PAH)s deposited with the particulate matter (PM) of snow in the city of Tyumen were determined by liquid chromatography. In the background area, the rate of atmospheric particulate deposition was shown to be low, and the mean total content of 14 PAHs had a value of 6.2 ng L^-1, which is lower than many unpolluted areas on Earth. In the city of Tyumen, the mean content of PM was five times higher and the mean total content of 14 PAHs was twenty times higher as compared to the background. The contents of chrysene, benzo(k)fluoranthene, and benzo(a)pyrene were increased by multiples of 78, 77, and 32, respectively. The rates of ∑14 PAH deposition with airborne PM over the winter ranged from 1.1 to 65.5 μg m^-2. Calculations of BaP toxic equivalent showed maximal toxicity within the transport zone. Both analysis of spatial distribution and diagnostic ratios showed that the PAHs were mainly from coal combustion and vehicle emissions.

Polycyclic aromatic hydrocarbons, long non-coding RNA expression, and DNA damage in coke oven workers

Exposure to polycyclic aromatic hydrocarbons (PAHs) was associated with DNA damage, while the roles of long non-coding RNAs (lncRNAs) in the associations were unclear. We aimed to assess the association of lncRNA NR_024564 with urinary monohydroxy PAHs (OH-PAHs) and DNA damage among 332 coke oven workers. We determined 12 OH-PAHs by gas chromatography-mass spectrometry, and the expression level of NR_024564 by droplet digital RT-PCR and DNA damage by the comet assay. In total participants, we found that NR_024564 was not significantly associated with OH-PAHs or comet parameters. However, among workers with ≥ 20 working years, multiple OH-PAHs including urinary 1-hydroxyphenanthrene (1-OHPh), 2-OHPh, 3-OHPh, 9-OHPh, 1‑hydroxypyrene, and total PAH metabolites were related to increased comet parameters. Moreover, NR_024564 was significantly associated with 2-OHPh and four comet parameters. Each 1% increase in 2-OHPh was associated with 0.35% reduction (95% CI: 0.16%, 0.55%) in NR_024564 (P-_FDR = 0.005), and 2-OHPh was marginally interacted with working years in relation to NR_024564 decrease. Also, each 1% increment of NR_024564 was related to 0.04-0.13% decrease of Olive tail moment, percent DNA in the comet tail, tail length, and tail moment (all P-_FDR < 0.05). Furthermore, low NR_024564 level combined with high levels of 1-OHPh and 2-OHPh or ≥ 20 working years was positively associated with the comet parameters among the total participants. Our results indicated that NR_024564 might be linked to the adverse associations of PAHs with the DNA damage of coke oven workers who worked for ≥ 20 years.

Occupational Exposure to Polycyclic Aromatic Hydrocarbons and Lung Cancer Risk: Results from a Pooled Analysis of Case-Control Studies (SYNERGY)

BACKGROUND

Exposure to polycyclic aromatic hydrocarbons (PAH) occurs widely in occupational settings. We investigated the association between occupational exposure to PAH and lung cancer risk and joint effects with smoking within the SYNERGY project.

METHODS

We pooled 14 case-control studies with information on lifetime occupational and smoking histories conducted between 1985 and 2010 in Europe and Canada. Exposure to benzo[a]pyrene (BaP) was used as a proxy of PAH and estimated from a quantitative general population job-exposure matrix. Multivariable unconditional logistic regression models, adjusted for smoking and exposure to other occupational lung carcinogens, estimated ORs, and 95% confidence intervals (CI).

RESULTS

We included 16,901 lung cancer cases and 20,965 frequency-matched controls. Adjusted OR for PAH exposure (ever) was 1.08 (CI, 1.02-1.15) in men and 1.20 (CI, 1.04-1.38) in women. When stratified by smoking status and histologic subtype, the OR for cumulative exposure ≥0.24 BaP μg/m3-years in men was higher in never smokers overall [1.31 (CI, 0.98-1.75)], for small cell [2.53 (CI, 1.28-4.99)] and squamous cell cancers [1.33 (CI, 0.80-2.21)]. Joint effects between PAH and smoking were observed. Restricting analysis to the most recent studies showed no increased risk.

CONCLUSIONS

Elevated lung cancer risk associated with PAH exposure was observed in both sexes, particularly for small cell and squamous cell cancers, after accounting for cigarette smoking and exposure to other occupational lung carcinogens.

IMPACT

The lack of association between PAH and lung cancer in more recent studies merits further research under today's exposure conditions and worker protection measures.

Benzo[a]pyrene-Environmental Occurrence, Human Exposure, and Mechanisms of Toxicity

Benzo[a]pyrene (B[a]P) is the main representative of polycyclic aromatic hydrocarbons (PAHs), and has been repeatedly found in the air, surface water, soil, and sediments. It is present in cigarette smoke as well as in food products, especially when smoked and grilled. Human exposure to B[a]P is therefore common. Research shows growing evidence concerning toxic effects induced by this substance. This xenobiotic is metabolized by cytochrome P450 (CYP P450) to carcinogenic metabolite: 7β,8α-dihydroxy-9α,10α-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE), which creates DNA adducts, causing mutations and malignant transformations. Moreover, B[a]P is epigenotoxic, neurotoxic, and teratogenic, and exhibits pro-oxidative potential and causes impairment of animals' fertility. CYP P450 is strongly involved in B[a]P metabolism, and it is simultaneously expressed as a result of the association of B[a]P with aromatic hydrocarbon receptor (AhR), playing an essential role in the cancerogenic potential of various xenobiotics. In turn, polymorphism of CYP P450 genes determines the sensitivity of the organism to B[a]P. It was also observed that B[a]P facilitates the multiplication of viruses, which may be an additional problem with the widespread COVID-19 pandemic. Based on publications mainly from 2017 to 2022, this paper presents the occurrence of B[a]P in various environmental compartments and human surroundings, shows the exposure of humans to this substance, and describes the mechanisms of its toxicity.

Consistency between air and biological monitoring for assessing polycyclic aromatic hydrocarbon exposure and cancer risk of workers

BACKGROUND

Atmospheric levels of polycyclic aromatic hydrocarbons (PAHs) have been monitored in many companies since 1940. Because of the use of respiratory protective equipment (RPE) and cutaneous absorption, the measurement of urinary 1-hydroxypyrene (1-OHP), metabolite of pyrene (Pyr), and, more recently, 3-hydroxybenzo[a]pyrene (3-OHBaP), metabolite of benzo[a]pyrene (BaP), has been carried out to assess PAH exposure and estimate health risks.

OBJECTIVES

This study aimed to investigate the agreement between 523 air and biological levels recorded in the Exporisq-HAP database by taking into account the effectiveness of RPE.

METHODS

The agreement/consistency between 523 air and biological exposure levels was assessed by estimating and comparing the probability of exceeding French limit values (LVs) for both BaP and 3-OHBaP and ACGIH LV for 1-OHP, respectively. PAH airborne levels (_wPAHs) were weighted by an assigned protection factor (APF) depending on the type of mask worn by workers, while urinary 1-OHP concentrations were adjusted with the _wBaP/_wPyr ratio of each industrial sector (_wadj1-OHP).

RESULTS

Within occupational groups, there was an overall agreement between airborne PAH levels and urinary biomarker concentrations. A clear dichotomy was found between "petroleum-derived" and "coal-derived" groups, with much higher exposures in the latest group despite the use of RPEs by two-thirds of the workers. The type of RPE varied from one plant to another, which underlines the importance of taking into account their effectiveness. The analysis of urinary 3-OHBaP was not relevant for low PAH exposure levels. In addition, this biomarker underdiagnosed the exceedance of LV relative to BaP levels for 6% of "coal-derived" groups.

CONCLUSIONS

The use of urinary _wadj1-OHP seemed to be more protective to assess the exceedance of LVs than those of urinary 3-OHBaP and air _wBaP, but adjustment of the 1-OHP concentration by the BaP/Pyr ratio requires air sampling due to highly variable ratios observed in the studied occupational groups.

Dermal Exposure to Hazardous Chemicals in Baby Diapers: A Re-Evaluation of the Quantitative Health Risk Assessment Conducted by The French Agency for Food, Environmental and Occupational Health and Safety (ANSES)

In January 2019, the French Agency for Food, Environmental and Occupational Health and Safety (ANSES) published an opinion on risks related to the presence of hazardous chemicals in infant diapers. ANSES found that health reference values were largely exceeded for polycyclic aromatic hydrocarbons (PAHs), dioxins (PCCD/Fs) and dioxin-like polychlorobiphenyls (DL-PCBs). The levels of formaldehyde and some fragrances were also considered potentially unsafe. Therefore, ANSES concluded that actions have to be taken to restrict levels of these contaminants in diapers. Under the exposure scenario deemed the most reliable by ANSES, estimates of cancer risks of the most potent PAHs detected in diapers exceeded 10-3 and hazard quotients for neurobehavioral effects attained values up to 66. Regarding dioxins and DL-PCBs, ANSES derived a hazard quotient of 12 for the risk of decreased sperm count at adult age. The aim of this study was to examine whether the exposure and risk assessment conducted by ANSES contained potential flaws that could explain such a high exceedance of health reference values. This study also put into perspective the exposure from diapers with that from breast milk whose benefits for children's health are undisputable despite contamination by PAHs, dioxins and DL-PCBS.

Potential years of life lost due to PM2.5-bound toxic metal exposure: Spatial patterns across 60 cities in China

To clarify the spatial patterns of disease burden caused by toxic metals in fine particulate matter (PM_2.5) across China, annual concentration levels of typical toxic metals in PM_2.5 over 60 cities of China were retrieved. Then, potential years of life lost (PYLL) attributable to toxic metal (As, Cd, Cr (VI), Mn, and Ni) exposure was calculated from health risk assessments and lifetable estimates. The results show that Cr(VI) and As were the most polluted metals and greatly exceeded the recommended annual values in the National Ambient Air Quality Standard of China. PYLL for each death (mean ± standard deviation) of 19.8 ± 4.5 years was observed for lung cancer, followed closely by COPD and pneumonia. Furthermore, the PYLL rate (years per 100,000 people) attributable to exposure to these toxic metals was 457 (male: 505, female: 402) years for different cities; therein, Cr(VI) contributed the highest PYLL among these toxic metals, with a proportion of 72.7% (male: 75.3%, female: 69.5%), followed by As of 16.4% (male: 13.8%, female: 19.8%). The concentration level and PYLL both showed large spatial variability, of which the top-ranking cities were observed to be affected by well-developed metal-related industries and coal-powered industrial sectors.

Molecular Mechanisms of Action of Selected Substances Involved in the Reduction of Benzo[a]pyrene-Induced Oxidative Stress

Benzo[a]pyrene (BaP) is a polycyclic aromatic hydrocarbon (PAH) primarily formed by burning of fossil fuels, wood and other organic materials. BaP as group I carcinogen shows mutagenic and carcinogenic effects. One of the important mechanisms of action of (BaP) is its free radical activity, the effect of which is the induction of oxidative stress in cells. BaP induces oxidative stress through the production of reactive oxygen species (ROS), disturbances of the activity of antioxidant enzymes, and the reduction of the level of non-enzymatic antioxidants as well as of cytokine production. Chemical compounds, such as vitamin E, curcumin, quercetin, catechin, cyanidin, kuromanin, berberine, resveratrol, baicalein, myricetin, catechin hydrate, hesperetin, rhaponticin, as well as taurine, atorvastatin, diallyl sulfide, and those contained in green and white tea, lower the oxidative stress induced by BaP. They regulate the expression of genes involved in oxidative stress and inflammation, and therefore can reduce the level of ROS. These substances remove ROS and reduce the level of lipid and protein peroxidation, reduce formation of adducts with DNA, increase the level of enzymatic and non-enzymatic antioxidants and reduce the level of pro-inflammatory cytokines. BaP can undergo chemical modification in the living cells, which results in more reactive metabolites formation. Some of protective substances have the ability to reduce BaP metabolism, and in particular reduce the induction of cytochrome (CYP P450), which reduces the formation of oxidative metabolites, and therefore decreases ROS production. The aim of this review is to discuss the oxidative properties of BaP, and describe protective activities of selected chemicals against BaP activity based on of the latest publications.

Interaction of polycyclic aromatic hydrocarbon exposure and high-fasting plasma glucose on lung function decline in coke oven workers: a cross-lagged panel analysis

Individuals with abnormal fasting plasma glucose (FPG) may be more susceptible to lung diseases associated with environmental pollutants. A cross-sectional survey of 629 workers in 2017 and a panel study of 304 workers from 2014 to 2019 were performed in China. The results showed that elevated total hydroxylated polycyclic aromatic hydrocarbon (ΣOH-PAH) concentration was associated with lower the percentage of predicted forced vital capacity (FVC%) among high-FPG workers (β for the cross-sectional analysis: -1.78%, 95%CI: -2.92%, -0.64%; β for the panel study: -1.10%, 95%CI: -2.19%, -0.02%). The absolute value of the cross-lagged path coefficient from FPG to FVC% (β₂ = -0.096) was significantly greater than that from FVC% to FPG (β₁ = 0.037). Our results suggest that FPG abnormalities may precede the lung function decline induced by PAH exposure and that high-FPG and high ΣOH-PAH levels have an interactive effect on lung function decline.

Attenuation of Polycyclic Aromatic Hydrocarbon (PAH)-Mediated Pulmonary DNA Adducts and Cytochrome P450 (CYP)1B1 by Dietary Antioxidants, Omega-3 Fatty Acids, in Mice

Numerous human and animal studies have reported positive correlation between carcinogen-DNA adduct levels and cancer occurrence. Therefore, attenuation of DNA adduct levels would be expected to suppress tumorigenesis. In this investigation, we report that the antioxidants omega 3-fatty acids, which are constituents of fish oil (FO), significantly decreased DNA adduct formation by polycyclic aromatic hydrocarbons (PAHs). B6C3F1 male mice were fed an FO or corn oil (CO) diet, or A/J male mice were pre-fed with omega-3 fatty acids eicosapentaenoic acid (EPA) and/or docosahexaenoic acid (DHA). While the B6C3F1 mice were administered two doses of a mixture of seven carcinogenic PAHs including benzo(a)pyrene (BP), the A/J mice were treated i.p. with pure benzo[a]pyrene (BP). Animals were euthanized after 1, 3, or 7 d after PAH treatment. DNA adduct levels were measured by the ³²P-postlabeling assay. Our results showed that DNA adduct levels in the lungs of mice 7 d after treatment were significantly decreased in the FO or EPA/DHA groups compared with the CO group. Interestingly, both qPCR and Western blot analyses revealed that FO, DHA and EPA/DHA significantly decreased the expression of cytochrome P450 (CYP) 1B1. CYP1B1 plays a critical role in the metabolic activation of BP to DNA-reactive metabolites. qPCR also showed that the expression of some metabolic and DNA repair genes was induced by BP and inhibited by FO or omega-3 fatty acids in liver, but not lung. Our results suggest that a combination of mechanism entailing CYP1B1 inhibition and the modulation of DNA repair genes contribute to the attenuation of PAH-mediated carcinogenesis by omega 3 fatty acids.

Characteristics and health risks of personal exposure to particle-bound PAHs for Hong Kong adult residents: From ambient pollution to indoor exposure

Research on individual level polycyclic aromatic hydrocarbons (PAHs) exposure is scarce. Moreover, the independent contribution of ambient- and indoor-origin PAHs to personal exposure remains poorly studied. We performed simultaneous ambient, residential indoor, and personal exposure measurements in a panel of healthy adults to investigate particle-bound PAHs, focusing on their carcinogenic congeners (cPAHs). Average PAH concentrations were much higher in ambient and residential indoor than personal exposure, with distinct seasonal variations. We employed chrysene as a tracer to investigate residential indoor and personal PAHs exposure by origin. Personal cPAH exposure was largely attributable to ambient-origin exposures (95.8%), whereas a considerable proportion of residential indoor PAHs was likely attributable to indoor emissions (33.8%). Benzo[a]pyrene equivalent (BaPeq) concentrations of cPAH accounted for 95.2%-95.6% of total carcinogenic potential. Uncertainties in estimated PAHs (and BaPeq) exposure and cancer risks for adults were calculated using the Monte Carlo simulation. Cancer risks attributable to ambient, residential indoor, and personal cPAH inhalation exposures ranged from 4.0 × 10^-6 to 1.0 × 10^-5 . A time-activity weighted model was employed for personal PAH exposure estimations. Estimated cPAH exposures demonstrate high cancer risks for adults in Hong Kong, suggesting that exposure to indoor-generated PAHs should be of great concern to the general population.

Influence of Benzo(a)pyrene on Different Epigenetic Processes

Epigenetic changes constitute one of the processes that is involved in the mechanisms of carcinogenicity. They include dysregulation of DNA methylation processes, disruption of post-translational patterns of histone modifications, and changes in the composition and/or organization of chromatin. Benzo(a)pyrene (BaP) influences DNA methylation and, depending on its concentrations, as well as the type of cell, tissue and organism it causes hypomethylation or hypermethylation. Moreover, the exposure to polyaromatic hydrocarbons (PAHs), including BaP in tobacco smoke results in an altered methylation status of the offsprings. Researches have indicated a potential relationship between toxicity of BaP and deregulation of the biotin homeostasis pathway that plays an important role in the process of carcinogenesis. Animal studies have shown that parental-induced BaP toxicity can be passed on to the F1 generation as studied on marine medaka (Oryzias melastigma), and the underlying mechanism is likely related to a disturbance in the circadian rhythm. In addition, ancestral exposure of fish to BaP may cause intergenerational osteotoxicity in non-exposed F3 offsprings. Epidemiological studies of lung cancer have indicated that exposure to BaP is associated with changes in methylation levels at 15 CpG; therefore, changes in DNA methylation may be considered as potential mediators of BaP-induced lung cancer. The mechanism of epigenetic changes induced by BaP are mainly due to the formation of CpG-BPDE adducts, between metabolite of BaP-BPDE and CpG, which leads to changes in the level of 5-methylcytosine. BaP also acts through inhibition of DNA methyltransferases activity, as well as by increasing histone deacetylases HDACs, i.e., HDAC2 and HDAC3 activity. The aim of this review is to discuss the mechanism of the epigenetic action of BaP on the basis of the latest publications.

PIG-A gene mutation as a genotoxicity biomaker in polycyclic aromatic hydrocarbon-exposed barbecue workers

Background

The PIG-A gene mutation assay is a valuable tool for measuring in vivo gene mutations in blood cells. The human PIG-A assay, used as a potential genotoxicity biomarker, is minimally invasive, sensitive, and cost-efficient; however, the relationship between carcinogen exposure and PIG-A mutations is not well understood.

Methods

We investigated the genotoxic effect of red blood cells using PIG-A assay and lymphocyte cytokinesis-block micronucleus test in barbecue restaurant workers (N = 70) exposed to polycyclic aromatic hydrocarbons (PAHs) and self-identified healthy control subjects (N = 56). Urinary PAH metabolites were measured to evaluate internal exposure levels.

Results

Multivariate Poisson regression showed that the PAH-exposed workers exhibited significantly higher PIG-A mutant frequency (MF) (8.04 ± 6.81 × 10^− 6) than did the controls (5.56 ± 5.26 × 10^− 6) (RR = 0.707, 95% CI: 0.615–0.812, P < 0.001). These results indicate that PAH exposure is a risk factor for elevated PIG-A MF. The frequencies of micronuclei (MN) and nuclear buds (NBUD) in the PAH-exposed workers (MN: 3.06 ± 2.07 ‰, NBUD: 1.38 ± 1.02 ‰) were also significantly higher than in the controls (MN: 1.46 ± 0.64 ‰, P < 0.001; NBUD: 0.70 ± 0.60 ‰, P < 0.001). Additionally, PIG-A MFs showed better associations with several urinary hydroxylated PAH metabolites (P_2-OH-Flu = 0.032, r_2-OH-Flu = 0. 268; P_2-OH-Phe = 0.022, r_2-OH-Phe = 0.286; P_3-OH-Phe = 0.0312, r_3-OH-Phe = 0.270; P_4-OH-Phe = 0.018, r_4-OH-Phe = 0.296), while the increase in MN, NPB, and NBUD frequencies was not associated with any OH-PAH metabolites; and high-PAH-exposed workers showed the highest PIG-A MFs. Furthermore, there was a significant association between PIG-A MF and PAH exposure levels (Chi-square test for trend, P = 0.006).

Conclusions

Our results indicate that an increase in PIG-A MF in barbecue workers could reflect the response to PAH exposure, providing evidence of its potential as a genotoxicity biomarker in human risk assessment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41021-021-00230-1.

Associations of polycyclic aromatic hydrocarbons exposure and its interaction with XRCC1 genetic polymorphism with lung cancer: A case-control study

Humans are extensively exposed to polycyclic aromatic hydrocarbons (PAHs) daily via multiple pathways. Epidemiological studies have demonstrated that occupational exposure to PAHs increases the risk of lung cancer, but related studies in the general population are limited. Hence, we conducted a case-control study among the Chinese general population to investigate the associations between PAHs exposure and lung cancer risk and analyze the modifications of genetic polymorphisms in DNA repair genes. In this study, we enrolled 122 lung cancer cases and 244 healthy controls in Wuhan, China. Urinary PAHs metabolites were determined by gas chromatography-mass spectrometry, and rs25487 in X-ray repair cross-complementation 1 (XRCC1) gene was genotyped by the Agena Bioscience MassARRAY System. Then, multivariable logistic regression models were performed to estimate the potential associations. We found that urinary hydroxynaphthalene (OH-Nap), hydroxyphenanthrene (OH-Phe) and the sum of hydroxy PAHs (∑OH-PAHs) levels were significantly higher in lung cancer cases than those in controls. After adjusting for gender, age, BMI, smoking status, smoking pack-years, drinking status and family history, urinary ∑OH-Nap and ∑OH-Phe levels were positively associated with lung cancer risk, with dose-response relationships. Compared with those in the lowest tertiles, individuals in the highest tertiles of ∑OH-Nap and ∑OH-Phe had a 2.13-fold (95% CI: 1.10, 4.09) and 2.45-fold (95% CI: 1.23, 4.87) increased risk of lung cancer, respectively. Effects of gender, age, smoking status and smoking pack-years on the associations of PAHs exposure with lung cancer risk were shown in the subgroup analysis. Furthermore, associations of urinary ∑OH-Nap and ∑OH-PAHs levels with lung cancer risk were modified by XRCC1 rs25487 (P_interaction ≤ 0.025), and were more pronounced in wild-types of rs25487. These findings suggest that environmental exposure to naphthalene and phenanthrene is associated with increased lung cancer risk, and polymorphism of XRCC1 rs25487 might modify the naphthalene exposure-related lung cancer effect.

Protective effects of piperlongumin in the prevention of inflammatory damage caused by pulmonary exposure to benzopyrene carcinogen

Benzopyrene is one of the main polycyclic aromatic hydrocarbons with carcinogenic capacity. Research has shown that anti-inflammatory drugs can reduce the incidence of lung cancer. In this scenario, we highlight piperlongumin (PL), an alkaloid from Piper longum with anti-inflammatory properties. Therefore, our aim was to study the effect of PL administration in a model of pulmonary carcinogenesis induced by benzopyrene in Balb/c mice. Animals were divided into 3 groups (n = 10/group): sham (10% DMSO), induced by benzopyrene (100 mg/kg, diluted in DMSO) without treatment (BaP) for 12 weeks and induced by benzopyrene and treated with PL (BaP/PL) (2 mg/kg in 10% DMSO) from the eighth week post-induction. Animals were weighed daily and pletsmography was performed in the 12th week. Genotoxicity and hemoglobin levels were analyzed in blood and quantification of leukocytes in bronchoalveolar lavage (BAL). Lungs were collected for histopathological evaluation, immunohistochemical studies of annexin A1 (AnxA1), cyclooxygenase 2 (COX-2), anti-apoptotic protein Bcl-2 and nuclear transcription factor (NF-kB) and also the measurement of interleukin cytokines (IL)-1β, IL-17 and tumor necrosis factor (TNF) -α. Treatment with PL reduced the pulmonary parameters (p < 0,001) of frequency, volume and pulmonary ventilation, decreased lymphocytes, monocytes and neutrophils in BAL (p < 0,05) as well as blood hemoglobin levels (p < 0,01). PL administration also reduced DNA damage and preserved the pulmonary architecture compared to the BaP group. Moreover, the anti-inflammatory effect of PL was evidenced by the maintenance of AnxA1 levels, reduction of COX-2 (p < 0,05), Bcl-2 (p < 0,01) and NF-kB (p < 0,001) expressions and decreased IL-1β, IL-17 (p < 0,01) and TNF-α (p < 0,05) levels. The results show the therapeutic potential of PL in the treatment of pulmonary anti-inflammatory and anti-tumor diseases with promising therapeutic implications.

Key Factors for Improving the Carcinogenic Risk Assessment of PAH Inhalation Exposure by Monte Carlo Simulation

Monte Carlo simulation (MCS) is a computational technique widely used in exposure and risk assessment. However, the result of traditional health risk assessment based on the MCS method has always been questioned due to the uncertainty introduced in parameter estimation and the difficulty in result validation. Herein, data from a large-scale investigation of individual polycyclic aromatic hydrocarbon (PAH) exposure was used to explore the key factors for improving the MCS method. Research participants were selected using a statistical sampling method in a typical PAH polluted city. Atmospheric PAH concentrations from 25 sampling sites in the area were detected by GC-MS and exposure parameters of participants were collected by field measurement. The incremental lifetime cancer risk (ILCR) of participants was calculated based on the measured data and considered to be the actual carcinogenic risk of the population. Predicted risks were evaluated by traditional assessment method based on MCS and three improved models including concentration-adjusted, age-stratified, and correlated-parameter-adjusted Monte Carlo methods. The goodness of fit of the models was evaluated quantitatively by comparing with the actual risk. The results showed that the average risk derived by traditional and age-stratified Monte Carlo simulation was 2.6 times higher, and the standard deviation was 3.7 times higher than the actual values. In contrast, the predicted risks of concentration- and correlated-parameter-adjusted models were in good agreement with the actual ILCR. The results of the comparison suggested that accurate simulation of exposure concentration and adjustment of correlated parameters could greatly improve the MCS. The research also reveals that the social factors related to exposure and potential relationship between variables are important issues affecting risk assessment, which require full consideration in assessment and further study in future research.

The relevance analysis of GSTP1 rs1695 and lung cancer in the Chinese Han population

BACKGROUND

This study explored the relevance between rs1695 and susceptibility to the lung cancer in the Chinese Han population. Stratification analysis was conducted on the basis of age, gender, smoking status, tumor-related family history, and pathological type to observe relations between rs1695 and susceptibility to lung cancer in the subgroups.

METHODS

A case-control study was performed with 974 lung cancer patients who were pathologically diagnosed and 1005 healthy cases based on physical examination to analyze the association between rs1695 and the risk of lung cancer.

RESULTS

The frequencies of the AA, GA, and GG genotypes of rs1695 were 68.4%, 28.7%, and 2.9% in cases and 64.8%, 30.8%, and 4.2% in controls, respectively. After adjustment for age, gender, smoking status, and family history, it appears that the rs1695 G allele decreases the risk of lung cancer (OR = 0.811, 95% CI 0.684-0.961, P = 0.016). Moreover, compared with the AA genotype, the GA + GG genotype decreased lung cancer susceptibility (OR = 0.808, 95% CI 0.663-0.985, P = 0.035) and the GG genotype (OR = 0.591, 95% CI 0.347-0.988, P = 0.048). In a stratified analysis, the risk of lung cancer in the G allele carriers decreased among the males, patients without a tumor-related family history, and patients with lung adenocarcinoma, especially in smokers.

CONCLUSION

The polymorphism of locus rs1695 is related to the risk of lung cancer and is expected to be a target for the prediction of lung cancer.

Polycyclic aromatic hydrocarbons, pesticides, and metals in olive: analysis and probabilistic risk assessment

In the present study, levels of 22 pesticides, eight metals, and 16 polycyclic aromatic hydrocarbons (PAHs) in 1800 Iranian olive samples (20 cultivars from six different cultivation zones), were determined; then, health risk posed by oral consumption of the olive samples to Iranian consumers was assessed. Quantification of PAHs and pesticides was done by chromatography-mass spectrometry (GC-MS), and metal levels were determined using inductively coupled plasma-optical emission spectrometry (ICP-OES). There were no significant differences among the cultivars and zones in terms of the levels of the tested compounds. Target hazard quotients (THQ) were <1.0 for all pesticides, and total hazard indices (HI) indicated di minimis risk. At the 25th or 95th centiles, Incremental Life Time Cancer Risks (ILCRs) for carcinogenic elements, arsenic, and lead and noncarcinogenic metals did not exhibit a significant hazard (HI <1.0 for both cases). At the 25th or 95th centiles, ILCR and margins of exposure (MoE) for PAHs indicated di minimis risk. Sensitivity analysis showed that concentrations of contaminants had the most significant effect on carcinogenic and noncarcinogenic risks.

A Review of the Impact of Selected Anthropogenic Chemicals from the Group of Endocrine Disruptors on Human Health

BACKGROUND

The aim of the study was to review data on the impact of anthropogenic chemicals (endocrine disruptors) on various diseases, which, consequently, may facilitate their prevention and be used as a tool for managing public healthcare. Every day, humans are exposed to chemicals, including xenoestrogens, which are similar to female hormones.

METHODS

This manuscript was prepared based on a meta-analysis of research on the impacts of selected EDCs on human health.

RESULTS

Special attention should be paid to bisphenol A (BPA), benzo-α-pyrene, and phthalates due to their proven endocrine activity and presence in our daily lives. Xenoestrogens are absorbed by human organisms through the digestive system since they can migrate to food from food packages and drinks as well as from plastic products used daily. The presence of these chemicals in human organisms is considered a potential cause for some diseases commonly referred to as 'diseases of civilization'.

CONCLUSIONS

The biomonitoring of xenoestrogens, which are chemicals with unfavorable impacts on human health, is a crucial tool for assessing the risk from the pollution of the environment. The novelty is a holistic approach to assessing the occurrence of risk factors for civilization diseases.

DNA methylation and hydroxymethylation associated with gene expression regulatory network during 3-methylcholanthrene induced lung cell malignant transformation

3-methylcholanthrene (3-MCA) is a typical representative PAH. It has strong toxicity and is a typical chemical carcinogen. However, the epigenetic mechanisms underlying 3-MCA-induced tumourigenesis are largely unknown. In this study, a model of the 3-MCA-induced malignant transformation of human bronchial epithelial (HBE) cells was established successfully. The profiles of gene expression and DNA methylation and hydroxymethylation were obtained and analysed with an Illumina HiSeq 4000. A total of 707 genes were found to be significantly up-regulated, and 686 genes were found to be significantly down-regulated. Compared to control cells, 8545 mRNA-associated differentially methylated regions and 15,121 mRNA-associated differentially hydroxymethylated regions in promoters were found to be significantly altered in transformed cells. By using mRNA expression and DNA methylation and hydroxymethylation interaction analysis, 99 differentially expressed genes were identified. Among them, CA9 and EGLN3 were verified to be significantly down-regulated, and CARD6 and LCP1 were shown to be significantly up-regulated, and these genes mainly participated in cell growth, migration and invasion, indicating that these genes were key genes involved in the 3-MCA-induced malignant transformation of HBE cells. Gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that a large number of differentially expressed genes (DEGs) were involved mainly in RNA polymerase II transcription factor activity, chemical carcinogenesis, base-excision repair (BER), cytokine-cytokine receptor interactions, glycerolipid metabolism, steroid hormone biosynthesis, cAMP signalling pathways and other signalling pathways. Our study suggested that characteristic gene alterations associated with DNA methylation and hydroxymethylation could play important roles in environmental 3-MCA-induced lung carcinogenesis.

Urinary biomarkers of polycyclic aromatic hydrocarbons and their associations with liver function in adolescents

Associations between polycyclic aromatic hydrocarbons (PAHs) and respiratory diseases have been widely studied, but the effects of PAH on liver toxicity in adolescents are unclear. Here, 3194 adolescents with NHANES data from 2003 to 2016 were selected. PAH exposure was assessed by measuring PAH metabolites in urine. The outcome variables were the levels of alanine aminotransferase (ALT), aspartate amino transferase (AST) and gamma-glutamyl transpeptidase (GGT). The association between PAH exposure and liver function was evaluated by the weighted quantile sum (WQS) and logistic regression, and the associations between PAHs and inflammation and blood lipids were evaluated by linear regression. Covariates were adjusted for age, ethnicity, BMI, physical activity, family income, cotinine, and urinary creatinine. The results showed that for females, mixed PAH exposure was related to an increased ALT level (OR = 2.33, 95% CI 1.15, 4.72), and 2-fluorene contributed the most (38.6%). Urinary 2-fluorene was positively associated with an elevated ALT level (OR = 2.19 95% 1.12, 4.27, p for trend = 0.004). Mechanistically, 2-fluorene can cause a 3.56% increase in the white blood cell count, a 6.99% increase in the triglyceride level, and 1.70% increase in the total cholesterol level. PAHs may have toxic effects, possibly mediated by inflammation and blood lipids, on the adolescent female liver. Additional confirmatory studies are needed.

Extreme Exposure Levels of PCDD/Fs Inhaled from Biomass Burning Activity for Cooking in Typical Rural Households

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), emitted during biomass combustion, are carcinogenic chemicals. The association between indoor biomass burning and PCDD/Fs inhalation exposure levels is still poorly understood. This study first reports direct measurement of personal exposure to PCDD/Fs in real-world households with wood combustion. In homes where biomass burning is used for cooking, toxic equivalent quantity (TEQ) PCDD/Fs concentrations were found to be 545 ± 251 fg I-TEQ/m³ in kitchens, with levels of 4.5-, 6.9-, and 13.3-fold higher than those in living rooms (122 ± 92 fg I-TEQ/m³), bedrooms (79 ± 27 fg I-TEQ/m³), and ambient air (41 ± 15 fg I-TEQ/m³), respectively. PCDD/Fs exposure levels in populations using biomass fuels for cooking (353 ± 110 fg I-TEQ/m³) were 4.3-fold higher than those in the control groups (82 ± 32 fg I-TEQ/m³). Additionally, the average cancer risks for biomass cooking person were approximately 3.1-fold higher than those in factory workers. Overall, residents of household that use biomass fuels for cooking have the highest known risk of PCDD/Fs exposure. These results highlight that aiming to mitigate the PCDD/Fs exposure risk in the general population, the focus of dioxin emission source control measures should shift from industrial sectors to residential biomass combustion.

A consensus approach for estimating health risk: Application to inhalation cancer risks

Conducting a risk assessment is challenging because various and contrasting risk indicators are available, which can lead to discrepancies and, sometimes, conflicting conclusions. Constructing and using a consensus risk indicator (CRI) could provide a reliable alternative that is consistent and supports direct comparisons. The goal of this study is to propose a structured and pragmatic approach for constructing a CRI distribution and demonstrate its feasibility and easy implementation when conducting risk assessments. A CRI distribution is constructed as a weighted combination of existing indicators where the weights are obtained by using the overlapping areas of an individual indicator's distribution and an aggregated reference distribution. The approach is illustrated through an assessment of human cancer risk following inhalation exposure. The CRI is constructed using eight risk indicators. The CRI distribution parameters for 199 human carcinogenic chemicals associated with inhalation exposure were determined and are presented in an interactive table. To aid the wider implementation of the CRI approach, a user-friendly and interactive web application, named InCaRisk, was created to facilitate the cancer risk estimation following inhalation exposure. Our approach could be useful for enhancing the quality of regulatory decisions and protecting human health from environmental pollutants; our approach can be applied for a given health outcome, route of exposure and exposure setting.

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

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

Analysis of urinary metabolites of polycyclic aromatic hydrocarbons in precarious workers of highly exposed occupational scenarios in Mexico

Exposure to polycyclic aromatic hydrocarbons (PAHs) is a risk factor for human health. Workers are a vulnerable group due to their high exposure and therefore require special attention to mitigation measurements; however, some groups of workers are especially vulnerable, precarious workers. The objective of this research was to evaluate mixtures of hydroxylated PAHs (OH-PAHs) in precarious workers in Mexico. The following activities were evaluated: (i) brickmakers (TER), stonemasons (ESC), indigenous workers (TOC) and mercury miners (CAM). Ten OH-PAHS were analyzed: 1-hydroxynaphtalene and 2-hydroxynaphtalene; 2-,3- and 9-hydroxyfluorene; 1-,2-,3- and 4-hydroxyphenanthrene; and 1-hydroxypyrene in urine by GC-MS, chemical fingerprints of the sites were established by multivariate analysis. One hundred forty-nine precarious workers participated in the study. The populations presented total OH-PAHs concentrations of 9.20 (6.65-97.57), 14.8 (9.32-18.85), 15.7 (6.92-195.0), and 101.2 (8.02-134.4) μg/L for CAM, ESC, TER, and TOC, respectively (median (IQR)). The results of the multivariate analysis indicate that the indigenous population presented a different fingerprint compared to the three scenarios. The chemical fingerprints among the brickmakers and mercury mining population were similar. The results of the concentrations were similar and in some metabolites higher than workers in occupations classified as carcinogenic by the IARC; therefore, the control of exposure in these occupations acquires great importance and surveillance through biological monitoring of OH-PAHs should be applied to better estimate exposure in these working populations.

Exposure to Atmospheric Particulate Matter-Bound Polycyclic Aromatic Hydrocarbons and Their Health Effects: A Review

Particulate matter (PM) is a major factor contributing to air quality deterioration that enters the atmosphere as a consequence of various natural and anthropogenic activities. In PM, polycyclic aromatic hydrocarbons (PAHs) represent a class of organic chemicals with at least two aromatic rings that are mainly directly emitted via the incomplete combustion of various organic materials. Numerous toxicological and epidemiological studies have proven adverse links between exposure to particulate matter-bound (PM-bound) PAHs and human health due to their carcinogenicity and mutagenicity. Among human exposure routes, inhalation is the main pathway regarding PM-bound PAHs in the atmosphere. Moreover, the concentrations of PM-bound PAHs differ among people, microenvironments and areas. Hence, understanding the behaviour of PM-bound PAHs in the atmosphere is crucial. However, because current techniques hardly monitor PAHs in real-time, timely feedback on PAHs including the characteristics of their concentration and composition, is not obtained via real-time analysis methods. Therefore, in this review, we summarize personal exposure, and indoor and outdoor PM-bound PAH concentrations for different participants, spaces, and cities worldwide in recent years. The main aims are to clarify the characteristics of PM-bound PAHs under different exposure conditions, in addition to the health effects and assessment methods of PAHs.