Comparative genotoxic potential of 27 polycyclic aromatic hydrocarbons in three human cell lines

Nationwide monitoring of freely dissolved polycyclic aromatic hydrocarbons (PAHs) using high speed rotation-type passive sampling device in Korean coastal waters

Measuring the concentration of PAHs in the freely dissolved phase is crucial for assessing ecological impacts in the marine environment. However, various environmental conditions make short-term monitoring challenging. This study used an optimized High Speed Rotation-Type Passive Sampling Device (HSR-PSD) equipped with linear low-density polyethylene (LLDPE) to conduct the first nationwide monitoring of freely dissolved PAHs in Korean coastal waters. The HSR-PSD enabled faster short-term monitoring by measuring Cfree of PAHs within 12 h and was less affected by environmental conditions compared to conventional PSDs. Σ15PAH concentrations ranged from 2.8 to 9.4 ng/L, with significantly higher levels on the western coast. Anthropogenic activities and oceanic conditions affected Cfree distribution in coastal areas. Based on Cfree, the estimated PAH levels in bivalves and fish were aligned with reported tissue concentrations, exhibiting low ecological risk to aquatic organisms. Therefore, the HSR-PSD with LLDPE is a suitable tool for nationwide short-term monitoring.

Toxicity evaluation of water-accommodated fraction of heavy and light oils on the rainbow trout fish cell line RTL-W1

Fish are currently used models for the toxicity assessment of chemicals, including polycyclic aromatic hydrocarbons (PAHs). Alternative methods including fish cell lines are currently used to provide fast and reliable results on the toxic properties of chemicals while respecting ethical concerns about animal testing. The Rainbow trout liver cell line RTLW1 was used to analyze the effects of two water-accommodated fractions from two crude oils: Arabian Light crude oil (LO) and refined oil from Erika (HO). Several toxicity endpoints were assessed in this study, including cytotoxicity, EROD activity, DNA damage (comet and micronucleus assays), and ROS production. RTL-W1 cells were exposed for 24 h at two or three dilutions of WAF at 1000 µg/L (0.1% (1 μg/L), 1% (10 μg/L), and 10% (100 μg/L)) for cytotoxicity and EROD activity and 1% and 10% for ROS production and genotoxicity). Exposure of RTL-W1 cells to LO WAF induced a significant increase of EROD activity and ROS production and altered DNA integrity as revealed by both the comet assay and the micronucleus test for 10 µg/L of LO. On the other hand, HO WAF exhibited limited toxic effects except for an EROD induction for 1% WAF dilution. These results confirmed the usefulness of RTL-W1 cells for in vitro toxicological assessment of chemical mixtures.

Polycyclic Aromatic Hydrocarbons (PAHs) in Grilled Marshmallows

The aim of this study was to assess potential health risks among children and adolescents consuming various grilled marshmallows using a survey and to determine polycyclic aromatic hydrocarbons (PAHs) in these food products. PAH analysis in grilled marshmallows included a dilution stage with deionized water and liquid-liquid extraction with cyclohexane and solid-phase extraction (SPE). PAH fractions were initially analyzed via high-performance thin-layer chromatography, and PAH concentrations were determined via gas chromatography with a tandem mass detector using the selective reaction monitoring (SRM) mode. This study on the consumption of grilled marshmallows was conducted among approximately 300 children and adolescents. The preliminary results indicated that "raw" marshmallows did not contain PAHs. However, the obtained data suggested the exposure of young people to carcinogenic PAHs from grilled marshmallows (63.5% of them consumed marshmallows). Carcinogenic benzo(a)pyrene (BaP) was determined in all samples. The profile of PAH concentrations in the extracts isolated from various grilled types of marshmallows was similar (r2 > 0.8000), regardless of the grilling method. Compared to the white sugar confection, higher concentrations of PAHs were determined in multicolored marshmallows. The lack of social awareness about exposure to carcinogenic substances is alarming.

Global review, meta-analysis and health risk assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in chicken kebab using Monte Carlo simulation method

The primary concern with Polycyclic Aromatic Hydrocarbons (PAHs) is their harmful effects on health, including the risk of causing cancer. This study aimed to investigate the occurrence and concentration of 16 priority PAHs (PAH16) in chicken kebabs using a systematic review approach with meta-analysis. Additionally, the study estimated the possible risk assessment of the potential carcinogenic and non-carcinogenic effects of PAHs on consumers of chicken kebabs using the Monte Carlo simulation (MCS) method. The researchers collected data on the concentration of PAHs in chicken kebabs (grilled, smoked, roasted, or barbecued) from 99 original articles searched in the Web of Science, PubMed, Scopus, Science Direct, and Google Scholar databases from 2012 to April 2022. The concentration of PAHs was then analyzed using meta-analysis, and the Monte Carlo simulation (MCS) was used to evaluate the associated human health risks. The analysis showed that 68.6%, 21.1%, 7.1%, and 3.2% of chicken kebabs were prepared by grilling, smoking, barbecuing, and roasting, respectively. The meta-analysis and health risk assessment indicated that the mean values of HQ (hazard quotient) in Bap, Ace, Acy, Pyr, Flt, Flr, Nap, and Ant PAHs were 1.64, 1.38 × 10^-2, 1.10 × 10^-1, 1.09 × 10^-1, 2.55 × 10^-2, 1.60 × 10^-1, 8.13 × 10^-1, and 6.20 × 10^-3, respectively. Additionally, the mean values of LTCR (Incremental Lifetime Cancer Risk) in Bap, Ace, Acy, Pyr, Flt, Flr, Nap, and Ant were 4.85 × 10^-10, 8.06 × 10^-13, 6.65 × 10^-12, 3.23 × 10^-12, 1.01 × 10^-12, 6.38 × 10^-12, 1.62 × 10^-11, and 6.20 × 10^-3, respectively. The consumption of chicken kebabs prepared by barbecuing was found to be associated with an increased risk of cancer due to the formation of carcinogenic compounds, including benzo[a]pyrene (BaP). However, the non-cancer risk ratio of consuming grilled chicken other than BaP was found to be less than 1 (HQ < 1), indicating that there is no risk of carcinogenesis caused by PAHs from the consumption of chicken kebabs worldwide. The calculated values of the LTCR caused by PAHs in the consumption of chicken kebab throughout life were compared to the maximum acceptable risk value suggested by the EPA, which in the strictest case equals one cancer case per 10,000 people. The results indicate that there is no risk of carcinogenesis caused by PAHs due to the consumption of chicken kebab worldwide.

Characterization of airborne particulate matter and its toxic and proarrhythmic effects: A case study in Aburrá Valley, Colombia

Particle matter (PM) is a complex mixture of particles suspended in the air, mainly caused by fuel combustion from vehicles and industry, and has been related to pulmonary and cardiovascular diseases. The Metropolitan Area of Aburrá Valley in Colombia is the second most populous urban agglomeration in the country and the third densest in the world, composed of ten municipalities. Examining the physicochemical properties of PM is crucial in comprehending its composition and its effects on human health, as it varies based on the socioeconomic dynamics specific to each city. This study characterized the PM collected from the north, south, and central zones to evaluate its chemical composition and morphology. Different elements such as silicon, carbon, aluminum, potassium, calcium, sodium, iron, magnesium, and copper and the presence of unburned fuel, motor oil, and silicon fibers were identified. In vitro and in silico studies were conducted to evaluate the toxicity of the PM, and it was found that the PM collected from the central zone had the greatest impact on cell viability and caused DNA damage. The in silico study demonstrated that PM has concentration-dependent proarrhythmic effects, reflected in an action potential duration shortening and an increased number of reentries, which may contribute to the development of cardiac arrhythmias. Overall, the results suggest that the size and chemical composition of ambient PM can induce toxicity and play an important role in the generation of arrhythmias.

The influence of the co-exposure to polycyclic aromatic hydrocarbons and toxic metals on DNA damage in brazilian lactating women and their infants: A cross-sectional study using machine learning approaches

Polycyclic aromatic hydrocarbons (PAHs) and toxic metals are widely spread pollutants of public health concern. The co-contamination of these chemicals in the environment is frequent, but relatively little is known about their combined toxicities. In this context, this study aimed to evaluate the influence of the co-exposure to PAHs and toxic metals on DNA damage in Brazilian lactating women and their infants using machine learning approaches. Data were collected from an observational, cross-sectional study with 96 lactating women and 96 infants living in two cities. The exposure to these pollutants was estimated by determining urinary levels of seven mono-hydroxylated PAH metabolites and the free form of three toxic metals. 8-Hydroxydeoxyguanosine (8-OHdG) levels in the urine were used as the oxidative stress biomarker and set as the outcome. Individual sociodemographic factors were also collected using questionnaires. Sixteen machine learning algorithms were trained using 10-fold cross-validation to investigate the associations of urinary OH-PAHs and metals with 8-OHdG levels. This approach was also compared with models attained by multiple linear regression. The results showed that the urinary concentration of OH-PAHs was highly correlated between the mothers and their infants. Multiple linear regression did not show a statistically significant association between the contaminants and urinary 8OHdG levels. Machine learning models indicated that all investigated variables did not present predictive performance on 8-OHdG concentrations. In conclusion, PAHs and toxic metals were not associated with 8-OHdG levels in Brazilian lactating women and their infants. These novelty and originality results were achieved even after applying sophisticated statistical models to capture non-linear relationships. However, these findings should be interpreted cautiously because the exposure to the studied contaminants was considerably low, which may not reflect other populations at risk.

In Vitro Genotoxicity Evaluation of PAHs in Mixtures Using Experimental Design

Settled dusts are sinks for environmental pollutants, including Polycyclic Aromatic Hydrocarbons (PAHs) that are ubiquitous, persistent, and carcinogenic. To assess their toxicity in mixtures, Toxic Equivalent Factors (TEFs) are routinely used and based on the hypothesis of additive effects, although PAH interactions may occur and remain an open issue. This study investigated genotoxic binary interaction effects for six PAHs in mixtures using two in vitro assays and estimated Genotoxic Equivalent Factors (GEFs) to roughly predict the genotoxicity of PAH in mixtures. The Design of the Experiment approach was used with the micronucleus assay for cytostasis and micronuclei frequency and the alkaline comet assay for DNA damage. GEFs were determined for each PAH independently and in a mixture. For the cytostasis endpoint, no PAHs interaction was noted. BbF and BaP had a synergistic effect on DNA damage. All the PAH interacted between them regarding chromosomal damage. Although the calculated GEFs were similar to the TEFs, the latter may underestimate the genotoxic potential of a PAH mixture. GEFs calculated for PAH alone were lower than GEFs for PAHs in mixtures; thus, mixtures induce greater DNA/chromosomal damage than expected. This research helps to advance the challenging issue of contaminant mixtures' effects on human health.

Potential Toxicity Risk Assessment and Priority Control Strategy for PAHs Metabolism and Transformation Behaviors in the Environment

In this study, 16 PAHs were selected as the priority control pollutants to summarize their environmental metabolism and transformation processes, including photolysis, plant degradation, bacterial degradation, fungal degradation, microalgae degradation, and human metabolic transformation. Meanwhile, a total of 473 PAHs by-products generated during their transformation and degradation in different environmental media were considered. Then, a comprehensive system was established for evaluating the PAHs by-products' neurotoxicity, immunotoxicity, phytotoxicity, developmental toxicity, genotoxicity, carcinogenicity, and endocrine-disrupting effect through molecular docking, molecular dynamics simulation, 3D-QSAR model, TOPKAT method, and VEGA platform. Finally, the potential environmental risk (phytotoxicity) and human health risks (neurotoxicity, immunotoxicity, genotoxicity, carcinogenicity, developmental toxicity, and endocrine-disrupting toxicity) during PAHs metabolism and transformation were comprehensively evaluated. Among the 473 PAH's metabolized and transformed products, all PAHs by-products excluding ACY, CHR, and DahA had higher neurotoxicity, 152 PAHs by-products had higher immunotoxicity, and 222 PAHs by-products had higher phytotoxicity than their precursors during biological metabolism and environmental transformation. Based on the TOPKAT model, 152 PAH by-products possessed potential developmental toxicity, and 138 PAH by-products had higher genotoxicity than their precursors. VEGA predicted that 247 kinds of PAH derivatives had carcinogenic activity, and only the natural transformation products of ACY did not have carcinogenicity. In addition to ACY, 15 PAHs produced 123 endocrine-disrupting substances during metabolism and transformation. Finally, the potential environmental and human health risks of PAHs metabolism and transformation products were evaluated using metabolic and transformation pathway probability and degree of toxic risk as indicators. Accordingly, the priority control strategy for PAHs was constructed based on the risk entropy method by screening the priority control pathways. This paper assesses the potential human health and environmental risks of PAHs in different environmental media with the help of models and toxicological modules for the toxicity prediction of PAHs by-products, and thus designs a risk priority control evaluation system for PAHs.

Behavioral, histopathological, genetic, and organism-wide responses to phenanthrene-induced oxidative stress in Eisenia fetida earthworms in natural soil microcosms

Phenanthrene (PHE) contamination not only changes the quality of soil environment but also threatens to the soil organisms. There is lack of focus on the eco-toxicity potential of this contaminant in real soil in the current investigation. Here, we assessed the toxic effects of PHE on earthworms (Eisenia fetida) in natural soil matrix. PHE exhibited a relatively high toxicity to E. fetida in natural soil, with the LC₅₀ determined to be 56.68 mg kg^-1 after a 14-day exposure. Excessive ROS induced by PHE, leading to oxidative damage to biomacromolecules in E. fetida, including lipid peroxidation, protein carbonylation, and DNA damage. The antioxidant defense system (total antioxidant capacity, glutathione S-transferase, peroxidase, catalase, carboxylesterase, and superoxide dismutase) in E. fetida responded quickly to scavenge excess ROS and free radicals. Exposure to PHE resulted in earthworm avoidance responses (2.5 mg kg^-1) and habitat function loss (10 mg kg^-1). Histological observations indicated that the intestine, body wall, and seminal vesicle in E. fetida were severely damaged after exposure to high-dose PHE. Moreover, earthworm growth (weight change) and reproduction (cocoon production and the number of juvenile) were also inhibited after exposure to this pollutant. Furthermore, the integrated toxicity of PHE toward E. fetida at different doses and exposure times was assessed by the integrated biomarker response (IBR), which confirmed that PHE is more toxic to earthworms in the high-dose and long-term exposure groups. Our results showed that PHE exposure induced oxidative stress, disturbed antioxidant defense system, and caused oxidative damage in E. fetida. These effects can trigger behavior changes and damage histological structure, finally cause growth inhibition, genotoxicity, and reproductive toxicity in earthworms. The strength of this study is the comprehensive toxicity evaluation of PHE to earthworms and highlights the need to investigate the eco-toxicity potential of exogenous environmental pollutants in a real soil environment.

Transcriptomics and metabolomics analyses provide insights into the difference in toxicity of benzo[a]pyrene and 6-chlorobenzo[a]pyrene to human hepatic cells

The toxicological information of chlorinated polycyclic aromatic hydrocarbons (Cl-PAHs), as derivatives of PAHs, is still relatively lacking. In this study, a combination of transcriptomics and metabolomics approach was adopted to explore the changes in toxicity to human L02 hepatocytes after chlorination of benzo[a]pyrene (B[a]P) at 6 position. In general, 6-Cl-B[a]P produced a stronger toxicity to human hepatic cells than did parent B[a]P. When exposure concentrations were 5 and 50 nM, 6-Cl-B[a]P caused a weaker transcriptomic perturbation relative to B[a]P, whereas a stronger metabolomic perturbation, a stronger oxidative stress and a stronger inhibition effect on cell viability were caused by 6-Cl-B[a]P than did parent B[a]P. Pathway enrichment analysis indicated that 6-Cl-B[a]P produced a more widely perturbation to metabolic pathways than did B[a]P. Although they both significantly impaired the function of mitochondrial electron transport chain (ETC), the exact mechanism is different. B[a]P suppressed the expression of 20 genes regulating mitochondrial ETC mainly via AhR activation. However, 6-Cl-B[a]P produced a stronger inhibition on the activities of complexes I and V than did B[a]P. Meanwhile, 6-Cl-B[a]P also exhibited a stronger inhibition effect on mitochondrial β oxidation of fatty acid. Furthermore, 6-Cl-B[a]P and B[a]P both significantly disturbed the nucleotide metabolism, glycerophospholipid metabolism and amino acid metabolism in L02 cells.

Urinary Polycyclic Aromatic Hydrocarbon Metabolites Are Associated with Biomarkers of Chronic Endocrine Stress, Oxidative Stress, and Inflammation in Adolescents: FLEHS-4 (2016-2020)

Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants of public health concern. Multiple biological mechanisms have been hypothesized to contribute to PAHs-associated adverse health effects. Little is known about the impact of PAHs on endocrine stress and inflammation in adolescence. We examined 393 Flemish adolescents (14-15 years) cross-sectionally, measured urinary concentrations of hydroxylated naphthalene, fluorene, phenanthrene and pyrene metabolites, and calculated the sum of all measured metabolites. We determined hair cortisol concentration (HCC) as endocrine stress biomarker, leucocyte counts and neutrophil-lymphocyte ratio (NLR) in peripheral blood as inflammatory biomarkers, and urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) concentration as oxidative stress biomarker. Exposure-response associations were analyzed by multiple regression, adjusted for a priori selected covariates. A doubling of 1-hydroxypyrene concentration was associated with a factor of 1.13 (95% CI: 1.03, 1.24) increase in HCC and a factor of 1.07 (95% CI: 1.02, 1.13) increase in 8-oxodG. Doublings of 2- and 3-hydroxyphenanthrene concentrations were associated with a factor of 1.08 (95% CI: 1.02, 1.14) and 1.06 (95% CI: 1.00, 1.12) increase in 8-oxodG, respectively. Doubling of 2-hydroxyphenanthrene and of the sum of 2- and 3-hydroxyfluorene was associated with, respectively, a factor of 1.08 (95% CI: 1.02, 1.14) and 1.06 (95% CI: 1.01, 1.13) increase in NLR. Our results indicate the glucocorticoid pathway as a potential target for PAH exposure in adolescents and suggest oxidative stress, endocrine stress, and inflammation in adolescence as underlying mechanisms and early markers for PAH-related adverse health effects.

Anaerobic-petroleum degrading bacteria: Diversity and biotechnological applications for improving coastal soil

Due to the industrial emissions and accidental spills, the critical material for modern industrial society petroleum pollution causes severe ecological damage. The prosperous oil exploitation and transportation causes the recalcitrant, hazardous, and carcinogenic sludge widespread in the coastal wetlands. The costly physicochemical-based remediation remains the secondary and inadequate treatment for the derivatives along with the tailings. Anaerobic microbial petroleum degrading biotechnology has received extensive attention for its cost acceptable, eco-friendly, and fewer health hazards. As a result of the advances in biotechnology and microbiology, the anaerobic oil-degrading bacteria have been well developing to achieve the same remediation effects with lower operating costs. This review summarizes the advantages and potential scenarios of the anaerobic degrading bacteria, such as sulfate-reducing bacteria, denitrifying bacteria, and metal-reducing bacteria in the coastal area decomposing the alkanes, alkenes, aromatic hydrocarbons, polycyclic aromatic, and related derivatives. In the future, a complete theoretical basis of microbiological biotechnology, molecular biology, and electrochemistry is necessary to make efficient and environmental-friendly use of anaerobic degradation bacteria to mineralize oil sludge organic wastes.

PAH7 concentration reflects anthropization: A study using environmental biomonitoring with honeybees

Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants, mainly due to anthropogenic emission. In this study, we used honeybees as bioindicators of PAHs pollution in 36 industrial sites distributed in 14 French departments, covering more than 950 km² area of biomonitoring. Honeybees were sampled three times a year (spring, summer and autumn), during a period covering 2016 to 2019. Cluster and Principal Component Analysis allowed to classify sites in semi-natural, agricultural and urban lands according to their land use. We found that the higher the level of anthropization, the higher the concentration of PAH7 (PAH7: Benzo[a]Pyrene, Benzo[a]Anthracene, Benzo[b]Fluoranthene, Benzo[j]Fluoranthene, Benzo[k]Fluoranthene, Indeno[1,2,3-c,d]Pyrene and Dibenz[ah]Anthracene). We have found that 5 out of 20 compounds analyzed are significantly impacted by the landscape context (BjF, BaA, Chr, BbF and CPP). We observed significantly more 3-ringed PAHs in the autumnal samples than in the summer ones, but there was no seasonal effect on the PAH7 concentration. Moreover, diagnostic ratios show that high temperature processes are the main origin of PAHs, even in semi-natural environments.