Search Results (174)

Introduction: The temperature of rivers in the Iberian Peninsula has increased due to global warming. In addition, these rivers are polluted by contaminants of emerging concern, such as polycyclic aromatic hydrocarbons (PAHs). Higher temperatures and pollution concurrently impose threats to the Iberian Peninsula’s endemic species, including the brown trout (Salmo trutta), a cold-water species widely used in ecotoxicological studies. Because the liver is the main biotransformation organ, and is particularly sensitive to both chemical and temperature changes, in vitro liver models may represent valuable alternatives for assessing combined stressor effects, complying with the 3Rs principle. Objective: In line with the above, the present study aimed to evaluate the combined effects of a 4 °C temperature increase and the model PAH benzo[k]fluoranthene (B[k]F) on fish liver cells using a primary brown trout hepatocyte culture as a model. Methodology: Primary hepatocytes were seeded in 6-well plates at a density of 1.0 × 10⁶ cells/mL and exposed for 48 h to 1, 10, and 20 µM B[k]F at 18 °C (normothermia) and 22 °C (warming scenario). Cell viability was assessed using trypan blue, alamarBlue, and lactate dehydrogenase (LDH) assays. Cytochrome P450 (CYP)1A was evaluated in terms of its gene expression by RT-qPCR and its protein expression through immunocytochemistry (ICC). The immunostaining was quantified using a score system which considered five intensity staining levels. Results: Exposure to B[k]F and to the higher temperature increased LDH leakage without interaction effects. In contrast, the other viability assays did not show significant differences across conditions. Regarding CYP1A, both gene and protein expression increased with all B[k]F concentrations in relation to the controls, but were not influenced by temperature. Notably, the lowest B[k]F concentration (1 µM) elicited the highest CYP1A gene expression, suggesting a non-monotonic response. Conclusions: Overall, the model was responsive to both temperature (4 °C) increase and to B[k]F, validating its usefulness for assessing liver pollutant effects in the context of global warming. These findings support the application of fish primary hepatocyte models as relevant tools in ecotoxicology under environmentally realistic multi-stressor scenarios. Full article

Background: Oil spills have dramatically increased, causing significant damage and pollution to marine ecosystems. The entry of petroleum hydrocarbons into the ocean may lead to the occurrence of harmful algal blooms (HABs). The amino acid changes in harmful algae after oil spills remain unclear. Methods: In order to study the effect of oil spills on the amino acid mechanism of typical causative species, the composition and relative abundance of amino acids in Heterosigma akashiwo were investigated under different water accommodated fractions (WAFs) of 180# fuel oil. Results: Random forest prediction of polycyclic aromatic hydrocarbon toxicity to microalgae identified pyrene, benzo[k]fluoranthene, and fluoranthene as significant contributors. A total of 16 species of amino acids were detected in Heterosigma akashiwo, among which alanine, proline, aspartic acid, cysteine, lysine, and histidine were the predominant ones. As the concentration of the WAF increased, alanine abundance decreased significantly, indicating that the WAF disrupted the metabolic balance of alanine, with the degree of interference being positively correlated with exposure concentration. With the increase in culture time, the abundance of cysteine increased at 1%, 3%, and 5% WAFs, whereas the cysteine increased and then decreased at 7% and 10% WAFs. The abundance of aspartic acid and lysine showed no obvious pattern with culture time under WAF stress. Significant increases in the abundance of proline and histidine were observed in the WAF treatments. Conclusions: This study investigated the impact of oil spill pressure on the amino acid content of harmful algae, providing a scientific basis for understanding the potential impact of oil spills on the occurrence of HABs. Full article

The Kupa River (Croatia), a tributary of the Danube basin forming part of the Slovenian border, was heavily contaminated with polychlorinated biphenyls (PCBs) between 1962 and 1985 due to improper handling and downstream transport via the Krupa and Lahinja rivers. This study evaluated the occurrence, interspecific distribution, and human health implications of PCBs and polycyclic aromatic hydrocarbons (PAHs) in fish (Northern pike, Common carp, Grass carp, Pike-perch, Wels catfish, Bream, and Chub) from the Croatian Kupa River. PCB concentrations were consistently higher than PAH levels across all species. In 30% of samples, Σ6 non-dioxin-like PCBs exceeded the European Commission maximum permissible level for freshwater fish (125 ng⋅g⁻¹ wet weight). Of the 11 PAHs analyzed, only fluoranthene and pyrene were detected. Self-Organizing Map identified distinct pollutant patterns, with chub showing the highest variability and accumulation. PCB concentrations position the Kupa River among moderately to highly impacted European freshwater systems affected by legacy industrial contamination. Health risk assessment, incorporating updated national consumption data, indicates that long-term, uncontrolled consumption of Kupa River fish may pose risks due to PCB exposure, while PAH-related risks appear negligible. These findings highlight the persistence of legacy PCB pollution and the need for integrated sediment–biota monitoring. Full article

This study investigated the characteristics and interrelationships of polycyclic aromatic hydrocarbons (PAHs), phthalate esters (PAEs), and microbial communities in coastal river sediments and benthic mollusks collected from an e-waste recycling area in Taizhou, Zhejiang Province. In sediments, 16 PAHs and six PAEs were detected, with concentrations ranging from 2.66 to 379.99 μg/kg and 76.5 to 3426.57 μg/kg, respectively. Four-ring PAHs (particularly fluoranthene and pyrene) and Bis(2-ethylhexyl) phthalate (DEHP) were dominant, with DEHP posing a potential risk, especially at site 10, warranting further attention. In contrast, only eight PAHs and four PAEs were detected in mollusks, with concentrations of 60.14–523.10 μg/kg and 144.55–3005.71 μg/kg, respectively. Two-ring PAHs (particularly naphthalene) and Dibutyl phthalate (DBP) were dominant, likely derived directly from the overlying water. The PAHs in sediments primarily originated from fossil fuel combustion, biomass burning, and coal combustion, while PAEs were likely derived from the release of plastic waste from solid waste recycling. Lower concentrations and fewer PAH and PAE species were observed in the sediments near the ocean and at greater distances from the e-waste recycling sites. Significant differences were observed in microbial communities between sediment and mollusk samples. Dominant phyla shared by both sample types include proteobacteria, bacteroidetes, firmicutes, and acidobacteria. The concentration of low-ring PAHs was correlated with the microbial communities, particularly in mollusk samples. Relationships were also identified between microbial communities and DEHP concentrations in sediments or DBP concentrations in mollusks. Full article

This investigation was conducted in order to gain a first knowledge of concentrations, distribution patterns, and potential sources of 16 US EPA priority polycyclic aromatic hydrocarbons (PAHs) and organic molecular tracer compounds in deposition dust samples collected in the Valparaiso region, Chile. Dust was sampled in schools (indoor and outdoor) that are located in Puchuncaví and Quintero. Source apportionment analysis using the concentrations of PAHs; glucose, mannitol, sucrose, fructose; di-2-ethylhexyl phthalate; hopanes, and levoglucosan as molecular tracer compounds showed three sources of contribution. The first (46.38%) was related to incomplete combustion processes (Acy, Flu, Ant, Flt, Pyr, and BaA), a second source (20%) represented soil+ biomass burning (levoglucosan, α glucose, β glucose, mannitol, sucrose, and fructose), and a third source (10.26%) was dominated only by 27_norhopane, 27_hopane, which are related to traffic. To assess potential health risks for schoolchildren, the study calculated the benzo[a]pyrene equivalent (BaPE) toxicity and the incremental lifetime cancer risk (ILCR). Toxicity equivalent (TEQ) results showed that the main contributor to overall toxicity in PAHs, especially in schools located in Puchuncaví, was benzo[a]pyrene (BaP), followed by benzo[α]anthracene (BaA), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), indeno[1,2,3-cd] pyrene (IcdP), and dibenzo[a,h]anthracene (DahA). According to the calculated ILCR values, the highest cancer risk was associated with dust ingestion (both indoor and outdoor) for ∑16PAHs, ranging from 1.14 × 10⁻³ to 8.88 × 10⁻⁴. This was followed by dermal contact (1.27 × 10⁻⁵ to 7.27 × 10⁻⁷) and inhalation (1.22 × 10⁻⁸ to 9.99 × 10⁻⁹). Full article

The European Air Quality Directive defines benzo(a)pyrene as the chemical index for polycyclic aromatic hydrocarbon (PAH) carcinogenicity and sets a limit for its concentration in PM₁₀ to address the exposure risk associated with the class. It also mandates monitoring six additional PAHs at a limited number of selected sites to assess the benzo(a)pyrene’s contribution to the class in ambient air. For this aim, as part of the “Reti Speciali” project, benzo(a)pyrene and seven other PAHs were measured at 10 urban sites across Italy in 2016–2019, and the spatial and temporal pattern of these compounds were analyzed to evaluate benzo(a)pyrene’s effectiveness in representing the carcinogenicity of the entire PAH class. Results showed that in Italy, benzo(a)pyrene accounted for 61% ± 4.4% of total carcinogenicity when benzo(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, dibenzo(a-h)anthracene, and indenopyrene were considered, and about 1% less when chrysene and benzo(ghi)perylene were also added. This value varies by site (from 51% ± 11% in Taranto to 66% ± 7.5% in Cosenza) and decreases in summer due to benzo(a)pyrene’s strong photochemical degradation. In Europe, this percentage is generally similar or lower. For instance, in the United Kingdom, across 24 urban sites, it averages 56% ± 2.9%. These findings suggest that benzo(a)pyrene does not represent the overall carcinogenicity of PAHs nor a constant percentage, highlighting the need to further investigate the use of benzo(a)pyrene as the sole marker of PAH toxicity. Full article

Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental pollutants that can exert significant effects on living organisms. This study investigated the effects of fluoranthene, a representative PAH, on the activities of alkaline and acid phosphatases in the midgut, and on total lipid and trehalose concentrations in the hemolymph, of larvae of the forest insect species Lymantria dispar and Euproctis chrysorrhoea (Lepidoptera: Erebidae). The results revealed species-specific differences in midgut phosphatase responses to dietary fluoranthene exposure. In L. dispar larvae, the activity of non-lysosomal acid phosphatase decreased at the higher fluoranthene concentration. In contrast, the activities of total acid and lysosomal acid phosphatases increased in E. chrysorrhoea larvae exposed to the lower fluoranthene concentration, consistent with a defensive role. Zymogram analyses revealed different patterns of midgut phosphatase isoform expression in the two species. While lipid concentrations in the hemolymph were unaffected, a significant decrease in trehalose concentration was observed in L. dispar larvae exposed to the lower fluoranthene concentration. Furthermore, fluoranthene exposure resulted in reduced larval mass in both species, indicating the allocation of resources toward defense. These responses specify the significance of relationships between physiological changes and mass reduction in L. dispar and E. chrysorrhoea larvae affected by pollutant, and contribute to understanding their defense mechanisms and energy metabolism for coping with this environmental stressor. Full article

Microplastics (MPs) are recognised as emerging vectors for hydrophobic organic contaminants in aquatic environments due to their relatively large surface area and the diversity of their polymer chemistries compositions. This study investigates the sorption behaviour of two priority polycyclic aromatic hydrocarbons (PAHs), pyrene (PYR) and fluoranthene (FLU), onto six common MPs: poly(m-xylene adipamide) (PA-MXD6), high- and low-density polyethylene (HDPE, LDPE), polypropylene (PP), polyethylene terephthalate (PET), and polylactic acid (PLA). Sorption isotherms and kinetics were evaluated under simulated freshwater conditions at environmentally relevant concentrations (1–50 µg·L⁻¹). Despite the low MP concentration used (0.2 g·L⁻¹), over 80% of the initial PAH content was removed by polyolefins, and more than 50% by all other MPs. Sorption capacity was strongly dependent on particle surface area. Langmuir, Henry, and Freundlich isotherms models were fitted, with linear behaviour prevailing at low concentrations. Analysis using the Dubini–-Radushkevich model confirmed that sorption involves chemisorption contributions, mainly through π–π interactions and hydrophobic interactions (polyolefins). Mechanistically, molecular diffusion within the MP matrix was not governing the sorption process, as diffusion coefficients varied with particle size instead of polymer chemistry. Instead, sorption appears to be governed by PAH diffusion through the hydrodynamic boundary layer and subsequent retention on the MP surface. Empirically, kinetic data fitted the pseudo-second-order model, further supporting that the sorption process involves chemisorption. These findings highlight the role of MPs as vectors for PAHs in freshwater systems and their potential application in contaminant removal. Expressing sorption per unit surface area is recommended for accurate assessment. This work contributes to understanding the environmental behaviour of MPs and their implications for pollutant transport and toxicity. Full article

Traditional pork meat products produced through artisanal smoking and drying techniques are highly appreciated for their distinctive sensory characteristics; however, such practices may raise concerns regarding both chemical and microbiological safety. The present study aimed to assess the occurrence of selected polycyclic aromatic hydrocarbons (PAHs) and hygiene- and safety-related microorganisms in traditionally processed pork meat products collected from local markets and small-scale producers. A total of 140 samples were analyzed for four marker PAHs—benzo[a]pyrene (BaP), benz[a]anthracene (BaA), benzo[b]fluoranthene (BbF), and chrysene (Chr)—using gas chromatography–mass spectrometry (GC–MS). Microbiological contamination was evaluated through standard plate count techniques, and the presence of Listeria monocytogenes and Salmonella serovars was determined using selective isolation methods, followed by PCR confirmation of pathogenic strains. PAH concentrations varied widely: BaP (0.3–1.8 µg/kg), BaA (0.5–2.4 µg/kg), BbF (0.8–3.1 µg/kg) and Chr (0.4–2.0 µg/kg), with ΣPAH₄ (Sum of PAH4, referring to the total concentration of the four-priority polycyclic aromatic hydrocarbons) ranging from 2.5 to 8.3 µg/kg. Smoked sausages showed the highest contamination (BaP: 1.8 µg/kg; ΣPAH₄: 8.3 µg/kg), significantly exceeding levels in dry-cured ham (BaP: 1.2 µg/kg; ΣPAH₄: 6.1 µg/kg) and smoked bacon (BaP: 0.9 µg/kg; ΣPAH₄: 5.4 µg/kg) (Kruskal–Wallis, p < 0.0001). Although all samples complied with the EU ΣPAH₄ limit (12 µg/kg), 15% exceeded the BaP limit of 2.0 µg/kg, primarily among artisanal sausages. Microbiological analyses revealed total coliform counts between 1.5 × 10² and 6.2 × 10⁴ CFU/g, while Enterobacteriaceae ranged from 2.0 × 10² to 4.9 × 10⁴ CFU/g. Samples obtained from unregulated producers exhibited higher bacterial loads, indicating suboptimal hygiene during processing and storage. A moderate positive correlation was identified between total coliform and Enterobacteriaceae counts (r = 0.59, p < 0.05). Moreover, Salmonella serovars was detected in ten sausage samples, and Listeria monocytogenes was confirmed in three samples of traditional products. Overall, the findings suggest that although PAH contamination generally complied with EU safety limits, occasional exceedances of benzo[a]pyrene and elevated microbial indicators underscore the need for stricter control of smoking parameters, fuel sources, and hygienic handling. Implementation of standardized smoking protocols and good manufacturing practices (GMP) is recommended to enhance the safety and quality of traditional pork meat products Full article

This study explores the potential of two marine-derived bacteria, Cytobacillus kochii and Marinobacter, through in silico analysis of their catechol 2,3-dioxygenase (C23O) enzymes. Molecular docking simulations were conducted using AutoDock Vina to assess the binding interactions between C23O enzymes and ten hydrocarbon pollutants, including monocyclic and polycyclic aromatic hydrocarbons (PAHs). Binding affinities ranged from −4 to −8.7 kcal/mol for Cytobacillus kochii, with the highest affinity observed for fluoranthene (−8.7 kcal/mol), followed by pyrene (−8.5 kcal/mol) and phenanthrene (−8.2 kcal/mol). In comparison, Marinobacter’s C23O showed binding affinities between −4.1 and −8 kcal/mol, with fluoranthene (−8 kcal/mol) and phenanthrene (−7.9 kcal/mol) being top performers. Despite slightly lower affinity, Marinobacter exhibits superior environmental resilience under high salinity and temperature, making it valuable for application in fluctuating marine conditions. Structural interaction analysis revealed consistent pi-pi stacking and hydrogen bonding within the active sites, further supporting enzyme–substrate compatibility. These computational findings underscore Cytobacillus kochii ’s superior catalytic potential and Marinobacter’s ecological robustness. The integration of both strains into a microbial consortium offers a promising synergistic approach, combining enzymatic efficiency and environmental adaptability for effective hydrocarbon degradation. While these computational assessments offer valuable predictive insights, further validation through in vitro and in vivo experiments would be beneficial to determine the actual hydrocarbon degradation efficiencies. Full article

Polycyclic aromatic hydrocarbons (PAHs) can enter the human body through the consumption of contaminated food, particularly seafood, which can bioaccumulate these toxic compounds. This study evaluated PAH contamination levels in fish, crabs, and shellfish from the Parnaiba River estuary following the 2019 oil spill that impacted over 3000 km of Brazil’s northeastern coastline with weathered, heavy crude. The results showed that PAH concentrations in 2019 were approximately 50% higher than those detected in 2021, indicating an acute contamination event linked to the spill. Among the sampled organisms, crabs had the lowest PAH levels, followed by shellfish with intermediate contamination levels, and fish with the highest concentrations. PAH profiles varied by species: shellfish were dominated by high-molecular-weight (HMW) compounds typical of pyrogenic sources; fish were primarily contaminated with low-molecular-weight (LMW) PAHs associated with crude oil; and crabs exhibited a balanced mix of both. Toxicity equivalency analysis revealed the presence of benzo[a]pyrene (BaP) only in 2019 shellfish samples, while BaP contamination was found in both fish and shellfish in 2021. Some samples exceeded regulatory limits for indeno[1,2,3-cd]pyrene. Mollusks collected during the 2021 dry season presented BaP and benzo[k]fluoranthene levels above the threshold of concern. These findings demonstrate the acute impact of the oil spill, characterized by a predominance of LMW PAHs, as well as a residual contamination pattern in 2021, likely associated with pyrogenic sources and driven by environmental degradation processes. This study also indicates that although overall carcinogenic PAH levels decreased, some carcinogenic PAHs continue to exceed legal limits in fish and shellfish samples, even 2 years after the oil spill. This work highlights the need for long-term monitoring and reinforces the importance of including food safety in environmental impact assessments, especially in vulnerable fishing communities. Full article

Rapeseed (Brassica napus) honey is a popular monofloral honey produced in Poland and is often suspected of pesticide-residue contamination due to the extensive use of pesticides in oilseed rape cultivation. Moreover, because of the presence of fatty acids, it can absorb hydrophobic polycyclic aromatic hydrocarbons (PAHs) that occur as environmental pollutants. Thus, the aim of the study was to assess the safety of rapeseed honey in terms of pesticide residues and PAHs contamination in relation to its functional properties, including antioxidant properties, polyphenol profile, protein content, and enzymatic activity. Local honey samples originating from Lublin (five) and Podkarpackie (five) Voivodeships were compared with five samples purchased from commercial sources. None of 58 pesticides, including carbamates, organophosphorus, organochlorines, pyrethroids, and neonicotinoids, were detected in the tested honey samples. All samples were also completely free of four major harmful PAHs legally limited in food (benzo[a]pyrene, benz[a]anthracene, chrysene, and benzo[b]fluoranthene). Among other PAH compounds, seven were detected accidentally in samples of various origins. The total phenolic content and antioxidant activity determined by DPPH^•, FRAP, and CUPRAC assays were relatively uniform among the groups studied. High-performance thin-layer chromatography (HPTLC) revealed characteristic fingerprints including kaempferol, ferulic acid, and caffeic acid, providing a specific profile that can be considered a marker of rapeseed honey authenticity and used to detect adulteration. Protein content ranged from 18 to 85 mg/100 g, remaining within the range typical for light honeys, while α-glucosidase activity was significantly reduced in commercial products, reflecting the effects of processing and storage. The study confirmed the high functional value and safety of rapeseed honey offered on the South-Eastern Poland market, which confirm the cleanliness of the bees’ habitat in terms of pesticide residues and PAHs pollution. Nevertheless, regular monitoring of pesticide residues and PAHs in honeys from agricultural areas remains advisable. Full article

In this study, four polycyclic aromatic hydrocarbons (4PAHs: benz[a]anthracene, chrysene, benzo[b]fluoranthene, and benzo[a]pyrene (BaP)) were quantified in 110 herb and spice products marketed in South Korea. A validated gas chromatography–mass spectrometry (GC-MS) method achieved high sensitivity with limits of detection (LOD) ranging from 0.08 to 0.18 µg/kg and limits of quantification (LOQ) ranging from 0.24 to 0.55 µg/kg, with recoveries consistent with the Association of Official Analytical Chemists guidelines. Among the tested items, oregano contained the highest BaP concentrations with 7.13 µg/kg, while overall concentrations of the sum of 4PAHs remained below European Union limits. The BaP-based toxic equivalent (TEQ_BaP) and the toxic equivalent for the sum of 4PAHs (TEQ_Σ4PAHs) were 7.13 and 7.50 µg/kg, respectively, with oregano showing the highest values. Risk assessment using the margin of exposure (MOE) showed all values exceeded 10⁶, indicating negligible health concern. These findings provide a basis for continuous monitoring and regulatory management of PAHs in herbs and spices. Full article

A series of novel guanidino-aryl (GA) compounds containing phenanthrene, fluoranthene, fluorene, and naphthalene aromatic cores were synthesized to investigate their interactions with DNA, RNA, and G-quadruplex structures. Among the novel compounds, the phenanthrene-guanidino compound demonstrated the highest micromolar affinity for AT-DNA, possibly due to partial phenanthrene intercalation in addition to hydrogen bonding and electrostatic interactions of guanidine cation. All new guanidino-aryl GA compounds bind strongly to the Tel22 G-quadruplex structure with similar affinities regardless of aromatic core size. The 1:1 stoichiometric complex is stabilised by π-π stacking interactions with the top or bottom G-tetrad, together with strong electrostatic interactions of the guanidino cation. The guanidino-porphyrin PoGU displayed distinct binding stoichiometry, indicating possible sandwiching between two G-quadruplex structures. Within the GA compounds tested, guanidino-fluorene exhibited moderate antimetabolic activity against the HeLa cell line, without selectivity against the healthy cell line. Full article

While the cause of preterm birth (PTB) (i.e., delivery before 37 weeks of gestation) is likely multifactorial, ambient exposure to environmental chemicals has been postulated to play a role in its etiology. Our prior studies of exposure to polycyclic aromatic hydrocarbons (PAHs) in pregnancy have shown an increased level of placental PAH-induced bulky DNA adducts with increasing levels of PAH exposures. In this investigation, we hypothesized that higher levels of placental PAHs would be associated with an increased risk of PTB. Using gas chromatography and mass spectrometry (GC-MS/MS), we measured levels of benzo(a)pyrene (BaP), benzo(b)fluoranthene (BbF) and dibenz(a,h)anthracene (DBA) from n = 323 subjects. We found higher levels of BbF in placentae collected from preterm compared with term deliveries (mean 100.3 vs. 84.14 ng/mL, p = 0.038). Placental BbF levels negatively correlated with gestational age at delivery (r_s = −0.171, p = 0.002) and placental DBA levels were higher in placentae from spontaneous PTBs compared to those that were medically indicated (mean 743.7 vs. 599.9 ng/mL, p = 0.049), suggesting a potentially causal role in spontaneous preterm birth. Lastly, we analyzed placental levels of each PAH in male (n = 164) and female (n = 159) gestations and found that levels of BaP are significantly higher in males (mean 204.4 vs. 169.9 ng/mL, p = 0.049). These studies show a potential causal role of PAH exposure in the etiology of spontaneous preterm birth. Full article