From Oil Spills to Air Pollution: The Emergence of Phenanthrene as a Ubiquitous Cardiac Toxicant.

We previously demonstrated the role of Kvβ1.1 subunit of voltage-activated potassium channel in heart for its sensory roles in detecting changes in NADH/NAD and modulation of ion channel. However, the pharmacological role for the association of Kvβ1 via its binding to ligands such as cortisone and its analogs remains unknown. Therefore, we investigated the significance of Kvβ1.1 binding to cortisone analogs and AR inhibitor epalrestat. In addition, the aldose reductase (AR) inhibitor epalrestat was identified as a pharmacological target and modulator of cardiac activity via binding to the Kvβ1 subunit. Using a combination of ex vivo cardiac electrophysiology and in silico binding, we identified that Kvβ1 subunit binds and interacts with epalrestat. To identify the specificity of the action potential changes, we studied the sensitivity of the action potential prolongation by probing the electrical changes in the presence of 4-aminopyridine and evaluated the specificity of pharmacological effects in the hearts from Kvβ1.1 knock out mouse. Our results show that pharmacological modulation of cardiac electrical activity by cortisone analogs and epalrestat is mediated by Kvβ1.1.

Polycyclic aromatic hydrocarbons (PAHs) exhibit persistence in soils, and most of them are potentially mutagenic/carcinogenic and teratogenic for human beings but also influence the growth and development of soil organisms. The PAHs emitted into the atmosphere are ultimately deposited (by dry or wet deposition processes) onto the soil surface where they tend to accumulate. Soil organic matter (SOM) plays an important role in the fate and transformation processes of PAHs, affecting their mobility, availability, and persistence. Therefore, the aim of this research was to investigate the influence of SOM fractional diversification (fulvic acids—FA, humic acids—HA, and humins—HN) on PAH availability and persistence in soils. Twenty soil samples (n = 20) were collected from upper horizons (0–30 cm) of agricultural soils exposed to anthropogenic emissions from industrial and domestic sources. The assessment of PAH concentrations included the determination of medium-molecular-weight compounds from the US EPA list: fluoranthene—FLA, pyrene—PYR, benz(a)anthracene—BaA, and chrysene—CHR. The assessment was conducted using the GC-MS/MS technique. Three operationally defined fractions were investigated: total extractable PAHs (TE-PAHs) fraction, available/bioavailable PAHs (PB-PAHs) fraction, and nonavailable/residual PAHs (RE-PAHs) fraction, which was calculated as the difference between total and available PAHs. TE-PAHs were analyzed by dichloromethane extraction, while PB-PAHs were analyzed with a hydrophobic β-cyclodextrin solution. SOM was characterized by total organic carbon content (Turin method) and organic carbon of humic substances including FA, HA, HN (IHSS method). Concentrations of PAHs differed between soils from 193.5 to 3169.5 µg kg−1, 4.3 to 226.4 µg kg−1, and 148.6 to 3164.7 µg kg−1 for ∑4 TE-PAHs, ∑4 PB-PAHs, and ∑4 RE-PAHs, respectively. The ∑4 PB-PAHs fraction did not exceed 30% of ∑4 TE-PAHs. FLA was the most strongly bound in soil (highest content of RE-FLA), whereas PYR was the most available (highest content of PB-PYR). The soils were characterized by diversified total organic carbon (TOC) concentration (8.0–130.0 g kg−1) and individual SOM fractions (FA = 0.4–7.5 g kg−1, HA = 0.6–13.0 g kg−1, HN = 0.9–122.9 g kg−1). FA and HA as the labile fraction of SOM with short turnover time strongly positively influenced the potential ∑4 PAH availability (r = 0.56 and r = 0.52 for FA and HA, respectively). HN, which constitutes a stable fraction of organic matter with high hydrophobicity and poor degradability, was strongly correlated with ∑4 RE-PAHs (r = 0.75), affecting their persistence in soil.

Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants composed of fused benzene rings, released into the environment through fossil fuel combustion, industrial processes, forest fires, and natural events. Due to their hydrophobicity and low solubility, PAHs are resistant to degradation and accumulate in ecosystems. Recognized as mutagenic and carcinogenic, PAHs pose serious risks to human and environmental health. In aquatic systems, they can harm microbial, plant, and animal life by disrupting growth, metabolism, genetic stability, and membrane integrity. This review explores the extent of PAH contamination in aquatic environments, focusing on their toxic effects on both invertebrate and vertebrate aquatic species, particularly ichthyofauna. It also discusses microbial and plant-based degradation processes and evaluates bioremediation strategies aimed at reducing PAH concentrations and associated toxicity. Certain microorganisms and plants have adapted mechanisms to break down PAHs, and studies show that their combined action can accelerate pollutant degradation. By highlighting these natural remediation pathways, this review emphasizes the importance of sustainable strategies to mitigate PAH impacts on aquatic ecosystems and protect overall ecosystem health.

Unravelling mixed sources of polycyclic aromatic hydrocarbons (PAH) in urban soils by visual characterization of anthropogenic substrates and coal particles, 71 PAH and alkylated PAH patterns

ABSTRACTOne of the methods of sludge disposal in cities is its use as an amendment in adjoining agricultural soil. Contaminants in sludge can, however, nullify the benefits. Polycyclic aromatic hydrocarbons (PAHs) are a class of persistent organic pollutants, if present, can pose health risks by virtue of their carcinogenic potential and persistence in soil. The present study deals with profile analysis of PAHs in digested sewage sludge of a megacity, Delhi. Mean concentration of the sum of 16 PAHs in the sludge from 5 sewage treatment plants (STPs) was 20.67 ± 4.14 mg/kg, dry weight (dw). Carcinogenic PAHs represented ∼47% of the total PAHs. Benzo[g,h,i]perylene recorded the highest mean concentration followed by dibenzo[a,h]anthracene. Low molecular weight PAHs and high molecular weight PAHs contributed 19% and 81% to total PAHs content respectively. Principal component analysis identified the major sources of PAHs in sludge as coal and natural gas combustion. Wood combustion, oil and oil derivatives are the other identified sources. The observed PAH levels in sludge from selected STPs of Delhi were found to violate the limit values proposed by the European Union and the US legislation for application in agriculture.

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous constituents of air particulate matter and can be taken up by plants from the atmosphere. However, the purification of particulate-bound PAHs in the atmosphere by greening tree species has not been reported. In this study, we assess the concentrations, distribution, and sources of PM2.5-bound PAHs at three representative sites of Beijing in April, July, and November (non-heating period) and analyze the correlation between PAHs in Populus tomentosa leaves and in atmospheric PM2.5. The total PAH concentrations in PM2.5 were in the range of 19.85±13.59-42.01±37.17ng/m3 with mean value of 31.35ng/m3 at the three sites, and the PM2.5-bound PAHs concentrations in the two suburban sites (YF and YQ) were significantly higher than that in urban site (XZM) in November (autumn). At the three sites, the high molecular weight (HMW) PAHs in PM2.5 were dominant, accounting for 54.09-64.90% of total PAHs and the concentration of HMW PAHs was, on average, 9.1 times higher than that of low molecular weight (LWM) PAHs. Principal component analysis combined with diagnostic ratio analysis indicated that vehicle emission, wood combustion, and industrial processes were the main sources for PM2.5-bound PAHs in the non-heating period of Beijing. However, the LMW PAHs were dominant in P. tomentosa leaves. The concentrations of HMW PAHs (BbF, BkF, BaP, IcdP, and BghiP) in P. tomentosa leaves reached 26.11±2.39, 41.42±7.77, and 55.70±12.33ng/g at YQ, XZM, and YF in autumn, respectively, and were, on average, 2.1 times higher than those in April (spring) at the three sites. The ∑5PAHs concentration in P. tomentosa leaves accumulatively increased from spring to autumn, which was not related to the temporal variation of PM2.5-bound PAHs. Nevertheless, the ∑5PAHs mean concentrations followed the order of YF > XZM > YQ. This trend was consistent with spatial distribution of atmosphere PM2.5, indicating that HMW PAHs in leaves increased with the increase of atmosphere PM2.5 concentration. Our results indicated that P. tomentosa may be used as a useful species for removing PAHs from the air and biomonitoring PAHs in atmosphere.

Polycyclic aromatic hydrocarbons (PAHs) are released into the environment via several natural and anthropogenic sources leading to long-term consequences that severely affect the environment, ecosystem, human and animal health. In this study, the extent of PAH pollution was measured at two estuarine locations of the major rivers of Goa, Zuari and Mandovi. Out of the 16 PAHs marked as carcinogenic, 13 PAHs were detected from the sediment samples collected. Bacterial strains were isolated from these PAH-contaminated sediments using conventional plating method. Six of these selected bacterial isolates were checked for their efficacy to degrade both low (phenanthrene) and high molecular weight (fluoranthene and pyrene) hydrocarbons. Amongst them, two bacterial isolates exhibited over 80% degradation of phenanthrene. Isolate NIOSV7 (Pseudomonas pachastrellae) could degrade 83.33% phenanthrene, 40.22% fluoranthene and 45.28% pyrene, while isolate NIOSV8, identified as Pseudomonas oleovorans, showed 85.09% phenanthrene, 70.61% fluoranthene and 67.18% of pyrene degradation in 120 h, at 100 ppm initial concentration of phenanthrene and 75 ppm of fluoranthane and pyrene. Though many Pseudomonas sp. are documented for PAH degradation, this is the first report showing PAH-degradation by Pseudomonas oleovorans strain. This study also shows that the bacteria isolated from estuarine sediments contaminated with PAH have good potential to degrade low and high molecular weight PAHs. These toxic pollutants can be bio-transformed into nontoxic metabolites with the help of microorganisms isolated from the same habitat.

Biota – Sediment partitioning of aluminium smelter related PAHs and pulp mill related diterpenes by intertidal clams at Kitimat, British Columbia

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitary contaminants, which constitute a wide range of organic compounds. Many of them proved to be carcinogenic and mutagenic, produced mainly by industrial and non-industrial combustion processes, but also are present in water, air, soil, and as contaminants in foods, and beverages. Several industrial processes and artificial human activities can increase naturally environmental levels of these ubiquitary compounds, thereby increasing the levels of detected PAHs in final alimentary products. This paper reports PAHs extraction and detection techniques in beverages, including the analysis of beer, wine, spirits, tea, and coffee and, more generally, the standard drinks intended for human consumption. The state of the art in terms of sample pre-treatment techniques, and the main assays for their analysis by gas chromatography (GC) and high performance liquid chromatography (HPLC), with relative detection techniques, are described and catered. Moreover, major metabolites were determined in beverages, in order to provide a complete scenario for these kinds of ubiquitary contaminants. Keywords: Analytical methods, beverage, chromatographic and electrophoretic assay, extraction procedure, PAHs and PAHs metabolites.

Modeling the exposure functions of atmospheric polycyclic aromatic hydrocarbon mixtures in occupational environments.

Investigating industrial PAH air pollution in relation to population exposure in major countries: A scoring approach

White-rot fungi applied for soil bioremediation have to compete with indigenous soil microorganisms. The effect of competition on both indigenous soil microflora and white-rot fungi was evaluated with regard to degradation of polycyclic aromatic hydrocarbons (PAH) with different persistence in soil. Sterile and non-sterile soil was artificially contaminated with 14C-labeled PAH consisting of three (anthracene), four (pyrene, benz[a]anthracene) and five fused aromatic rings (benzo[a]pyrene, dibenz[a,h]anthracene). The two fungi tested,Dichomitus squalens and Pleurotus ostreatus, produced similar amounts of ligninolytic enzymes in soil, but PAH mineralization by P. ostreatus was significantly higher. Compared to the indigenous soil microflora, P.ostreatus mineralized 5-ring PAH to a larger extent, while the indigenous microflora was superior in mineralizing 3-ring and 4-ring PAH. In coculture the special capabilities of both soil microflora and P. ostreatus were partly restricted due to antagonistic interactions, but essentially preserved. Thus, soil inoculation with P. ostreatus significantly increased the mineralization of high-molecular-weight PAH, and at the same time reduced the mineralization of anthracene and pyrene. Regarding the mineralization of low-molecular-weight PAH, the stimulation of indigenous soil microorganisms by straw amendment was more efficient than application of white-rot fungi.

Polycyclic aromatic hydrocarbons (PAHs) are globally significant environmental contaminants due to their persistence, resistance to degradation, widespread distribution, and potential for bioaccumulation. Their physicochemical properties, particularly hydrophobicity, thermal stability, and lipophilicity, facilitate long-range transport and bioaccumulation in environmental matrices and living organisms. PAHs originate from both natural and human driven sources, with emissions from industrial operations, fossil fuel, and residential activities being the most significant contributors. Many PAHs exhibit mutagenic, carcinogenic, and teratogenic, and endocrine-disrupting effects, thereby posing significant ecological and public health risks. PAH are broadly categorized into low molecular weight PAHs (LMW PAHs) and high molecular weight PAHs (HMW PAHs). Although extensive research has been conducted on LMW PAHs, evidence indicates that HMW PAHs, typically with molecular weight exceeding 300 Da, demonstrate greater environmental persistence, stronger bioaccumulative behaviour and severe long-term toxicological impacts. These effects are largely mediated through metabolic activation, oxidative stress induction, DNA damage, and aryl hydrocarbon receptor-dependent pathways. Despite these concerns, no HMW PAHs is included on the United State Environmental Protection Agency (US EPA) priority pollutants list, underscoring a critical gap in risk assessment and policy. This review critically evaluates recent advances (2018-2025) on the physicochemical properties, environmental distribution, exposure pathways, toxicological mechanisms, and associated health effects of PAHs. Key conclusions highlight the underestimated health risks regarding PAH mixtures, the importance of isomer-specific toxicity, and the enhanced hazard potential of alkylated and substituted PAHs. In addition, the effectiveness of contemporary remediation strategies, including bioremediation, phytoremediation, and advanced oxidation processes, is assessed, with integrated site-specific approaches identified as the most promising for the removal of persistent HMW PAHs. The review emphasizes the need for improved mechanistic studies and innovative risk management strategies to reduce human and ecological impacts.

Dear Editor, Rapid industrialisation and urbanisation have placed Pakistan as the seventh-largest emitter of polycyclic aromatic hydrocarbons (PAHs) in the world (1). These hazardous organic compounds, consisting of fused aromatic rings, are released due to anthropogenic activities such as vehicular emissions, industrial processes, and agricultural practices (2). Traffic pollution contributes to 60% of urban PAH emissions in Pakistan (1). Humans are primarily exposed to PAHs through dermal contact, ingestion, inhalation and breast milk (3). Short-term exposure to high PAH levels can impair lung function in asthma patients and exacerbate thrombotic effects in individuals with coronary heart disease (4). Long-lasting exposure leads to malignancies of the skin, lungs and gastrointestinal tract (1). In 2009, 100 agents were classified as human carcinogens by International Agency for Research on Cancer (IARC); including PAHs (3). Developing countries usually have high levels of PAHs due to increasing industrialization and population coupled with lack of strategies to deal with the pollutant. Various studies have been conducted in Pakistan, and PAHs have been found in urban soils, vegetables, water, air and even mangrove leaves (3). Despite this, limited research exists on PAH remediation methods and their effectiveness. Traditionally, physical and chemical methods are used for remediation, which include but are not limited to, filtration, incineration, oxidation and photocatalysis. However, these only displace PAHs, without structurally breaking them down (2). Bioremediation, which relies on microbial degradation, is a promising solution but remains hindered by slow degradation rates and limited microbial efficiency. Synthetic biology presents a viable alternative by engineering microorganisms to enhance PAH degradation pathways. There have been developments in genome editing and synthetic genomics, which enable the growth of microbes that produce specific enzymes to help in biodegradation (5). The current situation in Pakistan raises a dire need for steps to be taken for remediation of PAHs. There is a lack of research on the methods being used and their effectiveness. Given the worsening pollution crisis, Pakistan urgently requires effective PAH remediation strategies. While synthetic biology offers a promising solution, its practical application in Pakistan remains unexplored. Studies are urgently needed to explore the mechanisms of genetic engineering, the associated legal frameworks in Pakistan, and the acceptability of such procedures among the general population, particularly with the worsening pollution crisis.

Polycyclic aromatic hydrocarbons (PAHs) in atmospheric PM2.5 and PM10 at a coal-based industrial city: Implication for PAH control at industrial agglomeration regions, China