Polycyclic aromatic hydrocarbons in the surface water and sediment along Euphrates River system: Occurrence, sources, ecological and health risk assessment

Comprehensive research of some semi-volatile organic compounds (SVOCs) at very low levels in Lake and marine waters in Antarctica on-site by SBSE thermal desorption GC-MS/MS: Distribution, source apportionment, ecological and human health implication

Antarctica is not immune to pollution, and Semi-volatile organic compounds (SVOCs) in Antarctica's water systems can reach the continent through long-range atmospheric transport, ocean currents, and human activities. The aim of this study was investigated the distribution of SVOCs, including PAHs, PCBs, and OCPs, in Antarctic lake and marine waters, assesses their potential sources, and evaluates the ecological and human health risks. The collected water samples were pretreated on-site in Antarctica using the stir bar sorptive extraction (SBSE) method. Water samples (500 mL) were extracted overnight (16 h), the SVOCs retained in the stir bars were analyzed by Thermal Desorption gas chromatography-tandem mass spectrometry (GC-MS/MS) in a competent laboratory in Türkiye. The method successfully extracted compounds with log Kow values above 2. A total of 33 water samples were analyzed, revealing ΣPAH concentrations between 0.484 and 2.570 ng/L (mean: 1.168 ng/L), ΣPCB between 0.099 and 0.343 ng/L (mean: 0.219 ng/L), and ΣOCP between 0.162 and 1.338 ng/L. Naphthalene, benz(a)anthracene, phenanthrene, and fluorene were the predominant PAHs, while PCB 101, PCB 52, PCB 28, biphenyl, cypermethrin, and beta-HCH were dominant among PCBs and OCPs. Elevated concentrations were observed at M4, L4, L5, and L9. Diagnostic ratios suggest petrogenic sources, particularly fossil fuel combustion and ship transportation emissions. Risk assessment showed that RQ values for SVOCs were below 1 in all samples, indicating negligible environmental risk. Furthermore, BaPeq values confirmed no immediate carcinogenic threat. Health risk analysis suggested that exposure to these pollutants does not pose significant non-carcinogenic or carcinogenic risks to children or adults based on regulatory criteria.

Distribution of polycyclic aromatic hydrocarbons in key fishing ports of Hainan Island, China

The widespread distribution and toxicity of polycyclic aromatic hydrocarbons (PAHs) pose significant environmental challenges for achieving sustainable development goals. Significant uncertainties exist in their emission sources driven by the complex social and economic activities. This study systematically quantified 16 priority PAHs in the aquatic environment of 10 key fishing ports around Hainan Island in China. The total PAH concentrations (∑16PAHs) were up to 3310 (mean: 569 ± 1050) ng L-1 in water and 3890 (mean: 1060 ± 1330) ng g-1 dry weight in sediment, respectively. A significant correlation was found between the concentrations of PAHs with fewer than 5 rings in water and dissolved oxygen. PAHs with 4 rings were predominant in all media, and they were used for source identification with diagnostic ratios. Results indicated small fishing boats as the primary emission source, and the emission pathways were delineated accordingly. The ecological risk assessment revealed that phenanthrene (Phe) and benzo[a]pyrene (BaP) posed potential chronic ecological risks, whereas anthracene (Ant) and pyrene (Pyr) presented potential acute ecological risks, varying by site. This study underscores the urgent need to ensure a balance between fishery activities and environmental sustainability.

Estimation of concentration and risk assessment of PAHs in urban water resources due to cigarette butt littering

Filtered cigarettes are now the dominant form of tobacco consumption worldwide, resulting in the production of 5 trillion/year cigarette butts as hazardous waste. Most cigarette butts are littered by smokers, and the trapped pollutants quickly leak into the environment. In this study, the density of littered cigarette butts in urban environment was interpreted by Cigarette Butt Pollution Index and the ecological risk and carcinogenic risk due to water pollution caused by leaked PAHs from the littered cigarette butts were assessed. The results showed that the density of littered cigarette butts in the most polluted location was 0.61 butts/m2, while in the best conditions the density was 0.01 butts/m2. According to the observed densities, the Cigarette Butte Pollution Index was 0.75 in the cleanest location and 12.2 in the most polluted location. The results showed that cigarette butt littering in the studied city caused the leakage of 88,181 g/year of polycyclic aromatic hydrocarbons. The average polycyclic aromatic hydrocarbons leakage into the urban environment was 0.2844 µg/m2. The ecological risk associated with the three types of PAHs, including Dibenzo(a, h)anthracene, Naphthalene, and Acenaphthene, was moderate, while the ILCR was calculated to be 5.4E-08. Reducing the density of littered cigarette butts in the studied urban environment and preventing the health and environmental consequences resulting from them requires reduce cigarette butt littering by smokers and increase the efficiency of the urban cleaning system.

Assessment of polycyclic aromatic hydrocarbon concentrations in the sediments of an estuary heavily affected by heavy industrial activities

The Aviles estuary is one of the most anthropized in Spain due to the significant pressure exerted on it by industry. This study assesses the concentrations, origins, sources, and environmental implications of 16 polycyclic aromatic hydrocarbons (PAHs) as persistent contaminants of the estuary sediments. A total of 79 sediment samples were studied. Results indicate ∑16PAH concentrations ranging from 0.086 to 305.771 μg g-1, with the highest values in the estuary's main channel. High-molecular-weight PAHs (4-6 rings) were predominant, suggesting a pyrogenic origin associated to industrial combustion processes. Lower molecular weight PAHs (2-3 rings) were mainly observed near the estuary mouth. Diagnostic ratio analysis confirmed that PAHs in the estuary predominantly originate from mixed combustion sources, including industrial processes, vehicle emissions, and maritime activities. Spatial distribution maps identified three contamination hotspots: (i) the Albares River, linked with steel industry emissions; (ii) a central estuary site near an aluminium smelter discharge point, connected to PAHs from industrial operations; and (iii) the estuary mouth, where PAHs from industrial wastewater discharges and shipping activities were detected. Cluster analysis further distinguished areas with similar contamination profiles, confirming the influence of industrial and maritime activities. Finally, the risk assessment comparisons with international pollution thresholds revealed that PAH levels in the Avilés Estuary are significantly higher than in other European and global estuarine environments. Over 90 % of samples exceeded both low and median effect range limits, indicating substantial toxicity risks. Moreover, ecological risk quotient classified 92 % of sediment samples as posing a high risk to aquatic life.

Distribution, sources and bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) in oysters of Sal estuary Goa, India

Present study aimed to unfurl occurrence and accumulation of Polycyclic Aromatic Hydrocarbons (PAHs) in water and oysters of Sal estuary (Goa, India). The highest total PAHs concentration were observed at mid estuary (SSJ2) region for water (594.36 μg L-1) and oyster (12,022.2 ng g-1 dry weight) respectively. Which is under high anthropogenic pressure and tidal influence. The lowest concentration of total PAHs were displayed by upper estuarine (SSJ1) region (1.04 μg L-1) for water and oyster (7019.1 ng g-1 dry weight) as it is well surrounded by mangroves and is relatively pristine. Diagnostic ratios suggested mixed source as primary PAHs source in the study area. According to EFSA guidelines, Exposure Daily Intake (EDI) values and Target Hazard Quotient (THQ) were within permissible limits thus risk to develop chronic systematic effects is low. Although, present scenario demonstrates low health risk, long term exposure might be detrimental. High prevalence low molecular weight PAHs were noted in water column while, significant accumulation of high molecular weight PAHs in oysters were due to hydrophobic and lipophilic characteristic of PAHs, which increases with molecular weight.

Sources, transport and fate of polycyclic aromatic hydrocarbons (PAHs) in a typical river-estuary system in the North China: From a new perspective of PAHs loading

Sediment particles and organic carbon regulate the transport and burial of polycyclic aromatic hydrocarbons (PAHs) in the suspended particle matter (SPM) of rivers and estuarine sediments. In this study, we assessed the source, biological and health risks of the PAHs, and examined the riverine transport and burial of PAHs based on their spatial distributions and sediment surface area (SSA) in river SPM and estuarine sediments in the North China. The results showed that the river SPM was dominated by low molecular weight PAHs (LMW, 2-3 rings; 59.3 %), while the river and estuarine sediments were dominated by high molecular weight PAHs (HMW, 4-6 rings; river sediments: 70.8 % and estuarine sediments: 72.2 %) due to the degradation of LMW PAHs during transport. Quantitative estimation using principal component analysis-multiple linear regression (PCA-MLR) revealed mixed combustion of petroleum and coal to be the dominant PAH source (river samples: 67.9 % and estuary samples: 85 %). The results based on the Incremental Lifetime Cancer Risk (ILCR) model indicated that the values of dermal contact were higher than 10-6, suggesting that there were potential carcinogenic health risks. Using PAHs loading (PAHs normalized to SSA), we estimated the burial efficiency of HMW PAHs (89.1 %) to be significantly higher than that of LMW PAHs (17.8 %) in the river SPM. These findings could provide new insights into the fate of contaminants in coastal sediments, and our results provide data support and theoretical basis for the ecological and environmental protection and policy formulation for river-estuary system.

Polycyclic Aromatic Hydrocarbons (PAHs) in Freshwater Systems: A Comprehensive Review of Sources, Distribution, and Ecotoxicological Impacts

This comprehensive review offers new perspectives on the distribution, sources, and ecotoxicological impacts of polycyclic aromatic hydrocarbons (PAHs) in freshwater systems. Unlike previous reviews, this work integrates recent findings on PAH dynamics within environmental matrices and emphasizes spatiotemporal variability across geographic regions. It critically examines both anthropogenic and natural sources, as well as the physical, chemical, and biological mechanisms driving PAH transport and fate. Special attention is given to the ecotoxicological effects of PAHs on freshwater organisms, including bioaccumulation, endocrine disruption, and genotoxicity. Notably, this review identifies key knowledge gaps and proposes an interdisciplinary framework to assess ecological risk and guide effective monitoring and management strategies for the protection of freshwater ecosystems.

Source identification of polycyclic aromatic hydrocarbons (PAHs) in river sediments within a hilly agricultural watershed of Southwestern China: an integrated study based on Pb isotopes and PMF method

Polycyclic aromatic hydrocarbons (PAHs) in sediments represent a pervasive environmental issue that poses significant ecological risks. This study employed a combination of geographic information systems, diagnostic ratios, correlation analysis, Pb isotope ratios, and positive matrix factorization (PMF) to elucidate the potential sources of 16 priority PAHs in river sediments from a hilly agricultural watershed in Southwestern China. The results indicated that PAHs concentrations ranged from 55.9 to 6083.5 ng/g, with a mean value of 1582.1 ± 1528.9 ng/g, reflecting high levels of contamination throughout the watershed. The predominant class of PAHs identified was high molecular weight (HMW) PAHs. Diagnostic ratios and correlation analysis suggested that the presence of PHAs is likely attributed primarily to emissions from industrial dust and combustion of coal and petroleum. Furthermore, correlation analysis revealed a significant association between Pb and PAHs, indicating potential shared sources for both pollutants. Additionally, Pb isotopic analysis demonstrated that aerosols may be the primary contributor to Pb accumulation within this environment. Given the similarity in origins between Pb and PAHs, it can be inferred that PAHs predominantly originate from aerosols associated with coal combustion, industrial dust emissions, and vehicle exhaust. This inference is further supported by PMF results which yielded consistent findings with those derived from Pb isotopes analysis. Moreover, PMF estimated three major sources contributing 57.63%, 23.57%, and 18.80%, respectively. These findings provide novel insights into identifying the sources of PAHs in river sediments within hilly agricultural watersheds in Southwest China, thereby establishing a scientific foundation for enhancing environmental quality in agricultural regions.

Polycyclic aromatic hydrocarbons (PAHs) occurrences in water bodies, extraction techniques, detection methods, and standardized guidelines for PAHs in aqueous solutions

Polycyclic aromatic hydrocarbons (PAHs) are a carcinogenic compound comprised of benzene ring(s). They occur naturally. However, the occurrence of anthropogenic PAHs (originates from human activities and man-made structures) may contribute to water pollution, risking the public health and aquatic life. This review describes occurrences of PAHs in water bodies, extraction techniques, detection methods, and standardized guidelines for PAHs in aqueous solutions. Previous research identifies PAH contamination across freshwater bodies due to proximity to pollution sources and hydrological factors. Despite analytical advancements, accurately quantifying and characterizing PAHs in complex environmental matrices remains challenging. Overall, this review supports the Sustainable Development Goals (SDGs) no. 6 (clean water and sanitation public) and no. 14 life below water.

Concentrations and human health risks attributed to potentially toxic elements (PTEs) in water resources in China: Systematic review and meta-analysis

Long-term exposure to potentially toxic elements (PTEs) increases carcinogenic and non-carcinogenic risks in the exposed population. The current study was conducted with the aims of meta-analysis concentrations of PTEs including Arsenic (As), Cadmium (Cd), Lead (Pb), Mercury (Hg), Nickel (Ni) and Copper (Cu) in the water resources and human health risk assessment for adult males and female consumers in China. Search was performed in international databases including Web of Science, Scopus, PubMed, Embase and Google Scholar (gery literature) from January 1, 2005 to April 1, 2024. The concentration of PTEs was meta-analyzed using random effects model in water resources (surface water and groundwater) and location of study (urban and rural locations) subgroups. Human health risk assessment due to PTEs in water from ingestion and dermal contact pathways was estimated using target hazard quintet (THQ) and carcinogenic (CR) in adult males and female consumers in China. One hundred and twenty-six papers with 237 data-reports (n = 13,083) were included in this study. The rank order of PTEs based on pooled concentration was As (12.6530 µg/l) > Cu (11.1810 µg/l)> Ni (2.4950 µg/l) > Pb (2.0660 µg/l) > Cd (0.5370 µg/l) > Hg (0.3600 µg/l). The rank order of PTEs based on percentage studies higher than standard limits was As (28.37 %) > Pb (16.67 %) > Hg (11.86 %) > Ni (9.91 %) > Cd (7.48 %) > Cu (2.38 %). The pooled concentration of Pb, Ni, Hg and Cu in surface water resources was higher than groundwater but concentration of As and Cd in groundwater water was higher than surface water. The rank order of PTEs based on percentage studies with the high non-carcinogenic risk (THQ ≥ 1) for male was As (30.49 %) > Cd (8.09 %)> Hg (6.90 %) > Ni (3.60 %)> Cu (3.39 %) > Pb (2.50 %) and for female, As (29.78 %) > Cd (8.09 %)> Hg (6.90 %) > Cu (3.39 %) > Ni (2.70 %)> Pb (1.25 %). The rank order of PTEs based on percentage studies with high carcinogenic risk (TCR ≥ 1E-4) for male was As (60.28 %) > Cd (33.33 %) and for female, As (56.73 %) > Cd (29.93 %). Therefore, to reduce the carcinogenic and non-carcinogenic risks of PTEs especially As, continuous monitoring and control release of As into water resources through novel approaches is recommended.

Assessment of pollution in Alibeykoy Dam Lake (Istanbul, Türkiye) and its influent streams: Phytoplankton composition and heavy metal accumulation

In this study, the pollution levels of Alibeykoy Dam Lake were assessed by examining phytoplankton distribution, physicochemical parameters, nutrient content, and heavy metal concentrations. Alibeykoy Dam is a critical drinking water source for the Istanbul metropolitan area. Water samples were collected from the lake and six influent streams (Cebeci, Pirincci, Sidan, Bolluca, Gulgen, and Kocaman) in January, February, May, and September of 2021. A total of 36 taxa from seven divisions were identified, including Bacillariophyta (14), Charophyta (2), Chlorophyta (9), Cryptophyta (1), Cyanobacteria (3), Euglenozoa (4), and Miozoa (3). Diatoms were found to be the dominant group in terms of species richness and abundance. The dominant species recorded in each site were as follows: Microcystis aeruginosa in Alibeykoy Dam and Sidan Creek, Cyclotella ocellata in Cebeci and Gulgen Creeks, Scenedesmus sp. in Pirincci Creek, Navicula cryptocephala in Bolluca Creek, and Sphaerocystis planctonica in Kocaman Creek. Mesotrophic and eutrophic phytoplankton species suggested that the lake is nearing eutrophic conditions. This conclusion was further supported by high concentrations of heavy metals and nutrients detected in the water samples. This research is significant because it provides a comprehensive understanding of the ecological status of Alibeykoy Dam Lake, a critical resource for drinking water in Istanbul. The study highlights potential risks associated with eutrophication and heavy metal accumulation by identifying pollution levels and dominant species. These findings are vital for implementing effective water resource management strategies, ensuring the lake's sustainability, and protecting public health. PRACTITIONER POINTS: The pollution rate of Alibeykoy Dam Lake was determined. The presence of mesotrophic and eutrophic species of phytoplankton indicated the lake's trophic structure. The measurements were done to estimate the lake's heavy metal and nutrient contents.

Source apportionment and probabilistic health risk assessment of polycyclic aromatic hydrocarbons in sediment from an urban shallow lake

Polycyclic aromatic hydrocarbons (PAHs) in sediment from urban shallow lake Bubanj (Serbia) were investigated in terms of their concentration, distribution, and potential effects on the environment and human health. The concentration of 16 PAHs (ΣPAHs) ranged from 24.4 to 107 ng/g dw. Low-molecular-weight PAHs (2- and 3-aromatic rings) were dominant, accounting for 71% of the total. Multivariate statistical analyses revealed that the main source of PAHs was the incomplete combustion of organic sources. Diagnostic ratios and positive matrix factorization (PMF) methods further indicated that combustion of organic matter and petroleum leakage were the dominant sources. The toxic equivalent quantity (TEQ) of ΣPAHs varied from 0.5 to 17.6 ng-TEQ/g-dry. BaP had the highest contribution to TEQ, followed by Ant, DahA, and BaA, with respective shares of 74.3%, 6.4%, 5.6%, and 5.3%. Dermal contact and ingestion were the primary exposure routes for PAHs, whereas inhalation posed negligible cancer risk. The incremental lifetime cancer risk (ILCR) values for adults were in the range of 3.9 × 10-9-1.4 × 10-7 and for children 5.3 × 10-9-1.9 × 10-7, indicating negligible carcinogenic health risks. Monte Carlo simulation showed that ILCR values for adults and children remained below the permissible limit of 1.0 × 10-6, even at the 90th percentile.

Characteristics, source apportionment and health risks of indoor and outdoor fine particle-bound polycyclic aromatic hydrocarbons in Jinan, North China

To investigate the pollution characteristics of polycyclic aromatic hydrocarbons (PAHs) indoors and outdoors and their influencing factors, PM2.5 samples were systematically collected from both environments in Jinan during the summer and autumn seasons. During the observation period, the concentration of ∑ 19PAHs was 18.57 ± 10.50 ng/m3 indoors and 23.79 ± 16.13 ng/m3 outdoors. Most PAHs exhibited indoor-to-outdoor (I/O) ratios less than 1, indicating that indoor PAHs were primarily derived from the infiltration of outdoor sources. Correlation analysis underscored the significant influence of temperature on both outdoor concentrations and I/O ratios of PAHs. By utilizing diagnostic ratios and principal component analysis (PCA), vehicle emissions were identified as the predominant source of outdoor PAHs. Our study found that the toxic equivalents of benzo[a]pyrene (TEQBaP) values exceeded the European Commission's standard of 1 ng/m3, with indoor values at 2.78 ng/m3 and outdoor values at 3.57 ng/m3. Moreover, the total incremental lifetime cancer risk (ILCRTotal) associated with exposure to PM2.5-bound PAHs surpassed the acceptable level of 10E-6, indicating potential adverse health effects. These results underscore the urgent necessity for more stringent regulatory measures to reduce PAH emissions. Additionally, our findings provide valuable insights into how environmental factors shape the relationship between indoor and outdoor PAHs.

Co-occurrence of polycyclic aromatic hydrocarbons and heavy metals in various environmental matrices of a chronic petroleum polluted region in Iran; Pollution characterization, and assessment of ecological and human health risks

Oil spills from pipeline accidents can result in long-lasting health effect in the people living in a ‎polluted region‎. In this study, the level of the 16 US EPA priority polycyclic aromatic hydrocarbons (PAHs‎) and heavy metals (HMs) have been ‎analyzed in environmental matrices of a region with frequent oil ‎pipeline accidents in Iran‎.‎ The results showed that the mean ‎concentration of ΣPAHs and ΣHMs decreased from the upstream to the downstream and also the levels were ‎higher in the wet season than those in the dry season. The average concentration of HMs in sediments was higher than that in other ‎environments. The 3-ring and 4-ring PAHs were dominant in all of the studied matrices with the average values of 32.61 % and 45.85 %, respectively. The ecological risks of PAHs and HMs were medium and high in all matrices, respectively. In wet season, the total cancer risk (TCR) related to PAHs in agricultural soil was greater than 10-4, whereas it's very close to the threshold for HMs in water. This study offers a reference for assessing the long-term impact of oil spills in contaminated environmental matrices. The results are crucial for developing effective strategies to mitigate oil pollution ‎impacts and protect environmental and public health.

Tracing sources of dissolved organic matter along the terrestrial-aquatic continuum in the Ore Mountains, Germany

There is growing concern about the rising levels of dissolved organic matter (DOM) in surface waters across the Northern hemisphere. However, only limited research has been conducted to unveil its precise origin. Compositional changes along terrestrial-aquatic pathways can help determine the terrestrial sources of DOM in streams. Stream water, soil water and soil horizons were sampled at four sites representing typical settings within a forested catchment in the Ore Mountains (Erzgebirge, Germany) from winter 2020 to spring 2022. The samples were analyzed using pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The resulting data were successfully subjected to semi-automatic processing of the molecular composition of DOM, reaching a percentage of identified peaks up to 98 %. Principal component analysis (PCA) and cluster analyses were carried out to identify distinct differences between DOM from the potential sources and in the streams. According to the PCA, organic soil horizons, soil water, and stream water samples could be clearly distinguished. Cluster analysis revealed that soil water DOM at all depths of Peats and deeper horizons of the Peaty Gleysols contributed the most to DOM in the stream section dominated by organic soils. In areas dominated by mineral soils, stream DOM resembled the DOM from the deeper mineral horizons of Cambisols and Podzols. Overall, our results suggested that most of the DOM exported from the catchment was derived from deeper mineral soil horizons, with little contribution of DOM derived from organic soils. Therefore, DOM fingerprint analysis of in-situ soil water proved to be a promising approach for tracing back the main sources of stream water DOM.

An Assessment of Polycyclic Aromatic Hydrocarbons Using Estimation Programs

In the environment, the class of chemicals known as polycyclic aromatic hydrocarbons (PAHs) behave somewhat differently. This review covers situations where PAHs can be 'labile' and where they can be persistent. The in-silico prediction of toxicity and the properties of selected 29 PAHs were estimated using programs developed by the U.S. Environmental Protection Agency (EPA), such as the Estimation Programs Interface (E.P.I.) and the Toxicity Estimation Software Tool (version 5.1.2) (TEST), with online software such as SwissADME and SwissDock. TEST was used to estimate the LC50 of the fathead minnow (with a range of 14.53 mg/L for 1-indanone and 2.14 × 10-2 mg/L for cyclopenta[c,d]pyrene), the LC50 of Daphnia magna (with a range of 14.95 mg/L for 1-indanone and 7.53 × 10-2 mg/L for coronene), the IGC50 of Tetrahymena pyriformis (with a range of 66.14 mg/L for 1-indanone and 0.36 mg/L for coronene), the bioconcentration factor (8.36 for 1,2-acenaphthylenedione and 910.1 for coronene), the developmental toxicity (0.30 (-) for 1,2-acenaphthylenedione and 0.82 (+) for 4-hydroxy-9-fluorenone), and the mutagenicity (0.25 (-) for 2-methyl-9-fluorenone and 1.09 (+) for coronene). The carbon chain and molecular weight have a significant effect on the properties of PAHs. Overall, it was found that PAHs with a lower molecular weight (LMW) have a higher water solubility and LC50 value and a smaller LogKow value, whereas the opposite is true for heavier PAHs, with TEST predicting that PAHs with an MW of over 168.2 g/mol, with a few exceptions, are mutagenic. Hence, LMW PAHs have a higher potential to be in the environment but are less toxic.

Polycyclic aromatic hydrocarbons in ship breaking area and associated ecological risk assessment: evidence from the Sitakund ship-breaking area in Bangladesh

Ship-breaking yards are recognized for releasing hazardous polycyclic aromatic hydrocarbons (PAHs), leading to severe environmental pollution in the sediment of ship-breaking areas. This study assessed the concentrations of 16 priority PAHs in surface sediments collected from the intertidal zone adjacent to the Sitakund ship-breaking yards. The samples underwent Soxhlet extraction and detection using PerkinElmer GC-Clarus 690 and MS-Clarus SQ8C with an Elite-5MS capillary column (30 m × 0.25 mm ID × 0.25 µm). The study utilized PAH concentrations to reveal spatial distribution patterns, identify point sources, and assess potential toxicity. The total PAH concentration ranged from 1899.2 to 156,800.08 ng g-1 dw, while the concentration of 7 carcinogenic PAHs ranged from 822.03 to 1899.15 ng g-1 dw. High molecular weight PAHs dominated among the 16 PAHs, whereas low molecular weight PAHs, such as 2-ring PAHs, were negligible. Source characterization based on different molecular ratios suggested that PAHs in the area originated from pyrolytic processes related to ship dismantling, fishing activities, and water transportation for people. The observed PAH concentrations exceeded both national and international standards for sedimentary PAH levels, indicating significant ecological risks. The total TEQcarc values of sediment samples varied from 564.41 to 10,695.12 ng g-1, with a mean value of 3091.25 ng g-1. The study's findings underscore the immediate biological damage that PAH contamination in the Sitakund ship-breaking area could cause, emphasizing the need for effective control measures to ensure ecological and human safety.

Spatial variations and health risk assessment of heavy metal levels in groundwater of Qatar

The present work's objective is to give a comprehensive overview of the quality of groundwater in Qatar in terms of heavy metals content as well as investigating the cause and effect of the elevation in their levels above the WHO/US-EPA standards. The scope of the study included (1) physical and chemical analysis of 82 groundwater samples collected from various locations around Qatar, (2) development of ArcGIS maps depicting the variations in the levels, (3) assessment of the human health risks associated with the existing levels using three of the most used models which are: Hazard index (HI), Nemerow comprehensive pollution index (NCPI) and Incremental Lifetime Cancer Risk (ILCR). There is no extensive study ever reported to assess the health risks linked with the consumption of groundwater characterized with such heavy metals levels in Qatar. The chronic daily intake (CDI) of the investigated heavy metals (Ag, Mn, Cr, V, Mo and Sr) through ingestion and dermal pathways had a range of 1.4 × 10-5-6.7 × 10-1 mg/kg/day while the NCPI's range was reported at 0-4.39. Moreover, the HI and ILCR were found to have a range of 0-3.2 and 5.6 × 10-4-5.5 × 10-2, respectively. The assessment of health risks, conducted in the present work, could be beneficial in building the baseline of heavy metals levels in groundwater in Qatar. This will also help in the determination of any future contamination of groundwater.

Association between exposure to water sources contaminated with polycyclic aromatic hydrocarbons and cancer risk: A systematic review

The recent scientific focus on polycyclic aromatic hydrocarbons (PAHs) has stemmed from their recognized genotoxic, mutagenic, and carcinogenic properties. This systematic review seeks to evaluate the nexus between exposure to water sources contaminated with PAHs and the associated cancer risk among global populations, encompassing both children and adults. Web of Science (WoS), Cochrane Library, PubMed, ProQuest, Scopus, and Google Scholar, were searched following the PRISMA guidelines, until December 31, 2023. Quality assessment of the selected studies was performed using the Newcastle-Ottawa Scale. The increased lifetime cancer risk (ILCR) attributed to PAH exposure through ingestion and dermal absorption was thoroughly examined across diverse age groups. After extensive searching, screening, and eligibility, 30 articles were included in this review, which was conducted in different parts of the world, including Nigeria (n = 11), China (n = 7), India (n = 4), Iran (n = 3), South Africa (n = 2), Italy (n = 1), Colombia (n = 1), and Iraq (n = 1). Our analysis underscores Nigeria's alarming prevalence of PAH contamination in its rivers, groundwaters, and seawater. Remarkably, the highest cancer risk was identified among children and adults, notably in proximity to the Atlas Cove jetty (seawater) and various Nigerian rivers. This elevated risk is primarily attributed to the combined effects of ingestion and dermal absorption. Furthermore, our findings emphasize the prominent role of combustion-derived and pyrogenic sources of PAH in the examined aquatic ecosystems. This study unequivocally establishes that PAH-contaminated water sources significantly amplify the risk of cancer among both children and adults. The extent of risk variation is influenced by the specific water source, duration of exposure, and age group. Consequently, proactive identification of contaminated water sources and their pollution origins, coupled with targeted educational campaigns, holds promise for reducing the global burden of PAH-related cancer.

An extensive investigation on human risk associated with PAHs in fish and sediment in Bushehr, Northern of Persian Gulf

Here, a comprehensive study was designed to estimate the human risk assessment attributed to exposure of polycyclic aromatic hydrocarbons (PAHs)in sediment and fish in most polluted shore area in north of Persian Gulf. To this end, a total of 20 sediment and inhabitual Fish, as one of most commercial fish, samples were randomly collected from 20 different stations along Bushehr Province coastline. The 16 different components of PAHs were extracted from sediment and edible parts of inhabitual fish and measured with high-performance liquid chromatography (HPLC) and gas chromatography (GC), respectively. In addition, dietary daily intake (DDI) values of PAHs via ingestion Indian halibut and the incremental lifetime cancer risk (ILCR) attributed to human exposure to sediments PAHs via (a) inhalation, (b) ingestion, and (c) dermal contact for two groups of ages: children (1-11 years) and adults (18-70 years) were estimated. The results indicated that all individual PAHs except for Benzo(b)flouranthene (BbF) and Benzo(ghi) perylene (BgP) were detected in different sediment sample throughout the study area with average concentration between 2.275 ± 4.993 mg.kg-1 dw. Furthermore, Naphthalene (Nap) with highest average concentration of 3.906 ± 3.039 mg.kg-1 dw was measured at the Indian halibut. In addition, the human risk analysis indicated that excess cancer risk (ECR) attributed to PAHs in sediment and fish in Asaluyeh with high industrial activities on oil and derivatives were higher the value recommended by USEPA (10-6). Therefore, a comprehensive analysis on spatial distribution and human risk assessment of PAHs in sediment and fish can improve the awareness on environmental threat in order to aid authorities and decision maker to find a sustainable solution.

Ecotoxicological and health risks associated with sediment-bound polycyclic aromatic hydrocarbons in peri-urban closed and open coastal lagoons

Coastal urbanisation has ramifications for the sustainable development of developing nations. There are often unquantified ecological and health risks associated with urbanisation. Sixteen polycyclic aromatic hydrocarbons (PAHs) were analysed in surface sediment from three peri-urban coastal lagoons in southern Ghana. We found significant spatial variations of sediment PAHs. These variations were attributed to physiography of the lagoons and diverse anthropogenic activities surrounding them. Total PAHs ranged from 20.81 to 24,801.38 μg/kg (dry weight), underscoring a low to very high pollution level. Diagnostic ratios revealed both pyrogenic and petrogenic origins. Over 50 % of individual PAHs were of moderate ecological risk to benthic organisms, and cancer risk to humans was above the World Health Organisation's recommended safety limit (1 × 10-6). These ecological and health risks should be wake-up call for a more integrated urban planning approach to coastal urbanisation as coastal communities largely depend on natural ecosystems for food and livelihood opportunities.

Polycyclic aromatic hydrocarbons in surface water of rivers in Sergipe State, Brazil: A comprehensive analysis of sources, spatial and temporal variation, and ecotoxicological risk

This study conducted in Sergipe State, Brazil, aimed to investigate the presence of polycyclic aromatic hydrocarbons (PAHs) in the surface water of five rivers, determining their sources, spatial and temporal variations, and ecotoxicological risks. Correlation and principal component analyses were utilized to identify the relationship between PAH concentrations and water sample properties. Results indicated higher PAH concentrations during the rainy season, attributed to increased run-off and sediment resuspension. The composition of PAHs suggested a main petroleum source with organic material combustion in minor scale. Ecological risk assessment revealed potential risks to the ecosystem, emphasizing the need for continuous monitoring of PAHs pollution. This study highlights the importance of understanding and mitigating PAHs contamination in rivers to protect aquatic ecosystems.

Seasonal variation and concentration of PAHs in Lake Balaton sediment: A study on molecular weight distribution and sources of pollution

The temporal and spatial variations of 16 Polycyclic Aromatic Hydrocarbons (PAHs) were examined at multiple sites around Lake Balaton from February 2023 to January 2024. The results indicated that the concentrations of PAHs in sediment were high during the winter months, 448.35 to 619.77 ng/g dry weight, and low during the summer months, 257.21 to 465.49 ng/g dry weight. The concentration of high molecular weight PAHs (HMWPAHs), consisting of 5-6 rings, was greater than that of low molecular weight PAHs (LMWPAHs), which had 2-3 rings. The total incremental lifetime cancer risk (ILCR) for both dermal and ingestion pathways was high for both adults and children during the four seasons, with the highest records as the following: winter > spring > summer > autumn. The ecological effects of the 16 PAHs were negligible except for acenaphthylene (Acy) and fluorene (Fl), which displayed slightly higher concentrations during the autumn and spring, respectively.

Temporal and spatial distribution of polycyclic aromatic hydrocarbons (PAHs) in the Danube River in Hungary

The Danube is a significant transboundary river on a global scale, with several tributaries. The effluents from industrial operations and wastewater treatment plants have an impact on the river's aquatic ecosystem. These discharges provide a significant threat to aquatic life by deteriorating the quality of water and sediment. Hence, a total of 16 Polycyclic Aromatic Hydrocarbons (PAHs) compounds were analyzed at six locations along the river, covering a period of 12 months. The objective was to explore the temporal and spatial fluctuations of these chemicals in both water and sediment. The study revealed a significant fluctuation in the concentration of PAHs in water throughout the year, with levels ranging from 224.8 ng/L during the summer to 365.8 ng/L during the winter. Similarly, the concentration of PAHs in sediment samples varied from 316.7 ng/g in dry weight during the summer to 422.9 ng/g in dry weight during the winter. According to the Europe Drinking Water Directive, the levels of PAHs exceeded the permitted limit of 100 ng/L, resulting in a 124.8% rise in summer and a 265.8% increase in winter. The results suggest that the potential human-caused sources of PAHs were mostly derived from pyrolytic and pyrogenic processes, with pyrogenic sources being more dominant. Assessment of sediment quality standards (SQGs) showed that the levels of PAHs in sediments were below the Effect Range Low (ERL), except for acenaphthylene (Acy) and fluorene (Fl) concentrations. This suggests that there could be occasional biological consequences. The cumulative Individual Lifetime Cancer Risk (ILCR) exceeds 1/104 for both adults and children in all sites.

A sustainable nano-hybrid system of laccase@M-MWCNTs for multifunctional PAHs and PhACs removal from water, wastewater, and lake water

This study examined the use of modified multiwall carbon nanotubes (M-MWCNTs) with immobilized laccase (L@M-MWCNTs) for removing ciprofloxacin (Cip), carbamazepine (Cbz), diclofenac (Dcf), benzo[a]pyrene (Bap), and anthracene (Ant) from different water samples. The synthesized materials were characterized using an array of advanced analytical techniques. The physical immobilization of laccase onto M-MWCNTs was confirmed through Scanning electron microscope (SEM)-dispersive X-ray spectroscopy (EDS) analysis and Brunner-Emmet-Teller (BET) surface area measurements. The specific surface area of M-MWCNTs decreased by 65% upon laccase immobilization. There was also an increase in nitrogen content seen by EDS analysis asserting successful immobilization. The results of Boehm titration and Fourier transform infrared (FTIR) exhibited an increase in acidic functional groups after laccase immobilization. L@M-MWCNTs storage for two months maintained 77.8%, 61.6%, and 57.6% of its initial activity for 4 °C, 25 °C, and 35 °C, respectively. In contrast, the free laccase exhibited 55.3%, 37.5%, and 23.5% of its initial activity at 4 °C, 25 °C, and 35 °C, respectively. MWCNTs improved storability and widened the working temperature range of laccase. The optimum removal conditions of studied pollutants were pH 5, 25 °C, and 1.6 g/L of M-MWCNTs. These parameters led to >90% removal of the targeted pollutants for four treatment cycles of both synthetic water and spiked lake water. L@M-MWCNTs demonstrated consistent removal of >90% for up to five cycles even with spiked wastewater. The adsorption was endothermic and followed Langmuir isotherm. Oxidation, dehydrogenation, hydroxylation, and ring cleavage seem to be the dominant degradation mechanisms.

Critical review on the formations and exposure of polycyclic aromatic hydrocarbons (PAHs) in the conventional hydrocarbon-based fuels: Prevention and control strategies

Polycyclic aromatic hydrocarbons (PAHs) are widely present in the atmosphere and primarily originate from the incomplete burning of fossil fuels and biofuels. Exposure to PAHs leads to harmful effects on human health and the environment. Diesel engines are a major source of PAH production in the transportation sector. Various approaches have been employed to reduce PAH emissions from diesel engines, including the use of biodiesel, green gaseous fuels, exhaust gas recirculation, exhaust after-treatment, and genetically modifying biodiesel with nanoparticles. This review focuses on PAH emissions from different generations of fuels and examines the remedial control actions taken to mitigate PAH formation. The study underscores the necessity for effective regulation of emissions from diesel engines, especially in developing countries where the reliance on fossil fuels is significant. Biodiesel has shown promise in reducing PAHs and carcinogenic pollutants, with higher biodiesel concentrations resulting in lower PAH formation. Replacing diesel with biodiesel and optimizing engine operating conditions are feasible methods to reduce PAH levels in the atmosphere. The use of nanoparticles in fuel blends and higher oxygen content in combustion chambers are also considered potential strategies for pollutant reduction. Additionally, the utilization of hydrogen and ammonia as secondary fuels has been explored as promising alternatives to fossil fuels. The study highlights the importance of further research on the presence of residual PAHs in the atmosphere and the implementation of strategies to curtail vehicular emissions.

Impact of Arieş River Contaminants on Algae and Plants

The Arieş River (Western Romania) represents one of the most important affluents of the Mureş River, with great significance in the Mureş Tisza basin. The environmental quality of the Arieş basin is significantly affected by both historic mining activities and contemporary impacts. Thus, an evaluation of the effects of the main contaminants found in water (organochlorine pesticides-OCPs, monocyclic aromatic hydrocarbons-MAHs, polycyclic aromatic hydrocarbons-PAHs, and metals) on cyanobacteria and plants was performed. Among OCPs, hexachlorocyclohexane isomers, dichlorodiphenyltrichloroethane, and derivatives were detected in plants while admissible concentrations were detected in water. Among MAHs, high levels of benzene were detected both in water and in plants. The levels of PAHs exceeded the allowable values in all samples. Increased concentrations of metals in water were found only at Baia de Arieş, but in plants, all metal concentrations were high. The pH, nitrates, nitrites, and phosphates, as well as metals, pesticides, and aromatic hydrocarbons, influenced the physiological characteristics of algae, test plants, and aquatic plants exposed to various compounds dissolved in water. Considering that the Arieş River basin is the site of intense past mining activities, these data provide information about the impact on water quality as a consequence of pollution events.

Comparison of the effects of use, protection, improper renovation and removal of asbestos products on the example of typical old office buildings in Poland

The study focused on old, German building types "LIPSK" and "BERLIN" used in Poland, since the 1960s in Eastern Europe. The different operations on buildings were analysed: protection and maintenance of asbestos products, asbestos removal and inadvertent damage to asbestos as a result of building renovation. Measurements of respirable (countable) asbestos fibres in the air were carried out using the PCOM + PLM method and SEM-EDS. In the case of the accidental destruction of products, initial contamination was ≈7000 f/m3. After 16 weeks from the end of the activity and 20 days of extreme ventilation, contamination decreased to about 500 f/m3. At the same time, in similar rooms, without extreme ventilation, the pollution was above 4000 f/m3. The average increase in pollution in a dozen or so similar buildings, after asbestos removal in places beyond the work zones, ranged from ≈ 1700-2700 f/m3 and lasted for one or two years. These buildings, used without ACM destruction or after product impregnation, have maintained low asbestos contamination < 300 f/m3 for more than 10-20 years. So, due to the easy release of asbestos that occurs with any ACM removal and the increased risk of occupant exposure, these works are often inappropriate for the buildings in question.

Ecological and human health risk assessment of polycyclic aromatic hydrocarbons (PAH) in Tigris river near the oil refineries in Iraq

Recent Iraqi battles against ISIS in 2014 and 2015 resulted in the destruction or severe damage to several refineries' infrastructure. This, along with other factors, has led to the release and accumulation of a wide range of hazardous chemicals into the environment, for instance, polycyclic aromatic hydrocarbons (PAH). Thus, for the first time, a comprehensive 16 PAHs measurements campaign over the course of six months near the oil refineries along the Tigris River and its estuaries was investigated. The 16 PAHs concentrations in surface water and the sediments for the following oil refineries: Baiji, Kirkuk, Al-Siniyah, Qayyarah, Al-Kasak, Daura, South Refineries Company, and Maysan were examined. The overall findings indicated that the 16 PAHs concentrations ranged from 567.8 to 3750.7 ng/L for water and 5619.2-12795.0 ng/g for sediment. Water samples in South Refineries Company recorded the highest PAH concentrations while Baiji oil refinery registered the highest PAH concentrations in the sediment samples. The percentages of high molecular weight PAH (5-6 rings) in water and sediment samples were the highest, ranging from 49.41% to 81.67% and from 39.06% to 89.39% of total PAH for water and sediment, respectively. The majority of 16 PAHs measured in water and sediment samples of the Tigris River were derived from pyrogenic sources. Based on sediment quality guidelines (SQGs), most sites showed a possible effect range with occasional biological effects of most of the PAH concentrations in all sediments' samples. The calculated incremental lifetime cancer risk (ILCR) value was high risk with adverse health effects, including cancer.

Estimation of Polycyclic Aromatic Hydrocarbons in Groundwater from Campania Plain: Spatial Distribution, Source Attribution and Health Cancer Risk Evaluation

The aim of this study was to evaluate the concentrations of polycyclic aromatic hydrocarbons (PAHs) in 1168 groundwater samples of the Campania Plain (Southern Italy), taken using a municipal environmental pressure index (MIEP), and to analyze the distribution of these compounds to determine source PAHs using ratios of isomers diagnostic. Lastly, this study also aimed to estimate the potential health cancer risk in groundwaters. The data indicated that the highest concentration of PAHs was found in groundwater from Caserta Province and the contents of BghiP, Phe, and Nap were detected in the samples. The spatial distribution of these pollutants was evaluated using the Jenks method; moreover, the data indicated that incremental lifetime cancer risk ILCR_ingestion ranged from 7.31 × 10^-20 to 4.96 × 10^-19, while ILCR_dermal ranged from 4.32 × 10^-11 to 2.93 × 10^-10. These research findings may provide information about the Campania Plain's groundwater quality and aid in the development of preventative measures to lessen PAH contamination in groundwater.