Impact of polycyclic aromatic hydrocarbons in mangroves from the Colombian pacific coast: Evaluation in sediments and bivalves

Determination of organic pollutants and pollution sources in sequentially collected rainwater samples in Isparta Province

Rainwater can accumulate organic airborne pollutants such as polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) due to atmospheric factors. There is an increasing interest in evaluating the temporal and spatial role of concentration changes of these pollutants and examining transport-based pollutants. This is of great importance especially for elements exposed to rapid environmental changes such as air and water. These residues can become a source of pollutants for virgin areas, surface waters, and soils through atmospheric deposition. Therefore, the determination of these compounds in rainwater samples can provide valuable information for the preliminary assessment of air quality in urban areas. In Isparta province of Türkiye, consecutive rainwater samples were collected and the concentrations of 50 OCPs and 16 PAHs were determined. Fluid management system-turbo trace parallel‒solid phase extraction (FMS‒TTP‒SPE) system, which is considered an environmentally friendly system by minimizing the use of solvents in sample preparation, was used. Back-orbit measurements (HYSPLIT) were used to investigate the atmospheric transport effect. In general, the quality of rainwater obtained from precipitation was determined to be good. The lowest concentration detected for benzo[k]fluoranthene was 0.99 µg L-1, while the highest concentration for phenanthrene was 213 µg L-1. In addition, 15 OCPs were detected, and the highest concentration was found in the pesticide chlordecone. These findings indicate that the detection of PAHs and OCPs in urban rainwater samples taken from a city with relatively good air quality may indicate significant atmospheric deposition of these pollutants.

Mangrove guardians: Unearthing the enrichment patterns of PAHs in the Zhangjiang estuary ecosystem

Understanding the bioaccumulation of PAHs in mangrove plants is crucial as it reflects the ecosystem's ability to mitigate pollution and minimize its impacts on surrounding environments. The Zhangjiang Estuary mangrove ecosystem is a vital ecological asset in Fujian Province, however, the interactions between contaminants, such as polycyclic aromatic hydrocarbons (PAHs), and mangrove plant tissues remain underexplored. This study investigates the different bioaccumulation patterns and machanism of 26 PAHs in three mangrove species (Kandelia obovata, Aegiceras corniculatum, and Avicennia marina). PAHs concentrations in mangrove and estuarine sediments ranged from 55.68 to 247.76 ng/g and 119.16 to 346.03 ng/g, while Σ26PAHs in the mangrove plants ranged from 13.03 to 172.17 ng/g, which was dominated by two- and five-ring PAHs. The bioconcentration factors (BCFs) of plant tissues showed a wide range, from 0 to 330.17, stems exhibited the highest PAHs concentrations compared to roots and leaves, with BCFs in stems following average enrichment factors: two-ring PAHs (37.23 ± 13.33) > alkylated PAHs (9.40 ± 4.66) > three-ring PAHs (3.09 ± 2.20) > six-ring PAHs (2.29 ± 0.36) > five-ring PAHs (0.52 ± 0.06) > four-ring PAHs (0.03 ± 0.01). The BCFs in roots showed strong positive correlations with logKow and Koc values, while the trends in stems and leaves were reversed, suggesting that roots showed high affinity for hydrophobic compounds, while stems and leaves preferred more water-soluble PAHs. The bioaccumulation capacity was highest in Aegiceras corniculatum, followed by Kandelia obovata and Avicennia marina. Additionally, alkylated PAHs were more enriched than their parent compounds, indicating selective uptake potential in mangrove plants. These findings underscore the critical role of mangrove species in mitigating PAHs contamination through selective absorption and accumulation. The results provide valuable insights into the application of mangrove ecosystems in bioremediation and offer guidance for environmental management in coastal regions.

Source attribution, health risk analysis, and policy implications of PAHs and NPAHs in PM[Formula: see text] in Northern Mexico

This research investigates the concentrations, sources, and health risks of polycyclic aromatic hydrocarbons (PAHs) and nitrated PAHs (NPAHs) in particulate matter with an aerodynamic diameter of 10 μm or less (PM[Formula: see text]) from critical urban centers in northern Mexico: Metropolitan Monterrey Area (MMA), Chihuahua (CHI), and Ciudad Juárez (CDJ). Advanced gas chromatography-mass spectrometry (GC-MS and GC-NCI-MS) revealed significant PAHs concentrations, with levels in MMA reaching 108.89 ± 99.90 ng/m[Formula: see text], CHI at 100.69 ± 122.60 ng/m[Formula: see text] and CDJ at 73.26 ± 90.85 ng/m[Formula: see text]. Significantly, 3-nitrofluoranthene (3N-FLA) and 1-nitropyrene (1N-PYR), known for their potent toxicity, were among the most prominent NPAHs, with total concentrations in MMA, CHI, and CDJ at 470.32 pg/m[Formula: see text], 247.26 pg/m[Formula: see text], and 193.20 pg/m[Formula: see text], respectively. Source apportionment using diagnostic ratios (DRs) and principal component analysis (PCA) indicated that biomass burning, vehicular emissions, and industrial activities were the primary sources of MMA. At the same time, CHI and CDJ were influenced more by industrial and diesel emissions. Health risk assessments based on benzo[a]pyrene equivalent (BaPeq) concentrations and excess cancer risk (ECR) demonstrated moderate to significant cancer risks, with CDJ exhibiting the highest NPAHs-related risk. This study makes several significant contributions: it presents the first analysis of PAHs and NPAHs levels in these urban areas, identifies key emission sources, and quantifies associated health risks, providing essential data for developing targeted public health policies and environmental regulations.

New solid phase microextraction fibers with green clay coating via radio frequency magnetron sputtering for detecting low-polar compounds in water samples

BACKGROUND

Developing highly sensitive and selective measurement techniques to detect trace compounds in diverse matrices is a significant challenge in analytical chemistry. These techniques must adhere to green chemistry principles by minimizing organic solvent use, simplifying sample preparation, and streamlining process steps. Additionally, there is a growing need for sustainable analytical methods due to increased environmental awareness. The problem addressed in this work is the need for an eco-friendly and efficient method for the extraction and detection of trace organochlorine pesticides in water samples.

RESULTS

We employed SPME using a novel clay thin film sorbent, deposited on a nickel-titanium alloy wire via magnetron sputtering. Montmorillonite clay was chosen for its excellent adsorption properties and eco-friendly nature, aligning with green chemistry principles. The approach involved coating the SPME fiber with hydrophobic modified montmorillonite clay, followed by silylation. The method was tested for extracting 12 model organochlorine pesticides, including BHC, lindane, and DDT, demonstrating high isolation efficiency. The coated thin film and its silylation modification were characterized using standard spectroscopic techniques, confirming the successful creation of a new adsorbent phase. The direct immersion SPME approach achieved relative recoveries ranging from 65 % to 99 %, with reproducibility (RSD) below 6 %. This method provided low detection limits (10-15 ng L-1) and quantitation limits (32-50 ng L-1).

SIGNIFICANCE

Our approach offers an eco-friendly, highly efficient solution for the extraction and detection of trace organochlorine pesticides. The significant improvement in recovery rates and reproducibility, combined with low detection and quantitation limits, underscores the potential of this method to enhance analytical practices in environmental monitoring and public health. Furthermore, the use of sustainable materials and processes aligns with global efforts to reduce environmental impact in analytical chemistry.

Polycyclic aromatic hydrocarbons in sediments and bivalves along the Moroccan Mediterranean coast: Spatial distribution, sources, and risk assessment

Polycyclic aromatic hydrocarbons (PAHs) are commonly found in the marine environment and can have harmful impacts on marine biodiversity. Therefore, investigation of the occurrence, source and risks of PAHs is of great importance to protect ecosystem and human health. The objectives of this work were to assess the concentrations and distribution of PAHs in marine sediments and in mollusc bivalve (Callista chione) along the Mediterranean coasts of Morocco and finally evaluate the risk to human health caused by exposure to PAHs. Five sediments samples and seventy five C. chione specimens, were collected along the Moroccan Mediterranean coasts. The ∑PAHs levels in sediment varied considerably, varying from 1 to 251 ng/g with an average of 50.38 ng/g, while values for bivalves varied from 1 to 51 ng/g dw with an average concentration of 16.76 ng/g dw. The PAHs profile indicates the dominance of 2 and 3 rings PAHs both in bivalves and sediments. PAH concentrations generally rise as one moves from northeast to northwest part of the studied area, closer to the Strait of Gibraltar. The assessment of PAH isomeric ratios revealed a mixed pyrolytic/petrogenic source. Based on the sediment quality guidelines (SQGs), the risk of PAHs in the sediments was considered to be comparatively low. Similarly, Ecological risk assessment based on risk quotient (RQ) and toxic equivalency factors (TEFs) revealed potentially low ecological risks from PAHs. Exposure to PAHs via bivalve consumption does not cause adverse impacts on the health of consumers following the calculated health risk indices. As the levels of PAHs in biota are not negligible, continuous mentioning marine organisms campaigns should be performed to highlight the distribution and concentration of PAHs and assess the risk for human health from consumption of seafood.

Polycyclic aromatic hydrocarbons in commercial marine bivalves: Abundance, main impacts of single and combined exposure and potential impacts for human health

Polycyclic aromatic hydrocarbons (PAHs) are emerging pollutants with a broad distribution in marine environments. They can interact with other pollutants and be bioaccumulated by marine bivalves, which can be consumed by humans. This is the first review that focuses on the presence and effects of PAHs, single or combined with other pollutants, in commercial marine bivalves. Around the world, researchers have detected several PAHs in valuable marine bivalves and reported immunological, genotoxic, neurotoxic, physiological, reproductive, and biochemical effects in these species caused by exposure to PAHs, alone or combined with other pollutants, using efficient and accurate methods. Commercial marine bivalves contaminated with PAHs may pose a risk to marine food chains and environments and to human health. We recommend further research on the abundance and neurotoxic, physiological, reproductive and biochemical effects of PAHs, alone and with other pollutants, in commercial marine bivalves and more human health risk assessments.

Identification of key anthropogenic and land use factors and ecological risk assessment of dissolved polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) in an urbanized estuary in China

This study investigated dissolved PAHs and OCPs in Quanzhou Bay estuaries, assessed their ecological risk, and examined anthropogenic impacts on contaminant distribution. Results showed that dissolved ∑24PAH concentrations ranged from 117 to 709 ng/L (mean: 358 ng/L), with dominance of 2-ring PAHs (Naphthalene, 1-Methylnaphthalene, and 2-Methylnaphthalene). Dissolved DDT levels ranged from 0.06 to 0.49 ng/L (mean: 0.28 ng/L), while HCBz concentrations varied from 0.02 to 0.44 ng/L (mean: 0.20 ng/L). PAHs were higher in the north due to urbanization and transport, while OCPs showed higher levels in the south due to historical agricultural use. Rural areas, water bodies, and wetlands significantly influenced the behavior of PAHs according to Spearman correlation and lasso regression analyses. Quanzhou Bay was categorized as a low to medium risk area based on dispersion simulation and ecological risk assessment, highlighting implications for future sustainable development and policy planning. CAPSULE: The coupled relationship between human activities and the distribution of dissolved PAHs and OCPs in urbanized estuaries was explored using statistical methods and GIS technology, providing valuable insights into environmental processes and pollutant control policies.

Does mangrove leave falling dominate the bury of polycyclic aromatic hydrocarbons in the mangrove of China?

Mangrove wetlands are vital coastal ecosystems that can absorb and accumulate pollutants. Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants that pose potential risks to ecosystems and human health. However, their source and transport fate in mangrove areas are poorly understood. This study investigates 29 PAHs pollution of water and sediment in Zhangjiangkou Mangrove Wetland, the northernmost large-scale mangrove wetland reserve in China. We examine the distribution, source, transport mechanisms and risk assessment of PAHs. The results show that the concentrations of PAHs in mangrove sediment range from 55.62 to 347.36 ng/g (DW), with 5-ring PAHs being the dominant species. While the concentrations of PAHs in surface water range from 10.61 to 46.39 ng/L, with 2-ring PAHs and alkylated PAHs being the dominant species. The PAHs concentrations in surface water and sediment of river are higher than those in mangrove area, indicating that mangrove water could receive PAHs through tidal exchange. Based on diagnostic ratios (DRs), principal component analysis (PCA), and positive matrix factorization (PMF), we infer that the leaf deposition (48.55%) could be an important pathway of PAHs in mangrove sediment except for river water transport (51.45%), while the PAHs in estuary water originate mainly from point sources such as biomass burning (50.96%) and traffic emission (49.04%). The range of toxic equivalents in surface water and sediment was 2.73-16.09 ng TEQ g-1 and 0.03-3.63 ng/L, respectively. Although the ecological risk assessment suggests that the PAHs pollution in surface water and sediment poses a low risk, we recommend more attention to the protection of the mangrove ecosystem. This study reveals that mangrove leaf falling might be a significant mechanism of PAH sequestration in the mangrove system, which deserves more attention in future research.

Osmoregulatory responses in the neotropical fish species Astyanax lacustris, exposed to single and combined microplastics, polycyclic aromatic hydrocarbons, and their mixture

Microplastic (MP) pollution poses a significant environmental threat. These MPs can adsorb toxic compounds such as polycyclic aromatic hydrocarbons (PAH), which are highly lipophilic and carcinogenic. To assess the potential effects of virgin MP, PAH, and MP+PAH in association with osmoregulation and energetic substrate, we conducted experiments with the tetra cardinal Astyanax lacustris. The environmentally relevant concentration of MP (10 mg L-1) and 20 % of the LC50-96 h of crude oil for A. lacustris (2.28 µg L-1) were used during the 96-h exposure. Fish were exposed to virgin MP, PAH, MPC (MP loaded with PAH), PAH+MP (PAH and MP in association), and the control without (CT) and with handling (CH). After 96 h, blood was collected for osmoregulatory parameters (plasma osmolality; Na+, K+, Cl-, Mg2+; glycose and lactate); gills for osmoregulatory enzyme activities (Na+, K+ ATPase, H+ ATPase, and carbonic anhydrase); and white muscle samples were used to determine glycogen as an energetic substrate. The low molecular weight PAH was not detected in PAH-loaded MP (MPC) and PAH in combination with MP (PAH+MP). The PAH concentration of the MPC and PAH+MP was similar and low compared to other works. Virgin MP, PAH, MPC, and PAH+MP were able to cause muscle glycogen depletion. The activity of v-type H+ ATPase and plasma Na+ concentrations were lower in PAH with MP (MPC). However, the hydromineral balance (K+, Mg2+, Cl-, and osmolality) was not affected by any treatment. In this sense, we can conclude that the MPC caused osmoregulatory disturbances not seen in the MP associated with PAH (MP+PAH). However, this seems unrelated to the PAH leaking from the MPC or the PAH absorption to the virgin MP once the PAH concentrations from the MPC and PAH+MP were similar.

Environmental risk assessment of petrogenic hydrocarbon spills in mangrove ecosystems: the Tumaco case study as a baseline, Colombian Pacific

Petrogenic hydrocarbon spills (PHS) are harmful to mangrove ecosystems along tropical coastlines in the short and long term. The aim of this study was to assess the environmental risk of recurrent PHS on mangrove ecosystems in Tumaco municipality, Colombian Pacific. Mangrove characteristics and management aspects led to subdividing the study area into 11 units-of-analysis (UAs) for which threats, vulnerability, potential impacts, and risks were assessed based on environmental factors and the formulation and use of indicators in a rating scale with five categories, which are very low, low, moderate, high, and very high. The results showed that all UAs are highly (64%; 15,525 ha) or moderately (36%; 4,464 ha) threatened by PHS, highly (45%; 13,478 ha) or moderately (55%; 6,511 ha) vulnerable to this kind of pollution, and susceptible to high (73%; 17,075 ha) or moderate (27%; 2,914 ha) potential impacts. The environmental risk was high in 73% (17,075 ha) of the UAs, indicating likely irreversible damage to mangrove ecosystems by PHS, thus pointing to the need of urgent intervention by responsible authorities to ease their recovery and conservation. The methodology and results of this study become technical inputs that serve for environmental control and monitoring, which can be incorporated into contingency and risk management plans.

A baseline study of polycyclic aromatic hydrocarbons distribution, source and ecological risk in Zhanjiang mangrove wetlands, South China

Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental contaminants and pose a severe threat to human health. Here, 38 surface sediment samples collected from the Gaoqiao mangrove wetland in Zhanjiang, south China, were analyzed to determine 16 Environmental Protection Agency (EPA) priority PAHs. Total PAHs concentrations ranged from 33.5 µg/kg to 404.8 µg/kg with an average of 147.7 ± 77.7 µg/kg, inferring a moderate pollution level. Three and four-ring compounds dominated the PAHs composition patterns. Significant positive correlations were observed between the PAHs and the physicochemical properties of the sediments. According to the characteristic molecular ratio method, PAHs in sediments were mainly derived from combustion sources, including the incomplete combustion of liquid fossil fuels, grass, wood, and coal. The result based on the PMF model indicates that the primary combustion sources of PAHs are coal combustion, diesel-powered vehicles, biomass combustion and gasoline-powered vehicles, with a share of 39.01%, 25.21%, 12.72% and 10.48%, respectively. The petrogenic source contributes 12.58% PAHs to the sediments. The mean effects range median quotient (m-ERM-Q) and toxic equivalent method (TEQ) indicate a low comprehensive ecological risk of PAHs in the study area. Still, the evaluation results of effects range low (ERL) suggest that PAHs in the sediment would occasionally have adverse biological effects. Therefore, this situation demands attention and calls for protection strategies in the processes of urbanization and industrialization in south China.

Polycyclic aromatic hydrocarbons (PAHs) in mangrove ecosystems: A review

Polycyclic aromatic hydrocarbons (PAHs) are organic pollutants of increasing concern in the different fields of the environment and human health. There are 16 of them that are recognized as priority pollutants by the US environmental protection agency due to their mutagenic and carcinogenic potentials. Due to their hydrophobicity and stability, they are persistent in the environment and can be transported over long distances. Their toxicological effects on multiple species, including humans, as well as their bioaccumulation in the food web became major topics in organic pollutants research this last decade. In the environment, multiple studies have been conducted on their accumulation in the soil and their degradation processes resulting in numerous review papers. However, the dynamics of PAHs in mangrove ecosystems is not yet completely understood. In this review paper, an exhaustive presentation of what is known about PAHs and their transfer, accumulation, and degradation in mangrove ecosystems is offered. This article brings to light the knowledge already acquired on the subject and the perspective research necessary to fully comprehend PAHs dynamics in mangrove ecosystems.

Accumulation of polycyclic aromatic hydrocarbons (PAHs) in surface sediment residues of Mahanadi River Estuary: Abundance, source, and risk assessment

In this study, we examined the distribution of polycyclic aromatic hydrocarbons (PAHs) in sediments from the Mahanadi River Estuary (MRE), identified sources, and evaluated the ecological toxicity. The PAHs distributions in MRE ranged from 13.1 to 685.4 ng g^-1 (dry weight), with a mean value of 192.91 ± 177.56 ng g^-1 (dry weight). Sediments at sites S11, S8, and S13 have the highest 3-rings, 4-rings, and 5-rings PAHs, respectively. In MRE, pyrene has a significantly higher concentration with a mean value of 30.51 ng g^-1, followed by Fluoranthene (86.2 ng g^-1), Chrysene (67.4 ng g^-1), and Benzo(k)fluoranthene (54.2 ng g^-1). Site S8 had a higher total PAH concentration than sites S11, S13, and S1. The diagnostic and principal component analysis suggests that PAHs originated from petroleum, oil, biomass, and coal combustion. Higher toxic and mutagenic equivalent quotients indicate potential aquatic toxicity and a need for continuous monitoring of MRE for PAHs pollution.