Distribution of polycyclic aromatic hydrocarbons (PAHs) in commonly consumed seafood from coastal areas of Bangladesh and associated human health implications

Determination of polychlorinated biphenyls in water by CO2-responsive switchable deep eutectic solvent based homogeneous liquid-liquid microextraction

A homogeneous liquid-liquid microextraction technique based on switchable deep eutectic solvent (SDES-HLLME), combined with gas chromatography-triple quadrupole tandem mass spectrometry (GC-MS/MS), was developed for the extraction and analysis of 16 polychlorinated biphenyls (PCBs) in water samples. CO2-responsive switchable deep eutectic solvent (SDES), which consists of monoethanolamine (MEA) being used as a hydrogen bond acceptor (HBA) and 3-methoxyphenol (3-MP) being used as a hydrogen bond donor (HBD), was used as the extractant, thus providing an environmentally friendly alternative to conventional toxic organic solvents. The study systematically investigated the effects of various parameters on extraction efficiency, including the type and volume of SDES, vortexing duration, CO2 bubbling time, centrifugation rate and time, ionic strength. Optimal extraction conditions were identified as follows: 40.0 μL of SDES, vortexing for 40.0 s, CO2 bubbling for 2.0 min, 5.0 % (w/v) salt concentration, a centrifugation rate of 5000 rpm, and a centrifugation duration of 3.0 min. Under these optimal conditions, the method exhibited a linear range of 0.1-300 ng·mL-1, with limits of detection (LODs) and quantification (LOQs) ranging from 0.003 to 0.096 ng·mL-1 and 0.009 to 0.321 ng·mL-1, while the relative standard deviation (RSD) <7.98 %. Finally, this method was successfully applied to determine the concentrations of 16 PCBs in various environmental water samples, yielding satisfactory recovery rates. This method provides a green, convenient and accurate new idea in the field of HLLME research.

Impacts of an intensive traditional mariculture model on offshore environments as evidenced by dissolved organic matter and bacterial communities

Mariculture is a key protein source and economic driver but traditional methods pollute coastal waters, hindering sustainable development. Current research on the ecological impacts of mariculture mainly focuses on specific pollutants and lacks an assessment of the biogeochemical impacts of mariculture discharge. This study examined Xiangshan Bay, a representative intensive mariculture area in China, to explore the impact of mariculture tailwater discharge on water quality, focusing on dissolved organic matter (DOM) and bacterial communities. Based on the fluorescence excitation-emission matrix combined with parallel factor analysis, a characteristic fluorescence component C4 was identified in mariculture tailwater (intensity of 40 ± 4 %, n = 8), while higher C4 components (47 ± 3 %, n = 15) were found throughout the bay. Humic-like components from riverine input (C1 + C2: 32 ± 3 %, n = 15) and protein-like components from domestic sewage (C5: 2 ± 1 %, n = 15) were significantly lower in the seawater samples, indicating the strong influence of mariculture tailwater on the entire DOM structure of the bay. The bacterial community structure showed a response consistent with DOM, as revealed by nonmetric multidimensional scaling analysis. This showed that bacterial communities in mariculture tailwater and bay water samples clustered together, independent of riverine input. The SourceTracker model indicated that mariculture tailwater (91 ± 5 %) predominantly contributed to the bacterial community, with minimal contributions from riverine input (< 5 %). Co-occurrence network analysis further showed that under long-term high-intensity mariculture discharge, the C4 component became the core DOM and was closely associated with the bacterial community. The results here demonstrate the profound impact of traditional mariculture on coastal water quality and show that riverine input is not the primary pollution source in this region, providing clear directions for coastal environmental restoration efforts.

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.

Evaluation of polycyclic aromatic hydrocarbon contents in marine products in South Korea and risk assessment using the total diet study

This study investigated levels of eight polycyclic aromatic hydrocarbons (PAH8) compounds in both raw and processed marine products in South Korea. Katsuobushi exhibited the highest concentration of benzo[a]pyrene, at 14.22 µg/kg, exceeding the European Commission's regulation level of 5.0 µg/kg. The total PAH8 concentration in katsuobushi was 220.5 µg/kg. Among the product categories, shellfish had the highest detection rate (70%), followed by fish (19%) and crustacea (8%), with chrysene being the most prominent PAH8 congener in all marine products. Grilled fish predominantly contained pyrogenic PAHs from combustion byproducts, while shellfish primarily contained petrogenic ones from the aquatic environment. Grilling, smoking, and drying processes significantly contributed to the formation of PAH8 in these food products. Based on the results of a risk assessment using a margin of exposure approach through a total diet study, exposure to PAH8 from marine products is considered to pose low concern to the South Korean population.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01491-y.

Sourcing aliphatic and polycyclic aromatic hydrocarbons (PAHs) in Jinga shrimp (Metapenaeus affinis) muscle tissues and surface sediments (study case: Northwest Persian Gulf)

This study addresses the sources of aliphatic hydrocarbons (AHs) and polycyclic aromatic hydrocarbons (PAHs) in the surface sediments of the northwestern Persian Gulf and the muscle tissues of Jinga shrimp (Metapenaeus affinis), a commercially important aquatic species. In November 2018, 28 Jinga shrimp samples were systematically collected from four key fishing areas in Behrgan and Khormusi: Imam Khomeini Port (S1), Mahshahr Port (S2), Sejafi (S3), and Behrgan Wharf (S4). Additionally, sediment samples were collected from these locations, and AHs and PAHs concentrations were analyzed using gas chromatography-mass spectrometry (GC-MS). The average aliphatic concentration in Jinga shrimp was 4800.32 (μg g-1 DW), exceeding the sediment samples' 2496.69 (μg g-1 DW) estimate. Hydrocarbon component analysis revealed EPA priority list (PAH-16) and measured PAHs (PAH-29) concentrations in Jinga shrimp ranging from 1095.8 to 2698.3 (ng g-1 DW) and in sediments from 653.6 to 1019.5 (ng g-1 DW). Elevated AHs and PAHs in Jinga shrimp, compared to sediments, suggest a petrogenic source, notably at station S4 near Behrgansar and Nowruz oil fields. Low molecular weight (LMW) compounds dominated in both shrimp and sediment PAHs. Aliphatic composition profiles in shrimps closely mirrored sediment profiles, illustrating an even-to-odd carbon dominance gradient. Diagnostic ratio examinations of hydrocarbons indicated pervasive petroleum derivatives in the environment. This study establishes a direct correlation between hydrocarbon concentrations in shrimp and sediment samples and the corresponding aliphatic groups, PAH-16, and PAH-29. The findings underscore the potential of Jinga shrimp as a reliable indicator of hydrocarbon pollution in the northwestern Persian Gulf.

Evaluating contamination of seafood purchased from U.S. retail stores by persistent environmental pollutants, pesticides and veterinary drugs

Studies have reported health risks associated with seafood contamination, but few data exist on levels in commercially available seafood in the US. To better understand, the magnitude of foodborne exposure and identify vulnerable populations in the US, we measured concentrations of veterinary drugs, persistent organic pollutants (POPs) (polycyclic aromatic hydrocarbons [PAHs], polybrominated diphenyl ethers [PBDEs] and polychlorinated biphenyls [PCBs]), and legacy and current-use pesticides in 46 seafood samples purchased from retail outlets. Measured levels were used to estimate risk based on available maximum residue limits (MRLs) and toxic equivalence (TEQ) factors for analytes. Only seventeen of the 445 analytes were detected, at low substance frequencies. However, half of the samples tested positive for one or more analyte, with total concentrations ranging from below the limit of detection (LOD) to as high as 156 µg/kg wet weight. Based on the risk assessment for individual pesticides and veterinary drugs, the hazard quotients (HQ) were all <1, indicating no risk. However, for the sum of PCB126 and PCB167, two dioxin-like PCBs detected in our samples, the TEQ was nearly two orders of magnitude higher than the WHO limits in one catfish sample. Moreover, vulnerable groups with higher rates of consumption of specific fish types may face higher risks.

Ameliorative potential of synbiotic combination of Lactobacillus sp. and polyphenols against Benzo[a]pyrene-induced toxicity in Caco-2 cell line

Exposure to benzo[a]pyrene (B[a]P), a major global food safety concern, is often associated with increasing incidence of colorectal cancers. This in-vitro study was focused on the identification of potential B[a]P-adsorbing Lactobacillus strains and evaluation of the ameliorative effect of synbiotic combination of selected Lactobacillus sp. and polyphenols (quercetin or resveratrol) against B[a]P-induced intestinal toxicity in Caco-2 cells. Preliminary studies lead to the selection of Lactiplantibacillus plantarum MTCC 25433 strain that showed 86% of B[a]P adsorption in 2 h as compared to L. rhamnosus GG that showed 74% of B[a]P adsorption. B[a]P adsorption by MTCC 25433 was reduced to 9%, 16% and 20% upon pre-treatment with SDS, NaIO4 and mutanolysin, attributing the involvement of cell wall proteins and polysaccharides in the adsorption. Additionally, peptidoglycan of both strains adsorbed >50% of B[a]P. In-vitro assays revealed that the selected LAB mitigated the B[a]P-induced epithelial cell damage. Among the polyphenols, quercetin, resveratrol and curcumin, varied in their potency to mitigate B[a]P-induced oxidative stress, with curcumin being least effective. Combinations of selected Lactobacillus sp. and polyphenols were more potent in averting B[a]P-induced toxicity via increase in GSH (17-30 %), SOD (50-88 %), catalase (19-45 %), and reduction in IL-8 secretion (14-28 %) and barrier dysfunction. Principal component analysis affirmed the superior potency of combination of L. plantarum MTCC 25433 and quercetin in averting B[a]P-induced toxicity. Overall, this study highlighted a novel promising strategy of synbiotic combination of Lactobacillus sp. and polyphenols (quercetin or resveratrol) in alleviating the B[a]P-induced toxicity in intestinal epithelial cells.

The concentrations of polycyclic aromatic hydrocarbons in fish: A systematic review

This study was conducted on the concentrations of PAHs, including benzo[a]pyrene and the sum of four PAHs (benz[a]anthracene, chryseno, benzo[b]fluoranthene, and benzo[a]pyrene), in unsmoked fish tissues. The values were related to the time period, locality (country and region), living habits, eating habits, and types of environments of the fish species. The data obtained has been also compared with the limits established by the United States Environmental Protection Agency (U.S. EPA) and European Union (E.U.) legislation. The data were collected through a PRISMA systematic review (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) from 1982 to 2020. Only documents that presented the PAHs concentration values were selected. China, Nigeria, and Iran had the highest number of studies. The species Coptodon zillii, Siganus punctatus, and Liza abu were the most commonly used bioindicators. Fish inhabiting demersal and pelagic environments showed the highest concentrations of PAHs. The majority of PAH concentrations of the analyzed documents fell within permissible limits for human consumption, representing a total percentage of 79.49 % for benzo[a]pyrene and 82.86 % for the sum of the 4 PAHs. Although some studies identified concentrations of benzo[a]pyrene alone and benzo[a]pyrene, benz[a]anthracene, chryseno, benzo[b]fluoranthene above the legislation limits, in most of them, the concentrations reported in fish tissue were below the limits defined by European Legislation for human consumption.

Investigating the effect of type of fish and different cooking methods on the residual amount of polycyclic aromatic hydrocarbons (PAHs) in some Iranian fish: A health risk assessment

The aim of this study was to assess the level of PAHs and associated health risks in different types of fish cooked with different methods, using the MSPE-GC/MS technique (magnetic solid phase extraction with gas chromatography/mass spectrometry). The limits of detection (LODs), limits of quantification (LOQs) and recovery percentages ranged from 0.1 to 0.63 μg/kg, 0.3-1.89 μg/kg, and 93.7 to 102.6%, respectively. The results showed that the mean of ƩPAHs in all samples was 20.31 ± 6.60 µg/kg. Additionally, PAH4 and BaP levels in all samples were 4.58 ± 1.40 and 1.08 ± 0.36 µg/kg, respectively, which were below the European Union (EU) standard level (12 and 2 µg/kg, respectively). The results showed that among 5 types of fish, starry sturgeon had highest average total PAHs (13.24 ± 1.84 µg/kg), while Caspian Sea sprat had the lowest average total PAHs (1.24 ± 0.8 µg/kg). In terms of cooking methods (charcoal-grilled fish, fried fish and oven-grilled fish), charcoal-grilled fish had the highest average total PAH level at 25.41 ± 7.31 µg/kg, while the lowest average total PAH was found in the raw fish sample at 16.44 ± 4.63 µg/kg. The Monte Carlo Simulation was used to determine the 95% ILCRs (Incremental Lifetime Cancer Risk) due to ingestion of fish. The results showed that the ILCR for adults was 2.85E-9, while for children it was 1.32E-8. Therefore, based on these findings, it can be concluded that the consumption of fish cooked with different methods does not pose a risk to human health in terms of the amount of PAHs (ILCR < 1 × 10-4).

Occurrence and distribution of polycyclic aromatic hydrocarbons (PAHs) in marine organisms from Shenzhen coastal waters and human health risk assessment

This study investigated the levels and composition of 16 priority polycyclic aromatic hydrocarbons (PAHs) in marine organisms from South China Sea and assessed their potential health risks. The results revealed that the pollution levels of total PAHs ranged from 3.56 to 392.21 ng/g dw. Notably, 4-ring PAHs constituted the predominant fraction (58.02 %) of the total PAHs, with pyrene being the most abundant congener across all species. Intriguingly, our findings suggested that consuming these organisms might pose a low non-cancer hazard. Nonetheless, benzo[a]pyrene was detected in most species, with levels ranging from non-detectable to 11.24 ng/g dw. The individual lifetime cancer risk levels associated with seafood consumption in studied regions ranged from 1.10 × 10-5 to 1.52 × 10-5, highlighting a potential cancer risk that warrants special attention. These findings emphasize the need to prioritize carcinogenic compounds over total PAHs and underscore the importance of continuous monitoring of PAH pollution in seafood.

Polycyclic aromatic hydrocarbon (PAH) exposure during pregnancy and child anthropometry from birth to 10 years of age: Sex-specific evidence from a cohort study in rural Bangladesh

Polycyclic aromatic hydrocarbons (PAHs) have endocrine disrupting properties and they cross the placental barrier, but studies on gestational exposure and child anthropometry are inconclusive. We aimed to elucidate the impact of early gestational PAH exposure on anthropometry from birth to 10 years of age in 1295 mother-child pairs from a nested sub-cohort of the MINIMat trial in Bangladesh. Several PAH metabolites [1-hydroxyphenanthrene (1-OH-Phe), Σ2-,3-hydroxyphenanthrene (Σ2-,3-OH-Phe), 4-hydroxyphenanthrene (4-OH-Phe), 1-hydroxypyrene (1-OH-Pyr), Σ2-,3-hydroxyfluorene (Σ2-,3-OH-Flu)] were quantified in spot urine collected around gestational week 8 using LC-MS/MS. Child weight and height were measured at 19 occasions from birth to 10 years. Multivariable-adjusted regression models were used to assess associations of maternal PAH metabolites (log₂-transformed) with child anthropometry. The median concentration of 1-OH-Phe, Σ2-,3-OH-Phe, 4-OH-Phe, 1-OH-Pyr and Σ2-,3-OH-Flu was 1.5, 1.9, 0.14, 2.5, and 2.0 ng/mL, respectively. All maternal urinary PAH metabolites were positively associated with newborn weight and length and all associations were more pronounced in boys than in girls (p interaction for all <0.14). In boys, the strongest associations were observed with Σ2-,3-OH-Phe and Σ2-,3-OH-Flu for which each doubling increased mean birth weight by 41 g (95% CI: 13; 69 and 12; 70) and length by 0.23 cm (0.075; 0.39) and 0.21 cm (0.045; 0.37), respectively. Maternal urinary PAH metabolites were not associated with child anthropometry at 10 years. In longitudinal analysis, however, maternal urinary PAH metabolites were positively associated with boys' weight-for-age (WAZ) and height-for-age Z-scores (HAZ) from birth to 10 years, but only the association of 4-OH-Phe with HAZ was significant (B: 0.080 Z-scores; 95% CI 0.013, 0.15). No associations were observed with girls' WAZ or HAZ. In conclusion, gestational PAH exposure was positively associated with fetal and early childhood growth, especially in boys. Further studies are needed to confirm causality and to explore long-term health effects.

Environmental fate and effects of PAHs in tropical mariculture ponds near the northern South China Sea: Rainfall plays a key role

The behavior and fate of PAHs are affected by multiple meteorological factors, but the main factors driving PAHs in tropical mariculture areas are still not clearly understood. This study continuously monitored PAHs in a few tropical land-based mariculture ponds, discussed their dynamic change trend, migration among the multiple media, and the relevant affected factors. Results indicated that PAHs were widely distributed in these environmental media, and the PAHs' concentration showed an obvious attenuation trend in the mariculture cycle. Wet deposition brought overwhelming majority atmospheric PAHs (92 % ± 5.7 %) to the aqueous system, and >72 % of these PAHs came from oil combustion-related sources and biomass combustion. Compared with the natural sea areas in the same region, mariculture ponds sediment could be changed from a sink at the early stage to a secondary release source of PAHs at the late stage of the rainy season, which intensifies the bioaccumulation of PAHs and the risk of edible carcinogenesis of aquatic products. Our research revealed that rainfall drove the occurrence and environmental behavior of PAHs in the tropical mariculture areas, while land-based mariculture ponds ecosystem affected the regional environmental fate of PAHs and weakened their transmission to the marine environment from land.

Persistent organic pollutants in foods, their interplay with gut microbiota and resultant toxicity

Persistent Organic Pollutants (POPs) have become immensely prevalent in the environment as a result of their unique chemical properties (persistent, semi-volatile and bioaccumulative nature). Their occurrence in the soil, water and subsequently in food has become a matter of concern. With food being one of the major sources of exposure, the detrimental impact of these chemicals on the gut microbiome is inevitable. The gut microbiome is considered as an important integrant for human health. It participates in various physiological, biochemical and immunological activities; thus, affects the metabolism and physiology of the host. A myriad of studies have corroborated an association between POP-induced gut microbial dysbiosis and prevalence of disorders. For instance, ingestion of polychlorinated biphenyls, polybrominated diphenyl ethers or organochlorine pesticides influenced bile acid metabolism via alteration of bile salt hydrolase activity of Lactobacillus, Clostridium or Bacteroides genus. At the same time, some chemicals such as DDE have the potential to elevate Proteobacteria and Firmicutes/Bacteriodetes ratio influencing their metabolic activity leading to enhanced short-chain fatty acid synthesis, ensuing obesity or a pre-diabetic state. This review highlights the impact of POPs exposure on the gut microbiota composition and metabolic activity, along with an account of its corresponding consequences on the host physiology. The critical role of gut microbiota in impeding the POPs excretion out of the body resulting in their prolonged exposure and consequently, enhanced degree of toxicity is also emphasized.

Occurrence, distribution, sources, and bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) in multi environmental media in estuaries and the coast of the Beibu Gulf, China: a health risk assessment through seafood consumption

The coastal zone is a crucial transitional area between land and ocean, which is facing enormous pressure due to global climate change and anthropogenic activities. It is essential to pay close attention to the pollution caused by polycyclic aromatic hydrocarbons (PAHs) in the coastal environment and their effect on human health. The pollution status of PAHs was investigated in the Beibu Gulf, taking into consideration various environmental media. The results showed that the total concentration of 16 PAHs (Σ16PAHs) was significantly higher in winter than in summer. Compared to the coastal area, the status of PAHs in the estuarine areas was found to be more severe in summer, while the regional difference was insignificant in winter. In summer, the Σ16PAHs in estuarine waters (71.4 ± 9.58 ng/L) > coastal waters (50.4 ± 9.65 ng/L); estuarine sediment (146 ± 116 ng/g) > coastal zone (76.9 ± 108 ng/g). The source apportionment indicated that spilled oil, biomass, and coal burning were the primary sources of PAHs in the water. The predominant sources of pollution in the sediments were spilled oil, fossil fuel burning, and vehicle emissions. With regard to the status of PAHs in marine organisms in the coastal area of the Beibu Gulf, the highest average concentration of PAHs was indicated in shellfishes (183 ± 165 ng/g), followed by fishes (73.7 ± 57.2 ng/g), shrimps (42.7 ± 19.2 ng/g), and crabs (42.7 ± 19.2 ng/g) in Beibu Gulf coastal area. The calculated bioaccumulation factor indicates a low bioaccumulation capacity of PAHs in various seafood considering the ambient environment. The human health risk assessment considering multiple age groups indicates minimal health risk on accidental ingestion of PAHs through seafood. However, it is suggested that the intake of shellfish in children be controlled.

PAHs impacts on aquatic organisms: contamination and risk assessment of seafood following an oil spill accident

Oil spills, intrinsically related to the petroleum production chain, represent a risk to the marine environment and a potential threat to humans through seafood consumption. We revised the NE Brazil oil spill and other accidents along the Brazilian coast, with a focus on seafood contamination, covering topics such as bioaccumulation, bioaccessibility, and risk analysis. Comprehensive knowledge of the impacts of spills helps in the interpretation of the dynamics of hydrocarbons released into the sea, contributing to actions to control their negative impacts. Currently, no legal limits have been established permanently in Brazil for PAHs in seafood edible tissues.

Industrialization and food safety for the Tsleil-Waututh Nation: An analysis of chemical levels in shellfish in Burrard Inlet

While Indigenous food systems remain critical for community well-being, traditionally harvested foods are a potential source of toxic exposures. The Tsleil-Waututh Nation (TWN) is seeking to restore shellfish harvesting in Burrard Inlet (British Columbia [BC], Canada), where the cumulative effects of industrial activity have nearly eliminated safe harvesting. The Trans Mountain Expansion project would triple the capacity to transport oil through the inlet, threatening TWN's progress to restore shellfish harvesting. To inform ongoing efforts we assessed contamination by heavy metals (arsenic, cadmium, lead, and mercury) and 48 polycyclic aromatic hydrocarbons (PAHs) congeners in different shellfish species (Softshell clams, Varnish clams, and Dungeness crab) in three areas. We compared our results against local screening values (SVs) established by the TWN and BC Ministry of Environment and Climate Change Strategy, as well as provincial and national benchmarks. In total, we analyzed 18 composite samples of Softshell clams and Varnish clams (5 individuals per sample), as well as 17 individual crabs. We found chemical contamination in all species at all sites. PAHs were most frequently detected in Softshell clams, highest in the site closest to the pipeline terminus. Clams presented higher levels of contamination than crabs for PAHs, but not for heavy metals. For Softshell and Varnish clams, all heavy metals across study sites exceeded at least one of the population-specific SVs. Of the 14 PAHs detected, benzo(a)pyrene presented a median concentration in Softshell clams of 3.25 μ/kg, exceeding local SV for subsistence fisher. Our results call for further assessment of human health impacts related to food harvesting within Burrard Inlet and establishing a long-term coordinated program co-led by the TWN to monitor contamination and inform future harvesting programs. The study draws attention to the need to consider locally-relevant toxicity benchmarks, and include potential health impacts of food contamination in appraising development project proposals.

Antibacterial Effect of Oregano Essential Oil against Vibrio vulnificus and Its Mechanism

Oregano essential oil (OEO) is an effective natural antibacterial agent, but its antibacterial activity against Vibrio vulnificus has not been widely studied. The aim of this study was to investigate the inhibitory effect and germicidal activity of OEO on V. vulnificus and its possible inhibition mechanism. The minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of OEO against four V. vulnificus strains (ATCC 27562 and three isolates from seafoods) were from 0.06 to 0.15 μL/mL. Compared with untreated bacteria, OEO reduced the concentration of intracellular adenosine triphosphate (ATP), hyperpolarized the cell membrane, increased the level of reactive oxygen species (ROS), and increased the concentration of intracellular malondialdehyde (MDA), but there was no obvious DNA damage at the OEO test concentration. It was indicated that OEO inactivated V. vulnificus by generating ROS which caused lipid peroxidation of cell membranes, thereby reducing the permeability and integrity of cell membranes and causing morphological changes to cells, but there was no obvious damage to DNA. In addition, OEO could effectively kill V. vulnificus in oysters at 25 °C, and the number of bacteria decreased by 48.2% after 0.09% OEO treatment for 10 h. The good inhibitory effect and bactericidal activity of OEO showed in this study, and the economy and security of OEO make it possible to apply OEO to control V. vulnificus contamination in oysters and other seafoods.

Occurrence, spatial distribution and ecological risk assessment of trace elements in surface sediments of rivers and coastal areas of the East Coast of Bangladesh, North-East Bay of Bengal

Coastal and estuarine ecosystems provide habitats for many organisms. Recently, the estuaries and coastal areas of the East Coast of Bangladesh have become heavily contaminated due to dumping of untreated wastewater into the rivers from a number of different industries. The current study analyzes potentially toxic elements contamination in surface sediments of the Karnaphuli, Sangu, Bakkhali and Naf Rivers, Kutubdia and Moheshkhali Channel, and St. Martin's Island, and assesses the consequent ecological risks. The pollution load index (PLI), geoaccumulation index (I_geo) and potential ecological risk (PER) indices show that the contaminated sediments have negative effects on the aquatic environments. The PLI values ranged between 0.45 and 1.67, which suggests the severity of trace-element contamination. The mean I_geo values showed the sediments range from uncontaminated to heavily contaminated state. The Enrichment Factor (EF) values suggested that the sediments were contaminated by anthropogenic sources, and PER values demonstrate that sites at Sangu, Naf and St Martin's Island are less contaminated compared to sites at Karnaphuli, Bakkhali, Kutubdia and Moheshkhali. Overall, results showed that Karnaphuli river is the most contaminated and St Martin's Island is the least based on the spatial distribution of PLI, C_d, PER and ∑TUs of trace metals in surface sediments. Comparing with the neighboring countries, the concentrations of Cd and Pb were found to be higher while Cr is lower in the East Coast of Bangladesh than the estuarine and coastal waters of the Bay of Bengal rim countries. The present study reveals that the lack of water quality guidelines in Bangladesh for the coastal, estuarine and marine water escalated the dumping of untreated wastewater. Immediate measures need to be taken to address the ecological risks so that an effective management program can be undertaken. A systematic approach for collecting pollutant data and use of isotopes to trace anthropogenic sources of contamination is recommended for pollutants like toxic metals, pesticides and other contaminants in sediment and aquatic products in the entire coastal waters of the Bay of Bengal.

Temporal and spatial characteristics of PAHs in oysters from the Pearl River Estuary, China during 2015-2020

Estuary connects the inland freshwater and open seawater, which may become a sink for pollutants from land-derived outflows, especially for persistent organic pollutants (e.g., polycyclic aromatic hydrocarbons, PAHs). Due to complex fluctuation in estuary, it's difficult to achieve a comprehensive assessment of the pollution characteristics by grabbed environmental samples. Oysters serve as efficient biomonitors of pollution status in highly dynamic and anthropogenically impacted estuaries, like the Pearl River Estuary (PRE), South China. Here, we investigated the annual, seasonal, and spatial variations of PAHs in the soft tissues of oysters from the PRE over the last six years (2015-2020) and quantitatively analyzed the influence of environmental factors on PAH occurrence in the oysters. The concentrations of Σ₁₅PAH in oysters ranged from 74 to 1164 (337 ± 218) ng/g dry wt., with a peak occurrence in 2017. Highly seasonal and geographical variations in PAH pollution were documented in the PRE, with higher concentrations in oysters during the wet season than dry season, and in the eastern coast than western coast. Furthermore, geographical variation in PAH levels in the oysters was enhanced during the wet season, indicating a possible contribution of heavy rainfall flushing from the Pearl River. In addition to precipitation, water temperature and salinity also significantly influenced PAH levels in the oysters from the PRE by changing the bioavailability and biokinetics. Long-term biomonitoring using oysters in the current study reflected the pollution status and variation trends of PAHs in the highly dynamic PRE.

Bioaccumulation of polycyclic aromatic hydrocarbons in Solea solea from Bizerte and Ghar El Melh Lagoons (Tunisia) and human health risk assessment

The present study objective was to assess polycyclic aromatic hydrocarbons in Bizerte and Ghar El Melh Lagoons Solea solea and to assess the potential risk to human health from its consumption. To reach these objectives twenty fish samples from each site were collected and 15 priority polycyclic aromatic hydrocarbons (PAHs) were analyzed in their muscles using high-performance liquid chromatography with a fluorescence detector. Total PAH sole concentrations from Bizerte and Ghar El Melh Lagoons were similar or lower to those recorded in other species from other regions across the world. In the studied fish species, the 2 and 3 ring PAHs are the dominated compounds that enter to the composition of PAHs which indicates that PAHs could be principally derived from a petrogenic origin for the both studied lagoons. The human health risk by sole consumption was evaluated and revealed to exhibit no hazard to the local population health concerning PAH intakes. The findings of this biomonitoring study will help in the implementation of sustainable environmental policies for effective water pollution control and the two investigated lagoons management.

Seaweeds as a “Palatable” Challenge between Innovation and Sustainability: A Systematic Review of Food Safety

Moderate or severe food insecurity affect 2 billion people worldwide. The four pillars of food security (availability, access, use and stability) are in danger due to the impact of climatic and anthropogenic factors which impact on the food system. Novel foods, like seaweeds, have the potential to increase food yields so that to contribute in preventing or avoiding future global food shortages. The purpose of this systematic review was to assess microbiological, chemical, physical, and allergenic risks associated with seaweed consumption. Four research strings have been used to search for these risks. Preferred Reporting Item for Systematic Reviews and Meta-analysis (PRISMA) guidelines were applied. Finally, 39 articles met the selected criteria. No significant hazards for microbiological, allergenic, and physical risks were detected. Regarding chemical risk, algae can accumulate various heavy metals, especially when harvested in polluted sites. Cultivating seaweeds in a controlled environment allows to avoid this risk. Periodic checks will be necessary on the finished products to monitor heavy metals levels. Since the consumption of algae seems to be on the rise everywhere, it seems to be urgent that food control authorities establish the safety levels to which eating algae does not represent any risk for human health.

Polycyclic aromatic hydrocarbons (PAHs), arsenic, chromium and lead in warty crab (Eriphia verrucosa): occurrence and risk assessment

This study assesses the PAH and heavy metal levels in muscle of warty crabs (Eriphia verrucosa), from the northern coast of the Campania region improving the data on toxic contaminants in this crustacean. The results showed a minimal PAH contamination; the mean concentrations were as follows: 0.2, 1.6 and 1.7 μg kg-1 wet weight (ww) for BaP, PAH4 and PAH6, respectively. Regarding the levels of the two PAHs not included in the European regulations, the BkF mean concentration was 0.1 μg kg-1 ww, while DahA was detected only in 10.7% of samples. Pb and Cr were also detected at low levels with mean values of 0.068 and 0.468 mg kg-1 ww, respectively; instead, high As levels, with a mean value of 5.021 mg kg-1 ww, were found. Considering the EWIs and the ILCRs calculated in this study, the PAH, Pb and Cr contamination levels found in the edible part of the crabs resulted safe for human consumption. Contrariwise, the ILCR calculated for the As exceeded the acceptable level of cancer risk, although the calculation did not refer to the inorganic form which is the only one recognized as carcinogenic. Hence, this study shows that warty crabs can accumulate environmental contaminants in their muscle tissue representing an important route of exposure to these toxics for the local population that regularly consumes them. This finding highlights the importance of monitoring the presence of these pollutants in crabs and in general in all fish and seafood in order to ensure food safety for consumers.

Occurrence, potential source, and cancer risk of PM2.5-bound polycyclic aromatic hydrocarbons and their halogenated derivatives in Shizuoka, Japan, and Dhaka, Bangladesh

Because of their unintentional formation and low vapor pressure, polycyclic aromatic hydrocarbons (PAHs) and their halogenated derivatives (XPAHs) in the atmosphere are distributed primarily to aerosolized particles with an aerodynamic diameter less than 2.5 μm (PM_2.5). However, no information is available regarding the occurrence of PM_2.5-bound PAHs and XPAHs in Bangladesh, one of the most highly PM_2.5-polluted regions worldwide. In this study, we investigated the occurrence of PM_2.5-bound PAHs and XPAHs in the atmospheres of Dhaka in Bangladesh and Shizuoka in Japan (as a reference) and estimated their incremental lifetime cancer risks (ILCRs). In addition, we statistically estimated the potential sources of PM_2.5-bound PAHs and XPAHs by using principal component analysis and positive matrix factorization. The median concentration of total PM_2.5-bound PAHs and XPAHs in Bangladesh was 24.2 times that in Japan. The estimated potential sources of PAHs clearly differed between Japan and Bangladesh, whereas those of XPAHs were largely (>80%) unknown in both countries. The median ILCR in Bangladesh was 2.81 × 10^-3, which greatly exceeded the upper limit of acceptable risk (10^-4). These results indicate that comprehensive monitoring and control of atmospheric PM_2.5-bound PAHs and XPAHs are needed urgently, especially in highly polluted countries.

Implications of anthropogenic effects on the coastal environment of Northern Persian Gulf, using jinga shrimp (Metapenaeus affinis) as indicator

The distribution and sources of PAHs in jinga shrimp (Metapenaeus affinis), and human health risks due to consumption was evaluated in collected samples from the Musa Bay, Persian Gulf. The total concentration of PAHs (∑16PAHs) ranged from 10 to 144 μg kg^-1 dry weight, indicating low to moderate level of pollution. The PAHs were dominated by three- (41%) and two-ring (38%) compounds. Source identification analyses indicated the PAH pollution mostly originated from petroleum inputs. A preliminary evaluation of human health risk using chronic daily intake, hazard index, benzo[a]pyrene-equivalent (BaP_eq) concentration (PEC) as well as the incremental life cancer risk and non-cancer risk assessment suggest low potential health risk for consumers of the Metapenaeus affinis. However, the results indicate minimal risks associated with the intake of PAHs via shrimp consumption, but long-term monitoring is required to evaluate the changes in ecological and human health impacts of contaminants in the region. MAIN FINDING: PAHs in Metapenaeus affinis from Musa bay, which influenced by anthropogenic activities were low to moderate level of pollution. Human health risk indicates low potential health risk for consumers.

ZEB316: A Small Stand-Alone Housing System to Study Microplastics in Small Teleosts

Many anthropogenic chemicals and plastic debris end up in the aquatic ecosystem worldwide, representing a major concern for the environment and human health. Small teleosts, such as zebrafish (Danio rerio) and Japanese medaka (Oryzias latipes), offer significant advantages over classical animal models and are currently used as first-line organisms to assess environmental risks associated with many aquatic toxicants. Toxicological studies require the use of inert materials and controlled conditions. Yet, none of the available commercialized systems is adequate to assess the toxic effect of microplastics, because they contain components made of plastic polymers that may release micrometric plastic particles, leach manufacturing compounds, or adsorb chemicals. The ZEB316 stand-alone housing system presented in this study is meant to be a cost-effective and easy-to-built solution to perform state-of-the-art toxicological studies. It is built with inert and corrosion-resistant materials and provides good housing conditions through efficient recirculation and filtration systems. Assessment of water parameters and fish growth performance showed that the ZEB316 provides housing conditions comparable to those available from commercial housing systems.