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

Insights into pollution characteristics and human health risks of plasticizer phthalate esters in shellfish species

The ubiquitous application of phthalate esters (PAEs) as plasticizers contributes to high levels of marine pollution, yet the contamination patterns of PAEs in various shellfish species remain unknown. The objective of this research is to provide the first information on the pollution characteristics of 16 PAEs in different shellfish species from the Pearl River Delta (PRD), South China, and associated health risks. Among the 16 analyzed PAEs, 13 were identified in the shellfish, with total PAE concentrations ranging from 23.07 to 3794.08 ng/g dw (mean = 514.35 ng/g dw). The PAE pollution levels in the five shellfish species were as follows: Ostreidae (mean = 1064.12 ng/g dw) > Mytilus edulis (mean = 509.88 ng/g dw) > Babylonia areolate (mean = 458.14 ng/g dw) > Mactra chinensis (mean = 378.90 ng/g dw) > Haliotis diversicolor (mean = 335.28 ng/g dw). Dimethyl phthalate (DMP, mean = 69.85 ng/g dw), diisobutyl phthalate (DIBP, mean = 41.39 ng/g dw), dibutyl phthalate (DBP, mean = 130.91 ng/g dw), and di(2-ethylhexyl) phthalate (DEHP, mean = 226.23 ng/g dw) were the most abundant congeners. Notably, DEHP constituted the most predominant fraction (43.98 %) of the 13 PAEs detected in all shellfish from the PRD. Principal component analysis indicated that industrial and domestic emissions served as main sources for the PAE pollution in shellfish from the PRD. It was estimated that the daily intake of PAEs via shellfish consumption among adults and children ranged from 0.004 to 1.27 μg/kgbw/day, without obvious non-cancer risks (< 0.034), but the cancer risks raised some alarm (2.0 × 10-9-1.4 × 10-5). These findings highlight the necessity of focusing on marine environmental pollutants and emphasize the importance of ongoing monitoring of PAE contamination in seafood.

Polycyclic Aromatic Hydrocarbons' Impact on Crops and Occurrence, Sources, and Detection Methods in Food: A Review

Polycyclic aromatic hydrocarbons (PAHs) represent a category of persistent organic pollutants that pose a global concern in the realm of food safety due to their recognized carcinogenic properties in humans. Food can be contaminated with PAHs that are present in water, air, or soil, or during food processing and cooking. The wide and varied sources of PAHs contribute to their persistent contamination of food, leading to their accumulation within these products. As a result, monitoring of the levels of PAHs in food is necessary to guarantee the safety of food products as well as the public health. This review paper attempts to give its readers an overview of the impact of PAHs on crops, their occurrence and sources, and the methodologies employed for the sample preparation and detection of PAHs in food. In addition, possible directions for future research are proposed. The objective is to provide references for the monitoring, prevention, and in-depth exploration of PAHs in food.

Fluorene-induced stress in the benthic oligochaete Tubifex tubifex: A multi-biomarker assessment of toxicological pathways and mechanisms under acute and subchronic exposures

This study examined the multifaceted impacts of fluorene exposure on Tubifex tubifex, encompassing acute (survival analysis and behavioral responses) and subchronic exposure regimens (antioxidant enzyme response and histopathology), molecular docking studies, and generalized read-across analysis. Survival analysis revealed concentration-dependent increases in toxicity over varying time intervals, with LC50 values decreasing from 30.072 mg/L at 24 h to 12.365 mg/L at 96 h, emphasizing the time-sensitive and concentration-responsive nature of the stressor. Behavioral responses were both concentration- and duration-dependent. While Erratic Movement and Clumping Tendency exhibited earlier responses (within 24 h) at lower concentrations, the wrinkling effect and mucus secretion) exhibited delayed onset, suggesting intricate regulatory mechanisms underlying adaptability to environmental challenges; moreover, the wrinkling effect was consistently induced at higher concentrations, indicating greater sensitivity to the toxic effects of fluorene. With sublethal environmentally relevant concentrations-1.24 mg/l and 2.47 mg/L i.e., 10% and 20% 96 h, respectively-the antioxidant enzyme response (i.e., upregulation of SOD, CAT, and GST) with increasing fluorene concentration, revealing a nonlinear, hormetic response, suggested adaptive protection at lower doses but inhibition at higher concentrations. Histopathological examination indicated that higher fluorene concentrations caused cellular proliferation, inflammation, and severe tissue damage in the digestive tract and body wall. Molecular docking studies demonstrated robust interactions between fluorene and major stress biomarker enzymes, disrupting their functions and inducing oxidative stress. Interactions with cytochrome c oxidase suggested interference with cellular energy production. Generalized Read-Across (GenRA) analysis unveiled shared toxicity mechanisms among fluorene and its analogs, involving the formation of reactive epoxides and the influence of cytochrome P450 enzymes. The diverse functional groups of these analogs, particularly chlorine-containing compounds, were implicated in toxicity through lipid peroxidation and membrane damage. Adverse outcome pathways and broader consequences for aquatic ecosystem health are discussed.

The ban on the sale of new petrol and diesel cars: Can it help control prospective marine pollution of polycyclic aromatic hydrocarbons (PAHs) in Shandong Province, China?

The constantly increasing amount of road vehicles causes massive exhaust emissions of pollutants, including polycyclic aromatic hydrocarbons (PAHs), necessitating a global responsibility to implement the policy of the ban on the sale of new petrol and diesel cars. Here, we assessed the policy control efficiency on marine pollution of PAHs in China through scenario modeling and prediction models, based on pollution monitoring, risk assessment, and source apportionment of PAHs in typical bays of Shandong Province. The results showed that in 2021, the pollution risk levels were relatively low (HI: 0.008-0.068, M-ERM-Q: 0.001-0.016, IBR: 1.23-2.69, ILCR: 8.11 ×10-6-1.99 ×10-5), and PAHs were mainly derived from traffic emissions (24.9%-35.2%), coal combustion (25.2%-32.9%), petroleum (17.2%-28.9%), and biomass combustion (17.6%-22.8%). In 2050, the predicted decrease of pollution risk values after the implementation of the policy was significant (12%-26%), and the gap between 2021 and 2050 was also significantly huge (18%-85%) without considering possible substitution of conventional energy. Collectively, this study built systematic approaches for assessing prospective marine pollution of PAHs. However, due to the particularity of Shandong Province, i.e., its national predominance of conventional energy consumption, the policy may be more effective when it comes to other coastal areas worldwide, calling for a larger scale research.

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.

Trophodynamics and bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) in marine food web from Laizhou Bay, China

Here, we collected 16 species (n = 298) from Laizhou Bay, China to investigate the trophodynamics, bioaccumulation and cancer risks of polycyclic aromatic hydrocarbons (PAHs). Results demonstrated that naphthalene was the most abundant PAH, followed by phenanthrene and fluorene in the marine organisms. The sum of 16 PAHs concentrations (Ʃ16PAHs) ranked with algae (19,435 ng·g-1 lipid weight, lw) > benthonic animals (6599 ng·g-1 lw) > fish (1760 ng·g-1 lw). Combustion and oil spill are two primary sources, contributing 60.3 % and 39.7 % of Ʃ16PAHs, respectively. High values of log BAF were found for 4-6 rings PAHs. Algae and benthonic animals showed a high ability to accumulate 2-4 rings PAHs and 5-6 rings PAHs, respectively. A biodilution pattern for PAHs was found in the marine food web. The carcinogenic risks of some benthos and fish were higher than 1 × 10-6, threatening resident health by consumption of these seafoods.

Dissemination and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in water and sediment of Buriganga and Dhaleswari rivers of Dhaka, Bangladesh

Concentration, source, ecological and health risks of sixteen polycyclic aromatic hydrocarbons (PAHs) were estimated for water and sediment samples of two urban rivers namely Buriganga River (BR) and Dhaleswari River (DR). The mean concentration of ∑PAHs in BR water and sediment were 9619.2 ngL-1 and 351.6 ngg-1, respectively. Furthermore, the average PAH concentrations detected in DR water and sediment were 1979.1 ngL-1 and 792.9 ngg-1, respectively. The composition profile showed that 3-ring PAHs were dominant in the water matrix; however, 5-ring PAHs were prevalent in the sediment samples of both rivers. Sources apportion study of PAHs indicated that mixed combustion and petroleum sources are responsible for PAHs contamination in the rivers. Ecological risk study of water suggested that the aquatic lives of both rivers are threatened by Fla, BbF, BkF, DahA, and IcdP, as presented above the threshold level. Comparison with sediment quality guidelines (SQGs) indicated that adverse effects might cause occasionally in the sediment ecosystem in DR at certain sampling sites for Nap, Acy, Fl, Phe, Ant, Pyr, Chr, BaP, and DahA. On the other hand, the presence of Nap, Acy and DahA might occasionally cause adverse biological effects in the BR sediment ecosystem. Estimated hazard quotient (HI > 1) and carcinogenic risk (CRtotal > 10-4) values indicated that local inhabitants living in the vicinity of the rivers are prone to high health risks.

Source apportionment and human health risk of PAHs accumulated in edible marine organisms: A perspective of "source-organism-human"

Most PAHs produced by human activities can be absorbed and accumulated by edible organisms and pose a potential hazard to human health. However, the source apportionment and human health risk of PAHs accumulated in edible organisms remains largely unknown. Therefore, we conducted source analysis and health risk assessment based on the PAH concentrations in ten marine fish from coastal areas of Guangdong, China. Results showed that the pollution of PAHs in fish organisms was at "Minimally polluted" level, and that all marine fish had the ability to accumulate PAHs. Risk assessment indicated Carcinogenic risk of PAHs in four populations was at a "Cautionary risk" level, with urban children suffered the highest risk. Petroleum pollution, Coal and biomass combustion, and Marine transport emissions were identified as the main anthropogenic sources for PAHs in organisms, and Marine transport emissions accounted for the highest Carcinogenic risk. The Acceptable daily intake for all populations were far below their actual daily intake without causing "Cautionary risk". Our findings provide new insights into the source apportionment and health risk of PAHs from a "source-organism-human" perspective, and suggested that joint management of three anthropogenic sources would be an effective way to prevent the health risks of PAHs.

Distribution and source assignments of polycyclic aromatic and aliphatic hydrocarbons in sediments and biota of the Lafayette River, VA

The Lafayette River comprises a tidal sub-estuary constrained by an urban watershed that is bounded by residential areas at its upper reaches and port activity at its mouth. We determined the concentrations and distributions of polycyclic aromatic hydrocarbons (PAHs) and aliphatic n-alkanes across 19 sites from headwaters to river mouth in surface sediments (0-2 cm). Potential atmospheric sources were investigated through the analysis of wet and dry deposition samples and intact coals from a major export terminal nearby. The potential consequences for human consumption were examined through analysis of native oyster (Crassostrea virginica) and blue crab tissues (Callinectes sapidus). A suite of up to 66 parent and alkyl-substituted PAHs were detected in Lafayette sediments with total concentrations ranging from 0.75 to 39.00 µg g^-1 dry wt. Concentrations of aliphatic n-alkanes (n-C₁₆ - n-C₃₁) ranged from 4.94 to 40.83 μg g^-1 dry wt. Source assignment using diagnostic ratios and multivariate source analysis suggests multiple sources contribute to the hydrocarbon signature in this metropolitan system with automotive and atmospheric transport of coal dust as the major contributors. Oyster tissues showed similar trends as PAHs observed in sediments indicating similar sources to water column particles which ultimately accumulate in sediments with crabs showing altered distributions as a consequence of metabolism.

Halogenated organic pollutants (HOPs) in marine fish from the Beibu Gulf, South China Sea: Levels, distribution, and health risk assessment

Six marine fish species, collected from the Beibu Gulf were statistically analyzed for polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), and dichlorodiphenyltrichloroethanes (DDTs). The concentrations of ∑₁₄PBDEs, ∑₂₆PCBs, and ∑₆DDTs ranged from 11.8-1431, 8.74-495, and 9.47-1263 ng g^-1 lipid weight (lw), respectively. In general, PBDEs were the predominant halogenated organic pollutants (HOPs) in the Beibu Gulf. The homologues profiles of Mugil cephalus and Trichiurus nanhaiensis differed from other four species. For example, the contributions of deca-BDEs in M. cephalus (14 %) and T. nanhaiensis (1 %) were lower than other four species (56 %). The ratio of (DDE + DDD)/ΣDDTs in all samples was >0.5, indicating that DDTs were mainly derived from historical residues. Intakes of HOPs through the consumption of the marine fish from the study areas might not subject residents of the coastal areas in the Beibu Gulf to health risks.

Bioaccumulation and trophic transfer of PAHs in tropical marine food webs from coral reef ecosystems, the South China Sea: Compositional pattern, driving factors, ecological aspects, and risk assessment

Multiple environmental pressures caused by global warming and human activities have aroused widespread concern about PAHs pollution in tropical marine coral reef regions (CRRs). However, the trophodynamics of PAHs in the food webs of the CRRs and the related influence factors have not been reported. This study investigated the occurrence, trophic amplification, and transmission of PAHs in various organisms selecting between at least representative species for each level in CRRs of the South China Sea (SCS); revealed their driving mechanisms; and explored the trophodynamics of PAHs in the food web of the coral reef ecosystem. Results showed that more PAHs can be accumulated in the mantle tissue of Tridacnidae, and the proportion of mantle tissue of Tridacnidae increases with the increase of latitude (y = 0.01x + 0.17, R² = 0.49, p < 0.05). Latitude drives the differential occurrence level and bioaccumulation of PAHs in tropical marine organisms, and also affects the trophodynamics of PAHs in aquatic ecosystem food webs. PAHs undergo trophic amplification in the food webs of tropical marine ecosystems represented by coral reefs, thus further aggravating the negative environmental impact on coral reef ecosystems. The cancer risk caused by accidental ingestion of PAHs by humans through consumption of seafood in CRRs is very low, but we should be alert to the biomagnification effect of PAHs.

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.