Biomagnification profiles of polycyclic aromatic hydrocarbons, alkylphenols and polychlorinated biphenyls in Tokyo Bay elucidated by delta13C and delta15N isotope ratios as guides to trophic web structure

Antibiotics and polycyclic aromatic hydrocarbons in marine food webs of the Yellow River Estuary: Occurrence, trophic transfer, and human health risks

Antibiotics and polycyclic aromatic hydrocarbons (PAHs) are common environmental contaminants in the aquatic region encompassing the estuary of the Yellow River and Laizhou Bay. But little information is available about the trophic transfer of antibiotics and PAHs in the marine food web of this area. This study investigated the occurrence and trophic transfer of 19 antibiotics and 16 PAHs in marine organisms from a food web of Laizhou Bay of the Yellow River estuary. Sulfonamides, fluoroquinolones, and 2 to 4-ring PAHs were the dominant contaminants in organisms. There was a significant positive correlation between the log total concentration of sulfonamides and trophic level (TL). Sulfadiazine, sulfamethazine, and erythromycin had biomagnification effects, while ciprofloxacin and ofloxacin had biological dilution effects. The log total concentration of PAHs had a significant negative correlation with TL. Naphthalene, fluorene, anthracene, pyrene, and benzo[g,h,i]perylene had biological dilution effects. The distinct correlations of trophic magnification factors Dow of antibiotics and Kow of 2 to 5-ring PAHs, indicating that the potential of these two coefficients for predicting their transfer. Risk assessment indicated that the consumption of seafood containing antibiotics and PAHs in Laizhou Bay of the Yellow River estuary posed health and carcinogenic risks to human, respectively.

Detection of benzotriazole-type ultraviolet stabilizers in sea turtles breeding in the Northwest Pacific Ocean

Benzotriazole-type ultraviolet stabilizers (BUVSs) are emerging contaminants whose exposure to wildlife is of concern. In this study, we investigated the contamination status of BUVSs in green turtles (Chelonia mydas) breeding at Ogasawara Islands, Japan, through chemical analysis of 10 BUVSs and 26 congeners of polychlorinated biphenyls (PCBs) in adipose tissue (n = 21) and blood plasma (n = 9). BUVSs were detected significant levels in adipose tissue (19 of 21 turtles), and UV-327 (not detected - 14.8 ng/g-lipid, detection frequency: 76 %), UV-326 (not detected - 24.1 ng/g-lipid, 29 %), and UV-328 (not detected - 5.8 ng/g-lipid, 24 %) were frequently detected. Turtles exhibiting sporadically high concentrations of BUVSs (>10 ng/g-lipid) did not necessarily correspond to individuals with high total PCB concentrations (1.03-70.2 ng/g-lipid). The sporadic occurrence pattern of BUVSs suggested that these contaminants in sea turtles cannot be explained solely by diet but are likely derived from plastic debris.

Persistent organic pollutants (POPs) in marine crustaceans: Bioaccumulation, physiological and cellular responses

Persistent organic pollutants (POPs) are ubiquitous in marine ecosystems. These compounds can be accumulated in water, sediments and organisms, persist in time, and have toxic effects in human and wildlife. POPs can be uptaken and bioaccumulated by crustaceans, affecting different physiological processes, including energy metabolism, immunity, osmoregulation, excretion, growth, and reproduction. Nonetheless, animals have evolved sub-cellular mechanisms for detoxification and protection from chemical stress. POPs induce the activity of enzymes involved in xenobiotic metabolism and antioxidant systems, that in vertebrates are importantly regulated at gene expression (transcriptional) level. However, the activation and control of these enzyme systems upon the exposure to POPs have been scarcely studied in invertebrate species, including crustaceans. Herein, we summarize various aspects of the bioaccumulation of POPs in marine crustaceans and their physiological effects. We specially focus on the regulation of xenobiotics metabolism and antioxidant enzymes as key sub-cellular mechanisms for detoxification and protection from chemical stress.

Assessment of polycyclic aromatic hydrocarbons (PAHs) in mediterranean top marine predators stranded in SE Spain

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants. Although they are not bioaccumulated in vertebrates, chronic exposures might still derive on serious toxic effects. We studied concentrations of 16 reference PAHs on blubber of two dolphin species (striped dolphin, n = 34; and bottlenose dolphin, n = 8) and one marine turtle (loggerhead turtle, n = 23) from the Mediterranean waters of SE Spain, an important or potential breeding area for these and other related species. Σ16 PAHs concentrations were relatively similar between the three species, but they were in the lower range in comparison to worldwide data. Of the six PAHs detected, fluoranthene was the only high molecular weight (HMW) PAH, so low molecular weight (LMW) PAHs predominated. Naphthalene and phenanthrene were invariably those PAHs with higher detection rates as well as those with higher concentrations. In accordance with the literature, sex and length did not have significant influence on PAHs concentrations, probably due to high metabolization rates which prevent for observation of such patterns. Despite LMW PAHs are considered less toxic, we cannot dismiss toxic effects. This is the first work assessing PAHs concentrations in cetaceans and sea turtles from the SE Spain, which could serve as the baseline for future research.

Occurrence and distribution of PAHs in stranded dolphin tissues from the Northwestern Mediterranean

There are few cetacean tissue-specific polycyclic aromatic hydrocarbon (PAH) concentration studies in the Mediterranean, despite this region is among the most subjected to chemical contamination. PAH analyses were conducted in different tissues of striped dolphins (Stenella coeruleoalba, N = 64) and bottlenose dolphins (Tursiops truncatus, N = 9) stranded along the French Mediterranean coastline from 2010 to 2016. Comparable levels were measured in S. coeruleoalba and T. trucantus (1020 and 981 ng g^-1 lipid weight in blubber, 228 and 238 ng g^-1 dry weight in muscle, respectively). The results suggested a slight effect of maternal transfer. The greatest levels were recorded by urban and industrial centers, and decreasing temporal trends were observed in males muscle and kidney, but not in other tissues. As a conclusion, the elevated levels measured could represent a serious threat to dolphins populations in this region, particularly by urban and industrial centers.

Trophic transfer of polycyclic aromatic hydrocarbons in marine mammals based on isotopic determination

The tissue distribution (liver, kidney, heart, lung, and muscle), source, and trophic transfer of 15 polycyclic aromatic hydrocarbons (PAHs) were studied on 14 stranded East Asian finless porpoises (Neophocaena asiaeorientalis sunameri), 14 spotted seals (Phoca largha), and 9 stranded minke whales (Balaenoptera acutorostrata) from Yellow Sea and Liaodong Bay. The PAHs levels ranged from below the limit of detection to 459.22 ng g^-1 dry weight in the tissues of the three marine mammals, and light molecular weight PAHs were the primary pollutants. Although the PAHs levels were relatively higher in internal organs of the three marine mammals, generally no tissue-specific distribution of the PAHs congeners was found, either for gender-specific distribution of PAHs in the East Asian finless porpoises. However, species specific PAHs concentration distribution were obtained. The PAHs were mainly originated from petroleum and biomass combustion in the East Asian finless porpoises, while those for the spotted seals and minke whales were complex. Trophic level associated biomagnification was found for phenanthrene, fluoranthene, and pyrene in the minke whale. Benzo(b)fluoranthene exhibited a significant biodilution with increasing trophic levels in the spotted seals, but the total concentration of the PAHs showed a significant biomagnification with increasing trophic levels. Trophic level-associated biomagnification of acenaphthene, phenanthrene, anthracene, and ∑PAHs were found in the East Asian finless porpoise, while pyrene exhibited obvious biodilution with increasing trophic levels. Our current study filled knowledge gaps on tissue distribution and trophic transfer of the PAHs in the investigated three marine mammals.

First study of bromophenols and hexabromocyclododecanes in seafood from North Africa (case of Bizerte Lagoon, Tunisia): occurrence and human health risk

In spite of the fact that bromophenols (BPs) and hexabromocyclododecanes (HBCDs) are widely used as flame retardants, no data was available until now on the levels of these two chemicals in North Africa biota. Seafood products might represent one of the main sources of dietary exposure to persistent organic pollutants such as non-dioxin-like polychlorinated biphenyls (ndl-PCBs), brominated flame retardants (BFRs), and polycyclic aromatic hydrocarbons (PAHs). In this study, the concentrations of the ndl-PCBs, PAH₄, and BFRs were determined in seafood products from a North African lagoon (Bizerte lagoon). Almost all the compounds were detected (15 out of 18) in the analyzed marine organisms. The accumulation of the contaminants followed the order BFRs > ndl-PCB > PAH₄. Mean contaminants concentrations ranged from 0.35 to 28.7 ng g^-1 ww for ∑ndl-PCBs; from below limit of quantification to 476 ng g^-1 ww for ∑BFRs and from below limit of quantification to 5.30 ng g^-1 ww for ∑PAH₄. PCB 138, 153, and 180 were the most frequently detected ndl-PCB congeners due to their high resistance to metabolic degradation. 2,4-dibromophenol (2,4-DBP) was the predominant BFR. Chrysene (Chr) was found to be the main contributor to the total PAH₄ concentration. Contaminant profiles varied significantly among seafood which may be due to the difference in lipid content, trophic level, feeding behavior, and metabolism. To assess the human health risks, the average daily dose exposure of ndl-PCBs, the dietary daily intake of PAHs and the estimated dietary intake of 3,3-,5,5-tetrabromobisphenol A (TBBPA) and HBCD from seafood were estimated. Findings indicated no adverse effects for human health from any of the analyzed contaminants, except for ndl-PCBs in eel.

Trophic transfer of polycyclic aromatic hydrocarbons through the food web of the Fildes Peninsula, Antarctica

The Antarctic ecosystem is characterized by few consumer species and simple trophic levels (TLs), rendering it an ideal setting to investigate the environmental behavior of contaminants. The paper aims to assess the presence, sources and biomagnification behavior of polycyclic aromatic hydrocarbons (PAHs) of the Antarctic food web and is the first study of biomagnifications of PAHs in the Fildes Peninsula in Antarctica. Nine representative species from the Fildes Peninsula in Antarctica were sampled and evaluated for PAH presence. PAH concentrations ranged from 477.41 to 1237.54 ng/g lipid weight (lw) in the sampled Antarctic biota, with low molecular weight PAHs (naphthalene, acenaphthylene, acenaphthene, and fluorene) comprising the majority of the PAHs. PAHs concentrations were negatively correlated with TLs. Further, the food web magnification factor (FWMF) of ∑PAHs was 0.63, suggesting biodilution of PAHs along the TLs. Source analyses revealed that the PAHs mainly originated from petroleum contamination and the combustion of fossil fuels.

Occurrence of polycyclic aromatic hydrocarbons (PAHs) in the seafood from an important fishing area in the East China Sea and a comparison between seafood from different origins

Polycyclic aromatic hydrocarbons (PAHs) were analyzed in a variety of coastal marine seafood from the Wentai fishing area, which is in proximity to highly urbanized areas and provides a significant portion of the marine aquatic products in Eastern China. Specifically, total PAHs ranged from 320 to 2500 ng/g d.w., whereas carcinogenic PAHs ranged from 21 to 92 ng/g d.w. According to the source diagnosis, the PAHs in the seafood were generally from sources highly related to fossil fuel. Thus, it is necessary to control the unintentional use of fossil fuels and optimize the energy structure in the terrestrial area nearby. Moreover, the food chain structure and the environmental behavior of PAHs through the food chain, which are relevant to dietary risk, were assessed. The δ¹⁵N values fell in a narrow range, which indicates a relatively short food chain, which is due to overfishing in this area. Furthermore, in this shortened food chain, the trophic magnification factors (TMFs) ranged from 0.23 to 6.6, which were generally higher than those in more complex food chains. The cancer risk (ILCR) ranged from 2.2 × 10^-8 to 2.2 × 10^-6. It is noted that the carcinogenic risk of consuming yellow croaker, which is one of the most popular seafood among people on the east coast of China, was the highest. In conclusion, trophic magnification implied a possible elevated risk through this marine food chain, and overfishing may have increased the uncertainty associated with TMF estimations.

Residual additives in marine microplastics and their risk assessment - A critical review

This review summarizes the current state of knowledge regarding the risk assessment of plastic-associated residual additives, i.e. residual monomers, degradation products and additives, in the marine environment, also considering effects of weathering and bioavailability. Experimental studies have found a number of organic and metal additive compounds in leachates from plastics, and the analysis of weathered plastic particles, such as polyethylene, polypropylene and polystyrene particles sampled on beaches and shorelines, has identified residual additives, such as flame retardants, plasticizers, UV stabilizers and antioxidants. While the transfer of e.g. PBDEs to organisms upon ingestion has been demonstrated, studies on uptake and bioaccumulation of plastic-associated chemicals are inconclusive. Studies on hazard and risk assessments are few, and focus on monomers and/or a limited number of high concentration additives, such as phthalates and flame retardants. The risk assessment results vary between low, moderate and high risks of specific additives, and are not necessarily consistent for the same compound. Given the large number of chemicals potentially introduced into the marine environment with plastic particles and the challenges associated with the correct quantification of exposure concentrations and toxicity thresholds, the question arises whether new risk assessment concepts may be needed.

Remote Sensing Detection of Algal Blooms in a Lake Impacted by Petroleum Hydrocarbons

The purpose of this study was to combine all available information on the state of Lake Pertusillo (Basilicata, Italy), both in the field and published, which included Sentinel-2A satellite data, to understand algal blooms in a lacustrine environment impacted by petroleum hydrocarbons. Sentinel-2A data was retrospectively used to monitor the state of the lake, which is located near the largest land-based oil extraction plant in Europe, with particular attention to chlorophyll a during algal blooms and petroleum hydrocarbons. In winter 2017, a massive dinoflagellate bloom (10.4 × 106 cell/L) of Peridinium umbonatum and a simultaneous presence of hydrocarbons were observed at the lake surface. Furthermore, a recent study using metagenomic analyses carried out three months later identified a hydrocarbonoclastic microbial community specialized in the degradation aromatic and nitroaromatic hydrocarbons. In this study, Sentinel-2A imagery was able to detect the presence of chlorophyll a in the waters, while successfully distinguishing the signal from that of hydrocarbons. Remotely sensed results confirmed surface reference measurements of lacustrine phytoplankton, chlorophyll a, and the presence of hydrocarbons during algal blooms, thereby explaining the presence of the hydrocarbonoclastic microbial community found in the lake three months after the oil spill event. The combination of emerging methodologies such as satellite systems and metagenomics represent an important support methodology for describing complex contaminations in diverse ecosystems.

Substituted Two- to Five-Ring Polycyclic Aromatic Compounds Are Potent Agonists of Atlantic Cod (Gadus morhua) Aryl Hydrocarbon Receptors Ahr1a and Ahr2a

Polycyclic aromatic hydrocarbons (PAHs) are among the most toxic and bioavailable components found in petroleum and represent a high risk to aquatic organisms. The aryl hydrocarbon receptor (Ahr) is a ligand-activated transcription factor that mediates the toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and other planar aromatic hydrocarbons, including certain PAHs. Ahr acts as a xenosensor and modulates the transcription of biotransformation genes in vertebrates, such as cytochrome P450 1A (cyp1a). Atlantic cod (Gadus morhua) possesses two Ahr proteins, Ahr1a and Ahr2a, which diverge in their primary structure, tissue-specific expression, ligand affinities, and transactivation profiles. Here, a luciferase reporter gene assay was used to assess the sensitivity of the Atlantic cod Ahrs to 31 polycyclic aromatic compounds (PACs), including two- to five-ring native PAHs, a sulfur-containing heterocyclic PAC, as well as several methylated, methoxylated, and hydroxylated congeners. Notably, most parent compounds, including naphthalene, phenanthrene, and partly, chrysene, did not act as agonists for the Ahrs, while hydroxylated and/or alkylated versions of these PAHs were potent agonists. Importantly, the greater potencies of substituted PAH derivatives and their ubiquitous occurrence in nature emphasize that more knowledge on the toxicity of these environmentally and toxicologically relevant compounds is imperative.

Polycyclic aromatic hydrocarbons in marine mammals: A review and synthesis

Most marine mammal species and populations are listed as endangered, threatened, or depleted under the Endangered Species Act and the Marine Mammal Protection Act. Organic contaminants such as polycyclic aromatic hydrocarbons from anthropogenic activities are part of the threat to marine mammals. The evaluation of the potential bioaccumulation of these compounds by marine mammals is a tool for adoption of policies to reduce polycyclic aromatic hydrocarbons discharges to the marine environment, where important players such as the oil and gas industries, maritime transport and sewage companies operate. This review seeks to present a bibliographic survey covering all published peer reviewed works of the contents of polycyclic aromatic hydrocarbons in biological tissues of marine mammals. It intended to compare the sampling protocols, procedures for preservation of the tissues, and the analytical method applied to quantify the polycyclic aromatic hydrocarbons, no to criticize any of them but to review the data and discuss how they can be compared.

Acritical review and weight of evidence approach for assessing the bioaccumulation of phenanthrene in aquatic environments

Bioaccumulation (B) assessment is challenging because there are various B-metrics from laboratory and field studies, multiple criteria and thresholds for classifying bioaccumulative (B), very bioaccumulative (vB), and not bioaccumulative (nB) chemicals, as well as inherent variability and uncertainty in the data. These challenges can be met using a weight of evidence (WoE) approach. The Bioaccumulation Assessment Tool (BAT) provides a transparent WoE assessment framework that follows Organisation for Economic Co-operation and Development (OECD) principles for performing a WoE analysis. The BAT guides an evaluator through the process of data collection, generation, evaluation, and integration of various lines of evidence (LoE) (i.e., B-metrics) to inform decision-making. Phenanthrene (PHE) is a naturally occurring chemical for which extensive B and toxicokinetics data are available. A B assessment for PHE using the BAT is described that includes a critical evaluation of 74 measured in vivo LoE for fish and invertebrate species from laboratory and field studies. The number of LoE are reasonably well balanced across taxa (i.e., fish and invertebrates) and the different B-metrics. Additionally, in silico and in vitro biotransformation rate estimates and corresponding model-predicted B-metrics are included as corroborating evidence. Application of the BAT provides a consistent, coherent, and scientifically defensible WoE evaluation to conclude that PHE is not bioaccumulative (nB) because the overwhelming majority of the bioconcentration, bioaccumulation, and biomagnification metrics for both fish and invertebrates are below regulatory thresholds. An analysis of the relevant data using fugacity ratios is also provided, showing that PHE does not biomagnify in aquatic food webs. The critical review identifies recommendations to increase the consistency of B assessments, such as improved standardization of B testing guidelines, data reporting requirements for invertebrate studies, and consideration of temperature and salinity effects on certain B-metrics. Integr Environ Assess Manag 2021;17:911-925. © 2021 Concawe. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Persistence, bioaccumulation and toxicity-assessment of petroleum UVCBs: A case study on alkylated three-ring PAHs

Substances with (very) persistent, (very) bioaccumulative, and/or toxic properties (PBT/vPvB) are of environmental concern and are identified via hazard-based PBT-assessment approaches. The PBT-assessment of well-defined substances is optimized over the past decades, but is under development for substances of unknown or variable composition, complex reaction products or biological materials (UVCBs). Particularly, the large number of constituents and variable composition complicate the PBT-assessment of UVCBs. For petroleum UVCBs, the use of the hydrocarbon block method (HBM) is proposed. Within this method, groups of constituents with similar physicochemical properties and structure are treated as a single entity and are expected to have comparable environmental fate and hazard properties. So far, however, there is a lack of experience with the application of the HBM for PBT-assessment purposes. The aim of this study is to investigate the suitability of the HBM for the PBT-assessment of petroleum UVCBs by evaluating the group of alkylated three-ring polycyclic aromatic hydrocarbons (PAHs). The presented approach is based on experimental data and model predictions and followed the guidelines of the European Chemicals Agency. Because of a lack of relevant experimental data, relative trend analyses were applied. The results indicate that alkylated three-ring PAHs are more persistent, bioaccumulative, and toxic than the parent three-ring PAHs. As the parent three-ring PAHs are currently identified within Europe as PBT/vPvB substances, the alkylated three-ring PAHs could also be considered as PBT/vPvB. Accordingly, this case study provides the prospects for the application of the HBM for the PBT-assessment of UVCBs using trend analysis.

Sea snail (Hexaplex trunculus) and sea cucumber (Holothuria polii) as potential sentinel species for organic pollutants and trace metals in coastal ecosystems

The seasonal bioaccumulation of trace metals, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorinated pesticides (OCPs) in sea snail (Hexaplex trunculus) and sea cucumber (Holothuria polii) from Mar Menor lagoon were characterised. The highest concentrations of p,p'-DDE were detected in the central and south part of Mar Menor lagoon. However, the highest concentrations of metals in sea snail and holothurians were detected in the influence area of El Beal wadi. Biomagnification factors (BMF) in sea snail from cockle (sea snail-cockle concentration ratio) were higher than 5 for metal and organochlorinated compounds. However, similar concentrations were observed in both species for PAHs due to gastropods capability of metabolising these pollutants. Consequently, sea snail is proposed as a sentinel for trace metals, PCBs and OCPs in the coastal lagoons, not only due to its bioaccumulation and biomagnification capacity but also the easy sampling and amply distribution in many coastal areas.

Trophic transfer of persistent toxic substances through a coastal food web in Ulsan Bay, South Korea: Application of compound-specific isotope analysis of nitrogen in amino acids

Trophic magnification factor (TMF) of persistent toxic substances (PTSs: Hg, PCBs, PAHs, and styrene oligomers (SOs)) in a coastal food web (12 fish and four invertebrates) was determined in Ulsan Bay, South Korea. The nitrogen stable isotope ratios (δ¹⁵N) of amino acids [δ¹⁵N_Glu-Phe based on glutamic acid (δ¹⁵N_Glu) and phenylalanine (δ¹⁵N_Phe)] were used to estimate the trophic position (TP_Glu-Phe) of organisms. The TP_Glu-Phe of organisms ranged from 1.64 to 3.69, which was lower than TP estimated by δ¹⁵N of bulk particulate organic matter (TP_Bulk: 2.46-4.21). Mercury and CB 138, 153, 187, and 180 were biomagnified through the whole food web (TMF > 1), while other PTSs, such as PAHs and SOs were not (biodilution of SOs firstly reported). In particular, the trophic transfer of PTSs was pronounced in the resident fish (e.g., rock bream, sea perch, Korean rockfish). Of note, CB 99, 101, 118, and 183 were additionally found to be biomagnifying PTSs in these species. Thus, fish residency appears to represent an important factor in determining the TMF of PTSs in the coastal environment. Overall, δ¹⁵N_Glu-Phe provided accurate TPs of organisms and could be applied to determine the trophic transfer of PTSs in coastal food webs.

Quantification of Brominated Polycyclic Aromatic Hydrocarbons in Environmental Samples by Liquid Chromatography Tandem Mass Spectrometry with Atmospheric Pressure Photoionization and Post-column Infusion of Dopant

A sensitive method for the quantification of brominated polycyclic aromatic hydrocarbons (BrPAHs) in environmental samples is yet to be developed. Here, we optimized the analytical conditions for liquid chromatography tandem mass spectrometry with atmospheric pressure photoionization and post-column infusion of dopant (LC-DA-APPI-MS/MS). We then compared the sensitivity of our developed method with that of conventional gas chromatography high-resolution MS (GC-HRMS) by comparing the limits of quantification (LOQs) for a range of BrPAHs. Finally, to evaluate our developed method, 12 BrPAHs in sediments and fish collected from Tokyo Bay, Japan, were analyzed; 9 common PAHs were also targeted. The LOQs of the developed analytical method were 14 - 160 times lower than those of GC-HRMS for the targeted BrPAHs. The developed analytical method is a sensitive approach for determining the concentrations of BrPAHs in sediment and fish samples.

Validation of analytical methods for organochlorine pesticide detection in shellfish and cephalopods by GC-MS/MS

This study validated the analysis of organochlorine pesticides (OCPs) in shellfish and cephalopods using a gas chromatograph equipped with a mass spectrometry (GC-MS/MS), and monitored residual pesticide levels. The QuEChERS method was used to analyze OCPs and was validated by checking the linearity, limit of detection (LOD), limit of quantitation (LOQ), accuracy, and precision. Octopus minor and Venerupis philippinarum, were purchased from four cities in the South Korean peninsula. The LOD values were 0.10-0.80 ng/g in shellfish and 0.21-0.77 ng/g in cephalopods, while the LOQ values were 0.31-2.41 ng/g in shellfish and 0.63-2.33 ng/g in cephalopods. Accuracy ranged from 83.5 to 117.4% and 79.8 to 118.4%, and precision ranged from 0.3 to 27.5% and 1.2 to 27.9%, in shellfish and cephalopods, respectively, conforming to the Codex Alimentarius Commission guidelines. Although residual OCP levels were below detection limits, the QuEChERS method may be effective for analyzing the OCPs in shellfish and cephalopods.

Trophic Transfer of Micropollutants and Their Metabolites in an Urban Riverine Food Web

Trophic magnification factors (TMFs, i.e., the average change in the log-concentration of a pollutant per trophic level) have been extensively assessed for the so-called persistent organic pollutants, especially organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs), which are biomagnified along the food web. In contrast, trophic dilution was documented for pollutants with a high metabolic conversion rate, such as phthalate plasticizers and polycyclic aromatic hydrocarbons (PAHs). However, the fate of their metabolites across the food web has been rarely investigated. In this comparative study, the trophodynamics of 104 micropollutants and 25 of their metabolites were investigated in a freshwater food web from the urban Orge River, France. Trophic levels were determined using stable isotopes. Pyrethroid pesticides and their metabolites were not detected. As predicted, PCBs and OCPs biomagnified (TMF >1), while all chlorinated paraffins (CPs), PAHs, and phthalates underwent a trophic dilution (TMF <1). TMFs significantly decreased with a metabolic transformation rate and increased with hydrophobicity. The levels of PAH or phthalate metabolites were not significantly correlated with trophic levels or underwent a trophic dilution. This study highlighted that the relative contribution of metabolite levels in TMF values calculated for both parent compound and its metabolite(s) is weak compared to TMF values of the parent compound only in a riverine food web.

A First Comprehensive Baseline of Hydrocarbon Pollution in Gulf of Mexico Fishes

Despite over seven decades of production and hundreds of oil spills per year, there were no comprehensive baselines for petroleum contamination in the Gulf of Mexico (GoM) prior to this study. Subsequent to the 2010 Deepwater Horizon (DWH) spill, we implemented Gulf-wide fish surveys extending over seven years (2011–2018). A total of 2,503 fishes, comprised of 91 species, were sampled from 359 locations and evaluated for biliary polycyclic aromatic hydrocarbon (PAH) concentrations. The northern GoM had significantly higher total biliary PAH concentrations than the West Florida Shelf, and coastal regions off Mexico and Cuba. The highest concentrations of biliary PAH metabolites occurred in Yellowfin Tuna (Thunnus albacares), Golden Tilefish (Lopholatilus chamaeleonticeps), and Red Drum (Sciaenops ocellatus). Conversely, biliary PAH concentrations were relatively low for most other species including economically important snappers and groupers. While oil contamination in most demersal species in the north central GoM declined in the first few years following DWH, more recent increases in exposure to PAHs in some species suggest a complex interaction between multiple input sources and possible re-suspension or bioturbation of oil-contaminated sediments. This study provides the most comprehensive baselines of PAH exposure in fishes ever conducted for a large marine ecosystem.

Bioaccumulation potential of naphthenic acids and other ionizable dissolved organics in oil sands process water (OSPW) - A review

Bitumen recovery via mining in Alberta's Athabasca region generates large quantities of oil sands process water (OSPW). Aquatic toxicity of OSPW has been well-studied and the class of organic compounds referred to as naphthenic acids (NAs) are consistently implicated as the primary driver. Proposed lease closure options include treated produced waters in reclaimed landscapes such as pit lakes and wetlands. Consequently, it is crucial to understand the bioaccumulation potential of NAs and other OSPW dissolved organics in these environments. Early studies were focussed only on NAs due to analytical limitations, however, later studies investigated additional classes of dissolved organics in OSPW. Reported bioconcentration factors (BCFs) for NAs in fish and amphibians range from 0.24 to 53 L/kg wet-weight. Most quantitative assessments of NAs bioaccumulation potential evaluated commercial NAs mixtures as a surrogate for OSPW and used using single-ion monitoring for measuring NAs concentrations. The resulting BCF values are based on the NA isomers that conform to the formula, C₁₃H₂₂O₂. More recently, an advanced analytical technique capable of determining the profile of different isomer classes in OSPW showed that NAs and other OSPW ionizable dissolved organics (OSPW-IDO) have low partitioning to simulated biological storage lipids, suggesting low bioaccumulation potential. Using the same analytical technique to assess in vivo fish exposures, a subsequent study reported a range of BCFs for OSPW NAs between 0.7 and 53 L/kg wet-weight and heteroatomic isomer classes containing S or N heteroatoms had BCFs between 0.6 and 28 L/kg wet-weight. Reported BCFs for all isomer classes of the OSPW-IDO fraction were less than the Canadian standard for bioaccumulative designation (i.e., BCF ≥ 5000).

Novel Approaches Utilizing Metal-Organic Framework Composites for the Extraction of Organic Compounds and Metal Traces from Fish and Seafood

The determination of organic and inorganic pollutants in fish samples is a complex and demanding process, due to their high protein and fat content. Various novel sorbents including graphene, graphene oxide, molecular imprinted polymers, carbon nanotubes and metal-organic frameworks (MOFs) have been reported for the extraction and preconcentration of a wide range of contaminants from fish tissue. MOFs are crystalline porous materials that are composed of metal ions or clusters coordinated with organic linkers. Those materials exhibit extraordinary properties including high surface area, tunable pore size as well as good thermal and chemical stability. Therefore, metal-organic frameworks have been recently used in many fields of analytical chemistry including sample pretreatment, fabrication of stationary phases and chiral separations. Various MOFs, and especially their composites or hybrids, have been successfully utilized for the sample preparation of fish samples for the determination of organic (i.e., antibiotics, antimicrobial compounds, polycyclic aromatic hydrocarbons, etc.) and inorganic pollutants (i.e., mercury, palladium, cadmium, lead, etc.) as such or after functionalization with organic compounds.

Tropical seabirds sample broadscale patterns of marine contaminants

Contaminants in the marine environment are widespread, but ship-based sampling routines are much narrower. We evaluated the utility of seabirds, highly-mobile marine predators, as broad samplers of contaminants throughout three tropical ocean regions. Our aim was to fill a knowledge gap in the distributions of, and processes that contribute to, tropical marine contaminants; and explore how species-specific foraging ecologies could inform or bias our understanding of contaminant distributions. Mercury and persistent organic pollutant (POPs) concentrations were measured in adults of five seabird species from four colonies in the central Pacific (Laysan and Tern Islands, Hawaii; Palmyra Atoll) and the eastern Caribbean (Barbuda). Blood-based total mercury (THg) and 89 POPs were measured in two seabird families: surface-foraging frigatebirds (Fregata spp.) and plunge-diving boobies (Sula spp.). Overall, largescale contaminant differences between colonies were more informative of contaminant distributions than inter-specific foraging ecology. Model selection results indicated that proximity to human populations was the best predictor of THg and POPs. Regional differences in contaminants were distinct: Barbudan Magnificent Frigatebirds had more compounds (n=52/89 POP detected) and higher concentrations (geometric mean THg=0.97μgg^-1; mean ΣPOP₅₃=26.6ngmL^-1) than the remote colonies (34-42/89 POP detected; range of THg geometric means=0.33-0.93μgg^-1; range of mean ΣPOP₅₃:7.3-17.0ngmL^-1) and had the most recently-synthesized POPs. Moderate differences in foraging ecologies were somewhat informative of inter-specific differences in contaminant types and concentrations between nearshore and offshore foragers. Across species, contaminant concentrations were higher in frigatebirds (THg=0.87μgg^-1; ΣPOP₅₃=17.5ngmL^-1) compared to boobies (THg=0.48μgg^-1; ΣPOP₅₃=9.8). Ocean currents and contaminants' physiochemical properties provided additional insight into the scales of spatial and temporal contaminant exposure. Seabirds are excellent, broad samplers with which we can understand contaminant distributions in the marine environment. This is especially important for tropical remote regions that are under-sampled.

Reduced bioavailability and ecological risks of polycyclic aromatic hydrocarbons in Yangshan port of East China Sea: Remediation effectiveness in the transition from construction to operation

To assess the remediation effectiveness of ecological restoration in the transition period from construction to operation of Yangshan Port, the largest deepwater port of East China Sea, we employed equilibrium passive sampling and partitioning theory to assess the changing bioavailability and flux of polycyclic aromatic hydrocarbons (PAHs) in relation to bioaccumulation and ecological risks in marine organisms. Due to the ecological restoration efforts, both the bulk and bioavailable concentrations of PAHs in sediment and surface seawater samples decreased dramatically after the port entered the operation phase, as compared with those reported during the last construction phase. PAH concentrations in the marine organisms also showed a dramatic decline, and corresponded to the change in the freely dissolved fractions of PAHs in sediment/surface water according to their thermodynamic potential for bioaccumulation. While trophic magnification of ΣPAHs was observed in the pelagic communities, concentrations of PAHs in benthic species were relatively consistent across multiple trophic levels, and were generally higher than those in pelagic species. The differing bioaccumulation between benthic and pelagic species may be related to the habitat-specific bioavailability of PAHs and the prey-predator relations among different species. The incremental lifetime cancer risks (ILCR) of PAHs in marine organisms also dropped by nearly three orders of magnitude, and were lower than the guideline (1 × 10^-6) proposed by the U.S. EPA, except for several species at higher trophic levels. Overall, our study highlights an integrated use of passive sampling and equilibrium partitioning theory as a robust tool that can be applied to assess the effectiveness of ecological remediation in the port environment with quantitative, mechanistic insights from bioavailability to bioaccumulation.

Trophodynamics and parabolic behaviors of polycyclic aromatic hydrocarbons in an urbanized lake food web, Shanghai

Understanding the trophic movement and trophic magnification factor (TMF) of polycyclic aromatic hydrocarbons (PAHs) is an important criterion to assess their fate and potential effects in an aquatic ecosystem. This study investigated concentrations and trophodynamics of 16 priority PAHs in food web_wb (food web comprising whole bodies) and food web_m (food web containing only muscles) of total 14 species ((including plankton, shrimp, whitebait, mussels, snails, red-eared terrapin and seven other fish species) from the Dianshan Lake. Values of δ¹³C and δ¹⁵N were determined to assign trophic levels to organisms. In general, there was no evidence of biomagnification because of biological degradation of PAHs compounds, but only 9 PAH compounds in food web_m showed a statistically significant negative relationship between trophic level and lipid normalized concentration compared to the 6 PAHs congeners in food web_wb. However, TMF values of PAHs in food web_m ranged from 0.32 for pyrene to 0.68 for phenanthrene compared to TMF values of food web_wb ranged from 0.34 for pyrene to 0.74 for fluorene. Because of two opposing scientific views for biomagnification and biodilution of PAHs in the food web, albeit based on a rather limited number of studies, our study investigated that there is parabolic behavior of most of the PAHs. Concentrations of PAHs in the red-eared terrapin (Trachemys scripta elegans) were biodiluted which showed that this species metabolises such compounds. There was no particular relationship between K_ow and TMFs of PAHs in the Dianshan Lake. Hepatobiliary system (such as gall bladder and liver) in the whole body considered to have higher bioaccumulation potential of organic compounds than extrahepatic tissue (muscles).

Comparison of trophic magnification factors of PCBs and PBDEs in Tokyo Bay based on nitrogen isotope ratios in bulk nitrogen and amino acids

Trophic positions (TPs) are key parameters for determining trophic magnification factors (TMFs) of environmental pollutants. We used compound-specific nitrogen isotope analysis of amino acids (CSIA-AA), with which we expected to obtain precise TPs, to estimate the TMFs of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in the pelagic and benthic food webs of Tokyo Bay. The objective of the present study was to evaluate the difference between TMFs derived from TPs estimated by CSIA-AA (TP_Glu/Phe) and TMFs derived from TPs estimated by bulk stable isotope analysis (TP_bulk). TP_Glu/Phe tended to be lower than TP_bulk for many pelagic and benthic fishes. In the pelagic food web, the slopes for the relationships between PCB concentrations and TP_Glu/Phe exceeded those between PCB concentrations and TP_bulk for many congeners in samples from December 2014, and TMF_Glu/Phe values (0.89-6.9) were higher than TMF_bulk values (0.92-3.8). However, there were no statistically significant differences between the slopes of the relationships between PCB and PBDE concentrations and TP_bulk or TP_Glu/Phe for any of the congeners (analysis of covariance, P ≥ 0.08). In the benthic food web, PCB concentrations correlated with TP_Glu/Phe for 9 PCB congeners in the samples collected during December 2014, although the concentrations of none of the PCB congeners correlated with TP_bulk. A decrease of TMF_Glu/Phe and TMF_bulk values from December 2014 to May 2015 suggested that variation of PCB and PBDE concentrations in the organisms had more effect than TPs on the TMFs.

Tissue distribution of organic contaminants in stranded pregnant sperm whale (Physeter microcephalus) from the Huizhou coast of the South China Sea

Twelve persistent organic pollutants (POPs) were measured in 11 tissue samples from a pregnant sperm whale stranded on the Huizhou coast of the South China Sea, China, in March 2017. POPs were found to be more concentrated in the irrigated tissues such as placenta, ovary, mammary gland, and liver than the less irrigated tissues such as epidermis. High POP levels detected in the placenta might result in abnormal hormone secretion in the placenta, which would affect the unborn offspring. We hypothesized that ovary is potentially vulnerable to the exposure of higher contaminant levels. The PAH concentrations were higher in the lung than in other tissues, which suggest that PAH levels in the lung were breath-dependent in the sperm whale. The concentrations of POPs except PAHs in the sperm whale blubber were lower than those in the same species in the Northern Hemisphere and were comparable to or lower than those in the same species in the Southern Hemisphere.

Polycyclic Aromatic Hydrocarbons (PAHs) in inland aquatic ecosystems: Perils and remedies through biosensors and bioremediation

Polycyclic Aromatic Hydrocarbons (PAHs) are among the most ubiquitous environmental pollutants of high global concern. PAHs belong to a diverse family of hydrocarbons with over one hundred compounds known, each containing at least two aromatic rings in their structure. Due to hydrophobic nature, PAHs tend to accumulate in the aquatic sediments, leading to bioaccumulation and elevated concentrations over time. In addition to their well-manifested mutagenic and carcinogenic effects in humans, they pose severe detrimental effects to aquatic life. The high eco-toxicity of PAHs has attracted a number of reviews, each dealing specifically with individual aspects of this global pollutant. However, efficient management of PAHs warrants a holistic approach that combines a thorough understanding of their physico-chemical properties, modes of environmental distribution and bioaccumulation, efficient detection, and bioremediation strategies. Currently, there is a lack of a comprehensive study that amalgamates all these aspects together. The current review, for the first time, overcomes this constraint, through providing a high level comprehensive understanding of the complexities faced during PAH management, while also recommending future directions through potentially viable solutions. Importantly, effective management of PAHs strongly relies upon reliable detection tools, which are currently non-existent, or at the very best inefficient, and therefore have a strong prospect of future development. Notably, the currently available biosensor technologies for PAH monitoring have not so far been compiled together, and therefore a significant focus of this article is on biosensor technologies that are critical for timely detection and efficient management of PAHs. This review is focussed on inland aquatic ecosystems with an emphasis on fish biodiversity, as fish remains a major source of food and livelihood for a large proportion of the global population. This thought provoking study is likely to instigate new collaborative approaches for protecting aquatic biodiversity from PAHs-induced eco-toxicity.

Levels and trends of polycyclic aromatic hydrocarbons in the Indo-Pacific humpback dolphins from the Pearl River Estuary (2012-2017)

We investigated the levels and trends of the 16 USEPA priority PAHs in the blubber of 37 Indo-Pacific humpback dolphins sampled during the period 2012-2017 from the Pearl River Estuary (PRE), China. Σ₁₆PAHs concentrations (17.6-6080 ng g^-1 wet weight) were at median level compared to dolphin species worldwide. Humpback dolphins affiliated with the hotspots of PAHs, had significantly higher levels of Σ₁₆PAHs than individuals from the other areas in the PRE. Moreover, dolphins stranded on the coast of Lingdingyang are significantly more contaminated by Σ₁₆PAHs than those in the West-four region of the PRE, which appears to reflect the heterogeneous distribution of PAHs in the environment. A marked decline in blubber Σ₁₆PAHs levels is observed over the studied period, with the control of a range of confounding factors. The trend is strongly and statistically significant (p < 0.0001), indicating that the loading of PAHs are gradually being reduced.

Investigating the potential impact of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) on gene biomarker expression and global DNA methylation in loggerhead sea turtles (Caretta caretta) from the Adriatic Sea

Polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) are priority contaminants that bioaccumulate through the food webs and affect the biology of a variety of resident and migratory species, including sea turtles. Few studies have evaluated toxicological biomarkers of exposure to PAHs and PCBs in these animals. The present paper reports the results of an initial field study to quantify the association between plasma concentrations of PAHs/PCBs and whole blood cell expression of gene biomarkers in juvenile loggerhead sea turtles (Caretta caretta) rescued along the Italian coasts of the northern and central areas of the Adriatic Sea. While detectable levels of PAHs were found in all plasma samples examined, only three PCB congeners (PCB52, PCB95, and PCB149) were noted, with detection percentages ranging between 48% and 57%. A significant correlation was found between 3 of the 6 gene biomarkers assessed (HSP60, CYP1A and ERα) and plasma levels of some PAH congeners. In contrast, no significant association between PCB burden and gene expression was observed. The global DNA methylation levels were significantly and positively correlated with the concentrations of most of the PAHs and only one of the PCB congeners (PCB52). The relation between PAH concentration and gene expression in whole blood cells suggests that these genes may respond to environmental contaminant exposure and are promising candidates for the development of biomarkers for monitoring sea turtle exposure to persistent organic pollutants (POPs).

Substituted Diphenylamine Antioxidants and Benzotriazole UV Stabilizers in Aquatic Organisms in the Great Lakes of North America: Terrestrial Exposure and Biodilution

Substituted diphenylamine antioxidants (SDPAs) and benzotriazole UV stabilizers (BZT-UVs) are industrial additives of emerging environmental concern. However, the bioaccumulation, biomagnification, and spatial distribution of these contaminants in the Great Lakes of North America are unknown. The present study addresses these knowledge gaps by reporting SDPAs and BZT-UVs in herring gull (Larus argentatus) eggs, lake trout (Salvelinus namaycush), and their food web in the Great Lakes for the first time. Herring gull eggs showed much higher detection frequency and concentrations of target SDPAs and 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol (UV328) than that of the whole body fish homogenate. For herring gull eggs, the samples from upper Great Lakes contained significantly greater levels of SDPAs than those eggs from lower lakes, possibly due to the differences in terrestrial food in diet. Interestingly, the predominant SDPAs in herring gull eggs were dinonyl- (C9C9) and monononyl-diphenylamine (C9) which were previously shown to be less bioaccumulative than other SDPAs in fish. In contrast, dioctyl-diphenylamine (C8C8) was the major SDPA in lake trout, and biodilution of C8C8 was observed in a Lake Superior lake trout food web. Such variations in herring gull eggs and fish indicate the differences in accumulation and elimination pathways of SDPAs and BZT-UVs and require further elucidation of these mechanisms.

Trophodynamics of Organic Pollutants in Pelagic and Benthic Food Webs of Lake Dianchi: Importance of Ingested Sediment As Uptake Route

Habitat is of great importance in determining the trophic transfer of pollutants in freshwater ecosystems; however, the major factors influencing chemical trophodynamics in pelagic and benthic food webs remain unclear. This study investigated the levels of p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE), polycyclic aromatic hydrocarbons (PAHs), and substituted PAHs (s-PAHs) in 2 plankton species, 6 invertebrate species, and 10 fish species collected from Lake Dianchi in southern China. Relatively high concentrations of PAHs and s-PAHs were detected with total concentrations of 11.4-1400 ng/g wet weight (ww) and 5.3-115 ng/g ww, respectively. Stable isotope analysis and stomach content analysis were applied to quantitatively determine the trophic level of individual organisms and discriminate between pelagic and benthic pathways, and the trophodynamics of the detected compounds in the two food webs were assessed. P,p'-DDE was found to exhibit relatively higher trophic magnification rate in the pelagic food web than in the benthic food web. In contrast, PAHs and s-PAHs exhibited greater dilution rates along the trophic levels in the pelagic food web. The lower species differences of pollutants accumulated in benthic organisms compared to pelagic organisms is attributable to extra uptake via ingested sediment in benthos. The average uptake proportions of PAHs and s-PAHs via ingested sediment in benthic biotas were estimated to be 31-77%, and that of p,p'-DDE was 46%. The uptake routes are of importance for assessing the trophic magnification potentials of organic pollutants, especially in eutrophic freshwater ecosystems.

Polycyclic Aromatic Hydrocarbons: A Critical Review of Environmental Occurrence and Bioremediation

The degree of polycyclic aromatic hydrocarbon contamination of environmental matrices has increased over the last several years due to increase in industrial activities. Interest has surrounded the occurrence and distribution of polycyclic aromatic hydrocarbons for many decades because they pose a serious threat to the health of humans and ecosystems. The importance of the need for sustainable abatement strategies to alleviate contamination therefore cannot be overemphasised, as daily human activities continue to create pollution from polycyclic aromatic hydrocarbons and impact the natural environment. Globally, attempts have been made to design treatment schemes for the remediation and restoration of contaminated sites. Several techniques and technologies have been proposed and tested over time, the majority of which have significant limitations. This has necessitated research into environmentally friendly and cost-effective clean-up techniques. Bioremediation is an appealing option that has been extensively researched and adopted as it has been proven to be relatively cost-effective, environmentally friendly and is publicly accepted. In this review, the physicochemical properties of some priority polycyclic aromatic hydrocarbons, as well as the pathways and mechanisms through which they enter the soil, river systems, drinking water, groundwater and food are succinctly examined. Their effects on human health, other living organisms, the aquatic ecosystem, as well as soil microbiota are also elucidated. The persistence and bioavailability of polycyclic aromatic hydrocarbons are discussed as well, as they are important factors that influence the rate, efficiency and overall success of remediation. Bioremediation (aerobic and anaerobic), use of biosurfactants and bioreactors, as well as the roles of biofilms in the biological treatment of polycyclic aromatic hydrocarbons are also explored.

Effects of preparation on nutrient and environmental contaminant levels in Arctic beluga whale (Delphinapterus leucas) traditional foods

For Canadian Arctic indigenous populations, marine mammal (MM) traditional foods (TFs) represent sources of both important nutrients and hazardous environmental contaminants. Food preparation is known to impact the nutrient and environmental contaminant content of processed items, yet the impacts of preparation on indigenous Arctic MM TFs remain poorly characterized. In order to determine how the various processes involved in preparing beluga blubber TFs affect their levels of nutrients and environmental contaminants, we collected blubber samples from 2 male beluga whales, aged 24 and 37 years, captured during the 2014 summer hunting season in Tuktoyaktuk, Northwest Territories, and processed them according to local TF preparation methods. We measured the levels of select nutrients [selenium (Se), polyunsaturated fatty acids (PUFAs)] and contaminants [organochlorine pesticides, perfluoroalkyl and polyfluoroalkyl substances (PFASs), polybrominated diphenyl ethers, polychlorinated biphenyls, polycyclic aromatic hydrocarbons (PAHs), mercury (Hg)] in raw and prepared (boiled, roasted, aged) beluga blubber TFs. The impacts of beluga blubber TF preparation methods on nutrient and environmental contaminant levels were inconsistent, as the majority of processes either did not appear to influence concentrations or affected the two belugas differently. However, roasting and ageing beluga blubber consistently impacted certain compounds: roasting blubber increased concentrations of hydrophilic substances (Se and certain PFASs) through solvent depletion and deposited PAHs from cookfire smoke. The solid-liquid phase separation involved in ageing blubber depleted hydrophilic elements (Se, Hg) and some ionogenic PFASs from the lipid-rich liquid oil phase, while PUFA levels appeared to increase, and hydrophobic persistent organic pollutants were retained. Ageing blubber adjacent to in-use smokehouses also resulted in considerable PAH deposition to processed samples. Our findings demonstrated that contaminant concentration differences were greater between the two sets of whale samples, based on age differences, than they were within each set of whale samples, due to variable preparation methods. When considering means to minimize human contaminant exposure while maximizing nutrient intake, consumption of aged liquid from younger male whales would be preferred, based on possible PUFA enhancement and selective depletion of hydrophilic environmental contaminants in this food item.

Optimized Multiresidue Analysis of Organic Contaminants of Priority Concern in a Daily Consumed Fish (Grass Carp)

The organic contaminants, including polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs), are of priority concern because of their persistence, toxicity, and long-distance transportation in global environment. Their residues in a daily consumed fish (grass carp) pose potential threat to human health and aquatic ecosystems. The present study optimized an analytical protocol of microwave-assisted extraction (MAE), lip-removal by gel permeation chromatography (GPC), cleanup by solid phase cartridge (SC) or adsorption chromatography column (CC), and gas chromatography-mass spectrometry (GC/MS). Besides traditional statistical parameters, some indicators were calculated to judge the performances of extraction by various methods. The optimization experiment showed that n-hexane/acetone was the best MEA extraction solvent; an optimal fraction time of 10-39 min could simultaneously elute all the target chemicals in a single GPC run. Both CC and SC showed good recoveries. However, CC performed better than SC (p < 0.05) for OCPs, and SC performed better than CC for PBDEs (p < 0.05). We also emphasized the limitations and advantages of SC and CC and finally proposed SC as the promising cleanup method because of its low-cost materials, time-saving steps, being free of manual filling, and operation by automated SPE system.

Biomagnification of endocrine disrupting chemicals (EDCs) by Pleuronectes yokohamae: Does P. yokohamae accumulate dietary EDCs?

We evaluated the potential for biomagnification of endocrine disrupting chemicals (EDCs) such as nonylphenol (NP), octylphenol (OP), bisphenol A (BP), and natural estrogens such as estrone (E1) and 17β-estradiol (E2) in a benthic fish, Pleuronectes yokohamae. The assimilation efficiencies (AE) of most EDCs ranged from 88 to 96% suggesting that they were efficiently incorporated and assimilated into P. yokohamae, except for NP (50%). However, the biomagnification factor (BMF) values were <1.0 suggesting that the compounds were not biomagnifying. Additionally, three of the target EDCs were not detected (BP, E1 and E2). Glucuronidation activity towards BP (11.44 ± 2.5 nmol/mg protein/min) and E2 (12.41 ± 3.2 nmol/mg protein/min) was high in the intestine suggesting that EDCs were glucuronidated prior to excretion into bile. Thus, we conclude that biomagnification of dietary EDCs is reduced in P. yokohamae because of effective glucuronidation.

Characteristics of the alkylphenol and bisphenol A distributions in marine organisms and implications for human health: A case study of the East China Sea

The distributions of alkylphenol (AP) and bisphenol A (BPA) in marine organisms, including fish, prawns and molluscs, could reflect the exposure of AP and BPA directly and effectively. This paper provides the first report on the species-dependent distribution and the human health risks of four APs (4-t-octylphenol, 4-t-OP; 4-octylphenol, 4-OP;4-nonylphenol, 4-NP; 4-n-nonylphenol, 4-n-NP) and BPA in 95 wild and 88 processed marine biota samples from the East China Sea of the Yangtze River Delta area. 4-NP was the predominant compound with the highest detected concentration of 19,890.50ng/g ww. Significant pollution was observed in Taizhou, Shanghai and Ningbo. The species-dependent distribution was related to food habits, living patterns and trophic transfer. Higher residual concentrations of 4-t-OP, 4-OP, 4-n-NP and BPA were observed in fish species that consumed benthic organisms or demersal fish species, whereas 4-NP showed different results due to trophic dilution. The trophic magnification factors (TMFs) of the linear APs (4-OP and 4-n-NP) (1.22-2.93) were higher than those of the branched ones (4-t-OP and 4-NP) (0.72-0.90), indicating the relative metabolism stability of linear APs. 4-NP has the lowest TMF value of 0.72, and its trophic dilution might be observed because the branched carbon chain exhibits the lowest dispersion force compared to that of the other APs. As for the health risk, 7-year old children may be exposed to the highest health risk of 4-NP with 95th percentile values of the hazard quotient of 0.22 to 0.23; however, the risks of the other chemicals were relatively low.

Somatic and gastrointestinal in vivo biotransformation rates of hydrophobic chemicals in fish

To improve current bioaccumulation assessment methods, a methodology is developed, applied, and investigated for measuring in vivo biotransformation rates of hydrophobic organic substances in the body (soma) and gastrointestinal tract of the fish. The method resembles the Organisation for Economic Co-operation and Development (OECD) 305 dietary bioaccumulation test but includes reference chemicals to determine both somatic and gastrointestinal biotransformation rates of test chemicals. Somatic biotransformation rate constants for the test chemicals ranged between 0 d(-1) and 0.38 (standard error [SE] 0.03)/d(-1) . Gastrointestinal biotransformation rate constants varied from 0 d(-1) to 46 (SE 7) d(-1) . Gastrointestinal biotransformation contributed more to the overall biotransformation in fish than somatic biotransformation for all test substances but 1. Results suggest that biomagnification tests can reveal the full extent of biotransformation in fish. The common presumption that the liver is the main site of biotransformation may not apply to many substances exposed through the diet. The results suggest that the application of quantitative structure-activity relationships (QSARs) for somatic biotransformation rates and hepatic in vitro models to assess the effect of biotransformation on bioaccumulation can underestimate biotransformation rates and overestimate the biomagnification potential of chemicals that are biotransformed in the gastrointestinal tract. With some modifications, the OECD 305 test can generate somatic and gastrointestinal biotransformation data to develop biotransformation QSARs and test in vitro-in vivo biotransformation extrapolation methods.

Replacing fish meal by food waste to produce lower trophic level fish containing acceptable levels of polycyclic aromatic hydrocarbons: Health risk assessments

This study aimed at using different types of food wastes (mainly containing cereal [food waste A] and meat meal [food waste B]) as major sources of protein to replace the fish meal used in fish feeds to produce quality fish. The traditional fish farming model used to culture low trophic level fish included: bighead, (Hypophthalmichthys nobilis), grass carp, (Ctenopharyngodon idellus), and mud carp, (Cirrhinus molitorella) of omnivorous chain. The results indicated that grass carp and bighead carp fed with food waste feeds were relatively free of PAHs. The results of health risk assessment showed that the fish fed with food waste feeds were safe for consumption from the PAHs perspective.

Assessment of Industry-Induced Urban Human Health Risks Related to Benzo[a]pyrenebased on a Multimedia Fugacity Model: Case Study of Nanjing, China

Large amounts of organic pollutants emitted from industries have accumulated and caused serious human health risks, especially in urban areas with rapid industrialization. This paper focused on the carcinogen benzo[a]pyrene (BaP) from industrial effluent and gaseous emissions, and established a multi-pathway exposure model based on a Level IV multimedia fugacity model to analyze the human health risks in a city that has undergone rapid industrialization. In this study, GIS tools combined with land-use data was introduced to analyze smaller spatial scales so as to enhance the spatial resolution of the results. An uncertainty analysis using a Monte Carlo simulation was also conducted to illustrate the rationale of the probabilistic assessment mode rather than deterministic assessment. Finally, the results of the case study in Nanjing, China indicated the annual average human cancer risk induced by local industrial emissions during 2002–2008 (lowest at 1.99×10^–6 in 2008 and highest at 3.34×10^–6 in 2004), which was lower than the USEPA prescriptive level (1×10^–6–1×10^–4) but cannot be neglected in the long term.The study results could not only instruct the BaP health risk management but also help future health risk prediction and control.

Differential gene expression analysis of benzo(a)pyrene toxicity in the clam, Ruditapes philippinarum

Polycyclic aromatic hydrocarbons (PAHs) are known for their carcinogenic, teratogenic and mutagenic properties. Benzo(a)pyrene (BaP) possesses the greatest carcinogenic potential among the various PAHs. In this study, digital gene expression (DGE) was performed to investigate the digestive gland transcriptome profile of the clam Ruditapes philippinarum exposed to BaP. A total of 10,508,312 and 11,414,297 clean reads were generated respectively, from control and BaP exposure DGE libraries. One hundred and forty-five differentially expressed genes were detected after comparing two libraries with 58 up-regulated and 87 down-regulated genes. GO annotation and KEGG pathway analyses were performed on all genes to understand their biological functions and processes. The results showed that numerous enriched differentially expressed genes are related to growth and development, antioxidant metabolism, apoptosis and detoxification metabolism. Quantitative real-time PCR was performed to verify the expressed genes of DGE. Our results provide evidences that RNA-seq is a powerful tool for toxicology and capable of generating novel and valuable information at the transcriptome level for characterizing deleterious effects caused by BaP.

Distribution and accumulation of polycyclic aromatic hydrocarbons (PAHs) in the food web of Nansi Lake, China

The concentrations of polycyclic aromatic hydrocarbons (PAHs) were analyzed in water, sediment, and biota (aquatic plant, shrimp, and fish) of Nansi Lake by gas chromatography-mass spectrometry (GC-MS). The concentrations of total PAHs were 27.54-55.04 ng L(-1) in water, 80.31-639.23 ng g(-1) dry weight (dw) in sediments, 20.92-192.78 ng g(-1) dw in aquatic plants, and 67.3-533.9 ng g(-1) dw in fish and shrimp muscles. The ratios of phenanthrene to anthracene (Ph/An), fluoranthene to pyrene (Flu/Pyr), and low molecular weight to high molecular weight (LMW/HMW) in sediment indicated that the sources of the PAHs were a mixture of pyrolytic and petrogenic contamination at most sampling sites in Nansi Lake. The composition profile of PAHs in plants was similar to that in water and animals with 2-3 ring PAHs being dominant. The 4-6 ring PAHs were the dominant PAH compounds in sediment. There is a positive correlation between sediment and aquatic plants, but their PAH composition profiles were different, implying that aquatic plant absorption of PAHs from sediment is selective and the accumulation of PAHs in aquatic plants is different. The concentration of PAHs in fish showed a positive correlation with plants, reflecting that the PAHs in fish are mainly absorbed from aquatic plants rather than directly from the water. Bioaccumulation of LMW PAHs in aquatic biota was higher than HMW PAHs. The biota-sediment accumulation factor (BSAF) values of total PAHs in the plants Potamogeton lucens Linn and Ceratophyllum demersum Linn were higher than that in most animals. The BSAF values of total PAHs in animals were in the following order: Cyprinus carpio>Macrobrachium nipponense>Carassius auratus>Channa argus. There was no significant relationship between PAH bioaccumulation and trophic levels in Nansi Lake. Risk assessment of PAHs in water, sediment, and animals indicated that the water environment of Nansi Lake is safe at present. It is worthwhile to note that benzo [a] anthracene (BaA), benzo [a] pyrene (BaP), indeno [1,2,3-cd] pyrene (InP), dibenz [a, h] anthracene (DBA), and benzo [ghi] perylene (BghiP) were detected in sediment, plants, and animals at all sampling sites, and they have potential carcinogenicity to the organisms of Nansi Lake.

Human health risk assessment of multiple contaminants due to consumption of animal-based foods available in the markets of Shanghai, China

To assess the health risks due to food consumption, the human daily intake and uptake of organochlorine pesticides, polychlorinated biphenyls, polybrominated diphenyl ethers, polycyclic aromatic hydrocarbons, and toxic trace elements (mercury, chromium, cadmium, lead, and arsenic) were estimated based on the animal-based foods collected from markets in Shanghai, China. The estimated daily intake and uptake considering the contaminant bioaccessibility via single food consumption were 9.4-399 and 4.2-282 ng/kg body weight/day for adults, and 10.8-458 and 4.8-323 ng/kg body weight/day for children, respectively. These values were 0.2-104 and 0.05-58.1, and 0.2-119 and 0.06-66.6 ng/kg body weight/day via multiple food consumption for adults and children, respectively. According to the United States Environmental Protection Agency risk assessment method, the non-cancer and cancer health risks posed by the contaminants were estimated using the hazard quotient and the lifetime cancer risk method, respectively. The results showed that the combined hazard quotient values for multiple contaminants via single or multiple food consumption were below 1, suggesting that the residents in Shanghai would not experience a significant non-cancer health risk. Among the contaminants investigated, the potential non-cancer risk of methylmercury was highest. However, the combined cancer risk posed by multiple contaminants in most foods exceeded the accepted risk level of 10(-6), and inorganic arsenic was the main contributor. The risks caused by polybrominated diphenyl ethers for cancer and non-cancer effects were negligible. The cancer risk of inorganic arsenic is a matter of concern in animal-based foods from Shanghai markets.

Multimedia model for polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs in Lake Michigan

Polycyclic aromatic hydrocarbon (PAH) contamination in the U.S. Great Lakes has long been of concern, but information regarding the current sources, distribution, and fate of PAH contamination is lacking, and very little information exists for the potentially more toxic nitro-derivatives of PAHs (NPAHs). This study uses fugacity, food web, and Monte Carlo models to examine 16 PAHs and five NPAHs in Lake Michigan, and to derive PAH and NPAH emission estimates. Good agreement was found between predicted and measured PAH concentrations in air, but concentrations in water and sediment were generally under-predicted, possibly due to incorrect parameter estimates for degradation rates, discharges to water, or inputs from tributaries. The food web model matched measurements of heavier PAHs (≥5 rings) in lake trout, but lighter PAHs (≤4 rings) were overpredicted, possibly due to overestimates of metabolic half-lives or gut/gill absorption efficiencies. Derived PAH emission rates peaked in the 1950s, and rates now approach those in the mid-19th century. The derived emission rates far exceed those in the source inventories, suggesting the need to reconcile differences and reduce uncertainties. Although additional measurements and physiochemical data are needed to reduce uncertainties and for validation purposes, the models illustrate the behavior of PAHs and NPAHs in Lake Michigan, and they provide useful and potentially diagnostic estimates of emission rates.

Trophodynamic behavior of hydrophobic organic contaminants in the aquatic food web of a tidal river

The bioaccumulation and biomagnification of sediment-bound hydrophobic organic contaminants (HOCs) are of major concern for environmental and human health. In dynamic estuaries, HOCs can be taken up from sediments, porewater, or the overlying water column concentrations directly or via the diet. The transfer of HOCs including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) to resident/migratory biota was investigated in 11 finfish species and blue crabs (Callinectes sapidus) in the Passaic River estuary. Concurrently, passive samplers were deployed to assess porewater and overlying water column concentrations. Biota were assigned to three trophic levels based on their tissue 15N isotope values and published life history strategies. There were no significant differences in trophic magnification factors (TMFs) calculated based on life-history scenarios, implying that the migratory species, mostly juveniles, had equilibrated with in situ sources of pollutants at the time they were sampled. Bioaccumulation factors and TMFs were >1 for most PCBs and tetra- and penta-CDD/DFs, indicating that they underwent biomagnification in the food web. All PAHs, PCB 11, and other lower chlorinated PCBs and PCDD/Fs did not magnify. Results from the analysis of HOC profiles implied that biota accumulated HOCs from sediments, porewater, and diet but not from overlying water.

Metamorphosis alters contaminants and chemical tracers in insects: implications for food webs

Insects are integral to most freshwater and terrestrial food webs, but due to their accumulation of environmental pollutants they are also contaminant vectors that threaten reproduction, development, and survival of consumers. Metamorphosis from larvae to adult can cause large chemical changes in insects, altering contaminant concentrations and fractionation of chemical tracers used to establish contaminant biomagnification in food webs, but no framework exists for predicting and managing these effects. We analyzed data from 39 studies of 68 analytes (stable isotopes and contaminants), and found that metamorphosis effects varied greatly. δ(15)N, widely used to estimate relative trophic position in biomagnification studies, was enriched by ∼ 1‰ during metamorphosis, while δ(13)C used to estimate diet, was similar in larvae and adults. Metals and polycyclic aromatic hydrocarbons (PAHs) were predominantly lost during metamorphosis leading to ∼ 2 to 125-fold higher larval concentrations and higher exposure risks for predators of larvae compared to predators of adults. In contrast, manufactured organic contaminants (such as polychlorinated biphenyls) were retained and concentrated in adults, causing up to ∼ 3-fold higher adult concentrations and higher exposure risks to predators of adult insects. Both food web studies and contaminant management and mitigation strategies need to consider how metamorphosis affects the movement of materials between habitats and ecosystems, with special regard for aquatic-terrestrial linkages.

Polychlorinated biphenyl (PCB) concentrations and congener composition in masu salmon from Japan: a study of all 209 PCB congeners by high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS)

We collected two subspecies of masu salmon: Oncorhynchus masou masou from four localities (southern Sea of Japan northward to Hokkaido) and O. masou ishikawae from upstream from Ise Bay close to a heavy industrial area. All 209 PCB congeners were analyzed using HRGC/HRMS. PCA ordination of congener concentrations divided data into three groups: (i) ssp. masou from Hokkaido, (ii) ssp. masou from the other regions and (iii) ssp. ishikawae. The highest ∑ PCB concentration (40.39 ng/wet wt) was in ssp. ishikawae followed by ssp. masou from southern waters; however the TEQdioxin-like PCBs was highest in ssp. masou from southern water (1.96 pg-TEQdioxin-like PCBs/g wet wt.) due to the high proportion of congener #126 in its complement (#126 has the highest toxic equivalency factor among congeners). There is likely a contamination source offshore in the southern Sea of Japan and/or along the migratory route of ssp. masou.