ABSTRACT Amino acid‐specific nitrogen isotope analysis (δ15N‐AA) is increasingly used to infer trophic ecology, yet remains poorly validated in marine predators. We analyzed bulk tissue δ15N (15N/14N) and δ13C (13C/12C), and δ15N‐AA in 105 skin samples collected from individually identified Norwegian killer whales between 2017 and 2023. Forty‐two individuals with best documented diets in 2010–2023, based on field observations and corroborated by mercury concentrations and bulk tissue δ15N values in skin, provided reference diet groups against which δ15N‐AA‐derived hypotheses were tested: Fish‐only (100% fish prey; n = 15), Intermediate mixed diet (~10% mammalian prey in addition to fish; n = 14), and Top mixed diet (~50% mammals, 50% fish prey; n = 13). Univariate and multivariate approaches identified diet as the primary driver of δ15N variation across individual amino acids and multivariate isotopic space, whereas sex and life stage had little effect. However, substantial inter‐individual variation remained unexplained and appeared to reflect metabolic processes. Metrics δ15NΣTrophic—ΣSource (δ15N difference between the sum of trophic amino acids and the sum of source amino acids) and isotopic difference between glutamic acid/glutamine (Glu) and phenylalanine (Phe) (δ15NGlu–Phe) successfully identified Top mixed diet whales but lacked the sensitivity to identify Intermediate mixed diet individuals, whilst δ15N values of Threonine showed no relationship with trophic position. Proline (Pro) and Phe used as trophic‐source pair provided the first plausible δ15N‐AA‐derived trophic position estimates for killer whales and performed better than bulk isotope‐derived trophic position when a priori knowledge was not available. Multivariate clustering of δ15N‐AA data complemented trophic position estimates by resolving finer‐scale dietary variation occurring within trophic levels.

Polychlorinated n-alkanes (PCAs), the largest component of the commercial product chlorinated paraffins, have been used globally in increasing amounts since the regulations of legacy contaminants, such as polychlorinated biphenyls (PCBs). The bioaccumulative potential of PCAs compared to legacy contaminants is inconclusive, with limited data available for PCAs with carbon chain length ≤9 and ≥18, particularly in food webs which include mammalian top predators. Here, we analysed and compared PCAs of different carbon chain length (very-short: PCAs-C6-9 [vSCCPs], short: PCAs-C10-13 [SCCPs], medium: PCAs-C14-17 [MCCPs], and long: PCAs-C18-24 [LCCPs]), 57 legacy contaminants, and total mercury (Hg) in killer whales (Orcinus orca) from northern Norway (n = 59) and a range of fish and marine mammals. We found that legacy organic contaminants dominated in concentration and pattern in marine mammals (54-87%), whereas PCAs and Hg dominated in fishes (58-98%). A species' physiology (poikilotherm or homeotherm) influenced the food web magnification of several contaminants, with estimated trophic magnification factors (TMFs) underestimated in PCAs, and overestimated in PCB-153, p.p'-DDE and Hg, if unaccounted for. PCAs-C6-9 and PCAs-C10-13 had similar and low TMFs for poikilotherms and homeotherms, and similar to PCB-28 (TMF range: 1.9-2.4 [95% confidence interval 0.9-5.7]). PCAs-C14-17 and PCAs-C18-24, had high TMFs in poikilotherms (4.8 [1.3-18] and 4.6 [1.2-18], respectively), and no significant trophic magnification in homeotherms (1.0 [0.5-2.3] and 1.0 [0.4-2.8], respectively), with the opposite pattern for PCB-153 and p.p'-DDE. Our results indicate higher PCA concentrations and biomagnification potential in poikilotherms than homeotherms, which is likely due to lower biotransformation and elimination ability.

Steroid hormones can give an indication of stress, physiological health and reproductive status in whales; however, analysis is often limited by sample mass. We developed a sensitive analytical method using solid phase extraction-liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) for the identification and quantification of eight steroid hormones (cortisol, cortisone, testosterone, androstenedione, progesterone, 11-deoxycortisol, 11-deoxycorticosterone and 17-hydroxyprogesterone) in small amounts of whale blubber (≤50 mg). Blubber biopsies were collected from stranded killer whales (Orcinus orca; n = 7), harbour porpoises (Phocoena phocoena; n = 3) and sperm whales (Physeter macrocephalus; n = 4), harvested common minke whales (n = 10; Balaenoptera acutorostrata) and free-living killer whales (n = 2) in Norway and the Barents Sea. Steroid hormones were separated using pentafluorophenyl propyl stationary phase and an optimized gradient programme with a total 20-min run. All samples (n = 26) were analysed at 50-mg sample mass, and a subset (n = 11) at 25 mg or lower. Low limit of detection and limit of quantification values resulted in high detection rates of hormones, and we found similar hormone concentrations between parallel samples and at the lowest tested sample mass (14 mg). Cortisol concentrations in sperm whales (4.3 ± 1.6 ng/g) were four times higher than stranded killer whales (1.1 ± 0.96 ng/g), which in turn were up to four times higher than free-living killer whales (0.23 ± 0.12 ng/g), harbour porpoise (0.64 ± 0.38 ng/g) and harvested minke whales (0.22 ± 0.13), possibly due to fatality type and duration of stress prior to death. We provide the first quantification of blubber steroid hormones in killer whale, minke whale, sperm whale and harbour porpoise, and in less than 50-mg sample mass. By minimizing sample mass without compromising precision or sensitivity, our method allows for steroid hormone analysis even on samples with limited availability, strengthening our ability to monitor and conserve marine mammal populations.

As part of the Marine Spatial Planning (MSP) for the Puducherry coast-a highly urbanized coastal area along India's southeast coast-an extensive assessment of organic pollutants was conducted in the sediments of the Thengaithittu Estuary, one of the major urban confluences in the region. Surface sediment samples were collected during both the dry season (June) and the wet season (September) in 2023 from six stations to measure polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs), including DDTs. The results indicated that high molecular weight (HMW) PAHs predominated in both seasons, primarily from pyrogenic sources with concentrations ranging from 0.26 to 369.16 ng g-1 dw. Carcinogenic PAHs (C-PAHs) accounted for 51-98 % of the total PAHs, although the overall PAH levels remained below the Effect Range Low (ERL) threshold, reflecting a low ecological risk. PCBs were detected only at the fishing harbour region at the estuary's mouth, with concentrations varying from 17.16 to 130.04 ng g-1 dw, where 5Cl and 6Cl biphenyls comprised 80 % of the total composition. DDT levels, ranging from below detection limit (BDL) to 2.30 ng g-1 dw, suggested minimal recent inputs. The mean sediment quality guideline quotient (mSQGq) indicated low overall biological adverse effects across all stations. These findings offer essential baseline data regarding organic pollutant levels and ecological risks, emphasizing the need for enhanced management strategies to mitigate contaminant inputs and protect both the estuarine ecosystem and public health.

Metapopulation dynamics can be shaped by foraging ecology, and thus be sensitive to shifts in prey availability. Genotyping 204 North Atlantic killer whales at 1346 loci, we investigated whether spatio-temporal population structuring is linked to prey type and distribution. Using population-based methods (reflecting evolutionary means), we report a widespread metapopulation connected across ecological groups based upon nuclear genome SNPs, yet spatial structuring based upon mitogenome haplotypes. These contrasting patterns of markers with maternal and biparental inheritance are consistent with matrilineal site fidelity and philopatry, and male-mediated gene flow among demes. Connectivity between fish-eating and ‘mixed-diet’ (eating both fish and mammal prey) killer whales, marks a deviation within a species renowned for its marked structure associated with ecology. However, relatedness estimates suggest distinct spatial clusters, and heterogeneity in recent gene flow between them. The contrasting patterns between inference of structure and inference of relatedness suggest that gene flow has been partially restricted over the past two to three generations (50–70 years). This coincides with the collapse of North Atlantic herring stocks in the late 1960s and the subsequent cessation of their seasonal connectivity. Statistically significant association between diet types and assignment of Icelandic killer whales to relatedness-based clusters indicated limited gene flow was maintained through Icelandic ‘mixed-diet’ whales when herring-mediated connectivity was diminished. Thus, conservation of dietary variation within this metapopulation is critical to ensure genetic health. Our study highlights the role of resource dynamics and foraging ecology in shaping population structure and emphasises the need for transnational management of this widespread migratory species and its prey.

Philopatric kin-based societies encourage a narrow breadth of conservative behaviours owing to individuals primarily learning from close kin, promoting behavioural homogeneity. However, weaker social ties beyond kin, and across a behaviourally diverse social landscape, could be sufficient to induce variation and a greater ecological niche breadth. We investigated a network of 457 photo-identified killer whales from Norway (548 encounters in 2008-2021) with diet data available (46 mixed-diet individuals feeding on both fish and mammals, and 411 exclusive fish-eaters) to quantify patterns of association within and between diet groups, and to identify underlying correlates. We genotyped a subset of 106 whales to assess patterns of genetic differentiation. Our results suggested kinship as main driver of social bonds within and among cohesive social units, while diet was most likely a consequence reflective of cultural diffusion, rather than a driver. Flexible associations within and between ecologically diverse social units led to a highly connected network, reducing social and genetic differentiation between diet groups. Our study points to a role of social connectivity, in combination with individual behavioural variation, in influencing population ecology in killer whales.

The widely reported increase of terrestrial dissolved organic matter (terrDOM) in northern latitude coastal areas (“coastal darkening”) can also impact contaminant dynamics in affected systems. One potential mechanism is based on the differences in chemical adsorption processes of the molecularly larger terrDOM compared to marine DOM (marDOM) that leads to increased emulsification of lipophilic contaminants with terrDOM. Filter feeders filter large amounts of water and DOM daily and thus are directly exposed to DOM and associated contaminants through their feeding activity. Differences in chemical adsorption profiles in DOM thus could potentially lead to an increase in bioaccumulation with terrDOM in filter feeders. To assess bioaccumulation in filter feeders, we exposed the ascidian Ciona intestinalis (formerly Ciona intestinalis Type B), a mucus-based filter feeder, to the lipophilic veterinary drug teflubenzuron (log KOW: 5.39) and four DOM treatments: TerrDOM, marDOM, a mix of the two called mixDOM, and seawater without DOM addition. After 15 days of exposure, individuals in all DOM treatments showed a trend towards higher bioaccumulation than those in the seawater control, however, with considerable overlap in posterior distributions. Against our expectations, marDOM resulted in the highest bioaccumulation factor (BAF), followed by mixDOM, with terrDOM resulting in the lowest BAF except for seawater (BAF median, 2.5% - 97.5% percentile marDOM 94 L/kg, 74 - 118 L/kg; mixDOM 82 L/kg, 63-104 L/kg; terrDOM 79 L/kg; 61-99 L/kg; seawater 61 L/kg, 44 – 79 L/kg). A similar study on blue mussels, which filter larger particles, yielded similar patterns. Both Ciona and blue mussel experiments resulted in BAF below the level of concern (BAF > 2000 L/kg) according to EU REACH (European Commission, 2006) and, therefore, likely not environmentally problematic in the examined context. However, the results show that DOM can act as a dietary vector; thus, different combinations of contaminants, DOM, and filter-feeding organisms should be tested further.

The widely reported increase of terrestrial dissolved organic matter (terrDOM) in northern latitude coastal areas ("coastal darkening") can impact contaminant dynamics in affected systems. One potential impact is based on differences in chemical adsorption processes of the molecularly larger terrDOM compared to marine DOM (marDOM) that leads to increased emulsification of lipophilic contaminants with terrDOM. Filter feeders filter large amounts of water and DOM daily and thus are directly exposed to associated contaminants through both respiration and feeding activity. Thus, increased exposure to terrDOM could potentially lead to an increase in bioaccumulation of lipid soluble contaminants in filter feeders. To assess the effect of DOM on bioaccumulation in filter feeders, we exposed the mucous based filter feeding ascidian Ciona intestinalis (formerly known as Ciona intestinalis Type B), to the lipophilic veterinary drug teflubenzuron (log KOW: 5.39) in combination with four DOM treatments: TerrDOM, marDOM, a mix of the two called mixDOM, and seawater without DOM addition. The exposure lasted for 15 days, after which the individuals in all DOM treatments showed a trend towards higher bioaccumulation of Teflubenzuron than those in the seawater control. However, there was considerable overlap in posterior distributions. Against our expectations, marDOM resulted in the highest bioaccumulation factor (BAF), followed by mixDOM, with terrDOM resulting in the lowest BAF except for seawater (kinetic BAF L/kg median, 2.5 %-97.5 % percentile marDOM 94, 74-118; mixDOM 82, 63-104; terrDOM 79; 61-99; seawater 61, 44-79). All BAFs were below the level of concern according to the EU REACH regulation (BAF < 2000 L / kg) and, therefore, likely not environmentally problematic in the examined context. However, the results show that DOM can act as a dietary vector; thus, different combinations of contaminants, DOM, and filter feeding organisms should be tested further.

Food Risk Assess EuropeVolume 2, Issue 2 0024E Technical reportOpen Access Risk assessment of grilled and barbecued food Espen Mariussen, Espen MariussenSearch for more papers by this authorJan Alexander, Jan AlexanderSearch for more papers by this authorBarbara A. Bukhvalova, Barbara A. BukhvalovaSearch for more papers by this authorLisbeth Dahl, Lisbeth DahlSearch for more papers by this authorAnn-Karin Hardie Olsen, Ann-Karin Hardie OlsenSearch for more papers by this authorHelen Engelstad Kvalem, Helen Engelstad KvalemSearch for more papers by this authorMartin Schlabach, Martin SchlabachSearch for more papers by this authorHeidi Amlund, Heidi AmlundSearch for more papers by this authorRita Hannisdal, Rita HannisdalSearch for more papers by this authorAnders Ruus, Anders RuusSearch for more papers by this authorIngunn Anita Samdal, Ingunn Anita SamdalSearch for more papers by this authorHelle K Knutsen, Helle K KnutsenSearch for more papers by this author Espen Mariussen, Espen MariussenSearch for more papers by this authorJan Alexander, Jan AlexanderSearch for more papers by this authorBarbara A. Bukhvalova, Barbara A. BukhvalovaSearch for more papers by this authorLisbeth Dahl, Lisbeth DahlSearch for more papers by this authorAnn-Karin Hardie Olsen, Ann-Karin Hardie OlsenSearch for more papers by this authorHelen Engelstad Kvalem, Helen Engelstad KvalemSearch for more papers by this authorMartin Schlabach, Martin SchlabachSearch for more papers by this authorHeidi Amlund, Heidi AmlundSearch for more papers by this authorRita Hannisdal, Rita HannisdalSearch for more papers by this authorAnders Ruus, Anders RuusSearch for more papers by this authorIngunn Anita Samdal, Ingunn Anita SamdalSearch for more papers by this authorHelle K Knutsen, Helle K KnutsenSearch for more papers by this author First published: 17 April 2024 https://doi.org/10.2903/fr.efsa.2024.FR-0024 Scientific Opinion of the Panel on Contaminants of the Norwegian Scientific Committee for Food and Environment VKM has assessed the health risk from grilled food consumption and summarized the knowledge on formation of several carcinogenic process contaminants in grilled food. Based on exposure scenarios for polycyclic aromatic hydrocarbons (PAH) in grilled food VKM concludes that the risk is low for most consumers. VKM noted a public health concern for those who often consume fat rich meat that is grilled in a way leading to high PAH formation, i.e., when fat burns on the heat source, food is grilled very well-done on charcoal or particularly campfire. Such conditions may also increase formation of other heat-induced contaminants. VKM Report 2024:2 Risk assessment of grilled and barbecued food Scientific Opinion of the Panel on Contaminants of the Norwegian Scientific Committee for Food and Environment 21.03.2024 Phone: +47 21 62 28 00 Email: [email protected] vkm.no Cover photo: Helen Engelstad Kvalem Suggested citation: Espen Mariussen, Jan Alexander, Barbara Alexandra Bukhvalova, Lisbeth Dahl, Ann-Karin Hardie Olsen, Helen Engelstad Kvalem, Martin Schlabach, Heidi Amlund, Rita Hannisdal, Anders Ruus, Ingunn Anita Samdal, Helle K Knutsen. Risk assessment of grilled and barbequed food. Scientific Opinion of the Panel on Contaminants of the Norwegian Scientific Committee for Food and Environment. VKM Report 2024:2, ISBN: 978-82-8259-438-7, ISSN: 2535-4019. Norwegian Scientific Committee for Food and Environment (VKM), Oslo, Norway. Preparation of the opinion: The Norwegian Scientific Committee for Food and Environment (Vitenskapskomiteen for mat og miljø, VKM) appointed a project group to draft the opinion. The project group consisted of five VKM members, 1 VKM staff. Three referees commented on and reviewed the draft opinion. The Committee, by the Panel on Contaminants assessed, and approved the final opinion. Authors of the opinion: The authors have contributed to the opinion in a way that fulfils the authorship principles of VKM (VKM, 2019). The principles reflect the collaborative nature of the work, and the authors have contributed as members of the project group and/or the VKM Panel on Contaminants. Members of the project group: (in alphabetical order after chair of the project group): Espen Mariussen – Chair of the project group. Member of the Panel on Contaminants. Affiliation: 1) VKM; 2) Norwegian Institute of Public Health Jan Alexander - Member of the Panel on Contaminants. Affiliation: 1) VKM; 2) Retired, former Norwegian Institute of Public Health Barbara Alexandra Bukhvalova, VKM staff. Affiliation: VKM Lisbeth Dahl - Member of the Panel on Contaminants. Affiliation: 1) VKM; 2) Institute of Marine Research Helen Engelstad Kvalem – Project leader, VKM staff. Affiliation: VKM Ann-Karin Hardie Olsen - Member of the Panel on Contaminants. Affiliation: 1) VKM; 2) Norwegian Institute of Public Health Martin Schlabach - Member of the Panel on Contaminants. Affiliation: 1) VKM; 2) Retired, former NILU Members of the Panel on Contaminants: (in alphabetical order before chair of the Panel/Scientific Steering Committee): Heidi Amlund – Member of the Panel on Contaminants. Affiliation: 1) VKM; 2) National Food Institute, Technical University of Denmark Rita Hannisdal - Member of the Panel on Contaminants. Affiliation: 1) VKM; 2) Institute of Marine Research Anders Ruus - Member of the Panel on Contaminants. Affiliation: 1) VKM; 2) Norwegian Institute for Water Research Ingunn Anita Samdal - Member of the Panel on Contaminants. Affiliation: 1) VKM; 2) Norwegian Veterinary Institute Espen Mariussen – Chair of the project group. Member of the Panel on Contaminants. Affiliation: 1) VKM; 2) Norwegian Institute of Public Health Jan Alexander - Member of the Panel on Contaminants. Affiliation: 1) VKM; 2) Retired, former Norwegian Institute of Public Health Lisbeth Dahl - Member of the Panel on Contaminants. Affiliation: 1) VKM; 2) Institute of Marine Research Helen Engelstad Kvalem – Project leader, VKM staff. Affiliation: VKM Ann-Karin Hardie Olsen - Member of the Panel on Contaminants. Affiliation: 1) VKM; 2) Norwegian Institute of Public Health Martin Schlabach - Member of the Panel on Contaminants. Affiliation: 1) VKM; 2) Retired, former NILU Helle Knutsen – Chair of the Panel on Contaminants. Affiliation: 1) VKM; 2) Norwegian Institute of Public Health Acknowledgement: VKM would like to thank the referees Wim Mennes (retired, RIVM, Netherlands), David Gott (Food Standards Agency, UK) and Peter Fürst (retired, Chemical and Veterinary Analytical Institute, Germany) for their valuable comments through critical review of the draft opinion. VKM emphasises that the referees are not responsible for the content of the final opinion. In accordance with VKM's routines for approval of a risk assessment (VKM, 2018), VKM received their comments before evaluation and approval by VKM Panel on Contaminants and before the opinion was finalised for publication. Trine Husøy is acknowledged for advice on probabilistic exposure assessment. Sagnik Sengupta (VKM secretariat) is acknowledged for his contributions with compiling the occurrence data on PAH and the data analysis in R. Gro Haarklou Mathisen (VKM secretariat) is acknowledged for her contribution with initiating work on the protocol and kind advice along the process with this report. The Library at the Norwegian Institute of Public Health is acknowledged for the valuable help an insight in the systematic literature search. Inger Therese Lillegaard (VKM secretariat) is acknowledged for her reflections and advice on food consumption and scenarios. We also express gratitude to all of our European colleagues that responded to our call for data through the EFSA focal point network on occurrence data of process contaminants; Finland, Italia, Poland, Slovenia, Spain, Sweden, Belgium and Hungary. Competence of VKM experts: Persons working for VKM, either as appointed members of the Committee or as external experts, do this by virtue of their scientific expertise, not as representatives for their employers or third-party interests. The Civil Services Act instructions on legal competence apply for all work prepared by VKM. AboutPDF ToolsExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat Summary Background It is well-known that heat treatment of food, such as grilling and frying may give rise to unwanted, harmful substances in food, so-called process contaminants. VKM summarized this in the previous risk assessment of grilled food from 2007. In 2022, the Norwegian Food Safety Authority asked VKM to update and summarize the knowledge on formation of processed contaminants in various food by different grilling methods, and to assess the risk this may pose. More specifically the tasks were: Identify process contaminants which are formed to a greater extent by grilling than by frying and create an overview of reported amounts of these process contaminants in various types of grilled food. Elucidate factors (for example grill type, grill method and food) that are important for the formation of the identified process contaminants in grilled food. If possible, based on available information, assess the health risks associated with the consumption of grilled food compared to fried food. Methods VKM prepared a protocol, published in February 2023, describing the scope and methods for this risk assessment. New knowledge since 2006 about the relationship between the consumption of grilled food and health outcomes in humans was collected through an umbrella review of systematic summaries on this topic. Information on which contaminants are formed in grilled food, the amount formed, and factors important for their formation were collected using non-systematic literature searches. Characterization of health hazards linked to the contaminants was obtained from assessments carried out by international risk assessment bodies. VKM considered that the identified data were considered sufficient for a quantitative risk assessment of exposure to polycyclic aromatic hydrocarbons (PAH), but not for other contaminants. The PAH exposure was estimated by a probabilistic approach, with two scenarios for the consumption of grilled food. This involved modelling e the content of PAHs in different grilled food items and exposure to PAHs. The total risk from dietary PAH exposure from was described by the margin of exposure (MOE) approach. Results Identification of process contaminants VKM identified several process contaminants formed during grilling. These were PAHs, PAH analogues such as chlorinated-PAHs and nitrated PAHs, polyphenols, heterocyclic aromatic amines (HAAs), 3- monochloropropane-1,2-diol (3-MCPD) and glycidyl esters, acrylamide, nitrosamines, nitrite, harmful Maillard reaction products, biogenic amines, 7-ketocholesterol, acridine derivatives, anthraquinone (ATQ), pyrazines, advanced glycation end products (AGE). For two groups of compounds, PAHs and HAAs, there was substantial or plausible evidence for higher concentration in grilled meat and fish than in fried food. There was few data available on process contaminants in other grilled food than meat and fish, such as e.g. vegetables and bread. Concentration data for PAHs in grilled food (mostly meat and meat products) was collected from a total of 81 studies. The highest concentrations of PAHs (BaP and PAH4) were found in campfire grilled sausages. Concentration data for BaP, regardless of grilling method, indicated variability ranging from levels below quantification limits to more than 100 ng/g in fatty pork meat and sausages. Most of the grilled food items had median BaP concentrations below approximately 1 ng/g but varied from 0.1 to 4.1 ng/g across all food items. The occurrence of the different HAAs in grilled food varied greatly, from below detection limits to about 50 ng/g. The concentrations could, however, be up to 240 ng/g for PhIP in very well-done grilled chicken, and with higher levels in meat than in fish. Factors (for example grill type, grill method and food) that are important for the formation of the identified process contaminants in grilled food. Main types of heat sources for grilling are electricity, gas, charcoal (lump charcoal, briquettes) and firewood. The type of heat source may influence the content of PAHs and HAAs differently. Other factors that may influence the formation of PAHs and HAAs include type of fuel, direct or indirect grilling, type of meat, distance from the heat source, grilling temperature, and grilling time. Contamination of food with PAHs may primarily occur through: (1) deposition on the food of fuel-related PAHs in smoke. Electric heating and gas emit no or little PAHs, while charcoal and in particular firewood may contribute significantly to PAH contamination. When using charcoal, the PAH emission is higher in the initial period after lighting the grill. (2) deposition of smoke from incomplete combustion (pyrolysis) of dripping fat onto the heating source or hot surfaces. Dripping fat on the heat source is a significant source of PAHs in grilled food and is related to the fat content of the food. Avoiding fat dripping directly on the heat source and diverting the smoke from the food may reduce PAH deposition on the food. Studies on the impact of marination are conflicting, as marination may both reduce and increase the content of PAHs. (3) over-heating the food resulting in burned surface during cooking. Temperature, proximity to the heat source, frequent flipping of the food, and cooking time are important for avoiding burning the food during grilling. HAAs are mainly formed in the crust or gravy by heating. Variables that affect the formation are (1) temperature and cooking time. Concentrations of HAAs increase with rising temperature, while regular turning of the meat during cooking reduce the surface temperature and mitigate HAA formation. (2) presence of precursors, such as creatine, reducing sugars and free amino acids in the food. More HAA is formed in lean meat than in fatty meat, fish or mixed products. (3) method of cooking, such as marination, may affect the formation of HAAs. Microwaving beef and chicken prior to charcoal grilling can reduce the content of HAAs. Health risk associated with consumption of grilled food The umbrella review of systematic reviews of epidemiological studies published since 2006 did not reveal additional knowledge on the association between consumption of grilled food and health outcomes in humans. Hence, the conclusion drawn in the previous VKM 2007 assessment remains pertinent, suggesting a possible association between intake of well-done fried or grilled meat and cancer in the colon, rectum, prostate, breast, and pancreas. It was beyond the scope of the present assessment to review original studies on the health effects of consumption of grilled food compared to other cooking methods. VKM therefore assessed the risk from exposure to process contaminants formed by grilling. VKM estimated PAH exposure in grilled food quantitatively based on scenarios of consumption of grilled food also including a background exposure of PAH from the rest of the diet. Due to lack of data, the risk from HAA exposure and other heat-induced contaminants could not be characterised. The PAH concentration distributions in various grilled food items based on the extracted information from the 81 identified publications were generated from all types of grilling methods, of which more than 60% of the data were from charcoal grilled food. Due to limitations in the database the data did not allow for differentiation among grilling methods. The cumulative concentration distribution in most of the foods showed a sharp increase in the PAH concentrations above the 75 percentiles. The simulated concentration at the 90- and 95-percentile may represent grilling methods known to increase formation of PAHs in the food. The highest concentrations of BaP were found in sausages grilled on campfire, and in hamburgers and fatty pork. The two grilled food consumption scenarios include only meat and salmon because of lack of occurrence data in other grilled food items, such as vegetables, bread and meat imitate. The scenarios illustrate possible consequences of different food preferences on the intake of PAHs from grilled foods. The scenario plate of 200 g grilled fat-rich meat contained fat rich pork meat, hamburger, sausages, and chicken with skin. The other plate with 200 g lean meat and fish contained beef, lean pork meat, chicken without skin and salmon. Based on concentration distribution of BaP and PAH4 in each food item on the plate the distribution of the contents of BaP and PAH4 on each plate was simulated. The exposure scenarios based on the two plates included background PAH exposure from the rest of the diet and 1 to 100 servings of each plate per year. Average daily intakes of BaP or PAH4 for one year were calculated. Risk was characterized by the MOE approach using BMDL10s for BaP and PAH4 from the EFSA risk assessment of PAHs in food from 2008 as reference points. VKM considers that exposure to PAH resulting in MOE below 10,000 is of public health concern. For the plate with lean meat and salmon the use of mean, median and 75 percentile exposure to BaP and PAH4 up to 100 servings per year, resulted in MOEs above 10,000. At the 90 percentile and 100 servings the MOEs were approximately 10,000 for BaP and slightly below for PAH4. For the plate with fat rich meat the MOEs for the scenario related exposures remained above 10,000 when consuming grilled fat rich meat with a mean BaP and PAH4 content up to 100 times a year. At concentrations equivalent to the 95 percentile of BaP and PAH4 the MOEs were below 10,000 when consuming grilled fat rich meat approximately 15 and 25 times a year, respectively. Using PAH4 as an indicator of total PAH exposure, instead of BaP, gave approximately the same result as that of BaP, with slightly higher MOEs for the fat rich meat plate and slightly lower for the lean meat and salmon plate. The impact of campfire grilling on exposure estimates and the associated MOEs was examined in a sensitivity analysis. Data on campfire grilled food was only available for food items on the fat rich meat plate. Excluding campfire grilled food from the fat rich plate substantially reduced impact on the mean, median and higher percentiles values for the contents of both PAH4 and BaP on the plate. The resulting MOEs were above 10,000 when consuming more than 100 servings per year of plates with a mean, median and 75 percentile content of BaP and PAH4. At a 95-percentile content of BaP and PAH4 the MOEs were above 10,000 for up to 30 servings per year. Due to limitations the database did not allow creation of exposure scenarios reflecting various grilling methods. The MOEs calculated from the mean, median and 75 percentile exposure to PAHs likely represent the use of varied grill methods and food not causing substantial PAH formation. This will probably apply to most grilling situations. The MOEs calculated for the 90- and 95-percentile exposures to PAH may represent frequent use of grilling methods known to increase formation of PAHs in the food, such as high temperature grilling with charcoal or even campfire for a longer grill time leading to well done food. Due to lack of data, the risk from HAA exposure and other heat-induced contaminants could not be characterised. The concentrations of HAAs seem to be higher in grilled meat than in fried meat, particularly when well done. Grilling of food is associated with higher and less controllable surface temperature than frying. As most of the HAAs are genotoxic and carcinogenic in rodents and some have been classified as possible human carcinogens, their formation during grilling may be of concern. Although not precisely known, it is plausible that several other heat-induced contaminants, such as of PAH-analogues, can occur in higher concentrations in grilled food than in fried food, as the mechanism of formation is presumed to be similar to that of the PAHs or due to a presumably higher and less controllable temperature in grilling. Uncertainty The uncertainties in this assessment are large. Exposure to PAH was estimated from simulated occurrence data and consumption scenarios. The health risk from exposure to PAHs in consumed grilled food characterised by the MOE approach may both be over- and underestimated. Due to lack of data, the health risk associated with exposure to heat-induced contaminants in grilled food other than PAH could not be assessed. Due to high and less controllable temperature during grilling, it is likely that HAAs and some other heat-induced contaminants may be present in higher concentrations in grilled food than in fried food. Therefore, the total risk associated with the presence of process contaminants in grilled food is likely to be higher than for PAH alone. Data gaps The main data gaps related to the health risk assessment of grilled food identified by VKM are the following: 1) systematic reviews on health outcomes related to consumption of grilled food in comparison with other cooking methods are lacking, 2) data on consumption of grilled food, food items, frequency of grilling and grilling method applied are missing, 3) data on occurrence of PAH and other heat-induced contaminants in food prepared by different grilling methods and by other comparable cooking methods are missing, 4) toxicological data on individual HAAs for better hazard characterization considering toxicokinetic differences between rodents and humans are missing, and 5) occurrence data on HAAs in grilled food analysed with controlled and validated analytical methods are missing. References Abramsson-Zetterberg, L., Darnerud, P. 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The increased export of terrestrial dissolved organic matter (terrDOM) to coastal marine ecosystems may affect local filter feeders and the local food web via the altered uptake of organic material and associated contaminants. To compare terrDOM to marine DOM (marDOM) as contaminant vectors to coastal biota, we exposed blue mussels (Mytilus sp.) to the different DOM types in combination with teflubenzuron, a widely applied lipophilic aquaculture medicine targeting salmon lice (Lepeophtheirus salmonis). A 16-day exposure of the blue mussels to DOM and teflubenzuron was followed by a depuration phase of 20 days without teflubenzuron. We calculated teflubenzuron adsorption rates and bioaccumulation factors (BAF) using a Bayesian model, expecting teflubenzuron uptake to be greater with terrDOM than marDOM due to the higher prevalence of large amphipathic humic acids in terrDOM. Humic acids have strong absorption properties and are able to envelope lipophilic molecules. Thus, humic acids can function as an efficient contaminant vector when taken up by filter feeders. Although there were varying degrees of overlap, the mussels tended to accumulate higher amounts of teflubenzuron in the DOM treatments than in the seawater control (bioaccumulation factor [BAF] in seawater: median 106 L/kg; 2.5 %-97.5 % percentile: 69-160 L/kg). Contrary to expectations, mussels exposed to marDOM showed a trend toward more bioaccumulation of teflubenzuron than those exposed to terrDOM (BAF marine 144 L/kg; 102-221 L/kg versus BAF terrestrial: 121 L/kg; 82-186 L/kg). The highest teflubenzuron accumulation was observed with the 50:50 mixture of marDOM and terrDOM (BAF mix: 165 L/kg; 117-244 L/kg). The slight difference in DOM-type accumulation rates observed in this experiment-especially the accumulation rate of terrDOM compared to that of the seawater-only treatment type-was not considered environmentally relevant. Further studies are necessary to see if the observed trends transfer to complex environmental systems.

Increased export of terrestrially derived dissolved organic matter (DOM) to coastal marine ecosystems may affect local filter feeders and the associated local food web via altered uptake of organic material and associated contaminants. To assess terrestrial derived DOM (terrDOM), compared to marine derived DOM (marDOM) as a contaminant vector to coastal biota, we exposed blue mussels (Mytilus sp.) to different types of DOM in combination with teflubenzuron. Teflubenzuron is a widely applied lipophilic aquaculture medicine targeting salmon lice (Lepeophtheirus salmonis). A 16-day exposure of the blue mussels to DOM and teflubenzuron was followed by depuration phase of 20 days without teflubenzuron. We calculated teflubenzuron adsorption rates as well as bioaccumulation factors (BAF) using a Bayesian model. We expected teflubenzuron uptake to be greater with terrDOM due to the higher prevalence of large amphipathic humic acids in terrDOM. Humic acids may result in strong absorption and potential for envelopment of lipophilic molecules, and thus could function as an efficient contaminant vector when taken up by filter feeders. In all DOM treatments, mussels showed a slight tendency towards accumulating higher amounts of teflubenzuron than the seawater control, although to varying degree overlapping with seawater (bioaccumulation factor (BAF) in seawater: median 106 L/kg; 2.5%–97.5% percentile: 69–160 L/kg). Contrary to expectations, mussels exposed to marDOM apparently bioaccumulated more teflubenzuron than those exposed to terrDOM (BAF marine 144 L/kg; 102–221 L/kg versus BAF terrestrial: 121 L/kg; 82–186 L/kg). The highest teflubenzuron accumulation was however observed for the 50:50 mixture of marDOM and terrDOM (BAF mix: 165 L/kg; 117–244 L/kg). The small difference in accumulation rates observed between terrDOM and the seawater only treatment type is likely not environmentally relevant, thus the effect of terrDOM alone as a vector for teflubenzuron seems negligible.

Quantifying the diet composition of apex marine predators such as killer whales (Orcinus orca) is critical to assessing their food web impacts. Yet, with few exceptions, the feeding ecology of these apex predators remains poorly understood. Here, we use our newly validated quantitative fatty acid signature analysis (QFASA) approach on nearly 200 killer whales and over 900 potential prey to model their diets across the 5000 km span of the North Atlantic. Diet estimates show that killer whales mainly consume other whales in the western North Atlantic (Canadian Arctic, Eastern Canada), seals in the mid-North Atlantic (Greenland), and fish in the eastern North Atlantic (Iceland, Faroe Islands, Norway). Nonetheless, diet estimates also varied widely among individuals within most regions. This level of inter-individual feeding variation should be considered for future ecological studies focusing on killer whales in the North Atlantic and other oceans. These estimates reveal remarkable population- and individual-level variation in the trophic ecology of these killer whales, which can help to assess how their predation impacts community and ecosystem dynamics in changing North Atlantic marine ecosystems. This new approach provides researchers with an invaluable tool to study the feeding ecology of oceanic top predators.

There are limited data on organic contaminants in marine biota from coastal Tanzania, especially on the occurrence of industrial-use contaminants such as polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). The present study, performed in 2018-2019 in coastal Tanzania and Zanzibar Island, aimed at assessing spatial variation in the occurrence of PCBs; brominated flame retardants (BFRs), including PBDEs; and organochlorine pesticides, including dichlorodiphenyltrichloroethane (DDT), among three locations that differ in degree of anthropogenic activity. Analyzed samples included edible tissues of marine fishes and prawns representing different trophic levels and habitats. The results indicate a mainland-island difference, with fishes and prawns collected on Zanzibar having significantly lower PCB and DDT concentrations but higher concentrations of hexachlorobenzene compared to the two mainland locations. The highest contaminant concentrations were found in fishes and prawns collected around central Dar es Salaam harbor, with median ΣPCBs ranging from 22.3 to 577 ng/g lipid weight and ΣDDTs from 22.7 to 501 ng/g lipid weight, suggesting local sources. Concentrations of PBDEs were similar among locations, suggesting more diffuse sources. None of the "newer-type" BFRs, including compounds introduced as replacements for PBDEs, were detected in the present study. Stable isotope values of carbon (δ13 C) and nitrogen (δ15 N) varied among locations, and the relationship between contaminants and δ15 N varied among locations and habitat (pelagic/demersal). Concentrations measured in the present study are below European guidelines for human consumption of fishes and prawns. However, industrial-use contaminants should be monitored in developing countries because they are contaminants of emerging concern as a result of increasing industrialization and global trade of used products and wastes. Environ Toxicol Chem 2022;41:321-333. © 2021 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Hexachlorobenzene (HCB), listed on the Stockholm Convention on persistent organic pollutants and regulated as a hazardous priority pollutant by the Water Framework Directive (WFD), is ubiquitously distributed in the environment and assumed to mildly biomagnify in aquatic foodwebs. The proposal to include trophic magnification factors (TMFs) in the procedure for comparing contaminant levels in biota at different trophic levels (TLs) with WFD environmental quality standards requires adequate selection of TMFs. In the first step of our study, we compared two independently obtained datasets of pentachlorobenzene (PeCB) and HCB concentration ratios from passive sampling (PS) in water and in fish through routine monitoring programs in Norway to evaluate possible biomagnification. In this procedure, PeCB is used for benchmarking the bioconcentration in fish, and the observed HCB/PeCB ratios in fish are compared with ratios expected in the case of (i) HCB bioconcentration or (ii) biomagnification using published TMF values. Results demonstrate that it is not possible to confirm that HCB biomagnifies in fish species that would be used for WFD monitoring in Norway and challenges the proposed monitoring procedures for such compounds in Norwegian or European waters. In the second step, fish-water chemical activity ratios for HCB and PeCB as well as for polychlorinated biphenyls where biota and PS were conducted alongside were calculated and found to rarely exceed unity for cod (Gadus morhua), a fish species with a TL of approximately 4.

Decades of atmospheric and oceanic long-range transport from lower latitudes have resulted in deposition and storage of persistent organic pollutants (POPs) in Arctic regions. With increased temperatures, melting glaciers and thawing permafrost may serve as a secondary source of these stored POPs to freshwater and marine ecosystems. Here, we present concentrations and composition of legacy POPs in glacier- and permafrost-influenced rivers and coastal waters in the high Arctic Svalbard fjord Kongsfjorden. Targeted contaminants include polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), dichlorodiphenyltrichloroethanes (DDTs), hexachlorocyclohexanes (HCHs) and chlordane pesticides. Dissolved (defined as fraction filtered through 0.7 μm GF/F filter) and particulate samples were collected from rivers and near-shore fjord stations along a gradient from the heavily glaciated inner fjord to the tundra-dominated catchments at the outer fjord. There were no differences in contaminant concentration or pattern between glacier and tundra-dominated catchments, and the general contaminant pattern reflected snow melt with some evidence of pesticides released with glacial meltwater. Rivers were a small source of chlordane pesticides, DDTs and particulate HCB to the marine system and the particle-rich glacial meltwater contained higher concentrations of particle associated contaminants compared to the fjord. This study provides rare insight into the role of small Arctic rivers in transporting legacy contaminants from thawing catchments to coastal areas. Results indicate that the spring thaw is a source of contaminants to Kongsfjorden, and that expected increases in runoff on Svalbard and elsewhere in the Arctic could have implications for the contamination of Arctic coastal food-webs.

Herring gulls (Larus argentatus) are opportunistic feeders, resulting in contaminant exposure depending on area and habitat. We compared contaminant concentrations and dietary markers between two herring gull breeding colonies with different distances to extensive human activity and presumed contaminant exposure from the local marine diet. Furthermore, we investigated the integrity of DNA in white blood cells and sensitivity to oxidative stress. We analyzed blood from 15 herring gulls from each colony—the urban Oslofjord near the Norwegian capital Oslo in the temperate region and the remote Hornøya island in northern Norway, on the Barents Sea coast. Based on d13C and d34S, the dietary sources of urban gulls differed, with some individuals having a marine and others a more terrestrial dietary signal. All remote gulls had a marine dietary signal and higher relative trophic level than the urban marine feeding gulls. Concentrations (mean ± standard deviation [SD]) of most persistent organic pollutants, such as polychlorinated biphenyl ethers (PCBs) and perfluorooctane sulfonic acid (PFOS), were higher in urban marine (PCB153 17 ± 17 ng/g wet weight, PFOS 25 ± 21 ng/g wet wt) than urban terrestrial feeders (PCB153 3.7 ± 2.4 ng/g wet wt, PFOS 6.7 ± 10 ng/g wet wt). Despite feeding at a higher trophic level (d15N), the remote gulls (PCB153 17 ± 1221 ng/g wet wt, PFOS 19 ± 1421 ng/g wet wt) were similar to the urban marine feeders. Cyclic volatile methyl siloxanes were detected in only a few gulls, except for decamethylcyclopentasiloxane in the urban colony, which was found in 12 of 13 gulls. Only hexachlorobenzene was present in higher concentrations in the remote (2.6 ± 0.42 ng/g wet wt) compared with the urban colony (0.34 ± 0.33 ng/g wet wt). Baseline and induced DNA damage (doublestreak breaks) was higher in urban than in remote gulls for both terrestrial and marine feeders. Environ Toxicol Chem 2022;41:2466–2478. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Climate and land-use changes are leading to impacts on individual ecosystems as well as shifts in transfer dynamics between interconnected systems. At the land-ocean interface, changes in riverine inputs of organic matter (OM) and nutrients have the potential to lead to shifts in coastal carbon and nutrient cycling with consequences for ecosystem structure and function. In this study, we assess OM and nutrient dynamics for two contrasting Norwegian river-to-fjord systems: a boreal system with a forested catchment draining into a narrow fjord (Marrow boreal system'), and a subarctic system where lowland forests and mountainous regions drain into a broad fjord broad subarctic system'). We characterized seasonal organic carbon and nutrient concentrations and DOM absorption properties for samples collected along transects from river to outer fjord during 2015/2016. While differences in catchment properties drove contrasts in river chemistry between the two study rivers, fjord morphology and hydrodynamics as well as dissolved organic carbon (DOC) and nutrient concentrations in marine receiving waters predicted water-chemistry patterns along the transect. The narrow boreal system, with high riverine DOC and nutrient concentrations, was structured mainly by a horizontal salinity gradient from river to outer fjord, with limited impact of seasonality. In contrast, the broad subarctic system tended to be dominated by vertical salinity stratification, with strong between-date differences in surface water salinity linked to seasonality in river discharge. These dynamics were also reflected in the strong horizontal gradients in DOC, nutrients and DOM properties in the narrow boreal system, in contrast to the broad subarctic system, where strong seasonality paired with a lack of strong contrast between riverine and marine concentrations of DOC and most nutrients led to an uncoupling between salinity and other water chemistry variables. In the narrow boreal system, terrestrial OM dominated both the particulate and dissolved OM pools, while OM in the broad subarctic system was derived primarily from marine phytoplankton. Non-linear declines in NO3 + NO2 were observed consistently in the boreal system and during the productive spring season in the subarctic system, suggesting biological uptake and a potentially important role of these rivers as sources of bioavailable N to coastal ecosystems. The results from these two case studies highlight the complex and interacting effects of catchment landcover, river water chemistry and discharge, fjord morphometry and hydrodynamics in structuring the transport, fate and potential impacts of terrestrially-derived nutrients and organic matter in northern coastal environments.

Climate change-driven increases in air and sea temperatures are rapidly thawing the Arctic cryosphere with potential for remobilization and accumulation of legacy persistent organic pollutants (POPs) in adjacent coastal food webs. Here, we present concentrations of selected POPs in zooplankton (spatially and seasonally), as well as zoobenthos and sculpin (spatially) from Isfjorden, Svalbard. Herbivorous zooplankton contaminant concentrations were highest in May [e.g., ∑polychlorinated biphenyls (8PCB); 4.43, 95% CI: 2.72–6.3 ng/g lipid weight], coinciding with the final stages of the spring phytoplankton bloom, and lowest in August (∑8PCB; 1.6, 95% CI: 1.29–1.92 ng/g lipid weight) when zooplankton lipid content was highest, and the fjord was heavily impacted by sediment-laden terrestrial inputs. Slightly increasing concentrations of α-hexachlorocyclohexane (α-HCH) in zooplankton from June (1.18, 95% CI: 1.06–1.29 ng/g lipid weight) to August (1.57, 95% CI: 1.44–1.71 ng/g lipid weight), alongside a higher percentage of α-HCH enantiomeric fractions closer to racemic ranges, indicate that glacial meltwater is a secondary source of α-HCH to fjord zooplankton in late summer. Except for α-HCH, terrestrial inputs were generally associated with reduced POP concentrations in zooplankton, suggesting that increased glacial melt is not likely to significantly increase exposure of legacy POPs in coastal fauna.

The identification and prioritisation of water bodies presenting elevated levels of anthropogenic chemicals is a key aspect of environmental monitoring programmes. Albeit this is challenging owing to geographical scales, choice of indicator aquatic species used for chemical monitoring, and inherent need for an understanding of contaminant fate and distribution in the environment. Here, we propose an innovative methodology for identifying and ranking water bodies according to their levels of hydrophobic organic contaminants (HOCs) in water. This is based on a unique passive sampling dataset acquired over a 10-year period with silicone rubber exposures in surface water bodies across Europe. We show with these data that, far from point sources of contamination, levels of hexachlorobenzene (HCB) and pentachlorobenzene (PeCB) in water approach equilibrium with atmospheric concentrations near the air/water surface. This results in a relatively constant ratio of their concentrations in the water phase. This, in turn, allows us to (i) identify sites of contamination with either of the two chemicals when the HCB/PeCB ratio deviates from theory and (ii) define benchmark levels of other HOCs in surface water against those of HCB and/or PeCB. For two polychlorinated biphenyls (congener 28 and 52) used as model chemicals, differences in contamination levels between the more contaminated and pristine sites are wider than differences in HCB and PeCB concentrations endorsing the benchmarking procedure.