Levels Of Persistent Organic Pollutants Research Articles

Soil's Hidden Power: The Stable Soil Organic Carbon Pool Controls the Burden of Persistent Organic Pollutants in Background Soils.

Persistent organic pollutants (POPs) tend to accumulate in cold regions by cold condensation and global distillation. Soil organic matter is the main storage compartment for POPs in terrestrial ecosystems due to deposition and repeated air-surface exchange processes. Here, physicochemical properties and environmental factors were investigated for their role in influencing POPs accumulation in soils of the Tibetan Plateau and Antarctic and Arctic regions. The results showed that the soil burden of most POPs was closely coupled to stable mineral-associated organic carbon (MAOC). Combining the proportion of MAOC and physicochemical properties can explain much of the soil distribution characteristics of the POPs. The background levels of POPs were estimated in conjunction with the global soil database. It led to the proposition that the stable soil carbon pools are key controlling factors affecting the ultimate global distribution of POPs, so that the dynamic cycling of soil carbon acts to counteract the cold-trapping effects. In the future, soil carbon pool composition should be fully considered in a multimedia environmental model of POPs, and the risk of secondary release of POPs in soils under conditions such as climate change can be further assessed with soil organic carbon models.

Combined Contaminant Levels from Local Harvested Food Items in the Norwegian–Finnish–Russian Border Region

This paper presents the results of a multidisciplinary study with the aim of assessing the potential combined risk from consuming locally harvested food products in the Euro-Arctic region of Norway, Finland, and Russia. The three important contaminant groups—radioactive substances, heavy metals, and persistent organic pollutants (POPs)—were measured in food samples such as berries, mushrooms, fish, birds, reindeer, and moose; they were sampled in 2013–2015. To assess the combined pollution levels and investigate the trends, similarities, and variations between different contaminant groups, subsequent multivariate statistical analysis was performed. The results showed that, in general, the levels of radioactive substances, toxic elements, and POPs were below the permitted EU maximum content in food products. However, statistical analysis revealed some correlations, similarities, and peculiarities between the accumulation of different contaminants in various species, which allowed for a better understanding of the mechanisms of accumulation and interaction between different contaminant groups. It also gave a better insight into the possible added risks and helped pinpoint species that could serve as reference markers for the accumulation of different contaminants in food. Mushrooms, fish, and reindeer were found to be important markers in the combined risk assessments for the contents of metals and radioactive substances. Further research, as well as the development of methodologies for combined assessments, are recommended.

Blood and Tissue Levels of Persistent Organic Pollutants and Genetic Susceptibility in Patients with Breast Cancer

We investigated possible associations between the internal concentrations of POPs and correlations between blood and tumor tissue concentrations in patients who underwent surgery for breast cancer and breast reduction as controls. Genetic variations in CYP1A1, GSTP1, GSTM1, and GSTT1 and hOGG1 were evaluated to determine whether they represent risk factors for breast cancer. Certain POPs have been found to be associated with breast cancer development. GST-P1 polymorphism represented a significant risk for breast cancer with unadjusted OR. However, the GSTT1 null polymorphism represented a significant risk for breast cancer when OR adjusted for age and smoking status. CYP1A1 polymorphism was a significant risk factor for breast cancer, regardless of whether the OR was adjusted. These results suggest that exposure to certain POPs, GSTT1 and CYP1A1 polymorphisms, age, and smoking status are risk factors for breast cancer. In addition, the blood concentrations of some POPs represent surrogates for breast tissue concentrations.

The red listed eagle owl (Bubo bubo) population in Norway is exposed to POP levels exceeding threshold values for adverse health effects

The eagle owl (Bubo bubo) population in Norway is today classified as critically endangered on the red list of endangered species. Because previous studies have detected high concentrations of Persistent Organic Pollutants (POPs) in birds of prey, concerns have been raised whether POPs exposure are a significant factor to the substantial decline of the eagle owl population.The aims of this study were to measure the levels of POPs in eagle owls and to assess whether POPs may represent a potential health risk. POPs were analysed in liver samples from 100 eagle owls collected between 1994 and 2014.The concentrations of POPs were generally very high and individual birds had levels among the highest measured worldwide. The contaminant groups analysed were highly correlated (p < 0.0001). The concentrations of sum of Polychlorinated Biphenyls (∑PCB) exceeded the threshold value from moderate to severe health risk in 90% of the birds. The birds with cachectic or lean body condition had significantly higher levels of contaminants than those with higher body condition scores. No significant temporal or spatial trends were noted.The lack of temporal trends, suggest that the downward trend of POPs, appear to be levelling off. The lack of differences between inland and coastal regions suggest that the risk of exposure may be comparable between predatory birds feeding in marine or terrestrial food webs. The significantly higher POPs levels detected in individuals with poor body condition may be due to reduced fat stores and thereby higher concentration in the remaining fat and/or the weight loss could be induced by toxic effects. The high proportion of birds exceeding the threshold values for severe and high risk of adverse effects, suggest that the high contamination load may reduce the eagle owl’s fitness and survival and, thus, contribute to decline of the eagle owl population.

Emerging and legacy contaminants on the Brazilian southern coast (Santa Catarina): A multi-biomarker approach in oysters Crassostrea gasar (Adanson, 1757)

Coastal environments, such as those in the Santa Catarina State (SC, Brazil), are considered the primary receptors of anthropogenic pollutants. In this study, our objective was to evaluate the levels of emerging contaminants (ECs) and persistent organic pollutants (POPs) in indigenous Crassostrea gasar oysters from different regions of SC coast in the summer season (March 2022). Field collections were conducted in the São Francisco do Sul, Itajaí, Florianópolis and Laguna coastal zones. We analyzed the bioaccumulation levels of 75 compounds, including antibiotics (AB), endocrine disruptors (ED), non-steroidal anti-inflammatory drugs (NSAIDs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and pesticides. Furthermore, we assessed biomarker responses related to biotransformation, antioxidant defense, heat shock protection and oxidative damage in oysters' gills. Prevalence of ECs was observed in the central and southern regions, while the highest concentrations of POPs were detected in the central-northern regions of SC. Oysters exhibited an induction in biotransformation systems (cyp2au1 and cyp356a1, sult and GST activity) and antioxidant enzymes activities (SOD, CAT and GPx). Higher susceptibility to lipid peroxidation was observed in the animals from Florianópolis compared to other regions. Correlation analyses indicated possible associations between contaminants and environmental variables in the biomarker responses, serving as a warning related to climate change. Our results highlight the influence of anthropogenic activities on SC, serving as baseline of ECs and POPs levels in the coastal areas of Santa Catarina, indicating more critical zones for extensive monitoring, aiming to conserve coastal regions.

Assessment of metal and organic pollutants in combination with stable isotope analysis in tunas from the Gulf of Cadiz (east Atlantic)

Bioaccumulation patterns of heavy metals (Pb, Cd, Cr, Ni, Fe and Cu) and organic (priority and emerging) pollutants, in combination with stable isotope analysis (SIA), were assessed in muscle and liver of three tuna species from the Gulf of Cadiz (Atlantic bluefin tuna, Thunnus thynnus; Atlantic bonito, Sarda sarda, and skipjack tuna, Katsuwonus pelamis). SIA and contaminant (heavy metal and organic) profiles separately discriminated between species. There was no significant overlap between the trophic niches estimated from isotopic data, suggesting that there are diet differences which may determine differential bioaccumulation patterns. The levels of heavy metals and persistent organic pollutants in muscle of all the individuals analyzed were below the allowable limits established by the current legislation. Concentrations of most contaminants were higher in liver than in muscle, underlining the powerful detoxifying capacity of the liver in tunas. In addition to diet, other factors such as size and age (exposure time to environmental chemicals) explain differences in pollutant accumulation patterns in tissues between species, each with varying degrees of involvement depending on the pollutant class. Our results show that combining contaminant profile data with trophic features based on SIA may help understand pollutant bioaccumulation patterns in upper levels of marine food webs.

HBM4EU E-waste study: Assessing persistent organic pollutants in blood, silicone wristbands, and settled dust among E-waste recycling workers in Europe

E-waste recycling is an increasingly important activity that contributes to reducing the burden of end-of-life electronic and electrical apparatus and allows for the EU's transition to a circular economy. This study investigated the exposure levels of selected persistent organic pollutants (POPs) in workers from e-waste recycling facilities across Europe.The concentrations of seven polychlorinated biphenyls (PCBs) and eight polybrominated diphenyl ethers (PBDEs) congeners were measured by GC-MS. Workers were categorized into five groups based on the type of e-waste handled and two control groups. Generalized linear models were used to assess the determinants of exposure levels among workers. POPs levels were also assessed in dust and silicone wristbands (SWB) and compared with serum.Four PCB congeners (CB 118, 138, 153, and 180) were frequently detected in serum regardless of worker's category. With the exception of CB 118, all tested PCBs were significantly higher in workers compared to the control group. Controls working in the same company as occupationally exposed (Within control group), also displayed higher levels of serum CB 180 than non-industrial controls with no known exposures to these chemicals (Outwith controls) (p < 0.05). BDE 209 was the most prevalent POP in settled dust (16 μg/g) and SWB (220 ng/WB). Spearman correlation revealed moderate to strong positive correlations between SWB and dust. Increased age and the number of years smoked cigarettes were key determinants for workers exposure. Estimated daily intake through dust ingestion revealed that ΣPCB was higher for both the 50th (0.03 ng/kg bw/day) and 95th (0.09 ng/kg bw/day) percentile exposure scenarios compared to values reported for the general population.This study is one of the first to address the occupational exposure to PCBs and PBDEs in Europe among e-waste workers through biomonitoring combined with analysis of settled dust and SWB. Our findings suggest that e-waste workers may face elevated PCB exposure and that appropriate exposure assessments are needed to establish effective mitigation strategies.

A comprehensive multiplatform metabolomic analysis reveals alterations of 2-hydroxybutyric acid among women with deep endometriosis related to the pesticide trans-nonachlor

BackgroundExposure to persistent organic pollutants (POPs) has been related to the risk of endometriosis however the mechanisms remain unclear. The objective of the present study was to characterize the metabolic profiles underpinning the associations between POPs and endometriosis risk. MethodologyA hospital-based case-control study was conducted in France to recruit women with and without surgically confirmed deep endometriosis. Women's serum was analyzed using gas and liquid chromatography coupled to high-resolution mass spectrometry (HRMS) to measure the levels of polychlorinated biphenyls (PCBs), organochlorinated pesticides (OCPs) and per-/polyfluoroalkyl substances (PFAS). A comprehensive metabolomic profiling was conducted using targeted HRMS and 1H nuclear magnetic resonance (1H NMR) to cover polar and non-polar fractions. A “meet-in-the-middle” statistical framework was applied to identify the metabolites related to endometriosis and POP levels, using multivariate linear and logistic regressions adjusting for confounding variables. ResultsFourteen PCBs, six OCPs and six PFAS were widely found in almost all serum samples. The pesticide trans-nonachlor was the POP most strongly and positively associated with deep endometriosis risk, with odds ratio (95 % confidence interval) of 2.42 (1.49; 4.12), followed by PCB180 and 167. Women with endometriosis exhibited a distinctive metabolic profile, with elevated serum levels of lactate, ketone bodies and multiple amino acids and lower levels of bile acids, phosphatidylcholines (PCs), cortisol and hippuric acid. The metabolite 2-hydroxybutyrate was simultaneously associated to endometriosis risk and exposure to trans-nonachlor. ConclusionsTo the best of our knowledge, this is the first comprehensive metabolome-wide association study of endometriosis, integrating ultra-trace profiling of POPs. The results confirmed a metabolic alteration among women with deep endometriosis that could be also associated to the exposure to POPs. Further observational and experimental studies will be required to delineate the causal ordering of those associations and gain insight on the underlying mechanisms.

Assessment of persistent organic pollutants in killer whales (Orcinus orca) of the Canadian Arctic: Implications for subsistence consumption and conservation strategies

Killer whales (Orcinus orca) historically restricted to certain Arctic regions due to extensive sea ice have recently been documented farther north and for longer durations in the Canadian Arctic. These apex predators accumulate high levels of persistent organic pollutants (POPs). The objective of this study was to evaluate the concentrations and profiles of POPs in killer whales of the Canadian Arctic, thus determining potential risks for Inuit communities if consumed. Biopsies were collected from 33 killer whales across areas of the Canadian Arctic between 2009 and 2021. Significant variability in POP concentrations was observed among whales. The cumulative POP concentrations ranged from 12 to >2270 mg/kg lw, representing ∼200-fold increase from the least to the most contaminated individual. The rank order of concentrations of the top five contaminant classes was ∑DDT, ∑PCB, ∑CHL, ∑Toxaphene, and Dieldrin. Several emerging Arctic contaminants were detected, including chlorpyrifos, endosulfan, pentachloroanisole, and polychlorinated naphthalenes, although at relatively lower concentrations than legacy POPs. Considering the elevated blubber POP levels in killer whales, recommended daily consumption thresholds, established based on human tolerable daily intake (TDI) values, were notably restricted for ∑PCB (<0.14 g), ∑DDT (<6.9 g), ∑CHL (<13 g), dieldrin (<8 g) and heptachlor epoxide (<5 g). Killer whales in the Canadian Arctic exhibited higher POP concentrations than other commonly hunted species such as polar bears, ringed seals, and Arctic char. We acknowledge that a more holistic risk assessment of diet is required to assess the cumulative impacts of contaminant mixtures as well as nutritional quality of tissues commonly consumed by northern communities.

Air monitoring of organochlorine pesticides (OCPs) in Bursa Türkiye: Levels, temporal trends and risk assessment

Monitoring concentration levels of persistent organic pollutants (POPs) is required to evaluate the effectiveness of international regulations to minimize the emissions of persistent organic pollutants (POPs) into the environment. In this manner, we evaluated the spatial and temporal variations of 22 organochlorine pesticides (OCPs) using polyurethane foam passive air samplers at ten stations in Bursa in 2017 and 2018. The highest concentration value for Σ22OCPs was detected in Ağaköy (775 pg/m3) and Demirtaş (678 pg/m3) sampling sites, while the lowest value was observed in Uludağ University Campus (UUC, 284 pg/m3) site. HCB, γ-HCH, Endo I, and Mirex were the most frequently detected OCPs, which shows their persistence. Diagnostic ratios of β−/(α + γ)-HCH have pointed to historical and possible illegal OCP usage in the study area. The seasonality of air concentrations (with spring and summer concentrations higher than winter and autumn concentrations) was well exhibited by α-HCH, β-HCH, ɣ-HCH, HCB, Endo I, and Mirex but not aldrin, dieldrin, and α-chlordane (CC). Levels of OCPs detected in ambient air in the current study were relatively similar to or lower than those reported in previous studies conducted in Türkiye. Back trajectory analysis was applied to identify the possible sources of OCPs detected in the sampling regions. The Clausius-Clapeyron approach was used to investigate the temperature dependence of OCP gas-phase atmospheric concentrations. The data showed that long-range atmospheric transport affects ambient air OCP concentrations in the study area.

Levels of persistent organic pollutants (POPs) and the role of anthropic subsidies in the diet of avian scavengers tracked by stable isotopes

Persistent Organic Pollutants (POPs) have been identified as a significant factor driving declines in wildlife populations. These contaminants exhibit a dual tendency to biomagnify up the food chains and persist within tissues, rendering long-lived vertebrates, such as raptors, highly vulnerable to their adverse effects. We assessed the concentrations of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in fledglings of two vulture species, the Egyptian vulture (Neophron percnopterus) and the griffon vulture (Gyps fulvus), coexisting in northern Spain. Vultures, currently facing a severe threat with a population decline exceeding 90%, represent one of the most critically endangered avian groups in the Old World. Despite this critical situation, there remains a scarcity of research examining the intricate relationship between contaminant levels and individual foraging behaviors. In parallel, we analyzed stable isotope levels (δ15N and δ13C) in fledgling's feathers and prey hair to determine the association between individual dietary and contaminant burdens. Our findings revealed higher levels of PCBs in Egyptian vultures, while pesticide concentrations remained very similar between focal species. Furthermore, higher individual values of δ13C, indicating a diet based on intensive farming carcasses and landfills, were associated with higher levels of PCBs. While the levels of POPs found do not raise immediate alarm, the presence of individuals with unusually high values reveals the existence of accessible contamination sources in the environment for avian scavengers. The increasing reliance of these birds on intensive livestock farming and landfills, due to the decline of extensive livestock farming, necessitates long-term monitoring of potential contaminant effects on their populations.

Persistent Halogenated Organic Pollutants in Deep-Water-Deposited Particulates from South China Sea.

POP data are limited in the marine environment; thus, this study aimed to investigate background persistent organic pollutant (POP) levels in oceanic deep-water-deposited particulates in the South China Sea (SCS). Six POPs, including polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (DL-PCBs), polybrominated diphenyl ethers (PBDEs), polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs), polychlorinated diphenyl ethers (PCDEs), and polybrominated biphenyls (PBBs), were investigated in eight pooled samples from the SCS from 20 September 2013 to 23 March 2014 and 15 April 2014 to 24 October 2014 at depths of 2000 m and 3500 m. PBDEs were the most predominant compounds, with the highest mean Σ14PBDE of 125 ± 114 ng/g dry weight (d.w.), followed by Σ17PCDD/F, Σ12PBDD/F, and Σ12DL-PCB (275 ± 1930, 253 ± 216, and 116 ± 166 pg/g d.w., respectively). Most PBDD/F, PBB, and PCDE congeners were below the detection limits. PCDDs had the highest toxic equivalency (TEQ), followed by PBDDs and DL-PCBs. Among the six POPs, PBDEs were the major components of the marine-deposited particles, regarding both concentrations and mass fluxes. Compared to 3500 m, PBDE levels were higher at a depth of 2000 m. PBDE mass fluxes were 20.9 and 14.2 ng/m2/day or 68.2 and 75.9 ng/m2/year at deep-water 2000 and 3500 m, respectively. This study first investigated POP levels in oceanic deep-water-deposited particles from existing global data.

POPs in long-finned pilot whales mass stranded in Iceland as a proxy for their physiological condition

Long-finned pilot whales (Globicephala melas) are the most frequently stranded cetaceans in the world; however, the predominant drivers of these events are poorly understood. In this study the levels of persistent organic pollutants from pilot whales stranded in North-east Iceland were quantified and compared to historical data and physical parameters to investigate whether contaminant load may have influenced the physiological state of stranded individuals, how these loads fluctuate with sex and age group, and if this is consistent with the literature. Historical comparison was also carried out to discern how pollutant contamination has changed throughout the past few decades. DDE, transnonachlor and PCB-153 were the top three pollutants respectively. The accumulation of POPs was greater on average in immature individuals than adults, whilst among adults, males had higher concentration than females. Moreover, despite an indication of decreasing POP loads throughout the years, knowledge of harmful thresholds remains exceedingly limited.

Polychlorinated biphenyl and polybrominated diphenyl ether profiles vary with feeding ecology and marine rearing distribution among 10 Chinook salmon (Oncorhynchus tshawytscha) stocks in the North Pacific Ocean

Chinook salmon (Oncorhynchus tshawytscha) along the west coast of North America have experienced significant declines in abundance and body size over recent decades due to several anthropogenic stressors. Understanding the reasons underlying the relatively high levels of persistent organic pollutants (POPs) in Chinook stocks is an important need, as it informs recovery planning for this foundation species, as well for the Chinook-dependent Resident killer whales (Orcinus orca, RKW) of British Columbia (Canada) and Washington State (USA). We evaluated the influence of stock-related differences in feeding ecology, using stable isotopes, and marine rearing ground on the concentrations and patterns of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in Chinook salmon. A principal components analysis (PCA) revealed a clear divergence of PCB and PBDE congener patterns between Chinook with a nearshore rearing distribution (‘shelf resident’) versus a more offshore distribution. Shelf resident Chinook had 12-fold higher PCB concentrations and 46-fold higher PBDE concentrations relative to offshore stocks. Shelf resident Chinook had PCB and PBDE profiles that were heavier and dominated by more bioaccumulative congeners, respectively. The higher δ13C and δ15N in shelf resident Chinook compared to the offshore rearing stocks, and their different marine distributions explain the large divergence in contaminant levels and profiles, with shelf resident stocks being heavily influenced by land-based sources of industrial contamination. Results provide compelling new insight into the drivers of contaminant accumulation in Chinook salmon, raise important questions about the consequences for their health, and explain a major pathway to the heavily POP-contaminated Resident killer whales that consume them.

The dynamics of persistent organic pollutant (POP) transfer from female bottlenose dolphins (Tursiops truncatus) to their calves during lactation

Persistent organic pollutants (POPs) are lipophilic compounds that can accumulate in high concentrations in the blubber of marine mammals, which are long-lived, top-level predators in their ecosystems. These compounds, which include DDTs, PCBs, PBDEs, HCHs, and CHLDs, impact mammalian health, including neurological effects, reduced immune system efficiency, and reproductive failure. POPs are transferred from females to their offspring during gestation and lactation, which have implications for the health of newborn marine mammals, particularly first-born offspring who receive higher concentrations. The dynamics of POP transfer during lactation have been studied in a few pinniped species, but there are no comparable studies on living cetaceans. Because life history strategies and behavior of lactating phocids differ from dolphins, a study on delphinid maternal transfer is warranted. To accomplish this, placenta and longitudinally collected blood and milk samples were taken concurrently from trained bottlenose dolphin, Tursiops truncatus, mother/calf pairs to assess the dynamics of maternal contaminant transfer. Initial POP levels in placenta, blood serum, and milk varied by individual and were related to the age and reproductive history of the females. Regardless of initial POP levels, maternal serum and milk concentrations decreased while calf serum POP levels increased over time. Pollutant transfer varied by POP class and by congener. Contaminant transfer efficiency to calves was most apparent for 4- to 6‑chlorine PCBs, DDT isomers p,p′-DDD, p,p′-DDT, o,p′-DDD, and o,p′-DDE, trans-nonachlor, cis-nonachlor, heptachlor epoxide, nonachlor III, and oxychlordane. By the end of the lactation period, calf serum POP levels were considerably greater than those of their mothers, particularly for compounds with fewer chlorines. POP levels were most biomagnified in the calf born to the primiparous female. These results provide critical information on one component of contaminant transfer in the marine ecosystem and for understanding potential risks of POP exposure to developing odontocete calves.

Diet, lifestyle and contaminants in three east Greenland Inuit municipalities

Persistent organic pollutants (POP) are environmental contaminants transported over long distances to the Arctic where they biomagnify in marine mammals subsistence hunted by Inuit and may therefore affect human health. Marine mammals in east Greenland are known to have the highest POP concentrations in the circumpolar Arctic area. Due to high intake of marine mammals, east Greenlandic Inuit likewise have the highest POP body burdens across the Arctic. This cross-sectional study aims to investigate the levels of POP and metals in Inuit with a high intake of top predatory species including killer whales and polar bears. Study participants include 37 men and 21 women from Kulusuk, Tasiilaq and Ittoqqortoormiit during year 2013–2015. Lipophilic POP (11 organochlorine-pesticides, 14 polychlorinated-biphenyls (PCB), 10 polybrominated diphenyl ethers), polyunsaturated fatty acids (PFUA) and cotinine were determined in plasma. Fifteen perfluoroalkylated substances (PFAS) were measured in serum and urine and the renal clearance was estimated. Finally the concentration of 10 metals were measured in whole blood. The median age was 38 years, Ittoqqortoormiit Inuit being the oldest. The smoking rate was around 70%, and Kulusuk participants had the lowest PFUA concentrations. Significant municipality differences were observed for lipophilic POP, serum PFAS, mercury, arsenic and selenium with highest concentrations in Ittoqqortoormiit Inuit. Males had higher blood concentrations of PFAS and lead. The estimated PFAS renal clearance and ratio of urine to serum were significantly higher for females, suggesting a sex difference in excretion via the kidney, maybe partly because men had higher serum PFAS concentrations. We observed that Inuit with intake of >200 g polar bear per week had significantly higher levels of PCB, PFAS, arsenic and selenium. In summary, the level of blood POP and heavy metals seems to relate to sex and the frequency intake of meat from marine mammals.

Levels of persistent organic pollutants in cane toads (Rhinella marina) differ among sites with varying industrial and agricultural activities

In this study, we captured cane toads (Rhinella marina) in four sites located in different regions affected by anthropogenic activities in Mexico. Subsequently we analyzed liver tissue for the presence of organochlorine pesticides (OCs) and polychlorinated biphenyls (PCBs) The levels of these POPs in the toads’ livers ranged from 863.2 to 3109.6 ng/g of lipid weight across all sites. A multivariate statistical analysis highlighted two sites with the highest POPs levels, with the most polluted site displaying a high level of PCBs, suggesting influence of industrial activities. The second most polluted site displayed significant amounts of OCs, linking this location to agricultural activity. Additionally, we found pesticide metabolites and isomers that allowed us to distinguish past and recent exposure events. Our observations indicate that R. marina is suitable bioindicator of sites impacted by anthropogenic activities.

Sedimentary records of contaminant inputs in Frobisher Bay, Nunavut

Contaminants, such as polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), heavy metals, and per and polyfluoroalkyl substances (PFASs), primarily reach the Arctic through long-range atmospheric and oceanic transport. However, local sources within the Arctic also contribute to the levels observed in the environment, including legacy sources and new sources that arise from activities associated with increasing commercial and industrial development. The City of Iqaluit in Frobisher Bay, Nunavut (Canada), has seen rapid population growth and associated development during recent decades yet remains a site of interest for ocean protection, where Inuit continue to harvest country food. In the present study, seven dated marine sediment cores collected in Koojesse Inlet near Iqaluit, and from sites in inner and outer Frobisher Bay, respectively, were analyzed for total mercury (THg), major and trace elements, PAHs, PCBs, and PFASs. The sedimentary record in Koojesse Inlet shows a period of Aroclor 1260-like PCB input concurrent with military site presence in the 1950–60s, followed by decades of input of pyrogenic PAHs, averaging about ten times background levels. Near-surface sediments in Koojesse Inlet also show evidence of transient local-source inputs of THg and PFASs, and recycling or continued slow release of PCBs from legacy land-based sources. Differences in PFAS congener composition clearly distinguish the local sources from long-range transport. Outside Koojesse Inlet but still in inner Frobisher Bay, 9.2 km from Iqaluit, sediments showed evidence of both local source (PCB) and long-range transport. In outer Frobisher Bay, an up-core increase in THg and PFASs in sediments may be explained by ongoing inputs of these contaminants from long-range transport. The context for ocean protection and country food harvesting in this region of the Arctic clearly involves both local sources and long-range transport, with past human activities leaving a long legacy insofar as levels of persistent organic pollutants are concerned.

Evaluating Alternative and Sustainable Food Resources: A Review of the Nutritional Composition of Myctophid Fishes

Additional and alternative sustainable food resources are needed as the global human population increases. Marine fishes have long provided essential nutrients, such as omega-3 long-chain (≥C20) polyunsaturated fatty acids (n-3 LC-PUFA), protein, and vitamins to meet human dietary requirements and feed for agricultural production. Many current commercial fish stocks are depleted or fully exploited, but oceanic mesopelagic fishes, particularly the myctophids (lanternfishes), represent a potentially very large and unfished resource. This review analysed the literature on nutritional and biochemical compositions of myctophids as a first step towards understanding the health benefits and risks of consuming them. We found that myctophids have high levels of protein (11–23% wet weight, WW) and variable lipid content (0.5–26% WW). In most species, desirable triacylglycerols or phospholipids dominated over less-desirable wax esters, and most have abundant amounts of health-promoting n-3 LC-PUFA, such as DHA and EPA. Myctophids have low levels of heavy metals and persistent organic pollutants. Most nutritional information is available for species from the Pacific and Southern Oceans and for the genera Benthosema, Electrona, and Diaphus. Myctophids generally possess favourable nutritional profiles, but major gaps in knowledge regarding their stock assessment, ecology and the economic viability for their harvest are barriers to developing sustainable fisheries.

Environmentally realistic concentrations of chlorinated, brominated, and fluorinated persistent organic pollutants induce the unfolded protein response as a shared stress pathway in the liver of Atlantic cod (Gadus morhua).

In the North Sea and North Atlantic coastal areas, fish experience relatively high background levels of persistent organic pollutants. This study aimed to compare the mode of action of environmentally relevant concentrations of mixtures of halogenated compounds in Atlantic cod. Juvenile male cod with mean weight of 840 g were exposed by gavage to dietary mixtures of chlorinated (PCBs, DDT analogs, chlordane, lindane, and toxaphene), brominated (PBDEs), and fluorinated (PFOS) compounds for 4 weeks. One group received a combined mixture of all three compound groups. The results showed that the accumulated levels of chemicals in cod liver after 4weeks of exposure reflected concentrations found in wild fish in this region. Pathway analysis revealed that the treatment effects by each of the three groups of chemicals (chlorinated, brominated, and fluorinated) converged on activation of the unfolded protein response (UPR). Upstream regulator analysis predicted that almost all the key transcription factors (XBP1, ERN1, ATF4, EIF2AK3, and NFE2L2) regulating the UPR were significantly activated. No additive effect was observed in cod co-treated with all three compound groups. In conclusion, the genome-wide transcriptomic study suggests that the UPR pathway is a sensitive common target of halogenated organic environmental pollutants in fish.