Atmospheric deposition of semivolatile aromatic hydrocarbons accounts for an important input of organic matter to the surface ocean. Nevertheless, the biogeochemical cycling and sinks of semivolatile aromatic hydrocarbons in the ocean remain largely uncharacterized. Here we present measurements of 64 polycyclic aromatic hydrocarbons in plankton and seawater from the Atlantic, Pacific, Indian and Southern Oceans, as well an assessment of their microbial degradation genes. Concentrations of the more hydrophobic compounds decreased when the plankton biomass was higher, consistent with the relevance of the biological pump. The mass balance for the global oceans showed that the settling fluxes of aromatic hydrocarbons in the water column were two orders of magnitude lower than the atmospheric deposition fluxes. This imbalance was high for low molecular weight hydrocarbons, such as phenanthrene and methylphenanthrenes, highly abundant in the dissolved phase. Parent polycyclic aromatic hydrocarbons were depleted to a higher degree than alkylated polycyclic aromatic hydrocarbons, and the degradation genes for polycyclic aromatic hydrocarbons were found to be ubiquitous in oceanic metagenomes. These observations point to a key role of biodegradation in depleting the bioavailable dissolved hydrocarbons and to the microbial degradation of atmospheric inputs of organic matter as a relevant process for the marine carbon cycle. © 2019, The Author(s), under exclusive licence to Springer Nature Limited.

Numerous studies to date have reported concentrations of Persistent Organic Pollutants (POPs) in different marine mammal species worldwide. Yet data on sperm whales are scarce from rich and unique biodiverse areas such as the Mediterranean Sea. This work aimed to assess levels of dioxin-like polychlorinated biphenyls (dl-PCBs), polybrominated diphenyl ethers (PBDEs), and polychlorodibenzo-p-dioxins and furans (PCDD/Fs) in blubber of sperm whales stranded along the Italian coast between 2008 and 2016. POP mean concentrations (dl-PCBs: 6410 ng/g l.w.; PBDEs: 612 ng/g l.w.; PCDD/Fs: 57.8 pg/g l.w.) were mostly in line with what has been previously reported on the same species in the Mediterranean environment and tended to be higher than those reported from other geographical regions. The relative abundance followed the order dl-PCBs > PBDEs ≫ PCDD/Fs. Interestingly, the non-ortho dl-PCB pattern (126 > 169 > 77) was similar to that described in other studies worldwide and different from what is described in its main prey. This could be linked to particular metabolic activities in sperm whales against these highly toxic contaminants. Total TEQs ranged from 275 to 987 pg/g l.w. and showed the pattern Σnon-ortho-dl-PCBs > Σortho-dl-PCBs > PCDDs > PCDFs, with PCBs’ contribution about 96\%. These findings highlight the high abundance of PCBs still found in the Mediterranean environment despite having been banned for decades. All sperm whales analyzed in this study surpassed the threshold of 210 pg WHO-TEQ/g l.w. proposed as starting point of immunosuppression in harbour seals; a level of contamination that may have contributed to an impairment of their immune system. © 2018

Persistent organic pollutants (POPs) were assessed for the first time in blue whales from the South Pacific Ocean. Concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), hexachlorobenzene (HCB) and dichlorodiphenyltrichloroethane and its main metabolites (DDTs), were determined in 40 blubber samples from 36 free-ranging individuals and one stranded, dead animal along the coast of southern Chile between 2011 and 2013. PCBs were the most abundant pollutants (2.97–975 ng/g l.w.), followed by DDTs (3.50–537 ng/g l.w.), HCB (nd–77.5 ng/g l.w.) and PBDEs (nd–33.4 ng/g l.w). There was evidence of differences between sexes, with lower loads in females potentially due to pollutants passing to calves. POP concentrations were higher in specimens sampled in 2013; yet, between-year differences were only statistically significant for HCB and PBDEs. Lower chlorinated (penta > tetra > tri) and brominated (tetra > tri) congeners were the most prevalent among PCBs and PBDEs, respectively, mostly in agreement with findings previously reported in blue and other baleen whales. The present study provides evidence of lower levels of contamination by POPs in eastern South Pacific blue whales in comparison to those reported for the Northern Hemisphere. © 2018

Atmospheric PM1 has an impact on health and the environment, and is highly variable. PM1 filter samples were collected in urban roof and street sites in two Mediterranean cities in Europe (Barcelona and Madrid) to study the spatial and temporal trends of primary and secondary organic tracer compounds. Both cities are exposed to modern urban emission sources with intensive traffic in their centers. Moreover, their geographical situation in the Mediterranean region favors photo-chemical reactions and accumulation of secondary aerosols, due to sunny anti-cyclonic weather conditions. Barcelona is located along the coast with high relative humidity and an active sea-mountain breeze system, while the relative humidity in Madrid is low in summer, due to its location in the center of the Iberian Peninsula. These differences may influence the accumulation of primary air pollutants and the formation of secondary aerosols. In street site samples, the levels of primary organics, such as polycyclic aromatic hydrocarbons, hopanes and nicotine, were about two times higher than those collected simultaneously at roof sites. Primary emitted levoglucosan and isomers from biomass burning were observed in higher concentrations in winter in both urban areas, but without significant difference between the road and roof sites samples, indicating regional transport of biomass smoke to the cities. Similar roof and street site sample concentrations were also observed for secondary organic aerosol (SOA) compounds, i.e. dicarboxylic acids and oxidation products of isoprene and α-pinene. The SOA compound concentrations were ten times higher in summer compared to winter samples, emphasizing the importance of SOA formation processes in summer. More evidence was obtained that linked the presence of cis-pinonic acid in the filter samples to new particle formation during nucleation. The urban organic PM1 is dominated by SOA, while the primary organic aerosol (POA) tracer compounds from combustion sources, including traffic and biomass burning, dominates in winter. © 2018 Elsevier Ltd

The Stockholm Convention (SC) on Persistent Organic Pollutants (POPs) calls for the Parties’ effectiveness evaluation of those measures taken to meet the reduction and eventual elimination of POPs from the environment. With that goal, air concentrations of different POP families have been measured uninterruptedly since 2008 under the Spanish Monitoring Program (SMP) by means of passive air sampling. This work focuses on data for polybrominated diphenyl ethers (PBDEs) determined in a total of 321 samples collected seasonally each year in 5 urban and 7 background sites. Neither significant temporal trends nor significant seasonal variations for total PBDE air burdens were detected. In contrast, significant variations were found among PBDE congeners. Those related to the octa-PBDE formulation significantly decreased in the study period. However, PBDEs related to the penta-formulation showed steady concentrations while PBDE-209, the congener found at the greatest levels, showed increasing or steady levels in most sampling sites. Seasonal variations were also markedly different among congeners. Concentrations of the lightest PBDEs (tri- to penta-substituted) were highly influenced by ambient temperature (T), showing maximum values in summer probably due to higher volatilization rates compared to those of heavier PBDEs. Contrarily, no clear seasonal trends were found for hexa- to deca-PBDEs, which were negatively related to precipitation; thereby, indicating an efficient atmospheric wash out by wet deposition episodes. Regarding spatial patterns, overall significant greater PBDE levels were found in cities compared to background areas, pointing out the role of highly populated areas as sources for these pollutants in Spain. Yet and especially in the case of PBDE-209, our results suggested the presence of significant unknown sources of PBDEs in some background sites. Further monitoring efforts are needed to assess potential unknown sources in the sampling network as well as to ensure temporal trends of these pollutants in Spain. © 2018 Elsevier B.V.

The main aim of this chapter is to document the contamination by persistent organic pollutants (POPs) in cetaceans living in the Mediterranean Sea, which is a hotspot area for both its biodiversity and its pollution. In fact, the Mediterranean Sea is particularly distressed by environmental contamination because of its half-closed basin geomorphology and its high coastal anthropization. Seven of the eight common cetacean species in the Mediterranean Sea are odontocetes and, as such, are at the top of the trophic chain. For this reason and because of physiologic characteristics that have allowed them to live a completely aquatic life, such as thick adipose tissue, cetaceans accumulate high levels of lipophilic environmental contaminants (i.e., POPs). The only mysticete species, the long-living fin whale, is the largest filter feeder in the Mediterranean Sea and is highly contaminated by small particles, such as microplastics, which are abundant in the basin and also act as vectors of POPs. © 2018 Elsevier Inc. All rights reserved.

The atmosphere-land-ocean dynamics of semivolatile organic compounds in polar regions is poorly understood, also for the abundant and ubiquitous polycyclic aromatic hydrocarbons (PAHs). We report the concentrations and fluxes of PAHs in a polar coastal ecosystem (Livingston Island, Antarctica). From late spring (December 2014) to late summer (February 2015), we sampled air, snow, coastal seawater, plankton, and the fugacity in soils and snow. The concentrations of PAHs in seawater were low but increased during the austral summer. The PAH concentrations in snow were significantly higher than in coastal seawater. Soil-air fugacity ratios showed a net volatilization of PAH when soils were covered with lichens, and close to air-soil equilibrium for bare soils. Concentrations in surface snow were also close to equilibrium with atmospheric PAHs. Conversely, there was a net diffusive deposition of PAHs to coastal seawater during late spring, but a net volatilization from seawater during late summer. Volatilization fluxes were correlated with seawater temperature and salinity, consistent with a key role of snowmelt to the fluxes and dissolved phase concentrations during the austral summer. The comprehensive assessment provided here shows that the fugacity amplification in snow is transferred to soils and coastal seawater supporting PAH concentrations and fluxes. Copyright © 2018 American Chemical Society.

Time series (2008–2015) of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in ambient air from the Spanish Monitoring Program were analyzed. A total of 321 samples were collected seasonally each year in 5 urban and 7 background sites by means of passive air sampling. Air concentrations were higher at urban than background sites (urban vs. background concentration ranges): PCDD/Fs (26.9–1010 vs. 20.0–357 fg/m3), non-ortho PCBs (0.113–3.14 vs. 0.042–2.00 pg/m3) and mono-ortho PCBs (0.644–41.3 vs. 0.500–32.8 pg/m3). Results showed significant decreases from 2009 for non-ortho PCBs and PCDD/Fs as well as for WHO2006-TEQs. These declines were sharper, and sometimes only significant, in urban places resulting in converging levels at urban and background sites for these pollutants at the end of the study period. In contrast, mono-ortho PCBs did not show any significant variation but a steady flat temporal behavior in their concentrations, suggesting the existence of different sources between mono-ortho and non-ortho PCBs. Seasonality was observed for air burdens of all these POPs. PCDD/Fs were mostly measured at higher concentrations in colder than in hot seasons, and the opposite was true for dl-PCBs. Seasonal variations for PCDD/Fs appeared to be related to changes in their sources (e.g. domestic heating, open burning) rather than to temperature per se. In contrast, environmental temperature dependent factors (e.g. increased partitioning into the gas phase) drove seasonal variations in dl-PCBs instead of seasonal changes in their sources. Regarding spatial patterns, significant greater levels of PCDD/Fs and dl-PCBs were generally found in cities compared to background areas, pointing out the role of densely populated areas as sources for these pollutants in Spain. As proven by our results, long-term monitoring activities are essential to assess and understand temporal behaviors for these POPs, as well as to evaluate the achievement of Stockholm Convention objectives. © 2018 Elsevier B.V.

Perfluoroalkyl substances (PFAS) are ubiquitous in the environment, including remote polar regions. To evaluate the role of snow deposition as an input of PFAS to Maritime Antarctica, fresh snow deposition, surface snow, streams from melted snow, coastal seawater, and plankton samples were collected over a three-month period (December 2014-February 2015) at Livingston Island. Local sources of PFASs were significant for perfluoroalkyl sulfonates (PFSAs) and C7-14 perfluoroalkyl carboxylates (PFCAs) in snow but limited to the transited areas of the research station. The concentrations of 14 ionizable PFAS (-PFAS) in freshly deposited snow (760-3600 pg L -1 ) were 1 order of magnitude higher than those in background surface snow (82-430 pg L -1 ). -PFAS ranged from 94 to 420 pg L -1 in seawater and from 3.1 to 16 ng g dw -1 in plankton. Ratios of individual PFAS concentrations in freshly deposited snow relative to surface snow (C SD /C Snow ), snowmelt (C SD /C SM ), and seawater (C SD /C SW ) were close to 1 (from 0.44 to 1.4) for all perfluorooctanesulfonate (PFOS) isomers, suggesting that snowfall does not contribute significantly to PFOS in seawater. Conversely, these ratios for PFCAs ranged from 1 to 33 and were positively correlated with the number of carbons in the PFCA alkylated chain. These trends suggest that snow deposition, scavenging sea-salt aerosol bound PFAS, plays a role as a significant input of PFCAs to the Maritime Antarctica. © 2017 American Chemical Society.

The bioaccumulation of perfluoroalkylated substances (PFASs) in plankton has previously been evaluated only in freshwater and regional seas, but not for the large oligotrophic global oceans. Plankton samples from the tropical and subtropical Pacific, Atlantic and Indian Oceans were collected during the Malaspina 2010 circumnavigation expedition, and analyzed for 14 ionizable PFASs, including perfluorooctanoate (PFOA), perfluorooctanesulfonate (PFOS) and their respective linear and branched isomers. PFOA and PFOS concentrations in plankton ranged from 0.1 to 43 ng g dw -1 and from 0.5 to 6.7 ng g dw -1 , respectively. The relative abundance of branched PFOA in the northern hemisphere was correlated with distance to North America, consistent with the historical production and coherent with previously reported patterns in seawater. The plankton samples showing the highest PFOS concentrations also presented the largest relative abundances of branched PFOS, suggesting a selective cycling/fractionation of branched PFOS in the surface ocean mediated by plankton. Bioaccumulation factors (BAFs) for plankton were calculated for six PFASs, including short chain PFASs. PFASs Log BAFs (wet weight) ranged from 2.6 ± 0.8 for perfluorohexanesulfonic acid (PFHxS), to 4.4 ± 0.6 for perfluoroheptanoic acid (PFHpA). The vertical transport of PFASs due to the settling of organic matter bound PFAS (biological pump) was estimated from an organic matter settling fluxes climatology and the PFAS concentrations in plankton. The global average sinking fluxes were 0.8 ± 1.3 ng m -2 d -1 for PFOA, and 1.1 ± 2.1 ng m -2 d -1 for PFOS. The residence times of PFAS in the surface ocean, assuming the biological pump as the unique sink, showed a wide range of variability, from few years to millennia, depending on the sampling site and individual compound. Further process-based studies are needed to constrain the oceanic sink of PFAS. © 2017 American Chemical Society.

A comparative study for 62 toxic chemicals based on the simultaneous monthly collection of aerosol samples during 2015-2016 in two coastal cities at both the African (Bizerte, Tunisia) and European (Marseille, France) edges of the Western Mediterranean basin is presented. Legacy polychlorinated biphenyls (Σ18PCBs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (Σ17PCDD/Fs) show generally higher median levels at the African edge (2.1 and 0.2 pg m-3, respectively) compared to the European coastal site (1.0 and 0.08 pg m-3, respectively). Contrarily, the emerging polybrominated diphenyl ethers' (Σ27PBDEs) median concentrations were higher in Marseille (∼9.0 pg m-3) compared to Bizerte (∼6.0 pg m-3). Different past usages and current emission patterns were found at both edges of the Western Mediterranean, most probably linked to the respective different regulatory frameworks for toxic chemicals. Our results indicate that the total organic carbon (TOC) and/ or the elemental carbon (EC) contents in the atmospheric aerosol may have a stronger effect than the total suspended particle (TSP) content as a whole on the spatial-temporal variability and the long-range atmospheric transport potential of the studied POPs. A jumping of the PBDE local atmospheric stocks from the Northwestern European Mediterranean edge to the Northwestern African coast seems to be possible under favorable conditions at present. While a higher PBDE median loading is estimated for the Marseille area (∼550 ng m-2 y-1) compared to Bizerte (∼400 ng m-2 y-1), the median PCB and PCDD/F dry deposition fluxes were higher at the African site, resulting in a 3-fold higher toxic equivalent (TEQ) loading of dioxin-like pollutants (400 pg TEQ m-2 y-1) compared to Marseille (∼140 pg TEQ m-2 y-1), with potential implications for aquatic organisms. However, the inhalation exposure assessment points to a minimum risk for human health at both sites. © 2017 American Chemical Society.

The whale shark (Rhincodon typus) is an endangered species that may be exposed to micro- and macro-plastic ingestion as a result of their filter-feeding activity, particularly on the sea surface. In this pilot project we perform the first ecotoxicological investigation on whale sharks sampled in the Gulf of California exploring the potential interaction of this species with plastic debris (macro-, micro-plastics and related sorbed contaminants). Due to the difficulty in obtaining stranded specimens of this endangered species, an indirect approach, by skin biopsies was used for the evaluation of the whale shark ecotoxicological status. The levels of organochlorine compounds (PCBs, DDTs), polybrominated diphenyl ethers (PBDEs) plastic additives, and related biomarkers responses (CYP1A) were investigated for the first time in the whale shark. Twelve whale shark skin biopsy samples were collected in January 2014 in La Paz Bay (BCS, Mexico) and a preliminary investigation on microplastic concentration and polymer composition was also carried out in seawater samples from the same area. The average abundance pattern for the target contaminants was PCBs > DDTs > PBDEs > HCB. Mean concentration values of 8.42 ng/g w.w. were found for PCBs, 1.31 ng/g w.w. for DDTs, 0.29 ng/g w.w. for PBDEs and 0.19 ng/g w.w. for HCB. CYP1A-like protein was detected, for the first time, in whale shark skin samples. First data on the average density of microplastics in the superficial zooplankton/microplastic samples showed values ranging from 0.00 items/m3 to 0.14 items/m3. A focused PCA analysis was performed to evaluate a possible correlation among the size of the whale sharks, contaminants and CYP1A reponses. Further ecotoxicological investigation on whale shark skin biopsies will be carried out for a worldwide ecotoxicological risk assessment of this endangerd species. © 2017 Elsevier Inc.

A simplified, miniaturised matrix solid-phase dispersion (MSPD)-based method allowing the simultaneous extraction and purification of contaminants belonging to selected families of regulated persistent organic pollutants (POPs), i.e. polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and penta- to octa-polybrominated diphenyl ethers (PBDEs), and related contaminants of emerging concern, such as deca-BDE and Dechlorane Plus (DP), has been proposed. Wild bird eggs were used as biotic fat-containing model matrices. Once optimised, the procedure allowed sample preparation to be accomplished within 30 min, in a single step, and with minimal sample and reagent consumption and waste generation. These features contributed to speeding up and greening the analytical process as compared to the large-scale multistep procedures for these types of analyses. The method was combined with gas chromatography-quadrupole mass spectrometry (GC-qMS) for PCB and OCP analysis and with GC-negative ion chemical ionisation-quadrupole mass spectrometry (NCI-qMS) for PBDE and DP determination. The complete analytical method provided satisfactory recoveries of the target compounds (above 83\% for all analytes, except for PBDE 209, 63\%), although as small an amount of sample as 0.300 g was used. The repeatability of the complete procedure was less than 16\% (with the only exception for PCB 153, which looked to be affected by an interference). The limits of detection were in all cases lower than 34 pg g−1 dry weight (as calculated for real samples), demonstrating the feasibility of the proposed procedure for accurate determination of the target compounds in biological samples. The proposed procedure was applied to the analysis of the target POPs in unhatched eggs of wild bird species. [Figure not available: see fulltext.]. © 2017, Springer-Verlag Berlin Heidelberg.

Polycyclic aromatic hydrocarbons, and other semivolatile aromatic-like compounds, are an important and ubiquitous fraction of organic matter in the environment. The occurrence of semivolatile aromatic hydrocarbons is due to anthropogenic sources such as incomplete combustion of fossil fuels or oil spills, and other biogenic sources. However, their global transport, fate and relevance for the carbon cycle have been poorly assessed, especially in terms of fluxes. Here we report a global assessment of the occurrence and atmosphere-ocean fluxes of 64 polycyclic aromatic hydrocarbons analysed in paired atmospheric and seawater samples from the tropical and subtropical Atlantic, Pacific and Indian oceans. The global atmospheric input of polycyclic aromatic hydrocarbons to the global ocean is estimated at 0.09 Tg per month, four times greater than the input from the Deepwater Horizon spill. Moreover, the environmental concentrations of total semivolatile aromatic-like compounds were 10 2 -10 3 times higher than those of the targeted polycyclic aromatic hydrocarbons, with a relevant contribution of an aromatic unresolved complex mixture. These concentrations drive a large global deposition of carbon, estimated at 400 Tg C yr -1, around 15\% of the oceanic CO2 uptake. © 2016 Macmillan Publishers Limited.

This article describes the toxicokinetics of perfluorooctane sulfonate (PFOS) in rabbits under low repeated dosing, equivalent to 0.085. μg/kg per day, and the observed differences between rabbits and chickens. The best fitting for both species was provided by a simple pseudo monocompartmental first-order kinetics model, regulated by two rates, and accounting for real elimination as well as binding of PFOS to non-exchangeable structures. Elimination was more rapid in rabbits, with a pseudo first-order dissipation half-life of 88 days compared to the 230 days observed for chickens. By contrast, the calculated assimilation efficiency for rabbits was almost 1, very close to full absorption, significantly higher than the 0.66 with confidence intervals of 0.64 and 0.68 observed for chickens. The results confirm a very different kinetics than that observed in single-dose experiments confirming clear dose-related differences in apparent elimination rates in rabbits, as previously described for humans and other mammals; suggesting the role of a capacity-limited saturable process resulting in different kinetic behaviours for PFOS in high dose versus environmentally relevant low dose exposure conditions. The model calculations confirmed that the measured maximum concentrations were still far from the steady state situation, and that the different kinetics between birds and mammals should may play a significant role in the biomagnifications assessment and potential exposure for humans and predators. For the same dose regime, the steady state concentration was estimated at about 36. μg PFOS/L serum for rabbits, slightly above one-half of the 65. μg PFOS/L serum estimated for chickens. The toxicokinetic parameters presented here can be used for higher-tier bioaccumulation estimations of PFOS in rabbits and chickens as starting point for human health exposure assessments and as surrogate values for modeling PFOS kinetics in wild mammals and bird in exposure assessment of predatory species. © 2015.

Foraging ecology and the marine regions exploited by Antarctic seabirds outside of breeding strongly influence their exposure to persistent organic pollutants (POPs). However, relationships between them are largely unknown, an important knowledge gap given that many species are capital breeders and POPs may be deleterious to seabirds. This study investigates the relationship between Antarctic seabird foraging ecology (measured by δ13C and δ15N) and POPs accumulated in their eggs prior to breeding. Organochlorinated pesticides, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and dechlorane plus (DP) were measured in eggs of chinstrap, Adélie, and gentoo penguins (Pygoscelis antarctica, P. adeliae, P. papua), as well as south polar skua (Catharacta maccormicki), sampled on King George Island. Total POP levels were as follows: skua (3210 ± 3330 ng/g lipid weight) > chinstrap (338 ± 128 ng/g) > Adélie (287 ± 43.3 ng/g) > gentoo (252 ± 49.4 ng/g). Trophic position and pre-breeding foraging sites were important in explaining POP accumulation patterns across species. The most recalcitrant compounds were preferentially accumulated in skuas, occupying one trophic level above penguins. In contrast, their Antarctic endemism, coupled with influence from cold condensation of pollutants, likely contributed to penguins exhibiting higher concentrations of more volatile compounds (e.g., hexachlorobenzene, PCB-28 and − 52) than skuas. Regional differences in penguin pre-breeding foraging areas did not significantly affect their POP burdens, whereas the trans-equatorial migration and foraging sites of skuas were strongly reflected in their pollutant profiles, especially for PBDEs and DPs. Overall, our results provide new insights on migratory birds as biovectors of POPs, including non-globally regulated compounds such as DP, from northern regions to Antarctica. © 2016

Within the framework of the Spanish monitoring program, this study reports on air concentration of DDTs, HCB, HCHs, NDL-PCBs, DL-PCBs, PCDD/Fs and PBDEs measured during the five-year sampling period 2008–2013. Spanish coastal remote and urban locations were studied using PUF disk passive air samplers which were deployed and collected every three months. Despite the wide range of concentrations measured for most contaminants, a common pattern of relative abundance (median values): NDL-PCBs (36.6 pg/m3) > HCB (24.8 pg/m3) ≈ HCHs (17.9 pg/m3) ≈ DDTs (16.6 pg/m3) > PBDEs (3.65 pg/m3) > DL-PCBs (2.99 pg/m3) >> PCDD/Fs (0.060 pg/m3) was found fairly consistent across most seasons and locations. Nevertheless, important variations in yearly concentrations were measured for different POPs. In general, higher levels of DDTs, HCHs, NDL-PCBs, DL-PCBs and PCDD/Fs were found in urban sites highlighting important differences between remote and urban sampling locations for most target contaminants. Greater concentrations of the banned organochlorine pesticides in urban locations suggested the existence of unexpected pointed sources that need to be further investigated and characterized. The limited dataset collected thus far rendered no clear temporal trends for most study target compounds, which emphasizes the necessity of the Spanish monitoring program future maintenance in time. © 2016 Elsevier Ltd

The impact of pollution caused by severe anthropogenic pressure in the Mediterranean Sea, an important biodiversity hotspot, requires continuous research efforts. Sources of highly toxic chemicals such as Persistent Organic Pollutants (POPs) are misunderstood in representative Mediterranean species, which limits our capability to establish proper conservation strategies. In the present study, eggs of Audouin's and yellow-legged gulls (Larus audouinii and L. michahellis) were used to investigate the trophic sources, as measured by δ13C, δ15N, and δ34S, of legacy POPs, in particular, polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) and non-ortho polychlorinated biphenyls (no-PCBs), as well as recently-regulated POPs, e.g., polybrominated diphenyl ethers (PBDEs). Special attention was paid to the usefulness of rarely-explored δ34S ratios in explaining POP exposure in wildlife, and δ34S was the isotopic ratio that best explained POP variations among gulls in most cases, thus demonstrating its usefulness for understanding POP exposure in wildlife. Significant relationships between stable isotope signatures and POP concentrations revealed increasing levels of no-PCBs and low halogenated PCDD/Fs and PBDEs in Mediterranean gulls as the consumption of marine resources increases. In contrast, highly chlorinated and brominated congeners appeared to preferentially accumulate in gulls feeding primarily on refuse from dump sites and terrestrial food webs. The use of suitable dietary tracers in the study of POPs in yellow-legged gulls revealed the importance of dump sites as a source of POPs in Mediterranean seabirds, which has not previously been reported. In contrast, the preferential accumulation through marine food webs of low chlorinated PCCD/Fs and no-PCBs, which show the highest toxic equivalents factors (TEFs), led to a significantly greater toxicological concern in Audouin's as compared to yellow-legged gulls. Audouin's gull exposure to POPs appears primarily related to the pelagic food webs commonly exploited by fisheries, highlighting the need for further research given the potential impact on human consumption. © 2016 Elsevier Ltd. All rights reserved.

Within the framework of the Spanish monitoring program, this study reports on air concentration of DDTs, HCB, HCHs, NDL-PCBs, DL-PCBs, PCDD/Fs and PBDEs measured during the five-year sampling period 2008–2013. Spanish coastal remote and urban locations were studied using PUF disk passive air samplers which were deployed and collected every three months. Despite the wide range of concentrations measured for most contaminants, a common pattern of relative abundance (median values): NDL-PCBs (36.6 pg/m3) > HCB (24.8 pg/m3) ≈ HCHs (17.9 pg/m3) ≈ DDTs (16.6 pg/m3) > PBDEs (3.65 pg/m3) > DL-PCBs (2.99 pg/m3) >> PCDD/Fs (0.060 pg/m3) was found fairly consistent across most seasons and locations. Nevertheless, important variations in yearly concentrations were measured for different POPs. In general, higher levels of DDTs, HCHs, NDL-PCBs, DL-PCBs and PCDD/Fs were found in urban sites highlighting important differences between remote and urban sampling locations for most target contaminants. Greater concentrations of the banned organochlorine pesticides in urban locations suggested the existence of unexpected pointed sources that need to be further investigated and characterized. The limited dataset collected thus far rendered no clear temporal trends for most study target compounds, which emphasizes the necessity of the Spanish monitoring program future maintenance in time. © 2016 Elsevier Ltd

Studies on Persistent Organic Pollutants (POPs) in Antarctic wildlife are scarce, and usually limited to a single locality. As a result, wildlife exposure to POPs across the Southern Ocean is poorly understood. In this study, we report the differential exposure of the major southern ocean scavengers, the giant petrels, to POPs across a wide latitudinal gradient. Selected POPs (PCBs, HCB, DDTs, PBDEs) and related compounds, such as Dechlorane Plus (DP), were analyzed in plasma of southern giant petrels (Macronectes giganteus) breeding on Livingston (62°S 61°W, Antarctica), Marion (46°S 37°E, sub-Antarctic), and Gough (40°S 10°W, cool temperate) islands. Northern giant petrels (Macronectes halli) from Marion Island were also studied. Stable isotope ratios of C and N (δ 13 C and δ 15 N) were used as dietary tracers of the marine habitat and trophic level, respectively. Breeding locality was a major factor explaining petrel exposure to POPs compared with species and sex. Significant relationships between δ 13 C values and POP burdens, at both inter- and intra-population levels, support latitudinal variations in feeding grounds as a key factor in explaining petrel pollutant burdens. Overall, pollutant levels in giant petrels decreased significantly with latitude, but the relative abundance (\%) of the more volatile POPs increased towards Antarctica. DP was found at negligible levels compared with legacy POPs in Antarctic seabirds. Spatial POP patterns found in giant petrels match those predicted by global distribution models, and reinforce the hypothesis of atmospheric long-range transport as the main source of POPs in Antarctica. Our results confirm that wildlife movements out of the polar region markedly increase their exposure to POPs. Therefore, strategies for Antarctic wildlife conservation should consider spatial heterogeneity in exposure to marine pollution. Of particular relevance is the need to clarify the exposure of Antarctic predators to emerging contaminants that are not yet globally regulated. © 2016 Elsevier Inc.