Potential toxicological hazard due to endocrine-disrupting chemicals on Mediterranean top predators: state of art, gender differences and methodological tools

Persistent Organic Pollutants (POPs) in three bathyal chondrichthyes from the North-Western Mediterranean Sea

The deep-sea can act as a sink for legacy contaminants such as organochlorines (OCs), causing damages in its inhabitants for their persistence and their prolonged effects in the organisms. HCB, DDT and its isomers, and 28 PCBs congeners were detected in muscle and embryonic tissues of three deep-sea chondrichthyes Chimaera monstrosa (n = 16), Dalatias licha (n = 12) and Etmopterus spinax (n = 51) sampled in Ligurian and Tyrrhenian Sea (Mediterranean Sea). Contaminant distribution in E. spinax and C. monstrosa was PCBs > DDTs ≫ HCB while in D. licha was DDTs > PCBs ≫ HCB. Statistically significant differences were highlighted in OC levels among the species, but no such differences were found among sexes. Ratios between DDT isomers highlighted an historical input of the pesticide in the environment. For the first time was also demonstrated maternal transfer in deep water chondrichthyes, specifically in E. spinax where was highlighted that transfer of contaminants increases with increasing compound's Log Kow.

Influence of chemical dose and exposure duration on protein synthesis in green sea turtle primary cells

Understanding the impacts of chemical exposure in marine wildlife is challenging, due to practical and ethical constraints that preclude traditional toxicology research on these animals. This study addressed some of these limitations by presenting an ethical and high throughput cell-based approach to elucidate molecular-level effects of contaminants on sea turtles. The experimental design addressed basic questions of cell-based toxicology, including chemical dose and exposure time. Primary green turtle skin cells were exposed to polychlorinated biphenyl (PCB) 153 and perfluorononanoic acid (PFNA) for 24 and 48 h, at three sub-lethal, environmentally relevant concentrations (1, 10 and 100 μg/L). Sequential window acquisition of all theoretical mass spectra (SWATH-MS) identified over 1000 differentially abundant proteins within the 1% false discovery rate (FDR) threshold. The 24 h exposure resulted in a greater number of differentially abundant proteins, compared to 48 h exposure, for both contaminants. However, there were no statistically significant dose-response relationships for the number of differentially synthesised proteins, nor differences in the proportion of increased vs decreased proteins between or within exposure times. Known in vivo markers of contaminant exposure, superoxide dismutase and glutathione S-transferase, were differentially abundant following exposure to PCB153 and PFNA. SIGNIFICANCE: Cell-based (in vitro) proteomics provides an ethical and high throughput approach to understanding the impacts of chemical contamination on sea turtles. Through investigating effects of chemical dose and exposure duration on unique protein abundance in vitro, this study provides an optimised framework for conducting cell-based studies in wildlife proteomics, and highlights that proteins detected in vitro could act as biomarkers of chemical exposure and effect in vivo.

Fin Whale (Balaenoptera physalus) Mortality along the Italian Coast between 1624 and 2021

The Mediterranean Sea hosts a population of fin whale (Balaenoptera physalus), the only species of Mysticete regularly occurring in the basin. Observed and inferred mortality suggests that the population is likely declining. Accordingly, understanding the causes of mortality and assessing the health status is pivotal to the survival of this endangered population. While such studies are inherently difficult for a highly roaming species with a pelagic distribution, mortality events provide the opportunity to investigate biological and epidemiological traits linked to these events, and evaluate the footprint of human activity, especially when long-term data series exist. We present a comprehensive spatial-temporal overview of fin whale mortality events along the Italian coast encompassing four centuries (1624-2021). Time series analysis was used to highlight structural changes in the evolution of mortality through time, while spatial-temporal patterns in the distribution of mortality events were assessed through emerging hot spot analysis methods. Recent mortality events (1964-2021) were further explored to evaluate, where possible, the primary causes of mortality and to identify anthropogenic threats of conservation concerns. This long-term survey offers the basis for an understanding of the health status of this B. physalus population and provides much-needed information for developing an effective management and conservation plan for the species in the region.

Endocrine disruptor chemicals. A review of their effects on male reproduction and antioxidants as a strategy to counter it

Endocrine disruptor chemicals are exogenous molecules that generate adverse effects on human health by destabilizing the homeostasis of endocrine system and affecting directly human reproductive system by inhibiting or activating oestrogenic or androgenic receptors. Endocrine disruptor chemicals generate transgenerational epigenetic problems, besides being associated with male infertility. Epidemiological data indicate that the increase in reproductive problems in males in the last 50 years is correlated with the increase of endocrine disrupting chemicals in the environment, being associated with a decrease in semen quality and direct effects on spermatozoa, such as alterations in motility, viability and acrosomal reaction, due to the generation of oxidative stress, and have also been postulated as a possible cause of testicular dysgenesis syndrome. Diverse antioxidants, such as C and E vitamins, N-acetylcysteine, selenium and natural vegetable extracts, are among the alternatives under study to counter the effects of endocrine disruptor chemicals. In some cases, the usage of them has given positive results and the opposite in others. In this review, we summarize the recent information about the effects of endocrine disruptor chemicals on male reproduction, on sperm cells, and the results of studies that have tested antioxidants as a strategy to diminish their harmful effects.

No evidence that vitellogenin protein expression is induced in marine mussels after exposure to an estrogenic chemical

A wide variety of endocrine disrupting chemicals reach the marine environment and can cause harmful effects in different marine organisms. Vitellogenin (Vtg), the egg-yolk precursor, is a commonly used endocrine disruption biomarker in fish and more recently in marine invertebrates under the assumption of high expected similarities in the endocrine system of vertebrates and invertebrates. However, this assumption has been recently questioned. The results from previous studies focused on bivalve molluscs showed that Vtg induction could be misleading because of the use of either non-robust or indirect techniques to measure Vtg. In this study, mussels (Mytilus galloprovincialis) were exposed to either 10 or 100 ng/L of the synthetic hormone 17α-ethinylestradiol (EE2) at different exposure times (4 and 24 days) and under different feeding regimes (representing different energy balances), and Vtg levels in both male and female mussel gonads were quantified by label free shotgun LC-MS/MS proteomic analysis. Vtg protein was not detected in male gonads. In female gonads, Vtg levels were not significantly affected by EE2 at any exposure time or EE2 concentration tested, whereas a significant correlation was found between the degree of maturation of the gonad and Vtg levels in females. Results obtained in the present study critically question the use of Vtg as a biomarker of endocrine disruption in marine mussels, and show that the degree of maturation of the gonad can be an important confounding factor in the attempts to evaluate estrogenic effects through Vtg measurement in mussel gonads.

Insights Into Cetacean Immunology: Do Ecological and Biological Factors Make the Difference?

The aim of this study was to evaluate the expression of Major histocompatibility complex (MHC) class I chain-related protein A (MICA) in fibroblast cell cultures of cetaceans (skin biopsies of free-ranging specimens and skin samples of freshly stranded cetaceans) by an immunofluorescence technique and to outline possible variations in MICA expression linked to different ecological and biological factors, while also investigating MICA expression after in vitro treatments with different contaminants. Free-ranging or stranded specimens of cetaceans were sampled in the Sea of Cortez (Mexico) (Balaenoptera edeni, Delphinus capensis, and Orcinus orca) and in the Mediterranean Sea (Balaenoptera physalus, Physeter macrocephalus, Tursiops truncatus, and Stenella coeruleoalba). Cell cultures were treated with an OC mixture, flame retardants, PAHs, MeHg, and BPA. The three species from the Sea of Cortez showed higher basal activity of MICA and lower levels of DDTs and PCBs than the Mediterranean species. A Pearson's linear coefficient equal to −0.45 also confirmed this tendency to have high levels of MICA and low total OC levels. Treatment of cultured fibroblasts with different contaminants mostly resulted in the upregulation of MICA protein expression by at least one treatment dose; downregulation was also found in some species or treatments. MICA alteration indicates a state of stress of the organism and a modification of the immune system's response and can be proposed as a non-invasive immunological marker that can be measured in skin biopsy samples, thus offering a good alternative to blood measurements.

Electron Spin Resonance (ESR) for the study of Reactive Oxygen Species (ROS) on the isolated frog skin (Pelophylax bergeri): A non-invasive method for environmental monitoring

BACKGROUND

Reactive oxygen species (ROS) in biological tissues of elected biosentinels represent an optimal biomarker for eco-monitoring of polluted areas. Electron spin resonance (ESR) is the most definitive method for detecting, quantifying and possibly identifying radicals in complex systems.

OBJECTIVE

A non-invasive method for monitoring polluted areas by the quantitative determination of ROS in frog skin biopsy is presented.

METHODS

We assessed by ESR spectroscopy the ROS level in adult male of Pelophylax bergeri, specie not a risk of extinction, collected from the polluted Sarno River (SA, Italy) basin. The spin-trap ESR method was validated by immunohistochemical analysis of the well-assessed pollution biomarkers cytochrome P450 aromatase 1A (CYP1A) and glutathione S-transferase (GST), and by determining the poly(ADPribose) polymerase (PARP) and GST enzymatic activity.

RESULTS

ROS concentration in skin samples from frogs collected in the polluted area is significantly higher than that determined for the unpolluted reference area. Immunohistochemical analysis of CYP1A and GST supported the reliability of our approach, even in the absence of evident morphological and ultrastructural differences. PARP activity assay, connected to possible oxidative DNA damage, and the detoxification index by GST enzymatic assay give statistically significant evidence that higher levels of ROS are associated to alterations of the different biomarkers.

CONCLUSIONS

ROS concentration, measured by ESR on isolated frog skin, through the presented non-lethal method, is a reliable biomarker for toxicity screening and represents a useful basic datum for future modelling studies on environmental monitoring and biodiversity loss prevention.

Charting a path towards non-destructive biomarkers in threatened wildlife: A systematic quantitative literature review

Threatened species are susceptible to irreversible population decline caused by adverse sub-lethal effects of chemical contaminant exposure. It is therefore vital to develop the necessary tools to predict and detect these effects as early as possible. Biomarkers of contaminant exposure and effect are widely applied to this end, and a significant amount of research has focused on development and validation of sensitive and diagnostic biomarkers. However, progress in the use biomarkers that can be measured using non-destructive techniques has been relatively slow and there are still many difficulties to overcome in the development of sound methods. This paper systematically quantifies and reviews studies that have aimed to develop or validate non-destructive biomarkers in wildlife, and provides an analysis of the successes of these methods based on the invasiveness of the methods, the potential for universal application, cost, and the potential for new biomarker discovery. These data are then used to infer what methods and approaches appear the most effective for successful development of non-destructive biomarkers of contaminant exposure in wildlife. This review highlights that research on non-destructive biomarkers in wildlife is severely lacking, and suggests further exploration of in vitro methods in future studies.

Phthalates, heavy metals and PAHs in an overpopulated coastal region: Inferences from Abruzzo, central Italy

Phthalates are an emerging class of environmental pollutants whose distribution and effects in aquatic environments are not well characterized. We analyzed intertidal and emerged beach sediments from the Abruzzo coastline, along the Adriatic Sea, finding significant phthalate concentrations in marine sediments. Phthalate baseline levels in the intertidal environment, marked by substantial interplay of sediment, water and air, were determined. We used statistical rank methods to select representative phthalate compositions, for which we derived risk levels for ingestion, dermal absorption and inhalation. Our study shows that phthalates are a major cause of pollution along the Abruzzo coast, with river transport of sediments a continuous source of replenishment. Phthalate concentrations in two specific sites were determined to be of the same order of magnitude as the safety, remediation-warranting, threshold set by Italian law. Phthalates, heavy metals, PAHs appear to be correlated. We discuss possible intervention and mitigation strategies.

Marine mammal cell cultures: To obtain, to apply, and to preserve

The world's oceans today have become a place for the disposal of toxic waste, which leads to the degradation of marine mammal habitats and populations. Marine mammal cell cultures have proven to be a multifunctional tool for studying the peculiarities of the cell physiology and biochemistry of these animals as well as the destructive effects of anthropogenic and natural toxicants. This review describes the sources of marine mammal live tissues and the methods required for establishing cell cultures, their use, and long-term storage. Approaches to conserving rare animal species by applying cell biology methodologies are also discussed.

Satellite tagging of Mediterranean fin whales: working towards the identification of critical habitats and the focussing of mitigation measures

Mediterranean fin whales comprise a genetically distinct population, listed as Vulnerable (VU) in the IUCN Red List. Collisions with vessels are believed to represent the main cause of human-induced mortality. The identification of critical habitats (including migration routes) incorporating satellite telemetry data is therefore crucial to develop focussed conservation efforts. Between 2012 and 2015 thirteen fin whales were equipped with satellite transmitters, 8 in the Pelagos Sanctuary (although two ceased within two days) and 5 in the Strait of Sicily, to evaluate movements and habitat use. A hierarchical switching state-space model was used to identify transiting and area-restricted search (ARS) behaviours, believed to indicate foraging activities. All whales undertook mid- to long-distance migrations, crossing some of the world's busiest maritime routes. Areas where the animals predominantly engaged in ARS behaviour were identified in both study areas. The telemetry data were compared with results from ecosystem niche modelling, and showed that 80% of tagged whale positions was near (<7 km) the closest suitable habitat. The results contribute to the view that precautionary management should include establishment of a coordinated and dynamic basin-wide management scheme; if appropriate, this may include the establishment of protected areas by specific regional Conventions.

Distribution, potential sources and ecological risks of two persistent organic pollutants in the intertidal sediment at the Shuangtaizi Estuary, Bohai Sea of China

Spatial distribution, source apportionment, and potential ecological risks of sixteen polycyclic aromatic hydrocarbons (PAHs) and seven endocrine disrupting compounds (EDCs) in the intertidal sediment at the Shuangtaizi Estuary, Bohai Sea of China were analyzed. Results showed that the total PAH concentrations ranged from 28.79ngg^-1 dw to 281.97ngg^-1 dw (mean: 115.92ngg^-1 dw) and the total EDC concentrations from 0.52ngg^-1 dw to 126.73ngg^-1 dw (mean: 37.49ngg^-1 dw). The distribution pattern for the PAHs was generally different from that of the EDCs possibly due to their distinct sources and n-octanol-/water partition coefficients (K_OW). Qualitative and quantitative analytical results showed that PAH sources were mainly from a mixture of pyrogenic and petrogenic contributions. The higher levels at the southeast of Geligang indicated that the EDC pollutants may have mainly originated from the plastic industry and other chemical plants located along the Liao River. Ecological risk assessment revealed that PAHs exhibited low ecotoxicological effects, whereas EDCs, especially 4-tert-octylphenol and bisphenol A, had high ecological hazard to the estuarine biota.

Cetacean Morbillivirus-Associated Pathology: Knowns and Unknowns

The present minireview deals with the pathology of Cetacean Morbillivirus (CeMV) infection in free-ranging cetaceans. In this respect, while "classical" CeMV-associated lesions were observed in the lung, brain, and lymphoid tissues from striped dolphins (Stenella coeruleoalba) and pilot whales (Globicephala melas) which were victims of the 1990-1992 and 2006-2008 epidemics in the Western Mediterranean, an apparent reduction in CeMV neurovirulence, along with a different viral antigen's tissue and cell distribution, were found during the 2010-2011 and the 2013 outbreaks in the same area. Of remarkable concern are also the documented CeMV ability to induce maternally acquired infections in wild cetaceans, coupled with the progressively expanding geographic and host range of the virus in both Hemispheres, as well as in conjunction with the intriguing forms of "brain-only" morbilliviral infection increasingly reported in Mediterranean-striped dolphins. Future research in this area should address the virus-host interaction dynamics, with particular emphasis on the cell receptors specifying viral tissue tropism in relation to the different cetacean species and to their susceptibility to infection, as well as to the CeMV strains circulating worldwide.

First evidence of presence of plastic debris in stomach of large pelagic fish in the Mediterranean Sea

This study focuses, for the first time, on the presence of plastic debris in the stomach contents of large pelagic fish (Xiphias gladius, Thunnus thynnus and Thunnus alalunga) caught in the Mediterranean Sea between 2012 and 2013. Results highlighted the ingestion of plastics in the 18.2% of samples. The plastics ingested were microplastics (<5mm), mesoplastics (5-25mm) and macroplastics (>25mm). These preliminary results represent an important initial phase in exploring two main ecotoxicological aspects: (a) the assessment of the presence and impact of plastic debris on these large pelagic fish, and (b) the potential effects related to the transfer of contaminants on human health.

Cetacean morbillivirus: current knowledge and future directions

We review the molecular and epidemiological characteristics of cetacean morbillivirus (CeMV) and the diagnosis and pathogenesis of associated disease, with six different strains detected in cetaceans worldwide. CeMV has caused epidemics with high mortality in odontocetes in Europe, the USA and Australia. It represents a distinct species within the Morbillivirus genus. Although most CeMV strains are phylogenetically closely related, recent data indicate that morbilliviruses recovered from Indo-Pacific bottlenose dolphins (Tursiops aduncus), from Western Australia, and a Guiana dolphin (Sotalia guianensis), from Brazil, are divergent. The signaling lymphocyte activation molecule (SLAM) cell receptor for CeMV has been characterized in cetaceans. It shares higher amino acid identity with the ruminant SLAM than with the receptors of carnivores or humans, reflecting the evolutionary history of these mammalian taxa. In Delphinidae, three amino acid substitutions may result in a higher affinity for the virus. Infection is diagnosed by histology, immunohistochemistry, virus isolation, RT-PCR, and serology. Classical CeMV-associated lesions include bronchointerstitial pneumonia, encephalitis, syncytia, and lymphoid depletion associated with immunosuppression. Cetaceans that survive the acute disease may develop fatal secondary infections and chronic encephalitis. Endemically infected, gregarious odontocetes probably serve as reservoirs and vectors. Transmission likely occurs through the inhalation of aerosolized virus but mother to fetus transmission was also reported.

An "ex vivo" model to evaluate toxicological responses to mixtures of contaminants in cetaceans: integumentum biopsy slices

The need for powerful new tools to detect the effects of chemical pollution, in particular of persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs) on Mediterranean cetaceans led us to develop and apply a suite of sensitive biomarkers for integument biopsies of stranded and free-ranging animals. This multi-response ex vivo method has the aim to detect toxicological effects of contaminant mixtures. In the present study, we applied an ex vivo assay using skin biopsy and liver slices, combining molecular biomarkers [Western blot of Cytochrome P450 1A1 (CYP1A1) and Cytochrome P450 2B (CYP2B)] and gene expression biomarkers (Quantitative real-time PCR of CYP1A1, heat shock protein 70, estrogen receptor alpha and E2F transcription factor) in response to chemical exposure [organochlorines compounds (OCs), polybrominated diphenyl ethers (PBDEs), and PAHs] for stranded Mediterranean Stenella coeruleoalba. The main goal of this experiment was to identify the biomarker and/or a suite of biomarkers that could best detect the presence of a specific class of pollutants (OCs, PBDEs, and PAHs) or a mixture of them. This multi-response biomarker methodology revealed an high sensitivity and selectivity of responses (such as CYP1A and ER α mRNA variations after OCs and PAHs exposure) and could represent a valid future approach for the study of inter- and intra-species sensitivities to various classes of environmental contaminants.

Effects of in vitro exposure to titanium dioxide on DNA integrity of bottlenose dolphin (Tursiops truncatus) fibroblasts and leukocytes

In the present study, the genotoxic potential of nanosized TiO2 anatase and micro-sized rutile on bottlenose dolphin (Tursiops truncatus) fibroblasts and leukocytes was investigated. Human and mouse cells were also studied in order to compare susceptibility to TiO2 in different mammalian species. Cell lines were exposed for 4, 24, and 48 h to different concentrations of TiO2 (20, 50, 100, 150 μg/ml) and DNA damage was investigated by single cell gel electrophoresis (Comet assay). Both anatase and rutile induced increased DNA damage, even though statistically significant effects were scattered according to species and cell lines. Bottlenose dolphin leukocytes and murine fibroblasts exhibited increased DNA damage after rutile exposure at some doses/times, while human fibroblasts showed a significant dose-response effect after a 4 h exposure to anatase. Human leukocytes were tolerant to both anatase and rutile. Ultrastructural investigation showed that TiO2 particles entered the cell and were compartmentalized within membrane-bound vesicles.

Amount and distribution of neustonic micro-plastic off the western Sardinian coast (Central-Western Mediterranean Sea)

A plethora of different sampling methodologies has been used to document the presence of micro-plastic fragments in sea water. European Marine Strategy suggests to improve standard techniques to make future data comparable. We use Manta Trawl sampling technique to quantify abundance and distribution of micro-plastic fragments in Sardinian Sea (Western Mediterranean), and their relation with phthalates and organoclorine in the neustonic habitat. Our results highlight a quite high average plastic abundance value (0.15 items/m(3)), comparable to the levels detected in other areas of the Mediterranean. "Site" is the only factor that significantly explains the differences observed in micro-plastic densities. Contaminant levels show high spatial and temporal variation. In every station, HCB is the contaminant with the lowest concentration while PCBs shows the highest levels. This work, in line with Marine Strategy directives, represents a preliminary study for the analysis of plastic impact on marine environment of Sardinia.

Assessment of current dietary intake of organochlorine contaminants and polycyclic aromatic hydrocarbons in killer whales (Orcinus orca) through direct determination in a group of whales in captivity

We determined the levels of 16 polycyclic aromatic hydrocarbons (PAHs), 19 organochlorine pesticides (OCPs) and 18 polychlorinated biphenyls (PCBs) in the plasma of captive adult killer whales and in their food. The goal of this research was the assessment of the dietary exposure of killer whales to these pollutants to gain insight on what is the actual magnitude of the exposure in this species, which is considered among the most contaminated in the planet. Plasma median ∑OCP and ∑PCB contents were 3150.3 and 7985.9 ng g(-1)l.w., respectively. A total of 78.9% of the PCBs were marker-PCBs, and 21.1% were dioxin-like PCBs (6688.7 pg g(-1)l.w. dioxin toxic equivalents). This is the first report of the blood levels of PAHs in killer whales, and their median value was 1023.1 ng g(-1)l.w. In parallel, we also determined the levels of these contaminants in the fish species that are used to feed these animals to estimate the orcas' average daily dietary intake of pollutants. All the contaminants in the fish were detected in the plasma of the killer whales, and proportionality between the intake and the blood levels was observed in all the animals. The calculated intake was extremely high for certain contaminants, which is a concern, giving a glimpse of what possibly occurs in the wild, where exposure to these contaminants can be even higher. Therefore, although many of these chemicals have been banned for decades, even today, the levels of these chemicals could reach very toxic concentrations in the tissues of these endangered animals because of their diet.

Impacts of endocrine disrupting chemicals on reproduction in wildlife

The European Environment Agency (The Weybridge + 15 (1996-2011) report. EEA Technical report, vol 2. Copenhagen, 2012) and the United Nations Environment programme together with the World Health Organisation (State of the science of endocrine disrupting chemicals-2012. Geneva, Switzerland) both recently published major and highly authoritative reviews of endocrine disrupting chemicals in the natural environment and their effects on reproduction and health in both humans and wildlife. One surprising conclusion to emerge from these reviews was that there are relatively few well documented reports of endocrine disruption (ED) in wild mammals, mainly because much of the available evidence is correlative and does not conclusively demonstrate that the chemicals in question cause the physiological and phenotypic problems attributed to them. However, based on strong evidence from studies of wild birds, reptiles, invertebrates, and laboratory animals, it is difficult to imagine that wild mammals would be the exception. This chapter is therefore included to emphasize the point that the role of reproductive science within wildlife conservation is much broader than a narrow focus on artificial breeding technologies.

The effect of 17α-ethynylestradiol on steroidogenesis and gonadal cytokine gene expression is related to the reproductive stage in marine hermaphrodite fish

Pollutants have been reported to disrupt the endocrine system of marine animals, which may be exposed through contaminated seawater or through the food chain. Although 17α-ethynylestradiol (EE₂), a drug used in hormone therapies, is widely present in the aquatic environment, current knowledge on the sensitivity of marine fish to estrogenic pollutants is limited. We report the effect of the dietary intake of 5 µg EE₂/g food on different processes of testicular physiology, ranging from steroidogenesis to pathogen recognition, at both pre-spermatogenesis (pre-SG) and spermatogenesis (SG) reproductive stages, of gilthead seabream (Sparus aurata L.), a marine hermaphrodite teleost. A differential effect between pre-SG and SG specimens was detected in the sex steroid serum levels and in the expression profile of some steroidogenic-relevant molecules, vitellogenin, double sex- and mab3-related transcription factor 1 and some hormone receptors. Interestingly, EE₂ modified the expression pattern of some immune molecules involved in testicular physiology. These differences probably reflect a developmental adjustment of the sensitivity to EE₂ in the gilthead seabream gonad.

Occurrence and partitioning of endocrine-disrupting compounds in the marine environment of Thermaikos Gulf, Northern Aegean Sea, Greece

An integrated study was conducted to determine the presence of phenolic and steroid endocrine-disrupting compounds (EDCs), in the marine environment of Thermaikos Gulf, Northern Aegean Sea, Greece. Seawater, suspended particulate matter, sediments and biota were examined for nonylphenol, octylphenol, their mono- and diethoxylate oligomers, bisphenol A, estrone, 17α-estradiol, 17β-estradiol, estriol, mestranol and 17 α -ethynylestradiol. Phenolic compounds were detected in all of the compartments, with nonylphenol and its ethoxylates being the dominant pollutants. The occurrence of nonylphenol in sediments presents a significant risk to the biota. Mussels exhibited relatively low concentrations and low bioconcentration factors for NP and OP. The effect of terrestrial sources of the EDCs on the marine environment is discussed. The influence of suspended particulate matter and organic carbon in the partition of the EDCs between the dissolved and the particulate phase was investigated.

A yeast estrogen screen without extraction provides fast, reliable measures of estrogenic activity

Yeast estrogen screen (YES) has been used since 1996 as a bioassay to quantify activity in wastewater. Here we present a modification of YES to measure estrogenic activity in water. This modification, called yeast estrogen screen no extraction (YESne), is faster and easier than the common method. The modified method can detect 17β-estradiol equivalent concentrations down to 1.1 ng/L. The median effective concentration value (EC50) is 1.2E-10. It detected average influent concentrations of 16.4 and 17.5 ng/L of 17β-estradiol equivalent at four Lehigh Valley, Pennsylvania, USA, wastewater treatment plants on September 18 and October 23, 2008, respectively, and average effluent concentrations of 5.1 and 8.1 ng/L of 17β-estradiol equivalent at the same plants on the two dates, respectively. Reduction in 17β-estradiol equivalent activity for the four wastewater treatment plants averaged 67.8 and 52.3%, respectively, for the September 18 and October 23 samples. The YESne is a simple, quick method for quantifying estrogenic activity that has been used successfully in nonmajor undergraduate classes and could be adapted by wastewater treatment plant laboratory technicians to measure influent and effluent estrogenicity on a regular basis. This practice will greatly increase our knowledge base of estrogenicity in wastewater before and after treatment.

Monitoring winter and summer abundance of cetaceans in the Pelagos Sanctuary (northwestern Mediterranean Sea) through aerial surveys

Systematic long-term monitoring of abundance is essential to inform conservation measures and evaluate their effectiveness. To instigate such work in the Pelagos Sanctuary in the Mediterranean, two aerial surveys were conducted in winter and summer 2009. A total of 467 (131 in winter, 336 in summer) sightings of 7 species was made. Sample sizes were sufficient to estimate abundance of fin whales in summer (148; 95% CI = 87–254) and striped dolphins in winter (19,462; 95% CI = 12 939–29 273) and in summer (38 488; 95% CI = 27 447–53 968). Numbers of animals within the Sanctuary are significantly higher in summer, when human activities and thus potential population level impacts are highest. Comparisons with data from past shipboard surveys suggest an appreciable decrease in fin whales within the Sanctuary area and an appreciable increase in striped dolphins. Aerial surveys proved to be more efficient than ship surveys, allowing more robust estimates, with smaller CIs and CVs. These results provide essential baseline data for this marine protected area and continued regular surveys will allow the effectiveness of the MPA in terms of cetacean conservation to be evaluated and inform future management measures. The collected data may also be crucial in assessing whether ship strikes, one of the main causes of death for fin whales in the Mediterranean, are affecting the Mediterranean population.

Toxicants exposures as novel zoonoses: reflections on sustainable development, food safety and veterinary public health

The modern concept of zoonosis considers any detriment to the health and/or quality of human life resulting from relationships with (other) vertebrate or edible or toxic invertebrate animals. Whereas exposure to toxicants through foods of animal origin (a.o.) is a well-established issue, hereby we discuss it as novel zoonoses, from the standpoints of health implications as well as similarities and differences with classical zoonoses caused by biological agents. Novel toxicant-related zoonoses are linked with new issues in food safety, such as the environment-feed-food chain. In fact, the potential effect of the combined and repeated exposure to dietary toxicants is generally long-term and not readily discernible. Endocrine disrupting chemicals in staple foods of a.o. are discussed as a telling example of a food safety issue summing up critical points covered by the definition of sustainable development, also implicating health risks for generations to come. We suggest some critical points to implement the veterinary public health action in sustainable food safety, such as enhancement of Hazard Analysis and Critical Control Points systems for toxicological risk management.

Marine mammals as sentinel species for oceans and human health

The long-term consequences of climate change and potential environmental degradation are likely to include aspects of disease emergence in marine plants and animals. In turn, these emerging diseases may have epizootic potential, zoonotic implications, and a complex pathogenesis involving other cofactors such as anthropogenic contaminant burden, genetics, and immunologic dysfunction. The concept of marine sentinel organisms provides one approach to evaluating aquatic ecosystem health. Such sentinels are barometers for current or potential negative impacts on individual- and population-level animal health. In turn, using marine sentinels permits better characterization and management of impacts that ultimately affect animal and human health associated with the oceans. Marine mammals are prime sentinel species because many species have long life spans, are long-term coastal residents, feed at a high trophic level, and have unique fat stores that can serve as depots for anthropogenic toxins. Marine mammals may be exposed to environmental stressors such as chemical pollutants, harmful algal biotoxins, and emerging or resurging pathogens. Since many marine mammal species share the coastal environment with humans and consume the same food, they also may serve as effective sentinels for public health problems. Finally, marine mammals are charismatic megafauna that typically stimulate an exaggerated human behavioral response and are thus more likely to be observed.

Organochlorine pesticides and polychlorinated biphenyls in fin whales (Balaenoptera physalus) from the Gulf of California

The present study reports unique data on concentrations of several classes of organochlorine pesticides and polychlorinated biphenyls in blubber biopsies from healthy living fin whales (Balaenoptera physalus) from the Gulf of California, Mexico, one of the most isolated and unstudied population in the world. OC levels in this population were generally lower than levels reported in fin whales from other regions. The rank order of OCs were SigmaDDTs (range from 300 to 2400 ng g(-1) lw) > SigmaPCBs (range from 40 to 290 ng g(-1) lw) > SigmaHCHs (range from <LOQ to 92 ng g(-1) lw) > or = SigmaCHLORs (from < LOQ to 100 ng g(-1) lw). The most abundant OC pesticide measured was the DDT metabolite, p,p'-DDE. The PCBs 138, 153, and 180 were the most abundant PCBs congeners found in the fin whales samples. Males had significant higher concentrations of SigmaOC, SigmaDDTs and SigmaPCBs than females (P < 0.05), although the p,p'-DDE/SigmaDDTs ratios were similar between the sexes. Although the OC concentrations found in this population were generally below the levels that would be expected to cause deleterious health effects, the maximum values observed (2700 ng g(-1) lw) in some animals were higher than those associated with reproductive effects in whales. Given the small population size and highly isolated characteristics of Gulf of California fin whales, health effects in individuals could readily translate into population-level effects. Future research on this topic will be necessary to better understand the role that these compounds may have on the health of this population.

Genotoxic potential of TiO2 on bottlenose dolphin leukocytes

Titanium dioxide is extensively used in a variety of products, including industrial materials and cosmetics. Studies mainly performed on human cell lines and in vivo exposure on experimental animals have raised concern about the toxic effects of ultrafine titanium dioxide; however, scarce information is available about its impact on aquatic life. The aim of this article was to assess the genotoxic potential of TiO(2) (anatase and rutile) on bottlenose dolphin leukocytes. Blood samples were obtained from four male and one female specimens reared at the Adriatic SeaWorld "Oltremare" (Riccione, Italy). Leukocytes were isolated by the lyses procedure and in vitro exposed to TiO(2) in RPMI. Experimental solutions were sonicated immediately before dosing the cells. Three exposure times (4, 24 and 48 h) and three doses (20, 50 and 100 microg/ml) were tested. Genotoxicity was detected by the single-cell gel electrophoresis (or comet assay) at pH > or = 13, assessing single/double-strand breaks and alkali-labile sites. Cytotoxicity was also detected by the Trypan blue exclusion method. Results showed that both the crystalline forms of TiO(2) were genotoxic for bottlenose dolphin leukocytes, with a statistically significant increase of DNA fragmentation after exposure to 50 and 100 microg/ml for 24 and 48 h. Although preliminary, these are the first data regarding the genetic susceptibility of toothed cetaceans toward an "emerging" pollutant, such as TiO(2) particles.

Effect-directed identification of naphthenic acids as important in vitro xeno-estrogens and anti-androgens in North sea offshore produced water discharges

Produced water from offshore oil production platforms represents the largest direct discharge of effluent into the offshore environment. Produced water effluents contain a complex mixture of substances which are known to bind to the estrogen receptor (ER) and antagonize the androgen receptor (AR). Short-chain petrogenic alkylphenols have been identified as responsible for around 35% of the ER agonist activity measured in vitro while the compounds responsible for antagonizing the androgen receptor are unknown. For the first time we report that petrogenic naphthenic acids are weak ER agonists that account for much of the 65% of the "unknown" ER agonist potency in North Sea produced waters while also disrupting the binding of AR agonists to the AR ligand receptor. We also report other known petrogenic components such as polycyclic aromatic hydrocarbons (PAHs) and alkylphenols as environmental AR antagonists. Our investigation shows that these petrogenic components are responsible for the majority of the ER and AR receptor mediated activity in produced waters. This hypothesis is supported by data from an effects-directed analysis of produced water using normal-phase high-performance liquid chromatography (HPLC) fractionation in combination with the yeast estrogen and androgen assays as well as androgen receptor binding assays of commercially available mixtures of naphthenic acids.

p,p'-DDE induces apoptosis of rat Sertoli cells via a FasL-dependent pathway

One,1-dichloro-2,2 bis(p-chlorophenyl) ethylene (p,p′-DDE), the major metabolite of 2,2-bis(4-Chlorophenyl)-1,1,1-trichloroethane (DDT), is a known persistent organic pollutant and male reproductive toxicant. It has antiandrogenic effect. However, the mechanism by which p,p′-DDE exposure causes male reproductive toxicity remains unknown. In the present study, rat Sertoli cells were used to investigate the molecular mechanism involved in p,p′-DDE-induced toxicity in male reproductive system. The results indicated that p,p′-DDE exposure at over 30 μM showed the induction of apoptotic cell death. p,p′-DDE could induce increases in FasL mRNA and protein, which could be blocked by an antioxidant agent, N-acetyl-l-cysteine (NAC). In addition, caspase-3 and -8 were activated by p,p′-DDE treatment in these cells. The activation of NF-κB was enhanced with the increase of p,p′-DDE dose. Taken together, these results suggested that exposure to p,p′-DDE might induce apoptosis of rat Sertoli cells through a FasL-dependent pathway.

Are Atlantic cod in Store Lungegårdsvann, a seawater recipient in Bergen, affected by environmental contaminants? A qRT-PCR survey

The aim of this study was to examine the transcriptional levels of selected genes in liver and head kidney of Atlantic cod Gadus morhua sampled in Store Lungegårdsvann, a seawater recipient situated in the middle of the city of Bergen, Norway, for effects of contaminants released from municipal sewage effluents and former dump sites. Five males and six females were caught with fish traps in Store Lungegårdsvann in 2006. Cod from a location near Jondal in the Hardanger Fjord were used as controls (five males and four females). The following 12 genes were picked as potential markers of contaminant exposure: cytochrome P-450 1A (CYP1A), cytochrome P-450 2C33-like (CYP2C33-like), cytochrome P-450 3C (CYP3C), glutathione S-transcriptase pi (GST) (detoxification and biotransformation), Mn superoxide dismutase (Mn SOD), glutathione reductase (GR), heat-shock protein 70 (HSP70) (oxidative stress), vitellogenin A (VtgA), vitellogenin B (VtgB), zona pellucida 2 (ZP2) (effects of estrogen disruptors), B-cell lymphoma 2 (Bcl-2), and cyclin-dependent kinase inhibitor 1A (CDKN1A) (radiation). The results showed that two males caught in Store Lungegårdsvann possessed high transcriptional levels of VtgA, VtgB, and ZP2 mRNA in the liver. In addition, CYP1A was 4.9-fold higher expressed in males from Store Lungegårdsvann compared to males from the reference population. CYP2C33-like mRNA expression was significantly higher (1.8-fold) in females from Store Lungegårdsvann than in females from the reference population. CYP1A was significantly lower (4.7-fold) expressed in head kidney of females from Store Lungegårdsvann than in females from Hardanger Fjord. In a follow-up examination with sexually mature cod sampled in Store Lungegårdsvann in 2007, the livers were shown to contain high levels of polychlorinated biphenyls (PCB) and dioxin-like PCB. In conclusion, fish inhabiting Store Lungegårdsvann are exposed not only to endocrine disruptors but also to other contaminants that affect the transcription of phase I biotransformation genes.

Polybrominated diphenyl ethers, perfluorinated compounds and chlorinated pesticides in swordfish (Xiphias gladius) from the Mediterranean Sea

The relative isolation of the Mediterranean population, their feeding habits, and the widespread use of their fillets for human consumption make the Mediterranean swordfish, Xiphias gladius, an interesting species from an ecotoxicological and commercial point of views. High resolution gas chromatography and tandem mass spectrometry detected 19 PBDE congeners, perfluorooctane sulfonate (PFOS), and perfluorooctanoic acid (PFOA), hexachlorobenzene (HCB), p,p' and o,p' isomers of DDT, DDE, and DDD in all samples. The presence of PBDEs was reported for the first time in Mediterranean swordfish from the South Tyrrhenian Sea; total PBDE concentrations were 2218 +/- 3291 and 612 +/- 598 pg/g wet wt in the liver and in the muscle, respectively. Significant correlations were identified between BDE47 and sigmaPBDE liver concentrations versus sex and sexual maturity of specimens. The lipid-normalized concentrations ratio BDEn(liver)/BDEn(muscle+liver) suggested that this species mostly accumulates POPs in the liver. PFOS and PFOA were below the LOD (1.5 and 3 ng/g wet wt, respectively) in all the samples. The sigmaDDTs was 155 +/- 125 and 309 +/- 273 ng/g wet wt in the muscle and the liver, respectively. The estimated daily ingestion of PBDEs and DDTs through diet was lower than the acceptable weekly intakes proposed by the World Health Organization.