Preliminary assessment of environmental safety (ecosafety) of dextrin-based nanosponges for environmental applications.

The ability to employ waste products, such as vegetable scraps, as raw materials for the synthesis of new promising adsorbing materials is at the base of the circular economy and end of waste concepts. Dextrin-based nanosponges (D_NS), both cyclodextrin (CD) and maltodextrin (MD), have shown remarkable adsorption abilities in the removal of toxic compounds from water and wastewater, thus representing a bio-based low-cost solution which is establishing itself in the market. Nevertheless, their environmental safety for either aquatic or terrestrial organisms has been overlooked, raising concern in terms of potential hazards to natural ecosystems. Here, the environmental safety (ecosafety) of six newly synthesized batches of D_NS was determined along with their full characterization by means of dynamic light scattering (DLS), thermogravimetric analysis (TGA), Fourier transformed infrared spectroscopy with attenuated total reflection (FTIR-ATR) and transmission electron microscopy (SEM). Ecotoxicity evaluation was performed using a battery of model organisms and ecotoxicity assays, such as the microalgae growth inhibition test using the freshwater Raphidocelis subcapitata and the marine diatom Dunaliella tertiolecta, regeneration assay using the freshwater cnidarian Hydra vulgaris and immobilization assay with the marine brine shrimp Artemia franciscana. Impact on seedling germination of a terrestrial plant of commercial interest, Cucurbita pepo was also investigated. Ecotoxicity data showed mild to low toxicity of the six batches, up to 1 mg/mL, in the following order: R. subcapitata > H. vulgaris > D. tertiolecta > A. franciscana > C. pepo. The only exception was represented by one batch (NS-Q+_BDE_(GLU2) which resulted highly toxic for both freshwater species, R. subcapitata and H. vulgaris. Those criticalities were solved with the synthesis of a fresh new batch and were hence attributed to the single synthesis and not to the specific D_NS formulation. No effect on germination of pumpkin but rather more a stimulative effect was observed. To our knowledge this is the first evaluation of the environmental safety of D_ NS. As such we emphasize that current formulations and exposure levels in the range of mg/mL do not harm aquatic and terrestrial species thus representing an ecosafe solution also for environmental applications.

Transcriptomic responses of Antarctic clam Laternula elliptica to nanoparticles, at single and combined exposures reveal ecologically relevant biomarkers.

In recent years micro- and nanoplastics and metal-oxide nanomaterials have been found in several environmental compartments. The Antarctic soft clam Laternula elliptica is an endemic Antarctic species having a wide distribution in the Southern Ocean. Being a filter-feeder, it could act as suitable bioindicator of pollution from nanoparticles also considering its sensitivity to various sources of stress. The present study aims to assess the impact of polystyrene nanoparticles (PS-NP) and the nanometal titanium-dioxide (n-TiO2) on genome-wide transcript expression of L. elliptica either alone and in combination and at two toxicological relevant concentrations (5 and 50 µg/L) during 96 h exposure. Transcript-target qRT-PCR was performed with the aim to identify suitable biomarkers of exposure and effects. As expected, at the highest concentration tested, the clustering was clearer between control and exposed clams. A total of 221 genes resulted differentially expressed in exposed clams and control ones, and 21 of them had functional annotation such as ribosomal proteins, antioxidant, ion transport (osmoregulation), acid-base balance, immunity, lipid metabolism, cell adhesion, cytoskeleton, apoptosis, chromatin condensation and cell signaling. At functional level, relevant transcripts were shared among some treatments and could be considered as general stress due to nanoparticle exposure. After applying transcript-target approach duplicating the number of clam samples, four ecologically relevant transcripts were revealed as biomarkers for PS-NP, n-TiO2 and their combination at 50 µg/L, that could be used for monitoring clams' health status in different Antarctic localities.

Circumpolar assessment of mercury contamination: the Adélie penguin as a bioindicator of Antarctic marine ecosystems.

Due to its persistence and potential ecological and health impacts, mercury (Hg) is a global pollutant of major concern that may reach high concentrations even in remote polar oceans. In contrast to the Arctic Ocean, studies documenting Hg contamination in the Southern Ocean are spatially restricted and large-scale monitoring is needed. Here, we present the first circumpolar assessment of Hg contamination in Antarctic marine ecosystems. Specifically, the Adélie penguin (Pygoscelis adeliae) was used as a bioindicator species, to examine regional variation across 24 colonies distributed across the entire Antarctic continent. Mercury was measured on body feathers collected from both adults (n = 485) and chicks (n = 48) between 2005 and 2021. Because penguins' diet represents the dominant source of Hg, feather δ13C and δ15N values were measured as proxies of feeding habitat and trophic position. As expected, chicks had lower Hg concentrations (mean ± SD: 0.22 ± 0.08 µg·g‒1) than adults (0.49 ± 0.23 µg·g‒1), likely because of their shorter bioaccumulation period. In adults, spatial variation in feather Hg concentrations was driven by both trophic ecology and colony location. The highest Hg concentrations were observed in the Ross Sea, possibly because of a higher consumption of fish in the diet compared to other sites (krill-dominated diet). Such large-scale assessments are critical to assess the effectiveness of the Minamata Convention on Mercury. Owing to their circumpolar distribution and their ecological role in Antarctic marine ecosystems, Adélie penguins could be valuable bioindicators for tracking spatial and temporal trends of Hg across Antarctic waters in the future.

Impact of Microbial Colonization of Polystyrene Microbeads on the Toxicological Responses in the Sea Urchin Paracentrotus lividus.

The sea urchin Paracentrotus lividus (P. lividus) was exposed to either virgin or biofilm-covered polystyrene microbeads (micro-PS, 45 µm) in order to test the effect of microbial colonization on the uptake, biodistribution, and immune response. The biofilm was dominated by bacteria, as detected by scanning electron microscopy and 16S rRNA sequencing. A higher internalization rate of colonized micro-PS inside sea urchins compared to virgin ones was detected, suggesting a role of the plastisphere in the interaction. Colonized and virgin micro-PS showed the same biodistribution pattern by accumulating mainly in the digestive system with higher levels and faster egestion rates for the colonized. However, a significant increase of catalase and total antioxidant activity was observed only in the digestive system of colonized micro-PS-exposed individuals. Colonized micro-PS also induced a significant decrease in the number of coelomocytes with a significant increase in vibratile cells, compared to control and virgin micro-PS-exposed animals. Moreover, a general time-dependent increase in the red/white amoebocytes ratio and reactive oxygen species and a decrease in nitrogen ones were observed upon exposure to both colonized and virgin micro-PS. Overall, micro-PS colonization clearly affected the uptake and toxicological responses of the Mediterranean sea urchin P. lividus in comparison to virgin micro-PS.

Plastics everywhere: first evidence of polystyrene fragments inside the common Antarctic collembolan Cryptopygus antarcticus.

There is evidence and serious concern that microplastics have reached the most remote regions of the planet, but how far have they travelled in terrestrial ecosystems? This study presents the first field-based evidence of plastic ingestion by a common and central component of Antarctic terrestrial food webs, the collembolan Cryptopygus antarcticus. A large piece of polystyrene (PS) foam (34 × 31 × 5 cm) covered by microalgae, moss, lichens and microfauna was found in a fellfield along the shores of the Fildes Peninsula (King George Island). The application of an improved enzymatic digestion coupled with Fourier transform infrared microscopy (µ-FTIR), unequivocally detected traces of PS (less than 100 µm) in the gut of the collembolans associated with the PS foam and documented their ability to ingest plastic. Plastics are thus entering the short Antarctic terrestrial food webs and represent a new potential stressor to polar ecosystems already facing climate change and increasing human activities. Future research should explore the effects of plastics on the composition, structure and functions of polar terrestrial biota.

TiO2 nanoparticles in seawater: Aggregation and interactions with the green alga Dunaliella tertiolecta.

Titanium dioxide nanoparticles (TiO2 NPs) have been widely employed in industrial applications, thus rising concern about their impact in the aquatic environment. In this study we investigated the chemical behaviour of TiO2 NPs in the culture medium and its effect on the green alga Dunaliella tertiolecta, in terms of growth inhibition, oxidative stress, ROS (Reactive Oxygen Species) accumulation and chlorophyll content. In addition, the influence of exopolymeric substances (EPS) excreted by the microalgae on the stability of NPs has been evaluated. The physicochemical characterization showed a high propensity of TiO2 NPs to form micrometric-sized aggregates within 30min, large enough to partially settle to the bottom of the test vessel. Indeed, an increasing amount of TiO2 particles settled out with time, but the presence of EPS seemed to mitigate this behaviour in the first 6h of exposure where the main effects in D. tertiolecta were observed. TiO2 NPs did not inhibit the 72-h growth rate of D. tertiolecta, nor affected the cellular chlorophyll concentration in the range 0.01-10mgL-1. The time-course of ROS production showed an initial transient increase of ROS in TiO2 NP-exposed algae compared to the control, concomitant with an enhancement of catalase activity. Interestingly, intracellular ROS was a small fraction of total ROS, the highest amount being extracellular. The occurrence of cell-mediated chemical transformations of TiO2 NPs in the external medium, related to the presence of EPS, has been evaluated. Our results showed that carbohydrates were the major component of EPS, whereas proteins of medium molecular weight (20-80kDa) were preferentially bound to TiO2 NPs, likely influencing their biological fate.

Combined effects of n-TiO2 and 2,3,7,8-TCDD in Mytilus galloprovincialis digestive gland: A transcriptomic and immunohistochemical study.

Despite the growing concern over the potential biological impact of nanoparticles (NPs) in the aquatic environment, little is known about their interactions with other pollutants. In the marine mussel Mytilus galloprovincialis, exposure to nanosized titanium dioxide (n-TiO2), one of the most widespread type of NPs in use, in combination with and 2,3,7,8-tetrachlorodibenzo-p-dioxins (TCDD), chosen as model organic xenobiotic, was shown to induce significant changes in different biomarkers in hemocytes, gills and digestive gland, with distinct effects depending on cell/tissue and type of response measured. In this work, the interactive effects of n-TiO2 and TCDD at the tissue level were further investigated in mussel digestive gland using an integrated approach transcriptomics/immunohistochemistry. Mussels were exposed to n-TiO2 (100µgL(-1)) and TCDD (0.25µgL(-1)), alone and in combination, for 96h. Transcriptomic analysis identified 48-, 49- and 62 Differentially Expressed Genes (DEGs) in response to n-TiO2, TCDD and n-TiO2/TCDD, respectively. Gene Ontology (GO) term analysis revealed distinct biological processes affected in different experimental conditions. n-TiO2 mainly up-regulated cytoskeletal genes, while TCDD up-regulated endocrine and signal transduction related processes. Co-exposure induced transcriptional changes common to individual treatments, and identified a newly generated process, response to chemical stimulus. Transcription of selected genes was verified by qPCR. Moreover, expression of tubulin, as an example of target protein of interest identified by gene transcription data, was evaluated in tissue sections by immunolabelling. Tissue TCDD accumulation was evaluated by immunofluorescence with an anti-dioxins antibody. The results demonstrate both distinct and interactive effects of n-TiO2 and TCDD in mussel digestive gland at the molecular and tissue level, identify the main molecular targets involved, and underline how exposure to the n-TiO2/TCDD mixture does not result in increased TCDD accumulation and overall stressful conditions in the tissue. These represent the first data on transcriptional responses of marine invertebrates to exposure not only to n-TiO2 as a model of NP, but also to a legacy contaminant like TCDD.

Interactions of cationic polystyrene nanoparticles with marine bivalve hemocytes in a physiological environment: Role of soluble hemolymph proteins.

The bivalve Mytilus galloprovincialis has proven as a suitable model invertebrate for evaluating the potential impact of nanoparticles (NPs) in the marine environment. In particular, in mussels, the immune system represents a sensitive target for different types of NPs. In environmental conditions, both NP intrinsic properties and those of the receiving medium will affect particle behavior and consequent bioavailability/uptake/toxicity. However, the evaluation of the biological effects of NPs requires additional understanding of how, once within the organism, NPs interact at the molecular level with cells in a physiological environment. In mammalian systems, different NPs associate with serum soluble components, organized into a "protein corona", which affects particle interactions with target cells. However, no information is available so far on the interactions of NPs with biological fluids of aquatic organisms. In this work, the influence of hemolymph serum (HS) on the in vitro effects of amino modified polystyrene NPs (PS-NH2) on Mytilus hemocytes was investigated. Hemocytes were incubated with PS-NH2 suspensions in HS (1, 5 and 50µg/mL) and the results were compared with those obtained in ASW medium. Cell functional parameters (lysosomal membrane stability, oxyradical production, phagocytosis) were evaluated, and morphological changes were investigated by TEM. The activation state of the signalling components involved in Mytilus immune response (p38 MAPK and PKC) was determined. The results show that in the presence of HS, PS-NH2 increased cellular damage and ROS production with respect to ASW medium. The effects were apparently mediated by disregulation of p38 MAPK signalling. The formation of a PS-NH2-protein corona in HS was investigated by centrifugation, and 1D- gel electrophoresis and nano-HPLC-ESI-MS/MS. The results identified the Putative C1q domain containing protein (MgC1q6) as the only component of the PS-NH2 hard protein corona in Mytilus hemolymph. These data represent the first evidence for the formation of a NP bio-corona in aquatic organisms and underline the importance of the recognizable biological identity of NPs in physiological exposure medium when testing their potential impact environmental model organisms. Although the results obtained in vitro do not entirely reflect a realistic exposure scenario and the more complex formation of a bio-corona that is likely to occur in vivo, these data will contribute to a better understanding of the effects of NPs in marine invertebrates.

Nano-sized polystyrene affects feeding, behavior and physiology of brine shrimp Artemia franciscana larvae.

Nano-sized polymers as polystyrene (PS) constitute one of the main challenges for marine ecosystems, since they can distribute along the whole water column affecting planktonic species and consequently disrupting the energy flow of marine ecosystems. Nowadays very little knowledge is available on the impact of nano-sized plastics on marine organisms. Therefore, the present study aims to evaluate the effects of 40nm anionic carboxylated (PS-COOH) and 50nm cationic amino (PS-NH2) polystyrene nanoparticles (PS NPs) on brine shrimp Artemia franciscana larvae. No signs of mortality were observed at 48h of exposure for both PS NPs at naplius stage but several sub-lethal effects were evident. PS-COOH (5-100µg/ml) resulted massively sequestered inside the gut lumen of larvae (48h) probably limiting food intake. Some of them were lately excreted as fecal pellets but not a full release was observed. Likewise, PS-NH2 (5-100µg/ml) accumulated in larvae (48h) but also adsorbed at the surface of sensorial antennules and appendages probably hampering larvae motility. In addition, larvae exposed to PS-NH2 undergo multiple molting events during 48h of exposure compared to controls. The activation of a defense mechanism based on a physiological process able to release toxic cationic NPs (PS-NH2) from the body can be hypothesized. The general observed accumulation of PS NPs within the gut during the 48h of exposure indicates a continuous bioavailability of nano-sized PS for planktonic species as well as a potential transfer along the trophic web. Therefore, nano-sized PS might be able to impair food uptake (feeding), behavior (motility) and physiology (multiple molting) of brine shrimp larvae with consequences not only at organism and population level but on the overall ecosystem based on the key role of zooplankton on marine food webs.

When isolated at full receptivity, in vitro fertilized wheat (Triticum aestivum, L.) egg cells reveal [Ca2+]cyt oscillation of intracellular origin.

During in vitro fertilization of wheat (Triticum aestivum, L.) in egg cells isolated at various developmental stages, changes in cytosolic free calcium ([Ca2+]cyt) were observed. The dynamics of [Ca2+]cyt elevation varied, reflecting the difference in the developmental stage of the eggs used. [Ca2+]cyt oscillation was exclusively observed in fertile, mature egg cells fused with the sperm cell. To determine how [Ca2+]cyt oscillation in mature egg cells is generated, egg cells were incubated in thapsigargin, which proved to be a specific inhibitor of the endoplasmic reticulum (ER) Ca2+-ATPase in wheat egg cells. In unfertilized egg cells, the addition of thapsigargin caused an abrupt transient increase in [Ca2+]cyt in the absence of extracellular Ca2+, suggesting that an influx pathway for Ca2+ is activated by thapsigargin. The [Ca2+]cyt oscillation seemed to require the filling of an intracellular calcium store for the onset of which, calcium influx through the plasma membrane appeared essential. This was demonstrated by omitting extracellular calcium from (or adding GdCl3 to) the fusion medium, which prevented [Ca2+]cyt oscillation in mature egg cells fused with the sperm. Combined, these data permit the hypothesis that the first sperm-induced transient increase in [Ca2+]cyt depletes an intracellular Ca2+ store, triggering an increase in plasma membrane Ca2+ permeability, and this enhanced Ca2+ influx results in [Ca2+]cyt oscillation.

Preliminary investigation on the potential involvement of an ABC-like gene in Halomicronema metazoicum (Cyanobacteria) tolerance to low seawater pH in an ocean acidification scenario.

Decreasing ocean surface pH, called ocean acidification (OA), is among the major risks for marine ecosystems due to human-driven atmospheric pCO2 increase. Understanding the molecular mechanisms of adaptation enabling marine species to tolerate a lowered seawater pH could support predictions of consequences of future OA scenarios for marine life. This study examined whether the ATP-binding cassette (ABC)-like gene slr2019 confers tolerance to the marine cyanobacterium Halomicronema metazoicum to low seawater pH conditions (7.7, 7.2, 6.5) in short- and long-term exposures (7 and 30 d). Photosynthetic pigment content indicated that the species can tolerate all three lowered-pH conditions. At day 7, slr2019 was up-regulated at pH 7.7 while no changes were observed at lower pH. After 30-d exposure, a significant decrease in slr2019 transcript levels was observed in all low-pH treatments. These first results indicate an effect of low pH on the examined transporter expression in H. metazoicum.

Reproductive toxicity assessment of cellulose nanofibers, citric acid, and branched polyethylenimine in sea urchins: Eco-design of nanostructured cellulose sponge framework (Part B).

In the framework of a safe-by-design approach, we previously assessed the eco-safety of nanostructured cellulose sponge (CNS) leachate on sea urchin reproduction. It impaired gamete quality, gamete fertilization competence, and embryo development possibly due to the leaching of chemical additives used during the CNS synthesis process. To extend this observation and identify the component(s) that contribute to CNS ecotoxicity, in the present study, we individually screened the cytotoxic effects on sea urchin Arbacia lixula and Paracentrotus lividus gametes and embryos of the three main constituents of CNS, namely cellulose nanofibers, citric acid, and branched polyethylenimine. The study aimed to minimize any potential safety risk of these components and to obtain an eco-safe CNS. Among the three CNS constituents, branched polyethylenimine resulted in the most toxic agent. Indeed, it affected the physiology and fertilization competence of male and female gametes as well as embryo development in both sea urchin species. These results are consistent with those previously reported for CNS leachate. Moreover, the characterisation of CNS leachate confirmed the presence of detectable branched polyethylenimine in the conditioned seawater even though in a very limited amount. Altogether, these data indicate that the presence of branched polyethylenimine is a cause-effect associated with a significant risk in CNS formulations due to its leaching upon contact with seawater. Nevertheless, the suggested safety protocol consisting of consecutive leaching treatments and conditioning of CNS in seawater can successfully ameliorate the CNS ecotoxicity while maintaining the efficacy of its sorbent properties supporting potential environmental applications.

Living in a challenging environment: Monitoring stress ecology by non-destructive methods in an Antarctic seabird.

How Antarctic species are facing historical and new stressors remains under-surveyed and risks to wildlife are still largely unknown. Adélie penguins Pygoscelis adeliae are well-known bioindicators and sentinels of Antarctic ecosystem changes, a true canary in the coal mine. Immuno-haematological parameters have been proved to detect stress in wild animals, given their rapid physiological response that allows them tracking environmental changes and thus inferring habitat quality. Here, we investigated variation in Erythrocyte Nuclear Abnormalities (ENAs) and White Blood Cells (WBCs) in penguins from three clustered colonies in the Ross Sea, evaluating immuno-haematological parameters according to geography, breeding stage, and individual penguin characteristics such as sex, body condition and nest quality. Concentrations of mercury (Hg) and stable isotopes of carbon and nitrogen (as proxies of the penguin's trophic ecology) were analysed in feathers to investigate the association between stress biomarkers and Hg contamination in Adélie penguins. Colony and breeding stage were not supported as predictors of immuno-haematological parameters. ENAs and WBCs were respectively ∼30 % and ∼20 % higher in male than in female penguins. Body condition influenced WBCs, with penguins in the best condition having a ∼22 % higher level of WBCs than those in the worst condition. Nest position affected the proportion of micronuclei (MNs), with inner-nesting penguins having more than three times the proportion of MNs than penguins nesting in peripheral positions. Heterophils:Lymphocytes (H:L) ratio was not affected by any of the above predictors. Multiple factors acting as stressors are expected to increase prominently in Antarctic wildlife in the near future, therefore extensive monitoring aimed to assess the health status of penguin populations is mandatory.

Silver Nanoparticles Supported onto TEMPO-Oxidized Cellulose Nanofibers for Promoting Cd2+ Cation Adsorption.

Nanocellulose constitutes a sustainable and biobased solution both as an efficient sorbent material for water treatment and as support for other inorganic nanomaterials with sorbent properties. Herein, we report the synthesis of a nanocomposite by deposition of in situ-generated silver nanoparticles (AgNPs) onto TEMPO-oxidized cellulose nanofibers (TOCNFs). Following an in-depth analytical investigation, we unveil for the first time the key role of AgNPs in enhancing the adsorption efficiency of TOCNF toward Cd2+ ions, chosen as model heavy metal contaminants. The obtained nanocomposite shows a value of Cd2+ sorption capacity at equilibrium from 150 mg L-1 ion aqueous solutions of ∼116 mg g-1 against the value of 78 mg g-1 measured for TOCNF alone. A combination of field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray (EDX), and X-ray photoelectron spectroscopy (XPS) analyses suggests that Cd2+ ions are mainly adsorbed in the neighborhood of AgNPs. However, XPS characterization allows us to conclude that the role of AgNPs relies on increasing the exposure of carboxylic groups with respect to the original TOCNF, suggesting that these groups are still responsible for absorption. In fact, X-ray absorption spectroscopy (XAS) analysis of the Cd-K edge excludes a direct interaction between Ag0 and Cd2+, supporting the XPS results and confirming the coordination of the latter with carboxyl groups.

Exposure to nanoplastics and nanomaterials either single and combined affects the gill-associated microbiome of the Antarctic soft-shelled clam Laternula elliptica.

Nanoplastics and engineering nanomaterials (ENMs) are contaminants of emerging concern (CECs), increasingly being detected in the marine environment and recognized as a potential threat for marine biota at the global level including in polar areas. Few studies have assessed the impact of these anthropogenic nanoparticles in the microbiome of marine invertebrates, however combined exposure resembling natural scenarios has been overlooked. The present study aimed to evaluate the single and combined effects of polystyrene nanoparticles (PS NP) as proxy for nanoplastics and nanoscale titanium dioxide (nano-TiO2) on the prokaryotic communities associated with the gill tissue of the Antarctic soft-shell clam Laternula elliptica, a keystone species of marine benthos Wild-caught specimens were exposed to two environmentally relevant concentrations of carboxylated PS NP (PS-COOH NP, ∼62 nm size) and nano-TiO2 (Aeroxide P25, ∼25 nm) as 5 and 50 µg/L either single and combined for 96h in a semi-static condition.Our findings show a shift in microbiome composition in gills of soft-shell clams exposed to PS NP and nano-TiO2 either alone and in combination with a decrease in the relative abundance of OTU1 (Spirochaetaceae). In addition, an increase of gammaproteobacterial OTUs affiliated to MBAE14 and Methylophagaceae (involved in ammonia denitrification and associated with low-quality water), and the OTU Colwellia rossensis (previously recorded in polluted waters) was observed. Our results suggest that nanoplastics and nano-TiO2 alone and in combination induce alterations in microbiome composition by promoting the increase of negative taxa over beneficial ones in the gills of the Antarctic soft-shell clam. An increase of two low abundance OTUs in PS-COOH NPs exposed clams was also observed. A predicted gene function analysis revealed that sugar, lipid, protein and DNA metabolism were the main functions affected by either PS-COOH NP and nano-TiO2 exposure. The molecular functions involved in the altered affiliated OTUs are novel for nano-CEC exposures.

Occurrence of PCDD/PCDFs and PCBs in soil and comparison with CYP1A response in PLHC-1 cell line.

The responsiveness of CYP1A (gene transcription and EROD enzyme activity) in the cell line Poeciliopsis lucida hepatoma (PLHC-1) upon exposure to extracts of contaminated soil samples was investigated and compared to levels of PCDD/PCDFs and PCBs including non-ortho obtained by GC/MS analysis. Soil samples A and B were collected in sites A and B. Two fractions, not purified (np) and purified (p), were obtained from each sample and analyzed for PCDD/PCDF and PCB content by GC/MS; in parallel they were tested for 24 h with PLHC-1. CYP1A response was investigated at gene (RT-qPCR) level and as 7-ethoxyresorufin-O-deethylase (EROD) enzyme activity. Chem-TEQs and Bio-TEQs were then calculated. ∑TEQ calculated for PCDD/Fs and PCBs was 0.081 pg/g and 20.32 pg/g for samples A and B, respectively. PLHC-1 showed less up-regulation of cyp1a gene on exposure to the two purified fractions (Ap 2.1-fold and Bp 1.8-fold) than to non-purified fractions (up to 15-fold for Anp and 13-fold for Bnp). EROD was also induced 2.38- and 9.44-fold in the two purified fractions (Ap and Bp) compared to model inducer 2,3,7,8-TCDD, and up to 16.03-fold for non-purified Anp and 33.79-fold for Bnp. The combination of CYP1A response, obtained in a PLHC-1 cell-based bioassay, with contaminant residue analysis provided a better description of the presence and toxicity of dioxin-like compounds in an environmental matrix.

Environmental safety of nanotechnologies: The eco-design of manufactured nanomaterials for environmental remediation.

Nanosafety is paramount considering the risks associated with manufactured nanomaterials (MNMs) whose implications could outweigh their advantages for environmental applications. Although nanotechnology-based solutions to implement pollution control, remediation and prevention are incremental with clear benefits for public health and Earth' natural ecosystems, nanoremediation is having a setback due to the risks associated with the safety of MNMs for humans and the environment. MNMs are diverse, work differently and bionano-interactions occurring upon environmental exposure will guide their fate and hazardous outcomes. Here we propose a new ecologically-based design strategy (eco-design) having its roots in green nanoscience and LCA that will ground on an Ecological Risk Assessment approach, which introduces the evaluation of MNMs' ecotoxicity along with their performances and efficacies at the design stage. As such, the proposed eco-design strategy will allow recognition and design-out since the very beginning of material synthesis, those hazardous peculiar features that can be hazardous to living beings and the natural environment. A more ecologically sound eco-design strategy in which nanosafety is conceptually included in MNMs design will sustain safer nanotechnologies including those for the environment as remediation by leveraging any risks for humans and natural ecosystems.

Occurrence and distribution of legacy and emerging pollutants including plastic debris in Antarctica: Sources, distribution and impact on marine biodiversity.

Since the first explorers reached Antarctica, their activities have quickly impacted both land and sea and thus, together with the long-range transport, hazardous chemicals began to accumulate. It is commonly recognized that anthropogenic pollution in Antarctica can originate from either global or local sources. Heavy metals, organohalogenated compounds, hydrocarbons, and (more recently) plastic, have been found in Antarctic biota, soil sediments, seawater, air, snow and sea-ice. Studies in such remote areas are challenging and expensive, and the complexity of potential interactions occurring in such extreme climate conditions (i.e., low temperature) makes any accurate prediction on potential impacts difficult. The present review aims to summarize the current state of knowledge on occurrence and distribution of legacy and emerging pollutants in Antarctica, such as plastic, from either global or local sources. Future actions to monitor and mitigate any potential impact on Antarctic biodiversity are discussed.

Nanostructured cellulose sponge engineered for marine environmental remediation: Eco-safety assessment of its leachate on sea urchin reproduction (Part A).

Nanostructured cellulose sponges (CNS) have been developed as eco-friendly and sustainable engineered materials for marine environmental remediation. Despite their functionality, sensitivity, efficiency and specificity have been proved, CNS application is still limited since their environmental safety (eco-safety) has not been completely assessed. In this study, CNS were allowed to leach in natural seawater simulating the remediation process condition and the eco-safety of CNS leachate on sea urchin reproduction has been assessed by carrying out a multi-response integrated approach, combining standardized ecotoxicity tests, innovative bioassays and gamete quality assessment. Overall, the ecotoxicity data indicate that CNS leachate affects gamete quality, gamete fertilisation competence, and embryo development probably associated with the release of chemical additives used during the synthesis process. However, in the framework of the eco-design approach, consecutive leaching treatments and conditioning of CNS in seawater open the route for a new safety protocol successfully solving the ecotoxicity while maintaining CNS sorbent properties. A safe environmental application of the resulting conditioned CNS for seawater pollution remediation is envisaged.