Biodegradation of e-waste microplastics by Penicillium brevicompactum.

Electronic and electric waste (e-waste) management strategies often fall short in dealing with the plastic constituents of printed circuit boards (PCB). Some plastic materials from PCB, such as epoxy resins, may release contaminants, but neither potential environmental impact has been assessed nor mitigation strategies have been put forward. This study assessed the biodegradation of microplastics (1-2 mm in size) from PCB by the fungus Penicillium brevicompactum over 28 days, thus contributing to the discussion of mitigation strategies for decreasing the environmental impact of such plastics in the environment. The capacity of P. brevicompactum to induce microplastic fragmentation and degradation has been determined by the increased the number of smaller-sized particles and microplastic mass reduction (up to 75 % within 14 days), respectively. The occurrence of chain scission and oxidation of microplastics exposed to P. brevicompactum when compared with the control conditions (which occurred only after 28 days of exposure) can be observed. Furthermore, Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy performed in dried biomass put in evidence an increase in the absorption intensities in regions that could be attributed to functional groups associated with carbohydrates. The results underline the potential role of the genus Penicillium, particularly P. brevicompactum, in the biodegradation of microplastics from PCB, thus providing the basis for further exploration of its potential for e-waste bioremediation and research on the underlying mechanisms for sustainable approaches to mitigate e-waste pollution.

Microplastics from agricultural mulch films: Biodegradation and ecotoxicity in freshwater systems.

The application of bio-based biodegradable mulch films in agriculture has raised environmental concerns regarding their potential impacts on adjacent freshwater ecosystems. This study investigated the biodegradation of microplastics derived from a bio-based biodegradable mulch (bio-MPs) and its acute and chronic ecotoxicity considering relevant scenarios (up to 200 and 250 mg/kg of sediment, using pristine and/or UV-aged particles), using the fungus Penicillium brevicompactum and the dipteran Chironomus riparius as model organisms, respectively, due to their ecological relevance in freshwater environments. Fourier-transform infrared spectroscopy analysis suggested changes in the fungus's carbohydrate reserves and bio-MP degradation through the appearance of low molecular weight esters throughout a 28 day biodegradation test. In a short-term exposure (48 h), C. riparius larvae exposed to pristine or UV-aged bio-MPs had up to 2 particles in their gut. Exposure to pristine bio-MPs decreased larval aerobic metabolism (<20 %) and increased neurotransmission (>15 %), whereas exposure to UV-aged bio-MPs activated larval aerobic metabolism (>20 %) and increased antioxidant defences (catalase activity by >30 % and glutathione-s-transferase by >20 %) and neurotransmission (>30 %). Longer-term (28-d) exposure to UV-aged bio-MPs did not affect larval survival and growth nor the dipteran's emergence but increased male numbers (>30 %) at higher concentrations. This study suggests that the selected agricultural bio-based mulch film is prone to biodegradation by a naturally occurring fungus. However, there is a potential for endocrine disruption in the case of prolonged exposures to UV-aged microplastics. This study emphasises the importance of further research to elucidate the potential ecological effects of these plastic products, to ensure effective management practices, and to establish new regulations governing their use.

Facemasks: An insight into their abundance in wetlands, degradation, and potential ecotoxicity.

Disposable facemasks represent a new form of environmental contamination worldwide. This study aimed at addressing the abundance of facemasks in an overlooked natural environment with high ecological and economic value - the wetlands (Ria de Aveiro, Portugal, as study case), evaluating their potential biodegradation using naturally occurring fungi and assessing the potential ecotoxicity of released microfibres on local bivalves. All masks collected within 6500 m2 area of Aveiro wetland were 100 % disposable ones (PP-based, confirmed by Fourier transform infrared spectroscopy - FTIR) with an initial abundance of 0.0023 items/m2 in Sept. 2021, which was reduced by ∼40 % in Apr. 2022 and ∼87 % in Sept. 2022, as a reflection of the government policies. Analysis of the carbonyl index (0.03 to 1.79) underlined their state of degradation, primarily due to sun exposure during low tides. In laboratory conditions, 1 mm2 microplastics obtained from new disposable facemasks were prone to biodegradation by Penicillium brevicompactum and Zalerion maritimum inferred from microplastics mass loss (∼22 to -26 % and ∼40 to 50 %, respectively) and FTIR spectra (particularly in the hydroxyl and carbonyl groups). In addition, microfibres released from facemasks induced sublethal effects on the clam, Venerupis corrugata, mostly in their UV-aged form when compared to pristine ones, characterised by a decrease in cellular energy allocation (CEA) and an increase in aerobic energy metabolism (ETS). Concomitantly, clams exposed to 1250 items/L of UV-aged microplastics (similar to field-reported concentrations) expressed greater clearance capacity, indicating a need to compensate for the potential energy unbalance. This study provides the first baseline monitoring of facemasks in wetlands while bringing new evidence on their biodegradation and ecotoxicity, considering environmentally relevant conditions and keystone organisms in such environments. Such studies require scientific attention for rapid regulatory action against this emerging and persistent pollutant, also targeting remediation and mitigation strategies considering these items under pandemic scenarios.

Microplastics altered cellular responses, physiology, behaviour, and regeneration of planarians feeding on contaminated prey.

Freshwater benthic environments are among the major sinks of microplastics (MPs, < 5 mm) sourced on inland anthropogenic activities. The ecotoxicological effects of MPs on benthic macroinvertebrates have been assessed preferably in collectors, shredders, and filter-feeders, but resulting in insufficient knowledge on the potential trophic transfer and its effects on macroinvertebrates with predator behaviour such as planarians. This work evaluated the behavioural (feeding, locomotion), physiological (regeneration) and biochemical responses (aerobic metabolism, energy reserves, oxidative damage) of the planarian Girardia tigrina after consuming contaminated live prey Chironomus riparius larvae previously exposed to microplastics of polyurethane (PU-MPs; 7-9 µm in size; 375 mg PU-MPs/kg). After the feeding period (3 h), planarians consumed 20 % more contaminated prey than uncontaminated prey, probably related to increased curling/uncurling movements of larvae (that might be more appellative to planarians). Histological analysis revealed planarians' limited intake of PU-MPs, mainly detected near the pharynx. The consumption of contaminated prey (and intake of PU-MPs) did not result in oxidative damage but slightly increased the aerobic metabolism and energy reserves which show that the consumption of more prey was sufficient to cope with the potential adverse effects of internalized MPs. Moreover, no effects were observed in the locomotion of planarians in good agreement with the hypothesis of sufficient energy acquired by the exposed planarians. Despite the previous, it seems that the energy acquired was not allocated for planarians' regeneration since a significant delay in the regeneration of the auricles was observed for planarians feeding on contaminated prey. Therefore, further studies should be performed considering the potential long-term effects (i.e., reproduction/fitness) and the effects of MPs that might result from continuous feeding on contaminated prey, representing a more realistic exposure scenario.

Current knowledge on the presence, biodegradation, and toxicity of discarded face masks in the environment.

During the first year of the COVID-19 pandemic, facemasks became mandatory, with a great preference for disposable ones. However, the benefits of face masks for health safety are counteracted by the environmental burden related to their improper disposal. An unprecedented influx of disposable face masks entering the environment has been reported in the last two years of the pandemic, along with their implications in natural environments in terms of their biodegradability, released contaminants and ecotoxicological effects. This critical review addresses several aspects of the current literature regarding the (bio)degradation and (eco)toxicity of face masks related contaminants, identifying uncertainties and research needs that should be addressed in future studies. While it is indisputable that face mask contamination contributes to the already alarming plastic pollution, we are still far from determining its real environmental and ecotoxicological contribution to the issue. The paucity of studies on biodegradation and ecotoxicity of face masks and related contaminants, and the uncertainties and uncontrolled variables involved during experimental procedures, are compromising eventual comparison with conventional plastic debris. Studies on the abundance and composition of face mask-released contaminants (microplastics/fibres/ chemical compounds) under pre- and post-pandemic conditions should, therefore, be encouraged, along with (bio)degradation and ecotoxicity tests considering environmentally relevant settings. To achieve this, methodological strategies should be developed to overcome technical difficulties to quantify and characterise the smallest MPs and fibres, adsorbents, and leachates to increase the environmental relevancy of the experimental conditions.

Mechanisms influencing the impact of microplastics on freshwater benthic invertebrates: Uptake dynamics and adverse effects on Chironomus riparius.

Chironomids inhabit freshwater benthic ecosystems which are prone to microplastic contamination. This work aimed at understanding the factors and mechanisms influencing microplastic uptake and related adverse effects on Chironomus riparius, by exploring an extensive project database, conducting a literature review, and performing an agent-based model to explore trends in data. Results reveal that high concentrations of small microplastics fill the gut of fourth instar C. riparius (99.7 %). Ingested microplastics had an average size of 38-61 µm, presenting slower elimination rates than undigested organic or mineral particles. Ingestion rates of microplastics depend mainly on encounter rates, and therefore on available concentrations, until reaching a plateau corresponding to the maximum gut volume. Short-term toxicity of microplastics seems to result from damage to gut epithelium, with inflammatory reactions, production of reactive oxygen species, and a negative energy balance exacerbated by the lack of food (organic matter). Long-term toxicity is characterized by a reduction in larval body length and increase in mean time to emergence, seemly from increased energy costs rather than a decrease in nutrient absorption. Wild chironomids already present microplastics in their guts and environmental concentrations in hotspots may already exceed no effect concentrations. Therefore, environmental exposure to microplastics may induce adverse effects to wild C. riparius in freshwater benthic ecosystems, which could compromise their ecologic role as deposit-feeders (e.g., reducing their nutrient cycling ability) and key-stone species in aquatic food webs.

Are mulch biofilms used in agriculture an environmentally friendly solution? - An insight into their biodegradability and ecotoxicity using key organisms in soil ecosystems.

Biobased and biodegradable plastic mulch films (aka, mulch biofilm) have emerged as a sustainable alternative to conventional plastic mulch films in agriculture, promising to reduce soil contamination with plastic residues through in situ biodegradation. However, current standards certifying biodegradable plastics cannot predict biodegradability in natural settings. The scarce studies considering the possible biodegradation and ecotoxicity of mulch biofilms in soil systems question the environmental friendliness of these alternative options. This study assessed the biodegradation of a commercially available mulch biofilm by the soil-dwelling fungus Penicillium brevicompactum (in solid culture media and soil for 15 and 28 days, respectively), and the ecotoxicological effects of mulch biofilm microplastics on the earthworm Eisenia andrei (pristine or UV-weathered, at 0.125-0.250-0.500 g/kg). Results (from microplastics' mass loss, microscopy, and FTIR spectroscopy) suggest that the presence of P. brevicompactum promotes mulch biofilm's biodegradation. Exposure to environmental concentrations of pristine biofilm microplastics (and its ingestion) increased earthworms' sensitivity to touch, induced physiological alterations, decreased energy reserves, and decreased their reproduction (>30%). Conversely, exposure to weathered biofilm microplastics slightly increased earthworms' sensitivity, as well as carbohydrate reserves,without affecting their reproduction. The tested mulch biofilm seems to be, at first sight, an environmentally friendly alternative as it presented susceptibility for biodegradation by a widespread fungus, and the absence of ecotoxicological chronic effects on a key macroinvertebrate species in soil ecosystems when considering environmental relevant concentrations and plastics weathered conditions. Notwithstanding, the obtained results highlight the need to revise current standards, as they often neglect the role of, and their chronic effects on, naturally occurring organisms.

Microplastics in freshwater sediments: Effects on benthic invertebrate communities and ecosystem functioning assessed in artificial streams.

The high levels of microplastics (MPs) found in freshwaters, particularly in riverine sediments, may impose a threat to the macroinvertebrate communities with possible consequences at ecosystem-level. The present study aimed to assess the effects of a mixture of different sizes of polyethylene microplastics (PE-MPs) on the composition and structure of macroinvertebrate communities and key-functions, such as primary production and leaf litter decomposition. MPs were mixed in the sediment at three different concentrations (0.1, 1, and 10 g kg-1) already found in freshwater sediments to enhance the relevance of the work. After eight days of exposure to PE-MPs, the observed changes in macroinvertebrate community structure were mostly due to the reduction in the abundance of deposit-feeders and grazers that were reduced by ca 31-50% and 34-39%, in the two highest MPs concentrations respectively, in comparison with the control treatment after 8 days of exposure. MPs internal concentrations were detected only in organisms exposed to plastic particles within artificial streams with chironomids and mayflies presenting higher MPs internal levels (average of 115 particles/individual found in chironomids, 166/individual for Baetis sp. and 415 particles/individual for Ephemerella sp.) suggesting higher ingestion of plastic microparticles. Nevertheless, the alterations in the community structure did not translate into impairments in the functional endpoints analysed, leaf litter decomposition and primary production, that were expected due to possible sub-lethal effects (e.g., feeding inhibition) on detritivores and grazers. This study represents one of the few assessments of MPs effects on freshwater benthic macroinvertebrate community structure and the first that simultaneously considered ecosystem-level functional endpoints. Further research combining different microplastics and longer exposure periods are needed to raise knowledge on potential ecological consequences of MPs to freshwaters.

Can the toxicity of polyethylene microplastics and engineered nanoclays on flatfish (Solea senegalensis) be influenced by the presence of each other?

Microplastics and nanomaterials are applied in a myriad of commercial and industrial applications. When leaked to natural environments, such small particles might threaten living organisms' health, particularly when considering their potential combination that remains poorly investigated. This study investigated the physiological and biochemical effects of polyethylene (PE; 64-125 µm in size, 0.1, 1.0, and 10.0 mg·L-1) single and combined with an engineered nanomaterial applied in antifouling coatings, the copper-aluminium layered double hydroxides (Cu-Al LDH; 0.33, 1.0, and 3.33 mg·L-1) in the flatfish Solea senegalensis larvae (8 dph) after 3 h exposure, in a full factorial design. Particles ingestion, histopathology, and biochemical biomarkers were assessed. Fish larvae presented <1 PE particles in their gut, independently of their concentration in the medium. The histological health index showed minimal pathological alterations at PE combined exposure, with a higher value observed at 1 mg LDH·L-1 × 0.1 mg PE·L-1. Gut deformity and increased antioxidant defences (catalase), neurotransmission (acetylcholinesterase), and aerobic energy production (electron transport system) were observed at PE ≥ 1.0 mg·L-1. No oxidative damage (lipid peroxidation) or alterations in the detoxification capacity (glutathione-S-transferase) was observed on single and combined exposures. PE, combined or not with Cu-Al LDH, does not seem to compromise larvae's homeostasis considering levels reported so far in the marine and aquaculture environments. However, harsh effects are expected with MP contamination rise, as projections suggest.

Implications of COVID-19 pandemic on environmental compartments: Is plastic pollution a major issue?

The COVID-19 anthropause has impacted human activities and behaviour, resulting in substantial environmental and ecological changes. It has assisted in restoring the ecological systems by improving, for instance, air and water quality and decreasing the anthropogenic pressure on wildlife and natural environments. Notwithstanding, such improvements recessed back, even to a greater extent, when considering increased medical waste, hazardous disinfectants and other chemical compounds, and plastic waste disposal or mismanagement. This work critically reviews the short- and long-term implications of measures against COVID-19 spreading, namely on human activities and different environmental compartments. Furthermore, this paper highlights strategies towards environmental restoration, as the recovery of the lost environment during COVID-19 lockdown suggests that the environmental degradation caused by humans can be reversible. Thus, we can no longer delay concerted international actions to address biodiversity, sustainable development, and health emergencies to ensure environmental resilience and equitable recovery.

Risks of Covid-19 face masks to wildlife: Present and future research needs.

The use of disposable face masks became essential to fight against the COVID-19 pandemic, resulting in an unprecedented rise in their production and, unfortunately, to a new form of environmental contamination due to improper disposal. Recent publications reported the abundance of COVID-19-related litter in several environments, wildlife interaction with such items, and the contaminants that can be released from such protective equipment that has the potential to induce ecotoxicological effects. This paper provides a critical review of COVID-19 face mask occurrence in diverse environments and their adverse physiological and ecotoxicological effects on wildlife. It also outlines potential remediation strategies to mitigate the environmental challenge impose by COVID-19-related litter.

Are Biobased Plastics Green Alternatives?-A Critical Review.

Environmental sustainability is driving an intense search for "green materials". Biobased plastics have emerged as a promising alternative. Their building blocks can now be obtained from diverse biomass, by-products, and organic residues due to the advances in biorefineries and bioprocessing technologies, decreasing the demand for fossil fuel resources and carbon footprint. Novel biobased polymers with high added value and improved properties and functionalities have been developed to apply diverse economic sectors. However, the real opportunities and risks of such novel biobased plastic solutions have raised scientific and public awareness. This paper provides a critical review on the recent advances in biobased polymers chemistry and emerging (bio)technologies that underpin their production and discusses the potential for biodegradation, recycling, environmental safety, and toxicity of these biobased solutions.

Suborganismal responses of the aquatic midge Chironomus riparius to polyethylene microplastics.

Freshwater riverbeds are a major repository of microplastics (MPs) from inland activities. Benthic macroinvertebrates that live in close contact with sediments seem to ingest a considerable amount of such plastic particles. The effects of MPs on life-history traits are relatively well-known, but the suborganismal mechanisms underlying such effects remain unclear. This study addressed the potential effects of low-density polyethylene (LDPE) MPs on Chironomus riparius larvae at cellular and molecular levels. Fourth instar C. riparius larvae were exposed to 0.025 and 2.5 g/kg LDPE of dry sediment (sizes: <32 and 32-45 µm; with irregular shape) under laboratory conditions for 48 h. These short-term exposures to environmental concentrations of LDPE MPs induced changes in the energy reserves (mostly by decreasing carbohydrates and increasing lipids), increased antioxidant and detoxification responses (tGSH, CAT, and GST), and induced increases in the activity of AChE (related to neurotransmission). In addition, at the gene level, exposure to MPs modified mRNA levels of InR, Dis, EcR, Dronc, Met (endocrine system), Def (immune system), PARP, ATM, NLK, and Decay (DNA repair), generating important alterations in the C. riparius development and response to unfavorable situations. This study provides new evidence of the effects of LDPE MPs at the suborganismal level, filling the gap in knowledge regarding the mechanisms underlying the toxicity of MPs and spotlighting gene expression analyses as early indicators of MP toxicity in C. riparius which were confirmed by Integrated biomarker response analyses highlighting the gene expression as sensible and useful endpoints for LPDE pollution in freshwaters. These results, coupled with previous investigations on responses at the organismal level, emphasizes the potential adverse effects of LDPE MPs on C. riparius, which may compromise freshwater benthic communities, considering its ecological role within these habitats.

Immune response triggered by the ingestion of polyethylene microplastics in the dipteran larvae Chironomus riparius.

The activation of insects' immune system due to the ingestion of microplastics (MPs) has only been evidenced by the upregulation of specific genes. The activation of phenoloxidase (PO) system is one of the primary responses involved in insects' innate immunity when facing parasites and pathogens, and ingestion of MPs can trigger a similar process. This study aimed at addressing the activities of basal PO and total PO (PO+ prophenoloxidase - proPO), in Chironomus riparius larvae (a model species in ecotoxicology) exposed to sediments spiked with polyethylene microplastics (PE-MPs; size-range 32-63 µm; concentrations: 1.25; 5; to 20 g kg-1) for 48 h. The ingestion of PE-MPs by larvae triggered a significant increase of basal PO activity at 5 and 20 g PE-MPs kg-1, by 26% and 29%, respectively, whereas total PO increased significantly in the latter (+48%), suggesting de novo synthesis of proPO by organisms. Considering the particle size, the immune response's activation is probably linked to damage in the epithelial cells of the gut lumen. This research work provides the first evidence on the activation of the insect's innate immune system after ingestion of MPs and underlines the PO activity as a good indicator of the immune response induced by MPs' ingestion.

An urgent call to think globally and act locally on landfill disposable plastics under and after covid-19 pandemic: Pollution prevention and technological (Bio) remediation solutions.

Landfilling and illegal waste disposal have risen to deal with the COVID-19 potentially infectious waste, particularly in developing countries, which aggravates plastic pollution and inherent environmental threats to human and animal health. It is estimated that 3.5 million metric tonnes of masks (equivalent to 601 TIR containers) have been landfilled worldwide in the first year, with the potential to increase global plastic municipal solid waste by 3.5%, alter biogas composition, and release 2.3 × 1021 microplastics to leachates or adjacent environments, in the coming years. This paper reviews the challenges raised in the pandemic scenario on landfills and discusses the potential environmental and health implications that might drive us apart from the 2030 U.N. sustainable goals. Also, it highlights some innovative technologies to improve waste management (from collection to disposal, waste reduction, sterilization) and mitigates plastic leakage (emission control approaches, application of biotechnological and monitoring/computational tools) that can pave the way to environmental recovery. COVID-19 will eventually subside, but if no action is taken in the short-term towards effective plastic policies, replacement of plastics for sustainable alternatives (e.g., biobased plastics), improvement of waste management streams (prioritising flexible and decentralized approaches), and a greater awareness and responsibility of the general public, stakeholders, industries; we will soon reach a tipping-point in natural environments worldwide.

Increased plastic pollution due to COVID-19 pandemic: Challenges and recommendations.

Plastics have become a severe transboundary threat to natural ecosystems and human health, with studies predicting a twofold increase in the number of plastic debris (including micro and nano-sized plastics) by 2030. However, such predictions will likely be aggravated by the excessive use and consumption of single-use plastics (including personal protective equipment such as masks and gloves) due to COVID-19 pandemic. This review aimed to provide a comprehensive overview on the effects of COVID-19 on macroplastic pollution and its potential implications on the environment and human health considering short- and long-term scenarios; addressing the main challenges and discussing potential strategies to overcome them. It emphasises that future measures, involved in an emergent health crisis or not, should reflect a balance between public health and environmental safety as they are both undoubtedly connected. Although the use and consumption of plastics significantly improved our quality of life, it is crucial to shift towards sustainable alternatives, such as bio-based plastics. Plastics should remain in the top of the political agenda in Europe and across the world, not only to minimise plastic leakage and pollution, but to promote sustainable growth and to stimulate both green and blue- economies. Discussions on this topic, particularly considering the excessive use of plastic, should start soon with the involvement of the scientific community, plastic producers and politicians in order to be prepared for the near future.

Oxidative damage and decreased aerobic energy production due to ingestion of polyethylene microplastics by Chironomus riparius (Diptera) larvae.

Riverine sediments are major sinks of microplastics from inland anthropogenic activities, imposing a threat to freshwater benthic invertebrates. This study investigated the ingestion of three size-classes (SC) of irregularly shaped polyethylene microplastics (PE-MPs; SC I: 32-63 µm; II: 63-250 µm; III: 125-500 µm) after 48 h by dipteran larvae (detritivore/collector) Chironomus riparius, and the consequent effects on neurotransmission, energy allocation and oxidative stress. The tested PE-MPs concentrations (1.25; 5; 20 g kg-1) were within the range of concentrations reported in riverbanks from highly urbanised areas (1 - 9 g kg-1), except for 20 g kg-1 representing the worst-case scenario. After exposure to SC I, larvae presented high amounts (up to ∼2400 particles/organism) of PE-MPs in their guts, with an average size-range of 30-60 µm. In the SC II and III, larvae presented PE-MPs of higher diameter (up to 125 µm) and a visible gut obstruction. The high number of particles in the larval gut (SC I) and/or difficulties for their egestion (SC I, II and III) induced oxidative damage and reduced aerobic energy production. In addition, larvae exposed to SC II and III revealed depletion in their total lipid reserves as a consequence of lacking nutrients, and the ones exposed to SC III presented a decrease in their detoxification capacity. These results highlight that freshwater detritivores with low selective feeding behaviour (e.g., chironomids) are more prone to ingest microplastics, with potentially adverse effects on cellular metabolism, redox status and antioxidant-detoxification defences. These harmful effects at lower levels of the biological organisation may ultimately affect organisms' physiology and fitness.

Lumbriculus variegatus (oligochaeta) exposed to polyethylene microplastics: biochemical, physiological and reproductive responses.

Freshwater sediments are a repository of microplastics (MPs) resulting from inland anthropogenic activities. Benthic invertebrates, particularly endobenthic sediment-ingesting species such as the annelid Lumbriculus variegatus (blackworm), are commonly found in contaminated sediments where they likely find and ingest MPs. In the present study, L. variegatus was exposed to concentrations between 0.51 and 20 g kg-1 dry sediment of four size-classes of irregularly-shaped polyethylene MPs (PE-MPs; size-class A: 32-63, B: 63-125, C: 125-250 and D: 250-500 µm) for 48 h to assess their sub-cellular responses to particles ingested, and for 28 days to determine chronic effects on worm's reproduction and biomass. After the short-term exposure (48 h), number of PE-MPs in blackworms' gut were related to MPs concentration in the sediment. In general, PE-MPs ingestion by blackworms induced depletion of their energy reserves (e.g., sugars in all size classes and lipids in the size-classes of PE-MPs > 125 µm), concomitant with the activation of antioxidant and detoxification mechanisms (increased level of total glutathione in all size-classes, and increased glutathione-S-transferase activity in PE-MPs > 250 µm), preventing lipid peroxidation. In addition, it was observed a reduction of aerobic energy production (decreased activity of the electron transport system) and a slight increase in neurotransmission (cholinesterase activity). After a long-term exposure (28 d), the presence and ingestion of PE-MPs did not affect reproduction and biomass of L. variegatus. The activation and efficiency of the antioxidant and detoxification mechanisms allied with the anatomy and physiology of L. variegatus, its feeding strategy and potentially dynamic ingestion/egestion capacity seem to be key features preventing MP deleterious effects under short- and chronic-exposures. Considering the MPs levels reported for freshwater sediments, and despite evidence of MPs ingestion and some sub-organismal effects, our results suggest no adverse impacts of PE-MPs contamination on L. variegatus populations fitness. This study applies an integrative approach in which data concerning the ingestion of different sized MPs and subsequent sub-cellular and apical responses are delivered, raising knowledge on endobenthic invertebrates' strategies to potentially overcome MP toxicity in field contaminated sites.

Rethinking and optimising plastic waste management under COVID-19 pandemic: Policy solutions based on redesign and reduction of single-use plastics and personal protective equipment.

Plastics have been on top of the political agenda in Europe and across the world to reduce plastic leakage and pollution. However, the COVID-19 pandemic has severely disrupted plastic reduction policies at the regional and national levels and induced significant changes in plastic waste management with potential for negative impacts in the environment and human health. This paper provides an overview of plastic policies and discusses the readjustments of these policies during the COVID-19 pandemic along with their potential environmental implications. The sudden increase in plastic waste and composition due to the COVID-19 pandemic underlines the crucial need to reinforce plastic reduction policies (and to implement them into action without delays), to scale up in innovation for sustainable and green plastics solutions, and to develop dynamic and responsive waste management systems immediately. Policy recommendations and future research directions are discussed.

Effect of freeze-thaw cycles and 4-nonylphenol on cellular energy allocation in the freeze-tolerant enchytraeid Enchytraeus albidus.

Due to climate change and intense anthropogenic activity, organisms from cold regions are often exposed to combined effects of temperature fluctuations and contaminants. In this investigation, we assessed the lipid, protein, and carbohydrate energy budgets; the energy available (Ea); consumed (Ec); and cellular energy allocation (CEA) of the freeze-tolerant Enchytraeus albidus, when exposed to sublethal concentrations of 4-nonylphenol (a lipophilic contaminant) for 7 days, followed by exposure to different temperature regimes (continuous 2 °C, continuous -4 °C, and daily freeze-thaw cycles (FTC) (2 to -4 °C) for additional 10 days. Results showed that a pre-exposure to 4-nonylphenol (4-NP) induced important changes in the worms' energy budgets and CEA and increased mortality with most severe effects observed for the FTC events. For FTC, lipids were the most accumulated energy source, whereas during freezing (-4 °C), proteins were the most used. FTC caused the highest Ec, indicating the higher energy requirements for organisms when shifting between freezing and thawing events. This is also in line with the higher mortality observed in FTC compared to continuous -4 °C or 2 °C. Worms exposed to continuous freezing presented relatively stable and positive levels of Ea and low levels of Ec, possibly related with the decrease in metabolism.