Fat, oil, and grease (FOG) deposits in the urban sewer system affect the optimal performance of the wastewater collection system and treatment plant, while increasing sewer maintenance costs. The interaction of microplastics (MPs) and FOG in the sewer system could drastically change the quality of deposited materials and the fate of MPs in raw sewage. In this study, the batch experiment was conducted to explain the mechanism of FOG formation by synthetic wastewater and its interaction with polystyrene (PS) and polymethyl methacrylate (PMMA) particles. We found three different segments for FOG deposits in the batch, namely static and buoyant micro-deposits, gel-like, and solid deposits. The average size of micro-deposits adhered to the solid-liquid interface of the container was 25 µm and buoyant deposits with a small size of 3 µm adsorbed onto the MPs at the liquid-air interface. The gel-like formation promoted a virtual liquid phase where PS and PMMA were confined and segregated. Some PMMA particles were entrapped in the self-assembly of biopolymers that formed between the PS particles. This research indicates that FOG deposition in the urban sewers contains high numbers of MPs, such that any plan involving a reuse or disposal program requires a risk assessment.

Infectious diseases of humans and wildlife are increasing globally but the contribution of novel artificial anthropogenic entities such as nano-sized plastics to disease dynamics remains unknown. Despite mounting evidence for the adverse effects of nanoplastics (NPs) on single organisms, it is unclear whether and how they affect the interaction between species and thereby lead to ecological harm. In order to incorporate the impact of NP pollution into host-parasite-environment interactions captured in the “disease triangle”, we evaluated disease outcomes in the presence of polystyrene NP using an ecologically-relevant host-parasite system consisting of a common planktonic cyanobacterium and its fungal parasite. NP at high concentrations formed hetero-aggregates with phytoplankton and inhibited their growth. This coincided with a significant reduction in infection prevalence, highlighting the close interdependency of host and parasite fitness. Lower intensity of infection in the presence of NP indicates that reduced disease transmission results from the parasite’s diminished ability to establish new infections as NP formed aggregates around phytoplankton cells. We propose that NP aggregation on the host’s surface acts as a physical barrier to infection and, by reducing host light harvesting, may also hamper parasite chemotaxis. These results demonstrate that the consequences of NP pollution go well beyond toxic effects at the individual level and modulate the intensity of species interactions, thereby potentially eliciting diverse cascading effects on ecosystem functioning.

Microplastics pollution is a serious ecological threat, severely affecting environments and human health. Tackling microplastics pollution requires an effective methodology to detect minute polymer particles in environmental samples and organisms. Here were report a novel methodology to visualise and identify nanoscale (down to 100 nm) and microscale synthetic commercially-available uniform spherical polymer particles using dark-field hyperspectral microscopy in visible-near infrared (400–1000 nm) wavelength range. Polystyrene particles with diameters between 100 nm–1 μm, polymethacrylate 1 μm and melamine formaldehyde 2 μm microspheres suspended in pure water samples were effectively imaged and chemically identified based on spectral signatures and image-assisted analysis. We succeeded in visualisation and spectral identification of pure and mixed nano- and microplastics in vivo employing optically-transparent Caenorhabditis elegans nematodes as a model to demonstrate the ingestion and tissue distribution of microplastics. As we demonstrate here, dark-field hyperspectral microscopy is capable for differentiating between chemically-different microplastics confined within live invertebrate intestines. Moreover, this optical technology allows for quantitative identification of microplastics ingested by nematodes. We believe that this label-free non-destructive methodology will find numerous applications in environmental nano- and microplastics detection and quantification, investigation of their biodistribution in tissues and organs and nanotoxicology.

The presence of polystyrene (PS) waste increases constantly. Styrofoam, the most popular form of PS, is one of the major plastic pollutants in the environment. An efficient and environmentally friendly method of PS recycling is still needed. The biodegradation of PS by insects has been presented by researchers as a promising alternative to chemical, mechanical and thermal methods. The main aim of this study was to assess the survival, growth, and development of yellow mealworms (the larvae of Tenebrio molitor) fed with PS to determine if the insects are able to use PS as a source of mass and energy. The Dynamic Energy Budget (DEB) model was used to analyze the effects of food type on the growth trajectory and metabolism of tested organisms. We investigated five possible modes of influence of PS diet on DEB model parameters including a decrease of food availability, an increase in somatic maintenance power, an increase in costs for structure, allocation of energy, and a decrease in somatic maintenance power. Our results show that changes in the development of larvae fed with PS are mainly caused by a decrease in reserves density and reaction of the organism to the insufficient food supply. The inability or difficulty in completing the life cycle of T. molitor larvae fed with PS raises doubts about the use of mealworms as an effective technology for utilizing polystyrene.

Microplastics have attracted much attention in recent years as they can interact with pollutants in water environment. However, nanoplastics (NPs) with or without the surface functionalization modification have not been thoroughly explored. Here, the sorption behaviors of two fluoroquinolones (FQs), including norfloxacin (NOR) and levofloxacin (LEV) on polystyrene NPs (nano-PS) and carboxyl-functionalized polystyrene NPs (nano-PS-COOH) were investigated. The results showed that sorption isotherms were nonlinear and well fitted by Langmuir model. The sorption capacities of NOR and LEV on nano-PS-COOH were higher than those on nano-PS, and their physical interactions, including polar interaction, electrostatic interaction and hydrogen bonding may be the dominant mechanisms. Moreover, the increase of pH firstly increased the sorption of two FQs on NPs and then decreased because NOR and LEV had a reverse charge at different pH values. Salinity and dissolved organic matter both inhibited the sorption process. These findings show that NPs with or without the surface functionalization modification have different sorption behaviors for environmental pollutants, which deserve our further concern.

The presence of microplastics in aquatic ecosystems has recently received increased attention. Small plastic particles may resemble natural food items of larval fish and other aquatic organisms, and create strong selective pressures on the feeding traits in exposed populations. Here, we examined if larval ingestion of 90 μm polystyrene microspheres, in the presence of zooplankton (Artemia nauplii, mean length = 433 μm), shows adaptive variation in the European whitefish (Coregonus lavaretus). A full-factorial experimental breeding design allowed us to estimate the relative contributions of male (sire) and female (dam) parents and full-sib family variance in early feeding traits, and also genetic (co)variation between these traits. We also monitored the magnitude of intake and elimination of microplastics from the alimentary tracts of the larvae. In general, larval whitefish ingested small numbers of microplastics (mean = 1.8, range = 0–26 particles per larva), but ingestion was marginally affected by the dam, and more strongly by the full-sib family variation. Microsphere ingestion showed no statistically significant additive genetic variation, and thus, no heritability. Moreover, microsphere ingestion rate covaried positively with the ingestion of Artemia, further suggesting that larvae cannot adaptively avoid microsphere ingestion. Together with the detected strong genetic correlation between food intake and microplastic intake, the results suggest that larval fish do not readily possess additive genetic variation that would help them to adapt to the increasing pollution by microplastics. The conflict between feeding on natural food and avoiding microplastics deserves further attention.

Microplastics are hardly biodegradable and thus accumulate rather than decompose in the environment. Due to sedimentation processes, meiobenthic fauna is exposed to microplastics. Within the meiofauna, nematodes are a very abundant taxon and occupy an important position in benthic food webs by connecting lower and higher trophic levels. However, the key determinants of the uptake of microplastics by freshwater nematodes are still unknown. To investigate the bioaccessibility of microplastics for nematodes, we performed single- and multi-species ingestion experiments in which the ability of seven nematode species (six bacterial and one fungal feeder), diverse in their buccal cavity morphology (1.3–10.5 μm), to ingest fluorescence-labelled polystyrene (PS) beads along with their natural diet was examined. Applied beads sizes (0.5, 1.0, 3.0 and 6.0 μm), exposure time (4, 24 and 72 h) and concentration (3 × 10⁶ PS beads ml⁻¹ and 10⁷ PS beads ml⁻¹) were varied. Ingested beads were localized and quantified via fluorescence microscopy in the nematodes. In contrast to fungal-feeding nematode species with a stylet, bacterial-feeding species ingested 0.5- and 1.0-μm PS beads with up to 249 and 255 beads after 24 h, respectively. Microplastics ≥0.5 μm could only be ingested and transported into the gastrointestinal tract, if the buccal cavities were considerably (>1.3 times) larger than the beads. At concentrations of 10⁷ PS beads ml⁻¹ ingestion rates were influenced by exposure time and PS bead concentration. In case of a known microplastic size distribution in the environment, predictions on the potential ingestion for nematode communities can be made based on the feeding type composition and the size of their buccal cavities.

Plastic debris has become an environmental problem during recent years. Among the plastic debris, microplastics (<5 mm; MPLs) imply an extra problem due to their capacity to enter into the fauna through ingestion. In this work, we study the capacity of three MPLs, that include high-density polyethylene (HDPE), polystyrene (PS) and polystyrene carboxylate (PS-COOH), to sorb 18 perfluoroalkyl substances (PFASs; including carboxylic acids, sulphonates and one sulphonamide) from the surrounding waters (freshwater and seawater).Conclusions drawn from the results are that perfluoro sulphonates and sulphonamides have more tendency to be sorbed onto MPLs. In addition, PS and PS-COOH have more affinity for PFASs than HDPE. Finally, the increment of conductivity and pH of the water decreases the exposure time that is necessary to reach equilibrium. However, the presence of salts decreases the tendency of PFASs to be sorbed onto plastic surfaces. These results highlight the problem associated with the presence of MPLs in inland and marine waters since toxic compounds can be sorbed onto surrounding plastics that could be ingested by aquatic fauna.

The objective of this study is to investigate the qualitative contribution of internal and external factors of the area contaminated by polystyrene (PS) in coastal marine environments. This study is based on the extensive results of monitoring the styrene oligomers (SOs) present in sand and seawater samples along various coastlines of the Pacific Ocean. Here, anthropogenic SOs is derived from PS during manufacture and use, and can provide clues about the origin of SOs by PS pollution. The monitoring results showed that, if the concentration of SOs in water is higher than those concentrations in beach sand, this area could be affected by PS plastic caused by an external factor. On the other hand, if the concentration of SOs is higher in the beach sand, the region can be mainly influenced by PS plastic derived from its own area. Unlike the case of an external factor, in this case (internal influence), it is possible to take policy measures of the area itself for the PS plastic problem. Thus, this study is motivated by the need of policy measures to establish a specific alternative to the problems of PS plastic pollution in ocean environments.

Plastic is ubiquitous in global oceans and constitutes a newly available habitat for surface-associated bacterial assemblages. Microplastics (plastic particles <5 mm) are especially susceptible to ingestion by marine organisms, as the size of these particles makes them available also to lower trophic levels. Because many marine invertebrates harbour potential pathogens in their guts, we investigated whether bacterial assemblages on polystyrene are selectively modified during their passage through the gut of the lugworm Arenicola marina and are subsequently able to develop pathogenic biofilms. We also examined whether polystyrene acts as a vector for gut biofilm assemblages after subsequent incubation of the egested particles in seawater. Our results showed that after passage through the digestive tract of A. marina, the bacterial assemblages on polystyrene particles and reference glass beads became more similar, harbouring common sediment bacteria. By contrast, only in the presence of polystyrene the potential symbiont Amphritea atlantica was enriched in the investigated biofilms, faeces, and water. Thus, especially in areas of high polystyrene contamination, this polymer may impact the bacterial composition of different habitats, with as yet unknown consequences for the respective ecosystems.