Plastic Particle Size Research Articles

Nanoplastic Size and Surface Chemistry Dictate Decoration by Human Saliva Proteins.

Environmental pollution with plastic polymers has become a global problem, leaving no continent and habitat unaffected. Plastic waste is broken down into smaller parts by environmental factors, which generate micro- and nanoplastic particles (MNPPs), ultimately ending up in the human food chain. Before entering the human body, MNPPs make their first contact with saliva in the human mouth. However, it is unknown what proteins attach to plastic particles and whether such protein corona formation is affected by the particle's biophysical properties. To this end, we employed polystyrene MNPPs of two different sizes and three different charges and incubated them individually with saliva donated by healthy human volunteers. Particle zeta potential and size analyses were performed using dynamic light scattering complemented by nanoliquid chromatography high-resolution mass spectrometry (nLC/HRMS) to qualitatively and quantitatively reveal the protein soft and hard corona for each particle type. Notably, protein profiles and relative quantities were dictated by plastic particle size and charge, which in turn affected their hydrodynamic size, polydispersity, and zeta potential. Strikingly, we provide evidence of the latter to be dynamic processes depending on exposure times. Smaller particles seemed to be more reactive with the surrounding proteins, and cultures of the particles with five different cell lines (HeLa, HEK293, A549, HepG2, and HaCaT) indicated protein corona effects on cellular metabolic activity and genotoxicity. In summary, our data suggest nanoplastic size and surface chemistry dictate the decoration by human saliva proteins, with important implications for MNPP uptake in humans.

Down to size: Exploring the influence of plastic particle Dimensions on physiological and nervous responses in early-stage zebrafish

The chorion is the first protective barrier set to prevent numerous pollutants from damaging the developing embryo. However, depending on their size, some nanoplastics (NPs) can pass through this barrier and reach the embryo, while all microplastics (MPs) remain on the outside. This study brings a straight approach to compare MPs and NPs, and assess their direct and indirect effects on zebrafish embryos and larvae. Zebrafish eggs were exposed before 2 h post fertilization (hpf) to polystyrene MPs (5 μm) and NPs (250 nm) at a concentration of 1000 μg/L until 96 hpf. Physiotoxicity and neurotoxicity were assessed prior and post-hatching through several biomarkers. Response to hypoxia (upregulation of hif-1aa and hif-1ab) were found in embryos exposed to MPs, and partly found in those exposed to NPs. Embryos exposed to NPs showed significant tachycardia, reduced O2 consumption and increased apoptosis in the eyes, whereas MPs affected the expressions of all genes related to the neurodevelopment of embryos (elavl3, pax2a, pax6a, act1b). Post-hatching, physiological responses were muted. MPs and NPs exposures ended by evaluating larval behaviours during dark-and-light cycles. Both sizes of plastic particles negatively affected the visual motor response (VMR) and vibrational startle response (VSR). Thigmotaxis levels were significantly increased by NPs whereas MPs showed anxiolytic properties. This study shows that both MPs and NPs affect the physiology and neurodevelopment of zebrafish at different levels, before and after hatching.

Important Factors Affecting Induction of Cell Death, Oxidative Stress and DNA Damage by Nano- and Microplastic Particles In Vitro.

We have described the influence of selected factors that increase the toxicity of nanoplastics (NPs) and microplastics (MPs) with regard to cell viability, various types of cell death, reactive oxygen species (ROS) induction, and genotoxicity. These factors include plastic particle size (NPs/MPs), zeta potential, exposure time, concentration, functionalization, and the influence of environmental factors and cell type. Studies have unequivocally shown that smaller plastic particles are more cytotoxic, penetrate cells more easily, increase ROS formation, and induce oxidative damage to proteins, lipids, and DNA. The toxic effects also increase with concentration and incubation time. NPs with positive zeta potential are also more toxic than those with a negative zeta potential because the cells are negatively charged, inducing stronger interactions. The deleterious effects of NPs and MPs are increased by functionalization with anionic or carboxyl groups, due to greater interaction with cell membrane components. Cationic NPs/MPs are particularly toxic due to their greater cellular uptake and/or their effects on cells and lysosomal membranes. The effects of polystyrene (PS) vary from one cell type to another, and normal cells are more sensitive to NPs than cancerous ones. The toxicity of NPs/MPs can be enhanced by environmental factors, including UV radiation, as they cause the particles to shrink and change their shape, which is a particularly important consideration when working with environmentally-changed NPs/MPs. In summary, the cytotoxicity, oxidative properties, and genotoxicity of plastic particles depends on their concentration, duration of action, and cell type. Also, NPs/MPs with a smaller diameter and positive zeta potential, and those exposed to UV and functionalized with amino groups, demonstrate higher toxicity than larger, non-functionalized and environmentally-unchanged particles with a negative zeta potential.

Nanoplastic Exposure Mediates Neurodevelopmental Toxicity by Activating the Oxidative Stress Response in Zebrafish (Danio rerio).

The global accumulation and adverse effects of nanoplastics (NPs) are a growing concern for the environment and human health. In recent years, more and more studies have begun to focus on the toxicity of plastic particles for early animal development. Different particle sizes of plastic particles have different toxicities to biological development. Nevertheless, the potential toxicological effects of 20 nm NPs, especially on neurodevelopment, have not been well investigated. In this paper, we used fluorescence microscopy to determine neurotoxicity in zebrafish at different concentrations of NPs. Moreover, the behavioral analysis demonstrated that NPs induced abnormal behavior of zebrafish. The results revealed developmental defects in zebrafish embryos after exposure to different concentrations (0, 0.3, 3, and 9 mg/L) of NPs. The morphological deformities, including abnormal body length and the rates of heart, survival, and hatching, were induced after NP exposure in zebrafish embryos. In addition, the development of primary motor neurons was observed the inhibitory effects of NPs on the length, occurrence, and development of primary motor neurons in Tg(hb9:GFP). Quantitative polymerase chain reaction analysis suggested that exposure to NPs significantly affects the expression of the genes involved in the occurrence and differentiation of primary motor neurons in zebrafish. Furthermore, the indicators associated with oxidative stress and apoptosis were found to be modified in zebrafish embryos at 24 and 48 h following exposure to NPs. Our findings demonstrated that NPs could cause toxicity in primary motor neurons by activating the oxidative stress response and inducing apoptosis, consequently impairing motor performance.

Sunlight-Driven Photochemical Removal of Polypropylene Microplastics from Surface Waters Follows Linear Kinetics and Does Not Result in Fragmentation.

Floating microplastics are susceptible to sunlight-driven photodegradation, which can convert plastic carbon to dissolved organic carbon (DOC) and can facilitate microplastic fragmentation by mechanical forces. To understand the photochemical fate of sub-millimeter buoyant plastics, ∼0.6 mm polypropylene microplastics were photodegraded while tracking plastic mass, carbon, and particle size distributions. Plastic mass loss and carbon loss followed linear kinetics. At most time points DOC accumulation accounted for under 50% of the total plastic carbon lost. DOC accumulation followed sigmoidal kinetics, not the exponential kinetics previously reported for shorter irradiations. Thus, we suggest that estimates of plastic lifespan based on exponential DOC accumulation are inaccurate. Instead, linear plastic-C mass and plastic mass loss kinetics should be used, and these methods result in longer estimates of photochemical lifetimes for plastics in surface waters. Scanning electron microscopy revealed that photoirradiation produced two distinct patterns of cracking on the particles. However, size distribution analyses indicated that fragmentation was minimal. Instead, the initial population of microplastics shrank in size during irradiations, indicating photoirradiation in tranquil waters (i.e., without mechanical forcing) dissolved sub-millimeter plastics without fragmentation.

Bidimensional Dynamic Magnetic Levitation: Sequential Separation of Microplastics by Density and Size.

There is a current gap in sample preparation techniques integrating the separation of microplastics according to their different material types and particle sizes. We describe herein the Bidimensional Dynamic Magnetic Levitation (2D-MagLev) technique, enabling the resolution of mixtures of microplastics sorting them by plastic type and particle size. Separations are carried out in a bespoke flow cell sandwiched between two ring magnets and connected to programmable pumps for flow control. The first separation dimension is based on sequential increases in the concentration of a paramagnetic salt (MnCl2), enabling magnetic levitation of microplastics with determined densities. The second dimension is based on increasing flow rate gradients and maintaining constant MnCl2 concentrations. This fractionates the magnetically levitating microplastics according to their different particle sizes. Microplastics are therefore collected by their increasing density, and the particles corresponding to each density are fractionated from smaller to larger size. Using polyethylene microspheres with defined density (1.03-1.13 g cm-3) and size (98-390 μm) as microplastic mimicking materials, we investigated their optimum threshold velocities for their size fractionation, potential effects of medium viscosity and sample loading, and types of flow rate gradients (linear, step). Performing a separation using a combination of step gradients in both MnCl2 concentration and flow rate, mixtures comprising microplastics of two different densities and three different particle sizes were separated. 2D-MagLev is simple, fast, versatile, and robust, opening new avenues to facilitate the study of the environmental presence and impact of microplastics.

Effects of micro‐ and nanoplastics on the physiology and metabolism of Portunus trituberculatus

AbstractPortunus trituberculatus is important in coastal benthic communities and a favorite seafood for coastal residents. However, microplastics have been detected in different tissues of P. trituberculatus, but the toxicological effects of micro‐ and nanoplastics (MNPs) on the different tissues of P. trituberculatus have not been reported. We found that the lethal effect of MNPs on P. trituberculatus is not obvious, but they can stimulate the body's stress response. The responses of P. trituberculatus tissues to MNPs are different, which may be due to differences in enzyme reactions between tissues and organs. Compared with microplastics (MPs), nanoplastics (NPs) have a more significant physiological and metabolic stress effect on P. trituberculatus because of their smaller particle size. In summary, plastic particles have physiological stress effects on the physiological metabolism of P. trituberculatus, which may be closely related to the plastic's particle size and concentration.

Implications of exposure route for the bioaccumulation potential of nanopolystyrene particles

Microplastics and nanoplastics are found in marine biota across a wide range of trophic levels and environments. While a large portion of the information about plastic exposure comes from gastrointestinal (GI) data, the relevance of particle accumulation from an oral exposure compared with other types of exposure (e.g. dermal, respiratory) is unknown. To address this gap in knowledge, larval zebrafish (7 days post fertilization) were exposed to two different sizes of nanoplastics through either oral gavage or a waterborne exposure. Larvae were tracked for 48 h post exposure (hpe) to assess the migration and elimination of plastics. Larvae eliminated orally gavaged nanoplastics within 48 hpe. Oral gavage showed limited particle movement from the GI tract into other tissues. In contrast, waterborne nanoplastic-exposed larvae displayed notable fluorescence in tissues outside of the GI tract. The 50 nm waterborne-exposed larvae retained the particles past 48 hpe, and showed accumulation with neuromasts. For both sizes of plastic particles, the nanoplastics were eliminated from non-GI tract tissues by 24 hpe. Our results suggest that waterborne exposure leads to greater accumulation of plastic in comparison to oral exposure, suggesting that plastic accumulation in certain tissues is greater via routes of exposure other than oral consumption.

Soil contamination by plastic particles in the floodplain of the small Danilikha River in an urbanized area

The aim of the study. To assess the content, morphology and surface degradation degree of plastic particles in the Danilikha river floodplain soils in an urbanized area. Location and time of the study. The study was conducted in a recreational area in the projected “Kamensky Square”, located on the left bank of the low floodplain of the small Danilikha River (a left-bank tributary of the Kama River) in the city of Perm. Urban-alluvial gray-humus gley soils were identified in the area. Soil samples were taken from surface horizons in July 2023. Methods. To extract plastic particles from soil we used visual selection, sieving, and flotation in a saturated NaCl solution. The shape and type of plastic particles were determined visually by external features. Natural organic matter was removed with Fenton's reagent. Surface morphology of the of plastic particles and their number were determined using a stereomicroscope. Information-logical analysis was used to determine the relationship between the shape of plastic particles and their sizes. Results. In the combined soil sample from the surface horizons, the number of plastic particles reached 177 pieces/kg (excluding fibers). The mass of plastic particles, including fibers, was 0.7 g/kg. Films prevailed quantitatively among the forms of plastic particles (62%), whereas foam and foam balls made up 34% and 4%, respectively. By mass, particles predominated in the following sequence: foam balls ˃ film ˃ fiber ˃ foam. The size range was dominated by large plastic particles from 1.1 to 15 mm. Specific sizes of plastic particles for different shapes were established. Conclusions. For the first time, the content of plastic particles in the surface soil horizons of the Danilikha river floodplain in an urbanized territory was studied using the case of a recreational zone in the projected Kamensky Square. Plastic particles had different sizes and shapes, which indicated a variety of contamination sources. Contamination of the studied soils with plastic particles can be regarded as moderate. The surface degradation degree of plastic particles indicated their active weathering, which occurs in soil under neutral reaction. The surface degradation of the plastic particles was also actively influenced by external factors that act before plastics enter alluvial soils. To detect soil contamination with plastic particles, we recommend Perm municipal authorities to organize monitoring of plastics content in areas with high anthropogenic pressure.

Mineralisation and priming effects of a biodegradable plastic mulch film in soils: Influence of soil type, temperature and plastic particle size

There is increasing use of biodegradable mulch films (BDMs) as an environmentally sustainable alternative to traditional mulch films in agriculture. However, their degradation fate and priming effect (PE) on native soil organic matter (SOM), including in the form of microplastics (MPs) after disintegration, are not well known. In this study, we investigated mineralisation of a BDM (0–2000 μm MPs) and its PEs in three soils, i.e., a Ferralsol, a Vertisol and a Solonetz. The MPs were incubated at a concentration of 0.8% (w/w) separately in the three soils at three temperatures i.e., 20, 30 and 40 °C for 150 days. We also evaluated the effect of BDM MP particle size on its mineralisation and PEs in two soils (a Ferralsol and a Vertisol). Six size fractions (i.e., <100, 100–250, 250–500, 500–1000, 1000–2000, 2000–4750 μm) were incubated in the soils at 30 °C for 150 days. A δ13C technique was employed to determine the proportion of C mineralised from MPs and SOM owing to their distinct δ13C values. Temperature, soil type, particle size and their interactions were all key factors in the mineralisation of MPs and PEs. The mineralisation of MPs increased with the increasing temperatures from 20 to 40 °C in the three soils over time with few exceptions. At 20 and 40 °C, the Ferralsol with greater carbon and clay content showed greater MP mineralisation than the Vertisol and Solonetz. Opposite trends were observed for the MP mineralisation and PEs in the Vertisol at 20 and 30 °C and in the Ferralsol at 20 °C. However, at 40 °C, both MP mineralisation and PEs exhibited similar trends in the three soils suggesting that a ‘co-metabolism’ may be dominant at high temperatures. Furthermore, we observed that smaller MPs tended to induce greater mineralisation, whereas the larger MPs caused greater PEs than small particles.

Size-dependent long-term weathering converting floating polypropylene macro- and microplastics into nanoplastics in coastal seawater environments

In this study, we systematically developed the long–term photoaging behavior of different-sized polypropylene (PP) floating plastic wastes in a coastal seawater environment. After 68 d of laboratory accelerated UV irradiation, the PP plastic particle size decreased by 99.3 ± 0.15%, and nanoplastics (average size: 435 ± 250 nm) were produced with a maximum yield of 57.9%, evidencing that natural sunlight irradiation–induced long-term photoaging ultimately converts floating plastic waste in marine environments into micro- and nanoplastics. Subsequently, when comparing the photoaging rate of different sized PP plastics in coastal seawater, we discovered that large sized PP plastics (1000–2000 and 5000–7000 μm) showed a lower photoaging rate than that of small sized PP plastic debris (0–150 and 300–500 μm), with the decrease rate of plastic crystallinity as follow: 0–150 μm (2.01 d−1) > 300–500 μm (1.25 d−1) > 1000–2000 μm (0.780 d−1) and 5000–7000 μm (0.900 d−1). This result can be attributed to the small size PP plastics producing more reactive oxygen species (ROS) species, with the formation capacity of hydroxyl radical •OH as follows: 0–150 μm (6.46 × 10−15 M) > 300–500 μm (4.87 × 10−15 M) > 500–1000 (3.61 × 10−15 M) and 5000–7000 μm (3.73 × 10−15 M). The findings obtained in this study offer a new perspective on the formation and ecological risks of PP nanoplastics in current coastal seawater environments.

Distinguish the toxic differentiations between acute exposure of micro- and nano-plastics on bivalves: An integrated study based on transcriptomic sequencing

Plastic pollution represents one of the most severe marine environmental issues today. In the present study, mussel Mytilus coruscus, was selected as the model organism to probe the toxic effects of acute exposure to different sizes of plastic particles using integrated transcriptomic techniques and histological and biochemical analysis. Nanoplastics (NPs) were efficiently ingested by mussels, thereby inducing a severe inflammatory response. Although no distinct aggregation of microplastics (MPs) was observed, a slight inflammatory response has still occurred. Biochemical analysis revealed a significant up-regulation of biomarkers after exposure to plastic particles. Further, NPs caused more ROS production and higher T-AOC level than MPs. Transcriptomic sequencing was performed, and these differentially expressed genes after MNPs exposure were mostly enriched in pathways involved in stress and immune response. Notably, a contrast expression, substantial upregulation in MPs treatment and downregulation in NPs treatment of specific genes include in these pathways were revealed. Collectively, these results indicated that acute exposure to NPs is more toxic than MPs. Additionally, MPs exposure perhaps caused the impairment of olfactory function and neurotoxicity to mussels. These data provided some new clues for the elucidating of ecotoxicological mechanisms underlying plastic particles exposure.

Interactions between soil physical fractions and microplastics – An attenuated total reflectance-mid infrared and chemometrics study

As the volume of plastics produced, used, and discarded around the world continues to increase, the environmental pollution presented by these polymers and their by-products continues to be impacted. Different methods and techniques have been proposed to evaluate plastics in environmental samples, including soils. However, in most cases, the effect of variables such as plastic particle size, soil physical fractions, and interactions between them, was not evaluated or not well understood. The aim of this study was to evaluate the effect of different polystyrene (PS) fractions added to laboratory standard soil particle sizes (clay, sand, and silt) on the attenuated total reflectance (ATR) mid-infrared (MIR) spectra of the samples. Additive-free PS was sieved in four particle sizes, namely fraction 1 (∼500–251 µm), fraction 2 (∼250–181 µm), fraction 3 (∼180–107 µm) and fraction 4 (∼106–46 µm). The PS fractions were used to spike four physical soil fractions such as clay, loam, sand and sandy and analysed using ATR-MIR spectroscopy (4000–400 cm−1). The results of this study indicated that the MIR absorbances at specific frequencies of the binary soil-PS mixtures are different and depend on the combination of the soil physical fraction and PS particle size. Overall, no linearities were observed depending on the fraction analysed. This is of importance as the data indicates a different behaviour on the MIR spectral properties of the sample. Although further validation is needed, these results might have a direct effect on the development of robust protocols to monitor MPs in complex matrices such as soil using MIR spectroscopy.

Stimulation versus inhibition: The effect of microplastics on pak choi growth

As an exogenous pollutant, microplastics in soils may affect plant performance. In this study, pot experiments were conducted to evaluate the effects of various concentrations of polyethylene (PE) and polypropylene (PP) with different particle sizes on pak choi (Brassica rapa L. ssp. chinensis) growth. Morphological and physiological indicators of pak choi, and soil properties were measured. The toxic effects of microplastics on pak choi growth varied among the plastic type, concentration, and particle size. The effect of PE on pak choi fresh weight was negligible. However, the inhibition rate of 5% (w/w) PE on the total protein (TP) content reached 84.6% (p < 0.01). PP microplastics, especially those with small particle sizes, significantly reduced the fresh weight, leaf number, and TP content of pak choi. PE and PP had no significant impacts on the photosynthetic pigments in pak choi leaves. Pak choi root activity decreased by 6.7%–14.4% after exposure to PP, suggesting mechanical damage may have occurred. Conversely, Pak choi root activity increased by 13.5%–85.5% after exposure to PE. This may improve pak choi growth, thereby counteracting the negative effects of PE exposure. The activities of superoxide dismutase and peroxidase were lower after exposure to PP with a small particle size than the control. A plausible explanation is that the production of reactive oxygen species under PP stress exceeds pak choi tolerance, thereby inhibiting the expression of antioxidant enzymes. In contrast, pak choi resisted the oxidative stress caused by 5% (w/w) PE by improving the activities of antioxidant enzymes. Furthermore, PP and PE may indirectly inhibit the growth of pak choi by reducing soil aeration. These findings provide basic information for evaluating the phytotoxicity of microplastics in soil-vegetable systems.

Effect of Physical Characteristics and Hydrodynamic Conditions on Transport and Deposition of Microplastics in Riverine Ecosystem

Microplastic disposal into riverine ecosystems is an emergent ecological hazard that mainly originated from land-based sources. This paper presents a comprehensive review on physical processes involved in microplastics transport in riverine ecosystems. Microplastic transport is governed by physical characteristics (e.g., plastic particle density, shape, and size) and hydrodynamics (e.g., laminar and turbulent flow conditions). High-density microplastics are likely to prevail near riverbeds, whereas low-density particles float over river surfaces. Microplastic transport occurs either due to gravity-driven (vertical transport) or settling (horizontal transport) in river ecosystems. Microplastics are subjected to various natural phenomena such as suspension, deposition, detachment, resuspension, and translocation during transport processes. Limited information is available on settling and rising velocities for various polymeric plastic particles. Therefore, this paper highlights how appropriately empirical transport models explain vertical and horizontal distribution of microplastic in riverine ecosystems. Microplastics interact, and thus feedback loops within the environment govern their fate, particularly as these ecosystems are under increasing biodiversity loss and climate change threat. This review provides outlines for fate and transport of microplastics in riverine ecosystems, which will help scientists, policymakers, and stakeholders in better monitoring and mitigating microplastics pollution.

Human Health Effects of Microplastics in Drinking Water: A Review

Introduction: Polymer products have become inexpensive, convenient and widely used in all spheres of everyday life recently. Microplastics are found in seawater, wastewater, fresh water, foodstuffs, and air. Over the past few years, the presence of microplastics in treated tap and bottled water has been reported, raising questions and concerns about their potential human health effects. Objective: To summarize and systematize the results of studying health effects of exposure to microplastics in potable water. Materials and methods: A literature review was done based on ten topical articles and reviews published in 2014–2021 out of 64 sources found in the PubMed and Scopus international databases and the Russian Science Citation Index (RSCI). Results and conclusions: Generalization and systematization of the published research data demonstrated the lack of strong evidence to draw conclusions about human health effects of microplastics. Information on toxicokinetics and toxicodynamics of ingested microplastic particles is absent just like the studies of the most common shapes and sizes of plastic particles and health risks from exposure to such particles in drinking water.

Demographic Differences in the Quantity, Mass, and Anatomical Location of Ingested Plastic in Northern Fulmars (Fulmarus glacialis): A Review and Reconsideration of NE Pacific Ocean Samples

On the Washington and Oregon coast of the NE Pacific Ocean from 2008-2015, we found that juveniles represented 83% of Northern Fulmars that were beached. In comparison to older birds, juveniles averaged more mass and pieces of plastic in stomachs. This reflected relatively larger plastic loads in the cranial stomach section, the proventriculus, which we found was associated with relatively large accumulations in the caudal stomach section, the ventriculus. We estimate that the proventriculus could retain almost 10 times as much plastic as the ventriculus and that retention of proventricular plastic largely accounted for the difference in juveniles versus older birds. Our findings contrast with published Atlantic Ocean reports where the proportion of immatures was lower and plastic was retained mostly in ventriculi. The differences in demography and gastric distribution between NE Pacific and Atlantic fulmars may reflect the different sizes of plastic particles that were available. The preponderance of juveniles in NE Pacific Ocean samples and associated relatively large plastic loads overestimate the load for the species. Without accounting for age and gastric distribution, comparison to other regions is ill-advised. An unrecognized complication in stomach-based sampling is that differences in size of plastic at spatiotemporal scales could affect the utility of stomach samples as bioindicators of oceanic plastic pollution.

Transgenerational effects on development following microplastic exposure in Drosophila melanogaster.

BackgroundPlastic pollution affects all ecosystems, and detrimental effects to animals have been reported in a growing number of studies. However, there is a paucity of evidence for effects on terrestrial animals in comparison to those in the marine realm.MethodsWe used the fly Drosophila melanogaster to study the effects that exposure to plastics may have on life history traits and immune response. We reared flies in four conditions: In media containing 1% virgin polyethylene, with no chemical additives; in media supplemented with 1% or 4% polyvinyl chloride, known to have a high content of added chemicals; and control flies in non-supplemented media. Plastic particle size ranged from 23–500 µm. We studied fly survival to viral infection, the length of the larval and pupal stage, sex ratios, fertility and the size of the resultant adult flies. We then performed crossings of F1 flies in non-supplemented media and looked at the life history traits of the F2.ResultsFlies treated with plastics in the food media showed changes in fertility and sex ratio, but showed no differences in developmental times, adult size or the capacity to fight infections in comparison with controls. However, the offspring of treated flies reared in non-supplemented food had shorter life cycles, and those coming from both polyvinyl chloride treatments were smaller than those offspring of controls.

Transport and deposition of plastic particles in porous media during seawater intrusion and groundwater-seawater displacement processes

Visible flow chamber systems packed with porous media (at both macroscale and pore scale) and packed column systems for the first time were used to systematically investigated the impacts of seawater intrusion and groundwater-seawater displacement on the transport behaviors of marine plastic particles with different sizes in porous media. We found that seawater intrusion could transfer all three sized plastics into coastal porous media and their transport would be affected by seawater flow velocity. For example, 8.5%, 24.8% and 39.8% of 1 μm plastic particles could pass through the columns during the 10, 50 and 250 m/d seawater intrusion processes, respectively. The groundwater-seawater displacement process could re-mobilize plastic particles pre-attached onto sand. The percentages of released plastic particles were negatively correlated with the sizes of plastic particles and the ionic strength of displacement groundwater. Groundwater velocity did not obviously affect the release of plastic particles from sand. The percentages of released plastic particles were affected by seawater intrusion cycles. XDLVO was employed to theoretically explain the transport behaviors of plastic particles under different conditions. Our study showed that seawater intrusion would transfer marine plastic particles into coastal aquifer and groundwater-seawater displacement could affect the release of plastic particles from porous media.

Investigation of the Presence and Possible Migration from Microplastics of Phthalic Acid Esters and Polycyclic Aromatic Hydrocarbons

The work detailed here examined the presence and possibility of leaching of phthalic acid esters (PAEs) and polycyclic aromatic hydrocarbons (PAHs) from various products in everyday use. Due to the complicated matrix, which is plastic, extraction parameters should be selected separately each time. The properties of both the extractant and the material selected for testing should also be taken into account, which is very difficult in practice. In addition, when designing new methods, it is particularly important to take into account the principles of green chemistry so as not to burden the environment additionally. For this purpose, it is important to know the factors that affect the extraction of impurities. Therefore, the main objective was to assess the impact of selected environmental conditions on the process by which such pollutants in plastics like polyvinyl chloride (PVC), polystyrene (PS), polypropylene (PP) and rubber migrate. Analysis inter alia addressed the impacts of type of plastic, migration time, temperature and microplastic particle size. It proved possible to note the presence in PVC and rubber of both PAEs and PAHs—as substances posing a particular threat to the environment. One of the former is the commonly-used plasticiser di(2-ethylhexyl) phthalate (DEHP), a listed priority hazardous substance under the provisions of Directive 2013/39/EU as regards priority substances in the field of water policy. As monitoring of this substance in the environment indicates amounts that are increasing steadily, the design of effective removal methods needs to start with initial estimates of amounts appearing in the environment over time. Main sources need to be explored, albeit in the certain knowledge that the ubiquitous microplastics are among these, inter alia as influenced by elution mechanisms. An attempt was also made to identify and characterise other auxiliary substances added to plastics as they are being produced. Indeed, chromatograms and GC/MS spectra suggest leaching of many other plastic substances. Relationships between eluted pollutants were also sought.